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Wyszukujesz frazę "expansion" wg kryterium: Temat


Tytuł:
Holomorphic non-holonomic differential systems on complex manifolds
Autorzy:
Dimiev, S.
Powiązania:
https://bibliotekanauki.pl/articles/1312446.pdf
Data publikacji:
1991
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
power -expansion
Opis:
We study coherent subsheaves of the holomorphic tangent sheaf of a complex manifold. A description of the corresponding -stable ideals and their closed complex subspaces is sketched. Our study of non-holonomicity is based on the Noetherian property of coherent analytic sheaves. This is inspired by the paper [3] which is related with some problems of mechanics.
Źródło:
Annales Polonici Mathematici; 1991, 55, 1; 65-73
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coherent and strong expansions of spaces coincide
Autorzy:
Mardešić, Sibe
Powiązania:
https://bibliotekanauki.pl/articles/1205303.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
coherent expansion
coherent homotopy
inverse system
strong expansion
strong shape
Opis:
In the existing literature there are several constructions of the strong shape category of topological spaces. In the one due to Yu. T. Lisitsa and S. Mardešić [LM1-3] an essential role is played by coherent polyhedral (ANR) expansions of spaces. Such expansions always exist, because every space admits a polyhedral resolution, resolutions are strong expansions and strong expansions are always coherent. The purpose of this paper is to prove that conversely, every coherent polyhedral (ANR) expansion is a strong expansion. This result is obtained by showing that a mapping of a space into a system, which is coherently dominated by a strong expansion, is itself a strong expansion.
Źródło:
Fundamenta Mathematicae; 1998, 158, 1; 69-80
0016-2736
Pojawia się w:
Fundamenta Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coefficient of thermal expansion as a component quality estimation of alloys on pistons of combustion engines
Autorzy:
Sieminska, B.
Powiązania:
https://bibliotekanauki.pl/articles/245892.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion engines
engine pistons
thermal expansion
coefficient of thermal expansion
Opis:
The aim of realized works in the area of materials on pistons is: low thermal expansion, small differences of coefficient of thermal expansion between heating and cooling, high stiffness at elevated temperatures, high hardness and wear resistance. Changes in thermal expansion coefficient during heating and cooling may be very large, as well as during subsequent cycles of heating and cooling of an internal combustion engine pis ton with respect to standard silumin alloys usedfor pistons of internal combustion engines. The paper presents: coefficient of linear expansion a for the AlSi standard alloy, coefficient of linear expansion a for the AlSi alloy with the apositive differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the a negative differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the apositive and negative differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the apositive, negative and positive differences between cooling and heating, coefficient of linear expansion a for the AlSi alloy with the very small a differences between cooling and heating, coefficient relative elongation as afunction of temperature with the positive elongation differences between cooling and heating, coefficient relative elongation with the very small elongation differences between cooling and heating, coefficient the course of derivative as a function of temperature (T) during heating and cooling with the positive elongation differences.
Źródło:
Journal of KONES; 2009, 16, 4; 575-583
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ekspansja islamu w Ruandzie po 1994 roku w świetle teorii sekularyzacji
Expansion of Islam in Rwanda after 1994 in Light of Secularization Theories
Autorzy:
Bachmann, Klaus
Bieniek, Karolina
Powiązania:
https://bibliotekanauki.pl/articles/567070.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie. Instytut Nauk Politycznych
Tematy:
Rwanda
Secularization
Islam expansion
Opis:
The article discusses Islam in Rwanda and three secularization theories: Durkheim's religious supply theory; religious demand theory put forward by Finke and Stark; and proposed by Inglehart -security theory. The research the article is based upon was carried out just before 1994 genocide and in 2001. We seek the answer to whether the 1994 genocide brought about any changes in the religious structure in Rwanda and how relevant the above mentioned theories are in explaining the changes. In the first section, the theoretical background is provided; then the history of Rwanda up to 1994 is briefly discussed; the penultimate section focuses on how Islam spread in Rwanda and finally we examine whether the three secularization theories are relevant in explaining the changes in the Rwandan religious structure.
Źródło:
Forum Politologiczne; 2006, 4 - Islam we współczesnej Afryce; 149-166
1734-1698
Pojawia się w:
Forum Politologiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Testing contraction and thermal expansion coefficient of construction and moulding polymer composites
Autorzy:
Pyrzowski, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/259644.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
polymer composites
contraction
thermal expansion
Opis:
The paper presents results of systematic tests of contraction and thermal expansion coefficients of materials based on polymer composites. The information on the above material properties is essential both at the design stage and during the use of finished products. Components for the samples were selected in such a way as to represent typical materials used for production of construction and moulding elements. The performed tests made it possible to monitor the analysed parameters at different stages of the technological process.
Źródło:
Polish Maritime Research; 2018, S 1; 151-158
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A characterization of planar median graphs
Autorzy:
Peterin, Iztok
Powiązania:
https://bibliotekanauki.pl/articles/744189.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
median graphs
planar graphs
expansion
Opis:
Median graphs have many interesting properties. One of them is-in connection with triangle free graphs-the recognition complexity. In general the complexity is not very fast, but if we restrict to the planar case the recognition complexity becomes linear. Despite this fact, there is no characterization of planar median graphs in the literature. Here an additional condition is introduced for the convex expansion procedure that characterizes planar median graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2006, 26, 1; 41-48
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mitologia pogranicza. Australia i Stany Zjednoczone Sygurda Wiśniowskiego
Mythology of a borderland. Sygurd Wiśniowski on Australia and the United States
Autorzy:
Forajter, Wacław
Powiązania:
https://bibliotekanauki.pl/articles/511546.pdf
Data publikacji:
2016
Wydawca:
Wydawnictwo Uniwersytetu Śląskiego
Tematy:
borderland
frontier
expansion
modernity
journey
Opis:
The article discusses the concept of ‘borderland’ in selected works by Sygurd Wiśniowski: a 19th century Polish traveller who encountered the territorial and cultural expansion of the white settlers in Australia and North America. The author of the article aims to present both the specificity and the complexity of ‘borderland phenomenon’ as described by Wiśniowski. The author concentrates also on absent or omitted e lements in Wiśniowski’s discourse (which can be observed in his attitude towards the native inhabitants and women) and reveals Wiśniowski’s utopian ideas (such as equality of opportu nity).
Źródło:
Postscriptum Polonistyczne; 2016, 1(17); 23-32
1898-1593
2353-9844
Pojawia się w:
Postscriptum Polonistyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Expansion of a cylindrical cavity in sand
Autorzy:
Osinov, V. A.
Cudmani, R.
Powiązania:
https://bibliotekanauki.pl/articles/1954562.pdf
Data publikacji:
2000
Wydawca:
Politechnika Gdańska
Tematy:
cavity expansion
sand
hypoplasticity
critical state
Opis:
The paper presents numerical solution to the problem of the symmetri quasi-static large-strain expansion of a cylindrical cavity in sand. The boundary value problem is solved with the use of a constitutive equation of hypoplasticity calibrated for a particular sand. As the radius of the cavity increases, the stresses and the density on the cavity surface asymptotically approach limit values which correspond to a so-called critical state of the sand. The limit values depend on the initial stresses and the initial density. The solutions are compared with experimental results for the same sand available in the literature. A comparison is also made with numerical solutions obtained by other authors.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2000, 4, 3; 421-437
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the results of the design process performed on the historic architectural structure based on the example of the extension of historical didactic complex in Rzeszów
Autorzy:
Gosztyła, M.
Lichołai, R.
Powiązania:
https://bibliotekanauki.pl/articles/104787.pdf
Data publikacji:
2018
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
historical architectural complex
design
architectural expansion
Opis:
The article analyses the issue of the extension of the historical architectural didactic complex in Poland. The conditions of the building before the design process was described and the adopted design solutions were analyzed. Design works allowed to arrange form of facades. The results of the work is an additional didactic and administrative space. The article analyses the results of cooperation between local delegation of Regional Office of Protection of Historical Monuments and the architect, which allowed to extend the possibilities of historical use of the object in combination with the newly design part.
Źródło:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury; 2018, 65, 4; 121-127
2300-5130
2300-8903
Pojawia się w:
Czasopismo Inżynierii Lądowej, Środowiska i Architektury
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Swelling, expansion and shrinkage properties of selected clays in the Mazowsze province, central Poland
Autorzy:
Pająk-Komorowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/2059631.pdf
Data publikacji:
2003
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
tertiary clay
tills
swelling
expansion
shrinkage
Opis:
Tertiary clays and tills, the most widespread soils in Poland, were used for the examination of swelling, expansion and shrinkage properties. Results of laboratory tests and the values of selected parameters obtained by indirect methods show that the Tertiary clays examined, when compared with Quaternary tills, show greater volumetric changes under the influence of water, which is primarily connected with their higher silt content.
Źródło:
Geological Quarterly; 2003, 47, 1; 55-62
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wilgotności powietrza na wielkości decydujące o jakości produktu w procesie termicznego ekspandowania nasion w strumieniu gorącego powietrza
Influence of air humidity on values that decide of product quality in thermal expansion of seeds in a hot air stream
Autorzy:
Konopko, H.
Powiązania:
https://bibliotekanauki.pl/articles/290725.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
ekspandowanie termiczne
nasiona
thermal expansion
seeds
Opis:
W pracy przedstawiono wyniki symulacji komputerowej procesu termicznego ekspandowania nasion prosa w przewodzie pneumatycznym. Świadczą one o znaczącym wpływie początkowej wilgotności nasion na podstawowe parametry procesu.
The study presents the results of computer simulation of the process of thermal expansion of millet seeds in a pneumatic conduit. It shows a considerable influence of initial seed moistness on basic process parameters.
Źródło:
Inżynieria Rolnicza; 2006, R. 10, nr 7(82), 7(82); 269-275
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PixSel : Images as Book Cipher Keys : An Efficient Implementation Using Partial Homophonic Substitution Ciphers
Autorzy:
Shumay, M.
Srivastava, G.
Powiązania:
https://bibliotekanauki.pl/articles/226555.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
book ciphers
ciphertext enlargement
ciphertext expansion
Opis:
In this paper we introduce a novel encryption Technique, which we call PixSel. This technique uses images in place of literature as the book cipher’s key. Conventional book ciphers possess an unwieldy ciphertext enlargement, creating ciphertexts multiple times the length of the plaintext. As well, there is often the issue of a given book not containing the necessary material for the encipherment of some plaintexts. We sought to rectify these nuisances with PixSel, possessing a typical ciphertext enlargement of merely 1% to 20% for text. Using PixSel, there are also no limitations on encipherable data type, given a suitable image.
Źródło:
International Journal of Electronics and Telecommunications; 2018, 64, 2; 151-158
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Imigracja na Hawaje z Japonii w latach 1885–1900
Immigration to Hawaii from Japan in 1885–1900
Autorzy:
Puchacz, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/2142620.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet w Białymstoku. Wydawnictwo Uniwersytetu w Białymstoku
Tematy:
Hawaii
Japan
United States
immigration
expansion
Opis:
In the first half of the 19th century the Kingdom of Hawaii was declared to be a part of the American sphere of influence. Americans and Europeans had a great influence on the country’s internal and foreign policy. They built their position on agriculture, in particular on the cultivation of sugar cane. Due to the lack of local manpower, they brought to Hawaii Asians – the Chinese, and then the Japanese. The Japanese government agreed to emigration of its laborers because of various reasons, including economic problems affecting rural areas. The conditions of their work and life were strictly regulated by the immigration convention concluded in 1886. In the years 1885–1894, 29,000 people came to work on plantations under the contract system. The proclamation of the Republic of Hawaii in 1894, which replaced the overthrown monarchy, coincided with the withdrawal of the government of this state from recruitment and importing workers from Japan. The resulting gap was filled in by Japanese emigre companies that brought not only contract workers but also non-contractual immigrants to Hawaii. The Government of the Republic of Hawaii considered the increased and uncontrolled inflow of the Japanese to be a threat. For this reason, it decided to limit this immigration. The refusal to let hundreds of Japanese enter Hawaii led to an immigration dispute between Tokyo and Honolulu. It contributed to the decision of the United States to annex Hawaii in 1897. Such a step evoked protests from Japan, yet, they were withdrawn at the end of the year, due to the growing competition of the powers in the Far East. The immigration dispute between Hawaii and Japan was finally resolved under the pressure from Washington in 1898, after the republic’s government paid out $75,000 compensation.
Źródło:
Białostockie Teki Historyczne; 2018, 16; 105-128
1425-1930
Pojawia się w:
Białostockie Teki Historyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of a static expansion standard for calibrating medium and high vacuum pressure gauges
Autorzy:
Duarte Franco, Jonathan Javier
Villamizar Mora, Carlos Mauricio
García Sánchez, Carlos Eduardo
Powiązania:
https://bibliotekanauki.pl/articles/1849022.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
static expansion system
calibration
vacuum
characterization
Opis:
The Centro de Desarrollo Tecnológico del Gas developed a static expansion system to enable the calibration of medium and high vacuum pressure gauges in Colombia. The system can generate pressures between 0.1 Pa and 100 kPa. The characterization tests included the evaluation of pressure stability and desorption rate, a trueness test, and the analysis of the uncertainty budget of the calibration result. The pressure stability test was successfully completed and showed the positive effect of baking on the final pressure in the system. The trueness test allowed concluding that the calibration results with the system are comparable with those obtained with a reference meter traceable to a national metrology institute. The uncertainty budget analysis indicated the dominance of the pressure of the unit under calibration and of the initial pressure in the small tank in different pressure ranges on the uncertainty of the result. A comparison with a Monte Carlo simulation led to the conclusion that in this situation, the GUM (Guide to the Expression of Uncertainty in Measurement) method is not ideal for estimating the uncertainty of the results.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 593-604
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of a static expansion standard for calibrating medium and high vacuum pressure gauges
Autorzy:
Duarte Franco, Jonathan Javier
Villamizar Mora, Carlos Mauricio
García Sánchez, Carlos Eduardo
Powiązania:
https://bibliotekanauki.pl/articles/1849054.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
static expansion system
calibration
vacuum
characterization
Opis:
The Centro de Desarrollo Tecnológico del Gas developed a static expansion system to enable the calibration of medium and high vacuum pressure gauges in Colombia. The system can generate pressures between 0.1 Pa and 100 kPa. The characterization tests included the evaluation of pressure stability and desorption rate, a trueness test, and the analysis of the uncertainty budget of the calibration result. The pressure stability test was successfully completed and showed the positive effect of baking on the final pressure in the system. The trueness test allowed concluding that the calibration results with the system are comparable with those obtained with a reference meter traceable to a national metrology institute. The uncertainty budget analysis indicated the dominance of the pressure of the unit under calibration and of the initial pressure in the small tank in different pressure ranges on the uncertainty of the result. A comparison with a Monte Carlo simulation led to the conclusion that in this situation, the GUM (Guide to the Expression of Uncertainty in Measurement) method is not ideal for estimating the uncertainty of the results.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 593-604
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wilgotności powietrza na wymianę ciepła w procesie termicznego ekspandowania nasion w strumieniu gorącego powietrza
Influence of air humidity on heat exchange in the process of thermal expansion of sedes in a stream of hot air
Autorzy:
Konopko, H.
Powiązania:
https://bibliotekanauki.pl/articles/290727.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
ekspandowanie termiczne
nasiona
thermal expansion
seeds
Opis:
W pracy przedstawiono wyniki symulacji komputerowej procesu termicznego ekspandowania nasion prosa w przewodzie pneumatycznym. Świadczą one o znaczącym wpływie początkowej wilgotności nasion na wymianę ciepła w tym procesie.
The study presents the results of computer simulation of the process of thermal expansion of millet seeds in a pneumatic conduit. It shows a considerable influence of initial seed moistness on basic process parameters.
Źródło:
Inżynieria Rolnicza; 2006, R. 10, nr 7(82), 7(82); 263-268
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation on Irreversible Expansion of 1,3,5-Triamino-2,4,6-trinitrobenzene Cylinder
Autorzy:
Sun, J.
Kang, B.
Zhang, H.
Liu, Y.
Xia, Y.
Yao, Y.
Liu, X.
Powiązania:
https://bibliotekanauki.pl/articles/357936.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
TATB
irreversible expansion
XRD
lattice parameters
Opis:
In this study, the irreversible expansion of TATB cylinder is investigated. No evident variation of the lattice parameters is observed on TATB crystal. The density of TATB powder decreases by only about 0.02% after it suffered from thermal cycling process at the range from -54 C to 74 C, while the density of TATB cylinder decreases by about 1.0%. It is suggested that the density variation of TATB powder has little contribution to the density decrease of TATB cylinder. Therefore, the increasing interstices between TATB powder originated from the thermal cycling should be responsible to the irreversible expansion of TATB cylinder.
Źródło:
Central European Journal of Energetic Materials; 2011, 8, 1; 69-79
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of a static expansion standard for calibrating medium and high vacuum pressure gauges
Autorzy:
Duarte Franco, Jonathan Javier
Villamizar Mora, Carlos Mauricio
García Sánchez, Carlos Eduardo
Powiązania:
https://bibliotekanauki.pl/articles/1848994.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
static expansion system
calibration
vacuum
characterization
Opis:
The Centro de Desarrollo Tecnológico del Gas developed a static expansion system to enable the calibration of medium and high vacuum pressure gauges in Colombia. The system can generate pressures between 0.1 Pa and 100 kPa. The characterization tests included the evaluation of pressure stability and desorption rate, a trueness test, and the analysis of the uncertainty budget of the calibration result. The pressure stability test was successfully completed and showed the positive effect of baking on the final pressure in the system. The trueness test allowed concluding that the calibration results with the system are comparable with those obtained with a reference meter traceable to a national metrology institute. The uncertainty budget analysis indicated the dominance of the pressure of the unit under calibration and of the initial pressure in the small tank in different pressure ranges on the uncertainty of the result. A comparison with a Monte Carlo simulation led to the conclusion that in this situation, the GUM (Guide to the Expression of Uncertainty in Measurement) method is not ideal for estimating the uncertainty of the results.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 593-604
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MANAGEMENT OF AN AGRICULTURAL ENTERPRISE ON THE BASIS OF ITS ECONOMIC STATE FORECASTING
Autorzy:
Atamanyuk, Igor
Kondratenko, Yuriy
Sirenko, Natalia
Powiązania:
https://bibliotekanauki.pl/articles/453387.pdf
Data publikacji:
2014
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:
accidental sequence
canonical expansion
algorithm of extrapolation
Opis:
On the basis of the mechanism of accidental sequences canonical expansions the algorithm of the economic state of agricultural enterprise forecasting is obtained which allows to estimate the results of its work in future under the realization of a certain reorganization (change of land resources, labour resources, fixed assets).
Źródło:
Metody Ilościowe w Badaniach Ekonomicznych; 2014, 15, 2; 7-16
2082-792X
Pojawia się w:
Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Immunoregulation of antigen presenting and secretory functions of monocytic cells by Helicobacter pylori antigens in relation to impairment of lymphocyte expansion
Autorzy:
Mnich, Eliza
Gajewski, Adrian
Rudnicka, Karolina
Gonciarz, Weronika
Stawerski, Paweł
Hinc, Krzysztof
Obuchowski, Michał
Chmiela, Magdalena
Powiązania:
https://bibliotekanauki.pl/articles/1038873.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
H. pylori
antigen presenting cells
lymphocyte expansion
Opis:
The role of Helicobacter pylori (H. pylori) antigens in driving a specific immune response against the bacteria causing gastroduodenal disorders is poorly understood. Using a guinea pig model mimicking the natural history of H. pylori infection, we evaluated the effectiveness of immature and mature macrophages in promoting the blastogenesis of splenocytes from H. pylori infected and uninfected animals, in response to H. pylori antigens: glycine acid extract (GE), cytotoxin associated gene A protein (CagA), urease A (UreA) and lipopolysaccharide (LPS). Lymphocyte expansion was assessed in 72 h cell cultures, containing: immature or mature macrophages derived from bone marrow monocytes, unstimulated or stimulated with H. pylori antigens for 2 h. The proliferation was expressed as a ratio of [3H]-thymidine incorporation into DNA of antigen-stimulated to unstimulated cells and the DNA damage was determined by DAPI cell staining. TGF-β and IFN-γ were assessed immunoenzymatically in cell culture supernatants. Lymphocytes of control and H. pylori-infected animals proliferated intensively in response to phytohaemagglutinin (PHA) and in co-cultures with immature or mature macrophages treated with CagA or UreA (significantly) and GE (slightly) exluding the cultures containing H. pylori or E. coli LPS. This lymphocyte growth inhibition was related to DNA damage of monocytic cells in response to H. pylori or E. coli LPS and secretion of regulatory TGF-β, but not proinflammatory IFN-γ. Impaired homeostasis of monocytic cell function related to DNA damage and TGF-β release, in response to H. pylori LPS may lead to the suppression of adaptive immune response against the bacteria and development of chronic infection.
Źródło:
Acta Biochimica Polonica; 2015, 62, 4; 641-650
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porównanie ekspansji brykietów wytworzonych ze słomy z dodatkiem polietylenu jako lepiszcza
Comparison of expansion of briquettes made of straw with addition of polyethylene as a binding agent
Autorzy:
Kajda-Szcześniak, M.
Powiązania:
https://bibliotekanauki.pl/articles/288021.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
słoma
polietylen
brykietowanie
ekspansja
polyethylene
briquetting
expansion
Opis:
W artykule przedstawiono możliwości wykorzystania biomasy rolniczej oraz odpadowych tworzyw sztucznych z grupy poliolefin jako surowców do produkcji brykietów. Omówiono również tematykę związaną z ekspansją brykietów. Porównano w jakim stopniu brykiety ulegają rozprężeniu bezpośrednio po opuszczeniu matrycy oraz w przyjętych jednostkach czasu. Do analizy porównawczej wybrano brykiety wytworzone ze słomy owsa i kukurydzy z dodatkiem polietylenu o niskiej gęstości (PE-LD). Określono również w jakim stopniu na ekspansję wpływa dobór parametrów procesu wytwarzania brykietów, a w jakim dobór mieszanki zagęszczanych surowców. W doborze komponentów kierowano się różnicami wynikającymi z budowy i struktury badanych rodzajów słomy oraz postacią użytego polietylenu. Stwierdzono, że gęstość brykietów w czasie 20 minut od ich wytworzenia zmniejszyła się w skrajnych przypadkach o 2,33% dla brykietów ze słomy owsa i PE-LD rozdrobnionego (82 MPa i 210°C) i 4,73% dla brykietów ze słomy kukurydzy i PE-LD nie rozdrobnionego (95 MPa i 200°C).
The article presents possibilities of using agricultural biomass and waste plastics from the polyolefin group as raw materials for production of briquettes. Moreover, the issues, which are related to expansion of briquettes was discussed. A comparison of the degree of expansion of briquettes directly after leaving a matrix and within time units was carried out. Oat hay briquettes and corn briquettes with addition of low density polyethylene (PE-LD) were selected for comparative analysis. Furthermore, the influence of the selection of briquettes production parameters on the expansion and the influence of the selection of the concentrated raw materials mixture were determined. Differences resulting from the structure of the examined hay types and the form of polyethylene which was used were the basis for the selection of components. It was determined that density of briquettes within 20 minutes from the moment of their production decreased in extreme cases of 2.33% for oat hay briquettes and the ground PE-LD briquettes (82 MPa and 210°C) and 4.73 for corn hay briquettes and not ground PE-LD briquettes (95 MPa and 200°C).
Źródło:
Inżynieria Rolnicza; 2012, R. 16, nr 4, t. 1, 4, t. 1; 123-133
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-zero constant Jacobian polynomial maps of $ℂ²$
Autorzy:
Chau, Nguyen
Powiązania:
https://bibliotekanauki.pl/articles/1294068.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Jacobian conjecture
polynomial automorphism
Newton-Puiseux expansion
Opis:
We study the behavior at infinity of non-zero constant Jacobian polynomial maps f = (P,Q) in ℂ² by analyzing the influence of the Jacobian condition on the structure of Newton-Puiseux expansions of branches at infinity of level sets of the components. One of the results obtained states that the Jacobian conjecture in ℂ² is true if the Jacobian condition ensures that the restriction of Q to the curve P = 0 has only one pole.
Źródło:
Annales Polonici Mathematici; 1999, 71, 3; 287-310
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The meaning of universities in the post-truth era
Autorzy:
Wilkin, Jerzy
Powiązania:
https://bibliotekanauki.pl/articles/704249.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
post-truth
truth
university
expansion of lies
Opis:
The main statement of the paper is that the post-truth is expanding at an unprecedented rate, continuously forcing itself into new areas of public life and permeating millions of minds. This phenomenon has not so far been satisfactorily explained by researchers of global-range social phenomena. The paper presents various definitions of post-truth and its interpretations. The argument revolves around what truth means and what it is threatened by, as well as the most important institution that is, by definition, concerned about the truth: the university. The article outlines the functions of the university and contemporary conditions of its functioning, including the threats to the preservation of its mission and axiological foundation: striving towards the truth. The idea of the university, created in Europe at the beginning of the second millennium, has shown to be strong and durable. It has adopted various organisational forms, depending on the period and region. The secret of the universities’ persistence and meaning cannot be considered apart from the history of the European civilisation. However, the phenomenon of post-truth expansion is the most serious threat to this institution. The expansion of post-truth also leads to changes in the quality of the public life, bringing about its degeneration, with considerable contributions of the numerous pathologies of the Internet, distribution of lies and surprisingly quickly growing acceptance of this phenomenon.
Źródło:
Nauka; 2020, 1
1231-8515
Pojawia się w:
Nauka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Początki ekspansji Arabów i islamu na terytoria Zande Mbomou w okresie przedkolonialnym
The Beginnings of Arab and Islam Expansion into Zande Mbomou Territory During Pre-Colonial Period
Autorzy:
Łubińska, Edyta
Powiązania:
https://bibliotekanauki.pl/articles/566846.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie. Instytut Nauk Politycznych
Tematy:
Islam expansion
Zande Mbomou
Pre-colonial Africa
Opis:
Pre-colonial history of the Zande is the history of migration and conquest, characterized by expansion, annexation, assimilation and amalgamation, followed by further expansion. In the course of the 17th and 18th centuries the clans of the Vongara and the Bandia became the rulers of the (Mbomou-) Zande and Nzakara people. Important to note in this period are divergent and ambivalent attitudes of Vongara and Bandia kings vis-a-vis slave traders and the consequences of this trade in human. From the mid-19th century Arab slave raiders and traders established permanent armed forts in south-western Sudan, the so-called zariba. With the discovery, by the Khartoumers, of the free channel of the Bahr-el-Ghazal river and the foundation of the landing stage at Meshra-el-Req in 1865, the traders were able to sail upstream the Bahr-el-Ghazal, the Bahr-el-Arab, and their tributaries. As a result the watershed between the Nile and Congo-Ouban-gui basin got lined with a series of new zariba whence trading and raiding operations in eastern CAR were launched. By 1865 three major trading routes passed throught Zandeland. An increased de¬mand for slaves in the Muslim world, combined with the availability of advanced firearms and the readiness of some local chiefs to make alliances with the Khartoumers, all escalated in slave raiding and trading on an unprecedented and unimaginable scale. Slaves and ivory were traded in exchange for beads, cloth, copper, iron tools, and firearms. The upheavals caused by the slave trade and the intensifying spiral of violence had some fundamental consequences for the local societies. Agriculture changed significantly, but the most dramatic impact of the slave trade was on the region's demography.
Źródło:
Forum Politologiczne; 2006, 4 - Islam we współczesnej Afryce; 139-148
1734-1698
Pojawia się w:
Forum Politologiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Corporate entrepreneurship and international performance of Nigerian banks
Autorzy:
Abosede, Julius Adebiyi
Fayose, Joseph
Eze, Benneth Uchenna
Powiązania:
https://bibliotekanauki.pl/articles/522431.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Banks
Corporate entrepreneurship
International performance
Market expansion
Opis:
Aim/purpose – This study investigated the effect of corporate entrepreneurship (measured by innovation, risk taking, proactiveness, strategic renewal and corporate venturing) on the international performance (measured by managers’ perceived measures of international business performance) of Nigerian international banks. Design/methodology/approach – Survey research design was used for the study, through the administration of structured questionnaire to management staff in strategy, foreign operations and finance departments. The study employed a census survey, in which the entire 427 management staff of strategy, foreign operation and finance departments of the ten CBN (Central Bank of Nigeria) licensed international banks constituted the population and the sample (census survey). The models were estimated using ordinary least square, using STATA 14 software.Finding – The study revealed that corporate entrepreneurship elements (innovation, proactiveness, risk taking, strategic renewal and corporate venturing) all have individual and combined positive and significant effect on banks international performance at 95% confidence level. However, innovation has the most effect on Nigerian banks international performance. Research implications/limitations – The study employed managers’ perceived measures of international business performance to measure Nigerian banks international performance, which is subjective. A measure like revenue from the foreign subsidiary would have been considered but for the paucity of data. This of course can form the basis for further studies and expanded to cover the entire West Africa region. Originality/value/contribution – Studies examining the effect of corporate entrepreneurship on banks’ international performance in Africa are rare. Most Nigerian banks set-up foreign subsidiary in other Africa countries and there has been a debate on the contributions of the foreign subsidiaries to the banks’ bottom line and as well as a form of market expansion. The study expands the frontier of knowledge on Nigerian banks international performance by unbundling corporate entrepreneurship to see how each element will affect performance.
Źródło:
Journal of Economics and Management; 2018, 32; 5-17
1732-1948
Pojawia się w:
Journal of Economics and Management
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CULTURAL, POLITICAL AND ECONOMIC ASPECTS OF THE INTERNATIONAL EXPANSION OF BANKS FROM CENTRAL AND EASTERN EUROPE – CASES: POLISH PKO BP AND HUNGARIAN OTP BANK
Autorzy:
Kurkliński, Lech
Powiązania:
https://bibliotekanauki.pl/articles/659938.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
banks
Polska
Hungary
international expansion
cultural background
Opis:
Polish PKO BP and Hungarian OTP Bank are the largest, dominant national bankinginstitutions of a similar nature – universal banks with a strong emphasis on retail operations.However, they differ significantly because of international activities. PKO BP has only local bankin Ukraine, and the OTP group is present in 9 countries in CEE. The relatively strong economicposition of both banks, similar history would indicate that their activities related to foreignexpansions should develop in the same way. However, this hasnʼt happen. Among a number ofreasons we should include cultural aspects, closely bound up with the legacy of the past, politicaland economic circumstances for both countries.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2014, 1, 299
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Expanders for dispersed power generation: maintenance and diagnostics problems
Autorzy:
Żywica, G.
Kaczmarczyk, T.
Ihnatowicz, E.
Powiązania:
https://bibliotekanauki.pl/articles/175441.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
expansion devices
expanders
turbines
ORC systems
cogeneration
Opis:
The article discusses the problems related to the operation of various types of expansion devices used in small cogeneration systems. Both volumetric and dynamic expanders were considered, including scroll, screw, vane, piston and turbine expanders. For each of these solutions, principles of operation were explained as well as major advantages and disadvantages. The results of experimental research on several expanders of various types were also presented. The overview of expanders included in this paper, along with basic operational problems and functional characteristics, is the collection of valuable information facilitating selection of a suitable expander for specific applications. This is particularly important in the context of search for new energy sources and opportunities to improve the energy efficiency of available energy resources.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 131; 173-188
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary research no vel composite materials with small hysteresis and high functional parameters for combustion engines pistons
Autorzy:
Siemińska-Jankowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/246073.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion engines
engine pistons
thermal expansion
hysteresis
Opis:
Pistons of internal-combustion engines are the most loaded elements of internal-combustion engines, belong to these specialistic elements, which have essential influence on the ecological properties of engines, their durability and reliability. The object of paper is pistons manufactured from the standard material and from new research alloy. The investigations were performed with dilatometer permitting on the registration of changes of the dimensions of sample in the function of temperature and time. The measurements are possible in straight system and in differential system. Exemplary results of investigations are presented in the paper. During the piston heating, period preutectic phases succumb the partial dissolution in solid solution a, but in the cooling process they secrete again. As a consequence the piston partial deformation occurs, which by result is gradual growth of difference between its expansibility during the warming and contraction in the process of cooling (so-called hysteresis occurs). The characteristics of the new piston silumin alloys give possibility of dearances minimalization and the obtainments of a correct engine performance in the full range of engine rotational velocities and loads. The effect are the decrease of the oil expenditure, the decrease of the emission of hydrocarbons in exhaust gases, the decrease of blowbys to crankcase, the decrease of the expenditure of piston rings grooves wear and the piston skirt wear, the decrease of the piston deformation and the increase of engine durability and reliability.
Źródło:
Journal of KONES; 2009, 16, 1; 447-452
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the sewage system expandability in Mściwojów commune
Autorzy:
Bergel, T.
Bugajski, P.
Pawełek, J.
Powiązania:
https://bibliotekanauki.pl/articles/100285.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie
Tematy:
sewage system
expansion
sewage
kanalizacja
rozwój
ścieki
Opis:
The aim of the study is to analyze the hydraulic conditions of the existing sewage system and the sewage treatment plant in the commune of Mściwojów. This is in relation to the aspect of connecting new buildings, as a part of the investments in the pilot project VITAL LANDSCAPES no. 2CE164P3. The analysis led to the conclusion that an increased wastewater inflow from the new buildings is manageable. The current capacity of the sewage treatment plant will be increased by 3 to 5%, which will not affect the stability of the existing treatment process. The hydraulic analysis of the sewer network proved that the existing sewer collectors can handle the increased flow.
Źródło:
Geomatics, Landmanagement and Landscape; 2013, 2; 7-14
2300-1496
Pojawia się w:
Geomatics, Landmanagement and Landscape
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Asymptotics of two-dimensional copulas
Autorzy:
Jaworski, P.
Powiązania:
https://bibliotekanauki.pl/articles/747908.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Two-dimensional copulas, homogeneous expansion, modelling risk
Opis:
Artykuł nie zawiera streszczenia
The paper deals with simple properties of two-dimensional copulas. The focus is on particular cases when a copula has a homogeneous expansion of the lower tail. Properties of the corresponding main part are studied. For particular cases of copulas the main parts are calculated and possible applications in modelling risk are discussed.
Źródło:
Mathematica Applicanda; 2003, 31, 45/04
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of the surface location approach in the modeling of periodically nonhomogeneous slender visco-elastic beams
Wykorzystanie metody lokalizacji powierzchniowej w modelowaniu cienkich belek lepkosprężystych
Autorzy:
Kula, D.
Powiązania:
https://bibliotekanauki.pl/articles/2084055.pdf
Data publikacji:
2021
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
periodically nonhomogeneous beams
tolerance modeling
Fourier expansion
Opis:
The aim of the study is to develop an analytical reformulation the known theory for thin periodically nonhomogeneous viscoelastic beams, which should to form the basis for the planned research of the full beam dispersion relation. The methodology applied in the paper is similar to that described in paper Tolerance Modelling of Vibrations and Stability for Periodic Slender Visco-Elastic Beams on a Foundation will Damping. Revisiting by Jarosław Jędrysiak, published in scientific journal “Materials” in 2020, but it differs in the way of the use of tolerance modeling in the beam theory. The mathematical tool of considerations is a special choice of the micro-macro decomposition of the beam deflection. It is based on a certain regularization of the displacement field (in the small neighborhood of discontinuity surfaces) and results a certain reformulations of the classical beams theory. Obtained model equations is an alternative proposal for model equations obtained in mentioned paper by Professor Jędrysiak as a certain approximation for periodically nonhomogeneous viscoelastic beams theory as a result of the original tolerance modeling developed. The standardization of the beam deflection field proposed in the presented paper allows us to use the infinite Fourier expansion for deflection field in any region occupied by a homogeneous periodic composite material, which can be modeled in a typical way using the virtual work principle for commonly used beam constrains. The deflection field of the beam is written in the form of an infinite Fourier series, using periodically distributed region of material homogeneity of the beam. Applied method can be viewed as an attempt to use an infinite number of shape functions in the tolerance modeling but at the same time as an equivalent reformulation of the equations of the beam vibration theory. The obtained system of equations is an infinite system of ordinary differential equations for infinitely many Fourier coefficients in the mentioned Fourier expansion of the beam deflection field with respect to the base described in the surface location method.
Źródło:
Acta Scientiarum Polonorum. Architectura; 2021, 20, 3; 19-25
1644-0633
Pojawia się w:
Acta Scientiarum Polonorum. Architectura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study on the Pull-out Resistance of Dynamically Driven Nails and the Cavity Expansion Method
Autorzy:
Sawicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/241374.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
soil nailing
cavity expansion
cone penetration tests
Opis:
The problem is how to assess normal stresses around dynamically driven nails. Pull-out tests show that these stresses are much higher than it would follow from classical analyses. Therefore, an analysis of the cavity expansion method was applied to study this problem. It was shown that the cavity expansion method, widely applied in soil mechanics, suffers from many shortcomings. It was also shown that this method is not closely related to cone penetration tests, nor to the technology of dynamic soil nailing.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2010, 57, 3-4; 243-260
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Liczebność i stanowiska bobra europejskiego w Magurskim Parku Narodowym w latach 1996-2021
The European beaver population in the Magurski National Park during the period 1996-2021
Autorzy:
Wacławczyk, Patryk
Szubert, Piotr
Siwka, Maciej
Gołąb, Agata
Piątek, Dawid
Powiązania:
https://bibliotekanauki.pl/articles/16728967.pdf
Data publikacji:
2021
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
Castor fiber
beaver population
dams
expansion
ponds
Opis:
In recent years, a significant growth in the population of the European beaver Castor fiber L., both in Poland and around the world, has been observed. Beavers significantly transform the natural environment around the sites where they occur. Therefore, it is important to accurately recognize the colonization patterns of new territories by the European beaver and to gain knowledge about the longevity of populations in already occupied areas. This applies especially to areas of natural value, including protected areas. Fieldwork carried out in the spring of 2021, provided information on the distribution of the European beaver and number of individuals in the Magura National Park (MNP) in the Beskid Niski, an arboreous mountain range in southern Poland. The collected data were compared with similar mappings conducted in this Park in 1996 and 2010. This allowed us to characterize the change dynamics of the beaver population in the MNP area and to describe the changes in spatial distribution of sites inhabited by beavers. During the period of 1996-2021, the population of the European beaver increased from 23-26 to 64 individuals in the study area, with a maximum of 68 in 2010. Beaver colonization of ever smaller watercourses draining higher-located catchments and a change in the characteristics of beaver-inhabited sites have been observed. The average number of dam structures within one site as well as site length have increased. Furthermore, the dominant dwelling type has changed from burrows and open-water lodges to bank lodges, which combine characteristics of the two former. We estimate that the period when beavers migrated further up along the watercourses in the studied area was in the years 2010-2021.
Źródło:
Leśne Prace Badawcze; 2021, 82, 4; 143-152
1732-9442
2082-8926
Pojawia się w:
Leśne Prace Badawcze
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermophysical properties of selected vermicular graphite cast iron alloy
Autorzy:
Homa, M.
Sobczak, N.
Turalska, P.
Bruzda, G.
Bacior, M.
Warmuzek, M.
Polkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/391848.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa
Tematy:
vermicular cast iron
thermophysical properties
transformation temperatures
melting heat
thermal expansion
thermal expansion coefficient
thermal diffusivity
thermal conductivity
Opis:
The paper presents the results of thermophysical properties of selected vermicular graphite cast iron with nominal chemical composition of 3.70 C; 2.30 Si; 0.44 Mn; 0.054 P; 0.015 S; 0.017 Mg (wt. %). The comparative studies of the alloy were performed using differential scanning calorimetry, dilatometry and laser flash analysis. The calorimetric investigations proved that upon the heating to melting temperature (~1200°C), four endothermic transformations take place: 1) ferromagnetic → paramagnetic at 742°C, 2) pearlite → austenite at 824.2°C, 3) allotropic transformation of bcc ferrite to fcc austenite at 802°C, 4) melting at 1173.1°C. The character of the dilatometric curve shows small deviation at the temperature above 810°C corresponding to the pearlite → austenite transformation. The values of thermal diffusivity and thermal conductivity change throughout the entire examined temperature range. Both curves showed a changeover from negative to positive trends between 700 and 800°C. This effect might be associated with the pearlite → austenite transformation.
Źródło:
Prace Instytutu Odlewnictwa; 2017, 57, 4; 345-350
1899-2439
Pojawia się w:
Prace Instytutu Odlewnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Expansion of ZrO2-20 mol% Gd2O3
Autorzy:
Kang, Kweonho
Hong, Seok-Min
Lee, Changhwa
Cho, Yongjun
Powiązania:
https://bibliotekanauki.pl/articles/2125531.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ZrO2-20 mol% Gd2O3 pellet
thermal expansion
thermal expansion coefficient
density
thermo-mechanical analyzer
Opis:
The thermal expansion of a ZrO2-20 mol% Gd2O3 pellet has been systematically investigated using a thermo-mechanical analyzer in the temperature range of 293-1773 K. Variations in the thermal expansion coefficient and density upon temperature change were calculated using the thermal expansion data. The average linear thermal expansion coefficient of theZrO2-20 mol% Gd2O3 pellet was found to be 9.522 × 10-6 K-1 in the range of 298-1073 K. This value is smaller than that of ZrO2 and larger than that of Gd2O3. Further, with an increase in temperature to 1773 K, the density of ZrO2-20 mol% Gd2O3 pellet was found to decrease to 94.98 % of the initial density at 293 K.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 3; 909--912
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza możliwości pomiarów rozszerzalności liniowej kompozytów o dużej przewodności cieplnej z wykorzystaniem metod analitycznych
Analysis of possibility of lineat expansion measurements on composites of high thermal conductivity using analytical methods
Autorzy:
Dul, Łukasz
Powiązania:
https://bibliotekanauki.pl/articles/2164929.pdf
Data publikacji:
2013-12-15
Wydawca:
Ostrołęckie Towarzystwo Naukowe
Tematy:
rozszerzalność cieplna
liniowy współczynnik rozszerzalności
cieplnej
metody analityczne
kompozyty
thermal expansion
linear coefficient of thermal expansion
analytical
methods
composites
Opis:
Przedmiotem opracowania jest analiza możliwości pomiarów rozszerzalności liniowej kompozytów o dużej przewodności cieplnej z wykorzystaniem metod analitycznych. W pierwszej części analizy przedstawiony został liniowy współczynnik rozszerzalności cieplnej, w tym również w odniesieniu do materiałów kompozytowych o dużym współczynniku przewodzenia ciepła. Następnie w pracy zaprezentowano szereg metod analizy rozszerzalności liniowej dla kompozytów, w tym o dużej przewodności cieplnej. Opracowanie zawiera bardzo szeroki zakres przedstawionych metod, co może być bardzo cenne z punktu widzenia osób lub ośrodków zainteresowanych badaniem rozszerzalności liniowej, w szczególności kompozytów o dużej przewodności cieplnej.
The purpose of the study is analysis of possibility of linear expansion measurements on composites of high thermal conductivity using analytical methods. First part of the analysis presents the linear coefficient of thermal expansion, also in relation to composite materials with high thermal conductivity. Then, the paper presents, a number of analytic methods of analysis of linear expansion of composites, also with a high thermal conductivity. The study contains a very wide range of presented methods, which can be very valuable in terms of scientists or institutions interested in the study of linear expansion, in particular composites with high thermal conductivity.
Źródło:
Zeszyty Naukowe Ostrołęckiego Towarzystwa Naukowego; 2013, Zeszyt, XXVII; 244-259
0860-9608
Pojawia się w:
Zeszyty Naukowe Ostrołęckiego Towarzystwa Naukowego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the mill feeding system of an elastic variable universe fuzzy control based on particle swarm optimization algorithm
Autorzy:
Tian, Niu
Huang, Songwei
He, Lifang
Du, Lingpan
Yang, Sheping
Huang, Bin
Powiązania:
https://bibliotekanauki.pl/articles/24085898.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fuzzy control
contraction-expansion factor
particle swarm optimization
Opis:
The grinding process in the concentrator is a part of the largest energy consumption, but also the most likely to cause a waste of resources, so the optimization of the grinding process is a very important link.The traditional fuzzy controller relies solely on the expert knowledge summary to construct control rules, which can cause significant steady-state errors in the model. In order to solve the above problem, this paper proposes an elastic variable universe fuzzy control based on Particle Swarm Optimization (PSO) algorithm. The elastic universe fuzzy control model does not need precise fuzzy rules, but only needs to input the general trend of the rules, and the division of the universe is performed by the contraction-expansionfactor. The control performance is directly related to the contraction-expansionfactor, so this article also proposes using particle swarm optimization to optimize the scaling factor to achieve the optimal value. Finally, simulation models of traditional fuzzy control and elastic universe fuzzy control of feeding system of mill were built using Python to verify the control effect. Itssimulation results show that the time of the reaction of the fuzzy control system in the elastic variable theory universe based on particle swarm optimization was shorter by 34.48% comparing to the traditional one. Elastic variable universe fuzzy control based on particle swarm optimization (PSO) effectively improved the control accuracy of the mill feeding system and improved the response speed of the system to a certain extent.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 3; art. no. 169942
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza sposobów ekspandowania nasion oraz warzyw i owoców metodą przemiany fazowej wody
The analysis of expansion ways for seeds and vegetables and fruit using water phase transition method
Autorzy:
Konopko, H.
Powiązania:
https://bibliotekanauki.pl/articles/286357.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
ekspandowanie
nasiona
owoce
warzywa
expansion
seeds
fruit
vegetables
Opis:
W pracy przedstawiono sposoby ekspandowania takich surowców pochodzenia roślinnego jak nasiona oraz warzywa i owoce. Analiza tych sposobów świadczy o dużym ich wpływie na stopień ekspansji surowców.
The paper presents expansion ways for plant products including seeds and vegetables and fruit. Completed analysis of these expanding ways proves their substantial impact on the products expansion degree.
Źródło:
Inżynieria Rolnicza; 2009, R. 13, nr 2, 2; 75-81
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wielkości nasion na niezbędną długość przewodu pneumatycznego w procesie ekspandowania nasion
Impact of the seed size on the necessary pneumatic tube length in the process of seed expansion
Autorzy:
Konopko, H.
Powiązania:
https://bibliotekanauki.pl/articles/288767.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
ekspandowanie
nasiona
wielkość nasion
expansion
seeds
seed size
Opis:
Celem pracy było określenie wpływu wielkości nasion na przebieg i rezultaty procesu ekspandowania nasion w strumieniu gorącego powietrza w pionowym przewodzie pneumatycznym. Analizy problemu dokonano na podstawie wyników symulacji komputerowej procesu dla dwóch klas ziarnowych tego samego gatunku nasion. Wykazały one, że dla każdej klasy ziarnowej należy odrębnie ustalać optymalne, z punktu widzenia jakości produktu, parametry procesu.
The purpose of the study was to determine the impact of seed size on the course and results of the seed expansion process in a stream of hot air in a vertical pneumatic tube. The problem analysis was done based on the results of a computer simulation of the process for two grain classes of the same grain type. It was found that for each grain class it is necessary to establish separately the process parameters that would be optimal from the point of view of the quality of the product.
Źródło:
Inżynieria Rolnicza; 2006, R. 10, nr 5(80), 5(80); 291-296
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A verification approach to thermoelastic steam turbine rotor analysis during transient operation
Autorzy:
Dominiczak, K.
Banaszkiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/175490.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
steam turbine
thermal stress
thermal growth
differential expansion
Opis:
This paper presents a verification approach to thermoelastic steam turbine rotor analysis. Neither temperature nor stresses are measured on the rotor surface in utility power plants. Therefore analysis of the steam turbine rotor can be verified only based on absolute and differential thermal expansion measurements in vicinity of the steam turbine. Absolute and differential expansion measurements and steam turbine fixed points arrangement allow to calculate thermal growth of the steam turbine rotor during transients. Thermal growth of the rotor can be a baseline for the calculation using a numerical model.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 131; 55-65
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ właściwości izolacji na proces ekspandowania nasion w strumieniu gorącego powietrza
Impact of insulation properties on the process of seed expansion in hot air stream
Autorzy:
Konopko, H.
Pacuk, W.
Wyszomirska, T.
Powiązania:
https://bibliotekanauki.pl/articles/288765.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
ekspandowanie
nasiona
strata ciepła
expansion
heat losses
seeds
Opis:
Celem pracy było określenie wpływu właściwości izolacji termicznej na proces ekspandowania nasion w strumieniu gorącego powietrza w przewodzie pneumatycznym. Zastosowano symulację komputerową procesu metodą "krok po kroku'. Obliczenia przeprowadzono dla trzech rodzajów izolacji. Wyniki obliczeń wykazały, że jakość izolacji ma znaczący wpływ na rezultaty procesu.
The purpose of the study was to determine the impact of thermal insulation properties on the process of seed expansion in hot air stream in a pneumatic conduit. A computer simulation was done by using the "step-by-step" method. The calculations were done for three types of insulation. The calculation results showed that the quality of the insulation has a significant effect on results of the process.
Źródło:
Inżynieria Rolnicza; 2006, R. 10, nr 5(80), 5(80); 297-304
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research results of novel composite materials with low hysteresis during heating and cooling for pistons of combustion engines
Autorzy:
Sieminska, B.
Powiązania:
https://bibliotekanauki.pl/articles/245037.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
internal combustion engines
engine piston
thermal expansion
emissions
Opis:
Research results of novel silumins on pistons for combustion engines, which have high mechanical properties within the range of piston higher operating temperatures, 100-300°C, are presented in the paper. Silumins contain enlarging concentration of the nickel and copper alloy additives up to 4.0, and chrome and molybdenum alloy additives up to 1.0%. Occurrence of given microstructure in piston-silumins results in almost the same values of the coefficient thermal expansion during the heating up to the 300 °C temperature and during the next cooling into the ambient temperature. Small values of the coefficient of expansion of thermal and small differences between values of the coefficient of thermal expansion during heating and cooling enable on application of small values of working clearances between piston and the cylinder liner. As a consequence they make possible, the low exhaust emission level, and the low noise level. The pistons from alloys with small values ofthe coefficient of thermal expansion, small differences of this coefficient during heating and cooling are novel aspects presented in paper. Research results of strength and metallographic parameters, research results of the coefficient of thermal expansion, comparative engine research results are represented in the paper. In particular representative chemical components for a standard alloy and novel alloy, mechanical properties investigated alloys after solution heat treatment, wear resistance of novel alloy compared with two cast irons, ATD curves, fibrous construction, silicon construction, microstructure of novel alloy, courses of changes of the coefficient of thermal expansion in the function of the temperature during heating and cooling are presented in the paper.
Źródło:
Journal of KONES; 2010, 17, 1; 421-432
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and Numerical Study of NACA and Conventional Riveting Procedure
Autorzy:
Wronicz, W.
Kaniowski, J.
Malicki, M.
Kucio, P.
Klewicki, R.
Powiązania:
https://bibliotekanauki.pl/articles/97783.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
rivet
NACA riveting
fatigue
hole expansion
computed tomography
Opis:
Fatigue behaviour is one of the most important properties of modern airplanes and rivets influence it strongly. According to the literature, the NACA riveting offers a multiple increase in the fatigue life of joints. The aim of this paper is to investigate the benefits offered by the NACA riveting procedure with respect to the residual stress and strain distribution after riveting as well as rivet hole expansion. Experimental and numerical approaches were adopted. The conventional riveting with both the universal and countersunk rivets was compared with the NACA riveting. The countersunk angle and depth in the case of the NACA riveting was modified somewhat relative to the values met in the literature. For these three cases, strain gauge measurements during riveting, hole expansion measurements and FE calculations were performed. The hole expansion measurement with the use of Computer Tomography(CT) was proposed. Only the FE calculations unambiguously indicate better fatigue properties of the NACA riveting. The proposed method of hole expansion measurement requires further research to increase its accuracy.
Źródło:
Fatigue of Aircraft Structures; 2017, 9; 157-170
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The periphery graph of a median graph
Autorzy:
Brešar, Boštjan
Changat, Manoj
Subhamathi, Ajitha
Tepeh, Aleksandra
Powiązania:
https://bibliotekanauki.pl/articles/744496.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
median graph
Cartesian product
geodesic
periphery
peripheral expansion
Opis:
The periphery graph of a median graph is the intersection graph of its peripheral subgraphs. We show that every graph without a universal vertex can be realized as the periphery graph of a median graph. We characterize those median graphs whose periphery graph is the join of two graphs and show that they are precisely Cartesian products of median graphs. Path-like median graphs are introduced as the graphs whose periphery graph has independence number 2, and it is proved that there are path-like median graphs with arbitrarily large geodetic number. Peripheral expansion with respect to periphery graph is also considered, and connections with the concept of crossing graph are established.
Źródło:
Discussiones Mathematicae Graph Theory; 2010, 30, 1; 17-32
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmodyfikowany test Hole Expansion
Modified Hole Expansion test
Autorzy:
Molenda, R.
Kuziak, R.
Powiązania:
https://bibliotekanauki.pl/articles/181765.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Metalurgii Żelaza im. Stanisława Staszica
Tematy:
Test Hole Expansion
stal DP
ferryt
bainit
martenzyt
wskaźnik HE
Hole Expansion test
DP steel
ferrite
bainite
martensite
HE index
Opis:
W artykule przedstawiono propozycję modyfikacji testu Hole Expansion w ten sposób by możliwy był pomiar wskaźnika HE na taśmach stalowych o szerokości 50mm obrabianych cieplnie w symulatorze Gleeble 3800. Zaprojektowano i wykonano oprzyrządowanie , które współpracując z maszyną wytrzymałościową Zwick Z250 umożliwia wyznaczenie wskaźnika HE na zmodyfikowanych próbkach taśm stalowych. Pomiary wskaźnika HE przeprowadzone na taśmach ze stali DP potwierdziły przydatność opracowanego testu badawczego.
This article presents the proposal for modification of the Hole Expansion test so that HE index measurements are possible on steel strips of 50mm in width after heat treatment with Gleeble 3800 simulator. The tooling which can operate with Zwick Z250 testing machine to allow the determination of HE index on modified steel strip test pieces was designed and made. The HE index measurements taken on DP steel strips have confirmed the suitability of the developed research test.
Źródło:
Prace Instytutu Metalurgii Żelaza; 2013, T. 65, nr 4, 4; 60-64
0137-9941
Pojawia się w:
Prace Instytutu Metalurgii Żelaza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Specialized Knowledge Representation: from Terms to Frames
Autorzy:
Faber, Pamela
Cabezas-García, Melania
Powiązania:
https://bibliotekanauki.pl/articles/1026716.pdf
Data publikacji:
2019-06-30
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
context expansion
frame
multi-word term
phrase
specialized discourse
Opis:
Understanding specialized discourse requires the identification and activation of knowledge structures underlying the text. The expansion and enhancement of knowledge is thus an important part of the specialized translation process (Faber 2015). This paper explores how the analysis of terminological meaning can be addressed from the perspective of Frame-Based Terminology (FBT) (Faber 2012, 2015), a cognitive approach to domain-specific language, which directly links specialized knowledge representation to cognitive linguistics and cognitive semantics. In this study, context expansion was explored in a three-stage procedure: from single terms to multi-word terms, from multi-word terms to phrases, and from phrases to frames. Our results showed that this approach provides valuable insights into the identification of the knowledge structures underlying specialized texts.
Źródło:
Research in Language; 2019, 17, 2; 197-211
1731-7533
Pojawia się w:
Research in Language
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Expansion of Eucalypt Woodlot and Its Factors in Cheha District, Southern Ethiopia
Autorzy:
Gizachew, Kebede
Powiązania:
https://bibliotekanauki.pl/articles/1182757.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Eucalypts
Eucalypts woodlot
Expansion
Management
Rural households
wealth status
Opis:
Growing eucalypts at a farm level in the form of woodlot has become popular among rural household in Ethiopia. Households in the study area establish mainly eucalypts woodlot as a component of livelihood portfolio both for meeting household wood consumption and generating cash income. However, there were no sufficient information on the extent of eucalypts woodlot, and factors influencing the household decision on their establishment on the individual farm lands. This study was conducted in Cheha Districts in Guraghe zone with the aims of assessing the magnitude of eucalypts woodlots and factors influencing their establishment at household level. The data was collected by employing formal survey using structured questionnaire and Woodlot inventory. The latest version of Stata, version 13 and Microsoft excel were used to analyze the data. The result of the study revealed that some 58% (n = 61) of the sampled farmers in the study area had eucalypts woodlot, and among these 27% and 24% are those farmers who have converted their crop and grazing lands to eucalypts woodlots targeting either to earn more income or to increase the productivity of the land which has denied to grow cereal crops and pastures. Most of the farmers considered eucalypts as one of the major sources of income and risk aversion. The study is concluding that different socioeconomic factors, family size, crop income and accessibility of road had significant negative effect whereas total land holding and education level of the household heads had significant positive effects on the household’s decision for the allocation of land and establishment of eucalypts woodlot on the farm lands. Further studies are needed to compare the return from Eucalyptus with other crops in terms of economic and environmental benefits and finally management aspect of eucalypts needed further research for the productivity of allocated land.
Źródło:
World Scientific News; 2017, 66; 163-180
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prognozowanie i planowanie jako istotny czynnik rozwoju przedsiębiorstw przemysłu wydobywczego
Forecasting and strategic planning as an important factor in development of coal companies
Autorzy:
Sukiennik, M.
Powiązania:
https://bibliotekanauki.pl/articles/349424.pdf
Data publikacji:
2007
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
węgiel kamienny
prognozowanie
planowanie
rozwój
coal
planning
forecasting
expansion
Opis:
Celem niniejszego artykułu jest zaprezentowanie kierunków rozwoju przedsiębiorstw działających w przemyśle wydobywczym. W związku z nieustannie zmieniającymi się warunkami działania oraz specyfiką przemysłu wydobywczego, planowanie i prognozowanie odgrywa tu szczególną rolę. W artykule przedstawiono m.in. możliwości alternatywnego wykorzystania węgla oraz kierunki zmian lub rozwoju dla przedsiębiorstw górniczych.
This paper contain considerations about usage strategic planning and forecasting in companies from mining industry. Difficult situation in Polish mining and variability economic conditions causes necessity of applying forecasting and efficiency strategic planning to the companies works in mining industry. Paper shows forecast for coal and suggest the directions of changes for mining companies.
Źródło:
Górnictwo i Geoinżynieria; 2007, 31, 1; 73-84
1732-6702
Pojawia się w:
Górnictwo i Geoinżynieria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Available pipe connectors versus their geometrical correctness
Łączniki dostępne w porównaniu do poprawych geometrycznie
Autorzy:
Tytkowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/119130.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Geometrii i Grafiki Inżynierskiej
Tematy:
pipe connectors
constructing
expansion
złącza do rur
budowa
rozwój
Opis:
The paper discusses different constructional solutions of pipe connectors, indicating various level of background of designers who have designed them. Construction of connectors made of plate (ruled surface) and plastics have been presented.
W pracy przedstawiono różne rozwiązania konstrukcyjne łączników, wskazujące na zróżnicowane przygotowanie konstruktorów, którzy je projektowali. Przedstawiono konstrukcje łączników z blachy (powierzchnie rozwijalne) i z tworzyw sztucznych.
Źródło:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics; 2013, 25; 67-72
1644-9363
Pojawia się w:
Journal Biuletyn of Polish Society for Geometry and Engineering Graphics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wavelet-based solution for vibrations of a beam on a nonlinear viscoelastic foundation due to moving load
Falkowe rozwiązanie problemu drgań belki spoczywającej na nieliniowym lepko sprężystym podłożu generowanych przez poruszające się obciążenie
Autorzy:
Hryniewicz, Z.
Kozioł, P.
Powiązania:
https://bibliotekanauki.pl/articles/279856.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
Timoshenko beam
Adomian’s decomposition
coiflet expansion
moving load
Opis:
The paper presents a new analytical solution for the dynamic response of an infinitely long Timoshenko beam resting on a nonlinear viscoelastic foundation. Vibrations of the beam are analysed by using Adomian’s decomposition method combined with wavelet based approximation alleviating difficulties related to Fourier analysis and numerical integration. The developed approach allows various parametric analyses leading to full characteristics of the investigated dynamic system.
Artykuł prezentuje nowe analityczne rozwiązanie problemu dynamicznej odpowiedzi nieskończenie długiej belki Timoshenki spoczywającej na nieliniowym lepkosprężystym podłożu, poddanej ruchomemu obciążeniu rozłożonemu na odcinku i harmonicznemu w czasie. Analiza drgań belki została przeprowadzona przy użyciu dekompozycji Adomiana połączonej z aproksymacją falkową pozwalającą ominąć trudności związane z numerycznym całkowaniem oraz zminimalizować niedogodności analizy Fouriera. Uzyskane rozwiązanie daje możliwość parametrycznej analizy badanego układu dynamicznego prowadzącej do opisu jego fizycznych własności. Opracowana metoda wykorzystująca filtry falkowe typu coiflet może być zastosowana do rozwiązania nieliniowych równań różniczkowych opisujących inne układy dynamiczne typu belka-podłoże.
Źródło:
Journal of Theoretical and Applied Mechanics; 2013, 51, 1; 215-224
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pęcznienie a odprężenie nienasyconych iłów warszawskich
Swelling and/ or rebound unsaturated Warsaw clay
Autorzy:
Lendo-Siwicka, M.
Garbulewski, K.
Powiązania:
https://bibliotekanauki.pl/articles/403117.pdf
Data publikacji:
2013
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
iły warszawskie
pęcznienie
odprężenie
Warsaw clay
expansion
rebound strain
Opis:
W artykule przedstawiono charakterystyki pęcznienia i odprężenia nienasyconych iłów występujących w rejonie Warszawy (iłów warszawskich). W badaniach przyjęto założenie, że odkształcenie objętościowe εv iłów składa się z dwóch części – odkształcenia pęcznienia εp i odkształcenia odprężenia εo, których procentowy udział zależy przede wszystkim od warunków gruntowo-wodnych w podłożu (wilgotności i stopnia nasycenia) oraz od wartości składowej pionowej naprężenia efektywnego σ’v = σv - ua. W badaniach zastosowano konsolidometr KKSW (konsolidometr z kontrolowanym ciśnieniem ssania i wilgotnością) zaprojektowany i wykonany w Katedrze Geoinżynierii SGGW oraz zmodyfikowane edometry standardowe. Z przeprowadzonych badań wynika, że odkształcenia odprężenia iłów określone w badaniach edometrycznych mieszczą się w zakresie od 0,19% do 0,62%, natomiast odkształcenia pęcznienia od 2,38% do 5,45%. Odprężenie iłów jest procesem krótkotrwałym i stanowi średnio około 20,8% czasu całkowitych zmian objętości, w przeciwieństwie do pęcznienia, które jest procesem długotrwałym i wypełnia pozostały całkowitych zmian objętości.
The paper presents the characteristics of unsaturated expansive clays occurring in the area of Warsaw (Warsaw clays). It was assumed that the volumetric strain (εv) consists of two components – the swelling deformation (εp) and the rebound strain (εo), which percentage depends primarily on the ground – water conditions (moisture content and degree of saturation) and the vertical effective stress σ'v = σv - ua. In the study the consolidometr KKSW (designed at the Department of Geotechnical Engineering Warsaw University of Live Sciences) with suction and water content controlling was used. The study shows that the rebound strains in the Warsaw clays are in the range from 0.19% to 0.62%, and the swelling deformation of 2.38% to 5.45%. Rebound of clays is the short-term process, average about 20,8% of time for total volume changes. The swelling is a lengthy process and provides an average of about 79,2% of time to total volume changes.
Źródło:
Budownictwo i Inżynieria Środowiska; 2013, 4, 2; 135-142
2081-3279
Pojawia się w:
Budownictwo i Inżynieria Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wave Generation by a Finite Baffle Array in Application to Beam-Forming Analysis
Autorzy:
Tasinkevych, Y.
Powiązania:
https://bibliotekanauki.pl/articles/177857.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
phased array
beamforming
mixed boundary value problem
BIS expansion
Opis:
Directional excitation of sound in an aperiodic finite baffle system is analyzed using a method developed earlier in electrostatics. The solution to the corresponding boundary value problem is obtained in the spatial-frequency domain. The acoustic pressure and normal particle velocity distribution in acoustic media can be easily computed by the inverse Fourier transform from their spatial spectra on the baffle plane. The presented method can be used for linear acoustic phased arrays modeling with finite element size and inter-element interactions taken into account. Some illustrative numerical examples presenting the far-field radiation pattern and wavebeam steering are given.
Źródło:
Archives of Acoustics; 2010, 35, 4; 677-686
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of extrusion process parameters based on its response to the step function
Identyfikacja parametrów procesu ekstruzji na podstawie jego odpowiedzi na wymuszenie skokowe
Autorzy:
Żelaziński, T.
Ekielski, A.
Powiązania:
https://bibliotekanauki.pl/articles/93419.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
extrusion
extruder
expansion
Taguchi
disturbances
ekstruzja
ekstruder
ekspansja
zakłócenia
Opis:
The paper presents results of the research on the single-screw extruder strength on sudden changes of dosing raw material during the extrusion process. The tests were carried out in a short single-screw extruder KZM-2 whose relation of length to diameter of a screw was 6:1 and rotational speed was 200 rpm. Grits moistened up to 15% moisture and five disturbing samples of mass 0.2-1.2 kg prepared from the same raw material constituted a research material. Particular samples were used for disturbing a stable course of the extrusion process. Disturbance of the process consisted in fast introduction of the whole disturbing dose to the extruder input and measurement of the value of intensity change of current consumed by the extruder engine, time of return to stable conditions and changes in the image of obtained samples of extruder. Measurements of the impact of disturbance on the measured amounts were carried out for three settings of extruder performance. It was found out that a single-screw extruder at all set performances reacted with fast increase of electric current consumption; moreover, time of process stabilization changed each time. Moreover, it was reported that particular disturbing doses affected significantly the changes of quality parameters of extrudates.
W pracy przedstawiono wyniki badań odporności ekstrudera jednoślimakowego na nagłe zmiany dawki podawania surowca w trakcie procesu ekstruzji. Badania przeprowadzono w krótkim ekstruderze jednoślimakowym KZM-2 o stosunku długości do średnicy ślimaka 6:1 i prędkości obrotowej 200 obr·min-1 (rpm). Materiałem badawczym była kaszka kukurydziana nawilżana do wilgotności 15% oraz pięć próbek zakłócających o masie 0,2-1,2 kg przygotowanych z tego samego surowca. Poszczególne próbki posłużyły do zakłócenia ustabilizowanego przebiegu procesu ekstruzji. Zakłócenie procesu polegało na szybkim wprowadzeniu do wejścia ekstrudera całej dawki zakłócającej i pomiarach wartości zmiany natężenia prądu pobieranego przez silnik ekstrudera, czasu powrotu do warunków stabilnych oraz zmian w obrazie otrzymanych próbek ekstrudatu. Pomiary wpływu zakłócenia na mierzone wielkości przeprowadzano dla trzech ustawień wydajności ekstrudera. Stwierdzono, że ekstruder jednoślimakowy przy wszystkich ustawionych wydajności reagował szybkim zwiększeniem poboru prądu elektrycznego, każdorazowo zmieniał się także czas ustabilizowania procesu. Zaobserwowano również, że poszczególne dawki zakłócające wpływały istotnie na zmiany parametrów jakościowych ekstrudatów.
Źródło:
Agricultural Engineering; 2014, 18, 2; 241-252
2083-1587
Pojawia się w:
Agricultural Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic analysis of medium pressure reciprocating natural gas expansion engines
Autorzy:
Farzaneh-Gord, M.
Izadi, S.
Pishbin, S. I.
Sheikhani, H.
Deymi-Dashtebayaz, M.
Powiązania:
https://bibliotekanauki.pl/articles/777996.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Expansion engine
thermodynamic
first law
optimization
ideal gas model
Opis:
Natural gas pressure has to be reduced from medium pressure of 1.724 MPa (250 psia) to lower pressure of 0.414 MPa (60 psia) at Town Border pressure reduction Station (TBS). Currently, the pressure reduction is carried out by throttling valves while considerable amount of pressure energy is wasted. One of the equipment which could be used to recover this waste energy is the reciprocating expansion engine. The purpose of this research is to simulate one-sided reciprocating expansion engine thermodynamically for TBS pressure range. The simulation is based on first law of thermodynamics, conversation of mass and ideal gas assumptions. The model could predict in-cylinder pressure and in-cylinder temperature at various crank angles. In addition, the effects of the engine geometrical characteristics, such as intake and exhaust port area and ports timing on the Indicated work per cycle output are investigated.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 2; 119-125
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Lab-scale HVAC Hissing-type Noise and Vibration Characterization with Vehicle System Validation
Autorzy:
Satar, Mohd Hafiz Abdul
Mazlan, Ahmad Zhafran Ahmad
Hamdan, Muhd Hidayat
Isa, Mohd Syazwan Md
Paiman, Muhd Abdul Rahman
Ghapar, Mohd Zukhairi Abd
Powiązania:
https://bibliotekanauki.pl/articles/1953472.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
hissing noise
HVAC system
vibration
evaporator
thermal expansion valve
Opis:
Heating, ventilation and air conditional (HVAC) system provides a cold ventilation for the comfort of the driver and passengers in a vehicle. However, the vibration induced by the HVAC contributes to a reasonable level of noise emission, and hissing is one of the critical noises. So far, the characterization of hissing noise from the vehicle is least to be reported compared to other type of noises. Hence, this paper investigates the occurrence of hissing noise from several HVAC components. A lab-scale HVAC system was developed to imitate the real-time operations of the vehicle HVAC system. Two engine conditions, namely as ambient and operating conditions, were tested at speed of 850 rpm and 850-1400 rpm, with the blower speed maintained constantly at one level. The result shows that the hissing noise from the labscale HVAC was produced at frequency range of 4000-6000 Hz. The finding also highlights that the main component contributors of noise emission are an evaporator and a thermal expansion valve. The validation with a real vehicle system showed a good consensus whereby the hissing noise was produced at the similar operating frequency ranges. Also, the hissing noise was found to be louder when in an operating condition which could be taken into consideration by the vehicle manufacturers to improve the HVAC design.
Źródło:
Archives of Acoustics; 2021, 46, 2; 365-373
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Probabilistic Model of the Fatigue Durability of Knitted Fabrics Produced from Standard Smooth and Fancy Flame Cotton Yarns
Probabilistyczny model trwałości zmęczeniowej dzianin wytworzonych z przędz bawełnianych gładkich i płomykowych
Autorzy:
Drobina, R.
Powiązania:
https://bibliotekanauki.pl/articles/233264.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
knitted fabric
fatigue durability
probabilistic model
Weibull’s expansion
lognormal expansion
dzianina
zmęczeniowa trwałość
probabilistyczny model
teoria Weibulla
logarytmiczno-normalny rozkład
Opis:
The possibility of the introduction of probabilistic models based on Weibull’s theory applied to modelling the problems of fatigue durability and reliable structures as well as models based on log-normal distribution is presented. It was found that the assessment of the quality of knitted fabrics on the basis of classic static durability is not sufficient and it can often lead to incorrect conclusions, having no grounds in real conditions of use. The question of the fatigue durability of knitted fabrics produced from standard smooth and fancy flame cotton yarns was considered. Quantitative description by means of probabilistic and statistical models was proposed. Attention was mainly given to working out probabilistic models based on graphic methods, enabling verification of experimental data.
Przedstawiono możliwość wprowadzenia modeli probabilistycznych opartych na teorii Weibulla zastosowanych do modelowania problemów wytrzymałości zmęczeniowej i struktur niezawodnościowych, a także modeli bazujących na rozkładzie logarytmiczno-normalnym. Stwierdzono, że ocenianie jakości dzianin na podstawie klasycznej wytrzymałości statycznej nie jest wystarczające i często może prowadzić do błędnych wniosków i nie mieć uzasadnienia w rzeczywistych warunkach użytkowania. Rozpatrzono zagadnienie trwałości zmęczeniowej dzianin o splocie lewo-prawym wytworzonych z przędz bawełnianych, zarówno gładkich, jak i ozdobnych. Zaproponowano ich kwantytatywny opis za pośrednictwem modeli statystycznych i probabilistycznych, z zamiarem uzyskania największej konwergencji rezultatów uzyskanych teoretycznie, z wynikami badań otrzymanymi drogą eksperymentu. Główną uwagę skoncentrowano na opracowaniu modeli probabilistycznych bazujących na metodach graficznych, umożliwiających weryfikację danych eksperymentalnych trwałości zmęczeniowej uwzględniających aspekty fizykalne procesów przędzalniczych.
Źródło:
Fibres & Textiles in Eastern Europe; 2013, 4 (100); 75-84
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Umbria i jej mieszkańcy wobec ekspansji rzymskiej w IV–II wieku p.n.e.
Autorzy:
Piegdoń, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/640547.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Umbria, Umbrians, Roman Republic, Roman Expansion, Colonisation, Roman Conquest
Opis:
Umbria and Umbrians’ attitude towards the Roman expansion in 4th–2nd century BCE This article is an attempt to present the role of the Roman Republic’s policies towards Umbrian tribes (in 4th–2nd century BCE) and show the effects of those policies. Umbria was initially an area inhabited by a mosaic of Umbrian’s tribes representing various levels of development. The policy of first conquering and then subordinating this area, as well as the powerful influence of Roman law, ideas, and cultural models, indicates not only the great military might of republican Rome but also the attractiveness of its civilization. Rome’s effectiveness resulted mainly from the fact that its actions complemented each other. After victorious military operations, or sometimes simultaneously with those operations, came settlement campaigns (colonies: Narnia, Interamna Nahars, Spoletium etc.) Rome was also a master of diplomacy. It mollified its recent enemies by concluding alliances (foederae with Camerinum, Ocriculum etc.) that created a system of friendly state and tribal organisms and enabled its citizens to live peaceably on the conquered territories. All these actions made it possible to subordinate the region, make the Roman presence permanent, and effectively repulse the invaders (Hannibal and his brother – Hasdrubal during the Second Punic War). The intensified settlement policy in Umbria and the expansion of its infrastructure (roads), facilitated economic contacts between Roman settlements and the centers of the subjugated, allied native tribes.
Źródło:
Prace Historyczne; 2013, 140, 2
0083-4351
Pojawia się w:
Prace Historyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Urządzenia dylatacyjne podstawowym problemem utrzymaniowym mostów zarządzanych przez GDDKiA
Expansion joint devices as a basic issue of maintaining bridges managed by General Directorate for National Roads and Motorways (GDDKIA)
Autorzy:
Kaszyński, A.
Powiązania:
https://bibliotekanauki.pl/articles/145004.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Inżynierów i Techników Komunikacji Rzeczpospolitej Polskiej
Tematy:
utrzymanie mostów
urządzenia dylatacyjne
maintenance of bridges
expansion joints
Opis:
W artykule przedstawiono informacje o obecnym stanie ewidencyjnym oraz stanie technicznym infrastruktury mostowej znajdującej się w zarządzie GDDKiA. Zaprezentowano dane o aktualnym stanie technicznym podstawowych elementów obiektów mostowych. Wskazano elementy, których stan techniczny jest oceniany najniżej. Przedstawiono typowe uszkodzenia urządzeń dylatacyjnych i ich wpływ na stan obiektu. Wskazano, na przykładach kilku zrealizowanych remontach i przebudowach obiektów mostowych, na błędy popełniane w trakcie projektowania oraz montażu urządzeń dylatacyjnych jako główną przyczynę późniejszych problemów z ich utrzymaniem.
The study provides information about current registration status and technical condition of the bridge infrastructure managed by the GDDKiA. Moreover, it also includes current technical condition of basic bridge structure elements. There are indicated items whose technical conditions are evaluated as the lowest. I have presented typical damages of the expansion joint devices and their impact on the object state. By means of examples of the several completed renovations and reconstruction of bridge objects, there are indicated mistakes made during designing and execution of the expansion joint devices. Those mistakes are considered to be main cause of the further maintenance problems.
Źródło:
Drogownictwo; 2018, 4; 123-133
0012-6357
Pojawia się w:
Drogownictwo
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model updating in structural dynamics through a confluence algorithm
Udoskonalanie modeli w dynamice konstrukcji za pomocą algorytmu konfluencji
Autorzy:
Chierichetti, M.
Ruzzene, M.
Powiązania:
https://bibliotekanauki.pl/articles/279238.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
displacement mapping
inverse problem
FEM
experimental update
modal expansion
Opis:
The identification of the dynamic response of a structure in the presence of structural degradation has potential practical use on health monitoring systems and can contribute to improve the safety of rotorcraft flight and wind-turbine operations and to decrease their handling costs. A combined numerical and experimental procedure, called Property Identification Algorithm, updates the numerical model based on a limited set of experimental measurements in order to accurately predict the dynamic response of a system in the presence of structural degradations. The algorithm is designed based on modal decomposition and discrete experimental measurements, and is formulated in the case of periodic excitations. It is demonstrated that the updated dynamic response represents an accurate map of the experimental response in the domain. The paper describes the proposed algorithm and presents validation cases.
Identyfikacja dynamicznej odpowiedzi konstrukcji wykazującej cechy degradacji strukturalnej ma praktyczne zastosowanie w układach monitorowania stanu i może przyczynić się do poprawy bezpieczeństwa lotu śmigłowców oraz zwiększenia efektywności pracy turbin wiatrowych przy jednoczesnym obniżeniu kosztów eksploatacji. W pracy przedstawiono tzw. Algorytm Identyfikacji Właściwości (Property Identification Algorithm) będący kombinacją numerycznej i eksperymentalnej procedury, której celem jest udoskonalenie modelu przy ograniczonym zbiorze danych doświadczalnych do precyzyjnego przewidywania dynamicznej odpowiedzi układu z degradacją strukturalną. Algorytm oparto na dekompozycji modalnej i dyskretnych pomiarów eksperymentalnych oraz sformułowano dla przypadku wymuszeń harmonicznych. Wykazano, że odpowiedzi dynamiczne modelu udoskonalonego pozwala na uzyskanie dokładnej mapy rzeczywistych odpowiedzi w zadanym obszarze parametrów. W artykule opisano zaproponowany algorytm i przedstawiono kilka przykładów jego weryfikacji.
Źródło:
Journal of Theoretical and Applied Mechanics; 2011, 49, 3; 665-683
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Researches novel materials on the pistons with low hysteresis to combustion engines
Autorzy:
Sieminska, B.
Slawinski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/243012.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion engines
engine pistons
composite alloy
thermal expansion
hysteresis
Opis:
The researches were carried out at the use of the precise dilatometer of the firm BAHR 802/801. The device makes possible the registration of changes of measurements of the sample in the function of the temperature. Measurements in the simpler and differential are possible. Heating and cooling is performed in the special device, which realizes the programme temperature, controlled computer. Changes of dimensions are measured with an inductive sensor. Samples were placed in the quartz-pipe and changes of their length were transferred by quartz-rods. The temperature of tested material was measured by means of the Pt-PtRh thermocouple. Material on the pistons has a fundamental meaning for the value of the clearances between the cylinder and the piston. Too small clearness between the piston and cylinder on the cold engine cannot be applying, because during the work of an engine it would be able to occur seizing of an engine. From here, also the large resistance on seizing of material of the piston is essential. Investigated composite materials performed based on piston-silumins AK12 and AK18 in which a composite addition was silicon carbide (SiC) and ferric sulphide (FeS).
Źródło:
Journal of KONES; 2012, 19, 4; 549-554
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis and research of piston working conditions of combustion engine in high thermal load conditions
Autorzy:
Jankowska-Sieminska, B.
Jankowski, A.
Slezak, M.
Powiązania:
https://bibliotekanauki.pl/articles/243400.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion engine
piston
thermal load
thermal expansion
thermal shock
Opis:
Explanation of phenomena occurring in pistons of combustion engines which appear during heating and cooling processes in reference to standard materials and composite materials of high material proprieties is aim of the paper. Bring over researches were mostly directed on measurements of difference dimensions which appear during the piston work in the combustion engine. The paper concentrates on phenomenon of different proprieties of materials. The thermal stresses and shocks differ. In the thermal shock, thermal stresses are caused by instantaneous temperature gradients which appear at high engine speed. These stresses are determined thro temperature distribution and they do not differ from stresses in steady-state conditions. Researches concerning thermal expansions were performed by means of sensitive dilatometer which can work in simple and differential system. Changes of dimensions versus temperature function were measured with inductive sensor and the sensitive Pt-ptrh thermocouple, and results were referred to reference material-Platinum. Research results are illustrated on diagrams of different courses of changes of the of thermal expansion coefficient during heating and cooling of standard and composite materials. Values of the thermal expansion coefficient a for the heating and cooling are smaller for composite alloys. The course of the coefficient â during cooling can be higher or lower from the coefficient a during heating. Similar values were also received. Maximum differences were of 10%. Smaller values of the coefficient a for composite alloys cause that for such the same thermal loads temperature gradients will be smaller for composite alloys. Courses of changes of the coefficient â have a different characteristics suited from chemical composition of alloy, granularity of the composite component and thermal treatment.
Źródło:
Journal of KONES; 2007, 14, 3; 233-243
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Semi-analytical solution of optimization on moon-pool shaped WEC
Autorzy:
Zhang, W. C.
Liu, H. X.
Zhang, X. W.
Zhang, L.
Powiązania:
https://bibliotekanauki.pl/articles/963397.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
wave energy
eigenfunction expansion
moon pool
conversion ability
optimization
Opis:
In order to effectively extract and maximize the energy from ocean waves, a new kind of oscillating-body WEC (wave energy converter) with moon pool has been put forward. The main emphasis in this paper is placed on inserting the damping into the equation of heaving motion applied for a complex wave energy converter and expressions for velocity potential added mass, damping coefficients associated with exciting forces were derived by using eigenfunction expansion matching method. By using surface-wave hydrodynamics, the exact theoretical conditions were solved to allow the maximum energy to be absorbed from regular waves. To optimize the ability of the wave energy conversion, oscillating system models under different radius-ratios are calculated and comparatively analyzed. Numerical calculations indicated that the capture width reaches the maximum in the vicinity of the natural frequency and the new kind of oscillating-body WEC has a positive ability of wave energy conversion.
Źródło:
Polish Maritime Research; 2016, S 1; 25-31
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On intersections of Cantor sets: Hausdorff measure
Autorzy:
Pedersen, S.
Phillips, J. D.
Powiązania:
https://bibliotekanauki.pl/articles/254741.pdf
Data publikacji:
2013
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Hausdorff measure
fractal
Cantor set
translation
intersection
digit expansion
Opis:
We establish formulas for bounds on the Haudorff measure of the intersection of certain Cantor sets with their translates. As a consequence we obtain a formula for the Hausdorff dimensions of these intersections.
Źródło:
Opuscula Mathematica; 2013, 33, 3; 575-598
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Genetic diversity of a tick, Dermacentor reticulatus, in an expansion zone in central Europe
Autorzy:
Bajer, A.
Mierzejewska, E.J.
Karbowiak, G.
Slivinska, K.
Alsarraf, M.
Rodo, A.
Kowalec, M.
Dwuznik, D.
Kloch, A.
Powiązania:
https://bibliotekanauki.pl/articles/5936.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Parazytologiczne
Tematy:
genetic diversity
tick
Dermacentor reticulatus
expansion zone
Central Europe
Źródło:
Annals of Parasitology; 2016, 62, Suppl.
0043-5163
Pojawia się w:
Annals of Parasitology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Economic expansion of China: determinants, perspectives, limits
Chińska ekspansja gospodarcza: uwarunkowania, perspektywy, granice
Autorzy:
Kołodko, G.W.
Powiązania:
https://bibliotekanauki.pl/articles/2051676.pdf
Data publikacji:
2018
Wydawca:
Akademia Bialska Nauk Stosowanych im. Jana Pawła II w Białej Podlaskiej
Tematy:
economic expansion
China
globalization
global economy
Asia
determinant
perspective
Opis:
Two centuries ago, Asia delivered over 60 percent of world production; in the middle of the 20th century it was less than 20 percent. Currently, it is twice as large and this share is still increasing, above all but not only, because of China whose production is still growing at a rate twice as fast as the world average. China is trying to maintain high economic dynamics, inter alia, through investment external expansion. This aim is to be served, among others, by the infrastructure project, drawn up with enormous verve, known as the New Silk Road, which the Middle Kingdom addresses to 65 countries on three continents. While some hope for accelerating their own economic growth, others warn against the risk of becoming dependent on China. The article analyzes these challenges, pointing to the desired directions of irreversible evolution globalization by giving it a more inclusive character, which is also strongly emphasized by the Chinese authorities in their official enunciations.
Dwa wieki temu Azja wytwarzała ponad 60 proc. światowej produkcji, a w połowie XX wieku było to poniżej 20 proc. Obecnie jest dwakroć więcej i udział ten nadal rośnie, przede wszystkim, acz nie tylko za sprawą Chin, których produkcja zwiększa się wciąż w tempie dwukrotnie szybszym niż średnia światowa. Chiny starają się utrzymać wysoką dynamikę gospodarczą między innymi poprzez inwestycyjną ekspansję zewnętrzną. Temu między innymi ma służyć nakreślony z ogromnych rozmachem projekt infrastrukturalny znany jako Nowy Jedwabny Szlak, który Państwo Środka adresuje do 65 krajów na trzech kontynentach. O ile jedni pokładają w tym nadzieję na przyspieszenie własnego wzrostu gospodarczego, inni przestrzegają przed ryzykiem uzależnienia się od Chin. Artykuł analizuje te wyzwania, wskazując na pożądane kierunki ewolucji nieodwracalnej globalizację poprzez nadawanie jej bardziej inkluzyjnego charakteru, co mocno akcentują także chińskie władze w swoich oficjalnych enuncjacjach.
Źródło:
Economic and Regional Studies; 2018, 11, 1; 7-19
2083-3725
2451-182X
Pojawia się w:
Economic and Regional Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extension of a phase transformation model for partial hardening in hot stamping
Autorzy:
Hart-Rawung, T.
Buhl, J.
Bambach, M.
Powiązania:
https://bibliotekanauki.pl/articles/99913.pdf
Data publikacji:
2018
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
coefficient of thermal expansion
phase transformation model
hot stamping
Opis:
The quality of predicted microstructural and mechanical properties in hot stamping simulations relies considerably on the material model. Many researchers studied the effect of the plastic deformation on the phase transformation of the most commonly used hot stamping steel 22MnB5, and proved that the deformation applied at high temperature promotes the formation of ferrite, pearlite and bainite. This behaviour has to be integrated into materials modelling. In this study, the effect of pre-strain on the phase transformation of the material is considered. The specimens are heated to austenitization temperature, isothermally deformed at 700°C, and quenched down to room temperature. The phase fractions and the temperature-dilatation behaviour obtained from the experiments are used to calibrate the material model. By using the experimental data obtained from dilatometer testing, the accuracy of the material model is evaluated. Additionally, an attempt to predict the results between the tested data points by using interpolation was made and compared with the simulation results.
Źródło:
Journal of Machine Engineering; 2018, 18, 3; 87-97
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast, non-destructive measurement of roof-bolt loads
Autorzy:
Skrzypkowski, Krzysztof
Korzeniowski, Waldemar
Zagórski, Krzysztof
Dominik, Ireneusz
Lalik, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/178690.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
expansion-shell bolt
monitoring
non-destructive method
laboratory tests
Opis:
This paper discusses the pull-out laboratory tests and the monitoring of expansion-shell bolts with a length of 1.82 m. The bolts comprised the KE-3W expansion shell, a rod with a diameter of 0.0183 m and a profiled, circular plate with a diameter of 0.14 m, and a gauge of 0.006 m. The bolts were installed in a concrete block with a compressive strength of 75 MPa. The tests were conducted on a state-of-the-art test stand owned by the Department of Underground Mining of the AGH University of Science and Technology. The test stand can be used to test roof bolts on a geometric scale of 1:1 under static and rapidly varying loads. Also, the stand is suitable for testing rods measuring 5.5 m in length. The stand has a special feature of providing the ongoing monitoring of bolt load, displacement and deformation. The primary aim of the study was to compare the results recorded by two different measurement systems with the innovative Self-Excited Acoustic System (SAS) for measuring stress variations in roof bolts. In order to use the SAS, a special handle equipped with an accelerometer and exciter mounted to the nut or the upset end of the rod was designed at the Faculties of Mining and Geoengineering and Mechanical Engineering and Robotics of the AGH University of Science and Technology. The SAS can be used for non-destructive evaluation of performance of bolts around mining workings and in tunnels. Through laboratory calibration tests, roof bolt loads can be assessed using the in-situ non-destructive method.
Źródło:
Studia Geotechnica et Mechanica; 2019, 41, 2; 93-101
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
When mere multiple group memberships are not enough: Individual self-expansion through involvement in social groups and self-efficacy belief
Autorzy:
Besta, Tomasz
Tomiałowicz, Elżbieta
Bojko, Julianna
Pytlos, Aleksandra
Kosakowska-Berezecka, Natasza
Bäck, Emma
Vazquez, Alexandra
Powiązania:
https://bibliotekanauki.pl/articles/2127287.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
self-expansion
group processes
self-efficacy
agency
social identity
Opis:
According to the self-expansion model, people are motivated to increase their sense of personal agency by expanding their sense of self through the acquisition of new identities. We conducted two studies to explore whether the feeling of self-expansion, resulting from multiple group memberships, is related to self-efficacy, and to test whether agentic and communal self-stereotyping mediated this relation. In Study 1 conducted in Poland (N1 = 102), and Study 2 among undergraduate students from Poland, Spain, and Sweden (N2 = 450), a significant indirect effect of self-expansion on self-efficacy through agentic (but not communal) self-stereotyping emerged.
Źródło:
Polish Psychological Bulletin; 2018, 49, 1; 77-85
0079-2993
Pojawia się w:
Polish Psychological Bulletin
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Direct financial instruments supporting foreign expansion of Polish companies used by Bank Gospodarstwa Krajowego
Autorzy:
Trwoga, Jarosław
Powiązania:
https://bibliotekanauki.pl/articles/18104641.pdf
Data publikacji:
2020-01-19
Wydawca:
Szkoła Główna Handlowa w Warszawie. Kolegium Zarządzania i Finansów
Tematy:
exports
foreign expansion
internationalisation
enterprises financing
BGK
banking sector
Opis:
Expansion to foreign markets usually implies the selection of an adequate financing facility that would fit a given transaction, as well as the specificity of a particular foreign market. This paper explores how Bank Gospodarstwa Krajowego (BGK) in its capacity of a state development bank funding the expansion of Polish business to other countries, i.e., exports and foreign direct investment projects carried out by Polish businesses or their foreign affiliates. The author's considerations focus on instruments offered by BGK, which provide direct financing, such as loans to foreign buyers and investment loans dedicated to projects carried out in other countries. Moreover, the paper discusses, inter alia, the current data for Polish exports, as well as selected transactions that BGK supported financially over the period 2015-2018.
Źródło:
Journal of Management and Financial Sciences; 2019, 39; 95-111
1899-8968
Pojawia się w:
Journal of Management and Financial Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ temperatury na ciśnienie w oponach samochodów ciężarowych
The influence of temperature on the pressure in tires of lorries
Autorzy:
Kotyk, M.
Troszyński, A.
Powiązania:
https://bibliotekanauki.pl/articles/95448.pdf
Data publikacji:
2013
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydawnictwo PB
Tematy:
ciśnienie
azot
powietrze
rozszerzalność cieplna
pressure
nitrogen
air
thermal expansion
Opis:
W pracy opisano wpływ temperatury powietrza oraz temperatury azotu na ciśnienie w oponach samochodów ciężarowych. Prawidłowe ciśnienie w oponie samochodu ciężarowego pozwala na zapewnienie komfortu oraz bezpieczeństwa podczas jazdy. Zbadano, jaki wpływ na zachowanie prawidłowego ciśnienia w oponie ma temperatura. Po to, aby uzyskać pewne porównanie, oponę samochodu ciężarowego napełniono najpierw powietrzem, a następnie azotem i wystawiono ją na działanie niskich temperatur.
The article concerns the research on the influence of the air and azote temperature on the pressure in the tyres of the lorries. A normal pressure in the tire of a lorry allows to ensure the driving comfort and safety. It has been studied the influence which the temperature has on the keeping the normal pressure in the tire. In order to achieve the plausible comparison, the tire of a lorry has been filled up first with the air and then with the azote and it has been exposed to the low temperatures.
Źródło:
Postępy w Inżynierii Mechanicznej; 2013, 2(1); 31-39
2300-3383
Pojawia się w:
Postępy w Inżynierii Mechanicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sub-phase power electronics inverters
Autorzy:
Gwóźdź, M.
Powiązania:
https://bibliotekanauki.pl/articles/97361.pdf
Data publikacji:
2011
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
inverter
Generalized Sampling Expansion
Whittaker-Kotelnikov-Shannon sampling theorem
WKS
Opis:
Dynamic changes of parameters of energy sources and receivers are reasons that decrease exactitude of output signals towards reference signals. To improve these parameters more advanced solutions of power electronics systems are necessary. Ones of possible solutions are a sub-phase inverters. The output quantity regulator there is based on Generalized Sampling Expansion, being crucial extension of Whittaker-Kotelnikov-Shannon sampling theorem. Wide-band power electronics current source with regulator based on that extension is analyzed further.
Źródło:
Computer Applications in Electrical Engineering; 2011, 9; 190-199
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adaptive finite elements based on sensitivities fortopological mesh changes
Autorzy:
Friederich, J.
Leugering, G.
Steinmann, P.
Powiązania:
https://bibliotekanauki.pl/articles/205694.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
adaptive mesh refinement
sensitivity-based refinement
topological sensitivity
asymptotic expansion
Opis:
We propose a novel approach to adaptive refinement in FEM based on local sensitivities for node insertion. To this end, we consider refinement as a continuous graph operation, for instance by splitting nodes along edges. Thereby, we introduce the concept of the topological mesh derivative for a given objective function. For its calculation, we rely on the first-order asymptotic expansion of the Galerkin solution of a symmetric linear second-order elliptic PDE. In this work, we apply this concept to the total potential energy, which is related to the approximation error in the energy norm. In fact, our approach yields local sensitivities for minimization of the energy error by refinement. Moreover, we prove that our indicator is equivalent to the classical explicit a posteriori error estimator in a certain sense. Numerical results suggest that our method leads to efficient and competitive adaptive refinement.
Źródło:
Control and Cybernetics; 2014, 43, 2; 279-306
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Planowanie rozwoju infrastruktury elektroenergetycznej w obecnych uwarunkowaniach administracyjno-prawnych
Power infrastructure expansion planning in present administrative and law conditions
Autorzy:
Dołęga, W.
Powiązania:
https://bibliotekanauki.pl/articles/282473.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
planowanie
rozwój
infrastruktura elektroenergetyczna
prawo
planning
expansion
power infrastructure
law
Opis:
W nawiązaniu do historycznych idei zapewnienia krajom Europejskiej Wspólnoty Węgla i Stali taniej energii, przedstawiono negatywne skutki, jakie dla gospodarstw domowych niesie obecna polityka UE walki z „globalnym ociepleniem”. Omówiono definicje ubóstwa dochodowego, bazującą na wzglednym progu wynoszącym 60% mediany dochodów rozporządzalnych gospodarstw domowych i wskaźnik zagrożenia wykluczeniem społecznym przyjete przez Eurostat. Podano miejsce Polski w hierarchii ubóstwa na tle innych krajów UE. Zwrócono uwage na drastyczne różnice progów ubóstwa (wyznaczonych zarówno w euro jak i w jednostkach standardu siły nabywczej PPS) pomiedzy starymi i nowymi członkami UE. Przedstawiono skale rosnącego ubóstwa w Polsce i zwiekszającego sie rozwarstwienia dochodów (udokumentowane poziomem ilorazu V. i I. kwintyla dochodów gospodarstw domowych i wskaźnikiem Giniego) na tle danych UE, pomimo dodatniego wzrostu PKB. Porównano gospodarstwa domowe w Polsce i UE zwracając uwage na udział energii i paliw w ich wydatkach. Przedstawiono historie rosnących cen nośników energii w euro oraz zwrócono uwage na wyjątkowo wysoki poziom cen energii w Polsce mierzony w jednostkach PPS. Omówiono pojecie ubóstwa energetycznego oraz przedstawiono prognozy wzrostu udziału zakupów energii i paliw w budżetach gospodarstw w świetle dalszych wzrostów ich cen w związku z wdrażaniem pakietu energetyczno-klimatycznego. Skrytykowano posługiwanie sie względnymi progami ubóstwa dochodowego i energetycznego, proponując w zamian bezwzgledne wskaźniki oparte na minimalnym koszyku dóbr niezbednych do przeżycia i minimalnej ilooci energii niezbednej do zapewnienia akceptowalnego standardu ogrzania mieszkania i funkcjonowania gospodarstwa domowego.
Within the historical context of attempting to provide cheap energy to countries of the European Coal and Steel Community, this article presents the negative effects for households of the current EU policy to combat “global warming”. The definition of income poverty is outlined based on a relative threshold of 60% of the households’ disposable income median with the social exclusion indicator adopted by Eurostat. Poland’s place in the poverty hierarchy is presented and compared to other EU countries. The analysis focuses attention on the drastic differences in poverty thresholds (in euro and in purchasing power standard PPS) between old and new EU members. The data shows the scale of increasing poverty and income inequalities in Poland (documented by the ratio of the V. and I. households’ income quintile and the Gini index). It provides a comparison of households in Poland and the EU with attention paid to the share of energy and fuels in household
Źródło:
Polityka Energetyczna; 2012, 15, 3; 51-63
1429-6675
Pojawia się w:
Polityka Energetyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-quality silumin on pistons of combustion engines
Autorzy:
Jankowski, A.
Pietrowski, S.
Sieminska, B.
Szymczak, T.
Powiązania:
https://bibliotekanauki.pl/articles/245889.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion engines
piston
composite alloys
heat treatment
thermal expansion
hysteresis
Opis:
In the paper the test results are presented for the AlSH2Cu5Ni5MgO.5CrO.05MoO.05WO.05VO.05 newly worked out silumin close to eutectic piston-silumin with the elevated content ofcopper and nickel to approx. 5% with relation to generally applied the AISH2 piston silumin. The novel silumin contains also Cr, Mo, In and V micro alloy additions in quantity approx. 0.05 percent for every element. Research of microstructure, HB hardness and coefficient of lineal thermal expansion a for the AlSil2Cu5Ni5MgO.5CrO.05MoO.05WO.05VO.05 silumin in the cast state, after the separation strengthening and additional short duration high-temperature heat-treatment were performed. Research of the microstructure of the AlSH2Cu5Ni5MgO.5CrO.05MoO.05WO.05VO.05 silumin showed the occurrence in it following constituent phases: alfa(Al), beta(Si), Al2Cu and AlMoCrWVMgNiSiCuFe. The separation strengthening brought about the coagulation of silicon emissions. The short duration high-temperature heat-treatment caused additional coagulation of silicon emissions and also its coalescence. Measurement of the HB hardness showed high hardness investigated alloy in the rough state, approx. 30% higher from the AlSi2 piston silumin. Measurement of the a coefficient of thermal expansion showed beneficial effects of novel alloy connected with the value decreasing of this coefficient as well so called hysteresis. Further studies on novel alloy will concentrate on alloy-additional and processes of the heat treatment.
Źródło:
Journal of KONES; 2009, 16, 4; 563-573
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Thermal Expansion of Unbonded Foundry Sands on the Deformation of Resin Bonded Cores
Autorzy:
Svidró, J.
Diószegi, A.
Tóth, L.
Svidró, J. T.
Powiązania:
https://bibliotekanauki.pl/articles/355691.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
foundry sand
hot distortion
moulding material
phenolic resin
thermal expansion
Opis:
Depending on the preparation and the applied materials, moulds and cores can be of high rigidity or can be flexible. Although, chemically bonded moulding materials have relatively good flexibility, their high temperature behaviour determines the dimensional accuracy, the stresses in the castings and can induce several casting defects, such as rattail, veining, etc. The phenomenon is based on two major effects: the thermal expansion of the unbonded foundry sands and the deformation of the sand mixtures. The main objective of the present work was to study the relationship between these two effects, and to improve the knowledge related to the thermo-mechanical interactions between the casting and the mould. Dilatometric analysis of unbonded sand samples were performed and compared to the results of hot distortion tests of moulding mixture specimens. The results showed, that the thermal expansion of foundry sand largely influences the hot distortion behaviour, but depending on the type of binder used.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 795-798
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Raman Spectroscopy Studies of Carbon-Based Cathode Materials during Aluminum Electrolysis
Autorzy:
Wang, Wei
Chen, Weijie
Powiązania:
https://bibliotekanauki.pl/articles/352779.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aluminium electrolysis
carbon cathodes
Raman spectroscopy
creep deformation
sodium expansion
Opis:
The sodium expansion and creep strain of semi-graphitic cathodes are investigated using a modified Rapoport apparatus. To further understanding of the sodium and bath penetration damage processes, the impact of external stress fluence on the carbon cathode microstructure has been defined with XRD analysis, Raman spectroscopy and scanning electron microscope (SEM). Graphite atoms fracture into smaller fragments that are less directional than the pristine platelets, which allows for a possible filling of the cracks that thus develop by the sodium and bath during aluminum electrolysis. The average microcrystalline size (calculated by Raman spectroscopy) is reduced by the deformation. The decreased intensity and widened 'G' and 'D' peaks in the analysis indicate the poor order of the sheets along the stacking direction while the consistent layered graphite structure is sustained.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1257-1261
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Turbine stage expansion model including internal air film cooling and novel method of calculating theoretical power of a cooled stage
Autorzy:
Trawiński, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/2134930.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gas turbine
expansion line
air film cooling
theoretical stage power
Opis:
Systematic attempts to maximise the efficiency of gas turbine units are achieved, among other possibilities, by increasing the temperature at the inlet to the expansion section. This requires additional technological solutions in advanced systems for cooling the blade rows with air extracted from the compressor section. This paper introduces a new mathematical model describing the expansion process of the working medium in the turbine stage with air film cooling. The model includes temperature and pressure losses caused by the mixing of cooling air in the path of hot exhaust gases. The improvement of the accuracy of the expansion process mathematical description, compared with the currently used models, is achieved by introducing an additional empirical coefficient estimating the distribution of the cooling air along the profile of the turbine blade. The new approach to determine the theoretical power of a cooled turbine stage is also presented. The model is based on the application of three conservation laws: mass, energy and momentum. The advantage of the proposed approach is the inclusion of variable thermodynamic parameters of the cooling medium. The results were compared with the simplified models used in the literature: separate Hartsel expansion, mainstream pressure, weighted-average pressure and fully reversible. The proposed model for expansion and the determination of theoretical power allows for accurate modelling of the performance of a cooled turbine stage under varying conditions.
Źródło:
Archives of Thermodynamics; 2022, 43, 3; 3--27
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experiences from operation of different expansion devices for application in domestic micro CHP
Autorzy:
Mikielewicz, D.
Mikielewicz, J.
Wajs, J.
Powiązania:
https://bibliotekanauki.pl/articles/240544.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
micro CHP
ogrzewanie centralne
rozbudowa urządzeń
central heating
expansion devices
Opis:
In the paper presented are experiences from operation of three different expansion devices for possible implementation in the domestic micro CHP. These were the modified scroll expander and two designs based on the variable working chamber volume pneumatic devices. Experiments showed the superiority of both "pneumatic devices" over the scroll expander, indicating the possible internal efficiencies in the range of 61 82Such efficiencies are very attractive, especially at the higher end of that range. The volume of these devices is much smaller than the scroll expander which makes it again more suitable for a domestic micro CHP. Small rotational velocities enable to conclude that connection to electricity grid will also be simpler in the case of "pneumatic devices". The "pneumatic devices" under scrutiny here could be an alternative to the typical vapour turbine in the ORC cycle, which is in the process of development at the IFFM.
Źródło:
Archives of Thermodynamics; 2010, 31, 4; 3-13
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On an improvement of Carnot-like cycles devoted to turbines with isothermal expansion
Autorzy:
Kraszewski, B.
Powiązania:
https://bibliotekanauki.pl/articles/175360.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
isothermal turbine expansion
ericsson cycle
open gas cycle
organic cycle
Opis:
This paper presents a novel, procedure of calculations of simple thermodynamic cycles with the main isothermal expansion process. Calculation assumptions are based on the use of technologically advanced flow devices. Firstly the theoretical Ericsson cycle with description of isothermal process has been presented. Then the calculations for open gas cycle with external combustion chamber, realising Ericsson cycle with upper temperature of 1473 K were carried out, showing the possibilities of turbines with isothermal expansion and achieving record-breaking efficiency. The use of isothermal compression has also been considered. The second, supercritical cycle with organic medium and condensation process also shows predispositions to achieve record-high efficiency at upper cycle temperature of 573 K. For both cycles, graphs of linearized thermodynamic transformations were made as well as graphs of efficiency dependence on the pressure. At the end, unit work of turbines in cycles has been compared and discussed.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2018, 140; 3-21
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of elastic material compressibility on parameters of the expanding spherical stress wave. I. Analytical solution to the problem
Teoretyczna analiza wpływu ściśliwości ośrodka sprężystego naparametry ekspandującej kulistej fali naprężenia. I. Analityczne rozwiązanie problemu
Autorzy:
Włodarczyk, E.
Zielenkiewicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/280202.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
expansion of spherical stress wave
isotropic elastic material
dynamic load
Opis:
We investigated the influence of elastic material compressibility on parameters of the expanding spherical stress wave. The material compressibility is represented by Poisson’s ratio . The stress wave is generated by pressure created inside the spherical cavity. The isotropic elastic material surrounds this cavity. Analytical closed form formulae determining the dynamical state of mechanical parameters (displacement, particle velocity, strains, stresses, and material density) in the material have been derived. These formulae were obtained for surge pressure p(t) = p0 = const inside the cavity. From analysis of these formulae it results that Poisson’s ratio v substantially influences the course of material parameters in space and time. All parameters intensively decrease in space together with increase of the Langrangian coordinate r. On the contrary, these parameters oscillate versus time around their static values. These oscillations decay with a lapse of time. We can mark out two ranges of the parameter v values in which vibrations of the parameters are damped with a different degree. Thus, a decrease in Poisson’s ratio in the range v < 0.4 causes an intense decay of oscillation of parameters. On the other hand, in the range 0.4 < < 0.5, i.e. in quasi-compressible materials the damping of parameters vibrations is very low. In the limiting case when = 0.5, i.e. in the incompressible material damping vanishes, and the parameters harmonically oscillate around their static values. The abnormal behaviour of the material occurs in the range 0.4 < < 0.5. In this case an insignificant increment of Poisson’s ratio causes considerable an increase of the parameters vibration amplitude. The specific influence of Poisson’s ratio on the parameters of the expanding spherical stress wave in elastic media is the main result of this paper. As we see it, this fact may be the contribution supplementing the description of properties of the expanding spherical stress wave in elastic media.
Zbadano wpływ ściśliwości materiału, reprezentowanej przez współczynnik Poissona v, na parametry ekspandującej kulistej fali naprężeń, wywołanej ciśnieniem wewnątrz kulistej kawerny w nieskończonym izotropowym ośrodku sprężystym. Wyprowadzono zamknięte wzory określające dynamiczny stan mechanicznych parametrów (przemieszczenia, prędkości przemieszczenia, odkształcenia, naprężenia oraz gęstości materiału) w ośrodku dla stałego ciśnienia p(t) = p0 = const przyłożonego w sposób nagły. Z analizy tych wzorów wynika, że współczynnik Poissona wpływa zasadniczo na przebiegi tych parametrów w czasie i przestrzeni. Wszystkie parametry maleją intensywnie wraz ze wzrostem współrzędnej Lagrange’a r. Z drugiej strony, parametry te oscylują w czasie wokół ich wartości statycznych. Oscylacje te z czasem zanikają. Możemy wyróżnić dwa przedziały wartości parametru v, w których tłumienie oscylacji zachodzi z różną intensywnością. Tak więc dla v< 0.4 tłumienie jest bardzo intensywne. Natomiast w przedziale 0.4 < < 0.5, tzn. w materiałach quasi-ściśliwych, poziom tłumienia jest bardzo niski. W przypadku granicznym dla v = 0.5, tzn. dla materiałów nieściśliwych, tłumienie zanika i parametry mechaniczne oscylują wokół ich wartości statycznych. Ponadto w przedziale 0.4 < v < 0.5 można zaobserwować anormalne zachowanie materiału. Niewielki przyrost wartości współczynnika Poissona skutkuje znaczącym wzrostem amplitudy drgań parametrów. Opis szczególnego wpływu współczynnika Poissona na parametry ekspandującej kulistej fali naprężenia jest głównym rezultatem niniejszej pracy. Według autorów może ona być uzupełnieniem opisu właściwości ekspandującej kulistej fali naprężeń w ośrodku sprężystym.
Źródło:
Journal of Theoretical and Applied Mechanics; 2009, 47, 1; 127-141
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some problems pistons made from composite materials with small hysteresis to combustion engines
Autorzy:
Jankowska-Sieminska, B.
Powiązania:
https://bibliotekanauki.pl/articles/245555.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion engines
combustion engine piston
composite alloys
thermal expansion
hysteresis
Opis:
Novel composite ma hysteresisterials on the pistons are characterised that they occur in them multiple intermetallic phases which crystallize in the high temperature, before crystallization of the alfa+beta (Al+Si) eutectic. For forming of pre-eutectic phases, chromium and molybdenum are introduced to silumins, and for derivation of multiple increased concentration of nickel and copper and decreased concentration of magnesium are accomplished. On the basis of evaluations of mechanical and thermal loads of combustion engines pistons applying essence of composite materials of combustion engines pistons, as well requirements for combustion engines pistons, especially high loaded engines are expressed. Test results of hardness, influence of temperature of casting, test results of mechanical properties, friction coefficient and coefficient of thermal expansion are presented in the paper. The special attention devoted to so called hysteresis coefficient of thermal expansion and hysteresis of the relative elongation in function temperature and time. Courses of coefficient of thermal expansion for standard and composite material are presented. Differences of the a coefficient during heating and cooling in function temperature are relative to kind of heat treatment. Two-stage heat treatment is beneficial for the obtainment small values of the a coefficient.
Źródło:
Journal of KONES; 2011, 18, 3; 123-128
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utrudnienia i bariery formalno-prawne rozbudowy i modernizacji sieciowej infrastruktury elektroenergetycznej
Hindrances and formal and legal barriers of expansion and modernization of power network infrastructure
Autorzy:
Dołęga, W.
Powiązania:
https://bibliotekanauki.pl/articles/283060.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
infrastruktura sieciowa
rozbudowa
modernizacja
prawo
network infrastructure
expansion
modernization
law
Opis:
W artykule przedstawiono analizę i ocenę obowiązujących rozwiązań prawnych związanych z rozbudową i modernizacją sieciowej infrastruktury elektroenergetycznej oraz zidentyfikowano utrudnienia i bariery formalno-prawne w tym obszarze. Zwrócono szczególną uwagę na ustawy: o planowaniu i zagospodarowaniu przestrzennym; o gospodarce nieruchomościami; Prawo Budowlane; Prawo Ochrony Środowiska; o ochronie przyrody; o udostępnianiu informacji o środowisku i jego ochronie; udziale społeczeństwa w ochronie środowiska oraz o ocenach oddziaływania na środowisko; o ochronie gruntów rolnych i leśnych; Kodeks Postępowania Administracyjnego; Kodeks Cywilny i o drogach publicznych.
In this paper, analysis of present legal solutions connected with expansion and modernization of power network infrastructure and identification of formal and legal barriers and hindrances are shown. Attention is paid to the Special Development Act, the Real Estate Management Act, the Construction Law, the Environment Protection Law, the Nature Conservation Act, the Act on Providing Information on the Environment and Environmental Protection, Public Participation in Environmental Protection and Environmental Impact Assessment, the Act on the Protection of Agricultural and Forest Land, the Code of Administrative Proceedings, the Civil Code and the Public Roads Act.
Źródło:
Polityka Energetyczna; 2011, 14, 2; 51-64
1429-6675
Pojawia się w:
Polityka Energetyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations of strength, thermal expansion and engine of novel pistons for combustion engines
Autorzy:
Siemińska, B.
Powiązania:
https://bibliotekanauki.pl/articles/243623.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion engine
engine pistons
novel alloys
novel materials
thermal expansion
Opis:
Pistons of internal-combustion engines work in the conditions of high mechanical and thermal loads. The typical alloy materials applied on pistons of internal-combustion engines have inadequate parameters for such applications. It mainly refers to the fatigue strength of the mechanical and thermal character and to the thermal shocks. In relation with fact that the piston of internal-combustion engine has unsymmetrical shape, that in every case of the piston temperature increase the unequal deformations appear and stresses related with this, what causes fatigue loads of the piston structure. The paper presents special demands, which pistons of contemporary of internal-combustion engines must fulfil with respect to strength, thermal and useful properties, mirrored in the engine work parameters, like engine oil consumption, fuel consumption, noise, gas blow by to the crankcase and the emission of toxic exhaust elements, mainly hydrocarbons. One turned attention on the new material that can be used in manufacture of pistons for the internal-combustion engines, which is the carbon material. In the article the results of research for the mechanical, thermal and engine properties are submitted for the pistons manufactured from a new material. On the emphasis deserve fact, that the application of new materials permits on the obtainment of the small difference in the coefficient of linear thermal expansion during the heating and the cooling, that will bring many profitable effects of both functional and useful nature.
Źródło:
Journal of KONES; 2008, 15, 3; 471-478
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the statistical characteristics of crosstalk in naval ships wiring harness based on Polynomial Chaos Expansion method
Autorzy:
Chi, Y.
Li, B.
Yang, X.
Wang, T.
Yang, K.
Gao, Y.
Powiązania:
https://bibliotekanauki.pl/articles/260090.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
naval ships wiring harness
crosstalk
Polynomial Chaos Expansion
statistical characteristics
Opis:
Crosstalk in wiring harness has been studied extensively for its importance in the naval ships electromagnetic compatibility field. An effective and high-efficiency method is proposed in this paper for analyzing Statistical Characteristics of crosstalk in wiring harness with random variation of position based on Polynomial Chaos Expansion (PCE). A typical 14-cable wiring harness was simulated as the object of research. Distance among interfering cable, affected cable and GND is synthesized and analyzed in both frequency domain and time domain. The model of naval ships wiring harness distribution parameter was established by utilizing Legendre orthogonal polynomials as basis functions along with prediction model of statistical characters. Detailed mean value, mean square error, probability density function and reasonable varying range of crosstalk in naval ships wiring harness are described in both time domain and frequency domain. Numerical experiment proves that the method proposed in this paper, not only has good consistency with the MC method can be applied in the naval ships EMC research field to provide theoretical support for guaranteeing safety, but also has better time-efficiency than the MC method. Therefore, the Polynomial Chaos Expansion method.
Źródło:
Polish Maritime Research; 2017, S 2; 205-214
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On extensions of the Mittag-Leffler theorem
Autorzy:
Ligocka, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/1294436.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
hyperfunction
Laurent expansion
elliptic
polyharmonic
hypoelliptic
P-convex for supports
Opis:
The classical Mittag-Leffler theorem on meromorphic functions is extended to the case of functions and hyperfunctions belonging to the kernels of linear partial differential operators with constant coefficients.
Źródło:
Annales Polonici Mathematici; 1998, 68, 3; 249-256
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Text : now in 2D! A framework for lexical expansion with contextual similarity
Autorzy:
Biemann, C.
Riedl, M.
Powiązania:
https://bibliotekanauki.pl/articles/103919.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Podstaw Informatyki PAN
Tematy:
distributional semantics
lexical expansion
contextual similarity
lexical substitution
computational semantics
Opis:
A new metaphor of two-dimensional text for data-driven semantic modeling of natural language is proposed, which provides an entirely new angle on the representation of text: not only syntagmatic relations are annotated in the text, but also paradigmatic relations are made explicit by generating lexical expansions. We operationalize distributional similarity in a general framework for large corpora, and describe a new method to generate similar terms in context. Our evaluation shows that distributional similarity is able to produce high-quality lexical resources in an unsupervised and knowledge-free way, and that our highly scalable similarity measure yields better stores in a WordNet-based evaluation than previous measures for very large corpora. Evaluating on a lexical substitution task, we find that our contextualization method improves over a non-contextualized baseline across all parts of speech, and we show how the metaphor can be applied successfully to part-of-speech tagging. A number of ways to extend and improve the contextualization method within our Framework are discussed. As opposed to comparable approaches, our framework defines a model of lexical expansions in context that can generate the expansions as opposed to ranking a given list, and thus does not require existing lexical-semantic resources.
Źródło:
Journal of Language Modelling; 2013, 1, 1; 55-95
2299-856X
2299-8470
Pojawia się w:
Journal of Language Modelling
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Mechanical Stress Analysis of Ladle Lining with Integral Brick Joint
Autorzy:
Chang, W.
Li, G.
Kong, J.
Sun, Y.
Jiang, G.
Liu, H.
Powiązania:
https://bibliotekanauki.pl/articles/354915.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ladle
heat transfer model
lining
expansion joint
thermal mechanical stress
Opis:
Based on the theory of heat transfer, the influence of expansion joints on the temperature and stress distribution of ladle lining is discussed. In view of the current expansion joint, the mathematical model of heat transfer and the three dimensional finite element model of ladle lining brick are established. By analyzing the temperature and stress distribution of ladle lining brick when the expansion joints are in different sizes, the thermal mechanical stress caused by the severe temperature difference can be reduced by the suitable expansion joint of the lining brick during the ladle baking and working process. The analysis results showed that the thermal mechanical stress which is caused by thermal expansion can be released through the 2 mm expansion joint, which is set in the building process. So we can effectively reduce the thermal mechanical stress of the ladle lining, and there is no risk of steel leakage, thus the service life of ladle can be effectively prolonged.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 659-666
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reinforcement of underground excavation with expansion shell rock bolt equipped with deformable component
Autorzy:
Korzeniowski, W.
Skrzypkowski, K.
Zagórski, K.
Powiązania:
https://bibliotekanauki.pl/articles/178960.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
rock bolting
expansion shell rock bolt stiffness
deformable component
mining
Opis:
The basic type of rock mass reinforcement method for both preparatory and operational workings in underground metal ore mines, both in Poland and in different countries across the world, is the expansion shell or adhesive-bonded rock bolt. The article discusses results of static loading test of the expansion shell rock bolts equipped with originally developed deformable component. This component consists of two profiled rock bolt washers, two disk springs, and three guide bars. The disk spring and disk washer material differs in stiffness. The construction materials ensure that at first the springs under loading are partially compressed, and then the rock bolt washer is plastically deformed. The rock bolts tested were installed in blocks simulating a rock mass with rock compressive strength of 80 MPa. The rock bolt was loaded statically until its ultimate loading capacity was exceeded. The study presents the results obtained under laboratory conditions in the test rig allowing testing of the rock bolts at their natural size, as used in underground metal ore mines. The stress-strain/displacement characteristics of the expansion shell rock bolt with the deformable component were determined experimentally. The relationships between the geometric parameters and specific strains or displacements of the bolt rod were described, and the percentage contribution of those values in total displacements, resulting from the deformation of rock bolt support components (washer, thread) and the expansion shell head displacements, were estimated. The stiffness of the yielded and stiff bolts was empirically determined, including stiffness parameters of every individual part (deformable component, steel rod). There were two phases of displacement observed during the static tension of the rock bolt which differed in their intensity.
Źródło:
Studia Geotechnica et Mechanica; 2017, 39, 1; 39-52
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Expansion of the North American amphipod Gammarus tigrinus Sexton, 1939 to the Neva Estuary (Easternmost Baltic Sea)
Autorzy:
Berezina, N.A.
Powiązania:
https://bibliotekanauki.pl/articles/48222.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
amphipod
expansion
American amphipod
history
Gammarus tigrinus
Baltic Sea
Neva Estuary
Opis:
The North American gammaridean amphipod, Gammarus tigrinus, was found in the easternmost part of the Baltic Sea (Neva Estuary) near a new oil terminal. This species may well have been transported to the Neva Estuary with ballast waters from the Finnish area of the Gulf of Finland, where it was recorded recently. In 2005, the mid-summer density of G. tigrinus was 27 indiv. m−2. By 2006 this species had spread 100 km to the east from the first site, colonizing the northern coastal zone of the estuary. Its density reached 99–126 indiv. m−2. Fecund females and juveniles contributed about 50% to the entire population density, which testifies to the successful reproduction and establishment of G. tigrinus in the Neva Estuary. There is a high risk of further expansions of G. tigrinus from the new area to the various lakes of Eastern Europe via inland canal-river systems, which may lead to unforeseeable changes in aquatic communities.
Źródło:
Oceanologia; 2007, 49, 1
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of wheat straw pretreatment by thermo-gravimetric method
Charakterystyka wstępnej obróbki słomy pszenicznej metodą termograwimetryczną
Autorzy:
Šulc, R.
Krátký, L.
Powiązania:
https://bibliotekanauki.pl/articles/2072605.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
hydroliza termiczna
termograwimetria
słoma pszeniczna
thermal expansion hydrolysis thermogravimetry
wheat straw
Opis:
The sequential static thermogravimetry was used in the assessment of effect of hydrolysis temperature on wheat straw pre-treatment. It was found that temperature of 50% conversion T0.5 was lower for all studied solid residues after hydrolysis comparing with untreated straw, regardless of hydrolysis temperature. Lower value of T0.5 indicates that the straw structure was destructed by hydrolysis into more volatile products. The minimum temperature T0.5 and corresponding highest participation of light fraction was observed at hydrolysis temperature of 185°C.
Statyczną termograwimetrię sekwencyjną wykorzystano do oceny wpływu temperatury hydrolizy we wstępnej obróbce słomy pszenicznej Stwierdzono, że temperatura T0.5 konwersji 50% jest niższa dla wszystkich przebadanych stałych pozostałości po hydrolizie w porównaniu ze słomą przed przeróbką, bez względu na temperaturę hydrolizy. Niższe wartości temperatury T0.5 wskazuję na to, że hydroliza zniszczyła strukturę słomy tworząc ardziej lotne frakcje. Minimalna temperatura T0.5 oraz odpowiadający jej wysoki udział lekkiej frakcji zaobserwowano dla temperatury hydrolizy wynoszącej 185 °C.
Źródło:
Inżynieria i Aparatura Chemiczna; 2013, 3; 264--265
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New design of the five-stroke SI engine
Autorzy:
Noga, M.
Sendyka, B.
Powiązania:
https://bibliotekanauki.pl/articles/245394.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
five-stroke engine
spark ignition
additional expansion
increase of total efficiency
Opis:
The paper describes design of the five-stroke engine developed in the Chair of Combustion Engines at Cracow University of Technology. The idea of five-stroke engine, in which the expansion ratio is significantly greater than the compression ratio has been presented by the Belgian engineer Gerhard Schmitz. The prototype of such an engine was made by Ilmor Engineering. Engine developers have released results of preliminary research, but there is no detailed information on the toxic exhaust emissions. For this reason, at Cracow University of Technology the research was undertaken to determine the impact of implementing the five-stroke cycle into the engine with spark ignition to reduce toxic emissions and increase total efficiency. To achieve this goal, the test engine was built, which is based on a concept similar to the idea of Gerhard Schmitz, with the difference that it has not been designed from the ground up, and it is based on an existing four-cylinder four-stroke engine. In comparison with the original solution, the engine built in Cracow has a completely different design of timing system, four valves per cylinder and petrol direct injection. This paper presents a detailed description of the engine design and the results of its preliminary research. The results of the tests of the five-stroke engine confirm an increase of specific torque and power (related to unit of engine displacement) and improve of total efficiency within a certain range of the engine map.
Źródło:
Journal of KONES; 2013, 20, 1; 239-246
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Povysenie kratnosti peny vodnyh rastvorov pav
Zwiększenie liczby spienienia roztworów wodnych
Autorzy:
Nawrocki, O. D.
Kotow, S. G.
Powiązania:
https://bibliotekanauki.pl/articles/373977.pdf
Data publikacji:
2007
Wydawca:
Centrum Naukowo-Badawcze Ochrony Przeciwpożarowej im. Józefa Tuliszkowskiego
Tematy:
spienianie
środek pianotwórczy
roztwór wodny
expansion
fire extinguishing foams
aqueous solution
Opis:
W artykule omówione zostały zagadnienia dotyczące sposobów podwyższania krotności spienienia wodnych roztworów środków pianotwórczych. Opisane zostały zmiany spienienia pod wpływem różnych wybranych dodatków chemicznych.
Źródło:
Bezpieczeństwo i Technika Pożarnicza; 2007, 2; 49-56
1895-8443
Pojawia się w:
Bezpieczeństwo i Technika Pożarnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ dodatku gryki na własności ekstrudatu kukurydzianego
The influence of buckwheat supplement on the properties of maize extrudate
Autorzy:
Ekielski, A.
Majewski, Z.
Żelaziński, T.
Powiązania:
https://bibliotekanauki.pl/articles/290692.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
gryka
ekstrudat
rozpuszczalność
stopień ekspansji
buckwheat
extrudate
solubility
degree of expansion
Opis:
Celem podjętych badań było określenie wpływu dodatku gryki na własności technologiczne i fizyczne ekstrudatu mieszanki śruty kukurydzianej i mąki gryczanej. Wyniki przeprowadzonych badań wykazały, że gryka może być bardzo dobrym surowcem stosowanym w procesie ekstruzji. Wysoka zawartość skrobi i białka oraz duża wodochłonność ziarna gryki sprawia, że surowiec ten z łatwością poddaje się obróbce.
The aim of the research was to determine the influence of buckwheat supplement on technological and physical properties of an extrudate of a mix of ground maize grains and buckwheat flour. The results of the research indicated that buckwheat may be a very good raw material used in the extrusion process. High content of starch and protein and high water absorption of buckwheat seeds make it a raw material which can be treated easily.
Źródło:
Inżynieria Rolnicza; 2006, R. 10, nr 7(82), 7(82); 155-161
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The System of Register Labels in plWordNet
Autorzy:
Maziarz, Marek
Piasecki, Maciej
Szpakowicz, Stan
Powiązania:
https://bibliotekanauki.pl/articles/677096.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Slawistyki PAN
Tematy:
wordnets
plWordNet
lexical register
large-scale wordnet expansion
inter-annotator agreement
Opis:
The System of Register Labels in plWordNetStylistic registers influence word usage. Both traditional dictionaries and wordnets assign lexical units to registers, and there is a wide range of solutions. A system of register labels can be flat or hierarchical, with few labels or many, homogeneous or decomposed into sets of elementary features. We review the register label systems in lexicography, and then discuss our model, designed for plWordNet, a large wordnet for Polish. There follows a detailed comparative analysis of several register systems in Polish lexical resources. We also present the practical effect of the adoption of our flat, small and homogeneous system: a relatively high consistency of register assignment in plWordNet, as measured by inter-annotator agreement on a manageable sample. Large-scale conclusions for the whole plWordNet remain to be made once the annotation has been completed, but the experience half-way through this labour-intensive exercise is very encouraging.
Źródło:
Cognitive Studies; 2015, 15
2392-2397
Pojawia się w:
Cognitive Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Water supply network expansion in the commune of Mściwojów as relates to the pilot project vital landscapes
Autorzy:
Bergel, T.
Bugajski, P.
Pawełek, J.
Powiązania:
https://bibliotekanauki.pl/articles/100663.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie
Tematy:
rural water supply
expansion
concept
zaopatrzenie wsi w wodę
rozwój
koncepcja
Opis:
This article presents the analysis of the water supply system expandability in the commune of Mściwojów. Such necessity of the expansion resulted from the locations of the new investments covered by the pilot program VITAL LANDSCAPES. Hydraulic calculations, covering two possible solutions, have proven that the existing water supply network is sufficient now and will be sufficient in the near future (after expansion), in supplying all the consumers with water.
Źródło:
Geomatics, Landmanagement and Landscape; 2013, 2; 15-24
2300-1496
Pojawia się w:
Geomatics, Landmanagement and Landscape
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza eksperymentalna ruchu promieniowego pierścieni rozciąganych elektromagnetycznie
Experimental analysis of radial motion of rings expanded electromagnetically
Autorzy:
Janiszewski, J.
Rutyna, K.
Powiązania:
https://bibliotekanauki.pl/articles/210402.pdf
Data publikacji:
2009
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
elektromagnetyczna metoda pierścieniowa
elektromagnetyczne rozpęczanie pierścieni
electromagnetic ring expansion
electromagnetic forming
Opis:
W pracy przedstawiono wyniki badań doświadczalnych dotyczących rozciągania promieniowego pierścieni metalowych za pomocą impulsowego pola elektromagnetycznego. Badaniom poddano pierścienie wykonane z miedzi Cu-ETP oraz duraluminium AW-2017A. Rozciąganie próbek przeprowadzono z wykorzystaniem stanowiska eksperymentalnego zaprezentowanego w pracy [1]. Do rejestracji kształtu pierścienia w poszczególnych fazach jego ruchu zastosowano system kamer cyfrowych, które zapewniały otrzymanie obrazów o rozdzielczości 1360 x 1024 pikseli. Stwierdzono, że dla zastosowanych parametrów napędzania elektromagnetycznego, pierścienie miedziane rozciągają się z maksymalną prędkością wynoszącą około 170 m/s, podczas gdy pierścienie z duraluminium osiągają prędkość około 160 m/s. Ponadto potwierdzono, że pierścień jest rozciągany osiowosymetrycznie, jednakże w późniejszej fazie napędzania ruch ścianek pierścienia jest zaburzony przez niestabilność pola magnetycznego wywołanego uskokiem linii nawojowej pomiędzy uzwojeniami cewki.
The experimental investigation results of a radial ring expansion caused by an impulse electromagnetic field are presented in our paper. The Cu-ETP copper and AW-2017A aluminum alloy rings were studied. The ring expansion was performed by using laboratory apparatus, which was presented in [1]. The ring motion was recorded by means of the optical record system, which consisted of five digital cameras. They ensured to obtain images with relatively high resolution 1360 x 1024 pixels. For applied electromagnetic loading condition, it was found copperrings expanded with a maximum velocity of approximately 170 m/s, whereas aluminum alloy rings were driven with the velocity of approximately 160 m/s. Moreover, it was confirmed an axissymmetric ring expansion, which, however, at further stages of the ring motion, was perturbed by a local instability in a magnetic field. This local magnetic field perturbation was induced by kinks in transition strip of the solenoid.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2009, 58, 2; 7-25
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Newcomers and autochthons. Preliminary report on the 2014–2015 survey in the Kurdistan Autonomous Region, Iraq
Autorzy:
Ławecka, Dorota
Powiązania:
https://bibliotekanauki.pl/articles/1707814.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Warszawski. Wydawnictwa Uniwersytetu Warszawskiego
Tematy:
Late Chalcolithic
Late Uruk
Uruk expansion
Kurdistan Autonomous Region
archaeological survey
Opis:
The paper presents the results of the “Newcomers and autochthons” project conducted within the framework of the UGZAR field project in the Upper Greater Zab region in 2014– 2015 (continued from 2012 and 2013). A preliminary recapitulation of the Late Chalcolithic 3–5 settlement pattern focuses on the so-called Uruk expansion, manifested in the presence of artifacts belonging to the southern Mesopotamian Uruk culture on some of the surveyed sites.
Źródło:
Polish Archaeology in the Mediterranean; 2016, 25; 511-519
1234-5415
Pojawia się w:
Polish Archaeology in the Mediterranean
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determinanty bezpośrednich inwestycji polskich przedsiębiorstw na rynkach zagranicznych
The Determinants of Polish Companies’ Direct Investment Abroad
Autorzy:
Karpińska-Mizielińska, Wanda
Smuga, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/574511.pdf
Data publikacji:
2007-09-30
Wydawca:
Szkoła Główna Handlowa w Warszawie. Kolegium Analiz Ekonomicznych
Tematy:
direct investment abroad
potential investors
investment plans
foreign expansion
barriers
benefits
Opis:
The paper offers a comprehensive analysis of direct investments made by Polish companies abroad. Such investments have intensified in recent years, especially since Poland joined the European Union on May 1, 2004. Foreign expansion is an important part of the development strategies of many Polish companies today. The empirical research described in the paper identifies the factors that determine direct investment by Polish companies abroad, with a special focus on barriers to such projects. The studies in question were carried out at the Foreign Trade Research Institute (IKiCHZ) in 2006 and involved two groups of businesses: those that have already invested abroad in recent years, and those that may carry out such projects in the future. The latter group comprises potential investors who stand out in the corporate sector because of their market position, financial condition and the fact that exports account for a large part of their sales. The analysis involved the following aspects of direct investment abroad: an evaluation of the financial condition of investors and their prospects for the coming years; the possible determinants and barriers to investment on foreign markets; investment plans; the financial, organizational and legal conditions involved; feasibility studies; and the expected benefits and forms of public assistance to Polish companies investing abroad. The empirical studies discussed by the authors reveal that Polish entrepreneurs are interested in direct investment abroad and see it as an opportunity for the further development of their companies. The research shows that Polish investors on foreign markets primarily include large companies that export their products and are doing well financially. Poland’s EU accession has had a positive influence on Polish companies’ direct investment abroad. Still, the authors conclude that direct investment by Polish companies on foreign markets is still in its infancy. This is confirmed by the scope and forms of these projects as well as by the considerable caution displayed by the analyzed businesses in undertaking such operations.
Źródło:
Gospodarka Narodowa. The Polish Journal of Economics; 2007, 218, 9; 31-53
2300-5238
Pojawia się w:
Gospodarka Narodowa. The Polish Journal of Economics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Entwicklung der Graphematik im Schöffenbuch von Markenhau/Markowa
Autorzy:
Chromik, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/700321.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Germanistów Polskich
Tematy:
German Language Island, Markowa, German eastward expansion, Early New High German
Opis:
The former German Language Island Markowa (Eastern Poland) was grounded in the 14th century. There is only one written testimony of its language preserved – the Court Book. In was written in 16th and 17th century by two writters. The second one was the local priest Thomas Kraus who was born in the neighbor village of Albigowa. The language of the Court book consists many characteristics of the Central German.
Źródło:
Zeitschrift des Verbandes Polnischer Germanisten; 2015, 4, 4
2353-656X
2353-4893
Pojawia się w:
Zeitschrift des Verbandes Polnischer Germanisten
Dostawca treści:
Biblioteka Nauki
Artykuł

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