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Wyszukujesz frazę "Dabrowski, B." wg kryterium: Autor


Tytuł:
A proposition of a torsional-bending vibrations modelling of combustion engines
Autorzy:
Dąbrowski, Z.
Chiliński, B.
Pankiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/244766.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
rotational system
system of differential equation
crankshaft system
numerical solutions
Opis:
The article presents the problem of modelling coupled bending-torsional vibrations in crank systems. Because during the design of modern drive systems a growing number of phenomena are taken into account, model description of such vibrations has a practical meaning. Commonly used models of dynamics of systems assume the independence of torsional and bending vibrations, which leads to simultaneous analysis of transverse and angular vibrations. Further analysis is carried out with the use of superposition principle. Such an approach is justified in the case of quite rigid drive shafts, where vibrations are relatively small. Current trends in the design of reducing weight, reduction of toxic emissions and reducing fuel consumption, lead to the situation where shafts in crank systems become less stiff. Therefore, phenomena neglected earlier may have significant meaning. Analysis of couplings of transverse and torsional vibrations is so important that the occurrence of these phenomena usually leads to new critical states, which may be especially dangerous for engine operation. Considerations on the reasons of the occurrence and kinds of vibration couplings were presented in the introduction of the article. Further part of the article proposes the linear-bending model of the crankshaft, where transverse and angular displacements are dependent. It was tantamount to the assumption of linear relation between the vector of generalized co-ordinates and generalized forces occurring in the system. The next chapter presents the system of equations describing the dynamics of the crankshaft together with a discussion of the co-ordinate system used in the considerations. In addition, there were presented the results of numerical simulations in frequency domain confirming the conclusions taken from the analysis. The whole paper is concluded with synthetic conclusions on the formulated system of equations, simulations and the influence of the coupling on the dynamics of the whole crank system.
Źródło:
Journal of KONES; 2016, 23, 4; 71-77
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza pracy spalarni odpadów Szpitala Wojewódzkiego w Koszalinie - spaliny, ścieki, wtórny odpad
Analysis of hospital waste incineration plant work in provincial hospital in Koszalinie - flue gas, wastewater, secondary Waste
Autorzy:
Piecuch, T.
Dąbrowski, T.
Dąbrowski, J.
Lubierski, M.
Juraszka, B.
Kościerzyńska-Siekan, G.
Jantos, K.
Powiązania:
https://bibliotekanauki.pl/articles/1826213.pdf
Data publikacji:
2003
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
spalarnia odpadów szpitalnych
ochrona atmosfery
odpady wtórne
Opis:
Każda spalarnia obok likwidacji odpadów stwarza zagrożenie dla środowiska. Głównie dotyczy to ochrony atmosfery. Stopień zagrożenia zależy od rodzaju wsadu do tej spalarni, który może być szczególnie niebezpieczny np. rtęć lub chlor usytuowany w strukturze materiału odpadowego. W niniejszej publikacji podjęto próbę możliwie obiektywnej oceny pracy spalarni odpadów szpitalnych, w oparciu o materiały dostępne i badania własne. Spalarnia ta jest nową inwestycją i pracuje od stycznia 2001 roku. Przeprowadzona analiza pracy Spalarni Odpadów Medycznych, której charakterystyka technologiczna została przedstawiona w niniejszej publikacji - w oparciu o wizję lokalną, analizę studialną przeprowadzonych badań [4,14,16] oraz badania własne przeprowadzone w Katedrze Techniki Wodno-Mułowej i Utylizacji Odpadów - pozwala na wysunięcie ogólnych wniosków, które mogą być pomocne w przyszłości dla Inwestora, który pragnie zakupić i uruchomić tego typu spalarnie projektu i wykonawstwa Gdańskiego Przedsiębiorstwa Produkcyjno-Usługowego G.P.P.U. Analiza zanieczyszczeń w spalinach jako prób losowych nie daje podstaw do jednoznacznie pozytywnej oceny pracy układu technologicznego oczyszczania spalin wobec norm Unii Europejskiej oraz pochodnych tych norm tj. obostrzeń obowiązujących w państwach Unii Europejskiej. Wtórny odpad poeksploatacyjny z tej Spalarni nie ma charakteru typowego odpadu popirolitycznego tzw. koksiku, ani też w pełni wypalonego odpadu typu żużel (substancja mineralna) i nie może być składowany luzem, a to oznacza, że najłatwiej go solidyfikować. Jeżeli tak, to solidyfikację powinno się prowadzić na miejscu, co jest rozwiązaniem tańszym niż płacenie odbiorcy wtórnego odpadu oddalonego o około 200 km od Koszalina. Technologia pracy tej Spalarni nie uwzględnia rozwiązania gospodarki wodno-ściekowej; niedopuszczalne jest odprowadzanie tych ścieków bezpośrednio do kanalizacji, co ma aktualnie miejsce.
This paper presents the try of possibly objective opinion of hospital waste incineration plant of type SP-100 (with semi-automatic loading) work basing on own investigations and accessible materials. This plant was designed and made by Gdańskie Przedsiębiorstwo Produkcyjno-Usługowe. Incineration plant is a new investment and has been working since January 2001. The operational diagram of the incineration plant is shown in the Fig. 1. The efficiency of analysed device reaches 100 kg of incinerated waste during one hour (by nominal density of waste - 200 kg/m3). The technical and the technological description of the incineration plan work with the critical analysis of technological arrangement of the incineration plant is presented in the paper. Also water and wastewater in the incineration plant was presented. Authors also present the results of own investigations relating to quantities of pollutants washed out from the secondary waste from the incineration plant as well as test of that secondary waste utilization applying the method of solidification in concrete cubes of polbruk type. Own investigations also include measurements of pollutants concentrations in flue gas, using the mobile incineration gas analyser GA-21 plus. Conducted analysis Medical Waste Incineration Plant work, which technological description was introduced in this paper - basing on the visits in the incineration plant, the studial analysis of conducted investigations [4,14,17] as well as own investigations conducted in Department of Water-Sludge Technique and Utilization of Waste - allows to draw some general conclusions which may be helpful in the future for investors, which plan to buy and to start this the type of the incineration plant, designed and made by Gdańskie Przedsiębiorstwo Produkcyjno-Usługowe GPPU. Analysis of pollutants in the flue gas (as random tests) does not give basis to have unambiguously positive opinion on work of technological installation of combustion gas cleaning running of the in the face of the European Union standards as well as derivatives of these standards i.e. of the greater rigours valid in countries of European Union. Analysis secondary waste management which are produced in this incineration plant shows sure doubts of economical nature which regard to the collection of the waste by EKOPAL Company which is situated about 200 km from Koszalin, for payment over 1000 PLN per ton. This payment has a significant influence on the total unit cost of utilization of one ton of medical waste taken by Waste Incineration Plant from deliverers of waste and reaching over 3000 PLN per ton (data from year 2002). This is is 6 and even 7 times larger price than the average typical price for delivery of waste to the thermal waste utilization plants in European countries. The secondary waste from the waste incineration plant is not the like the typical post-pirolitic waste (so called koksik). It is not also fully burned waste of the slag type (the mineral substance) and it cannot be stored loosely, and this means that the easiest method of its utilization is the solidification. If so - this solidification should be conducted on the terrain of the Waste Incineration Plant, which is the cheaper solution than paying recepient of secondary waste situated about 200 km from Koszalin. The technology of the Waste Incineration Plant work does not include solution of water and wastewater management; invalid is piping of wastewater from the incineration plant directly to the sewage system, which at present takes place.
Źródło:
Rocznik Ochrona Środowiska; 2003, Tom 5; 163-189
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of SS-VF Bed for the Treatment of High Concentrated Reject Water from Autothermal Termophilic Aerobic Sewage Sludge Digestion
Autorzy:
Dąbrowski, W.
Malinowski, P.
Karolinczak, B.
Powiązania:
https://bibliotekanauki.pl/articles/123643.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
autothermal thermophilic aerobic digestion
ATAD
reject water
vertical flow constructed wetland
SS VF
Opis:
The autothermal termophilic aerobic digestion (ATAD) technology is used in the municipal and industrial wastewater treatment plants (WWTPs) with personal equivalent up to 30.000. The process provides a high level of sewage sludge stabilization and its hygienization. The main operation problems are caused by the high concentration of nitrogen and phosphorus in the reject water from sewage sludge treatment and air purification (odor removal). Reject water usually is returned to the main sewage treatment, which has a negative impact, especially on the sewage treatment systems based on the sequence batch reactors (SBR). Applying high-performance and expensive separate reject water treatment methods such as SHARON, Anammox or CANON in small facilities is not justified economically. The article presents the research results concerning the effectiveness of applying subsurface vertical flow constructed wetlands (SS VF) for reject water treatment from the ATAD process. An innovative type of bed filling was used, which was produced from waste (ash from a heat and power plant). The efficiency of reject water treatment during the research period was on average at 45.6% for ammonia nitrogen, 32.3% for total phosphorus and 85.1% for BOD5. Applying SS VF beds for separate reject water treatment might ensure a stable and effective functioning of municipal WWTPs by decreasing the load of biological part of a WWTP.
Źródło:
Journal of Ecological Engineering; 2018, 19, 4; 103-110
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Applying Machine Learning to Software Fault Prediction
Autorzy:
Wójcicki, B.
Dabrowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/384105.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
classifier
fault prediction
machine learning
metric
Naïve Bayes
Python
quality
software intelligence
Opis:
Introduction: Software engineering continuously suffers from inadequate software testing. The automated prediction of possibly faulty fragments of source code allows developers to focus development efforts on fault-prone fragments first. Fault prediction has been a topic of many studies concentrating on C/C++ and Java programs, with little focus on such programming languages as Python. Objectives: In this study the authors want to verify whether the type of approach used in former fault prediction studies can be applied to Python. More precisely, the primary objective is conducting preliminary research using simple methods that would support (or contradict) the expectation that predicting faults in Python programs is also feasible. The secondary objective is establishing grounds for more thorough future research and publications, provided promising results are obtained during the preliminary research. Methods: It has been demonstrated that using machine learning techniques, it is possible to predict faults for C/C++ and Java projects with recall 0.71 and false positive rate 0.25. A similar approach was applied in order to find out if promising results can be obtained for Python projects. The working hypothesis is that choosing Python as a programming language does not significantly alter those results. A preliminary study is conducted and a basic machine learning technique is applied to a few sample Python projects. If these efforts succeed, it will indicate that the selected approach is worth pursuing as it is possible to obtain for Python results similar to the ones obtained for C/C++ and Java. However, if these efforts fail, it will indicate that the selected approach was not appropriate for the selected group of Python projects. Results: The research demonstrates experimental evidence that fault-prediction methods similar to those developed for C/C++ and Java programs can be successfully applied to Python programs, achieving recall up to 0.64 with false positive rate 0.23 (mean recall 0.53 with false positive rate 0.24). This indicates that more thorough research in this area is worth conducting. Conclusion: Having obtained promising results using this simple approach, the authors conclude that the research on predicting faults in Python programs using machine learning techniques is worth conducting, natural ways to enhance the future research being: using more sophisticated machine learning techniques, using additional Python-specific features and extended data sets.
Źródło:
e-Informatica Software Engineering Journal; 2018, 12, 1; 199-216
1897-7979
Pojawia się w:
e-Informatica Software Engineering Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automatic proxy generation and load-balancing-based dynamic choice of services
Autorzy:
Dąbrowski, J.
Feduniak, S.
Baliś, B.
Bartyński, T.
Funika, W.
Powiązania:
https://bibliotekanauki.pl/articles/305465.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
proxy
load-balancer
load balancing
automatic generation
Opis:
The paper addresses the issues of invoking services from within workflows which are becoming an increasingly popular paradigm of distributed programming.The main idea of our research is to develop a facility which enables load balancing between the available services and their instances. The system consists of three main modules: a proxy generator for a specific service according to its interface type, a proxy that redirects requests to a concrete instance of the service and load-balancer (LB) to choose the least loaded virtual machine (VM) which hosts a single service instance. The proxy generator was implemented as a bean (in compliance to EJB standard) which generates proxy according to the WSDL service interface description using XSLT engine and then deploys it on a GlassFish application server using GlassFish API, the proxy is a BPEL module and load-balancer is a stateful Web Service.
Źródło:
Computer Science; 2012, 13 (3); 45-59
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania nad ekstrakcją cyklicznych peptydów z materiałów odpadowych lnu zwyczajnego
Studies on the extraction of cyclic peptides from flax waste materials
Autorzy:
Jezierska-Zięba, M.
Kąkol, B.
Bujnowski, Z.
Brzozowski, R.
Dąbrowski, Z.
Kuczyńska, A.
Szpakiewicz, M.
Szarlik, S.
Cybulski, J
Powiązania:
https://bibliotekanauki.pl/articles/1287086.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
len
ekstrakcja
nadkrytyczny i ciekły CO2
extraction
supercritical and liquid CO2
Opis:
Cyklopeptydy wydzielono z makuchów i plew lnianych dwiema metodami: ekstrakcją za pomocą nadkrytycznego i ciekłego CO2 oraz tradycyjną ekstrakcją rozpuszczalnikową. Przeprowadzono badania zależności wydajności ekstrakcji cyklopeptydów za pomocą CO2 od temperatury i czasu trwania procesu. Badania wykazały, że wysoka temperatura rozpuszczalników zwiększa zawartość cyklopeptydu CLA w otrzymanych ekstraktach. W przypadku plew lnianych obie zastosowane metody ekstrakcji dały porównywalne wyniki.
Cyclopeptides were separated from linseed cakes and chaff using two methods: supercritical and liquid CO2 extraction and traditional solvent extraction. Tests were carried out on the dependencies of cyclopeptide extraction using CO2 on the temperaturę and duration of the process. Studies have shown that high temperaturę of solvents increases the content of cyclopeptide CLA in the obtained extracts. In case of chaff both applied extraction methods have given similar results.
Źródło:
Chemik; 2011, 65, 9; 837-848
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania właściwości mechanicznych spiekanych biomateriałów na bazie tytanu
Investigation of mechanical properties of sintered titanium-based biomaterials
Autorzy:
Deptuła, P.
Dąbrowski, J. R.
Hościło, B.
Powiązania:
https://bibliotekanauki.pl/articles/284496.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
biomateriały
stopy tytanu
właściwości mechaniczne
biomaterials
titanium alloys
mechanical properties
Opis:
Przy wykorzystaniu metod metalurgii proszków otrzymano szereg materiałów spiekanych na bazie tytanu – potencjalnych biomateriałów, bez toksycznych dodatków glinu i wanadu. Wykonano badania właściwości mechanicznych otrzymanych materiałów. Badano stopy tytanu: Ti-15Mo-2,8Nb i Ti-7,5Mo-2Fe oraz materiały kompozytowe na bazie tytanu z dodatkami 10% grafitu. Wyniki badań wytrzymałościowych wskazują, że otrzymane biomateriały charakteryzują się dobrymi właściwościami mechanicznymi. Materiały posiadają odpowiednią wytrzymałość na ściskanie i jednocześnie niskie współczynniki sprężystości, co jest bardzo ważne w przypadku materiałów do zastosowań biomedycznych.
With the use of powder metallurgy methods, a number of titanium-based sintered materials were obtained without toxic additives of aluminium or vanadium – potential biomaterials. Experiments on mechanical properties of the obtained materials were carried out. Ti-15Mo-2.8Nb and Ti-7.5Mo-2Fe alloys, as well as titanium-based composite materials with 10% of graphite added, were tested. The results of strength tests indicate that the obtained biomaterials are characterised by good mechanical properties. The materials are appropriately resistant to compression and yet they have low modulus of elasticity, which is very important in the case of materials for biomedical application.
Źródło:
Engineering of Biomaterials; 2010, 13, 92; 11-13
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania właściwości tribologicznych resorbowalnych biomateriałów na bazie polilaktydu
Tribological properties of resorbable polylactide-based biomaterials
Autorzy:
Karalus, W.
Szaraniec, B.
Gryń, K.
Chłopek, J.
Dąbrowski, J. R.
Jałbrzykowski, M.
Szymaniuk, E.
Powiązania:
https://bibliotekanauki.pl/articles/285633.pdf
Data publikacji:
2015
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
trybologia
kompozyty degradowalne
polilaktyd
hydroksyapatyt
włókna węglowe
fosforan trójwapnia
tribology
degradable composites
polylactide
hydroxyapatite
carbon fibers
tricalcium phosphate
Opis:
Celem pracy było przeprowadzenie badań tribologicznych i ocena zużycia biokompozytów polimerowych. Do badań przygotowano trzy rodzaje kompozytów z polilaktydu modyfikowanego dodatkami w postaci: włókien węglowych, fosforanu trójwapnia oraz hydroksyapatytu. Ich zachowanie w warunkach tarciowych porównywano z próbkami referencyjnymi (PLA). Badania tribologiczne realizowano w warunkach tarcia suchego oraz w obecności smaru – soli fizjologicznej (roztwór wodny 0,9% NaCl). Na podstawie badań stwierdzono, że wprowadzenie modyfikatorów ceramicznych do osnowy polilaktydowej poprawiło charakterystyki tribologiczne, zaś dodatek włókien węglowych wpłynął najkorzystniej na obniżenie współczynnika tarcia (μ). Stwierdzono istotny wpływ środka smarnego. O ile w obecności smaru wartości μ dla wszystkich badanych materiałów obniżyły się, to zużycie - wyznaczone na podstawie zmian masy - zmniejszyło się tylko dla czystego polilaktydu oraz polilaktydu modyfikowanego włóknem węglowym. W przypadku kompozytów z fosforanem trójwapniowym i hydroksyapatytem zarejestrowano intensyfikację zużycia. Uzupełnieniem przeprowadzonych badań były obserwacje powierzchni testowanych próbek przy pomocy elektronowego mikroskopu skaningowego (SEM). Niezależnie od warunków (ze smarem czy też bez) najmniejszą odpornością na zużycie tarciowe cechował się czysty polilaktyd. Kompozyty z dodatkami ceramicznymi wykazywały wyraźne ślady zużycia, zaś obserwacje powierzchni kompozytów wzmacnianych włóknami węglowymi ujawniły, że zewnętrzne warstwy poddawane oddziaływaniu tarcia narażone są na fragmentacje włókien węglowych. Zjawisko to może mieć niekorzystny wpływ na możliwość aplikacji takich materiałów w warunkach pracy, w których są narażone na ścieranie.
The objective of this study was the observation and evaluation of tribological characteristics and behavior of biocomposites with polymer matrix under different friction conditions. Three types of polylactide composites were considered: with addition of carbon fibers (CF), tricalcium phosphate (TCP) and hydroxyapatite (HAP). As a reference pure polylactide (PLA) samples were prepared. Tribological tests were conducted under dry friction conditions and in the presence of a lubricant – physiological saline (0.9% NaCl aqueous solution). The results clearly show that introduction of ceramic modifiers to the polylactide matrix enhanced tribological resistance of the composite and carbon fibers addition reduced the value of friction coefficient (μ). It was observed that when the lubricant was present lower values of μ were recorded for all composites but when the wear process was analyzed it was revealed that the loss of mass was reduced only for pure PLA and PLA modified with carbon fibers. For ceramic modified composites the wear processes were more intense. Scanning electron microscopy was used for surface observations of tested samples. Regardless of friction conditions (with or without lubricant) pure polylactide samples, as the softest, wear the most. When surface of composites with ceramic additives were analyzed the biggest grooves and hollows ware observed. Samples with CF exposed to friction conditions reveal inclination to fibers fragmentation, thus application of such composites in kinematic joints in biomedical devices is limited.
Źródło:
Engineering of Biomaterials; 2015, 18, 132; 24-30
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Building sentiment lexicons based on recommending services for the Polish language
Autorzy:
Gliwa, B.
Zygmunt, A.
Dąbrowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/305732.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
sentiment analysis
sentiment lexicons
polarity lexicons
sentiment classification
Opis:
Sentiment analysis has become a prominent area of research in computer science. It has numerous practical applications; e.g., evaluating customer satisfaction, identifying product promoters. Many methods employed in this task require language resources such as sentiment lexicons, which are unavailable for the Polish language. Such lexicons contain words annotated with their emotional polarization, but the manual creation of sentiment lexicons is very tedious. Therefore, this paper addresses this issue and describes a new method of building sentiment lexicons automatically based on recommending services. Next, the built lexicons were used in the task of sentiment classification.
Źródło:
Computer Science; 2016, 17 (2); 163-185
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and performance of a system for two - dimensional readout of gas electron multiplier detectors for proton range radiography
Autorzy:
Wiącek, P.
Dąbrowski, W.
Fiutowski, T.
Mindur, B.
Zielińska, A.
Powiązania:
https://bibliotekanauki.pl/articles/146722.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
front-end electronics
GEM detectors
2-D imaging
proton range radiography
Opis:
The proton range radiography (PRR) technique being developed is expected to provide significant improvements in precision delivery of the therapeutic dose in the hadron therapy. The technique requires measuring residual energies and trajectories of mono-energetic protons passing through an object to be imaged. Such an imaging system can be operated in-situ before and after the treatment allowing real time monitoring of the irradiated tissue position. A detector system suitable for such applications must be capable of measuring proton tracks with submillimeter spatial resolution over area of 30 x 30 cm2. In order to limit the exposure time and obtain real-time images the detector and data acquisition must provide capability of measuring high proton rates up to 106 s-1. In this paper we present novel concept of two-dimensional (2-D) readout of the gas electron multiplier (GEM) detectors used as the position sensitive detectors. The key component of the system is an application specific integrated circuit (ASIC) named GEMROC. The GEMROC comprises 32 independent channels, each one capable of measuring the amplitude and the time of incoming signals. The positions are then reconstructed by coincidences of signals from the X- and Y-readout strips. The design and performance of the GEMROC ASIC are discussed and the results obtained for a test bench based on a smaller 10 x 10 cm2 GEM chamber are presented. The test results demonstrate clearly that with respect to the two critical parameters, i.e. the noise and the count rate capability, the developed readout system meets the requirements for clinical applications of the PRR technique.
Źródło:
Nukleonika; 2012, 57, 4; 513-519
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design Rules for Manganites with Novel Magnetic and Electronic Properties
Autorzy:
Dabrowski, B.
Chmaissem, O.
Mais, J.
Kolesnik, S.
Powiązania:
https://bibliotekanauki.pl/articles/2037095.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.12.-q
75.50.-y
Opis:
We have been systematically developing strategies for making new perovskite manganites with novel magnetic and electronic properties. This effort requires a two-fold approach: understanding the dependence of properties on chemical and structural factors and development of the ability to synthesize desired compounds. We show that, similar to other single valent 3d systems, the magnetic superexchange interactions in AMnO$\text{}_{3}$ manganites (A = rare or alkaline earth's) are dependent on the Mn-O-Mn bond angle which is a function of interatomic distances A-O and Mn-O. The local structural disorder on the A-site suppresses magnetic interactions. Recently, by comparing disordered (randomly mixed La/Ba) and ordered (forming Ba/La/Ba layers along the c-axes) perovskites we have demonstrated much more conspicuous effects of structural and charge disorder for mixed-valent manganites. We show that by stabilizing the ordered structure; i.e., by suppressing local structural and charge disorder on the A-site, a substantial increase in T$\text{}_{C}$ from 340 to 365~K can be achieved. A similar control of order on the Mn-site was achieved for SrMn$\text{}_{1-y}$Ga$\text{}_{y}$ O$\text{}_{3-\text{}_{y}\text{}_{/}\text{}_{2}$ compounds near y=0.5, while SrMn$\text{}_{1-y}$Fe$\text{}_{y}$O$\text{}_{3}$ compounds are always randomly mixed. To achieve these compounds, we have been systematically developing special synthesis techniques for extending chemical composition ranges far beyond those previously achieved, developing rules for predicting which compositions should be possible to produce by these special techniques, and establishing methods for selectively ordering or disordering mixtures of metal atoms on the A- or Mn-sites.
Źródło:
Acta Physica Polonica A; 2004, 105, 1-2; 45-56
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of Orientational Order Parameters of Two Tri-Component Mixtures from Optical Birefringence and X-Ray Diffraction Measurements
Autorzy:
Basak, S.
Dasgupta, P.
Das, B.
Das, M.
Dabrowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/1492775.pdf
Data publikacji:
2011-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.cp
61.30.-v
42.70.Df
Opis:
Two tri-component mixtures as base mixtures for vertically aligned mode LCD's were prepared. The eutectic compositions were theoretically estimated and experimentally verified from differential scanning calorimetry studies. A room temperature nematic mixture with fairly broad operating range emerged from each of the tri-component mixtures. The optical birefringence of these mixtures at the eutectic composition was measured as a function of temperature. X-ray diffraction measurements were done on these mixtures to obtain the orientational order parameters as a function of temperature. The order parameter values were also determined from birefringence measurements and the results were compared with mean field theory. Structural parameters like intermolecular distance and apparent molecular length have also been determined.
Źródło:
Acta Physica Polonica A; 2011, 120, 6; 1037-1042
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dielectric Permittivity and Viscoelastic Measurements οf Two Tricomponent Mixtures Consisting οf Laterally Fluorinated Terphenyl Derivatives
Autorzy:
Basak, S.
Dasgupta, P.
Das, B.
Das, M.
Dabrowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/1400143.pdf
Data publikacji:
2013-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.30.-v
78.20.Fm
87.19.rd
87.19.rf
83.60.Bc
Opis:
Two tricomponent room temperature nematic eutectic mixtures ABC and ABD with laterally fluorinated constituents A and B were prepared as base mixtures for vertically aligned mode LCD's. The physical properties of these mixtures viz. birefringence, dielectric anisotropy, bend elastic constant, relaxation time and rotational viscosities were determined in order to compare with the optimum values required to achieve the target specifications of VA mode materials. The dielectric anisotropy, Δ ε, and optical birefringence, Δ n, of these mixtures were found to be in the range of (-1.3 to -1.4) and (0.13 and 0.14), respectively, at around 20°C. The figure of merit for the ABD mixture has been found to be higher than that of ABC mixture throughout the entire temperature range. The pretilt angle effect in the physical parameters has also been studied. At T=20°C, the response time decreases to 25% and 35% for mixture ABC for 2° and 5° pretilt respectively in comparison to zero pretilt. On the other hand, at the same temperature for the ABD mixture these values are reduced by 16% and 35%, respectively.
Źródło:
Acta Physica Polonica A; 2013, 123, 4; 714-719
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dielectric Properties of Liquid Crystalline Isothiocyanato-tolane Derivatives with Fluorine Atom at Various Lateral Positions
Autorzy:
Czub, J.
Urban, S.
Dąbrowski, R.
Gestblom, B.
Powiązania:
https://bibliotekanauki.pl/articles/2043376.pdf
Data publikacji:
2005-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
64.70.Md
77.22.Gm
77.84.Nh
Opis:
Dielectric studies were performed for several isothiocyanato-tolane compounds having the F atom attached to the benzene rings at different lateral positions and the alkoxy or alkyl chain at the p-position. They form the nematic phase in broad temperature intervals. The static as well as dynamic properties of the compounds in the nematic and isotropic phases were studied. Tensor permittivity components: ε$\text{}_{ǁ}$, ε$\text{}_{⊥}$, Δε, as functions of temperature were measured. The complex dielectric permittivity, ε$\text{}^{*}$(f)=ε'(f)-iε''(f), was measured in the frequency range of 1 kHz - 3 GHz from which the relaxation times τ$\text{}_{ǁ}$ and τ$\text{}_{⊥}$ were calculated. The order parameter S(T) was determined from the dielectric data. It was found that the close vicinity of the F atom and the alkoxy group results in blocking of the internal rotation of the wing around the O-phenyl bond.
Źródło:
Acta Physica Polonica A; 2005, 107, 6; 947-958
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Doskonalenie procedury zakupowej w procesie przygotowania produkcji
Improvement purchasing procedure in a process of production’s preparation
Autorzy:
Waszkiewicz-Flasza, A.
Dąbrowski, M.
Białecka, B.
Powiązania:
https://bibliotekanauki.pl/articles/320994.pdf
Data publikacji:
2016
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
łańcuch dostaw
zakupy zaopatrzeniowe
wewnętrzne zapytania ofertowe
supply chain
purchasing
request for quotation
Opis:
Artykuł obejmuje problematykę procesu zakupów w wybranym przedsiębiorstwie branży automotive. Analizie poddano istotę zakupów zaopatrzeniowych oraz procedurę procesu zakupu. Omówiono główne zadania procesu zakupu oraz występujące w nim problemy. Przedstawiono możliwości pozyskania oszczędności przy zakupie materiałów u dostawców. Opisano także nowe rozwiązanie w dziale zakupów.
The article contains of purchasing process in the production company. It provides the description of purchasing. The article covers procedure of purchasing department. It takes the main issue of purchasing process. An article is presented the possibilities for savings. Also this part of article look at the new solution in purchasing department.
Źródło:
Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska; 2016, 92; 383-394
1641-3466
Pojawia się w:
Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł

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