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Tytuł:
Diffusive and Displacive Phase Transformations in Nanocomposites under High Pressure Torsion
Autorzy:
Straumal, B.
Kilmametov, A.
Gornakova, A.
Mazilkin, A.
Baretzky, B.
Korneva, A.
Zięba, P.
Powiązania:
https://bibliotekanauki.pl/articles/356575.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high-pressure torsion
Ti-Fe alloys
phase transitions
high-pressure phases
Opis:
The high-pressure torsion (HPT) of Ti-Fe alloys with different iron content has been studied at 7 GPa, 5 anvil rotations and rotation speed of 1 rpm. The alloys have been annealed before HPT in such a way that they contained different amounts of α/α' and β phases. In turn, the β phase contained different concentration of iron. The 5 anvil rotations correspond to the HPT steady-state and to the dynamic equilibrium between formation and annihilation of microstructure defects. HPT leads to the transformation of initial α/α' and β-phases into mixture of α and high-pressure ω-phase. The α → ω and β → ω phase transformations are martensitic, and certain orientation relationships exist between α and ω as well as β and ω phases. However, the composition of ω-phase is the same in all samples after HPT and does not depend on the composition of β-phase (which is different in different initial samples). Therefore, the martensitic (diffusionless) transformations are combined with a certain HPT-driven mass-transfer. We observed also that the structure and properties of phases (namely, α-Ti and ω-Ti) in the Ti – 2.2 wt. % Fe and Ti – 4 wt. % Fe alloys after HPT are equifinal and do not depend on the structure and properties of initial α'-Ti and β-Ti before HPT.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 2; 457-465
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technical aspects of coal disintegration using high pressure water jet
Autorzy:
Borkowski, P.
Borkowski, J.
Bielecki, M.
Powiązania:
https://bibliotekanauki.pl/articles/99756.pdf
Data publikacji:
2012
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
high-pressure water jet
coal
disintegration
Opis:
The high-pressure water jet comminution of coal is presents in the paper. For such procedure a special prototype of hydrojetting apparatus have been developed. Three different types of coal were examined: hard-, brown-, and charcoal. Obtained results point out that high-pressure water jet usage for such a purpose is very effective. Brown coal is slightly for charcoal. Such micronization effect gives even over 100,000 times increase Moreover charcoal susceptibility for intensive hydro-comminution causes that one can get the most comminuted structure what is a good prognosis for its modification into bio-fuels.
Źródło:
Journal of Machine Engineering; 2012, 12, 2; 7-19
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of pascalization in the Polish food industry – characteristics and prospects®
Zastosowanie paskalizacji w polskim przemyśle spożywczym – charakterystyka i perspektywy®
Autorzy:
Gruchelski, Marek
Gruchelski, Marcin
Porębska, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/1535993.pdf
Data publikacji:
2020
Wydawca:
Wyższa Szkoła Menedżerska w Warszawie
Tematy:
pascalization
food processing
food industry
sustainable development
HPP
high pressure processing
high pressure pasteurization
HHP technology
high hydrostatic pressure
UHP
ultra high pressure
paskalizacja
przetwórstwo spożywcze
przemysł spożywczy
rozwój zrównoważony
wysokociśnieniowe utrwalanie żywności
technologia HHP
Opis:
In recent years, pro-health food has become more and more popular. Particular attention is paid not only to unprocessed, nutritional fruit and vegetable products, but also high-quality meat products, dairy products and ready meals. It is the changes in consumer preferences that constitute the main, amongst others, driving force for scientists and food producers who are looking for new concepts and directions to develop the food industry.One of the hi-tech solutions, in line with the principle of “minimal processing”, as well as responding to the market demand, is the method of high-pressure food preservation, often referred to as “pascalization”. The advantage of this method is the combination of effective degradation of microorganisms and pathogens while maintaining the high quality of the pre-served product. Additionally, it allows to influence the texture, functional properties and sensory features of the product wit-hout adversely affecting its nutrients.Modern technologies of food preservation are still rarely used on the domestic food processing market. This is due, inter alia, to the fact that innovations in the production sector require high capital outlays, and individual food processing plants most often do not have a sufficient capital base to invest in modern technologies. The current limitations in the large-scale application of the high-pressure food preservation method in the Polish food processing sector result directly from the high price of high-pressure systems and higher processing costs than contemporary methods.The solution to the problem of currently limited use of these technologies on the Polish market should be sought, first of all, in the approach to the issue of capital cooperation be-tween economic entities and in changing the states policy towards small and medium-sized enterprises.The aim of this article is to present pascalization as an alternative and a modern method of pressure food preservation as well as an indication of the prospects and possibilities of introducing this technology on a large scale in the Polish food processing sector.
W ostatnich latach żywność prozdrowotna cieszy się coraz większą popularnością. Szczególne zainteresowanie budzą nie tylko nieprzetworzone, wartościowe produkty owocowo-warzywne, ale również wysokiej jakości produkty mięsne, nabiał oraz dania gotowe. To właśnie zmiany preferencji konsumentów stanowią główną, choć nie jedyną, przyczynę poszukiwania przez naukowców oraz producentów żywności nowych koncepcji i kierunków rozwoju przemysłu spożywczego. Jednym z nowoczesnych rozwiązań, zgodnych z zasadą „minimalnego przetwarzania”, jak również, odpowiadających na zapotrzebowanie rynku jest metoda wysokociśnieniowego utrwalania żywności, często określana mianem „paskalizacji”. Zaletą tej metody jest połączenie skutecznej degradacji drobnoustrojów oraz patogenów z jednoczesnym zachowa-niem wysokiej jakości utrwalanego produktu. Dodatkowo, pozwala ona wpływać na kształtowanie tekstury, właściwości funkcjonalne oraz cechy sensoryczne produktu bez wywierania negatywnych skutków na jego składniki odżywcze. Nowoczesne technologie utrwalania żywności są jeszcze do-syć rzadko wykorzystywane na rodzimym rynku przetwórstwa spożywczego. Wynika to między innymi z faktu, iż innowacje w sektorze produkcyjnym wymagają wysokich nakładów kapitałowych, a pojedyncze zakłady przetwórstwa spożywczego najczęściej nie posiadają wystarczającej bazy kapitałowej po-zwalającej na inwestycje w nowoczesne technologie. Obecne ograniczenia w zastosowaniu na szeroką skalę metody wysokociśnieniowego utrwalania żywności w polskim sektorze przetwórstwa spożywczego wynikają bezpośrednio z wysokiej ceny systemów wysokociśnieniowych oraz wyższych, względnym metod klasycznych, kosztów przetwarzania. Rozwiązania problemu ograniczonego obecnie wykorzystania tych technologii na polskim rynku należy szukać, przede wszystkim, w sposobie podejścia do kwestii współpracy kapitałowej pomiędzy podmiotami gospodarczymi oraz w zmianie polityki państwa wobec małych i średnich przedsiębiorstw. Celem artykułu jest przedstawienie paskalizacji, jako alternatywnej i nowoczesnej metody ciśnieniowego utrwalania żywności oraz wskazanie perspektyw i możliwości wprowadzenia tej technologii na szeroką skalę w polskim sektorze przetwórstwa spożywczego.
Źródło:
Postępy Techniki Przetwórstwa Spożywczego; 2020, 2; 203-208
0867-793X
2719-3691
Pojawia się w:
Postępy Techniki Przetwórstwa Spożywczego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Protection From Steam at High Pressures: Development of a Test Device and Protocol
Autorzy:
Sati, R.
Crown, E. M.
Ackerman, M.
Gonzalez, J.
Dale, D.
Powiązania:
https://bibliotekanauki.pl/articles/90402.pdf
Data publikacji:
2008
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
steam protection
high pressure steam
protective materials
Opis:
Extensive use of pressurized steam in the oil and gas sectors has led to incidents where workers were seriously injured. In this study a test device and procedure to measure heat transfer through fabrics during steam exposure were developed and evaluated. Several factors were considered while designing the test device to simulate work site conditions. Fabrics were exposed to steam at 2 distances (50 and 100 mm) and 2 pressures (207 and 69 kPa). Theoretical considerations included heat and mass transfer, and fabric structure and performance properties. The test device and procedure differentiated well among both fabric and exposure conditions. For all fabrics, maximum heat transfer was observed at highest steam pressure and shortest distance. Laminated and coated fabrics performed better than a fabric without such treatments.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2008, 14, 1; 29-41
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Positrons in naphthalene : critical remarks on the relation between o-Ps lifetime and void size
Autorzy:
Goworek, T.
Zgardzińska, B.
Wawryszczuk, J.
Powiązania:
https://bibliotekanauki.pl/articles/148003.pdf
Data publikacji:
2013
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
high pressure
naphthalene
positronium quenching
free volume
Opis:
Lowering the temperature or applying high pressure leads to elimination of positronium component in the e+ lifetime spectrum in solid naphthalene. Disappearance of positronium means reaching the free volume size limit at which there is no energy level in the potential well. It allows to estimate that size, which is found inconsistent with predictions of the popular Tao-Eldrup model. The range of applicability of that model is discussed. The dependence of the free e+ decay constant on pressure indicates that positronium is formed not only in the blob processes, but during the whole free positron life. The lifetime of free positrons begins to rise with temperature earlier than Ps intensity.
Źródło:
Nukleonika; 2013, 58, 1; 183-187
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The high-pressure sorptomat - a novel apparatus for volumetric sorption studies under isobaric high gas pressure conditions
Autorzy:
Kudasik, Mateusz
Anioł, Łukasz
Skoczylas, Norbert
Powiązania:
https://bibliotekanauki.pl/articles/2173899.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sorptomat
sorption
high-pressure apparatus
volumetric method
Opis:
As part of the work the high-pressure sorptomat - a novel apparatus for sorption tests under conditions of high gas pressure was developed. The sorption measurement is carried out using the volumetric method, and the precise gas flow pressure regulator is used in the device to ensure isobaric conditions and regulate the sorption pressure in the range of 0-10 MPa. The uniqueness and high precision of sorption measurements with the constructed apparatus are ensured by the parallel use of many pressure sensors with a wide measurement range as well as high precision of measurement - due to the use of precise pressure sensors. The obtained results showed, i.a. that the time of reaching the isobaric conditions of the measurement is about 6-7 seconds and it is so short that it can be considered a quasi-step initiation of sorption processes. Moreover, the results of the measurement pressure stabilization tests, during the CO2 sorption test on activated carbon, have shown that the built-in pressure regulator works correctly and ensures isobaric sorption measurement conditions with the precision of pressure stabilization of ±1% of the measurement pressure. The maximum range of sorption measurement using the high-pressure sorptomat is 0-86 400 cm3/g, and the maximum measurement uncertainty is ±2% of the measured value. The activated carbon sample used for the tests was characterized by a high sorption capacity, reaching 104.4 cm3/g at a CO2 pressure of 1.0 MPa.
Źródło:
Metrology and Measurement Systems; 2022, 29, 4; 607--620
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristics of the NiAl/Ni3Al Matrix Composite with TiB2 Particles Fabricated by High Pressure - High Temperature Sintering
Autorzy:
Hyjek, P.
Sulima, I.
Jaworska, L.
Powiązania:
https://bibliotekanauki.pl/articles/352345.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sintering
High Pressure High Temperature process
metal matrix composites
tribological properties
Opis:
The article presents the results of tests carried out on the manufactured composite materials based on a two-phase NiAl/Ni3Al matrix, which was enriched with the addition of TiB2 ceramic particles added in an amount of 4 and 7 vol%. The resulting mixtures were sintered by the High Pressure High Temperature (HP-HT) process. The results were compared to the results obtained for the sole matrix material produced under the same conditions. It has been shown that, at a lower density, the addition of reinforcing particles increases the composite hardness, Young’s modulus and resistance to frictional wear. However, higher addition of TiB2 (7 vol%) was observed to yield less satisfactory results, and despite higher hardness and lower density caused a decrease in other properties tested. The produced materials were characterized by a compact and highly differentiated microstructure free from any noticeable cracks and pores.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 3; 1511-1520
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Examination of High-Pressure Water Jet Usability for High Explosives (HE) Washing Out from Artillery Ammunition
Autorzy:
Borkowski, P.
Borkowski, J.
Woźniak, D.
Maranda, A.
Powiązania:
https://bibliotekanauki.pl/articles/358851.pdf
Data publikacji:
2008
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
high-pressure water jet
explosive material
artillery ammunition
Opis:
The method of explosives materials washing-out process from old artillery ammunition using high-pressure water jet technology was discussed in the paper. Presented experimental results let to define explosives washing-out mechanism and its potential effectiveness. Finally, exemplary structures of washedout explosives pointing on methods of its utilization are presented.
Źródło:
Central European Journal of Energetic Materials; 2008, 5, 2; 21-35
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of 200 MPa pressure on specific surface area of clay
Autorzy:
Koszela-Marek, E.
Powiązania:
https://bibliotekanauki.pl/articles/178875.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
clay
high pressure
specific surface area
microstructural changes
Opis:
The paper presents the results of laboratory studies of the 200 MPa pressure effect on specific surface area of clay. The original high-pressure investigation stand was used for the pressure tests. Determination of the specific surface area was performed by the methylene blue adsorption method. The results of the specific surface area test were compared for non-pressurized clays and for clays pressured in a high-pressure chamber. It was found that the specific surface area of pressurized soil clearly increased. This shows that some microstructural changes take place in the soil skeleton of clays.
Źródło:
Studia Geotechnica et Mechanica; 2014, 36, 4; 3-6
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of a high-pressure water jet structure as an innovative tool for pulverizing copper ore in KGHM Polska Miedź S.A.
Autorzy:
Borkowski, P.
Shimizu, S.
Peng, G.
Oguma, Y.
Powiązania:
https://bibliotekanauki.pl/articles/972348.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa
Tematy:
copper ore
comminution
high-pressure water jet
simulations
Opis:
Effective comminution of copper ore for further processing during flotation is still a challenge, both as a technological problem as well as for the high energy costs of such processing. A high-pressure water jet is one alternative method of preparing copper ore for final flotation, causing distinct enlargement of the surface of micronized particles, which could be profitable for copper production. As a consequence of such innovative processing, particles of copper ore become micronized, ensuring grain fractions directly useful for flotation at the exit of the pulverizing apparatus (the hydro-jetting mill).The paper presents some results of simulation as well as describing an analysis of the phenomena occurring inside the high-pressure water and abrasive-water jets of specific structures, elaborated in the aspect of developing hybrid jets of maximum erosive efficiency, potentially useful for effective pulverization.
Źródło:
Mining Science; 2015, 22; 147-159
2300-9586
2353-5423
Pojawia się w:
Mining Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza uszkodzeń pomp wysokiego ciśnienia układów zasilania common rail
Analysis of damages to high-pressure pumps in the common rail fuel system
Autorzy:
Kurczyński, Dariusz
Adrian, Augustyn
Powiązania:
https://bibliotekanauki.pl/articles/1366675.pdf
Data publikacji:
2015
Wydawca:
Instytut Naukowo-Wydawniczy TTS
Tematy:
pompa wysokiego ciśnienia
Common Rail
high pressure pump
Opis:
Tłokowe silniki spalinowe o zapłonie samoczynnym w ostatnich latach uległy intensywnemu rozwojowi. Rozwój ten był możliwy dzięki wprowadzeniu do stosowania zasobnikowych układów zasilania Common Rail. Układy te pozwalają spełnić rygorystyczne wymagania stawiane silnikom ZS. Ich prawidłowa praca w dużej mierze zależy od jakości paliwa. W artykule przedstawiono analizę uszkodzeń pomp wysokiego ciśnienia z układów zasilania Com-mon Rail różnych producentów i różnych konstrukcji. Przeprowadzona analiza wskazuje, że najczęściej występują-cą przyczyną uszkodzeń pomp wysokiego ciśnienia jest zużycie ścierne współpracujących elementów pojawiające się na skutek zanieczyszczeń mechanicznych zawartych w paliwie lub niewystarczających właściwości smarnych paliwa.
Internal combustion, compression ignition, piston engines have been largely modified in recent years. The development of those engines was possible due to the introduction of the later generation fuel systems, espe-cially the Common Rail. The system allows meeting strict emissions legislation. The quality of fuel is critical to the correct operation of the system. The paper pre-sents the analysis of damages to high-pressure pumps in the Common Rail systems with different design and produced by different manufacturers. The analysis indi-cates that the most frequently, damages to common rail high-pressure pumps originate from abrasive wear of mating components, which results from mechanical impurities in the fuel or poor lubricating properties of the fuel.
Źródło:
TTS Technika Transportu Szynowego; 2015, 12; 1986-1991
1232-3829
2543-5728
Pojawia się w:
TTS Technika Transportu Szynowego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructure and Mechanical Properties of Al-3 Vol% CNT Nanocomposites Processed by High-Pressure Torsion
Autorzy:
Asgharzadeh, H.
Kim, H. S.
Powiązania:
https://bibliotekanauki.pl/articles/354004.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high-pressure torsion
aluminum
CNT
microstructure
mechanical properties
Opis:
Al-3 vol% CNT nanocomposites were processed by high-pressure torsion (HPT) at room temperature under the pressure in the range of 2.5-10 GPa for up to 10 turns. Optical microscopy, scanning electron microscopy, and transmission electron microscopy (TEM) were used to investigate the microstructural evolutions upon HPT. Mechanical properties of the HPT-processed disks were studied using tensile tests and microhardness measurements. The results show gradual evolutions in the density, microstructure, and hardness with increasing the number of turns and applied presure. Nanostructured and elongated Al grains with an average grain thickness of ~40 nm perpendicular to the compression axis of HPT and an aspect ratio of ~3 are formed after 10 turns under 6 GPa. Evaluating the mechanical properties of the 10-turn processed Al/CNT nanocomposites indicates a tensile strength of 321 MPa and a hardness of 122 Hv. The tensile fracture surface of the Al/CNT nanocomposite mostly demonstrates a smooth fracture manner with fine dimples resulting in a low tensile ductility of ~1.5%.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2B; 1109-1112
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative study on the effect of using conventional and high pressure grinding rolls crushing on the ball mill grinding kinetics of an iron ore
Autorzy:
Barani, K.
Balochi, H.
Powiązania:
https://bibliotekanauki.pl/articles/109893.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
high pressure grinding rolls
HPGR
grinding
iron ore
Opis:
The effect of using conventional and high pressure grinding rolls (HPGR) crushing on the ball mill grinding of an iron ore was assessed to determine how these different comminution processes affect the ball mill grinding kinetic. For this purpose, the sample was obtained from the Jalalabad Iron Ore Mine and crushed by conventional crusher and HPGR. Then, the crushing products were ground in a laboratory ball mill. Five single-sized fractions of (–4+3.15 mm), (–2+1.7 mm), (–1+0.850 mm), (–0.500+0.420 mm), and (–0.212+0.180 mm) were selected as the ball mill feed. The specific rates of breakage (Si) and cumulative breakage distribution function (Bi,j) values were determined for those size fractions. It was found that for all fraction the Bi,1 values of the HPGR product were higher than those for the crusher product. It means that the particles produced by the dry ball milling of the HPGR product were finer than by the crusher. Also, the results showed that the specific breakage rate of the material crushed by HPGR at coarse fractions (–4+3.15 mm, -2+1.7 mm, and -1+0.850 mm) was higher than the material crushed by conventional crushers. However, at fine fractions (–0.500+0.420 mm and -0.212+0.180 mm), there was a small difference and the specific breakage rates were the same. This issue can be explained by the fact, that for coarse fractions the particles had longer side surfaces and thus were more affected by the lateral pressure. The results of verification test showed that after 60 seconds of grinding the 80% passing size of the HPGR and crusher products (D80) were reduced from 3311 μm to 760 μm and 1267 μm, respectively.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 920-931
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of dynamic characteristics of an experimental bench of high-pressure water fracturing assisted cutting
Autorzy:
Liu, Zhiming
Zhang, Qiang
Sun, Yuliang
Liu, Junming
Powiązania:
https://bibliotekanauki.pl/articles/2200892.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
high-pressure water fracturing
experimental bench
dynamic characteristics
Opis:
Aiming at the problem that the cutting efficiency of a drum shearer is low when mining hard coal seams, an experimental bench of high-pressure water fracturing assisted cutting is designed. Compared with normal ones, the maximum equivalent stress of the improved experimental bench is reduced by 55.38%, and the maximum total deformation is reduced by 27.23%. According to the results of dynamic response analysis, it is concluded that the experimental bench of high-pressure water fracturing assisted cutting is stable and reliable under extreme working conditions, and meets design requirements for strength and stiffness.
Źródło:
Journal of Theoretical and Applied Mechanics; 2023, 61, 2; 317--330
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Penogenerator vysokokratnykh pen dlja ochistki gazoprovodov pod davleniem
Spumegenerator highmultiple spumes for peelings gas pipeline under pressure
Autorzy:
Red'ko, A.
Kapcov, I.
Powiązania:
https://bibliotekanauki.pl/articles/78084.pdf
Data publikacji:
2014
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
spumegenerator
high-multiple sud
closed system
high pressure
cleaning
pipeline
Źródło:
Motrol. Motoryzacja i Energetyka Rolnictwa; 2014, 16, 6
1730-8658
Pojawia się w:
Motrol. Motoryzacja i Energetyka Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of pumping units equipped with oscillating hydraulic pressure intensifiers for displacement of cylinders with heavy loads over the entire stroke
Autorzy:
Popescu, Teodor-Costinel
Chiriță, Alexandru Polifron
Popescu, Ana-Maria Carla
Popescu, Alina-Iolanda
Powiązania:
https://bibliotekanauki.pl/articles/27324338.pdf
Data publikacji:
2022
Wydawca:
Instytut Techniki Górniczej KOMAG
Tematy:
low-pressure pumping unit
oscillating hydraulic pressure intensifier
high pressure
hydraulic cylinder
Opis:
Working and moving in confined, limited and narrow spaces, specific to underground mining activities, also requires the use of hydraulically operated equipment, capable of developing large forces, with small dimensions. An example of such equipment includes pumping units comprising low-pressure electric pumps and oscillating hydraulic pressure intensifiers. They use low pressure in the primary side of the intensifier and generate high pressure in the secondary side of the intensifier. Such pumping units are usually used to achieve and maintain high pressure, either in the volumes of closed spaces (in strength tests on pipes and tanks) or at the end of the active stroke of hydraulic cylinders (in hydraulic presses). On an experimental laboratory bench, which comprises a test cylinder, powered by a pumping unit, equipped with an oscillating hydraulic pressure intensifier, and a load cylinder, powered by another pumping unit, with the possibility of load control, the authors show that: the application range of these pumping units can be extended in the third direction, too, useful for underground mining activities, namely for drive of hydraulic cylinders with low gauge / displacement speeds and constant high load (high working pressure) over the entire working stroke length; the uniformity of displacement of these cylinders, with load throughout the stroke length, which are powered and driven with such pumping units, is slightly affected by the pulsating mode of operation of the hydraulic pressure intensifier. A set of experimental measurement results is presented for a constant value of the load over the entire displacement stroke of the test cylinder.
Źródło:
Mining Machines; 2022, 40, 4; 238--248
2719-3306
Pojawia się w:
Mining Machines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of High Pressure-High Temperature Method on the Selected Mechanical Properties of Steel AISI 316L with 2% TiB2
Autorzy:
Kurtyka, P.
Sulima, I.
Hyjek, P.
Jaworska, L.
Powiązania:
https://bibliotekanauki.pl/articles/356857.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high pressure-high temperature
physical properties
mechanical properties
steel matrix composites
titanium diboride
Opis:
AISI 316L/TiB2/2p composites were manufactured by HP-HT using different pressures (5 and 7 GPa) and temperatures (900-1300°C), with constant reinforcing particle content 2 vol%. The mechanical properties of the composites were evaluated on the basis of hardness (HV0.3) and compression tests (20°C, 10-5 s-1). The results showed that the role of sintering pressure increased with increasing process temperature. At temperatures of 900°C and pressures of 5 and 7 GPa the difference in measured values of compressive strength was 1-2%, while at 1300°C they reached 20%. At constant pressure of 5 GPa, a change in hardness and compressive strength of 40% were obtained with a temperature change of 900 to 1300°C. Changes in mechanical properties in the composite occurred without substantial changes in density, microstructure, reinforcement phase distribution, and phase composition in the matrix.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1585-1592
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Nonlinearity Parameter B/A, Internal Pressure, and Acoustic Impedance Determined at Pressures up to 100 MPa for 1-Ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide
Autorzy:
Zorębski, E.
Zorębski, M.
Dzida, M.
Powiązania:
https://bibliotekanauki.pl/articles/177585.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nonlinearity parameter
speed of sound
high pressure
ionic liquids
internal pressure
Opis:
The nonlinearity parameter B/A, internal pressure, and acoustic impedance are calculated for a room temperature ionic liquid, i.e. for 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl] imide for temperatures from (288.15 to 318.15) K and pressures up to 100 MPa. The B/A calculations are made by means of a thermodynamic method. The decrease of B/A values with the increasing pressure is observed. At the same time B/A is temperature independent in the range studied. The results are compared with corresponding data for organic molecular liquids. The isotherms of internal pressure cross at pressure in the vicinity of 70 MPa, i.e. in this range the internal pressure is temperature independent.
Źródło:
Archives of Acoustics; 2016, 41, 1; 59-66
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of length of high pressure pipes on injection process in common rail system of diesel engine
Autorzy:
Ustrzycki, A.
Kuszewski, H.
Woś, P.
Powiązania:
https://bibliotekanauki.pl/articles/247609.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
common rail
fuel injection
injection control
high-pressure pipe
Opis:
The storage supply systems of Common Rail type are characterized by high possibilities in shaping the rate of injection. The possibility to implement multi-injection at high pressure, easiness of adapting the system to the engine, relatively easiness of compensation the arrangement of injector parameters resulting from work tolerance, as well as easiness of making changes in the electronic engine controller enabling the production of engines with various performances, cause that type of these solutions currently are widely used injection systems in diesel engines. Injection system should be characterized above all by high precision fuel dosing into engine cylinders, the accuracy in starts controlling of individual phase of injection, repeatability and reliability and durability, as well as the up keep of these parameters for long time during operating duration. Fuel injection system works in difficult conditions resulting from high pressure, vibrations, electromagnetic interference affecting electronic executive systems and high temperatures. Especially the injector and injection pipes are open to high temperatures. The dimensions of used elements are also important. The article presents selected results concerning the effect of the length of high-pressure pipes on injection process parameters such as fuel amount, overflow in injector, and the fuel pressure course in injection pipe in front of electromagnetic injector socket. The study was conducted with test stand with electronic measurement system of fuel amount. The tests were made at different pressures in the rail and for different durations of the injector opening.
Źródło:
Journal of KONES; 2010, 17, 3; 477-482
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review of loss models for high pressure turbines
Autorzy:
Back da Trindade, D.
Bugała, P.
Simone, D.
Powiązania:
https://bibliotekanauki.pl/articles/244992.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
turbomachinery
gas turbines
high-pressure turbine
HPT
loss model
Opis:
This article presents a literature review about the physical analysis of the loss models, which are used in offdesign procedure for high-pressure turbines. A high-pressure turbine is designed to have maximum performance at design point. However, engines are operating in different conditions, and the comprehension of off-design conditions is very important. The loss mechanisms are very complex and predictions considering empirical methods are a good approach to have preliminary results. Based on these results, different researches have proposed theories about the loss mechanisms, and over the time, these models have been modified to describe better the phenomena involved between blades and flow. Once the physical mechanisms behind the loss models are known, it is possible to compare them and understand the reason why the results given for some methods present a higher agreement to experimental or numerical data. In this framework, 2D numerical simulations of the flow around the blades of an axial high pressure turbine with different off design conditions have been realized, by using ANSYS FLUENT® code, to show the losses described by some of these models. Using these simulations a loss model has been selected and implemented in Matlab® to compare its results with the experimental data found in literature.
Źródło:
Journal of KONES; 2018, 25, 2; 38-44
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of parameters of high-pressure die casting on occurrence of casting nonconformities in sleeves of silumin alloy EN AB 47100
Autorzy:
Pałyga, Ł.
Stachowicz, M.
Granat, K.
Powiązania:
https://bibliotekanauki.pl/articles/352331.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high-pressure die casting
casting nonconformities
structure
silumin
microhardness
Opis:
The paper presents a research on the effect of extreme - for the technology of the considered silumin EN AB 47100 - parameters of high-pressure die casting on occurrence of casting nonconformities. Considered was influence of the way of assembling the mould cooled-down to 140-160°C, non-standard for the selected casting, and pouring temperature in the range of 705 to 720°C (higher than the recommended) of non-refined alloy. The castings were prepared with use of a high-pressure casting machine made by Kirov with mould closing force of 2500 kN. Occurrence of nonconformities was evaluated on properly prepared specimens taken from the castings manufactured with various parameters of the injection piston and various multiplication pressures. The results were subjected to quantitative and qualitative analyses of casting nonconformities and distribution of major alloying elements. It was found that proper selection of working parameters of the casting machine, in spite of disadvantageous pouring conditions, makes it possible to reduce occurrence of some casting defects, like shrinkage cavities and porosity, to improve tightness of castings even when the alloy refining process is omitted.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 1; 373-378
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimisation of reliability and maintenance plan of the high-pressure fuel pump system on marine engine
Autorzy:
Knežević, Vlatko
Stazić, Ladislav
Orović, Josip
Pavin, Zoran
Powiązania:
https://bibliotekanauki.pl/articles/32898209.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
reliability
maintenance modification
high-pressure fuel pump
risk analysis
Opis:
This paper presents a method of adjusting and designing the maintenance scheme for the high-pressure fuel pumps of a slow-speed two-stroke marine engine, MAN 6S70MC-C. The maintenance database for the marine fuel system was obtained from the planned maintenance software, and covered a period of 11 years. During this period, 29 failures occurred that required corrective actions. Our methodology includes failure mode analysis, risk analysis, reliability calculation and maintenance interval adjustment. Each failure is described using a failure mode analysis, based on a combination of the mode and cause of failure. The objective of this study is to recommend a new preventive maintenance interval based on the exponential reliability results and the analysed maintenance data. The initial maintenance plan for each fuel pump was set to 8,000 running hours, whereas in the modified plan, it is recommended to set this to 4,000 hours. Our results show an increase in the system reliability from 60% to 95% when the new modified maintenance plan is applied. In addition, the results and the recommended initial maintenance schedule are validated based on three similar types of engine with the same fuel pump system. The new maintenance approach can reduce the risk of component failure, which will lead to increased reliability of the fuel pump system and the optimisation of maintenance costs.
Źródło:
Polish Maritime Research; 2022, 4; 97-104
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical Calculations for Elastic and Thermodynamic Properties of NbN₂ under High Pressure
Autorzy:
Hou, Bao-Sen
Liu, Ke
Mao, Xiao-Chun
Tan, Jiao
Zhou, Xiao-Lin
Powiązania:
https://bibliotekanauki.pl/articles/1032591.pdf
Data publikacji:
2017-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
high temperature and high pressure
elastic constants
anisotropy
Debye temperature
NbN₂
Opis:
The structural and elastic properties of NbN₂ at high pressures were investigated through the first-principles calculation. Results indicate that NbN₂ is a potential hard material. NbN₂ meets mechanical stability criteria and possesses ductility within the pressure of 100 GPa. The elastic anisotropy under high pressure was achieved by the elastic anisotropy factors, which reduce with increasing pressure. Using the quasi-harmonic Debye model, we also investigated the thermodynamic properties of NbN₂.
Źródło:
Acta Physica Polonica A; 2017, 132, 4; 1363-1370
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deviation angle models in off-design high-pressure turbines
Autorzy:
Bugała, P.
Powiązania:
https://bibliotekanauki.pl/articles/247825.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
turbomachinery
gas turbines
high-pressure turbine
HPT
deviation angle
Opis:
In the article, a set of deviation angle models, which are used to predict the off-design performance high-pressure turbines, has been presented, basing on a literature study. The deviation angle is a deviation between the actual flow angle and the blade inclination angle. It is an essential parameter in turbine performance evaluation. This angle shall be obtained accurately in 1-D design and evaluation, so as to ensure the validity of blade profiling and calculation results. If deviation angle is ignored, the turbine will produce a lower change of tangential velocity, and consequently a lower torque, output work and enthalpy drop than intended by the designer. For this reason, the deviation angle model needs to be established. There exist a number of different deviation models, resulting in varying degrees of flow deviation when applied. In the article, correlations for gas outlet angle, dependent on the Mach number at outlet and determined by the blade loading towards the trailing edge has been presented. The main difficulty in establishing the deviation model is a continuity in defining the angle for all speed ranges (both subcritical and supercritical). Each of the models presented in the article deals with this problem in a different way. A few deviation models, briefly discussed in the article, are based on experimental data and one is based on analytical approach.
Źródło:
Journal of KONES; 2018, 25, 2; 69-74
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Under Pressure DFT Investigations on Optical and Electronic Properties of PbZrO₃
Autorzy:
Nazir, G.
Tariq, Saad
Afaq, A.
Mahmood, Q.
Saad, S.
Mahmood, A.
Tariq, Samar
Powiązania:
https://bibliotekanauki.pl/articles/1030608.pdf
Data publikacji:
2018-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
density functional theory
optical properties
electronic structure
high pressure
Opis:
In this article, density functional theory has been used to investigate the structural and optoelectronic properties of PbZrO₃ (PZO) under pressure from 0 to 350 GPa. In order to achieve ground state structural stability, generalized gradient approximations has been utilized. By studying electronic properties, indirect band-gap nature of PZO appears to change at 15 GPa to direct band-gap. Optical analysis include under pressure responses of real and imaginary parts of dielectric function, optical conductivity, optical absorption coefficient, energy loss function, refractive index, reflectivity and extinction coefficient. Most of the results have been found to be consistent with literature. Study reveals that static dielectric constant and band-gap are in accordance with the Penn model which validates our computed results. Moreover, static dielectric constant and static refractive index directly increases with pressure. Material preserves its positive value of refractive index at all pressures and therefore, it is not a negative index metamaterial. Plasma frequency increases directly with pressure that destabilize the under study material. Our results could be very useful for developing novel optoelectronic devices based on PZO suitable to work under extreme conditions.
Źródło:
Acta Physica Polonica A; 2018, 133, 1; 105-113
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of the upper flammability limits for alkanes in air at increased pressures
Autorzy:
Wan, Xin
Wang, Min
Cao, Chunyan
Zhao, Shuang
Song, Zhiguo
Powiązania:
https://bibliotekanauki.pl/articles/2106480.pdf
Data publikacji:
2022
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Upper flammability limit
Adiabatic flame temperature
High pressure
Alkanes
Opis:
A method is proposed to predict the upper flammability limits for alkanes in air at increased pressures. The upper flammability limits for methane, ethane, propane and n-butane/air mixtures at ambient temperature and initial pressure of 0.3 MPa–2.0 MPa are identified through the adiabatic flame temperature calculation model. The association of calculated adiabatic flame temperature with pressure is presented to determine the upper flammability limit. Research shows the good agreement between the forecast upper flammability limits with pressure dependence and the experimental upper flammability limit values. The average relative error of the estimated upper flammability limits for alkanes in air at high pressures reaches 2.52%.
Źródło:
Polish Journal of Chemical Technology; 2022, 24, 2; 35--41
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Creation of bas-relief basing on photography using high-pressure abrasive-water jet
Autorzy:
Borkowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/1429429.pdf
Data publikacji:
2008
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
high-pressure abrasive-water jet
spatial superficial material forming
Opis:
Presented technology of spatial superficial material forming based on flat virtual image (picture) luminance is a new, original own application of high-pressure abrasive-water jet forming. Basis of spatial forming of ceramic and rock materials with high-pressure abrasive-water jet in conjunction with depth and jet velocity parameters are described in. It was built a control system and developed adequate algorithms allowing the 3D sculpturing operation of different complex objects to be mechanized.
Źródło:
Journal of Machine Engineering; 2008, 8, 2; 43-51
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Encapsulation of power electronics components for operation in harsh environments
Autorzy:
Stosur, M.
Sowa, K.
Piasecki, W.
Płatek, R.
Balcerek, P.
Powiązania:
https://bibliotekanauki.pl/articles/141365.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
passive components
encapsulation
epoxy
high pressure
measurements
harsh environments
Opis:
This paper reports on analyses and testing of sensitive power electronics components encapsulation concept, enabling operation in harsh, especially high pressure environments. The paper describes development of the concept of epoxy modules that can be used for protecting of the power electronics components against harsh environmental conditions. It covers modeling of the protective capsules using a simple analytical approach and Finite Element Method (FEM) models and validation of the developed models with the high pressure tests on samples fabricated. The analyses covered two types of the epoxy modules: of sphere- and elongated- shape, both with electrical penetrators that enable electrical connection of the encapsulated components with external power sources as well as other power modules and components. The tests were conducted in a pressure chamber, with a maximum applied pressure of 310 bars, for which online strain measurements have been conducted. The experimental results were compared with the simulation results obtained with analytical and FEM models, providing validation of the models employed. The experimental part of this work was conducted in collaboration with Polish Naval Academy in Gdynia.
Źródło:
Archives of Electrical Engineering; 2017, 66, 4; 855-866
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indications of HP events in the volcanosedimentary succession of the Orlica–Śnieżnik Dome, NE Bohemian Massif: data from a marble-amphibolite interface
Autorzy:
Twyrdy, M.
Żelaźniewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/2060385.pdf
Data publikacji:
2017
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
high-pressure episode
P-T path
marble-amphibolite association
Sudetes
Opis:
A volcanosedimentary succession of the Młynowiec-Stronie Group (MSG) in the Orlica–Śnieżnik Dome (OSD), the Sudetes, NE Bohemian Massif underwent multiple folding and shearing during the Variscan Orogeny. In the sheared domains, there are less deformed pods in which rocks preserve better records of metamorphic events prior to the regional temperature peak. In one such pod, near Gniewoszów on the western limb of the dome, marbles enclosed by massive amphibolites occur. In these rocks, zoned plagioclase with actinolite and epidote inclusions and zoned amphibole grains allowed recognition of three mineral assemblages and three P-T stages at: (1) 310°C/3–4 kbar, (2) 480–500°C/10.5 kbar, (3) 500–530°C/6–6.5 kbar, based on isopleth intersections and checked against conventional thermobarometry. These define a steep clockwise P-T path and a geothermal gradient of 17°C/km before peak conditions were attained, which suggests subduction of the metavolcano-sedimentary rocks (Stronie Formation of the MSG) on the western limb of the OSD, with a transient yet discrete higher pressure episode. Mineral relicts capable of demonstrating a higher pressure event are scarce in the supracrustal rocks of the dome, mainly because they became more thoroughly equilibrated and obliterated during the temperature peak at mid-amphibolite facies conditions and the subsequent ubiquitous greenschist facies overprint.
Źródło:
Geological Quarterly; 2017, 61, 2; 435--449
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of strains in a multilayer composite pipe
Autorzy:
Krysiak, P.
Kaleta, J.
Gąsior, P.
Błachut, A.
Rybczyński, R.
Powiązania:
https://bibliotekanauki.pl/articles/348523.pdf
Data publikacji:
2017
Wydawca:
Akademia Wojsk Lądowych imienia generała Tadeusza Kościuszki
Tematy:
filament wound composites
high-pressure pipe
deformation measurement
FEM analysis
Opis:
The paper presents the measurements and the analysis of deformations between layers and the outside surface of a multilayer filament wound composite pipe. The pipe was made through the hoop wrap of roving stripes hence ring-shaped samples were prepared for test purposes. Carbon fibers and glass fibers were used for winding. In the course of their manufacturing, strain gauges and fiber optic sensors were placed between the composite layers. Then, the strength tests were performed. The samples were subjected to the internal pressure of 30 MPa. During the tests peripheral deformations were measured on outside surfaces of individual layers of the structure.
Źródło:
Zeszyty Naukowe / Wyższa Szkoła Oficerska Wojsk Lądowych im. gen. T. Kościuszki; 2017, 4; 272-282
1731-8157
Pojawia się w:
Zeszyty Naukowe / Wyższa Szkoła Oficerska Wojsk Lądowych im. gen. T. Kościuszki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of dense-phase pneumatic conveying in vertical pipe for gasifier
Autorzy:
Gao, Yuzhen
Chan, Choon Kit
Powiązania:
https://bibliotekanauki.pl/articles/27315652.pdf
Data publikacji:
2023
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Pneumatic conveying
Flow characteristics
Dense phase
High pressure
Process innovation
Opis:
The stable transportation of pulverized coal in the vertical pipe is significant for the operation of the gasifier. There are few studies on the flow characteristics and flow pattern transition of particles in vertical pipes with small diameters. This paper has modeled and analyzed the flow characteristic of powder in dense-phase pneumatic conveying through 25 mm vertical pipe using CFD. Firstly, the grid independence is verified to determine the optimal mesh size. Then, the influences of different solid loading ratios (SLRs) and conveying velocities on particle flow characteristics, flow stability, and flow pattern transition are investigated. The results show that the flow pattern in the vertical pipe changes from annular flow to uniform flow at high SLR and low conveying velocity. Moreover, the evolution regulation of resistance characteristics under different conveying velocities is further revealed. Considering the conveying stability and economic benefit, the most suitable conveying velocity is 6 m/s
Źródło:
Polish Journal of Chemical Technology; 2023, 25, 3; 14--22
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High pressure processing for food safety
Autorzy:
Fonberg-Broczek, Monika
Windyga, B
Szczawiński, J
Szczawińska, M
Pietrzak, D
Prestamo, G
Powiązania:
https://bibliotekanauki.pl/articles/1041383.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Aeromonas hydrophila
Enterococcus hirae
Listeria monocytogenes
food safety
high pressure processing
Opis:
Food preservation using high pressure is a promising technique in food industry as it offers numerous opportunities for developing new foods with extended shelf-life, high nutritional value and excellent organoleptic characteristics. High pressure is an alternative to thermal processing. The resistance of microorganisms to pressure varies considerably depending on the pressure range applied, temperature and treatment duration, and type of microorganism. Generally, Gram-positive bacteria are more resistant to pressure than Gram-negative bacteria, moulds and yeasts; the most resistant are bacterial spores. The nature of the food is also important, as it may contain substances which protect the microorganism from high pressure. This article presents results of our studies involving the effect of high pressure on survival of some pathogenic bacteria - Listeria monocytogenes, Aeromonas hydrophila and Enterococcus hirae - in artificially contaminated cooked ham, ripening hard cheese and fruit juices. The results indicate that in samples of investigated foods the number of these microorganisms decreased proportionally to the pressure used and the duration of treatment, and the effect of these two factors was statistically significant (level of probability, P ≤ 0.001). Enterococcus hirae is much more resistant to high pressure treatment than L. monocytogenes and A. hydrophila. Mathematical methods were applied, for accurate prediction of the effects of high pressure on microorganisms. The usefulness of high pressure treatment for inactivation of microorganisms and shelf-life extention of meat products was also evaluated. The results obtained show that high pressure treatment extends the shelf-life of cooked pork ham and raw smoked pork loin up to 8 weeks, ensuring good micro-biological and sensory quality of the products.
Źródło:
Acta Biochimica Polonica; 2005, 52, 3; 721-724
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-pressure water jet technology application for abyssal well renovation
Zastosowanie wysokociśnieniowej strugi wody do czyszczenia studni głębinowych
Autorzy:
Borkowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/1819817.pdf
Data publikacji:
2009
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
czyszczenia studni głębinowych
wysokociśnieniowa struga
abyssal well renovation
high-pressure water
Opis:
In order to ensure long lasting and efficient delivery of water characterized with good quality, it is necessary to own high efficiency technical equipment but first of all abyssal well enabling to draw the water up. However usual exploitation of such wells leads to constant growing old, what depends on many constructional parameters, technical equipment as well as on hydraulic and hydro-chemical properties of near organic belt and underground water [7]. Taking above purposes into consideration, in order to choose adequate renovation strategy and conservation, the fact of well ageing process is unavoidable. This process causes parallel well efficiency decrease that in consequence might effects in well devastation and irreversible changes to the water intake [11]. Therefore, the main reason of all renovation processes is to restore well efficiency and stop aging processes. One of the most efficient renovation method of deep well is to introduce high-pressure water jet technique [2, 3]. Adequate water jets are selected each time for practical incrustation conditions of the filters and water-bearing layers silting-up. This paper presents own experiences in effective renovation of deep well filters utilizing high-pressure water jet.
W artykule zaprezentowano efektywną metodę hydrostrumieniowego czyszczenia zakolmatowanych rur i filtrów studni głębinowych po kilkudziesięciu latach ich eksploatacji. Metoda ta polega na wprowadzeniu do wnętrza regenerowanej studni specjalnie skonstruowanej wysokociśnieniowej głowicy roboczej, z której wypływa wysokociśnieniowa struga wody charakteryzująca się turbulentną wielofazową strukturą. Struga ta zapewnia wystarczająco wysoką energię, aby skutecznie rozbić zalegające wewnątrz osady a jednocześnie nie spowodować zniszczenia delikatnej konstrukcji filtrującej. Wytrącone w ten sposób osady, odsysane są następnie wraz z poprocesową wodą na zewnątrz rurociągu a całość operacji regeneracyjnej kończy etap płukania. Metoda ta zapewnia wysoką, przeszło 90% skuteczność odtwarzania pierwotnej wydajności studni i jest zarazem ekologicznie przyjazną gdyż czynnikiem roboczym jest strumień czystej wody.
Źródło:
Rocznik Ochrona Środowiska; 2009, Tom 11; 39-48
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza równań przepływu dla ustalenia odległości pomiędzy tłoczniami na trasie gazociągu wysokoprężnego
Analysis of equations of flow for set distances between pumping stations and the route of a high-pressure gas pipeline
Autorzy:
Duliński, W.
Ropa, C.E.
Powiązania:
https://bibliotekanauki.pl/articles/299527.pdf
Data publikacji:
2005
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
równania przepływu
gazociąg wysokoprężny
equations of flow
high-pressure gas pipeline
Opis:
Korzystając z równań określających spadek ciśnienia w gazociągach wysokoprężnych, w artykule przeprowadzono obliczenia dla wyznaczenia długości krytycznej i na jej podstawie ustalenia odległości między tłoczniami. Obliczenia przeprowadzono różnymi wzorami przy założeniu stosunku sprężania (epsilon) w granicach od 1,25 do 1,8. Stwierdzono, że najbardziej zbliżone wartości do danych uzyskanych z energetycznego równania Jacoba otrzymano za pomocą równań WNII-Gaz i Instytutu Technologii Gazu - USA. Na podstawie przytoczonego przykładu stwierdzono również, że zalecane odległości między tłoczniami, wynosząca L = 0,5 Lkr, mieści się w granicach podanego stosunku sprężania. W końcowej części rozpatrzono zagadnienie gazociągu wysokoprężnego jako magazynu dla wyrównania dobowych nierównomierności poboru gazu.
Employing equations for pressure drop in high-pressure gas pipelines, calculations were made for a critical length, and on this basis - the distance between the pumping stations. Calculations were conducted with the use of various formulae under the assumption tah the epsilon ratio of compressibility ranges between 1.25 and 1.8. Values produced by equations of WNII-Gas and Institute of Gas Technology, U.S.A. were closest to those obtained with the Jacob equation. The presented example also showed that the recommended distances between pumping stations L=0.5 Lkr, stays within the compressibility ratio. The authors also discussed the issue of a high-pressure gas pipeline as a gas storage for covering uneven gas demands.
Źródło:
Wiertnictwo, Nafta, Gaz; 2005, 22, 1; 117-126
1507-0042
Pojawia się w:
Wiertnictwo, Nafta, Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of cooling air mass flux variation on the convective heat transfer coefficient of HPT rotor disk
Autorzy:
Domański, R.
Jedliński, K.
Powiązania:
https://bibliotekanauki.pl/articles/243193.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
CFD
Fluent
High Pressure Turbine
Rotor Disk
convective heat transfer coefficient
Opis:
The paper is focused on the convective heat transfer phenomena on the High Pressure Turbine (HPT) rotor disk wall. The disk is a part of PW6000 turbojet engine (designed by Pratt & Whitney Company) and is a base of the 1st stage of HPT blades having very high temperature (combustion gases leaving combustion chamber have temperature around 1800 K). The analyzed disk is cooled by the air taken from one of the compressor's stages. The air gets to the gap between HPT disk and mini disk through discrete pump holes and then divides into two streams. One of them is used to decrease temperature of turbine blades and the second one is directed to the sequent turbine stages. Numerical analysis (made in Fluent) is based on the two dimensional aerodynamic model (in steady state) which is the cross section of the real geometry. There are three different sets of boundary conditions analyzed. Each of them has the same flow splits (40% of air is used to cool turbine blades and 60% gets to the next turbine stage) and all settings except cooling air mass flow on the inlet. Convective heat transfer coefficients are calculated using different method then proposed by Fluent (WFHTC and SHTC options give wrong results in this case). Coefficients are presented along disk wall and are compared with Fluent calculation methods.
Źródło:
Journal of KONES; 2007, 14, 2; 107-114
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High pressure impact on changes in potato starch granules
Autorzy:
Słomińska, L.
Zielonka, R.
Jarosławski, L.
Krupska, A.
Szlaferek, A.
Kowalski, W.
Tomaszewska-Gras, J.
Nowicki, M.
Powiązania:
https://bibliotekanauki.pl/articles/779573.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
potato starch
high pressure
shape and structure of starch
gelatinization-enthalpy
Opis:
Air dry potato starch (84.9% d.s.) was subjected to pressurizing under the pressure of 50, 100, 250, 500, 750, 1000 and 2000 MPa for 1 h. The physical properties of pressurized starch, such as morphology, surface and crystalline structure, gelatinization parameters, were studied by means of scanning and atomic force microscopy (SEM/AFM), X-ray diffraction (X-ray), differential scanning calorimetry (DSC). The susceptibility to the amylolytic enzyme (α-amylase) was also measured. Application of pressure in the range of 50–2000 MPa results in an increase in the compressed potato starch bulk density, change in the contours of the granules from oval to polyhedral, increase in the roughness of the granule surface, vanishing of the X-ray reflexes generated by the orthogonal structure and weakening of the reflexes generated by the hexagonal structure, lowering of the enthalpy of starch gelatinization, and the enhancement of hydrolytic susceptibility of starch granules to the amylolytic enzyme.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 4; 65-73
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of the high-pressure homogenization on some microorganisms and enzymes – a review®
Wpływ homogenizacji wysokociśnieniowej na wybrane mikroorganizmy i enzymy – przegląd publikacji®
Autorzy:
Kabziński, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/1535873.pdf
Data publikacji:
2020
Wydawca:
Wyższa Szkoła Menedżerska w Warszawie
Tematy:
high pressure homogenization
food
microorganisms
enzymes
homogenizacja wysokociśnieniowa
żywność
drobnoustroje
enzymy
Opis:
The article presents the effect of high-pressure homogeniza-tion (HPH) on the reduction of microbial growth and changes in the activity of enzymes in food. The publications on the impact of HPH on the bacteria of the Alicyclobacillus, Escheri-chia and Lactobacillus genies, yeasts of the Zygosaccharomy-ces genus, as well as changes in the activity of the enzymes: alpha-amylase, amyloglucosidase, pectin methylesterase, glucose oxidase and neutral protease were reviewed.
W artykule przedstawiono wpływ homogenizacji wysokociśnieniowej (HPH) na redukcję wzrostu drobnoustrojów oraz zmiany aktywności enzymów w żywności. Dokonano przeglądu publikacji dotyczących wpływu HPH na bakterie z rodzaju Alicyclobacillus, Escherichia oraz Lactobacillus, drożdży z rodzaju Zygosaccharomyces, a także zmiany aktywności enzymów: alfa-amylazy, amyloglukozydazy, metyloesterazy pektynowej, oksydazy glukozowej i neutralnej proteazy.
Źródło:
Postępy Techniki Przetwórstwa Spożywczego; 2020, 2; 195-202
0867-793X
2719-3691
Pojawia się w:
Postępy Techniki Przetwórstwa Spożywczego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model of HPGR-based comminution circuit performance
Model pracy układu rozdrabniania z prasą walcową
Autorzy:
Saramak, D.
Powiązania:
https://bibliotekanauki.pl/articles/318177.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
comminution
optimization
high-pressure grinding rolls
rozdrabnianie
optymalizacja
wysokociśnieniowe prasy walcowe
Opis:
Article concerns the issues of modeling and optimizational approach for ore comminution circuits performance. The circuit under the analysis is based on HPGR devices operating on a fine crushing stage. In order to determine the HPGR-based comminution circuit performance a suitable model was built. The target function in presented model considers the issue in terms of the flotation operation effectiveness.
Artykuł dotyczy zagadnień związanych z modelowaniem i optymalizacją pracy układów rozdrabniania rud. W analizo¬wanym układzie występuje wysokociśnieniowa prasa walcowa zainstalowana na drugim stopniu rozdrabniania. Aby określić efektywność pracy układu technologicznego przeróbki rud został zbudowany odpowiedni model matematyczny pracy układu rozdrabniania, w którym funkcja celu została powiązana z efektywnością procesów flotacyjnych.
Źródło:
Inżynieria Mineralna; 2013, R. 14, nr 2, 2; 149-152
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations of metal gaskets for high-pressure joints
Autorzy:
Trojnacki, A.
Krasiński, M.
Szybiński, B.
Powiązania:
https://bibliotekanauki.pl/articles/244507.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
high-pressure closures
metal gaskets
stress-strain analysis
leak tightness
FEM
Opis:
The article deals with the stress-strain analysis and investigations of operating properties of metal high-pressure gaskets. The simplified analytical approach is applied in the examinations of wave-ring gasket and lens-ring gasket. A cylindrical shell of constant mean thickness is introduced to simulate the gaskets. It is assumed that the shell is simply supported at the inner surfaces of the gasket seats. The influence of certain geometric, material and assembly parameters on the strength and leak-tightness of the closures is analytically investigated. Certain selected parameters of the closure are examined versus applied operating pressure for the assumed materials of the gasketed members and fixed several another data of the gaskets. The analysis is carried out in dimensionless variables in order to generalize the results. The region of admissible solutions for the gaskets parameters such as dimensions, applied assembly requirements and operating pressure is determined. The static tensile tests were carried out to determine the real mechanical properties of materials applied for the gaskets and the seats. The analytical solutions are verified by FEM calculations, which take into account the hardening of the material, friction at the surfaces and contact effects. Theoretical considerations are illustrated by numerical examples and compared with the experimental results obtained under assembly conditions with no operating pressure applied to the closures. Some conclusions may be recommended in design procedures of the high-pressure closures with metal gaskets.
Źródło:
Journal of KONES; 2016, 23, 1; 397-404
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza powiązań pomiędzy parametrami technologicznymi pras walcowych z wykorzystaniem analizy czynnikowej
Analysis of relationships between technological parameters of roller presses with using the factor analysis
Autorzy:
Saramak, D.
Powiązania:
https://bibliotekanauki.pl/articles/349464.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
wysokociśnieniowe prasy walcowe
analiza czynnikowa
high-pressure grinding rolls
factor analysis
Opis:
W artykule przedstawiono wybrane zagadnienia związane z analizą wielowymiarową i ich potencjalne zastosowanie do modelowania procesów rozdrabniania w prasach walcowych. Proces rozdrabniania w prasie charakteryzuje wiele parametrów technicznych, technologicznych oraz wskaźników, które są wzajemnie powiązane ze sobą. Przedstawione podejście polega na zbadaniu struktury w grupie analizowanych zmiennych oraz zaprezentowanie analizy interpretacyjnej polegającej na wyodrębnieniu czynników powiązanych z wybranymi zmiennymi wejściowymi (parametrami operacyjnymi urządzenia i procesu). W wyniku tego otrzymujemy model opisujący zjawisko, który ułatwia analizę i interpretację badanego procesu.
Chosen issues concern the multi dimensional analysis and their potential application for modeling of comminution processes in roller presses were presented in the article. The comminution process in HPGR can be described with using many technical and technological parameters and indices, which are mutually connected. The presented approach assumes the investigation over the structure of analyzed variables, and presents the interpretation consisted in marking off the factors related to the input variables (operating parameters of the comminution process). The model characterizing the issue, obtained as a result of research, makes easier the interpretation of the process under analysis.
Źródło:
Górnictwo i Geoinżynieria; 2010, 34, 4/1; 251-263
1732-6702
Pojawia się w:
Górnictwo i Geoinżynieria
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synergy of the Plastic Treatment HPT and Shot Peening in Aluminium Alloy Al-Mg-Mn-Sc-Zr
Autorzy:
Stegliński, M.
Byczkowska, P.
Sawicki, J.
Kaczmarek, Ł.
Januszewicz, B.
Klich, M.
Powiązania:
https://bibliotekanauki.pl/articles/355364.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high-pressure torsion
shot peening
numerical analysis
residual stresses
fatigue strength
Opis:
An improvement in fatigue strength is one of the main factors enabling the use of high-durability Al-Mg-Mn-Sc-Zr alloys in functional components of mobile robots. As part of this study, a computer simulation was carried out using ANSYS LS-DYNA software that involved the hybridization of high pressure torsion (HPT) and shot peening (SP) forming processes. The numerical analysis was aimed at determining residual stresses and strains that affect the durability and stress characteristics of the analyzed Al alloy. Results of the study indicate that tensile stresses of σ = 300 MPa generated as a result of HPT are transformed into a beneficial stress of σ = 25 MPa resulting from plastic strains caused by SP surface treatment.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2B; 1135-1142
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ ciśnienia na konwersję paliw gazowych w strukturalnych reaktorach katalitycznych
Effect of pressure on conversion of gaseous fuels in structured catalytic reactors
Autorzy:
Budzianowski, W. M.
Powiązania:
https://bibliotekanauki.pl/articles/2071028.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
wysokie ciśnienie
reaktor strukturalny
gradient stężenia
high pressure
structured reactor
concentration gradient
Opis:
Zbadano wpływ wysokiego ciśnienia na konwersję i gradienty stężeniowe w procesie spalania i oksyformowania węglowodorów w strukturalnym reaktorze katalitycznym. Zdefiniowano, scharakteryzowano i wykorzystano w przykładzie wyrażenia S przydatne w analizie oporów dyfuzyjnych występujących w reaktorach strukturalnych wysokociśnieniowych. Zaproponowano metodykę nastawiania ciśnienia w reaktorach strukturalnych.
The paper investigated the effect of high pressure on conversion and concentration gradients in combustion and oxyforming of hydrocarbons in structured catalytic reactors. The terms S were defined, characterized and used for the analysis of transport resistances exhibited in high-pressure structured reactors. The method for pressure elevation in structured reactors was proposed.
Źródło:
Inżynieria i Aparatura Chemiczna; 2010, 1; 21-22
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ modyfikacji rozmieszczenia źródeł światła na intensywność doświetlania roślin w szklarni
The impact of light sources layout modification on plant light exposure intensity in a greenhouse
Autorzy:
Kurpaska, S.
Powiązania:
https://bibliotekanauki.pl/articles/287154.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
wysokoprężna lampa sodowa
oświetlenie
szklarnia
high-pressure sodium discharge lamp
lighting
greenhouse
Opis:
W pracy przedstawiono zmianę w natężeniu oświetlenia powierzchni uprawowej szklarni przy zastosowaniu modyfikacji w rozmieszczeniu elementów systemu doświetlania roślin. Jako źródła światła uwzględniono powszechnie spotykane na rynku wysokoprężne lampy sodowe wraz z odbłyśnikiem kierunkującym rozsył światła. Analizę zmian w oświetleniu przeprowadzono w oparciu o zweryfikowaną metodykę umożliwiającą analizę natężenia źródła światła.
The paper presents the change in the illumination of greenhouse cultivated area resulting from modification in layout of plant light exposure system elements. Commonly available in the market high-pressure sodium discharge lamps with a reflector directing light distribution were taken into account as light sources. The analysis of changes in lighting was carried out on the basis of verified methodology allowing to analyse light source illumination intensity.
Źródło:
Inżynieria Rolnicza; 2008, R. 12, nr 10(108), 10(108); 145-152
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High pressures studies on hydrides of selected manganese alloys
Autorzy:
Sugiura, H.
Filipek, S.
Paul-Boncour, V.
Marchuk, I.
Liu, R.
Pyun, S.
Powiązania:
https://bibliotekanauki.pl/articles/146225.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
deuterides/hydrides
high pressure
ferromagnetic fcc-manganese
Laves phases
equation of state
Opis:
Specific behavior found in hydrides formed in manganese, Mn-Ni and YMn2 under high pressure is presented and discussed. The synthesis of ferromagnetic fcc-manganese was proved. Parameters of the equations of state (EOS) derived from measurements in the diamond anvil cell (DAC) are summarized for manganese hydrides and for hydrides derived from YMn2 Laves phase. It was found that the compression behavior of recently discovered YMn2H6 is different from YMn2-based hydrides with lower hydrogen content.
Źródło:
Nukleonika; 2006, 51,suppl.1; 73-77
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of stator-rotor interspace overlap of meridional contours on the efficiency of high-pressure steam turbine stages
Autorzy:
Rusanov, Andrii
Rusanov, Roman
Powiązania:
https://bibliotekanauki.pl/articles/1845496.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high-pressure steam turbine
cavern
overlap
impulse type stage
reactive type stage
Opis:
The results of a systematic study of the influence of meridional contours overlap in the stator-rotor axial interspace of the impulse and reactive type stages of a high-pressure steam turbine on the flow structure and gas-dynamic efficiency of the flow part are introduced. The studied flow parts of the impulse and reactive stages are typical for high-power high-pressure steam turbines. It is shown that the stages that have no overlaps and/or have a smooth shape of meridional contours have the best gasdynamic efficiency, and the most negative effect on the flow part is caused by the presence of caverns in the stator-rotor interspace. For cases where, due to technological limitations, it is impossible to avoid the presence of caverns and overlaps with a sharp (step-wise) change in the shape of the meridional contours, it is recommended to perform overlaps with positive size of overlap values near the rotor blades.
Źródło:
Archives of Thermodynamics; 2021, 42, 1; 97-114
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tłumienie wybuchu metanu z wykorzystaniem wysokociśnieniowej gaśnicy
Suppression of methane explosion with the use of the high-pressure extinguisher
Autorzy:
Szkudlarek, Z.
Klemens, R.
Gieras, M.
Powiązania:
https://bibliotekanauki.pl/articles/166777.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Górnictwa
Tematy:
wysokociśnieniowa gaśnica
tłumienie wybuchu metanu
high-pressure extinguisher
suppression of methane explosion
Opis:
W artykule przedstawiono wstępne badania laboratoryjne nad skutecznością tłumienia wybuchów metanu z wykorzystaniem wysokociśnieniowej gaśnicy. Jako materiału tłumiącego użyto proszku gaśniczego składającego się głównie z kwaśnego węglanu sodu (NaHCO3). Badania prowadzone były w komorach wybuchowych o pojemnościach 1,3 m3 i 10 m3, w których badano wpływ parametrów decydujących o procesie rozpylania i określano skuteczność tłumienia wybuchu metanu oraz na poligonie doświadczalnym, gdzie badano kształt i zasięg obłoku proszku gaśniczego wysokociśnieniowej gaśnicy. Przeprowadzone badania laboratoryjne pozwoliły na wyeliminowanie niedoskonałości w konstrukcji gaśnicy o objętości 10 dm3 oraz wykazały, że możliwe jest skuteczne tłumienie w początkowej fazie wybuchu metanu.
This paper presents the initial laboratory tests on efficiency of suppression of methane explosion with the use of the high- -pressure fire extinguisher. Extinguishing powder consisting mainly of sodium bicarbonate (NaHCO3) was used. The tests were carried out in explosion chambers of capacity 1.3 m3 and 10 m3, in which the parameters decisive in powder spraying were tested as well as efficiency of suppression of methane explosion was determined. In addition, the shape and range of powder cloud ejected from high-pressure extinguisher were tested in the experimental field. The tests enable w eliminate any imperfections in the design of fire extinguisher of capacity 10 dm3 and have proved that it is possible to extinguish successfully methane explosion at its early stage.
Źródło:
Przegląd Górniczy; 2014, 70, 4; 74-80
0033-216X
Pojawia się w:
Przegląd Górniczy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural and Electronic Properties of the BN, BP and BAs in the Different Phases of Zinc-Blende, NaCl and CsCl
Autorzy:
Bencherif, K.
Yakoubi, A.
Mebtouche, H.
Powiązania:
https://bibliotekanauki.pl/articles/1030312.pdf
Data publikacji:
2017-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
binary alloys
ab initio
lattice parameter
high pressure
band-structure
charge density
Opis:
In this work we used the first ab initio calculations to study the stability of the binary alloys BN, BP and BAs and their behavior in the different phases of zinc-blende, Nacl and CsCl. The full potential linearized augmented plane wave method was employed within density functional theory. Our results show the difference in the calculated structural properties and the band structure is obtained for the zinc-blende structure. We have investigated the lattice parameters and band gap energies. We also give the valence charge density at a high pressure and the analysis of the density of states.
Źródło:
Acta Physica Polonica A; 2017, 131, 2; 209-212
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of regular diving on the condition of the middle ear
Autorzy:
Stieler, Olgierd
Loba, Wawrzyniec
Gawęcki, Wojciech
Urbaniak-Olejnik, Marta
Majewska, Anna
Warchoł, Wojciech
Hojan-Jezierska, Dorota
Powiązania:
https://bibliotekanauki.pl/articles/2093855.pdf
Data publikacji:
2021-12-13
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
tympanometry
middle ear
high pressure
wideband tympanometry
scuba diving
acoustic impedance tests
Opis:
ObjectivesIt is generally held that exposure to both high-pressure and long-lasting contact with water makes diving a potentially hazardous sports activity as far as the ears are concerned. There is a number of research investigating the condition of the middle ear in a short period following diving; however, the knowledge regarding the long-term effects of regularly repeated diving remains limited.Material and methodsThe aim of this study is to evaluate the function of the middle ear after a diving season in a group of 31 adults diving regularly (1–17 years) by means of the following methods: 1) interview, 2) otoscopy, 3) pure tone audiometry, 4) classic tympanometry, and 5) wideband tympanometry.ResultsPeriodic problems with pressure equalization in the middle ear were observed in 12 individuals (38.7%). In all the analyzed cases, the authors found a normal condition of the external auditory canal and the tympanic membrane in otoscopy, normal hearing in pure tone audiometry, curve type A, and normal gradient in both classic and wideband tympanometry. Conclusions: Safe diving (according to safety precautions) does not have any long-term negative effects on the condition of the middle ear. However, these observations should be verified in a larger group of divers.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2021, 34, 6; 779-788
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of a High-Pressure Comminution Technology on Concentrate Yields in Copper Ore Flotation Processes
Wpływ technologii wysokociśnieniowego rozdrabniania na wychody koncentratów w procesach flotacji rud miedzi
Autorzy:
Saramak, D.
Młynarczykowska, A.
Krawczykowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/356153.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high-pressure grinding rolls
flotation
copper ore
rozdrabnianie wysokociśnieniowe
flotacja
rudy miedzi
Opis:
The article concerns the issues of flotation process effectiveness in relationship to the operating conditions of a high-pressure comminution process course. Experimental programme covering a flotation laboratory batch tests was a verification technique of a high-pressure crushing operations course. The most favorable values of flotation concentrate weight recoveries were obtained for the pressing force 6 kN and 4% of the feed moisture. It was also determined the model of the concentrate weight recovery as a function of pressing force in the press and feed moisture content. This model was the basis for the optimization of effects of copper ore flotation processes preceded in high-pressure crushing operation in roller presses.
W przedstawionym artykule przebadano efektywność procesu flotacji w zależności od warunków pracy technologii wysokociśnieniowego rozdrabniania w prasach walcowych. Zrealizowane testy flotacyjne stanowiły technikę weryfikacji przebiegu procesu rozdrabniania nadawy. Najwyższe wartości wychodów koncentratów flotacyjnych uzyskano przy sile nacisku w prasie wynoszącej 6 kN oraz wilgotności nadawy 4%. Wyznaczono model wychodu koncentratu flotacyjnego jako funkcję siły nacisku w prasie oraz wilgotności nadawy. Model ten był podstawą optymalizacji efektów procesu flotacyjnego poprzedzonego rozdrabnianiem rudy w wysokociśnieniowych prasach walcowych.
Źródło:
Archives of Metallurgy and Materials; 2014, 59, 3; 951-955
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the costs and cost-efficiency of regeneration of modern fuel injection systems in CI engines
Autorzy:
Osipowicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/410899.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
Common Rail system
injection pump
fuel injector
high pressure system
low pressure system
diesel engine
Opis:
This paper presents the analysis of costs and cost-efficiency of the repair of modern fuel injection systems in compression-ignition engines. The requirements for modern Diesel engines are low emission of toxic substances into the atmosphere and low fuel consumption. In order to meet the rigorous standards, the Common Rail fuel injection system has been implemented. By increasing fuel injection pressure to 200 MPa and introducing multi-stage dosing, engine designers have improved the process of air-fuel mixture combustion and engine ecological and economic parameters. The price for these changes is an accelerated wear of fuel injection equipment in modern CI engines. Regular fuel filter replacement and periodical cleaning of the systems would minimise the risk of damage. Unfortunately, most users do not comply with vehicle servicing times, and come to car repair shops only when a failure occurs, but then it is too late and the repair costs are high.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2016, 5, 2; 45-50
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
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