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Wyszukujesz frazę "Krzyżak, R." wg kryterium: Autor


Wyświetlanie 1-5 z 5
Tytuł:
The temperature and stress field of the ceramic-capped cylinder head of the hypothetical adiabatic diesel engine
Autorzy:
Jaskólski, J.
Krzyżak, R.
Powiązania:
https://bibliotekanauki.pl/articles/241933.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
cylinder head
PtAu alloy
thermal conductivity
thermal stress
Opis:
Four of five models of the ceramic-slab-capped cast-iron cylinder head for a prospective adiabatic engine were numerically investigated. The models were designed using several crystallochemical-mineralogical considerations. The outcome of some short radiation and convection Fortran95 programmes became the input data for the FEM programme of temperatures and stresses. It turns out, that in general the material that cannot withstand will hardly be ceramics, but the cast iron. Thence, the latter should be replaced, plated or the ceramics should cover it at the injection jet. The temperatures and stresses were analysed with and without an interlayer. Two models, with feldspars and Ti6Al4V or Pt30Au70, were quite promising, the first one being surely at once applicable even without interlayer i.e. according to FEM. The stresses in the models with YSZ, cerium disilicide and/or pyroxene, in spite of the crystallochemical hattrics deemed successful, betoken spallation of the YSZ. The problems of emissivity were addressed as well. There exists a blank range of temperature where neither radiation-related algorithm nor the common conductivity one can perform well. The surface of the head under hood appears 'quite cold', except the exhaust pipe, the TBC solution of which is left in abeyance in this paper. Adiabatic engines using ceramic as the material for the combustion camber walls were developed for the reduction of cooling loss and the in crease of exhaust energies.
Źródło:
Journal of KONES; 2008, 15, 4; 635-640
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The temperature - and stress fields of valves of IC engine
Autorzy:
Jaskólski, J.
Krzyżak, R.
Powiązania:
https://bibliotekanauki.pl/articles/243403.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
intake valve
output valve
YSZ
ferberite
scheelite
silicides
pyroxene
composite
joining of materials
thermal conductivity
radiative transfer
thermal expansion
Opis:
The paper concerns building up one exhaust valve of composite-steel and two intake ceramics-steel valves of a hypothetical adiabatic engine. The input temperatures were computed using three diverse FORTRAN95 programs, solving a shortened optical integral equation with radiative transfer, transient differential equation while starting and switching off the engine and a rod like diff. Equation with 'progonka' (Thomas) solution. The ANSYS11 programme was fed up with the output of the programs. It turns out that, generally, a mineralogical, crystal-chemical approach to the joining of materials results in stresses known from the common metal engines. Such problems as CTE enhancing (partly hypothetical) by means of doping the anionic compounds by cationic ones, swelling of structures, compressibility versus coefficient of thermal expansion (CTE) , compatibility of crystal motifs while joining, thermal shock resistance, switching the bonds, mechanical longevity, radiation protection etc were addressed. It turns out that true nature of the temperature and stress field, especially of the exhaust valve is closer to the FORTRAN temperature computation than, e.g. From the heat film coefficients (ANSYS11).
Źródło:
Journal of KONES; 2007, 14, 3; 245-252
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the properties of polymer composites with carbon nanotubes in the aspect of their abrasive wear
Autorzy:
Krzyżak, A.
Kosicka, E.
Szczepaniak, R.
Szymczak, T.
Powiązania:
https://bibliotekanauki.pl/articles/367013.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
polymer composites
tribology
reinforcement
carbon nanotubes
CNTs
wear
kompozyty polimerowe
trybologia
wzmocnienie
nanorurki węglowe
zużycie
Opis:
Purpose: Carbon nanotubes are used in composite materials due to the improvement of (including tribological) properties of composites, especially thermoplastic matrix composites. This demonstrates the potential of CNTs and the validity of research on determining the impact of this type of reinforcement on the composite materials under development. Design/methodology/approach: The article presents selected results of research on polymer composites made of C.E.S. R70 resin, C.E.S. H72 hardener with the addition of a physical friction modifier (CNTs) with a percentage by volume of 18.16% and 24.42%, respectively, which also acts as a reinforcement. The produced material was subjected to hardness measurements according to the Shore method and EDS analysis. The study of abrasive wear in reciprocating movement was carried out using the Taber Linear Abraser model 5750 tribotester and a precision weight. The surface topography of the composite material after tribological tests was determined using scanning electron microscopy (SEM). Some of the mentioned tests were carried out on samples made only of resin, used as the matrix of the tested polymer composite. Findings: Carbon nanotubes used in polymer matrix composites, including bisphenol A/F epoxy resin have an influence on the tribological properties of the material. The addition of carbon nanotubes contributed to a 24% increase in the Ra parameter relative to pure resin, to a level corresponding to rough grinding of steel. Research limitations/implications: The results of the tests indicate the need to continue research in order to optimize the composition of composites in terms of operating parameters of friction nodes in broadly understood aviation. Originality/value: The analysed literature did not find any studies on the impact of the addition of carbon nanotubes on epoxy resins based on bisphenol A/F. Due to the wide scope of application of such resins, the properties of such composite materials in which carbon nanotubes are the reinforcing phase have been investigated.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2019, 95, 1; 5-12
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of the addition of nanotubes upon the thermo-protective properties of the aramid-reinforced composite
Autorzy:
Przybylek, P.
Korbela, M.
Szczepaniak, R.
Komorek, A.
Krzyzak, A,
Babel, R.
Powiązania:
https://bibliotekanauki.pl/articles/243743.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ablative materials
composites
thermal resistance
ablation properties
Opis:
The aim of this article is to present findings concerning the thermo-protective research into ablative materials. The authors analysed the impact of the addition of carbon nanotubes upon the selected ablation properties, i.e. the ablation mass waste, average linear rate of ablation and the backside temperature of the specimens. The performed tests as well as the obtained findings allowed formulating a number of conclusions, which are useful in creating future composites. Composition of individual test samples; ablation testing; average relative ablation mass loss, depending on the volume share of carbon nanotubes; average ablation rate, depending on the volume share of carbon nanotubes; temperature of the rear surface of the insulating sample, depending on the volume share of carbon nanotubes; temperature inside the composite, depending on the volume share of carbon nanotubes; comparison of the temperature of ablation surface, temperature inside the composite and temperature on the rear surface of the wall of carbon nanotubes after the exposition to a heat flux are presented in the article.
Źródło:
Journal of KONES; 2018, 25, 2; 295-301
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Culture methods as indicators of the biological quality of phytostabilized heavy metal-contaminated soil
Autorzy:
Krzyżak, J.
Wasilkowski, D.
Płaza, G. A.
Mrozik, A.
Brigmon, R. L.
Pogrzeba, M.
Powiązania:
https://bibliotekanauki.pl/articles/363080.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
aided phytostabilization
EP indices
CD indices
contaminated soil
cadmium
lead
soil microbial populations
zanieczyszczenie gleby
ołów
kadm
fitostabilizacja
wskaźniki
drobnoustroje
gleba
Opis:
The short-term effect of aided phytostabilization of heavy metalcontaminated soil on microorganisms under outdoor field conditions was tested. Heavy metal contaminated soil from a mining site was amended with lignite, lime and two commercial fertilizers and vegetated with grass Festuca arundinacea. Results demonstrated that the amended phytostabilization approach of Pb-Cd contaminated soil gave a positive change on the native microbial populations evaluated by culturable techniques during the first 28 weeks of the experimental period. In the end of the experiment, the number of bacteria, actinomycetes and fungi increased in treated soil about 16-fold, 10-fold and 2-fold, respectively. Changes in the biodiversity of bacterial populations were evaluated by the Ecophysiological Index (EP) and the Colony Development Index (CD) for oligotrophs and copiotrophs. During the experimental period slower growing microorganisms (K-strategists) predominated. The application of amendments to the soil led to an increase of the CD index in both copiotroph and oligotroph populations after 28 weeks. EP, CD, bacteria, actinomycetes and fungi increased in the treated soil. Traditional microbiological methods based on culture techniques can be used to evaluate the biological quality of the phytostabilized heavy metal-contaminated soil.
Źródło:
Environmental Biotechnology; 2013, 9, 1; 6-13
1734-4964
Pojawia się w:
Environmental Biotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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