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Wyszukujesz frazę "thermal transformation" wg kryterium: Temat


Wyświetlanie 1-15 z 15
Tytuł:
Investigations of Temperatures of Phase Transformations of Low-Alloyed Reinforcing Steel Within the Heat Treatment Temperature Range
Autorzy:
Kargul, T.
Powiązania:
https://bibliotekanauki.pl/articles/351831.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermal analysis
DSC
solid phase transformation
hypoeutectoid steel
Opis:
The paper presents the results of DSC analysis of steel B500SP produced in the process of continuous casting, which is intended for the production reinforcement rods with high ductility. Studies were carried out in the temperature range below 1000°C in a protective atmosphere of helium during samples heating program. The main objective of the study was to determine the temperature range of austenite structure formation during heating. As a result of performed experiments: Ac1s, Ac1f – temperatures of the beginning and finish of the eutectoid transformation, Ac2 – Curie temperature of the ferrite magnetic transformation and the temperature Ac3 of transformation of proeutectoid ferrite into austenite were elaborated. Experimental determination of phase transformations temperatures of steel B500SP has great importance for production technology of reinforcement rods, because good mechanical properties of rods are formed by the special thermal treatment in Tempcore process.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 891-897
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermophysical properties of selected vermicular graphite cast iron alloy
Autorzy:
Homa, M.
Sobczak, N.
Turalska, P.
Bruzda, G.
Bacior, M.
Warmuzek, M.
Polkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/391848.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Odlewnictwa
Tematy:
vermicular cast iron
thermophysical properties
transformation temperatures
melting heat
thermal expansion
thermal expansion coefficient
thermal diffusivity
thermal conductivity
Opis:
The paper presents the results of thermophysical properties of selected vermicular graphite cast iron with nominal chemical composition of 3.70 C; 2.30 Si; 0.44 Mn; 0.054 P; 0.015 S; 0.017 Mg (wt. %). The comparative studies of the alloy were performed using differential scanning calorimetry, dilatometry and laser flash analysis. The calorimetric investigations proved that upon the heating to melting temperature (~1200°C), four endothermic transformations take place: 1) ferromagnetic → paramagnetic at 742°C, 2) pearlite → austenite at 824.2°C, 3) allotropic transformation of bcc ferrite to fcc austenite at 802°C, 4) melting at 1173.1°C. The character of the dilatometric curve shows small deviation at the temperature above 810°C corresponding to the pearlite → austenite transformation. The values of thermal diffusivity and thermal conductivity change throughout the entire examined temperature range. Both curves showed a changeover from negative to positive trends between 700 and 800°C. This effect might be associated with the pearlite → austenite transformation.
Źródło:
Prace Instytutu Odlewnictwa; 2017, 57, 4; 345-350
1899-2439
Pojawia się w:
Prace Instytutu Odlewnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extension of a phase transformation model for partial hardening in hot stamping
Autorzy:
Hart-Rawung, T.
Buhl, J.
Bambach, M.
Powiązania:
https://bibliotekanauki.pl/articles/99913.pdf
Data publikacji:
2018
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
coefficient of thermal expansion
phase transformation model
hot stamping
Opis:
The quality of predicted microstructural and mechanical properties in hot stamping simulations relies considerably on the material model. Many researchers studied the effect of the plastic deformation on the phase transformation of the most commonly used hot stamping steel 22MnB5, and proved that the deformation applied at high temperature promotes the formation of ferrite, pearlite and bainite. This behaviour has to be integrated into materials modelling. In this study, the effect of pre-strain on the phase transformation of the material is considered. The specimens are heated to austenitization temperature, isothermally deformed at 700°C, and quenched down to room temperature. The phase fractions and the temperature-dilatation behaviour obtained from the experiments are used to calibrate the material model. By using the experimental data obtained from dilatometer testing, the accuracy of the material model is evaluated. Additionally, an attempt to predict the results between the tested data points by using interpolation was made and compared with the simulation results.
Źródło:
Journal of Machine Engineering; 2018, 18, 3; 87-97
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Internal Heat Generation on the Thermal Stability of a Porous Fin
Autorzy:
Sobamowo, M. G.
Jayesimi, L. O.
Waheed, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/1031875.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Differential Transformation Method
Porous Fin
Temperature-Dependent Internal Heat Generation
Thermal analysis
Thermal performance
Opis:
In this study, the effects of internal heat generation on thermal stability of porous fin is theoretical investigated using differential transform method. The parametric studies reveal increase in the internal heat generation leads to increase in the value or the range of the thermal stability of the fin. The internal heat generation can be used to control the thermal instability in the fin. Also, as the porosity parameter increase, the rate of heat transfer from the base of the fin and consequently improve the efficiency of the fin increase. However, a high value or an excessive internal heat generation results in an undesirable situation where some of the heat energy cannot escape to the sink and instead ends up flowing into the prime surface and the fin tends to store heat rather than dissipating it. This scenario defeats the prime purpose of the cooling fin. Therefore, the operational parameters must be carefully selected to ensure that the fin retains its primary purpose of removing heat from the primary surface.
Źródło:
World Scientific News; 2020, 149; 110-127
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The transformation and migration of contaminants during the remediation process of heterogeneous strata by the in-situ thermal conductive heating (TCH) technology : A literature review
Autorzy:
Ji, Wei
Fu, Rong-Bing
Gao, Cai-Hong
Yao, Jia-Bin
Powiązania:
https://bibliotekanauki.pl/articles/27311577.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
migration
transformation
soil remediation
heterogeneous strata
in-situ thermal desorption
Opis:
There are currently large quantities of heterogeneous contaminated sites and the in-situ thermal conductive heating (TCH) technology have been widely used in soil remediation. Some engineering cases have shown that when soil remediation of heterogeneous sites use TCH technology, the gases carrying contaminants migrate laterally and contaminate clean areas. However, there are relatively few domestic studies on this phenomenon. Some international scholars have confirmed the occurrence of this phenomenon on the laboratory scale, but have not proposed an effective solution to the above scientific question. This study first introduced the heating mechanism and heating process of TCH. Meanwhile, the forms and transformation mechanism of organic contaminants were fully expounded during soil remediation by TCH. In addition, the formation, migration, accumulation, and lateral diffusion of gaseous contaminants were comprehensively reviewed during the in-situ thermal desorption of heterogeneous strata. Finally, arrangement methods of extraction pipes to effectively capture gas are provided for the heterogeneous contaminated soils remediated by TCH. The results of this study will provide theoretical and technical support for in-depth understanding of steam movement in heterogeneous formations and the remediation of heterogeneous contaminated sites by TCH technology.
Źródło:
Archives of Environmental Protection; 2023, 49, 1; 94--102
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Differential Transform Method for the Kinetic Analysis of Thermal Inactivation of Enzyme as Applied in Biotechnology
Autorzy:
Adeleye, O. A.
Sobamowo, M. G.
Akinnukawe, B. I.
Powiązania:
https://bibliotekanauki.pl/articles/1031487.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Analytical solution
Differential transformation method
Enzyme
Kinetic analysis
Thermal inactivation
Opis:
In this work, approximate analytical solution is developed using differential transformation method for finding the molar concentration of the native and denatured enzyme in terms of second-order rate constant. Also, the obtained solutions are used to study the kinetics of thermal inactivation of enzyme as applied in biotechnology. The analytical solution was validated with numerical solution using fourth- order Runge-Kutta. Good agreement was established between the numerical and approximated analytical solutions.
Źródło:
World Scientific News; 2020, 142; 135-149
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Cooling Curves of Nodular Cast Iron
Autorzy:
Bartošová, M.
Pribulová, A.
Eperješi, Š.
Futáš, P.
Powiązania:
https://bibliotekanauki.pl/articles/106981.pdf
Data publikacji:
2018
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
cooling curve
nodular cast iron
eutectic transformation
thermal analysis
metallurgical quality
Opis:
The solidification of cast iron is a complex process with characterized entrance and marginal conditions. Thermal analysis is one of the processes that allows us to observe the solidification of alloys. There is a possibility of gaining information about the melted cast iron quality and predicting the final properties of the cast by evaluating the scanned cooling curves by solidification (stable and metastable system). This article deals with the study and analysis of cooling curves taken from production conditions of a foundry during ductile cast iron production. The aim is to discover the reproduction and reliability of the thermal analysis results of cast iron. The study of the progress of the cooling curves and their first derivation to follow the reactions of the curves to changing factors in the production process.
Źródło:
Journal of Casting & Materials Engineering; 2018, 2, 1; 1-4
2543-9901
Pojawia się w:
Journal of Casting & Materials Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical investigation of heat transfer in a moving convective porous fin with temperature dependent thermal conductivity and internal heat generation
Autorzy:
Sobamowo, M. G.
Waheed, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/1031762.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Convective fin
Differential transformation method
Moving fin
Porous Fin
Thermal analysis
Opis:
In the present study, thermal performance of a rectangular moving porous fin with temperature dependent thermal conductivity and internal heat generation are analyzed the differential transformation method. The developed approximate analytical solutions are used to investigate the effects of thermal –geometric and thermo-physical fin parameters such as the Peclet number, thermal conductivity parameter, convection parameter, porosity parameter, Internal heat generation parameter on the dimensionless temperature distribution and heat transfer rate are discussed. From the results, it is found that increase in porosity and convective parameters, the rate of heat transfer from the fin increases and consequently improve the efficiency of the fin. Also, the values of the temperature distribution in the fin increases as the Peclet number increases. However, as thermal conductivity and the internal heat generation increase, the rate of heat transfer from the fin decreases. The analytical solution is found to be in good agreement with the direct numerical solution.
Źródło:
World Scientific News; 2020, 150; 1-21
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrocarbon generation modelling in the Permian and Triassic strata of the Polish Basin: implications for hydrocarbon potential assessment
Autorzy:
Botor, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/31342965.pdf
Data publikacji:
2023
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
hydrocarbon potential
kerogen transformation ratio
thermal maturity modelling
Polish Basin
Permian
Triassic
Opis:
Hydrocarbon generation in the Zechstein Main Dolomite and Upper Triassic potential source rocks of the Polish Basin was investigated by 1-D thermal maturity modelling in 90 boreholes across the basin. This identified major zones potentially worthy of further exploration efforts. The maximum burial depth of the Zechstein Main Dolomite and Upper Triassic reached >5 km during the Late Cretaceous leading to maximum thermal maturity of organic matter. Hydrocarbon generation development reveals considerable differences between particular zones of the Zechstein Main Dolomite and Upper Triassic. The kerogen transformation ratio (TR) in the Zechstein Main Dolomite reached values approaching 100% along the basin axis. The TR in the Upper Triassic source rocks is generally lower than in the Zechstein Main Dolomite due to lesser burial. The Upper Triassic source rocks have the highest TR values (>50%) along the basin axis, in the area between boreholes Piła IG 1 and Piotrków Trybunalski IG 1, with the most pronounced zone in the Krośniewice Trough (i.e., between the Krośniewice IG 1 and Budziszewice IG 1 boreholes), where the TR reached >90%. The Zechstein Main Dolomite and Upper Triassic entered the oil window in the Late Triassic to Early–Middle Jurassic, respectively. Hydrocarbon generation continued until the Late Cretaceous, and was completed during tectonic inversion of the basin.
Źródło:
Geological Quarterly; 2023, 67, 2; art. no. 20
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparative study of differential transformation and homotopy perturbation methods for transient combustion analysis for iron micro-particles in a gaseous oxidizing medium
Autorzy:
Yinusa, A. A.
Sobamowo, M. G.
Powiązania:
https://bibliotekanauki.pl/articles/1046539.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Differential transformation method
Homotopy perturbation method
Iron particle combustion
Temperature distribution
Thermal radiation
Opis:
In this paper, a comparative study of differential transformation and homotopy perturbation methods for transient combustion analysis of iron micro-particles in a gaseous oxidizing medium is presented. Also, parametric studies are carried out to properly understand the reaction of the process and the associated burning time. Thermal radiation effect from the external surface of burning particle and variation of iron particle density with temperature are considered. The solutions obtained by DTM and HPM are compared with those of the fourth order Runge-Kutta numerical method. Results show that DTM has more accurate results between the two approximate analytical methods considered. Also, results show that by increasing the heat realized parameter, combustion temperature increased and it faster reaches to its constant value. It is envisaged that the present study will create tremendous insight into means of properly managing combustible micro particles exiting factories and production process organization.
Źródło:
World Scientific News; 2019, 138, 2; 93-112
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal modernization of building resources in line with the transformation towards a climate-neutral economy in Polish conditions
Autorzy:
Lis, Anna
Powiązania:
https://bibliotekanauki.pl/articles/29521080.pdf
Data publikacji:
2023
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
zero emission building
zero energy building
decarbonization
energy transformation of buildings
thermal quality
thermal modernization
energy efficiency
EU policy assumptions
Opis:
The search for opportunities to save and use energy efficiently should primarily focus on sectors of the economy with the highest energy consumption. One such sector is construction. Buildings built in Poland in different periods according to the introduced and successively tightened thermal protection requirements have different energy characteristics, which differ from contemporary standards and future expectations in this respect. This article presents guidelines for the energy transformation of building resources towards climate neutrality and the condition of these resources in Poland to an extent relevant for estimating the energy savings potential as a result of their thermal modernization. The economic aspect relating to the implementation of the energy policy is also presented. Over the last twenty years, there has been a nearly 37% increase in final energy consumption and a close to 34% decrease in final energy intensity of gross domestic product (GDP) recorded in Poland, which proves that energy efficiency is growing virtually without increasing energy demand. Significant potential for rationalizing energy consumption is found, as well as the need to incur high costs relating to the construction sector transformation. The problem is the lack of databases on the technical condition, age, and energy performance of various groups of buildings, which means it is difficult to determine the thermal modernization needs and the achievable effects of energy savings for the entire building stock. Some inconveniences relating to the implementation of zero-emission guidelines are also pointed out due to the fact that the Polish energy system is largely based on fossil fuels.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2023, 76 (148); 5-16
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crystal-to-crystal investigations of highly thermally stable three-dimensional coordination polymer based on sodium(I) ions and 4,4’-stilbenedicarboxylic acid
Autorzy:
Groszek, Marcin
Łyszczek, Renata
Ostasz, Agnieszka
Vlasyuk, Dmytro
Powiązania:
https://bibliotekanauki.pl/articles/24085725.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coordination polymer
4,4’stilbenedicarboxylic acid
crystal structure
thermal analysis
crystal-to-crystal transformation
Opis:
The new three-dimensional coordination polymer termed {[Na2SDC(H2O)]} n (SDC2-= C16H10O42-) has been synthesized using workstation Easymax 102 while controlling the conditions and monitoring in-situ reagents. The metal complex was obtained in the reaction of sodium hydroxide with a suspension of 4,4’-stilbenedicarboxylic acid in aqueous medium. The compound was characterized by elemental analysis, single crystal, and powder X-ray diffraction methods, ATR-FTIR spectroscopy, SEM and optical microscopy, TG-DSC and TG-FTIR thermal analysis in air and nitrogen atmosphere. In the crystal structure of {[Na2SDC(H2O)]} n appears penta- and hexacoordinated sodium atoms joined by octa- and decadentate SDC2- linkers. Aqua ligand acts as bridge between Na1 and Na2 atoms. The as-synthesized sodium complex is thermally stable up to 86°C whereas its dehydrated form has extreme stability up to 491°C. Removal of water molecule leads to the crystal-to-crystal transformation yielded changes in coordination modes of COO groups. Reversibility of the hydration process in the studied complex was also examined.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 4; art. no. 172683
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Study of Phase Transformations of AlSi9Cu3 Alloy by DSC Method
Autorzy:
Piątkowski, J.
Przeliorz, R.
Gontarczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/380349.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al-Si cast alloy
differential scanning calorimetry
thermal analysis
phase transformation
enthalpy
stop odlewniczy Al-Si
skaningowa kalorymetria różnicowa
analiza termiczna
przemiana fazowa
entalpia
Opis:
With the use of differential scanning calorimetry (DSC), the characteristic temperatures and enthalpy of phase transformations were defined for commercial AlSi9Cu3 cast alloy (EN AC-46000) that is being used for example for pressurized castings for automotive industry. During the heating with the speed of 10ºC∙min-1 two endothermic effects has been observed. The first appears at the temperature between 495 ºC and 534 ºC, and the other between 555 ºC and 631 ºC. With these reactions the phase transformation enthalpy comes up as +6 J g-1 and +327 J g-1. During the cooling with the same speed, three endothermic reactions were observed at the temperatures between 584 ºC and 471 ºC. The total enthalpy of the transitions is – 348 J g-1. Complimentary to the calorimetric research, the structural tests (SEM and EDX) were conducted on light microscope Reichert and on scanning microscope Hitachi S-4200. As it comes out of that, there are dendrites in the structure of α(Al) solution, as well as the eutectic (β) silicon crystals, and two types of eutectic mixture: double eutectic α(Al)+β(Si) and compound eutectic α+Al2Cu+β.
Źródło:
Archives of Foundry Engineering; 2016, 16, 4; 109-112
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scientific principles of natural coals transformation in situ
Naukowe zasady przetwarzania węgla kamiennego in situ
Autorzy:
Vasyuchkov, Y. F.
Powiązania:
https://bibliotekanauki.pl/articles/300528.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
metody konwencjonalne
metody niekonwencjonalne
węgiel kamienny
paliwa gazowe
współczynnik wydajności cieplnej
mieszanina generatorowa
wzbogacona mieszanina gazowa
pozyskiwanie gazu z warstw węglowych
zasady naukowe
przetwarzanie węgla w paliwo gazowe
conventional technology
unconventional technology
hard natural coal
gas fuel
thermal coefficient of effectivinesss
generator mixture
enriched gas mixture
coalbed methane recovery
scientific principles
transformation of coal into gas fuel
Opis:
The conventional technologies of the coal seams mining have several shortages. The ones are in technical and economical and ecology and energy effectiveness of coal utilization aspects. Many of these shortages may be removed with unconventional technologies use. One of them is technology of coal seam transformation to a gas fuel. Main object of the technology use is coal thermal effectiveness increase for energy industry. The increase may be achieved to several times. Main principle the technology consists in thermal and electrical energy recovery in situ or in the coal suite from the gas fuel. Advantages of this technology use consist in social and environment saving effects. The report has established the fact being of the principles which have basis for the unconventional technology development. The report shows technical methods and processes for the technology promotion in commercial scale. The report views possibility to produce hydrogen during the technology realization.
Metody konwencjonalne produkcji węgla kamiennego mają pewne ograniczenia, np. techniczne, ekonomiczne, ekologiczne oraz związane z efektywnością wykorzystania węgla. Wiele z nich można rozwiązać stosując metody niekonwencjonalne. Jedną z nich jest przetworzenie złoża węgla w paliwo gazowe. Podstawowym celem tej metody jest wykorzystanie wzrostu współczynnika wydajności cieplnej w przemyśle energetycznym. Może to być nawet kilkakrotny wzrost. Metoda ta głównie polega na pozyskiwaniu energii cieplnej i elektrycznej in situ, bądź z paliwa gazowego z pokładów węgla. Zalety tego rozwiązania mają charakter społeczny i ekologiczny. Z raportu wynikają zasady, jakimi powinna się rządzić metoda niekonwencjonalna. Pokazano również metody i procesy technologiczne w zastosowaniu na skalę przemysłową. Przeanalizowano możliwość produkcji wodoru w czasie prowadzenia procesu technologicznego.
Źródło:
Wiertnictwo, Nafta, Gaz; 2010, 27, 1--2; 449-456
1507-0042
Pojawia się w:
Wiertnictwo, Nafta, Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-15 z 15

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