Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Arrhenius" wg kryterium: Temat


Tytuł:
Arrheniusan activation energy of separation for different parameters regulating the process
Autorzy:
Drzymała, J.
Powiązania:
https://bibliotekanauki.pl/articles/109713.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
activation energy
separation
Gibbs potential
Arrhenius plot
Opis:
The Arrhenius model, that relates the activation energy with the kinetic constant and process temperature, was applied for flotation as a separation process, and next was extended to other incentive parameters such as the frother concentration, NaCl content and hydrophobicity. It was shown that determination of the activation energy caused by other incentive parameters (i.e. particle size, surface potential) was also possible. The units of the activation energy depend on the type of the separation process and incentive parameter. For contact angle regulating flotation the activation energy unit is mJ/m2, while for the frother concentration is J. It is known that instead in joules, the activation energy can also be expressed in J/mol and in kT or RT units, where k is the Boltzmann constant, R gas constant and T is absolute temperature in kelvins. Even though different formulas of the specific Gibbs potential were used for calculation of activation energy caused by various incentive parameters, there was generally a good agreement between the extend of changes of the first order kinetic constants of the process and activation energy value. It was found that for flotation of copper-bearing carbonaceous shale the activation energy was equal to 1.1 kT for NaCl as the incentive parameter, 3.0 kT for temperature and 32.7 kT for butyl diethylglycol ether used as a flotation frother. For methylated quartz the hydrophobicity-induced activation energy was 42 mJ/m2 for contact angle as the incentive parameter.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 4; 1152-1158
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A procedure of Arrhenius activation energy determination for salt flotation of particles in the vicinity of one molar salt aqueous solutions
Autorzy:
Ratajczak, Tomasz
Kurkiewicz, Szymon
Drzymala, Jan
Powiązania:
https://bibliotekanauki.pl/articles/1450643.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
activation energy
salt flotation
Arrhenius equation
Gibbs potential
Opis:
A modified Arrhenius equation, in which thermal energy is replaced with chemical (Gibbs) potential, and a special calculation procedure were used to evaluate the flotation activation energy for salt solutions in the one molar range of concentrations. The proposed formula overcomes the difficulties of calculating the salt flotation activation energy caused by mathematical problems of finding 1/(ln($c$/$c_o$)) for the standard salt concentration $C_o$ =1 M (1 kmol/m3 and when the applied salt concentration c is in the vicinity of 1 M. The salt flotation activation energy was calculated for flotation of copper-bearing carbonaceous shale in the 0.25, 0.50, 1.00 and 2.00 M NaCl solutions performed in a laboratory machine as equal to 1.9 RT for standard salt solution equal to 1 M.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 6; 1-5
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of the thermal damage process of the tissue-blood vessel system and distribution of oxygen in the tissue
Autorzy:
Jasiński, Marek
Powiązania:
https://bibliotekanauki.pl/articles/2086966.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
bioheat transfer
oxygen transport
Arrhenius integral
laser-tissue interactions
Opis:
The paper presents a numerical analysis of the thermal damage process taking place in biological tissue containing a blood vessel during laser irradiation. The internal heat source resulting from laser irradiation based on the solution of the optical diffusion equation is taken into account. The investigation was concerned with the influence of tissue denaturation and oxygen content in blood on temperature distribution. The analysis of oxygen transport to the tissue is treated as a part of the analysis of thermal damage processes. At the stage of numerical computations, the boundary element method and the finite difference method were used.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 2; 199--212
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural and functional changes of bovine carbonic anhydrase as a consequence of temperature.
Autorzy:
Sarraf, N
Saboury, A
Ranjbar, B
Moosavi-Movahedi, A
Powiązania:
https://bibliotekanauki.pl/articles/1041543.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
activation energy
Arrhenius plot
circular dichroism
bovine carbonic anhydrase
Opis:
The temperature dependence of the activity and structure of the enzyme carbonic anhydrase was studied. The Arrhenius plot shows a jump which is seen usually in proteins with more than one subunit or with one subunit but more than one domain. Since carbonic anhydrase has only one subunit with one domain, the fine conformational changes of the protein motifs could only be detected through circular dichroism polarimetry. It seems that the jump in Arrhenius plot is a result of some slight structural changes in the secondary and tertiary structures of the enzyme.
Źródło:
Acta Biochimica Polonica; 2004, 51, 3; 665-671
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent advances in the study of the initiation of energetic materials rusing characteristics of their thermal decomposition. Part I, Cyclic nitramines
Autorzy:
Zeman, S.
Yan, Q.-L.
Vlček, M.
Powiązania:
https://bibliotekanauki.pl/articles/358411.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
arrhenius parameters
detonation velocity
explosives
initiation
manometric method
nitramines
Opis:
Arrhenius parameters, Ea and log A, of 17 cyclic nitramines, derived from the Russian vacuum manometric method (SMM) and compatible thermoanalytical methods, have been used in this study. The detonation velocity, D, at maximum theoretical crystal density, of the nitramines in this study was taken as a characteristic of their detonation. On the basis of known relationships between their Ea and D2 values (modified Evans-Polanyi-Semenov equation), the specific influence of some physicochemical properties on their thermal decomposition was shown. A new logarithmic relationship was found between the rate constant k, of the unimolecular thermal decomposition of the nitramines studied at 230 °C, and their D values. A fundamental characteristic of this new relationship rests on the equivalency of the primary fission processes in the low-temperature thermal decomposition and on the detonation initiation of the nitramines under study. Both these relationships confirm the problems encountered in the kinetic specification of the thermal decomposition of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12hexaazaisowurtzitane (HNIW, CL-20) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX). These problems, and also the possible influence of the pre-decomposition states on the thermal decomposition of the nitramines studied, are discussed.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 2; 173-189
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of tissue thermal injury formation process with application of direct sensitivity method
Autorzy:
Jasiński, M.
Powiązania:
https://bibliotekanauki.pl/articles/280597.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
bioheat transfer
Arrhenius scheme
boundary element method
sensitivity analysis
Opis:
In the paper, numerical analysis of thermal processes proceeding in a biological tissue is presented. The tissue is subjected to the external heat impulse and a 2D problem is taken into account. In order to determine the influence of variations of thermophysical parameters of the tissue on the value of tissue injury integral and the area of the lesion, a direct approach of sensitivity analysis is applied. The process of thermal injury formation is also analyzed. At the stage of numerical simulation, the boundary element method is used. In the final part of the paper, an example of numerical simulation is shown.
Źródło:
Journal of Theoretical and Applied Mechanics; 2014, 52, 4; 947-957
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of biological tissue damage process with application of interval arithmetic
Autorzy:
Korczak, Anna
Jasiński, Marek
Powiązania:
https://bibliotekanauki.pl/articles/279929.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
directed interval arithmetic
bioheat transfer
optical diffusion equation
Arrhenius scheme
Opis:
In the paper, the numerical analysis of thermal processes proceeding in a 2D soft biological tissue subjected to laser irradiation is presented. The transient heat transfer is described by the bioheat transfer equation in Pennes formulation. The internal heat source resulting from the laser-tissue interaction based on the solution of the diffusion equation is taken into account. Thermophysical and optical parameters of the tissue are assumed as directed intervals numbers. At the stage of numerical realization. the interval finite difference method has been applied. In the final part of the paper, the results obtained are shown.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 1; 249-261
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Accelerated aging studies of the selected commercial films
Badania przyspieszonego starzenia wybranych folii handlowych
Autorzy:
Cichecka, Magdalena
Pałys, Beata
Wilbik-Hałgas, Bożena
Struszczyk, Marcin H.
Powiązania:
https://bibliotekanauki.pl/articles/1790064.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
films
mechanical properties
accelerated aging
Arrhenius method
folie
właściwości mechaniczne
przyspieszone starzenie
metoda Arrheniusa
Opis:
The Arrhenius method was used to investigate the effect of accelerated aging conditions on the physical and mechanical properties of polymer films for technical, medical, food and office applications. Temperature and UV radiation were taken into account as environmental factors. It was shown that the tested films are more sensitive to thermal degradation than UV radiation. The reduction in tensile strength after thermal aging does not exceed 40%, and in the case of UV radiation, 14%. The estimated lifetime of the tested films is over 5 years.
Metodą Arrheniusa zbadano wpływ warunków przyspieszonego starzenia na właściwości fizyko-mechaniczne folii polimerowych do zastosowań technicznych, medycznych, spożywczych i biurowych. Jako czynniki środowiskowe uwzględniono temperaturę i promieniowanie UV. Wykazano, że badane folie są bardziej wrażliwe na degradację termiczną niż promieniowanie UV. Zmniejszenie wytrzymałości na rozciąganie po starzeniu termicznym nie przekracza 40%, a w przypadku promieniowania UV, 14%. Oszacowany czas życia badanych folii wynosi ponad 5 lat.
Źródło:
Polimery; 2021, 66, 6; 350--356
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of High Strain Rate Flow Behavior of 7175 Aluminum Alloy Based on Arrhenius-Type Constitutive Equations
Autorzy:
Shin, Young-Chul
Joung, Dae-Kwan
Ha, Seong-Ho
Choi, Ho-Joon
Hyun, Soong-Keun
Powiązania:
https://bibliotekanauki.pl/articles/356627.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
aluminum alloy
hot compression
Arrhenius-type equation
high strain rate flow behavior
flow stress
Opis:
The flow behavior of 7175 aluminum alloy was modeled with Arrhenius-type constitutive equations using flow stress curves during a hot compression test. Compression tests were conducted at three different temperatures (250°C, 350°C, and 450°C) and four different strain rates (0.005, 0.05, 0.5, and 5 s-1). A good consistency between measured and set values in the experimental parameters was shown at strain rates of 0.005, 0.05, and 0.5 s-1, while the measured data at 5 s-1 showed the temperature rise of the specimen, which was attributable to deformation heat generated by the high strain rate, and a fluctuation in the measured strain rates. To minimize errors in the fundamental data and to overcome the limitations of compression tests at high strain rates, constitutive equations were derived using flow curves at 0.005, 0.05, and 0.5 s-1 only. The results indicated that the flow stresses predicted according to the derived constitutive equations were in good agreement with the experimental results not only at strain rates of 0.005, 0.05, and 0.5 s-1 but also at 5 s-1. The prediction of the flow behavior at 5 s-1 was correctly carried out by inputting the constant strain rate and temperature into the constitutive equation.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 4; 1361-1364
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of thermal damage in laser irradiated tissue
Autorzy:
Jasiński, M.
Powiązania:
https://bibliotekanauki.pl/articles/122504.pdf
Data publikacji:
2015
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
bioheat transfer
Arrhenius scheme
tissue damage
laser irradiation
przepływ biociepła
schemat Arrheniusa
uszkodzenia tkanki
promieniowanie laserowe
Opis:
In the paper the numerical analysis of thermal processes proceeding in the 2D homogeneous biological tissue subjected to laser irradiation is presented. In particular, the influence of necrotic changes in tissue on the values of the perfusion coefficient and effective scattering coefficient are discussed. The transient heat transfer is described by the bioheat transfer equation in the Pennes formulation. As a model of light distribution in tissue, the first-order scattering approach has been used. At the stage of numerical realization the 1st scheme of the boundary element method has been applied.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2015, 14, 4; 67-78
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The diversity and plant species composition of the spontaneous vegetation on coal mine spoil heaps in relation to the area size
Autorzy:
Woźniak, Gabriela
Bakr, Jawdat
Dyczko, Artur
Jarosz, Jacek
Ryś, Karolina
Radosz, Łukasz
Kaul, Szymon
Adamik, Kamila
Besenyei, Lynn
Prostański, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/44265502.pdf
Data publikacji:
2023
Wydawca:
Instytut Techniki Górniczej KOMAG
Tematy:
species-area relationship
Arrhenius equation
spontaneous succession
biodiversity–ecosystem functioning
non-analogous species composition
novel ecosystems
Opis:
Any newly created area includes human-created habitats such as the mineral material of post-coal mining spoil heaps undergoing natural colonization and ecosystem development during the succession processes of vegetation colonization. The study of the factors that influence the succession dynamics, and the mechanisms behind this, have a long history (including the species-area relationship or Arrhenius equation). Nevertheless, the list of scientific questions is increasing. One of the significant issues in the study of these processes is the relationship between factors influencing the Biodiversity–Ecosystem Functioning (BEF) relationships. The main prerequisite is the relationships between the plant species' assemblage mechanisms including diversity and the variety of assembly rules concerning the environmental abiotic habitat processes and these properties are not straightforward. At the large scale, parameters such as age and area of the colonized sites are considered to be important. These relationships are more complicated in newly established post-mineral excavation habitats where novel ecosystems are developing. Regardless of the degree of disturbances, vegetation re-establishes in such environments, as a result of spontaneous succession, by the colonization and establishment of the best-adapted organisms. In the habitats of post-coal mining spoil heaps with pure oligotrophic mineral conditions, the non-analogous, newly formed composition of flora, fauna, and saprophytes has been stated in many previous field studies. This study aimed to explore the biodiversity versus area size relationships, in particular, it investigated the species composition and diversity found in the development of the spontaneous vegetation formed during primary succession on mineral substrate habitats of postcoal mining spoil heaps of different area sizes. We tested the hypothesis: species diversity of the vegetation patches on coal mine spoil heaps becomes more diverse on larger sites over time. These results indicate that the area size of the spoil heap significantly affects the diversity of the vegetation. Regardless of which of the characteristics of the vegetation type (dominant species) is compared, the vegetation on the heaps differs depending on its area size.
Źródło:
Mining Machines; 2023, 41, 1; 68-84
2719-3306
Pojawia się w:
Mining Machines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of multi-tine electrode configuration in realistic hepatic RF ablative heating
Autorzy:
Gas, Piotr
Wyszkowska, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/141022.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
percutaneous RF ablation
multi-tine electrode
tumor heating techniques
Arrhenius thermal damaged model
hepatocellular carcinoma
finite element method
Opis:
Percutaneous RF ablation is one of alternative treatment for non-surgical liver tumors. Ablative changes in hepatic tissue can be successfully estimated using the finite element method. The authors created a 3D model of a multi-tine applicator immersed in liver tissue, and then determined the optimal values of voltage applied to such an RF electrode, which do not exceed the therapeutic temperature range valid during thermal ablation procedure. Importantly, the simulations were carried out for the RF electric probes with 2 to 5 evenly spaced arms. Additionally, the thermal damage of hepatic tissue for multi-armed applicators working at pre-defined limit values of voltages was established based on the Arrhenius model.
Źródło:
Archives of Electrical Engineering; 2019, 68, 3; 521-533
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of thermal damage process in soft tissue subjected to laser irradiation
Autorzy:
Jasiński, M.
Powiązania:
https://bibliotekanauki.pl/articles/122854.pdf
Data publikacji:
2018
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
bioheat transfer
optical diffusion equation
Arrhenius scheme
Boundary element method
finite difference method
przepływ ciepła
metoda różnic skończonych
metoda elementów brzegowych
równanie dyfuzji
uszkodzenie termiczne
Opis:
The numerical analysis of thermal damage process proceeding in biological tissue during laser irradiation is presented. Heat transfer in the tissue is assumed to be transient and two-dimensional. The internal heat source resulting from the laser irradiation based on the solution of the diffusion equation is taken into account. The tissue is regarded as a homogeneous domain with perfusion coefficient and effective scattering coefficient treated as dependent on tissue injury. At the stage of numerical realization, the boundary element method and the finite difference method have been used. In the final part of the paper the results of computations are shown.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2018, 17, 2; 29-41
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of an adaptive accelerated model and a data transfer method based on a Reliability Enhancement Test
Badania adaptacyjnego modelu przyspieszonego oraz metody transferu danych w oparciu o test poprawy niezawodności
Autorzy:
Tao, J.
Yu, Z.
Ren, Z.
Yi, X.
Powiązania:
https://bibliotekanauki.pl/articles/301882.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
test poprawy niezawodności
model Arrheniusa
model Duane’a
adaptacyjny model przyspieszony
współczynnik przyspieszenia
reliability enhancement test
Arrhenius model
Duane model
adaptive accelerated model
acceleration factor
Opis:
Aby ocenić niezawodność produktu za pomocą testu poprawy niezawodności (Reliability Enhancement Test, RET), w badaniach najpierw rozważano proces zmiany parametrów modelu Arrheniusa poprzez połączenie modelu Arrheniusa z modelem Duane'a oraz przedstawiono adaptacyjny model przyspieszony i metodę oceny parametrów. Następnie, na podstawie adaptacyjnego modelu przyspieszonego opisano metodę transferu danych z RET do badań przy normalnym oddziaływaniu czynników zewnętrznych. Wreszcie, omówiono różnice obserwowane przy zastosowaniu RET do badań identyfikacyjnych niezawodności i badań wzrostu niezawodności. Na przykładzie zagadnienia inżynierskiego przedstawiono także metodę obliczania wskaźnika niezawodności produktu za pomocą RET.
To assess the reliability of a product using a Reliability Enhancement Test (RET), this study first considers the change process of the Arrhenius model parameters by combining the Arrhenius model with the Duane model and gives an adaptive accelerated model and a parameter estimation method. Then, the data transfer method from the RET to normal test stress are described based on the adaptive accelerated model. Finally, the differences observed when the RET is used for a reliability identity test or a reliability growth test are discussed, and an engineering case demonstrates a method for obtaining the reliability index of a product using the RET.
Źródło:
Eksploatacja i Niezawodność; 2014, 16, 1; 128-132
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimations of shelf life of catfish skin crackers in polypropylene plastic packaging using the ASLT (Accelerated Shelf Life Testing) method
Autorzy:
Umam, Ade Khoerul
Rostini, Iis
Subiyanto, Subiyanto
Intan, Rusky
Powiązania:
https://bibliotekanauki.pl/articles/1062799.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Accelerated Shelf Life Testing
Arrhenius
Pangasius humeralis
Pangasius hypophtalmus
Pangasius jambal
Pangasius lithostoma
Pangasius nasutus
Pangasius nieuwenhuisii
Pangasius pangasius
Pangasius polyuranodon
catfish skin crackers
polypropylene plastic packaging
shelf life
Opis:
This research aims to determine the shelf life of catfish skin crackers in polypropylene plastic packaging using the ASLT method. This test was conducted in the Fisheries Product Processing Laboratory of the Faculty of Fisheries and Marine Sciences, Padjadjaran University and testing the content of water content and TBA (Thiobarbituric Acid) of catfish skin crackers at the Food Technology Laboratory, Faculty of Food Science Technology, Padjadjaran University from September to November 2018. This study used an experimental method consisting of 3 storage temperature treatments at 25 ºC, 35 ºC and 45 ºC. Observations carried out include sensory (hedonic) test, water content test, and TBA (Thiobarbituric Acid) test. For the calculation, Arrhenius model was chosen with odor as a critical parameter to determine the shelf life which had the biggest R2 value with equation Arrhenius Ln K = 1079.8 (1/T) – 5.5161, with R2 value equal to 0.9212. The shelf life of catfish skin crackers that was saved at the room temperature (25 ºC) was 39 days or 1.3 month.
Źródło:
World Scientific News; 2019, 133; 248-262
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies