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1

45 Years of Deliberations on the Thermo-Mechanical Interpretation of Friction and Wear. Part I. The Macroscopic Interpretation of the Tribological Process

Sadowski Jan

Tribologia

|

2022

|

nr 2

55--66

EN

This first part will consider the friction couple or its part, identified with the open thermodynamic system. Dependences among extensive parameters and energetic interactions in the system and its boundaries with the environment are described in analytical terms. The dimensions of the energy dissipation zone, where the friction of solids takes place, are established. The thermo-mechanical nature of the tribological process is demonstrated. The wear conditions and distribution of energy generated by its particular elements are determined. A new quantity is introduced – the specific work of wear, which characterises the wear resistance of the tribological system and its parts. The effect of the reciprocal cover of solids’ friction surfaces on the energy balance structure in calorimetric testing is analysed. The concept of generalised wear is introduced and standardised. The discussion is restricted to processes at the macroscopic level of matter organisation.

PL

Przedmiotem rozważań w pierwszej części pracy jest para tarciowa lub jej fragment utożsamiona z systemem termodynamicznym otwartym. Opisano analitycznie zależności między parametrami ekstensywnymi i oddziaływaniami energetycznymi w systemie i na jego graniach z otoczeniem. Ustalono wymiary strefy dyssypacji energii, w której zachodzi tarcie ciał stałych. Wykazano cieplno-mechaniczną naturę procesu tribologicznego. Ustalono warunki zachodzenia zużywania i rozdziału energii rozproszonej przez poszczególne jego elementy. Wprowadzono nową wielkość – pracę właściwą zużycia, charakteryzującą odporność na zużywanie systemu tribologicznego i jego elementów. Zanalizowano wpływ wzajemnego przykrycia powierzchni tarcia ciał na strukturę bilansu energii w badaniach kalorymetrycznych. Wprowadzono pojęcie zużycia uogólnionego i jego standaryzację. Rozważania ograniczono do procesów zachodzących na makroskopowym poziomie hierarchicznym organizacji materii.

2

Physical Characteristics of Aceh Traditional Salt and Its Potential as Raw Material for Thermal Energy Storage

Gunawati, Humaidi Syahrul, Setiawan Adi, Sirait Makmur, Jalil Zulkarnain, Ramadhani Nadilla, Makruf Amar, Riskina Shafira, Irhamni

Journal of Ecological Engineering

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2022

|

Vol. 23, nr 2

116--122

EN

Thermal energy storage is an important element in order to conserve the energy and optimize the overall efficiency. Development of energy storage system for local purposes requires some information on the raw material which is abundantly available in the local market. This study aimed to investigate the characteristics of traditionally produced salt in Aceh in terms of its potential use as a raw material for thermal energy storage. The sample was collected from the Aceh Besar District and treated by heating at temperatures of 400 °C and 800 °C in a muffle furnace. This treatment is carried out to study the changes in properties and define the best procedure for salt preparation. All samples were characterized under a number of techniques including XRF, XRD, SEM/EDS, TGA/DSC analysis, density, thermal conductivity, and electrolytic conductivity. The XRF characterization showed that the local Aceh salt was graded as a category III salt. Furthermore, according to the TGA/DSC characterization, the melting temperature is close to 800 °C, and the enthalpy value is close to 492 kJ/kg. It is ample evidence that the Aceh salt can be used as a thermal energy storage material. Furthermore, increasing the temperature of local salt’s heat treatment contributes to increasing the enthalpy value, crystal size, density, thermal conductivity, and electrolyte conductivity.

3

Calculation of the molar heat of formation of fatty acid triglycerides from the heat of combustion of vegetable oils

Jęczmionek Łukasz

Science, Technology and Innovation

|

2020

|

Vol. 11, no. 4

8--15

EN

The results of the research on estimation the molar heat of formation (enthalpy) of model triglycerides found in natural oils and fats are presented. In this work a calculation method and calorimetric one were used. It was found that combustion heat values determined by separate methods are comparable; their difference was a maximum of 155 kJ/kg, and thus was significantly lower than the tolerance for the calorimetric method according to PN 86/C-04062.

4

Evaluating the uncertainty of the amount of thermal energy for metering systems with differential pressure flowmeters

Byts Oksana, Kurytnik Igor, Matiko Fedir, Lesovoy Leonid, Matiko Halyna

Napędy i Sterowanie

|

2020

|

R. 22, nr 4

57--63

EN

In commercial metering systems of thermal energy it is important to obtain not only the measured value of the amount of thermal energy, but also the characteristic of the uncertainty of this value. The paper presents the developed technique for evaluating the uncertainty of the measurement result of the amount of thermal energy for metering systems with differential pressure flowmeters used for metering the heat carrier flowrate. The technique uses the dependencies developed by the authors for calculating the relative standard uncertainty of the amount of thermal energy, enthalpy and flowrate of heat carrier. The equation for calculating the uncertainty of heat carrier enthalpy was developed by applying the dependencies of the technique IAPWS IF 97. The approaches proposed by the authors make it possible to develop dependencies for evaluating the uncertainty of the measurement result of the amount of thermal energy for systems of different configurations and systems with different types of flowmeters.

PL

Dla systemów komercyjnego rozliczania energii cieplnej ważne jest uzyskanie nie tylko zmierzonej ilości energii cieplnej, ale również charakterystyki niepewności tej ilości. W artykule opracowano technikę oceny niepewności wyniku pomiaru energii cieplnej dla systemów pomiarowych, w których do pomiaru przepływu nośnika ciepła stosowane są przepływomierze zwężkowe. Opracowana technika polega na wykorzystaniu opracowanych przez autorów zależności do obliczenia względnej standardowej niepewności ilości energii cieplnej, entalpii i przepływu nośnika ciepła. Zależność do obliczania niepewności entalpii nośnika ciepła opracowano przy użyciu zależności metody IAPWS IF 97. Podejścia zaproponowane przez autorów umożliwiają opracowanie zależności do szacowania niepewności zmierzonej wartości ilości energii cieplnej dla układów o różnej konfiguracji, a także układów wykorzystujących przepływomierze różnych typów.

5

Entalpia - wskaźnik jakości powietrza w pomieszczeniach o podwyższonej temperaturze i wilgotności

Piasecki Michał, Kostyrko Krystyna

Ciepłownictwo, Ogrzewnictwo, Wentylacja

|

2020

|

T. 54, nr 10

15--20

PL

Analizowano tezę badawczą, mówiącą że wpływ wilgotności powietrza na niezadowolenie użytkowników budynków w pomieszczeniach ciepłych i wilgotnych może być większy niż wynika to z modelu komfortu cieplnego Fangera. Autorzy zbadali eksperymentalnie wpływ wilgotności powietrza wewnątrz budynku w zakresie od 60% do 90% na percepcję panelistów w zakresie temperatury od 26 do 28°C. W prezentowanym eksperymencie zbadano postrzeganie jakości powietrza przez panelistów (n = 28) w komorze testowej w budynku o niemal zerowym zużyciu energii. Autorzy opracowali eksperymentalną zależność służącą do prognozowania satysfakcji użytkowników budynku, w której przewidywany odsetek niezadowolonych użytkowników PD jest określany jako funkcja entalpii powietrza h, PD = f(h). Dodatkowo przedstawiono wartości temperatury, w których predykcja komfortu cieplnego wg. modelu Fangera wskazuje niższe wyniki niezadowolenia użytkowników budynku niż wynika to z wartości uzyskanych eksperymentalnie.

EN

The research thesis that the influence of air humidity on the dissatisfaction of building users in warm and humid rooms may be greater than it results from the Fanger’s thermal comfort model has been analysed. The authors have examined experimentally the influence of indoor air humidity in the range of 60 to 90% on the perception of panellists in the temperature range from 26°C to 28°C. The presented experiment examined the panellists’ perception of air quality (n = 28) in a test chamber in a building with almost zero energy consumption. The authors developed an experimental dependence to predict the satisfaction of building users, in which the predicted percentage of dissatisfied PD users is defined as a function of air enthalpy h, PD = f(h). Additionally, temperature values were presented, in which prediction of thermal comfort according to Fanger’s model shows lower results of dissatisfaction of building users than it results from the values obtained experimentally.

6

Water-paraffin dispersion systems: manufacturing and application

Yovchenko Alla, Bespalko Sergii, Tryhub Oksana, Poliakov Sviatoslav, Baret Guy, Munoz Miranda Alberto

Acta Innovations

|

2020

|

no. 36

31--47

EN

The paper presents the study results of the stability and heat storage capacity of paraffin-in-water phase change suspensions (PCSs) obtained by the homogenization of paraffin and water in the developed rotary hydrodynamic homogenizer. The optimal concentration of components for obtaining stable paraffin-in-water suspensions is found. It is shown that the stable PCSs in the form of pastes, gels, and liquids can be obtained depending on the concentration of water, paraffin, and the surface active agent (SAA) as well as its type. In addition, the scheme of the solar heating system with the heat storage tank where the PCS functions both as the heat transfer fluid and the heat storage media is presented. It is shown that the use of PCS in the domestic solar heating system allowed the heat storage capacity of the storage tank to be increased by 25% as a result of the high fusion heat of paraffin and the high value of the water specific heat capacity. The estimation of the saving rate from applying fluid PCS as a heat storage medium is also presented and discussed.

7

Wykorzystanie wykresów entalpia - entropia do obliczeń inżynierskich w gazownictwie

Barczyński Andrzej, Barczyński Paweł

Gaz, Woda i Technika Sanitarna

|

2019

|

Nr 9

282--285

PL

W artykule omówiono możliwości zastosowania wykresów entalpia - entropia do obliczeń inżynierskich w branży gazowniczej. Jest on przeznaczony dla kadry technicznej zajmującej się projektowaniem, budową oraz eksploatacją obiektów gazowniczych (tłocznie, stacje redukcyjne, instalacje wykorzystujące energię potencjalną zawartą w sprężonym gazie). Dzięki tym wykresom można w sposób prosty wyznaczyć np. ilość ciepła jaką należy doprowadzić do strumienia gazu, aby go podgrzać (ciepło technologiczne) lub ochłodzić od temperatury t1, do t2, po jego sprężeniu, określić moc sprężarki zainstalowanej na tłoczni gazu, moc turbiny uzyskanej w wyniku rozprężenia gazu [8,9], parametry pracy reduktora takie jak: temperatura gazu za reduktorem, najniższa temperatura jaka może się pojawić w reduktorze itp.

8

Tunable dielectric and conductivity properties of two 4-n alkoxy benzoic acid

Patari S., Nath A.

Opto-Electronics Review

|

2018

|

Vol. 26, No. 1

35--43

EN

We have presented dielectric and conductivity studies of two liquid crystal (LC) compounds- p-octyloxybenzoic acid (8OBA) and p-decyloxybenzoic acid (10OBA). Dielectric permittivity study of those compounds gives the evidence of space charge polarization and ionic conductance in the samples. Dielectric permittivity is found to be the highest for 8OBA than 10OBA. Both compounds found to exhibit positive dielectric anisotropy. Splay elastic constant as a function of temperature has also been investigated. Frequency and temperature dependent electrical conductivity of these two LC compounds have been studied in detail. Activation energy has been estimated from both dc and ac conduction process.

9

Structural, optical, thermal and NLO behavior of zinc hydrogen maleate dihydrate single crystal

Karuna S., Balu A. R., Muthu S., Shyamala D., Delci Z., Ramkumaar G. R.

Materials Science Poland

|

2017

|

Vol. 35, No. 4

773--784

EN

Single crystal of zinc hydrogen maleate dihydrate (ZHMD) is grown by slow evaporation method at room temperature. The compound crystallizes in triclinic system with noncentrosymmetric space group P1. FT-IR and FT-Raman spectra of ZHMD are recorded. The versatile DFT is employed to understand the band structure of the crystal. Dipole moment of the molecule, ionization energy and electron affinity are established. The potential energy distribution PED of the vibrational modes is calculated using VEDA4. The results of the optimized molecular structure are compared with the single crystal XRD data. The Mulliken and NBO charges are calculated and interpreted. Optical properties of the grown crystal are analyzed using UV-Vis spectrum. Energy gap determined by Tauc plot is in a good agreement with the theoretical value calculated from HOMO-LUMO energies. Thermogravimetric analysis is done to assess the thermal behavior of the ZHMD crystal. Various thermodynamic parameters are calculated using the basis set B3LYP. The first order hyper polarizability values of ZHMD establish its NLO nature. The molecular electrostatic potential MEP of the molecule is obtained. Third-order nonlinear response is studied using Z-scan technique and the corresponding parameters such as absorption coefficient, refractive index and third-order susceptibility are determined.

10

Entalpia i entropia jako wielkości kryterialne stanów krytycznych podczas odkształceń plastycznych materiałów metalicznych

Śloderbach Z.

Energetyka

|

2017

|

nr 10

653--657

PL

W artykule przedstawiono szczególną postać potencjału termodynamicznego energii swobodnej (dla materiałów metalicznych) dla przypadku ciała termoplastycznego z izotropowym wzmocnieniem. Autor wykazał, że zmagazynowana energia deformacji plastycznej (z.e.d.p.) może pełnić użyteczną rolę w ocenie stanu materiału i stanu procesu plastycznego kształtowania metali oraz ich stopów. Część artykułu poświęcona jest strumieniowi entropii („produkcji” entropii) i jej wielkości. Stwierdzono, że czas życia każdego systemu energetycznego zdeterminowany jest przez przyrost entropii tego systemu. Entropia jest bowiem pewnym „zegarem” odmierzającym czas życia systemu (układu) energetycznego (technicznego). Jeżeli system energetyczny ma żyć długo, to produkcja entropii w tym systemie powinna być minimalizowana.

EN

In the article a special form of the thermodynamic potential of the free energy (for metallic materials) for the case of the thermoplastic body with the isotropic hardening was introduced. Author demonstrated, that energy stored of the plastic deformation (s.e.p.d), can perform the certain useful role, being used for an evaluation e.g. of state of material and state of the process of the plastic forming of metals and their alloys. Part of the work is devoted for stream of the entropy („production” of entropy) and her quantities. Author stated that the time of life of every power system was determined by the increase in the entropy of this system. Because the entropy is certain of „clock” measuring the time of life of the system. If power system (technical system) is supposed to have a long life, then a production of the entropy in this system should be minimized.

11

Necessary Thermodynamics Factors to Obtain Simple Solid Solutions in High-Entropy Alloys from the Al-Ti-Co-Ni-Fe System

Górecki K., Bała P., Kozieł T., Cios G.

Archives of Metallurgy and Materials

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2017

|

Vol. 62, iss. 4

2141--2145

EN

In this paper findings regarding the design and synthesis of High-Entropy Alloys based on mixing enthalpy, mixing entropy, δ parameter, Ω parameter and valence electron concentration are presented. Four alloys were synthesised with different predicted crystalline structures. Results of the microstructure and crystal structure studies are presented. It was shown that predicted structures as well as complex intermetallic phases exist in the material. The validity of valence electron concentration as well as additional parameters such as mixing enthalpy, mixing entropy and others necessary to obtain only the solid solution in High-Entropy Alloys were examined.

12

The Application of ATD and DSC Methods to Study of the EN AC-48000 Alloy Phase Transformations

Piątkowski J., Przeliorz R., Szymszal J.

Archives of Foundry Engineering

|

2017

|

Vol. 17, iss. 2

207--211

EN

Tests concerning EN AC 48000 (AlSi12CuNiMg) alloy phase transition covered (ATD) thermal analysis and (DSC) differential scanning calorimetry specifying characteristic temperatures and enthalpy of transformations. ATD thermal analysis shows that during cooling there exist: pre-eutectic crystallization effect of Al9Fe2Si phase, double eutectic and crystallization α(Al)+β(Si) and multi-component eutectic crystallization. During heating, DSC curve showed endothermic effect connected with melting of the eutectic α(Al)+β(Si) and phases: Al2Cu, Al3Ni, Mg2Si and Al9Fe2Si being its components. The enthalpy of this transformation constitutes approx. +392 J g-1. During freezing of the alloy, DSC curve showed two exothermal reactions. One is most likely connected with crystallization of Al9Fe2Si phase and the second one comes from freezing of the eutectic α(Al)+β(Si). The enthalpy of this transformation constitutes approx. –340 J g-1. Calorimetric test was accompanied by structural test (SEM) conducted with the use of optical microscope Reichert and scanning microscope Hitachi S-4200. There occurred solution's dendrites α(Al), eutectic silicon crystal (β) and two types of eutectic solution: double eutectic α(Al)+β(Si) and multi-component eutectic α+AlSiCuNiMg+β.

13

Właściwości gazów doskonałych i półdoskonałych

Litke B.

Problemy Nauk Stosowanych

|

2016

|

T. 4

95--106

PL

Wstęp i cele: W pracy przedstawiono pojęcie gazu doskonałego i półdoskonałego. Podano prawa Boyle’a-Mariotte’a, Gay Lussaca-Charlesa, Avogadra. Pokazano równania stanu gazu doskonałego. Omówiono ciepło właściwe, energię wewnętrzną i entalpię dla gazów doskonałych i półdoskonałych. Przedstawiono pojęcie mieszaniny gazów doskonałych i półdoskonałych. Podano prawo Daltona i Leduca. Opisano udział masowy kilogramowy, molowy i objętościowy oraz ciśnienie cząstkowe, stałą gazową mieszaniny gazów, gęstość i masę molową mieszaniny. Podano zależności między udziałem objętościowym a masowym. Materiał i metody: Materiał stanowią źródła z literatury z zakresu termodynamiki. W pracy zastosowano metodę analizy teoretycznej. Wyniki: Rezultatem analizy jest opracowanie i podanie wzorów opisujących równanie stanu gazu doskonałego, ciepło właściwe oraz energię wewnętrzną gazów doskonałych i półdoskonałych. W pracy również opracowano wzory dotyczące mieszanin gazów doskonałych i półdoskonałych. Wniosek: Pojęcie gazu doskonałego wprowadzono w celu uproszczenia analizy zachowań gazów i par rzeczywistych.

EN

Introduction and aim: The paper presents the concept of the perfect and semi-perfect gas. Have been given the rights of Boyle-Mariotte, Gay Lussac-Charles and Avogadro. The perfect gas law has been shown in the paper. Has been discussed the specific heat, internal energy and enthalpy for iperfect and semi-perfect gases. The paper presents the concept of a mixture of perfect and semi-perfect gases. The right of Dalton and Leduc have been presented in this paper. In the considerations has been described pound mass, molar and volume participation. Also has been shown a partial pressure, gas constant of the gas mixture, density and molar mass of the mixture. Has been given the relationship between volume and mass participation. Material and methods: Material covers some sources based on the literature in the field of thermodynamics. The method of theoretical analysis has been shown in the paper. Results: The result of the analysis is the elaboration and presenting some formulas which describe the equation of perfect gas, specific heat and internal energy of perfect and semi-perfect gases. In the study also gives some formulas for the perfect and semi-perfect gas mixtures. Conclusion: The concept of a perfect gas was introduced to simplify the analysis of the behavior of real gases and vapors.

14

Closed system of coupling effects in generalized thermo-elastoplasticity

Śloderbach Z.

International Journal of Applied Mechanics and Engineering

|

2016

|

Vol. 21, no. 2

461--483

EN

In this paper, the field equations of the generalized coupled thermoplasticity theory are derived using the postulates of classical thermodynamics of irreversible processses. Using the Legendre transformations two new thermodynamics potentials P and S depending upon internal thermodynamic forces Π are introduced. The most general form for all the thermodynamics potentials are assumed instead of the usually used additive form. Due to this assumption, it is possible to describe all the effects of thermomechanical couples and also the elastic-plastic coupling effects observed in such materials as rocks, soils, concretes and in some metalic materials. In this paper not only the usual postulate of existence of a dissipation qupotential (the Gyarmati postulate) is used to derive the velocity equation. The plastic flow constitutive equations have the character of non-associated flow laws even when the Gyarmati postulate is assumed. In general formulation, the plastic strain rate tensor is normal to the surface of the generalized function of plastic flow defined in the the space of internal thermodynamic forces Π but is not normal to the yield surface. However, in general formulation and after the use the Gyarmati postulate, the direction of the sum of the plastic strain rate tensor and the coupled elastic strain rate tensor is normal to the yield surface.

15

The Effect of Thermophysical Parameters on Temperature Distribution in the Primary Cooling Zone

Miłkowska-Piszczek K.

Archives of Metallurgy and Materials

|

2016

|

Vol. 61, iss. 4

2079--2082

EN

The values of thermophysical properties obtained from the experimental research, and those that were calculated with thermodynamic databases, are crucial parameters which were used in the numerical modelling of the steel solidification process. This paper presents the results of research on the impact of specific heat and enthalpy, along with the method of their implementation, on temperature distribution in the primary cooling zone in the continuous steel casting process. A cast slab – with dimensions of 1100 mm and 220 mm and a S235 steel grade – was analysed. A mould with a submerged entry nozzle (SEN), based on the actual dimensions of the slab continuous casting machine, was implemented. The research problem was solved with the finite element method using the ProCAST software package. Simulations were conducted using the “THERMAL + FLOW” module.

16

Measurement the Thermal Profile of Steelmaking Ladle with Subsequent Evaluation the Reasons of Lining Damage

Vlček J., Jančar D., Burda J., Klárová M., Velička M., Machovčák P.

Archives of Metallurgy and Materials

|

2016

|

Vol. 61, iss. 1

279--282

EN

Based on the operational measurement, of which content was to determine ladle thermal profile, there were analysed causes of possible damage of lining in steel ladles by steel breakout through the ladle shell. There exists connection between thermal state of ladle lining during the operation and its lifetime. There were reached to the conclusion that the cause of failure in the lining of ladle is except for high temperature of bath, also wide interval of temperature change during the tap operation, in consequence with possible insufficient pre-heating of ladle, discontinuous operation of aggregate and damage of insulating lining layer, respectively deformation of ladles shell.

17

The Study of Phase Transformations of AlSi9Cu3 Alloy by DSC Method

Piątkowski J., Przeliorz R., Gontarczyk A.

Archives of Foundry Engineering

|

2016

|

Vol. 16, iss. 4

109--112

EN

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.

18

Differential scanning calorimetry (DSC) in researching the mineral carbonation processes of cement materials, in terms of CO2 sequestration

Lempart M., Labus M.

Nafta-Gaz

|

2015

|

R. 71, nr 12

998--1004

EN

Mineral carbonation is one of the mitigation strategies considered for reducing atmospheric CO2 concentrations. The reuse of industrial solid wastes and residues (e.g. waste building material, including cement – which readily sequester CO2 at ambient temperatures and pressures) is often taken into consideration. The main barrier to the use of mineral carbonation is the rather slow reaction progress. Based on a literature review it has been hypothesized, that knowledge of the reaction energy of formation and disintegration of carbonate phases is needed, and differential scanning calorimetry (DSC) measurement method could be used to obtain thermodynamic data of the mineral carbonation process.

PL

Mineralna karbonatyzacja jest jedną z wielu rozważanych metod, zmierzających do ograniczenia stężenia CO2 w atmosferze. Odpowiednim do wykorzystania w tym procesie materiałem wydają się odpady przemysłowe (np. gruz budowlany, zawierający cement, który łatwo sekwestruje CO2 w warunkach atmosferycznych). Główną barierą w stosowaniu na szerszą skalę tego rodzaju sekwestracji jest powolny postęp reakcji. Analiza literaturowa wskazuje na istniejące braki dotyczące energii reakcji tworzenia i rozpadu faz węglanowych (szczególnie – entalpii ΔH) w zależności od warunków procesu. W artykule wskazano na możliwość zastosowania skaningowej kalorymetrii różnicowej (DSC) do wyznaczenia danych termodynamicznych procesu karbonatyzacji materiału cementowego.

19

Efektywność oddziaływania reduktora w mieszance egzotermicznej na właściwości stopu

Lipiński T.

Mechanik

|

2015

|

R. 88 nr 4CD

33--37

PL

W pracy przestawiono wyniki badań efektywności oddziaływania reduktorów wprowadzonych do mieszanki w celu wywołania efektu egzotermicznego. Reduktory i mieszankę dobrano tak, aby składniki powstałe w wyniku reakcji podnosiły podstawowe właściwości mechaniczne obrabianego stopu. Uwzględniano również efekty cieplne powstałe w wyniku przebiegu reakcji.

EN

The article discusses the results of the effectiveness of the impact of reducing agents introduced into the mixture for the creation of the exothermic reaction. Reducers and mixture was chosen for the increased of basic mechanical properties of alloy by the components resulting from the chemical reaction and exothermic effect. Thermal effects resulting from the reaction are taken into account as well.

20

Thermodynamics of Ion-exchange reaction in predicting the ionic selectivity of Auchlite ARA-9366 and Auchlite A-378 anion exchange resins

Singare P. U., Patange A. N.

International Letters of Chemistry, Physics and Astronomy

|

2014

|

Vol. 6

1--7

EN

The paper deals with predicting the iodide ion selectivity of nuclear and non-nuclear grade anion exchange resins. The ionic selectivity prediction was made on the basis of thermodynamic data of Clˉ/I ˉ ion exchange reaction. It was observed that with rise in temperature from 30.0 °C to 45.0 °C, the equilibrium constant (K) values were observed to decreases from 59.77x10-2 to 23.77x10-2 for Auchlite ARA-9366 resins and from 9.01x10-2 to 4.05x10-2 for Auchlite A-378 resins. The decrease in K values with rise in temperature, indicate exothermic ion exchange reactions having enthalpy values of -47.87 and -39.51 kJ/mol respectively. The high K and low enthalpy values obtained for Auchlite ARA-9366 resins indicate their greater selectivity for the iodide ions in the solution as compared to Auchlite A-378 resins, when both the resins are present in chloride form.