International Journal of Thermodynamics最新文献

{"title":"Dissociation Constant Studies of 2-Substituted 4-Formylbenzoic Acid based on Conductometric Parameters using Fuoss-Hsia Theories","authors":"Kosrat N. Kaka, R. Omer, Salam G. Taher, W. M. H. Hamad","doi":"10.5541/ijot.1136209","DOIUrl":"https://doi.org/10.5541/ijot.1136209","url":null,"abstract":"The dissociation constant is a quantitative measure of the strength of an acid in solution. This study examines dissociation constant for the series substituted acids like Ortho-alkoxy-4-formylbenzoic acid. The use of (2-methoxy ethanol) as a solvent contributed to the study expected to form free ions or solvent separated ion pair which has been studied with the use conductometric method at different temperatures ranged from 293.15 to 318.15K. The study aims at figuring out dissociation constant, equivalent conductance at infinity dilution, and Walden product by minimization technique using Fuoss-Hsia for both (Modified and Complete) equations. It has been found in the results that the calculated values based on statistical sum square (different between practical and theoretical values) is equivalent conductance at infinity dilution and dissociation constant. It has also been observed that increase the temperature leads to the increase of the molar conductance at infinity dilution, and the increase in association. Moreover, the substituted alkoxy group also affected dissociation of compounds. In this study, the thermodynamic parameters (Ho, Go and So) have also been evaluated and discussed. Finally, the effect of substituent groups on rate of dissociation was studied and explained with agreement to the principles of mesomeric(M) and Inductive effect(I) of substituent groups on dissociation constant.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41289451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-Fractional Cattaneo-Type Thermoelastic Interior-Boundary Value Problem Within A Rigid Ball","authors":"G. Dhameja, L. Khalsa, V Varghese","doi":"10.5541/ijot.1170335","DOIUrl":"https://doi.org/10.5541/ijot.1170335","url":null,"abstract":"The paper discusses the solution of an interior-boundary value problem of one-dimensional time-fractional Cattaneo-type heat conduction and its stress fields for a rigid ball. The interior value problem describes the dependence of the boundary conditions within the ball's inner plane at any instant with a prescribed temperature state, in contrast to the exterior value problem, which relates the known surface temperature to boundary conditions. A single-phase-lag equation with Caputo fractional derivatives is proposed to model the heat equation in a medium subjected to time-dependent physical boundary conditions. The application of the finite spherical Hankel and Laplace transform technique to heat conduction is discussed. The influence of the fractional-order parameter and the relaxation time is examined on the temperature fields and their related stresses. The findings show that the slower the thermal wave, the bigger the fractional-order setting, and the higher the period of relaxation, the slower the heat flux propagates.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45217825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Bosons of the Conventional Superconductors","authors":"U. Köbler","doi":"10.5541/ijot.1169691","DOIUrl":"https://doi.org/10.5541/ijot.1169691","url":null,"abstract":"For the conventional superconductors it will be shown that not only the superconducting energy gap, Egap(T=0), and the critical field, Bc(T=0), but also the London penetration depth, λL(T=0), scale in a reasonable approximation with the superconducting transition temperature, TSC, as ~TSC, ~TSC2 and ~T-1/2, respectively. From these scaling relations the conclusion obtained earlier, using a completely different method, is confirmed that the London penetration depth corresponds to the diameter of the Cooper-pairs. As a consequence, only one layer of Cooper pairs is sufficient to shield an external magnetic field completely. The large diamagnetism of the superconductors is caused by the large orbital area of the Cooper-pairs. From the fact that, in the zero-field ground state, the temperature dependence of the superconducting heat capacity is given above and below TSC by power functions of absolute temperature it follows that the only critical point is T=0. The superconducting transitions of the element superconductors, therefore, are all within the critical range at T=0. As a consequence, above and below TSC there is short-range order only. As we know from Renormalization Group (RG) theory, in the critical range the dynamics is the dynamics of a boson field, exclusively. Evidently, the Cooper-pairs have to be considered as the short-range ordered units created by this boson field. It is reasonable to assume that the relevant bosons in the superconducting state are identical with the bosons giving rise to the universal linear-in-T electronic heat capacity above TSC. Plausibility arguments will be given that these bosons must be electric quadrupole radiation generated by the non-spherical charge distributions in the soft zones between the metal atoms. The radiation field emitted by an electric quadrupole can be assumed to be essentially curled or circular. In the ordered state below TSC, the bosons are condensed in resonating spherical modes which encapsulate the two Cooper-pair electrons and shield their charge perfectly.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48386750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamic Studies on Sr5Nb4O15","authors":"P. Samui, Santosh Bhojane, B. Singh, Swarup Rakshi̇t","doi":"10.5541/ijot.1157497","DOIUrl":"https://doi.org/10.5541/ijot.1157497","url":null,"abstract":"The SrO–Nb2O5 system, especially Sr5Nb4O15 compound is of interest for their use as an electroceramics. In this work, Sr5Nb4O15 compound was synthesized by solid-state reaction and characterised by XRD. Thermodynamic properties like heat capacity, enthalpy of formation and Gibbs energy of formation of Sr5Nb4O15 have been measured. The standard molar enthalpy of formation of Sr5Nb4O15(s) was determined using an oxide melt solution high temperature calorimeter. Based on these experimental data, a self-consistent thermodynamic function of this compound was also generated. This thermodynamic data is essential for the optimization of synthesis conditions for materials and for the evaluation of their stability under appropriate technological operating conditions.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43539222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solubility Prediction of Lornoxicam in Different Pure Solvents Using Semi-Empirical Correlations and Thermodynamic Models","authors":"Rahul Kumar, A. Thakur, A. Kulabhi, A. Mishra","doi":"10.5541/ijot.1138056","DOIUrl":"https://doi.org/10.5541/ijot.1138056","url":null,"abstract":"The solubility data of Active Pharmaceutical Ingredients in organic solvents is an essential for pharmaceutical crystallization and drug formulation. In this work, two semi-empirical correlations- the Yaws model and λ-h model- and two thermodynamic models – Wilson Model and the Non-random two-liquid model- are used to estimate the solubility of lornoxicam in ethanol and water. The model parameters and correlations coefficients are calculated by optimizing the average relative deviation. The values of these parameters will be helpful to estimate the solubility of lornoxicam at different temperatures where the experimental solubility data is not available. The predicted solubility data of lornoxicam can be further utilized in the pharmaceutical crystallization and drug formulation.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45168864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamic Properties of Ethanol + Pyridine, Ethanol + Benzene, and Pyridine + Benzene Mixtures at Temperature 298.15 K and Under Atmospheric Pressure","authors":"Arber Zeqiraj, A. Gjevori, Artan Llozana, N. Syla, F. Aliaj","doi":"10.5541/ijot.1173589","DOIUrl":"https://doi.org/10.5541/ijot.1173589","url":null,"abstract":"Experimental densities, viscosities, refractive indices, and sound speeds at temperature 298.15 K and atmospheric pressure are reported for the binary liquid mixtures of ethanol + benzene, ethanol + pyridine, and benzene + pyridine. From these experimental data, various thermodynamic excess and deviation properties were calculated and fitted by the Redlich-Kister polynomial to determine the adjustable coefficients and the standard deviations. The number of Redlich-Kister coefficients for significantly representing each thermodynamic property was optimized by applying the F-test. The variation of thermodynamic excess and deviation properties with composition has been interpreted in terms of molecular interactions between components of the mixture and structural effects. Furthermore, several theoretical and semi-empirical models were used to predict the refractive indices and sound speeds of the investigated mixtures. The predicting ability of each model was ascertained in terms of mean absolute percentage deviation between experimental and calculated data.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47503736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emissivity Prediction for an IR Camera During Laser Welding of Aluminum","authors":"A. Metallo","doi":"10.5541/ijot.1129559","DOIUrl":"https://doi.org/10.5541/ijot.1129559","url":null,"abstract":"Laser processing is becoming increasingly important in industrial applications. The success of the process relies on two fundamental parameters: the surface temperature of the medium and the thickness of the hardened layer. One of the most important factors during a laser process is certainly the temperature, which presents high temperature gradients. The speed at which a material undergoes a phase transition, the chemical reactions that take place during processing and the properties of the material are all dependent on temperature changes. Consequently, the measure of temperature is a demanding undertaking. This study proposes to measure temperature for the duration of laser welding with the infrared camera (IR) Optris PI. To restore the real temperature based on the brightness temperature values measured by the IR camera is needed to evaluate the emissivity to be attributed to the IR camera. For this purpose, firstly, the isotherms consistent with the melting point of aluminum (785 K) were assessed and then compared with the temperature distribution gauged in the zone of irradiation of the laser. Such data were then compared with the thickness of the melted zone. The use of the melting point isotherm allowed the calculation of the value of emissivity and the restoration of the temperature. Thermography software data acquisition wrongly presupposes the emissivity value does not change. This generates incorrect thermographic data. The surface emissivity normally hinges on temperature. Therefore, the values on which the literature relies may not work for materials of interest in the conditions of the process. This is particularly the case, where welding is carried out in keyhole mode (Tmax = Tvap). However, the physical phenomena involved, including evaporation and plasma plume formation, high spatial and temporal temperature gradients, and non-equilibrium phase transformations, influence the optical conditions of the brightness of the emission of light from the molten pool, making, De Facto, the emissivity value not constant. Thus, what we propose here is a methodological procedure that allows the measurement of the effective emissivity of the surface, at the same time taking into consideration the consequence of physical phenomena and the conditions of the surface. Two procedures (Standard and Simplified) capable of providing the correct emissivity value in relation to the working parameters have been proposed. The results showed that the procedures are correct, fast, and easy to use.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46874662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamic Modeling of Liquid-Liquid Equilibrium in Ternary Systems with Biodiesel and Isolated Ester (Methyl Palmitate)","authors":"Jéssyca K. A. Bezerra, Maria Rosiane de Almeida Andrade, Edyjancleide Rodrigues Si̇lva, L. J. N. Duarte, Gilson Gomes Medei̇ros, E. L. B. Barros Neto","doi":"10.5541/ijot.1136615","DOIUrl":"https://doi.org/10.5541/ijot.1136615","url":null,"abstract":"Liquid-liquid equilibrium data were measured and analyzed for two ternary systems (biodiesel + methanol + glycerol and methyl palmitate + methanol + glycerol). Biodiesel, produced by the conventional chemical route at 60 °C for 60 min, using methanol and soybean oil at a molar rate of 10:1 and potassium hydroxide concentration (KOH) of 1 wt% exhibited thermal decomposition at temperatures between 100 and 250 ºC, reaching mass loss of approximately 98.8%, confirming soybean oil conversion into biodiesel by gas chromatography and thermogravimetry. Tie line composition quality was verified using Othmer-Tobias and Hand correlation equations. The distribution and selectivity coefficients were calculated for the immiscibility regions. The experimental tie line data exhibited good correlation in the UNIQUAC and NRTL thermodynamic models. The biodiesel system displayed deviations of 0.66 and 0.53% for the UNIQUAC and NRTL models, respectively. In addition, the methyl palmitate system showed a 1.23 and 0.48% deviation for the UNIQUAC and NRTL model, respectively. The individual behavior of the main biodiesel esters , based on the UNIQUAC model parameters, demonstrated that the type of fatty acid does not interfere in model correlation, likely due to the similarity between their composition and properties.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44047158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamic Assessment of the Impact of Pregnancy and Lactation on the Longevity of Women","authors":"Gizem Ulu, Melek Ece Öngel, B. Yılmaz, M. Özilgen","doi":"10.5541/ijot.1145655","DOIUrl":"https://doi.org/10.5541/ijot.1145655","url":null,"abstract":"Effects of the pregnancy and the following lactation periods on the lifespan entropy of the women has been evaluated. In the case of singleton pregnancy, a wealthy woman may generate 1.5% and in the case of twin pregnancy 2.1% of the total lifespan entropy of a non-pregnant wealthy women. In the case of a poor woman the singleton pregnancy, may generate 1.8% and in case of the twin pregnancy 2.1% of the total lifespan entropy generated by the non-pregnant wealthy woman. Results of the diet-based thermodynamic calculations for the poor women are compared with the demographic data collected across pre-industrial Europe and a good agreement was found.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48392463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamic and Thermophysical Properties of Air as a Mixture by Using Schreiber-Pitzer EoS","authors":"Özay Akdemi̇r, M. T. Coban","doi":"10.5541/ijot.1169686","DOIUrl":"https://doi.org/10.5541/ijot.1169686","url":null,"abstract":"Air is one of the most important substances used in industrial and technological applications. Applications of air require a consistent set of reliable data on its thermodynamic and thermophysical properties. Over the last few decades, researchers have developed a number of empirical and theoretical models for the correlation and prediction of the thermodynamic and thermophysical properties of pure fluids and mixtures. The ideal gas Equation of State (EoS) is used in gas thermodynamic property calculations extensively, but in applications with higher pressure zones, the error levels are increasing. For most applications, an equation of state with better accuracy of thermodynamic properties will be required for extreme cases. In this study, Schreiber-Pitzer EoS is considered for better accuracy of the thermodynamic properties for air mixture. A set of computer programs were developed in java language to calculate the thermodynamic and thermophysical properties of air as a mixture of Nitrogen, Oxygen and Argon. The Schreiber-Pitzer EoS results are compared with Peng-Robinson EoS, Redlich-Kwong EoS, Van der Waals EoS, and ideal gas EoS utilizing cubic spline curve fitting for cp values. The thermodynamic and thermophysical property results and percentages of differences are calculated. The percentages of differences are increasing with increasing pressure and decreasing temperature.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43933356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}