Lili Liu, Cai Chen, Gang Xu, Youchang Jiang, Y. Wen, Xianshi Zeng
Results of first principles calculations of the lattice parameter, elastic constants and some thermody-namic properties in a wide range of pressures and temperatures are reported for the B2 structure AgY and CuY. The calculated lattice and elastic constants at 0 K and 0 GPa are in agreement with the previous experimental and theoretical values. Using the density functional perturbation theory (DFPT) under the quasi-harmonic approximation (QHA), the evolution of some thermodynamic parameters concluding bulk modulus, volume expansion, thermal expansion coeff icient and heat capacity at constant pressure with temperature and pressure is computed. This is the first quantitative theoretical prediction of the reported properties and it still awaits experimental confirmation.
{"title":"Elastic constants and thermodynamic properties of AgY and CuY compounds under pressure and temperature effects","authors":"Lili Liu, Cai Chen, Gang Xu, Youchang Jiang, Y. Wen, Xianshi Zeng","doi":"10.32908/hthp.v50.945","DOIUrl":"https://doi.org/10.32908/hthp.v50.945","url":null,"abstract":"Results of first principles calculations of the lattice parameter, elastic constants and some thermody-namic properties in a wide range of pressures and temperatures are reported for the B2 structure AgY and CuY. The calculated lattice and elastic constants at 0 K and 0 GPa are in agreement with the previous experimental and theoretical values. Using the density functional perturbation theory (DFPT) under the quasi-harmonic approximation (QHA), the evolution of some thermodynamic parameters concluding bulk modulus, volume expansion, thermal expansion coeff icient and heat capacity at constant pressure with temperature and pressure is computed. This is the first quantitative theoretical prediction of the reported properties and it still awaits experimental confirmation.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The phenomological model for cohesive energy of metallic nanomaterials is extended to investigate the variation in thermodynamic properties of bimetallic nanostructures. The systematic investigation of variation in melting temperature of bimetallic nanomaterials is done to study the impact of size, composition and dimension. Decrease in melting temperature of bimetallic nanoalloys is found as size of nanoalloy decreases. It is noted that for bimetallic nanoalloys of same composition and having same size, the melting temperature varies on the basis of dimension of nanoalloy in the sequence such that (Tmn)nanofilms> (Tmn)nanowires> (Tmn)nanoparticles. The present predicted results obtained from extended model are compared with the simulated and experimental results available. Good consistency is observed between the compared results which justify the present model theory.
{"title":"Composition and dimension dependence of melting temperature in bimetallic nanoalloys","authors":"M. Goyal","doi":"10.32908/hthp.v50.981","DOIUrl":"https://doi.org/10.32908/hthp.v50.981","url":null,"abstract":"The phenomological model for cohesive energy of metallic nanomaterials is extended to investigate the variation in thermodynamic properties of bimetallic nanostructures. The systematic investigation of variation in melting temperature of bimetallic nanomaterials is done to study the impact of size, composition and dimension. Decrease in melting temperature of bimetallic nanoalloys is found as size of nanoalloy decreases. It is noted that for bimetallic nanoalloys of same composition and having same size, the melting temperature varies on the basis of dimension of nanoalloy in the sequence such that (Tmn)nanofilms> (Tmn)nanowires> (Tmn)nanoparticles. The present predicted results obtained from extended model are compared with the simulated and experimental results available. Good consistency is observed between the compared results which justify the present model theory.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Myung Su Kim, S. Jeong, Gi Seong Lee, Yeon Suk Choi
One of the main sources of heat leakage in a low temperature vessel is the thermal conduction of the vessel wall between room temperature and the low temperature. The material of the vessel is generally stainless-steel, and it is fabricated by welding. To reduce the amount of the thermal conduction, materials having low thermal conductivity are chosen. Glass fiber reinforced plastic (GFRP) is one of the adequate candidate materials because it has low thermal conductivity and high mechanical strength. We use GFRP pipe instead of stainless-steel pipe, as a neck in a liquid nitrogen vessel (or Dewar). Epoxy, as a bonding material, is inserted between the GFRP neck and the main body of the vessel. Therefore, the thermal characteristics, especially the thermal expansion, are very important because the vessel is cooled and warmed periodically. The experimental results of thermal expansion between room temperature and the low temperature are presented in the paper. Leakage in a vacuum environment is incurred because of different linear thermal expansion coefficients of various materials. The leakage is investigated using a vacuum-level checking method during the thermal cycle. In addition, the amount of boil-off in a low temperature vessel is discussed in terms of the thermal characteristics of the neck’s material.
{"title":"Thermal characteristics of epoxy as a bonding material in a low temperature vessel","authors":"Myung Su Kim, S. Jeong, Gi Seong Lee, Yeon Suk Choi","doi":"10.32908/hthp.v50.1069","DOIUrl":"https://doi.org/10.32908/hthp.v50.1069","url":null,"abstract":"One of the main sources of heat leakage in a low temperature vessel is the thermal conduction of the vessel wall between room temperature and the low temperature. The material of the vessel is generally stainless-steel, and it is fabricated by welding. To reduce the amount of the thermal conduction, materials having low thermal conductivity are chosen. Glass fiber reinforced plastic (GFRP) is one of the adequate candidate materials because it has low thermal conductivity and high mechanical strength. We use GFRP pipe instead of stainless-steel pipe, as a neck in a liquid nitrogen vessel (or Dewar). Epoxy, as a bonding material, is inserted between the GFRP neck and the main body of the vessel. Therefore, the thermal characteristics, especially the thermal expansion, are very important because the vessel is cooled and warmed periodically. The experimental results of thermal expansion between room temperature and the low temperature are presented in the paper. Leakage in a vacuum environment is incurred because of different linear thermal expansion coefficients of various materials. The leakage is investigated using a vacuum-level checking method during the thermal cycle. In addition, the amount of boil-off in a low temperature vessel is discussed in terms of the thermal characteristics of the neck’s material.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":"38 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The heat treatment process of C919 aircraft landing gear has to go through a series of strict environments such as vacuum, high temperature, oil quenching, and it has been a difficult problem to accurately measure the temperature of landing gear during heat treatment. A black box hi-temp measurement system is designed on basis of heat transfer theory in this paper. The thermal insulation structures are simulated by finite element analysis software ANSYS, and the simulation results indicate that the system can work continuously for 7 hours at 900 °C. The number and distribution of temperature measurement points are determined according to the standard of AMS 2750E. The temperature variations of measurement points in the process of vacuum furnace heating and oil quenching are real-time recorded by binding the hi-temp measurement system and the landing gear as a whole into the vacuum furnace and oil pool. The results show that the designed hi-temp measurement system has good stability and high accuracy, which is fully capable of withstanding vacuum, high temperature and oil quenching environments. It is the first time in China that this kind of temperature measuring problem has been solved, which is of great significance for the accurate verification of C919 aircraft landing gear during heat treatment process.
{"title":"Research on the temperature measurement of C919 aircraft landing gear during heat treatment","authors":"W. Li, Junwei Jia, Zheng Li, Hongfei Cui, Xiaobo Lu, Jian Min, Zhan Liu, Shaofei Li, Jincheng Jia","doi":"10.32908/hthp.v50.1007","DOIUrl":"https://doi.org/10.32908/hthp.v50.1007","url":null,"abstract":"The heat treatment process of C919 aircraft landing gear has to go through a series of strict environments such as vacuum, high temperature, oil quenching, and it has been a difficult problem to accurately measure the temperature of landing gear during heat treatment. A black box hi-temp measurement system is designed on basis of heat transfer theory in this paper. The thermal insulation structures are simulated by finite element analysis software ANSYS, and the simulation results indicate that the system can work continuously for 7 hours at 900 °C. The number and distribution of temperature measurement points are determined according to the standard of AMS 2750E. The temperature variations of measurement points in the process of vacuum furnace heating and oil quenching are real-time recorded by binding the hi-temp measurement system and the landing gear as a whole into the vacuum furnace and oil pool. The results show that the designed hi-temp measurement system has good stability and high accuracy, which is fully capable of withstanding vacuum, high temperature and oil quenching environments. It is the first time in China that this kind of temperature measuring problem has been solved, which is of great significance for the accurate verification of C919 aircraft landing gear during heat treatment process.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saad Tariq, A. Batool, M. Faridi, M. Jamil, A. Mubarak, Nosheen Akbar
In the enclosure of density functional theory along with GGA (generalized gradient approximation), incorporated in Wien2k code has been utilized to explore structural, electronic and mechanical properties of SrNbO3 (SNO). It has been found that spin-polarized phase of SNO is most stable at 60 GPa with the calculated lattice constant of 3.801 Å. The calculated lattice constant and bulk modulus at 0 GPa are found to be in agreement with literature. The present calculations predict that SNO is stable and antiferromagnetic in nature up to 60 GPa. The calculated charge density contours and Cauchy pressure depicts majority of the bonding nature between the content atoms of SNO is ionic with a small contribution of covalent bond. The band-gap is found traverse from indirect R-Г gap under 0 GPa to wider direct Г-Г gap under 60 GPa. Furthermore, calculated elastic constants, C11, C12 and C44 suggest that compound is stable up to 60 GPa and exhibits ductile, anisotropic nature. Beneficial electronic and mechanical applications are predicted for SNO that could be used in optoelectronic applications.
{"title":"Influence of pressure on electro-mechanical properties of SrNbO3: A DFT study","authors":"Saad Tariq, A. Batool, M. Faridi, M. Jamil, A. Mubarak, Nosheen Akbar","doi":"10.32908/hthp.v48.763","DOIUrl":"https://doi.org/10.32908/hthp.v48.763","url":null,"abstract":"In the enclosure of density functional theory along with GGA (generalized gradient approximation), incorporated in Wien2k code has been utilized to explore structural, electronic and mechanical properties of SrNbO3 (SNO). It has been found that spin-polarized phase of SNO is most stable at 60 GPa with the calculated lattice constant of 3.801 Å. The calculated lattice constant and bulk modulus at 0 GPa are found to be in agreement with literature. The present calculations predict that SNO is stable and antiferromagnetic in nature up to 60 GPa. The calculated charge density contours and Cauchy pressure depicts majority of the bonding nature between the content atoms of SNO is ionic with a small contribution of covalent bond. The band-gap is found traverse from indirect R-Г gap under 0 GPa to wider direct Г-Г gap under 60 GPa. Furthermore, calculated elastic constants, C11, C12 and C44 suggest that compound is stable up to 60 GPa and exhibits ductile, anisotropic nature. Beneficial electronic and mechanical applications are predicted for SNO that could be used in optoelectronic applications.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":"48 1","pages":"399-411"},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69441430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qinghua Chen, Weihao Gao, G. Su, Weijuan Guan, S. Xu, Melangi Momo Valex, Y. Ma
At present, the thermophysical properties testing methods of solid materials are mostly based on infinite physical model. In order to ensure that the heat flux transmits within the sample and is not affected by the heat loss at the sample boundary, its boundary is usually set as an adiabatic boundary. Nevertheless, it will lead to the accumulation of heat. In order to achieve the hot wire method conveniently, solid material for which a thinner thickness can be measured and the effective test time of the experiment is flexible. By so doing, we improved the traditional parallel hot wire method. The temperature measuring points were arranged along the thickness direction of the sample instead of parallel to the hot wire, and the enantiomorphous heat-source theory was introduced to modify the effect of heat accumulation on the temperature rise of the sample. The thermophysical property of diatomite refractory brick, asbestos board and marble were measured. The results show that the revised calculated values are in good agreement with the existing test values, with a maximum error of 5%, effectively expanding the application range of the hot wire method.
{"title":"Measurement of thermophysical properties of solid materials by hot wire method combined with enantiomorphous heat-source theory","authors":"Qinghua Chen, Weihao Gao, G. Su, Weijuan Guan, S. Xu, Melangi Momo Valex, Y. Ma","doi":"10.32908/hthp.v49.901","DOIUrl":"https://doi.org/10.32908/hthp.v49.901","url":null,"abstract":"At present, the thermophysical properties testing methods of solid materials are mostly based on infinite physical model. In order to ensure that the heat flux transmits within the sample and is not affected by the heat loss at the sample boundary, its boundary is usually set as an adiabatic boundary. Nevertheless, it will lead to the accumulation of heat. In order to achieve the hot wire method conveniently, solid material for which a thinner thickness can be measured and the effective test time of the experiment is flexible. By so doing, we improved the traditional parallel hot wire method. The temperature measuring points were arranged along the thickness direction of the sample instead of parallel to the hot wire, and the enantiomorphous heat-source theory was introduced to modify the effect of heat accumulation on the temperature rise of the sample. The thermophysical property of diatomite refractory brick, asbestos board and marble were measured. The results show that the revised calculated values are in good agreement with the existing test values, with a maximum error of 5%, effectively expanding the application range of the hot wire method.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69441660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article concerns the analysis of selected and the most frequently used methods for temperature measurements in the aspect of their correct use in engineering applications related to industrial die forging processes. The research used the three most popular measuring devices, such as: monochromatic pyrometers with the simultaneous measurement of K-type thermocouple and thermal imaging camera. The research concerned mainly temperature measurements for forging tools divided into several stages in which individual tests were carried out, making detailed analyzes and indicating the most important measurement problems. Each subsequent research stage was in some way a consequence of the previous one. On this basis, the potential advantages and disadvantages of individual measurement methods were indicated and how one method can be verified by another one. It was indicated how and to what the best method or device should be used, so that the obtained result was correct and the person/engineer conducting such measurements was aware of the consequences of the conducted research and the problem of temperature measurements.
{"title":"Methods of temperature determination and measurement verification in applications related to hot die forging processes","authors":"M. Hawryluk, P. Widomski, M. Kaszuba, S. Polak","doi":"10.32908/hthp.v49.793","DOIUrl":"https://doi.org/10.32908/hthp.v49.793","url":null,"abstract":"The article concerns the analysis of selected and the most frequently used methods for temperature measurements in the aspect of their correct use in engineering applications related to industrial die forging processes. The research used the three most popular measuring devices, such as: monochromatic pyrometers with the simultaneous measurement of K-type thermocouple and thermal imaging camera. The research concerned mainly temperature measurements for forging tools divided into several stages in which individual tests were carried out, making detailed analyzes and indicating the most important measurement problems. Each subsequent research stage was in some way a consequence of the previous one. On this basis, the potential advantages and disadvantages of individual measurement methods were indicated and how one method can be verified by another one. It was indicated how and to what the best method or device should be used, so that the obtained result was correct and the person/engineer conducting such measurements was aware of the consequences of the conducted research and the problem of temperature measurements.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":"49 1","pages":"223-239"},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69441668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present quantum molecular dynamics calculations of thermophysical properties of solid and liquid rhenium in the vicinity of melting. We show that some pulse-heating experiments for rhenium can be independently described by the first-principle calculations. Our calculations predict significant volume change of about 6% at melting. We also provide our estimation of the enthalpy of fusion, which is about 33.6 kJ/mol.
{"title":"Interpretation of pulse-heating experiments for rhenium by quantum molecular dynamics","authors":"D. Minakov, M. Paramonov, P. Levashov","doi":"10.32908/hthp.v49.837","DOIUrl":"https://doi.org/10.32908/hthp.v49.837","url":null,"abstract":"We present quantum molecular dynamics calculations of thermophysical properties of solid and liquid rhenium in the vicinity of melting. We show that some pulse-heating experiments for rhenium can be independently described by the first-principle calculations. Our calculations predict significant volume change of about 6% at melting. We also provide our estimation of the enthalpy of fusion, which is about 33.6 kJ/mol.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":"49 1","pages":"211-219"},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69441916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A thermoelectric-hydraulic numerical model is built for thermoelectric recuperators with wavy and straight fins under large longitudinal temperature difference, and their performance is analyzed. It is found that the comprehensive performance of the wavy-fin thermoelectric recuperator is better than that of straight-fin thermoelectric recuperator. The maximum output powers of the two thermoelectric recuperators are 0.251 mW and 0.236 mW at inlet velocity of 1.7 m � s-1. When the ratio of wave height to wave length is 0.1, the maximum output power is 0.251 mW and output power per unit volume is 414.8 W � m-3. Taguchi method is used to optimize the wavy-fin thermoelectric recuperator. It is found that reducing channel width and plate thickness is beneficial to increase the output power and output power per unit volume for the wavy-fin thermoelectric recuperator. Increasing fin height and fin thickness is beneficial to the output power, but disadvantage to the output power per unit volume.
建立了大纵向温差下波浪翅片和直翅片热电回热器的热电-水力数值模型，并对其性能进行了分析。结果表明，波翅式热电回热器的综合性能优于直翅式热电回热器。在入口速度为1.7 m μ s-1时，两个热电回热器的最大输出功率分别为0.251 mW和0.236 mW。当波高波长比为0.1时，最大输出功率为0.251 mW，单位体积输出功率为414.8 W·m-3。采用田口法对波浪鳍式热电回热器进行优化。研究发现，减小通道宽度和板厚有利于提高波鳍式热电回热器的输出功率和单位体积输出功率。增加翅片高度和厚度对输出功率有利，但对单位体积输出功率不利。
{"title":"Numerical study on thermoelectric-hydraulic performance of thermoelectric recuperator with wavy thermoelectric fins","authors":"Na Li, Xingfei Yu, Jinhai Xu, Qiuwan Wang, T. Ma","doi":"10.32908/hthp.v49.961","DOIUrl":"https://doi.org/10.32908/hthp.v49.961","url":null,"abstract":"A thermoelectric-hydraulic numerical model is built for thermoelectric recuperators with wavy and straight fins under large longitudinal temperature difference, and their performance is analyzed. It is found that the comprehensive performance of the wavy-fin thermoelectric recuperator is better than that of straight-fin thermoelectric recuperator. The maximum output powers of the two thermoelectric recuperators are 0.251 mW and 0.236 mW at inlet velocity of 1.7 m � s-1. When the ratio of wave height to wave length is 0.1, the maximum output power is 0.251 mW and output power per unit volume is 414.8 W � m-3. Taguchi method is used to optimize the wavy-fin thermoelectric recuperator. It is found that reducing channel width and plate thickness is beneficial to increase the output power and output power per unit volume for the wavy-fin thermoelectric recuperator. Increasing fin height and fin thickness is beneficial to the output power, but disadvantage to the output power per unit volume.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69442379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A simple model based on thermodynamic variables is used to study the effect of shape, size and structure on the various thermodynamic properties of nanowires. The expression of cohesive energy derived by Qi and Wang [16] is used and ratio of surface atoms to total number of atoms is expressed in terms of shape parameter, radius of nanowire and atomic packing fraction. The variation in cohesive energy, activation energy, melting temperature surface energy, Bulk modulus, Energy band gap Debye temperature and coefficient of volume thermal expansion in nanowires of Zn, β-Sn, TiO 2 (rutile) is studied for cylindrical, triangular, tetragonal, hexagonal and rectangular nanowires using the model. The results obtained are compared with the experimental data available and results from Guisbiers model [11, 12]. The values predicated from the present model are found close to Guisbiers model results and available experimental data.
{"title":"Analysis of shape, size and structure dependent thermodynamic properties of nanowires","authors":"M. Goyal, B. Gupta","doi":"10.32908/hthp.v48.733","DOIUrl":"https://doi.org/10.32908/hthp.v48.733","url":null,"abstract":"A simple model based on thermodynamic variables is used to study the effect of shape, size and structure on the various thermodynamic properties of nanowires. The expression of cohesive energy derived by Qi and Wang [16] is used and ratio of surface atoms to total number of atoms is expressed in terms of shape parameter, radius of nanowire and atomic packing fraction. The variation in cohesive energy, activation energy, melting temperature surface energy, Bulk modulus, Energy band gap Debye temperature and coefficient of volume thermal expansion in nanowires of Zn, β-Sn, TiO 2 (rutile) is studied for cylindrical, triangular, tetragonal, hexagonal and rectangular nanowires using the model. The results obtained are compared with the experimental data available and results from Guisbiers model [11, 12]. The values predicated from the present model are found close to Guisbiers model results and available experimental data.","PeriodicalId":12983,"journal":{"name":"High Temperatures-high Pressures","volume":"48 1","pages":"481-495"},"PeriodicalIF":1.1,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69441247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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