Pub Date : 2023-01-01DOI: 10.56042/ijpap.v61i11.2657
Natural radioactivity is the term used to describe radioactivity that persists in the soil, rocks, and water due to fundamental radionuclides such as uranium, thorium, potassium, etc. As a result, radiation affects everyone on the planet. Researchers worldwide find this topic particularly interesting due to the hazardous effects of radionuclides on human health. A systematic survey employing trustworthy methodological approaches is necessary to objectively assess these radionuclides in the environment. In the present paper, ZnS:Ag scintillator-based SMART RnDuo (AQTEK System, India) is used to measure exhalation rates of isotopes 222Rn and 220Rn (radon and thoron) of soil samples. Forty soil samples were studied. For the study of 222Rn, monitoring of the mass exhalation (Rm) was conducted. In the case of 220Rn, monitoring of surface exhalation (Rs) was studied. The radon mass exhalation rate is found in the range of 14±1 to 55±5 mBqkg−1h−1 with an average of 34±10 mBqkg−1h−1 and thoron surface exhalation rate in the range of 2200±215 to 7560±420 Bqm−2h−1 with an average of 4280±960 Bqm−2h−1. Thus, elevated thoron level is observed in most of the samples. Results are compared with the world’s average values.
{"title":"Estimation of Exhalation Rates of Radon and Thoron in the Soil Samples Collected from Gurugram, Haryana, India","authors":"","doi":"10.56042/ijpap.v61i11.2657","DOIUrl":"https://doi.org/10.56042/ijpap.v61i11.2657","url":null,"abstract":"Natural radioactivity is the term used to describe radioactivity that persists in the soil, rocks, and water due to fundamental radionuclides such as uranium, thorium, potassium, etc. As a result, radiation affects everyone on the planet. Researchers worldwide find this topic particularly interesting due to the hazardous effects of radionuclides on human health. A systematic survey employing trustworthy methodological approaches is necessary to objectively assess these radionuclides in the environment. In the present paper, ZnS:Ag scintillator-based SMART RnDuo (AQTEK System, India) is used to measure exhalation rates of isotopes 222Rn and 220Rn (radon and thoron) of soil samples. Forty soil samples were studied. For the study of 222Rn, monitoring of the mass exhalation (Rm) was conducted. In the case of 220Rn, monitoring of surface exhalation (Rs) was studied. The radon mass exhalation rate is found in the range of 14±1 to 55±5 mBqkg−1h−1 with an average of 34±10 mBqkg−1h−1 and thoron surface exhalation rate in the range of 2200±215 to 7560±420 Bqm−2h−1 with an average of 4280±960 Bqm−2h−1. Thus, elevated thoron level is observed in most of the samples. Results are compared with the world’s average values.","PeriodicalId":13509,"journal":{"name":"Indian Journal of Pure & Applied Physics","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136305021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.56042/ijpap.v61i11.3113
In this investigation, we used a circular economy approach by recycling metal scrap from industry as a component in creating nanoparticles. For producing iron oxide NPs we used electrochemical method with scrapped rusted iron nails as electrodes. In this technique, we used 50mM ferrous sulphate solution as an electrolyte and a direct current power supply. Different methods were used to characterise the synthesised iron oxide NPs, including ultraviolet-visible (UV-visible) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results demonstrated that the synthesised iron oxide NPs have an average crystallite size of 7.54 nm. Iron oxide NPs has potential to adsorb Congo red dye hence prepared NPs have been utilised for the adsorption of Congo red dye.
{"title":"Synthesis of Iron Oxide Nanoparticles from Scrapped Waste Materials for Efficient Dye Removal to Purify Industrial Waste Water","authors":"","doi":"10.56042/ijpap.v61i11.3113","DOIUrl":"https://doi.org/10.56042/ijpap.v61i11.3113","url":null,"abstract":"In this investigation, we used a circular economy approach by recycling metal scrap from industry as a component in creating nanoparticles. For producing iron oxide NPs we used electrochemical method with scrapped rusted iron nails as electrodes. In this technique, we used 50mM ferrous sulphate solution as an electrolyte and a direct current power supply. Different methods were used to characterise the synthesised iron oxide NPs, including ultraviolet-visible (UV-visible) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results demonstrated that the synthesised iron oxide NPs have an average crystallite size of 7.54 nm. Iron oxide NPs has potential to adsorb Congo red dye hence prepared NPs have been utilised for the adsorption of Congo red dye.","PeriodicalId":13509,"journal":{"name":"Indian Journal of Pure & Applied Physics","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136305444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.56042/ijpap.v61i9.3152
The recent discovery of antimonide based Zintl phase compounds has sparked the research in finding high-performance thermoelectric materials. In present study, a ternary antimonide Zintl phase RbGaSb 2 is investigated using First-principles calculations. A good agreement observed between our computed results, such as lattice parameter and thermal conductivity, with the experimental report validating our theoretical framework. A direct band gap of 1.17 eV is obtained using Tran Blaha modified Becke Johnson approach. The negative value of Seebeck coefficient indicates its n-type character. We purpose a strategy for enhancing power factor via carrier concentration optimization. The calculated results reveal the anisotropic transport properties. The intrinsic ultralow lattice thermal conductivity about 0.094 Wm -1 K -1 along the x-direction, and 0.019 Wm -1 K -1 along z-direction at room temperature is obtained. The ZT value can reach 0.90 (in x-direction) and 0.85 (in z-direction) for n-type doping at 900 K, indicating RbGaSb 2 as promising thermoelectric material.
{"title":"Unravelling the Ultralow Thermal Conductivity of Ternary Antimonide Zintl Phase RbGaSb2: A First-principles Study","authors":"","doi":"10.56042/ijpap.v61i9.3152","DOIUrl":"https://doi.org/10.56042/ijpap.v61i9.3152","url":null,"abstract":"The recent discovery of antimonide based Zintl phase compounds has sparked the research in finding high-performance thermoelectric materials. In present study, a ternary antimonide Zintl phase RbGaSb 2 is investigated using First-principles calculations. A good agreement observed between our computed results, such as lattice parameter and thermal conductivity, with the experimental report validating our theoretical framework. A direct band gap of 1.17 eV is obtained using Tran Blaha modified Becke Johnson approach. The negative value of Seebeck coefficient indicates its n-type character. We purpose a strategy for enhancing power factor via carrier concentration optimization. The calculated results reveal the anisotropic transport properties. The intrinsic ultralow lattice thermal conductivity about 0.094 Wm -1 K -1 along the x-direction, and 0.019 Wm -1 K -1 along z-direction at room temperature is obtained. The ZT value can reach 0.90 (in x-direction) and 0.85 (in z-direction) for n-type doping at 900 K, indicating RbGaSb 2 as promising thermoelectric material.","PeriodicalId":13509,"journal":{"name":"Indian Journal of Pure & Applied Physics","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135494676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.56042/ijpap.v61i9.3407
This study focuses on synthesis of pure SnO2 nanoparticles and SnO2 nanoparticles doped with Erbium (Er) at 7% and Cerium (Ce) at 7% using sol-gel method. The aim was to evaluate their photocatalytic performance in degrading the harmful Rose bengal dye. XRD analysis confirmed that both undoped and rare earth-doped SnO2 nanoparticles exhibited a tetragonal rutile structure. Photoluminescence (PL) analysis revealed an increase in oxygen vacancy concentration with higher dopant incorporation. Furthermore, band gap of doped SnO2 nanoparticles was reduced compared to pure SnO2. The reduction in the band gap was primarily attributed to creation of vacancy defects caused by dopants. Photocatalytic experiments demonstrated that within 60 minutes of UV light exposure, Er 7% doped SnO2 nanoparticles achieved the degradation of 95.32% of Rose bengal dye. These findings highlight the potential of Er 7% doped SnO2 as a highly effective catalyst for large-scale degradation of industrial waste, specifically organic dyes.
{"title":"Adsorption of RB dye by Ce and Er Doped SnO2 Photocatalysts for Water Remediation","authors":"","doi":"10.56042/ijpap.v61i9.3407","DOIUrl":"https://doi.org/10.56042/ijpap.v61i9.3407","url":null,"abstract":"This study focuses on synthesis of pure SnO2 nanoparticles and SnO2 nanoparticles doped with Erbium (Er) at 7% and Cerium (Ce) at 7% using sol-gel method. The aim was to evaluate their photocatalytic performance in degrading the harmful Rose bengal dye. XRD analysis confirmed that both undoped and rare earth-doped SnO2 nanoparticles exhibited a tetragonal rutile structure. Photoluminescence (PL) analysis revealed an increase in oxygen vacancy concentration with higher dopant incorporation. Furthermore, band gap of doped SnO2 nanoparticles was reduced compared to pure SnO2. The reduction in the band gap was primarily attributed to creation of vacancy defects caused by dopants. Photocatalytic experiments demonstrated that within 60 minutes of UV light exposure, Er 7% doped SnO2 nanoparticles achieved the degradation of 95.32% of Rose bengal dye. These findings highlight the potential of Er 7% doped SnO2 as a highly effective catalyst for large-scale degradation of industrial waste, specifically organic dyes.","PeriodicalId":13509,"journal":{"name":"Indian Journal of Pure & Applied Physics","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135494681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.56042/ijpap.v61i9.4741
In this paper we report the study of mechanical energy harvesting of ambient energy based on triboelectric effect. We choose the bulk form of poly-tetrafluoroethylene (PTFE) as electronegative (E-) material and human hand and plywood as the electropositive (E+) materials, respectively making a single electrode based triboelectric generator (TEG). The E+ and E- material were rubbed together to produce a voltage output, which was measured by using a sensitive electrometer. This investigation was carried out for different surface morphology, surface areas of contact, thickness and types of electrode contacts and rubbing frequency. It was observed that sufficient voltage and charge generation was achieved to power low energy devices like LED bulbs, with the highest voltage generation of ~6.2 V for rectangular PTFE sheet, having one surface coated with a thin film of copper for making electrode and other one is made rough using sandpaper, as the E- material and plywood as the E+ material. We observed that the voltage output is influenced by the surface morphology, type of E+ material for the same E- material, frequency of rubbing strokes and frictional area of contact.
{"title":"Influence of Various Parameters on the Triboelectric Generation of Bulk Materials","authors":"","doi":"10.56042/ijpap.v61i9.4741","DOIUrl":"https://doi.org/10.56042/ijpap.v61i9.4741","url":null,"abstract":"In this paper we report the study of mechanical energy harvesting of ambient energy based on triboelectric effect. We choose the bulk form of poly-tetrafluoroethylene (PTFE) as electronegative (E-) material and human hand and plywood as the electropositive (E+) materials, respectively making a single electrode based triboelectric generator (TEG). The E+ and E- material were rubbed together to produce a voltage output, which was measured by using a sensitive electrometer. This investigation was carried out for different surface morphology, surface areas of contact, thickness and types of electrode contacts and rubbing frequency. It was observed that sufficient voltage and charge generation was achieved to power low energy devices like LED bulbs, with the highest voltage generation of ~6.2 V for rectangular PTFE sheet, having one surface coated with a thin film of copper for making electrode and other one is made rough using sandpaper, as the E- material and plywood as the E+ material. We observed that the voltage output is influenced by the surface morphology, type of E+ material for the same E- material, frequency of rubbing strokes and frictional area of contact.","PeriodicalId":13509,"journal":{"name":"Indian Journal of Pure & Applied Physics","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135496250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.56042/ijpap.v61i9.3498
The present study reports the successful fabrication of CTO/Ag/CTO multilayer thin films with different sandwiched layer (Ag) thickness on a glass substrate by the E-beam evaporation Method. The influence of sandwiched layer thickness and stacking of layers on electrical and optical properties was investigated. Several analytical tools such as X-ray diffraction, Atomic Force microscopy, Hall Effect measurement, and UV-visible spectroscopy were used to investigate the morphological, electrical, and optical properties of the multilayer thin film structure. Multilayer thin film with 14nm Ag thickness exhibited a good combination of conductivity and transmittance (i.e. 4.64 × 104 Ω-1cm-1, 69.3%). The conduction mechanism can be explained on the basis of the islands growth mechanism of Volmer-weber model as Ag film was grown on an amorphous CTO surface. The Haacke’s figure of merit was calculated for valuing the overall performance of the transparent conducting film. The maximum figure of merit is reported as 8.7 × 10-3 Ω-1 for multilayer thin film having Ag thickness of 14nm.
{"title":"Effect of Ag Layer Thickness and Interference of Cu-SnO2/Ag/Cu-SnO2 (CTO/Ag/CTO) Multilayer Thin Film on the Electrical and Optical Properties","authors":"","doi":"10.56042/ijpap.v61i9.3498","DOIUrl":"https://doi.org/10.56042/ijpap.v61i9.3498","url":null,"abstract":"The present study reports the successful fabrication of CTO/Ag/CTO multilayer thin films with different sandwiched layer (Ag) thickness on a glass substrate by the E-beam evaporation Method. The influence of sandwiched layer thickness and stacking of layers on electrical and optical properties was investigated. Several analytical tools such as X-ray diffraction, Atomic Force microscopy, Hall Effect measurement, and UV-visible spectroscopy were used to investigate the morphological, electrical, and optical properties of the multilayer thin film structure. Multilayer thin film with 14nm Ag thickness exhibited a good combination of conductivity and transmittance (i.e. 4.64 × 104 Ω-1cm-1, 69.3%). The conduction mechanism can be explained on the basis of the islands growth mechanism of Volmer-weber model as Ag film was grown on an amorphous CTO surface. The Haacke’s figure of merit was calculated for valuing the overall performance of the transparent conducting film. The maximum figure of merit is reported as 8.7 × 10-3 Ω-1 for multilayer thin film having Ag thickness of 14nm.","PeriodicalId":13509,"journal":{"name":"Indian Journal of Pure & Applied Physics","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135496252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-06DOI: 10.3390/books978-3-03943-367-4
A. Jayannavar
{"title":"Quantum Transport in Mesoscopic Systems","authors":"A. Jayannavar","doi":"10.3390/books978-3-03943-367-4","DOIUrl":"https://doi.org/10.3390/books978-3-03943-367-4","url":null,"abstract":"","PeriodicalId":13509,"journal":{"name":"Indian Journal of Pure & Applied Physics","volume":"34 1","pages":"603-612"},"PeriodicalIF":0.7,"publicationDate":"2021-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41560394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A model of pseudospin-lattice coupled mode for methyl ammonium aluminium alum (MASD) has been modified to include cubic and quartic phonon anharmonic interactions. With the help of double-time temperature dependent Green’s function method and modified Hamiltonian, expressions for soft mode frequency, dielectric constant and loss tangent have been evaluated. By fitting model values of physical quantities in the theoretical expressions, temperature dependence of soft mode frequency, dielectric constant and loss tangent have been obtained and compared with experimental results of Pepinsky et al. 15 , which show a good agreement.
修正了甲基铵铝明矾(MASD)的赝自旋-晶格耦合模式模型，使其包含立方和四次声子非调和相互作用。利用双时间温度相关格林函数法和修正哈密顿量，求出了软模频率、介电常数和损耗正切的表达式。通过拟合理论表达式中物理量的模型值，得到了软模频率、介电常数和损耗正切与温度的依赖关系，并与Pepinsky et al. 15的实验结果进行了比较，结果吻合较好。
{"title":"Temperature dependence of dielectric constant and loss tangent in methyl ammonium aluminium alum","authors":"A. Rawat","doi":"10.7598/cst2016.1206","DOIUrl":"https://doi.org/10.7598/cst2016.1206","url":null,"abstract":"A model of pseudospin-lattice coupled mode for methyl ammonium aluminium alum (MASD) has been modified to include cubic and quartic phonon anharmonic interactions. With the help of double-time temperature dependent Green’s function method and modified Hamiltonian, expressions for soft mode frequency, dielectric constant and loss tangent have been evaluated. By fitting model values of physical quantities in the theoretical expressions, temperature dependence of soft mode frequency, dielectric constant and loss tangent have been obtained and compared with experimental results of Pepinsky et al. 15 , which show a good agreement.","PeriodicalId":13509,"journal":{"name":"Indian Journal of Pure & Applied Physics","volume":"54 1","pages":"183-187"},"PeriodicalIF":0.7,"publicationDate":"2016-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71371281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The plasmon characteristics in stage-1 graphene intercalation compounds (GIC’s) using the massless Dirac fermion (MDF) gas approximation have been reported. The superlattice model of GIC’s with negligible c-axis conductivity has been considered. With the discussion of the weak and the strong c-axis coupling at graphene-intercalant hetrojunction plasmon characteristics of GIC’s are predicted. A reasonable agreement has been found between our results and the experimental results of Ritsko and Rice.
{"title":"Plasmon characteristics in stage-1 graphene intercalation compounds","authors":"S. Acharya, Raman Sharma","doi":"10.1063/1.4915393","DOIUrl":"https://doi.org/10.1063/1.4915393","url":null,"abstract":"The plasmon characteristics in stage-1 graphene intercalation compounds (GIC’s) using the massless Dirac fermion (MDF) gas approximation have been reported. The superlattice model of GIC’s with negligible c-axis conductivity has been considered. With the discussion of the weak and the strong c-axis coupling at graphene-intercalant hetrojunction plasmon characteristics of GIC’s are predicted. A reasonable agreement has been found between our results and the experimental results of Ritsko and Rice.","PeriodicalId":13509,"journal":{"name":"Indian Journal of Pure & Applied Physics","volume":"52 1","pages":"374-377"},"PeriodicalIF":0.7,"publicationDate":"2015-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1063/1.4915393","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59070223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thermodynamic optimization of an irreversible air heat pump with variable-temperature heat reservoirs and hot- and cold-side counter-flow heat exchangers has been studied. The expressions of the heating load, the exergetic efficiency and the ecological function of the heat pump cycle are derived. Performance comparisons among exergetic efficiency optimization, ecological optimization and traditional heating load optimization objectives are done. The effect of the pressure ratio of the compressor, the allocation of heat exchanger inventory and the heat capacity rate matching between the working fluid and the heat reservoirs on the optimal performance of the cycle has been investigated by detailed numerical examples. When the performance optimization of the cycle is carried out by selecting the pressure ratio, three optimization objectives give simultaneously attention to the coefficient of performance (COP). The pressure ratio should be the one that is little bigger than the optimum pressure ratio corresponding to maximum COP, however, the results of three optimization objectives are consistent by optimizing the allocation of heat exchanger inventory and optimizing the heat capacity rate matching between the working fluid and the heat reservoirs. The optimum allocations of heat conductance are close to each other, and they are all less than 0.5. The results may provide guidelines for the design and optimization of practical air heat pump plants.
{"title":"Ecological, exergetic efficiency and heating load optimizations for irreversible variable-temperature heat reservoir simple air heat pump cycles","authors":"Y. Bi, Lingen Chen, F. Sun","doi":"10.1093/IJLCT/CTP037","DOIUrl":"https://doi.org/10.1093/IJLCT/CTP037","url":null,"abstract":"Thermodynamic optimization of an irreversible air heat pump with variable-temperature heat reservoirs and hot- and cold-side counter-flow heat exchangers has been studied. The expressions of the heating load, the exergetic efficiency and the ecological function of the heat pump cycle are derived. Performance comparisons among exergetic efficiency optimization, ecological optimization and traditional heating load optimization objectives are done. The effect of the pressure ratio of the compressor, the allocation of heat exchanger inventory and the heat capacity rate matching between the working fluid and the heat reservoirs on the optimal performance of the cycle has been investigated by detailed numerical examples. When the performance optimization of the cycle is carried out by selecting the pressure ratio, three optimization objectives give simultaneously attention to the coefficient of performance (COP). The pressure ratio should be the one that is little bigger than the optimum pressure ratio corresponding to maximum COP, however, the results of three optimization objectives are consistent by optimizing the allocation of heat exchanger inventory and optimizing the heat capacity rate matching between the working fluid and the heat reservoirs. The optimum allocations of heat conductance are close to each other, and they are all less than 0.5. The results may provide guidelines for the design and optimization of practical air heat pump plants.","PeriodicalId":13509,"journal":{"name":"Indian Journal of Pure & Applied Physics","volume":"47 1","pages":"852-862"},"PeriodicalIF":0.7,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/IJLCT/CTP037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60782008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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