For a system at absolute zero temperature, all thermal fluctuations are frozen out, while quantum fluctuations prevail. These microscopic quantum fluctuations can induce a quantum phase transition (QPT) in the ground state of a many-body system when the relative strength of two competing energy terms is varied across a critical value. This paper presents a detailed and quantitative study of the magnetic properties of Ising two-spin system at zero temperature in the presence of longitudinal, transverse and mixed fields, and also at finite temperatures. At the critical longitudinal magnetic field, the system is found to undergo a QPT to a ferromagnetic state. For this system, an infinitesimal departure from zero transverse field is found to trigger off QPT and also remove the degeneracies that persisted even in the presence of longitudinal field. These quantum fluctuations, leading to QPT are more evident in the mixed field than the separate effect of longitudinal and transverse fields. The observed quantum effects at zero temperature for this system are found to be completely wiped out at finite temperatures due to thermal fluctuations. A temperature increase favours antiferromagnetic alignment of spins, while a decrease in temperature favours ferromagnetic alignment.
{"title":"Quantum and Thermal Fluctuations in the Ising Chains: A Case Study of Spin-Two System","authors":"S. Ehika, O. Ataman, S. Iyayi","doi":"10.9790/4861-0903023242","DOIUrl":"https://doi.org/10.9790/4861-0903023242","url":null,"abstract":"For a system at absolute zero temperature, all thermal fluctuations are frozen out, while quantum fluctuations prevail. These microscopic quantum fluctuations can induce a quantum phase transition (QPT) in the ground state of a many-body system when the relative strength of two competing energy terms is varied across a critical value. This paper presents a detailed and quantitative study of the magnetic properties of Ising two-spin system at zero temperature in the presence of longitudinal, transverse and mixed fields, and also at finite temperatures. At the critical longitudinal magnetic field, the system is found to undergo a QPT to a ferromagnetic state. For this system, an infinitesimal departure from zero transverse field is found to trigger off QPT and also remove the degeneracies that persisted even in the presence of longitudinal field. These quantum fluctuations, leading to QPT are more evident in the mixed field than the separate effect of longitudinal and transverse fields. The observed quantum effects at zero temperature for this system are found to be completely wiped out at finite temperatures due to thermal fluctuations. A temperature increase favours antiferromagnetic alignment of spins, while a decrease in temperature favours ferromagnetic alignment.","PeriodicalId":14502,"journal":{"name":"IOSR Journal of Applied Physics","volume":"160 1","pages":"32-42"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76627398","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}
I. Y. .. A. Alrhman, Abdulaziz B. M. Hamed, M. Tagabo
In this study, we concluded the Lagrangian Dynamics on standard 10Kahler, being a model. Finally introduce, some geometrical and physical results on the related mechanic systems have been discussed. Key word: configuration manifold, Lagrangian function, 10-Kahler ManifoldsLagrangian mechanics.
{"title":"New form Lagrangian Dynamics on the standard 10- Kahler Manifolds","authors":"I. Y. .. A. Alrhman, Abdulaziz B. M. Hamed, M. Tagabo","doi":"10.9790/4861-0903021731","DOIUrl":"https://doi.org/10.9790/4861-0903021731","url":null,"abstract":"In this study, we concluded the Lagrangian Dynamics on standard 10Kahler, being a model. Finally introduce, some geometrical and physical results on the related mechanic systems have been discussed. Key word: configuration manifold, Lagrangian function, 10-Kahler ManifoldsLagrangian mechanics.","PeriodicalId":14502,"journal":{"name":"IOSR Journal of Applied Physics","volume":"27 1","pages":"17-31"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74933053","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}
5 mol% (PVA+ZnO): (x mol%) Cu ions doped polymer films were prepared by solution casting technique. The obtained films are analyzed using different characterization techniques like SEM, FTIR, optical and EPR. The SEM micrographs shows the improvement in the crystallinity of the Cu 2+ doped PVAZn polymer films compared with the pure PVAZn film. The Fourier transform infrared spectroscopy (FTIR) spectrum shows a characteristic peaks of C-H, C=C, CH2 and C-O bonds. The optical absorption spectrum exhibits broad bands at 412 nm and 692 nm, which were corresponds to the 2 B1g → 2 Eg and 2 B1g → 2 B2g transition. The EPR spectra of all the polymer samples exhibits resonance signals characteristic of Cu 2+ ions. The spin-Hamiltonian parameter indicate that the ground state of Cu 2+ ions is dx 2 y 2 and the site symmetry around Cu 2+ ions is tetragonally distorted octahedral site. The number of spins participating in resonance (N) and paramagnetic susceptibility () were calculated from the EPR data for various concentrations of Cu ions.
{"title":"Preparation and Characterization of (PVA+ZnO) Polymer Films Doped With Cu2+ Ions","authors":"C. Rani, S. Bindu, M. Hemalatha, C. Raju","doi":"10.9790/4861-0903011824","DOIUrl":"https://doi.org/10.9790/4861-0903011824","url":null,"abstract":"5 mol% (PVA+ZnO): (x mol%) Cu ions doped polymer films were prepared by solution casting technique. The obtained films are analyzed using different characterization techniques like SEM, FTIR, optical and EPR. The SEM micrographs shows the improvement in the crystallinity of the Cu 2+ doped PVAZn polymer films compared with the pure PVAZn film. The Fourier transform infrared spectroscopy (FTIR) spectrum shows a characteristic peaks of C-H, C=C, CH2 and C-O bonds. The optical absorption spectrum exhibits broad bands at 412 nm and 692 nm, which were corresponds to the 2 B1g → 2 Eg and 2 B1g → 2 B2g transition. The EPR spectra of all the polymer samples exhibits resonance signals characteristic of Cu 2+ ions. The spin-Hamiltonian parameter indicate that the ground state of Cu 2+ ions is dx 2 y 2 and the site symmetry around Cu 2+ ions is tetragonally distorted octahedral site. The number of spins participating in resonance (N) and paramagnetic susceptibility () were calculated from the EPR data for various concentrations of Cu ions.","PeriodicalId":14502,"journal":{"name":"IOSR Journal of Applied Physics","volume":"21 12 1","pages":"18-24"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82910992","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}
: Solar energy is rapidly gaining importance as a source of renewable energies. Solar tracker system enables be generated more solar energy by using photovoltaic solar cells. The degree of use the solar radiation can be maximized by use of tracker system which can increase the enough efficiency. It receives the largest amount of solar radiation incident when it is perpendicular to the solar panel. In this paper a one axis solar tracker is designed and implemented to track the sun in azimuth axis by using an AVR microcontroller. The implemented system consists mainly of the ATmega328 controller, DC motor, light sensors, relay and solar panel. The results show that the designed low cost sun tracker increases the output power gain by 18-25% as compared with the fixed panel located at a latitude angel (35.47°) of the Kirkuk city, Iraq. To increase the amount of incident efficiency of solar radiation conversion from the panels of the sun tracker systems has been changed by adding rear panel (back side) which is opposite to the in front panel and it was shows that the efficiency of the output power increasing about (65%) compared with fixed panel and when adding the reflector made of Aluminum foil as (a mirror) to the opposite panel (rear panel) the output power increased about (72%) compared to fixed system. The overall power gains on our tracker system increased and become more efficient by adding rear side panel and reflector.
{"title":"Efficient Single Axis Sun Tracker Design for Photovoltaic System Applications","authors":"H. Akbar, Muayyad N. Fathallah, O. Raoof","doi":"10.9790/4861-0902025360","DOIUrl":"https://doi.org/10.9790/4861-0902025360","url":null,"abstract":": Solar energy is rapidly gaining importance as a source of renewable energies. Solar tracker system enables be generated more solar energy by using photovoltaic solar cells. The degree of use the solar radiation can be maximized by use of tracker system which can increase the enough efficiency. It receives the largest amount of solar radiation incident when it is perpendicular to the solar panel. In this paper a one axis solar tracker is designed and implemented to track the sun in azimuth axis by using an AVR microcontroller. The implemented system consists mainly of the ATmega328 controller, DC motor, light sensors, relay and solar panel. The results show that the designed low cost sun tracker increases the output power gain by 18-25% as compared with the fixed panel located at a latitude angel (35.47°) of the Kirkuk city, Iraq. To increase the amount of incident efficiency of solar radiation conversion from the panels of the sun tracker systems has been changed by adding rear panel (back side) which is opposite to the in front panel and it was shows that the efficiency of the output power increasing about (65%) compared with fixed panel and when adding the reflector made of Aluminum foil as (a mirror) to the opposite panel (rear panel) the output power increased about (72%) compared to fixed system. The overall power gains on our tracker system increased and become more efficient by adding rear side panel and reflector.","PeriodicalId":14502,"journal":{"name":"IOSR Journal of Applied Physics","volume":"8 1","pages":"53-60"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75886571","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}
In this paper α-Fe2O3, thin films were prepared by spray pyrolysis technique via spraying FeCl3·6H2O (10 -2 M) based aqueous solution with a spray flow of 8 ml/min onto heated glass substrates at 350 °C. After deposition, rust red and amorphous films was obtained. After a heat treatment at 400 ° C for six hours, the thin films are well crystallized. In order to study the surface morphology of the films and their crystalline structure, an electron scanning microscope (SEM) and X-ray diffraction were used (XRD). A UV-Vis-NIR spectrophotometer in the wavelength range 200–2500 nm was used to carry out the transmittance and the reflectance of the iron oxide films. The study of the optical properties of the iron oxide thin films was completed by the data acquired using a variable angle spectroscopic ellipsometer in the range 400–1800 nm of wavelength. The results reveal that the sprayed thin films were amorphous and after the heat treatment, the films crystallize in the α-Fe2O3 phase. SEM images show compact and homogeneous films, the estimated optical band gap for allowed direct transition of the iron oxide films was found to be 2.15 eV. On the other hand, the calculated thickness of the films from ellipsometry modeling is about 710 nm.
{"title":"Some Structural and Optical Properties of sprayed Iron Oxide Thin films","authors":"I. Tomsah","doi":"10.9790/4861-0902024652","DOIUrl":"https://doi.org/10.9790/4861-0902024652","url":null,"abstract":"In this paper α-Fe2O3, thin films were prepared by spray pyrolysis technique via spraying FeCl3·6H2O (10 -2 M) based aqueous solution with a spray flow of 8 ml/min onto heated glass substrates at 350 °C. After deposition, rust red and amorphous films was obtained. After a heat treatment at 400 ° C for six hours, the thin films are well crystallized. In order to study the surface morphology of the films and their crystalline structure, an electron scanning microscope (SEM) and X-ray diffraction were used (XRD). A UV-Vis-NIR spectrophotometer in the wavelength range 200–2500 nm was used to carry out the transmittance and the reflectance of the iron oxide films. The study of the optical properties of the iron oxide thin films was completed by the data acquired using a variable angle spectroscopic ellipsometer in the range 400–1800 nm of wavelength. The results reveal that the sprayed thin films were amorphous and after the heat treatment, the films crystallize in the α-Fe2O3 phase. SEM images show compact and homogeneous films, the estimated optical band gap for allowed direct transition of the iron oxide films was found to be 2.15 eV. On the other hand, the calculated thickness of the films from ellipsometry modeling is about 710 nm.","PeriodicalId":14502,"journal":{"name":"IOSR Journal of Applied Physics","volume":"326 1","pages":"46-52"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73137839","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}
Abstract: A useful generalization of an ansatz used to solve non relativistic Schroedinger equation for sextic potential of physical interest such that we obtain a class containing an infinite number of exact solutions for the given potential of physical importance. The exact solution may be used to get the accuracy and the reliability of numerical methods of solving Schroedinger equation.
{"title":"New Idea on Exact Solution of the Non Relativistic Schroedinger Equation for a Sextic Potential","authors":"V. Srivastava, S. Bose","doi":"10.9790/4861-0903019294","DOIUrl":"https://doi.org/10.9790/4861-0903019294","url":null,"abstract":"Abstract: A useful generalization of an ansatz used to solve non relativistic Schroedinger equation for sextic potential of physical interest such that we obtain a class containing an infinite number of exact solutions for the given potential of physical importance. The exact solution may be used to get the accuracy and the reliability of numerical methods of solving Schroedinger equation.","PeriodicalId":14502,"journal":{"name":"IOSR Journal of Applied Physics","volume":"29 24","pages":"19-24"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91446738","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":"Explanation of Expansion of Universe On The Basis Of Theory of Relativity and Consideration of Multiverse and Anti Gravity","authors":"R. Mishra","doi":"10.9790/4861-0903020407","DOIUrl":"https://doi.org/10.9790/4861-0903020407","url":null,"abstract":"","PeriodicalId":14502,"journal":{"name":"IOSR Journal of Applied Physics","volume":"18 1","pages":"04-07"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75518868","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}
In this paper I worked on the special case for studying the behavior of the universal gravitational constant by merging both Newtonian and relativistic mechanics. By that certain case I found that the value of the gravitational constant i.e. 6.67x N / is not actually a constant but vary with some conditions and reaches to zero at the speed of light. Keyword: Force, Lorentz transformation, Photon, Special relativity, speed of light, etc.
在本文中，我通过合并牛顿力学和相对论力学来研究万有引力常数的行为的特殊情况。通过这种特定的情况，我发现引力常数的值，即6.67x N /实际上不是一个常数，而是在某些条件下变化，并在光速下达到零。关键词:力，洛伦兹变换，光子，狭义相对论，光速等
{"title":"Varying Gravitational Constant under Special Case","authors":"Nikhil A. Khomane, Gaurav V. Kolhe","doi":"10.9790/4861-0903021516","DOIUrl":"https://doi.org/10.9790/4861-0903021516","url":null,"abstract":"In this paper I worked on the special case for studying the behavior of the universal gravitational constant by merging both Newtonian and relativistic mechanics. By that certain case I found that the value of the gravitational constant i.e. 6.67x N / is not actually a constant but vary with some conditions and reaches to zero at the speed of light. Keyword: Force, Lorentz transformation, Photon, Special relativity, speed of light, etc.","PeriodicalId":14502,"journal":{"name":"IOSR Journal of Applied Physics","volume":"23 1","pages":"15-16"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77506802","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}
Pub Date : 2017-05-01DOI: 10.9790/4861-090301100110
O. Onyejekwe
A numerical study has been carried out on the momentum and heat transfer characteristics of an incompressible magnetohydrodynamic boundary layer slip flow over a flat plate with both viscous and ohmic dissipations. Momentum boundary layer equation takes care of the magnetic field while the ohmic and viscous dissipations are accounted for by the thermal boundary layer equation. The governing equations constitute highly non-linear momentum and thermal boundary layer equations. Both are converted into similarity equations before being solved by the Runge-Kutta-Fehlberg technique with shooting. The results are analyzed for both isothermal and non-isothermal boundary conditions for various combinations of flow and heat transfer parameters. Some of the important findings show that in the absence of both the magnetic and velocity slip parameters, the flow profiles are identical to those of Bhattacharyya et al. [1]. The combined effect of increasing both the magnetic and the slip velocity parameters significantly affects the velocity and the shear stress profiles. An increase of slip parameter results in a decrease in skin friction, whereas an increase in Eckart number enhances viscous dissipation and a consequential temperature rise especially at the boundary. Sometimes this may escalate to a level where a Dirichlet temperature specification is exceeded. Furthermore, the temperature gradient is highly sensitive to prescribed values of Prandtl number and heat generation parameter.
{"title":"Magnetohydrodynamic Boundary Layer Slip Flow and Heat Transfer over a Flat Plate with Heat Generation/Absorption and Viscous Dissipation","authors":"O. Onyejekwe","doi":"10.9790/4861-090301100110","DOIUrl":"https://doi.org/10.9790/4861-090301100110","url":null,"abstract":"A numerical study has been carried out on the momentum and heat transfer characteristics of an incompressible magnetohydrodynamic boundary layer slip flow over a flat plate with both viscous and ohmic dissipations. Momentum boundary layer equation takes care of the magnetic field while the ohmic and viscous dissipations are accounted for by the thermal boundary layer equation. The governing equations constitute highly non-linear momentum and thermal boundary layer equations. Both are converted into similarity equations before being solved by the Runge-Kutta-Fehlberg technique with shooting. The results are analyzed for both isothermal and non-isothermal boundary conditions for various combinations of flow and heat transfer parameters. Some of the important findings show that in the absence of both the magnetic and velocity slip parameters, the flow profiles are identical to those of Bhattacharyya et al. [1]. The combined effect of increasing both the magnetic and the slip velocity parameters significantly affects the velocity and the shear stress profiles. An increase of slip parameter results in a decrease in skin friction, whereas an increase in Eckart number enhances viscous dissipation and a consequential temperature rise especially at the boundary. Sometimes this may escalate to a level where a Dirichlet temperature specification is exceeded. Furthermore, the temperature gradient is highly sensitive to prescribed values of Prandtl number and heat generation parameter.","PeriodicalId":14502,"journal":{"name":"IOSR Journal of Applied Physics","volume":"09 1","pages":"100-110"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81366692","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}
The density of ZrO2 ceramic carbon composites prepared by the conservative solid sintering technique is as close to any commercially available ZrO2. The Vicker's hardness as well as modulus of the sample with 1400°C high temperatures treated, is quite high compared to the lower 1200°C HTT samples. From S1 to S6 on comparison, it is found that porosity for S6 is minimum and maximum for S1. After comparing with ceramic monolith the flexural strength and modulus shows a remarkable improvement in its value. The average grain size measured from the width of the x-ray peaks, the information highlighted by x-ray diffractogram comes from a deeper level of the lattice. The optical micrograph shows the sample was uniform except for asperities arising due to leakage of pitch while carbonizing. The rest of the micrographs help in finding the grain size as well as the extent of infiltration of pitch into the system.
{"title":"Growth, Characterization and Comparison of Zirconia-Graphite Ceramic Carbon Composites","authors":"V. Kumari, S. Rani, Dharvendra Singh","doi":"10.9790/4861-0903015458","DOIUrl":"https://doi.org/10.9790/4861-0903015458","url":null,"abstract":"The density of ZrO2 ceramic carbon composites prepared by the conservative solid sintering technique is as close to any commercially available ZrO2. The Vicker's hardness as well as modulus of the sample with 1400°C high temperatures treated, is quite high compared to the lower 1200°C HTT samples. From S1 to S6 on comparison, it is found that porosity for S6 is minimum and maximum for S1. After comparing with ceramic monolith the flexural strength and modulus shows a remarkable improvement in its value. The average grain size measured from the width of the x-ray peaks, the information highlighted by x-ray diffractogram comes from a deeper level of the lattice. The optical micrograph shows the sample was uniform except for asperities arising due to leakage of pitch while carbonizing. The rest of the micrographs help in finding the grain size as well as the extent of infiltration of pitch into the system.","PeriodicalId":14502,"journal":{"name":"IOSR Journal of Applied Physics","volume":"08 1","pages":"54-58"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89713506","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}
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