Pub Date : 2021-07-09DOI: 10.11648/J.AJPA.20210903.11
Bayew Kebede
The current study concentrated on the risk associated with naturally occurring radioactive materials in opal minerals and the method of refinement from the opal deposit site. The study's goal was to raise awareness of people who cause disease, improper use of expectations, and of better income generated in scientific ways. Radiation exposure has been associated with most forms of leukemia and with cancers of many organs, such as the lung, breast and thyroid gland, but not with certain other organs, such as the prostate gland. Mineworkers are exposed to radiation when extracting minerals from the earth's crust, with the associated radiological risks being assessed. Earth mineralogy is associated with environmental risks during mining and refining, particularly in certain aspects. Opal is most commonly found in Wollo, Ethiopia's northernmost region. The mechanism people used to refine opal Minerals at Wegel Tena often use rudimentary tools, such as a hammer and chisel, to extract the opal from the exposed seam along the flank of the canyon. The people living in Wogel Tena unknowingly export opal minerals to traders. Nowadays, the government's energy and mineral ministers are concerned about the preservation of tourist attractions and commercial centers using scientific methods. The local opal trader was unconcerned about people's safety or the diversion of mining resources. The new opal deposit was discovered in the village of Wegel Tena. Unlike previous Ethiopian opals, the new material is mostly white, with a little brown opal, fire opal, and a colorless "crystal" opal thrown in for good measure. When soaked in water, the opaque-to-translucent opals become transparent, showing a remarkable hydrophane character.
{"title":"Assessing Geological Resource and Risk Associated Radiation While Refining Opal Minerals Using Local Mechanism","authors":"Bayew Kebede","doi":"10.11648/J.AJPA.20210903.11","DOIUrl":"https://doi.org/10.11648/J.AJPA.20210903.11","url":null,"abstract":"The current study concentrated on the risk associated with naturally occurring radioactive materials in opal minerals and the method of refinement from the opal deposit site. The study's goal was to raise awareness of people who cause disease, improper use of expectations, and of better income generated in scientific ways. Radiation exposure has been associated with most forms of leukemia and with cancers of many organs, such as the lung, breast and thyroid gland, but not with certain other organs, such as the prostate gland. Mineworkers are exposed to radiation when extracting minerals from the earth's crust, with the associated radiological risks being assessed. Earth mineralogy is associated with environmental risks during mining and refining, particularly in certain aspects. Opal is most commonly found in Wollo, Ethiopia's northernmost region. The mechanism people used to refine opal Minerals at Wegel Tena often use rudimentary tools, such as a hammer and chisel, to extract the opal from the exposed seam along the flank of the canyon. The people living in Wogel Tena unknowingly export opal minerals to traders. Nowadays, the government's energy and mineral ministers are concerned about the preservation of tourist attractions and commercial centers using scientific methods. The local opal trader was unconcerned about people's safety or the diversion of mining resources. The new opal deposit was discovered in the village of Wegel Tena. Unlike previous Ethiopian opals, the new material is mostly white, with a little brown opal, fire opal, and a colorless \"crystal\" opal thrown in for good measure. When soaked in water, the opaque-to-translucent opals become transparent, showing a remarkable hydrophane character.","PeriodicalId":329149,"journal":{"name":"American Journal of Physics and Applications","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114792006","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 : 2021-07-09DOI: 10.11648/j.ajpa.20210902.14
Bayew Kebede, Tadesse Gebeyehu
This research paper desired to illustrate the presence of naturally occurring radioactive minerals concentration and the way how naturally occurring radioactive minerals were identified in Wag-himra iron ore deposit soil site. The deposit area covers five Kebelles of the border of Sekota, Ziquale and Abergelle districts. We were used high pure germanium detector to identify the presence of natural occurring radioactivity concentration in iron ore/alloy deposit soil, and applied appropriate research methodology particularly experimental design were more preferable. The researcher was collected samples from ten places across iron ore deposit area by using judgmental sampling techniques and prepared as a desirable manner. The chosen sample was sealed for four weeks in order to obtain secular equilibrium, wherein the rate of decay of the daughter’s equivalent that of the parent. Radium equivalent activity, external hazard index and representative gamma index of the sample were 56.19, 0.1515, 0.804, 0.408, 0.00011 (Bq/kg) respectively. However, internal hazard index was slightly approaching to recommended value and it may cause the significant radiation hazard through long dwelling to the area. This study NORM was analysis from sample of soil from at mineral/iron ore deposit area. The natural occurrence of radioactive materials identified in the samples were 238U, 232Th and 40K. The radiation hazardous were external and internal index.
{"title":"Evaluation of Natural Radioactive Elements and Hazardous Indexes Using High Pure Germanium Gamma Ray Spectroscopy in Sekota, Waghimra, Zone, Ethiopia","authors":"Bayew Kebede, Tadesse Gebeyehu","doi":"10.11648/j.ajpa.20210902.14","DOIUrl":"https://doi.org/10.11648/j.ajpa.20210902.14","url":null,"abstract":"This research paper desired to illustrate the presence of naturally occurring radioactive minerals concentration and the way how naturally occurring radioactive minerals were identified in Wag-himra iron ore deposit soil site. The deposit area covers five Kebelles of the border of Sekota, Ziquale and Abergelle districts. We were used high pure germanium detector to identify the presence of natural occurring radioactivity concentration in iron ore/alloy deposit soil, and applied appropriate research methodology particularly experimental design were more preferable. The researcher was collected samples from ten places across iron ore deposit area by using judgmental sampling techniques and prepared as a desirable manner. The chosen sample was sealed for four weeks in order to obtain secular equilibrium, wherein the rate of decay of the daughter’s equivalent that of the parent. Radium equivalent activity, external hazard index and representative gamma index of the sample were 56.19, 0.1515, 0.804, 0.408, 0.00011 (Bq/kg) respectively. However, internal hazard index was slightly approaching to recommended value and it may cause the significant radiation hazard through long dwelling to the area. This study NORM was analysis from sample of soil from at mineral/iron ore deposit area. The natural occurrence of radioactive materials identified in the samples were 238U, 232Th and 40K. The radiation hazardous were external and internal index.","PeriodicalId":329149,"journal":{"name":"American Journal of Physics and Applications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129216424","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 : 2021-05-21DOI: 10.11648/J.AJPA.20210902.13
Tadesse Gebeyehu, Baye Zinabe, Teshager Akalie
The current study looked at the concentration of naturally occurring radioactivity and radiation hazards in iron ore deposited in soil. The aim of this study was to identify the dose of radiation which is emitted from rocks, soil and some building materials, the radiation dose and the effect in the area. In this work, analyses of the sample soils were performed with a computer-based gamma-spectrometry system with software of G-2000 for qualitative and quantitative determination of gamma-emitting radionuclide of natural occurrence of radioactive materials. The quantitative investigation of natural radioactive materials of 238U, 232Th and 40K were 11.688±0.42Bq/kg, 23.505±0.925Bq/kg and 141.48±4.403Bq/kg respectively. In addition to this, the results of absorbed dose rate, annual effective dose equivalent, radium equivalent activity and representative gamma index of the sample were much less as compared to recommended international values by UNSCEAR-2000. At low activity concentrations of the radionuclides produce low background radiation to the environment. The value obtained from the experiment reveals that the radiation hazards emitted by natural radionuclides in the soil cause insignificant harm to the public from the Wag-himra iron ore deposit soil. The concentration of natural radioactive elements in this area's soil could be used for construction purposes without causing any significant radiological hazards to humans for the time being.
{"title":"Estimation of Concentration of Naturally Occurring Radioactivity and Radiation Hazards, in Iron Ore Deposit Soil from Wag-Himra Zone, Ethiopia","authors":"Tadesse Gebeyehu, Baye Zinabe, Teshager Akalie","doi":"10.11648/J.AJPA.20210902.13","DOIUrl":"https://doi.org/10.11648/J.AJPA.20210902.13","url":null,"abstract":"The current study looked at the concentration of naturally occurring radioactivity and radiation hazards in iron ore deposited in soil. The aim of this study was to identify the dose of radiation which is emitted from rocks, soil and some building materials, the radiation dose and the effect in the area. In this work, analyses of the sample soils were performed with a computer-based gamma-spectrometry system with software of G-2000 for qualitative and quantitative determination of gamma-emitting radionuclide of natural occurrence of radioactive materials. The quantitative investigation of natural radioactive materials of 238U, 232Th and 40K were 11.688±0.42Bq/kg, 23.505±0.925Bq/kg and 141.48±4.403Bq/kg respectively. In addition to this, the results of absorbed dose rate, annual effective dose equivalent, radium equivalent activity and representative gamma index of the sample were much less as compared to recommended international values by UNSCEAR-2000. At low activity concentrations of the radionuclides produce low background radiation to the environment. The value obtained from the experiment reveals that the radiation hazards emitted by natural radionuclides in the soil cause insignificant harm to the public from the Wag-himra iron ore deposit soil. The concentration of natural radioactive elements in this area's soil could be used for construction purposes without causing any significant radiological hazards to humans for the time being.","PeriodicalId":329149,"journal":{"name":"American Journal of Physics and Applications","volume":"30 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113993663","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 : 2021-04-26DOI: 10.11648/J.AJPA.20210902.12
T. Dialynas
The objective of the article is the mathematical description of the car motion in the most possible general form using Newton’s second law and the forces that act on it when they are known. In the first section, the forces that act on the vehicle are described and the normal (usual) conditions of driving are considered. Secondly the dynamical equation of motion baced on Newton’s second law is introduced which is in general a non-linear second order ordinary differential equation. Various cases are discussed such as going uphill, downhill, accelerating, decelerating etc. In Section 3, the energy consumption of the fuel is discussed and it is stated that it is consisted of two parts this of the “idle” worke and this of the sustainment of the motion. Besides it is shown that for a certain space “s” there is one unique speed that minimizes the consumption of fuel. In Section 4, the basic “defect” of the equation of motion which is the inclusion in the equation of the unknown driving force F(t) it is shown that it can be “circumvented” with energetic considerations leading to an equation having at the right – hand side the speed in the denominator and the excess revolutions per minute in the numerator. The resulting equation is such that a knowledge of δr(t)=(rpm)(t) – (rpm)0 can, by the numerical solution of the equation, lead to the function of speed and so a relation is established detween the velocity (u(t)) and the excess (rpm) which can be cheched as true or false by the aposteriori resister of the tachograph (u(t)) and rotation – counter (rpm(t)). Finally, in Section 5, we calculate, using the decelerating motion of a car in a flat road (when somebody leaves the throttle) all the kinematical and “energetical” constants that are introduced in the previous sections for sixth gear such as Fc, 6, b6, σ6, λ6 which can be used, post – hoc, to examine together with δr(t) if the real velocityof a vehicle coincides with the prediction that a computer can make. Besides for a flat road, the power of a car can be estimated for instance when it has u=120 km/h at rpm=3000 and in the 6th gear, giving for power -45HP which is a very reasonable estimate in order of magnitude.
{"title":"The Wheel – Vehicle Considered as a Material Point: An Approximate Theory of Automobiles","authors":"T. Dialynas","doi":"10.11648/J.AJPA.20210902.12","DOIUrl":"https://doi.org/10.11648/J.AJPA.20210902.12","url":null,"abstract":"The objective of the article is the mathematical description of the car motion in the most possible general form using Newton’s second law and the forces that act on it when they are known. In the first section, the forces that act on the vehicle are described and the normal (usual) conditions of driving are considered. Secondly the dynamical equation of motion baced on Newton’s second law is introduced which is in general a non-linear second order ordinary differential equation. Various cases are discussed such as going uphill, downhill, accelerating, decelerating etc. In Section 3, the energy consumption of the fuel is discussed and it is stated that it is consisted of two parts this of the “idle” worke and this of the sustainment of the motion. Besides it is shown that for a certain space “s” there is one unique speed that minimizes the consumption of fuel. In Section 4, the basic “defect” of the equation of motion which is the inclusion in the equation of the unknown driving force F(t) it is shown that it can be “circumvented” with energetic considerations leading to an equation having at the right – hand side the speed in the denominator and the excess revolutions per minute in the numerator. The resulting equation is such that a knowledge of δr(t)=(rpm)(t) – (rpm)0 can, by the numerical solution of the equation, lead to the function of speed and so a relation is established detween the velocity (u(t)) and the excess (rpm) which can be cheched as true or false by the aposteriori resister of the tachograph (u(t)) and rotation – counter (rpm(t)). Finally, in Section 5, we calculate, using the decelerating motion of a car in a flat road (when somebody leaves the throttle) all the kinematical and “energetical” constants that are introduced in the previous sections for sixth gear such as Fc, 6, b6, σ6, λ6 which can be used, post – hoc, to examine together with δr(t) if the real velocityof a vehicle coincides with the prediction that a computer can make. Besides for a flat road, the power of a car can be estimated for instance when it has u=120 km/h at rpm=3000 and in the 6th gear, giving for power -45HP which is a very reasonable estimate in order of magnitude.","PeriodicalId":329149,"journal":{"name":"American Journal of Physics and Applications","volume":"11 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120996786","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 : 2021-04-26DOI: 10.11648/J.AJPA.20210902.11
B. K. Sahoo, B. Mishra, Subhalaxmi Das, S. K. Barik, P. Patnaik, Ruchi Bhuyan, B. Panda
We formulate a Model Hamiltonian of two band superconductivity for Magnesium Diboride superconductors (MgB2). It is a conventional BCS type metallic superconductor which has the highest critical temperature Tc=39K. It is assumed that the superconductivity in MgB2 arises due to metallic nature of the 2D sheets. From band structure calculations, it is observed that two types of bands i.e. σ and π bands are located at Fermi surface. Here, we consider phonon mediated superconductivity in which σ band is dominant over π band i.e. σ band is more coupled to a superconductor with much higher coupling. We consider a model Hamiltonian with mean field approach and solve this by calculating equations of motion of Green functions for a single particle. We determine the quasi-particle energy from the poles of the Green functions. We derive the single particle correlation functions and determine the two SC order parameters for both σ and π band. Here, the two SC order parameters for the bands are solved self- consistently and numerically. The conduction bandwidth (W) is considered as W=8t0, where t0 is the hopping integral. To make all the physical quantities dimensionless, we divide 2t0 in each of the physical quantities. We then calculate the gap ratio 2∆(0)/KBTc for both the bands. It is seen form our theoretical model that the two bands of MgB2 superconductors have two different SC gaps with the same critical temperature. We also observe the variation of dispersion curves of quasi-particles for different temperature parameters for both σ and π band.
{"title":"Microscopic Study of Two Band Superconductivity in Magnesium Diboride Superconductor (MgB2)","authors":"B. K. Sahoo, B. Mishra, Subhalaxmi Das, S. K. Barik, P. Patnaik, Ruchi Bhuyan, B. Panda","doi":"10.11648/J.AJPA.20210902.11","DOIUrl":"https://doi.org/10.11648/J.AJPA.20210902.11","url":null,"abstract":"We formulate a Model Hamiltonian of two band superconductivity for Magnesium Diboride superconductors (MgB2). It is a conventional BCS type metallic superconductor which has the highest critical temperature Tc=39K. It is assumed that the superconductivity in MgB2 arises due to metallic nature of the 2D sheets. From band structure calculations, it is observed that two types of bands i.e. σ and π bands are located at Fermi surface. Here, we consider phonon mediated superconductivity in which σ band is dominant over π band i.e. σ band is more coupled to a superconductor with much higher coupling. We consider a model Hamiltonian with mean field approach and solve this by calculating equations of motion of Green functions for a single particle. We determine the quasi-particle energy from the poles of the Green functions. We derive the single particle correlation functions and determine the two SC order parameters for both σ and π band. Here, the two SC order parameters for the bands are solved self- consistently and numerically. The conduction bandwidth (W) is considered as W=8t0, where t0 is the hopping integral. To make all the physical quantities dimensionless, we divide 2t0 in each of the physical quantities. We then calculate the gap ratio 2∆(0)/KBTc for both the bands. It is seen form our theoretical model that the two bands of MgB2 superconductors have two different SC gaps with the same critical temperature. We also observe the variation of dispersion curves of quasi-particles for different temperature parameters for both σ and π band.","PeriodicalId":329149,"journal":{"name":"American Journal of Physics and Applications","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124546139","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 : 2021-03-17DOI: 10.11648/J.AJPA.20210901.14
S. Olugbenga, Green Oluwole
A Photovoltaic (PV) power monitoring is important in PV systems for proper generation and transmission. With the need to monitor certain parameters like voltage, current and power in order to ascertain the power output of a solar system. In this project design, a GSM solar power monitoring system is designed in order to monitor the voltage, current and output power of a solar system and also transmit the monitored parameters in real time to a remote location via the SMS feature of the GSM technology. An 8 bit 18F452 PIC microcontroller is used as the control unit which controls the Pulse width Modulation (PWM) solar charge controller, IRF3205 MOSFETs as the switching transistors in the charge controller charging a 30AH 12v battery via a 30watts polycrystalline solar panel. Universal asynchronous synchronous receiver and transmitter (USART) is used as protocol for transmission between a Sim 900 GSM module and the microcontroller while the attention (AT) command is used as the communication protocol in sending measured power parameters from the microcontroller to the GSM module which in turn sends the measured parameters as SMS message to a remote location. ACS 712 hall effect current sensor for measuring current and a voltage divider network for measuring the PV cell voltage. The circuit board is printed on a Printed circuit board (PCB) using the traditional transfer method. C programming language is used in writing program codes embedded on the controller. This project design have been able to show that by employing the use of a wireless real time data monitoring (GSM technology), PV systems can be properly monitored remotely for consumption, operation, analysis and isolation in cases of fault detection.
{"title":"A GSM Based Intelligent Solar Energy Measuring System","authors":"S. Olugbenga, Green Oluwole","doi":"10.11648/J.AJPA.20210901.14","DOIUrl":"https://doi.org/10.11648/J.AJPA.20210901.14","url":null,"abstract":"A Photovoltaic (PV) power monitoring is important in PV systems for proper generation and transmission. With the need to monitor certain parameters like voltage, current and power in order to ascertain the power output of a solar system. In this project design, a GSM solar power monitoring system is designed in order to monitor the voltage, current and output power of a solar system and also transmit the monitored parameters in real time to a remote location via the SMS feature of the GSM technology. An 8 bit 18F452 PIC microcontroller is used as the control unit which controls the Pulse width Modulation (PWM) solar charge controller, IRF3205 MOSFETs as the switching transistors in the charge controller charging a 30AH 12v battery via a 30watts polycrystalline solar panel. Universal asynchronous synchronous receiver and transmitter (USART) is used as protocol for transmission between a Sim 900 GSM module and the microcontroller while the attention (AT) command is used as the communication protocol in sending measured power parameters from the microcontroller to the GSM module which in turn sends the measured parameters as SMS message to a remote location. ACS 712 hall effect current sensor for measuring current and a voltage divider network for measuring the PV cell voltage. The circuit board is printed on a Printed circuit board (PCB) using the traditional transfer method. C programming language is used in writing program codes embedded on the controller. This project design have been able to show that by employing the use of a wireless real time data monitoring (GSM technology), PV systems can be properly monitored remotely for consumption, operation, analysis and isolation in cases of fault detection.","PeriodicalId":329149,"journal":{"name":"American Journal of Physics and Applications","volume":"22 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130675698","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 : 2021-01-22DOI: 10.11648/J.AJPA.20210901.12
Li Pinjun
The thermalization of two blocks with different initial temperatures in an insulated recipient is an irreversible process, so the entropy of the system will increase during this process. Lima (Eur. J. Phys. 36 (2015) 068001) has given an elegant and concise proof for that which had been proved by Mungan (Eur. J. Phys. 36 (2015) 048004) with a complex method. However, there are still two problems in Lima’s proof: 1. It is assumed that the heat capacities of two blocks are constants, which is not true in most practical cases. 2. An inequality that describes the concavity of the logarithm function was used but it is still relatively uncommon for beginners. In this article, two stricter and simpler proof were given for the problem 1 by making use of 1/T–Q diagram and T-S diagram, respectively. In the Proof by 1/T–Q diagram, the area under the curve of 1/T over the domain [0, Q0] is the value of the entropy change of the cooler block, which is positive; while the area under the curve of 1/T’ over the domain [Q0, 0] is the value of the entropy change of the hotter block, which is negative. It is rather intuitive to compare these two values by using the monotonicity and domains of T and Т’. A similar method is adopted in the proof by T-S diagram. For the problem 2, another proof for the key inequality in Mungan’s paper was given by using elementary geometric method which is really more suitable for physics beginners.
{"title":"Some Notes on the Proof of Entropy Increase in the Thermalization of Two Blocks","authors":"Li Pinjun","doi":"10.11648/J.AJPA.20210901.12","DOIUrl":"https://doi.org/10.11648/J.AJPA.20210901.12","url":null,"abstract":"The thermalization of two blocks with different initial temperatures in an insulated recipient is an irreversible process, so the entropy of the system will increase during this process. Lima (Eur. J. Phys. 36 (2015) 068001) has given an elegant and concise proof for that which had been proved by Mungan (Eur. J. Phys. 36 (2015) 048004) with a complex method. However, there are still two problems in Lima’s proof: 1. It is assumed that the heat capacities of two blocks are constants, which is not true in most practical cases. 2. An inequality that describes the concavity of the logarithm function was used but it is still relatively uncommon for beginners. In this article, two stricter and simpler proof were given for the problem 1 by making use of 1/T–Q diagram and T-S diagram, respectively. In the Proof by 1/T–Q diagram, the area under the curve of 1/T over the domain [0, Q0] is the value of the entropy change of the cooler block, which is positive; while the area under the curve of 1/T’ over the domain [Q0, 0] is the value of the entropy change of the hotter block, which is negative. It is rather intuitive to compare these two values by using the monotonicity and domains of T and Т’. A similar method is adopted in the proof by T-S diagram. For the problem 2, another proof for the key inequality in Mungan’s paper was given by using elementary geometric method which is really more suitable for physics beginners.","PeriodicalId":329149,"journal":{"name":"American Journal of Physics and Applications","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124386417","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 : 2021-01-22DOI: 10.11648/J.AJPA.20210901.13
Ricky L. Moore
Scaled Effective Medium Theory (ScEMT) is applied to predict magnetic resonant and relaxation frequency in polymer-magnetic particle composites with favorable comparison to measured data. A single scaling function is identified that uses magnetic particulate resonant and relaxation frequencies, or magnetization and anisotropy field, volume fraction and DC susceptibility as predicted by ScEMT. Previous publications demonstrated that ScEMT improved the prediction of DC susceptibility as compared to classical models. Maxwell-Garnett (MGT) and Coherent Model Approximation (CMA) serve as theoretical baselines for comparison. However, both require separate scaling functions in their prediction of resonant and relaxation. Measured data are presented that suggest a single scaling function of ScEMT is sufficient to calculate both parameters. The paper emphasizes the application of the models and shows a wide range of particulate chemistries. ScEMT calculates susceptibility, resonant and relaxation frequency that agree with measurement. The paper concludes by predicting dispersive permeability that represents improvement over both CMA and MGT models. Future studies will address formulation of an EMT model (s) that describe mixtures of hard and soft magnetic materials mixed in a polymer composite. EMT for composite dielectric properties will be expanded to address the chaining. Early results of that effort will be reported in a separate paper.
{"title":"A Scaled Effective Medium Theory for Calculation of Resonant and Relaxation Frequency in Magnetic Composites","authors":"Ricky L. Moore","doi":"10.11648/J.AJPA.20210901.13","DOIUrl":"https://doi.org/10.11648/J.AJPA.20210901.13","url":null,"abstract":"Scaled Effective Medium Theory (ScEMT) is applied to predict magnetic resonant and relaxation frequency in polymer-magnetic particle composites with favorable comparison to measured data. A single scaling function is identified that uses magnetic particulate resonant and relaxation frequencies, or magnetization and anisotropy field, volume fraction and DC susceptibility as predicted by ScEMT. Previous publications demonstrated that ScEMT improved the prediction of DC susceptibility as compared to classical models. Maxwell-Garnett (MGT) and Coherent Model Approximation (CMA) serve as theoretical baselines for comparison. However, both require separate scaling functions in their prediction of resonant and relaxation. Measured data are presented that suggest a single scaling function of ScEMT is sufficient to calculate both parameters. The paper emphasizes the application of the models and shows a wide range of particulate chemistries. ScEMT calculates susceptibility, resonant and relaxation frequency that agree with measurement. The paper concludes by predicting dispersive permeability that represents improvement over both CMA and MGT models. Future studies will address formulation of an EMT model (s) that describe mixtures of hard and soft magnetic materials mixed in a polymer composite. EMT for composite dielectric properties will be expanded to address the chaining. Early results of that effort will be reported in a separate paper.","PeriodicalId":329149,"journal":{"name":"American Journal of Physics and Applications","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124307410","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 : 2021-01-15DOI: 10.11648/J.AJPA.20210901.11
Norsang Gelsor, L. Juan, Tsoja Wangmo, Lagba Tunzhup, Nuozhen Gelsor
Research on solar radiation in the Mt. Everest region provides great interests for the strategies of solar energy utilization, climate change and environmental sustainability etc. We present measurement results of global horizontal irradiance, solar spectral irradiance and solar UV irradiance performed with the Dutch CMP11 Pyranometers, the German RAMSES Hyperspectral Irradiance Sensors and the Norwegian NILU-UV Irradiance Meters respectively in the Mt. Everest region during 2008 to 2017. The results show that the solar energy resources are extremely rich in that area, the daily maximum of global horizontal irradiance levels are even frequently exceed the solar constant value of 1368W/m2 during monsoon season, from May to August in that region. The highest daily maximum value reached 1500 W/m2 occurred on July 13, 2017. The annual average of the daily global horizontal irradiance is about 18.4 MJ/m2/d, the daily global horizontal irradiance varies from 13.8 to 23.9 MJ/m2/d, indicates that there are abundant solar energy in that alpine zone. The instruments record that even during the winter time (October to January) more than 15 days of each month are absolute clear days, it shows 28 clear days in November of 2016. It points out that more solar energy can be existed during the winter time due to dry season. The solar spectral irradiance was performed for the first time in this special environment presenting the characteristics of solar spectrum over the region. It reveals not only how abundant the spectral irradiance is, but also rich information about the atmospheric composition over the sky. It is well known that the solar UV radiation strongly impacts on the ecological environment and human health. The measurement results of solar UV dose rates as well as their impact factors (ozone and cloud) during the period of 2008 to 2017 are also presented. Satellite data are also used to see how the solar irradiance is distributed over the Himalayan region in summer, including Mt. Everest.
{"title":"Measurements on Solar Energy Resources in the Mt. Everest Region","authors":"Norsang Gelsor, L. Juan, Tsoja Wangmo, Lagba Tunzhup, Nuozhen Gelsor","doi":"10.11648/J.AJPA.20210901.11","DOIUrl":"https://doi.org/10.11648/J.AJPA.20210901.11","url":null,"abstract":"Research on solar radiation in the Mt. Everest region provides great interests for the strategies of solar energy utilization, climate change and environmental sustainability etc. We present measurement results of global horizontal irradiance, solar spectral irradiance and solar UV irradiance performed with the Dutch CMP11 Pyranometers, the German RAMSES Hyperspectral Irradiance Sensors and the Norwegian NILU-UV Irradiance Meters respectively in the Mt. Everest region during 2008 to 2017. The results show that the solar energy resources are extremely rich in that area, the daily maximum of global horizontal irradiance levels are even frequently exceed the solar constant value of 1368W/m2 during monsoon season, from May to August in that region. The highest daily maximum value reached 1500 W/m2 occurred on July 13, 2017. The annual average of the daily global horizontal irradiance is about 18.4 MJ/m2/d, the daily global horizontal irradiance varies from 13.8 to 23.9 MJ/m2/d, indicates that there are abundant solar energy in that alpine zone. The instruments record that even during the winter time (October to January) more than 15 days of each month are absolute clear days, it shows 28 clear days in November of 2016. It points out that more solar energy can be existed during the winter time due to dry season. The solar spectral irradiance was performed for the first time in this special environment presenting the characteristics of solar spectrum over the region. It reveals not only how abundant the spectral irradiance is, but also rich information about the atmospheric composition over the sky. It is well known that the solar UV radiation strongly impacts on the ecological environment and human health. The measurement results of solar UV dose rates as well as their impact factors (ozone and cloud) during the period of 2008 to 2017 are also presented. Satellite data are also used to see how the solar irradiance is distributed over the Himalayan region in summer, including Mt. Everest.","PeriodicalId":329149,"journal":{"name":"American Journal of Physics and Applications","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123141597","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 : 2020-11-24DOI: 10.11648/J.AJPA.20200806.11
T. Ohnishi
When we divide our present society into real and cyber worlds, there exist no clear data on how the public attitude or opinion is formed and on what sort of opinion distribution is realized in the cyber world. We propose a methodology for the model calculation with which we can compare the observation of the public opinion formed under the environment of social media in the cyber world. The public viewpoint or the opinion about a certain matter, together with the standpoint of the information provided by the social media, can not be given by some discrete values, but they make fuzzy distributions within certain ranges of opinion around certain central values. With the assumption that the variation of the public opinion originates from the emotional contagion induced by the contact of the public with the social media, and that the force realized by this contagion is given in terms of the common area of such fuzzy distributions of the public opinion and the information on the social media, we derived an equation of motion for the variation of public opinion. By further assuming that the information diffuses from a top toward a bottom of a ramified tree structure of node networks, we exemplified some characteristic patterns of the distribution of collective opinion including the effect of echo-chamber, which are realized under certain input spectra of the information on the social media. Moreover, by using the observed data for the 2016 USA President election as an input, we made clear that the reversal of the approval rating might possibly occur between the political right and left wings in so far as the response character of supporters to the social media differ depending on the political situation of the public.
{"title":"Modelling the Influence of Social Media on Collective Opinion","authors":"T. Ohnishi","doi":"10.11648/J.AJPA.20200806.11","DOIUrl":"https://doi.org/10.11648/J.AJPA.20200806.11","url":null,"abstract":"When we divide our present society into real and cyber worlds, there exist no clear data on how the public attitude or opinion is formed and on what sort of opinion distribution is realized in the cyber world. We propose a methodology for the model calculation with which we can compare the observation of the public opinion formed under the environment of social media in the cyber world. The public viewpoint or the opinion about a certain matter, together with the standpoint of the information provided by the social media, can not be given by some discrete values, but they make fuzzy distributions within certain ranges of opinion around certain central values. With the assumption that the variation of the public opinion originates from the emotional contagion induced by the contact of the public with the social media, and that the force realized by this contagion is given in terms of the common area of such fuzzy distributions of the public opinion and the information on the social media, we derived an equation of motion for the variation of public opinion. By further assuming that the information diffuses from a top toward a bottom of a ramified tree structure of node networks, we exemplified some characteristic patterns of the distribution of collective opinion including the effect of echo-chamber, which are realized under certain input spectra of the information on the social media. Moreover, by using the observed data for the 2016 USA President election as an input, we made clear that the reversal of the approval rating might possibly occur between the political right and left wings in so far as the response character of supporters to the social media differ depending on the political situation of the public.","PeriodicalId":329149,"journal":{"name":"American Journal of Physics and Applications","volume":"50 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117312742","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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