Pub Date : 2020-02-01DOI: 10.18052/www.scipress.com/ifsl.15.9
Sergey G. Fedosin
In the framework of the special theory of relativity, elementary formulas are used to derive the formula for determining the relativistic angular momentum of a rotating ideal uniform ball. The moment of inertia of such a ball turns out to be a nonlinear function of the angular velocity of rotation. Application of this formula to the neutron star PSR J1614-2230 shows that due to relativistic corrections the angular momentum of the star increases tenfold as compared to the nonrelativistic formula. For the proton and neutron star PSR J1748-2446ad the velocities of their surface’s motion are calculated, which reach the values of the order of 30% and 19% of the speed of light, respectively. Using the formula for the relativistic angular momentum of a uniform ball, it is easy to obtain the formula for the angular momentum of a thin spherical shell depending on its thickness, radius, mass density, and angular velocity of rotation. As a result, considering a spherical body consisting of a set of such shells it becomes possible to accurately determine its angular momentum as the sum of the angular momenta of all the body’s shells. Two expressions are provided for the maximum possible angular momentum of the ball based on the rotation of the ball’s surface at the speed of light and based on the condition of integrity of the gravitationally bound body at the balance of the gravitational and centripetal forces. Comparison with the results of the general theory of relativity shows the difference in angular momentum of the order of 25% for an extremal Kerr black hole.
{"title":"On the Dependence of the Relativistic Angular Momentum of a Uniform Ball on the Radius and Angular Velocity of Rotation","authors":"Sergey G. Fedosin","doi":"10.18052/www.scipress.com/ifsl.15.9","DOIUrl":"https://doi.org/10.18052/www.scipress.com/ifsl.15.9","url":null,"abstract":"In the framework of the special theory of relativity, elementary formulas are used to derive the formula for determining the relativistic angular momentum of a rotating ideal uniform ball. The moment of inertia of such a ball turns out to be a nonlinear function of the angular velocity of rotation. Application of this formula to the neutron star PSR J1614-2230 shows that due to relativistic corrections the angular momentum of the star increases tenfold as compared to the nonrelativistic formula. For the proton and neutron star PSR J1748-2446ad the velocities of their surface’s motion are calculated, which reach the values of the order of 30% and 19% of the speed of light, respectively. Using the formula for the relativistic angular momentum of a uniform ball, it is easy to obtain the formula for the angular momentum of a thin spherical shell depending on its thickness, radius, mass density, and angular velocity of rotation. As a result, considering a spherical body consisting of a set of such shells it becomes possible to accurately determine its angular momentum as the sum of the angular momenta of all the body’s shells. Two expressions are provided for the maximum possible angular momentum of the ball based on the rotation of the ball’s surface at the speed of light and based on the condition of integrity of the gravitationally bound body at the balance of the gravitational and centripetal forces. Comparison with the results of the general theory of relativity shows the difference in angular momentum of the order of 25% for an extremal Kerr black hole.","PeriodicalId":262344,"journal":{"name":"International Frontier Science Letters","volume":"120-121 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131706430","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 : 2019-03-01DOI: 10.18052/WWW.SCIPRESS.COM/IFSL.14.41
N. A. Mohammad, M. Hasso
In this paper, we study the exact solution of singular integral equations using two methods, including Adomian Decomposition Method and Elzaki Transform Method. We propose an analytical method for solving singular integral equations and system of singular integral equations, and have some goals in our paper related to suggested technique for solving singular integral equations. The primary goal is for giving analytical solutions of such equations with simple steps, another goal is to compare the suggested method with other methods used in this study.
{"title":"On Solution of Singular Integral Equations by Operator Method","authors":"N. A. Mohammad, M. Hasso","doi":"10.18052/WWW.SCIPRESS.COM/IFSL.14.41","DOIUrl":"https://doi.org/10.18052/WWW.SCIPRESS.COM/IFSL.14.41","url":null,"abstract":"In this paper, we study the exact solution of singular integral equations using two methods, including Adomian Decomposition Method and Elzaki Transform Method. We propose an analytical method for solving singular integral equations and system of singular integral equations, and have some goals in our paper related to suggested technique for solving singular integral equations. The primary goal is for giving analytical solutions of such equations with simple steps, another goal is to compare the suggested method with other methods used in this study.","PeriodicalId":262344,"journal":{"name":"International Frontier Science Letters","volume":"231 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115660157","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 : 2019-03-01DOI: 10.18052/WWW.SCIPRESS.COM/IFSL.14.19
Sergey G. Fedosin
The generalized Poynting theorem is applied to the equilibrium system of particles, both inside and outside the system. The particles are bound to each other by means of the electromagnetic and gravitational fields, acceleration field and pressure field. As a result, the correlation is found between the acceleration field coefficient, the pressure field coefficient, the gravitational constant and the vacuum permittivity. This correlation also depends on the ratio of the charge density to the mass density of the particles inside the sphere. Due to the correlation between the given field coefficients the 4/3 problem is solved and the expression for the relativistic energy of the system is refined.
{"title":"The Generalized Poynting Theorem for the General Field and Solution of the 4/3 Problem","authors":"Sergey G. Fedosin","doi":"10.18052/WWW.SCIPRESS.COM/IFSL.14.19","DOIUrl":"https://doi.org/10.18052/WWW.SCIPRESS.COM/IFSL.14.19","url":null,"abstract":"The generalized Poynting theorem is applied to the equilibrium system of particles, both inside and outside the system. The particles are bound to each other by means of the electromagnetic and gravitational fields, acceleration field and pressure field. As a result, the correlation is found between the acceleration field coefficient, the pressure field coefficient, the gravitational constant and the vacuum permittivity. This correlation also depends on the ratio of the charge density to the mass density of the particles inside the sphere. Due to the correlation between the given field coefficients the 4/3 problem is solved and the expression for the relativistic energy of the system is refined.","PeriodicalId":262344,"journal":{"name":"International Frontier Science Letters","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122609586","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 : 2019-03-01DOI: 10.18052/WWW.SCIPRESS.COM/IFSL.14.1
E. Emagbetere, T. Salau, O. Oluwole
This work was set out to gain further insight into the kinetics of the human heart valve leaflet. The Korakianitis and Shi lumped parameter model was adopted for this study. The fixed points were determined, and then, their stability properties were assessed by evaluating eigenvalues of the Jacobian matrices. Normal physiological parameters for the valve model were simulated; based on which, a local bifurcation diagram was generated. Phase portraits were plotted from simulated responses, and were used to observe the qualitative properties of the valve leaflet motion. The evaluated fixed points were found to be dependent on pressure and flow effects, and independent on friction or damping effect. Observed switching of stability between the two fixed points indicated that the leaflet motion undergoes transcritical bifurcation. Of the two fixed points, one is always either a stable spiral or generative node while the other is a saddle. Numerical simulations were carried out to verify the analytical solutions.
{"title":"Fixed Points and Stability Analysis in the Motion of Human Heart Valve Leaflet","authors":"E. Emagbetere, T. Salau, O. Oluwole","doi":"10.18052/WWW.SCIPRESS.COM/IFSL.14.1","DOIUrl":"https://doi.org/10.18052/WWW.SCIPRESS.COM/IFSL.14.1","url":null,"abstract":"This work was set out to gain further insight into the kinetics of the human heart valve leaflet. The Korakianitis and Shi lumped parameter model was adopted for this study. The fixed points were determined, and then, their stability properties were assessed by evaluating eigenvalues of the Jacobian matrices. Normal physiological parameters for the valve model were simulated; based on which, a local bifurcation diagram was generated. Phase portraits were plotted from simulated responses, and were used to observe the qualitative properties of the valve leaflet motion. The evaluated fixed points were found to be dependent on pressure and flow effects, and independent on friction or damping effect. Observed switching of stability between the two fixed points indicated that the leaflet motion undergoes transcritical bifurcation. Of the two fixed points, one is always either a stable spiral or generative node while the other is a saddle. Numerical simulations were carried out to verify the analytical solutions.","PeriodicalId":262344,"journal":{"name":"International Frontier Science Letters","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114250874","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 : 2015-05-01DOI: 10.18052/WWW.SCIPRESS.COM/IFSL.6.6
Sergey G. Fedosin
Based on the similarity of properties of photons and money, and on the formula for the density of distribution of photon gas by energies, the corresponding mathematical formula for distribution of annual income per capita is obtained. Application of this formula for the data analysis reveals several independent groups of population with different average levels of their income. In particular four main groups of population contribute to the distribution of income in the economy of the USA.
{"title":"Group Function of Income Distribution in Society","authors":"Sergey G. Fedosin","doi":"10.18052/WWW.SCIPRESS.COM/IFSL.6.6","DOIUrl":"https://doi.org/10.18052/WWW.SCIPRESS.COM/IFSL.6.6","url":null,"abstract":"Based on the similarity of properties of photons and money, and on the formula for the density of distribution of photon gas by energies, the corresponding mathematical formula for distribution of annual income per capita is obtained. Application of this formula for the data analysis reveals several independent groups of population with different average levels of their income. In particular four main groups of population contribute to the distribution of income in the economy of the USA.","PeriodicalId":262344,"journal":{"name":"International Frontier Science Letters","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130185065","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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