Bijan Nikouravan | University of Malaya, Malaysia (original) (raw)

Papers by Bijan Nikouravan

HPGe c-ray spectrometry 232 Th/ 238 U ratio Mass concentration Granite rocks Crustal minerals a b... more HPGe c-ray spectrometry 232 Th/ 238 U ratio Mass concentration Granite rocks Crustal minerals a b s t r a c t Accurate quantification of naturally occurring radioactive materials in soil provides information on geological characteristics, possibility of petroleum and mineral exploration, radiation hazards to the dwelling populace etc. Of practical significance, the earth surface media (soil, sand and sediment) collected from the densely populated coastal area of Chittagong city, Bangladesh were analysed using a high purity germanium c-ray spectrometer with low background radiation environment. The mean activities of 226 Ra ( 238 U), 232 Th and 40 K in the studied materials show higher values than the respective world average of 33, 36 and 474 Bq/kg reported by the UNSCEAR (2000). The deduced mass concentrations of the primordial radionuclides 238 U, 232 Th and 40 K in the investigated samples are corresponding to the granite rocks, crustal minerals and typical rocks respectively. The estimated mean value of 232 Th/ 238 U for soil (3.98) and sediment (3.94) are in-line with the continental crustal average concentration of 3.82 for typical rock range reported by the National Council on Radiation Protection and Measurements (NCRP). But the tonalites and more silicic rocks elevate the mean value of 232 Th/ 238 U for sand samples amounting to 4.69. This indicates a significant fractionation during weathering or associated with the metasomatic activity in the investigated area of sand collection.

Modified Newtonian Dynamics (MOND) is a theory that suggests a modification in Newtonian dynamics... more Modified Newtonian Dynamics (MOND) is a theory that suggests a modification in Newtonian dynamics. It is an empirically motivated modification of Newtonian gravity without the need of dark matter. This theory is well fitted by explaining why the velocity of galaxies or stars are in linear and in flat curve. More than 84 galaxies are in a well fitting with MOND, and all fits of these galaxies can be found.

A recent experiment was achieved at HAARP to study the scaling of the ionospherically generated E... more A recent experiment was achieved at HAARP to study the scaling of the ionospherically generated ELF signal with power transmitted from the high frequency (HF) array. The results were in excellent agreement with computer simulations. The outcomes approving that the ELF power increases with the square of the incident HF power. This paper present a review on the situation of the ionized particles in Ionospheric layer when stimulated by artificial an ELF and VLF external high energy radio waves.

The mechanism of the femtosecond spin dynamics is still not properly understood. The remodeled Bl... more The mechanism of the femtosecond spin dynamics is still not properly understood. The remodeled Bloch-Schrödinger equation was incorporated into the Hamiltonian. The mechanism of the femtosecond dynamics was investigated under three quantum states. The spin relaxation mechanism operated in a single continuous time scale (>70ps) which was in variance with known postulate. The transient reflectivity was measured to be within an angular range of 18.6o to 90.0o at a pulse range of 1MHz to 6.5 MHz. Beyond the pulse intensity of -2.5, the system elapsed into a quasi-equilibrium state which explains the independence of the magnetic moment on the pulse intensity. Different possibilities of the femtosecond spin dynamics were worked out for future study.

Abstract. Friedmann equations are used to describe the evolution of the universe. Solving Friedma... more Abstract. Friedmann equations are used to describe the evolution of the universe. Solving Friedmann equations for the scale factor indicates that the universe starts from an initial singularity where all the physical laws break down. However, the Friedmann equations are well describing the late-time or large scale universe. Hence now, many physicists try to find an alternative theory to avoid this initial singularity. In this paper, we generate a version of first Friedmann equation which is added with an additional term. This additional term contains the quantum potential energy which is believed to play an important role at small scale. However, it will gradually become negligible when the universe evolves to large scale.

Applied Mathematical Sciences, 2013

A simple geometrical model considered to calculate redshift values of 378 celestial objects such ... more A simple geometrical model considered to calculate redshift values of 378 celestial objects such as Galaxies and Quasi stellar objects(QSO). In this model, Earth as a small point selected as center of observation. This constructed model, is based on the angle of observation from Earth. Although, theoretical and experimental results of this model show a well consistent for some objects, however final verification, need more and accurate data.

We derived Reissner-Nordstrom solution for non-rotating charged celestial objects with Elliptical... more We derived Reissner-Nordstrom solution for non-rotating charged celestial objects with Elliptical in shaped, such as stars and/or elliptical
galaxies. This metric is capable to describing the behavior of gravitational field outside any charged ellipsoidal celestial objects like stars, galaxies or Quasi-stellar object.

We study the evaluation of bending of light ray passing near a massive elliptical galaxy or star.... more We study the evaluation of bending of light ray passing near a massive elliptical galaxy or star. To obtain this solution we used two different, Einsteinian and Lagrangian method. In doing this, we consider and compare the difference deflection angle between spherical and elliptical shape objects which led to appear a small but not negligible coefficient as oblateness independent of mass but depend on shape and geometry of object.

Newton considered three-dimensional universe endowed with flat space Euclidean geometry, and trea... more Newton considered three-dimensional universe endowed with flat space Euclidean geometry, and treated the time as anoutside parameter and established his dynamics of the universe. Einstein along with space, considered time, and gener-ated a four-dimensional universe endowed with non-Euclidean curved space-time geometry with time as its fourth di-mension, and set up his field equations. Schwarzschild solved Einstein’s field equations around a star in space, which is,otherwise, flat, and obtained a solution. We, along with space and time, considered mass which also included energy ac-cording to Einstein’s mass-energy equivalence relation:
E=mc2 , and generated a five-dimensional universe with themass as its fifth dimension, and solved the Einstein’s field equations, in some simple cases, and obtained solutionsaround a star in space, which is otherwise, flat.

hindawi, 2013

Abstract In this paper a three-stage fifth-order Runge-Kutta method for the integration of a spec... more Abstract In this paper a three-stage fifth-order Runge-Kutta method for the integration of a special third order ordinary differential equation (ODE) is constructed. The zerostability of the method is proven. The numerical study of a third-order ODE arising in thin film flow of

It has been seen that the period of solar activity and its cycle has a decrease of seismic activ... more It has been seen that the period of solar activity and
its cycle has a decrease of seismic activity in the
compression zone of the Earth. In addition, at the
same time there is an increase of the activity in the
tension zones of the Earth. This study has been
emphasized on last 45 years (i.e. 1960-2005) cyclic
data in term of the number of seismic and sunspots
activities. The high correlation between sunspot and
earthquakes shows that there is long-term forecast for
the earthquakes mainly in Iran, Japan and USA in and
after 2010. The next maximum of seismic activities
and earthquakes with very high amplitude for the
tension zones on the Earth has forecasted for the
period 2012-2013 mainly in the night. This has been
alarming for the countries that fall within the seismic
region such as Iran, Japan, USA etc. and if the
Governments do not make the infrastructure
strengthen, there may be more disasters and loss of
life and properties in future.

International Journal of Fundamental Physical Sciences (IJFPS), Dec 2012

The general solution of a static sphere of perfect fluid of uniform density using isotropic line ... more The general solution of a static sphere of perfect fluid of uniform density using isotropic line element has been obtained by using the additional condition of continuity at the boundary . Here it is shown that, this solution is a solution of equation of Wyman with an additional integrating constant. If we do not put the condition of continuity at the boundary , then it can be shown that as 2 → ∞ using equation of Wyman so the solution of static sphere of dust can be obtained using Wyman’s solution by putting in the solution, so that in terms is for dust instead of in terms of fluid obtained by Wyman. The anomalies discussed in the present paper can be removed by new field equation. The new proposed field equation is given and it is shown that the new proposed equation can bring Newtonian approximation

International Journal of the Physical Sciences, Sep 2011

Einstein's field equations are based on Riemannian geometry. One of the great important in Rieman... more Einstein's field equations are based on Riemannian geometry. One of the great important in Riemannian
geometry is the curves that minimize the distance between two given points. The Ricci curvature
tensors are also broadly applicable to modern Riemannian geometry and general theory of relativity
(GTR). The solution of Einstein's field equations, need Ricci tensors. The line elements based on the
ellipsoidal coordinates systems usually are difficult to work but are more perfect than spherical
coordinate systems. Here we are trying to get all non-zero Ricci tensors coefficients of a line element in
an oblate spheroidal coordinate system for an elliptical shaped object. These objects can be as
galaxies, stars or planets and other celestial objects that we know today.

International Journal of Fundamental Physical Sciences (IJFPS), Jun 2012

The relationships between solar activities (sunspots, solar 10.7cm radio flux, solar irradiance, ... more The relationships between solar activities (sunspots, solar 10.7cm radio flux, solar irradiance, and solar proton events) and local earthquakes investigated in this paper. The geographical location of study is New Zealand area. All earthquakes data have been chosen for , from first of 1970 to Jun 2012. The study reveals the following conclusions: 1) The total numbers of earthquakes strongly show annually an increasing in number of earthquakes in New Zealand from 42 years ago. 2) The maximum earthquakes occur frequently around the minimum years of solar activities, 3) The maximum earthquakes occurs in minimum years of sunspots number with a good correlation coefficient. 4) The maximum earthquakes occur in the minimum solar cm radio flux with strong correlation coefficient.

Abstract For more effective use of ground fresh water resources, a remote sensing and GIS has bee... more Abstract For more effective use of ground fresh water resources, a remote sensing and GIS has been using in many places in last decades. The Pabdeh anticline belongs to the Zagros Mountains in the southwest Iran. This area is exposed in the karst region of Iran. The digital topographic maps in scale 1: 25000 within GIS environment have been studied to observe the risk reduction and changing of the water resources because of the tectonic activities which is a crucial to generate a groundwater disaster in the study area.

ABSTRACT The general solution of a static sphere of perfect fluid of uniform density using isotro... more ABSTRACT The general solution of a static sphere of perfect fluid of uniform density using isotropic line element has been obtained by using the additional condition of continuity at the boundary=. Here it is shown that, this solution is a solution of equation of Wyman with an additional integrating constant.

International Journal of Physical …, Jan 1, 2009

In solution of Einstein field equations it is necessary to contracting Riemann-Christofell tensor... more In solution of Einstein field equations it is necessary to contracting Riemann-Christofell tensor. The contraction of Riemann-Christofell tensor or simply the curvature tensor is called the Ricci tensor and denoted by . The calculation of Ricci tensor in 3 and especially in 4-dimension is not very difficult but, it is very tedious; and need more time with accuracy. In this paper, the focus has been given to construct a software programming for determination of Ricci tensors with Mathematica V 5.1. This software program is not only able to calculate for any dimension, but also has ability to add any coefficients that may be needed to assume in our line element with any coordinate systems.

IJPS (NASA Indexed), Jan 1, 2011

Approximate Kerr- like interior and exterior solutions for a very slowly rotating star of perfect... more Approximate Kerr- like interior and exterior solutions for a very slowly rotating star of perfect fluid is presented here which is valid for a very slowly rotating and hence very slightly oblate star of perfect fluid rotating with a very small constant angular velocity. Corresponding approximate exterior metric represents approximate Kerr exterior metric for a perfect fluid. The aim here is to obtain Kerr-like approximate exterior and interior solutions for a very slowly rotating star of perfect fluid simply following standard procedure used to obtain Schwarzschild solutions.

HPGe c-ray spectrometry 232 Th/ 238 U ratio Mass concentration Granite rocks Crustal minerals a b... more HPGe c-ray spectrometry 232 Th/ 238 U ratio Mass concentration Granite rocks Crustal minerals a b s t r a c t Accurate quantification of naturally occurring radioactive materials in soil provides information on geological characteristics, possibility of petroleum and mineral exploration, radiation hazards to the dwelling populace etc. Of practical significance, the earth surface media (soil, sand and sediment) collected from the densely populated coastal area of Chittagong city, Bangladesh were analysed using a high purity germanium c-ray spectrometer with low background radiation environment. The mean activities of 226 Ra ( 238 U), 232 Th and 40 K in the studied materials show higher values than the respective world average of 33, 36 and 474 Bq/kg reported by the UNSCEAR (2000). The deduced mass concentrations of the primordial radionuclides 238 U, 232 Th and 40 K in the investigated samples are corresponding to the granite rocks, crustal minerals and typical rocks respectively. The estimated mean value of 232 Th/ 238 U for soil (3.98) and sediment (3.94) are in-line with the continental crustal average concentration of 3.82 for typical rock range reported by the National Council on Radiation Protection and Measurements (NCRP). But the tonalites and more silicic rocks elevate the mean value of 232 Th/ 238 U for sand samples amounting to 4.69. This indicates a significant fractionation during weathering or associated with the metasomatic activity in the investigated area of sand collection.

Modified Newtonian Dynamics (MOND) is a theory that suggests a modification in Newtonian dynamics... more Modified Newtonian Dynamics (MOND) is a theory that suggests a modification in Newtonian dynamics. It is an empirically motivated modification of Newtonian gravity without the need of dark matter. This theory is well fitted by explaining why the velocity of galaxies or stars are in linear and in flat curve. More than 84 galaxies are in a well fitting with MOND, and all fits of these galaxies can be found.

A recent experiment was achieved at HAARP to study the scaling of the ionospherically generated E... more A recent experiment was achieved at HAARP to study the scaling of the ionospherically generated ELF signal with power transmitted from the high frequency (HF) array. The results were in excellent agreement with computer simulations. The outcomes approving that the ELF power increases with the square of the incident HF power. This paper present a review on the situation of the ionized particles in Ionospheric layer when stimulated by artificial an ELF and VLF external high energy radio waves.

The mechanism of the femtosecond spin dynamics is still not properly understood. The remodeled Bl... more The mechanism of the femtosecond spin dynamics is still not properly understood. The remodeled Bloch-Schrödinger equation was incorporated into the Hamiltonian. The mechanism of the femtosecond dynamics was investigated under three quantum states. The spin relaxation mechanism operated in a single continuous time scale (>70ps) which was in variance with known postulate. The transient reflectivity was measured to be within an angular range of 18.6o to 90.0o at a pulse range of 1MHz to 6.5 MHz. Beyond the pulse intensity of -2.5, the system elapsed into a quasi-equilibrium state which explains the independence of the magnetic moment on the pulse intensity. Different possibilities of the femtosecond spin dynamics were worked out for future study.

Abstract. Friedmann equations are used to describe the evolution of the universe. Solving Friedma... more Abstract. Friedmann equations are used to describe the evolution of the universe. Solving Friedmann equations for the scale factor indicates that the universe starts from an initial singularity where all the physical laws break down. However, the Friedmann equations are well describing the late-time or large scale universe. Hence now, many physicists try to find an alternative theory to avoid this initial singularity. In this paper, we generate a version of first Friedmann equation which is added with an additional term. This additional term contains the quantum potential energy which is believed to play an important role at small scale. However, it will gradually become negligible when the universe evolves to large scale.

Applied Mathematical Sciences, 2013

A simple geometrical model considered to calculate redshift values of 378 celestial objects such ... more A simple geometrical model considered to calculate redshift values of 378 celestial objects such as Galaxies and Quasi stellar objects(QSO). In this model, Earth as a small point selected as center of observation. This constructed model, is based on the angle of observation from Earth. Although, theoretical and experimental results of this model show a well consistent for some objects, however final verification, need more and accurate data.

We derived Reissner-Nordstrom solution for non-rotating charged celestial objects with Elliptical... more We derived Reissner-Nordstrom solution for non-rotating charged celestial objects with Elliptical in shaped, such as stars and/or elliptical
galaxies. This metric is capable to describing the behavior of gravitational field outside any charged ellipsoidal celestial objects like stars, galaxies or Quasi-stellar object.

We study the evaluation of bending of light ray passing near a massive elliptical galaxy or star.... more We study the evaluation of bending of light ray passing near a massive elliptical galaxy or star. To obtain this solution we used two different, Einsteinian and Lagrangian method. In doing this, we consider and compare the difference deflection angle between spherical and elliptical shape objects which led to appear a small but not negligible coefficient as oblateness independent of mass but depend on shape and geometry of object.

Newton considered three-dimensional universe endowed with flat space Euclidean geometry, and trea... more Newton considered three-dimensional universe endowed with flat space Euclidean geometry, and treated the time as anoutside parameter and established his dynamics of the universe. Einstein along with space, considered time, and gener-ated a four-dimensional universe endowed with non-Euclidean curved space-time geometry with time as its fourth di-mension, and set up his field equations. Schwarzschild solved Einstein’s field equations around a star in space, which is,otherwise, flat, and obtained a solution. We, along with space and time, considered mass which also included energy ac-cording to Einstein’s mass-energy equivalence relation:
E=mc2 , and generated a five-dimensional universe with themass as its fifth dimension, and solved the Einstein’s field equations, in some simple cases, and obtained solutionsaround a star in space, which is otherwise, flat.

hindawi, 2013

Abstract In this paper a three-stage fifth-order Runge-Kutta method for the integration of a spec... more Abstract In this paper a three-stage fifth-order Runge-Kutta method for the integration of a special third order ordinary differential equation (ODE) is constructed. The zerostability of the method is proven. The numerical study of a third-order ODE arising in thin film flow of

It has been seen that the period of solar activity and its cycle has a decrease of seismic activ... more It has been seen that the period of solar activity and
its cycle has a decrease of seismic activity in the
compression zone of the Earth. In addition, at the
same time there is an increase of the activity in the
tension zones of the Earth. This study has been
emphasized on last 45 years (i.e. 1960-2005) cyclic
data in term of the number of seismic and sunspots
activities. The high correlation between sunspot and
earthquakes shows that there is long-term forecast for
the earthquakes mainly in Iran, Japan and USA in and
after 2010. The next maximum of seismic activities
and earthquakes with very high amplitude for the
tension zones on the Earth has forecasted for the
period 2012-2013 mainly in the night. This has been
alarming for the countries that fall within the seismic
region such as Iran, Japan, USA etc. and if the
Governments do not make the infrastructure
strengthen, there may be more disasters and loss of
life and properties in future.

International Journal of Fundamental Physical Sciences (IJFPS), Dec 2012

The general solution of a static sphere of perfect fluid of uniform density using isotropic line ... more The general solution of a static sphere of perfect fluid of uniform density using isotropic line element has been obtained by using the additional condition of continuity at the boundary . Here it is shown that, this solution is a solution of equation of Wyman with an additional integrating constant. If we do not put the condition of continuity at the boundary , then it can be shown that as 2 → ∞ using equation of Wyman so the solution of static sphere of dust can be obtained using Wyman’s solution by putting in the solution, so that in terms is for dust instead of in terms of fluid obtained by Wyman. The anomalies discussed in the present paper can be removed by new field equation. The new proposed field equation is given and it is shown that the new proposed equation can bring Newtonian approximation

International Journal of the Physical Sciences, Sep 2011

Einstein's field equations are based on Riemannian geometry. One of the great important in Rieman... more Einstein's field equations are based on Riemannian geometry. One of the great important in Riemannian
geometry is the curves that minimize the distance between two given points. The Ricci curvature
tensors are also broadly applicable to modern Riemannian geometry and general theory of relativity
(GTR). The solution of Einstein's field equations, need Ricci tensors. The line elements based on the
ellipsoidal coordinates systems usually are difficult to work but are more perfect than spherical
coordinate systems. Here we are trying to get all non-zero Ricci tensors coefficients of a line element in
an oblate spheroidal coordinate system for an elliptical shaped object. These objects can be as
galaxies, stars or planets and other celestial objects that we know today.

International Journal of Fundamental Physical Sciences (IJFPS), Jun 2012

The relationships between solar activities (sunspots, solar 10.7cm radio flux, solar irradiance, ... more The relationships between solar activities (sunspots, solar 10.7cm radio flux, solar irradiance, and solar proton events) and local earthquakes investigated in this paper. The geographical location of study is New Zealand area. All earthquakes data have been chosen for , from first of 1970 to Jun 2012. The study reveals the following conclusions: 1) The total numbers of earthquakes strongly show annually an increasing in number of earthquakes in New Zealand from 42 years ago. 2) The maximum earthquakes occur frequently around the minimum years of solar activities, 3) The maximum earthquakes occurs in minimum years of sunspots number with a good correlation coefficient. 4) The maximum earthquakes occur in the minimum solar cm radio flux with strong correlation coefficient.

Abstract For more effective use of ground fresh water resources, a remote sensing and GIS has bee... more Abstract For more effective use of ground fresh water resources, a remote sensing and GIS has been using in many places in last decades. The Pabdeh anticline belongs to the Zagros Mountains in the southwest Iran. This area is exposed in the karst region of Iran. The digital topographic maps in scale 1: 25000 within GIS environment have been studied to observe the risk reduction and changing of the water resources because of the tectonic activities which is a crucial to generate a groundwater disaster in the study area.

ABSTRACT The general solution of a static sphere of perfect fluid of uniform density using isotro... more ABSTRACT The general solution of a static sphere of perfect fluid of uniform density using isotropic line element has been obtained by using the additional condition of continuity at the boundary=. Here it is shown that, this solution is a solution of equation of Wyman with an additional integrating constant.

International Journal of Physical …, Jan 1, 2009

In solution of Einstein field equations it is necessary to contracting Riemann-Christofell tensor... more In solution of Einstein field equations it is necessary to contracting Riemann-Christofell tensor. The contraction of Riemann-Christofell tensor or simply the curvature tensor is called the Ricci tensor and denoted by . The calculation of Ricci tensor in 3 and especially in 4-dimension is not very difficult but, it is very tedious; and need more time with accuracy. In this paper, the focus has been given to construct a software programming for determination of Ricci tensors with Mathematica V 5.1. This software program is not only able to calculate for any dimension, but also has ability to add any coefficients that may be needed to assume in our line element with any coordinate systems.

IJPS (NASA Indexed), Jan 1, 2011

Approximate Kerr- like interior and exterior solutions for a very slowly rotating star of perfect... more Approximate Kerr- like interior and exterior solutions for a very slowly rotating star of perfect fluid is presented here which is valid for a very slowly rotating and hence very slightly oblate star of perfect fluid rotating with a very small constant angular velocity. Corresponding approximate exterior metric represents approximate Kerr exterior metric for a perfect fluid. The aim here is to obtain Kerr-like approximate exterior and interior solutions for a very slowly rotating star of perfect fluid simply following standard procedure used to obtain Schwarzschild solutions.