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Jozsef Garai

Publications and source records attributed to Jozsef Garai.

At least 19 recordsLinked to original sources
arXiv2015

Nuclear lattice model and the electronic configuration of the chemical elements

The fundamental organizing principle resulting in the periodic table is the nuclear charge. Arranging the chemical elements in an increasing atomic number order, a symmetry pattern known as the Periodic Table is detectable. The correlation between nuclear charge and the Periodic System of the Chemical Elements (PSCE) indicates that the symmetry emerges from the nucleus. Nuclear symmetry can only exist if the relative positions of the nucleons in the nucleus are invariant. Pauli exclusion principle can also be interpreted as the nucleons should occupy a lattice position. Based on symmetry and other indicatives face centered cubic arrangement have been proposed for the nuclear lattice. A lattice model, representing the protons and the neutrons by equal spheres and arranging them alternately in a face centered cubic structure forming a double tetrahedron, is able to reproduce all of the properties of the nucleus including the quantum numbers and the periodicity of the elements. Based on the geometry of the nuclear structure it is shown that when a new 'layer' of the nuclear structure starts then the distance between the first proton in the new layer and the charge center of the nucleus is smaller than the distance of the proton, which completed the preceding 'layer'. Thus a new valence electron shell should start to develop when the nuclear structure is expanded. The expansion of the double tetrahedron FCC nuclear lattice model offers a feasible physical explanation how the nucleus affects the electronic configuration of the chemical elements depicted by the periodic table.

physics.gen-ph↗
arXiv2014

Electron configuration of the substitutional nitrogen defect in diamond

It is suggested that the substitutional nitrogen in diamonds bonded to three of the surrounding carbon atoms instead of four. This proposed electron configuration of the defect is deduced from previous experiments and theoretical considerations. Notably, the 1344 cm-1 band, characteristics of the substitutional Nitrogen, is independent of the isotopic change of Nitrogen but depend on the isotopic change of Carbon. The well established NV centre should not be stable if Nitrogen is bounded to four of the surrounding Carbon. Additional support comes from the substantially bigger size of the single substitutional nitrogen atom indicating loan pair electron. The proposed configuration of the substitutional Nitrogen was also tested by using a simple force constant model. Replacing force constant of C-N with 2/3 C-C:1/3 C=C reproduces the 1344 cm-1 band.

cond-mat.mtrl-sci↗
arXiv2011

Ionized Nitrogen Mono-hydride Bands are Identified in the Pre-solar and Carbonado Diamond Spectra

None of the well established Nitrogen related IR absorption bands, common in synthetic and terrestrial diamonds, have been identified in the pre-solar diamond spectra. In the carbonado diamond spectra only the single nitrogen impurity (C centre) is identified and the assignments of the rest of the nitrogen-related bands are still debated. It is speculated that the unidentified bands in the Nitrogen absorption region are not induced by Nitrogen but rather by Nitrogen-hydrides because in the interstellar environment Nitrogen reacts with Hydrogen and forms NH+; NH; NH2; NH3. Among these Hydrides the electronic configuration of NH+ is the closest to Carbon. Thus this ionized Nitrogen-mono-hydride is the best candidate to substitute Carbon in the diamond structure. The bands of the substitutional NH+ defect are deduced by red shifting the irradiation induced N+ bands due to the mass of the additional Hydrogen. The six bands of the NH+ defects are identified in both the pre-solar and the carbonado diamond spectra. The new assignments identify all of the nitrogen-related bands in the spectra, indicating that pre-solar and carbonado diamonds contain only single nitrogen impurities.

physics.geo-ph↗
arXiv2010

The First Law of Thermodynamics and the Thermodynamic Description of Elastic Solids

Historically, the thermodynamic behavior of gasses was described first and the derived equations were adapted to solids. It is suggested that the current thermodynamic description of solid phase is still incomplete because the isothermal work done on or by the system is not counted in the internal energy. It is also suggested that the isobaric work should not be deducted from the internal energy because the system does not do work when it expands. Further more it is suggested that Joule postulate regarding the mechanical equivalency of heat -the first law of thermodynamics- is not universal and not applicable to elastic solids. The equations for the proposed thermodynamic description of solids are derived and tested by calculating the internal energies of the system using the equation of state of MgO. The agreement with theory is good.

physics.chem-ph↗
arXiv2010

Upper bound on the disordered density of sphere packing and the Kepler Conjecture

The average distance of the equal hard spheres is introduced to evaluate the density of a given arrangement. The absolute smallest value is two radii because the spheres can not be closer to each other than their diameter. The absolute densest arrangement of two, three and four spheres is defined, which gives the absolute highest density in one, two and three dimensions. The absolute highest density of equal spheres in three dimensions is the tetrahedron formed by the centers of four spheres touching each other with density of 0.7796. The density of this tetrahedron unit can be maintained only locally because the tetrahedron units can not be expanded to form a tightly packed arrangement in three dimensions. The maximum number of tetrahedron units that one sphere is able to accommodate is twenty which corresponds to the density of 0.684. The only compatible formation of equal spheres which can be mixed with tetrahedron is octahedron. In order to mix the tetrahedron and octahedron units certain geometrical constrains must be satisfied. It is shown that the only possible mixture of tetrahedrons and octahedrons units is the one which accommodates eight tetrahedron and six octahedron vertexes which is identical to FCC and an alternative proof for the Kepler conjecture. It is suggested that there is a density gap between the FCC density and the highest density of disordered arrangements and that the icosahedrons configuration with its 0.684 density represents the upper bound on the disordered arrangements.

cond-mat.mtrl-sci↗
arXiv2009

Calculating the optimum pressure and temperature for vacancy minimization from theory; Niobium is an example

Self-resonance in the atomic vibration occurs when the average wavelength of the phonon thermal vibration is equivalent or harmonic of the diameters of the atoms. It is suggested that applying pressure at temperature corresponding to the self-resonance should effectively reduce the number of vacancies. This theoretical prediction is tested on Niobium by measuring the magnetic susceptibility of the untreated and treated samples. The applied pressure-temperature treatment increased the critical temperature of Niobium by about 30 percent which was also accompanied with volume increase.

physics.gen-ph↗
arXiv2009

P-V-T Equation of State for Periclase

Collecting the complete data set of previous experiments on periclase, covering a pressure and temperature range of 0-141.8 GPa and 100-3031 K respectively, the first comprehensive P-V-T description of MgO is presented comprising all previous experiments. The P-V-T EoS of Birch-Murnaghan, Rydberg-Vinet and Garai are determined by unrestricted fitting. The three EoSs are consistent and a unique set of parameters is able to cover the entire pressure and temperature range. The RMS misfits for the pressure are 0.371 GPa, 0.381 GPa and 0.396 GPa for the Garai, Birch-Murnaghan and Rydberg-Vinet EoSs. The RMS misfits for the volume and the temperature are 0.018 cm3 and 60.3 K for the EoS of Garai.

physics.geo-ph↗
arXiv2009

Physical model for vaporization

Based on two assumptions, the surface layer is flexible, and the internal energy of the latent heat of vaporization is completely utilized by the atoms for overcoming on the surface resistance of the liquid, the enthalpy of vaporization was calculated for 45 elements. The theoretical values were tested against experiments with positive result.

physics.chem-ph↗
arXiv2009

Impact Generated Shockwaves are Proposed for the Origin of Sunspots to Explain the Detected Planetary Effects on the Solar Activity

Five new correlations between sunspot activity and orbiting position of the Jovian planets are detected. In order to explain these correlations it is suggested that the resonance of the outer planets destabilizes the orbit of Kuiper Belt Objects and generates a cyclical impact frequency on the Sun. The vaporization of the object initiates a shock way disrupting the upwelling of the plasma resulting in a sunspot formation. The proposed model is able to explain the length of the cycle, the latitude distribution of the sunspots and the extremely long term stability of the cycles. Calculating the positions of the Jovian planets at conjunction and opposition allows the long term prediction of the solar activity.

physics.gen-ph↗
arXiv2009

Pressure effect on the melting temperature

Pressure-melting temperature relationship is proposed and tested against the experiments of metals (Pt and Al), salt (NaCl), and ceramic (MgO) with positive results. The equation contains one open parameter which remains constant for the investigated substances. The constant value of the parameter indicates that the presented equation for the melting curve might be the first one which does not contain any arbitrary constant which is left open to fit to the experiments.

physics.chem-ph↗
arXiv2009

The melting curve of Sodium: a theoretical approach

New model describing the pressure effect on the melting temperature is proposed by using four assumptions. One, the average wavelength of the phonon vibration at the Debye temperature corresponds to the length of the unit cell. Two, the phonon vibration at the melting temperature is in self-resonance with the lattice vibration of the surface atomic/molecular layer. Three, the phonon wavelength ratio of the Debye and the melting temperature does not be affected by the pressure. Four the pressure reduces the anharmonic part of the vibration. The relevant equations are derived and tested against the experiments of sodium with positive result.

physics.chem-ph↗
arXiv2009

Melting of crystalline solids

It is suggested that at the melting temperature the thermal phonon vibration is in self-resonance with the lattice vibration of the surface atomic/molecular layer. This self resonance occurs at a well defined temperature and triggers the detachment of the atomic/molecular sheet or platelets from the surface of the crystal. Thermodynamic data of five substances is used to test this hypothesis. The calculated average phonon vibrational wavelengths are equal with or harmonics of the d-spacing of the atomic/molecular sheets. The proposed model is able to explain all of the features of melting.

cond-mat.mtrl-sci↗
arXiv2009

Physics behind the Debye temperature

Textbooks introduce the Debye temperature to simplify the integration of the heat capacity. This approach gives the impression that the Debye temperature is a parameter which makes the integration more convenient. The Debye frequency cut occurs when the wavelength of the phonon frequency reaches the size of the smallest unit of the lattice which is the length of the unit cell. At frequencies higher than the cut off frequency the 'lattice' unable to 'see' the vibration because the wavelength of the vibration is smaller than the basic unit of the atomic arrangement; therefore, the vibration becomes independent from the lattice. The Debye cut off frequency or temperature separates the collective thermal lattice vibration from the independent thermal lattice vibration. The experimental data of highest packing monoatomic arrangements is used to calculate the wavelength of the Debye cut off frequency. The calculated values agree well with the unit cell parameters.

physics.chem-ph↗
arXiv2008

Universal Equation of States are Derived from the Isothermal Relationships of Elastic Solids

Universal P-V-T equations of states are derived from the original isothermal expressions of Birch-Murnaghan and the Vinet EoSs by using absolute reference frame and incorporating the temperature dependence of the parameters. The equations are tested against the experiments of perovskite [MgSiO3] and periclase [MgO]. The determined parameters of the EoSs are valid throughout the entire pressure and temperature ranges, which cover 0-142 GPa and 293-3000 K and 0-109 GPa and 293-2199 K for periclase and perovskite respectively. The root-mean-square (RMS) misfits of the universal Birch-Murnaghan EoS are 0.73 and 0.33 GPa and the misfit of the Vinet EoS are 0.74 and 0.32 GPa for perovskite and periclase respectively.

physics.geo-ph↗
arXiv2007

Semi-empirical pressure-volume-temperature equation of state; MgSiO3 perovskite is an example

Simple general formula describing the p-V-T relationships of elastic solids is derived from theoretical considerations. The new EoS was tested to experiments of perovskite 0-109 GPa and 293-2000 K. The parameters providing the best fit are: Ko = 267.5 GPa, Vo = 24.284 cm3, alpha_o = 2.079x10^-5 K^-1, the pressure derivative of Ko is 1.556 and the pressure derivative of alpha_o is -1.098x10^-7 K^-1GPa^-1 . The root-mean-square-deviations (RMSD) of the residuals are 0.043 cm3, 0.79 GPa, and 125 K for the molar volume, pressure, and temperature respectively. These RMSD values are in the range of the uncertainty of the experiments, indicating that the five parameters semi-empirical EoS correctly describes the p-V-T relationships of perovskite. Separating the experiments into 200 K ranges the semi-empirical EoS was compared to the most widely used finite strain, interatomic potential, and empirical isothermal EoSs such as the Birch-Murnaghan, the Vinet, and the Roy-Roy respectively. Correlation coefficients, RMSDs of the residuals and Akaike Information Criteria were used for evaluating the fitting. Based on these fitting parameters under pure isothermal conditions the semi-empirical p-V EoS is slightly weaker than the Birch-Murnaghan and Vinet EoSs; however, the semi-empirical p-V-T EoS is superior in every temperature range to all of the investigated conventional isothermal EoSs.

physics.gen-ph↗
arXiv2007

Global coupling at 660 km is proposed to explain plate tectonics and the generation of the earth's magnetic field

The presence of low viscosity layers in the mantle is supported by line of geological and geophysical observations. Recent high pressure and temperature investigations indicated that partial carbonate melt should exist at the bottom of the lithosphere and at 660 km. The presence of few percent carbonate melt reduces the viscosity by several order of magnitude. The globally existing 660 km very low viscosity layer allows the development of differential rotation between the upper and lower mantle. This differential rotation between the 660 km outer shell and the rest of the earth offers a plausible explanation for plate tectonics and for the generation of the earth's magnetic field. Simple dynamo model is proposed, which able to reproduce all of the features of the contemporary and, within reasonable uncertainty, the paleomagnetic field. The model is also consistent with geological and geophysical observations.

physics.gen-ph↗
arXiv2007

P-V-T equation of state of epsilon iron and its densities at core conditions

The author's new p-V-T Equation of State is tested against the available experiments of epsilon iron. The root-mean-square-deviations (RMSD) of the molar volume, pressure, and temperature are 0.021 cm3, 2.0 GPa and 144.9 K respectively. Separating the experiments into 200 K ranges the new EoS was compared to the most widely used finite strain, interatomic potential, and empirical isothermal EoSs such as the Burch-Murnaghan, the Vinet, and the Roy-Roy respectively. Correlation coefficients, RMSDs of the residuals and Akaike Information Criteria were used for evaluating the fittings. Based on these fitting parameters the new p-V-T EoS is equal or better than the conventional isothermal EoSs. The newly defined parameters were used to calculate the density of the inner core. The calculated densities are significantly lower than the current consensus indicating that it might be too early excluding the possibility of a pure iron-nickel core with no light elements.

physics.gen-ph↗