arXiv subjects

Jozsef Garai

Publications and source records attributed to Jozsef Garai.

31 records · Page 2Linked to original sources

arXiv2006

Infrared Absorption Investigations Confirm the Extraterrestrial Origin of Carbonado-Diamonds

The first complete infrared FTIR absorption spectra for carbonado-diamond confirm the interstellar origin for the most enigmatic diamonds known as carbonado. All previous attempts failed to measure the absorption of carbonado-diamond in the most important IR-range of 1000-1300 cm-1 (10.00-7.69 micro-m.) because of silica inclusions. In our investigation, KBr pellets were made from crushed silica-free carbonado-diamond and thin sections were also prepared. The 100 to 1000 times brighter synchrotron infrared radiation permits a greater spatial resolution. Inclusions and pore spaces were avoided and/or sources of chemical contamination were removed. The FTIR spectra of carbonado-diamond mostly depict the presence of single nitrogen impurities, and hydrogen. The lack of identifiable nitrogen aggregates in the infrared spectra, the presence of features related to hydrocarbon stretch bonds, and the resemblance of the spectra to CVD and presolar diamonds indicate that carbonado-diamonds formed in a hydrogen-rich interstellar environment. This is consistent with carbonado-diamond being sintered and porous, with extremely reduced metals, metal alloys, carbides and nitrides, light carbon isotopes, surfaces with glassy melt-like patinas, deformation lamellae, and a complete absence of primary, terrestrial mineral inclusions. The 2.6-3.8 billion year old fragmented body was of asteroidal proportions.

physics.space-ph↗

arXiv2006

Correlation between thermal expansion and heat capacity

Theoretically predicted linear correlation between the volume coefficient of thermal expansion and the thermal heat capacity was investigated for highly symmetrical atomic arrangements. Normalizing the data of these thermodynamic parameters to the Debye temperature gives practically identical curves from zero Kelvin to the Debye temperature. This result is consistent with the predicted linear correlation. At temperatures higher than the Debye temperature the normalized values of the thermal expansion are always higher than the normalized value of the heat capacity. The detected correlation has significant computational advantage since it allows calculating the volume coefficient of thermal expansion from one experimental data by using the Debye function.

physics.gen-ph↗

arXiv2006

Thermo-physical description of elastic solids

Experiments show that all the derivatives of the thermo-physical variables are nearly constant. The constant value of the derivatives indicates linear relationship between the variables. Neither the volume coefficient of thermal expansion nor the bulk modulus are constant and show pressure and temperature dependence. Besides the derivatives the only other quantity in the definition of the volume coefficient of thermal expansion and the bulk modulus is the volume. It is suggested that the pressure and temperature dependence of these parameters is resulted from the improper identification of the volume. In solid phase the actual volume is not an independent variable but rather comprises from three more fundamental volume components, initial, thermal, and elastic volumes. The pressure correlates to the elastic volume and the temperature to the thermal volume. New definitions for the volume coefficient of thermal expansion and the bulk modulus are proposed by identifying the fundamental volume parts specifically. The complete separation of the thermal and elastic volumes is consistent with theory since the vibrational and static energies are completely independent of each other. Based on the independence of the thermal and elastic deformations it is suggested that thermo elastic coupling should not exist in solid phase in the elastic domain with the exception of constant volume. It is also suggested that the thermo-elastic coupling is irreversible and exist only in the temperature-pressure direction.

physics.chem-ph↗

arXiv2006

Investigating the optical properties of carbonado-diamonds

Carbonado-diamond is the most enigmatic of diamond types, and surprisingly there are few optical studies. In some cases, the diamond peak at 1332.5 cm-1 is absent, and the presence of a D-band graphite peak around 1320 cm-1 is observed in our Raman investigation. The disappearance of the diamond peak in carbonado-diamond is interpreted as the combined effect of small crystal size and the high absorption of graphite. The photoluminescence spectra of carbonado-diamond shows two new zero phonon lines at 584.2 nm (2.12 eV) and at 743 nm (1.67 eV). By heating the carbonado-diamond to 1500 oC for ten minutes in argon the appearance of an additional peak at 693.5 nm (1.786 eV) is detected. The infrared absorption spectra of carbonado-diamond powder indicate either extremely low or extremely high absorption.

physics.geo-ph↗

arXiv2005

Heat capacities of elastic solids

The work function is embedded in the equation describing the relationship between the constant volume and constant pressure heat capacities. The modification of the work function results that the relationship between these quantities must be changed accordingly. Using the newly derived work functions of elastic solids the description of the heat capacities and the relationship between the heat capacities are given for solid phase.

physics.chem-ph↗

arXiv2005

The work function of elastic solids

In solid phase the pressure correlates to the elastic related volume change while the temperature to the thermal related volume change. These volume changes are not compatible with the exception of constant volume condition when the expanded volume converts completely compressed volume. Separating the thermal and elastic related volume changes the work functions for each of the thermodynamic conditions are derived. Based on theoretical consideration it is suggested that the thermal related volume change do not result mechanical work. Homogeneous model, both the system and the surrounding have the same phase, can completely explain the lack of the thermal related work and provide a self-consistent thermodynamic description for the elastic solids.

physics.gen-ph↗

arXiv2005

Inconsistencies in the current thermodynamic description of elastic solids

Using the contemporary thermodynamic equations of elastic solids leads to contradictions with the fundamental statements of thermodynamics. Two examples are presented to expose the inconsistencies. In example one the internal energy between the initial and final states shows path dependency while in example two changing the temperature of a system at constant volume produces mechanical work. These results are contradictory with the fundamentals of thermodynamics and indicate that the contemporary description of elastic solids needs to be revisited and revised.

physics.gen-ph↗

arXiv2004

Physical model for the latent heat of fusion

The atomic movement induced on melting has to overcome a viscous drag resistance. It is suggested that the latent heat of fusion supplies the required energy for this physical process. The viscosity model introduced here allows computation of the latent heat from viscosity, molar volume, melting temperature, and atomic mass and diameter. The correlation between these parameters and the latent heat of 14 elements with body and face centered cubic structures was exceptional, with the correlation coefficients of 0.97 and 0.95 respectively.

physics.chem-ph↗

arXiv2004

Entropy is a Mathematical Formula

The microscopic explanation of entropy has been challenged from both experimental and theoretical point of view. The expression of entropy is derived from the first law of thermodynamics indicating that entropy or the second law of thermodynamics is not an independent law.

physics.gen-ph↗

arXiv2004

Bernoulli process with 282 ky periodicity is detected in the R-N reversals of the earth's magnetic field

Investigating the polarity time scales for the last 118 My a Bernoulli process with p=0.5 overriding with a Gaussian noise have been detected for the R-N magnetic reversals. The Bernoulli trials are separated by 282 ky. The frequency of the Bernoulli process correlates to planetary cycles and consistent with an impact triggered global cooling mechanism. The detected pattern allows calculating the probability of an upcoming R-N reversal between any time intervals.

physics.geo-ph↗

arXiv2003

The double tetrahedron structure of the nucleus

Expanding a double tetrahedron formation of equal spheres arranged in fcc structure correlation between the positions of the nucleons and quantum numbers has been detected. The number of protons in the structure is not simply consistent with all the corresponding quantum numbers but also bears the same physical meaning as in quantum mechanics. The detected correlations between lattice positions of the protons and quantum numbers raise the possibility the solid nuclear structure might be able to provide an explanation for the single particle properties of the nuclei.

nucl-th↗

arXiv2003

Post glacial rebounds measure the viscosity of the lithosphere

The observed higher uplift rates before the end of deglaciation requires the existence of a low viscosity channel or layer. The uplifts observed after the end of deglaciation does not show any contribution from this low viscosity channel and a homogeneous viscosity model fits very well to the observed uplift. Most of the researchers therefore prefer the homogeneous model and suggest that the higher uplift rate before the end of deglaciation is the result of elastic contamination. It has been shown that the elastic deformation of the lithosphere is far too small to be responsible for the observed extra uplift; therefore, the homogeneous viscosity model should be discredited. The homogeneous viscosity of the postglacial period and the high uplift rate of the late glacial period can be explained with a model which has an upper layer determining the homogeneous viscosity and the layer below it which has a low viscosity. The contribution to the uplift of this low viscosity layer is indistinguishable from an instantaneous uplift. Current GPS deformation measurements indicating 10^21 Pas average viscosity for the lithosphere, which is consistent with this model. The viscosity of the low velocity zone should be between 10^18 Pas and 10^11 Pas. The lower constrain on the viscosity of the low velocity zone can be deduced from seismic observations. This viscosity model is consistent with post glacial rebounds and further supported by the lack of the dynamic topography.

physics.geo-ph↗

arXiv2003

Melting of San Carlos olivine in the presence of carbon at 6-12 GPa

Experiments at 6-12 GPa showed that San Carlos olivine surrounded by carbon melts incongruently at 1400 C and higher temperatures, producing olivine with lower Fe contents, pyroxene, carbide, and carbonate melt. The relatively low melting temperature of 1400 C, independent of pressure, is consistent with carbonate melting. The new evidence for the reduced stability of olivine at high temperatures in the presence of carbonate melts is consistent with geophysical observations, and results in a substantially improved agreement between the experimentally determined phase relations and the observed seismic velocity structure of the upper mantle.

physics.geo-ph↗