Journal for Foundations and Applications of Physics
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Curvature and the Electromagnetic Field
Get PDFMaxwell’s equations are derived from the curvature tensor and a vector potential. The results are combined with Einstein’s equations. Complete solutions to the resulting equation yield simultaneous solutions to both Einstein’s and Maxwell’s equations. This is a classical theoretical unification of electromagnetism and gravitation
On a Peculiar Attractor for Weakly Nonlinear Oscillators with a Two Period Quasiperiodic Forcing
Get PDFWe study a very peculiar nonlinear oscillator with an external two period quasiperiodic excitation, being the golden mean the ratio between the two frequencies. The two period quasi periodic forcing is characterized by an infinite frequencies number. As a consequence, we find that the motion settles down in a two period quasi periodic atttractor for a wide excitation amplitude range. The competition between the two frequencies does not produce a closed curve but fills a well defined phase space region in the Poincarè section. This attractor somehow resembles strange nonchaotic attractors because both are characterized by quasiperiodic forcing. Using a suitable perturbation method, we can understand the new attractor most important characteristics and find an approximate solution for its dynamical behavior. Numerical simulations are used to check out the analytical investigation
Analysis of the Impact of Relative Humidity and Mineral Nuclei Mode Aerosols Particle Concentration on the Visibility of Desert Aerosols
Get PDFThis paper presents the results of the Analysis of the Impact of relative humidity and water-soluble aerosol particle concentrations on the visibility and particle size distribution of desert aerosols based on microphysical properties of desert aerosols. The microphysical properties (the extinction coefficients, volume mix ratios, dry mode radii and wet mode radii) were extracted from Optical Properties of Aerosols and Clouds (OPAC 4.0) at eight relative humidities (00 to 99% RH) and at the spectral range of 0.4-0.8 mm. The concentrations of mineral nuclie component (MINN) were varied to obtain five different models. The angstrom exponent (a), the turbidity (b), the curvature (a2), humidification factor (g), the mean exponent of aerosol growth curve (µ) and the mean exponent of aerosol size distributions (n) were determined from the regression analysis of some standard equations. It was observed that the values of (a) are less than 1 throughout the 5 models which signifies the dominance of coarse mode particles over fine mode particles. It was observed that the curvature (a2) has both monomodal and bimodal types of distributions all through the 5 models and this signifies the dominance of coarse mode particles with some traces of fine mode particles. The visibility was observed to decrease with the increase in RH and increased with wavelength. The analysis further found that there is an inverse power law relationship between humidification factor, the mean exponent of the aerosol size distribution with the mean exponent of the aerosol growth curve (as the magnitude of (µ) decreases across the five models, the magnitudes of (g) and (n) increase, but the magnitude of both (g) and (n) increases for a given (µ) across the individual models). The mean exponent of aerosol size distribution (µ) being less than 3 indicate hazy condition of the desert atmosphere
A Reverse Infinite-Period Bifurcation for the Nonlinear Schrodinger Equation in 2+1 Dimensions with a Parametric Excitation
Get PDFWe consider the nonlinear Schrodinger equation in 2+1 dimensions and an external periodic excitation in parametric resonance with the frequency of a generic mode. Using an adequate perturbation method we get two coupled equations for the amplitude and phase. We show frequency-response curves and demonstrate the existence for the focusing case of a reverse infinite-period bifurcation when the parametric excitation increases its value. The same bifurcation is possible even in the defocusing case but for a different excitation amplitude value
Confinement and Asymptotic Freedom in a Purely Geometric Framework
Get PDFThe most important properties of strong interactions, confinement and asymptotic freedom, can be explained in a purely geometric way, using a non-local modification of the general relativity. At the same time, the dichotomy matter-field of the Einstein equation is eliminated and the physical world is described only by means of a unified field. Hadrons can be identified with “strong” black holes. The uncertainty principle emerges naturally in this model as consequence of the non-local modification of the General Relativity
Time Delay Control and Frequency Splitting in the forced Kadomtsev-Petviashvili Equation
Get PDFA time delay control is applied to the forced Kadomtsev-Petviashvili (KP) equation Using an appropriate perturbation method, we derive nonlinear equations describing amplitude and phase of the response and discuss in some detail external force-response and frequency-response curves for the fundamental resonance. For the uncontrolled system, we find a frequency splitting, a second frequency aappears in addition to the forcing one. Saddle-center bifurcation, jumps and hysteresis phenomena are observed together with closed orbits of the slow flow equations. There are stable two-period quasi-periodic modulated motion for the KP equation with amplitudes depending on the initial conditions. Subsequently, we study the controlled system finding sufficient conditions for a periodic behavior. We can accomplish a successful control because the amplitude peak of the fundamental resonance can be reduced and the saddle-center bifurcations and two-period quasi-periodic motions can be removed by adequate choices for delay and feedback gains
Evaluation of Computed Tomography doses in three medical diagnostic centres in Kano
Get PDFComputed tomography (CT), is an X-ray procedure that generates high quality cross-sectional images of the body, and by comparison to other radiological diagnosis, the use of CT in medical diagnosis delivers radiation doses to patients that are higher than those from other radiological procedures. Lack of optimized protocols could be an additional source of increased dose in developing countries. The aim of this study is to conduct radiation doses survey for head, chest and abdomen CT examinations of patients in three selected CT Diagnostics centers in Kano city. Detailed were obtained for 144 CT examinations for adult patients only. The results from the three Diagnostics centers (hospitals) were compared with each other as well as with the IAEA guidance level for this particular investigation. Survey of radiation doses were carried out by calculating Volume dose index (CTDIvol), and dose length product (DLP) using the SPSS software program. The study showed that the mean DLP of the one Diagnostics center (hospital) is 1522.6 mGy.cm which is far much higher than the two other diagnostic centers Mohammed Abdullahi Wase which stands at 661.0 mGy.cm, Providian medical diagnostic center which stand at 1121.3 mGy.cm as well as higher than the IAEA level which is 527 mGy.cm. The study showed that the mean CTDIvol for patients in AKTH is 38.6 mGy which again is higher than the two other diagnostic centers Mohammed Addullahi Wase which is 9.5 mGy, Providian medical diagnostic center is 9.6 mGy though, it is less than the IAEA level which is 47.0 mGy.
This study showed that there is an urgent need for optimizing patient doses in Kano city CT examinations. This can be ensured by providing training and retraining for workers and conducting quality control measurements and preventive maintenance regularly so as to detect any unnecessary outflow of ionization radiation early enough before they negatively affect the image which may necessitate re-imaging and then increase patients’ dose
Superconducting State Parameters of IN(1-x)Tl(x) Binary Alloys
Get PDFA universal model potential of Fiohais et al. with five local field correction functions due to Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are used for the first time to study the superconducting state parameters viz. electron-phonon coupling strength, Coulomb pseudopotential, transition temperature, isotope effect exponent and effective interaction strength of binary alloys. Very strong effect of the various local field correction functions is established from the present study. The comparison with other such theoretical values is promising, which confirms the applicability of model potential in clarifying the superconducting natures of binary mixture
Explanation of the observed dynamics of matter in the Universe in the framework of classical gravity
Get PDFThe paper shows the prematurity of introduction of a new category of "dark energy" into the theory. The observed dynamics of matter in the Universe can be explained within the framework of classical gravity, if the assumption about the existence of a primary plasma cloud at a certain evolutionary stage of the Universe is considered false. Comments are given on why this step is correct. The expansion of the Universe is not associated with the pressure that existed at any stage of its development; therefore, under the influence of gravitational forces, it must turn into compression, despite the observed accelerated motion of galaxies in the direction away from the terrestrial observer. In general, the Universe is not cooling down, but heating up. The brief review of astronomical observations, presented in this paper, confirms the need to develop a new view of cosmology
Physical model of dimensional regularization II: complex dimensions, non-scalar fields and the cosmological constant
Get PDFIn an earlier paper on the foundations of dimensional regularization, I formulated a model of a scalar quantum field whose propagator exhibits short-distance power-law screening with real positive exponent. In this paper, I heuristically generalize the model so that the propagator exhibits power-law screening at short distance with complex exponent. I further extend the model to Abelian gauge fields and Dirac spinors. As an unexpected byproduct, the spinor case leads to interesting extensions of the “bag” boundary conditions for the Dirac and Weyl equations. If the world really had complex dimension, it might explain in a natural way why the preponderance of observed fundamental interactions are renormalizable; and why the non-renormalizability of quantum gravity, which balances dimensional-regularization poles against a very weak coupling constant, is both acceptable and too small to be observed under ordinary circumstances. It might also motivate the famous factor of 10-120 between the observed cosmological constant and naïve dimensional analysis