The analysis of travel times with moveout velocities represents one of the most widely used seismic signal processing techniques for the exploration and monitoring of oil and gas reservoirs. In travel time analysis for anisotropic elastic media with fractures, the knowledge of the conversion point at interfaces with incident longitudinal and reflected transversal elastic response impulses taking into account the azimuthal dependence is important for both seismic data analysis acquired in multicomponent surveys and the correct interpretation of seismic in reservoirs. Henceforth, this work shows how to derive analytical expressions for the longitudinal to transverse response impulse “P-Si” conversion points using the ellipsoidal approximation for fractured orthorhombic elastic media under kinematical considerations. These expressions can be used for vertical seismic profiles with small polar angles of aperture and azimuthal dependence in orthorhombic media when the elastic slowness is used as a main theoretical tool to resolve the Christoffel equation. We also explain some of the differences within the ellipsoidal inversion procedure of the elastic stiffnesses C13 and C23.

The galaxy central mass Mc and central velocity dispersion ?c have been found to correlate with large scale galaxy parameters for samples of galaxies with a limited range of characteristics. A scalar potential model (SPM) derived from considerations of galaxy clusters, redshift, discrete redshift, H I rotation curves (RCs) of spiral galaxies, and RC asymmetry is applied to central region parameters. The ?c and Mc are found to correlate to the host galaxy’s and neighboring galaxy’s B band luminosity. The sample included galaxies with rising, flat, and declining RCs; galaxies with a wide range of characteristics; and galaxies excluded from samples of other studies of ? c relationships. The equations have the same form as the SPM equations for the parameters of the H I RCs. Because the SPM is consistent with the ?c and Mc observations of the sample galaxies, the Sources and Sinks act as monopoles at the center of the galaxies around them. This suggests the outward scalar potential force of a Source holds the Mc from collapse into a supermassive black hole.

Ever since Oliver Heaviside’s suggestion of the possible existence of a set of equations, analogous to Maxwell’s equations for the electromagnetic field, to describe the gravitational field, others have considered and built on the original notion. However, if such equations do exist and really are analogous to Maxwell’s electromagnetic equations, new problems could arise related to presently accepted notions concerning special relativity. This note, as well as offering a translation of a highly relevant paper by Carstoiu, addresses these concerns in the same manner as similar concerns regarding Maxwell’s equations were.

In this paper, we obtained some spherically stellar configurations that represent new models of dark energy stars specifying particular forms for gravitational potential and the electric field intensity that allow solving the Einstein- Maxwell field equations. We have chosen the metric potential proposed by Finch and Skea (1989) with the equation of state such as pr = ??, where pr is the radial pressure, ? is the dark energy density, and ? is the dark energy parameter. We found that the radial pressure, anisotropy factor, energy density, metric coefficients, mass function, charge density are regular and well behaved in the stellar interior but the causality conditions of strong energy are not satisfied. These models have great application in physics and cosmology due to the fact that several independent observations indicate that the universe is in a phase of accelerated expansion which can be explained by the presence of dark energy that has not been detected.

With the development of science and technology, the advent of computed tomography (CT) in 1970s was a milestone of medical imaging. Its use in the medical field has increased dramatically. In spite of great advances of CT in medical field, however, some attention is required to avoid imposing high risks associated with the ionizing radiation on patients during CT procedures, such as radiation induced cancer because greater radiation dose is used in CT in comparison to most of the radiological examinations. In addition of that early reports of MDCT indicated higher doses delivered to patients when comparing to traditional CT. However, comparable or reduced patient doses will be achieved if dose reduction strategies such as optimizing settings used in traditional CT are applied. The objective of this review is to evaluate the different CT radiation dose reduction strategies leading to identification of the most effective strategy suitable for clinical utilization. In this study 83 articles were collected in the literature search and four common dose reduction strategies including manipulations of kVp, mAs and pitch and shielding were identified. The results indicates that Shielding technique has the highest overall mean of 53% while the pitch manipulation has the lowest value (39%). However, all ANOVA p-values are greater than 0.05 and hence no statistically significant difference was noted among the mean performances of dose reduction techniques.

The possibility of the phenomenon of Bose condensation having a part to play in the discussion of neutron stars has been around for some time. In this short report, the sorts of temperatures and densities that might be involved are discussed. Also, an alternative way of viewing the Bose condensation phenomenon is examined once more and, although found to lead to more accurate results in traditional examples, is found to have little numerical effect in astrophysical examples.

In this short paper, the authors described one prototype of the communication system based on the quantum entanglement between two related objects. A short introduction to the phenomena of the quantum entanglement is represented, and how it manifests in the living organisms, and how it can be used with nonliving objects. It is also represented construction of the communication system and shown some test results.

Knowledge of environmental radiation status is very necessary in quantifying health risks. In this regard, the objective of this study was to obtain in-situ measurement of background ionizing radiation (BIR) level of Elebele community in Bayelsa State. This was carried out using a well calibrated radiation meter, Radalert-200. The results of BIR obtained in the four zones ranged from 0.009 to 0.035 mRh-1 with a mean value of 0.022 mRh-1>0.013m Rh-1. The mean value of BIR was used to compute hazard indices; absorbed dose (AD), annual effective dose equivalent (AEDE) and excess lifetime cancer risk (ELCR) and their means. Computed values of absorbed dose ranged from 104-743.5 nGyh-1with a mean of 462.01nGyh-1>84.0 nGyh-1. Mean values of annual effective dose equivalents were 0.39, 0.611, 0.39 and 0.53 mSvy-1 < 1 mSvy-1. Also the mean values of excess lifetime cancer risk were 1.01x10-3, 1.19x10-3 1.04x10-3 and 1.08x10-3>0.29x10-3. These results exceeded the permissible limits therefore further study using gamma spectrometry is required on the soil and water samples of the area though the elevations may be attributed to the oil and gas exploitation activities within the area.