Asian Journal of Research and Reviews in Physics
EISSN : 2582-5992
Published by: Sciencedomain International (10.9734)
Total articles ≅ 90
Latest articles in this journal
Published: 24 November 2021
Asian Journal of Research and Reviews in Physics pp 32-41; https://doi.org/10.9734/ajr2p/2021/v5i230160
In this study, assessment of outdoor background exposure levels in some selected swampy agricultural soil in Nasarawa West, Nigeria has been conducted. An in-situ measurement of outdoor background exposure rate (in mRhr-1) for a total of fifty farms (ten each from Keffi (KF), Kokona (KK), Karu (KR), Toto (TT), and Nasarawa (NS)) were done using a well calibrated portable halogen-quenched Geiger Muller (GM) detector (Inspector alert Nuclear radiation monitor SN:3544). A geographical positioning system (GPS) was used at an elevation of 1.0 m above ground level to obtain the geographical location. The radiological hazard parameters were evaluated using the measured outdoor background exposure rates. The values obtained were compared with recommended permissible limits to ascertain the radiological hazard status of the swampy agricultural farms. The mean values of the outdoor background exposure levels (0.23, 0.038, 0.028, 0.022, and 0.039 mRh-1), absorbed dose rates (458.49, 334.95, 188.79, 194.01, and 343.65 nGyh-1) and excess lifetime cancer risk (1.968, 1438, 0.810, 0.832, and 1.475) each for KF, KK, KR, TT, and NS respectively, are higher than the recommended safe limits of 0.013 mRh-1, 84.0 nGyh-1, 0.00029 respectively as recommended by UNSCEAR and ICRP. On the other hand, the mean annual effective dose equivalent (AEDE) values (0.563, 0.410, 0.232, 0.238, and 0.421 mSvy-1 for KF, KK, KR, TT, and NS respectively) are below the recommended permissible limits of 1.00 mSvy-1 for general public exposure. Generally, the study revealed that swampy agricultural soils in Nasarawa west are radiologically safe with little contamination which could be attributed to the geological formation and partly due to human activity in the area.
Published: 23 November 2021
Asian Journal of Research and Reviews in Physics pp 19-31; https://doi.org/10.9734/ajr2p/2021/v5i230159
In this study, we consider an holographic dark energy and dark matter interacting model in the Bianchi Type-V universe with a stretched exponential scale factor. We obtain the Hubble, shear, deceleration, and equation of state parameters based on the presented model and give the numerical solutions. We show that the anisotropy in the early universe plays an important role in the time evolution of the universe. Furthermore, we show that an interacting anisotropic model with stretched exponential scale factors can explain all epochs of the universe.
Published: 12 October 2021
Asian Journal of Research and Reviews in Physics pp 12-18; https://doi.org/10.9734/ajr2p/2021/v5i230158
In this study, the monthly average minimum and maximum temperature meteorological data obtained from the European Centre for Medium-Range Weather Forecasts (ECMWF) during the period of thirty eight years (1979 – 2016) were used to estimate the mean velocity and most probable velocity of atomic Oxygen and Hydrogen for Ilorin. The values of the mean velocity and most probable velocity for these atoms were compared to the value of escape velocity. The results revealed that the highest values of mean velocity and most probable velocity for atomic Oxygen were found to be in the month of March with and respectively and the highest values of mean velocity and most probable velocity for atomic Hydrogen were found to be in the month of March with and respectively. Based on the values of the mean velocity and most probable velocity for atomic Oxygen and Hydrogen obtained during the studied period suggests that these atoms cannot escape the gravitational field as their values are less than the escape velocity .
Published: 1 October 2021
Asian Journal of Research and Reviews in Physics pp 1-11; https://doi.org/10.9734/ajr2p/2021/v5i230157
This paper discuss the numerical simulation of one step block method for treatment of second order forced motions in mass-spring systems of initial value problems. The one step block method has been developed with the introduction of off-mesh point at both grid and off- grid points using interpolation and collocation procedure to increase computational burden which may jeopardize the accuracy of the method in terms of error. The basic properties of the one step block method was established and numerical analysis shown that the one step block method was found to be consistent, convergent and zero-stable. The one step block method was simulated on three highly stiff mathematical problems to validate the accuracy of the block method without reduction, and obviously the results shown are more accurate over the existing method in literature.
Published: 30 September 2021
Asian Journal of Research and Reviews in Physics pp 33-42; https://doi.org/10.9734/ajr2p/2021/v5i130156
Substrates used in perovskite solar cells as front contact are usually transparent conductive oxide (TCO) to allow light to pass through the device. The dominating TCO employed in perovskite solar cells are indium-doped tin oxide (ITO) and fluorine-doped tin oxide (FTO). However, it is imperative to investigate alternative TCOs due to the scarcity of indium metal, relatively low electrical conductivity and high leakage current in ITO and FTO. In this study, simulation has been carried out using Solar Capacitance Simulator (SCAPS) to investigate the efficiency of methyl-ammonium tin iodide (CH3NH3SnI3) based solar cells including various TCOs such as boron-doped zinc oxide (BZO), molybdenum trioxide (MoO3) and zinc oxide (ZnO). TCO parameters such as thickness, donor concentration and operating temperature were varied to study their influence on device performance. The best device performance was achieved using MoO3 with power conversion efficiency of 25.83 % and Jsc, Voc and FF of 32.44 mA/cm2, 0.979 V and 81.38 % respectively. The work shows the potential of fabricating an improved CH3NH3SnI3 perovskite solar cell with MoO3 as front contact.
Published: 24 September 2021
Asian Journal of Research and Reviews in Physics pp 26-32; https://doi.org/10.9734/ajr2p/2021/v5i130155
Aim: The aim of this research is to design an automatic fire detection and control. Methodology: The system consists of two sensors, microcontroller, buzzer and a pump/sprinkler. An LM35 integrated chip has been used as temperature sensor while MQ-2 gas sensor has been used as smoke sensor. All sensors are connected to the microcontroller through an input/output port. The controlling software for the whole system was designed in C programming language. The popular high performance, low power 8-bit microcontroller from the AVR family microcontrollers has been used. The system was finally tested by introducing fire parameters (smoke and temperature) close to the smoke and temperature detectors respectively. When the parameters go above the set level in the detectors, audio alarm, light indicator and pump/sprinkler were activated. The measured temperature of the system was compared with the reference temperature. Results: The result showed that there was a mean deviation of 1.550C between the measured values and reference values which served as the control. Conclusion: The constructed system is compact and easy to install. The constructed fire control device is quite cheap and affordable to every category of person.
Published: 22 September 2021
Asian Journal of Research and Reviews in Physics pp 18-25; https://doi.org/10.9734/ajr2p/2021/v5i130154
Aim: Design Analysis of 7.5KW Stand-alone Solar Photovoltaic Power System for an Intermediate Household. Methodology: A design analysis of standalone 7.5KW PV system was carried out using PV modeling equations based on load estimated. The analyzed data of the solar photovoltaic components was used to determine the estimated output power of 7.5KW. Therefore, a number of modeling equations and methodologies for designing a PV system based on application have been developed and simplified in order to ensure the optimum performance of the system. The analyzed solar powered 7.5KW system was achieved by designing 24 solar panels of 335W each, 16 deep cycle battery of 200A each, and a pulse width modulation (PWM) charge controller of 60A to monitor the output of the battery for safety operation. The battery will be connected to the inverter circuit (DC-AC) to generate 220V alternating current in its output via a step-up transformer. In this paper, design analysis of a standalone PV system enables of producing power to a household with approximate consumption of 7.5KW was conducted. Results: The standalone PV system along with the cost implications was analysed and designed. In this analysis a sequential design plan of an independent standalone solar powered photovoltaic structure was analysed and overviewed to supply continuous and uninterrupted power to a typical utility with maximum power consumption of 7500W (7.5KVA). The calculated/computed values of all the components yield a result that can serve the purpose. Based on the design analysis, the result implies that the estimate consumption of 7.5KW in a day requires 24 PV panels of 335 Watts each, 16 (12V, 200Ah) batteries, 10KW inverter, (12V, 60A) charge controller and copper wire of cross-sectional area (1.688mm2) for installation. Conclusion: In Nigeria, to generate a solar power of 7.5KVA requires almost $15,585.70 which is equivalent to N 5,965,426.66.
Published: 15 September 2021
Asian Journal of Research and Reviews in Physics pp 12-17; https://doi.org/10.9734/ajr2p/2021/v5i130153
We report comparative effect of radiation on Germanium incapacitated Optical fibres and commercially available TLD-100. The experiments were carried out using Siemens linear accelerator (LINAC) Primus Multileaf Collimator (MLC) 3339 to deliver photon and electron beams. The Harshaw model 3500 TLD reader with WinREMS software were used in this experiment. Both media were irradiated with 6 x106 eV electrons and 6 x106 volts photons beam. We found a good linearity for TL dose in the range from 20 to 240 mGy. Comparative studies of these compounds indicate that the TL responses using photon and electron irradiation are similar and the average intensity is enhanced by about 1.30 times in electrons than those for photon irradiation. The information of the mini review report of this paper presents in valuable for clinical linear accelerators applications.
Published: 11 September 2021
Asian Journal of Research and Reviews in Physics pp 1-11; https://doi.org/10.9734/ajr2p/2021/v5i130152
As it is known that General Theory of Relativity does not explain the current acceleration of the universe, so there are many attempts to generalize this theory in order to explain the cosmic acceleration without introducing some dark components such as the Dark Energy. Because of the crowd of models in literature, a need to check the models according to some criteria arises. In this study, we analyze two classes of models by means of energy condition restrictions and illustrate the analysis of those classes by graphical simulations. We consider the conservative and non-conservative cases of two classes of models to perform the analysis. The results of the viability of the classes are discussed and it is found that the value of the Hubble constant has no effect on the viability of the models. Focusing on some general classes for the models, we restrict them by means of the so-called energy conditions the energy-momentum tensor on physical grounds. Besides, we find numerical values for coefficients of those classes of models.
Published: 1 September 2021
Asian Journal of Research and Reviews in Physics pp 39-46; https://doi.org/10.9734/ajr2p/2021/v4i430151
An analysis of Geothermal Gradients in the Eastern Niger Delta basin was done using Bore Hole Temperature (BHT) data from three (3) adjacent oil fields. BHT data was converted to static formation temperature by using the conventional method of increasing measured BHT data by 10% and Geothermal Gradient computed using its simple linear relationship with depth, surface temperature and static temperature at depth. Projections were then made for change in Geothermal gradients at 1km intervals to a depth of 4 km. Results obtained showed significant variations across Idama, Inda and Robertkiri fields with average geothermal gradients of 17.3⁰C/Km, 22.6⁰C/Km and 23.1⁰C/Km respectively. Variation in the geothermal gradients in the area is attributed to lithological control and differential rates of sedimentation during basin evolution. Also, results showed that the Geothermal Gradient in the area are generally moderate and could be a good reason for the occurrence of more oil hydrocarbons than gas in the area.