Abstract This paper explores the fundamental cosmological principle, with a specific focus on the homogeneity and isotropy assumptions inherent in the Friedmann model that underpins the standard model. We propose a modified redshift model that is based on the spatial distribution of luminous matter, examining three key astronomical quantities: light intensity, number density, and the redshift of galaxies. Our analysis suggests that the model can account for cosmic accelerated expansion witho...
Abstract Ion layer gas reaction (ILGAR) method allows for deposition of Cl-containing and Cl-free In2S3 layers from InCl3 and In(OCCH3CHOCCH3)3 precursor salts, respectively. A comparative study was performed to investigate the role of Cl on the diffusion of Cu from CuSCN source layer into ILGAR deposited In2S3 layers. The Cl concentration was varied between 7 and 14 at.% by varying deposition parameters. The activation energies and exponential pre-factors for Cu diffusion in Cl-containing s...
Abstract Pd-F:SnO2 thin films have been prepared by spray pyrolysis technique. Optimization has been done by doping SnO2 with palladium at varying levels of concentration and then recording sheet resistance. The sheet resistivity has been observed to decrease gradually as at% Pd concentration is increased; an optimum sheet resistivity value of 2.71 × 10−2 Ω cm has been recorded. The decrease in sheet resistivity has been attributed to presence of Pd ions which contribute in increment of...
Abstract Hydrogenated Amorphous silicon (a:Si:H) has low amounts of defects making it attractive for photovoltaic applications. To improve power conversion efficiency (PCE) of a:Si:H solar cells, this study investigated the effect of introducing FTO/TiO2 multilayer thin films into its structure to serve as antireflection coating. The multilayer thin films were characterized and optimized by optical simulations using a computer program, GLSIM (glazing simulator). The program was written in FO...
Abstract The influence of the 15th January 2010 annular solar eclipse on traveling ionospheric disturbances (TIDs) and equatorial plasma bubbles (EPBs) is studied using data from six global navigation and satellite system (GNSS) receivers spread across the path of annularity over the low latitude region of East Africa. The GNSS receivers are stationed at Nairobi (RCMN), Malindi (MAL2), and Eldoret (MOIU) in Kenya; Mbarara (MBAR) in Uganda; Kigali (NURK) in Rwanda; and Mtwara (MTWA) in Tanzan...
Abstract Endosphere and rhizosphere microbes offer plant growth promotion and pest suppression ecosystem services in banana-based agroecosystems. Interest has been growing towards the use of such beneficial microbes in protecting vulnerable tissue culture banana plants against pathogens such as Radopholus similis and Fusarium oxysporum. A screenhouse experiment with potted tissue culture banana plants was conducted using sterile and non-sterile soil to investigate the effect of soil biota on...
Abstract Fractional variants of distance-based parameters have application in the fields of sensor networking, robot navigation, and integer programming problems. Complex networks are exceptional networks which exhibit significant topological features and have become quintessential research area in the field of computer science, biology, and mathematics. Owing to the possibility that many real-world systems can be intelligently modeled and represented as complex networks to examine, administ...
Abstract Copper antimony sulphide has ability in applications on photovoltaics since it is a promising, less toxic, earth abundant absorber material. In this study, the photovoltaic characteristics of copper antimony sulphide (CuSbS2) photovoltaic cell were simulated and studied by one dimensional solar cell capacitance simulator (SCAPS-1D) to improve their operations. This study investigated the impact of modifying the thicknesses of fluorine-doped tin oxide (FTO), cadmium sulphide (CdS), c...
Abstract: Universities are isomorphic not because of the effectiveness of their processes but because of the legitimacy assigned by institutional logic. However, sustainable development discourses invoke a novel mission for producing knowledge and innovation for sustainable development. Accordingly, this research collected data from five types of internal stakeholders’ intellections of the four pillars of green university infrastructure. The analysis of data collected from 89 universit...
Semiconductors are substances with electrical conductivity characteristics halfway between insulators and conductors. They are the basis for devices like transistors, diodes, and integrated circuits, crucial parts of contemporary electronics. The capacity to conduct electricity under certain circumstances, such as an applied voltage or exposure to light, defines semiconductors. Semiconductors can have their conductivity altered and regulated, unlike conductors, which have high conductivity, a...
We describe a novel and cost-effective method to enhance the photo-conversion efficiency of blended PbI2/TiO2 perovskite photovoltaic cells by pre-annealing the constituent film components during the fabrication. This approach is also unique because it does not presume a strictly controlled fabrication environment. The average conversion efficiencies of the cells of the final devices were observed to rise from 6.6% to 10.8% for annealing temperatures of 60 ◦C to 100 ◦C, respectively. Anne...
ABSTRACT Flow rate of salt-water and fresh-water through porous media depends on the hydraulic gradient, porosity and hydraulic conductivity of the sand materials and the properties of the fluids such as density and viscosity. This study examined flow rate of salt-water and fresh-water in porous media in a modeled laboratory experiment. Porous materials were filled into the conduit of two arms glass cylindrical tube with valve (control) at the middle. Salt-water and fresh-water were made to ...
ABSTRACT The natural radionuclides (226Ra, 232Th and 40K) content of ceramic wall and floor tiles commonly used in Nigeria have been determined by a gamma ray spectroscopy system using a high purity germanium detector. The activity concentrations of 226Ra, 232Th and 40K ranged from 52 ± 2 to 105 ± 3, 56 ± 1 to 115 ± 2 and 185 ± 9 to 893 ± 17 Bq kg-1 with mean values of 72 ± 14, 84 ± 18 and 629 ± 198 Bq kg-1, respectively for the wall tiles. For the floor tiles, the activity concentra...
Abstract: Radiation emissions from the University of Ibadan National Institute of Radiation Protection and Research (NIRPR), physico-chemical properties measurement and insect’s fauna collection around the surrounding of the Institute were conducted for a period of six months (November, 2011-April, 2012). Radiation survey meter model (RDS-30) type was used to take readings along the immediate surroundings of the NIRPR surroundings. Soil samples were collected at five points in the study si...
ABSTRACT Magnetic Resonance Imaging (MRI) of the brain has seen a rising clinical request during diagnosis. The ohmic heating of tissue results in rising human temperature during MRI. This may be as a result of the unintentional heating which seems to be an under-appreciated risk especially of high-field-strength MRI. This study modelled Penne‘s bio-heat equation and used Matlab programming language to predict in-vivo power deposition in brain tissues during ...