Comets are small bodies consisting of aggregates of ice mixed with rock and dust. They are usually influenced by galactic forces and stellar encounters, and may have contributed to the formation of ice giants and transport gases across the solar system. Their orbits vary widely, and their frozen water sublimates around 3 AU, forming a coma, though some remain active beyond this distance. In this study, the line element in the gravitational field due to a static and ellipsoidal isolated gravitating mass point was used to study the motion of comets, and the relativistic equation of motion of an ellipsoidal mass was obtained via the metric tensor, affine connections and geodesics equation. The results show that the explicit equations of comets along the equatorial plane are second-order differential equations similar to reported results in the literature for different gravitational fields.

This study investigates the effect of varying dielectric layer thickness on the optical properties of solar cells using MATLAB. Dielectric layers with thickness ranging from 10 to 100 nm were analyzed across 200 to 1200 nm wavelengths. Results showed that absorption efficiency increased with thickness, reaching a peak at 100 nm, where the absorption value was approximately 0.9 at 600 nm. Reflectance stabilized around 0.45 to 0.50, while transmittance was minimized to about 0.05, indicating that almost all incident light was absorbed or reflected at this thickness. The highest efficiency recorded was 94.86%, confirming that the 100 nm dielectric layer provided the best balance between absorption and reflectance. These findings align with previous studies, which identified the 80–100 nm thickness range as optimal for enhancing solar cell performance. This research highlights the importance of precise thickness control in solar cell design to achieve maximum light absorption and device efficiency.

Fertilizers, pesticides and herbicides contain toxic chemicals which leach into groundwater bodies resulting in the generation of high Biological Oxygen Demand (BOD), and thus contaminating the groundwater system. In order to save the environment from further degradation, a geophysical investigation was carried out across agricultural lands at Kaura Local Government Area (LGA) of Kaduna State, Nigeria where prevalent use of fertilizer, pesticides and herbicides is a norm. The research aims to delineate areas of possible contamination plumes and their migration path. For this purpose, Electrical Resistivity Tomography (ERT) data were acquired along six (6) Traverses and the results were inverted using the RES2DINV Software. Distinct low-resistivity zones adjudged to represent the contamination plumes were obtained from the ERT results. Water samples collected from boreholes, hand-dug wells and river channels were also analyzed. The analyzed water samples results revealed that the total dissolved solids (TDS) ranged between (2.30x101 - 8.20x101) ?Scm-1 as against the Nigerian Standard for Water Quality (NSDWQ) value of 1x103 ?Scm-1. Biochemical Oxygen Demand (BOD), chemical oxygen demand (COD) and dissolved oxygen (DO) values ranged between 1-10, <2 - <98 and 0.01 - 0.12 mg/L respectively. The water samples had detectable levels of Cu, Cd, Ni, Mn, Pb and Zn contents which were below the permissible limits, and microbiologically revealed the presence of faecal contamination with bacteria pathogens such as Coliform and Escherichia coli, whose levels were above the acceptable limit while the mould yeast and total aerobic were below the permissible limit. Ultimately, the results obtained showed that the agricultural land constitutes a serious threat to groundwater bodies in the area.

Undoped and yttrium-doped manganese selenide thin films were synthesized via spray pyrolysis deposition technique for photovoltaic purposes by utilizing manganese (II) acetate tetrahydrate, selenium (iv) oxide and yttrium. The deposited samples were characterized with instruments such as X-ray diffractometry, Uv-Vis spectrophotometry, four-point probe and SEM/EDX for structural, optical, electrical and morphological analysis. The X-ray diffraction pattern for both undoped and Y-doped MgSe samples shows the presence of crystal peaks along (111), (200), (210), (211) and (300) planes indicating polycrystalline and hexagonal structural nature. Optical analysis reveals a decrease in absorbance and an increase in transmittance as the wavelength increases for all the samples. The addition of a higher percentage (0.04 mol%) of yttrium dopant narrowed the bandgap energy (1.15 eV) of the undoped MnSe, making these materials promising for solar cell fabrication. Electrical analysis reveals that as yttrium dopant concentration in MnSe increases from 0 to 0.04 mol%, the film thickness increases from 110.0 nm to 115.13 nm with increasing resistivity and decreasing conductivity of 11.68 x 10-4 to 11.68 x 10-4 ?.m and 8.561 x 102 to 8.467 x 102 (?.m)-1 respectively. The overall electrical result of both undoped and y-doped MnSe conforms to that of a typical semiconductor. For the morphology result, the addition of yttrium dopant altered the microstructure of undoped MnSe. For undoped MnSe a smooth dense layer was observed while Y-doped MnSe reveals an agglomeration with no defined shape but is also dense. EDX result confirms the growth of a novel yttrium manganese selenide (YMnSe) thin material. YMnSe films offer features like narrowed band gap energy, improved charge transport characteristics and enhanced light trapping, making them potential materials for photovoltaic applications.

This study is aimed at delineating groundwater aquifer and subsurface structures of some selected areas within Chikun local government area of Kaduna State, Nigeria, using the Vertical Electrical Sounding (VES) method. To obtain the electrical resistivity values of the subsurface within the study area, electric current was conducted into the ground through two current electrodes while measuring the corresponding values of the potential difference using two potential electrodes. VES was conducted in twenty (20) different stations and was named profiles A, B, C and D with each having five stations with several layers, and four Vertical Electrical Sounding curves which were A, H, Q and QH were obtained. The results obtained from Vertical Electrical Sounding (VES) revealed the aquifer was at depths 7.3 m, 0.141 m 22.7 m, and 14 m for VES A, B, C and D respectively. Results from the 2D map revealed low resistivity within the weathered basement and fracture basement with resistivity values ranging between 1.929 – 885 ?m which correlates with the results obtained from the VES. The reflection coefficient (r) was used to determine the aquifer protective capacity of the study area and the isoresistvity map depicted that 7% was good (with r values ranging between 0.8 – 4.9), 43% was moderate (with r values ranging between 0.2 - 0.79), 33% was weak (with r values ranging between 0.10 - 0.19) and 17% was poor (with r values <0.10). Aquifer with low reflection coefficient values (r<0.8) favors groundwater potentiality but with high vulnerability to contamination. The study area has an aquiferous zone characterized by fractures and porosity aiding groundwater permeability and storage

Radon gas, a naturally occurring radioactive element, presents significant health risks, particularly in areas with fractured basement geology, where subsurface characteristics can elevate its concentration. As the second leading cause of lung cancer globally, after smoking, radon exposure is a critical public health concern. This study seeks to evaluate the concentration levels of radon gas, analyze its potential health risks to the residents, and provide insights into the environmental factors influencing radon accumulation in this area. Thirty (30) samples were collected for groundwater from various locations within the study area. Groundwater samples were collected from selected drinking water sources using 1.5 litre plastic bottles. Radon gas concentration was measured using a RAD7 electronic radon detector for soil and RAD7 H2O for groundwater. The data obtained was analysed using a statistical tool to perform a one-way Analysis of Variance (ANOVA). The samples were also subjected to decay corrections to ensure the accuracy of the results. The data were analysed using descriptive and inferential statistics, with statistical significance set at p<0.05. Groundwater radon concentrations ranged from 0.576Bq/L to 6.54Bq/L with a mean concentration value of 2.81 Bq/L and a standard deviation of 1.73 Bq/L. The mean annual effective dose for radon due to inhalation, ingestion and whole- body are 0.0254 mSvy^(-1), 0.00987 mSvy^(-1) and 0.0352 mSvy^(-1) respectively. The results were all below the recommended threshold of 0.1 mSvy^(-1) set by the World Health Organization (WHO). The Excess Lifetime Cancer Risk (ELCR) value of 12.34 × 10^(-5) was obtained which corresponds to about 1.23 in 10,000 risk of developing cancer over a lifetime due to radon exposure through water. The study on radon concentration in groundwater from the Ayetoro Housing Scheme, Oyo, found an average radon level of 2.82 Bq/L, below the EPA's maximum contaminant level (MCL) of 11.1 Bq/L. This indicates that residents in the area are not at significant risk from radon exposure at the time of the study. However, it was observed that inhalation of radon from water presents a higher radiological hazard than ingestion. The study recommends regular radon monitoring in the area to ensure continued safety.

This study investigates the optical, structural, and electrical properties of manganese selenide (MnSe) thin films synthesized using the Successive Ionic Layer Adsorption and Reaction (SILAR) method, with varying volumes of triethylamine (TEA) as a complexing agent. The MnSe films exhibited high absorbance in the ultraviolet (UV) region, peaking at values from 0.61 to 0.91 depending on TEA concentration, and declining towards the near-infrared (NIR) region. Transmittance varied from 12.53% to 92.17%, decreasing with higher TEA concentrations. The energy band gap of the films decreased from 2.90 eV with 2 ml of TEA to 2.30 eV with 10 ml, highlighting the tunability of MnSe for photovoltaic applications. Film thickness varied from 190.82 nm to 381.63 nm, reflecting a direct relationship with TEA concentration. Structurally, the MnSe films crystallized in the cubic phase with improved crystallinity and reduced defects at higher TEA volumes, as evidenced by a crystallite size increase from 20.10 nm to 25.09 nm and decreased dislocation density and microstrain. Morphological analysis revealed uniform grain-like structures at moderate TEA concentrations, which are optimal for photovoltaic performance. The electrical properties highlighted a trade-off between resistivity and conductivity. Films deposited with lower TEA volumes exhibited higher electrical conductivity of 2.72 ×10^(-5) S/cm at 2 ml compared to 1.02 ×10^(-5) S/cm at 10 ml. These findings confirm the suitability of MnSe thin films for absorber layers in solar cells, particularly where tunable optical and electrical properties are desired. The ability to control these properties by varying TEA concentration enhances the material's versatility for applications beyond photovoltaics, including optoelectronic and photodetector devices.

The Vredefort Dome has undergone some geologic processes that result in changes in the temperature of the rocks. This study contributes to the discussion on the thermal effect of the impact in the area on a regional scale and also delineates the linear structures around the Dome. The outcome shows that the center of the Dome is characterized by a low Curie point depth (CPD), indicating a high-temperature status that agrees with previous temperature reports in that area. The high-temperature tendency is observed to extend south of the Vredefort dome. The center-south of the Vredefort structure has a high thermal gradient and heat flow. The fractal distribution of the Vredefort structure correlates with the multi-ring structure around the Dome, which is peculiar to a few impact structures on Earth. The trend of the Fractal exponent contour around the center suggests that the contact of the meteoritic body at that region occurs at an angle and then pushes southwards. The structural analysis results show linear structures that are believed to be faults/fractures trending in North-NorthEast (NNE), NorthEast (NE), EastWest (EW), and NorthSouth (NS) directions whose effects have been explained in previous works in the area and were also identified on the ground. Some closures are observed at the center of the multi-ring structure, indicating the melt-dykes around the Vredefort dome. The Euler depth solutions cluster suggests the lineaments are about 7 km deep.