Physics Access

Delineating Hot Zone and Lineaments within Vredefort Crater in South Africa through Aeromagnetic Data Inversions

2025-03-13T09:20:17+00:00

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.

Profiling the Properties of SILAR Synthesized MnSe Films as Potential Material for Absorber Layer of Thin Film Solar Cells

2025-03-13T09:41:13+00:00

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 × 10ିହ S/cm at 2 ml compared to 1.02 × 10ିହ 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.

Radon Gas Risk Indices in Water on Fractured Basement of Ayetoro Housing Scheme, Oyo

2025-03-13T14:09:04+00:00

No Abstract

Delineation of Groundwater Aquifer and Subsurface Structures of Some Selected Areas in Chikun Local Government Area of Kaduna State, Nigeria using Electrical Resistivity

2025-03-13T10:58:45+00:00

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 Ωm 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.

Impact of Yttrium Dopant on Physical Properties of Manganese Selenide Nanoparticles synthesized via Spray Pyrolysis for Photovoltaic Applications

2025-03-13T11:25:35+00:00

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 Ω.m and 8.561 x 10² to 8.467 x 10² (Ω.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.

Investigation of Groundwater Contamination from the Use of Fertilizers, Pesticides and Herbicides on Agricultural Lands in Parts of Kaduna State Using Electrical Resistivity Imaging Technique

2025-03-13T14:25:08+00:00

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 ) μScm^-1 as against the Nigerian Standard for Water Quality (NSDWQ) value of 1x10³ μScm-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.