On the Use of Electrical Resistivity Method in Mapping Potential Sources and Extent of Pollution of Groundwater Systems in Lapai Town, Niger State, Nigeria.

<p>Electrical resistivity method employing the Schlumberger array was used to occupy forty four (44) vertical electrical sounding points in Lapai town with the aim of determining the depth to aquifers, aquifer thicknesses and aquifer protective capacity. The G41 Geotron resistivity meter was used in obtaining the apparent resistivity data which was processed using Interpex 1XD resistivity interpretation software. The results revealed four lithologic sections which include top lateritic soil, sandy clay, fractured basement and fresh basement. Both confined and unconfined aquifers were identified within the area, with four classes of aquifer proactive capacities as high, moderate, weak and poor. While the aquifer at VES 20 was highly protected, twenty other aquifers were moderately protected, eight others had weak protection and fifteen aquifers were poorly protected. The aquifers were generally of good thicknesses and at varying reasonable depths, making them good reservoirs of water in appreciable quantity. The average aquifer thickness was estimated to be 48.36m while the average depth to aquifers was estimated to be 56.68m.</p>

Synthesis of Water Soluble Chitosan Inhibitor from Shrimp Shells and its Corrosion Rate on Mild Steel in Acidic Solution

<span>Synthesis of WSCI (Water Soluble Chitosan Inhibitor) </span><span>from shrimp shell waste is carried out through demineralization, deproteination, and deacetylation processes. WSCI is obtained from monomer termination and H₂O₂ assistance. WSCI was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and the degree of deacetylation was determined using the baseline method. The effect of adding WSCI to low carbon steel SS400 with a 1 M HCl corrosive environment was studied using the weight loss method at various concentrations and temperatures. The overall results of the research show that WSCI synthesis used in the prevention of corrosion have an inhibition efficiency of up to 74.6% at a concentration of 200 ppm at a temperature of 28^oC. Inhibition efficiency and corrosion rate are known to increase with increasing WSCI concentration and corrosion rate decreasing with increasing temperature.</span>

Identification of Surface Functional Group on Activated Carbon from Waste Sago

Activated carbon is a powerful adsorption material which mainly used as pollutants adsorption. The adsorption properties own derived from the main functional groups or chemical atoms derived from the activation processes. In this study, the activated carbon was prepared from waste sago and activated using two different chemicals activation agents called phosphoric acid and potassium hydroxide. The aim of this study was to identify the surface functional group on waste sago activated carbon produced. The results showed that activated carbon with phosphoric acid activator contained OH, C=C, CO and CH functional groups, while activated carbon with potassium hydroxide activator contained O-H, C≡C, C=C, C-O and C-H functional groups. These results lead to support the recommendations for the development of the application of waste sago activated carbon made as adsorbents in the purification of lead (II) and cadmium (II) wastewater.

Oxidation State analysis of LiFeSixP1-xO4/C (x = 0.06) with X-ray Absorption Near Edge Structure (XANES) in Fe K-edge and Si K-edge

The development of LiFePO₄ as a cathode materials on lithium-ion battery was increased with the use of additional techniques such as atomic doping and coating. The material used in this report was LiFeSi_0.06P_0.94O₄/C (LFP Si-6%), synthesized with doping silicon 6% and 11wt% carbon coating by a solid state method. X-ray Absorption Spectroscopy (XAS) characterization was used to investigate the effect on electronic and atomic structure of LFP Si-6%, especially in X-ray Absorption Near Edge Strucuture (XANES) region. XANES data measured on Fe K-edge and Si K-edge. Fe foil, FeO, Fe₂O₃, FePO₄, Si powder, SiO, SiO₂ were used as a standard sample for comparison with the result of LFP Si-6%. XANES analysis showed that the energy absorption of Fe K-edge and Si K-edge in LFP Si-6% was 7124.94 eV and 1846.16 eV, respectively. The oxidation state of Fe was Fe^2.576+ between Fe²⁺ and Fe³⁺, while Si was close to the estimation of Si⁴⁺. In addition, the linear combination fitting (LCF) in XANES Fe K-edge was performed to show the ratio of Fe²⁺/Fe³⁺ (FeO/Fe₂O₃).

The Influence of AC Driving Current on Magnetoimpedance in [Ni80Fe20/Cu]x/Cu/[Ni80Fe20/Cu]6-x Multilayers

The phenomenon of magnetoimpedance in the multilayer configuration of [Ni80Fe20/Cu]x/Cu/[Ni80Fe20/Cu]6-x with x = 1, 2, and 3 has been successfully investigated. The electrodeposition method used for the multilayer film preparation on the meander pattered of Cu PCB. The obtained multilayer samples were evaluated the MI effect at room temperature with a frequency of 100 kHz. Here, the MI effects were evaluated for a variation of the AC driving current i.e. IAC = 4 mA, 8 mA, 12 mA, 16 mA, and 20 mA. The MI measurement results show that the multilayer x = 3 has the largest MI ratio and the multilayer with x = 1 was the smallest one. It is indicated that interlayer coupling contributes to the MI effect. Whereas the skin depth also confirms to contribute the MI ratio that showed the MI ratio increase with the increase of the I_AC.

The effect of housing volume of a converting loudspeaker on the output electric power of a loudspeaker-based acoustic energy harvester

Acoustic energy harvester is a device that converts sound or acoustic energy into electrical energy. Generally, the main components of this instrument are an acoustic transducer and an acoustic resonator. In this study, the transducer used was a 4-inch woofer loudspeaker, without acoustic resonator but equipped with a cylindrical housing with a fixed cross-sectional area and a length that can be varied from 6 cm until 25 cm by using a piston. Experimental results for various housing volumes showed a similar pattern of the dependence of the generated electric power on the incoming sound frequencies. In addition, it was found that (within the range of the volume variations) the output electric power increased significantly when the volume of the housing was increased. The highest root-mean-square (rms) electric power obtained was 1.72 mW resulting from sound with a sound pressure level (SPL) of 105 dB and a frequency of 84 Hz and by using a length of the housing cylinder of 25 cm (housing volume of 3243.7 cm³)

The application bispherical coordinate in Schrödinger equation for Mobius square plus modified Yukawa potential using Nikiforov Uvarov Functional Analysis (NUFA) method

<p class="Abstract">The application bispherical coordinates in Schrödinger equation for the Mobius square plus modified Yukawa potential have been obtained. The Schrödinger equation in bispherical coordinates for the separable Mobius square plus modified Yukawa potential consisting of the radial part and the angular part for the Mobius square plus modified Yukawa potential is solved using the variable separation method to reduce it to the radial part and angular part Schrödinger equation. The aim of this study was to solve the Schrödinger's equation of radial in bispherical coordinates for the Mobius square plus modified Yukawa potential using the Nikiforov Uvarov Functional Analysis (NUFA) method. Nikiforov Uvarov Functional Analysis (NUFA) method used to obtained energy spectrum equation and wave function for the Mobius square plus modified Yukawa potential. The result of energy spectrum equation for Mobius square plus modified Yukawa potential can be shown in Equation (50). The result of un-normalized wave function equation for Mobius square plus modified Yukawa potential can be shown in Table 1.</p>

Photoacoustic tomography system based on Diode Laser to Imaging of some types of materials

<p>Photoacoustic tomography imaging research has been conducted to distinguish several types of materials. The photoacoustic tomography imaging system used in this study uses a diode laser as a source of radiation and a condenser microphone as a detection tool. The sample is a combination of two types of materials, namely plasticine + iron wire, plasticine + cardboard, plasticine + mica plastic, and mica plastic + cardboard. Optimum setting of laser modulation frequency and duty cycle system to distinguish images from plasticine samples + iron wire and plasticine + cardboard, i.e., 19 kHz and 50%, while to recognize images from plasticine samples + mica plastic and mica plastic + cardboard, which is 19.5 kHz and 50%. The photoacoustic tomography image system used can detect and image the sample clearly, the striking color difference between one material, and another shows the difference in sound intensity.</p>

Evaluation of geothermal potential in some parts of Bida Basin of Nigeria using Curie point depths and heat flow from spectral analysis of aeromagnetic data.

The Centroid method of Spectral Depth analysis was used to evaluate the Curie point depth (CPD), Geothermal Gradient and Heat Flow in some parts of the Bida Basin of Nigeria with a view to determining the energy potential of the area. The reduced-to-pole aeromagnetic data was divided into 16 overlapping ensembles and Fast Fourier Transformed to decompose the anomalies into their energy and wavenumber components using Oasis montaj software. The radial power spectrum was calculated for each of the grid points with the locations of the centres of the ensembles and a plot of Energy spectrum versus frequency was carried out to generate two different gradients: s₁ and s₂ representing different depth source models. These gradients were used to evaluate the average depth to the top of the deepest crustal block, Z_t, depth to the centroid of the deepest crustal block, Z₀, CPD, Geothermal Gradient and Heat flow. From the results obtained, the CPD varied from 2.59 to 8.23 Km while the thermal gradient and heat flow in the area revealed values ranging from 70.45 to 224.15 ^oCKm^-1 and 176.13 to 560.37mWm^-2respectively. The results of the contouring in conjunction with the CPD, geothermal gradient and the heat flow values have shown that the area has a greater energy potential in the south-eastern block of Katonkarfi, with shallow CPD and high geothermal gradient and heat flow. These results could be incorporated in the GIS and available geological, geophysical and geochemical information of the area to facilitate selection of the optimum site for energy exploration.

Identification of surface-basement layer distribution of Wangi-Wangi Island based on HVSR method of microtremor data

<span class="jlqj4b"><span>To find out the distribution of the surface-basement layer of Wangi-Wangi Island, it can be done by calculating the surface layer thickness of each measurement point using microtremor data. The surface layer thickness (<em>h</em>) also indicates the position of the basement to the surface. The microtremor recording data used in this study were 47 data. Furthermore, the data were processed using the HVSR method to obtained the soil predominant frequencies which together with the <em>V</em>_s30 values were used to calculated the <em>h </em>values. The results showed that the thickness of the surface layer or sediment layer of Wangi-Wangi Island was in the range of 5.7339 to 241.2557 meters. Based on its distribution, the areas with a thick surface layer are in the areas of Sombu, North Wandoka, Wandoka, South Wandoka, Pada Raya Makmur and Wanci. In the case of a disaster, these areas are thought to have the most potential to experience damage if an earthquake shakes.</span></span>