Oxidative stress in Primigravida attending an antenatal clinic in Northern Nigeria

The demand for oxygen increases during pregnancy, and this may lead to oxidative stress. The aim of this study was to determine the oxidative stress level in Primigravida attending antenatal clinic at Gombe town Gidan Magani Maternity, Gombe State, North-eastern Nigeria. The concentration of plasma Malondialdehyde (MDA) was measured as biomarker of oxidative stress. The concentrations of Copper, Zinc, Manganese, Lead, Nickel and Cadmium in relation to oxidative stress were measured. Thirty primigravida and ten aged-matched non-pregnant women who served as control were involved in the study. The result of this research shows that the level of Malondialdehyde significantly (P < 0.05) increased in the 1st, 2nd and 3rd trimesters, with the increase being higher in the 2nd trimester. The levels of Cu and Zn increased significantly (P < 0.05) in all the three trimesters, while the level of Mn significantly (P < 0.05) decreased in all the three trimesters. There was no reading detected for Ni, Cd and Pb in both primigravida and control subjects under this study, indicating that neither the primigravida nor the control were exposed to them. All these are proves that oxidative stress occurs in Primigravida These findings emphasized the need for increased awareness among Primigravida on the existence of oxidative stress during pregnancy and also points to the need for measures to be taken against oxidative stress in Primigravida, so as to reduce the complications that arise during pregnancy, and ensure the safety of both mother and fetus during pregnancy and after delivery

The Shift in Bandgap and Dielectric Constant Due to lattice Expansion in CH3NH3SnI3 Using FHI-aims

Although methyl ammonium lead iodide, (CH3NH3PbI3) has proven to be an effective photovoltaic material, there remains a main concern about the toxicity of lead, therefore determination of a lead free halide perovskite is of outstanding interest.  Sn2+ metal cations are the most obvious substitute for Pb2+ in the perovskite structure because of the similar s2 valence electronic configuration to Pb2+. Sn2+ can form a perovskite with a basic formula ASnX3 (A= CH3NH3 and X = halide) because the ionic radius of Sn2+ is similar to that of Pb2+. With the above similarity, methyl ammonium tin iodide CH3NH3SnI3 is one of the common replacement for CH3NH3PbI3 in the fabrication of organic-inorganic perovskite solar cells. FHI-aims code was used to perform the simulation of CH3NH3SnI3 in this work. Geometry building, parameter optimization, determination of the best exchange functional, k-grid convergence test along with determination of equilibrium lattice constant and geometry relaxation for CH3NH3SnI3 were carried out. An energy direct band gap of 1.051 eV was obtained, with an underestimation of 0.249 eV which amount to 19.2% when compared with experimental value. The lattice constant obtained using phonopy with ZPE is close to experimental reported values with an underestimation of 3.01%. The temperature dependent of lattice constant was studied in the temperature range of 0 to 318 K. At the same temperature range, shift in energy bandgap and dielectric constant due to lattice expansion was also investigated

First Principle Study on Lead-Free CH3NH3GeI3 and CH3NH3GeBr3 Perovskite solar cell using FHI-aims Code

An Ab-initio calculation in the framework of Density Functional Theory (DFT), as implemented in the FHI-aims package within Generalized Gradient Approximation (GGA) with the pbe parameterization was carried out in this work. Although methyl ammonium lead iodide (CH3NH3PbI3) has proven to be an effective photovoltaic material, there remains a main concern about the toxicity of lead.  An investigation into the possible replacement of CH3NH3PbI3 with CH3NH3GeI3 and CH3NH3GeBr3 as the active layer in perovskite solar cell was carried out. The electronic band structure, band gap energy and dielectric constants were calculated for CH3NH3GeI3 and CH3NH3GeBr3. The effect of temperature on linear thermal expansion coefficient and temperature dependence of lattice constant were studied in the temperature range of 273 to 318 K. Band gap shift due to lattice expansion was also studied. The dielectric constants of these materials were also determined. The energy band gap calculated for CH3NH3GeI3 and CH3NH3GeBr3 at their respective equilibrium lattice constant are 1.606 and 1.925eV respectively. A numerical simulation with some of these materials as the active layer in a perovskite solar cell was performed using General-purpose Photovoltaic Device Model (GPVDM) and the conversion efficiency of the resulting solar cell was obtained. Conversion efficiency of 10% and 8.4% were obtained for CH3NH3GeI3 and CH3NH3GeBr3 respectively

On the fuzzy nature of constructed algebraic structure

No Abstract

The Effect of Temperature and Active layer thickness on the Performance of CH3NH3PbI3 Perovskite Solar Cell: A Numerical Simulation Approach.

In this work, General-purpose Photovoltaic Device Model (GPVDM) software was used to investigate the performance of a perovskite solar cell with CH3NH3PbI3 as its active layer. GPVDM is a free general-purpose tool for simulation of light harvesting devices. The model solves both electrons and holes drift-diffusion, and carrier continuity equations in position space to describe the movement of charge within the device. The model also solves Poisson's equation to calculate the internal electrostatic potential. Recombination and carrier trapping are described within the model using a Shockley-Read-Hall (SRH) formalism, the distribution of trap states can be arbitrarily defined. The software gives an output that contains the Current-Voltage (I-V) characteristic curves. A study into the effect of active layer thickness and temperature on the performance of the solar cell device was carried out. The optimal active layer thickness was found to be 3 x 10-7m. When the thickness exceeds 3 x 10-7 m, then the efficiency drops. At the optimal thickness of 3 x 10-7m, the devices were found to have power conversion efficiency up to 14.7%. On other hand the fill factor (FF) decreases as the thickness increases. The FF is highest at active layer thickness of 1 x 10-7m. The effect of device temperature also studied and the optimal working temperature was found to be 300 K, where power conversion efficiency and FF are 15.4 % and 0.76 respectively

Lineaments Analysis to Identify Favourable Areas for Groundwater in Kano City, Northwestern Nigeria

This work was carried out to investigate groundwater potentials of Kano city using lineament analysis, and to study the relationship between the characteristics and occurrence of groundwater in aquifers of about 200m deep in crystalline basement rocks of the area by examining the possibility of groundwater occurrence at such depths; despite the general understanding that fractures closes with depth. It shows the use of LANDSAT ETM+ imagery and geological map to investigate areas favorable for groundwater development.  This was achieved by plotting the lineament trends, and lineament density to know the groundwater potentials. Rose (azimuth-frequency) diagram of the lineaments delineated on the imagery shows trends in the directions of N-S, E-W, NE-SW, and NW-SE. The dominant trend is NW-SE. The analyses have shown that the study area has numerous fractures whose major trends are mainly in north-south and northwestern-southeastern directions. Lineament density map shows the cross-cutting lineaments are relatively high in areas around the north-eastern and south-western parts of the study area but low in the other areas. The zones of high lineament intersection density are feasible zones for groundwater prospecting.  The positions of deep boreholes on the map of the area do not coincide with the cross cutting lineaments, and are therefore the yields of the deep boreholes are not sustainable. Keywords: Lineaments, groundwater, boreholes, aquifer, fracture

Influence of catalyst (Yeast) on the Biomethanization of Selected Organic Waste Materials

Yeast catalyzed the rate of biomethanization of waste materials and rate at which it alter the reaction rate has been determined. It was observed that addition of yeast improved the quality and quantity of biogas generated and also fastened the acid and methane forming stages during biomethanization. The volumes of biogas in the catalyzed process was found to be 6550 cm3 for cow dung, 5640 cm3 for millet husk, 3240 cm3 for rice husk ,1000 cm3 for saw dust and 800 cm3 for the paper waste, as against 5430 cm3, 5230 cm3, 2110 cm3, 950 cm3 and 590 cm3 respectively for the uncatalyzed biomethanization process

Evaluation of Physicochemical Properties of Biodiesel Produced From Some Vegetable Oils of Nigeria Origin

The non-edible vegetable oils of Jatropha curcas, neem, castor, rubber and edible oils of soyabean and cotton were investigated for their use as biodiesel feedstock. The analysis of different oil properties, fuel properties of non-edible and edible vegetable oils were investigated in detail. A two-step and transesterification process was used to produce biodiesel from high free fatty acid (FFA) non-edible oils and edible vegetable oils respectively. This process gives yields of 96.1 – 98.5 % of biodiesel using potassium hydroxide (KOH) as a catalyst. The fuel properties of biodiesel produced were compared with diesel. The properties of the oils analysed showed that biodiesel from non-edible and edible vegetable oil are comparable with ASTM biodiesel standards and is quiet suitable as an alternative to diesel. Keywords: Biodiesel, Edible oil, Non Edible oil, Transesterification

Comparative Study of Biogas Production from Locally Sourced Substrate Materials

Comparative study of biogas production from Cow dung (CD), Millet husk (MH), Rice husk (RH), Saw dust (SD) and Paper waste (PW) was conducted. The biogas production potentials for the substrates were of the order: Cow dung (8772.50cm3) > Millet husk (6680 cm3) > Rice husk (1386.25 cm3) > Saw dust (973.75 cm3) > Paper waste (476.25 cm3). Physico - chemical analysis revealed decreasing pH in the spent slurry indicating acidification of the content. The ash content is higher in the spent slurry ranging from 16 – 24% for the raw substrate and between 18 and 29% for the spent slurry. Kinetic studies show the slurry concentration have a direct relationship to the volume of biogas produced from all the substrates. There was strong  correlation between slurry concentration and the volume of biogas generated