Forms and Distribution of Potassium along a Toposequence on Basaltic Soils of Vom, Jos Plateau State of Nigeria

The study was conducted in Vom, Jos Plateau state in the Southern Guinea Savanna zone of Nigeria to accentuate the forms of potassium distribution associated with topographic positions. The study area lies between longitudes 080 45' 01” and 80 47' 56'' E, latitudes 90 43' 17'' and 90 45' 15'' N, with an elevation of about 1270m above sea level. A stratified purposive sampling procedure was adapted, where four landscape positions were identified using Global Positioning System (GPS). The crest, upper slope, middle, and lower slope positions were identified, each representing changes in geomorphology. Two pedons were georeferenced at each topographic position, where they were sunk and described. Result show that the forms of K varied with topographic positions. Potassium distribution varied from surface to subsurface in different topographic positions. Water soluble K was higher at crest surface (0.0569 cmolkg-1) and decreased with soil profile depth. Exchangeable K has highest value of 0.1317 and 0.1308 cmol/kg-1 at both lower slope positions in general. Non exchangeable K values where higher at all surfaces than the subsurfaces of topographic positions. HCl soluble K values were higher at lower and upper slopes surface, moderately at middle and least at crest slope positions. Total K values were higher at upper slope subsurface, middle, and lower slope surface with low variations at the crest positions. However, the distribution of the K forms did not shown a well – defined trend with respect to topographic positions

A review on reversible logic gates

In recent years, reversible logic circuits have applications in the emerging field of digital signal processing, optical information processing, quantum computing and nano technology. Reversibility plays an important role when computations with minimal energy dissipation are considered. The main purpose of designing reversible logic is to decrease the number of reversible gates, garbage outputs, constant inputs, quantum cost, area, power, delay and hardware complexity of the reversible circuits. This paper reveals a comparative review on various reversible logic gates. This paper provides some reversible logic gates, which can be used in designing more complex systems having reversible circuits and can execute more complicated operations using quantum computers. Future digital technology will use reversible logic gates in order to reduce the power consumption and propagation delay as it effectively provides negligible loss of information in the circuit.   Keywords: Garbage output, Power dissipation, quantum cost, Reversible Gate, Reversible logic

Comparitive study of electrical properties of carbon nano tube (CNT) and silicon nanowire (SNW) MOSFET devices

Metal oxide semiconductor field effect transistor (MOSFET) is a semiconductor device used in many electronic devices for amplification and switching electrical signals. MOSFET downscaling has been the driving force towards the technological advancement, but continuous scaling down of MOSFET causes problem of high power dissipation, high leakage current, Short Channel Effects (SCEs), excessive process variation and reliability issues. In this work, comparative study of electrical properties of carbon nanotube (CNT) and silicon nanowire (SWN) were carried out using CNT and SNW as channel materials, silicon dioxide as the gate dielectric, silicon substrate as base material. The analysis is carried out using FETTOY simulating software for oxide thickness (0.3,0.5,0.7,0.9 and 1.2nm). The results show that carbon nanotube channel material have highest transconductance (gm) of 1.00 x 10-4S, highest conductance (g4) of 4.00 x 10-6S, highest carrier injection velocity (vinj)of 5.43 x 10 5m/s, highest on current (Ion) of 59.79uA, at oxide thickness of 0.3nm when used as MOSFET device and improved short channel effects with subthreshold swing (S) of 67.79 mV/dec and drain induced barrier lowering (DIBL) of 39.67. More results such as drain current (Id) versus gate voltage ( Vg) , quantum capacitance (QC) versus gate voltage (Vg) , and average velocity of mobile electron versus gate voltage (Vg) for all devices are also investigated. Various results obtained indicate that CNT has the higher performance of decreasing gate capacitance with decrease in oxide thickness ( TOx) in deep nanometer regime. This decrease in gate capacitance is observed at a gate voltage of 0.5V and above which leads to the reduction of propagation delay, lower leakage current, low power dissipation, short channel effects (SCEs) as compared to silicon nanowire MOSFET device.KEYWORDS: Ballistic nanoscale MOSFET, Channel materials, FETTOY simulating software, Short channel effects (SCEs), Drain Induces Barrier Lowering (DIBL

Assessment of serum total protein, albumin and calcium in pregnant women attending ante-natal clinic, University of Maiduguri Teaching Hospital

Background: Pregnancy is a normal physiological phenomenon with many biochemical changes including calcium metabolism. Calcium requirement increases during pregnancy, thereby increasing the chances of developing hypocalcaemia and hypoalbuminaemia. Aim: The aim of the present study was to assess serum levels of total protein, albumin, and calcium among pregnant women in University of Maiduguri Teaching Hospital Maiduguri, Borno State. Methodology: A total of two hundred (200) subjects were recruited for this study. One hundred and twenty (120) are confirmed pregnant women and 80 non pregnant women age matched were used as controls, out of the 120 pregnant women that participated in the study, 30 were in first trimester, 50 were in second trimester and 40 were in third trimester. Blood chemistry analysis was conducted spectrophotometrically using Biurets method (For Total protein), Bromocresol green method (for Albumin) and O-Cresolphthalein complex one (for calcium). Results: The results show a significant lower value of calcium and albumin (p<0.05) among first trimester pregnant women when compared to the control subjects. The results show a significant decrease in calcium and albumin (p<0.05) among second trimester pregnant women when compared to control subjects. The results show a significant lower value in calcium and albumin (p<0.05) among third trimester pregnant women when compared to control subjects. The results between 1st, 2nd and 3rd trimester pregnant women subjects show a significant difference in calcium and albumin (p<0.05), but there were no significant differences in total protein (p>0.05). The result shows no significant difference in total protein level (p> 0.005)among the first trimester pregnant women when compared to the control subjects. It also shows no any significant difference in total protein level (p> 0.005) among the third trimester pregnant women when compared to the control subjects. Conclusion: There is reduction or decrease in calcium and albumin levels in pregnant women especially in the third trimester. Key words: Pregnancy; Total Protein; Albumin; Calciu

The Effect of Varying Water Soluble Components on the Radiative Forcing of Continental Average Aerosols

This work embodies the results of the effect of the water soluble components on the radiative forcing of continental average aerosols, from aerosol data extracted from optical properties of aerosols and cloud (OPAC) 4.0 software package using FORTRAN program to model the effect of water soluble on optical depth, asymmetric parameter,  scattering and absorption coefficients at the spectral range of (0.25-0.80µm) and at eight relative humidities (0%,50%,70%,80%,90%,95%,98% & 99%). The concentration of water soluble was varied while concentrations of water insoluble and soot were kept constant. The optical parameters were used to compute numerically the radiative forcing using the concept of chylek and wong, the Angstrom exponent (α), turbidity (β) and Curvature .......Keywords: Angstrom exponent, Curvature, Optical depth, Radiative forcing, Turbidity.DOI: 10.7176/APTA/79-04Publication date:September 30th 201

Estimation of turbidity in water treatment plant using hammerstein-wiener and neural network technique

Turbidity is a measure of water quality. Excessive turbidity poses a threat to health and causes pollution. Most of the available mathematical models of water treatment plants do not capture turbidity. A reliable model is essential for effective removal of turbidity in the water treatment plant. This paper presents a comparison of Hammerstein Wiener and neural network technique for estimating of turbidity in water treatment plant. The models were validated using an experimental data from Tamburawa water treatment plant in Kano, Nigeria. Simulation results demonstrated that the neural network model outperformed the Hammerstein-Wiener model in estimating the turbidity. The neural network model may serve as a valuable tool for predicting the turbidity in the plant

PHYTOCHEMICAL AND ANTIMICROBIAL EFFECTS OF CHROZOPHORA SENEGALENSIS

The in vitro antimicrobial activities of the whole plant extract (ethanolic-CEE) of Chrozophora senegalensis and its fractions (ethyl acetate-EAA, n-butanol-NBE, aqueous-AQE) were assayed using the agar plate diffusion and nutrient broth dilution methods. Test microorganisms were Bacillus subtilis (NCTC 8326 B76), Escherichia coli (ATCC 11775), Pseudomonas aeruginosa (ATCC 10145), Staphylococcus aureus (ATCC 021001). Aspergillus flavus, Aspergillus niger, Candida albicans and Salmonella typhi - laboratory isolates. CEE, EAA and NBE inhibited all the test bacterial organisms and a fungus-Aspergillus flavus. AQE inhibited only Salmonella typhi and Bacillus subtilis. None of the extracts had activity on other 3 fungal organisms tested. CEE and EAA showed minimum inhibition concentration (MIC) of 0.390 and 3.125 mg/ml against S. typhi and E. coli, while NBE and AQE had MIC of 3.125 and 1.563 mg/ml against S. typhi respectively. NBE had an MIC of 12.500 mg/ml against E. coli. The minimum bactericidal concentration (MBC) of CEE and EAA was found to b

Association of Chlamydia serology with HIV in Nigerian women

This research was carried out to detect the presence of Chlamydia in pregnant women and gynaecologic patients in the North-central geopolitical zone of Nigeria. Blood samples were collected and analysed by ELISA techniques. The blood samples were also screened for HIV infection. A sero-prevalence of 59.0% was recorded for the study area. The sero-prevalence was higher among the gynaecologic patients (62.0%) than the pregnant women (57.5%). The difference was statistically significant (P = 0.0001). Of the four centers chosen for the study, the Federal Capital Territory (Abuja) had the highest prevalence (84.7%), while Niger State had the least (28.7%). The difference was also statistically significant (P<0.0001). The prevalence rate of HIV among the participants in the study center was found to be 17.2%. Abuja had the highest prevalence rate of 24.6%, followed by Benue, 16.7%, then Kogi, 12.0% and finally, Niger, 4.7%. Chlamydia was found to be associated with HIV (p<0.0001). The sero-prevalence of chlamydia in the North-Central zone of Nigeria was found to be high. Chlamydia was found to be correlated with HIV in the study area and may have contributed to the zone emerging with the highest HIV prevalence in the country. For an infection that is largely asymptomatic but has devastating effects on populations, only a preventive approach would have beneficial effects in controlling the disease and its effects on women’s health in the country.Keywords: Chlamydia trachomatis, HIV, pregnant women, gynaecologic patients, co-infectio

The impact of dividend policy on the shareholders value of listed firms in the Nigerian petroleum marketing industry

Dividend policy is directed towards establishing the proportion of current income that should be retained in the firm and the proportion that should be distributed among its shareholders. This study, therefore, assessed the impact of dividend policy on the value of listed firms in the Nigerian petroleum marketing industry. six firms, out of eight that are quoted on the Nigerian Stock Exchange (NSE) were selected as sample for the study. Data were collected from secondary sources. Annual reports and accounts of the selected firms, daily official lists and facts books of the NSE for the period of 2008-2017 form the source of the data. egression was used in analyzing the data. The findings revealed that payment of dividend by petroleum marketing firms in Nigeria positively influence the market price of their shares. Based on these findings, the study concluded that dividend policy of petroleum marketing firms in Nigeria affects the value of the firms. Based on this conclusion, the study recommends that management need to identify the shareholder’s interest in setting up a dividend policy that would balance their needs and retention for recapitalization to maximize value of the firms

The Effect of Kelvin Effect on the Equilibrium Effective Radii and Hygroscopic Growth of Atmospheric Aerosols

In this paper we extracted microphysical properties of six types of atmospheric aerosols from Optical Properties of Aerosols and Clouds (OPAC) and numerically analyzed the analytical expressions for the changes in the equilibrium relative humidity (RH), effective radius, effective hygroscopic growth, the magnitudes and fractional changes in the effective radii  and the effective hygroscopic growth on the effects of surface tension (the Kelvin effect) on ambient atmospheric aerosols. The expressions were applied to two - one parameter models. We discovered from the analysis of the data extracted that, to the lowest order error, the change in the equilibrium RH, effective radii and effective hygroscopic growth depend on the compositions of the aerosols. From the two models used, we also discovered that the fractional changes in the ambient RH, effective radii and effective hygrosocopic growth, also depend on the aerosols compositions. Finally, we discovered that the magnitude of the Kelvin effect and its consequences on the atmospheric aerosols depend on the hygroscopicity of the aerosols. Keywords: Kelvin effect, effective radius, effective hygroscopic growth, atmospheric aerosols, ambient Relative Humidity