142 research outputs found

    Synthesis, characterisation and antimicrobial studies on 2 - [(2 -hydroxyphenyl) methylidene] hydrazine-1-carbothioamide and its Ni(II) and Cu(II) complexes

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    2-[(2-hydroxyphenyl)methylidene]hydrazine-1-carbothioamide was obtained by the condensation of salicyldehyde and thiosemicarbazone. Ni(II) and Cu(II) complexes were prepared and characterized by elemental (CHNOSO) analysis, FTIR, UV – visible, magnetic susceptibility, and molar conductance measurements. The ligand sharp peak at 1616cm-1 in the FTIR spectra indicating the formation of azomethine (-C=N-) bond. A shift shows band to the band regions 1597cm-1 and 1510cm-1 confirmed the coordination of the azomethine nitrogen with Nickel(II) and Cu(II) ions respectively. The ligand formed a chelate with 1:2 metal : ligand stoichiometry. All the compounds have been screened for antibacterial and antifungal activity by disc diffusion method against Staphylococcus aureus, Escherichia coli and Salmonella typhi as well as Aspergillus flavus bacterial and fungal isolates respectively. The compounds are found to be active against the tested isolates.Keywords: Schiff base, Chacterisation, Ligand, Antibacterial, Antifunga

    Effects of Phosphorus and Rhizobium Inoculation on Yield Components and Grain Yield of Some Selected Cowpea Genotypes

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    The effects of phosphorus (0, 20, 40kg P2O5ha-1) and rhizobium inoculation (inoculated and un-inoculated) on the yield components and grain yield of three cowpea genotypes (IT93K-452-1, IT97K-573-1-1 and IT98K-499-35) were investigated under field conditions at Bayero University, Kano, Teaching and Research Farm (11059 N; 8025 E; 466m above sea level) and Agricultural Research Station Farm, Minjibir (12010’ N,  8039’ E; 402m  above sea level) in 2014 rainy season. Cowpea genotypes were assigned to the main plot, while phosphorus levels were assigned to the sub-plots. The inoculation was assigned to the sub-sub plot. These were laid out in Split-split plot design and replicated three times. Results of the study indicated significant effect of genotype in all the characters measured except shelling percent. Significantly (p˂ 0.05) higher number of pods per plant, pod weight, fodder and grain yield was observed from IT99K-573-1-1 than all other genotypes evaluated. Similarly, the number of pods per plant, pod weight, fodder and grain yield were significantly influenced by application of phosphorus with better results recorded from 40 kg P2O5 treated plants. Inoculation of cowpea with rhizobium MC92 strain, also recorded significant effect on the measured characters and grain yield. Inoculation of cowpea with rhizobium MC92 along with 40kgP2O5 ha-1 could enhance performance of cowpea particularly with an adaptable genotype like IT99K-573-1-1. Keywords: Cowpea, grain yield, inoculation, yield component

    The Effect of Varying Soot Concentration and Relative Humidity on Visibility and Particle Size Distribution in Urban Atmosphere

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    This research used extracted extinction coefficients and common mode radii of urban aerosols to carry out visibility simulations at corresponding spectral wavelengths from 0.4-0.8µm from the improved version of the Optical Properties of Aerosols and Clouds (OPAC 4.0) data at eight relative humidities(RH) (0%, 50%, 70%, 80%, 90%, 95%, 98% and 99% RH). Five models of the urban aerosols used comprised of insoluble (INSO), Water-soluble (WASO) and Soot (Black Carbon). From the average concentration set up by OPAC 4.0, the concentrations of the Soot (Black Carbon) were varied by external mixing. The Angstrom exponent (α), the curvature (α2) and the urban atmospheric turbidity (β) were obtained from the regression analysis of the first and second order polynomial of Kaufman’s representation of the Koschmieder equation for atmospheric visibility. The mean exponents of the aerosol size growth curve (µ) were determined from the aerosol effective hygroscopic growth (geff) while the humidification factors (γ) were determined from the visibility enhancement factors f(RH,λ). With µ and γ, the mean exponents of aerosol size distributions (υ) were determined for all the models. It was observed that at varying Soot (Black Carbon) concentrations and RH there were non-linear relationships between them and visibilities. The values of α > 1 showed the presence of fine mode particles from the WASO part of the aerosol mixture and α2 being positive indicated bimodal aerosol particle distributions. Additionally, visibility deterioration is predicted because of the increase in turbidity (β) with the variation of Soot and RH

    The role of biosensors and biological weapons in national defence and security operations

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    The knowledge of biotechnology plays an important role in the development of biological weapons. Biological weapons are considered an attractive factor in war for several reasons: ease of manufacture, low cost, confirmed injury, increased number of victims, large losses incurred by other countries. Biological weapons detection methods are among the most important means of military defense. Biological sensors are used in early detection of weapons. Biotechnology is of paramount importance in all fields of medicine, engineering, agriculture, industry, as well as military life. The key applications of biotechnology in the military are in the areas of sensor systems and systems for protection from espionage. Among the most important countries that have applied knowledge of bioweapons technology into their security system are the USA and China. Despite the enormous advantages of biotechnology, it has negative effects in biological weapon production. Therefore, the near future will witness a tremendous boom in biotechnology. DNA profiling also plays an important role in detection of crime. The overall aim of the review is to emphasize the importance of biotechnology towards solving bioterrorism and other forms of security challenges in an environment

    Effect of Heat Treatment and Sulfuric Acid Anodization on Corrosion Resistance of Aluminum Alloy (AA7075)

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    This paper, studied the effect of heat treatment and anodization on corrosion resistance of aluminum alloy 7075 (AA7075), with a view to improving its corrosion resistance. Microstructure and micro hardness of the anodic film of the samples were studied with the aid of optical metallurgical microscope and automated micro hardness testing machine. Linear polarization methods were used to assess the corrosion behaviour of the alloy in 0.5M HCl. The microstructure of the annealed sample showed formation of dendrites while precipitation hardened samples in palm kernel oil and SAE 40 engine oil showed precipitates of MgZn2. The SEMS result showed pores and micro cracks on the surfaces of the anodized samples, with the as cast and anodized sample in sulfuric acid exhibiting most compact with few pores. The as cast and sulfuric acid anodized sample shows highest micro hardness value of 205.33 HV, while the least value of 150.67 HV was recorded in sample precipitation hardened in SAE 40 engine oil and anodized in sulfuric acid. Analysis of the potentiodynamic polarization data and curves showed a linear relationship (decrease in icorr, decreases the corrosion rate) between current density and the corrosion rate in all the samples. Higher polarization resistance of 15.093 Ω/cm2 was recorded by the as cast and Sulfuric acid (SA) anodized sample while the precipitation treated in SAE 40 engine oil plus SA anodized sample recorded lowest polarization resistance of 5.2311 Ω/cm2. Heat treatment alone improves corrosion resistance of AA 7075 in 0.5 M HCl solution but heat treatment plus SA anodization does not improve corrosion resistance in the same environment

    Knowledge, sources of information, and risk factors for sexually transmitted infections among secondary school youth in Zaria, Northern Nigeria

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    Background: Sexually transmitted infections (STIs) are responsible for a variety of health problems especially among the youth who engage in risky sexual behavior. There are few studies that describe STIs among the youths in Northern Nigeria. The objective of the study was to assess knowledge of STIs and risk factors among secondary school youth. Materials and Methods: This was a cross‑sectional study in which structured, self‑administered questionnaire was used to collect data on socio‑demographics, knowledge on STIs, and risk factors. Three senior secondary schools were purposively selected for the study. Results: A total of 1765 youths aged 10‑30 years with mean age of 16.9 ± 2.0 years participated in the study. 1371 (77.7%) and 394 (22.3%) were respectively Muslim and Christian. Mean age at first sexual intercourse was 16.7 ± 2.0 years.A majority (67.6%) of them heard about STIs; sources of information of STIs were school lessons 23.6%, mass media 23.3%, and health magazines 19.2%, respectively. Generally, knowledge on STIs was good as 75.4% of respondents knew how the disease is transmitted. This knowledge was significantly associated with class of student, place of treatment, and religious teaching (χ2 = 9.6, P = 0.047, χ2 = 22.1, P = 0.035 and 42.6, P = 0.001, respectively). Mean knowledge score was 0.698 ± 0.01. A majority of respondents were engaged in risky sexual behavior as only 16.2% use condom as a preventive measure. Eleven percent reported ever having an STI in the past and majority (52.8%) go to government hospital for treatment of acquired STI. 56% of the youth had two or more boy/girl friends and 30% had sexual relationships. Conclusion: It was concluded that secondary school youth had good knowledge about STIs; however, the opposite is true when it comes to preventive practice (use of condom). Interventions such as periodic publicity awareness and school seminars focusing on STI preventions are needed to control the disease among the youth

    Modelling hatchability and mortality in muscovy ducks using automatic linear modelling and artificial neural network

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    This study was embarked upon to predict hatchability and mortality rate of Muscovy ducks in Nasarawa State, Nigeria. Data were obtained from a total of 119 duck farmers. The automatic linear modelling (ALM) and artificial neural network (ANN) models were employed. The average flock size was 9.84±0.60 per household. The predicted hatchability mean values using ALM (8.66) and ANN (8.65) were similar to the observed value (8.66). The predicted mortality mean values using ALM (2.95) and ANN (3.03) were also similar to the observed value of 2.95. Experience in duck rearing, the educational status of farmers, source of foundation stock and season were the variables of importance in the prediction of hatchability using ALM and ANN models. However, primary occupation, source of foundation stock, experience in duck rearing, land holding and management system were the important variables automatically selected for the prediction of mortality. Moderate coefficients of determination (R2 = 0.422 vs 0.376) and adjusted R2 (0.417 vs 0.371) estimates were obtained for hatchability and mortality using ALM. Different patterns were obtained under the ANN models as regards the prediction of hatchability (R2= 0.573 and adjusted R2= 0.569) and mortality (R2= 0.615 and adjusted R2= 0.612). The present information may aid management decisions towards better hatchability and mortality performance in Muscovy ducks

    PHYTOCHEMICAL SCREENING, ANTIOXIDANT POTENTIAL AND CYTOTOXIC ACTIVITY OF MELASTOMA MALABATHRICUM LINN. FROM DIFFERENT LOCATIONS

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    Objective: The initial study was to screen the phytochemical content of methanol extract of M. malabathricum from seven different locations. The other objective was to evaluate the total phenolic content (TPC), Total flavonoid content (TFC), antioxidant potential and cytotoxic activity (on Hepatoma G2 cells) of these extracts and to determine the relationship between TPC and other parameters.Methods: The preliminary phytochemical screening for the presence of the secondary metabolite was carried out according to standard procedures. TheTPC,TFC and antioxidant activity were determined using Folin-Ciocalteu method, aluminium chloride (colorimetric) methodand1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity respectively.Results: Qualitative phytochemical screening showed the presence of tannins, analkaloid, steroids, flavonoid, phenols, terpenoids and fixed oil but tested negative for the presence of glycoside and saponins. The samples were found to have high TPC and antioxidant activity. The Bachok Kelantan sample (L7) showed highest phenolic content (671.51±50.07 mg of GAE/g) as well as highest DPPH free radical scavenging activity (80.81% and IC50 102 µg/ml). The highest cytotoxic activity against HepG2 cells (IC50 1.4µg/ml) was shown by KualaTerengganu, Terengganu sample (L1). The Spearman correlation showed that, there is a strong positive correlation between TPC and antioxidant activity (r = 0.714) as well as strong negative correlation between MTT IC50 and TPC (R =-0.649) of M. malabathricum from different locations. Moreover, there is a weak positive correlation between TFC and antioxidant activity (R = 0.286, p= 0.535). Also, there is poor correlation between TFC and cytotoxicity (R =-0.216, p= 0.64).Conclusion: The phenolic compounds are associated with the cytotoxic and antioxidant activities of M. malabathricum, whereas flavonoids are poorly and weakly associated with cytotoxic and antioxidant activities of M. malabathricum respectively. The total phenolic content, mean flavonoid content and mean antioxidant activity of M. malabathricum from different locations were significantly different across seven locations (p<0.05).Â

    Simulation of Hydrodesulphurization (HDS) Unit of Kaduna Refining and Petrochemical Company Limited

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    This research was carried out to simulate the Hydrodesulphurization unit using ASPEN HYSYS with the aim of removing impurities such as Sulphur, Nitrogen and Oxygen in raw Kerosene. The simulation is based on conditions and parameters (mass flow rates, temperature and pressure readings) obtained from the Linear Alkyl Benzene (LAB) plant of the Kaduna Refining and Petrochemical Company (KRPC). After the successful completion of the simulation, total removal of impurities was achieved as the concentration of sulphur, nitrogen and oxygen in mole fraction present in the treated Kerosene stream was approximately zero. The treated Kerosene composition indicated 0.0021, 0.3342, 0.3322 and 0.3315 mole fractions of n-C13, n-C14, n-C15 and n-C16 respectively. Key words: Simulation, Hydrodesulphurization, Aspen Hysys, Impurities

    EFFECT OF SOLUTION pH AND TEMPERATURE ON PHENOL ADSORPTION ONTO CARBONIZED RICE HUSK CHEMICALLY ACTIVATED WITH PHOSPHORIC ACID

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    Operating conditions such as pH and temperature are important factors that influence the performance of activated carbon and solute uptake in adsorption process. Thus, this research work was aimed at studying the effect of solution pH and temperature on phenol adsorption onto rice husk activated carbon. Results obtained showed that when pH was increased from 2 to 4, adsorption capacity and removal efficiency increased, and thereafter, decreased progressively with additional increase in pH. Results also showed that when temperature was increased from 30 to 50 oC adsorption capacity and removal efficiency decreased. Therefore, this study has established that the optimum solution pH for adsorption of phenol onto phosphoric acid modified rice husk activated carbon is 4, and better performance of the adsorption process was occurred at lower solution temperatures
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