416 research outputs found
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DEVELOPMENT OF MICROCONTROLLER BASED AUTOMATIC POWER SWITCH WITH GENERATOR START AND STOP CONTROLS
Get PDFThe erratic nature of power supply and use of generators as alternative source of electricity in the developing countries like Nigeria has necessitated the need for a mechanism that switches power to a given load between two sources of supply.. This study was therefore initiated to focus on the design and implementation of an automated system that executes switching functions usually from public supply to generator and vice versa when mains supply is unavailable and when it is restored. The device consists of power supply unit for converting from alternating current (A.C.) to direct current (D.C.), logic circuit for detecting when mains power is restored, relay unit for performing power switch as well as control unit for starting and stopping a generator. It was observed that the device eliminates the stress and possible downtime associated with manual operation of a change over switch. The study recommends the device to be essential in hospitals, banks, government and private agencies where critical operations requiring constant availability of power are carried out. 
PHYSICO-CHEMICAL COMPOSITION OF EARLY AND LATE HARVESTED IMPROVED AND LOCAL SWEET POTATO (Ipomoea batatas (L) Lam) CULTIVARS ON THE JOS PLATEAU
Get PDFThe physicochemical composition and the energy values of the flours of both identified improved sweet potato (Ipomoea batatas (L) Lam) cultivars: CIP4400168, Ex-Igbariam, Tanzania, TIS 8164 and TIS 87/0087 and three local varieties (Land-races) of sweet potato were investigated. The cultivars were harvested after 4 months (early harvest) and 6 months (late harvest) to determine their suitability for the formulation of sweet potato secondary products. The root of each harvestwas weighed, washed, scrubbed, chipped to 1 x 1 x 6mm dimension, dried, milled into powder, sieved through 250μm mesh size sieve to obtain sweet potato flour. The flour was proximately analysed for moisture content (MC), Protein, Lipid, Fibre, Ash, Starch, Calorific value and pH using standard methods.The late harvest differed significantly in the parameters examined. The flour had low percentage moisture content ranging between 5 and 7.04% for late and early harvests respectively, indicative of long shelf life characteristics and low chances of attack by microorganisms. The crude protein values were higher (7.04%) in the flours of the early harvest but low (0.77%) for late harvest. The lipid concentration of the cultivars was low, 0.24 and 1.67% for the flours of 4 and 6 months harvests respectively. The fibre mean values of the flours were high (3.80%) in the 6 months harvest but low (1.24%) in the 4 months harvest.The ash content of the samples ranged between 0.83 and 2.56% for the flours of 6 and 4 months harvest respectively. The mean percentage values for starch of the flours were high ranging between 79.43 and 89.76% for 4 and 6 months harvested cultivars. 
ANALYTICAL STUDY OF HYDROKINETIC ENERGY POTENTIALS IN SOME TIDAL-RIVERS OF KANO STATE NIGERIA
Get PDFNigeria is heavily dependent on fossil fuel for electricity generation. With the rapidly diminishing of the fuel reserve and the increasingly negative effects of fossil fuels to the environment, government is considering exploiting alternative energy sources. However, the potential of harnessing other renewable sources, particular ocean energy, in Nigeria has not been fully realized. This study was carried out to identify the potential of harnessing ocean energy for electricity generation. Delft3D3D interactive modelling was used to create a three-dimensional numerical ocean model for some rivers in Kano State, Nigeria, which was calibrated againstmeasurement by a means of adjoin data assimilation approach. A set of reliable tidal speed and tidal elevation data was therefore generated to determine the types of tides available in aimed locations, the potential areas of installing river current turbines (RCTs), the total amount of electricity to be generated by RCT, the economic viability and the environmental benefits of using RCT in the studied areas. It was discovered that Tiga and Challawa are the areas with terrific prospect for tidal energy extraction. The total amount of electricity that can be generated by RCTs on those areas is about 8.86 GWh/year. The total amount of CO2 to be avoided is 1,333tonnes per year. Owners of RCTs may be able to recover the cost of the system after 10 years and can make profits after that. The results are critical to public policy makers and potentialprivate investors on hydrokinetic energy in Nigeria for consideration. 
DEVELOPMENT OF A DOOR LOCK SECURITY SYSTEM BASED ON AUTOMATIC SPEECH RECOGNITION
Get PDFThe security of homes and properties are of utmost importance and various methods have been employed by researchers to achieve this aim. This work developed a door lock security system based on automatic speech recognition. The developed system was programmed to recognize certain users and give a particular user access to a door. In training the system, MFCC feature extraction technique was used to extract appropriate features from five different individual’s speech signal and Vector Quantization using LBG algorithm (VQLBG) was done to recognize a speaker. A prototype door was designed and implemented to test the developed system.Euclidean distance was used in calculating the parametric representation of individual speech signal to be recognized and an accuracy of 75% was obtained by calculating the Word Error Rate (WER). Results show that the developed system is more reliable in securing door lock in homes than traditional method. 
EVALUATION OF THE EFFICACY OF ALCHORNEA CORDIFOLIA MÜLL. ARG., AGERATUM CONYZOIDES LINN AND EUPHORBIA HIRTA LINN PLANT EXTRACTS AGAINST VIRULENT ASPERGILLUS SPECIES
Get PDFAntifungal activities of the aqueous and ethanolic extracts of Alchonea cordifolia Müll. Arg., Ageratum conyzoides Linn. and Euphorbia hirta Linn. plants were evaluated both in vitro and in vivo against Aspergillus fumigatus, A. niger, A terreus, A, tamarii Kita. and A. ustus; these are mostly implicated in plant and animal fungal diseases. Thin layer chromatography was used to separate and identify the plant components and confirmation of phytochemical screening. Antifungal potential of the extracts were evaluated quantitativelyin vitro using well diffusion method and in vivo by studying the survival rate of Drosophila melanogaster challenged with the test standard isolates and compared with controls. The percentage yields of aqueous extracts were greater than that of ethanolic. Both extracts showed a potentially good antifungal activity, however aqueous extract had more activity. The activities increased with increasing concentration. Maximum antifungal activity was shown by aqueous of A. conyzoides against A. niger and A. ustus with the average inhibition of 20 mm each while the least activity were extracts of A. cordifolia against A. fumigatus at the concentration of 800mg/ml with 7mm zones of inhibition. Itraconazole (positive control) at 16.667m/ml, ranged from 15±0.13mm to 20±0.13mm with MIC values from 2.630mg/ml to 6.761 mg/ml. The MIC values of extracts ranged from 50mg/ml to 794mg/ml. The phytochemical screening revealed the presence of some phytochemicals. The activities of the plant extracts against the standard organisms in vivo did not correlate well with the in vitro. 
LEAST SQUARE REGRESSION METHOD FOR LOAD MANAGEMENT IN ELECTRICITY DISTRIBUTION NETWORK OF A 33 KV FEEDER AT FEDERAL UNIVERSITY OF AGRICULTURE ABEOKUTA, NIGERIA
Get PDFA stabilized electricity power system requires that its demand matches its supply. However, in a developing nation such as Nigeria, demand for electric power is continuously growing without comminserate supply s need. Consequently, load management is used to manage this inadequacy. One credible alternative in addressing this shortfall is load forecasting. This research work presents the least square regression method for load management in electricity distribution network using the Federal University Abeokuta (FUNAAB) 33kV feeder as a case study. Using the five years (2012-2016) load data collected from 132/33 kV Transmission Station at Gboniyi, Abeokuta, Ogun State on the sample network, a polynomial regression model was developed 
ON THE Dar-Zarrouk PARAMETERS AND AQUIFER HYDRAULIC CONDUCTIVITY DETERMINATION: A CASE STUDY OF ISHARA/ ODE-REMO GEOLOGICAL TRANSITION ZONE, SOUTHWESTERN NIGERIA
No full textFluid transmissivity and electric transverse resistance are important parameters in groundwater exploration. Determination of these parameters provides a good knowledge of the potential of porous media, because they relate fluid flow to electric-current conduction, in terms of layer thickness, permeability and resistivity. In this study, both parameters were determined in this study from the interpretation of Vertical electrical sounding data obtained. Direct relationships between both parameters were obtained and the relationship can be used to determine the transmissivity and hydraulic conductivity of the aquifer. The relationship suggests that anincrease in both parameters indicate presence of zones of high water potential within the aquifers. In the absence of pumping test, these Dar-Zarrouk parameters can be used to determined the hydraulic conductivity of aquifer in an area and groundwater potential evaluation 
NEW RESULT ON A FLUID FLOW INDUCED BY A ROTATING MAGNETIC FIELD
Get PDFThis research paper provides a new result on induced fluid flow in a circular cylinder under the influence of a rotating magnetic field. Maxwell’s induction equation and asymptotic technique are used to obtain the new result and it is observed that the convective term which Mofatt neglected in his work is significant in the boundary layer
EVALUATION OF EARTHWORM AS BIOFILTRATION AGENT IN ORGANICALLY POLUTED WATER
Get PDFThis research work evaluated the potentials of earthworms in the treatment of organically polluted water. Physiochemical parameters tested based on APHA standards to evaluate the qualities of water were Biolgical Oxygen Demand(BOD), Chemical Oxygen Demand(COD), Total Soluble Solids(TSS), Total Dissolved Solid (TDS), Electrical conductivity, pH, and temperature. The experiment was carried out in three batches in a vermi-filter where mass and time was varied to evaluate the removal efficiencies of organic matter from waste water samples using the physiochemical parameters. The results of the experiment showed that the removalpercentages of BOD, COD, TSS, TDS was between 65.5 - 80%, 68.2-85.8%, 59.1-92.7% and 60.6-91.5% respectively depending on the hydraulic retention time of the waste water in the vermifilter and masses of the earthworm in each vermin-filter. Earthworm successfully treated organically polluted water. 
EFFECT OF LAGOON AND FRESH WATERS ON THE COMPRESSIVE AND SPLIT TENSILE STRENGTH OF GRADE 40 CONCRETE
Get PDFof Lagoon water and fresh water on compressive and split tensile strength of concrete. A total specimen of 10 cubes and 10 cylinders including specimens for reference concrete were cast for both mixes and exposed to 28 days period of curing. The concrete samples was fully submerged in the lagoon and cured for 28days. For this concrete cubes and cylinders were cast with Portland limestone cement of 42.5-R using fresh water and cured using both fresh water and lagoon water.The result showed that the average compressive strength of concrete obtained using fresh water was 42.6N/mm2 compared to 36.4N/mm2 of Lagoon water and the average split tensile strength of concret