| 1 |
Author(s):
Kuburi, L.S., Dauda, M., Yaro, S.A., Abdulwahab, M..
Page No : 1-9
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ASSESSMENT OF MECHANICAL AND MICROSTRUCTURAL PROPERTIES OF Al-3%Mg/SiCp COMPOSITE
Abstract
The research was aimed at developing silicon carbide (SiCp) reinforced aluminium-magnesium (Al-Mg) matrix composite with better mechanical and microstructural properties than the conventional marine grade Al-Mg alloy presently used as structures in marine and coastal areas. Stir-casting process was used in developing the test mate-rials with Al-3%Mg alloy having 0% SiCp used as control sample and compared with the performance of the samples containing 5% SiCp, 10% SiCp, 15% SiCp, 20% SiCp and 25% SiCp reinforcements respectively. X-ray fluorescence (XRF), Scanning electron microscope (SEM) and energy dispersive x-ray (EDX) analyses of the materials have shown that the materials contain about 2-3% of Mg and also the reinforcement was found to be well distributed in the matrix without any serious flaws or cracks observed. Highest hardness value of 75.4 HRB was obtained on the sam-ple containing 10% SiCp compared to the control sample with 53.8 HRB. Highest tensile strength of 108 N/mm2 was recorded on sample with 15% SiCp as compared to the control sample with 93.2 N/mm and highest impact en-ergy of 18.98 J was also obtained on the sample with 15% SiCp compared to the value of 9.97J as observed on the control sample. The composite materials developed are found to be of better mechanical properties than the marine grade matrix alloy under test condition.
| 2 |
Author(s):
Bala, B.D, Muhammad, B. , Zakariyya, R.A., Saleh, M.A., Hamza, A.N..
Page No : 10-16
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DESING AND SIMULATION OF CIRCULAR PATCH ANTENNA WITH A RECONFIGURABLE POLARIZATION
Abstract
A circular patch antenna with reconfigurable polarizations is proposed. Linear polarized (LP) antennas suf-fers from poor signal transmission during adverse weather condition and multipath effects as a result of sec-ondary transmission from nearby environment. Therefore circular polarized (CP) antennas prove to be a good candidate in this regard. The proposed antenna uses strip lines connected via a copper strip switch to achieve both right hand circular polarization and left hand circular polarizations. The overall size of the antenna is 0.52λo x 0.52λo at the operating frequency of 2.40 GHz. The antenna is compact and versatile due to its re-configurable ability. The simulated gain and radiation efficiency of 6.25 dBi and 84.5 % is obtained respec-tively for both polarization at the resonance frequency. The antenna performances in terms of reflection coef-ficients, electric field distributions and the radiation patterns are presented and discussed. The reflection coef-ficient and the gains obtained shows that the antenna has potential applications for WLAN (2.39-2.45 GHz) operations.
| 3 |
Author(s):
Bala, B.D., Muhammad, B., Abdu, A.M., Iliyasu, A.Y., Tijjani, A..
Page No : 17-24
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MICROSTRIP PATCH ANTENNA ARRAY WITH GAIN ENHANCEMENT FOR WLAN APPLICATIONS
Abstract
A microstrip patch antenna array with gain enhancement is proposed. A single patch antenna is gain limited with low
data rate for WLAN applications. High gain antennas are required to increase upload/download data rate for WLAN
applications. An n x n patch antennas are combined in a corporate array network for gain enhancement. Therefore,
1x2, 1x4, 2x2 and 2x4 antenna arrays were studied and investigated. The antennas transmission networks are designed
using quarter wave transformers and are probe fed. The overall size of the main radiating element is 0.25λo x
0.30λo (30.2 mm x 37 mm) at 2.44 GHz. Simulated results shows a gain enhancement of 7dB from a single patch to
2x4 array patch antenna. Also a narrow beam-width is obtained at 3dB which improves from 90.9 degree for a single
patch to 56 degrees for a 2x4 array patch. The simulated antenna performances in terms of reflection coefficients,
gains, surface current distributions and the radiation patterns are presented and discussed. The reflection coefficient
and the gains obtained show that the antenna has potential applications for WLAN (2.39-2.45 GHz) operations.
| 4 |
Author(s):
Waziri1, B.S., Yusuf M.I..
Page No : 25-36
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REGRESSION AND BACK PROPAGATION NEURAL NETWORK MODELS FOR PREDICTING HIGHWAY CONSTRUCTION DURATION IN NIGERIA
Abstract
Reliable prediction of construction duration at the planning phase is essential for project feasibility studies, budgeting decisions, project monitoring and performance evaluation. This research examined the performances of parametric models for the prediction of duration of highway construction projects. Three generalized linear regression models in the form of linear, semi log and log-log and a Back Propagation Neural Network (BP-NN) model were developed using a dataset of 57 successfully completed highway projects. 80% of the data were used for developing the models while the remaining 20% were used as test samples for validating the models. The results of the regression analysis revealed that the linear, semi-log and log-log models have R2 values of 0.546, 0.631 and 0.940 respectively indicating a good fit to the data in all cases. The training and testing results of thirty different BP-NN architectures using the sigmoid transfer function and the delta learning rule showed that the network with a single hidden layer having five hidden neurons is the best network with training and testing errors of 0.002 and 0.000 respectively. The evaluation results of the four models over a test samples indicated that the BP-NN outperformed the regression models with an average error of -2.76% and Mean Absolute Percent Error (MAPE) of 4.53%. The neural network model showed satisfactory performance therefore it can be used by both clients and contractors for estimating highway construction duration at the planning phase.
| 5 |
Author(s):
Yusuf, A.S., Mohammad, A., Hamisu, A.A., Ahmad, K..
Page No : 37-43
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EXCITATION SIGNAL FOR IDENTIFICATION OF ILL- CONDITIONED NON-LINEAR PROCESS
Abstract
This paper presents a study of the effect of different identification signals on the richness of identification data for illconditioned
processes. Previous works have suggested that the use of correlated test signals result in identification
that is not persistently exciting. However, there have been suggestions that for ill-conditioned systems, the use of
correlated signals gives better excitation. This paper aims to investigate the effect of the use of correlated signals for
the excitation of a nonlinear ill-conditioned process. To achieve this, three different test signal pairs were used to
excite a non-linear model of the high purity binary distillation column. The three tests were carried out using an
uncorrelated signal pair, a partly correlated signal pair and a signal pair formed by the summation of an
uncorrelated signal with a correlated signal. The effects of these tests were compared using plots of output
directions. The use of uncorrelated signals resulted in a maximum range of 0.001 in the low gain direction. The use
of two specially designed partly correlated signals resulted in maximum ranges of 0.005 and 0.01 giving
improvements of 400% and 900% respectively. Therefore, significant benefits in terms of excitation were achieved by
using a partly correlated and a summation of correlated and uncorrelated signals. This means, models developed
from the specially designed partly correlated signals would capture more relevant information in the low gain
direction
| 6 |
Author(s):
Sumaila, M., Ibhadode, A.O.A..
Page No : 44-51
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COMPARATIVE STUDY OF EPOXY-BASED COMPOSITE REINFORCED WITH DIFFERENT PLANT FIBERS
Abstract
Present ecological concerns have motivated the quest for materials that are low in weight, cheap, environmentally friendly and renewable, while having high specific strength and stiffness. This paper describes the production of a chopped strand, random oriented, non-woven plant fibre mat reinforced epoxy composite for automotive applications. Fibers from eight fibrous plants found in northern Nigeria were used as reinforcement of epoxy resin to produce the composites at 40%v/v filler content. The tensile and flexural strengths, impact energy, density and moisture absorption of each formulation were determined and compared with those reinforced with E-glass fibre mat. The results obtained for the tensile, flexural strengths and the impact energy of plant fibre composite samples were aggregated and ranked. Sisal (Agave sisalana), Lalloh (Corchorus accitangulus B.) and Kenaf (Hibiscus cannabinus L.) fiber reinforced composites exhibited the best mechanical property combination in that order. The flexural modulus and the impact energy of the plant fiber were respectively 70% and 40% higher than the glass fiber reinforced composite.
| 7 |
Author(s):
Rabiu, H., Obahor, A.O., Danisa, A..
Page No : 52-60
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APPLICATION OF ARTIFICIAL NEURAL NETWORK FOR DIAGNOSIS OF TUBERCULOUS MYCOBACTERIUM IN INFECTED LUNGS USING IMAGE PROCESSING TECHNIQUES
Abstract
The high level of manual work flow in the diagnostic procedure for Mycobacterium Tuberculous (TB) introduces varying degrees of subjectivity at different stages in the process. This affects the final accuracy and increases diagnosis time. This paper presents an automatic method of segmenting TB bacilli using cascade threshold filters. A multi layer artificial neural network (ANN) with scaled conjugate gradient descent algorithm was used to classify the presence or absence of TB bacilli in the processed images. Results of the ANN classifier gave a MSE of 0.025 and accuracy of 94.7%. These results suggest that the proposed procedure can help detect the presence or absence of TB bacilli in Ziehl-Neelsen (ZN)-stained sputum smear samples with high accuracy.
| 8 |
Author(s):
Maina, M.M. , Zakari, M.D. .
Page No : 61-68
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IRRIGATION WATER QUALITY ASSESSMENT FOR SOIL NUTRIENTS CONTENT AT TANJUNGKARANG IRRIGATION SCHEME MALAYSIA
Abstract
Excessive fertilizers were applied to crops due to lack of precise nutrients content assessment of soil and water in SawahSempadan area. However, assessing the nutrients elements content of the irrigation water is essential in prescribing fertilizeron the irrigated farm. Three water samples were obtained from the study area in four different locations; Canal, Field, Drains and Shallow groundwater. These samples were subjected to a standard method of chemical analysis to quantify the following parameters; pH, Turbidity, Alkalinity, Potassium, Nitrate, Ammonia and Phosphorus. The results showed all were within the safe range for plants growth. While the quantity of some of the major fertilizer components such as nitrogen, potassium and phosphorus were significantly high. The canal water contained 118.4 kg/ha and 8.6 kg/ha of potassium and phosphorus respectively, these quantities were significant enough to affect the rate at which fertilizeris being applied to the farm. The total amount of potassium added by canal water amount to 20% of the total fertilizer applied throughout the season. Following these findings, it is strongly recommended that fertilizer application should not be based on soil nutrient mapping only but also nutrients content of irrigation water. This will reduce the cost of inputs, soil damage and increase profit.
| 9 |
Author(s):
Attanda, M. L., Abubakar, M.S. .
Page No : 69-74
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DEVELOPMENT OF A SIMPLE PREDICTION MODEL FOR SOIL COMPACTION DUE TO WHEEL TRAFFIC IN SAMARU – ZARIA.
Abstract
A prediction model using the least square criterion of regression technique was developed to predict soil
compaction under tractor wheels. The two soil parameters of moisture content and bulk density used in the
model development were observed in the calibration test of the field soil through pressure gauge
measurement approach. Evaluation of the developed model showed that the model coefficient of efficiency
is 0.86 while its consistency as indicated in the value of sum of residuals is 18.67. The unbiased of the
model is shown in the value of the accuracy as 1.23 MPa and an assessment of error of the predicted
values related to measured values of the soil compaction is indicated in the value of mean square
prediction error as 1.56.
| 10 |
Author(s):
Shuka, M. E., Yola, I.A..
Page No : 75-81
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COMPARATIVE ANALYSIS OF COMBUSTION BEHAVIOUROF RICE HUSK PELLETS WITH CHARCOAL
Abstract
This paper presents the comparative analysis of combustion behavior of rice husk pellets with charcoal. Rice husk
was selected because of its abundance and rich crude fiber content which is a good property for pellet production.
The rice husk pellets were produced using wet process of densification technology at 0.6 MPa compaction pressure
and different binder ratios with tamarind starch and cassava starch as binders. The results of the flame tests have
shown that, rice husk pellets with binders have higher flame height of 6-10cm than that of charcoal with 1-2 cm.
Emissions test was conducted on the rice husk pellets and charcoal and the toxic gases tested were CO, SO2, NO2 and
H2S using portable gas analyzer). The results show that binder ratio have significant effect on the combustion
behavior of the rice husk pellets. Results from the emissions tests show that, the rice husk pellets produced with
tamarind starch and cassava starch have SO2 (0.3 ppm), H2S (0.2 ppm), CO (0.3 ppm) and NO2 (0.4 ppm) emissions
of the harmful gases at 20% binder ratio while charcoal has SO2 (1.2 ppm), H2S (0.1 ppm), CO (4.2 ppm) and NO2
(0.2 ppm ) emissions respectively. Rice husk pellets can be used as a substitute to charcoal considering it’s high
temperature and less emission of toxic gases. The tamarind starch can serve as replacement to cassava starch for
pellets production because it has exhibited good binding effect and better combustion characteristics.
| 11 |
Author(s):
Muhammad, H., Yola, I.A..
Page No : 82-90
|
PERFORMANCE OF SHEA BUTTER BIODIESEL AS FUEL FOR COMPRESSION IGNITION ENGINES
Abstract
This study investigated the effectiveness of shea butter biodiesel as fuel for compression ignition engine. Acid-base catalyst transesterification method was used to produce the biodiesel from the shear butter oil. The density and viscosity were found to be 893 kg/m3 and 4.35 mm2/s, respectively. Single cylinder four stroke 165F compression ignition engine was used to examine the engine performance. The results have shown that, the brake thermal efficiency (30.9%.) decreases with an increase in engine load, while the specific fuel consumption (300 kWh) increases with an increase in engine load. On the other hand, the brake power (30.9 W) increases with an increase in engine load while the air/fuel ratio (22.5) decreases with an increase in engine load. Gas analyzer was used to determine exhaust gases emitted when shea butter biodiesel was used as fuel. From the results, the amount of nitrogen dioxide (NO2) emitted was 3.8 ppm and hydrocarbon (HC) was 2.5 ppm, while that of carbon-monoxide (CO) was 18 ppm. The study revealed that the performance (brake power and specific fuel consumption) of the engine using shea butter biodiesel increases with an increase in engine load.
| 12 |
Author(s):
Lawal, U., Rufai, I.A..
Page No : 91-96
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POSSIBILITY OF EXTRACTING SOLAR GRADE SILICON FROM RICE HUSK ASH
Abstract
Thepaper presents experimental extraction of silicon from rice husk (RH) of NERICA rice variety obtained from Basawa, Zaria in Kaduna State, for possible use as a material for Solar Cells. Magnesium reduction techniques was employed for the extraction process. The rice husk sample was pretreated, charred and calcined at different temperatures ranging from 500°C to 1000°C to produce rice husk ash (RHA). The RHA produced ware characterized using X – ray fluorescence (XRF) and X – ray diffraction (XRD) techniques to ascertain a purer silica for the reduction process. The magnesium reduction was realized by pyrolyzing the mixture (Silica and Magnesium) at 700°C for 4 hours, followed by leaching of the reduction product in diluted hydrochloric acid (HCl). Characterization of theash calcined at 700°C and the final reduction product with XRF techniques revealed Silica of 98.1% and silicon of 97.69% purity with 14 other elements as impurities such as Aluminum (Al), Calcium (Ca) and with Iron (Fe) having the highest concentration of 0.706%wt. Analysis of the extracted silicon by XRD shows structural formation of silicon having all the major reflections of standardsilicon. Solar grade silicon has a minimum purity level of 98%, while the extracted silicon has purity level of 97.69% which seems to be not suitable for solar cells application. However, the extracted silicon, being a natural semiconductor, canbe altered to be either an insulator, such as glass, or a conductor.
| 13 |
Author(s):
Bukata, B.B..
Page No : 97-107
|
ANFIS BASED POWER QUALITY SOLUTION USING UNIFIED POWER QUALITY CONDITIONER
Abstract
Nowadays, the increase use of sensitive power electronic devices leads to the increase of equipment that introduces power quality (PQ) problems in distribution system. This necessitates the need to find the means to compensate pow-er quality disturbances so that, reliable and quality power will be delivered to customers. This paper investigates an efficient control scheme for unified power quality conditioner (UPQC) with Neuro-fuzzy (NF) techniques. The voltage and current reference signals are derived using the synchronous reference frame (SRF) theory. The derived reference signals and sensed signals are injected in to pulse width modulation (PWM) control technique to generate switching signals. The performances of the proposed Neuro-fuzzy based UPQC system are evaluated in terms of solving voltage sag, voltage swell and harmonics problems using SimPowerSystem toolbox residing in MATLAB/SIMULINK envi-ronment. The results were also compared with FL (fuzzy logic) and NN (neural network) performances.
| 14 |
Author(s):
Dan’azumi, S., Abdullahi, S.Y..
Page No : 108-114
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PRESSURE HEAD ANALYSIS OF WATER DISTRIBUTION NETWORKOF BAUCHI METROPOLIS
Abstract
In Bauchi metropolis water reticulation, water is pumped from a treatment plant at Gubi to two overhead reservoirs at Warinji and then distributed to the network. The network analysed comprises of flow from the reservoirs to major pipes that pass through the city and this includes 97 pipes of different sizes connected at 72 nodes. The current (2015) and future (2035) water demands were estimated to be 42,856 and 63,214 m3/day respectively. Presently, most parts of Bauchi receive water for only 4 hours per day and therefore, 4 hours of extended period simulation was conducted using EPANET 2.0. Similarly, future design was proposed in which 12 hours of water supply was analysed. Results of proposed design indicate that 68 nodes, out of the 78 will have pressure head above 25 m which satisfies many standards and is a good step towards achieving the ultimate goal of 24 hours water supply.
| 15 |
Author(s):
Yadima, S.G., Babagana Sa’ad., Ibrahim, U.A..
Page No : 115-122
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EFFECTS OF SHELF LIFE ON COLOUR REMOVAL FROM NATURAL COAGULANTS SEEDS EXTRACTS
Abstract
This study examined the effects of shelf life on the colour removal efficiencies of extracts from Moringa oleifera, Hibiscus sabdariffa and Hibiscus esculentus seeds in coagulation of high turbid water. The seeds were collected from a vegetable garden in Kayamla village on the outskirt of Maiduguri, Nigeria. About 3250 g of each seed was used in the study. Two different methods of seeds storage were investigated. One part of each seed was placed in a clay pot and covered which was labelled as “N” while the other part was placed in a polythene bag of 700 gauge and placed in a clay pot and covered which was labelled as “P”. The seeds were subjected to ethanoic extraction each month for six consecutive months. One litre of the ethanol was used for the extraction process. The extraction process was conducted based on soxhlet method using soxhlet solvent extractor. The coagulation activities of the seeds extracts were conducted using the jar test experiment. The seeds extract of varying dosages of 30, 40, 50, 60, 70 and 80 mg/l were used on pond waters having turbidity strengths ranging from 343-385 NTU. The optimum dose was then determined by selecting the beaker with the highest colour removal efficiency at a reasonable time and with large floc size formation. The experiment was repeated for each of the three seeds stored in the two different storage methods for six months. Results revealed that the efficiencies of colour removal of all the seeds extracts decreased as storage time increased. Higher values of colour removal were associated with storage method “P”. The effect of shelf life of six months for colour removal with respect to the two storage methods was insignificant for all the three seeds extracts. The efficiency of colour removal of the three seeds extracts decreased as storage duration increased. The storage method with polythene bag inside clay pot was found to be the best method. The paper calls for the propagation of the use of polythene bag and clay pot for seeds storage among rural dwellers when the seeds are being considered for water treatment.
