1 |
Author(s):
Muttaqa Uba Zango, Ado Yusuf Abdulfatah, Abba Tijjani Kademi, Ahmad Idris.
Page No : 1-9
|
HYPERBOLIC STRESS – STRAIN PARAMETERS OF REMOULDED TROPICAL BLACK COTTON SOIL
Abstract
This paper reports the experimental program and results obtained by performing laboratory direct shear box test on
black cotton soil. Hyperbolic stress strain parameters of the soil at different moulding water content (ranging from
-4%OMC to +4%OMC) were determined using Duncan – Chang (1970) model. Preliminary index properties test
results of the soil show that it was highly plastic soil with liquid limit of more than 50% and plasticity index of 33%.
A relationship between cohesion and moulding water content was also formulated in the paper. Finally, the hyperbolic
models parameters (i.e. K, n and Rf) determined had been found to conform with those specified in various literatures
and they could be used to predict numerically, stress-strain behaviour for the particular tested black cotton
soil
2 |
Author(s):
S. Garba., E. A. Ntuen., A. T. Salawudeen., A. Y. Zubairu., A. S. Abubakar., B. Adebiyi..
Page No : 10-16
|
DESIGN OF AN OPTIMIZED CONTROLLER FOR DC MOTOR SPEED CONTROL USING ABC AND PSO: A COMPARATIVE STUDY
Abstract
This paper presents a comparative analysis of a PID based DC motor speed control, using particle swarm
optimization (PSO) algorithm and artificial bee colony (ABC) algorithm. A model of a DC motor is obtained for its
speed control, and a PID controller is designed through a unity feedback for proper control of the speed. PSO
algorithm and ABC algorithm are used to optimize the parameters (Kp, Ki & Kd) of the PID controller using the
Integral of the Absolute Error (IAE) as cost function. A comparative analysis of the performance of each algorithm is
made with respect to maximum overshoot, settling time and rise time obtained from a step response. Result indicates
that the PSO performs better than ABC algorithm in term of settling time (with 5.81% improvement) and rise time.
However, the ABC converges faster with lesser overshoot of 12.61%.
3 |
Author(s):
Musa, U., Ali, A.S., Babani, S..
Page No : 17-23
|
DESIGN AND SIMULATION OF 2-SECTION MICROSTRIP WILKINSON POWER DIVIDER
Abstract
Power division is always required in most wireless/wire line communications such as industrial systems and
consumer electronics. However, the design of an unequal Wilkinson power divider, particularly with a large
division ratio, becomes a challenge in engineering because of the impractical realization of the high- or lowimpedance
transmission lines on a dielectric substrate. In this paper a 2-Section microstrip Wilkinson Power
divider is designed, the circuit was designed and simulated using advanced design system (ADS) Simulator.
with equal output power division of -3dB matched to 50 Ω transmission line, and frequency centered at
3.5GHz with Chebyshev multisection quarter wave transformer and maximum reflection coefficient in the
passband=0.05. The proposed power divider has a typical Wilkinson power divider performance of 0.2 dB
insertion loss within 85% fractional bandwidth (17 dB return loss) and -25 dB isolation at the operating
frequency
4 |
Author(s):
Babajo, S. A., Enaburekhan, J. S., Rufai, I. A..
Page No : 24-34
|
A REVIEW ON CO-PYROLYSIS OF BIOMASS WITH PLASTIC WASTE: AN OPTIONAL TECHNIQUE TO OBTAIN A HIGH-GRADE PYROLYSIS OIL
Abstract
The oil produced by the pyrolysis of biomass has potential for use as a substitute for fossil fuels. However, the oil
needs to be upgraded since it contains high levels of oxygen, which causes low caloric value, corrosion problems,
and instability. Generally, upgrading the pyrolysis oil involves the addition of a catalyst, solvent and large amount
hydrogen, which can cost more than the oil itself. In this regard, the co-pyrolysis technique offers simplicity and
effectiveness in order to produce a high-grade pyrolysis oil. Co-pyrolysis is a process which involves two or more
materials as feedstock. Many studies have shown that the use of co-pyrolysis is able to improve the characteristics of
pyrolysis oil, e.g. increase the oil yield, reduce the water content, and increase the calorific value of oil. Besides, the
use of this technique also contributed to reduce the production cost and solve some issues on waste management.
This article tried to review the co-pyrolysis process through several points of view, including the process
mechanism, feedstock, the exploration on co-pyrolysis studies, co-pyrolysis phenomena, characteristics of
byproducts, and economic assessment. Additionally, several outlooks based on studies in the literature are also
presented in this paper.
5 |
Author(s):
Mohammed S. Abdullahi , Okorie A. Uche., Muhammad T. Abdulwahab.
Page No : 35-46
|
FLEXURAL RELIABILITY ASSESSMENT OF REINFORCED CONCRETE BRIDGE DECK WITH CARBON FIBRE REINFORCED POLYMER (CFRP) EXPOSED TO CORROSION
Abstract
The strength of reinforced concrete elements retrofitted in flexure by means of externally bonded Carbon Fibre
Reinforced Polymers (CFRP) has attracted the attention of researchers due to many advantages highlighted by a
wide set of experimental results. This research presents reliability study on reinforced concrete (RC) bridge deck
strengthened with externally bonded CFRP subject to corrosion. The deck was subjected to reliability analysis, using
First Order Reliability Method (FORM), enhanced with genetic algorithms and the inherent safety was found to yield
safety index of 3.8, this agreed with the recommendation of the Joint Committee of Structural Safety Code (JCSS
2001) for structures with moderate consequence of failure. The reliability analysis for the intact and the corrosion
affected deck were executed through a developed program, written using MATLAB Simulink and the result showed the
detrimental effect of corrosion on reinforcement of steel in the bridge deck. Flexural capacity restoration was also
undertaken for the bridge deck using Carbon Fibre Reinforced Polymer (CFRP) with the adoption of adhesive
bonding technique. The results of the reliability-based analysis of the strengthened deck with Carbon Fibre
Reinforced Polymer (CFRP) yielded a flexural capacity restoration up to 100%. Sensitivity analysis for the bending
mode of failure were also conducted and it was observed that the critical mode of failure to be strengthened is flexure.
6 |
Author(s):
J. Suleiman, N. D. Dangora, M. L. Attanda.
Page No : 47-53
|
DEVELOPMENT OF A REGRESSION MODEL FOR PREDICTING RICE GRAIN BREAKAGES FOR DEUTZ-FAHR M1202 COMBINE HARVESTER
Abstract
A multiple linear regression analysis was used to develop a performance model on grain breakages for
Deutz-Fahr M1202 combine harvester with grain moisture content (MC) and cylinder-concave clearance
as the two independent variables and grain breakages as the dependent variable. Field experiments were
conducted at constant combine harvester forward speed 1.70 km/h. Combination of three different grain
moisture contents 11, 13 and 15 % (wet basis) and three different cylinder-concave clearances 12, 20 and
26 mm were used as independent variables to determine the dependent variable of grain breakages.
Analysis of variance shows that there was highly significant difference in the mean values obtained for
grain breakages at different MC and concave clearances. Theoretical field capacity, effective field
capacity and field efficiency were 0.77 ha/h, 0.68 ha/h and 88 % respectively. The predicted values
obtained through the developed model were compared to another set of observed field data in order to
validate it. High value of R2(0.901) which is significant indicate good agreement between the real values
and the predicted values of grain breakages for the combine harvester. The accuracy and precision was
calculated as 0.083 while bias value of 0.00077 was obtained. The mean square of predicted error (MSPE)
was found to be 0.083.
7 |
Author(s):
AARON ABOSHIO, ABDULRASHEED LAWAL.
Page No : 54-62
|
ASSESSMENT OF THE ENGINEERING PROPERTIES OF DELEB PALM TIMBER
Abstract
In this study, the engineering properties of the medullary (sub-dormal) zone of a Nigerian grown deleb palm timber was
assessed in the laboratory based on BS EN 13183-1 (2002), BS EN 408 (2003) and ASTM D193 (2000) standards. Samples
of the timber specie were procured and cut to various sizes for determinations of moisture content, density and strengths in
compression and flexure based on the three point bending technique using a Cussons made universal testing machine.
Results indicate that the assessed timber was dry and of relatively high density. Average moisture content and density of the
samples obtained were 4.72 % and 766.24 kg/m3 respectively. Flexural strength assessments indicate that the deleb palm
wood have strength ranging from 62.34 to 75.43 N/mm2. Compressive strength for specimens loaded parallel to grain for
the deleb palm timber ranges from 10.50 to 12.08 N/mm2 while the compressive strength for specimens loaded
perpendicular to grain as 2.19 to 3.07 N/mm2, much lower than those loaded parallel to grains as consistent with results of
other timbers in the literature. Typical failure modes observed were splitting and brooming failure modes for the deleb palm
timber under compression for specimen of height measuring 450 mm. For specimens between 75 and 100 mm the failure
modes observed were crushing and shearing respectively. The material here assessed can be suitably used in structural
applications and as viable alternative to popular hardwoods.
8 |
Author(s):
Aaron Aboshio.
Page No : 63-70
|
ASSESSMENT OF THE DYNAMIC AMPLIFICATION OF A PRISMATIC REINFORCED CONCRETE SLAB
Abstract
In this study, static and dynamic responses of a typical reinforced concrete solid slab, designed to British Standard
(BS 8110: 1997) and under self and live loadings for dance halls are reported. Linear perturbation analysis using
finite element method was employed for modal, impulse loading and frequency response analyses of the slab. Results
from the static and dynamic analyses, comprising of the slab fundamental frequencies and mode shapes, dynamic
amplification factor, maximum deflection, stress distributions among other valuable outcomes are presented and
discussed. These were gauged with the limiting provisions in the design code with a view of justifying valid optimization
objective function for the structure that can ensure both adequate strength and economical section for large
clear span slabs. This is necessary owing to the continued increase in cost of erecting building structures and the
squeeze on public finance globally.
9 |
Author(s):
Babajo, S. A, Enaburekhan, J. S.
Page No : 71-77
|
PHYSIO – CHEMICAL PROPERTIES OF JATROPHA BIODIESEL – KEROSENE BLENDS USED AS FUEL IN A PRESSURIZED COOKING STOVE
Abstract
Physio- chemical properties of jatropha biodiesel- kerosene blends were carried out to investigate their
potential use as conventional substitute for kerosene in a pressurized kerosene cooking stove. The assessments
were done by comparing some of the combustion characteristics of the blends of jatropha biodiesel with
kerosene. The blends were categorized as B100 (100% biodiesel), BK20 (20% jatropha biodiesel and 80%
kerosene), BK15 (15% jatropha biodiesel and 85% kerosene), BK10 (10% jatropha biodiesel and 90%
kerosene), BK05 (5% jatropha biodiesel and 95% kerosene) and BK0 (pure kerosene). The result showed that
the calorific value of BK100 was less than that of BK0 and decreasing in the order of jatropha biodiesel. The
maximum calorific value obtained was 45400kJ/kg. The results showed a general decrease in calorific value
with a decrease in kerosene content for all the fuel blends. Thus pure biodiesel had quite appreciable
combustion potentials as kerosene with jatropha biodiesel used as fuel in the pressurized kerosene cooking
stove.
10 |
Author(s):
Musa, U., Babani, S., Ali, A.S..
Page No : 78-84
|
DESIGN AND SIMULATION OF AN RF/MICROWAVE AMPLIFIER AT 5 GHz FOR MAXIMUM GAIN AND LOW NOISE-USING ATF-36077
Abstract
In this paper, a maximum gain and low noise amplifier using S parameter for field effect transistor (FET)
devices using avago technologies (ATF 36077) was designed and simulated. The low noise amplifier (LNA) has
a VDS of 1.5V and IDS of 10Ma. The design specifications consist of 5.0 GHz operating frequency, microstrip
line with substrate Ԑr=4.5, thickness of 1.6 mm and tangent loss of 0.019. High Electron Mobility Transistor
(HEMT) was used. Advanced design system (ADS) software was used for the design and simulation process.
The maximum available gain, the associated power gain when the input matched for the minimum noise figure
and Gain of transistor (S21) in dB were 12.912 dB, 10.714 dB and 9.033 dB respectively when operating at 5
GHz.
11 |
Author(s):
Sani Haruna, Isyaka Abdulkadir.
Page No : 85-94
|
ASSESSMENT OF FLEXURAL BEHAVIOUR OF COCONUT SHELL CONCRETE BEAM REINFORCED BAMBOO WOOD AND STEEL STIRRUPS
Abstract
This paper presents the study on the flexural behaviour of bamboo reinforced coconut shell aggregate concrete beams
together with normal weight concrete beams (NWCB). The grade of coconut shell aggregate concrete, a lightweight
concrete (LWC) produced using coconut shell aggregate obtained from agricultural waste as lightweight aggregate,
referred to here as CSC was 20N/mm2 at 28 days. The grade for normal weight concrete was 20N/mm2 using
conventional stone aggregates. The beams prepared for study were of size 150 mm x 250 mm x 1500 mm and tested in
flexure. Three beams were of normal weight concrete with steel reinforcement (NWCB), three beams were of CSC
with steel reinforcement (CSCB), three beams were of CSC with split bamboo as reinforcement (BCSC) and three
beams were of CSC with split bamboo wrapped with binding wire as reinforcement (BCSCB) - totally twelve (12)
beams were tested and their behaviour was reported. From the experimental results, it was observed that the load
carrying capacity of the NWC beams were 8.04%, 23.21% and 17.86% higher than CSCB, BCSCB, and BCSCB*
beams respectively. The stiffness behaviour of BCSC beam showed similar pattern with that of NWC up to failure.
CSCB beams also exhibited various cracks thus, the crack width and crack spacing was small. The CSCB and
BCSCB beams exhibited higher deflection under constant load until failure, compared to NWCB beams. Higher
concrete strains for the reinforcement in the CSCB shows stronger bond between CSC and the reinforcements,
12 |
Author(s):
S. M. Lawan, B. D. Bala, F. A. Umar, I. Abba, A. Y. Abdullahi, A. Aminu.
Page No : 95-101
|
DESIGN OF AN IMPROVED BIOMASS TO HEAT COMBUSTER AND ITS EXPEREMENTAL VALIDATIONS
Abstract
Pulp and paper industry in Nigeria is heavily dependent on fossil fuels. Fossil-based fuel pollutes lower layer of the
atmosphere, causes greenhouse gases (GHC) and other environmental worries. Renewable energy sources are clean
and cost-effective nowadays. An innovative horizontal air staged inclined biomass combustion for drying purpose in
the production of paper egg trays is developed and evaluation is performed with oil groundnut kernel shell and wood
chip as the fuel. The development of the Biomass-to-Heat-Converter (B2HC) can serve as useful insight in the design
and development a laboratory biomass combustion chamber. The influence of the air mixture ratio on the flue gas
composition (combustible gases: carbon monoxide and hydrogen) and the B2HC converter (pyrolysis chamber,
exhaust gas, surrounding) temperature profile is determined from the fuels. Temperature obtained for the pyrolysis
chamber, exhaust gas and surroundings at the optimum condition were 304.41± 49.750C, 119.50± 26.840C and
32.14± 1.380C respectively. The average emission of carbon monoxide and hydrogen from the optimum condition
were 274.71± 52.890C ppmv and 91.11± 33.660C ppmv respectively. The optimum average combustion efficiency
determined is 62.47 %. The geometrical design in this B2HC shows that carbon monoxide is reduced compared to
other works.
13 |
Author(s):
Wada, I.M., U.I. Markus., A. Ibrahim.
Page No : 102-113
|
SUBSURFACE DRAINAGE DESIGN AND COST ANALYSIS AT HADEJIA VALLEY RIVER BASIN JIGAWA STATE, NIGERIA.
Abstract
The twin problem of waterlogging and salinization in irrigated lands remains a serious challenge around the world.
This study was conducted to provide a solution in combating the effect of waterlogging and salinization along the
command area of Hadejia valley river basin. Soil samples were collected from the study area using stratified random
sampling techniques to identify the extent of salinity or sodicity in the study area. Nineteen observations wells were
drilled randomly in the study area to measure the water table depth and the depth of impervious layer. The result
obtained from the soil test indicates that Calcium was generally the dominant base in the exchange complex.
However, the levels of exchangeable sodium was high in some areas and increase with soil depth ranging from 0.2 to
8.1 cmol (+) kg-1 and 0.3 to 12.4 cmol (+) kg-1 for topsoil and subsoil respectively. The ESP mean values ranged
from 14.8% and 17.5% for the top soil and subsoil, respectively. Soil pH varied from 5.6 to 9.9 in the top soil and 4.8
to 9.8 in the subsoil. Values for Electrical Conductivity (EC) of the soil saturation extract were generally very low,
indicating that the soils are generally non-saline. Strong evidence shows that Soil sodicity was the most serious
problem in the area. Results from observation wells indicated that the study area has a shallow impervious layer of
2.6m. Seepage from adjacent River Hadejia contributes to the high water table (WT) and subsequent waterlogging.
For optimum use of the land, a subsurface drainage was designed and the drain depth was calculated as 1.6m, drain
diameter of 20cm and drain spacing of 14m and 10m using Hooghoudt’s and Glover Dumm’s conditions
respectively. However, the WT was lowered to 1.1m suitable for most agricultural activities in the area. The overall
pre-construction and construction cost was calculated as ₦635,000 and ₦1,520,000 respectively for a hectare of
land.