
ARPN Journal of Engineering and
Applied Sciences October 2007  Vol.2 No.5 
Title: 
PCbased lowcost CNC
automation of plasma profile cutting of pipes 
Author (s): 
James N. Keraita and
KyoHyoung Kim 
Abstract: 
In modern fabrication
shops, it is important to invest in affordable, stateoftheart
technology; including material handling systems, computerized motion
control, advanced cutting systems and dedicated software programs in
order to compete effectively in the market. In pipe profile cutting
operations using plasma arc, CNC automation introduces higher precision,
repeatability and speed. One method of simplifying the automation and
hence improving the profit margins is the reduction of the number of
controlled axes. Further by simplifying the design, the CNC machine is
made more compliant to the technique of error modeling and compensation.
This research investigated the suitability of a PCbased CNC pipe
cutting machine by simultaneous control of only two axes. The developed
machine competes well with similar machines having higher number of
axes. The shortcomings arising from such simplification of the machine
and the plasma arc cutting (PAC) process in general; are pointed out and
possible improvements suggested. 



Title: 
Effect of microbial growth
on biogas generation using carrier material in the self circulating
biogas plant 
Author (s): 
N. Stalin and H. J. Prabhu 
Abstract: 
A modified three stage
methane fermentation system was developed to digest animal manure
effectively. The digester having an effective volume of 200 liter is
constructed with central tube filled with burnt bricks. The burnt brick
in the central portion of the digester increase the microbial
concentration by immobilizing the bacteria on the surface of the burnt
brick. The size of brick materials is not more than 3 to 5 mm size. The
carrier materials used in the digester are 5%, 10%, 15%, and 20% of the
total volume of the digester and also for each percentage 3.5kg of cow
dung and 3.5kg of water (1:1) is well mixed and added daily. The
readings were taken between biogas generations versus time for each
percentage continuously up to 90 days. It was observed that 10 to 15
percentage of carrier material from the total volume for microbial
growth gave more gas generation. Operational temperature was from 30°C
to 50°C. In this study we examined the effect of microbe growth,
temperature on biogas generation and hydraulic retention time. 



Title: 
MHD unsteady free
convective Walter’s memory flow with constant suction and heat sink 
Author (s): 
M.V Ramana Murthy, G.
Noushima Humera, Rafiuddin and M. Chenna Krishan Reddy 
Abstract: 
The study of unsteady
hydromagnetic free convective memory flow of incompressible and
electrically conducting fluids past an infinite vertical porous plate in
the presence of constant suction and heat absorbing sinks have been
made. Approximate solutions have been derived for the mean velocity,
mean temperature, mean skinfriction and mean rate of heat transfer
using multiparameter perturbation technique. It is observed that
magnetic field strength decreases the mean velocity of the fluid. Also
the mean skinfriction and mean rate of heat transfer of the conducting
fluid decreases with the increase in magnetic field strength. 



Title: 
The targeting problem for
Stype quality characteristics 
Author (s): 
K. Tahera, R. N. Ibrahim
and P. B. Lochert 
Abstract: 
The targeting problem
generally identifies the process parameters such as the initial process
means of a production process. The joint determination of the initial
process means and the production run has been reported in the
literature. Most of these studies considered a process with multiple
independent nominalthebetter type (NType) of quality characteristics.
In a real industrial situation, the quality characteristics may depend
on each other. In addition, the process could have other types of
quality characteristics. In this paper, a mathematical model is
developed that jointly determines the optimum initial process means and
production run of a process with multiple dependent smallerthebetter
type (SType) of quality characteristics. A Numerical example is also
provided to demonstrate the application of the proposed model. 



Title: 
Transient mathematical
model of both side single pass photovoltaic thermal air collector 
Author (s): 
Ebrahim M. Ali Alfegi,
Kamaruzzaman Sopian, Mohd Yusof Hj Othman and Baharudin Bin Yatim 
Abstract: 
A mathematical model
and solution procedure of a single pass photovoltaic thermal air
collector (PVT) with Compound Parabolic Concentrator (CPC) and fins with
both sides of the absorber for predicting the thermal and combined
photovoltaic thermal performance of the system is presented. The air
which is the working fluid flows between top glass and absorber plate
and between absorber and bottom plates. The mathematical model is
composed of five couple unsteady nonlinear partial equations which are
solved by using Gear implicit numerical scheme. The temperatures of the
circulated air as a function of distance in the flow direction for both
sides are predicted. Results at solar irradiance of 400 W/m2 show that
the combined pv/t efficiency is increasing from 26.6 % to 39.13 % at
mass flow rates varies from 0.0316 to 0.09 kg/s. 



Title: 
Characterization and
frequency analysis of one day annual maximum and two to five consecutive
days’ maximum rainfall of Accra, Ghana 
Author (s): 
Xeflide Seth Kwaku and
Ophori Duke 
Abstract: 
Annual one day maximum
rainfall and two to five consecutive day’s maximum rainfall
corresponding to a return period of 2 to 100 years has been conducted
for Accra, Ghana. Three commonly used probability distributions; normal,
lognormal and gamma distribution have been tested to determine the best
fit probability distribution that describes the annual one day maximum
and two to five consecutive days’ maximum rainfall series by comparing
with the Chisquare value. The results revealed that the lognormal
distribution was the best fit probability distribution for one day
annual maximum as well as two to five consecutive days’ maximum rainfall
for the region. Based on the best fit probability distribution a maximum
of 84.05 mm in 1 day, 91.60 mm in 2 days, 100.40 mm in 3 days, 105.67 mm
in 4 days and 109.47 mm in 5 days is expected to occur at Accra every
two years. Similarly a maximum rainfall of 230.97 mm, 240.49, 272.77 mm,
292.07 mm and 296.54 mm is expected to occur in 1 day, 2, 3, 4 and 5
days respectively every 100 years. The results from the study could be
used as a rough guide by engineers and hydrologists during the design
and construction of drainage systems in the Accra metropolis as poor
drainage has been identified as one of the major factors causing
flooding in Accra. 



Title: 
Performance test of IC
engine using Karanja biodiesel blending with diesel 
Author (s): 
N. Stalin and H. J. Prabhu 
Abstract: 
Biodiesel production is
a modern and technological area for researchers due to constant increase
in the prices of petroleum diesel and environmental advantages. This
paper presents a review of the alternative technological methods that
could be used to produce this fuel. Biodiesel from karanja oil was
produced by alkali catalyzed transesterification process. Performance of
IC engine using karanja biodiesel blending with diesel and with various
blending ratios has been evaluated. The engine performance studies were
conducted with a prony brakediesel engine set up. Parameters like speed
of engine, fuel consumption and torque were measured at different loads
for pure diesel and various combinations of dual fuel. Brake power,
brake specific fuel consumption and brake thermal efficiency were
calculated. The test results indicate that the dual fuel combination of
B40 can be used in the diesel engines without making any engine
modifications. Also the cost of dual fuel (B40) can be considerably
reduced than pure diesel. 



Title: 
Mixing time estimation and
analysis in a jet mixer 
Author (s): 
P. Kalaichelvi, Y.
Swarnalatha and T. Raja 
Abstract: 
Mixing of reactants,
catalysts, etc. in a chemical reactor may be achieved using jets which
offer the advantage of having no moving parts inside the reactor. While
there have been many experimental studies and thumb rules for the design
of jets, the details of mixing process is not properly understood. An
experiment was carried out to study the effects of various parameters
such as nozzle diameter, angle of inclination, jet position and jet
velocity on mixing time. Results show that, for a given geometric
arrangement, the angle of the jet injection is significantly more
important in determining the time required for 95% mixing than the
length of the jet. The optimum angle was found to be an injection angle
of 30º for jet located either at twothird of the volume of the tank or
top and bottom of the tank, which gave the shortest mixing time. The
optimum angle is not universal and varies with the location of the jet
inlet. An increase in the nozzle diameter was found to reduce the mixing
time at a given level of power consumption and in turn the energy
efficiency can be improved. 



Title: 
Effects of variable
viscosity, heat and mass transfer on nonlinear mixed convection flow
over a porous wedge with heat radiation in the presence of homogenous
chemical reaction 
Author (s): 
R. Kandasamy, I. Hashim,
Muhaimin and Ruhaila 
Abstract: 
An analysis is carried
out to study the variable viscosity and chemical reaction effects on
flow, heat and mass transfer characteristics in a viscous fluid over a
porous wedge in the presence of heat radiation. The wall of the wedge is
embedded in a uniform Darcian porous medium in order to allow for
possible fluid wall suction or injection. The governing boundary layer
equations are written into a dimensionless form by similarity
transformations. The transformed coupled nonlinear ordinary differential
equations are solved numerically by using the R. K. Gill and shooting
methods. The effects of different parameters on the dimensionless
velocity, temperature and concentration profiles are shown graphically.
Comparisons with previously published works are performed and excellent
agreement between the results is obtained. The results are presented
graphically and the conclusion is drawn that the flow field and other
quantities of physical interest are significantly influenced by these
parameters. 



Title: 
Study on strength and
sorptivity characteristics of fly ash concrete 
Author (s): 
Anurag Misra, Rohit
Ramteke and Madan Lal Bairwa 
Abstract: 
When fly ash is added
in concrete, the reactive silica present in fly ash reacts with calcium
hydroxide liberated during cement hydration and forms calcium silicate
hydrate (CSH) gel. Compact CSH gel gives higher strength and lower
permeability and absorption characteristics. They are indicators of
durability of concrete. Therefore, a study was carried out on influence
of fly ash on sorptivity of OPCFly Ash concrete. The experiments were
conducted using a mix proportion of cement (1) : sand (1.57) : 10 mm
aggregates (1.35) : 20 mm aggregates (2.03) with four water to
cementitious material (Cement + Fly Ash) ratios (w/cm) (0.55, 0.475,
0.40 and 0.340). The cement replacement by fly ash was varied between 0
to 50%. Compressive strength and water absorption tests were conducted
on each of the twentyfour mixes. The sorptivity of concrete was
compared with that of the control concrete. The results indicated that
higher volume of cement replacement and lower w/cm ratios have lower
values of cumulative water absorption and sorptivity. There was a small
reduction in 28 days compressive strength of concrete with increase in
fly ash content. However, it was found to be almost the same or
marginally higher than that of control mix at 90 days. 



Title: 
Characterisation and
optimisation of deferration of Kankara clay 
Author (s): 
J. A. Lori, A. O. Lawal
and E. J. Ekanem 
Abstract: 
The mineralogy of clay
from the Kankara deposit in Katsina (Nigeria) has been studied by xray
diffraction (XRD). Kaolinite is the dominant mineral phase with minor
amounts of quartz, goethite and muscovite. The diffraction pattern of
the glycolated clay sample did not indicate the presence of mixed layer
clay (swelling clay such as smectites). Iron impurities (FeOOH), alumina
(Al_{2}O_{3}) and silica (SiO_{2}) contents of
untreated and beneficiated clays were monitored by Energy Dispersive
Xray Fluorescence (EDXRF). The total iron impurity (FeOOH) in the clay
sample was 0.081%. Alumina (Al_{2}O_{3}) and silica (SiO_{2})
contents were 39.097% and 44.158%, respectively. The iron content of the
oxalic acidleached clay decreased with increase in oxalic acid
concentration. The efficiency of the acid solution was more, when the
iron/acid mole ratio was less than or equal to 0.045. Iron removal
efficiency of the oxalic acid solutions was not dependent on the amount
of iron present in the clay, but on the mole proportion of the acid
used. The optimum conditions for about 99% deferration were temperature
of 75°C, oxalic acid concentration of 1.8mol/dm3 and shearing time of
7hrs. The use of magnetic separator showed no improvement on iron
removal from the clay. 







