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ARPN Journal of Engineering and Applied
Sciences
August 2011 | Vol. 6 No. 8 |
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Title: |
Effect of
skew angle on behavior of simply supported R. C. T- beam bridge
decks |
Author (s): |
Ibrahim S. I.
Harba |
Abstract: |
T-beam Bridge is a common choice among the
designers for small and medium span bridges. In order to cater
to greater speed and more safety of present day traffic, the
modern high ways are to be straight as far as possible. This
requirement, along with other requirements for fixing
alignment of the bridges, is mainly responsible for provision
of increasing number of skew bridges. The presence of skew in
a bridge makes the analysis and design of bridge decks
intricate. For the T- beam bridges with small skew angle, it
is frequently considered safe to ignore the angle of skew and
analyze the bridge as a right bridge with a span equal to the
skew span. However, T-beam bridges with large angle of skew
can have a considerable effect on the behavior of the bridge
especially in the short to medium range of spans. In this
paper an analytical study using three dimensional finite
element methods was performed to investigate the effect of
skew angle on behavior of simply supported reinforced concrete
T-beam bridge decks. The parameters investigated in this
analytical study were the span lengths and skew angle. The
finite element analysis (FEA) results for skewed bridges were
compared to the reference straight bridges (nonskewed). The
geometric dimensions of the T-beam bridge decks and the
loading used are in compliance with AASHTO standard
specifications. The FEA results and comparison of skewed
bridge with straight bridge indicate that max. Live load
bending moments and deflections decreases in T- beams for
skewed bridges, while max. shear, torsion and supports
reactions increases in some T-beams for skewed bridges for all
considered span lengths (12, 16, 20 and 24m). This study
disagreement with the AASHTO standard specifications as well as the LRFD in
recommending that bridges with skew angle less than or equal
20° be designed as straight (non skewed) bridges also it
recommended that engineers are better to perform three
dimensional finite element analysis for skewed T-beam bridge
decks. |
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Title: |
Beam width
enhancement of L1 and L5 of global positioning system (GPS)
antenna |
Author (s): |
Ahmed Al-Shaheen |
Abstract: |
In this paper we enhance
the beam width for Global Positioning system (GPS) application
rectangular patch microstrip antenna for two designs at L1
centered at 1.75742 GHz and L5 centered at 1.17642 GHz. Tow
antennas are mounted on the hexa-pyramidal ground plane to
utilize for broadening the beam width for wide coverage area
with circularly polarized radiation pattern, the antenna
substrate is FR4 of
er = 4.4 with thickness of 3.2 mm. The
parametric study has been done to choose the optimum
parameters for the top ground plane, base of ground plane, and
drooped angle, the yielding results of this study shows that
the beam width is up to 160° and 170° for E-plane and H-plane
respectively, with a gain of -1.2 dB for RHCP radiation
pattern at resonance frequency of 1.575 GHz antenna at top
ground plane 40 mm and base ground plane 125 mm and 50° for
drooped angle. While, for the beam width is up to 150° and 160°
for E-plane and H-plane respectively, with a gain of -1.67 dB
for RHCP radiation pattern at resonance frequency of 1.176 GHz
antenna at top ground plane 60 mm and base ground plane 150 mm
and 60° for drooped angle. The results are compared with the
traditional rectangular patch microstrip antenna for the GPS
application. The band width is 43 MHz and 54.7 MHz for to
1.57542 GHz and 1.17642, respectively. |
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Title: |
Design and
fabrication of equipment for low velocity impact testing of
composite sandwich panels |
Author (s): |
Ramesh S.
Sharma and V. P. Raghupathy |
Abstract: |
Polymer composite sandwich
panels are being utilized increasingly as primary
load-carrying components in aircraft and aerospace structures.
Serving in this capacity, these structures are subjected to
impacts such as tool drops, hail, bird strikes, and runway
debris. Unlike for their solid metallic counterparts,
predictions of the effects of low-velocity impact damage are
difficult and are still relatively immature. Sandwich panels
in particular are sensitive to localized impact. For making a
systematic study of impact on composite sandwich panels under
these conditions, suitable equipment was designed and
fabricated. This article describes the salient features of
indigenously developed test equipment for testing localized,
penetrating impact on sandwich panels. The size of the
sandwich panels in question are 150 X 150 mm2 with a typical
thickness of 16-25 mm. The impact velocities are in the region
2 - 6 m/s, with an impactor mass between 2.5 and 12.5 kg, and
two types of impactors were used: hemispherical impactor with
diameter of 12.5 mm and flat impactor of 25 x 25 mm. Using
this equipment laminated composites, sandwich panels and
polymer sheets can be tested to assess the resistance to
falling weight in the low velocity region. The piezeo -
electric sensor of the tester facilitates evaluation of
absorbed load and absorbed energy and thus the performance of
sandwich structure subjected to single impact, which in turn
is useful for the development of useful criteria for materials
selection. |
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Title: |
Modeling and
simulation of the effects of crude oil dispersion on land |
Author (s): |
M. Abdulkadir
and S. Yahaya |
Abstract: |
This study was carried out
to develop a model equation for dispersion of crude oil on
land. The developed model equation in this work is Y = 21.81 +
84.50X - 91.40X2. The equation was simulated with
the aid of MINITAB software. The experimental and model
results obtained from the simulation of the model equation
were plotted on the same axis against time of dispersion and
distance of dispersion. The model results revealed good
agreement. |
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Title: |
Realistic
estimate of agricultural power in Andhra Pradesh, India- A case
study |
Author (s): |
K. Swarna Sri
and SVL Narasimham |
Abstract: |
Energy supply to
agriculture is gaining importance in many states in India.
Average increase in number of tube wells for irrigation by
many folds has raised the agricultural demand on the grid
which is not being metered or monitored. This consumption is
considered as residue in the process of estimation of
Transmission and Distribution (T and D) losses by utilities
every year. Hence this paper finds its importance while
estimating actual electrical energy consumed by agricultural
sector. Experiments are conducted near the pump sets in fields
to find actual electricity consumption at various pumping
rates. Along with the drawbacks of current methods of arriving
at agricultural demand, the paper proposes a conceptual method
to estimate actual agricultural energy consumption by
agricultural sector. The results are compared with the actual
consumptions from Annual Revenue Requirements (ARR) filed by
distribution companies of Andhra Pradesh. |
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Title: |
Study the
effect of flow bypass on the performance of a shrouded
longitudinal fin array |
Author (s): |
Ahmed F.
Khudheyer |
Abstract: |
Theoretical and
experimental studies were carried out to investigate the
effects of duct velocity, fin density and tip-to-shroud
clearance on the flow bypass and its impact on the pressure
drop across a longitudinal aluminum fin array and its thermal
performance. The clearance was varied parametrically, stating
with the fully shrouded case and variations of the channel
height giving partially shrouded configuration of different
clearance ratios were also carried out. The flow bypass was
found to increase with increasing fin density and insensitive
to the air flow rate. That effect of fin density decreased as
the clearance increased. The calculated total pressure was
greatly affected by fin density. For fully-shrouded fin array,
with Hf /S equals to 8 and 12.75, the pressure drop increased
by a factor of 4.3 and 20 of that with Hf /S equals to 3.4,
respectively. The total pressure drop and the average
convective heat transfer coefficients corresponding to the
fully and partially shrouded fin array of Hf /S = 3.4 were
compared. Going from fully to partially shrouded one of the
largest clearance ratio (C/Hf = 0.89), the total pressure drop
reduced by about 50%. For clearance ratios equal to 0.36,
0.56, and 0.89, the average heat transfer coefficients were
reduced by about 12, 17, and 30 percent of those for the fully
shrouded configuration at ReD of about 3 x 103.
That percentage reduction in heat transfer coefficients
decreased with the increase of air flow rate. |
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Title: |
Mixed
convective heat transfer in rectangular enclosures filled with
porous media |
Author (s): |
M. A. Waheed,
G. A. Odewole and S. O. Alagbe |
Abstract: |
The mixed convective heat
transfer in a fluid-saturated porous medium has been
investigated numerically using the generalized non-Darcy
model. The problem governing equations including the
continuity, the generalized Darcy-Brinkman-Forchheimer
extended momentum and the energy transport equations were
thereby solved using the finite difference method. The flow
governing parameters including the Darcy, Richardson and
Péclet numbers, and the length-to-height aspect ratio were
varied in the range 10-3 ≤ Da ≤ 10, 0.1 ≤
Ri ≤ 10, 1 ≤ Pe ≤ 103, and 0.5 ≤ AR
≤ 4, respectively while the Reynolds number was held constant
at a value of Re = 100 for all computations. The
results are presented in the form of the streamlines and
isotherms contours, and the profiles for horizontal component
of velocity, temperature and the local heat flux. The results
show that all the flow governing parameters have strong
influence on the flow pattern and heat distribution within the
enclosure. |
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Title: |
Development
of animal drawn rotary tiller |
Author (s): |
S. M. Nage,
B. P. Mishra, A. K. Dave and J. S. Nikhade |
Abstract: |
Rotary tiller generally
refers to breaking down soil aggregates into ultimate soil
particles. The degree of clod breaking depends on moisture
content, tillage implements and intensity of clod breaking.
One unit of animal drawn rotary tiller with L - shapes of
blades was developed and fabricated at workshop of Faculty of
Agricultural Engineering, Raipur. The effective field capacity
of animal drawn rotary tiller (18 blades) was found 0.12 ha/h
at a forward speed of 2.5 km/h. The field efficiency of 62.85%
was observed during the field performance. The draft
requirement of the developed animal drawn rotary tiller is 378
N. Mean Mass Diameter (MMD) of soil clod size was found 28.42
mm. The operational cost was found 384 Rs/ha. |
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Title: |
Evaluation of
produced water discharge in the Niger-delta |
Author (s): |
Isehunwa S.
O. and Onovae S. |
Abstract: |
Water produced during
petroleum production often contain chemicals, oil and
sometimes, naturally occurring radioactive materials which
could harm the environment. Management involves significant
cost and is guided by strict regulations, is normally aimed at
minimizing or reducing the toxicity of discharged volumes.
This study evaluated the physico-chemical properties and
constituents of produced water from three selected flow
stations and two oil terminals in the Niger Delta to determine
the extent of compliance with standards and global best
practices in the treatment and discharge. It was observed that
while physico-chemical properties like pH (8.4±0.25) and BOD
(6.2±2.0) were within recommended limits, oil and grease
content (60±20), TDS (6200±700) and others exceeded limits.
Similarly, ion concentrations of Lead, Nickel, Zinc and
Sulphates were within acceptable limits while chloride ions
(4100 ±500) exceeded limits. There is therefore the need to
improve treatment facilities and procedures, while regulatory
agencies must improve current guidelines, ensure proper
monitoring and enforcing compliance. |
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Title: |
Batch type
synthesis of high free fatty acid Jatropha Curcus oil biodiesel-
India as supplying country |
Author (s): |
Sanjay Gandhi
Bojan, Senthil Kumaran and Sam Chelladurai |
Abstract: |
The Jatropha Curcas oil
grown and extracted in the rural belts of western ghat section
of South India was tested for its physical and chemical
properties to determine its suitability as a feedstock for
biodiesel production. A compact, simple, 4-litre biodiesel
processor was developed locally. The biodiesel processor was
capable of producing biodiesel sufficient in quantity for
formers in village level to run the commonly used farm engine
for producing electricity for agricultural and other purposes.
The properties like kinematic viscosity, acid number, specific
gravity, Cetane number, etc of the biodiesel produced meet the
ASTM standard but the yield quantity was comparatively low
(80.50%) because of the high free fatty acid content in the
raw Jatropha Curcas oil. The overall efficiency of the
biodiesel produced as a fuel in a four stroke diesel engine
coupled with a electric generator was high (24.38%) at maximum
load conditions compare to raw Jatropha Curcas oil and petro
diesel as fuels which gives only 19.6% and 20.11%, respectively
shows the possibilities of using biodiesel produced as a fuel
in diesel engine. |
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Title: |
Transient
free convection MHD flow between two long vertical parallel
porous plates with variable temperature and mass diffusion |
Author (s): |
U. S. Rajput
and P. K. Sahu |
Abstract: |
The unsteady MHD transient
free convection flow of an incompressible viscous electrically
conducting fluid between two infinite vertical parallel porous
plates with Variable temperature and mass diffusion has been
considered, under the assumption that the induced magnetic
field is negligible. Applied magnetic field is fixed relative
to the fluid and plates. The Laplace transform method has been
used to find the solutions for the velocity, temperature and
concentration profiles. The velocity, temperature and
concentration profiles have been studied for different
parameters like Prandtl number, Schmidt number, magnetic
parameter, buoyancy ratio parameter, permeability parameter
and time. The value of the skin-friction for different
parameters has been tabulated. |
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Title: |
Examinations
of the performance of a gas lift for oil well production |
Author (s): |
M. Abdulkadir
and S.Yahaya |
Abstract: |
Gas lift is a method of
artificial lift that uses an external source of high pressure
gas for supplementing formation gas to lift the well fluids.
The primary limitations for gas lift operations are the lack
of formation gas or of an outside source of gas, wide well
spacing and available space for compressors on offshore
platforms. Generally, gas lift is not applicable to
single-well installations and widely spaced wells that are not
suited for a centrally located power system. Gas lift can
intensify the problems associated with production of viscous
crude, super-saturated brine, or an emulsion. Old casing, sour
gas and long, small - internal diameter flow lines can rule
out gas lift operations. Wet gas without dehydration will
reduce the reliability of gas lift operations. A model
relating the factors affecting potential production rate along
the tubing of a gas lift oil well was developed to optimize
production using analytical approach. Modified Darcy equation
was employed alongside some other equation of flow such as
Fanning’s equation, Reynolds’ equation and a host of others
which resulted in the developed model equation. Data from four
wells were used in applying the model equation and it was
found that, for the four wells and the square of the velocity
of oil flow is equal to the oil production rate and both vary
directly with the difference in pressure between the reservoir
and the well bore. This implies, the lower the well bore
pressure the higher the oil production rate and oil velocity. |
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Title: |
Efficient
FPGA implementation of 2nd order digital controllers using
Matlab/Simulink |
Author (s): |
Vikas gupta,
K. Khare and R. P. Singh |
Abstract: |
This paper explains a
method for the design and implementation of digital controller
based on Field Programmable Gate Array (FPGA) device. It is
more compact, power efficient and provides high speed
capabilities as compared to software based PID controllers.
The proposed method is based on implementation of Digital
controller as digital filters using DSP architectures. The PID
controller is designed using MATLAB and Simulink to generate a
set of coefficients associated with the desired controller
characteristics. The controller coefficients are then included
in VHDL that implements the PID controller on to FPGA. MATLAB
program is used to design PID controller to calculate and plot
the time response of the control system. The synthesis report
concludes the resource utilization of selected FPGA. |
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Title: |
Prediction of
vapor liquid equilibrium (VLE) data for binary systems: A case
study of methane/tetrafluoromethane |
Author (s): |
A. R.
Moghadassi, M. R. Nikkholgh, S. M. Hosseini, F. Parvizian and A.
Sanaeirad |
Abstract: |
In this research, the
ability of multilayer perceptron neural networks to estimate
vapor liquid equilibrium data have been studied. Isothermal
vapor-liquid equilibrium (VLE) data for the binary mixture of
methane (R50) + tetrafluoromethane (R14) have been
investigated at (159.61, 161.58, 169.38, 173.90, and 178.93)
K. Two different models with one hidden layer consisted of
five hidden neurons are developed as the optimal structures.
For this binary system, uncertainties of ANN models were 0.14,
0.26%. In addition, the abilities of ANNs are shown by
comparisons with Margules, van Laar, and some other
correlations. |
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Title: |
Mixing time
effects on properties of self compacting concrete |
Author (s): |
M. M. Rahman,
M. H. Rashid, M. A. Hossain, F .S. Adrita and T. Hossain |
Abstract: |
Self Compacting Concrete (SCC)
is an innovative concrete that flows under its own self
weight. Besides the composition and raw materials of SCC,
mixing time has a great influence on the mechanical properties
of SCC such as compressive strength, splitting tensile
strength, amount of water added and permeability of concrete.
These properties vary with general mixing time 5 minutes and
extended mixing time 90 and 180 minutes. The observations show
that compressive and splitting tensile strength decrease and
amount of water added increases with the increase of mixing
period of SCC. Furthermore, permeability of SCC also increases
with the extended mixing period. |
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Title: |
Nodal analysis models of looped water distribution networks |
Author (s): |
Ioan Sarbu |
Abstract: |
There are three methods for
analyzing flow and pressure distribution in looped water
supply networks (the loop method, the node method, the element
method) taking into consideration hydraulic parameters chosen
as unknown. For all these methods, the nonlinear system of
equations can be solved by iterative procedures (Hardy–Cross,
Newton–Raphson, linear theory). In the case of extending or
rehability distribution networks the unknown parameters being
the piezometric heads at nodes, the node method for network
analysis is preferred. In this paper is formulated a
generalized classic model for the nodal analysis of complex
looped systems with nonstandard network components and the
solvability of new problems, alongside the determination of
pressure state in the system. Also, this paper shows a
different approach to this problem by using the method of
variational formulations for the development of an improved
model based on the unconditional optimization procedures. This
model has the advantage that it uses a specialized
optimization algorithm which minimizes directly an objective
multivariable function without constraints, implemented in a
computer program. The paper compares proposed models to the
classic Hardy-Cross method, and shows the good performance of
these models. Based on these models a study regarding
implications of pipe network longtime operation on energy
consumption is performed. |
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