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ARPN Journal of Engineering and
Applied Sciences
April 2007 | Vol.2 No.2 |
Title: |
Role of PI and fuzzy
controllers in unified power quality conditioner |
Author (s): |
A. Jaya Laxmi, G.
Tulasi Ram Das and K. Uma Rao |
Abstract: |
Any electrical power
system consists of wide range of electrical, electronic and power
electronic equipment in commercial and industrial applications. Since
most of the electronic equipment is nonlinear in nature these will
induce harmonics in the system, which affect the sensitive loads to be
fed from the system. One among the many compensating devices is Unified
Power Quality Conditioner (UPQC) which specifically aims at the
integration of series-active and shunt-active power filters to mitigate
any type of voltage and current fluctuations and power factor correction
in a power distribution network, such that improved power quality can be
made available at the point of common coupling. The present work
discusses the compensation principle and different control strategies
(PI, FUZZY) of the UPQC in detail. The control strategies are modeled
using MATLAB/SIMULINK. The performance of UPQC is examined by
considering, a thyristor rectifier feeding an RL load (non linear load)
that acts as a source of harmonics, to the system of concern. The
performance is also observed under influence of utility side
disturbances such as sag, swell, flicker and spikes. The simulation
results are listed in comparison of different control strategies and for
the verification of results. |
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Title: |
Adsorption of phenol
from aqueous solution by water hyacinth ash |
Author (s): |
M. T. Uddin, M. S.
Islam, and M. Z. Abedin |
Abstract: |
The potential of water
hyacinth ash for phenol adsorption from aqueous solution was studied.
Batch kinetic and isotherm studies were carried out under varying
experimental conditions of contact time, phenol concentration, adsorbent
dosage and pH. The adsorption of phenol decreased with increasing pH.
The Freundlich and Langmuir adsorption models were used for the
mathematical description of adsorption equilibrium and it was found that
the experimental data fitted very well to the Langmuir model. Batch
adsorption models, based on the assumption of the pseudo-first-order and
pseudo-second-order models, were applied to examine the kinetics of the
adsorption. The results showed that kinetic data followed closely to the
pseudo-second-order model. |
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Title: |
Modeling of
transportation behavior for coercive measures for car driving in
Kuala Lumpur |
Author (s): |
Abdullah Nurdeen, Riza
Atiq O. K. Rahmat and Amiruddin Ismail |
Abstract: |
The rapid increase of
car ownership associated with inadequate public transport has largely
contributed to increase traffic congestion, accidents and environmental
pollution. A policy proposed to improve public transport and control car
ownership simultaneously has become necessary for solving the problems
the objectives of this research are to develop mode choice models to
expressing car users and public transport users’ behavior and
investigate their response to scenario of a reduction in bus and train
travel time and travel cost. In this paper, a survey of 1200 car, bus
and train users was conducted in Kuala Lumpur city center. A binary
logit model was developed for the three alternative modes, bus, train
and car. It was found that travel time, travel cost, gender, age, income
level and car ownership are significant in influencing car users’ mode
choice behavior. The probability of car drivers shifting to public
transport was also examined based on a scenario of a reduction in bus
and train travel time and travel cost. Reduction of total travel time
and travel cost for the bus and train mode emerges as the most important
element in a program aimed at attracting car users towards public
transport and away from car mode. |
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Title: |
Numerical study of
opposing mixed convection in a vented enclosure |
Author (s): |
M. M. Rahman, M. A.
Alim, M. A. H. Mamun, M. K. Chowdhury and A. K. M. S. Islam |
Abstract: |
A numerical study has
been performed on mixed convection in a vented enclosure by finite
element method. An external fluid flow enters the enclosure through an
opening in the left vertical wall and exits from another fixed opening
in the right vertical wall. Various inlet port configurations are
extensively studied with the change of governing parameters. For mixed
convection, the significant parameters are Grashof number (Gr),
Richardson number (Ri) and Reynolds number (Re) by which different fluid
and heat transfer characteristics inside the cavity are obtained. In
present study streamlines, isotherms, average temperature and average
Nusselt number of the heated wall are reported for Ri = 0 to 10, Re =
50, 100 and 200; Pr = 0.71, 7.5 and 50 and different inlet position Hi =
0.05, 0.50 and 0.95. From the present analysis it is found that with the
increase of Reynolds and Richardson numbers the convective heat transfer
becomes predominant over the conduction heat transfer and the rate of
heat transfer from the heated wall significantly depends on the position
of the inlet port. Higher Nusselt number is observed at very large
Prandtl number. Empirical correlations are developed to express the
above relation mathematically. |
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Title: |
Use of Photogrammetry
in 3D modeling and visualization of buildings |
Author (s): |
M. Shashi and Kamal
Jain |
Abstract: |
3D Models of
architectural structures are very important in order to study, analyze
and also to reconstruct and document these structures. Visualization of
these models allows the user to get the photo realistic impression of
the structures than graphic based object models. 3D visualization has
many applications in the areas of architecture, civil engineering,
tourism etc. Normally, field surveys are more accurate than
photogrammetric measurements; nevertheless, they involve more personnel
and consume a lot of time. Photogrammetry is a measurement technology
that can be used for the extraction of 3D points from images. The
present paper highlights the project using photogrammetry for accurate
3D modeling and visualization of structures. |
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Title: |
A finite element method
for steady-state natural convection in a square tilt open cavity |
Author (s): |
Goutam Saha, Sumon Saha
and Md. Arif Hasan Mamun |
Abstract: |
A numerical simulation
of two-dimensional laminar steady-state natural convection in a square
tilt open cavity has been numerically studied. The opposite wall to the
aperture is placed at either isothermal heat source or isoflux heat
source, while the surrounding fluid interacting with the aperture is
maintained at an ambient temperature. The two remaining walls are
assumed to be adiabatic. The fluid concerned is air with Prandtl number
fixed at 0.71. The governing mass, momentum and energy equations are
expressed in a normalized primitive variables formulation. In this
paper, a finite element method for steady-state incompressible natural
convection flows has been developed. The streamlines and isotherms are
produced, heat transfer characteristics is obtained for Rayleigh numbers
from 103 to 106 and for an inclination angles of the cavity ranges from
0º to 60º. The results show that the Nusselt numbers increases with the
Rayleigh numbers. Also the average Nusselt number changes substantially
with the inclination angle of the cavity while better thermal
performance is also sensitive to the boundary condition of the heated
wall. |
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Title: |
Studies on pressure
loss in sudden expansion in flow through nozzles: a fuzzy logic approach |
Author (s): |
R. Jagannath, N. G.
Naresh and K. M. Pandey |
Abstract: |
In this paper pressure
loss in suddenly expanded ducts is studied with the help of fuzzy logic
as a tool. It is observed that minimum pressure loss takes place when
the length to diameter ratio is one and it is seen that the results
given by fuzzy logic formulation are very logical and it can be used for
qualitative analysis of fluid flow in flow through nozzles in sudden
expansion. |
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