Title: |
A two species
commensalism model with limited resources- A numerical approach |
Author (s): |
N.
Phani Kumar, B. Ravindra Reddy and N. Ch. Pattabhi Ramacharyulu |
Abstract: |
In this paper a mathematical
model of commensalism between two species (S1 and S2)
with limited resources is investigated. The commensal species
(S1), in spite of the limitation of its natural
resources flourishes drawing strength from the host species (S2).
This model is characterized by a pair of first order
non-linear coupled differential equations. All the four
equilibrium points of the model are identified and the
criteria for the stability are discussed. The non-lin ear
coupled system-equations are solved numerically by employing
fourth order Runge-Kutta method and the results are presented.
Further, some threshold results are stated. |
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Title: |
Steady state
motion of rail vehicle with controlled creep forces on curved
track |
Author (s): |
M. Messouci |
Abstract: |
A linear analysis of
steady state curve traversing is developed for rail vehicle
with wheels coupled with a torsional viscous damper. The
governing equations are given and are solved numerically. We
consider the equilibrium of the bogie with two wheel sets
acted upon by the forces of gravity and the transverse force.
The approach is based on
providing guidance by creep forces in conjunction with wheel
conicity, so that flange contact is normally avoided. It
describes the behavior of the vehicle in the curves of
different radii. It is therefore important to define the
characteristics of the
torsional damper.
It gives the modulus (magnitude) of the moment of friction in
the dampers produced by the relative motion of the wheels as
well as the bogie yaw, the relative lateral and yaw
displacement of the leading and trailing wheel set at each
curve track of constant curvature. |
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Title: |
Darcy scale
NAPL dissolution in heterogeneous stratified porous media |
Author (s): |
B.
Mabiala, C. Tathy and D. Nganga |
Abstract: |
The aim of this study is to
develop NAPL dissolution in heterogeneous porous media by one
and two dimensional physical model at macroscopic Darcy scale.
The model describes the movement of a water phase in the
presence of a trapped polluting phase at residual saturation.
Two limit cases of dissolution were studied: local equilibrium
case and the local non equilibrium case. The construction uses
the finite volume methods for the approximation of equations.
The numerical tests emphasize particularly the evolution of
the zone of exchange between the organic and water phases.
Local non equilibrium situations obtained following the
mechanisms hereafter, heterogeneity effects of the medium and
heterogeneity effects of the initial saturations induced by
hydrodynamic instabilities or particular conditions of
installation, were characterized. |
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Title: |
Experimental
study of temperature stratification in a thermal storage tank in
the static mode for different aspect ratios |
Author (s): |
Abdul Jabbar
N. Khalifa, Ayad T. Mustafa and Farhan A. Khammas |
Abstract: |
Thermal stratified storage tanks
are an effective method to improve the efficiency of thermal
storage devices that are commonly used in thermal systems when
the available energy source is irregular or when a time lag
exists between the production and the demand. It has been
shown that thermal stratification is affected by a number of
factors such as mixing due to the inlet and outlet streams,
heat losses to the environment and tank configuration such as
the aspect (height to diameter) ratio. Thermal behavior and
stratification of hot water storage tanks during the
stagnation mode is investigated experimentally in this study
for three different aspect ratios (AR) of the tank, namely 2,
1 and ˝. The study addresses the change in water
stratification during the cool down of the water inside the
storage tank of thermal systems in the 85oC to 30oC
temperature range, which lies within the operating range of
most conventional and solar hot water and liquid based heating
systems. |
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Title: |
A study of
process parameters of friction stir welded AA 6061 aluminum
alloy in O and T6 conditions |
Author (s): |
Indira
Rani M., Marpu R. N. and A. C. S. Kumar |
Abstract: |
Friction Stir Welding (FSW) is
fairly a recent technique that uses a non consumable rotating
welding tool to generate frictional heat and plastic
deformation at the welding location while the material is in
solid state. The principal advantages are low distortion,
absence of melt related defects and high joint strength. Tool
design and material plays a vital role in addition to the
important parameters like tool rotational speed, welding speed
and axial force. The paper focuses on optimization of FSW
parameters in different conditions of base material and the
microstructures of the as-welded condition are compared with
the post weld heat treated microstructures welded in annealed
and T6 condition. |
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Title: |
Petri net to
ladder logic diagram converter and a batch process simulation |
Author (s): |
Mostafa M.
Gomaa |
Abstract: |
Discrete-event dynamic systems (DEDS)
are characterized by a set of states which the system can
take, and by the set of asynchronous events that cause the
state changes at discrete time points. Programmable logic
controllers (PLCs) are still important
special purpose computers used to
automate the DEDS in industry. Ladder logic diagrams (LLDs)
are still the most popular graphical programming tools of the
PLCs; but the major problem is that programming is done
heuristically and the LLDs are difficult to be used for both
analysis and performance evaluation. Petri nets (PNs) are
nowadays the most effective modeling environment for both the
design and implementation of DEDS. This paper proposes a PN to
LLD conversion tool, used for graphical editing of a PN net
model of a DEDS controller and for converting this PN into the
equivalent LLD for programming a PLC. The conversion algorithm
is presented, considering many types of transitions, places,
and arcs with generality that many types of PNs can be
considered. This paper also presents a simulation of a batch
process, on a personal computer from one side, interfaced with
a real PLC from the other side, that is programmed using a LLD
obtained from the conversion of a suitable PN model using the
proposed conversion tool. Compared with a LDD got
heuristically, the LLD got from a PN conversion is simpler,
understandable, and meeting all the characteristics obtained
from the PN analysis. |
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Title: |
Decision
support system for transport demand management: Object oriented
approach using kappa pc 2.4 expert system shell |
Author (s): |
Resdiansyah Mansyur, Riza Atiq O. K. Rahmat, Amiruddin Ismail
and Mohamad Raduan Kabit |
Abstract: |
In view of the fact that
supply strategies alone could not solve urban congestion, many
cities around the globe have adopted Transport Demand
Management (TDM) strategies as part and partial of their
congestion mitigation plan. TDM comprises several strategies
and policies that aim to modifying travelers’ behaviour. TDM
comprises strategies and policies that are different in nature
which can be divided into several categories according to how
they affect travelers’ behavior. Selecting and determining
suitable TDM strategies for a particular congestion mitigation
goal can be a complex task; thus requires expertise. In this
regards, the effectiveness of a TDM strategy is primarily
depending on whether its selection was appropriately examined
prior to its field implementation. This
paper presents the development of an expert system shell for
TDM. The process of organizing the available knowledge of TDM
strategies, as well as the process leading to the selection of
one or more strategy advice, is encoded in the knowledge based
expert system shell developed for the purpose by using shell
expert system Kappa-PC version 2.4 which was adopted object
oriented approach and high resolution graphical user
interface. The advice given from the working system was
evaluated and validated by comparing the output of the system
against the recommendations made by transportation
professionals. The evaluations indicate favourable results for
the system. The expert advisory system can be used as a
decision support system as well as a teaching tool for junior
transportation engineers, planners, private developers, and
government officials. |
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Title: |
On
utilization of wind energy potential in Nigeria |
Author (s): |
M. S.
Adaramola |
Abstract: |
The aim of this paper is to
review wind energy availability in Nigeria and discuss the
potential of using this resource for generation of wind power
in the country. The power output from a wind turbine is
strongly depend on the wind speed and accurate information
about the wind data in a targeted location for wind turbine is
essential. The wind speeds in Nigeria range from about 2 to
9.5 m/s based on recent reported data and the trend show that
wind speeds are low in the south and gradually increases to
relatively high speeds in the north. The areas that are
suitable for exploitation of wind energy for electricity
generation as well as for water pumping were identified. Also
some of the challenges facing the development of wind energy
and suggested solutions were presented. |
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Title: |
Allocation of
FACTS devices for ATC enhancement using genetic algorithm |
Author (s): |
K.
Radha Rani, J. Amarnath and S. Kamakshaiah |
Abstract: |
In this paper, a method using
Genetic Algorithm is proposed to determine the optimal
allocation of FACTS devices for maximizing the Available
Transfer Capability (ATC) of power transactions between source
and sink areas in the deregulated power system. Two types of
FACTS are simulated in this study namely Thyristor Controlled
Series Compensator (TCSC) and Unified Power Flow Controller (UPFC)
for enhancing the available transfer capability of the
interconnected power system. A Repeated Power Flow with FACTS
devices including ATC is used to evaluate the feasible ATC
value within real and reactive power generation limits, line
thermal limits and voltage limits. An IEEE24- bus (single
area) system is used to demonstrate the effectiveness of the
algorithm as an optimization tool to enhance ATC. A Genetic
Algorithm technique is used for validation purposes. The
results clearly indicate that the introduction of FACTS
devices in a right location could enhance ATC. |
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Title: |
Performance
and combustion characteristics of a typical motor bike engine
operated on blends of CNG and hydrogen using electronically
controlled solenoid actuated injection system |
Author (s): |
S. S.
Sandhu, M. K. G. Babu and L. M. Das |
Abstract: |
This paper discusses the
development of an electronically controlled gas injection
system for hydrogen supplemented single cylinder Enfield
engine. In view of its typical combustion characteristics, the
fuel induction technique plays a very dominant and sensitive
role in the performance as well as the combustion
characteristics of hydrogen supplemented CNG engine. The
designed system should have adequate flexibility to provide
the appropriate mixture into the engine at the appropriate
point in the engine cycle operation. The motor bike engine was
fuelled with neat CNG and mixtures of hydrogen in natural gas
(HCNG) of 5, 10, 15 and 20% by energy. The designed Electronic
Fuel Injection System ensured successful operation of engine
running on different fuel blends over a wide range of load and
speed without causing any undesirable combustion phenomena
such as backfire or pre-ignition. The performance and
combustion characteristics were determined under various
operating conditions. |
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Title: |
Conceptual
design of an amphibious vehicle: VECTOR |
Author (s): |
Bart
Sitek and Wei Yang |
Abstract: |
This work is to present
conceptual design of an amphibious vehicle named “VECTOR” that
has great high-speed and long range capabilities. The vehicle
is designed to carry up to 50+ personnel or 14 tons of
payloads in a range of 1800 km at nominal speed of 360 km/h.
The VECTOR not only possesses pros of current helicopter
technology, that is, efficient vertical flight and hover
capability, but also is capable to take-off/land on water,
land, grass, and other relatively flat surfaces. It also
introduces a brand new concept of fuselage and chassis design.
Tiltrotor continues to be the best candidate for diverse field
and rescue operations. All the important aspects, including
material, power, propulsion systems, aerodynamics and
stability are thoroughly studied and analyzed in the following
paper. Capabilities of the VECTOR can fulfill the
ever-expanding civil requirements and contribute to the
current search and rescue teams in any part of the world. |
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