Abstract: Petroleum refineries discharged large amount of
wastewater -during the refining process- that contains hazardous
constituents that is hard to degrade. Anaerobic treatment process is
well known as an efficient method to degrade high strength
wastewaters. Up-flow Anaerobic Sludge Blanker (UASB) is a
common process used for various wastewater treatments. Two UASB
reactors were set up and operated in parallel to evaluate the treatment
efficiency of petroleum refinery wastewater. In this study four
organic volumetric loading rates were applied (i.e. 0.58, 0.89, 1.21
and 2.34 kg/m3·d), two loads to each reactor. Each load was applied
for a period of 60 days for the reactor to acclimatize and reach steady
state, and then the second load applied. The chemical oxygen demand
(COD) removals were satisfactory with the removal efficiencies at the
loadings applied were 78, 82, 83 and 81 % respectively.
Abstract: Modeling of the dynamic behavior and motion are
renewed interest in the improved tractive performance of an
intelligent air-cushion tracked vehicle (IACTV). This paper presents
a new dynamical model for the forces on the developed small scale
intelligent air-cushion tracked vehicle moving over swamp peat. The
air cushion system partially supports the 25 % of vehicle total weight
in order to make the vehicle ground contact pressure 7 kN/m2. As the
air-cushion support system can adjust automatically on the terrain, so
the vehicle can move over the terrain without any risks. The springdamper
system is used with the vehicle body to control the aircushion
support system on any undulating terrain by making the
system sinusoidal form. Experiments have been carried out to
investigate the relationships among tractive efficiency, slippage,
traction coefficient, load distribution ratio, tractive effort, motion
resistance and power consumption in given terrain conditions.
Experiment and simulation results show that air-cushion system
improves the vehicle performance by keeping traction coefficient of
71% and tractive efficiency of 62% and the developed model can
meet the demand of transport efficiency with the optimal power
consumption.
Abstract: The damage tolerance behavior of integrally and
conventional stiffened panel is investigated based on the fracture
mechanics and finite element analysis. The load bearing capability
and crack growth characteristic of both types of the stiffened panels
having same configuration subjected to distributed tensile load is
examined in this paper. A fourteen-stringer stiffened panel is
analyzed for a central skin crack propagating towards the adjacent
stringers. Stress intensity factors and fatigue crack propagation rates
of both types of the stiffened panels are then compared. The analysis
results show that integral stiffening causes higher stress intensity
factor than conventional stiffened panel as the crack tip passes
through the stringer and the integrally stiffened panel has less load
bearing capability than the riveted stiffened panel.
Abstract: The Inter feeder Power Flow Regulator (IFPFR)
proposed in this paper consists of several voltage source inverters
with common dc bus; each inverter is connected in series with one of
different independent distribution feeders in the power system. This
paper is concerned with how to transfer power between the feeders for
load sharing purpose. The power controller of each inverter injects
the power (for sending feeder) or absorbs the power (for receiving
feeder) via injecting suitable voltage; this voltage injection is
simulated by voltage drop across series virtual impedance, the
impedance value is selected to achieve the concept of power exchange
between the feeders without perturbing the load voltage magnitude of
each feeder. In this paper a new control scheme for load sharing using
IFPFR is proposed.
Abstract: This paper presents application artificial intelligent (AI) techniques, namely artificial neural network (ANN), adaptive neuro fuzzy interface system (ANFIS), to estimate the real power transfer between generators and loads. Since these AI techniques adopt supervised learning, it first uses modified nodal equation method (MNE) to determine real power contribution from each generator to loads. Then the results of MNE method and load flow information are utilized to estimate the power transfer using AI techniques. The 25-bus equivalent system of south Malaysia is utilized as a test system to illustrate the effectiveness of both AI methods compared to that of the MNE method. The mean squared error of the estimate of ANN and ANFIS power transfer allocation methods are 1.19E-05 and 2.97E-05, respectively. Furthermore, when compared to MNE method, ANN and ANFIS methods computes generator contribution to loads within 20.99 and 39.37msec respectively whereas the MNE method took 360msec for the calculation of same real power transfer allocation.
Abstract: This study determines the effect of naked and heparinbased
super-paramagnetic iron oxide nanoparticles on the human
cancer cell lines of A2780. Doxorubicin was used as the anticancer
drug, entrapped in the SPIO-NPs. This study aimed to decorate
nanoparticles with heparin, a molecular ligand for 'active' targeting
of cancerous cells and the application of modified-nanoparticles in
cancer treatment. The nanoparticles containing the anticancer drug
DOX were prepared by a solvent evaporation and emulsification
cross-linking method. The physicochemical properties of the
nanoparticles were characterized by various techniques, and uniform
nanoparticles with an average particle size of 110±15 nm with high
encapsulation efficiencies (EE) were obtained. Additionally, a
sustained release of DOX from the SPIO-NPs was successful.
Cytotoxicity tests showed that the SPIO-DOX-HP had higher cell
toxicity than the individual HP and confocal microscopy analysis
confirmed excellent cellular uptake efficiency. These results indicate
that HP based SPIO-NPs have potential uses as anticancer drug
carriers and also have an enhanced anticancer effect.
Abstract: In this paper, the application of neural networks to study the design of short-term load forecasting (STLF) Systems for Illam state located in west of Iran was explored. One important architecture of neural networks named Multi-Layer Perceptron (MLP) to model STLF systems was used. Our study based on MLP was trained and tested using three years (2004-2006) data. The results show that MLP network has the minimum forecasting error and can be considered as a good method to model the STLF systems.
Abstract: The line start permanent magnet motor (LSPMM)
combines a permanent magnet rotor for a better motor efficiency
during synchronous running with an induction motor squirrel cage
rotor to permit the motor starting by direct coupling to power source.
In this paper effect of the rotor structure on a line start synchronous
permanent magnet motor (LSPMM) is analyzed. LSPMM motor with
three different structures for rotor is designed by using RMxprt
software; efficiency and line current of LSPMM motor for different
structures in full-load condition have been presented. The results
indicate that with correct choosing of rotor structure, maximum
efficiency can be found.
Abstract: Load forecasting has always been the essential part of
an efficient power system operation and planning. A novel approach
based on support vector machines is proposed in this paper for annual
power load forecasting. Different kernel functions are selected to
construct a combinatorial algorithm. The performance of the new
model is evaluated with a real-world dataset, and compared with two
neural networks and some traditional forecasting techniques. The
results show that the proposed method exhibits superior performance.
Abstract: The term hybrid composite refers to the composite
containing more than one type of fiber material as reinforcing fillers.
It has become attractive structural material due to the ability of
providing better combination of properties with respect to single fiber
containing composite. The eco-friendly nature as well as processing
advantage, light weight and low cost have enhanced the attraction
and interest of natural fiber reinforced composite. The objective of
present research is to study the mechanical properties of jute-coir
fiber reinforced hybrid polypropylene (PP) composite according to
filler loading variation. In the present work composites were
manufactured by using hot press machine at four levels of fiber
loading (5, 10, 15 and 20 wt %). Jute and coir fibers were utilized at a
ratio of (1:1) during composite manufacturing. Tensile, flexural,
impact and hardness tests were conducted for mechanical
characterization. Tensile test of composite showed a decreasing trend
of tensile strength and increasing trend of the Young-s modulus with
increasing fiber content. During flexural, impact and hardness tests,
the flexural strength, flexural modulus, impact strength and hardness
were found to be increased with increasing fiber loading. Based on
the fiber loading used in this study, 20% fiber reinforced composite
resulted the best set of mechanical properties.
Abstract: Many difficulties are faced in the process of learning
computer programming. This paper will propose a system framework
intended to reduce cognitive load in learning programming. In first
section focus is given on the process of learning and the
shortcomings of the current approaches to learning programming.
Finally the proposed prototype is suggested along with the
justification of the prototype. In the proposed prototype the concept
map is used as visualization metaphor. Concept maps are similar to
the mental schema in long term memory and hence it can reduce
cognitive load well. In addition other method such as part code
method is also proposed in this framework to can reduce cognitive
load.
Abstract: Characteristics and sonocatalytic activity of zeolite
Y catalysts loaded with TiO2 using impregnation and ion exchange
methods for the degradation of amaranth dye were investigated.
The Ion-exchange method was used to encapsulate the TiO2 into
the internal pores of the zeolite while the incorporation of TiO2
mostly on the external surface of zeolite was carried out using the
impregnation method. Different characterization techniques were
used to elucidate the physicochemical properties of the produced
catalysts. The framework of zeolite Y remained virtually
unchanged after the encapsulation of TiO2 while the crystallinity of
zeolite decreased significantly after the incorporation of 15 wt% of
TiO2. The sonocatalytic activity was enhanced by TiO2
incorporation with maximum degradation efficiencies of 50% and
68% for the encapsulated titanium and titanium loaded onto the
zeolite, respectively after 120min of reaction. Catalysts
characteristics and sonocatalytic behaviors were significantly
affected by the preparation method and the location of TiO2
introduced with zeolite structure. Behaviors in the sonocatalytic
process were successfully correlated with the characteristics of the
catalysts used.
Abstract: Text-based game is supposed to be a low resource
consumption application that delivers good performances when
compared to graphical-intensive type of games. But, nowadays, some
of the online text-based games are not offering performances that are
acceptable to the users. Therefore, an online text-based game called
Star_Quest has been developed in order to analyze its behavior under
different performance measurements. Performance metrics such as
throughput, scalability, response time and page loading time are
captured to yield the performance of the game. The techniques in
performing the load testing are also disclosed to exhibit the viability
of our work. The comparative assessment between the results
obtained and the accepted level of performances are conducted as to
determine the performance level of the game. The study reveals that
the developed game managed to meet all the performance objectives
set forth.
Abstract: Many footbridges have natural frequencies that
coincide with the dominant frequencies of the pedestrian-induced
load and therefore they have a potential to suffer excessive vibrations
under dynamic loads induced by pedestrians. Some of the design
standards introduce load models for pedestrian loads applicable for
simple structures. Load modeling for more complex structures, on the
other hand, is most often left to the designer. The main focus of this
paper is on the human induced forces transmitted to a footbridge and
on the ways these loads can be modeled to be used in the dynamic
design of footbridges. Also design criteria and load models proposed
by widely used standards were introduced and a comparison was
made. The dynamic analysis of the suspension bridge in Kolin in the
Czech Republic was performed on detailed FEM model using the
ANSYS program system. An attempt to model the load imposed by a
single person and a crowd of pedestrians resulted in displacements
and accelerations that are compared with serviceability criteria.
Abstract: This paper presents the buckling analysis of short and
long functionally graded cylindrical shells under thermal and
mechanical loads. The shell properties are assumed to vary
continuously from the inner surface to the outer surface of the shell.
The equilibrium and stability equations are derived using the total
potential energy equations, Euler equations and first order shear
deformation theory assumptions. The resulting equations are solved
for simply supported boundary conditions. The critical temperature
and pressure loads are calculated for both short and long cylindrical
shells. Comparison studies show the effects of functionally graded
index, loading type and shell geometry on critical buckling loads of
short and long functionally graded cylindrical shells.
Abstract: Computations with higher than the IEEE 754 standard double-precision (about 16 significant digits) are required recently. Although there are available software routines in Fortran and C for high-precision computation, users are required to implement such routines in their own computers with detailed knowledges about them. We have constructed an user-friendly online system for octupleprecision computation. In our Web system users with no knowledges about high-precision computation can easily perform octupleprecision computations, by choosing mathematical functions with argument(s) inputted, by writing simple mathematical expression(s) or by uploading C program(s). In this paper we enhance the Web system above by adding the facility of uploading Fortran programs, which have been widely used in scientific computing. To this end we construct converter routines in two stages.
Abstract: All practical real-time scheduling algorithms in multiprocessor systems present a trade-off between their computational complexity and performance. In real-time systems, tasks have to be performed correctly and timely. Finding minimal schedule in multiprocessor systems with real-time constraints is shown to be NP-hard. Although some optimal algorithms have been employed in uni-processor systems, they fail when they are applied in multiprocessor systems. The practical scheduling algorithms in real-time systems have not deterministic response time. Deterministic timing behavior is an important parameter for system robustness analysis. The intrinsic uncertainty in dynamic real-time systems increases the difficulties of scheduling problem. To alleviate these difficulties, we have proposed a fuzzy scheduling approach to arrange real-time periodic and non-periodic tasks in multiprocessor systems. Static and dynamic optimal scheduling algorithms fail with non-critical overload. In contrast, our approach balances task loads of the processors successfully while consider starvation prevention and fairness which cause higher priority tasks have higher running probability. A simulation is conducted to evaluate the performance of the proposed approach. Experimental results have shown that the proposed fuzzy scheduler creates feasible schedules for homogeneous and heterogeneous tasks. It also and considers tasks priorities which cause higher system utilization and lowers deadline miss time. According to the results, it performs very close to optimal schedule of uni-processor systems.
Abstract: This paper deals with a numerical analysis of the
transient response of composite beams with strain rate dependent
mechanical properties by use of a finite difference method. The
equations of motion based on Timoshenko beam theory are derived.
The geometric nonlinearity effects are taken into account with von
Kármán large deflection theory. The finite difference method in
conjunction with Newmark average acceleration method is applied to
solve the differential equations. A modified progressive damage
model which accounts for strain rate effects is developed based on
the material property degradation rules and modified Hashin-type
failure criteria and added to the finite difference model. The
components of the model are implemented into a computer code in
Mathematica 6. Glass/epoxy laminated composite beams with
constant and strain rate dependent mechanical properties under
dynamic load are analyzed. Effects of strain rate on dynamic
response of the beam for various stacking sequences, load and
boundary conditions are investigated.
Abstract: Heat powered solid sorption is a feasible alternative to
electrical vapor compression refrigeration systems. In this paper,
activated carbon (powder type Maxsorb and fiber type ACF-A10)-
CO2 based adsorption cooling cycles are studied using the pressuretemperature-
concentration (P-T-W) diagram. The specific cooling
effect (SCE) and the coefficient of performance (COP) of these two
cooling systems are simulated for the driving heat source
temperatures ranging from 30 ºC to 90 ºC in terms of different
cooling load temperatures with a cooling source temperature of 25
ºC. It is found from the present analysis that Maxsorb-CO2 couple
shows higher cooling capacity and COP. The maximum COPs of
Maxsorb-CO2 and ACF(A10)-CO2 based cooling systems are found
to be 0.15 and 0.083, respectively. The main innovative feature of
this cooling cycle is the ability to utilize low temperature waste heat
or solar energy using CO2 as the refrigerant, which is one of the best
alternative for applications where flammability and toxicity are not
allowed.
Abstract: In this paper, a particle swarm optimization (PSO)
algorithm is proposed to solve machine loading problem in flexible
manufacturing system (FMS), with bicriterion objectives of
minimizing system unbalance and maximizing system throughput in
the occurrence of technological constraints such as available
machining time and tool slots. A mathematical model is used to
select machines, assign operations and the required tools. The
performance of the PSO is tested by using 10 sample dataset and the
results are compared with the heuristics reported in the literature. The
results support that the proposed PSO is comparable with the
algorithms reported in the literature.