Abstract: In this paper the Differential Quadrature Method (DQM) is employed to study the coupled lateral-torsional free vibration behavior of the laminated composite beams. In such structures due to the fiber orientations in various layers, the lateral displacement leads to a twisting moment. The coupling of lateral and torsional vibrations is modeled by the bending-twisting material coupling rigidity. In the present study, in addition to the material coupling, the effects of shear deformation and rotary inertia are taken into account in the definition of the potential and kinetic energies of the beam. The governing differential equations of motion which form a system of three coupled PDEs are solved numerically using DQ procedure under different boundary conditions consist of the combinations of simply, clamped, free and other end conditions. The resulting natural frequencies and mode shapes for cantilever beam are compared with similar results in the literature and good agreement is achieved.
Abstract: Construction delay is unavoidable in developing
countries including Malaysia. It is defined as time overrun or
extension of time for completion of a project. The purpose of the
study is to determine the causes of delay in Malaysian construction
industries based on previous worldwide research. The field survey
conducted includes the experienced developers, consultants and
contractors in Malaysia. 34 causes of the construction delay have
been determined and 24 have been selected using the Rasch model
analysis. The analysis result will be used as the baseline for the next
research to find the causes of delay in the Malaysian construction
industry taking place in Malaysian higher learning institutions.
Abstract: It is essential to have a uniform and calm flow field
for a settling tank to have high performance. In general, the
recirculation zones always occurred in sedimentation tanks. The
presence of these regions may have different effects. The nonuniformity
of the velocity field, the short-circuiting at the surface and
the motion of the jet at the bed of the tank that occurs because of the
recirculation in the sedimentation layer, are affected by the geometry
of the tank. There are some ways to decrease the size of these dead
zones, which would increase the performance. One of the ways is to
use a suitable baffle configuration. In this study, the presence of
baffle with different position has been investigated by a finite volume
method, with VOF (Volume of Fluid) model. Besides, the k-ε
turbulence model is used in the numerical calculations. The results
indicate that the best position of the baffle is obtained when the
volume of the recirculation region is minimized or is divided to
smaller part and the flow field trend to be uniform in the settling
zone.
Abstract: This paper presents the design and analysis of a parallel
connected inverter configuration of. The configuration consists of
parallel connected three-phase dc/ac inverter. Series resistors added
to the inverter output to maintain same current in each inverter of the
two parallel inverters, and to reduce the circulating current in the
parallel inverters to the minimum. High frequency third harmonic
injection PWM (THIPWM) employed to reduce the total harmonic
distortion and to make maximum use of the voltage source. DSP was
used to generate the THIPWM and the control algorithm for the
converter. Selected experimental results have been shown to validate
the proposed system.
Abstract: The storage of chemical fertilizers in concrete building often leads to durability problems due to chemical attack. The damage of concrete is mostly caused by certain ammonium salts. The main purpose of the research is to investigate the durability properties of concrete being exposed to ammonium nitrate solution. In this investigation, experiments are conducted on concrete type G50 and G60. The leaching process is achieved by the use of 20% concentration solution of ammonium nitrate. The durability properties investigated are water absorption, volume of permeable voids, and sorptivity. Compressive strength, pH value, and degradation depth are measured after a certain period of leaching. A decrease in compressive strength and an increase in porosity are found through the conducted experiments. Apart from that, the experimental data shows that pH value decreases with increased leaching time while the degradation depth of concrete increases with leaching time. By comparing concrete type G50 and G60, concrete type G60 is more resistant to ammonium nitrate attack.
Abstract: Background: Tissue Doppler Echocardiography
(TDE) assesses diastolic function more accurately than routine pulse
Doppler echo. Assessment of the effects of dynamic and static
exercises on the heart by using TDE can provides new information
about the athlete-s heart syndrome. Methods: This study was
conducted on 20 elite wrestlers, 14 endurance runners at national
level and 21 non-athletes as the control group. Participants underwent
two-dimensional echocardiography, standard Doppler and TDE.
Results: Wrestlers had the highest left ventricular mass index, enddiastolic
inter-ventricular septum thickness and left ventricular
Posterior wall thickness. Runners had the highest Left ventricular
end-diastolic volume, LV ejection fraction, stroke volume and
cardiac output. In TDE, the early diastolic velocity of mitral annulus
to the late diastolic velocity ratio in athletic groups was greater than
the controls with no significant difference. Conclusion: In spite of
cardiac morphological changes in athletes, TDE shows that cardiac
diastolic function won-t be adversely affected.
Abstract: In this paper we evaluated the efficacy of
photodynamic treatment of infected wounds on pig animal model by
diffuse reflectance spectrometry. The study was conducted on fifteen
wounds contaminated with Staphylococcus aureus bacteria that were
incubated for 30 min with methylene blue solution (c = 3.3 x 10-3 M)
and exposed to laser radiations (λ = 670 nm, P = 15 mW) for 15 min.
The efficiency of photodynamic inactivation of bacteria was
evaluated by microbiological exams and diffuse reflectance
spectrometry. The results of the microbiological exams showed that
the bacterial concentration has decreased from 6.93±0.138
logCFU/ml to 3.12±0.108 logCFU/ml. The spectral examination
showed that the diffuse reflectance of wounds contaminated with
Staphylococcus aureus has decreased from 5.06±0.036 % to
3.36±0.025 %. In conclusion, photodynamic therapy is an effective
method for the treatment of infected wounds and there is a correlation
between the CFU count and diffuse reflectance.
Abstract: Green buildings have been commonly cited to be more
expensive than conventional buildings. However, limited research
has been conducted to clearly identify elements that contribute to this
cost differential. The construction cost of buildings can be typically
divided into “hard" costs and “soft" cost elements. Using a review
analysis of existing literature, the study identified six main elements
in green buildings that contribute to the general cost elements that are
“soft" in nature. The six elements found are insurance, developer-s
experience, design cost, certification, commissioning and energy
modeling. Out of the six elements, most literatures have highlighted
the increase in design cost for green design as compared to
conventional design due to additional architectural and engineering
costs, eco-charettes, extra design time, and the further need for a
green consultant. The study concluded that these elements of soft cost
contribute to the green premium or cost differential of green
buildings.
Abstract: Conventionally the selection of parameters depends
intensely on the operator-s experience or conservative technological
data provided by the EDM equipment manufacturers that assign
inconsistent machining performance. The parameter settings given by
the manufacturers are only relevant with common steel grades. A
single parameter change influences the process in a complex way.
Hence, the present research proposes artificial neural network (ANN)
models for the prediction of surface roughness on first commenced
Ti-15-3 alloy in electrical discharge machining (EDM) process. The
proposed models use peak current, pulse on time, pulse off time and
servo voltage as input parameters. Multilayer perceptron (MLP) with
three hidden layer feedforward networks are applied. An assessment
is carried out with the models of distinct hidden layer. Training of the
models is performed with data from an extensive series of
experiments utilizing copper electrode as positive polarity. The
predictions based on the above developed models have been verified
with another set of experiments and are found to be in good
agreement with the experimental results. Beside this they can be
exercised as precious tools for the process planning for EDM.
Abstract: This paper reports the fatigue crack growth behaviour
of gas tungsten arc, electron beam and laser beam welded Ti-6Al-4V
titanium alloy. Centre cracked tensile specimens were prepared to
evaluate the fatigue crack growth behaviour. A 100kN servo
hydraulic controlled fatigue testing machine was used under constant
amplitude uniaxial tensile load (stress ratio of 0.1 and frequency of
10 Hz). Crack growth curves were plotted and crack growth
parameters (exponent and intercept) were evaluated. Critical and
threshold stress intensity factor ranges were also evaluated. Fatigue
crack growth behaviour of welds was correlated with mechanical
properties and microstructural characteristics of welds. Of the three
joints, the joint fabricated by laser beam welding exhibited higher
fatigue crack growth resistance due to the presence of fine lamellar
microstructure in the weld metal.
Abstract: This research was conducted to determine responses
of chickpeas to drought in different periods (early period, late period,
no-irrigation, two times irrigation as control). The trial was made in
“Randomized Complete Block Design" with three replications on
2010 and 2011 years in Konya-Turkey. Genotypes were consisted
from 7 lines of ICARDA, 2 certified lines and 1 local population. The
results showed that; as means of years and genotypes, early period
stress showed highest (207.47 kg da-1) seed yield and it was followed
by control (202.33 kg da-1), late period (144.64 kg da-1) and normal
(106.93 kg da-1) stress applications. The genotypes were affected too
much by drought and, the lowest seed was taken from non-irrigated
plots. As the means of years and stress applications, the highest
(196.01 kg da-1) yield was taken from genotype 22255. The reason of
yield variation could be derived from different responses of
genotypes to drought.
Abstract: In order to monitor the water table depth on soil profile
salinity buildup, a field study was carried out during 2006-07. Wheat
(Rabi) and Sorghum (Kharif) fodder were sown in with three
treatments. The results showed that watertable depth lowered from
1.15m to 2.89 m depth at the end of experiment. With lower of
watertable depth, pH, ECe and SAR decreased under crops both
without and with gypsum and increased in fallowing. Soil moisture
depletion was directly proportional to lowering of watertable. With the
application of irrigation water (58cm) pH, ECe and SAR were reduced
in cropped plots, reduction was higher in gypsum applied plots than
non-gypsum plots. In case of fallowing, there was increase in pH, EC,
while slight reduction occurred in SAR values. However, soil salinity
showed an increasing upward trend under fallowing and its value in
0-30 cm soil layer was the highest amongst the treatments.
Abstract: In this paper first, Two buildings have been modeled
and then analyzed using nonlinear static analysis method under two
different conditions in Nonlinear SAP 2000 software. In the first
condition the interaction of soil adjacent to the walls of basement are
ignored while in the second case this interaction have been modeled
using Gap elements of nonlinear SAP2000 software. Finally,
comparing the results of two models, the effects of soil-structure on
period, target point displacement, internal forces, shape deformations
and base shears have been studied. According to the results, this
interaction has always increased the base shear of buildings,
decreased the period of structure and target point displacement, and
often decreased the internal forces and displacements.
Abstract: Fluid flow and heat transfer of vertical full cone
embedded in porous media is studied in this paper. Nonlinear
differential equation arising from similarity solution of inverted cone
(subjected to wall temperature boundary conditions) embedded in
porous medium is solved using a hybrid neural network- particle
swarm optimization method.
To aim this purpose, a trial solution of the differential equation is
defined as sum of two parts. The first part satisfies the initial/
boundary conditions and does contain an adjustable parameter and
the second part which is constructed so as not to affect the
initial/boundary conditions and involves adjustable parameters (the
weights and biases) for a multi-layer perceptron neural network.
Particle swarm optimization (PSO) is applied to find adjustable
parameters of trial solution (in first and second part). The obtained
solution in comparison with the numerical ones represents a
remarkable accuracy.
Abstract: Employees commonly encounter unpredictable and
unavoidable work related stressors. Exposure to such stressors can
evoke negative appraisals and associated adverse mental, physical,
and behavioral responses. Because Acceptance and Commitment
Therapy (ACT) emphasizes acceptance of unavoidable stressors and
diffusion from negative appraisals, it may be particularly beneficial
for work stress. Forty-five workers were randomly assigned to an
ACT intervention for work stress (n = 21) or a waitlist control group
(n = 24). The intervention consisted of two 3-hour sessions spaced
one week apart. An examination of group process and outcomes was
conducted using the Revised Sessions Rating Scale. Results indicated
that the ACT participants reported that they perceived the
intervention to be supportive, task focused, and without adverse
therapist behaviors (e.g., feelings of being criticized or discounted).
Additionally, the second session (values clarification and
commitment to action) was perceived to be more supportive and task
focused than the first session (mindfulness, defusion). Process ratings
were correlated with outcomes. Results indicated that perceptions of
therapy supportiveness and task focus were associated with reduced
psychological distress and improved perceived physical health.
Abstract: The impact of fixed speed squirrel cage type as well as
variable speed doubly fed induction generators (DFIG) on dynamic
performance of a multimachine power system has been investigated.
Detailed models of the various components have been presented and
the integration of asynchronous and synchronous generators has been
carried out through a rotor angle based transform. Simulation studies
carried out considering the conventional dynamic model of squirrel
cage asynchronous generators show that integration, as such, could
degrade to the AC system performance transiently. This article
proposes a frequency or power controller which can effectively
control the transients and restore normal operation of fixed speed
induction generator quickly. Comparison of simulation results
between classical cage and doubly-fed induction generators indicate
that the doubly fed induction machine is more adaptable to
multimachine AC system. Frequency controller installed in the DFIG
system can also improve its transient profile.
Abstract: In this study, we investigated the effects of ginger and
L-carnitine on the reproductive performance of male rats with respect
to semen parameters, male sex hormones and the testicular
antioxidant system. A total of sixty mature male albino rats were
divided into four groups of fifteen rats. The control group received
saline, whereas the other three groups received ginger (100 mg kg-1 d-
1.), L-carnitine (150 mg kg-1 d-1.) or a combination of both ginger
(100 mg kg-1 d-1.) and L-carnitine (150 mg kg-1 d-1.) via a stomach
tube daily for one month. At the end of the treatment period, the rats
were sacrificed, and their sperm characteristics (count, motility and
viability), antioxidant enzyme factors levels (reduced glutathione,
catalase, superoxide dismutase and total antioxidant capacity) and sex
hormone levels (testosterone, Follicle stimulating hormone(FSH) and
luteinizing hormone (LH) were analysed. Our results showed that the
three experimental treatments improved sperm parameters,
antioxidant enzyme activity and testosterone hormone levels; the
most pronounced positive effects were observed in the group that
received a combination of both ginger and L-carnitine. Therefore, the
administration of a combination of ginger and L-carnitine may be
beneficial for improving male sexual performance.
Abstract: A mathematical model of the surface roughness
has been developed by using response surface methodology
(RSM) in grinding of AISI D2 cold work tool steels. Analysis
of variance (ANOVA) was used to check the validity of the
model. Low and high value for work speed and feed rate are
decided from design of experiment. The influences of all
machining parameters on surface roughness have been
analyzed based on the developed mathematical model. The
developed prediction equation shows that both the feed rate
and work speed are the most important factor that influences
the surface roughness. The surface roughness was found to be
the lowers with the used of low feed rate and low work speed.
Accuracy of the best model was proved with the testing data.
Abstract: Modular multiplication is the basic operation
in most public key cryptosystems, such as RSA, DSA, ECC,
and DH key exchange. Unfortunately, very large operands
(in order of 1024 or 2048 bits) must be used to provide
sufficient security strength. The use of such big numbers
dramatically slows down the whole cipher system, especially
when running on embedded processors.
So far, customized hardware accelerators - developed on
FPGAs or ASICs - were the best choice for accelerating
modular multiplication in embedded environments. On the
other hand, many algorithms have been developed to speed
up such operations. Examples are the Montgomery modular
multiplication and the interleaved modular multiplication
algorithms. Combining both customized hardware with
an efficient algorithm is expected to provide a much faster
cipher system.
This paper introduces an enhanced architecture for computing
the modular multiplication of two large numbers X
and Y modulo a given modulus M. The proposed design is
compared with three previous architectures depending on
carry save adders and look up tables. Look up tables should
be loaded with a set of pre-computed values. Our proposed
architecture uses the same carry save addition, but replaces
both look up tables and pre-computations with an enhanced
version of sign detection techniques. The proposed architecture
supports higher frequencies than other architectures.
It also has a better overall absolute time for a single operation.
Abstract: In this research work, a novel parallel manipulator
with high positioning and orienting rate is introduced. This
mechanism has two rotational and one translational degree of
freedom. Kinematics and Jacobian analysis are investigated.
Moreover, workspace analysis and optimization has been performed
by using genetic algorithm toolbox in Matlab software. Because of
decreasing moving elements, it is expected much more better
dynamic performance with respect to other counterpart mechanisms
with the same degrees of freedom. In addition, using couple of
cylindrical and revolute joints increased mechanism ability to have
more extended workspace.