Abstract: We have investigated the effect of piezoelectric (PZ)
polarization property in binary as well as in ternary wurtzite nitrides.
It is found that with the presence of PZ polarization property, the
phonon group velocity is modified. The change in phonon group
velocity due to PZ polarization effect directly depends on
piezoelectric tensor value. Using different piezoelectric tensor values
recommended by different workers in the literature, percent change in
group velocities of phonons has been estimated. The Debye
temperatures and frequencies of binary nitrides GaN, AlN and InN
are also calculated using the modified group velocities. For ternary
nitrides AlxGa(1-x)N, InxGa(1-x)N and InxAl(1-x)N, the phonon group
velocities have been calculated as a functions of composition. A
small positive bowing is observed in phonon group velocities of
ternary alloys. Percent variations in phonon group velocities are also
calculated for a straightforward comparison among ternary nitrides.
The results are expected to show a change in phonon relaxation rates
and thermal conductivity of III-nitrides when piezoelectric
polarization property is taken into consideration.
Abstract: The effect of the rotational speed and axial torque on
the diagnostics of tapered rolling element bearing defects was
investigated. The accelerometer was mounted on the bearing housing
and connected to Sound and Vibration Analyzer (SVAN 958) and
was used to measure the accelerations from the bearing housing. The
data obtained from the bearing was processed to detect damage of the
bearing using statistical tools and the results were subsequently
analyzed to see if bearing damage had been captured. From this study
it can be seen that damage is more evident when the bearing is
loaded. Also, at the incipient stage of damage the crest factor and
kurtosis values are high but as time progresses the crest factors and
kurtosis values decrease whereas the peak and RMS values are low at
the incipient stage but increase with damage.
Abstract: In this paper an alternative visualisation approach of
the wake behind different vehicle body shapes with simplified and
fully-detailed underbody has been proposed and analysed. This
allows for a more clear distinction among the different wake regions.
This visualisation is based on a transformation of the cartesian
coordinates of a chosen wake plane to polar coordinates, using as
filter velocities lower than the freestream. This transformation
produces a polar wake plot that enables the division and
quantification of the wake in a number of sections. In this paper,
local drag has been used to visualise the drag contribution of the flow
by the different sections. Visually, a balanced wake can be observed
by the concentric behaviour of the polar plots. Alternatively,
integration of the local drag of each degree section as a ratio of the
total local drag yields a quantifiable approach of the wake uniformity,
where different sections contribute equally to the local drag, with the
exception of the wheels.
Abstract: How to effectively allocate system resource to process
the Client request by Gateway servers is a challenging problem. In
this paper, we propose an improved scheme for autonomous
performance of Gateway servers under highly dynamic traffic loads.
We devise a methodology to calculate Queue Length and Waiting
Time utilizing Gateway Server information to reduce response time
variance in presence of bursty traffic. The most widespread
contemplation is performance, because Gateway Servers must offer
cost-effective and high-availability services in the elongated period,
thus they have to be scaled to meet the expected load. Performance
measurements can be the base for performance modeling and
prediction. With the help of performance models, the performance
metrics (like buffer estimation, waiting time) can be determined at
the development process. This paper describes the possible queue
models those can be applied in the estimation of queue length to
estimate the final value of the memory size. Both simulation and
experimental studies using synthesized workloads and analysis of
real-world Gateway Servers demonstrate the effectiveness of the
proposed system.
Abstract: Solutions for the temperature profile around a moving
heat source are obtained using both analytic and finite element
(FEM) methods. Analytic and FEM solutions are applied to study the
temperature profile in welding. A moving heat source is represented
using both point heat source and uniform distributed disc heat source
models. Analytic solutions are obtained by solving the partial
differential equation for energy conservation in a solid, and FEM
results are provided by simulating welding using the ANSYS
software. Comparison is made for quasi steady state conditions. The
results provided by the analytic solutions are in good agreement with
results obtained by FEM.
Abstract: This research investigates the effects of the opening
shape and location on the structural behavior of reinforced concrete
deep beam with openings, while keeping the opening size unchanged.
The software ANSYS 12.1 is used to handle the nonlinear finite
element analysis. The ultimate strength of reinforced concrete deep
beam with opening obtained by ANSYS 12.1 shows fair agreement
with the experimental results, with a difference of no more than 20%. The present work concludes that the opening location has much more effect on the structural strength than the opening shape. It was
concluded that placing the openings near the upper corners of the
deep beam may double the strength, and the use of a rectangular
narrow opening, with the long sides in the horizontal direction, can save up to 40% of structural strength of the deep beam.
Abstract: Irradiation is considered one of the most efficient technological processes for the reduction of microorganisms in food. It can be used to improve the safety of food products, and to extend their shelf lives. The aim of this study was to evaluate the effects of gamma irradiation for improvement of saffron shelf life. Samples were treated with 0 (none irradiated), 1.0, 2.0, 3.0 and 4.0 kGy of gamma irradiation and held for 2 months. The control and irradiated samples were underwent microbial analysis, chemical characteristics and sensory evaluation at 30 days intervals. Microbial analysis indicated that irradiation had a significant effect (P < 0.05) on the reduction of microbial loads. There was no significant difference in sensory quality and chemical characteristics during storage in saffron.
Abstract: An attempt has been made to determine the strength
and impact properties of Cr-Mo steel weld and base materials by
varying the current during manual metal arc welding. Toughness over
a temperature range from -32 to 100°C of base, heat affected zone
(HAZ) and weld zones at three current settings are made. It is
observed that the deterioration in notch toughness at any zone with
the temperature decreases. The values of notch toughness for all
zones at -32°C are almost same for any current settings. The values
of notch toughness at HAZ area are higher than that of weld area due
to the coarsening of ferrite grain of HAZ occurs with higher heat
input. From microhardness and microstructure result, it can be
concluded that large inclusion content in weld deposit is the cause of
lower notch toughness value.
Abstract: Air quality studies were carried out in the towns of
Putrajaya, Petaling Jaya and Nilai in the Malaysian Peninsular. In this
study, the variations of Ozone (O3) concentrations over a four year
period (2008-2011) were investigated using data obtained from the
Malaysian Department of the Environment (DOE). This study aims to
identify and describe the daily and monthly variations of O3
concentrations at the monitoring sites mentioned. The SPPS program
(Statistical Package for the Social Science) was used to analyze this
data in order to obtain the variations of O3 and also to clarify the
relationship between the stations. The findings of the study revealed
that the highest concentration of O3 occurred during the midday and
afternoon (between 13:00-15:00 hrs). The comparison between
stations also showed that highest O3 concentrations were recorded in
Putrajaya. The comparisons of average and maximum concentrations
of O3 for the three stations showed that the strongest significant
correlation was recorded in the Petaling Jaya station with the value
R2= 0.667. Results from this study indicate that in the urban areas of
Peninsular Malaysia, the concentration of O3 depends on the
concentration of NOx. Furthermore, HYSPLIT back trajectories
(-72h) indicated that air-mass transport patterns can also influence the
O3 concentration in the areas studied.
Abstract: In order to investigate water deficit stress on 24 of
soybean (Glycine Max. L) cultivars and lines in temperate climate, an
experiment was conducted in Iran Seed and Plant Improvement
Institute. Stress levels were irrigation after evaporation of 50, 100,
150 mm water from pan, class A. Randomized Completely Block
Design was arranged for each stress levels. Some traits such as, node
number, plant height, pod number per area, grain number per pod,
grain number per area, 1000 grains weight, grain yield and harvest
index were measured. Results showed that water deficit stress had
significant effect on node number, plant height, pod number per area,
grain number per pod, grain number per area, 1000 grains weight and
harvest index. Also all of agronomic traits except harvest index
influenced significantly by cultivars and lines. The least and most
grain yield was belonged to Ronak X Williams and M41 x Clark
respectively.
Abstract: Currently searching through internet is very popular especially in a field of academic. A huge of educational information such as research papers are overload for user. So community-base web sites have been developed to help user search information more easily from process of customizing a web site to need each specifies user or set of user. In this paper propose to use association rule analyze the community group on research paper bookmarking. A set of design goals for community group frameworks is developed and discussed. Additionally Researcher analyzes the initial relation by using association rule discovery between the antecedent and the consequent of a rule in the groups of user for generate the idea to improve ranking search result and development recommender system.
Abstract: In this work, study the location of interface in a stirred vessel with Rushton impeller by computational fluid dynamic was presented. To modeling rotating the impeller, sliding mesh (SM) technique was used and standard k-ε model was selected for turbulence closure. Mean tangential, radial and axial velocities and also turbulent kinetic energy (k) and turbulent dissipation rate (ε) in various points of tank was investigated. Results show sensitivity of system to location of interface and radius of 7 to 10cm for interface in the vessel with existence characteristics cause to increase the accuracy of simulation.
Abstract: Coarse and fine particulate matter were collected at a
residential area at Vashi, Navi Mumbai and the filter samples were
analysed for trace elements using PIXE technique. The trend of
particulate matter showed higher concentrations during winter than
the summer and monsoon concentration levels. High concentrations
of elements related to soil and sea salt were found in PM10 and
PM2.5. Also high levels of zinc and sulphur found in the particulates
of both the size fractions. EF analysis showed enrichment of Cu, Cr
and Mn only in the fine fraction suggesting their origin from
anthropogenic sources. The EF value was observed to be maximum
for As, Pb and Zn in the fine particulates. However, crustal derived
elements showed very low EF values indicating their origin from
soil. The PCA based multivariate studies identified soil, sea salt,
combustion and Se sources as common sources for coarse and
additionally an industrial source has also been identified for fine
particles.
Abstract: This paper deals with the comparison between two proposed control strategies for a DC-DC boost converter. The first control is a classical Sliding Mode Control (SMC) and the second one is a distance based Fuzzy Sliding Mode Control (FSMC). The SMC is an analytical control approach based on the boost mathematical model. However, the FSMC is a non-conventional control approach which does not need the controlled system mathematical model. It needs only the measures of the output voltage to perform the control signal. The obtained simulation results show that the two proposed control methods are robust for the case of load resistance and the input voltage variations. However, the proposed FSMC gives a better step voltage response than the one obtained by the SMC.
Abstract: Using a methodology grounded in business process
change theory, we investigate the critical success factors that affect
ERP implementation success in United States and India.
Specifically, we examine the ERP implementation at two case study
companies, one in each country. Our findings suggest that certain
factors that affect the success of ERP implementations are not
culturally bound, whereas some critical success factors depend on the
national culture of the country in which the system is being
implemented. We believe that the understanding of these critical
success factors will deepen the understanding of ERP
implementations and will help avoid implementation mistakes,
thereby increasing the rate of success in culturally different contexts.
Implications of the findings and future research directions for both
academicians and practitioners are also discussed.
Abstract: Design and land use are closely linked to the
energy efficiency levels for an urban area. The current city
planning practice does not involve an effective land useenergy
evaluation in its 'blueprint' urban plans. The study
proposed an appraisal method that can be embedded in GIS
programs using five planning criteria as how far a planner can
give away from the planning principles (criteria) for the most
energy output s/he can obtain. The case of Balcova, a district
in the Izmir Metropolitan area, is used conformingly for
evaluating the proposed master plan and the geothermal
energy (heating only) use for the concern district.
If the land use design were proposed accordingly at-most
energy efficiency (a 30% obtained), mainly increasing the
density around the geothermal wells and also proposing more
mixed use zones, we could have 17% distortion (infidelity to
the main planning principles) from the original plan. The
proposed method can be an effective tool for planners as
simulation media, of which calculations can be made by GIS
ready tools, to evaluate efficiency levels for different plan
proposals, letting to know how much energy saving causes
how much deviation from the other planning ideals. Lower
energy uses can be possible for different land use proposals
for various policy trials.
Abstract: This paper presents a simple and sensitive kinetic
spectrophotometric method for the determination of ramipril in
commercial dosage forms. The method is based on the reaction of the
drug with 1-chloro-2,4-dinitrobenzene (CDNB) in dimethylsulfoxide
(DMSO) at 100 ± 1ºC. The reaction is followed
spectrophotometrically by measuring the rate of change of the
absorbance at 420 nm. Fixed-time (ΔA) and equilibrium methods are
adopted for constructing the calibration curves. Both the calibration
curves were found to be linear over the concentration ranges 20 - 220
μg/ml. The regression analysis of calibration data yielded the linear
equations: Δ A = 6.30 × 10-4 + 1.54 × 10-3 C and A = 3.62 × 10-4 +
6.35 × 10-3 C for fixed time (Δ A) and equilibrium methods,
respectively. The limits of detection (LOD) for fixed time and
equilibrium methods are 1.47 and 1.05 μg/ml, respectively. The
method has been successfully applied to the determination of ramipril
in commercial dosage forms. Statistical comparison of the results
shows that there is no significant difference between the proposed
methods and Abdellatef-s spectrophotometric method.
Abstract: Tungsten trioxide has been prepared by using P-PTA
as a precursor on alumina substrates by spin coating method.
Palladium introduced on WO3 film via electrolysis deposition by
using palladium chloride as catalytic precursor. The catalytic
precursor was introduced on the series of films with different
morphologies. X-ray diffractometry (XRD), Scanning electron
microscopy (SEM) and XPS were applied to analyze structure and
morphology of the fabricated thin films. Then we measured variation
of samples- electrical conductivity of pure and Pd added films in air
and diluted hydrogen. Addition of Pd resulted in a remarkable
improvement of the hydrogen sensing properties of WO3 by detection
of Hydrogen below 1% at room temperature. Also variation of the
electrical conductivity in the presence of diluted hydrogen revealed
that response of samples depends rather strongly on the palladium
configuration on the surface.
Abstract: Wind turbines with double output induction
generators can operate at variable speed permitting conversion
efficiency maximization over a wide range of wind velocities. This
paper presents the performance analysis of a wind driven double
output induction generator (DOIG) operating at varying shafts speed.
A periodic transient state analysis of DOIG equipped with two
converters is carried out using a hybrid induction machine model.
This paper simulates the harmonic content of waveforms in various
points of drive at different speeds, based on the hybrid model
(dqabc). Then the sinusoidal and trapezoidal pulse-width–modulation
control techniques are used in order to improve the power factor of
the machine and to weaken the injected low order harmonics to the
supply. Based on the frequency spectrum, total harmonics distortion,
distortion factor and power factor. Finally advantages of sinusoidal
and trapezoidal pulse width modulation techniques are compared.
Abstract: Semiconductor materials with coatings have a wide range of applications in MEMS and NEMS. This work uses transfermatrix method for calculating the radiative properties. Dopped silicon is used and the coherent formulation is applied. The Drude model for the optical constants of doped silicon is employed. Results showed that for the visible wavelengths, more emittance occurs in greater concentrations and the reflectance decreases as the concentration increases. In these wavelengths, transmittance is negligible. Donars and acceptors act similar in visible wavelengths. The effect of wave interference can be understood by plotting the spectral properties such as reflectance or transmittance of a thin dielectric film versus the film thickness and analyzing the oscillations of properties due to constructive and destructive interferences. But this effect has not been shown at visible wavelengths. At room temperature, the scattering process is dominated by lattice scattering for lightly doped silicon, and the impurity scattering becomes important for heavily doped silicon when the dopant concentration exceeds1018cm-3 .