Abstract: The effect of various humidities on process yields and
degrees of crystallinity for spray-dried powders from spray drying of
lactose with humid air in a straight-through system have been
studied. It has been suggested by Williams–Landel–Ferry kinetics
(WLF) that a higher particle temperature and lower glass-transition
temperature would increase the crystallization rate of the particles
during the spray-drying process. Freshly humidified air produced by
a Buchi-B290 spray dryer as a humidifier attached to the main spray
dryer decreased the particle glass-transition temperature (Tg), while
allowing the particle temperature (Tp) to reach higher values by using
an insulated drying chamber. Differential scanning calorimetry
(DSC) and moisture sorption analysis were used to measure the
degree of crystallinity for the spray-dried lactose powders. The
results showed that higher Tp-Tg, as a result of applying humid air,
improved the process yield from 21 ± 4 to 26 ± 2% and crystallinity
of the particles by decreasing the latent heat of crystallization from
43 ± 1 to 30 ± 11 J/g and the sorption peak height from 7.3 ± 0.7% to
6 ± 0.7%.
Abstract: It is well known, that any interpolating polynomial
p (x, y) on the vector space Pn,m of two-variable polynomials with
degree less than n in terms of x and less than m in terms of y, has
various representations that depends on the basis of Pn,m that we
select i.e. monomial, Newton and Lagrange basis e.t.c.. The aim of
this short note is twofold : a) to present transformations between the
coordinates of the polynomial p (x, y) in the aforementioned basis
and b) to present transformations between these bases.
Abstract: The growth of wireless devices affects the availability
of limited frequencies or spectrum bands as it has been known that
spectrum bands are a natural resource that cannot be added.
Meanwhile, the licensed frequencies are idle most of the time.
Cognitive radio is one of the solutions to solve those problems.
Cognitive radio is a promising technology that allows the unlicensed
users known as secondary users (SUs) to access licensed bands
without making interference to licensed users or primary users (PUs).
As cloud computing has become popular in recent years, cognitive
radio networks (CRNs) can be integrated with cloud platform. One of
the important issues in CRNs is security. It becomes a problem since
CRNs use radio frequencies as a medium for transmitting and CRNs
share the same issues with wireless communication systems. Another
critical issue in CRNs is performance. Security has adverse effect to
performance and there are trade-offs between them. The goal of this
paper is to investigate the performance related to security trade-off in
CRNs with supporting cloud platforms. Furthermore, Queuing
Network Models with preemptive resume and preemptive repeat
identical priority are applied in this project to measure the impact of
security to performance in CRNs with or without cloud platform. The
generalized exponential (GE) type distribution is used to reflect the
bursty inter-arrival and service times at the servers. The results show
that the best performance is obtained when security is disabled and
cloud platform is enabled.
Abstract: This paper presents the voltage problem location
classification using performance of Least Squares Support Vector
Machine (LS-SVM) and Learning Vector Quantization (LVQ) in
electrical power system for proper voltage problem location
implemented by IEEE 39 bus New- England. The data was collected
from the time domain simulation by using Power System Analysis
Toolbox (PSAT). Outputs from simulation data such as voltage, phase
angle, real power and reactive power were taken as input to estimate
voltage stability at particular buses based on Power Transfer Stability
Index (PTSI).The simulation data was carried out on the IEEE 39 bus
test system by considering load bus increased on the system. To verify
of the proposed LS-SVM its performance was compared to Learning
Vector Quantization (LVQ). The results showed that LS-SVM is faster
and better as compared to LVQ. The results also demonstrated that the
LS-SVM was estimated by 0% misclassification whereas LVQ had
7.69% misclassification.
Abstract: In Egypt, girls have traditionally been educationally
disadvantaged. This disadvantage, however, has been focused on the
failure to enter school. Increasingly it is recognized that girls who
ever-enroll are at least as likely to complete primary and secondary
education as boys. Still the belief persists that girls, especially those
from poor families, will be disadvantaged in terms of school
expenditures and the transitions to secondary and higher education.
We examine expenditures on tutoring during the final year of
preparatory school, and the transition to specific tracks of secondary
education. Tests during the last year of preparatory largely determine
a student’s educational future. Results show that girls, even girls from
poor families, are not disadvantaged in terms of expenditures,
whether for tutoring, fees or general expenses. Moreover, girls are
more likely than boys to advance to general secondary education, the
track that leads to higher education.
Abstract: Recently, to cope with the rapidly changing
construction trend with aging infrastructures, modular bridge
technology has been studied actively. Modular bridge is easily
constructed by assembling standardized precast structure members in
the field. It will be possible to construct rapidly and reduce
construction cost efficiently. However, the shape of the transverse
connection of T-type girder newly developed between the segmented
modules is not verified. Therefore, the verification of the connection
shape is needed. In this study, shape of the modular T-girder bridge
transverse connection was analyzed by finite element model that was
verified in study which was verified model of transverse connection
using Abaqus. Connection angle was chosen as the parameter. The
result of analyses showed that optimal value of angle is 130 degree.
Abstract: This study models the use of transcutaneous electrical
nerve stimulation on skin with a disk electrode in order to simulate
tissue damage. The current density distribution above a disk electrode
is known to be a dynamic and non-uniform quantity that is intensified
at the edges of the disk. The non-uniformity is subject to change
through using various electrode geometries or stimulation methods.
One of these methods known as edge-retarded stimulation has shown
to reduce this edge enhancement. Though progress has been made in
modeling the behavior of a disk electrode, little has been done to test
the validity of these models in simulating the actual heat transfer
from the electrode. This simulation uses finite element software to
couple the injection of current from a disk electrode to heat transfer
described by the Pennesbioheat transfer equation. An example
application of this model is studying an experimental form of
stimulation, known as edge-retarded stimulation. The edge-retarded
stimulation method will reduce the current density at the edges of the
electrode. It is hypothesized that reducing the current density edge
enhancement effect will, in turn, reduce temperature change and
tissue damage at the edges of these electrodes. This study tests this
hypothesis as a demonstration of the capabilities of this model. The
edge-retarded stimulation proved to be safer after this simulation. It is
shown that temperature change and the fraction of tissue necrosis is
much greater in the square wave stimulation. These results bring
implications for changes of procedures in transcutaneous electrical
nerve stimulation and transcutaneous spinal cord stimulation as well.
Abstract: It is known that residual welding deformations give
negative effect to processability and operational quality of welded
structures, complicating their assembly and reducing strength.
Therefore, selection of optimal technology, ensuring minimum
welding deformations, is one of the main goals in developing a
technology for manufacturing of welded structures.
Through years, JSC SSTC has been developing a theory for
estimation of welding deformations and practical activities for
reducing and compensating such deformations during welding
process. During long time a methodology was used, based on analytic
dependence. This methodology allowed defining volumetric changes
of metal due to welding heating and subsequent cooling. However,
dependences for definition of structures deformations, arising as a
result of volumetric changes of metal in the weld area, allowed
performing calculations only for simple structures, such as units, flat
sections and sections with small curvature. In case of complex 3D
structures, estimations on the base of analytic dependences gave
significant errors.
To eliminate this shortage, it was suggested to use finite elements
method for resolving of deformation problem. Here, one shall first
calculate volumes of longitudinal and transversal shortenings of
welding joints using method of analytic dependences and further,
with obtained shortenings, calculate forces, which action is
equivalent to the action of active welding stresses. Further, a finiteelements
model of the structure is developed and equivalent forces
are added to this model. Having results of calculations, an optimal
sequence of assembly and welding is selected and special measures to
reduce and compensate welding deformations are developed and
taken.
Abstract: This paper proposes a cooperative Alamouti space time
transmission scheme with low relay complexity for the cooperative
communication systems. In the proposed scheme, the source node
combines the data symbols to construct the Alamouti-coded form at
the destination node, while the conventional scheme performs the
corresponding operations at the relay nodes. In simulation results,
it is shown that the proposed scheme achieves the second order
cooperative diversity while maintaining the same bit error rate (BER)
performance as that of the conventional scheme.
Abstract: Disasters are quite experienced in our days. They are
caused by floods, landslides, and building fires that is the main
objective of this study. To cope with these unexpected events,
precautions must be taken to protect human lives. The emphasis on
disposal work focuses on the resolution of the evacuation problem in
case of no-notice disaster. The problem of evacuation is listed as a
dynamic network flow problem. Particularly, we model the
evacuation problem as an earliest arrival flow problem with load
dependent transit time. This problem is classified as NP-Hard. Our
challenge here is to propose a metaheuristic solution for solving the
evacuation problem. We define our objective as the maximization of
evacuees during earliest periods of a time horizon T. The objective
provides the evacuation of persons as soon as possible. We
performed an experimental study on emergency evacuation from the
tunisian children’s hospital. This work prompts us to look for
evacuation plans corresponding to several situations where the
network dynamically changes.
Abstract: ‘Steganalysis’ is one of the challenging and attractive interests for the researchers with the development of information hiding techniques. It is the procedure to detect the hidden information from the stego created by known steganographic algorithm. In this paper, a novel feature based image steganalysis technique is proposed. Various statistical moments have been used along with some similarity metric. The proposed steganalysis technique has been designed based on transformation in four wavelet domains, which include Haar, Daubechies, Symlets and Biorthogonal. Each domain is being subjected to various classifiers, namely K-nearest-neighbor, K* Classifier, Locally weighted learning, Naive Bayes classifier, Neural networks, Decision trees and Support vector machines. The experiments are performed on a large set of pictures which are available freely in image database. The system also predicts the different message length definitions.
Abstract: Second line antiretroviral therapy (ART) regimen is
used when patients fail their first line regimen. There are many
factors such as non-adherence, drug resistance as well as virological
and immunological failure that lead to second line highly active
antiretroviral therapy (HAART) regimen treatment failure. This study
was aimed at determining predictor factors to treatment failure with
second line HAART and analyzing median survival time.
An observational, retrospective study was conducted in Sungai
Buloh Hospital (HSB) to assess current status of HIV patients treated
with second line HAART regimen. Convenience sampling was used
and 104 patients were included based on the study’s inclusion and
exclusion criteria. Data was collected for six months i.e. from July
until December 2013. Data was then analysed using SPSS version 18.
Kaplan-Meier and Cox regression analyses were used to measure
median survival times and predictor factors for treatment failure.
The study population consisted mainly of male subjects, aged 30-
45 years, who were heterosexual, and had HIV infection for less than
6 years. The most common second line HAART regimen given was
lopinavir/ritonavir (LPV/r)-based combination. Kaplan-Meier
analysis showed that patients on LPV/r demonstrated longer median
survival times than patients on indinavir/ritonavir (IDV/r) based
combination (p
Abstract: Recently GPS data is used in a lot of studies to
automatically reconstruct travel patterns for trip survey. The aim is to
minimize the use of questionnaire surveys and travel diaries so as to
reduce their negative effects. In this paper data acquired from GPS and
accelerometer embedded in smart phones is utilized to predict the
mode of transportation used by the phone carrier. For prediction,
Support Vector Machine (SVM) and Adaptive boosting (AdaBoost)
are employed. Moreover a unique method to improve the prediction
results from these algorithms is also proposed. Results suggest that the
prediction accuracy of AdaBoost after improvement is relatively better
than the rest.
Abstract: This paper presents circular polar coordinates
transformation of periodic fuzzy membership function. The purpose
is identification of domain of periodic membership functions in
consequent part of IF-THEN rules. Proposed methods in this paper
remove complicatedness concerning domain of periodic membership
function from defuzzification in fuzzy approximate reasoning.
Defuzzification on circular polar coordinates is also proposed.
Abstract: The biomass-based fuels have become great concern in order to replace the petroleum-based fuels. Biofuels are a wide range of fuels referred to liquid, gas and solid fuels produced from biomass. Recently, higher chain alcohols such as 3-methyl-1-butanol and isobutanol have become a better candidate compared to bioethanol in order to replace gasoline as transportation fuel. Therefore, in this study, 3-methyl-1-butanol was produced through a fermentation process by yeast. Several types of yeast involved in this research including Saccharomyces cerevisiae, Kluyveromyces lactis GG799 and Pichia pastoris (KM71H, GS115 and X33). The result obtained showed that K. lactis GG799 gave the highest concentration of 3-methyl-1-butanol at 274 mg/l followed by S. cerevisiae, P. pastoris GS115, P. pastoris KM71H and P. pastoris X33 at 265 mg/l, 190 mg/l, 182 mg/l and 174 mg/l respectively. Based on the result, it proved that yeast have a potential in producing 3-methyl-1-butanol naturally.
Abstract: In the present work, detailed analysis on flow characteristics of a pair of immiscible liquids through horizontal pipeline is simulated by using ANSYS FLUENT 6.2. Moderately viscous oil and water (viscosity ratio = 107, density ratio = 0.89 and interfacial tension = 0.024 N/m) have been taken as system fluids for the study. Volume of Fluid (VOF) method has been employed by assuming unsteady flow, immiscible liquid pair, constant liquid properties, and co-axial flow. Meshing has been done using GAMBIT. Quadrilateral mesh type has been chosen to account for the surface tension effect more accurately. From the grid independent study, we have selected 47037 number of mesh elements for the entire geometry. Simulation successfully predicts slug, stratified wavy, stratified mixed and annular flow, except dispersion of oil in water, and dispersion of water in oil. Simulation results are validated with horizontal literature data and good conformity is observed. Subsequently, we have simulated the hydrodynamics (viz., velocity profile, area average pressure across a cross section and volume fraction profile along the radius) of stratified wavy and annular flow at different phase velocities. The simulation results show that in the annular flow, total pressure of the mixture decreases with increase in oil velocity due to the fact that pipe cross section is completely wetted with water. Simulated oil volume fraction shows maximum at the centre in core annular flow, whereas, in stratified flow, maximum value appears at upper side of the pipeline. These results are in accord with the actual flow configuration. Our findings could be useful in designing pipeline for transportation of crude oil.
Abstract: Image segmentation process based on mathematical morphology has been studied in the paper. It has been established from the first principles of the morphological process, the entire segmentation is although a nonlinear signal processing task, the constituent wise, the intermediate steps are linear, bilinear and conformal transformation and they give rise to a non linear affect in a cumulative manner.
Abstract: The purpose of this work is to optimize a Switched Reluctance Motor (SRM) for an automotive application, specifically for a fully electric car. A new optimization approach is proposed. This unique approach transforms automotive customer requirements into an optimization problem, based on sound knowledge of a SRM theory. The approach combines an analytical and a finite element analysis of the motor to quantify static nonlinear and dynamic performance parameters, as phase currents and motor torque maps, an output power and power losses in order to find the optimal motor as close to the reality as possible, within reasonable time. The new approach yields the optimal motor which is competitive with other types of already proposed motors for automotive applications. This distinctive approach can also be used to optimize other types of electrical motors, when parts specifically related to the SRM are adjusted accordingly.
Abstract: A theoretical study has been presented to describe the boundary layer flow and heat transfer on an exponentially shrinking sheet with a variable wall temperature and suction, in the presence of magnetic field. The governing nonlinear partial differential equations are converted into ordinary differential equations by similarity transformation, which are then solved numerically using the shooting method. Results for the skin friction coefficient, local Nusselt number, velocity profiles as well as temperature profiles are presented through graphs and tables for several sets of values of the parameters. The effects of the governing parameters on the flow and heat transfer characteristics are thoroughly examined.
Abstract: In this paper the vibration of a synchronous belt drive
during start-up is analyzed and discussed. Besides considering the
belt elasticity, the model here proposed also takes into consideration
the electromagnetic response of the DC motor. The solution of the
motion equations is obtained by means of the modal analysis in
state space, which allows to obtain the decoupling of all equations,
without introducing the hypothesis of proportional damping. The
mathematical model of the transmission and the solution algorithms
have been implemented within a computing software that allows the
user to simulate the dynamics of the system and to evaluate the effects
due to the elasticity of the belt branches and to the electromagnetic
behavior of the DC motor. In order to show the details of the
calculation procedure, the paper presents a case study developed with
the aid of the above-mentioned software.