Abstract: In this study, stress distributions on dental implants
made of functionally graded biomaterials (FGBM) are investigated
numerically. The implant body is considered to be subjected to axial
compression loads. Numerical problem is assumed to be 2D, and
ANSYS commercial software is used for the analysis. The cross
section of the implant thread varies as varying the height (H) and the
width (t) of the thread. According to thread dimensions of implant
and material properties of FGBM, equivalent stress distribution on
the implant is determined and presented with contour plots along
with the maximum equivalent stress values. As a result, with
increasing material gradient parameter (n), the equivalent stress
decreases, but the minimum stress distribution increases. Maximum
stress values decrease with decreasing implant radius (r). Maximum
von Mises stresses increases with decreasing H when t is constant.
On the other hand, the stress values are not affected by variation of t
in the case of H = constant.
Abstract: Combustion of sprays is of technological importance, but its flame behavior is not fully understood. Furthermore, the multiplicity of dependent variables such as pressure, temperature, equivalence ratio, and droplet sizes complicates the study of spray combustion. Fundamental study on the influence of the presence of liquid droplets has revealed that laminar flames within aerosol mixtures more readily become unstable than for gaseous ones and this increases the practical burning rate. However, fundamental studies on turbulent flames of aerosol mixtures are limited particularly those under near mono-dispersed droplet conditions. In the present work, centrally ignited expanding flames at near atmospheric pressures are employed to quantify the burning rates in gaseous and aerosol flames. Iso-octane-air aerosols are generated by expansion of the gaseous pre-mixture to produce a homogeneously distributed suspension of fuel droplets. The effects of the presence of droplets and turbulence velocity in relation to the burning rates of the flame are also investigated.
Abstract: This article proposes a voltage-mode
multifunction filter using differential voltage current
controllable current conveyor transconductance amplifier
(DV-CCCCTA). The features of the circuit are that: the
quality factor and pole frequency can be tuned independently
via the values of capacitors: the circuit description is very
simple, consisting of merely 1 DV-CCCCTA, and 2
capacitors. Without any component matching conditions, the
proposed circuit is very appropriate to further develop into
an integrated circuit. Additionally, each function response
can be selected by suitably selecting input signals with
digital method. The PSpice simulation results are depicted.
The given results agree well with the theoretical anticipation.
Abstract: In this article, we aim to discuss the formulation of two explicit group iterative finite difference methods for time-dependent two dimensional Burger-s problem on a variable mesh. For the non-linear problems, the discretization leads to a non-linear system whose Jacobian is a tridiagonal matrix. We discuss the Newton-s explicit group iterative methods for a general Burger-s equation. The proposed explicit group methods are derived from the standard point and rotated point Crank-Nicolson finite difference schemes. Their computational complexity analysis is discussed. Numerical results are given to justify the feasibility of these two proposed iterative methods.
Abstract: Xanthan gum is one of the major commercial
biopolymers. Due to its excellent rheological properties xanthan gum
is used in many applications, mainly in food industry. Commercial
production of xanthan gum uses glucose as the carbon substrate;
consequently the price of xanthan production is high. One of the
ways to decrease xanthan price, is using cheaper substrate like
agricultural wastes. Iran is one of the biggest date producer countries.
However approximately 50% of date production is wasted annually.
The goal of this study is to produce xanthan gum from waste date
using Xanthomonas campestris PTCC1473 by submerged
fermentation. In this study the effect of three variables including
phosphor and nitrogen amount and agitation rate in three levels using
response surface methodology (RSM) has been studied. Results
achieved from statistical analysis Design Expert 7.0.0 software
showed that xanthan increased with increasing level of phosphor.
Low level of nitrogen leaded to higher xanthan production. Xanthan
amount, increasing agitation had positive influence. The statistical
model identified the optimum conditions nitrogen amount=3.15g/l,
phosphor amount=5.03 g/l and agitation=394.8 rpm for xanthan. To
model validation, experiments in optimum conditions for xanthan
gum were carried out. The mean of result for xanthan was 6.72±0.26.
The result was closed to the predicted value by using RSM.
Abstract: Leptospirosis is recognized as an important zoonosis
in tropical regions well as an important animal disease with
substantial loss in production. In this study, the model for the
transmission of the Leptospirosis disease to human population are
discussed. Model is described the vector population dynamics and
the Leptospirosis transmission to the human population are
discussed. Local analysis of equilibria are given. We confirm the
results by using numerical results.
Abstract: Identity verification of authentic persons by their multiview faces is a real valued problem in machine vision. Multiview faces are having difficulties due to non-linear representation in the feature space. This paper illustrates the usability of the generalization of LDA in the form of canonical covariate for face recognition to multiview faces. In the proposed work, the Gabor filter bank is used to extract facial features that characterized by spatial frequency, spatial locality and orientation. Gabor face representation captures substantial amount of variations of the face instances that often occurs due to illumination, pose and facial expression changes. Convolution of Gabor filter bank to face images of rotated profile views produce Gabor faces with high dimensional features vectors. Canonical covariate is then used to Gabor faces to reduce the high dimensional feature spaces into low dimensional subspaces. Finally, support vector machines are trained with canonical sub-spaces that contain reduced set of features and perform recognition task. The proposed system is evaluated with UMIST face database. The experiment results demonstrate the efficiency and robustness of the proposed system with high recognition rates.
Abstract: In this research, heat transfer of a poly Ethylene
fluidized bed reactor without reaction were studied experimentally
and computationally at different superficial gas velocities. A multifluid
Eulerian computational model incorporating the kinetic theory
for solid particles was developed and used to simulate the heat
conducting gas–solid flows in a fluidized bed configuration.
Momentum exchange coefficients were evaluated using the Syamlal–
O-Brien drag functions. Temperature distributions of different phases
in the reactor were also computed. Good agreement was found
between the model predictions and the experimentally obtained data
for the bed expansion ratio as well as the qualitative gas–solid flow
patterns. The simulation and experimental results showed that the gas
temperature decreases as it moves upward in the reactor, while the
solid particle temperature increases. Pressure drop and temperature
distribution predicted by the simulations were in good agreement
with the experimental measurements at superficial gas velocities
higher than the minimum fluidization velocity. Also, the predicted
time-average local voidage profiles were in reasonable agreement
with the experimental results. The study showed that the
computational model was capable of predicting the heat transfer and
the hydrodynamic behavior of gas-solid fluidized bed flows with
reasonable accuracy.
Abstract: The objectif of the present work is to determinate the
potential of the solar parabolic trough collector (PTC) for use in the
design of a solar thermal power plant in Algeria. The study is based
on a mathematical modeling of the PTC. Heat balance has been
established respectively on the heat transfer fluid (HTF), the absorber
tube and the glass envelop using the principle of energy conservation
at each surface of the HCE cross-sectionn. The modified Euler
method is used to solve the obtained differential equations. At first
the results for typical days of two seasons the thermal behavior of the
HTF, the absorber and the envelope are obtained. Then to determine
the thermal performances of the heat transfer fluid, different oils are
considered and their temperature and heat gain evolutions compared.
Abstract: In this paper, the solubility of CO2 in AMP solution
have been measured at temperature range of ( 293, 303 ,313,323)
K.The amine concentration ranges studied are (2.0, 2.8, and 3.4) M.
A solubility apparatus was used to measure the solubility of CO2 in
AMP solution on samples of flue gases from Thermal and Central
Power Plants of Esfahan Steel Company. The modified Kent
Eisenberg model was used to correlate and predict the vapor-liquid
equilibria of the (CO2 + AMP + H2O) system. The model predicted
results are in good agreement with the experimental vapor-liquid
equilibrium measurements.
Abstract: An experimental and simulation flight test has been carried out to evaluate the longitudinal gliding characteristics of a lifting body with blunted half-cone geometry. The novelty here is the lifting body's pitch control mechanism, which consists of a pair of leading-edge rotating cylinders. Flight simulation uses aerodynamic data from computational fluid dynamics supported by wind-tunnel test. Flight test consists of releasing an aluminum lifting body model from a moving vehicle at the appropriate wind speed while measuring the lifting body's variation of altitude against time of flight. Results show that leading-edge rotating cylinder is able to give small amounts of improvement to the longitudinal stability and pitch control to the lifting body.
Abstract: The purpose of this article is to briefly review the opportunities that social media present to counselors and psychologists. Particular attention was given to understanding some of the more important common risks inherent in social media and the potential ethical dilemmas which may arise for counselors and psychologists who embrace them in their practice. Key considerations of issues pertinent to an online presence such as multiple relationships, visibility and privacy, maintaining ethical principles and professional boundaries are being discussed.
Abstract: The aim of this paper is to propose a mathematical
model to determine invariant sets, set covering, orbits and, in
particular, attractors in the set of tourism variables. Analysis was
carried out based on a pre-designed algorithm and applying our
interpretation of chaos theory developed in the context of General
Systems Theory. This article sets out the causal relationships
associated with tourist flows in order to enable the formulation of
appropriate strategies. Our results can be applied to numerous cases.
For example, in the analysis of tourist flows, these findings can be
used to determine whether the behaviour of certain groups affects that
of other groups and to analyse tourist behaviour in terms of the most
relevant variables. Unlike statistical analyses that merely provide
information on current data, our method uses orbit analysis to
forecast, if attractors are found, the behaviour of tourist variables in
the immediate future.
Abstract: Fuel cell's system requires regulating circuit for
voltage and current in order to control power in case of connecting to
other generative devices or load. In this paper Fuel cell system and
convertor, which is a multi-variable system, are controlled using
sliding mode method. Use of weighting matrix in design procedure
made it possible to regulate speed of control. Simulation results show
the robustness and accuracy of proposed controller for controlling
desired of outputs.
Abstract: With the globalized production and logistics
environment, the need for reducing the product development interval
and lead time, having a faster response to orders, conforming to quality
standards, fair tracking, and boosting information exchanging
activities with customers and partners, and coping with changes in the
management environment, manufacturers are in dire need of an
information management system in their manufacturing environments.
There are lots of information systems that have been designed to
manage the condition or operation of equipment in the field but
existing systems have a decentralized architecture, which is not
unified. Also, these systems cannot effectively handle the status data
extraction process upon encountering a problem related to protocols or
changes in the equipment or the setting. In this regard, this paper will
introduce a system for processing and saving the status info of
production equipment, which uses standard representation formats, to
enable flexible responses to and support for variables in the field
equipment. This system can be used for a variety of manufacturing and
equipment settings and is capable of interacting with higher-tier
systems such as MES.
Abstract: In recent years, sustainable supply chain management
(SSCM) has been widely researched in academic domain. However,
due to the traditional operational role and the complexity of supply
chain management in the cement industry, a relatively small amount
of research has been conducted on cement supply chain simulation
integrated with sustainability criteria. This paper analyses the cement
supply chain operations using the Push-Pull supply chain
frameworks, the Life Cycle Assessment (LCA) methodology; and
proposal integration approach, proposes three supply chain scenarios
based on Make-To-Stock (MTS), Pack-To-Order (PTO) and Grind-
To-Order (GTO) strategies. A Discrete-Event Simulation (DES)
model of SSCM is constructed using Arena software to implement
the three-target scenarios. We conclude with the simulation results
that (GTO) is the optimal supply chain strategy that demonstrates the
best economic, ecological and social performance in the cement
industry.
Abstract: This paper presents a web based remote access
microcontroller laboratory. Because of accelerated development in
electronics and computer technologies, microcontroller-based devices
and appliances are found in all aspects of our daily life. Before the
implementation of remote access microcontroller laboratory an
experiment set is developed by teaching staff for training
microcontrollers. Requirement of technical teaching and industrial
applications are considered when experiment set is designed.
Students can make the experiments by connecting to the experiment
set which is connected to the computer that set as the web server. The
students can program the microcontroller, can control digital and
analog inputs and can observe experiment. Laboratory experiment
web page can be accessed via www.elab.aku.edu.tr address.
Abstract: The quantitative determination of several trace
elements (Cr, As, Se, Cd, Hg, Pb) existing as inorganic impurities in
some oriental herb-products such as Lingzhi Mushroom capsules,
Philamin powder, etc using ICP-MS has been studied. Various
instrumental parameters such as power, gas flow rate, sample depth, as
well as the concentration of nitric acid and thick background due to
high concentration of possible interferences on the determination of
these above-mentioned elements was investigated and the optimum
working conditions of the sample measurement on ICP-MS
(Agilent-7500a) were reported. Appropriate isotope internal standards
were also used to improve the accuracy of mercury determination.
Optimal parameters for sampling digestion were also investigated. The
recovery of analytical procedure was examined by using a Certified
Reference Material (IAEA-CRM 359). The recommended procedure
was then applied for the quantitative determination of Cr, As, Se, Cd,
Hg, Pb in Lingzhi Mushroom capsule, and Philamine powder samples.
The reproducibility of sample measurement (average value between
94 and 102%) and the uncertainty of analytical data (less than 20%)
are acceptable.
Abstract: This study was aimed to explain the influence of surface roughness of the drawbead on non-symmetry deep drawing cold rolled steel sheet to improve the drawability of cold rolled steel sheet. The variables used in this study included semi-circle drawbead with 3 levels of surface roughness which are 6.127 mm Ra, 0.963 mm Ra and 0.152 mm Ra and cold rolled steel sheet according to 3 grades of the JIS standards which are SPCC, SPCE and SPCD with the thickness of 1.0 mm and the blankholder force which is 50% of the drawing force and the depth of 50 mm. According to the test results, when there was the increase in the surface roughness of drawbead, there would be the increase in deep drawing force, especially the SPCC cold rolled steel sheet. This is similar to the increase in the equivalent strain and the wall thickness distribution when the surface roughness of the drawbead increased. It could be concluded that the surface roughness of drawbead has an influence on deep drawing cold rolled steel sheet, especially the drawing force, the equivalent strain and the wall thickness distribution.
Abstract: In this paper a unified approach via block-pulse functions (BPFs) or shifted Legendre polynomials (SLPs) is presented to solve the linear-quadratic-Gaussian (LQG) control problem. Also a recursive algorithm is proposed to solve the above problem via BPFs. By using the elegant operational properties of orthogonal functions (BPFs or SLPs) these computationally attractive algorithms are developed. To demonstrate the validity of the proposed approaches a numerical example is included.