Abstract: We report the results of an lattice Boltzmann
simulation of magnetohydrodynamic damping of sidewall convection
in a rectangular enclosure filled with a porous medium. In particular
we investigate the suppression of convection when a steady magnetic
field is applied in the vertical direction. The left and right vertical
walls of the cavity are kept at constant but different temperatures
while both the top and bottom horizontal walls are insulated. The
effects of the controlling parameters involved in the heat transfer and
hydrodynamic characteristics are studied in detail. The heat and mass
transfer mechanisms and the flow characteristics inside the enclosure
depended strongly on the strength of the magnetic field and Darcy
number. The average Nusselt number decreases with rising values of
the Hartmann number while this increases with increasing values of
the Darcy number.
Abstract: To deal with random delays in Networked Control System (NCS), Modified Fuzzy PID Controller is introduced in this paper to implement real-time control adaptively. Via adjusting the control signal dynamically, the system performance is improved. In this paper, the design process and the ultimate simulation results are represented. Finally, examples and corresponding comparisons prove the significance of this method.
Abstract: Nanotechnology is the science of creating, using and
manipulating objects which have at least one dimension in range of
0.1 to 100 nanometers. In other words, nanotechnology is
reconstructing a substance using its individual atoms and arranging
them in a way that is desirable for our purpose.
The main reason that nanotechnology has been attracting
attentions is the unique properties that objects show when they are
formed at nano-scale. These differing characteristics that nano-scale
materials show compared to their nature-existing form is both useful
in creating high quality products and dangerous when being in
contact with body or spread in environment.
In order to control and lower the risk of such nano-scale particles,
the main following three topics should be considered:
1) First of all, these materials would cause long term diseases that
may show their effects on body years after being penetrated in human
organs and since this science has become recently developed in
industrial scale not enough information is available about their
hazards on body.
2) The second is that these particles can easily spread out in
environment and remain in air, soil or water for very long time,
besides their high ability to penetrate body skin and causing new
kinds of diseases.
3) The third one is that to protect body and environment against
the danger of these particles, the protective barriers must be finer than
these small objects and such defenses are hard to accomplish.
This paper will review, discuss and assess the risks that human and
environment face as this new science develops at a high rate.
Abstract: Assessment of IEP (Individual Education Plan) is an
important stage in the area of special education. This paper deals
with this problem by introducing computer software which process
the data gathered from application of IEP. The software is intended
to be used by special education institution in Turkey and allows
assessment of school and family trainings. The software has a user
friendly interface and its design includes graphical developer tools.
Abstract: Several methods have been proposed for color image
compression but the reconstructed image had very low signal to noise
ratio which made it inefficient. This paper describes a lossy
compression technique for color images which overcomes the
drawbacks. The technique works on spatial domain where the pixel
values of RGB planes of the input color image is mapped onto two
dimensional planes. The proposed technique produced better results
than JPEG2000, 2DPCA and a comparative study is reported based
on the image quality measures such as PSNR and MSE.Experiments
on real time images are shown that compare this methodology with
previous ones and demonstrate its advantages.
Abstract: This paper presents the outcomes of a qualitative
study which aims to investigate the pedagogical potentials of serious
games in the preparation of future teachers. The authors discuss the
existing problems and barriers associated with the organization of
teaching practices in Bulgaria as part of the pre-service teacher
training, as well as the attitudes and perceptions of the interviewed
academics, teachers and trainees concerning the integration of serious
games in the teaching practicum. The study outcomes strongly
confirm the positive attitudes of the respondents to the introduction
of virtual learning environments for the development of professional
skills of future teachers as a supplement to the traditional forms of
education. Through the inclusion of serious games it is expected to
improve the quality of practical training of pre-service teachers as
they overcome many of the problems identified in the existing
teaching practices. The outcomes of the study will inform the design
of the educational simulation software which is part of the project
SimAula Tomorrow's Teachers Training.
Abstract: Heating is inevitable in any bearing operation. This
leads to not only the thinning of the lubricant but also could lead to a
thermal deformation of the bearing. The present work is an attempt to
analyze the influence of thermal deformation on the thermohydrodynamic
lubrication of infinitely long tilted pad slider rough
bearings. As a consequence of heating the slider is deformed and is
assumed to take a parabolic shape. Also the asperities expand leading
to smaller effective film thickness. Two different types of surface
roughness are considered: longitudinal roughness and transverse
roughness. Christensen-s stochastic approach is used to derive the
Reynolds-type equations. Density and viscosity are considered to be
temperature dependent. The modified Reynolds equation, momentum
equation, continuity equation and energy equation are decoupled and
solved using finite difference method to yield various bearing
characteristics. From the numerical simulations it is observed that the
performance of the bearing is significantly affected by the thermal
distortion of the slider and asperities and even the parallel sliders
seem to carry some load.
Abstract: Water is the main component of biological processes.
Water management is important to obtain higher productivity. In this
study, some of the yield components were investigated together with
different drought levels. Four chickpea genotypes (CDC Frontier,
CDC Luna, Sawyer and Sierra) were grown in pots with 3 different
irrigation levels (a dose of 17.5 ml, 35 ml and 70 ml for each pot per
day) after three weeks from sowing. In the research, flowering, pod
set, pod per plant, fertile pod, double seed/pod, stem diameter, plant
weight, seed per plant, 1000 seed weight, seed diameter, vegetation
length and weekly plant height were measured. Consequently,
significant differences were observed on all the investigated
characteristics owing to genotypes (except double seed/pod and stem
diameter), water levels (except first pod, seed weight and height on
3rd week) and genotype x water level interaction (except first pod,
double seed/pod, seed weight and height).
Abstract: Renewable water resources are crucial production
variables in arid and semi-arid regions where intensive agriculture is
practiced to meet ever-increasing demand for food and fiber. This is
crucial for the Dez and Moghan command areas where water delivery
problems and adverse environmental issues are widespread. This
paper aims to identify major problems areas using on-farm surveys of
200 farmers, agricultural extensionists and water suppliers which was
complemented by secondary data and field observations during 2010-
2011 cultivating season. The SPSS package was used to analyze and
synthesis data. Results indicated inappropriate canal operations in
both schemes, though there was no unanimity about the underlying
causes. Inequitable and inflexible distribution was found to be rooted
in deficient hydraulic structures particularly in the main and
secondary canals. The inadequacy and inflexibility of water
scheduling regime was the underlying causes of recurring pest and
disease spread which often led to the decline of crop yield and
quality, although these were not disputed, the water suppliers were
not prepared to link with the deficiencies in the operation of the main
and secondary canals. They rather attributed these to the prevailing
salinity; alkalinity, water table fluctuations and leaching of the
valuable agro-chemical inputs from the plants- route zone with farreaching
consequences. Examples of these include the pollution of
ground and surface resources due to over-irrigation at the farm level
which falls under the growers- own responsibility. Poor irrigation
efficiency and adverse environmental problems were attributed to
deficient and outdated farming practices that were in turn rooted in
poor extension programs and irrational water charges.
Abstract: A CFD study on heat flux reduction in hypersonic flow with opposing jet has been conducted. Flowfield parameters, reattachment point position, surface pressure distributions and heat flux distributions are obtained and validated with experiments. The physical mechanism of heat reduction has been analyzed. When the opposing jet blows, the freestream is blocked off, flows to the edges and not interacts with the surface to form aerodynamic heating. At the same time, the jet flows back to form cool recirculation region, which reduces the difference in temperature between the surface and the nearby gas, and then reduces the heat flux. As the pressure ratio increases, the interface between jet and freestream is gradually pushed away from the surface. Larger the total pressure ratio is, lower the heat flux is. To study the effect of the intensity of opposing jet more reasonably, a new parameter RPA has been introduced by combining the flux and the total pressure ratio. The study shows that the same shock wave position and total heat load can be obtained with the same RPA with different fluxes and the total pressures, which means the new parameter could stand for the intensity of opposing jet and could be used to analyze the influence of opposing jet on flow field and aerodynamic heating.
Abstract: ICT and supply chain management (SCM) are two
notions, which have attracted much attention among both
academicians and practitioners during the last decade. However, the
discussion of the relationship between the two notions has been
limited and fragmented. In this paper, we will present a summary of
the discussion of ICT components and SCM on an extensive
literature review. Then, we will discuss the interrelation between ICT
and SCM from some major components and applications of ICT
perspective. After all, we can introduce e-SCM concept, that arisen
recently in management literature, in order to cover the whole topic.
The authors look at all of the major components of electronic supply
chain management and demonstrate that the future holds tremendous
opportunity for those firms that take advantage of all of its
possibilities.
Abstract: Development, calibration and validation of a threedimensional
model of the Legform impactor for pedestrian crash with
bumper are presented. Lower limb injury is becoming an increasingly
important concern in vehicle safety for both occupants and
pedestrians. In order to prevent lower extremity injuries to a
pedestrian when struck by a car, it is important to elucidate the
loadings from car front structures on the lower extremities and the
injury mechanism caused by these loadings. An impact test
procedure with a legform addressing lower limb injuries in car
pedestrian accidents has been proposed by EEVC/WG17. In this
study a modified legform impactor is introduced and validated
against EEVC/WG17 criteria. The finite element model of this
legform is developed using LS-DYNA software. Total mass of
legform impactor is 13.4 kg.Technical specifications including the
mass and location of the center of gravity and moment of inertia
about a horizontal axis through the respective centre of gravity in
femur and tibia are determined. The obtained results of legform
impactor static and dynamic tests are as specified in the
EEVC/WG17.
Abstract: Since the driving speed and control accuracy of
commercial optical disk are increasing significantly, it needs an
efficient controller to monitor the track seeking and following
operations of the servo system for achieving the desired data
extracting response. The nonlinear behaviors of the actuator and servo
system of the optical disk drive will influence the laser spot
positioning. Here, the model-free fuzzy control scheme is employed to
design the track seeking servo controller for a d.c. motor driving
optical disk drive system. In addition, the sliding model control
strategy is introduced into the fuzzy control structure to construct a
1-D adaptive fuzzy rule intelligent controller for simplifying the
implementation problem and improving the control performance. The
experimental results show that the steady state error of the track
seeking by using this fuzzy controller can maintain within the track
width (1.6 μm ). It can be used in the track seeking and track
following servo control operations.
Abstract: In this study, the possibility of using potato as a
substrate for glutamic acid production by Brevibacterium linens
was investigated. For preparation of fermentation medium, potato
was hydrolyzed by hydrochloridric acid. The medium contained
potato hydrolysate, tween 80, mineral solution, glucose, and
potassium hydrogen phosphate. The initial pH of the medium was
adjusted to 7-7.5. For achieving the optimum time with maximum
yield, the beakers containing the medium and the inoculums were
incubated in a rotary water bath flask shaker for one to five days.
Thin layer choromatography was used for quantitative and
qualitative assay of the glutamic acid produced. The results
revealed that as fermentation time increased, pH of the
fermentation medium significantly decreased (P
Abstract: Knowledge of factors, which influence stress and its
distribution, is of key importance to the successful production of
durable restorations. One of this is the marginal geometry. The
objective of this study was to evaluate, by finite element analysis
(FEA), the influence of different marginal designs on the stress
distribution in teeth prepared for cast metal crowns. Five margin
designs were taken into consideration: shoulderless, chamfer,
shoulder, sloped shoulder and shoulder with bevel. For each kind of
preparation three dimensional finite element analyses were initiated.
Maximal equivalent stresses were calculated and stress patterns were
represented in order to compare the marginal designs. Within the
limitation of this study, the shoulder and beveled shoulder margin
preparations of the teeth are preferred for cast metal crowns from
biomechanical point of view.
Abstract: In spite of the advent of new materials, clay bricks
remain, arguably, the most popular construction materials today.
Nevertheless the low cost and versatility of clay bricks cannot always
be associated with high environmental and sustainable values,
especially in terms of raw material sources and manufacturing
processes. At the same time, the worldwide agricultural footprint is
fast growing, with vast agricultural land cultivation and active
expansion of the agro-based industry. The resulting large quantities of
agricultural wastes, unfortunately, are not always well managed or
utilised. These wastes can be recycled, such as by retrieving fibres
from disposed leaves and fruit bunches, and then incorporated in
brick-making. This way the clay bricks are made a 'greener' building
material and the discarded natural wastes can be reutilised, avoiding
otherwise wasteful landfill and harmful open incineration. This study
examined the physical and mechanical properties of clay bricks made
by adding two natural fibres to a clay-water mixture, with baked and
non-baked conditions. The fibres were sourced from pineapple leaves
(PF) and oil palm fruit bunch (OF), and added within the range of
0.25-0.75 %. Cement was added as a binder to the mixture at 5-15 %.
Although the two fibres had different effects on the bricks produced,
cement appeared to dominate the compressive strength. The
non-baked bricks disintegrated when submerged in water, while the
baked ones displayed cement-dependent characteristics in
water-absorption and density changes. Interestingly, further increase
in fibre content did not cause significant density decrease in both the
baked and non-baked bricks.
Abstract: The use of composite materials in offshore engineering for deep sea oil production riser systems has drawn considerable interest due to the potential weight savings and improvement in durability. The design of composite risers consists of two stages: (1) local design based on critical local load cases, and (2) global analysis of the full length composite riser under global loads and assessment of critical locations. In the first stage, eight different material combinations were selected and their laminate configurations optimised under local load considerations. Stage two includes a final local stress analysis of the critical sections of the riser under the combined loads determined in the global analysis. This paper describes two design methodologies of the composite riser to provide minimum structural weight and shows that the use of off angle fibre orientations in addition to axial and hoop reinforcements offer substantial weight savings and ensure the structural capacity.
Abstract: Design should be viewed concurrently by three ways
as transformation, flow and value generation. An innovative approach
to solve design – related problems is described as the integrated
product - process design. As a foundation for a formal framework
consisting of organizing principles and techniques, Work Structuring
has been developed to guide efforts in the integration that enhances
the development of operation and process design in alignment with
product design.
Vietnam construction projects are facing many delays, and cost
overruns caused mostly by design related problems. A better design
management that integrates product and process design could resolve
these problems. A questionnaire survey and in – depth interviews
were used to investigate the feasibility of applying Work Structuring
to construction projects in Vietnam.
The purpose of this paper is to present the research results and to
illustrate the possible problems and potential solutions when Work
Structuring is implemented to construction projects in Vietnam.
Abstract: Enzymatic hydrolysis of starch from natural sources
finds potential application in commercial production of alcoholic
beverage and bioethanol. In this study the effect of starch
concentration, temperature, time and enzyme concentration were
studied and optimized for hydrolysis of cassava (Manihot esculenta)
starch powder (of mesh 80/120) into glucose syrup by immobilized
(using Polyacrylamide gel) a-amylase using central composite
design. The experimental result on enzymatic hydrolysis of cassava
starch was subjected to multiple linear regression analysis using
MINITAB 14 software. Positive linear effect of starch concentration,
enzyme concentration and time was observed on hydrolysis of
cassava starch by a-amylase. The statistical significance of the model
was validated by F-test for analysis of variance (p < 0.01). The
optimum value of starch concentration temperature, time and enzyme
concentration were found to be 4.5% (w/v), 45oC, 150 min, and 1%
(w/v) enzyme. The maximum glucose yield at optimum condition
was 5.17 mg/mL.
Abstract: In this paper we consider the problem of change
detection and non stationary signals tracking. Using parametric
estimation of signals based on least square lattice adaptive filters we
consider for change detection statistical parametric methods using
likelihood ratio and hypothesis tests. In order to track signals
dynamics, we introduce a compensation procedure in the adaptive
estimation. This will improve the adaptive estimation performances
and fasten it-s convergence after changes detection.