Abstract: A magnetohydrodynamic mixed convective flow in a
cavity was studied in this paper. The lower surface of cavity was
heated from below whereas other walls of the cavity were thermally
isolated. The governing two-dimensional flow equations have been
solved by using finite volume code. The effects of magnetic field
were studied on flow and temperature field and heat transfer
performance at a wide range of parameters, Such as Hartmann
(0≤Ha≤100) and Reynolds (1≤Re≤100) numbers. The results showed
that as Hartman number increases the Nusselt number, representing
heat transfer from the cavity decreases.
Abstract: In this paper a comprehensive model of a fossil fueled
power plant (FFPP) is developed in order to evaluate the
performance of a newly designed turbine follower controller.
Considering the drawbacks of previous works, an overall model is
developed to minimize the error between each subsystem model
output and the experimental data obtained at the actual power plant.
The developed model is organized in two main subsystems namely;
Boiler and Turbine. Considering each FFPP subsystem
characteristics, different modeling approaches are developed. For
economizer, evaporator, superheater and reheater, first order models
are determined based on principles of mass and energy conservation.
Simulations verify the accuracy of the developed models. Due to the
nonlinear characteristics of attemperator, a new model, based on a
genetic-fuzzy systems utilizing Pittsburgh approach is developed
showing a promising performance vis-à-vis those derived with other
methods like ANFIS. The optimization constraints are handled
utilizing penalty functions. The effect of increasing the number of
rules and membership functions on the performance of the proposed
model is also studied and evaluated. The turbine model is developed
based on the equation of adiabatic expansion. Parameters of all
evaluated models are tuned by means of evolutionary algorithms.
Based on the developed model a fuzzy PI controller is developed. It
is then successfully implemented in the turbine follower control
strategy of the plant. In this control strategy instead of keeping
control parameters constant, they are adjusted on-line with regard to
the error and the error rate. It is shown that the response of the
system improves significantly. It is also shown that fuel consumption
decreases considerably.
Abstract: The separation efficiency of a hydrocyclone has
extensively been considered on the rigid particle assumption. A
collection of experimental studies have demonstrated their
discrepancies from the modeling and simulation results. These
discrepancies caused by the actual particle elasticity have generally
led to a larger amount of energy consumption in the separation
process. In this paper, the influence of particle elasticity on the
separation efficiency of a hydrocyclone system was investigated
through the Finite Element (FE) simulations using crude oil droplets
as the elastic particles. A Reitema-s design hydrocyclone with a
diameter of 8 mm was employed to investigate the separation
mechanism of the crude oil droplets from water. The cut-size
diameter eter of the crude oil was 10 - Ðçm in order to fit with the
operating range of the adopted hydrocylone model. Typical
parameters influencing the performance of hydrocyclone were varied
with the feed pressure in the range of 0.3 - 0.6 MPa and feed
concentration between 0.05 – 0.1 w%. In the simulation, the Finite
Element scheme was applied to investigate the particle-flow
interaction occurred in the crude oil system during the process. The
interaction of a single oil droplet at the size of 10 - Ðçm to the flow
field was observed. The feed concentration fell in the dilute flow
regime so the particle-particle interaction was ignored in the study.
The results exhibited the higher power requirement for the separation
of the elastic particulate system when compared with the rigid
particulate system.
Abstract: Technology transfer is a common method for
companies to acquire new technology and presents both challenges
and substantial benefits. In some cases especially in developing
countries, the mere possession of technology does not guarantee a
competitive advantage if the appropriate infrastructure is not in place.
In this paper, we identify the localization factors needed to provide a
better understanding of the conditions necessary for localization in
order to benefit from future technology developments. Our
theoretical and empirical analyses allow us to identify several factors
in the technology transfer process that affect localization and provide
leverage in enhancing capabilities and absorptive capacity.The
impact factors are categorized within different groups of government,
firms, institutes and market, and are verified through the empirical
survey of a technology transfer experience. Moreover, statistical
analysis has allowed a deeper understanding of the importance of
each factor and has enabled each group to prioritize their
organizational policies to effectively localize their technology.
Abstract: Ice cover County has a significant impact on rivers as it affects with the ice melting capacity which results in flooding, restrict navigation, modify the ecosystem and microclimate. River ices are made up of different ice types with varying ice thickness, so surveillance of river ice plays an important role. River ice types are captured using infrared imaging camera which captures the images even during the night times. In this paper the river ice infrared texture images are analysed using first-order statistical methods and secondorder statistical methods. The second order statistical methods considered are spatial gray level dependence method, gray level run length method and gray level difference method. The performance of the feature extraction methods are evaluated by using Probabilistic Neural Network classifier and it is found that the first-order statistical method and second-order statistical method yields low accuracy. So the features extracted from the first-order statistical method and second-order statistical method are combined and it is observed that the result of these combined features (First order statistical method + gray level run length method) provides higher accuracy when compared with the features from the first-order statistical method and second-order statistical method alone.
Abstract: This paper describes Nano-particle based Planar Laser
Scattering (NPLS) flow visualization of angled supersonic jets into a
supersonic cross flow based on the HYpersonic Low TEmperature
(HYLTE) nozzle which was widely used in DF chemical laser. In
order to investigate the non-reacting flowfield in the HYLTE nozzle, a
testing section with windows was designed and manufactured. The
impact of secondary fluids orifice separation on mixing was examined.
For narrow separation of orifices, the secondary fuel penetration
increased obviously compared to diluent injection, which means
smaller separation of diluent and fuel orifices would enhance the
mixing of fuel and oxidant. Secondary injections with angles of 30, 40
and 50 degrees were studied. It was found that the injectant
penetration increased as the injection angle increased, while the
interfacial surface area to entrain the freestream fluid is largest when
the injection angle is 40 degree.
Abstract: Nowadays pharmaceutical care departments located in
hospitals are amongst the important pillars of the healthcare system.
The aim of this study was to evaluate quality of hospital drugstores
affiliated with Kermanshah University of Medical Sciences.
In this cross-sectional study a validated questionnaire was used.
The questionnaire was filled in by the one of the researchers in all
seventeen hospital drugstores located in the teaching and nonteaching
hospitals affiliated with Kermanshah University of Medical
Sciences. The results shows that in observed hospitals,24% of
pharmacy environments, 25% of pharmacy store and storage
conditions, 49% of storage procedure, 25% of ordering drugs and
supplies, 73% of receiving supplies (proper procedure are fallowed
for receiving supplies), 35% of receiving supplies (prompt action
taken if deterioration of drugs received is suspected), 23.35% of
drugs delivery to patients and finally 0% of stock cards are used for
proper inventory control have full compliance with standards.
Abstract: Photo-BJMOSFET (Bipolar Junction Metal-Oxide-
Semiconductor Field Effect Transistor) fabricated on SOI film was proposed. ITO film is adopted in the device as gate electrode to reduce
light absorption. Depletion region but not inversion region is formed
in film by applying gate voltage (but low reverse voltage) to achieve
high photo-to-dark-current ratio. Comparisons of photoelectriccharacteristics
executed among VGK=0V, 0.3V, 0.6V, 0.9V and 1.0V
(reverse voltage VAK is equal to 1.0V for total area of 10×10μm2). The
results indicate that the greatest improvement in photo-to-dark-current
ratio is achieved up to 2.38 at VGK=0.6V. In addition,
photo-BJMOSFET is compatible with CMOS integration due to big
input resistance
Abstract: Single crystals of Magnesium alloys such as pure Mg,
Mg-1Zn-0.5Y, Mg-0.1Y, and Mg-0.1Ce alloys were successfully
fabricated in this study by employing the modified Bridgman method.
To determine the exact orientation of crystals, pole figure
measurement using X-ray diffraction were carried out on each single
crystal. Hardness and compression tests were conducted followed by
subsequent recrysatllization annealing. Recrystallization kinetics of
Mg alloy single crystals has been investigated. Fabricated single
crystals were cut into rectangular shaped specimen and solution
treated at 400oC for 24 hrs, and then deformed in compression mode
by 30% reduction. Annealing treatment for recrystallization has been
conducted on these cold-rolled plates at temperatures of 300oC for
various times from 1 to 20 mins. The microstructure observation and
hardness measurement conducted on the recrystallized specimens
revealed that static recrystallization of ternary alloy single crystal was
very slow, while recrystallization behavior of binary alloy single
crystals appeared to be very fast.
Abstract: In this paper the application of rule mining in order to
review the effective factors on supplier selection is reviewed in the
following three sections 1) criteria selecting and information
gathering 2) performing association rule mining 3) validation and
constituting rule base. Afterwards a few of applications of rule base
is explained. Then, a numerical example is presented and analyzed
by Clementine software. Some of extracted rules as well as the
results are presented at the end.
Abstract: Flash memory has become an important storage device
in many embedded systems because of its high performance, low
power consumption and shock resistance. Multi-level cell (MLC) is
developed as an effective solution for reducing the cost and increasing
the storage density in recent years. However, most of flash file system
cannot handle the error correction sufficiently. To correct more errors
for MLC, we implement Reed-Solomon (RS) code to YAFFS, what is
widely used for flash-based file system. RS code has longer computing
time but the correcting ability is much higher than that of Hamming
code.
Abstract: As data to be stored in storage subsystems
tremendously increases, data protection techniques have become more
important than ever, to provide data availability and reliability. In this
paper, we present the file system-based data protection (WOWSnap)
that has been implemented using WORM (Write-Once-Read-Many)
scheme. In the WOWSnap, once WORM files have been created, only
the privileged read requests to them are allowed to protect data against
any intentional/accidental intrusions. Furthermore, all WORM files
are related to their protection cycle that is a time period during which
WORM files should securely be protected. Once their protection cycle
is expired, the WORM files are automatically moved to the
general-purpose data section without any user interference. This
prevents the WORM data section from being consumed by
unnecessary files. We evaluated the performance of WOWSnap on
Linux cluster.
Abstract: This paper aims at numerically analysing the effect
of an active flow control (AFC) by a vortex generator jet (VGJ)
submerged in a boundary layer via Chimera Grids and Detached-
Eddy Simulation (DES). The performance of DES results are
judged against Reynolds-Averaged Navier-Stokes (RANS) and
compared with the experiments that showed an unsteady vortex
motion downstream of VGJ. Experimental results showed that
the mechanism of embedding logitudinal vortex structure in the
main stream flow is quite effective in increasing the near wall
momentum of separated aircraft wing. In order to simulate such
a flow configuration together with the VGJ, an efficient numerical
approach is required. This requirement is fulfilled by performing
the DES simulation over the flat plate using the DLR TAU Code.
The DES predictions identify the vortex region via smooth hybrid
length scale and predict the unsteady vortex motion observed in
the experiments. The DES results also showed that the sufficient
grid refinement in the vortex region resolves the turbulent scales
downstream of the VGJ, the spatial vortex core postion and nondimensional
momentum coefficient RVx .
Abstract: The aerodynamic stall control of a baseline 13-percent
thick NASA GA(W)-2 airfoil using a synthetic jet actuator (SJA) is
presented in this paper. Unsteady Reynolds-averaged Navier-Stokes
equations are solved on a hybrid grid using a commercial software to
simulate the effects of a synthetic jet actuator located at 13% of the
chord from the leading edge at a Reynolds number Re = 2.1x106 and
incidence angles from 16 to 22 degrees. The experimental data for the
pressure distribution at Re = 3x106 and aerodynamic coefficients at
Re = 2.1x106 (angle of attack varied from -16 to 22 degrees) without
SJA is compared with the computational fluid dynamic (CFD)
simulation as a baseline validation. A good agreement of the CFD
simulations is obtained for aerodynamic coefficients and pressure
distribution.
A working SJA has been integrated with the baseline airfoil and
initial focus is on the aerodynamic stall control at angles of attack
from 16 to 22 degrees. The results show a noticeable improvement in
the aerodynamic performance with increase in lift and decrease in
drag at these post stall regimes.
Abstract: Purpose: To develop a method for automatic segmentation of adipose and muscular tissue in thighs from magnetic resonance images. Materials and methods: Thirty obese women were scanned on a Siemens Impact Expert 1T resonance machine. 1500 images were finally used in the tests. The developed segmentation method is a recursive and multilevel process that makes use of several concepts such as shaped histograms, adaptative thresholding and connectivity. The segmentation process was implemented in Matlab and operates without the need of any user interaction. The whole set of images were segmented with the developed method. An expert radiologist segmented the same set of images following a manual procedure with the aid of the SliceOmatic software (Tomovision). These constituted our 'goal standard'. Results: The number of coincidental pixels of the automatic and manual segmentation procedures was measured. The average results were above 90 % of success in most of the images. Conclusions: The proposed approach allows effective automatic segmentation of MRIs from thighs, comparable to expert manual performance.
Abstract: Providing authentication for the messages exchanged
between group members in addition to confidentiality is an important
issue in Secure Group communication. We develop a protocol for
Secure Authentic Communication where we address authentication
for the group communication scheme proposed by Blundo et al.
which only provides confidentiality. Authentication scheme used is a
multiparty authentication scheme which allows all the users in the
system to send and receive messages simultaneously. Our scheme is
secure against colluding malicious parties numbering fewer than k.
Abstract: Bay leaves have been shown to improve insulin
function in vitro but the effects on people have not been determined.
The objective of this study was to determine if bay leaves may be
important in the prevention and/or alleviation of type 1 diabetes.
Methods: Fifty five people with type 1 diabetes were divided into
two groups, 45 given capsules containing 3 g of bay leaves per day
for 30 days and 10 given a placebo capsules. Results All the patients
consumed bay leaves shows reduced serum glucose with significant
decreases 27% after 30 d. Total cholesterol decreased, 21 %, after 30
days with larger decreases in low density lipoprotein (LDL) 24%.
High density lipoprotein (HDL) increased 20% and Triglycerides
also decreased 26%. There were no significant changes in the
placebo group. Conclusion, this study demonstrates that consumption
of bay leaves, 3 g/d for 30 days, decreases risk factors for diabetes
and cardiovascular diseases and suggests that bay leaves may be
beneficial for people with type 1 diabetes.
Abstract: The Pads have unique values of thermophysical
properties (THP) having important contribution over heat transfer
into the PCB structure.
Materials with high thermal diffusivity (TD) rapidly adjust their
temperature to that of their surroundings, because the HT is quick in
compare to their volumetric heat capacity (VHC).
In the paper is presenting the diffusivity tests (ASTM E1461 flash
method) for PCBs with different core materials. In the experiments,
the multilayer structure of PCBA was taken into consideration, an
equivalent property referring to each of experimental structure be
practically measured.
Concerning to entire structure, the THP emphasize the major
contribution of substrate in establishing of reflow soldering process
(RSP) heat transfer necessities. This conclusion offer practical
solution for heat transfer time constant calculation as function of
thickness and substrate material diffusivity with an acceptable error
estimation.
Abstract: We introduce an extended resource leveling model that abstracts real life projects that consider specific work ranges for each resource. Contrary to traditional resource leveling problems this model considers scarce resources and multiple objectives: the minimization of the project makespan and the leveling of each resource usage over time. We formulate this model as a multiobjective optimization problem and we propose a multiobjective genetic algorithm-based solver to optimize it. This solver consists in a two-stage process: a main stage where we obtain non-dominated solutions for all the objectives, and a postprocessing stage where we seek to specifically improve the resource leveling of these solutions. We propose an intelligent encoding for the solver that allows including domain specific knowledge in the solving mechanism. The chosen encoding proves to be effective to solve leveling problems with scarce resources and multiple objectives. The outcome of the proposed solvers represent optimized trade-offs (alternatives) that can be later evaluated by a decision maker, this multi-solution approach represents an advantage over the traditional single solution approach. We compare the proposed solver with state-of-art resource leveling methods and we report competitive and performing results.
Abstract: Cooling with sound is a physical phenomenon allowed by Thermo-Acoustics in which acoustic energy is transformed into a negative heat transfer, in other words: into cooling! Without needing any harmful gas, the transformation is environmentally friendly and can respond to many needs in terms of air conditioning, food refrigeration for domestic use, and cooling medical samples for example. To explore the possibilities of this cooling solution on a small scale, the TACS prototype has been designed, consisting of a low cost thermoacoustic refrigerant “pipe” able to lower the temperature by a few degrees. The obtained results are providing an interesting element for possible future of thermo-acoustic refrigeration.