Abstract: A three-dimensional and pulsatile blood flow in the left ventricle of heart model has been studied numerically. The geometry was derived from a simple approximation of the left ventricle model and the numerical simulations were obtained using a formulation of the Navier-Stokes equations. In this study, simulation was used to investigate the pattern of flow velocity in 3D model of heart with consider the left ventricle based on critical parameter of blood under steady condition. Our results demonstrate that flow velocity focused from mitral valve channel and continuous linearly to left ventricle wall but this skewness progresses into outside wall in atrium through aortic valve with random distribution that is irregular due to force subtract from ventricle wall during cardiac cycle. The findings are the prediction of the behavior of the blood flow velocity pattern in steady flow condition which can assist the medical practitioners in their decision on the patients- treatments.
Abstract: This paper presents the IP traffic analysis. The traffic
was collected from the network of Suranaree University of
Technology using the software based on the Simple Network
Management Protocol (SNMP). In particular, we analyze the
distribution of the aggregated traffic during the hours of peak load
and light load. The traffic profiles including the parameters described
the traffic distributions were derived. From the statistical analysis
applying three different methods, including the Kolmogorov Smirnov
test, Anderson Darling test, and Chi-Squared test, we found that the
IP traffic distribution is a non-normal distribution and the
distributions during the peak load and the light load are different. The
experimental study and analysis show high uncertainty of the IP
traffic.
Abstract: In geometrical camera calibration, the objective is to
determine a set of camera parameters that describe the mapping
between 3D references coordinates and 2D image coordinates. In this
paper, a technique of calibration and tracking based on both a least
squares method is presented and a correlation technique developed as
part of an augmented reality system. This approach is fast and it can
be used for a real time system
Abstract: In practice, we often come across situations where it is
necessary to make decisions based on incomplete or uncertain data.
In control systems it may be due to the unknown exact mathematical
model, or its excessive complexity (e.g. nonlinearity) when it is
necessary to simplify it, respectively, to solve it using a rule base. In
the case of databases, searching data we compare a similarity
measure with of the requirements of the selection with stored data,
where both the select query and the data itself may contain vague
terms, for example in the form of linguistic qualifiers. In this paper,
we focus on the processing of uncertain data in databases and
demonstrate it on the example multi-criteria decision making in the
selection of variants, specified by higher number of technical
parameters.
Abstract: Power system stabilizers (PSS) are now routinely used in the industry to damp out power system oscillations. In this paper, real-coded genetic algorithm (RCGA) optimization technique is applied to design robust power system stabilizer for both singlemachine infinite-bus (SMIB) and multi-machine power system. The design problem of the proposed controller is formulated as an optimization problem and RCGA is employed to search for optimal controller parameters. By minimizing the time-domain based objective function, in which the deviation in the oscillatory rotor speed of the generator is involved; stability performance of the system is improved. The non-linear simulation results are presented under wide range of operating conditions; disturbances at different locations as well as for various fault clearing sequences to show the effectiveness and robustness of the proposed controller and their ability to provide efficient damping of low frequency oscillations.
Abstract: The elution process for the removal of Co and Cu from clinoptilolite as an ion-exchanger was investigated using three parameters: bed volume, pH and contact time. The present paper study has shown quantitatively that acid concentration has a significant effect on the elution process. The favorable eluant concentration was found to be 2 M HCl and 2 M H2SO4, respectively. The multi-component equilibrium relationship in the process can be very complex, and perhaps ill-defined. In such circumstances, it is preferable to use a non-parametric technique such as Neural Network to represent such an equilibrium relationship.
Abstract: The present study describes the biosynthesis of a milkclotting
protease by solid state fermentation (SSF) of a locally
isolated mould, Rhizopus stolonifer. The production medium was
prepared using wheat bran at 50% (w/v). The production conditions
are optimized by varying 7 parameters: carbon and nitrogen sources,
medium moisture, temperature, pH, fermentation time and
inoculum-s size. The maximum enzyme synthesis was measured after
96 h of incubation time at temperature of 28°C. The optimum pH
determined was 6 and the inoculum size was 3.106spores/ml. The
optimum initial moisture content is comprised between 50 to 70%.
The formation of milk clotting protease is enhanced when galactose
and peptone are used at 10% (w/v) and 1% (w/v) concentrations
respectively. The maximum production of milk clotting protease is
120 US/ml.
Abstract: The evolution of logic circuits, which falls under the heading of evolvable hardware, is carried out by evolutionary algorithms. These algorithms are able to automatically configure reconfigurable devices. One of main difficulties in developing evolvable hardware with the ability to design functional electrical circuits is to choose the most favourable EA features such as fitness function, chromosome representations, population size, genetic operators and individual selection. Until now several researchers from the evolvable hardware community have used and tuned these parameters and various rules on how to select the value of a particular parameter have been proposed. However, to date, no one has presented a study regarding the size of the chromosome representation (circuit layout) to be used as a platform for the evolution in order to increase the evolvability, reduce the number of generations and optimize the digital logic circuits through reducing the number of logic gates. In this paper this topic has been thoroughly investigated and the optimal parameters for these EA features have been proposed. The evolution of logic circuits has been carried out by an extrinsic evolvable hardware system which uses (1+λ) evolution strategy as the core of the evolution.
Abstract: The motion planning procedure described in this paper has been developed in order to eliminate or reduce the residual vibrations of electromechanical positioning systems, without augmenting the motion time (usually imposed by production requirements), nor introducing overtime for vibration damping. The proposed technique is based on a suitable choice of the motion law assigned to the servomotor that drives the mechanism. The reference profile is defined by a Bezier curve, whose shape can be easily changed by modifying some numerical parameters. By means of an optimization technique these parameters can be modified without altering the continuity conditions imposed on the displacement and on its time derivatives at the initial and final time instants.
Abstract: Optimal supplementary damping controller design for Thyristor Controlled Series Compensator (TCSC) is presented in this paper. For the proposed controller design, a multi-objective fitness function consisting of both damping factors and real part of system electromachanical eigenvalue is used and Real- Coded Genetic Algorithm (RCGA) is employed for the optimal supplementary controller parameters. The performance of the designed supplementary TCSC-based damping controller is tested on a weakly connected power system with different disturbances and loading conditions with parameter variations. Simulation results are presented and compared with a conventional power system stabilizer and also with the TCSC-based supplementary controller when the controller parameters are not optimized to show the effectiveness and robustness of the proposed approach over a wide range of loading conditions and disturbances.
Abstract: With the long-term objective of Critical Heat Flux (CHF) prediction, a Direct Numerical Simulation (DNS) framework for simulation of subcooled and saturated nucleate pool boiling is developed. One case of saturated, and three cases of subcooled boiling at different subcooling levels are simulated. Grid refinement study is also reported. Both boiling and condensation phenomena can be computed simultaneously in the proposed numerical framework. Computed bubble detachment diameters of the saturated nucleate pool boiling cases agree well with the experiment. The flow structures around the growing bubble are presented and the accompanying physics is described. The relation between heat flux evolution from the heated wall and the bubble growth is studied, along with investigations of temperature distribution and flow field evolutions.
Abstract: The refueling of a transparent rectangular fuel tank
fitted with a standard filler pipe and roll-over valve was
experimentally studied. A fuel-conditioning cart, capable of
handling fuels of different Reid vapor pressure at a constant
temperature, was used to dispense fuel at the desired rate. The
experimental protocol included transient recording of the tank and
filler tube pressures while video recording the flow patterns in the
filler tube and tank during the refueling process. This information
was used to determine the effect of changes in the vent tube
diameter, fuel-dispense flow rate and fuel Reid vapor pressure on the
pressure-time characteristics and the occurrence of premature fuel
filling shut-off and fuel spill-back. Pressure-time curves for the case
of normal shut-off demonstrated the classic, three-phase
characteristic noted in the literature. The variation of the maximum
values of tank dome and filler tube pressures are analyzed in relation
to the occurrence of premature shut-off.
Abstract: High-velocity oxygen fuel (HVOF) thermal spraying
uses a combustion process to heat the gas flow and coating material.
A computational fluid dynamics (CFD) model has been developed to
predict gas dynamic behavior in a HVOF thermal spray gun in which
premixed oxygen and propane are burnt in a combustion chamber
linked to a parallel-sided nozzle. The CFD analysis is applied to
investigate axisymmetric, steady-state, turbulent, compressible,
chemically reacting, subsonic and supersonic flow inside and outside
the gun. The gas velocity, temperature, pressure and Mach number
distributions are presented for various locations inside and outside
the gun. The calculated results show that the most sensitive
parameters affecting the process are fuel-to-oxygen gas ratio and
total gas flow rate. Gas dynamic behavior along the centerline of the
gun depends on both total gas flow rate and fuel-to-oxygen gas ratio.
The numerical simulations show that the axial gas velocity and Mach
number distribution depend on both flow rate and ratio; the highest
velocity is achieved at the higher flow rate and most fuel-rich ratio.
In addition, the results reported in this paper illustrate that the
numerical simulation can be one of the most powerful and beneficial
tools for the HVOF system design, optimization and performance
analysis.
Abstract: Pomegranate and pomegranate juices (PJs) have taken
great attention for their health benefits in the last years. As there is an
increasing concern about potential health benefits of ellagic acid, it is
of great interest to evaluate alterations in ellagic acid concentration of
commercial PJs. The purpose of this study is to analyze total
phenolic, free and total ellagic acid content of six commercial PJs
sold in Turkish markets using HPLC.
The results showed that some commercial PJs had markedly high
total phenolic and ellagic acid content. Total phenolic substances of
commercial PJs range from 796.71 to 4608.91 mg GAE/l. Free
amount of ellagic acid in commercial PJs range from 27.64 to 111.78
mg/l. Samples are hydrolyzed with concentrated HCl at 93oC for 2
and 24 hour and influences of temperature and time parameters on
hydrolization were investigated. Thermal processing for
pasteurization increased ellagic acid via ellagitannins hydrolysis.
Abstract: The study aimed to investigate characteristics of
vegetative tissue for taxonomic purpose and possibly trend of waste
application in industry. Stems and branches of 15 species in Solanum
found in Thailand were prepared for fiber and examined by light
microscopy. Microstructural characteristic data of fiber i.e. fiber
length and width, fiber lumen diameter and fiber cell wall thickness
were recorded. The longest average fiber cell length (>3.9 mm.) were
obtained in S. lycopersicum L. and S. tuberosum L. Fiber cells from
S. lycopersicum also revealed the widest average diameter of whole
cell and its lumen at >45.5 μm and >29 μm respectively. However
fiber cells with thickest wall of > 9.6 μm were belonged to the
ornamental tree species, S. wrightii Benth. The results showed that
the slenderness ratio, Runkel ratio, and flexibility coefficient, with
potentially suitable for feedstock in paper industry fell in 4 exotic
species, i.e. Solanumamericanum L., S. lycopersicum, S.
seaforthianum Andr., and S. tuberosum L
Abstract: This paper presents the 20-GHz fractional PLL (Phase
Locked Loop) circuit for the next generation Wi-Fi by using 90 nm
TSMC process. The newly suggested millimeter wave 16/17
pre-scalar is designed and verified by measurement to make the
fractional PLL having a low quantization noise. The operational
bandwidth of the 60 GHz system is 15 % of the carrier frequency
which requires large value of Kv (VCO control gain) resulting in
degradation of phase noise. To solve this problem, this paper adopts
AFC (Automatic Frequency Controller) controlled 4-bit millimeter
wave VCO with small value of Kv. Also constant Kv is implemented
using 4-bit varactor bank. The measured operational bandwidth is 18.2
~ 23.2 GHz which is 25 % of the carrier frequency. The phase noise of
-58 and -96.2 dBc/Hz at 100 KHz and 1 MHz offset is measured
respectively. The total power consumption of the PLL is only 30 mW.
Abstract: In this paper, a uniform calculus-based approach for
synthesizing monitors checking correctness properties specified by a
large variety of logics at runtime is provided, including future and past
time logics, interval logics, state machine and parameterized temporal
logics. We present a calculus mechanism to synthesize monitors from
the logical specification for the incremental analysis of execution
traces during test and real run. The monitor detects both good and bad
prefix of a particular kind, namely those that are informative for the
property under investigation. We elaborate the procedure of calculus
as monitors.
Abstract: Some Chromium (III) complexes were synthesized
with three amino acids: L Glutamic Acid, Glycine, and L-cysteine as
the ligands, in order to provide a new supplement containing Cr(III)
for patients with type 2 diabetes mellitus. The complexes have been
prepared by refluxing a mixture of Chromium(III) chloride in
aqueous solution with L-glutamic acid, Glycine, and L-cysteine after
pH adjustment by sodium hydroxide. These complexes were
characterized by Infrared and Uv-Vis spectrophotometer and
Elemental analyzer. The product yields of four products were 87.50
and 56.76% for Cr-Glu complexes, 46.70% for Cr-Gly complex and
40.08% for Cr-Cys complex respectively. The predicted structure of
the complexes are [Cr(glu)2(H2O)2].xH2O, Cr(gly)3..xH2O and
Cr(cys)3.xH2O., respectively.
Abstract: TiO2/Ag composite films were prepared by
incorporating Ag in the pores of mesoporous TiO2 films using a
photoreduction method. The Ag nanoparticle sizes were in a range of
3.66-38.56 nm. The TiO2/Ag composite films were characterized by
X-ray diffraction (XRD), scanning electron microscopy (SEM) and
transmission electron microscropy (TEM). The TiO2 films and
TiO2/Ag composite films were immersed in a 0.3 mM N719 dye
solution and characterized by UV-Vis spectrophotometer. The
TiO2/Ag/N719 composite film showed that an optimal size of Ag
nanoparticles was 19.12 nm and, hence, gave the maximum optical
absorption spectra. The improved absorption was due to surface
plasmon resonance induced by the Ag nanoparticles to enhance the
absorption coefficient of the dye.
Abstract: This study was carried out to reveal the bacterial composition of aerosol in the studied abattoirs. Bacteria isolated were characterized according to microbiological standards. Factors such as temperature and distance were considered as variable in this study. The isolation was carried out at different temperatures such as 27oC, 31oC and 29oC and at various distances of 100meters and 200meters away from the slaughter sites. Result obtained showed that strains of Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Lactobacillus alimentarius and Micrococcus sp. were identified. The total viable counts showed that more microorganisms were present in the morning while the least viable count of 388cfu was recorded in the evening period of this study. This study also showed that more microbial loads were recorded the further the distance is to the slaughter site. Conclusively, the array of bacteria isolated suggests that abattoir sites may be a potential source of pathogenic organisms to commuters if located within residential environment.