Abstract: This paper presents a new ultra-wideband (UWB) bandpass filter (BPF) with sharp roll-off and dual-notched bands. The filter consists of a triangle ring multi-mode resonator (MMR) with the stub-loaded resonator (SLR) for controlling the two transmission zeros at 2.8 / 11 GHz, the embedded open-circuited stub and the asymmetric tight coupled input/output (I/O) lines for introducing the dual notched bands at 5.2 / 6.8 GHz. The attenuation slope in the lower and higher passband edges of the proposed filter show 160- and 153-dB/GHz, respectively. This study mainly provides a simple method to design a UWB bandpass filter with high passband selectivity and dual-notched bands for satisfying the Federal Communications Commission (FCC-defined) indoor UWB specification
Abstract: We present a Large-Eddy simulation of a vortex cell
with circular shaped. The results show that the flow field can be sub
divided into four important zones, the shear layer above the cavity,
the stagnation zone, the vortex core in the cavity and the boundary
layer along the wall of the cavity. It is shown that the vortex core
consits of solid body rotation without much turbulence activity. The
vortex is mainly driven by high energy packets that are driven into the
cavity from the stagnation point region and by entrainment of fluid
from the cavity into the shear layer. The physics in the boundary
layer along the cavity-s wall seems to be far from that of a canonical
boundary layer which might be a crucial point for modelling this
flow.
Abstract: This work is focused on the numerical prediction of the fracture resistance of a flat stiffened panel made of the aluminium alloy 2024 T3 under a monotonic traction condition. The performed numerical simulations have been based on the micromechanical Gurson-Tvergaard (GT) model for ductile damage. The applicability of the GT model to this kind of structural problems has been studied and assessed by comparing numerical results, obtained by using the WARP 3D finite element code, with experimental data available in literature. In the sequel a home-made procedure is presented, which aims to increase the residual strength of a cracked stiffened aluminum panel and which is based on the stochastic design improvement (SDI) technique; a whole application example is then given to illustrate the said technique.
Abstract: There was a high rate of corrosion in Pyrolysis
Gasoline Hydrogenation (PGH) unit of Arak Petrochemical Company
(ARPC), and it caused some operational problem in this plant. A
commercial chemical had been used as anti-corrosion in the
depentanizer column overhead in order to control the corrosion rate.
Injection of commercial corrosion inhibitor caused some
operational problems such as fouling in some heat exchangers. It was
proposed to replace this commercial material with another more
effective trouble free, and well-known additive by R&D and
operation specialists.
At first, the system was simulated by commercial simulation
software in electrolytic system to specify low pH points inside the
plant. After a very comprehensive study of the situation and technical
investigations ,ammonia / monoethanol amine solution was proposed
as neutralizer or corrosion inhibitor to be injected in a suitable point
of the plant. For this purpose, the depentanizer column and its
accessories system was simulated again in case of this solution
injection.
According to the simulation results, injection of new anticorrosion
substance has no any side effect on C5 cut product and
operating conditions of the column. The corrosion rate will be
cotrolled, if the pH remains at the range of 6.5 to 8 . Aactual plant
test run was also carried out by injection of ammonia / monoethanol
amine solution at the rate of 0.6 Kg/hr and the results of iron content
of water samples and corrosion test coupons confirmed the
simulation results.
Now, ammonia / monoethanol amine solution is injected to a
suitable pint inside the plant and corrosion rate has decreased
significantly.
Abstract: Moulded parts contribute to more than 70% of
components in products. However, common defects particularly in
plastic injection moulding exist such as: warpage, shrinkage, sink
marks, and weld lines. In this paper Taguchi experimental design
methods are applied to reduce the warpage defect of thin plate
Acrylonitrile Butadiene Styrene (ABS) and are demonstrated in two
levels; namely, orthogonal arrays of Taguchi and the Analysis of
Variance (ANOVA). Eight trials have been run in which the optimal
parameters that can minimize the warpage defect in factorial
experiment are obtained. The results obtained from ANOVA
approach analysis with respect to those derived from MINITAB
illustrate the most significant factors which may cause warpage in
injection moulding process. Moreover, ANOVA approach in
comparison with other approaches like S/N ratio is more accurate and
with the interaction of factors it is possible to achieve higher and the
better outcomes.
Abstract: The customary practice of identifying industrial sickness is a set traditional techniques which rely upon a range of manual monitoring and compilation of financial records. It makes the process tedious, time consuming and often are susceptible to manipulation. Therefore, certain readily available tools are required which can deal with such uncertain situations arising out of industrial sickness. It is more significant for a country like India where the fruits of development are rarely equally distributed. In this paper, we propose an approach based on Artificial Neural Network (ANN) to deal with industrial sickness with specific focus on a few such units taken from a less developed north-east (NE) Indian state like Assam. The proposed system provides decision regarding industrial sickness using eight different parameters which are directly related to the stages of sickness of such units. The mechanism primarily uses certain signals and symptoms of industrial health to decide upon the state of a unit. Specifically, we formulate an ANN based block with data obtained from a few selected units of Assam so that required decisions related to industrial health could be taken. The system thus formulated could become an important part of planning and development. It can also contribute towards computerization of decision support systems related to industrial health and help in better management.
Abstract: The present study aims at determining the effect of ageing on the impact toughness and microstructure of 2024 Al-Cu - Mg alloy. Following the 2 h solutionizing treatment at 450°C and water quench, the specimens were aged at 200°C for various periods (1 to 18 h). The precipitation stages during ageing were monitored by hardness measurements. For each specimen group, Charpy impact and hardness tests were carried out. During ageing the impact toughness of the alloy first increased, and then, following a maxima decreased due to the precipitation of intermediate phases, finally it reached its minimum at the peak hardness. Correlations between hardness and impact toughness were investigated.
Abstract: The objective of this study was to develop safety practices which is suitable for Thai industrial operators from Incident and Injury Free, IIF to create safety behavior and reduce the un-safe records in the petroleum industry. A number of 310 technicians i.e., 295 males and 15 females, in service maintenance section participated in this program. The safety attitude level and safety behavior level for pre-attended and post-attended the developed safety practices of the technicians were evaluated using questionnaire procedure and on-site observation. After applied the developed practice program, both of the safety attitudes and safety behavior were increased to be at very good level and good level, respectively. Evaluating the follow-up unsafe records, it was found that the injury was reduced from 0.11 to 0 case/month, the medical treatment case was reduced from 0.22 to 0 case/month and the first aid case was reduced from 1 to 0.33 case/month. The developed safety working practice was successfully implemented to Thai industrial operators.
Abstract: Oxyleotris marmorata is considered as
undomesticated fish, and its culture occasionally faces a problem of
food deprivation. The present study aims to evaluate alteration of
hematological indices, blood chemical associated with liver function
during 4 weeks of fasting. A non-linear relationships between fasting
days and hematological parameters (red blood cell number; y = -
0.002x2 + 0.041x + 1.249; R2=0.915, P0.05), mean corpuscular
volume; y = -0.180x2 + 2.183x + 149.61; R2=0.732, P>0.05, mean
corpuscular hemoglobin; y = -0.041x2 + 0.862x + 29.864; R2=0.818,
P>0.05 and mean corpuscular hemoglobin concentration; y = -
0.044x2 + 0.711x + 21.580; R2=0.730, P>0.05) were demonstrated.
Significant change in hematocrit (Ht) during fasting period was
observed. Ht elevated sharply increase at the first weeks of fasting
period. Higher Ht also was detected during week 2-4 of fasting time.
The significant reduction of hepatosomatic index was observed (y = -
0.007x2 - 0.096x + 1.414; R2=0.968, P0.05, serum glutamic oxaloacetic transaminase;
y = 0.005x2 – 0.201x2 + 1.297x + 33.256; R2=1, P0.05). Taken together, prolonged fasting has
deleterious effects on hematological indices, liver mass and enzyme
associated in liver function. The marked adverse effects occurred
after the first week of fasting state.
Abstract: Malate dehydrogenase-glutamate oxaloacetate
aminotransferase (MDh-GOAT) enzyme complex (the EC) was
isolated and purified from wheat and rise, their some main physicchemical
properties were studied. Michael-s constants of the EC
MDh-GOAT to malate, glutamate and NAD were investigated. This
kinetic results show a high relationship to glutamate. Taking into
account important role of the the EC in catabolism of glutamate – the
central amino acid of a nitric exchange, there is a sharp necessity of
deeper studying of this enzyme complex. Therefore the basic purpose
of the work is studying the basic physical and chemical properties of
this enzyme complex discovered by us, which would be very
important for understanding the mechanisms of reaction catalyzed by
the EC.
Abstract: The bypass exhaust system of a 160 MW combined cycle has been modeled and analyzed using numerical simulation in 2D prospective. Analysis was carried out using the commercial numerical simulation software, FLUENT 6.2. All inputs were based on the technical data gathered from working conditions of a Siemens V94.2 gas turbine, installed in the Yazd power plant. This paper deals with reduction of pressure drop in bypass exhaust system using turning vanes mounted in diverter box in order to alleviate turbulent energy dissipation rate above diverter box. The geometry of such turning vanes has been optimized based on the flow pattern at diverter box inlet. The results show that the use of optimized turning vanes in diverter box can improve the flow pattern and eliminate vortices around sharp edges just before the silencer. Furthermore, this optimization could decrease the pressure drop in bypass exhaust system and leads to higher plant efficiency.
Abstract: This paper describes the process used in the
automation of the Maritime UAV commands using the Kinect sensor.
The AR Drone is a Quadrocopter manufactured by Parrot [1] to be
controlled using the Apple operating systems such as iPhones and
Ipads. However, this project uses the Microsoft Kinect SDK and
Microsoft Visual Studio C# (C sharp) software, which are compatible
with Windows Operating System for the automation of the navigation
and control of the AR drone.
The navigation and control software for the Quadrocopter runs on
a windows 7 computer. The project is divided into two sections; the
Quadrocopter control system and the Kinect sensor control system.
The Kinect sensor is connected to the computer using a USB cable
from which commands can be sent to and from the Kinect sensors.
The AR drone has Wi-Fi capabilities from which it can be connected
to the computer to enable transfer of commands to and from the
Quadrocopter.
The project was implemented in C#, a programming language that
is commonly used in the automation systems. The language was
chosen because there are more libraries already established in C# for
both the AR drone and the Kinect sensor.
The study will contribute toward research in automation of
systems using the Quadrocopter and the Kinect sensor for navigation
involving a human operator in the loop. The prototype created has
numerous applications among which include the inspection of vessels
such as ship, airplanes and areas that are not accessible by human
operators.
Abstract: The waverider is proved to be a remarkably useful
configuration for hypersonic glide vehicle (HGV) in terms of the high
lift-to-drag ratio. Due to the severe aerodynamic heating and the
processing technical restriction, the sharp leading edge of waverider
should be blunted, and then the flow characteristics and the
aerodynamic performance along the trajectory will change. In this
paper, the flow characteristics of a HGV, including the rarefied gas
effect and transition phenomenon, were studied based on a reference
trajectory. A numerical simulation was carried out to study the
performance of the HGV under a typical condition.
Abstract: This study comprehensively simulate the use of k-ε
model for predicting flow and heat transfer with measured flow field
data in a stationary duct with elucidates on the detailed physics
encountered in the fully developed flow region, and the sharp 180°
bend region. Among the major flow features predicted with accuracy
are flow transition at the entrance of the duct, the distribution of
mean and turbulent quantities in the developing, fully developed, and
sharp 180° bend, the development of secondary flows in the duct
cross-section and the sharp 180° bend, and heat transfer
augmentation. Turbulence intensities in the sharp 180° bend are
found to reach high values and local heat transfer comparisons show
that the heat transfer augmentation shifts towards the wall and along
the duct. Therefore, understanding of the unsteady heat transfer in
sharp 180° bends is important. The design and simulation are related
to concept of fluid mechanics, heat transfer and thermodynamics.
Simulation study has been conducted on the response of turbulent
flow in a rectangular duct in order to evaluate the heat transfer rate
along the small scale multiple rectangular duct
Abstract: Artificial Neural Network (ANN)s are best suited for
prediction and optimization problems. Trained ANNs have found
wide spread acceptance in several antenna design systems. Four
parameters namely antenna radiation resistance, loss resistance, efficiency,
and inductance can be used to design an antenna layout though
there are several other parameters available. An ANN can be trained
to provide the best and worst case precisions of an antenna design
problem defined by these four parameters. This work describes the
use of an ANN to generate the four mentioned parameters for a loop
antenna for the specified frequency range. It also provides insights
to the prediction of best and worst-case design problems observed
in applications and thereby formulate a model for physical layout
design of a loop antenna.
Abstract: Controlled modification of appropriate sharpness for
nanotips is of paramount importance to develop novel materials and
functional devices at a nanometer resolution. Herein, we present a
reliable and unique strategy of laser irradiation enhanced
physicochemical etching to manufacture super sharp tungsten tips
with reproducible shape and dimension as well as high yields
(~80%). The corresponding morphology structure evolution of
tungsten tips and laser-tip interaction mechanisms were
systematically investigated and discussed using field emission
scanning electron microscope (SEM) and physical optics statistics
method with different fluences under 532 nm laser irradiation. This
work paves the way for exploring more accessible metallic tips
applications with tunable apex diameter and aspect ratio, and,
furthermore, facilitates the potential sharpening enhancement
technique for other materials used in a variety of nanoscale devices.
Abstract: In this paper, a vision based system has been used for
controlling an industrial 3P Cartesian robot. The vision system will
recognize the target and control the robot by obtaining images from
environment and processing them. At the first stage, images from
environment are changed to a grayscale mode then it can diverse and
identify objects and noises by using a threshold objects which are
stored in different frames and then the main object will be
recognized. This will control the robot to achieve the target. A vision
system can be an appropriate tool for measuring errors of a robot in a
situation where the experimental test is conducted for a 3P robot.
Finally, the international standard ANSI/RIA R15.05-2 is used for
evaluating the path-related characteristics of the robot. To evaluate
the performance of the proposed method experimental test is carried
out.
Abstract: World has entered in 21st century. The technology of
computer graphics and digital cameras is prevalent. High resolution
display and printer are available. Therefore high resolution images
are needed in order to produce high quality display images and high
quality prints. However, since high resolution images are not usually
provided, there is a need to magnify the original images. One
common difficulty in the previous magnification techniques is that of
preserving details, i.e. edges and at the same time smoothing the data
for not introducing the spurious artefacts. A definitive solution to this
is still an open issue. In this paper an image magnification using
adaptive interpolation by pixel level data-dependent geometrical
shapes is proposed that tries to take into account information about
the edges (sharp luminance variations) and smoothness of the image.
It calculate threshold, classify interpolation region in the form of
geometrical shapes and then assign suitable values inside
interpolation region to the undefined pixels while preserving the
sharp luminance variations and smoothness at the same time.
The results of proposed technique has been compared qualitatively
and quantitatively with five other techniques. In which the qualitative
results show that the proposed method beats completely the Nearest
Neighbouring (NN), bilinear(BL) and bicubic(BC) interpolation. The
quantitative results are competitive and consistent with NN, BL, BC
and others.
Abstract: White scar oyster (Crassostrea belcheri) is often eaten
raw and being the leading vehicle for foodborne disease, especially
Salmonella Weltevreden which exposed the prominent and most
resistant to radiation. Gamma irradiation at a low dose of 1 kGy was
enough to eliminate S. Weltevreden contaminated in oyster meat at a
level up to 5 log CFU/g while it still retain the raw characteristics and
equivalent sensory quality as the non-irradiated one. Process
development of ready-to-eat chilled oyster meat was conducted by
shucking the meat, individually packed in plastic bags, subjected to 1
kGy gamma radiation at chilled condition and then stored in 4oC
refrigerated temperature. Microbiological determination showed the
absence of S. Weltevreden (5 log CFU/g initial inoculated) along the
whole storage time of 30 days. Sensory evaluation indicated the
decreasing in sensory scores along storage time which determining
the product shelf life to be 18 days compared to 15 days of nonirradiated
one. The most advantage of developed process was to
provide the safe raw oyster to consumers and in addition sensory
quality retained and 3-day extension shelf life also exist.
Abstract: In this study a two dimensional axisymmetric, steady state and incompressible laminar flow in a rotating single disk is numerically investigated. The finite volume method is used for solving the momentum equations. The numerical model and results
are validated by comparing it to previously reported experimental data for velocities, angles and moment coefficients. It is
demonstrated that increasing the axial distance increases the value of axial velocity and vice versa for tangential and total velocities. However, the maximum value of nondimensional radial velocity
occurs near the disk wall. It is also found that with increase rotational Reynolds number, moment coefficient decreases.