Abstract: Ti6Al4V alloy is highly used in the automotive and
aerospace industry due to its good machining characteristics. Micro
EDM drilling is commonly used to drill micro hole on extremely hard
material with very high depth to diameter ratio. In this study, the
parameters of micro-electrical discharge machining (EDM) in drilling
of Ti6Al4V alloy is optimized for higher machining accuracy with
less hole-dilation and hole taper ratio. The micro-EDM machining
parameters includes, peak current and pulse on time. Fuzzy analysis
was developed to evaluate the machining accuracy. The analysis
shows that hole-dilation and hole-taper ratio are increased with the
increasing of peak current and pulse on time. However, the surface
quality deteriorates as the peak current and pulse on time increase.
The combination that gives the optimum result for hole dilation is
medium peak current and short pulse on time. Meanwhile, the
optimum result for hole taper ratio is low peak current and short pulse
on time.
Abstract: Maize constitutes a major agrarian production for use
by the vast population but despite its economic importance; it has not
been produced to meet the economic needs of the country. Achieving
optimum yield in maize can meaningfully be supported by land
suitability analysis in order to guarantee self-sufficiency for future
production optimization. This study examines land suitability for
maize production through the analysis of the physicochemical
variations in soil properties and other land attributes over space using
a Geographic Information System (GIS) framework.
Physicochemical parameters of importance selected include slope,
landuse, physical and chemical properties of the soil, and climatic
variables. Landsat imagery was used to categorize the landuse,
Shuttle Radar Topographic Mapping (SRTM) generated the slope and
soil samples were analyzed for its physical and chemical components.
Suitability was categorized into highly, moderately and marginally
suitable based on Food and Agricultural Organisation (FAO)
classification, using the Analytical Hierarchy Process (AHP)
technique of GIS. This result can be used by small scale farmers for
efficient decision making in the allocation of land for maize
production.
Abstract: Analysis of the properties of coconut (Cocos nucifera)
and its oil was evaluated in this work using standard analytical
techniques. The analyses carried out include proximate composition
of the fruit, extraction of oil from the fruit using different process
parameters and physicochemical analysis of the extracted oil. The
results showed the percentage (%) moisture, crude lipid, crude
protein, ash and carbohydrate content of the coconut as 7.59, 55.15,
5.65, 7.35 and 19.51 respectively. The oil from the coconut fruit was
odourless and yellowish liquid at room temperature (30oC). The
treatment combinations used (leaching time, leaching temperature
and solute: solvent ratio) showed significant differences (P
Abstract: The aim of this work is to build a model based on
tissue characterization that is able to discriminate pathological and
non-pathological regions from three-phasic CT images. With our
research and based on a feature selection in different phases, we are
trying to design a neural network system with an optimal neuron
number in a hidden layer. Our approach consists of three steps:
feature selection, feature reduction, and classification. For each
region of interest (ROI), 6 distinct sets of texture features are
extracted such as: first order histogram parameters, absolute gradient,
run-length matrix, co-occurrence matrix, autoregressive model, and
wavelet, for a total of 270 texture features. When analyzing more
phases, we show that the injection of liquid cause changes to the high
relevant features in each region. Our results demonstrate that for
detecting HCC tumor phase 3 is the best one in most of the features
that we apply to the classification algorithm. The percentage of
detection between pathology and healthy classes, according to our
method, relates to first order histogram parameters with accuracy of
85% in phase 1, 95% in phase 2, and 95% in phase 3.
Abstract: The wide use of the Internet-based applications bring many challenges to the researchers to guarantee the continuity of the connections needed by the mobile hosts and provide reliable Internet access for them. One of proposed solutions by Internet Engineering Task Force (IETF) is to connect the local, multi-hop, and infrastructure-less Mobile Ad hoc Network (MANET) with Internet structure. This connection is done through multi-interface devices known as Internet Gateways. Many issues are related to this connection like gateway discovery, handoff, address auto-configuration and selecting the optimum gateway when multiple gateways exist. Many studies were done proposing gateway selection schemes with a single selection criterion or weighted multiple criteria. In this research, a review of some of these schemes is done showing the differences, the features, the challenges and the drawbacks of each of them.
Abstract: The Cone Penetration Test (CPT) is a common in-situ
test which generally investigates a much greater volume of soil more
quickly than possible from sampling and laboratory tests. Therefore,
it has the potential to realize both cost savings and assessment of soil
properties rapidly and continuously. The principle objective of this
paper is to demonstrate the feasibility and efficiency of using
artificial neural networks (ANNs) to predict the soil angle of internal
friction (Φ) and the soil modulus of elasticity (E) from CPT results
considering the uncertainties and non-linearities of the soil. In
addition, ANNs are used to study the influence of different
parameters and recommend which parameters should be included as
input parameters to improve the prediction. Neural networks discover
relationships in the input data sets through the iterative presentation
of the data and intrinsic mapping characteristics of neural topologies.
General Regression Neural Network (GRNN) is one of the powerful
neural network architectures which is utilized in this study. A large
amount of field and experimental data including CPT results, plate
load tests, direct shear box, grain size distribution and calculated data
of overburden pressure was obtained from a large project in the
United Arab Emirates. This data was used for the training and the
validation of the neural network. A comparison was made between
the obtained results from the ANN's approach, and some common
traditional correlations that predict Φ and E from CPT results with
respect to the actual results of the collected data. The results show
that the ANN is a very powerful tool. Very good agreement was
obtained between estimated results from ANN and actual measured
results with comparison to other correlations available in the
literature. The study recommends some easily available parameters
that should be included in the estimation of the soil properties to
improve the prediction models. It is shown that the use of friction
ration in the estimation of Φ and the use of fines content in the
estimation of E considerable improve the prediction models.
Abstract: The detection of the polymer melt state during
manufacture process is regarded as an efficient way to control the
molded part quality in advance. Online monitoring rheological
property of polymer melt during processing procedure provides an
approach to understand the melt state immediately. Rheological
property reflects the polymer melt state at different processing
parameters and is very important in injection molding process
especially. An approach that demonstrates how to calculate
rheological property of polymer melt through in-process
measurement, using injection molding as an example, is proposed in
this study. The system consists of two sensors and a data acquisition
module can process the measured data, which are used for the
calculation of rheological properties of polymer melt. The rheological
properties of polymer melt discussed in this study include shear rate
and viscosity which are investigated with respect to injection speed
and melt temperature. The results show that the effect of injection
speed on the rheological properties is apparent, especially for high
melt temperature and should be considered for precision molding
process.
Abstract: Micro-alloyed steel components are used in
automotive industry for the necessity to make the manufacturing
process cycles shorter when compared to conventional steel by
eliminating heat treatment cycles, so an important saving of costs and
energy can be reached by reducing the number of operations. Microalloying
elements like vanadium, niobium or titanium have been
added to medium carbon steels to achieve grain refinement with or
without precipitation strengthening along with uniform
microstructure throughout the matrix. Present study reports the
applicability of medium carbon vanadium micro-alloyed steel in hot
forging. Forgeability has been determined with respect to different
cooling rates, after forging in a hydraulic press at 50% diameter
reduction in temperature range of 900-11000C. Final microstructures,
hardness, tensile strength, and impact strength have been evaluated.
The friction coefficients of different lubricating conditions, viz.,
graphite in hydraulic oil, graphite in furnace oil, DF 150 (Graphite,
Water-Based) die lubricant and dry or without any lubrication were
obtained from the ring compression test for the above micro-alloyed
steel. Results of ring compression tests indicate that graphite in
hydraulic oil lubricant is preferred for free forging and dry lubricant
is preferred for die forging operation. Exceptionally good forgeability
and high resistance to fracture, especially for faster cooling rate has
been observed for fine equiaxed ferrite-pearlite grains, some amount
of bainite and fine precipitates of vanadium carbides and
carbonitrides. The results indicated that the cooling rate has a
remarkable effect on the microstructure and mechanical properties at
room temperature.
Abstract: Unmanned Aircraft Systems (UAS) become
indispensable parts of modern airpower as force multiplier. One of
the main advantages of UAS is long endurance. UAS have to take
extra payloads to accomplish different missions but these payloads
decrease endurance of aircraft because of increasing drag. There are
continuing researches to increase the capability of UAS. There are
some vertical thermal air currents, which can cause climb and
increase endurance, in nature. Birds and gliders use thermals to gain
altitude with no effort. UAS have wide wings which can use
thermals like birds and gliders. Thermal regions, which is area of
2000-3000 meter (1 NM), exist all around the world. It is natural and
infinite source. This study analyses if thermal regions can be adopted
and implemented as an assistant tool for UAS route planning. First
and second part of study will contain information about the thermal
regions and current applications about UAS in aviation and climbing
performance with a real example. Continuing parts will analyze the
contribution of thermal regions to UAS endurance. Contribution is
important because planning declaration of UAS navigation rules will
be in 2015.
Abstract: In this research (using induction furnace process)
nodular iron with three different percentages of copper (residual,
0.5% and 1,2%) was obtained. Chemical analysis was performed by
mass spectrometry and microstructures were characterized by Optical
Microscopy (ASTM E3) and Scanning Electron Microscopy (SEM).
The study of mechanical behavior was carried out in a mechanical
test machine (ASTM E8) and a Pin on disk tribometer (ASTM G99)
was used to assess wear resistance. It is observed that the dissolution
of copper in crystal lattice increases the pearlite structure improving
the wear and hardness behavior, but producing a contrary effect on
the energy absorption.
Abstract: The aim of research was to define the relations
between volatile compounds, some parameters (pH, titratable acidity
(TA), total soluble solid (TSS), lactic acid bacteria count) and
consumer preference of commercial fermented milks. These relations
tend to be used for controlling and developing new fermented milk
product. Three leading commercial brands of fermented milks in
Thailand were evaluated by consumers (n=71) using hedonic scale
for four attributes (sweetness, sourness, flavour, and overall liking),
volatile compounds using headspace-solid phase microextraction
(HS-SPME) GC-MS, pH, TA, TSS and LAB count. Then the
relations were analyzed by principal component analysis (PCA). The
PCA data showed that all of four attributes liking scores were related
to each other. They were also related to TA, TSS and volatile
compounds. The related volatile compounds were mainly on
fermented produced compounds including acetic acid, furanmethanol,
furfural, octanoic acid and the volatiles known as artificial fruit
flavour (beta pinene, limonene, vanillin, and ethyl vanillin). These
compounds were provided the information about flavour addition in
commercial fermented milk in Thailand.
Abstract: In order to detect and quantify the phenolic contents
of a wastewater with biosensors, two working electrodes based on
modified Poly(Pyrrole) films were fabricated. Enzyme horseradish
peroxidase was used as biomolecule of the prepared electrodes.
Various phenolics were tested at the biosensor. Phenol detection was
realized by electrochemical reduction of quinones produced by
enzymatic activity. Analytical parameters were calculated and the
results were compared with each other.
Abstract: Fluid viscous damping systems are well suited for
many air vehicles subjected to shock and vibration. These damping
system work with the principle of viscous fluid throttling through the
orifice to create huge pressure difference between compression and
rebound chamber and obtain the required damping force. One
application of such systems is its use in aircraft door system to
counteract the door’s velocity and safely stop it. In exigency
situations like crash or emergency landing where the door doesn’t
open easily, possibly due to unusually tilting of fuselage or some
obstacles or intrusion of debris obstruction to move the parts of the
door, such system can be combined with other systems to provide
needed force to forcefully open the door and also securely stop it
simultaneously within the required time i.e. less than 8 seconds. In
the present study, a hydraulic system called snubber along with other
systems like actuator, gas bottle assembly which together known as
emergency power assist system (EPAS) is designed, built and
experimentally studied to check the magnitude of angular velocity,
damping force and time required to effectively open the door.
Whenever needed, the gas pressure from the bottle is released to
actuate the actuator and at the same time pull the snubber’s piston to
operate the emergency opening of the door. Such EPAS installed in
the suspension arm of the aircraft door is studied explicitly changing
parameters like orifice size, oil level, oil viscosity and bypass valve
gap and its spring of the snubber at varying temperature to generate
the optimum design case. Comparative analysis of the EPAS at
several cases is done and conclusions are made. It is found that
during emergency condition, the system opening time and angular
velocity, when snubber with 0.3mm piston and shaft orifice and
bypass valve gap of 0.5 mm with its original spring is used, shows
significant improvement over the old ones.
Abstract: The effects of basil and/or chamomile seed
supplementation on the growth of Hubbard broiler chicks were
evaluated. The antioxidant effects of these supplements were also
assessed. 120 1-day-old broiler chicks were randomly divided into
four equal groups. The control group (group 1) was fed a basal diet
(BD) without supplementation. Groups 2, 3, and 4 were fed the BD
supplemented with 10g basil, 10g chamomile, and 5g basil plus 5g
chamomile per kg of food, respectively. Basil supplementation alone
or in combination with chamomile non-significantly (P≥0.05)
increased final body weight (3.2% and 0.3%, respectively) and
weight gain (3.5% and 3.6%, respectively) over the experimental
period. Chamomile supplementation alone non-significantly (P≥0.05)
reduced final body weight and weight gain over the experimental
period by 1.7% and 1.7%, respectively. In comparison to the control
group, herbal seed supplementation reduced feed intake and
improved the feed conversion and protein efficiency ratios. In
general, basil seed supplementation stimulated chicken growth and
improved the feed efficiency more effectively than chamomile seed
supplementation. The antioxidant activities of basil and/or chamomile
supplementation were examined in the thymus, bursa, and spleen. In
chickens that received supplements, the level of malondialdehyde
was significantly decreased, whereas the activities of glutathione,
superoxide dismutase, and catalase were significantly increased
(P
Abstract: Based on the experimental data, the impact of
resistance and reactance of the winding, as well as the magnetic
permeability of the magnetic circuit steel material on the value of the
electromotive force of the induction converter is investigated. The
obtained results allow estimating the main technological spreads and
determining the maximum level of the electromotive force change.
By the method of experiment planning, the expression of a
polynomial for the electromotive force which can be used to estimate
the adequacy of mathematical models to be used at the investigation
and design of induction converters is obtained.
Abstract: This study investigates the cleaning performance of
high intensity 360 kHz frequency on removal of nano-dimensional
and sub-micron particles from various surfaces, uniformity of the
cleaning tank and run to run variation of cleaning process. The
uniformity of the cleaning tank was measured by two different
methods i.e. 1. ppbTM meter and 2. Liquid Particle Counting (LPC)
technique. The result indicates that the energy was distributed more
uniformly throughout the entire cleaning vessel even at the corners
and edges of the tank when megasonic sweeping technology is
applied. The result also shows that rinsing the parts with 360 kHz
frequency at final rinse gives lower particle counts, hence higher
cleaning efficiency as compared to other frequencies. When
megasonic sweeping technology is applied each piezoelectric
transducers will operate at their optimum resonant frequency and
generates stronger acoustic cavitational force and higher acoustic
streaming velocity. These combined forces are helping to enhance the
particle removal and at the same time improve the overall cleaning
performance. The multiple extractions study was also carried out for
various frequencies to measure the cleaning potential and asymptote
value.
Abstract: Artificial intelligence applications are commonly used
in industry in many fields in parallel with the developments in the
computer technology. In this study, a fire room was prepared for the
resistance of wooden construction elements and with the mechanism
here, the experiments of polished materials were carried out. By
utilizing from the experimental data, an artificial neural network
(ANN) was modelled in order to evaluate the final cross sections of
the wooden samples remaining from the fire. In modelling,
experimental data obtained from the fire room were used. In the
developed system, the first weight of samples (ws-gr), preliminary
cross-section (pcs-mm2), fire time (ft-minute), and fire temperature
(t-oC) as input parameters and final cross-section (fcs-mm2) as output
parameter were taken. When the results obtained from ANN and
experimental data are compared after making statistical analyses, the
data of two groups are determined to be coherent and seen to have no
meaning difference between them. As a result, it is seen that ANN
can be safely used in determining cross sections of wooden materials
after fire and it prevents many disadvantages.
Abstract: The pullout strength had an effect on the stability of
plate screw fixation when inserted in the cervical spine. Nine
different titanium alloy bone screws were used to test the pullout
strength through finite element analysis. The result showed that the
Moss Miami I can bear the highest pullout force at 1,075 N, which
causes the maximum von Mises stress at 858.87 MPa, a value over
the yield strength of titanium. The bone screw should have large
outer diameter, core diameter and proximal root radius to increase the
pullout strength.
Abstract: Many aluminum motorcycle parts produced by a high
pressure die casting. Some parts such as fuel caps were a thin and
complex shape. This part risked for porosities and blisters on surface
if it only depended on an experience of mold makers for mold design.
This research attempted to use CAST-DESIGNER software
simulated the high pressure die casting process with the same process
parameters of a motorcycle fuel cap production. The simulated results
were compared with fuel cap products and expressed the same
porosity and blister locations on cap surface. An average of absolute
difference of simulated results was obtained 0.094 mm when
compared the simulated porosity and blister defect sizes on the fuel
cap surfaces with the experimental micro photography. This
comparison confirmed an accuracy of software and will use the
setting parameters to improve fuel cap molds in the further work.
Abstract: This study was developed to compare the behavior
and the ability of polymer foam composites towards sound absorption
test of Shorea leprosula wood (SL) of acid hydrolysis treatment with
particle size