Abstract: This research presents the development of simulation
modeling for WIP management in semiconductor fabrication.
Manufacturing simulation modeling is needed for productivity
optimization analysis due to the complex process flows involved
more than 35 percent re-entrance processing steps more than 15 times
at same equipment. Furthermore, semiconductor fabrication required
to produce high product mixed with total processing steps varies from
300 to 800 steps and cycle time between 30 to 70 days. Besides the
complexity, expansive wafer cost that potentially impact the
company profits margin once miss due date is another motivation to
explore options to experiment any analysis using simulation
modeling. In this paper, the simulation model is developed using
existing commercial software platform AutoSched AP, with
customized integration with Manufacturing Execution Systems
(MES) and Advanced Productivity Family (APF) for data collections
used to configure the model parameters and data source. Model
parameters such as processing steps cycle time, equipment
performance, handling time, efficiency of operator are collected
through this customization. Once the parameters are validated, few
customizations are made to ensure the prior model is executed. The
accuracy for the simulation model is validated with the actual output
per day for all equipments. The comparison analysis from result of
the simulation model compared to actual for achieved 95 percent
accuracy for 30 days. This model later was used to perform various
what if analysis to understand impacts on cycle time and overall
output. By using this simulation model, complex manufacturing
environment like semiconductor fabrication (fab) now have
alternative source of validation for any new requirements impact
analysis.
Abstract: Traffic flow in adverse weather conditions have been investigated in this study for general traffic, week day and week end traffic. The empirical evidence is strong in support of the view that rainfall affects macroscopic traffic flow parameters. Data generated from a basic highway section along J5 in Johor Bahru, Malaysia was synchronized with 161 rain events over a period of three months. This revealed a 4.90%, 6.60% and 11.32% reduction in speed for light rain, moderate rain and heavy rain conditions respectively. The corresponding capacity reductions in the three rainfall regimes are 1.08% for light rain, 6.27% for moderate rain and 29.25% for heavy rain. In the week day traffic, speed drops of 8.1% and 16.05% were observed for light and heavy conditions. The moderate rain condition speed increased by 12.6%. The capacity drops for week day traffic are 4.40% for light rain, 9.77% for moderate rain and 45.90% for heavy rain. The weekend traffic indicated speed difference between the dry condition and the three rainy conditions as 6.70% for light rain, 8.90% for moderate rain and 13.10% for heavy rain. The capacity changes computed for the weekend traffic were 0.20% in light rain, 13.90% in moderate rain and 16.70% in heavy rain. No traffic instabilities were observed throughout the observation period and the capacities reported for each rain condition were below the norain condition capacity. Rainfall has tremendous impact on traffic flow and this may have implications for shock wave propagation.
Abstract: This study reports the preparation of soft magnetic
ribbons of Fe-based amorphous alloys using the single-roller melt-spinning technique. Ribbon width varied from 142 mm to 213
mm and, with a thickness of approximately 22 μm ± 2 μm. The microstructure and magnetic properties of the ribbons were
characterized by differential scanning calorimeter (DSC), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and electrical resistivity measurements (ERM). The amorphous material
properties dependence of the cooling rate and nozzle pressure have uneven surface in ribbon thicknesses are investigated. Magnetic
measurement results indicate that some region of the ribbon exhibits good magnetic properties, higher saturation induction and lower coercivity. However, due to the uneven surface of 213 mm wide
ribbon, the magnetic responses are not uniformly distributed. To
understand the transformer magnetic performances, this study analyzes the measurements of a three-phase 2 MVA amorphous-cored transformer. Experimental results confirm that the transformer with a
ribbon width of 142 mm has better magnetic properties in terms of lower core loss, exciting power, and audible noise.
Abstract: In this study, the kinetic of biogas production was studied by performing a series laboratory experiment using rumen fluid of animal ruminant as inoculums. Cattle manure as substrate was inoculated by rumen fluid to the anaerobic biodigester. Laboratory experiments using 400 ml biodigester were performed in batch operation mode. Given 100 grams of fresh cattle manure was fed to each biodigester and mixed with rumen fluid by manure : rumen weight ratio of 1:1 (MR11). The operating temperatures were varied at room temperature and 38.5 oC. The cumulative volume of biogas produced was used to measure the biodigester performance. The research showed that the rumen fluid inoculated to biodigester gave significant effect to biogas production (P
Abstract: Hair is a non homogenous complex material which
can be associated with a polymer. It is made up 95% of Keratin.
Hair has a great social significance for human beings. In the High
Middle Ages, for example, long hairs have been reserved for kings
and nobles.
Most common interest in hair is focused on hair growth, hair types
and hair care, but hair is also an important biomaterial which can
vary depending on ethnic origin or on age, hair colour for example
can be a sign of ethnic ancestry or age (dark hair for Asiatic, blond
hair for Caucasian and white hair for old people in general).
In this context, different approaches have been conducted to
determine the differences in mechanical properties and characterize
the fracture topography at the surface of hair depending on its type
and its age.
A tensile testing machine was especially designed to achieve
tensile tests on hair. This device is composed of a microdisplacement
system and a force sensor whose peak load is limited to
3N. The curves and the values extracted from each experiment, allow
us to compare the evolution of the mechanical properties from one
hair to another.
Observations with a Scanning Electron Microscope (SEM) and
with an interferometer were made on different hairs. Thus, it is
possible to access the cuticle state and the fracture topography for
each category.
Abstract: Seasonal survey of freshwater snails in different water
courses in Egypt during two successive years included 13 snail
species. They represented by Biomphalaria alexandrina, Bulinus
truncatus, Physa acuta, Helisoma duryi, Lymnaea natalensis,
Planorbis pantries, Cleopatra bulimoides, Lanistes carinatus,
Bellamya unicolor, Melanoides tuberculata, Theodoxus niloticus,
Succinia cleopatra and Valvata nilotica. B. alexandrina was most
abundant during autumn and spring represented by 26and14
snails/site, respectively. B. truncatus was most abundant during
winter (7.7and3.6snails/site) of the two years, respectively. L.
natalensis was represented by 7snails/site in summer. The tolerance
of different snail species to the chemical elements was determined
seasonally and correlated to their abundance. In spring, autumn and
winter, B. alexandrina was significantly found to live under the
highest level of Pb, Cd,Cu, Na, K and Ca concentrations than the
other species (p
Abstract: Landfill gas, particularly methane is one of the
greenhouse gases which contributes to global warming. This paper presents the findings of a study on methane gas production from
simulated landfill reactor under saturated conditions. A reactor was constructed to represent a landfill cell of 2.5 m thickness on sandy
soil. The reactor was 0.2 m in diameter and 4 m in height. One meter of sand and pebble layer was packed at the bottom of the reactor
followed by 2.5 m of solid waste layer and 0.4 m of sand layer as the cover soil. Degradation of waste in the solid waste layer was at
acidification stage as indicated by the leachate quality with COD as
high as 55,511 mg/L and pH as low as 5.1. However, methanogenic
environment was established at the bottom sand layer after one year of operation indicated by pH of 7.2 and methane gas generation.
Leachate degradation took place as the leachate moved through the
sand layer at an infiltration of rate 0.7 cm/day. This resulted in landfill gas production of 77 mL/day/kg containing 55 to 65% methane. The application of sand layer contributed to the gas
production from landfill by an in-situ degradation of leachate in the
sand at the bottom of the landfill.
Abstract: In this paper, the effects of radiation, chemical
reaction and double dispersion on mixed convection heat and mass
transfer along a semi vertical plate are considered. The plate is
embedded in a Newtonian fluid saturated non - Darcy (Forchheimer
flow model) porous medium. The Forchheimer extension and first
order chemical reaction are considered in the flow equations. The
governing sets of partial differential equations are nondimensionalized
and reduced to a set of ordinary differential
equations which are then solved numerically by Fourth order Runge–
Kutta method. Numerical results for the detail of the velocity,
temperature, and concentration profiles as well as heat transfer rates
(Nusselt number) and mass transfer rates (Sherwood number) against
various parameters are presented in graphs. The obtained results are
checked against previously published work for special cases of the
problem and are found to be in good agreement.
Abstract: Power system state estimation is the process of
calculating a reliable estimate of the power system state vector
composed of bus voltages' angles and magnitudes from telemetered
measurements on the system. This estimate of the state vector
provides the description of the system necessary for the operation
and security monitoring. Many methods are described in the
literature for solving the state estimation problem, the most important
of which are the classical weighted least squares method and the nondeterministic
genetic based method; however both showed
drawbacks. In this paper a modified version of the genetic
algorithm power system state estimation is introduced, Sensitivity of
the proposed algorithm to genetic operators is discussed, the
algorithm is applied to case studies and finally it is compared with
the classical weighted least squares method formulation.
Abstract: In the present research, two nutraceuticals made from
red grape and walnut that showed previously to improve kidney
dysfunction were incorporated separately into functional foods' bread
made from barley and rice bran. The functional foods were evaluated
in rats in which chronic renal failure was induced through feeding
diet rich in adenine and phosphate (APD). The evaluation based on
assessing kidney function, oxidative stress, inflammatory biomarkers
and body weight gain. Results showed induction of chronic kidney
failure reflected in significant increase in plasma urea, creatinine,
malondialdehyde, tumor necrosis factor- α and low density
lipoprotein cholesterol along with significant reduction of plasma
albumin, and total antioxidant and creatinine clearance and body
weight gain on feeding APD compared to control healthy group.
Feeding the functional foods produced amelioration in the different
biochemical parameters and body weight gain indicating
improvement in kidney function.
Abstract: In our recent study, we have used ZnO nanoparticles assisted with UV light irradiation to investigate the photocatalytic degradation of Phenol Red (PR). The ZnO photocatalyst was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), specific surface area analysis (BET) and UVvisible spectroscopy. X-ray diffractometry result for the ZnO nanoparticles exhibit normal crystalline phase features. All observed peaks can be indexed to the pure hexagonal wurtzite crystal structures, with the space group of P63mc. There are no other impurities in the diffraction peak. In addition, TEM measurement shows that most of the nanoparticles are rod-like and spherical in shape and fairly monodispersed. A significant degradation of the PR was observed when the catalyst was added into the solution even without the UV light exposure. In addition, the photodegradation increases with the photocatalyst loading. The surface area of the ZnO nanomaterials from the BET measurement was 11.9 m2/g. Besides the photocatalyst loading, the effect of some parameters on the photodegradation efficiency such as initial PR concentration and pH were also studied.
Abstract: Wet chemistry methods are used to prepare the
SiO2/Au nanoshells. The purpose of this research was to synthesize
gold coated SiO2 nanoshells for biomedical applications. Tunable
nanoshells were prepared by using different colloidal concentrations.
The nanoshells are characterized by FTIR, XRD, UV-Vis
spectroscopy and atomic force microscopy (AFM). The FTIR results
confirmed the functionalization of the surfaces of silica nanoparticles
with NH2 terminal groups. A tunable absorption was observed
between 470-600 nm with a maximum range of 530-560 nm. Based
on the XRD results three main peaks of Au (111), (200) and (220)
were identified. Also AFM results showed that the silica core
diameter was about 100 nm and the thickness of gold shell about 10
nm.
Abstract: Requirements that should be met when determining the regimes of circuits with variable elements are formulated. The interpretation of the variations in the regimes, based on projective geometry, enables adequate expressions for determining and comparing the regimes to be derived. It is proposed to use as the parameters of a generalized equivalent generator of an active two-pole with changeable resistor such load current and voltage which provide the current through this resistor equal to zero.
Abstract: Multicarrier transmission system such as Orthogonal
Frequency Division Multiplexing (OFDM) is a promising technique
for high bit rate transmission in wireless communication system.
OFDM is a spectrally efficient modulation technique that can achieve
high speed data transmission over multipath fading channels without
the need for powerful equalization techniques. However the price
paid for this high spectral efficiency and less intensive equalization
is low power efficiency. OFDM signals are very sensitive to nonlinear
effects due to the high Peak-to-Average Power Ratio (PAPR),
which leads to the power inefficiency in the RF section of the
transmitter. This paper investigates the effect of PAPR reduction on
the performance parameter of multicarrier communication system.
Performance parameters considered are power consumption of Power
Amplifier (PA) and Digital-to-Analog Converter (DAC), power amplifier
efficiency, SNR of DAC and BER performance of the system.
From our analysis it is found that irrespective of PAPR reduction
technique being employed, the power consumption of PA and DAC
reduces and power amplifier efficiency increases due to reduction in
PAPR. Moreover, it has been shown that for a given BER performance
the requirement of Input-Backoff (IBO) reduces with reduction in
PAPR.
Abstract: The agriculture lignocellulosic by-products are receiving increased attention, namely in the search for filter materials that retain contaminants from water. These by-products, specifically almond and hazelnut shells are abundant in Portugal once almond and hazelnuts production is a local important activity. Hazelnut and almond shells have as main constituents lignin, cellulose and hemicelluloses, water soluble extractives and tannins. Along the adsorption of heavy metals from contaminated waters, water soluble compounds can leach from shells and have a negative impact in the environment. Usually, the chemical characterization of treated water by itself may not show environmental impact caused by the discharges when parameters obey to legal quality standards for water. Only biological systems can detect the toxic effects of the water constituents. Therefore, the evaluation of toxicity by biological tests is very important when deciding the suitability for safe water discharge or for irrigation applications.
The main purpose of the present work was to assess the potential impacts of waters after been treated for heavy metal removal by hazelnut and almond shells adsorption systems, with short term acute toxicity tests.
To conduct the study, water at pH 6 with 25 mg.L-1 of lead, was treated with 10 g of shell per litre of wastewater, for 24 hours. This procedure was followed for each bark. Afterwards the water was collected for toxicological assays; namely bacterial resistance, seed germination, Lemna minor L. test and plant grow. The effect in isolated bacteria strains was determined by disc diffusion method and the germination index of seed was evaluated using lettuce, with temperature and humidity germination control for 7 days. For aquatic higher organism, Lemnas were used with 4 days contact time with shell solutions, in controlled light and temperature. For terrestrial higher plants, biomass production was evaluated after 14 days of tomato germination had occurred in soil, with controlled humidity, light and temperature.
Toxicity tests of water treated with shells revealed in some extent effects in the tested organisms, with the test assays showing a close behaviour as the control, leading to the conclusion that its further utilization may not be considered to create a serious risk to the environment.
Abstract: The Emergency Department of a medical center in
Taiwan cooperated to conduct the research. A predictive model of
triage system is contracted from the contract procedure, selection of
parameters to sample screening. 2,000 pieces of data needed for the
patients is chosen randomly by the computer. After three
categorizations of data mining (Multi-group Discriminant Analysis,
Multinomial Logistic Regression, Back-propagation Neural
Networks), it is found that Back-propagation Neural Networks can
best distinguish the patients- extent of emergency, and the accuracy
rate can reach to as high as 95.1%. The Back-propagation Neural
Networks that has the highest accuracy rate is simulated into the triage
acuity expert system in this research. Data mining applied to the
predictive model of the triage acuity expert system can be updated
regularly for both the improvement of the system and for education
training, and will not be affected by subjective factors.
Abstract: The aim of this retrospective study was to evaluate the
parameters of dental implants such as patient gender, number of
implant, failed implant before prosthetic restorations and failed
implant after implantation and failed implant after prosthetic
restorations. 135 male and 99 female patients, total 234 implant
patients which have been treated with 450 implant between 2005-
2009 years in GATA Haydarpasa Training Hospital Dental Service.
Twelve implants were failed before prosthetic restorations. Four
implant were failed after fixed prosthetic restorations. Cumulative
survival rate after prostheses were 97.56 % during 6 years period.
Abstract: Optimization of cutting parameters important in precision machining in regards to efficiency and surface integrity of the machined part. Usually productivity and precision in machining is limited by the forces emanating from the cutting process. Due to the inherent varying nature of the workpiece in terms of geometry and material composition, the peak cutting forces vary from point to point during machining process. In order to increase productivity without compromising on machining accuracy, it is important to control these cutting forces. In this paper a fuzzy logic control algorithm is developed that can be applied in the control of peak cutting forces in milling of spherical surfaces using ball end mills. The controller can adaptively vary the feedrate to maintain allowable cutting force on the tool. This control algorithm is implemented in a computer numerical control (CNC) machine. It has been demonstrated that the controller can provide stable machining and improve the performance of the CNC milling process by varying feedrate.
Abstract: The Yasuj city stream named the Beshar supply
water for different usages such as aquaculture farms , drinking,
agricultural and industrial usages. Fish processing plants
,Agricultural farms, waste water of industrial zones and hospitals
waste water which they are generate by human activity produce a
considerable volume of effluent and when they are released in to the
stream they can effect on the water quality and down stream aquatic
systems. This study was conducted to evaluate the effects of outflow
effluent from different human activity and point and non point
pollution sources on the water quality and health of the Beshar
river next to Yasuj. Yasuj is the biggest and most important city in
the Kohkiloye and Boyerahmad province . The Beshar River is one
of the most important aquatic ecosystems in the upstream of the
Karun watershed in south of Iran which is affected by point and non
point pollutant sources . This study was done in order to evaluate the
effects of human activities on the water quality and health of the
Beshar river. This river is approximately 190 km in length and
situated at the geographical positions of 51° 20' to 51° 48' E and 30°
18' to 30° 52' N it is one of the most important aquatic ecosystems of
Kohkiloye and Boyerahmad province in south-west Iran. In this
research project, five study stations were selected to examine water
pollution in the Beshar River systems. Human activity is now one of
the most important factors affecting on hydrology and water quality
of the Beshar river. Humans use large amounts of resources to sustain
various standards of living, although measures of sustainability are
highly variable depending on how sustainability is defined. The
Beshar river ecosystems are particularly sensitive and vulnerable to
human activities. The water samples were analyzed, then some
important water quality parameters such as pH, dissolve oxygen
(DO), Biochemical Oxygen Demand (BOD5), Chemical Oxygen
Demand (COD), Total Suspended Solids (TDS),Turbidity,
Temperature, Nitrates (NO3) and Phosphates (PO4) were estimated
at the two stations. The results show a downward trend in the water
quality at the down stream of the city. The amounts of
BOD5,COD,TSS,T,Turbidity, NO3 and PO4 in the down stream
stations were considerably more than the station 1. By contrast the
amounts of DO in the down stream stations were less than to the
station 1. However when effluent discharge consequence of human
activities are released into the Beshar river near the city, the quality
of river are decreases and the environmental problems of the river
during the next years are predicted to rise.
Abstract: The primary objective of this paper was to construct a
“kinematic parameter-independent modeling of three-axis machine
tools for geometric error measurement" technique. Improving the
accuracy of the geometric error for three-axis machine tools is one of
the machine tools- core techniques. This paper first applied the
traditional method of HTM to deduce the geometric error model for
three-axis machine tools. This geometric error model was related to the
three-axis kinematic parameters where the overall errors was relative
to the machine reference coordinate system. Given that the
measurement of the linear axis in this model should be on the ideal
motion axis, there were practical difficulties. Through a measurement
method consolidating translational errors and rotational errors in the
geometric error model, we simplified the three-axis geometric error
model to a kinematic parameter-independent model. Finally, based on
the new measurement method corresponding to this error model, we
established a truly practical and more accurate error measuring
technique for three-axis machine tools.