Abstract: The performance of Advection Upstream Splitting
Method AUSM schemes are evaluated against experimental flow
fields at different Mach numbers and results are compared with
experimental data of subsonic, supersonic and hypersonic flow fields.
The turbulent model used here is SST model by Menter. The
numerical predictions include lift coefficient, drag coefficient and
pitching moment coefficient at different mach numbers and angle of
attacks. This work describes a computational study undertaken to
compute the Aerodynamic characteristics of different air vehicles
configurations using a structured Navier-Stokes computational
technique. The CFD code bases on the idea of upwind scheme for the
convective (convective-moving) fluxes. CFD results for GLC305
airfoil and cone cylinder tail fined missile calculated on above
mentioned turbulence model are compared with the available data.
Wide ranges of Mach number from subsonic to hypersonic speeds are
simulated and results are compared. When the computation is done
by using viscous turbulence model the above mentioned coefficients
have a very good agreement with the experimental values. AUSM
scheme is very efficient in the regions of very high pressure gradients
like shock waves and discontinuities. The AUSM versions simulate
the all types of flows from lower subsonic to hypersonic flow without
oscillations.
Abstract: In the last decade, carbohydrates have attracted great
attention as renewable resources for the chemical industry.
Carbohydrates are abundantly found in nature in the form of
monomers, oligomers and polymers, or as components of
biopolymers and other naturally occurring substances. As natural
products, they play important roles in conferring certain physical,
chemical, and biological properties to their carrier molecules.The
synthesis of this particular carbohydrate glycomonomer is part of our
work to obtain biodegradable polymers. Our current paper describes
the synthesis and characterization of a novel carbohydrate
glycomonomer starting from D-glucose, in several synthesis steps,
that involve the protection/deprotection of the D-glucose ring via
acetylation, tritylation, then selective deprotection of the aromaticaliphatic
protective group, in order to obtain 1,2,3,4-tetra-O-acetyl-
6-O-allyl-β-D-glucopyranose. The glycomonomer was then obtained
by the allylation in drastic conditions of 1,2,3,4-tetra-O-acetyl-6-Oallyl-
β-D-glucopyranose with allylic alcohol in the presence of
stannic chloride, in methylene chloride, at room temperature. The
proposed structure of the glycomonomer, 2,3,4-tri-O-acetyl-1,6-di-
O-allyl-β-D-glucopyranose, was confirmed by FTIR, NMR and
HPLC-MS spectrometry. This glycomonomer will be further
submitted to copolymerization with certain acrylic or methacrylic
monomers in order to obtain competitive plastic materials for
applications in the biomedical field.
Abstract: A fast adaptive Tomlinson Harashima (T-H) precoder structure is presented for indoor wireless communications, where the channel may vary due to rotation and small movement of the mobile terminal. A frequency-selective slow fading channel which is time-invariant over a frame is assumed. In this adaptive T-H precoder, feedback coefficients are updated at the end of every uplink frame by using system identification technique for channel estimation in contrary with the conventional T-H precoding concept where the channel is estimated during the starting of the uplink frame via Wiener solution. In conventional T-H precoder it is assumed the channel is time-invariant in both uplink and downlink frames. However assuming the channel is time-invariant over only one frame instead of two, the proposed adaptive T-H precoder yields better performance than conventional T-H precoder if the channel is varied in uplink after receiving the training sequence.
Abstract: Charging and discharging phenomenon on the surface
of materials can be found in plasma display panel, spacecraft
charging, high voltage insulator, etc. This report gives a simple
explanation on this phenomenon. A scanning electron microscope
was used not only as a tool to produce energetic electron beam to
charge an insulator without metallic coating and to produce a surface
discharging (surface breakdown/flashover) but also to observe the
visible charging and discharging on the sample surface. A model of
electric field distribution on the surface was developed in order to
explain charging and discharging phenomena. Since charging and
discharging process involves incubation time, therefore this process
can be used to evaluate the insulation property of materials under
electron bombardment.
Abstract: In this paper back-propagation artificial neural
network (BPANN) is employed to predict the limiting drawing ratio
(LDR) of the deep drawing process. To prepare a training set for
BPANN, some finite element simulations were carried out. die and
punch radius, die arc radius, friction coefficient, thickness, yield
strength of sheet and strain hardening exponent were used as the
input data and the LDR as the specified output used in the training of
neural network. As a result of the specified parameters, the program
will be able to estimate the LDR for any new given condition.
Comparing FEM and BPANN results, an acceptable correlation was
found.
Abstract: In this paper, a simple microfluidic device for monitoring algal cell behavior is proposed. An array of algal microwells is fabricated by PDMS soft-lithography using X-ray LIGA mold, placed on a glass substrate. Two layers of replicated PDMS and substrate are attached by oxygen plasma bonding, creating a microchannel for the microfluidic system. Algal cell are loaded into the microfluidic device, which provides positive charge on the bottom surface of wells. Algal cells, which are negative charged, can be attracted to the bottom of the wells via electrostatic interaction. By varying the concentration of algal cells in the loading suspension, it is possible to obtain wells with a single cell. Liquid medium for cells monitoring are flown continuously over the wells, providing nutrient and waste exchange between the well and the main flow. This device could lead to the uncovering of the quantitative biology of the algae, which is a key to effective and extensive algal utilizations in the field of biotechnology, food industry and bioenergy research and developments.
Abstract: Checkpointing is one of the commonly used techniques to provide fault-tolerance in distributed systems so that the system can operate even if one or more components have failed. However, mobile computing systems are constrained by low bandwidth, mobility, lack of stable storage, frequent disconnections and limited battery life. Hence, checkpointing protocols having lesser number of synchronization messages and fewer checkpoints are preferred in mobile environment. There are two different approaches, although not orthogonal, to checkpoint mobile computing systems namely, time-based and index-based. Our protocol is a fusion of these two approaches, though not first of its kind. In the present exposition, an index-based checkpointing protocol has been developed, which uses time to indirectly coordinate the creation of consistent global checkpoints for mobile computing systems. The proposed algorithm is non-blocking, adaptive, and does not use any control message. Compared to other contemporary checkpointing algorithms, it is computationally more efficient because it takes lesser number of checkpoints and does not need to compute dependency relationships. A brief account of important and relevant works in both the fields, time-based and index-based, has also been included in the presentation.
Abstract: This paper presents an analytical model to estimate
the cost of an optimized design of reinforced concrete isolated
footing base on structural safety. Flexural and optimized formulas for
square and rectangular footingare derived base on ACI building code
of design, material cost and optimization. The optimization
constraints consist of upper and lower limits of depth and area of
steel. Footing depth and area of reinforcing steel are to be minimized
to yield the optimal footing dimensions. Optimized footing materials
cost of concrete, reinforcing steel and formwork of the designed
sections are computed. Total cost factor TCF and other cost factors
are developed to generalize and simplify the calculations of footing
material cost. Numerical examples are presented to illustrate the
model capability of estimating the material cost of the footing for a
desired axial load.
Abstract: Low power consumption is a major constraint for battery-powered system like computer notebook or PDA. In the past, specialists usually designed both specific optimized equipments and codes to relief this concern. Doing like this could work for quite a long time, however, in this era, there is another significant restraint, the time to market. To be able to serve along the power constraint while can launch products in shorter production period, objectoriented programming (OOP) has stepped in to this field. Though everyone knows that OOP has quite much more overhead than assembly and procedural languages, development trend still heads to this new world, which contradicts with the target of low power consumption. Most of the prior power related software researches reported that OOP consumed much resource, however, as industry had to accept it due to business reasons, up to now, no papers yet had mentioned about how to choose the best OOP practice in this power limited boundary. This article is the pioneer that tries to specify and propose the optimized strategy in writing OOP software under energy concerned environment, based on quantitative real results. The language chosen for studying is C# based on .NET Framework 2.0 which is one of the trendy OOP development environments. The recommendation gotten from this research would be a good roadmap that can help developers in coding that well balances between time to market and time of battery.
Abstract: Doubly fed induction machines DFIM are used
mainly for wind energy conversion in MW power plants. This paper
presents a new strategy of field oriented control ,it is based on the
principle of a double flux orientation of stator and rotor at the same
time. Therefore, the orthogonality created between the two oriented
fluxes, which must be strictly observed, leads to generate a linear and
decoupled control with an optimal torque. The obtained simulation
results show the feasibility and the effectiveness of the suggested
method.
Abstract: We decribe a formal specification and verification of the Rabin public-key scheme in the formal proof system Is-abelle/HOL. The idea is to use the two views of cryptographic verification: the computational approach relying on the vocabulary of probability theory and complexity theory and the formal approach based on ideas and techniques from logic and programming languages. The analysis presented uses a given database to prove formal properties of our implemented functions with computer support. Thema in task in designing a practical formalization of correctness as well as security properties is to cope with the complexity of cryptographic proving. We reduce this complexity by exploring a light-weight formalization that enables both appropriate formal definitions as well as eficient formal proofs. This yields the first computer-proved implementation of the Rabin public-key scheme in Isabelle/HOL. Consequently, we get reliable proofs with a minimal error rate augmenting the used database. This provides a formal basis for more computer proof constructions in this area.
Abstract: Land with low pH soil spread widely in Indonesia
can be used for soybean (Glycine max) cultivation, however the
production is low. The use of acid tolerant soybean and acidaluminium
tolerant nitrogen-fixing bacteria formula was an
alternative way to increase soybean productivity on acid soils.
Bradyrhizobium japonicum is one of the nitrogen fixing bacteria
which can symbiose with soybean plants through root nodule
formation. Most of the nitrogen source required by soybean plants
can be provided by this symbiosis. This research was conducted to
study the influence of acid-aluminium tolerant B. japonicum strain
BJ 11 formula using peat as carrier on growth of Tanggamus and
Anjasmoro cultivar soybean planted on acid soil fields (pH 5.0-
5.5). The results showed that the inoculant was able to increase the
growth and production of soybean which were grown on fields acid
soil at Sukadana (Lampung) and Tanah Laut (South Kalimantan),
Indonesia.
Abstract: A novel and efficient approach to realize
fractional-order capacitors is investigated in this paper. Meanwhile, a
new approach which is more efficient for semiconductor
implementation of fractional-order capacitors is proposed. The
feasibility of the approach has been verified with the preliminary
measured results.
Abstract: The dynamic speckle or biospeckle is an interference
phenomenon generated at the reflection of a coherent light by an
active surface or even by a particulate or living body surface. The
above mentioned phenomenon gave scientific support to a method
named biospeckle which has been employed to study seed viability,
biological activity, tissue senescence, tissue water content, fruit
bruising, etc. Since the above mentioned method is not invasive and
yields numerical values, it can be considered for possible automation
associated to several processes, including selection and sorting.
Based on these preliminary considerations, this research work
proposed to study the interaction of a laser beam with vegetative
samples by measuring the incident light intensity and the transmitted
light beam intensity at several vegetative slabs of varying thickness.
Tests were carried on fifteen slices of apple tissue divided into three
thickness groups, i.e., 4 mm, 5 mm, 18 mm and 22 mm. A diode laser
beam of 10mW and 632 nm wavelength and a Samsung digital
camera were employed to carry the tests. Outgoing images were
analyzed by comparing the gray gradient of a fixed image column of
each image to obtain a laser penetration scale into the tissue,
according to the slice thickness.
Abstract: This study1 holds for the formation of international financial crisis and political factors for economic crisis in Turkey, are evaluated in chronological order. The international arena and relevant studies conducted in Turkey work in the literature are assessed. The main purpose of the study is to hold the linkage between the crises and political stability in Turkey in details, and to examine the position of Turkey in this regard. The introduction part follows the literature survey on the models explaining causes and results of the crises, the second part of the study. In the third part, the formations of the world financial crises are studied. The fourth part, financial crisis in Turkey in 1994, 2000, 2001 and 2008 are reviewed and their political reasons are analyzed. In the last part of the study the results and recommendations are held. Political administrations have laid the grounds for an economic crisis in Turkey. In this study, the emergence of an economic crisis in Turkey and the developments after the crisis are chronologically examined and an explanation is offered as to the cause and effect relationship between the political administration and economic equilibrium in the country. Economic crises can be characterized as follows: high prices of consumables, high interest rates, current account deficits, budget deficits, structural defects in government finance, rising inflation and fixed currency applications, rising government debt, declining savings rates and increased dependency on foreign capital stock. Entering into the conditions of crisis during a time when the exchange value of the country-s national currency was rising, speculative finance movements and shrinking of foreign currency reserves happened due to expectations for devaluation and because of foreign investors- resistance to financing national debt, and a financial risk occurs. During the February 2001 crisis and immediately following, devaluation and reduction of value occurred in Turkey-s stock market. While changing over to the system of floating exchange rates in the midst of this crisis, the effects of the crisis on the real economy are discussed in this study. Administered politics include financial reforms, such as the rearrangement of banking systems. These reforms followed with the provision of foreign financial support. There have been winners and losers in the imbalance of income distribution, which has recently become more evident in Turkey-s fragile economy.
Abstract: Continuous pyrolysis of Cogongrass by control
temperature in the novel pyrolysis reactor were conducted at three
difference temperatures 400, 450 and 500°C. Preliminary calculate of
the product yields founded the liquid yield of Cogongrass was
highest of 41.45 %, at 500 oC. Indicated that the liquid yield from
Cogongrass had good received yields because it gave over 40 % and
its produced more liquid than that solid and gas. The compounds
detected in bio-oil from Cogongrass showed the functional group,
especially; Phenol, Phenol, 2,5-dimethyl, Phenol, 3-methyl, 2-
methyl-1,3-oxathiofane, Benzene,1-ethyl-4-methoxy, 2-Cyclopenten-
1-one,2,3-dimethyl, 2- Cyclopenten-1- one, 3-Methyl.
Abstract: The electroencephalograph (EEG) signal is one of the most widely signal used in the bioinformatics field due to its rich information about human tasks. In this work EEG waves classification is achieved using the Discrete Wavelet Transform DWT with Fast Fourier Transform (FFT) by adopting the normalized EEG data. The DWT is used as a classifier of the EEG wave's frequencies, while FFT is implemented to visualize the EEG waves in multi-resolution of DWT. Several real EEG data sets (real EEG data for both normal and abnormal persons) have been tested and the results improve the validity of the proposed technique.
Abstract: The objective of this research was to study the career
success and the satisfaction of female executives working for schools
in Bangkok, Thailand. This paper drew upon the survey data
collected from 68 female executives. The survey conducted in on
Bangkok schools. The statistics utilized in this paper included
percentage, mean, standard deviation as well as t-test. The findings
revealed that the majority of samples had more than 30 years of
experience, held a master degree, and had an average income of less
than 40,000 baht. The majority of respondents worked not more than
50 hours per week. In addition, the mean score revealed career
development was ranked as their number one career satisfaction and
having a job related to education was ranked as their number one job
satisfaction. Also, the mean score of all categories of satisfaction was
4.61 with standard deviation of 1.677 which indicated that female
executive level of satisfaction was high. In terms of the subjectivity
career success, the hypothesis testing’s result disclosed that female
executives with different married status had a difference in their job
satisfaction which was significant at the 0.05 confidence level.
Abstract: In the present work, Pulsed Electro Acoustic (PEA)
technique was adopted to understand the space charge dynamics in
elastomeric material. It is observed that the polarity of the applied
DC voltage voltage and its magnitude alters the space charge
dynamics in insulation structure. It is also noticed that any addition
of compound to the base material/processing technique have
characteristic variation in the space charge injection process. It could
be concluded based on the present work that the plasticizer could
inject heterocharges into the insulation medium. Also it is realized
that space charge magnitude is less with the addition of plasticizer. In
the PEA studies, it is observed that local electric field in the
insulating material can be much more than applied electric field due
to space charge formation. One of the important conclusions arrived
at based on PEA technique is that one could understand the safe
operating electric field of an insulation material and the charge trap
sites.
Abstract: In this paper, several different types of natural gas liquefaction cycle. First, two processes are a cascade process with two staged compression were designed and simulated. These include Inter-cooler which is consisted to Propane, Ethylene and Methane cycle, and also, liquid-gas heat exchanger is applied to between of methane and ethylene cycles (process2) and between of ethylene and propane (process2). Also, these cycles are compared with two staged cascade process using only a Inter-cooler (process1). The COP of process2 and process3 showed about 13.99% and 6.95% higher than process1, respectively. Also, the yield efficiency of LNG improved comparing with process1 by 13.99% lower specific power. Additionally, C3MR process are simulated and compared with Process 2.