Abstract: In the present study, Convective heat transfer
coefficient and pressure drop of Al2O3/water nanofluid in laminar
flow regime under constant heat flux conditions inside a circular tube
were experimentally investigated. Al2O3/water nanofluid with 0.5%
and 1% volume concentrations with 15 nm diameter nanoparticles
were used as working fluid. The effect of different volume
concentrations on convective heat transfer coefficient and friction
factor was studied. The results emphasize that increasing of particle
volume concentration leads to enhance convective heat transfer
coefficient. Measurements show the average heat transfer coefficient
enhanced about 11-20% with 0.5% volume concentration and
increased about 16-27% with 1% volume concentration compared to
distilled water. In addition, the convective heat transfer coefficient of
nanofluid enhances with increase in heat flux. From the results, the
average ratio of (fnf/fbf) was about 1.10 for 0.5% volume
concentration. Therefore, there is no significant increase in friction
factor for nanofluids.
Abstract: Acoustic Imaging based sound localization using microphone
array is a challenging task in digital-signal processing.
Discrete Fourier transform (DFT) based near-field acoustical holography
(NAH) is an important acoustical technique for sound source
localization and provide an efficient solution to the ill-posed problem.
However, in practice, due to the usage of small curtailed aperture
and its consequence of significant spectral leakage, the DFT could
not reconstruct the active-region-of-sound (AROS) effectively, especially
near the edges of aperture. In this paper, we emphasize the
fundamental problems of DFT-based NAH, provide a solution to
spectral leakage effect by the extrapolation based on linear predictive
coding and 2D Tukey windowing. This approach has been tested to
localize the single and multi-point sound sources. We observe that
incorporating extrapolation technique increases the spatial resolution,
localization accuracy and reduces spectral leakage when small curtail
aperture with a lower number of sensors accounts.
Abstract: In this study it is aimed to determine the level of preservice teachers- computer phobia. Whether or not computer phobia meaningfully varies statistically according to gender and computer experience has been tested in the study. The study was performed on 430 pre-service teachers at the Education Faculty in Rize/Turkey. Data in the study were collected through the Computer Phobia Scale consisting of the “Personal Knowledge Questionnaire", “Computer Anxiety Rating Scale", and “Computer Thought Survey". In this study, data were analyzed with statistical processes such as t test, and correlation analysis. According to results of statistical analyses, computer phobia of male pre-service teachers does not statistically vary depending on their gender. Although male preservice teachers have higher computer anxiety scores, they have lower computer thought scores. It was also observed that there is a negative and intensive relation between computer experience and computer anxiety. Meanwhile it was found out that pre-service teachers using computer regularly indicated lower computer anxiety. Obtained results were tried to be discussed in terms of the number of computer classes in the Education Faculty curriculum, hours of computer class and the computer availability of student teachers.
Abstract: The purposes of this study are to study political
information exposure, politicians- perceptions, political attitudes and
political participations among people in Bangkok Metropolitan Area.
The sample consisted of 420 which were selected by using accidental sampling method. Questionnaires were administered to all of the
respondents to obtain the data for this research. T-test, one-way ANOVA and Pearson-s correlation coefficient were used to analyze the data. The findings are as follows: The difference in gender,
education, income and occupation has significantly effect upon political information exposures. The difference in age, income has
significantly effect upon politicians- perceptions. The difference in income has significantly effect upon political attitudes. The
difference in gender, income and occupation has significantly effect
upon political participations. There were a significantly relations between political information exposures, political attitudes, political
participations and between politicians- perceptions, political attitudes and political participations.
Abstract: In the last decades, the problem of perforation
damage has been considered as the major factor for the
reduction of oil productivity. Underbalance perforation is
considered as one of the best means to minimize or overcome
this problem. By maintaining wellbore pressure lower than
formation pressure, perforation damage could be minimize or
eliminated. This can be achieved by the use of nontraditional
lightweight completion fluid. This paper presents the effect of
natural clay in formulating nontraditional completion fluid to
ensure successful perforation job and increase of production
rate. Natural clay is used as homogenizing agent to create a
stable and non-damaging low-density completion fluid.
Results indicate that the addition of natural clay dramatically
increase the stability of the final fluids. In addition, field test
has shown that the application of nontraditional completion
fluid increases oil production by three folds.
Abstract: In this paper we describe our efforts to design and
implement an agent development framework that has the potential to
scale to the size of any underlying network suitable for various ECommerce
activities. The main novelty in our framework is it-s
capability to allow the development of sophisticated, secured agents
which are simple enough to be practical.
We have adopted FIPA agent platform reference Model as
backbone for implementation along with XML for agent
Communication and Java Cryptographic Extension and architecture
to realize the security of communication information between agents.
The advantage of our architecture is its support of agents
development in different languages and Communicating with each
other using a more open standard i.e. XML
Abstract: This work aims to test the application of computational fluid dynamics (CFD) modeling to fixed bed catalytic cracking reactors. Studies of CFD with a fixed bed design commonly use a regular packing with N=2 to define bed geometry. CFD allows us to obtain a more accurate view of the fluid flow and heat transfer mechanisms present in fixed bed equipment. Naphtha was used as feedstock and the reactor length was 80cm. It is divided in three sections that catalyst bed packed in the middle section of the reactor. The reaction scheme was involved one primary reaction and 24 secondary reactions. Because of high CPU times in these simulations, parallel processing have been used. In this study the coke formation process in fixed bed and empty tube reactor was simulated and coke in these reactors are compared. In addition, the effect of steam ratio and feed flow rate on coke formation was investigated.
Abstract: This research studied recycled wastes by Recyclable Material Bank project of 17 universities of Thailand for evaluation of reducing greenhouse gasses emission compared with landfilling activity during January 2011 to December 2011. The results showed that the projects collected total amount of recyclable wastes about 1,626.917 metric ton. The office paper has the largest amount among these recycled wastes (55.61 % of total recycled wastes). Groups of recycled waste can be prioritized from high to low according to their amount as paper, plastic, glass, mixed recyclables and metal, respectively. The project reduced greenhouse gasses emission equivalent to about 5,263.481 metric ton of carbon dioxide. The most significant recycled waste that affects the reduction of greenhouse gasses emission is office paper which is 73.45% of total reduced greenhouse gasses emission. According to amount of reduced greenhouse gasses emission, groups of recycled waste can be prioritized from high to low significances as paper, plastic, metal, mixed recyclables and glass, respectively.
Abstract: Residual dye contents in textile dyeing wastewater have complex aromatic structures that are resistant to degrade in biological wastewater treatment. The objectives of this study were to determine the effectiveness of nanoscale zerovalent iron (NZVI) to decolorize Reactive Black 5 (RB5) and Reactive Red 198 (RR198) in synthesized wastewater and to investigate the effects of the iron particle size, iron dosage and solution pHs on the destruction of RB5 and RR198. Synthesized NZVI was confirmed by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The removal kinetic rates (kobs) of RB5 (0.0109 min-1) and RR198 (0.0111 min-1) by 0.5% NZVI were many times higher than those of microscale zerovalent iron (ZVI) (0.0007 min-1 and 0.0008 min-1, respectively). The iron dosage increment exponentially increased the removal efficiencies of both RB5 and RR198. Additionally, lowering pH from 9 to 5 increased the decolorization kinetic rates of both RB5 and RR198 by NZVI. The destruction of azo bond (N=N) in the chromophore of both reactive dyes led to decolorization of dye solutions.
Abstract: Character segmentation is an important preprocessing
step for text recognition. In degraded documents, existence of
touching characters decreases recognition rate drastically, for any
optical character recognition (OCR) system. In this paper we have
proposed a complete solution for segmenting touching characters in
all the three zones of printed Gurmukhi script. A study of touching
Gurmukhi characters is carried out and these characters have been
divided into various categories after a careful analysis. Structural
properties of the Gurmukhi characters are used for defining the
categories. New algorithms have been proposed to segment the
touching characters in middle zone, upper zone and lower zone.
These algorithms have shown a reasonable improvement in
segmenting the touching characters in degraded printed Gurmukhi
script. The algorithms proposed in this paper are applicable only to
machine printed text. We have also discussed a new and useful
technique to segment the horizontally overlapping lines.
Abstract: The main objective of our study is to collect data
about the profile of the asthmatic patients in Assam and thereby have
a comprehensive knowledge of the factors influencing the asthmatic
patients of the state and their medication pattern. We developed a
search strategy to find any publication about the community based
survey asthma related and used. These to search the MEDLINE
(1996 to current literature) CINAHL DOAJ pubmed databases using
the key phrases, Asthma, Respiratory disorders, Drug therapy of
Asthma, database decision support system and asthma. The
appropriate literature was printed out from the online source and
library (Journal) source. The study was conducted through a set of
structured and non-structured questionnaires targeted on the
asthmatic patients belonging to the rural and urban areas of Assam,
during the month of Dec 2006 to July 2007, 138 cases were studied
in Gauwathi Medical College & Hospital located in Bhangagarh,
Assam in India. The demographic characteristics a factor in 138
patients with asthma with allergic rhinitis (cases) gives the detail
profile of asthmatic patient-s distribution of Assam as classified on
the basis of age and sex. It is evident from the study that male
populations (66%) are more prone to asthma as compared to the
females (34%).Another striking features that emerged from this
survey is the maximum prevalence of asthma in the age group of 20-
30 years followed by infants belonging to the age group of 7 (0.05%)
0-10years among both male and female populations of Assam. The
high incidence of asthma in the age group of 20-30 years may
probably be due to the allergy arising out of sudden exposure to dust
and pollen which the children face while playing and going to the
school. The rural females in the age group of 30-40 years are more
prone to asthma than urban females in the same age group may be
due to sex differentiation among the tribal population of the state.
Pharmacists should educate the asthmatics how to use inhalers
considering growing menace of asthma in the state. Safer drugs
should be produced in the form of aerosol so that easy administration
by the asthmatic patients and physicians of the state is possible for
curing asthma. The health centers should be more equipped with the
medicines to cure asthma in the state like Assam.
Abstract: The problem of agricultural-soil pollution is closely
linked to the production of ecologically pure foodstuffs and to human health. An important task, therefore, is to rehabilitate agricultural
soils with the help of state-of-the-art biotechnologies, based on the use of metal-accumulating plants. In this work, on the basis of
literature data and the results of prior research from this laboratory, plants were selected for which the growing technology is well
developed and which are widespread locally: sugar sorghum (Sorghum saccharatum), sudangrass (Sorghum sudanense (Piper.)
Stapf.), and sunflower (Helianthus annuus L.). I report on laboratory
experiments designed to study the influence of synthetic indole-3-
acetic acid and the extracellular indole-3-acetic acid released by the
plant-growth-promoting rhizobacterium Azospirillum brasilense Sp245 on growth of and arsenic accumulation by these plants.
Abstract: The present study aimed to investigate whether
chlorophyll meter readings (SPAD) can be used as criterion of singleplant
selection in maize breeding. Experimentation was performed at
the ultra-low density of 0.74 plants/m2 in order the potential yield per
plant to be fully expressed. R-31 honeycomb experiments were
conducted in three different areas in Greece (Thessaloniki, Giannitsa
and Florina) using 30 inbred lines at well-watered and water-stressed
conditions during the 2012 growing season. The chlorophyll meter
readings had higher rates at dry conditions, except location of
Giannitsa where differences were not significant. Genotypes of
highest chlorophyll meter readings were consistent across areas,
emphasizing on the character’s stability. A positive correlation
between the chlorophyll meter readings and grain yield was
strengthening over time and culminated at the physiological maturity
stage. There was a clear sign that the chlorophyll meter readings has
the potential to be used for the selection of stress-adaptive genotypes
and may permit modern maize to be grown at wider range of
environments addressing the climate change scenarios.
Abstract: Power system stability enhancement by simultaneous tuning of a Power System Stabilizer (PSS) and a Static Var Compensator (SVC)-based controller is thoroughly investigated in this paper. The coordination among the proposed damping stabilizers and the SVC internal voltage regulators has also been taken into consideration. The design problem is formulated as an optimization problem with a time-domain simulation-based objective function and Real-Coded Genetic Algorithm (RCGA) is employed to search for optimal controller parameters. The proposed stabilizers are tested on a weakly connected power system with different disturbances and loading conditions. The nonlinear simulation results are presented to show the effectiveness and robustness of the proposed control schemes over a wide range of loading conditions and disturbances. Further, the proposed design approach is found to be robust and improves stability effectively even under small disturbance and unbalanced fault conditions.
Abstract: The main purpose of this research was to study how to communicate the identity of the Bangpoo, Samu tPrakan province for ecotourism. The qualitative data was collected through studying related materials, exploring the area, in-depth interviews with three groups of people: three directly responsible officers who were key informants of the district, twenty foreign tourists and five Thai tourist guides. A content analysis was used to analyze the qualitative data. The two main findings of the study were as follows:
The identity of Bangpoo, Samut Prakan province. This establishment was near the Mouth of the Gulf of Thailand for normal people and tourists, consisting of rest accommodations. There are restaurants where food and drinks are served, rich mangrove forests, Banpoo seaside resort and mangrove trees. Bangpoo seaside resort is characterized by muddy beacheswhere the greatest number of seagulls can be seen from March to May each year.
The communication of the identity of Bangpoo, Samut Prakan province which the researcher could find and design to present in English materials can be summed up in 3 items: 1) The history of Bangpoo, Samut Prakan province 2) The Learning center of Ecotourism: Seagulls and Mangrove forest 3) How to keep Banpoo, Samut Prakran province for ecotourism.
Abstract: A novel low-cost impedance control structure is
proposed for monitoring the contact force between end-effector and
environment without installing an expensive force/torque sensor.
Theoretically, the end-effector contact force can be estimated from the
superposition of each joint control torque. There have a nonlinear
matrix mapping function between each joint motor control input and
end-effector actuating force/torques vector. This new force control
structure can be implemented based on this estimated mapping matrix.
First, the robot end-effector is manipulated to specified positions, then
the force controller is actuated based on the hall sensor current
feedback of each joint motor. The model-free fuzzy sliding mode
control (FSMC) strategy is employed to design the position and force
controllers, respectively. All the hardware circuits and software
control programs are designed on an Altera Nios II embedded
development kit to constitute an embedded system structure for a
retrofitted Mitsubishi 5 DOF robot. Experimental results show that PI
and FSMC force control algorithms can achieve reasonable contact
force monitoring objective based on this hardware control structure.
Abstract: This study shows the effect of carbon towards
molybdenum carbide alloy when exposed to Microwave. This
technique is also known as Microwave Induced Alloying (MIA) for
the preparation of molybdenum carbide. In this study ammonium
heptamolybdate solution and carbon black powder were
heterogeneously mixed and exposed to microwave irradiation for 2
minutes. The effect on amount of carbon towards the produced alloy
on morphological and oxidation states changes during microwave is
presented. In this experiment, it is expected carbon act as a reducing
agent with the ratio 2:7 molybdenum to carbon as the optimum for
the production of molybdenum carbide alloy. All the morphological
transformations and changes in this experiment were followed and
characterized using X-Ray Diffraction and FESEM.
Abstract: Because of the low maintenance and robustness induction motors have many applications in the industries. The speed control of induction motor is more important to achieve maximum torque and efficiency. Various speed control techniques like, Direct Torque Control, Sensorless Vector Control and Field Oriented Control are discussed in this paper. Soft computing technique – Fuzzy logic is applied in this paper for the speed control of induction motor to achieve maximum torque with minimum loss. The fuzzy logic controller is implemented using the Field Oriented Control technique as it provides better control of motor torque with high dynamic performance. The motor model is designed and membership functions are chosen according to the parameters of the motor model. The simulated design is tested using various tool boxes in MATLAB. The result concludes that the efficiency and reliability of the proposed speed controller is good.
Abstract: Copolymerization of ethylene with 1-hexene was
carried out using two ansa-fluorenyl titanium derivative complexes.
The substituent effect on the catalytic activity, monomer reactivity
ratio and polymer property was investigated. It was found that the
presence of t-Bu groups on fluorenyl ring exhibited remarkable
catalytic activity and produced polymer with high molecular weight.
However, these catalysts produce polymer with narrow molecular
weight distribution, indicating the characteristic of single-site
metallocene catalyst. Based on 13C NMR, we can observe that
monomer reactivity ratio was affected by catalyst structure. The rH
values of complex 2 were lower than that of complex 1 which might
be result from the higher steric hindrance leading to a reduction of 1-
hexene insertion step.
Abstract: Internet is without any doubt the fastest and effective mean of communication making it possible to reach a great number of people in the world. It draws its base from exchange points. Indeed exchange points are used to inter-connect various Internet suppliers and operators in order to allow them to exchange traffic and it is with these interconnections that Internet made its great strides. They thus make it possible to limit the traffic delivered via the operators of transits. This limitation allows a significant improvement of the quality of service, a reduction in the latency time just as a reduction of the cost of connection for the final subscriber. Through this article we will show how the installation of an IXP allows an improvement and a diversification of the services just as a reduction of the Internet connection costs.