Abstract: Today-s Voltage Regulator Modules (VRMs) face increasing design challenges as the number of transistors in microprocessors increases per Moore-s Law. These challenges have recently become even more demanding as microprocessors operate at sub voltage range at significantly high current. This paper presents a new multiphase topology with cell configuration for improved performance in low voltage and high current applications. A lab scale hardware prototype of the new topology was design and constructed. Laboratory tests were performed on the proposed converter and compared with a commercially available VRM. Results from the proposed topology exhibit improved performance compared to the commercially available counterpart.
Abstract: This research were investigated, determined, and
analyzed of the climate characteristically change in the provincial
Udon Thani in the period of 60 surrounding years from 1951 to 2010
A.D. that it-s transferred to effects of climatologically data for
determining global warming. Statistically significant were not found
for the 60 years- data (R2
Abstract: This paper presents a novel methodology for Maximum Power Point Tracking (MPPT) of a grid-connected 20 kW Photovoltaic (PV) system using neuro-fuzzy network. The proposed method predicts the reference PV voltage guarantying optimal power transfer between the PV generator and the main utility grid. The neuro-fuzzy network is composed of a fuzzy rule-based classifier and three Radial Basis Function Neural Networks (RBFNN). Inputs of the network (irradiance and temperature) are classified before they are fed into the appropriated RBFNN for either training or estimation process while the output is the reference voltage. The main advantage of the proposed methodology, comparing to a conventional single neural network-based approach, is the distinct generalization ability regarding to the nonlinear and dynamic behavior of a PV generator. In fact, the neuro-fuzzy network is a neural network based multi-model machine learning that defines a set of local models emulating the complex and non-linear behavior of a PV generator under a wide range of operating conditions. Simulation results under several rapid irradiance variations proved that the proposed MPPT method fulfilled the highest efficiency comparing to a conventional single neural network.
Abstract: The main issue in sweetening natural gas is H2S
dissociation. The present study is concerned with simulating thermal
dissociation of H2S in industrial natural gas carbon black furnace.
The comparison of calculated results against experimental
measurements shows good agreement. The results show that sulfur
derived from H2S thermal dissociation peaked at φ=0.95. H2S
thermal dissociation is enhanced in equivalence ratio upper than 1
and H2S oxidization is increased in equivalence ratio lower than 1.
H2 concentration of H2S thermal dissociation is increased with
increase of equivalence ratio up to 1. Also, H2S concentration
decreased in outlet as equivalence ratio increases. H2S thermal
dissociation to hydrogen and Sulfur reduces its toxic characteristics
and make economical benefits.
Abstract: Nanomaterials have attracted considerable attention
during the last two decades, due to their unusual electrical, mechanical
and other physical properties as compared with their bulky
counterparts. The mechanical properties of nanostructured materials
show strong size dependency, which has been explained within the
framework of continuum mechanics by including the effects of surface
stress. The size-dependent deformations of two-dimensional
nanosized structures with surface effects are investigated in the paper
by the finite element method. Truss element is used to evaluate the
contribution of surface stress to the total potential energy and the
Gurtin and Murdoch surface stress model is implemented with
ANSYS through its user programmable features. The proposed
approach is used to investigate size-dependent stress concentration
around a nanosized circular hole and the size-dependent effective
moduli of nanoporous materials. Numerical results are compared with
available analytical results to validate the proposed modeling
approach.
Abstract: Paper presents knowledge about types of test in area
of materials properties of selected methods of rapid prototyping
technologies. In today used rapid prototyping technologies for
production of models and final parts are used materials in initial state
as solid, liquid or powder material structure. In solid state are used
various forms such as pellets, wire or laminates. Basic range
materials include paper, nylon, wax, resins, metals and ceramics. In
Fused Deposition Modeling (FDM) rapid prototyping technology are
mainly used as basic materials ABS (Acrylonitrile Butadiene
Styrene), polyamide, polycarbonate, polyethylene and polypropylene.
For advanced FDM applications are used special materials as silicon
nitrate, PZT (Piezoceramic Material - Lead Zirconate Titanate),
aluminium oxide, hydroxypatite and stainless steel.
Abstract: The aim of this article is to narrate the utility of novel simulation approach i.e. convolution method to predict blood concentration of drug utilizing dissolution data of salbutamol sulphate microparticulate formulations with different release patterns (1:1, 1:2 and 1:3, drug:polymer). Dissolution apparatus II USP 2007 and 900 ml double distilled water stirrd at 50 rpm was employed for dissolution analysis. From dissolution data, blood drug concentration was determined, and in return predicted blood drug concentration data was used to calculate the pharmacokinetic parameters i.e. Cmax, Tmax, and AUC. Convolution is a good biwaiver technique; however its better utility needs it application in the conditions where biorelevant dissolution media are used.
Abstract: Knowledge capabilities are increasingly important for
the innovative technology enterprises to enhance the business
performance in terms of product competitiveness, innovation and
sales. Recognition of the company capability by auditing allows them
to further pursue advancement, strategic planning and hence gain
competitive advantages. This paper attempts to develop an
Organizations- Knowledge Capabilities Assessment (OKCA) method
to assess the knowledge capabilities of technology companies. The
OKCA is a questionnaire-based assessment tool which has been
developed to uncover the impact of various knowledge capabilities on
different organizational performance. The collected data is then
analyzed to find out the crucial elements for different technological
companies. Based on the results, innovative technology enterprises are
able to recognize the direction for further improvement on business
performance and future development plan. External environmental
factors affecting organization performance can be found through the
further analysis of some selected reference companies.
Abstract: This paper investigates the aerodynamic characters of a model ducted fan system, analyses the basic principle of the effect of thrust promotion and torque reduction, discovers the relationship between the revolutions per minute(RPM) of the fan and the characters of thrust, as well as system torque. Firstly a model ducted fan has been designed and manufactured according to the specific structure of flow field, then CFD simulation has been carried out to analyze such aerodynamics, finally bench tests have been used to validate the simulation results and system configuration.
Abstract: A study was conducted to determine the effect of
feeding glycerol on dairy cows performance. Twenty four Holstein
Friesian crossbred (>87.5% Holstein Friesian) lactating dairy cows in
early lactation; averaging 13+2.4 kg of milk, 64+45 days in milk,
55+16 months old and 325+26 kg live weight, were stratified for
milk yield, days in milk, age, stage of lactation and body weight, and
then randomly allocated to three treatment groups. All cows were fed
approximate 8 kg of concentrate together with ad libitum corn silage
and freely access to clean water. Nil or 150 and 300g of glycerol
were supplemented to the cows according to treatment groups. All
cows consumed similar concentrate, corn silage and total DM and
NELP. There were no significant differences in DM intake, CP intake,
NELP intake, milk and milk composition yields. All cows had similar
fat, protein, lactose, solid not fat and total solid percentage. All cows
gain similar live weight. The present study indicated that,
supplementation of glycerol did not enhance milk yield, milk
composition and live weight change.
Abstract: A new generation of manufacturing machines
so-called MIMCA (modular and integrated machine control
architecture) capable of handling much increased complexity in
manufacturing control-systems is presented. Requirement for more
flexible and effective control systems for manufacturing machine
systems is investigated and dimensioned-which highlights a need for
improved means of coordinating and monitoring production
machinery and equipment used to- transport material. The MIMCA
supports simulation based on machine modeling, was conceived by
the authors to address the issues. Essentially MIMCA comprises an
organized unification of selected architectural frameworks and
modeling methods, which include: NISTRCS, UMC and Colored
Timed Petri nets (CTPN). The unification has been achieved; to
support the design and construction of hierarchical and distributed
machine control which realized the concurrent operation of reusable
and distributed machine control components; ability to handle
growing complexity; and support requirements for real- time control
systems. Thus MIMCA enables mapping between 'what a machine
should do' and 'how the machine does it' in a well-defined but
flexible way designed to facilitate reconfiguration of machine
systems.
Abstract: Ultrastructure of duodenum mucosa of irradiated rat
was studied versus dose rate of irradiation following exposure to
gamma rays from 60-Cobalt source. The animals were whole body
irradiated at two dose rates (1 Gy.mn-1 and 1 Gy.h-1) and three total
doses (1, 2 or 4 Gy) for each dose rate. 24 or 48 h after irradiation,
their small intestine was removed and samples of duodenum were
processed for observations under a transmission electron microscopy.
Samples of duodenum mucosa of control rats were processed in the
same way. For the lower dose rate of 1 Gy.h-1, main lesions
characteristic of apoptosis were detected within irradiated enterocytes
at a total dose of 2 Gy and 24 h after exposure. Necrosis was noted in
the samples, 48 h after exposition. For the higher dose rate of 1
Gy.mn-1, fewer changes were detected at all total doses 24 or 48 h
irradiation. Thus, it was shown that the appearance of radiationinduced
alterations varies not only with increasing total dose and
post-irradiation time but especially with decreasing dose rate.
Abstract: Sunflower stalks were analysed for chemical
compositions: pentosan 15.84%, holocellulose 70.69%,
alphacellulose 45.74%, glucose 27.10% and xylose 7.69% based on
dry weight of 100-g raw material. The most optimum condition for
steam explosion pretreatment was as follows. Sunflower stalks were
cut into small pieces and soaked in 0.02 M H2SO4 for overnight.
After that, they were steam exploded at 207 C and 21 kg/cm2 for 3
minutes to fractionate cellulose, hemicellulose and lignin. The
resulting hydrolysate, containing hemicellulose, and cellulose pulp
contained xylose sugar at 2.53% and 7.00%, respectively.The pulp
was further subjected to enzymatic saccharification at 50 C, pH 4.8 citrate buffer) with pulp/buffer 6% (w/w)and Celluclast 1.5L/pulp
2.67% (w/w) to obtain single glucose with maximum yield 11.97%.
After fixed-bed fermentation under optimum condition using
conventional yeast mixtures to produce bioethanol, it indicated
maximum ethanol yield of 0.028 g/100 g sunflower stalk.
Abstract: This paper focuses on the use of project work as a
pretext for applying the conventions of writing, or the correctness of
mechanics, usage, and sentence formation, in a content-based class in
a Rajabhat University. Its aim was to explore to what extent the
student teachers’ academic achievement of the basic writing features
against the 70% attainment target after the use of project is. The
organization of work around an agreed theme in which the students
reproduce language provided by texts and instructors is expected to
enhance students’ correct writing conventions. The sample of the
study comprised of 38 fourth-year English major students. The data
was collected by means of achievement test and student writing
works. The scores in the summative achievement test were analyzed
by mean score, standard deviation, and percentage. It was found that
the student teachers do more achieve of practicing mechanics and
usage, and less in sentence formation. The students benefited from
the exposure to texts during conducting the project; however, their
automaticity of how and when to form phrases and clauses into
simple/complex sentences had room for improvement.
Abstract: On-line handwritten scripts are usually dealt with pen tip traces from pen-down to pen-up positions. Time evaluation of the pen coordinates is also considered along with trajectory information. However, the data obtained needs a lot of preprocessing including filtering, smoothing, slant removing and size normalization before recognition process. Instead of doing such lengthy preprocessing, this paper presents a simple approach to extract the useful character information. This work evaluates the use of the counter- propagation neural network (CPN) and presents feature extraction mechanism in full detail to work with on-line handwriting recognition. The obtained recognition rates were 60% to 94% using the CPN for different sets of character samples. This paper also describes a performance study in which a recognition mechanism with multiple thresholds is evaluated for counter-propagation architecture. The results indicate that the application of multiple thresholds has significant effect on recognition mechanism. The method is applicable for off-line character recognition as well. The technique is tested for upper-case English alphabets for a number of different styles from different peoples.
Abstract: Application of pesticides in the paddy fields has
deleterious effects on non-target organisms including cyanobacteria
which are photosynthesizing and nitrogen fixing micro-organisms
contributing significantly towards soil fertility and crop yield.
Pesticide contamination in the paddy fields has manifested into a
serious global environmental concern. To study the effect of one such
pesticide, three cyanobacterial strains; Anabaena fertilissima,
Aulosira fertilissima and Westiellopsis prolifica were selected for
their stress responses to an Organochlorine insecticide - 6, 7, 8, 9, 10,
10-hexachloro-1, 5, 5a, 6, 9, 9a-hexahydro-6, 9-methano-2, 4, 3-
benzodioxathiepine-3-oxide, with reference to their photosynthesic
pigments-chlorophyll-a and carotenoids as well as accessory
pigments-phycobiliproteins (phycocyanin, allophycocyanin and
phycoerythrin), stress induced biochemical metabolites like
carbohydrates, proteins, amino acids, phenols and enzymes-nitrate
reductase, glutamine synthetase and succinate dehydrogenase. All
the three cyanobacterial strains were adversely affected by the
insecticide doses and inhibition was dose dependent. Reduction in
photosynthetic and accessory pigments, metabolites, nitrogen fixing
and respiratory enzymes of the test organisms were accompanied
with an initial increase in their total protein at lower Organochlorine
doses. On the other hand, increased amount of phenols in all the
insecticide treated concentrations was indicative of stressed activities
of the organisms.
Abstract: In this study, direct numerical simulation for the bubble condensation in the subcooled boiling flow was performed. The main goal was to develop the CFD modeling for the bubble condensation and to evaluate the accuracy of the VOF model with the developed CFD modeling. CFD modeling for the bubble condensation was developed by modeling the source terms in the governing equations of VOF model using UDF. In the modeling, the amount of condensation was determined using the interfacial heat transfer coefficient obtained from the bubble velocity, liquid temperature and bubble diameter every time step. To evaluate the VOF model using the CFD modeling for the bubble condensation, CFD simulation results were compared with SNU experimental results such as bubble volume and shape, interfacial area, bubble diameter and bubble velocity. Simulation results predicted well the behavior of the actual condensing bubble. Therefore, it can be concluded that the VOF model using the CFD modeling for the bubble condensation will be a useful computational fluid dynamics tool for analyzing the behavior of the condensing bubble in a wide range of the subcooled boiling flow.
Abstract: The paper reports the preparation and photocatalytic
activity of ZnO/SnO2 and SnO2 nanoparticles. These nanoparticles
were synthesized by hydrothermal method. The products were
characterized by X-ray diffraction (XRD) and scanning electron
microscopy (SEM). Their grain sizes are about 50-100 nm. The
photocatalytic activities of these materials were investigated for
congo red removal from aqueous solution under UV light irradiation.
It was shown that the use of ZnO/SnO2 as photocatalyst have better
photocatalytic activity for degradation of congo red than SnO2 or
TiO2 (anatase, particle size: 30nm) alone.
Abstract: Most real world systems express themselves formally
as a set of nonlinear algebraic equations. As applications grow, the
size and complexity of these equations also increase. In this work, we
highlight the key concepts in using the homotopy analysis method
as a methodology used to construct efficient iteration formulas for
nonlinear equations solving. The proposed method is experimentally
characterized according to a set of determined parameters which
affect the systems. The experimental results show the potential and
limitations of the new method and imply directions for future work.
Abstract: The Želazny Most tailing pond is one of the largest
facilities worldwide for waste disposal from the copper mines located
in South-West Poland. A potential failure of the dam would allow
more than 10 million cubic meters of contaminated slurry to flow to
the valley, causing immense environmental problems to the
surrounding area. Thus, the determination of the strength properties
of the dam's soils and their variability is of utmost importance.
An extensive site investigation consisting of more than 480 cone
penetration tests (CPTs) with or without pore water pressure
measurements were conducted within a period of 13 years to study
the mechanical properties of the tailings body. The present work
investigates the point variability of the soil strength parameters
(effective friction angle