Abstract: In this paper, a thermal model of cast- resin dry type
transformer is proposed. The proposed thermal model is solved by
finite element technique to get the temperature at any location of the
transformer. The basic modes of heat transfer such as conduction;
convection and radiation are used to get the steady state temperature
distribution of the transformer. The predicted temperatures are
compared with experimental results reported in this paper and it is
found a good agreement between them. The effects of various
parameters such as width of air duct, ambient temperature and
emissivity of the outer surface were also studied.
Abstract: This paper proposes the method combining artificial neural network with particle swarm optimization (PSO) to implement the maximum power point tracking (MPPT) by controlling the rotor speed of the wind generator. With the measurements of wind speed, rotor speed of wind generator and output power, the artificial neural network can be trained and the wind speed can be estimated. The proposed control system in this paper provides a manner for searching the maximum output power of wind generator even under the conditions of varying wind speed and load impedance.
Abstract: Packing problems arise in a wide variety of application
areas. The basic problem is that of determining an efficient arrangement
of different objects in a region without any overlap and
with minimal wasted gap between shapes. This paper presents a
novel population based approach for optimizing arrangement of irregular
shapes. In this approach, each shape is coded as an agent and
the agents' reproductions and grouping policies results in arrangements
of the objects in positions with least wasted area between
them. The approach is implemented in an application for cutting
sheets and test results on several problems from literature are presented.
Abstract: Liquid-liquid extraction is a process using two immiscible
liquids to extract compounds from one phase without high
temperature requirement. Mostly, the technical implementation of
this process is carried out in mixer-settlers or extraction columns. In
real chemical processes, chemicals may have high viscosity and
contain impurities. These impurities may change the settling behavior
of the process without measurably changing the physical properties
of the phases. In the current study, the settling behavior and the affected
parameters in a high-viscosity system were observed. Batchsettling
experiments were performed to experimentally quantify the
settling behavior and the mixer-settler model of Henschke [1] was
used to evaluate the behavior of the toluene + water system. The
viscosity of the system was increased by adding polyethylene glycol
4000 to the aqueous phase. NaCl and Na2SO4 were used to study the
influence of electrolytes. The results from this study show that increasing
the viscosity of water has a higher influence on the settling
behavior in comparison to the effects of the electrolytes. It can be
seen from the experiments that at high salt concentrations, there was
no effect on the settling behavior.
Abstract: The development and use of mobile devices as well as its integration within education systems to deliver electronic contents and to support real-time communications was the focus of this research. In order to investigate the software engineering issues in using mobile devices a research on electronic content was initiated. The Developed MP3 mobile software solution was developed as a prototype for testing and developing a strategy for designing a usable m-learning environment. The mobile software solution was evaluated using mobile device using the link: http://projects.seeu.edu.mk/mlearn. The investigation also tested the correlation between the two mobile learning indicators: electronic content and attention, based on the Task Based learning instructional method. The mobile software solution ''M-Learn“ was developed as a prototype for testing the approach and developing a strategy for designing usable m-learning environment. The proposed methodology is about what learning modeling approach is more appropriate to use when developing mobile learning software.
Abstract: This research paper designs a unique motion planner
of multiple platoons of nonholonomic car-like robots as a feasible
solution to the lane changing/merging maneuvers. The decentralized
planner with a leaderless approach and a path-guidance principle
derived from the Lyapunov-based control scheme generates collision
free avoidance and safe merging maneuvers from multiple lanes to a
single lane by deploying a split/merge strategy. The fixed obstacles
are the markings and boundaries of the road lanes, while the moving
obstacles are the robots themselves. Real and virtual road lane
markings and the boundaries of road lanes are incorporated into a
workspace to achieve the desired formation and configuration of the
robots. Convergence of the robots to goal configurations and the
repulsion of the robots from specified obstacles are achieved by
suitable attractive and repulsive potential field functions,
respectively. The results can be viewed as a significant contribution
to the avoidance algorithm of the intelligent vehicle systems (IVS).
Computer simulations highlight the effectiveness of the split/merge
strategy and the acceleration-based controllers.
Abstract: Fuel cell is an emerging technology in the field
of renewable energy sources which has the capacity to replace
conventional energy generation sources. Fuel cell utilizes hydrogen
energy to produce electricity. The electricity generated by the fuel
cell can’t be directly used for a specific application as it needs
proper power conditioning. Moreover, the output power fluctuates
with different operating conditions. To get a stable output power
at an economic rate, power conditioning circuit is essential for fuel
cell. This paper implements a two-staged power conditioning unit for
fuel cell based distributed generation using hysteresis current control
technique.
Abstract: According to the European laws, there is the
possibility of reusing the washing wastes for the environmental
requalification of quarry lakes. The paper deals with the
hydrogeological aspects involved in this possibility, as the
introduction of finest wastes in the quarry lakes can generate
alterations of the hydrogeological setting of the area, and problems
for the future accessibility of the zone. To evaluate the
hydrogeological compatibility of the washing wastes reuse in quarry
lakes a groundwater numerical model was carried out, pointing out
both the hydrogeological feasibility of this intervention and some
guide lines for its optimization, in terms of inflow point with regard
the groundwater flow direction and loss of volume in the quarry lake.
Abstract: This experiment was conducted to investigate the
effect of different levels of dietary chromium yeast (Cr-yeast) on
thigh meat quality of broiler chicks reared under heat stress
condition. Two hundred and forty Ross male chickens in heat stress
condition (33±3°C) were allocated to five treatments in a completely
randomized design. Treatments were supplemented with 0 (control),
200, 400, 800 and 1200 μg kg-1 Cr in the form of Cr yeast. Twelve
chicks from each treatment were slaughtered at 42 d, to evaluate
moisture, protein, lipid, pH and lipid oxidation of thigh meat.
Protein, moisture, lipid and pH of thigh meat were not affected by
supplemental Cr. Thigh meat lipid tended to decrease in broilers
received 1200 μg kg-1. Storage time increased lipid oxidation of
meat (P
Abstract: Over recent years, the number of building integrated photovoltaic (BIPV) installations for home systems have been increasing in Malaysia. The paper concerns an analysis - as part of current Research and Development (R&D) efforts - to integrate photovoltaics as an architectural feature of a detached house in the new satellite township of Putrajaya, Malaysia. The analysis was undertaken using calculation and simulation tools to optimize performance of BIPV home system. In this study, a the simulation analysis was undertaken for selected bungalow units based on a long term recorded weather data for city of Kuala Lumpur. The simulation and calculation was done with consideration of a PV panels' tilt and direction, shading effect and economical considerations. A simulation of the performance of a grid connected BIPV house in Kuala Lumpur was undertaken. This case study uses a 60 PV modules with power output of 2.7 kW giving an average of PV electricity output is 255 kWh/month..
Abstract: Transdermal delivery of ondansetron hydrochloride (OdHCl) can prevent the problems encountered with oral ondansetron. In previously conducted studies, effect of amount of polyvinyl pyrrolidone, permeation enhancer and casting solvent on the physicochemical properties on OdHCl were investigated. It is feasible to develop ondansetron transdermal patch by using ethyl cellulose and polyvinyl pyrrolidone with dibutyl pthalate as plasticizer, however, the desired flux is not achieved. The primary aim of this study is to use dimethyl succinate (DMS) and propylene glycol that are not incorporated in previous studies to determine their effect on the physicochemical properties of an OdHCl transdermal patch using ethyl cellulose and polyvinyl pyrrolidone. This study also investigates the effect of permeation enhancer (eugenol and phosphatidylcholine) on the release of OdHCl. The results showed that propylene glycol is a more suitable plasticizer compared to DMS in the fabrication of OdHCl transdermal patch using ethyl cellulose and polyvinyl pyrrolidone as polymers. Propylene glycol containing patch has optimum drug content, thickness, moisture content and water absorption, tensile strength, and a better release profile than DMS. Eugenol and phosphatidylcholine can increase release of OdHCl from the patches. From the physicochemical result and permeation profile, a combination of 350mg of ethyl cellulose, 150mg polyvinyl pyrrolidone, 3% of total polymer weight of eugenol, and 40% of total polymer weight of propylene glycol is the most suitable formulation to develop an OdHCl patch. OdHCl release did not increase with increasing the percentage of plasticiser. DMS 4, PG 4, DMS 9, PG 9, DMS 14, and PG 14 gave better release profiles where using 300mg: 0mg, 300mg: 100mg, and 350mg: 150mg of EC: PVP. Thus, 40% of PG or DMS appeared to be the optimum amount of plasticiser when the above combination where EC: PVP was used. It was concluded from the study that a patch formulation containing 350mg EC, 150mg PVP, 40% PG and 3% eugenol is the best transdermal matrix patch compositions for the uniform and continuous release/permeation of OdHCl over an extended period. This patch design can be used for further pharmacokinetic and pharmacodynamic studies in suitable animal models.
Abstract: This research studied the hypoglycemic effect of
water soluble polysaccharide (WSP) extracted from yam (Dioscorea
hispida) tuber by three different methods: aqueous extraction, papain
assisted extraction, and tempeh inoculums assisted extraction. The
two later extraction methods were aimed to remove WSP binding
protein to have more pure WSP. The hypoglycemic activities were
evaluated by means in vivo test on alloxan induced hyperglycemic
rats, glucose response test (GRT), in situ glucose absorption test
using everted sac, and short chain fatty acids (SCFAs) analysis. All
yam WSP extracts exhibited ability to decrease blood glucose level in
hyperglycemia condition as well as inhibited glucose absorption and
SCFA formation. The order of hypoglycemic activity was tempeh
inoculums assisted- >papain assisted- >aqueous WSP extracts. GRT
and in situ glucose absorption test showed that order of inhibition
was papain assisted- >tempeh inoculums assisted- >aqueous WSP
extracts. Digesta of caecum of yam WSP extracts oral fed rats had
more SCFA than control. Tempeh inoculums assisted WSP extract
exhibited the most significant hypoglycemic activity.
Abstract: The critical period for weed control (CPWC) is the period in the crop growth cycle during which weeds must be controlled to prevent unacceptable yield losses. Field studies were conducted in 2005 and 2006 in the University of Birjand at the south east of Iran to determine CPWC of corn using a randomized complete block design with 14 treatments and four replications. The treatments consisted of two different periods of weed interference, a critical weed-free period and a critical time of weed removal, were imposed at V3, V6, V9, V12, V15, and R1 (based on phonological stages of corn development) with a weedy check and a weed-free check. The CPWC was determined with the use of 2.5, 5, 10, 15 and 20% acceptable yield loss levels by non-linear Regression method and fitting Logistic and Gompertz nonlinear equations to relative yield data. The CPWC of corn was from 5- to 15-leaf stage (19-55 DAE) to prevent yield losses of 5%. This period to prevent yield losses of 2.5, 10 and 20% was 4- to 17-leaf stage (14-59 DAE), 6- to 12-leaf stage (25-47 DAE) and 8- to 9-leaf stage (31-36 DAE) respectively. The height and leaf area index of corn were significantly decreased by weed competition in both weed free and weed infested treatments (P
Abstract: In order to supplement the brittle property of concrete,
fibers are added into concrete mixtures. Compared to general concrete,
various characteristics such as tensile strength, bending strength,
bending toughness, and resistance to crack are superior, and even
when cracks occur, improvements on toughness as well as resistance
to shock are excellent due to the growth of fracture energy. Increased
function of steel fiber reinforced concrete can be differentiated
depending on the fiber dispersion, and sand percentage can be an
important influence on the fiber dispersion. Therefore, in this research,
experiments were planned on sand percentage in order to apprehend
the influence of sand percentage on the bending properties and direct
tension of SFRC and basic experiments were conducted on bending
and direct tension in order to recognize the properties of bending
properties and direct tension following the size of the aggregates and
sand percentage.
Abstract: This paper aims to argue that religion and Faith-based Organizations (FBOs) contribute to building democratic process through the provision of education in Sierra Leone. Sierra Leone experienced a civil war from 1991 to 2002 and about 70 percent of the population lives in poverty. While the government has been in the process of rebuilding the nation, many forms of Civil Society Organizations (CSOs), including FBOs, have played a significant role in promoting social development. Education plays an important role in supporting people-s democratic movements through knowledge acquisition, spiritual enlightenment and empowerment. This paper discusses religious tolerance in Sierra Leone and how FBOs have contributed to the provision of primary education in Sierra Leone. This study is based on the author-s field research, which involved interviews with teachers and development stakeholders, notably government officials, Non-governmental Organizations (NGOs) and FBOs, as well as questionnaires completed by pupils, parents and teachers.
Abstract: An accurate procedure to determine free vibrations of
beams and plates is presented.
The natural frequencies are exact solutions of governing vibration
equations witch load to a nonlinear homogeny system.
The bilinear and linear structures considered simulate a bridge.
The dynamic behavior of this one is analyzed by using the theory of
the orthotropic plate simply supported on two sides and free on the
two others. The plate can be excited by a convoy of constant or
harmonic loads. The determination of the dynamic response of the
structures considered requires knowledge of the free frequencies and
the shape modes of vibrations. Our work is in this context. Indeed,
we are interested to develop a self-consistent calculation of the Eigen
frequencies.
The formulation is based on the determination of the solution of
the differential equations of vibrations. The boundary conditions
corresponding to the shape modes permit to lead to a homogeneous
system. Determination of the noncommonplace solutions of this
system led to a nonlinear problem in Eigen frequencies.
We thus, develop a computer code for the determination of the
eigenvalues. It is based on a method of bisection with interpolation
whose precision reaches 10 -12. Moreover, to determine the
corresponding modes, the calculation algorithm that we develop uses
the method of Gauss with a partial optimization of the "pivots"
combined with an inverse power procedure. The Eigen frequencies
of a plate simply supported along two opposite sides while
considering the two other free sides are thus analyzed. The results
could be generalized with the case of a beam by regarding it as a
plate with low width.
We give, in this paper, some examples of treated cases. The
comparison with results presented in the literature is completely
satisfactory.
Abstract: Since atmosphere pressure field is an actual envoy of
climatic signal the atmospheric Highs and Lows should be attributed
to the key active focal points within the ocean-atmosphere interplay
system. Here we were set a task to determine how the dynamics of
those centres of action relates to the climate change both on regional
and global scales. For this target the near-surface temperature and
atmospheric pressure differences between the Icelandic Low and the
Azores High were considered. The secular term of phase states of the
system under consideration was found divided into three
nonintersecting subsets. Each of that was put in consequence with
one of three climatic scenarios related to the periods of 1905-1935
(relatively warm phase), 1940-1970 (cold phase) and 1980-2000
(warm phase).
Abstract: In this paper, a new method is proposed to find the fuzzy optimal solution of fuzzy assignment problems by representing all the parameters as triangular fuzzy numbers. The advantages of the pro-posed method are also discussed. To illustrate the proposed method a fuzzy assignment problem is solved by using the proposed method and the obtained results are discussed. The proposed method is easy to understand and to apply for finding the fuzzy optimal solution of fuzzy assignment problems occurring in real life situations.
Abstract: This paper presents a simple and effective method for approximate indexing of instances for instance based learning. The method uses an interval tree to determine a good starting search point for the nearest neighbor. The search stops when an early stopping criterion is met. The method proved to be very effective especially when only the first nearest neighbor is required.
Abstract: The improvement of irrigation systems in the Nile
Delta is one of the most important attempts in Egypt to implement
more effective irrigation technology by improving the existing
irrigation networks. Demand delivery system in the existing irrigation
network is using of mechanical gates structures to automatically
divert water from one portion of an agricultural field to another in the
desired amount and sequence. This paper discusses evaluating main
irrigation networks system under the government managed before
and after improvement systems in the Nile Delta. The overall results
indicate that policy of using the demand delivery concept through
irrigation networks is successful by improving water delivery
performance among them than the rotation delivery concept that used
before. It is provided fair share of water delivery among irrigation
districts and available water in the end of irrigation network,
although this system located in an end of irrigation networks in the
Nile Delta.