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: The RANS method with Saffman-s turbulence model
was employed to solve the time-dependent turbulent Navier-Stokes
and energy equations for oscillating pipe flows. The method of
partial sums of the Fourier series is used to analyze the harmonic
velocity and temperature results. The complete structures of the
oscillating pipe flows and the averaged Nusselt numbers on the tube
wall are provided by numerical simulation over wide ranges of ReA
and ReR. Present numerical code is validated by comparing the
laminar flow results to analytic solutions and turbulence flow results
to published experimental data at lower and higher Reynolds
numbers respectively. The effects of ReA and ReR on the velocity,
temperature and Nusselt number distributions have been di scussed.
The enhancement of the heat transfer due to oscillating flows has
also been presented. By the way of analyzing the overall Nusselt
number over wide ranges of the Reynolds number Re and Keulegan-
Carpenter number KC, the optimal ratio of the tube diameter over
the oscillation amplitude is obtained based on the existence of a
nearly constant optimal KC number. The potential application of the
present results in sea water cooling has also been discussed.
Abstract: We propose photo-BJMOSFET (Bipolar Junction Metal-Oxide-Semiconductor Field Effect Transistor) fabricated on SOI film. ITO film is adopted in the device as gate electrode to reduce light absorption. I-V characteristics of photo-BJMOSFET obtained in dark (dark current) and under 570nm illumination (photo current) are studied furthermore to achieve high photo-to-dark-current contrast ratio. Two variables in the calculation were the channel length and the thickness of the film which were set equal to six different values, i.e., L=2, 4, 6, 8, 10, and 12μm and three different values, i.e., dsi =100, 200 and 300nm, respectively. The results indicate that the greatest photo-to-dark-current contrast ratio is achieved with L=10μm and dsi=200 nm at VGK=0.6V.
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.
Abstract: Spray chilling using air-mist nozzles has received
much attention in the food processing industry because of the
benefits it has shown over forced air convection. These benefits
include an increase in the heat transfer coefficient and a reduction in
the water loss by the product during cooling. However, few studies
have simulated the heat transfer and aerodynamics phenomena of the
air-mist chilling process for optimal operating conditions. The study
provides insight into the optimal conditions for spray impaction, heat
transfer efficiency and control of surface flooding. A computational
fluid dynamics model using a two-phase flow composed of water
droplets injected with air is developed to simulate the air-mist
chilling of food products. The model takes into consideration
droplet-to-surface interaction, water-film accumulation and surface
runoff. The results of this study lead to a better understanding of the
heat transfer enhancement, water conservation, and to a clear
direction for the optimal design of air-mist chilling systems that can
be used in commercial applications in the food and meat processing
industries.
Abstract: Four phenylurea herbicides (isoproturon, chlortoluron, diuron and linuron) were dissolved in different water matrices in order to study their chemical degradation by using UV radiation, ozone and some advanced oxidation processes (UV/H2O2, O3/H2O2, Fenton reagent and the photo- Fenton system). The waters used were: ultra-pure water, a commercial mineral water, a groundwater and a surface water taken from a reservoir. Elimination levels were established for each herbicide and for several global quality parameters, and a kinetic study was performed in order to determine basic kinetic parameters of each reaction between the target phenylureas and these oxidizing systems.
Abstract: This paper shows the results obtained in the analysis
of the impact of distributed generation (DG) on distribution losses
and presents a new algorithm to the optimal allocation of distributed
generation resources in distribution networks. The optimization is
based on a Hybrid Genetic Algorithm and Particle Swarm
Optimization (HGAPSO) aiming to optimal DG allocation in
distribution network. Through this algorithm a significant
improvement in the optimization goal is achieved. With a numerical
example the superiority of the proposed algorithm is demonstrated in
comparison with the simple genetic algorithm.
Abstract: A major goal of any enterprise is to create a ratings
system of customer satisfaction, goods and services. It is obvious that
the company cannot change what is not measured. In order to get a
clearer picture of the preferences of the major consumer groups, this
stage should be based on extensive research, including a variety of
interviews and surveys. It is necessary to know the key benefits,
which determine customer satisfaction in the market segment, of the
properties of certain goods and services. It is important to estimate
the terms of these preferences from the viewpoint of the client. This
article discusses the importance of customer satisfaction, and ways of
assessing it.
Abstract: An ordered porous antimony-doped tin oxide (ATO) film was successfully prepared using a simple coating process with colloidal templates. The facile production was effective when a combination of 16-nm ATO (as a model of an inorganic nanoparticle) and polystyrene (PS) spheres (as a model of the template) weresimply coated to produce a composite ATO/PS film. Heat treatment was then used to remove the PS and produce the porous film. The porous film with a spherical pore shape and a highly ordered porous structure could be obtained. A potential way for the control of pore size could be also achieved by changing initial template size. The theoretical explanation and mechanism of porous formation were also added, which would be important for the scaling-up prediction and estimation.
Abstract: The compatibility of optical resonators with microfluidic systems may be relevant for chemical and biological applications. Here, a fluorescent-core microcavity (FCM) is investigated as a refractometric sensor for heavy oils. A high-index film of silicon quantum dots (QDs) was formed inside the capillary, supporting cylindrical fluorescence whispering gallery modes (WGMs). A set of standard refractive index oils was injected into a capillary, causing a shift of the WGM resonances toward longer wavelengths. A maximum sensitivity of 240 nm/RIU (refractive index unit) was found for a nominal oil index of 1.74. As well, a sensitivity of 22 nm/RIU was obtained for a lower index of 1.48, more typical of fuel hydrocarbons. Furthermore, the observed spectra and sensitivities were compared to theoretical predictions and reproduced via FDTD simulations, showing in general an excellent agreement. This work demonstrates the potential use of FCMs for oil sensing applications and the more generally for detecting liquid solutions with a high refractive index or high viscosity.
Abstract: New regulations and standards for noise emission increasingly compel the automotive firms to make some improvements about decreasing the engine noise. Nowadays, the perforated reactive mufflers which have an effective damping capability are specifically used for this purpose. New designs should be analyzed with respect to both acoustics and back pressure. In this study, a reactive perforated muffler is investigated numerically and experimentally. For an acoustical analysis, the transmission loss which is independent of sound source of the present cross flow, the perforated muffler was analyzed by COMSOL. To be able to validate the numerical results, transmission loss was measured experimentally. Back pressure was obtained based on the flow field analysis and was also compared with experimental results. Numerical results have an approximate error of 20% compared to experimental results.
Abstract: The aim of the present study was to investigate the
chemical and biological properties of local cowpea seed protein
cultivated in Gizan region. The results showed that the cowpea and
its products contain high level of protein (22.9-77.6%), high
carbohydrates (9.4-64.3%) and low fats (0.1-0.3%). The trypsin and
chymotrypsin activities were found to be 32.2 and 15.2 units,
respectively. These activities were not affected in both defatted and
protein concentrate whereas they were significantly reduced in
isolated protein and cooked samples. The phytate content of cooked
and concentrated cowpea samples varied from 0.25% -0.32%,
respectively. Tannin content was found to be 0.4% and 0.23% for
cooked and raw samples, respectively. The in vitro protein
digestibility was very high in cowpea seeds (75.04-78.76%). The
biological evaluation using rats showed that the group fed with
animal feed containing casein gain more weight than those fed with
that containing cowpea. However, the group fed with cooked cowpea
gain more weight than those fed with uncooked cowpea. On the
other hand, in vivo digestion showed high value (98.33%) among the
group consumed casein compared to other groups those consumed
cowpea contains feed. This could be attributed to low antinutritional
factors in casein contains feed compared to those of cowpea contains
feed because cooking significantly increased the digestion rate
(80.8% to 83.5%) of cowpea contains feed. Furthermore, the
biological evaluation was high (91.67%) of casein containing feed
compared to that of cowpea containing feed (80.83%-87.5%). The
net protein utilization (NPU) was higher (89.67%) in the group fed
with casein containing feed than that of cowpea containing feed
(56.33%-69.67%).
Abstract: The State of Rio de Janeiro, Brazil, will hold two important events in the nearby future. In 2014 it will have the final game of the Football World Cup, and in 2016 it will be holding the Olympic Games. Therefore, the public transportation system (mainly buses) is of a major concern to the Rio de Janeiro State authorities-. The main objective of this work is to compare the quality of service of the bus companies operating in the cities of ItaperunaandCampos, both cities situated in the state of Rio de Janeiro, Brazil. The outcome of thiscomparison, based on the opinion of the bus users, has shownthemdispleased with the quality of the service provided by the bus companies operating in both cities. It is urgent the need to find possible practical alternatives to minimize the consequences of the main problems detected in this work. With these practical alternatives available, we will be able to offer to the Rio de Janeiro State authorities- suggestions about possible solutions to the main problems identified in this survey, as well as the time of implantation and costs of these solutions.
Abstract: The flow field over a flat roof model building has been numerically investigated in order to determine threedimensional CFD guidelines for the calculation of the turbulent flow over a structure immersed in an atmospheric boundary layer. To this purpose, a complete validation campaign has been performed through a systematic comparison of numerical simulations with wind tunnel experimental data. Wind tunnel measurements and numerical predictions have been compared for five different vertical positions, respectively from the upstream leading edge to the downstream bottom edge of the analyzed model. Flow field characteristics in the neighborhood of the building model have been numerically investigated, allowing a quantification of the capabilities of the CFD code to predict the flow separation and the extension of the recirculation regions. The proposed calculations have allowed the development of a preliminary procedure to be used as guidance in selecting the appropriate grid configuration and corresponding turbulence model for the prediction of the flow field over a three-dimensional roof architecture dominated by flow separation.
Abstract: Principally, plants grown in soilless culture may be
attacked by the same pests and diseases as cultivated traditionally in
soil. The most destructive phytopathogens are fungi, such as
Phythium, Phytophthora and Fusarium, followed by viruses, bacteria
and nematodes. We investigated effect of carbon nanotube filters on
disease management of soilless culture. Tomato seedlings transplant
in plastic pots filled with a soilless media of vermiculite. The crop
irrigated and fertilized using a hydroponic nutrient solution. We used
carbon nanotube filters for nutrient solution disinfection. Our results
show that carbon nanotube filtration significantly reduces pathogens
on tomato plants. Fungal elimination (Fusarium oxysporum and
Pythium spp.) was usually successful at about 96 to 99.9% all over
the cultural season. It is seem that in tomato soilless culture,
nanofiltration constitutes a reliable method that allows control of the
development of diseases caused by pathogenic fungi
Abstract: Two Amphiphilic catalysts, iron (III) dodecylbenzene
sulfonate and nickel (II) dodecylbenzene sulfonate, were synthesized
and used in the catalytic aquathermolysis of heavy crude oil to reduce
its viscosity. The prepared catalysts exhibited good performance in
the aquathermolysis and the viscosity is reduced by ~ 78.9 % for
Egyptian heavy crude oil. The chemical and physical properties of
heavy oil both before and after reaction were investigated by FT-IR,
dynamic viscosity, molecular weight and SARA analysis. The results
indicated that the content of resin, asphaltene, average molecular
weight and sulfur content of heavy oil is reduced after the catalytic
aquathermolysis.
Abstract: The Far From Most Strings Problem (FFMSP) is to obtain a string which is far from as many as possible of a given set of strings. All the input and the output strings are of the same length, and two strings are said to be far if their hamming distance is greater than or equal to a given positive integer. FFMSP belongs to the class of sequences consensus problems which have applications in molecular biology. The problem is NP-hard; it does not admit a constant-ratio approximation either, unless P = NP. Therefore, in addition to exact and approximate algorithms, (meta)heuristic algorithms have been proposed for the problem in recent years. On the other hand, in the recent years, hybrid algorithms have been proposed and successfully used for many hard problems in a variety of domains. In this paper, a new metaheuristic algorithm, called Constructive Beam and Local Search (CBLS), is investigated for the problem, which is a hybridization of constructive beam search and local search algorithms. More specifically, the proposed algorithm consists of two phases, the first phase is to obtain several candidate solutions via the constructive beam search and the second phase is to apply local search to the candidate solutions obtained by the first phase. The best solution found is returned as the final solution to the problem. The proposed algorithm is also similar to memetic algorithms in the sense that both use local search to further improve individual solutions. The CBLS algorithm is compared with the most recent published algorithm for the problem, GRASP, with significantly positive results; the improvement is by order of magnitudes in most cases.
Abstract: This paper describes a novel approach for deriving
modules from protein-protein interaction networks, which combines
functional information with topological properties of the network.
This approach is based on weighted clustering coefficient, which
uses weights representing the functional similarities between the
proteins. These weights are calculated according to the semantic
similarity between the proteins, which is based on their Gene
Ontology terms. We recently proposed an algorithm for identification
of functional modules, called SWEMODE (Semantic WEights for
MODule Elucidation), that identifies dense sub-graphs containing
functionally similar proteins. The rational underlying this approach is
that each module can be reduced to a set of triangles (protein triplets
connected to each other). Here, we propose considering semantic
similarity weights of all triangle-forming edges between proteins. We
also apply varying semantic similarity thresholds between
neighbours of each node that are not neighbours to each other (and
hereby do not form a triangle), to derive new potential triangles to
include in module-defining procedure. The results show an
improvement of pure topological approach, in terms of number of
predicted modules that match known complexes.