Abstract: Axial flow fans, while incapable of developing high
pressures, they are well suitable for handling large volumes of air at
relatively low pressures. In general, they are low in cost and possess
good efficiency, and can have blades of airfoil shape. Axial flow fans
show good efficiencies, and can operate at high static pressures if
such operation is necessary. Our objective is to model and analyze
the flow through AXIAL FANS using CFD Software and draw
inference from the obtained results, so as to get maximum efficiency.
The performance of an axial fan was simulated using CFD and the
effect of variation of different parameters such as the blade number,
noise level, velocity, temperature and pressure distribution on the
blade surface was studied. This paper aims to present a final 3D CAD
model of axial flow fan. Adapting this model to the available
components in the market, the first optimization was done. After this
step, CFX flow solver is used to do the necessary numerical analyses
on the aerodynamic performance of this model. This analysis results
in a final optimization of the proposed 3D model which is presented
in this article.
Abstract: Laplace transformations have wide applications in
engineering and sciences. All previous studies of modified Laplace
transformations depend on differential equation with initial
conditions. The purpose of our paper is to solve the linear differential
equations (not initial value problem) and then find the general
solution (not particular) via the Laplace transformations without
needed any initial condition. The study involves both types of
differential equations, ordinary and partial.
Abstract: Self-compacting concrete (SCC) developed in Japan
in the late 80s has enabled the construction industry to reduce
demand on the resources, improve the work condition and also
reduce the impact of environment by elimination of the need for
compaction. Fuzzy logic (FL) approaches has recently been used to
model some of the human activities in many areas of civil
engineering applications. Especially from these systems in the model
experimental studies, very good results have been obtained. In the
present study, a model for predicting compressive strength of SCC
containing various proportions of fly ash, as partial replacement of
cement has been developed by using Fuzzy Inference System (FIS).
For the purpose of building this model, a database of experimental
data were gathered from the literature and used for training and
testing the model. The used data as the inputs of fuzzy logic models
are arranged in a format of five parameters that cover the total binder
content, fly ash replacement percentage, water content,
superplasticizer and age of specimens. The training and testing results
in the fuzzy logic model have shown a strong potential for predicting
the compressive strength of SCC containing fly ash in the considered
range.
Abstract: Bamboo is extensively used in construction industry.
Low durability of bamboo due to fungus infestation and termites
attack under storage puts certain constrains for it usage as modern
structural material. Looking at many chemical formulations for
bamboo treatment leading to severe harmful environment effects,
research on eco-friendly preservatives for bamboo treatment has been
initiated world-over. In the present studies, eco-friendly preservative
for bamboo treatment has been developed. To validate its application
for structural purposes, investigation of effect of treatment on
compressive strength has been investigated. Neemoil (25%)
integrated with copper naphthenate (0.3%) on dilution with kerosene
oil impregnated into bamboo culm at 2 bar pressure, has shown
weight loss of only 3.15% in soil block analysis method. The results
from compressive strength analysis using HEICO Automatic
Compression Testing Machine reveal that preservative treatment has
not altered the structural properties of bamboo culms. Compressive
strength of control (11.72 N/mm2) and above treated samples (11.71
N/mm2) was found to be comparable.
Abstract: Red blood cells (RBC) are the most common types of
blood cells and are the most intensively studied in cell biology. The
lack of RBCs is a condition in which the amount of hemoglobin level
is lower than normal and is referred to as “anemia”. Abnormalities in
RBCs will affect the exchange of oxygen. This paper presents a
comparative study for various techniques for classifying the RBCs as
normal or abnormal (anemic) using WEKA. WEKA is an open
source consists of different machine learning algorithms for data
mining applications. The algorithms tested are Radial Basis Function
neural network, Support vector machine, and K-Nearest Neighbors
algorithm. Two sets of combined features were utilized for
classification of blood cells images. The first set, exclusively consist
of geometrical features, was used to identify whether the tested blood
cell has a spherical shape or non-spherical cells. While the second
set, consist mainly of textural features was used to recognize the
types of the spherical cells. We have provided an evaluation based on
applying these classification methods to our RBCs image dataset
which were obtained from Serdang Hospital - Malaysia, and
measuring the accuracy of test results. The best achieved
classification rates are 97%, 98%, and 79% for Support vector
machines, Radial Basis Function neural network, and K-Nearest
Neighbors algorithm respectively.
Abstract: The levels of maximum power density of GSM
signals in the cities of Lagos, Ibadan and Abuja were studied.
Measurements were made with a calibrated hand held spectrum
analyzer 200m away from 271 base stations, at 1.2m to the ground
level. The maximum GSM 900 signal power density was
139.63μW/m2 in Lagos, 162.49μW/m2 in Ibadan and 5411.26μW/m2
in Abuja. Also, the maximum GSM 1800 signal power density was
296.82μW/m2 in Lagos, 116.82μW/m2 in Ibadan and 1263.00μW/m2
in Abuja. The level of power density of GSM 900 and GSM 1800
signals in the cities of Lagos, Ibadan and Abuja are far less than the
recommended value of 4.5W/m2 for GSM 900 and 9.0 W/m2 for
GSM 1800 by the ICNRP guideline. It can be concluded that
exposure to GSM signals in these cities cannot contribute to the
health detriments caused by thermal effects of radiofrequency
radiation.
Abstract: Exact solution of an unsteady flow of elastico-viscous
electrically conducting fluid through a porous media in a tube of
elliptical cross section under the influence of constant pressure
gradient and magnetic field has been obtained in this paper. Initially,
the flow is generated by a constant pressure gradient. After attaining
the steady state, the pressure gradient is suddenly withdrawn and the
resulting fluid motion in a tube of elliptical cross section by taking
into account of the transverse magnetic field and porosity factor of
the bounding surface is investigated. The problem is solved in twostages
the first stage is a steady motion in tube under the influence of
a constant pressure gradient, the second stage concern with an
unsteady motion. The problem is solved employing separation of
variables technique. The results are expressed in terms of a nondimensional
porosity parameter (K), magnetic parameter (m) and
elastico-viscosity parameter (β), which depends on the Non-
Newtonian coefficient. The flow parameters are found to be identical
with that of Newtonian case as elastic-viscosity parameter and
magnetic parameter tends to zero and porosity tends to infinity. It is
seen that the effect of elastico-viscosity parameter, magnetic
parameter and the porosity parameter of the bounding surface has
significant effect on the velocity parameter.
Abstract: The edge waviness in hot rolled steel is a common
defect. Variables that affect such defect include raw material and
machine. These variables are necessary to consider to understand
such defect. This research studied the defect of edge waviness for SS
400 of metal sheet manufacture. Defect of metal sheets were divided
into two groups. The specimens were investigated on chemical
composition and mechanical properties to find the difference. The
results of investigation showed that the difference was not significant.
Therefore the roll mill machine should be used to adjust to support
another location on a roller to avoide edge waviness.
Abstract: Reburning is a useful technology in reducing nitric
oxide through injection of a secondary hydrocarbon fuel. In this paper,
an experimental study has been conducted to evaluate the effect of fuel
lean reburning on NOx/CO reduction in LNG flame. Experiments
were performed in flames stabilized by a co-flow swirl burner, which
was mounted at the bottom of the furnace. Tests were conducted using
LNG gas as the reburn fuel as well as the main fuel. The effects of
reburn fuel fraction and injection manner of the reburn fuel were
studied when the fuel lean reburning system was applied. The paper
reports data on flue gas emissions and temperature distribution in the
furnace for a wide range of experimental conditions. At steady state,
temperature distribution and emission formation in the furnace have
been measured and compared. This paper makes clear that in order to
decrease both NOx and CO concentrations in the exhaust when the
pulsated fuel lean reburning system was adapted, it is important that
the control of some factors such as frequency and duty ratio. Also it
shows the fuel lean reburning is also effective method to reduce NOx
as much as reburning.
Abstract: In this paper a comprehensive review on various
factory layouts has been carried out for designing a lucrative process
layout for medium scale industries. Industry data base reveals that the
end product rejection rate is on the order of 10% amounting large
profit loss. In order to avoid these rejection rates and to increase the
quality product production an intermediate non-destructive testing
facility (INDTF) has been recommended for increasing the overall
profit. We observed through detailed case studies that while
introducing INDTF to medium scale industries the expensive
production process can be avoided to the defective products well
before its final shape. Additionally, the defective products identified
during the intermediate stage can be effectively utilized for other
applications or recycling; thereby the overall wastage of the raw
materials can be reduced and profit can be increased. We concluded
that the prudent design of a factory layout through critical path
method facilitating with INDTF will warrant profitable outcome.
Abstract: This paper investigates the joint effect of the
interconnected (n,k)-star network topology and Multi-Agent
automated control on restoration and reconfiguration of power
systems. With the increasing trend in development in Multi-Agent
control technologies applied to power system reconfiguration
in presence of faulty components or nodes. Fault tolerance is
becoming an important challenge in the design processes of the
distributed power system topology. Since the reconfiguration of a
power system is performed by agent communication, the (n,k)-star
interconnected network topology is studied and modeled in this
paper to optimize the process of power reconfiguration. In this paper,
we discuss the recently proposed (n,k)-star topology and examine its
properties and advantages as compared to the traditional multi-bus
power topologies. We design and simulate the topology model for
distributed power system test cases. A related lemma based on the
fault tolerance and conditional diagnosability properties is presented
and proved both theoretically and practically. The conclusion is
reached that (n,k)-star topology model has measurable advantages
compared to standard bus power systems while exhibiting fault
tolerance properties in power restoration, as well as showing
efficiency when applied to power system route discovery.
Abstract: This paper reports a structured literature review of the
application of Health Information Technology in developing
countries, defined as the World Bank categories Low-income
countries, Lower-middle-income, and Upper-middle-income
countries. The aim was to identify and classify the various
applications of health information technology to assess its current
state in developing countries and explore potential areas of research.
We offer specific analysis and application of HIT in Libya as one of
the developing countries. A structured literature review was
conducted using the following online databases: IEEE, Science
Direct, PubMed, and Google Scholar. Publication dates were set for
2000-2013. For the PubMed search, publications in English, French,
and Arabic were specified. Using a content analysis approach, 159
papers were analyzed and a total number of 26 factors were identified
that affect the adoption of health information technology. Of the 2681
retrieved articles, 159 met the inclusion criteria which were carefully
analyzed and classified. The implementation of health information
technology across developing countries is varied. Whilst it was
initially expected financial constraints would have severely limited
health information technology implementation, some developing
countries like India have nevertheless dominated the literature and
taken the lead in conducting scientific research. Comparing the
number of studies to the number of countries in each category, we
found that Low-income countries and Lower-middle-income had
more studies carried out than Upper-middle-income countries.
However, whilst IT has been used in various sectors of the economy,
the healthcare sector in developing countries is still failing to benefit
fully from the potential advantages that IT can offer.
Abstract: In wireless communication, space-time block code (STBC), cyclic delay diversity (CDD) and space-time cyclic delay diversity (STCDD)are used as the spatial diversity schemes and have been widely studied for the reliablecommunication. If these schemes are used, the communication system can obtain the improved performance. However,the quality of the system is degraded when the distance between a source and a destination is distant in wireless communication system. In this paper, the cooperative transmission scheme using two sources is proposed and improves the performance of the wireless communication system.
Abstract: The objective of meta-analysis is to combine results
from several independent studies in order to create generalization
and provide evidence base for decision making. But recent studies
show that the magnitude of effect size estimates reported in many
areas of research significantly changed over time and this can
impair the results and conclusions of meta-analysis. A number of
sequential methods have been proposed for monitoring the effect
size estimates in meta-analysis. However they are based on statistical
theory applicable only to fixed effect model (FEM) of meta-analysis.
For random-effects model (REM), the analysis incorporates the
heterogeneity variance, τ 2 and its estimation create complications.
In this paper we study the use of a truncated CUSUM-type test with
asymptotically valid critical values for sequential monitoring in REM.
Simulation results show that the test does not control the Type I error
well, and is not recommended. Further work required to derive an
appropriate test in this important area of applications.
Abstract: This paper presents the application of the Discrete
Component Model for heating and evaporation to multi-component
biodiesel fuel droplets in direct injection internal combustion engines.
This model takes into account the effects of temperature gradient,
recirculation and species diffusion inside droplets. A distinctive
feature of the model used in the analysis is that it is based on the
analytical solutions to the temperature and species diffusion
equations inside the droplets. Nineteen types of biodiesel fuels are
considered. It is shown that a simplistic model, based on the
approximation of biodiesel fuel by a single component or ignoring
the diffusion of components of biodiesel fuel, leads to noticeable
errors in predicted droplet evaporation time and time evolution of
droplet surface temperature and radius.
Abstract: Nanocrystalline powders of the lead-free piezoelectric
material, tantalum-substituted potassium sodium niobate
(K0.5Na0.5)(Nb0.9Ta0.1)O3 (KNNT), were produced using a Retsch
PM100 planetary ball mill by setting the milling time to 15h, 20h,
25h, 30h, 35h and 40h, at a fixed speed of 250rpm. The average
particle size of the milled powders was found to decrease from 12nm
to 3nm as the milling time increases from 15h to 25h, which is in
agreement with the existing theoretical model. An anomalous
increase to 98nm and then a drop to 3nm in the particle size were
observed as the milling time further increases to 30h and 40h
respectively. Various sizes of these starting KNNT powders were
used to investigate the effect of milling time on the microstructure,
dielectric properties, phase transitions and piezoelectric properties of
the resulting KNNT ceramics. The particle size of starting KNNT
was somewhat proportional to the grain size. As the milling time
increases from 15h to 25h, the resulting ceramics exhibit
enhancement in the values of relative density from 94.8% to 95.8%,
room temperature dielectric constant (εRT) from 878 to 1213, and
piezoelectric charge coefficient (d33) from 108pC/N to 128pC/N. For
this range of ceramic samples, grain size refinement suppresses the
maximum dielectric constant (εmax), shifts the Curie temperature (Tc)
to a lower temperature and the orthorhombic-tetragonal phase
transition (Tot) to a higher temperature. Further increase of milling
time from 25h to 40h produces a gradual degradation in the values of
relative density, εRT, and d33 of the resulting ceramics.
Abstract: PVC foam-fly ash composites (PVC-FA) are
characterized for their structural, morphological, mechanical and
thermal properties. The tensile strength of the composites increased
modestly with higher fly ash loading, while there was a significant
increase in the elastic modulus for the same composites. On the other
hand, a decrease in elongation at UTS was observed upon increasing
fly ash content due to increased rigidity of the composites. Similarly,
the flexural modulus increased as the fly ash loading increased,
where the composites containing 25 phr fly ash showed the highest
flexural strength. Thermal properties of PVC-fly ash composites were
determined by Thermo Gravimetric Analysis (TGA). The
microstructural properties were studied by Scanning Electron
Microscopy (SEM). SEM results confirm that fly ash particles were
mechanically interlocked in PVC matrix with good interfacial
interaction with the matrix. Particle agglomeration and debonding
was observed in samples containing higher amounts of fly ash.
Abstract: In this study, microcrystalline cellulose (MCC) was
extracted from oil palm empty fruit bunch (EFB) cellulose which was
earlier isolated from oil palm EFB fibre. In order to isolate the
cellulose, the chlorination method was carried out. Then, the MCC
was prepared by simultaneous ultrasonic and alkali treatment from
the isolated α-cellulose. Based on mass balance calculation, the yields
for MCC obtained from EFB was 44%. For fiber characterization, it
is observed that the chemical composition of the hemicellulose and
lignin for all samples decreased while composition for cellulose
increased. The structural property of the MCC was studied by X-ray
diffraction (XRD) method and the result shows that the MCC
produced is a cellulose-I polymorph, with 73% crystallinity.
Abstract: Due to the importance of ports to trade and economic
development of the regions in which they are inserted, in recent
decades the number of studies devoted to this subject has increased.
Part of these studies considers the ports as business agglomerations
and focuses on port governance. This is an important approach since
the port performance is the result of activities performed by actors
belonging to the port-logistics chain, which need to be properly
coordinated. This coordination takes place through a port governance
model. Given this context, this study aims to analyze the governance
model of the port of Santos from the perspective of port customers.
To do this, a closed-ended questionnaire based on a conceptual model
that considers the key dimensions associated with port governance
was applied to the international freight forwarders that operate in the
port. The results show the applicability of the considered model and
highlight improvement opportunities to be implemented at the port of
Santos.
Abstract: Animal fats (camel, sheep, goat, rabbit and chicken)
and vegetable oils (corn, sunflower, palm oil and olive oil) were
substituted with different proportions (1, 5, 10 and 20%) of lard.
Fatty acid composition in TG and 2-MG were determined using
lipase hydrolysis and gas chromatography before and after
adulteration. Results indicated that, genuine lard had a high
proportion (60.97%) of the total palmitic acid at 2-MG. However, it
was 8.70%, 16.40%, 11.38%, 10.57%, 29.97 and 8.97% for camel,
beef, sheep, goat, rabbit and chicken, respectively. It could be noticed
also the position-2-MG is mostly occupied by unsaturated fatty acids
among all tested fats except lard. Vegetable oils (corn, sunflower,
palm oil and olive oil) revealed that the levels of palmitic acid
esterifies at 2-MG position was 6.84, 1.43, 9.86 and 1.70%,
respectively. It could be observed also the studied oils had a higher
level of unsaturated fatty acids in the same position, compared with
animal fats under investigation. Moreover, palmitic acid esterifies at
2-MG and PAEF increased gradually as the substituted levels
increased among all tested fat and oil samples. Statistical analysis
showed that the PAEF correlated well with lard level. The detection
of lard in some commercial processed foods (5 French fries, 4 Butter
fats, 5 processed meat and 6 candy samples) was carried out. Results
revealed that 2 samples of French fries and 4 samples of processed
meat contained lard due to their higher PAEF, while butter fat and
candy were free of lard.