Abstract: Biodiesel production results in glycerol production as
the main by-product in biodiesel industry.One of the utilizations of
glycerol obtained from biodiesel production is as a cement grinding
aid (CGA). Results showed that crude glycerol content was 40.19%
whereas pure glycerol content was 82.15%. BSS value of the cement
with CGA supplementation was higher than that of nonsupplemented
cement (blank) indicating that CGA-supplemented
cement had higher fineness than the non-supplemented one. It was
also found that pure glycerol 95% and TEA 5% at 80ºC was the
optimum CGA used to result in finest cement with BSS value of
4.836 cm2/g. Residue test showed that the smallest percent residue
value (0.11%) was obtained in cement with supplementation of pure
glycerol 95% and TEA 5%. Results of residue test confirmed those of
BSS test showing that cement with supplementation of pure glycerol
95% and TEA 5% had the finest particle size.
Abstract: One of the important factors of cracks on the asphalt
pavements is bitumen aging that associated with the loss of volatile
components and oxidation of asphalt binder. This paper is about
effect of Styrene-Butadiene-Styrene (SBS) polymer on asphalt aging
In order to decrease asphalt aging effects. For this purpose samples of
base bitumen and SBS modified bitumen aged according to the
rolling thin film oven test (RTFOT) and pressure aging vessel (PAV),
respectively. Properties of each sample were evaluated using Fourier
Transform Infrared (FTIR) spectroscopy, n-heptane precipitation,
viscosity test, softening point test and penetration test. FT-IR
Analysis, showed lower oxidation of SBS modified bitumen than
base bitumen, after aging.
Abstract: A zero dimensional model has been used to investigate
the combustion performance of a single cylinder direct injection
diesel engine fueled by biofuels with options like supercharging and
exhaust gas recirculation. The numerical simulation was performed at
constant speed. The indicated pressure, temperature diagrams are
plotted and compared for different fuels. The emissions of soot and
nitrous oxide are computed with phenomenological models. The
experimental work was also carried out with biodiesel (palm stearin
methyl ester) diesel blends, ethanol diesel blends to validate
simulation results with experimental results, and observed that the
present model is successful in predicting the engine performance with
biofuels.
Abstract: This paper reports the results of an experimental study
conducted to characterise the gas-liquid multiphase flows
experienced within a vertical riser transporting a range of gas-liquid
flow rates. The scale experiments were performed using an
air/silicone oil mixture within a 6 m long riser. The superficial air
velocities studied ranged from 0.047 to 2.836 m/ s, whilst
maintaining a liquid superficial velocity at 0.047 m/ s. Measurements
of the mean cross-sectional and time average radial void fraction
were obtained using a wire mesh sensor (WMS). The data were
recorded at an acquisition frequency of 1000 Hz over an interval of
60 seconds. For the range of flow conditions studied, the average
void fraction was observed to vary between 0.1 and 0.9. An analysis
of the data collected concluded that the observed void fraction was
strongly affected by the superficial gas velocity, whereby the higher
the superficial gas velocity, the higher was the observed average void
fraction. The average void fraction distributions observed were in
good agreement with the results obtained by other researchers. When
the air-silicone oil flows were fully developed reasonably symmetric
profiles were observed, with the shape of the symmetry profile being
strongly dependent on the superficial gas velocity.
Abstract: People from different cultures favor web pages
characterized by the values of their culture and, therefore, tend to
prefer different characteristics of a website according to their cultural
values in terms of navigation, security, product information, customer
service, shopping and design tools. For a company aiming to
globalize its market it is useful to implement country specific cultural
interfaces and different web sites for countries with different cultures.
This paper, following the conclusions proposed by two models of
Hall and Hofstede, and the studies of Marcus and Gould, defines,
through an empirical analysis, the guidelines of web design for both
the Scandinavian countries and Malaysia.
Abstract: Attachment of the circulating monocytes to the
endothelium is the earliest detectable events during formation of
atherosclerosis. The adhesion molecules, chemokines and matrix
proteases genes were identified to be expressed in atherogenesis.
Expressions of these genes may influence structural integrity of the
luminal endothelium. The aim of this study is to relate changes in the
ultrastructural morphology of the aortic luminal surface and gene
expressions of the endothelial surface, chemokine and MMP-12 in
normal and hypercholesterolemic rabbits. Luminal endothelial
surface from rabbit aortic tissue was examined by scanning electron
microscopy (SEM) using low vacuum mode to ascertain
ultrastructural changes in development of atherosclerotic lesion. Gene
expression of adhesion molecules, MCP-1 and MMP-12 were studied
by Real-time PCR. Ultrastructural observations of the aortic luminal
surface exhibited changes from normal regular smooth intact
endothelium to irregular luminal surface including marked globular
appearance and ruptures of the membrane layer. Real-time PCR
demonstrated differentially expressed of studied genes in
atherosclerotic tissues. The appearance of ultrastructural changes in
aortic tissue of hypercholesterolemic rabbits is suggested to have
relation with underlying changes of endothelial surface molecules,
chemokine and MMP-12 gene expressions.
Abstract: This paper presents a method for determining the
uniaxial tensile properties such as Young-s modulus, yield strength
and the flow behaviour of a material in a virtually non-destructive
manner. To achieve this, a new dumb-bell shaped miniature
specimen has been designed. This helps in avoiding the removal of
large size material samples from the in-service component for the
evaluation of current material properties. The proposed miniature
specimen has an advantage in finite element modelling with respect
to computational time and memory space. Test fixtures have been
developed to enable the tension tests on the miniature specimen in a
testing machine. The studies have been conducted in a chromium
(H11) steel and an aluminum alloy (AR66). The output from the
miniature test viz. load-elongation diagram is obtained and the finite
element simulation of the test is carried out using a 2D plane stress
analysis. The results are compared with the experimental results. It is
observed that the results from the finite element simulation
corroborate well with the miniature test results. The approach seems
to have potential to predict the mechanical properties of the
materials, which could be used in remaining life estimation of the
various in-service structures.
Abstract: The presence of cold air with the convergent
topography of the Lut valley over the valley-s sloping terrain can
generate Low Level Jets (LLJ). Moreover, the valley-parallel
pressure gradients and northerly LLJ are produced as a result of the
large-scale processes. In the numerical study the regional MM5
model was run leading to achieve an appropriate dynamical analysis
of flows in the region for summer and winter. The results of this
study show the presence of summer synoptical systems cause the
formation of north-south pressure gradients in the valley which could
be led to the blowing of winds with the velocity more than 14 ms-1
and vulnerable dust and wind storms lasting more than 120 days.
Whereas the presence of cold air masses in the region in winter,
cause the average speed of LLJs decrease. In this time downslope
flows are noticeable in creating the night LLJs.
Abstract: Support vector machines (SVMs) have shown
superior performance compared to other machine learning techniques,
especially in classification problems. Yet one limitation of SVMs is
the lack of an explanation capability which is crucial in some
applications, e.g. in the medical and security domains. In this paper, a
novel approach for eclectic rule-extraction from support vector
machines is presented. This approach utilizes the knowledge acquired
by the SVM and represented in its support vectors as well as the
parameters associated with them. The approach includes three stages;
training, propositional rule-extraction and rule quality evaluation.
Results from four different experiments have demonstrated the value
of the approach for extracting comprehensible rules of high accuracy
and fidelity.
Abstract: Video Mosaicing is the stitching of selected frames of
a video by estimating the camera motion between the frames and
thereby registering successive frames of the video to arrive at the
mosaic. Different techniques have been proposed in the literature for
video mosaicing. Despite of the large number of papers dealing with
techniques to generate mosaic, only a few authors have investigated
conditions under which these techniques generate good estimate of
motion parameters. In this paper, these techniques are studied under
different videos, and the reasons for failures are found. We propose
algorithms with incorporation of outlier removal algorithms for better
estimation of motion parameters.
Abstract: In a bi-fuel diesel engine, the carburetor plays a vital
role in switching from fuel gas to petrol mode operation and viceversa.
The carburetor is the most important part of the fuel system of
a diesel engine. All diesel engines carry variable venturi mixer
carburetors. The basic operation of the carburetor mainly depends on
the restriction barrel called the venturi. When air flows through the
venturi, its speed increases and its pressure decreases. The main
challenge focuses on designing a mixing device which mixes the
supplied gas is the incoming air at an optimum ratio. In order to
surmount the identified problems, the way fuel gas and air flow in
the mixer have to be analyzed. In this case, the Computational Fluid
Dynamics or CFD approach is applied in design of the prototype
mixer. The present work is aimed at further understanding of the air
and fuel flow structure by performing CFD studies using a software
code. In this study for mixing air and gas in the condition that has
been mentioned in continuance, some mixers have been designed.
Then using of computational fluid dynamics, the optimum mixer has
been selected. The results indicated that mixer with 12 holes can
produce a homogenous mixture than those of 8-holes and 6-holes
mixer. Also the result showed that if inlet convergency was smoother
than outlet divergency, the mixture get more homogenous, the reason
of that is in increasing turbulence in outlet divergency.
Abstract: TiO2 supported nano-ZnO catalyst was prepared by
deposition-precipitation and tested for the trans-esterification
reaction of soybean oil to biodiesel. The TiO2 support stabilized the
nano-ZnO in a dispersed form with limited crystallite size compared
to the unsupported ZnO. The final ZnO dispersion and crystallite size
and the material transfer resistance in the catalyst significantly
influenced the supported nano-ZnO catalyst performance.
Abstract: Traffic density, an indicator of traffic
conditions, is one of the most critical characteristics to
Intelligent Transport Systems (ITS). This paper investigates
recursive traffic density estimation using the information
provided from inductive loop detectors. On the basis of the
phenomenological relationship between speed and density, the
existing studies incorporate a state space model and update the
density estimate using vehicular speed observations via the
extended Kalman filter, where an approximation is made
because of the linearization of the nonlinear observation
equation. In practice, this may lead to substantial estimation
errors. This paper incorporates a suitable transformation to
deal with the nonlinear observation equation so that the
approximation is avoided when using Kalman filter to
estimate the traffic density. A numerical study is conducted. It
is shown that the developed method outperforms the existing
methods for traffic density estimation.
Abstract: An electronic portal image device (EPID) has become
a method of patient-specific IMRT dose verification for radiotherapy.
Research studies have focused on pre and post-treatment verification,
however, there are currently no interventional procedures using EPID
dosimetry that measure the dose in real time as a mechanism to
ensure that overdoses do not occur and underdoses are detected as
soon as is practically possible. As a result, an EPID-based real time
dose verification system for dynamic IMRT was developed and was
implemented with MATLAB/Simulink. The EPID image acquisition
was set to continuous acquisition mode at 1.4 images per second. The
system defined the time constraint gap, or execution gap at the image
acquisition time, so that every calculation must be completed before
the next image capture is completed. In addition, the
Abstract: The last years have seen an increasing use of image analysis techniques in the field of biomedical imaging, in particular in microscopic imaging. The basic step for most of the image analysis techniques relies on a background image free of objects of interest, whether they are cells or histological samples, to perform further analysis, such as segmentation or mosaicing. Commonly, this image consists of an empty field acquired in advance. However, many times achieving an empty field could not be feasible. Or else, this could be different from the background region of the sample really being studied, because of the interaction with the organic matter. At last, it could be expensive, for instance in case of live cell analyses. We propose a non parametric and general purpose approach where the background is built automatically stemming from a sequence of images containing even objects of interest. The amount of area, in each image, free of objects just affects the overall speed to obtain the background. Experiments with different kinds of microscopic images prove the effectiveness of our approach.
Abstract: Health problems linked to urban growth are current
major concerns of developing countries. In 2002 and 2005, an
interdisciplinary program “Populations et Espaces ├á Risques
SANitaires" (PERSAN) was set up under the patronage of the
Development and Research Institute. Centered on health in
Cameroon-s urban environment, the program mainly sought to (i)
identify diarrhoea risk factors in Yaoundé, (ii) to measure their
prevalence and apprehend their spatial distribution. The crosssectional
epidemiological study that was carried out revealed a
diarrheic prevalence of 14.4% (437 cases of diarrhoea on the 3,034
children examined). Also, among risk factors studied, household
refuse management methods used by city dwellers were statistically
associated to these diarrhoeas. Moreover, it happened that levels of
diarrhoeal attacks varied consistently from one neighbourhood to
another because of the discrepancy urbanization process of the
Yaoundé metropolis.
Abstract: There is an ongoing controversy in the literature related
to the biological effects of weak, low frequency electromagnetic
fields. The physical arguments and interpretation of the experimental
evidence are inconsistent, where some physical arguments and
experimental demonstrations tend to reject the likelihood of any
effect of the fields at extremely low level. The problem arises of
explaining, how the low-energy influences of weak magnetic fields
can compete with the thermal and electrical noise of cells at normal
temperature using the theoretical studies. The magnetoreception in
animals involve radical pair mechanism. The same mechanism has
been shown to be involved in the circadian rhythm synchronization in
mammals. These reactions can be influenced by the weak magnetic
fields. Hence, it is postulated the biological clock can be affected
by weak magnetic fields and these disruptions to the rhythm can
cause adverse biological effects. In this paper, likelihood of altering
the biological clock via the radical pair mechanism is analyzed to
simplify these studies of controversy.
Abstract: The leaching behavior and structure of Li2O-CeO2- Fe2O3-P2O5 glasses incorporated with simulated high level nuclear wastes (HLW) were studied. The leach rates of gross and each constituent element were determined from the total weight loss of the specimen and the leachate analyses by inductively coupled argon plasma spectroscopy (ICP). The gross leach rate of the 4.5Li2O- 9.7CeO2-34.7Fe2O3-51.5P2O5 glass waste form containing 45 mass% simulated HLW is of the order of 10
Abstract: Added stresses due to adjacent structure should be
considered in foundation design and stress control in soil under the structure. This case is considered less than other cases in design and
calculation whereas stresses in implementation are greater than analytical stress.
Structure load are transmitted to earth by foundation and role of foundation is propagation of load on the continuous and half extreme
soil. This act cause that, present stresses lessen to allowable strength
of soil. Some researchers such as Boussinesq and westergaurd by
using of some assumption studied on this issue, theorically. Target of
this paper is study and evaluation of added stresses under structure
due to adjacent structure. For this purpose, by using of assumption, theoric relation and numeral methods, effects of adjacent structure
with 4 to 10 storeys on the main structure with 4 storeys are studied
and effect of parameters and sensitivity of them are evaluated.
Abstract: It has been always observed that the effectiveness of
MIS as a support tool for management decisions degenerate after
time of implementation, despite the substantial investments being
made. This is true for organizations at the initial stages of MIS
implementations, manual or computerized. A survey of a sample of
middle to top managers in business and government institutions was
made. A large ratio indicates that the MIS has lost its impact on the
day-to-day operations, and even the response lag time expands
sometimes indefinitely. The data indicates an infant mortality
phenomenon of the bathtub model. Reasons may be monotonous
nature of MIS delivery, irrelevance, irreverence, timeliness, and lack
of adequate detail. All those reasons collaborate to create a degree of
degeneracy. We investigate and model as a bathtub model the
phenomenon of MIS degeneracy that inflicts the MIS systems and
renders it ineffective. A degeneracy index is developed to identify
the status of the MIS system and possible remedies to prevent the
onset of total collapse of the system to the point of being useless.