Abstract: This work was one of the tasks of the
Manufacturing2Client project, whose objective was to develop a
frontal deflector to be commercialized in the automotive industry,
using new project and manufacturing methods. In this task, in
particular, it was proposed to develop the ability to predict
computationally the aerodynamic influence of flow in vehicles, in an
effort to reduce fuel consumption in vehicles from class 3 to 8. With
this aim, two deflector models were developed and their aerodynamic
performance analyzed. The aerodynamic study was done using the
Computational Fluid Dynamics (CFD) software Ansys CFX and
allowed the calculation of the drag coefficient caused by the vehicle
motion for the different configurations considered. Moreover, the
reduction of diesel consumption and carbon dioxide (CO2) emissions
associated with the optimized deflector geometry could be assessed.
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: 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: Aerated concrete is a load bearing construction
material, which has high heat insulation parameters. Walls can be
erected from aerated concrete masonry constructions and in perfect
circumstances additional heat insulation is not required. The most
common problem in aerated concrete heat insulation properties is the
humidity distribution throughout the cross section of the masonry
elements as well as proper and conducted drying process of the
aerated concrete construction because only dry aerated concrete
masonry constructions can reach high heat insulation parameters.
In order to monitor drying process of the masonry and detect
humidity distribution throughout the cross section of aerated concrete
masonry construction application of electrical impedance
spectrometry is applied. Further test results and methodology of this
non-destructive testing method is described in this paper.
Abstract: Search engine plays an important role in internet, to
retrieve the relevant documents among the huge number of web
pages. However, it retrieves more number of documents, which are
all relevant to your search topics. To retrieve the most meaningful
documents related to search topics, ranking algorithm is used in
information retrieval technique. One of the issues in data miming is
ranking the retrieved document. In information retrieval the ranking
is one of the practical problems. This paper includes various Page
Ranking algorithms, page segmentation algorithms and compares
those algorithms used for Information Retrieval. Diverse Page Rank
based algorithms like Page Rank (PR), Weighted Page Rank (WPR),
Weight Page Content Rank (WPCR), Hyperlink Induced Topic
Selection (HITS), Distance Rank, Eigen Rumor, Distance Rank Time
Rank, Tag Rank, Relational Based Page Rank and Query Dependent
Ranking algorithms are discussed and compared.
Abstract: Images are important source of information used as
evidence during any investigation process. Their clarity and accuracy
is essential and of the utmost importance for any investigation.
Images are vulnerable to losing blocks and having noise added to
them either after alteration or when the image was taken initially,
therefore, having a high performance image processing system and it
is implementation is very important in a forensic point of view. This
paper focuses on improving the quality of the forensic images.
For different reasons packets that store data can be affected,
harmed or even lost because of noise. For example, sending the
image through a wireless channel can cause loss of bits. These types
of errors might give difficulties generally for the visual display
quality of the forensic images.
Two of the images problems: noise and losing blocks are covered.
However, information which gets transmitted through any way of
communication may suffer alteration from its original state or even
lose important data due to the channel noise. Therefore, a developed
system is introduced to improve the quality and clarity of the forensic
images.
Abstract: In oases, the surface water resources are becoming
increasingly scarce and groundwater resources, which generally have
a poor quality due to the high levels of salinity, are often
overexploited. Water saving have therefore become imperative for
better oases sustainability. If drip irrigation is currently recommended
in Morocco for saving water and valuing, its use in the sub-desert
areas does not keep water safe from high evaporation rates. An
alternative to this system would be the use of subsurface drip
irrigation. This technique is defined as an application of water under
the soil surface through drippers, which deliver water at rates
generally similar to surface drip irrigation. As subsurface drip
irrigation is a recently introduced in Morocco, a better understanding
of the infiltration process around a buried source, in local conditions,
and its impact on plant growth is necessarily required. This study
aims to contribute to improving the water use efficiency by testing
the performance of subsurface irrigation system, especially in areas
where water is a limited source. The objectives of this research are
performance evaluation in arid conditions of the subsurface drip
irrigation system for young date palms compared to the surface drip.
In this context, an experimental test is installed at a farmer’s field in
the area of Erfoud (Errachidia Province, southeastern Morocco),
using the subsurface drip irrigation system in comparison with the
classic drip system for young date palms. Flow measurement to
calculate the uniformity of the application of water was done through
two methods: a flow measurement of drippers above the surface and
another one underground. The latter method has also helped us to
estimate losses through evaporation for both irrigation techniques. In
order to compare the effect of two irrigation modes, plants were
identified for each type of irrigation to monitor certain agronomic
parameters (cumulative numbers of palms and roots development).
Experimentation referred to a distribution uniformity of about 88%;
considered acceptable for subsurface drip irrigation while it is around
80% for the surface drip irrigation. The results also show an increase
in root development and in the number of palm, as well as a
substantial water savings due to lower evaporation losses compared
to the classic drip irrigation.
The results of this study showed that subsurface drip irrigation is
an efficient technique, which allows sustainable irrigation in arid
areas.
Abstract: Yttrium oxide (Y2O3) films have been successfully
deposited with yttrium-ethylenediamine tetraacetic acid (EDTA·Y·H)
complexes prepared by various milling techniques. The effects of the
properties of the EDTA·Y·H complex on the properties of the
deposited Y2O3 films have been analyzed. Seven different types of the
raw EDTA·Y·H complexes were prepared by various commercial
milling techniques such as ball milling, hammer milling, commercial
milling, and mortar milling. The milled EDTA·Y·H complexes
exhibited various particle sizes and distributions, depending on the
milling method. Furthermore, we analyzed the crystal structure,
morphology and elemental distribution profile of the metal oxide films
deposited on stainless steel substrate with the milled EDTA·Y·H
complexes. Depending on the milling technique, the flow properties of
the raw powders differed. The X-ray diffraction pattern of all the
samples revealed the formation of Y2O3 crystalline phase, irrespective
of the milling technique. Of all the different milling techniques, the
hammer milling technique is considered suitable for fabricating dense
Y2O3 films.
Abstract: This research work is concerned with the life cycle
assessment (LCA) of an expressway, as well as its infrastructure, in
Thailand. The life cycle of an expressway encompasses the raw
material acquisition phase, the construction phase, the use or service
phase, the rehabilitation phase, and finally the demolition and
disposal phase. The LCA in this research was carried out using CML
baseline 2000 and in accordance with the ISO 14040 standard. A
functional unit refers to transportation of one person over one
kilometer of a 3-lane expressway with a 50-year lifetime. This
research has revealed that the construction phase produced the largest
proportion of the environmental impact (81.46%), followed by the
service, rehabilitation, demolition and disposal phases and
transportation at 11.97%, 3.72% 0.33% and 2.52%, respectively. For
the expressway under study, the total carbon footprint over its
lifetime is equivalent to 245,639 tons CO2-eq per 1 kilometer
functional unit, with the phases of construction, service,
rehabilitation, demolition and disposal and transportation
contributing 153,690; 73,773; 3693, 755 and 13,728 tons CO2-eq,
respectively. The findings could be adopted as a benchmark against
which the environmental impacts of future similar projects can be
measured.
Abstract: The use of mobile phones is growing tremendously all
over the world. In Tanzania there are a number of operators licensed
by Tanzania Communications Regulatory Authority (TCRA) aiming
at attracting customers into their networks. So far
telecommunications market competition has been very stiff. Various
measures are being taken by mobile operators to survive in the
market. Such measure include introducing of different air time
bundles on daily, weekly and monthly at lower tariffs. Other
measures include the introduction of normal tariff, tourist package
and one network. Despite of all these strategies, there is a dynamic
competition in the market which needs to be explored. Some
influences which attract customers to choose a certain mobile
operator are of particular interest. This paper is investigating if the
network effects and Quality of Services (QoS) influence mobile
customers in selection of their mobile network operators. Seventy
seven students from high learning institutions in Dodoma
Municipality in Tanzania participated in responding to prepared
questionnaires. The data was analyzed using Statistical Package for
Social Science (SPSS) Software. The results indicate that, network
coverage does influence customers in selection of mobile operators.
In addition, this paper proposes further research in some areas
especially where the study came up with different findings from what
the theory has in place.
Abstract: This paper represents performance of particle swarm
optimisation (PSO) algorithm based integral (I) controller and
proportional-integral controller (PI) for interconnected hydro-thermal
automatic generation control (AGC) with generation rate constraint
(GRC) and Thyristor controlled phase shifter (TCPS) in series with
tie line. The control strategy of TCPS provides active control of
system frequency. Conventional objective function integral square
error (ISE) and another objective function considering square of
derivative of change in frequencies of both areas and change in tie
line power are considered. The aim of designing the objective
function is to suppress oscillation in frequency deviations and change
in tie line power oscillation. The controller parameters are searched
by PSO algorithm by minimising the objective functions. The
dynamic performance of the controllers I and PI, for both the
objective functions, are compared with conventionally optimized I
controller.
Abstract: Two micromechanical models for 3D smart composite
with embedded periodic or nearly periodic network of generally
orthotropic reinforcements and actuators are developed and applied to
cubic structures with unidirectional orientation of constituents.
Analytical formulas for the effective piezothermoelastic coefficients
are derived using the Asymptotic Homogenization Method (AHM).
Finite Element Analysis (FEA) is subsequently developed and used
to examine the aforementioned periodic 3D network reinforced smart
structures. The deformation responses from the FE simulations are
used to extract effective coefficients. The results from both
techniques are compared. This work considers piezoelectric materials
that respond linearly to changes in electric field, electric
displacement, mechanical stress and strain and thermal effects. This
combination of electric fields and thermo-mechanical response in
smart composite structures is characterized by piezoelectric and
thermal expansion coefficients. The problem is represented by unitcell
and the models are developed using the AHM and the FEA to
determine the effective piezoelectric and thermal expansion
coefficients. Each unit cell contains a number of orthotropic
inclusions in the form of structural reinforcements and actuators.
Using matrix representation of the coupled response of the unit cell,
the effective piezoelectric and thermal expansion coefficients are
calculated and compared with results of the asymptotic
homogenization method. A very good agreement is shown between
these two approaches.
Abstract: Paper presents a study about dynamic effects obtained
from the dynamic load testing of the city highway bridges in Latvia
carried out from 2005 to 2012. 9 prestressed concrete bridges and 4
composite bridges were considered. 11 of 13 bridges were designed
according to the Eurocodes but two according to the previous
structural codes used in Latvia (SNIP 2.05.03-84). The dynamic
properties of the bridges were obtained by heavy vehicle passing the
bridge roadway with different driving speeds and with or without
even pavement. The obtained values of the Dynamic amplification
factor (DAF) and the bridge natural frequency were analyzed and
compared to the values of built-in traffic load models provided in
Eurocode 1. The actual DAF values for even bridge pavement in the
most cases are smaller than the value adopted in Eurocode 1. Vehicle
speed for uneven pavements significantly influence Dynamic
amplification factor values.
Abstract: This paper deals with the problem of automatic rule
generation for fuzzy systems design. The proposed approach is based
on hybrid artificial bee colony (ABC) optimization and weighted least
squares (LS) method and aims to find the structure and parameters of
fuzzy systems simultaneously. More precisely, two ABC based fuzzy
modeling strategies are presented and compared. The first strategy
uses global optimization to learn fuzzy models, the second one
hybridizes ABC and weighted least squares estimate method. The
performances of the proposed ABC and ABC-LS fuzzy modeling
strategies are evaluated on complex modeling problems and compared
to other advanced modeling methods.
Abstract: In this paper, we introduce a generalized Chebyshev
collocation method (GCCM) based on the generalized Chebyshev
polynomials for solving stiff systems. For employing a technique
of the embedded Runge-Kutta method used in explicit schemes, the
property of the generalized Chebyshev polynomials is used, in which
the nodes for the higher degree polynomial are overlapped with those
for the lower degree polynomial. The constructed algorithm controls
both the error and the time step size simultaneously and further
the errors at each integration step are embedded in the algorithm
itself, which provides the efficiency of the computational cost. For
the assessment of the effectiveness, numerical results obtained by the
proposed method and the Radau IIA are presented and compared.
Abstract: This paper presents the electromagnetic interference
(EMI) shielding effectiveness of rice husk and carbon nanotubes
(RHCNTs) composites in the X-band region (8.2-12.4 GHz). The
difference weight ratio of carbon nanotubes (CNTs) were mix with
the rice husk. The rectangular waveguide technique was used to
measure the complex permittivity of the RHCNTs composites
materials. The complex permittivity is represented in terms of both
the real and imaginary parts of permittivity in X-band frequency. The
conductivity of RHCNTs shows increasing when the ratio of CNTs
mixture increases. The composites materials were simulated using
Computer Simulation Technology (CST) Microwave Studio
simulation software. The shielding effectiveness of RHCNTs and
pure rice husk was compared. The highest EMI SE of 30 dB is
obtained for RHCNTs composites of 10 wt % CNTs with 10mm
thickness.
Abstract: In this paper, numerical solution of system of
Fredholm and Volterra integral equations by means of the Spline
collocation method is considered. This approximation reduces the
system of integral equations to an explicit system of algebraic
equations. The solution is collocated by cubic B-spline and the
integrand is approximated by the Newton-Cotes formula. The error
analysis of proposed numerical method is studied theoretically. The
results are compared with the results obtained by other methods to
illustrate the accuracy and the implementation of our method.
Abstract: The current study explored the effect of economic
development, financial development and institutional quality on
environmental destruction in upper-middle income countries during
the time period of 1999-2011. The dependent variable is logarithm of
carbon dioxide emissions that can be considered as an index for
destruction or quality of the environment given to its effects on the
environment. Financial development and institutional development
variables as well as some control variables were considered. In order
to study cross-sectional correlation among the countries under study,
Pesaran and Friz test was used. Since the results of both tests show
cross-sectional correlation in the countries under study, seemingly
unrelated regression method was utilized for model estimation. The
results disclosed that Kuznets’ environmental curve hypothesis is
confirmed in upper-middle income countries and also, financial
development and institutional quality have a significant effect on
environmental quality. The results of this study can be considered by
policy makers in countries with different income groups to have
access to a growth accompanied by improved environmental quality.
Abstract: The aim of this paper is to trace the historical
development of the accounting profession in Libya, in order to
identify challenges facing the profession as the country moves from a
closed to emerging economy. The study is based on a literature
review and archival research. Accounting information has a vital role
to play in the achievement of economic goals in developing and
emerging economies, but a well qualified accounting profession is
required. In the context of institutional instability and unique cultural
factors, the accounting profession in Libya faces educational and
legal challenges if it is to achieve its potential in assisting the country
to reach its economic goals. This study focuses on one country,
which does limit its generalisability. However, it also suggests
fruitful research areas in considering the impact and challenge of
historic factors on the accounting profession in emerging economies.
Centrally planned economies require a body of well trained
professional accountants if they are to emerge onto the global
economic arena. Studies on the accounting profession have focused
primarily on those in developed economies, where the need for
meaningful accounting information for decision making is taken for
granted and there is a well trained, professional workforce. This study
of the profession in an emerging economy highlights the efforts that
will be needed to ensure the contribution of the profession to the
economic wellbeing of other emerging economies.
Abstract: The study was conducted to evaluate the efficiency of
Garlic and Chili combination solution on control of insect pests in
cabbage crop. The solution was sprayed at different intervals after
transplanting. The efficiency of Garlic and chili combination solution
on cabbage insect pests was measured. Results revealed that Garlic
and chili combination solution was the effectively reduced cabbage
insect pests. On other hand, the spray solution not only reduced the
number of days required for the cabbage growth but also greatly
enhanced the leaf number, head diameter, head weight, and quality of
cabbage. Garlic and chili combination solution have positive effects
on pests reduction and improve growth, yield and quality of cabbage
vegetable.