Abstract: The western Tombolo of the Giens peninsula in
southern France, known as Almanarre beach, is subject to coastal
erosion. We are trying to use computer simulation in order to propose
solutions to stop this erosion. Our aim was first to determine the main
factors for this erosion and successfully apply a coupled hydrosedimentological
numerical model based on observations and
measurements that have been performed on the site for decades.
We have gathered all available information and data about waves,
winds, currents, tides, bathymetry, coastal line, and sediments
concerning the site. These have been divided into two sets: one
devoted to calibrating a numerical model using Mike 21 software, the
other to serve as a reference in order to numerically compare the
present situation to what it could be if we implemented different
types of underwater constructions.
This paper presents the first part of the study: selecting and
melting different sources into a coherent data basis, identifying the
main erosion factors, and calibrating the coupled software model
against the selected reference period.
Our results bring calibration of the numerical model with good
fitting coefficients. They also show that the winter South-Western
storm events conjugated to depressive weather conditions constitute a
major factor of erosion, mainly due to wave impact in the northern
part of the Almanarre beach. Together, current and wind impact is
shown negligible.
Abstract: The tombolo of Giens is located in the town of Hyères
(France). We recall the history of coastal erosion, and prominent
factors affecting the evolution of the western tombolo. We then
discuss the possibility of stabilizing the western tombolo. Our
argumentation relies on a coupled model integrating swells, currents,
water levels and sediment transport. We present the conclusions of
the simulations of various scenarios, including pre-existing
propositions from coastal engineering offices. We conclude that
beach replenishment seems to be necessary but not sufficient for the
stabilization of the beach. Breakwaters reveal effective particularly in
the most exposed northern area. Some solutions fulfill conditions so
as to be elected as satisfactory. We give a comparative analysis of the
efficiency of 14 alternatives for the protection of the tombolo.
Abstract: Physical properties of uranium dinitride (UN2) were
investigated in detail using first principle calculations based on
density functional theory (DFT). To study the strong correlation
effects due to 5f uranium valence electrons, the on-site coulomb
interaction correction U via the Hubbard-like term (DFT+U) was
employed. The UN2 structural, mechanical and thermodynamic
properties were calculated within DFT and Various U of DFT+U
approach.
The Perdew–Burke–Ernzerhof (PBE.5.2) version of the
generalized gradient approximation (GGA) is used to describe the
exchange-correlation with the projector-augmented wave (PAW)
pseudo potentials.
A comparative study shows that results are improved by using the
Hubbard formalism for a certain U value correction like the structural
parameter. For some physical properties the variation versus
Hubbard-U is strong like Young modulus but for others it is weakly
noticeable such as bulk modulus.
We noticed also that from U=7.5 eV, elastic results don’t agree
with the cubic cell because of the C44 values which turn out to be
negative.
Abstract: A novel hybrid model of the lumbar spine, allowing
fast static and dynamic simulations of the disc pressure
and the spine mobility, is introduced in this work. Our
contribution is to combine rigid bodies, deformable finite
elements, articular constraints, and springs into a unique model
of the spine. Each vertebra is represented by a rigid body
controlling a surface mesh to model contacts on the facet
joints and the spinous process. The discs are modeled using
a heterogeneous tetrahedral finite element model. The facet
joints are represented as elastic joints with six degrees of
freedom, while the ligaments are modeled using non-linear
one-dimensional elastic elements. The challenge we tackle
is to make these different models efficiently interact while
respecting the principles of Anatomy and Mechanics.
The mobility, the intradiscal pressure, the facet joint force and
the instantaneous center of rotation of the lumbar spine are
validated against the experimental and theoretical results of
the literature on flexion, extension, lateral bending as well as
axial rotation.
Our hybrid model greatly simplifies the modeling task and
dramatically accelerates the simulation of pressure within the
discs, as well as the evaluation of the range of motion and the
instantaneous centers of rotation, without penalizing precision.
These results suggest that for some types of biomechanical
simulations, simplified models allow far easier modeling and
faster simulations compared to usual full-FEM approaches
without any loss of accuracy.
Abstract: The progress of industry integrated circuits in recent
years has been pushed by continuous miniaturization of transistors.
With the reduction of dimensions of components at 0.1 micron and
below, new physical effects come into play as the standard simulators
of two dimensions (2D) do not consider. In fact the third dimension
comes into play because the transverse and longitudinal dimensions
of the components are of the same order of magnitude. To describe
the operation of such components with greater fidelity, we must
refine simulation tools and adapted to take into account these
phenomena. After an analytical study of the static characteristics of
the component, according to the different operating modes, a
numerical simulation is performed of field-effect transistor with
submicron gate MESFET GaInP. The influence of the dimensions of
the gate length is studied. The results are used to determine the
optimal geometric and physical parameters of the component for their
specific applications and uses.
Abstract: Polysulfone (PSU) is a specialty engineering polymer
having various industrial applications. PSU is especially used in
waste water treatment membranes due to its good mechanical
properties, structural and chemical stability. But it is a hydrophobic
material and therefore its surface aim to pollute easily. In order to
resolve this problem and extend the properties of membrane, PSU
surface is rendered hydrophilic by addition of the sepiolite
nanofibers. Sepiolite is one of the natural clays, which is a hydrate
magnesium silicate fiber, also one of the well known layered clays of
the montmorillonites where has several unique channels and pores
within. It has also moisture durability, strength and low price.
Sepiolite channels give great capacity of absorption and good surface
properties. In this study, nanocomposites of commercial PSU and
Sepiolite were prepared by solvent mixing method. Different organic
solvents and their mixtures were used. Rheological characteristics of
PSU-Sepiolite solvent mixtures were analyzed, the solubility of
nanocomposite content in those mixtures were studied.
Abstract: The design and plantwide control of an integrated
plant where the endothermic 1,4-butanediol dehydrogenation and the
exothermic furfural hydrogenation is simultaneously performed in a
single reactor is studied. The reactions can be carried out in an
adiabatic reactor using small hydrogen excess and with reduced
parameter sensitivity. The plant is robust and flexible enough to
allow different production rates of γ-butyrolactone and 2-methyl
furan, keeping high product purities. Rigorous steady state and
dynamic simulations performed in AspenPlus and AspenDynamics to
support the conclusions.
Abstract: Exact solution of an unsteady flow of elastico-viscous
fluid through a porous media in a tube of spherical cross section
under the influence of constant pressure gradient 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
spherical cross section by taking into account of the 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) 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 tends to zero and porosity tends to
infinity. It is seen that the effect of elastico-viscosity parameter,
porosity parameter of the bounding surface has significant effect on
the velocity parameter.
Abstract: In the present work, the alloy of Bismuth-lead is
prepared on the basis of percentage of molecular weight 9:1, 5:5 and
1:9 ratios and grown by Zone- Refining Technique under a vacuum
atmosphere. The EDAX of these samples are done and the results are
reported. Micro hardness test has been used as an alternative test for
measuring material’s tensile properties. The effect of temperature and
load on the hardness of the grown alloy has been studied. Further the
comparative studies of work hardening coefficients are reported.
Abstract: Construction cost estimation is one of the most
important aspects of construction project design. For generations, the
process of cost estimating has been manual, time-consuming and
error-prone. This has partly led to most cost estimates to be unclear
and riddled with inaccuracies that at times lead to over- or underestimation
of construction cost. The development of standard set of
measurement rules that are understandable by all those involved in a
construction project, have not totally solved the challenges. Emerging
Building Information Modelling (BIM) technologies can exploit
standard measurement methods to automate cost estimation process
and improve accuracies. This requires standard measurement
methods to be structured in ontological and machine readable format;
so that BIM software packages can easily read them. Most standard
measurement methods are still text-based in textbooks and require
manual editing into tables or Spreadsheet during cost estimation. The
aim of this study is to explore the development of an ontology based
on New Rules of Measurement (NRM) commonly used in the UK for
cost estimation. The methodology adopted is Methontology, one of
the most widely used ontology engineering methodologies. The
challenges in this exploratory study are also reported and
recommendations for future studies proposed.
Abstract: Water contamination by toxic compound is one of the serious environmental problems today. These toxic compounds mostly originated from industrial effluents, agriculture, natural sources and human waste. These studies focus on modification of multiwalled carbon nanotube (MWCNTs) with nanoparticle of calixarene and explore the possibility of using this modification for the remediation of cadmium in water. The nanocomposites were prepared by dissolving calixarene in chloroform solution as solvent, followed by additional multiwalled carbon nanotube (MWCNTs) then sonication process for 3 hour and fabricated the nanocomposites on substrate by spin coating method. Finally, the nanocomposites were tested on cadmium ion (10 mg/ml). The morphology of nanocomposites was investigated by FESEM showing the formation of calixarene on the outer walls of carbon nanotube and cadmium ion also clearly seen from the micrograph. This formation was supported by using energy dispersive x-ray (EDX). The presence of cadmium ions in the films, leads to some changes in the surface potential and Fourier Transform Infrared spectroscopy (FTIR).The nanocomposites MWCNTs-calixarene have potential for development of sensor for pollutant monitoring and nanoelectronics devices applications.
Abstract: Image search engines rely on the surrounding textual
keywords for the retrieval of images. It is a tedious work for the
search engines like Google and Bing to interpret the user’s search
intention and to provide the desired results. The recent researches
also state that the Google image search engines do not work well on
all the images. Consequently, this leads to the emergence of efficient
image retrieval technique, which interprets the user’s search intention
and shows the desired results. In order to accomplish this task, an
efficient image re-ranking framework is required. Sequentially, to
provide best image retrieval, the new image re-ranking framework is
experimented in this paper. The implemented new image re-ranking
framework provides best image retrieval from the image dataset by
making use of re-ranking of retrieved images that is based on the
user’s desired images. This is experimented in two sections. One is
offline section and other is online section. In offline section, the reranking
framework studies differently (reference classes or Semantic
Spaces) for diverse user query keywords. The semantic signatures get
generated by combining the textual and visual features of the images.
In the online section, images are re-ranked by comparing the
semantic signatures that are obtained from the reference classes with
the user specified image query keywords. This re-ranking
methodology will increases the retrieval image efficiency and the
result will be effective to the user.
Abstract: The study of organisations’ information security
cultures has attracted scholars as well as healthcare services industry
to research the topic and find appropriate tools and approaches to
develop a positive culture. The vast majority of studies in Saudi
national health services are on the use of technology to protect and
secure health services information. On the other hand, there is a lack
of research on the role and impact of an organisation’s cultural
dimensions on information security. This research investigated and
analysed the role and impact of cultural dimensions on information
security in Saudi Arabia health service. Hypotheses were tested and
two surveys were carried out in order to collect data and information
from three major hospitals in Saudi Arabia (SA). The first survey
identified the main cultural-dimension problems in SA health
services and developed an initial information security culture
framework model. The second survey evaluated and tested the
developed framework model to test its usefulness, reliability and
applicability. The model is based on human behaviour theory, where
the individual’s attitude is the key element of the individual’s
intention to behave as well as of his or her actual behaviour. The
research identified a set of cultural and sub-cultural dimensions in SA
health information security and services.
Abstract: The adsorption efficiency of fired clayey pellets of 5
and 8 mm diameter size for Cu(II) and Zn(II) ion removal from a
waste printing developer was studied. In order to investigate the
influence of contact time, adsorbent mass and pellet size on the
adsorption efficiency the batch mode was carried out. Faster uptake
of copper ion was obtained with the fired clay pellets of 5 mm
diameter size within 30 minutes. The pellets of 8 mm diameter size
showed the higher equilibrium time (60 to 75 minutes) for copper and
zinc ion. The results pointed out that adsorption efficiency increases
with the increase of adsorbent mass. The maximal efficiency is
different for Cu(II) and Zn(II) ion due to the pellet size. Therefore,
the fired clay pellets of 5 mm diameter size present an effective
adsorbent for Cu(II) ion removal (adsorption efficiency is 63.6%),
whereas the fired clay pellets of 8 mm diameter size are the best
alternative for Zn(II) ion removal (adsorption efficiency is 92.8%)
from a waste printing developer.
Abstract: The main objective of this paper is study the influence
of carbon nano-tubes fibers and nano silica fibers on the
characteristic compressive strength and flexural strength on concrete
and cement mortar. Twelve tested specimens were tested with square
section its dimensions (4040 160) mm, divided into four groups.
The first and second group studied the effect of carbon nano-tubes
(CNTs) fibers with different percentage equal to 0.0, 0.11%, 0.22%,
and 0.33% by weight of cement and effect of nano-silica (nS) fibers
with different percentages equal to 0.0, 1.0%, 2.0%, and 3.0% by
weight of cement on the cement mortar. The third and fourth groups
studied the effect of CNTs fiber with different percentage equal to
0.0%, 0.11%, and 0.22% by weight of cement, and effect of nS fibers
with different percentages were equal to 0.0%, 1.0%, and 2.0% by
weight of cement on the concrete. The compressive strength and
flexural strength at 7, 28, and 90 days is determined. From analysis of
tested results concluded that the nano-fibers is more effective when
used with cement mortar more than used with concrete because of
increasing the surface area, decreasing the pore and the collection of
nano-fibers. And also by adding nano-fibers the improvement of
flexural strength of concrete and cement mortar is more than
improvement of compressive strength.
Abstract: The mechanics of rip currents are complex, involving
interactions between waves, currents, water levels and the bathymetry,
that present particular challenges for numerical models. Here,
the effects of a grid-spacing dependent horizontal mixing on the
wave-current interactions are studied. Near the shore, wave rays
diverge from channels towards bar crests because of refraction by
topography and currents, in a way that depends on the rip current
intensity which is itself modulated by the horizontal mixing. At
low resolution with the grid-spacing dependent horizontal mixing,
the wave motion is the same for both coupling modes because the
wave deviation by the currents is weak. In high resolution case,
however, classical results are found with the stabilizing effect of
the flow by feedback of waves on currents. Lastly, wave-current
interactions and the horizontal mixing strongly affect the intensity
of the three-dimensional rip velocity.
Abstract: It has experimentally been proved that the
performance of compression ignition (C.I.) engine is spray
characteristics related. In modern diesel engine the spray formation
and the eventual combustion process are the vital processes that offer
more challenges towards enhancing the engine performance. In the
present work the numerical simulation has been carried out for
evaporating diesel sprays using Fluent software. For computational
fluid dynamics simulation “Meshing” is done using Gambit software
before transmitting it into Fluent. The simulation is carried out using
hot bomb conditions under varying chamber conditions such as gas
pressure, nozzle diameter and fuel injection pressure. For comparison
purpose, the numerical simulations the chamber conditions were kept
the same as that of the experimental data. At varying chamber
conditions the spray penetration rates are compared with the existing
experimental results.
Abstract: In this paper, the electromagnetic shielding
characteristics of an up-to-date typical carbon filler material, carbon
fiber used with a metal mesh were investigated. Carbon fiber
12k-prepregs, where carbon fibers were impregnated with epoxy, were
laminated with wire meshes, vacuum bag-molded and hardened to
manufacture hybrid-type specimens, with which an electromagnetic
shield test was performed in accordance with ASTM D4935-10,
through which was known as the most excellent reproducibility is
obtainable among electromagnetic shield tests. In addition, glass fiber
prepregs whose electromagnetic shielding effect were known as
insignificant were laminated and formed with wire meshes to verify
the validity of the electromagnetic shield effect of wire meshes in
order to confirm the electromagnetic shielding effect of metal meshes
corresponding existing carbon fiber 12k-prepregs. By grafting carbon
fibers, on which studies are being actively underway in the
environmental aspects and electromagnetic shielding effect, with
hybrid-type wire meshes that were analysed through the tests, in this
study, the applicability and possibility are proposed.
Abstract: The development, operation and maintenance of
Integrated Waste Management Systems (IWMS) affects essentially
the sustainable concern of every region. The features of such systems
have great influence on all of the components of sustainability. In
order to reach the optimal way of processes, a comprehensive
mapping of the variables affecting the future efficiency of the system
is needed such as analysis of the interconnections among the
components and modeling of their interactions. The planning of a
IWMS is based fundamentally on technical and economical
opportunities and the legal framework. Modeling the sustainability
and operation effectiveness of a certain IWMS is not in the scope of
the present research. The complexity of the systems and the large
number of the variables require the utilization of a complex approach
to model the outcomes and future risks. This complex method should
be able to evaluate the logical framework of the factors composing
the system and the interconnections between them. The authors of
this paper studied the usability of the Fuzzy Cognitive Map (FCM)
approach modeling the future operation of IWMS’s. The approach
requires two input data set. One is the connection matrix containing
all the factors affecting the system in focus with all the
interconnections. The other input data set is the time series, a
retrospective reconstruction of the weights and roles of the factors.
This paper introduces a novel method to develop time series by
content analysis.
Abstract: A new method for determining the distribution of
birefringence and linear dichroism in optical polymer materials is
presented. The method is based on the use of polarizationholographic
diffraction grating that forms an orthogonal circular basis
in the process of diffraction of probing laser beam on the grating. The
intensities ratio of the orders of diffraction on this grating enables the
value of birefringence and linear dichroism in the sample to be
determined. The distribution of birefringence in the sample is
determined by scanning with a circularly polarized beam with a
wavelength far from the absorption band of the material. If the
scanning is carried out by probing beam with the wavelength near to
a maximum of the absorption band of the chromophore then the
distribution of linear dichroism can be determined. An appropriate
theoretical model of this method is presented. A laboratory setup was
created for the proposed method. An optical scheme of the laboratory
setup is presented. The results of measurement in polymer films with
two-dimensional gradient distribution of birefringence and linear
dichroism are discussed.