Abstract: The FOSDT (the First Order Shear Deformation
Theory) is taking into consideration to study the static behavior of a
bimorph beam, with a delamination zone between the upper and the
lower layer. The effect of limit conditions and lengths of the
delamination zone are presented in this paper, with a PVDF
piezoelectric material application. A FEM “Finite Element Method”
is used to discretize the beam. In the axial displacement, a
displacement field appears in the debonded zone with inverse effect
between the upper and the lower layer was observed.
Abstract: The heavy metal pollution degree in the soils around
the Zangezur copper and molybdenum combine in Syunik Marz,
Armenia was assessed. The results of the study showed that heavy
metal pollution degree in the soils mainly decreased with increasing
distance from the open mine and the ore enrichment combine which
indicated that the open mine and the ore enrichment combine were
the main sources of heavy metal pollution. The only exception was
observed in the northern part of the open mine where pollution
degree in the sites (along the open mine) situated 600 meters far from
the mine was higher than that in the sites located 300 meters far from
the mine. This can be explained by the characteristics of relief and air
currents as well as the weak vegetation cover of these sites and the
characteristics of soil structure. According to geo-accumulation index
(I-geo), contamination factor (Cf), contamination degree (Cd) and
pollution load index (PLI) values, the pollution degree in the soils
around the open mine and the ore enrichment combine was higher
than that in the soils around the tailing dumps which was due to the
proper and accurate operation of the Artsvanik tailing damp and the
recultivation of the Voghji tailing dump.
The high Cu and Mo pollution of the soils was conditioned by the
character of industrial activities, the moving direction of air currents
as well as the physicochemical peculiarities of the soils.
Abstract: An experimental study was performed to investigate
the behavior and strength of proposed technique to connect
reinforced concrete (RC) beam to steel or composite columns. This
approach can practically be used in several types of building
construction. In this technique, the main beam of the frame consists
of a transfer part (part of beam; Tr.P) and a common reinforcement
concrete beam. The transfer part of the beam is connected to the
column, whereas the rest of the beam is connected to the transfer part
from each side. Four full-scale beam-column connections were tested
under static loading. The test parameters were the length of the
transfer part and the column properties. The test results show that
using of the transfer part technique leads to modify the deformation
capabilities for the RC beam and hence it increases its resistance
against failure. Increase in length of the transfer part did not
necessarily indicate an enhanced behavior. The test results contribute
to the characterization of the connection behavior between RC beam -
steel column and can be used to calibrate numerical models for the
simulation of this type of connection.
Abstract: This paper introduces a proposal scheme for an
Intelligent System applied to Pedagogical Advising using Case-Based
Reasoning, to find consolidated solutions before used for the new
problems, making easier the task of advising students to the
pedagogical staff. We do intend, through this work, introduce the
motivation behind the choices for this system structure, justifying the
development of an incremental and smart web system who learns
bests solutions for new cases when it’s used, showing technics and
technology.
Abstract: Catalytic combustion of methane is imperative due to
stability of methane at low temperature. Methane (CH4), therefore,
remains unconverted in vehicle exhausts thereby causing greenhouse
gas GHG emission problem. In this study, heterogeneous catalysts of
palladium with bio-char (2 wt% Pd/Bc) and Al2O3 (2wt% Pd/ Al2O3)
supports were prepared by incipient wetness impregnation and then
subsequently tested for catalytic combustion of CH4. Support-porous
heterogeneous catalytic combustion (HCC) material were selected
based on factors such as surface area, porosity, thermal stability,
thermal conductivity, reactivity with reactants or products, chemical
stability, catalytic activity, and catalyst life. Sustainable and
renewable support-material of bio-mass char derived from palm shell
waste material was compared with those from the conventional
support-porous materials. Kinetic rate of reaction was determined for
combustion of methane on Palladium (Pd) based catalyst with Al2O3
support and bio-char (Bc). Material characterization was done using
TGA, SEM, and BET surface area. The performance test was
accomplished using tubular quartz reactor with gas mixture ratio of
3% methane and 97% air. The methane porous-HCC conversion was
carried out using online gas analyzer connected to the reactor that
performed porous-HCC. BET surface area for prepared 2 wt% Pd/Bc
is smaller than prepared 2wt% Pd/ Al2O3 due to its low porosity
between particles. The order of catalyst activity based on kinetic rate
on reaction of catalysts in low temperature was 2wt%
Pd/Bc>calcined 2wt% Pd/ Al2O3> 2wt% Pd/ Al2O3>calcined 2wt%
Pd/Bc. Hence agro waste material can successfully be utilized as an
inexpensive catalyst support material for enhanced CH4 catalytic
combustion.
Abstract: In this work, we attempt to analyze the contribution of
innovative activities to firm performance and growth. We examine
economic data from some of the economies that were heavily
affected by current economic crisis: the countries of southern Europe
(Portugal, Italy, Greece and Spain) and Ireland. Following literature,
an appropriate econometric model is developed and several indicators
are tested in order to disclose possible relation with innovative
activity. Findings confirm the crucial effect of innovative process in
economic activity, in firm and country level.
Abstract: The Al-MoO3-P-CdTe-Al MOS sandwich structures
were fabricated by vacuum deposition method on cleaned glass
substrates. Capacitance versus voltage measurements were performed
at different frequencies and sweep rates of applied voltages for oxide
and semiconductor films of different thicknesses. In the negative
voltage region of the C-V curve a high differential capacitance of the
semiconductor was observed and at high frequencies (
Abstract: The capability of CNC gantry milling machines in
manufacturing long components has caused the expanded use of such
machines. On the other hand, the machines’ gantry rigidity can
reduce under severe loads or vibration during operation. Indeed, the
quality of machining is dependent on the machine’s dynamic
behavior throughout the operating process. For this reason, these
types of machines have always been used widely and are not
efficient. Therefore, they can usually be employed for rough
machining and may not produce adequate surface finishing. In this
paper, a CNC gantry milling machine with the potential to produce
good surface finish has been designed and analyzed. The lowest
natural frequency of this machine is 202 Hz corresponding to 12000
rpm at all motion amplitudes with a full range of suitable frequency
responses. Meanwhile, the maximum deformation under dead loads
for the gantry machine is 0.565*m, indicating that this machine tool
is capable of producing higher product quality.
Abstract: Power Regeneration in Refrigeration Plant concept
has been analyzed and has been shown to be capable of saving about
25% power in Cryogenic Plants with the Power Regeneration System
(PRS) running under nominal conditions. The innovative component
Compressor Expander Group (CEG) based on turbomachinery has
been designed and built modifying CETT compressor and expander,
both selected for optimum plant performance. Experiments have
shown the good response of the turbomachines to run with R404a as
working fluid. Power saving up to 12% under PRS derated conditions
(50% loading) has been demonstrated. Such experiments allowed
predicting a power saving up to 25% under CEG full load.
Abstract: The present work describes the implementation of the
Enhanced Collaborative Optimization (ECO) multilevel architecture
with a gradient-based optimization algorithm with the aim of
performing a multidisciplinary design optimization of a generic
unmanned aerial vehicle with morphing technologies. The concepts
of weighting coefficient and dynamic compatibility parameter are
presented for the ECO architecture. A routine that calculates the
aircraft performance for the user defined mission profile and vehicle’s
performance requirements has been implemented using low fidelity
models for the aerodynamics, stability, propulsion, weight, balance
and flight performance. A benchmarking case study for evaluating
the advantage of using a variable span wing within the optimization
methodology developed is presented.
Abstract: The dissimilar joint between aluminum/titanium
alloys (Al 6082 and Ti G2) were successfully achieved by CO2 laser
welding with a single pass and without filler material using the
overlap joint design. Laser welding parameters ranges combinations
were experimentally determined using Taguchi approach with the
objective of producing welded joint with acceptable welding profile
and high quality of mechanical properties. In this study a joining of
dissimilar Al 6082 / Ti G2 was resulted in three distinct regions
fusion area in the weldment. These regions are studied in terms of its
microstructural characteristics and microhardness which are directly
affecting the welding quality.
The weld metal was mainly composed of martensite alpha prime.
In two different metals in the two different sides of joint HAZ, grain
growth was detected. The microhardness of the joint distribution also
has shown microhardness increasing in the HAZ of two base metals
and a varying microhardness in fusion zone.
Abstract: Semiconductor crystals smaller than about 10 nm,
known as quantum dots, have properties that differ from large
samples, including a band gap that becomes larger for smaller
particles. These properties create several applications for quantum
dots. In this paper new shapes of quantum dot arrays are used to
enhance the photo physical properties of gold nano-particles. This
paper presents a study of the effect of nano-particles shape, array, and
size on their absorption characteristics.
Abstract: Hurling a successful Construction and Demolition
Waste (C&DW) recycling operation around the globe is a challenge
today, predominantly because secondary materials markets are yet to
be integrated. Reducing, Reusing and recycling of (C&DW) have
been employed over the years, and various techniques have been
investigated. However, the economic and environmental viability of
its application seems limited. This paper discusses the costs and
benefits in using secondary materials and focus on investigating reuse
and recycling process for five major types of construction materials:
concrete, metal, wood, cardboard/paper and plasterboard. Data
obtained from demolition specialists and contractors are considered
and evaluated. The research paper found that construction material
recovery process fully incorporate a 3R’s principle contributing to
saving energy and natural resources. This scrutiny leads to the
empathy of grand challenges in construction material recovery
process. Recommendations to deepen material recovery process are
also discussed.
Abstract: Enterococci are important inhabitants of the animal
intestine and are widely used in probiotic products. A probiotic strain
is expected to possess several desirable properties in order to exert
beneficial effects. Therefore, the objective of this study was to
isolate, characterize and identify Enterococcus sp. from chicken cecal
and fecal samples to determine potential probiotic properties.
Enterococci were isolated from chicken ceca and feces of thirty three
clinically healthy chickens from a local farm. In vitro studies were
performed to assess antibacterial activity of the isolated LAB (using
agar well diffusion and cell free supernatant broth technique against
Salmonella enterica serotype Enteritidis), survival in acidic
conditions, resistance to bile salts, and their survival during simulated
gastric juice conditions at pH 2.5. Isolates were identified by
biochemical carbohydrate fermentation patterns using an API 50
CHL kit and API ZYM kits and by sequenced 16S rDNA. An isolate
belonging to E. faecium species exhibited inhibitory effect against S.
enteritidis. This isolate producing a clear zone as large as 10.30 mm
or greater and was able to grow in the coculture medium and at the
same time, inhibited the growth S. enteritidis. In addition, E. faecium
exhibited significant resistance under highly acidic conditions at pH
2.5 for 8 h and survived well in bile salt at 0.2% for 24 h and showing
ability to survive in the presence of simulated gastric juice at pH 2.5.
Based on these results, E. faecium isolate fulfills some of the criteria
to be considered as a probiotic strain and therefore, could be used as a
feed additive with good potential for controlling S. Enteritidis in
chickens. However, in vivo studies are needed to determine the safety
of the strain.
Abstract: This work deals with parameter identification of
permanent magnet motors, a class of ac motor which is particularly
important in industrial automation due to characteristics like
applications high performance, are very attractive for applications
with limited space and reducing the need to eliminate because they
have reduced size and volume and can operate in a wide speed range,
without independent ventilation. By using experimental data and
genetic algorithm we have been able to extract values for both the
motor inductance and the electromechanical coupling constant, which
are then compared to measured and/or expected values.
Abstract: Over the past four decades, the fatigue behavior of
nickel-based alloys has been widely studied. However, in recent
years, significant advances in the fabrication process leading to grain
size reduction have been made in order to improve fatigue properties
of aircraft turbine discs. Indeed, a change in particle size affects the
initiation mode of fatigue cracks as well as the fatigue life of the
material. The present study aims to investigate the fatigue behavior of
a newly developed nickel-based superalloy under biaxial-planar
loading. Low Cycle Fatigue (LCF) tests are performed at different
stress ratios so as to study the influence of the multiaxial stress state
on the fatigue life of the material. Full-field displacement and strain
measurements as well as crack initiation detection are obtained using
Digital Image Correlation (DIC) techniques. The aim of this
presentation is first to provide an in-depth description of both the
experimental set-up and protocol: the multiaxial testing machine, the
specific design of the cruciform specimen and performances of the
DIC code are introduced. Second, results for sixteen specimens
related to different load ratios are presented. Crack detection, strain
amplitude and number of cycles to crack initiation vs. triaxial stress
ratio for each loading case are given. Third, from fractographic
investigations by scanning electron microscopy it is found that the
mechanism of fatigue crack initiation does not depend on the triaxial
stress ratio and that most fatigue cracks initiate from subsurface
carbides.
Abstract: The thermal behavior of a large-scale, phase change material (PCM) enhanced building envelope system was studied in regard to the need for pre-fabricated construction in subtropical regions. The proposed large-scale envelope consists of a reinforced aluminum skin, insulation core, phase change material and reinforced gypsum board. The PCM impact on an energy efficiency of an enveloped room was resolved by validation of the EnergyPlus numerical scheme and optimization of a smart material location in the core. The PCM location was optimized by a minimization method of a cooling energy demand. It has been shown that there is good agreement between the test and simulation results. The optimal location of the PCM layer in Hong Kong summer conditions has been then recomputed for core thicknesses of 40, 60 and 80 mm. A non-dimensional value of the optimal PCM location was obtained to be same for all the studied cases and the considered external and internal conditions.
Abstract: The detection of moving objects from a video image
sequences is very important for object tracking, activity recognition,
and behavior understanding in video surveillance.
The most used approach for moving objects detection / tracking is
background subtraction algorithms. Many approaches have been
suggested for background subtraction. But, these are illumination
change sensitive and the solutions proposed to bypass this problem
are time consuming.
In this paper, we propose a robust yet computationally efficient
background subtraction approach and, mainly, focus on the ability to
detect moving objects on dynamic scenes, for possible applications in
complex and restricted access areas monitoring, where moving and
motionless persons must be reliably detected. It consists of three
main phases, establishing illumination changes invariance,
background/foreground modeling and morphological analysis for
noise removing.
We handle illumination changes using Contrast Limited Histogram
Equalization (CLAHE), which limits the intensity of each pixel to
user determined maximum. Thus, it mitigates the degradation due to
scene illumination changes and improves the visibility of the video
signal. Initially, the background and foreground images are extracted
from the video sequence. Then, the background and foreground
images are separately enhanced by applying CLAHE.
In order to form multi-modal backgrounds we model each channel
of a pixel as a mixture of K Gaussians (K=5) using Gaussian Mixture
Model (GMM). Finally, we post process the resulting binary
foreground mask using morphological erosion and dilation
transformations to remove possible noise.
For experimental test, we used a standard dataset to challenge the
efficiency and accuracy of the proposed method on a diverse set of
dynamic scenes.
Abstract: Meeting the growth in demand for digital services
such as social media, telecommunications, and business and cloud
services requires large scale data centres, which has led to an increase
in their end use energy demand. Generally, over 30% of data centre
power is consumed by the necessary cooling overhead. Thus energy
can be reduced by improving the cooling efficiency. Air and liquid
can both be used as cooling media for the data centre. Traditional
data centre cooling systems use air, however liquid is recognised as a
promising method that can handle the more densely packed data
centres. Liquid cooling can be classified into three methods; rack heat
exchanger, on-chip heat exchanger and full immersion of the
microelectronics. This study quantifies the improvements of heat
transfer specifically for the case of immersed microelectronics by
varying the CPU and heat sink location. Immersion of the server is
achieved by filling the gap between the microelectronics and a water
jacket with a dielectric liquid which convects the heat from the CPU
to the water jacket on the opposite side. Heat transfer is governed by
two physical mechanisms, which is natural convection for the fixed
enclosure filled with dielectric liquid and forced convection for the
water that is pumped through the water jacket. The model in this
study is validated with published numerical and experimental work
and shows good agreement with previous work. The results show that
the heat transfer performance and Nusselt number (Nu) is improved
by 89% by placing the CPU and heat sink on the bottom of the
microelectronics enclosure.
Abstract: The concentrations of cadmium and lead in sewage
sludge samples were determined by Atomic Absorption
Spectrometric Method. Samples of sewage sludge were obtained
from three sewage treatment plants localised in Middle Region of
Libya (Misrata, Msallata and Tarhünah cities).
The results shows that, the mean levels of Cadmium for all regions
are ranges from 81 to 123.4 ppm and these values are higher than the
limitations for the international standard which are not registered
more than 50 ppm (dry weight) in USA, Egypt and the EU countries.
While, the lead concentrations are ranged from 8.0 to 189.2 ppm and
all values are within the standard limits which graduated between
(275–613) ppm.