Abstract: Burnishing is increasingly used as a finishing operation to improve surface roughness and surface hardness. This can be achieved by applying a hard ball or roller onto metallic surfaces under pressure, in order to achieve many advantages in the metallic surface. In the present work, the feed rate, speed and force have been considered as the basic burnishing parameters to study the surface roughness and surface hardness of metallic matrix composites. The considered metal matrix composites were made from Aluminum-Magnesium-Graphite with five different weight percentage of graphite. Both effects of burnishing parameters mentioned above and the graphite percentage on the surface hardness and surface roughness of the metallic matrix composites were studied. The results of this investigation showed that the surface hardness of the metallic composites increases with the increase of the burnishing force and decreases with the increase in the burnishing feed rate and burnishing speed. The surface roughness of the metallic composites decreases with the increasing of the burnishing force, feed rate, and speed to certain values, then it starts to increase. On the other hand, the increase in the weight percentage of the graphite in the considered composites causes a decrease in the surface hardness and an increase in the surface roughness.
Abstract: Food is widely packaged with plastic materials to
prevent microbial contamination and spoilage. Ionizing radiation is
widely used to sterilize the food-packaging materials. Sterilization by
γ-radiation causes degradation such as embrittlement, stiffening,
softening, discoloration, odour generation, and decrease in molecular
weight. Many antioxidants can prevent γ-degradation but most of
them are toxic. The migration of antioxidants to its environment
gives rise to major concerns in case of food packaging plastics. In
this attempt, we have aimed to utilize synergistic mixtures of
stabilizers which are approved for food-contact applications.
Ethylene-propylene-diene terpolymer has been melt-mixed with
hindered amine stabilizers (HAS), phenolic antioxidants and organophosphites
(hydroperoxide decomposer). Results were discussed by
comparing the stabilizing efficiency of mixtures with and without
phenol system. Among phenol containing systems where we mostly
observed discoloration due to the oxidation of hindered phenol, the
combination of secondary HAS, tertiary HAS, organo-phosphite and
hindered phenol exhibited improved stabilization efficiency than
single or binary additive systems. The mixture of secondary HAS and
tertiary HAS, has shown antagonistic effect of stabilization.
However, the combination of organo-phosphite with secondary HAS,
tertiary HAS and phenol antioxidants have been found to give
synergistic even at higher doses of Gamma-irradiation. The effects
have been explained through the interaction between the stabilizers.
After γ-irradiation, the consumption of oligomeric stabilizer
significantly depends on the components of stabilization mixture. The
effect of the organo-phosphite antioxidant on the overall stability has
been discussed.
Abstract: The rate of natural gas dissociation from the Coal
Matrix depends on depressurization of reservoir through removing of
the cleat water from the coal seam. These waters are similar to brine
and aged of very long years. For improving the connectivity through
fracking /fracturing, high pressure liquids are pumped off inside the
coal body. A significant quantity of accumulated water, a combined
mixture of cleat water and fracking fluids (back flow water) is
pumped out through gas well. In Queensland, Australia Coal Seam
Gas (CSG) industry is in booming state and estimated of 30,000 wells
would be active for CSG production forecasting life span of 30 years.
Integrated water management along with water softening programs is
practiced for subsequent treatment and later on discharge to nearby
surface water catchment. Water treatment is an important part of the
CSG industry. A case study on a CSG site and review on the test
results are discussed for assessing the Standards & Practices for
management of CSG by-product water and their subsequent disposal
activities. This study was directed toward (i) water management and
softening process in Spring Gully CSG field, (ii) Comparative
analysis on experimental study and standards and (iii) Disposal of the
treated water. This study also aimed for alternative usages and their
impact on vegetation, living species as well as long term effects.
Abstract: A capacity spectrum method (CSM), one of methodologies to evaluate seismic fragilities of building structures, has been long recognized as the most convenient method, even if it contains several limitations to predict the seismic response of structures of interest. This paper proposes the procedure to estimate seismic fragility curves using an incremental dynamic analysis (IDA) rather than the method adopting a CSM. To achieve the research purpose, this study compares the seismic fragility curves of a 5-story reinforced concrete (RC) moment frame obtained from both methods; an IDA method and aCSM. Both seismic fragility curves are similar in slight and moderate damage states whereas the fragility curve obtained from the IDA method presents less variation (or uncertainties) in extensive and complete damage states. This is due to the fact that the IDA method can properly capture the structural response beyond yielding rather than the CSM and can directly calculate higher mode effects. From these observations, the CSM could overestimate seismic vulnerabilities of the studied structure in extensive or complete damage states.
Abstract: In this paper, the transient device performance analysis
of n-type Gate Inside JunctionLess Transistor (GI-JLT) has been
evaluated. 3-D Bohm Quantum Potential (BQP) transport device
simulation has been used to evaluate the delay and power dissipation
performance. GI-JLT has a number of desirable device parameters
such as reduced propagation delay, dynamic power dissipation,
power and delay product, intrinsic gate delay and energy delay
product as compared to Gate-all-around transistors GAA-JLT. In
addition to this, various other device performance parameters namely,
on/off current ratio, short channel effects (SCE), transconductance
Generation Factor (TGF) and unity gain cut-off frequency (fT ) and
subthreshold slope (SS) of the GI-JLT and GAA-JLT have been
analyzed and compared. GI-JLT shows better device performance
characteristics than GAA-JLT for low power and high frequency
applications, because of its larger gate electrostatic control on the
device operation.
Abstract: Photonic Crystal Fibers (PCFs) can be used in optical
communications as transmission lines. For this reason, the PCFs with
low confinement loss, low chromatic dispersion, and low nonlinear
effects are highly suitable transmission media. In this paper, we
introduce a new design of index-guiding nanostructured photonic
crystal fiber (IG-NPCF) with ultra-low chromatic dispersion, low
nonlinearity effects, and low confinement loss. Relatively low
dispersion is achieved in the wavelength range of 1200 to 1600nm
using the proposed design. According to the new structure of
nanostructured PCF presented in this study, the chromatic dispersion
slope is -30(ps/km.nm) and the confinement loss reaches below 10-7
dB/km. While in the wavelength range mentioned above at the same
time an effective area of more than 50.2μm2 is obtained.
Abstract: Worldwide, most PILC MV underground cables in use
are approaching the end of their design life; hence, failures are likely
to increase. This paper studies the electric field and potential
distributions within the PILC insulted cable containing common
void-defect. The finite element model of the performance of the
belted PILC MV underground cable is presented. The variation of the
electric field stress within the cable using the Finite Element Method
(FEM) is concentrated. The effects of the void-defect within the
insulation are given. Outcomes will lead to deeper understanding of
the modeling of Paper Insulated Lead Covered (PILC) and electric
field response of belted PILC insulted cable containing void defect.
Abstract: In this study, we propose a novel technique for acoustic
echo suppression (AES) during speech recognition under barge-in
conditions. Conventional AES methods based on spectral subtraction
apply fixed weights to the estimated echo path transfer function
(EPTF) at the current signal segment and to the EPTF estimated until
the previous time interval. However, the effects of echo path changes
should be considered for eliminating the undesired echoes. We
describe a new approach that adaptively updates weight parameters in
response to abrupt changes in the acoustic environment due to
background noises or double-talk. Furthermore, we devised a voice
activity detector and an initial time-delay estimator for barge-in speech
recognition in communication networks. The initial time delay is
estimated using log-spectral distance measure, as well as
cross-correlation coefficients. The experimental results show that the
developed techniques can be successfully applied in barge-in speech
recognition systems.
Abstract: In the present study, mixed convection in a horizontal
rectangular duct using Al2O3 is numerically investigated. The effects
of different Rayleigh number, Reynolds number and radiation on
flow and heat transfer characteristics are studied in detail. This study
covers Rayleigh number in the range of 2 × 10^6 ≤ Ra ≤ 2 × 10^7 and
Reynolds number in the range of 100 ≤ Re ≤ 1100. Results reveal that
the Nusselt number increases as Reynolds and Rayleigh numbers
increase. It is also found that the dimensionless temperature
distribution increases as Rayleigh number increases.
Abstract: In this article, we have elaborated a study over the
nature of financial intermediation in Islamic banks by comparison to
those of conventional ones. We have found a striking difference
between two kinds of intermediation. We tried, from another side, to
study the relationship between the capital level and deficiency risk
relying on econometric model, and we have obtained a positive and
significant relation between the capital and the deficiency risk for the
conventional banks. This means that when the capital of these banks
increases, the deficiency risk increases as well. In return, since the
Islamic banks are constrained to respect the Sharia Committee as well
as customers’ demands that may, in certain contracts, choose to
invest their capitals in projects they are interested in. These
constraints have as effects to reduce the deficiency risk even when
the capital increases.
Abstract: A feeding experiment was conducted to determine the
optimum dietary protein and lipid levels for juvenile fancy carp. Eight
experimental diets were formulated to contain four protein levels (200,
300, 400 and 500 g kg-1) with two lipid levels (70 and 140 g kg-1).
Triplicate groups of fish (initial weight, 12.1±0.2 g fish-1) were
hand-fed the diets to apparent satiation for 8 weeks. Fish growth
performance, feed utilization and feed intake were significantly
(P0.05). Weight gain and feed efficiency ratio tended to
increase as dietary protein level increased up to 400 and 500 g kg-1,
respectively. Daily feed intake of fish decreased with increasing
dietary protein level and that of fish fed diet contained 500 g kg-1
protein was significantly lower than other fish groups. The protein
efficiency ratio of fish fed 400 and 500 g kg-1 protein was lower than
that of fish fed 200 and 300 g kg-1 protein. Moisture, crude protein and
crude lipid contents of muscle and liver were significantly affected by
dietary protein, but not by dietary lipid level (P>0.05). The increase in
dietary lipid level resulted in an increase in linoleic acid in liver and
muscle paralleled with a decrease in n-3 highly unsaturated fatty acids
content in muscle of fish. In considering these results, it was concluded
that the diet containing 400 g kg-1 protein with 70 g kg-1 lipid level is
optimal for growth and efficient feed utilization of juvenile fancy carp.
Abstract: Due to water shortage, application of saline water for
irrigation is an urgent in agriculture. In this study the effect of
calcium and potassium application as additive in saline root media for
reduce salinity adverse effects was investigated on tomato growth in
a hydroponic system with unequal distribution of salts in the root
media, which was divided in to two equal parts containing full
Johnson nutrient solution and 40 mMNaCl solution, alone or in
combination with KCl (6 mM), CaCl2 (4 mM), K+Ca (3+2 mM) or
half-strength Johnson nutrient solution. The root splits were
exchanged every 7 days. Results showed that addition of calcium,
calcium-potassium and nutrition elements equivalent to half the
concentration of Johnson formula to the saline-half of culture media
minimized the reduction in plant growth caused by NaCl, although
addition of potassium to culture media wasn’t effective. The greatest
concentration of sodium was observed at the shoot of treatments
which had smallest growth. According to the results of this study, in
case of dynamic and non-uniform distribution of salts in the root
media, by addition of additive to the saline solution, it would be
possible to use of saline water with no significant growth reduction.
Abstract: Currently, thorium fuel has been especially noticed
because of its proliferation resistance than long half-life alpha emitter
minor actinides, breeding capability in fast and thermal neutron flux
and mono-isotopic naturally abundant. In recent years, efficiency of
minor actinide burning up in PWRs has been investigated. Hence, a
minor actinide-contained thorium based fuel matrix can confront both
proliferation resistance and nuclear waste depletion aims. In the
present work, minor actinide depletion rate in a CANDU-type nuclear
core modeled using MCNP code has been investigated. The obtained
effects of minor actinide load as mixture of thorium fuel matrix on
the core neutronics has been studied with comparing presence and
non-presence of minor actinide component in the fuel matrix.
Depletion rate of minor actinides in the MA-contained fuel has been
calculated using different power loads. According to the obtained
computational data, minor actinide loading in the modeled core
results in more negative reactivity coefficients. The MA-contained
fuel achieves less radial peaking factor in the modeled core. The
obtained computational results showed 140 kg of 464 kg initial load
of minor actinide has been depleted in during a 6-year burn up in 10
MW power.
Abstract: Climate change confronts the built environment with
many new challenges in the form of more severe and frequent hydrometeorological
events. A series of strategies is proposed whereby the
various aspects of buildings and their sites can be made more resilient
to the effects of such events.
Abstract: Over the last few decades, oilfield service rolling
equipment has significantly increased in weight, primarily because of
emissions regulations, which require larger/heavier engines, larger
cooling systems, and emissions after-treatment systems, in some
cases, etc. Larger engines cause more vibration and shock loads,
leading to failure of electronics and control systems.
If the vibrating frequency of the engine matches the system
frequency, high resonance is observed on structural parts and mounts.
One such existing automated control equipment system comprising
wire rope mounts used for mounting computers was designed
approximately 12 years ago. This includes the use of an industrialgrade
computer to control the system operation. The original
computer had a smaller, lighter enclosure. After a few years, a newer
computer version was introduced, which was 10 lbm heavier. Some
failures of internal computer parts have been documented for cases in
which the old mounts were used. Because of the added weight, there
is a possibility of having the two brackets impact each other under
off-road conditions, which causes a high shock input to the computer
parts. This added failure mode requires validating the existing mount
design to suit the new heavy-weight computer.
This paper discusses the modal finite element method (FEM)
analysis and experimental modal analysis conducted to study the
effects of vibration on the wire rope mounts and the computer. The
existing mount was modelled in ANSYS software, and resultant
mode shapes and frequencies were obtained. The experimental modal
analysis was conducted, and actual frequency responses were
observed and recorded.
Results clearly revealed that at resonance frequency, the brackets
were colliding and potentially causing damage to computer parts. To
solve this issue, spring mounts of different stiffness were modeled in
ANSYS software, and the resonant frequency was determined.
Increasing the stiffness of the system increased the resonant
frequency zone away from the frequency window at which the engine
showed heavy vibrations or resonance. After multiple iterations in
ANSYS software, the stiffness of the spring mount was finalized,
which was again experimentally validated.
Abstract: The paper examines the interaction between the
environmental taxation, size of government spending on
environmental protection and greenhouse gas emissions and gross
inland energy consumption. The aim is to analyze the effects of
environmental taxation and government spending on environmental
protection as an environmental policy instruments on greenhouse gas
emissions and gross inland energy consumption in the EU15. The
empirical study is performed using a VAR approach with the
application of aggregated data of EU15 over the period 1995 to 2012.
The results provide the evidence that the reactions of greenhouse gas
emission and gross inland energy consumption to the shocks of
environmental policy instruments are strong, mainly in the short term
and decay to zero after about 8 years. Further, the reactions of the
environmental policy instruments to the shocks of greenhouse gas
emission and gross inland energy consumption are also strong in the
short term, however with the deferred effects. In addition, the results
show that government spending on environmental protection together
with gross inland energy consumption has stronger effect on
greenhouse gas emissions than environmental taxes in EU15 over the
examined period.
Abstract: With a long history, dual-task has become one of the
most intriguing research fields regarding human brain functioning
and cognition. However, findings considering effects of taskinterrelations
are limited (especially, in combined motor and
cognitive tasks). Therefore, we aimed at developing a measurement
system in order to analyse interrelation effects of cognitive and motor
tasks. On the one hand, the present study demonstrates the
applicability of the measurement system and on the other hand first
results regarding a systematisation of different task combinations are
shown. Future investigations should combine imagine technologies
and this developed measurement system.
Abstract: The problematic of gender and socioeconomic status
biased differences in academic motivation patterns is discussed.
Gender identity is understood according to symbolic interactionism
perspective: as a result of reflected appraisals, social comparisons,
self-attributions, and identifications, shaped by social environment
and family context. The effects of socioeconomic status on academic
motivation are conceptualized according to Bourdieu’s habitus
concept, reflecting the role of unconscious and internalized cultural
signals, proper to low and high socioeconomic status family contexts.
Since families differ by various socioeconomic features, the
hypothesis about possible impact of parents’ socioeconomic status on
their children’s academic motivation interfering with gender
socialization effects is held. The survey, aiming to seize gender
differences in academic motivation and self-recorded improvementoriented
efforts as a result of socialization processes operating in the
families of low and high socioeconomic status, was designed. The
results of Lithuanian higher education students’ survey are presented
and discussed.
Abstract: In recent years, the compression of date (Phoenix
dactylifera L.) fruit powders (DP) to obtain date tablets (DT) has
been suggested as a promising form of valorization of non
commercial valuable date fruit (DF) varieties. To further improve
and characterize DT, the present study aims to investigate the
influence of the DP particle size and compression force on some
physical properties of DT. The results show that independently of
particle size, the hardness (y) of tablets increases with the increase of
the compression force (x) following a logarithmic law (y = a ln (bx)
where a and b are the constants of model). Further, a full factorial
design (FFD) at two levels, applied to investigate the erosion %,
reveals that the effects of time and particle size are the same in
absolute value and they are beyond the effect of the compression.
Regarding the disintegration time, the obtained results also by means
of a FFD show that the effect of the compression force exceeds 4
times that of the DP particle size. As final stage, the color parameters
in the CIELab system of DT immediately after their obtaining are
differently influenced by the size of the initial powder.
Abstract: The IEEE 802.22 working group aims to drive the
Digital Video Broadcasting-Terrestrial (DVB-T) bands for data
communication to the rural area without interfering the TV broadcast.
In this paper, we arrive at a closed-form expression for average
detection probability of Fusion center (FC) with multiple antenna
over the κ − μ fading channel model. We consider a centralized
cooperative multiple antenna network for reporting. The DVB-T
samples forwarded by the secondary user (SU) were combined using
Maximum ratio combiner at FC, an energy detection is performed
to make the decision. The fading effects of the channel degrades
the detection probability of the FC, a generalized independent and
identically distributed (IID) κ − μ and an additive white Gaussian
noise (AWGN) channel is considered for reporting and sensing
respectively. The proposed system performance is verified through
simulation results.