Abstract: These Monolayer and multilayer coatings of CrN and
AlCrN deposited on 100Cr6 (AISI 52100) substrate by PVD
magnetron sputtering system. The microstructures of the coatings
were characterized using atomic force microscopy (AFM). The AFM
analysis revealed the presence of domes and craters that are
uniformly distributed over all surfaces of the various layers.
Nanoindentation measurement of CrN coating showed maximum
hardness (H) and modulus (E) of 14 GPa and 190 GPa, respectively.
The measured H and E values of AlCrN coatings were found to be 30
GPa and 382 GPa, respectively. The improved hardness in both the
coatings was attributed mainly to a reduction in crystallite size and
decrease in surface roughness. The incorporation of Al into the CrN
coatings has improved both hardness and Young’s modulus.
Abstract: The effects of flame-holder position, the ratio of flame
holder diameter to combustion chamber diameter and injection angle
on fuel propulsive droplets sizing and effective mass fraction have
been studied by a cold flow. We named the mass of fuel vapor inside
the flammability limit as the effective mass fraction. An empty
cylinder as well as a flame-holder which are a simulator for duct
combustion has been considered. The airflow comes into the cylinder
from one side and injection operation will be done by four nozzles
which are located on the entrance of cylinder. To fulfill the
calculations a modified version of KIVA-3V code which is a
transient, three-dimensional, multiphase, multi component code for
the analysis of chemically reacting flows with sprays, is used.
Abstract: This paper is based on a large questionnaire study. The
paper presents how all participants and subgroups (upper- and
lower-level white-collar workers) answered the question, “Have you
had an ache, pain, or numbness, which you associate with desktop
computer use, in the different body parts during the last 12 months?’
14.6% of participants (19.4% of women and 8.2% of men) reported
that they had often or very often physical symptoms in the neck. Even
if our results cannot prove a causal relation of symptoms with
computer use, show that workers believe that computer use can
influence their wellbeing: this is important when devising treatment
modalities to decrease these physical symptoms.
Abstract: New design of three dimensional (3D) flywheel system
based on gimbal and gyro mechanics is proposed. The 3D flywheel
device utilizes the rotational motion of three spherical shells and the
conservation of angular momentum to achieve planar locomotion.
Actuators mounted to the ring-shape frames are installed within the
system to drive the spherical shells to rotate, for the purpose of steering
and stabilization. Similar to the design of 2D flywheel system, it is
expected that the spherical shells may function like a “flyball” to store
and supply mechanical energy; additionally, in comparison with
typical single-wheel and spherical robots, the 3D flywheel can be used
for developing omnidirectional robotic systems with better mobility.
The Lagrangian method is applied to derive the equation of motion of
the 3D flywheel system, and simulation studies are presented to verify
the proposed design.
Abstract: This study utilizes a frequency domain approach over
the period of 1996 to 2013 to examine the causal relationship between
governance and economic growth in ten Asian countries, which have
different levels of democracy; classified as “Free”, “Partly Free”, and
“Not Free” countries. The empirical results show that there is no
Granger causality running from governance to economic growth in
“Not Free” countries and “Partly Free” countries with the exception of
Singapore. As for “Free” countries such as South Korea and Taiwan,
there is a one-way causality running from governance to economic
growth. The findings of this study indicate that policy makers in South
Korea, Taiwan, and Singapore could use governance index to improve
their predictions of the future economic growth.
Abstract: This work presents an improved single fiber pull-out
test for fiber/matrix interface characterization. This test has been
used to study the Inter-Facial Shear Strength ‘IFSS’ of hemp fibers
reinforced polypropylene (PP). For this aim, the fiber diameter
has been carefully measured using a tomography inspired method.
The fiber section contour can then be approximated by a circle
or a polygon. The results show that the IFSS is overestimated if
the circular approximation is used. The Influence of the molding
temperature on the IFSS has also been studied. We find that a molding
temperature of 183◦C leads to better interfacial properties. Above or
below this temperature the interface strength is reduced.
Abstract: Distillery spentwash contains high chemical oxygen
demand (COD), biological oxygen demand (BOD), color, total
dissolved solids (TDS) and other contaminants even after biological
treatment. The effluent can’t be discharged as such in the surface
water bodies or land without further treatment. Reverse osmosis (RO)
treatment plants have been installed in many of the distilleries at
tertiary level in many of the distilleries in India, but are not properly
working due to fouling problem which is caused by the presence of
high concentration of organic matter and other contaminants in
biologically treated spentwash. In order to make the membrane
treatment a proven and reliable technology, proper pre-treatment is
mandatory. In the present study, ultra-filtration (UF) for pretreatment
of RO at tertiary stage has been performed. Operating
parameters namely initial pH (pHo: 2–10), trans-membrane pressure
(TMP: 4-20 bars) and temperature (T: 15-43°C) were used for
conducting experiments with UF system. Experiments were
optimized at different operating parameters in terms of COD, color,
TDS and TOC removal by using response surface methodology
(RSM) with central composite design. The results showed that
removal of COD, color and TDS was 62%, 93.5% and 75.5%
respectively, with UF, at optimized conditions with increased
permeate flux from 17.5 l/m2/h (RO) to 38 l/m2/h (UF-RO). The
performance of the RO system was greatly improved both in term of
pollutant removal as well as water recovery.
Abstract: Biodiesel production from vegetable oil will produce
glycerol as by-product about 10% of the biodiesel production. The
amount of glycerol that was produced needed alternative way to
handling immediately so as to not become the waste that polluted
environment. One of the solutions was to process glycerol to
polyglycidyl nitrate (PGN). PGN is synthesized from glycerol by
three-step reactions i.e. nitration of glycerol, cyclization of 13-
dinitroglycerine and polymerization of glycosyl nitrate. Optimum
condition of nitration of glycerol with nitric acid has not been known.
Thermodynamic feasibility should be done before run experiments in
the laboratory. The aim of this study was to determine the parameters
those affect nitration of glycerol and nitric acid and chose the
operation condition. Many parameters were simulated to verify its
possibility to experiment under conditions which would get the
highest conversion of 1, 3-dinitroglycerine and which was the ideal
condition to get it. The parameters that need to be studied to obtain
the highest conversion of 1, 3-dinitroglycerine were mol ratio of
nitric acid/glycerol, reaction temperature, mol ratio of
glycerol/dichloromethane and pressure. The highest conversion was
obtained in the range of mol ratio of nitric acid /glycerol between 2/1
– 5/1, reaction temperature of 5-25oC and pressure of 1 atm. The
parameters that need to be studied further to obtain the highest
conversion of 1.3 DNG are mol ratio of nitric acid/glycerol and
reaction temperature.
Abstract: In this study, to clarify the effectiveness of an
aluminum/chromium/tungsten-based-coated tool for cutting sintered
steel, tool wear was experimentally investigated. The sintered steel
was turned with the (Al60,Cr25,W15)N-, (Al60,Cr25,W15)(C,N)- and
(Al64,Cr28,W8)(C,N)-coated cemented carbide tools according to the
physical vapor deposition (PVD) method. Moreover, the tool wear of
the aluminum/chromium/tungsten-based-coated item was compared
with that of the (Al,Cr)N coated tool. Furthermore, to clarify the tool
wear mechanism of the aluminum/chromium/tungsten-coating film for
cutting sintered steel, Scanning Electron Microscope observation and
Energy Dispersive x-ray Spectroscopy mapping analysis were
conducted on the abraded surface. The following results were
obtained: (1) The wear progress of the (Al64,Cr28,W8)(C,N)-coated
tool was the slowest among that of the five coated tools. (2) Adding
carbon (C) to the aluminum/chromium/tungsten-based-coating film
was effective for improving the wear-resistance. (3) The main wear
mechanism of the (Al60,Cr25,W15)N-, the (Al60,Cr25,W15)(C,N)-
and the (Al64,Cr28,W8)(C,N)-coating films was abrasive wear.
Abstract: The economic use and ease of construction of profiled
deck composite slab is marred with the complex and un-economic
strength verification required for the serviceability and general safety
considerations. Beside these, albeit factors such as shear span length,
deck geometries and mechanical frictions greatly influence the
longitudinal shear strength, that determines the ultimate strength of
profiled deck composite slab, and number of methods available for its
determination; partial shear and slope-intercept are the two methods
according to Euro-code 4 provision. However, the complexity
associated with shear behavior of profiled deck composite slab, the
use of these methods in determining the load carrying capacities of
such slab yields different and conflicting values. This couple with the
time and cost constraint associated with the strength verification is a
source of concern that draws more attentions nowadays, the issue is
critical. Treating some of these known shear strength influencing
factors as random variables, the load carrying capacity violation of
profiled deck composite slab from the use of the two-methods
defined according to Euro-code 4 are determined using reliability
approach, and comparatively studied. The study reveals safety values
from the use of m-k method shows good standing compared with that
from the partial shear method.
Abstract: The aim of the present study is to detect the chaotic
behavior in monetary economic relevant dynamical system. The
study employs three different forms of Taylor rules: current, forward,
and backward looking. The result suggests the existence of the
chaotic behavior in all three systems. In addition, the results strongly
represent that using expectations in policy rule especially rational
expectation hypothesis can increase complexity of the system and
leads to more chaotic behavior.
Abstract: Bicycle Level of Service (BLOS) is a measure for
evaluating street conditions for cyclists. Currently, various methods
are proposed for BLOS. These analytical methods however have
some drawbacks: they usually assume cyclists as users that can share
street facilities with motorized vehicles, it is not easy to link them to
design process and they are not easy to follow. In addition, they only
support a narrow range of cycling facilities and may not be applicable
for all situations. Along this, the current paper introduces various
effective design factors for bicycle-friendly streets. This study
considers cyclists as users of streets who have special needs and
facilities. Therefore, the key factors that influence BLOS based on
different cycling facilities that are proposed by developed guidelines
and literature are identified. The combination of these factors
presents a complete set of effective design factors for bicycle-friendly
streets. In addition, the weight of each factor in existing BLOS
models is estimated and these effective factors are ranked based on
these weights. These factors and their weights can be used in further
studies to propose special bicycle-friendly street design model.
Abstract: We apply the non-parametric, unconditional,
hyperbolic order-α quantile estimator to appraise the relative
efficiency of Microfinance Institutions in Africa in terms of outreach.
Our purpose is to verify if these institutions, which must constantly
try to strike a compromise between their social role and financial
sustainability are operationally efficient.
Using data on African MFIs extracted from the Microfinance
Information eXchange (MIX) database and covering the 2004 to
2006 periods, we find that more efficient MFIs are also the most
profitable. This result is in line with the view that social performance
is not in contradiction with the pursuit of excellent financial
performance. Our results also show that large MFIs in terms of asset
and those charging the highest fees are not necessarily the most
efficient.
Abstract: Superabsorbent polymers received much attention and
are used in many fields because of their superior characters to
traditional absorbents, e.g., sponge and cotton. So, it is very
important but challenging to prepare highly and fast-swelling
superabsorbents. A reliable, efficient and low-cost technique for
removing heavy metal ions from wastewater is the adsorption using
bio-adsorbents obtained from biological materials, such as
polysaccharides-based hydrogels superabsorbents. In this study, novel multi-functional superabsorbent composites
type semi-interpenetrating polymer networks (Semi-IPNs) were
prepared via graft polymerization of acrylamide onto chitosan
backbone in presence of gelatin, CTS-g-PAAm/Ge, using potassium
persulfate and N,N’-methylene bisacrylamide as initiator and
crosslinker, respectively. These hydrogels were also partially
hydrolyzed to achieve superabsorbents with ampholytic properties
and uppermost swelling capacity. The formation of the grafted
network was evidenced by Fourier Transform Infrared Spectroscopy
(ATR-FTIR) and Thermogravimetric Analysis (TGA). The porous
structures were observed by Scanning Electron Microscope (SEM).
From TGA analysis, it was concluded that the incorporation of the Ge
in the CTS-g-PAAm network has marginally affected its thermal
stability. The effect of gelatin content on the swelling capacities of
these superabsorbent composites was examined in various media
(distilled water, saline and pH-solutions). The water absorbency was
enhanced by adding Ge in the network, where the optimum value was
reached at 2 wt. % of Ge. Their hydrolysis has not only greatly
optimized their absorption capacity but also improved the swelling
kinetic.These materials have also showed reswelling ability. We
believe that these super-absorbing materials would be very effective
for the adsorption of harmful metal ions from wastewater.
Abstract: Processing of Al-19.4Si alloy by high intensive
electron beam has been carried out and multiple increases in fatigue
life of the material have been revealed. Investigations of structure and
surface modified layer destruction of Al-19.4Si alloy subjected to
multicycle fatigue tests to fracture have been carried out by methods
of scanning electron microscopy. The factors responsible for the
increase of fatigue life of Al-19.4Si alloy have been revealed and
analyzed.
Abstract: In this study, nuclear magnetic resonance
spectroscopy and nuclear quadrupole resonance spectroscopy
parameters of 14N (Nitrogen in imidazole ring) in N–H…O hydrogen
bonding for Histidine hydrochloride monohydrate were calculated via
density functional theory. We considered a five-molecule model
system of Histidine hydrochloride monohydrate. Also we examined
the trends of environmental effect on hydrogen bonds as well as
cooperativity. The functional used in this research is M06-2X which
is a good functional and the obtained results has shown good
agreement with experimental data. This functional was applied to
calculate the NMR and NQR parameters. Some correlations among
NBO parameters, NMR and NQR parameters have been studied
which have shown the existence of strong correlations among them.
Furthermore, the geometry optimization has been performed using
M062X/6-31++G(d,p) method. In addition, in order to study
cooperativity and changes in structural parameters, along with
increase in cluster size, natural bond orbitals have been employed.
Abstract: In the cooperative transmission scheme, both the
cellular system and broadcasting system are composed. Two cellular
base stations (CBSs) communicating with a user in the cell edge use
cooperative transmission scheme in the conventional scheme. In the
case that the distance between two CBSs and the user is distant, the
conventional scheme does not guarantee the quality of the
communication because the channel condition is bad. Therefore, if the
distance between CBSs and a user is distant, the performance of the
conventional scheme is decreased. Also, the bad channel condition has
bad effects on the performance. The proposed scheme uses two relays
to communicate well with CBSs when the channel condition between
CBSs and the user is poor. Using the relay in the high attenuation
environment can obtain both advantages of the high bit error rate
(BER) and throughput performance.
Abstract: Steepest descent method is a simple gradient method
for optimization. This method has a slow convergence in heading to
the optimal solution, which occurs because of the zigzag form of the
steps. Barzilai and Borwein modified this algorithm so that it
performs well for problems with large dimensions. Barzilai and
Borwein method results have sparked a lot of research on the method
of steepest descent, including alternate minimization gradient method
and Yuan method. Inspired by previous works, we modified the step
size of the steepest descent method. We then compare the
modification results against the Barzilai and Borwein method,
alternate minimization gradient method and Yuan method for
quadratic function cases in terms of the iterations number and the
running time. The average results indicate that the steepest descent
method with the new step sizes provide good results for small
dimensions and able to compete with the results of Barzilai and
Borwein method and the alternate minimization gradient method for
large dimensions. The new step sizes have faster convergence
compared to the other methods, especially for cases with large
dimensions.
Abstract: EEG correlates of mathematical and trait anxiety level
were studied in 52 healthy Russian-speakers during execution of
error-recognition tasks with lexical, arithmetic and algebraic
conditions. Event-related spectral perturbations were used as a
measure of brain activity. The ERSP plots revealed alpha/beta
desynchronizations within a 500-3000 ms interval after task onset
and slow-wave synchronization within an interval of 150-350 ms.
Amplitudes of these intervals reflected the accuracy of error
recognition, and were differently associated with the three conditions.
The correlates of anxiety were found in theta (4-8 Hz) and beta2 (16-
20 Hz) frequency bands. In theta band the effects of mathematical
anxiety were stronger expressed in lexical, than in arithmetic and
algebraic condition. The mathematical anxiety effects in theta band
were associated with differences between anterior and posterior
cortical areas, whereas the effects of trait anxiety were associated
with inter-hemispherical differences. In beta1 and beta2 bands effects
of trait and mathematical anxiety were directed oppositely. The trait
anxiety was associated with increase of amplitude of
desynchronization, whereas the mathematical anxiety was associated
with decrease of this amplitude. The effect of mathematical anxiety
in beta2 band was insignificant for lexical condition but was the
strongest in algebraic condition. EEG correlates of anxiety in theta
band could be interpreted as indexes of task emotionality, whereas
the reaction in beta2 band is related to tension of intellectual
resources.
Abstract: Artificial neural networks have gained a lot of interest
as empirical models for their powerful representational capacity,
multi input and output mapping characteristics. In fact, most feedforward
networks with nonlinear nodal functions have been proved to
be universal approximates. In this paper, we propose a new
supervised method for color image classification based on selforganizing
feature maps (SOFM). This algorithm is based on
competitive learning. The method partitions the input space using
self-organizing feature maps to introduce the concept of local
neighborhoods. Our image classification system entered into RGB
image. Experiments with simulated data showed that separability of
classes increased when increasing training time. In additional, the
result shows proposed algorithms are effective for color image
classification.