Abstract: Theoretical optimization of a copper-water negative
inclination heat pipe with internal composite wick structure had been
performed, regarding a new introduced parameter: the ratio between
the coarse mesh wraps and the fine mesh wraps of the composite
wick. Since in many cases, the design of a heat pipe matches specific
thermal requirements and physical limitations, this work
demonstrates the optimization of a 1m length, 8mm internal diameter
heat pipe without an adiabatic section, at a negative inclination angle
of -10º. The optimization is based on a new introduced parameter, LR:
the ratio between the coarse mesh wraps and the fine mesh wraps.
Abstract: In the present work, the effects of additives, including
contents of the added antioxidants and type of the selected metallic
stearates (either calcium stearate (CaSt) or zinc stearate (ZnSt)), on
the thermal stabilities of carbon black (CB)/high density polyethylene
(HDPE) compounds were studied. The results showed that the AO
contents played a key role in the thermal stabilities of the CB/HDPE
compounds — the higher the AO content, the higher the thermal
stabilities. Although the CaSt-containing compounds were slightly
superior to those with ZnSt in terms of the thermal stabilities, the
remaining solid residue of CaSt after heated to the temperature of 600
°C (mainly calcium carbonate (CaCO3) as characterized by the X-ray
diffraction (XRD) technique) seemed to catalyze the decomposition
of CB in the HDPE-based compounds. Hence, the quantification of
CB in the CaSt-containing compounds with a muffle furnace gave an
inaccurate CB content — much lower than actual value. However,
this phenomenon was negligible in the ZnSt-containing system.
Abstract: OEE has been used in many industries as measure of
performance. However due to limitations of original OEE, it has been
modified by various researchers. OEE for mining application is
special version of classic equation, carries these limitation over. In
this paper it has been aimed to modify the OEE for mining
application by introducing the weights to the elements of it and
termed as Mine Production index (MPi). As a special application of
new index MPishovel has been developed by authors. This can be used
for evaluating the shovel effectiveness. Based on analysis, utilization
followed by performance and availability were ranked in this order.
To check the applicability of this index, a case study was done on
four electrical and one hydraulic shovel in a Swedish mine. The
results shows that MPishovel can evaluate production effectiveness of
shovels and can determine effectiveness values in optimistic view
compared to OEE. MPi with calculation not only give the
effectiveness but also can predict which elements should be focused
for improving the productivity.
Abstract: This study is an attempt to raise the awareness of the
stakeholders and the authorities on the sensitivity of Algerian
secondary school teachers of English as a Foreign Language about
the students’ loss of English language skills learned during formal
schooling with effort and at expense and the supposed measures to
arrest that loss. Data was collected from secondary school teachers of
EFL and analyzed quantitatively using a questionnaire containing
open-ended and close-ended questions. The results advocate a
consensus about the need for actions to be adopted to make
assessment techniques outcome-oriented. Most of the participants
were in favor of including curricular activities involving
contextualized learning, problem-solving learning critical selfawareness,
self and peer-assisted learning, use of computers and
internet so as to make learners autonomous.
Abstract: Different order modulations combined with different
coding schemes, allow sending more bits per symbol, thus achieving
higher throughputs and better spectral efficiencies. However, it must
also be noted that when using a modulation technique such as 64-
QAM with less overhead bits, better signal-to-noise ratios (SNRs) are
needed to overcome any Inter symbol Interference (ISI) and maintain
a certain bit error ratio (BER). The use of adaptive modulation allows
wireless technologies to yielding higher throughputs while also
covering long distances. The aim of this paper is to implement an
Adaptive Modulation and Coding (AMC) features of the WiMAX
PHY in MATLAB and to analyze the performance of the system in
different channel conditions (AWGN, Rayleigh and Rician fading
channel) with channel estimation and blind equalization. Simulation
results have demonstrated that the increment in modulation order
causes to increment in throughput and BER values. These results
derived a trade-off among modulation order, FFT length, throughput,
BER value and spectral efficiency. The BER changes gradually for
AWGN channel and arbitrarily for Rayleigh and Rician fade
channels.
Abstract: Information and Communication Technologies (ICTs)
are pervasive nowadays, including in education where they are
expected to improve the performance of learners. However, the hope
placed in ICTs to find viable solutions to the problem of poor
academic performance in schools in the developing world has not yet
yielded the expected benefits. This problem serves as a motivation to
this study whose aim is to examine the perceptions of educators on
the advantages and disadvantages of e-learning. This aim will be
subdivided into two types of research objectives. Objectives on the
identification and design of theories and models will be achieved
using content analysis and literature review. However, the objective
on the empirical testing of such theories and models will be achieved
through the survey of educators from different schools in the
Pinetown District of the South African Kwazulu-Natal province.
SPSS is used to quantitatively analyse the data collected by the
questionnaire of this survey using descriptive statistics and Pearson
correlations after assessing the validity and the reliability of the data.
The main hypothesis driving this study is that there is a relationship
between the demographics of educators’ and their adherence to
learning theories on one side, and their perceptions on the advantages
and disadvantages of e-learning on the other side, as argued by
existing research; but this research views these learning theories
under three perspectives: educators’ adherence to self-regulated
learning, to constructivism, and to progressivism. This hypothesis
was fully confirmed by the empirical study except for the
demographic factor where teachers’ level of education was found to
be the only demographic factor affecting the perceptions of educators
on the advantages and disadvantages of e-learning.
Abstract: This paper presents a new method to design nonlinear
feedback linearization controller for PEMFCs (Polymer Electrolyte
Membrane Fuel Cells). A nonlinear controller is designed based on
nonlinear model to prolong the stack life of PEMFCs. Since it is
known that large deviations between hydrogen and oxygen partial
pressures can cause severe membrane damage in the fuel cell,
feedback linearization is applied to the PEMFC system so that the
deviation can be kept as small as possible during disturbances or load
variations. To obtain an accurate feedback linearization controller,
tuning the linear parameters are always important. So in proposed
study NSGA (Non-Dominated Sorting Genetic Algorithm)-II method
was used to tune the designed controller in aim to decrease the
controller tracking error. The simulation result showed that the
proposed method tuned the controller efficiently.
Abstract: Ongoing landscape transformation is one of the major
causes behind disappearance of traditional landscapes, and lead to
species and resource loss. Tree in paddy fields in the northeast of
Thailand is one of those traditional landscapes. Using three different
historical time layers, we acknowledged the severe deforestation and
rapid urbanization happened in the region. Despite the general
thinking of decline in tree density as consequences, the heterogeneous
trend of changes in total tree density in three studied landscapes denied
the hypothesis that number of trees in paddy field depend on the length
of land use practice. On the other hand, due to selection of planting
new trees on levees, existence of trees in paddy field now relies on
their values for human use. Besides, changes in land use and landscape
structure had a significant impact on decision of which tree density
level is considered as suitable for the landscape.
Abstract: The effect of Zn2+, Mg2+, and Ba2+ on Saccharomyces
pastorianus performance was evaluated in this study at independent
and three variable combinations. After 96 h of fermentation, high
wort fermentability (%F) = 29.53 was obtained in medium containing
900:4 ppm Mg2+ + Ba2+. Increased ethanol yield 7.35 %(v/v) and
7.13 %(v/v) were obtained in media containing 900:4 ppm Mg2+ +
Ba2+ and 12:900 ppm Zn2+ + Mg2+. Decrease %F = 22.54 and ethanol
yield 6.18 % (v/v) was obtained in medium containing 12:4 ppm Zn2+
+ Ba2+. In media containing the individual ions, increased %F =
27.94 and 26.03 were recorded for media containing 700 ppm Mg2+
and 2 ppm Ba2+ , with ethanol yield of 7.88% (v/v) and 7.62% (v/v)
respectively. Reduced %F and ethanol yield was observed for 10 ppm
Zn2+ and 4 ppm Ba2+ media. The impact of Ba2+ at 1 and 2 ppm was
significant.
Abstract: This study was conducted to evaluate the manganese
removal from aqueous solution using Banana peels activated carbon
(BPAC). Batch experiments have been carried out to determine the
influence of parameters such as pH, biosorbent dose, initial metal ion
concentrations and contact times on the biosorption process. From
these investigations, a significant increase in percentage removal of
manganese 97.4% is observed at pH value 5.0, biosorbent dose 0.8 g,
initial concentration 20 ppm, temperature 25 ± 2°C, stirring rate 200
rpm and contact time 2h. The equilibrium concentration and the
adsorption capacity at equilibrium of the experimental results were
fitted to the Langmuir and Freundlich isotherm models; the Langmuir
isotherm was found to well represent the measured adsorption data
implying BPAC had heterogeneous surface. A raw groundwater
samples were collected from Baharmos groundwater treatment plant
network at Embaba and Manshiet Elkanater City/District-Giza,
Egypt, for treatment at the best conditions that reached at first phase
by BPAC. The treatment with BPAC could reduce iron and
manganese value of raw groundwater by 91.4% and 97.1%,
respectively and the effect of the treatment process on the
microbiological properties of groundwater sample showed decrease
of total bacterial count either at 22°C or at 37°C to 85.7% and 82.4%,
respectively. Also, BPAC was characterized using SEM and FTIR
spectroscopy.
Abstract: One- and two-dimensional carbon nanostructures with
sp2 hybridization of carbon atoms (single walled carbon nanotubes
and graphene) are promising materials in future electronic and
spintronics devices due to specific character of their electronic
structure. In this paper we present a comparative study of graphene
and single-wall carbon nanotubes by Raman spectro-microscopy in
strong magnetic field. This unique method allows to study changes in
electronic band structure of the two types of carbon nanostructures
induced by a strong magnetic field.
Abstract: This paper presents a hybrid three phase rectifier for
high power factor application. This rectifier is composed by zero
voltage transition (ZVT) and zero current transition (ZCT) boost
converter with three phase diode bridge rectifier, in parallel with a six
pulse three phase pulse width modulation (PWM) controlled rectifier.
The proposed topology is capable of high power factor with DC
output voltage regulation by providing sinusoidal input. Also, it
increases the overall efficiency of the new hybrid rectifier to 94.56%
and the total harmonic distortion of the hybrid structure varies from
0% to 16% at nominal output power. This topology was simulated in
MATLAB/SIMULINK environment and the output waveforms
presented with experimental result.
Abstract: Persea declinata (Bl.) Kosterm is a member of the
Lauraceae family, widely distributed in Southeast Asia. It is from the
same genus with avocado (Persea americana Mill), which is widely
consumed as food and for medicinal purposes. In the present study,
we examined the anticancer properties of Persea declinata (Bl.)
Kosterm bark methanolic crude extract (PDM). PDM exhibited a
potent antiproliferative effect in MCF-7 human breast cancer cells,
with an IC50 value of 16.68 .g/mL after 48h of treatment. We
observed that PDM caused cell cycle arrest and subsequent apoptosis
in MCF-7 cells, as exhibited by increased population at G0/G1 phase,
higher lactate dehydrogenase (LDH) release, and DNA
fragmentation. Mechanistic studies showed that PDM caused
significant elevation in ROS production, leading to perturbation of
mitochondrial membrane potential, cell permeability, and activation
of caspases-3/7. On the other hand, real-time PCR and Western blot
analysis showed that PDM treatment increased the expression of the
proapoptotic molecule, Bax, but decreased the expression of
prosurvival proteins, Bcl-2 and Bcl-xL, in a dose-dependent manner.
These findings imply that PDM could inhibit proliferation in MCF-7
cells via cell cycle arrest and apoptosis induction, indicating its
potential as a therapeutic agent worthy of further development.
Abstract: The manufacturing technology of band cotton is very
delicate and depends to choice of certain parameters such as torsion
of warp yarn.
The fabric elasticity is achieved without the use of any elastic
material, chemical expansion, artificial or synthetic and it’s capable
of creating pressures useful for therapeutic treatments.
Before use, the band is subjected to treatments of specific
preparation for obtaining certain elasticity, however, during its
treatment, there are some regression parameters. The dependence of
manufacturing parameters on the quality of the chemical treatment
was confirmed.
The aim of this work is to improve the properties of the fabric
through the development of manufacturing technology appropriately.
Finally for the treatment of the strip pancake 100% cotton, a
treatment method is recommended.
Abstract: The organizations of European and Czech critical
infrastructure have specific position, mission, characteristics and
behaviour in European Union and Czech state/business environments,
regarding specific requirements for regional and global security
environments. They must respect policy of national security and
global rules, requirements and standards in all their inherent and
outer processes of supply - customer chains and networks. A
controlling is generalized capability to have control over situational
policy. This paper aims and purposes are to introduce the controlling
as quite new necessary process attribute providing for critical
infrastructure is environment the capability and profit to achieve its
commitment regarding to the effectiveness of the quality
management system in meeting customer/ user requirements and also
the continual improvement of critical infrastructure organization’s
processes overall performance and efficiency, as well as its societal
security via continual planning improvement via DYVELOP
modelling.
Abstract: This paper attempts to evaluate the effect of fire
damage on concrete by using nonlinear resonance vibration method,
one of the nonlinear nondestructive method. Concrete exhibits not
only nonlinear stress-strain relation but also hysteresis and discrete
memory effect which are contained in consolidated materials.
Hysteretic materials typically show the linear resonance frequency
shift. Also, the shift of resonance frequency is changed according to
the degree of micro damage. The degree of the shift can be obtained
through nonlinear resonance vibration method. Five exposure
scenarios were considered in order to make different internal micro
damage. Also, the effect of post-fire-curing on fire-damaged concrete
was taken into account to conform the change in internal damage.
Hysteretic nonlinearity parameter was obtained by amplitudedependent
resonance frequency shift after specific curing periods. In
addition, splitting tensile strength was measured on each sample to
characterize the variation of residual strength. Then, a correlation
between the hysteretic nonlinearity parameter and residual strength
was proposed from each test result.
Abstract: Well-designed composite steel and concrete structures
highlight the good material properties and lower the deficiencies of
steel and concrete, in particular they make use of high tensile strength
of steel and high stiffness of concrete. The most common composite
steel and concrete structure is a simply supported beam, which
concrete slab transferring the slab load to a beam is connected to the
steel cross-section. The aim of this paper is to find the most adequate
numerical model of a simply supported composite beam with the
cross-sectional and material parameters based on the results of a
processed parametric study and numerical analysis. The paper also
evaluates the suitability of using compact concrete with the
lightweight aggregates for composite steel and concrete beams. The
most adequate numerical model will be used in the resent future to
compare the results of laboratory tests.
Abstract: Load Forecasting plays a key role in making today's
and future's Smart Energy Grids sustainable and reliable. Accurate
power consumption prediction allows utilities to organize in advance
their resources or to execute Demand Response strategies more
effectively, which enables several features such as higher
sustainability, better quality of service, and affordable electricity
tariffs. It is easy yet effective to apply Load Forecasting at larger
geographic scale, i.e. Smart Micro Grids, wherein the lower available
grid flexibility makes accurate prediction more critical in Demand
Response applications. This paper analyses the application of
short-term load forecasting in a concrete scenario, proposed within the
EU-funded GreenCom project, which collect load data from single
loads and households belonging to a Smart Micro Grid. Three
short-term load forecasting techniques, i.e. linear regression, artificial
neural networks, and radial basis function network, are considered,
compared, and evaluated through absolute forecast errors and training
time. The influence of weather conditions in Load Forecasting is also
evaluated. A new definition of Gain is introduced in this paper, which
innovatively serves as an indicator of short-term prediction
capabilities of time spam consistency. Two models, 24- and
1-hour-ahead forecasting, are built to comprehensively compare these
three techniques.
Abstract: Diabetes is a growing health problem in worldwide.
Especially, the patients with Type 1 diabetes need strict glycemic
control because they have deficiency of insulin production. This
paper attempts to control blood glucose based on body mathematical
body model. The Bergman minimal mathematical model is used to
develop the nonlinear controller. A novel back-stepping based sliding
mode control (B-SMC) strategy is proposed as a solution that
guarantees practical tracking of a desired glucose concentration. In
order to show the performance of the proposed design, it is compared
with conventional linear and fuzzy controllers which have been done
in previous researches. The numerical simulation result shows the
advantages of sliding mode back stepping controller design to linear
and fuzzy controllers.
Abstract: Artemisia species, which are medically beneficial, are
widespread in temperate regions of both Northern and Southern
hemispheres among which Iran is located. About 35 species of
Artemisia are indigenous in Iran among them some are widespread in
all or most provinces, yet some are restricted to some specific
regions. In this review paper, initially, GC-Mass results of some
experiments done in different provinces of Iran are mentioned among
them some compounds are common among species, some others are
mostly restricted to other species; after that, medical advantages
based on some researches on species of this genus are reviewed;
different qualities such as anti-leishmania, anti-bacteria, antiviral as
well as anti-proliferative could be mentioned.