Abstract: In recent years, the use of the aluminum based alloys
in the industry and technology are increasing. Alloying elements in
aluminum have further been improving the strength and stiffness
properties that provide superior compared to other metals. In this
study, investigation of physical properties (microstructure,
microhardness, tensile strength, electrical conductivity and thermal
properties) in the Al-12.6wt.%Si-%2wt.Ni ternary alloy were
investigated. Al-Si-Ni alloy was prepared in vacuum atmosphere. The
samples were directionally solidified upwards with different growth
rate V (8.3−165.45 μm/s) at constant temperature gradient G (7.73
K/mm). The flake spacings (λ), microhardness (HV), ultimate tensile
strength (σ), electrical resistivity (ρ) and thermal properties (H, Cp,
Tm) of the samples were measured. Influence of the growth rate and
spacings on microhardness, ultimate tensile strength and electrical
resistivity were investigated and relationships between them were
obtained. According to results, λ values decrease with increasing V,
but HV, σ and ρ values increase with increasing V. Variations of
electrical resistivity (ρ) of solidified samples were also measured.
The enthalpy of fusion (H) and specific heat (Cp) for the alloy was
also determined by differential scanning calorimeter (DSC) from
heating trace during the transformation from liquid to solid. The
results in this work were compared with the previous similar
experimental results.
Abstract: Photovoltaic (PV) power generation systems, mainly
small scale, are rapidly being deployed in Jordan. The impact of these
systems on the grid has not been studied or analyzed. These systems
can cause many technical problems such as reverse power flows and
voltage rises in distribution feeders, and real and reactive power
transients that affect the operation of the transmission system. To
fully understand and address these problems, extensive research,
simulation, and case studies are required. To this end, this paper
studies the cloud shadow effect on the power generation of a ground
mounted PV system installed at the test field of the Renewable
Energy Center at the Applied Science University.
Abstract: The LSTF experiment simulating the SGTR accident at
the Mihama Unit-2 reactor is analyzed using the RELAP5/MOD3.3
code. In the accident, and thus in the experiment, the ECC water was
injected not only into the cold legs but into the upper plenum. Overall
transients during the experiment such as pressures and fluid
temperatures are simulated well by the code. The cold-leg fluid
temperatures are shown to decrease if the upper plenum injection
system is connected to the cold leg. It is found that the cold-leg fluid
temperatures also decrease if the upper-plenum injection is not used
and the cold-leg injection alone is actuated.
Abstract: Expansive soils are often encountered in many parts
of the world, especially in arid and semi-arid fields. Such kind of
soils, generally including active clay minerals in low water content,
enlarge in volume by absorbing the water through the surface and
cause a great harm to the light structures such as channel coating,
roads and airports. The expansive soils were encountered on the path
of Apa-Hotamış conveyance channel belonging to the State
Hydraulic Works in the region of Konya. In the research done in this
area, it is predicted that the soil has a swollen nature and the soil
should be filled with proper granular equipments by digging the
ground to 50-60 cm. In this study, for purpose of helping the other
research to be done in the same area, it is thought that instead of
replacing swollen soil with the granular soil, by stabilizing it with
polypropylene fiber and using it its original place decreases effect of
swelling percent, in this way the cost will be decreased. Therefore,
laboratory tests were conducted to study the effects of polypropylene
fiber on swelling characteristics of expansive soil. Test results
indicated that inclusion of fiber reduced swell percent of expansive
soil. As the fiber content increased, the unconfined compressive
strength was increased. Finally, it can be said that stabilization of
expansive soils with polypropylene fiber is an effective method.
Abstract: This paper presents the influences on the entrainment
of serpentines by grinding and reagents during copper–nickel sulfide
flotation. The previous bench flotation tests were performed to extract
the metallic values from the ore in Yunnan Mine, China and the
relatively satisfied results with recoveries of 86.92% Cu, 54.92% Ni,
and 74.73% Pt+Pd in the concentrate were harvested at their grades of
4.02%, 3.24% and 76.61 g/t, respectively. However, the content of
MgO in the concentrate was still more than 19%. Micro-flotation tests
were conducted with the objective of figuring out the influences on the
entrainment of serpentines into the concentrate by particle size,
flocculants or depressants and collectors, as well as visual
observations in suspension by OLYMPUS camera. All the tests results
pointed to the presences of both “entrapped-in” serpentines and its
coating on the hydrophobic flocs resulted from strong collectors
(combination of butyl xanthate, butyl ammonium dithophosphate,
even after adding carboxymethyl cellulose as effective depressant.
And fine grinding may escalate the entrainment of serpentines in the
concentrate.
Abstract: In this work, the plastic behaviour of cold-rolled zinc
coated dual-phase steel sheets DP600 and DP800 grades is firstly
investigated with the help of uniaxial, hydraulic bulge and Forming
Limit Curve (FLC) tests. The uniaxial tensile tests were performed in
three angular orientations with respect to the rolling direction to
evaluate the strain-hardening and plastic anisotropy. True stressstrain
curves at large strains were determined from hydraulic bulge
testing and fitted to a work-hardening equation. The limit strains are
defined at both localized necking and fracture conditions according to
Nakajima’s hemispherical punch procedure. Also, an elasto-plastic
localization model is proposed in order to predict strain and stress
based forming limit curves. The investigated dual-phase sheets
showed a good formability in the biaxial stretching and drawing FLC
regions. For both DP600 and DP800 sheets, the corresponding
numerical predictions overestimated and underestimated the
experimental limit strains in the biaxial stretching and drawing FLC
regions, respectively. This can be attributed to the restricted failure
necking condition adopted in the numerical model, which is not
suitable to describe the tensile and shear fracture mechanisms in
advanced high strength steels under equibiaxial and biaxial stretching
conditions.
Abstract: The Multiple Intelligences theory characterizes human
intelligence as a multifaceted entity that exists in all human beings
with varying degrees. The most important contribution of this theory
to the field of English Language Teaching (ELT) is its role in
identifying individual differences and designing more learnercentered
programs. The present study aims at investigating the
relationship between different elements of multiple intelligence and
grammar scores. To this end, 63 female Iranian EFL learner selected
from among intermediate students participated in the study. The
instruments employed were a Nelson English language test, Michigan
Grammar Test, and Teele Inventory for Multiple Intelligences
(TIMI). The results of Pearson Product-Moment Correlation revealed
a significant positive correlation between grammatical accuracy and
linguistic as well as interpersonal intelligence. The results of
Stepwise Multiple Regression indicated that linguistic intelligence
contributed to the prediction of grammatical accuracy.
Abstract: Below-knee amputees commonly experience
asymmetrical gait patterns. It is generally believed that ischemia is
related to the formation of pressure sores due to uneven distribution
of forces. Micro-vascular responses can reveal local malnutrition.
Changes in local skin blood supply under various external loading
conditions have been studied for a number of years. Radionuclide
clearance, photo-plethysmography, trans-cutaneous oxygen tension
along with other studies showed that the blood supply would be
influenced by the epidermal forces, and the rate and the amount of
blood supply would decrease with increased epidermal loads being
shear forces or normal forces. Several cases of socket designs were
investigated using Finite Element Model (FEM) and Design of
Experiment (DOE) to increase flexibility and minimize the pressure
at the limb/socket interface using ultra high molecular weight
polyethylene (UHMWPE) and polyamide 6 (PA6) or Duraform. The
pressure reliefs at designated areas where reducing thickness is
involved are seen to be critical in determination of amputees’ comfort
and are very important to clinical applications. Implementing a hole
between the Patellar Tendon (PT) and Distal Tibia (DT) would
decrease stiffness and increase prosthesis range of motion where
flexibility is needed. In addition, displacement and prosthetic energy
storage increased without compromising mechanical efficiency and
prosthetic design integrity.
Abstract: Useful lifetime evaluation of chevron rubber spring
was very important in design procedure to assure the safety and
reliability. It is, therefore, necessary to establish a suitable criterion
for the replacement period of chevron rubber spring. In this study, we
performed characteristic analysis and useful lifetime prediction of
chevron rubber spring. Rubber material coefficient was obtained by
curve fittings of uniaxial tension equibiaxial tension and pure shear
test. Computer simulation was executed to predict and evaluate the
load capacity and stiffness for chevron rubber spring. In order to
useful lifetime prediction of rubber material, we carried out the
compression set with heat aging test in an oven at the temperature
ranging from 50°C to 100°C during a period 180 days. By using the
Arrhenius plot, several useful lifetime prediction equations for rubber
material was proposed.
Abstract: This paper presents a fully Lagrangian coupled
Fluid-Structure Interaction (FSI) solver for simulations of
fluid-structure interactions, which is based on the Moving Particle
Semi-implicit (MPS) method to solve the governing equations
corresponding to incompressible flows as well as elastic structures.
The developed solver is verified by reproducing the high velocity
impact loads of deformable thin wedges with three different materials
such as mild steel, aluminium and tin during water entry. The present
simulation results for aluminium are compared with analytical solution
derived from the hydrodynamic Wagner model and linear Wan’s
theory. And also, the impact pressure and strain on the water entry
wedge with three different materials, such as mild steel, aluminium
and tin, are simulated and the effects of hydro-elasticity are discussed.
Abstract: The nickel-manganese (Ni-Mn) alloy coating prepared
from DC electrodeposition process in sulphamate bath was studied.
The effects of process parameters, such as current density and
electrolyte composition, on the cathodic current efficiency,
microstructure, internal stress and mechanical properties were
investigated. Because of its crucial effect on the application to the
electroforming of microelectronic components, the development of
low internal stress coating with high leveling power was emphasized.
It was found that both the coating’s manganese content and the
cathodic current efficiency increased with the raise in current density.
In addition, the internal stress of the deposited coating showed
compressive nature at low current densities while changed to tensile
one at higher current densities. Moreover, the metallographic
observation, X-ray diffraction measurement, and polarization curve
measurement were conducted. It was found that the Ni-Mn coating
consisted of nano-sized columnar grains and the maximum hardness of
the coating was associated with (111) preferred orientation in the
microstructure. The grain size was refined along with the increase in
the manganese content of the coating, which accordingly, raised its
hardness and resistance to annealing softening. In summary, the
Ni-Mn coating prepared at lower current density of 1-2 A/dm2 had low
internal stress, high leveling power, and better corrosion resistance.
Abstract: This study presents three different approaches to
estimate bubble point pressures for the binary system of CO2 and
ethyl palmitate fatty acid ethyl ester. The first method involves the
Peng-Robinson (PR) Equation of State (EoS) with the conventional
mixing rule of Van der Waals. The second approach involves the PR
EOS together with the Wong Sandler (WS) mixing rule, coupled with
the UNIQUAC GE model. In order to model the bubble point
pressures with this approach, the volume and area parameter for ethyl
palmitate were estimated by the Hansen group contribution method.
The last method involved the Peng-Robinson, combined with the
Wong-Sandler method, but using NRTL as the GE model. Results
using the Van der Waals mixing rule clearly indicated that this
method has the largest errors among all three methods, with errors in
the range of 3.96-6.22%. The PR-WS-UNIQUAC method exhibited
small errors, with average absolute deviations between 0.95 to 1.97
percent. The PR-WS-NRTL method led to the least errors, where
average absolute deviations ranged between 0.65-1.7%.
Abstract: The aim of this work was to characterize a potential
target group of people interested in participating into a training
program in organic farming in the context of mobile-learning. The
information sought addressed in particular, but not exclusively,
possible contents, formats and forms of evaluation that will
contribute to define the course objectives and curriculum, as well as
to ensure that the course meets the needs of the learners and their
preferences. The sample was selected among different European
countries. The questionnaires were delivered electronically for
answering on-line and in the end 135 consented valid questionnaires
were obtained. The results allowed characterizing the target group
and identifying their training needs and preferences towards m-learning
formats, giving valuable tools to design the training offer.
Abstract: Commercial banks in Nigeria adopted many strategies
to attract fresh deposits including the use of high deposit rate.
However, pricing of banking services moved in favor of the banks at
the expense of customers, resulting in their seeking other investment
alternatives rather than saving their money in the bank. Both deposit
and lending rates were greatly influenced by the Central Bank of
Nigeria (CBN) decision on interest rate. Therefore, commercial bank
effort to attract deposits via manipulation of her rates was greatly
limited, otherwise the banks will be giving out more than it earned.
The study aimed at examining the relationship between interest rate
and fixed fund deposit of commercial banks, how policy-controlled
interest rate affected commercial bank’s fixed fund deposit The
researcher employed ordinary least square technique, using, multiple
linear regression, unrestricted vector auto-regression, correlation
matrix test, granger causality and impulse response graph in the
analysis. Commercial bank’s interest rates affected commercial
bank’s fixed fund deposit significantly while policy-controlled
interest rate did not significantly transmit through the commercial
bank’s interest rates to affect fixed fund deposit. While commercial
banks seek creative ways to expand their fixed fund deposit, policy
authorities in Nigeria should better coordinate interest rate fluctuation
and induce competition in the entire financial sector.
Abstract: This study integrates a larger research empirical
project that examines second language (SL) learners’ profiles and
valid procedures to perform complete and diagnostic assessment in
schools. 102 learners of Portuguese as a SL aged 7 and 17 years
speakers of distinct home languages were assessed in several
linguistic tasks. In this article, we focused on writing performance in
the specific task of narrative essay composition. The written outputs
were measured using the score in six components adapted from an
English SL assessment context (Alberta Education): linguistic
vocabulary, grammar, syntax, strategy, socio-linguistic, and
discourse. The writing processes and strategies in Portuguese
language used by different immigrant students were analysed to
determine features and diversity of deficits on authentic texts
performed by SL writers. Differentiated performance was based on
the diversity of the following variables: grades, previous schooling,
home language, instruction in first language, and exposure to
Portuguese as Second Language. Indo-Aryan languages speakers
showed low writing scores compared to their peers and the type of
language and respective cognitive mapping (such as Mandarin and
Arabic) was the predictor, not linguistic distance. Home language
instruction should also be prominently considered in further research
to understand specificities of cognitive academic profile in a
Romance languages learning context. Additionally, this study also
examined the teachers’ representations that will be here addressed to
understand educational implications of second language teaching in
psychological distress of different minorities in schools of specific
host countries.
Abstract: A solar dish collector has been designed, fabricated
and tested for its performance on 10-03-2015 in Salem, Tamilnadu,
India. The experiments on cooking vessels of coated and un-coated
with 5 Liters capacity have been used for cooking Rice. The results
are shown in graphs. The solar cooker is always capable of cooking
food within the expected length of time and based on the solar
radiation levels. With minimum cooking power, the coated pressure
cooker of 5 Liters capacity cooks the food at faster manner. This is
due to the conductivity of the coating material provided in the cooker.
Abstract: An approach was evaluated for the retrieval of soil
moisture of bare soil surface using bistatic scatterometer data in the
angular range of 200 to 700 at VV- and HH- polarization. The
microwave data was acquired by specially designed X-band (10
GHz) bistatic scatterometer. The linear regression analysis was done
between scattering coefficients and soil moisture content to select the
suitable incidence angle for retrieval of soil moisture content. The 250
incidence angle was found more suitable. The support vector
regression analysis was used to approximate the function described
by the input output relationship between the scattering coefficient and
corresponding measured values of the soil moisture content. The
performance of support vector regression algorithm was evaluated by
comparing the observed and the estimated soil moisture content by
statistical performance indices %Bias, root mean squared error
(RMSE) and Nash-Sutcliffe Efficiency (NSE). The values of %Bias,
root mean squared error (RMSE) and Nash-Sutcliffe Efficiency
(NSE) were found 2.9451, 1.0986 and 0.9214 respectively at HHpolarization.
At VV- polarization, the values of %Bias, root mean
squared error (RMSE) and Nash-Sutcliffe Efficiency (NSE) were
found 3.6186, 0.9373 and 0.9428 respectively.
Abstract: Determination of genetic variation is useful for plant
breeding and hence production of more efficient plant species under
different conditions, like drought stress. In this study a sample of 28
recombinant inbred lines (RILs) of wheat developed from the cross of
Norstar and Zagross varieties, together with their parents, were
evaluated for two years (2010-2012) under normal and water stress
conditions using split plot design with three replications. Main plots
included two irrigation treatments of 70 and 140 mm evaporation
from Class A pan and sub-plots consisted of 30 genotypes. The effect
of genotypes and interaction of genotypes with years and water
regimes were significant for all characters. Significant genotypic
effect implies the existence of genetic variation among the lines
under study. Heritability estimates were high for 1000 grain weight
(0.87). Biomass and grain yield showed the lowest heritability values
(0.42 and 0.50, respectively). Highest genotypic and phenotypic
coefficients of variation (GCV and PCV) belonged to harvest index.
Moderate genetic advance for most of the traits suggested the
feasibility of selection among the RILs under investigation. Some
RILs were higher yielding than either parent at both environments.
Abstract: New environmental regulations and the increasing
market preference for companies that respect the ecosystem had
encouraged the industry to look after new treatments for its effluents.
The sugar industry, one of the largest emitter of environmental
pollutants, follows this tendency. Membrane technology is
convenient for separation of suspended solids, colloids and high
molecular weight materials that are present in a wastewater from
sugar industry. The idea is to microfilter the wastewater, where the
permeate passes through the membrane and becomes available for
recycle and re-use in the sugar manufacturing process. For
microfiltration of this effluent a tubular ceramic membrane was used
with a pore size of 200 nm at transmembrane pressure in range of 1–3
bars and in range of flow rate of 50–150 l/h. Kenics static mixer was
used for permeate flux enhancement. Turbidity and suspended solids
were removed and the permeate flux was continuously monitored
during the microfiltration process. The flux achieved after 90 minutes
of microfiltration was in a range of 50–70 l/m2h. The obtained
turbidity decrease was in the range of 50-99 % and total amount of
suspended solids was removed.
Abstract: The possibility of application the dietary fibers in
production of crackers was observed in this work, as well as their
influence on rheological and textural properties on the dough for
crackers and influence on sensory properties of obtained crackers.
Three different dietary fibers, oat, potato and pea fibers, replaced
10% of wheat flour. Long fermentation process and baking test
method were used for crackers production. The changes of dough for
crackers were observed by rheological methods of determination the
viscoelastic dough properties and by textural measurements. Sensory
quality of obtained crackers was described using quantity descriptive
method (QDA) by trained members of descriptive panel. Additional
analysis of crackers surface was performed by videometer. Based on
rheological determination, viscoelastic properties of dough for
crackers were reduced by application of dietary fibers. Manipulation
of dough with 10% of potato fiber was disabled, thus the recipe
modification included increase in water content at 35%. Dough
compliance to constant stress for samples with dietary fibers
decreased, due to more rigid and stiffer dough consistency compared
to control sample. Also, hardness of dough for these samples
increased and dough extensibility decreased. Sensory properties of
final products, crackers, were reduced compared to control sample.
Application of dietary fibers affected mostly hardness, structure and
crispness of the crackers. Observed crackers were low marked for
flavor and taste, due to influence of fibers specific aroma. The sample
with 10% of potato fibers and increased water content was the most
adaptable to applied stresses and to production process. Also this
sample was close to control sample without dietary fibers by
evaluation of sensory properties and by results of videometer method.