Abstract: The influence of three different types of halloysite
nanotubes (HNTs) with different dimensions, namely as camel lake
(CLA), Jarrahdale (JA) and Matauri Bay (MB), on their reinforcing
ability of ethylene propylene dine monomer (EPDM) were
investigated by varying the HNTs loading (from 0-15 phr).
Mechanical properties of the nanocomposites improved with addition
of all three HNTs, but CLA based nanocomposites exhibited a
significant enhancement compared to the other HNTs. For instance,
tensile properties of EPDM nanocomposites increased by 120%,
256% and 340% for MB, JA and CLA, respectively, with addition of
15 phr of HNTs. This could be due to the higher aspect ratio and
higher surface area of CLA compared to others. Scanning electron
microscopy (SEM) of nanocomposites at 15 phr of HNT loadings
showed low amounts of pulled-out nanotubes which confirmed the
presence of more embedded nanotubes inside the EPDM matrix, as
well as aggregates within the fracture surface of EPDM/HNT
nanocomposites
Abstract: This paper evaluates the performance of a multi-lane
four legged modern roundabout operating in Muscat using SIDRA
model. The performance measures include Degree of Saturation
(DOS), average delay, and queue lengths. The geometric and traffic
data were used for model preparation. Gap acceptance parameters,
critical gap and follow up headway, were used for calibration of
SIDRA model. The results from the analysis showed that currently
the roundabout is experiencing delays up to 610 seconds per vehicle
with DOS 1.67 during peak hour. Further, sensitivity analysis for
general and roundabout parameters was performed, amongst lane
width, cruise speed, inscribed diameter, entry radius and entry angle
showed that inscribed diameter is most crucial factor affecting delay
and DOS. Up gradation of roundabout to fully signalized junction
was found as the suitable solution which will serve for future years
with LOS C for design year having DOS of 0.9 with average control
delay of 51.9 seconds per vehicle.
Abstract: Essential oils are expensive phytochemicals produced
and extracted from specific species belonging to particular families in
the plant kingdom. In the United Arab Emirates country (UAE), is
located in the arid region of the world, nine species, from the
Lamiaceae family, having the capability to produce therapeutic grade
essential oils. These species include; Mentha spicata, Ocimum
forskolei, Salvia macrosiphon, Salvia aegyptiaca, Salvia macilenta,
Salvia spinosa, Teucrium polium, Teucrium stocksianum and Zataria
multiflora. Although, such potential species are indigenous to the
UAE, however, there are almost no studies available to investigate
the chemical composition and the quality of the extracted essential
oils under the UAE climatological conditions. Therefore, great
attention has to be given to such valuable natural resources, through
conducting highly supported research projects, tailored to the UAE
conditions, and investigating different extraction techniques,
including the application of the latest available technologies, such as
superficial fluid CO2. This is crucially needed; in order to accomplish
the greatest possibilities in the medicinal field, specifically in the
discovery of new therapeutic chemotypes, as well as, to achieve the
sustainability of this natural resource in the country.
Abstract: Two micromechanical models for 3D smart composite
with embedded periodic or nearly periodic network of generally
orthotropic reinforcements and actuators are developed and applied to
cubic structures with unidirectional orientation of constituents.
Analytical formulas for the effective piezothermoelastic coefficients
are derived using the Asymptotic Homogenization Method (AHM).
Finite Element Analysis (FEA) is subsequently developed and used
to examine the aforementioned periodic 3D network reinforced smart
structures. The deformation responses from the FE simulations are
used to extract effective coefficients. The results from both
techniques are compared. This work considers piezoelectric materials
that respond linearly to changes in electric field, electric
displacement, mechanical stress and strain and thermal effects. This
combination of electric fields and thermo-mechanical response in
smart composite structures is characterized by piezoelectric and
thermal expansion coefficients. The problem is represented by unitcell
and the models are developed using the AHM and the FEA to
determine the effective piezoelectric and thermal expansion
coefficients. Each unit cell contains a number of orthotropic
inclusions in the form of structural reinforcements and actuators.
Using matrix representation of the coupled response of the unit cell,
the effective piezoelectric and thermal expansion coefficients are
calculated and compared with results of the asymptotic
homogenization method. A very good agreement is shown between
these two approaches.
Abstract: The present study involved analysis of certain
characteristics of the perennial ryegrass (Lolium perenne L.)
genotypes collected from the natural flora of Ankara, and explores a
correlation among them. In order to evaluate the plants for breeding
purpose as per Turkey's environmental conditions, the perennial
ryegrass plants were collected from natural pasture of Ankara in 2004
and were utilized for the study. Seeds of the collected plants were
sown in pots and seedlings were prepared in a greenhouse. In 2005,
the seedlings were transplanted at 50 × 50 cm2 intervals in
Randomized Complete Blocks Design in an experimental field. In
2007 and 2008, data were recorded from the observations and
measurements of 568 perennial ryegrasses. The plant characteristics,
which were investigated, included re-growth time in spring, color,
density, growth habit, tendency to form inflorescence, time of
inflorescence, plant height, length of upper internode, spike length,
leaf length, leaf width, leaf area, leaf shape, number of spikelets per
spike, seed yield per spike and 1000 grain weight and the correlation
analyses were made using this data. Correlation coefficients were
estimated between all paired combinations of the studied traits. The
yield components exhibited varying trends of association among
themselves. Seed yield per spike showed significant and positive
association with the number of spikelets per spike, 1000 grain weight,
plant height, length of upper internode, spike length, leaf length, leaf
width, leaf area and color, but significant and negative association
with the growth habit and re-growth time in spring.
Abstract: Pesticides and drugs used in agriculture and veterinary
medicine may end up in aquatic environments and bioaccumulate in
the food chain, thus causing serious problems for fauna and human
health. For determination of the toxic effects of atrazine herbicide on
Caspian kutum, Rutilus frisii kutum larvae, the 96-h LC50 of atrazine
was measured for newly hatched larvae as 18.53 ppm. Toxicity of
atrazine herbicide on Caspian kutum larvae was investigated using
concentrations: 9.25ppm, 4.62 ppm and 2.31 ppm for 7 days.
Comparison of the length, weight and condition factor showed that
no significant differences between atrazine exposed and control
groups. The concentration of Na+, K+, Ca2+, Mg2+ and Cl- in whole
body of larvae in control and atrazine exposure groups were
measured and the results showed that concentrations of all these ions
is higher in atrazine exposure group than control group. It is obvious
from this study that atrazine negatively affects osmoregulation
process and changes ion compositions of the body even at sublethal
concentration and acute exposure but have no effects on growth
parameters of the body.
Abstract: Musculoskeletal injuries in school children could be
reduced improving trunk strength and hamstring flexibility. Low
levels of trunk muscle strength and hamstring flexibility may result in
acute and musculoskeletal chronic diseases. The Pilates Method can
be appropriate to improve these physical condition attributes and has
been rarely employed by this social group. On the other hand, it has
been shown that trunk strength and flexibility are different between
genders, but there is no evidence about the effect of exercise
programs designed to improve both items in school children.
Therefore the objective of this study was to measure the effect of a
six-week Pilates-based exercise program in 14 year old school
children trunk strength and hamstring flexibility, establishing
differences in gender. The sample was composed of 57 students
divided into experimental group (EG; n=30) and control group (CG;
n=27). Bench Trunk Curl test (BTC), Sörensen test and Toe-touch
test (TT) were used to measure dynamic muscular resistance in trunk
flexion, isometric strength in trunk extension and hamstring
flexibility, respectively. EG utilized the Pilates exercise program
during six-weeks (2 days/week, 55minutes/session). After this period
of training, EG improved trunk strength and hamstring flexibility
significantly but there were no significant differences within CG.
Although boys were better in BTC test and girls were better in TT
test, there were no significant differences between them.
Abstract: Taro Scarab beetles (Papuana uninodis, Coleoptera:
Scarabaeidae) inflict severe damage on important root crops and
plants such as Taro or Cocoyam, yam, sweet potatoes, oil palm and
coffee tea plants across Africa and Asia resulting in economic
hardship and starvation in some nations. Scoliid wasps and
Metarhizium anisopliae fungus - bio-control agents; are shown to be
able to control the population of Scarab beetle adults and larvae using
a newly created simulation model based on non-linear ordinary
differential equations that track the populations of the beetle life
cycle stages: egg, larva, pupa, adult and the population of the scoliid
parasitoid wasps, which attack beetle larvae. In spite of the challenge
driven by the longevity of the scarab beetles, the combined effect of
the larval wasps and the fungal bio-control agent is able to control
and drive down the population of both the adult and the beetle eggs
below the environmental carrying capacity within an interval of 120
days, offering the long term prospect of a stable and eco-friendly
environment; where the population of scarab beetles is: regulated by
parasitoid wasps and beneficial soil saprophytes.
Abstract: Energy consumption and users’ satisfaction were
compared in three LEED certified office buildings in turkey and an
office building in Egypt. The field studies were conducted in summer
2012. The measured environmental parameters in the four buildings
were indoor air temperature, relative humidity, CO2 percentage and
light intensity. The traditional building is located in Smart Village in
Abu Rawash, Cairo, Egypt. The building was studied for 7 days
resulting in 84 responds. The three rated buildings are in Istanbul;
Turkey. A Platinum LEED certified office building is owned by
BASF and gained a platinum certificate for new construction and
major renovation. The building was studied for 3 days resulting in 13
responds. A Gold LEED certified office building is owned by BASF
and gained a gold certificate for new construction and major
renovation. The building was studied for 2 days resulting in 10
responds. A silver LEED certified office building is owned by
Unilever and gained a silver certificate for commercial interiors. The
building was studied for 7 days resulting in 84 responds.
The results showed that all buildings had no significant difference
regarding occupants’ satisfaction with the amount of lighting, noise
level, odor and access to the outdoor view. There was significant
difference between occupants’ satisfaction in LEED certified
buildings and the traditional building regarding the thermal
environment and the perception of the general environment (colors,
carpet and decoration. The findings suggest that careful design could
lead to a certified building that enhances the thermal environment and
the perception of the indoor environment leading to energy
consumption without scarifying occupants’ satisfaction.
Abstract: The biosynthesis of nanoparticles by microorganisms,
on the contrary to chemical synthesis, is an environmentally-friendly
process which has low energy requirements. In this investigation, we
used the microorganism Geobacillus wiegelii, strain GWE1, an
aerobic thermophile belonging to genus Geobacillus, isolated from a
drying oven. This microorganism has the ability to reduce selenite
evidenced by the change of color from colorless to red in the culture.
Elemental analysis and composition of the particles were verified
using transmission electron microscopy and energy-dispersive X-ray
analysis. The nanoparticles have a defined spherical shape and a
selenium elemental state. Previous experiments showed that the
presence of the whole microorganism for the reduction of selenite
was not necessary. The results strongly suggested that an intracellular
NADPH/NADH-dependent reductase mediates selenium
nanoparticles synthesis under aerobic conditions. The enzyme was
purified and identified by mass spectroscopy MALDI-TOF TOF
technique. The enzyme is a 1-pyrroline-5-carboxylate dehydrogenase.
Histograms of nanoparticles sizes were obtained. Size distribution
ranged from 40-160 nm, where 70% of nanoparticles have less than
100 nm in size. Spectroscopic analysis showed that the nanoparticles
are composed of elemental selenium. To analyse the effect of pH in
size and morphology of nanoparticles, the synthesis of them was
carried out at different pHs (4.0, 5.0, 6.0, 7.0, 8.0). For
thermostability studies samples were incubated at different
temperatures (60, 80 and 100 ºC) for 1 h and 3 h. The size of all
nanoparticles was less than 100 nm at pH 4.0; over 50% of
nanoparticles have less than 100 nm at pH 5.0; at pH 6.0 and 8.0 over
90% of nanoparticles have less than 100 nm in size. At neutral pH
(7.0) nanoparticles reach a size around 120 nm and only 20% of them
were less than 100 nm. When looking at temperature effect,
nanoparticles did not show a significant difference in size when they
were incubated between 0 and 3 h at 60 ºC. Meanwhile at 80 °C the
nanoparticles suspension lost its homogeneity. A change in size was
observed from 0 h of incubation at 80ºC, observing a size range
between 40-160 nm, with 20% of them over 100 nm. Meanwhile
after 3 h of incubation at size range changed to 60-180 nm with 50%
of them over 100 nm. At 100 °C the nanoparticles aggregate forming
nanorod structures. In conclusion, these results indicate that is
possible to modulate size and shape of biologically synthesized
nanoparticles by modulating pH and temperature.
Abstract: The presence of endocrine-disrupting compounds,
such as bisphenol A (BPA), in the environment can cause serious
health problems. However, there are controversial opinions. This
study investigated the reproductive, metabolic, oxidative and
immunologic-disrupting effects of bisphenol A in male rabbits.
Rabbits were divided into five groups. The first four rabbit groups
were administered oral BPA (1, 10, 50, or 100 mg/kg/day) for ten
weeks. The fifth group was administered corn oil as the vehicle. BPA
significantly decreased serum testosterone, estradiol and the free
androgen index (FAI) and significantly increased sex hormone
binding globulin (SHBG) compared with the placebo group. The
higher doses of BPA showed a significant decrease in follicular
stimulating hormone (FSH) and luteinizing hormone (LH). A
significant increase in blood glucose levels was identified in the BPA
groups. The non-significant difference in insulin levels is a novel
finding. The cumulative testicular toxicity of BPA was clearly
demonstrated by the dose-dependent decrease in absolute testes
weight, primary measures of semen quality and a significant increase
in testicular malonaldehyde (MDA). Moreover, BPA significantly
decreased total antioxidant capacity (TAC) and significantly
increased immunoglobulin G (IgG) at the highest concentration. Our
results suggest that BPA, especially at higher doses, is associated
with many adverse effects on metabolism, oxidative stress, immunity,
sperm quality and markers of androgenic action.
Abstract: The objective of the Economic Dispatch(ED) Problems
of electric power generation is to schedule the committed generating
units outputs so as to meet the required load demand at minimum
operating cost while satisfying all units and system equality and
inequality constraints. This paper presents a new method of ED
problems utilizing the Max-Min Ant System Optimization.
Historically, traditional optimizations techniques have been used,
such as linear and non-linear programming, but within the past
decade the focus has shifted on the utilization of Evolutionary
Algorithms, as an example Genetic Algorithms, Simulated Annealing
and recently Ant Colony Optimization (ACO). In this paper we
introduce the Max-Min Ant System based version of the Ant System.
This algorithm encourages local searching around the best solution
found in each iteration. To show its efficiency and effectiveness, the
proposed Max-Min Ant System is applied to sample ED problems
composed of 4 generators. Comparison to conventional genetic
algorithms is presented.
Abstract: A new relative efficiency in linear model in reference is
instructed into the linear weighted regression, and its upper and lower
bound are proposed. In the linear weighted regression model, for the
best linear unbiased estimation of mean matrix respect to the
least-squares estimation, two new relative efficiencies are given, and
their upper and lower bounds are also studied.
Abstract: Magnetic powder of Sr-ferrite was prepared by
conventional and sol-gel auto-combustion methods. In conventional
method, strontium carbonate and ferric oxide powders were mixed
together and then mixture was calcined. In sol-gel auto-combustion
method, a solution containing strontium nitrate, ferric nitrate and
citric acid was heated until the combustion took place automatically;
then, as-burnt powder was calcined. Thermal behavior, phase
identification, morphology and magnetic properties of powders
obtained by these two methods were compared by DTA, XRD, SEM
and VSM techniques. According to the results of DTA analysis,
formation temperature of Sr-ferrite obtained by conventional and solgel
auto-combustion methods were 1300°C and 1000°C, respectively.
XRD results confirmed the formation of pure Sr-ferrite at the
mentioned temperatures. Plate and hexagonal-shape particles of Srferrite
were observed using SEM. The Sr-ferrite powder obtained by
sol-gel auto-combustion method had saturation magnetization of
66.03 emu/g and coercivity of 5731 Oe in comparison with values of
58.20 emu/g and 4378 Oe obtained by conventional method.
Abstract: Assertion-Based software testing has been shown to
be a promising tool for generating test cases that reveal program
faults. Because the number of assertions may be very large for
industry-size programs, one of the main concerns to the applicability
of assertion-based testing is the amount of search time required to
explore a large number of assertions. This paper presents a new
approach for assertions exploration during the process of Assertion-
Based software testing. Our initial exterminations with the proposed
approach show that the performance of Assertion-Based testing may
be improved, therefore, making this approach more efficient when
applied on programs with large number of assertions.
Abstract: Series of laboratory tests were carried out to study the
extent of scour caused by a three-dimensional wall jets exiting from a
square cross-section nozzle and into a non-cohesive sand beds.
Previous observations have indicated that the effect of the tail water
depth was significant for densimetric Froude number greater than ten.
However, the present results indicate that the cut off value could be
lower depending on the value of grain size-to-nozzle width ratio.
Numbers of equations are drawn out for a better scaling of numerous
scour parameters. Also suggested the empirical prediction of scour to
predict the scour centre line profile and plan view of scour profile at
any particular time.
Abstract: Reduction of CO2 emissions has become a priority for
several countries due to increasing concerns about global warming
and climate change, especially in the developed countries. Residential
sector is considered one of the most important sectors for
considerable reduction of CO2 emissions since it represents a
significant amount of the total consumed energy in those countries. A
significant CO2 reduction cannot be achieved unless some initiatives
have been adopted in the policy of these countries. Introducing micro
combined heat and power (!CHP) systems into residential energy
systems is one of these initiatives, since such a technology offers
several advantages. Moreover, !CHP technology has the opportunity
to be operated not only by natural gas but it could also be operated by
renewable fuels. However, this technology can be operated by
different operation strategies. Each strategy has some advantages and
disadvantages.
This paper provides a review of different operation strategies of
such a technology used for residential energy systems, especially for
single dwellings. The review summarizes key points that outline the
trend of previous research carried out in this field.
Abstract: The main objective of the study is focused in
producing slag based geopolymer concrete obtained with the addition
of alkali activator. Test results indicated that the reaction of silicates
in slag is based on the reaction potential of sodium hydroxide and the
formation of alumino-silicates. The study also comprises on the
evaluation of the efficiency of polymer reaction in terms of the
strength gain properties for different geopolymer mixtures.
Geopolymer mixture proportions were designed for different binder
to total aggregate ratio (0.3 & 0.45) and fine to coarse aggregate ratio
(0.4 & 0.8). Geopolymer concrete specimens casted with normal
curing conditions reported a maximum 28 days compressive strength
of 54.75 MPa. The addition of glued steel fibres at 1.0% Vf in
geopolymer concrete showed reasonable improvements on the
compressive strength, split tensile strength and flexural properties of
different geopolymer mixtures. Further, comparative assessment was
made for different geopolymer mixtures and the reinforcing effects of
steel fibres were investigated in different concrete matrix.
Abstract: Heightened concerns over the amount of carbon
emitted from coal-related processes are generating shifts to the
application of biomass. In co-gasification, where coal is gasified
along with biomass, the biomass may be fed together with coal (cofeeding)
or an independent biomass gasifier needs to be integrated
with the coal gasifier. The main aim of this work is to evaluate the
biomass introduction methods in coal co-gasification. This includes
the evaluation of biomass concentration input (B0 to B100) and its
gasification performance. A process model is developed and
simulated in Aspen HYSYS, where both coal and biomass are
modelled according to its ultimate analysis. It was found that the
syngas produced increased with increasing biomass content for both
co-feeding and independent schemes. However, the heating values
and heat duties decreases with biomass concentration as more CO2
are produced from complete combustion.
Abstract: Medical imaging produces human body pictures in
digital form. Since these imaging techniques produce prohibitive
amounts of data, compression is necessary for storage and
communication purposes. Many current compression schemes
provide a very high compression rate but with considerable loss of
quality. On the other hand, in some areas in medicine, it may be
sufficient to maintain high image quality only in region of interest
(ROI). This paper discusses a contribution to the lossless
compression in the region of interest of Scintigraphic images based
on SPIHT algorithm and global transform thresholding using
Huffman coding.