Abstract: Natural fibers are used in polymer composites to
improve mechanical properties to replace inorganic reinforcing
agents produced by non-renewable resources. The present study
investigates the tensile and flexural behaviors of palm fibers-high
density polyethylene (HDPE) composite as a function of volume
fraction. The surface of the fibers was treated by mercerization
treatments to improve the wetting behavior of the apolar HDPE. The
treatment characterization was obtained by scanning electron
microscopy, X-Ray diffraction and infrared spectroscopy. Results
evidences that a good adhesion interfacial between fibers-matrix
caused an increase strength and modulus flexural as well as tensile
strength in the modified fibers/HDPE composites when compared to
the pure HDPE and untreated fibers reinforced composites.
Abstract: The purpose of the present work was to develop an innovative food product with good textural and sensorial characteristics. The product, a new type of bread, was prepared with wheat (90%) and lupin (10%) flours, without the addition of any conservatives. Several experiences were also done to find the most appropriate proportion of lupin flour. The optimized product was characterized considering the rheological, physical-chemical and sensorial properties. The water absorption of wheat flour with 10% of lupin was higher than that of the normal wheat flours, and Wheat Ceres flour presented the lower value, with lower dough development time and high stability time. The breads presented low moisture but a considerable water activity. The density of bread decreased with the introduction of lupin flour. The breads were quite white, and during storage the colour parameters decreased. The lupin flour clearly increased the number of alveolus, but the total area increased significantly just for the Wheat Cerealis bread. The addition of lupin flour increased the hardness and chewiness of breads, but the elasticity did not vary significantly. Lupin bread was sensorially similar to wheat bread produced with WCerealis flour, and the main differences are the crust rugosity, colour and alveolus characteristics.
Abstract: The first laboratory synthesis of hard materials such as
diamond proceeded to attack of developing materials with high
hardness to compete diamond. Boron rich solids are good candidates
owing to their short interatomic bond lengths and strong covalent
character. Boron containing hard material was synthesized by modifiedmicrowave
method under nitrogen atmosphere by using a fuel
(glycine or urea), amorphous boron and/or boric acid in appropriate
molar ratio. Characterizations were done by x-ray diffraction (XRD),
Fourier transform infrared (FTIR) spectroscopy, scanning electron
microscopy/energy dispersive analyze (SEM/EDS), thermo
gravimetric/differential thermal analysis (TG/DTA).
Abstract: Chitosan polyacrylic acid composite membranes were
prepared by a bulk polymerization method in presence of N, N'-
methylene bisacrylamide (crosslinker) and ammonium persulphate as
initiator. Membranes prepared from this copolymer in presence and
absence of Ag nanoparticles were characterized by measuring
mechanical and physical properties, water up-take and antibacterial
properties. The results obtained indicated that the prepared
membranes have antibacterial properties which increase with adding
Ag nanoparticles.
Abstract: We report the design and characterization of ultra high
quality factor filter based on one-dimensional photonic-crystal Thue-
Morse sequence structure. The behavior of aperiodic array of
photonic crystal structure is numerically investigated and we show
that by changing the angle of incident wave, desired wavelengths
could be tuned and a tunable filter is realized. Also it is shown that
high quality factor filter be achieved in the telecommunication
window around 1550 nm, with a device based on Thue-Morse
structure. Simulation results show that the proposed structure has a
quality factor more than 100000 and it is suitable for DWDM
communication applications.
Abstract: This study was to explore and utilize the fresh rind of
mangosteen Index Colour 5 as an upcoming raw material for the
production of natural dyes. Rind from the fresh mangosteen Index
Colour 5 was utilized to extract the dyes. The established extracts
were experimented on silk fabrics via three types of mordanting and
dyeing procedures; pre-mordanting, simultaneous mordanting and
post-mordanting. As a result, the applications of the freeze-drying
methodology and mechanizable equipment have helped to produce
excellent range of natural colours. Silk fabric treated simultaneously
with mordanting and dyeing with extract dye Index Colour 5
produced a brilliant shade of the red colour and the colour from this
index is also discovered sensitive to light and washing during the
fastness tests. The preliminary evaluation and instrumentation
analysis allowed us to examine whether the application of different
mordanting and dyeing procedures with the same extract samples and
concentrations affected the colours and shades of the fabric samples.
Abstract: Work presented is interested in the characterization of
the quasistatic mechanical properties and in fatigue of a composite
laminated in jute/epoxy. The natural fibers offer promising prospects
thanks to their interesting specific properties, because of their low
density, but also with their bio-deterioration. Several scientific
studies highlighted the good mechanical resistance of the vegetable
fiber composites reinforced, even after several recycling. Because of
the environmental standards that become increasingly severe, one
attends the emergence of eco-materials at the base of natural fibers
such as flax, bamboo, hemp, sisal, jute. The fatigue tests on
elementary vegetable fibers show an increase of about 60% of the
rigidity of elementary fibers of hemp subjected to cyclic loadings. In
this study, the test-tubes manufactured by the method infusion have
sequences of stacking of 0/90° and ± 45° for the shearing and tensile
tests. The quasistatic tests reveal a variability of the mechanical
properties of about 8%. The tensile fatigue tests were carried out for
levels of constraints equivalent to half of the ultimate values of the
composite. Once the fatigue tests carried out for well-defined values
of cycles, a series of static tests of traction type highlights the
influence of the number of cycles on the quasi-static mechanical
behavior of the laminate jute/epoxy.
Abstract: Industries produce millions of cubic meters of effluent
every year and the wastewater produced may be released into the
surrounding water bodies, treated on-site or at municipal treatment
plants. The determination of organic matter in the wastewater
generated is very important to avoid any negative effect on the
aquatic ecosystem. The scope of the present work is to assess the
physicochemical composition of the wastewater produced from one
of the brewery industry in South Africa. This is to estimate the
environmental impact of its discharge into the receiving water bodies
or the municipal treatment plant. The parameters monitored for the
quantitative analysis of brewery wastewater include biological
oxygen demand (BOD5), chemical oxygen demand (COD), total
suspended solids, volatile suspended solids, ammonia, total oxidized
nitrogen, nitrate, nitrite, phosphorus and alkalinity content. In
average, the COD concentration of the brewery effluent was 5340.97
mg/l with average pH values of 4.0 to 6.7. The BOD5 and the solids
content of the wastewater from the brewery industry were high. This
means that the effluent is very rich in organic content and its
discharge into the water bodies or the municipal treatment plant could
cause environmental pollution or damage the treatment plant. In
addition, there were variations in the wastewater composition
throughout the monitoring period. This might be as a result of
different activities that take place during the production process, as
well as the effects of peak period of beer production on the water
usage.
Abstract: Particle size distribution, the most important
characteristics of aerosols, is obtained through electrical
characterization techniques. The dynamics of charged nanoparticles
under the influence of electric field in Electrical Mobility
Spectrometer (EMS) reveals the size distribution of these particles.
The accuracy of this measurement is influenced by flow conditions,
geometry, electric field and particle charging process, therefore by
the transfer function (transfer matrix) of the instrument. In this work,
a wire-cylinder corona charger was designed and the combined fielddiffusion
charging process of injected poly-disperse aerosol particles
was numerically simulated as a prerequisite for the study of a
multichannel EMS. The result, a cloud of particles with no uniform
charge distribution, was introduced to the EMS. The flow pattern and
electric field in the EMS were simulated using Computational Fluid
Dynamics (CFD) to obtain particle trajectories in the device and
therefore to calculate the reported signal by each electrometer.
According to the output signals (resulted from bombardment of
particles and transferring their charges as currents), we proposed a
modification to the size of detecting rings (which are connected to
electrometers) in order to evaluate particle size distributions more
accurately. Based on the capability of the system to transfer
information contents about size distribution of the injected particles,
we proposed a benchmark for the assessment of optimality of the
design. This method applies the concept of Von Neumann entropy
and borrows the definition of entropy from information theory
(Shannon entropy) to measure optimality. Entropy, according to the
Shannon entropy, is the ''average amount of information contained in
an event, sample or character extracted from a data stream''.
Evaluating the responses (signals) which were obtained via various
configurations of detecting rings, the best configuration which gave
the best predictions about the size distributions of injected particles,
was the modified configuration. It was also the one that had the
maximum amount of entropy. A reasonable consistency was also
observed between the accuracy of the predictions and the entropy
content of each configuration. In this method, entropy is extracted
from the transfer matrix of the instrument for each configuration.
Ultimately, various clouds of particles were introduced to the
simulations and predicted size distributions were compared to the
exact size distributions.
Abstract: Grains, including oats (Avena sativa L.), have been
recognized functional foods, because provide beneficial effect on the
health of the consumer and decrease the risk of various diseases. Oats
are good source of soluble fibre, essential amino acids, unsaturated
fatty acids, vitamins and minerals. Oat breeders have developed oat
varieties and improved yielding ability potential of oat varieties.
Therefore, the aim of investigation was to analyze the composition of
perspective oat varieties and breeding lines grains grown in different
conditions and evaluate functional properties. In the studied samples
content of protein, starch, β-glucans, total dietetic fibre, composition
of amino acids and vitamin E were determined. The results of
analysis showed that protein content depending of varieties ranged
9.70% to 17.30% total dietary fibre 13.66 g100g-1 to 30.17 g100g-1,
content of β-glucans 2.7 g100g-1 to 3.5 g100g-1, amount of
vitamin E (α-tocopherol) determined from 4 mgkg-1 to 9.9 mgkg-1.
The sums of essential amino acids in oat grain samples were
determined from 31.63 gkg-1 to 54.90 gkg-1. It is concluded that
amino acids composition of husked and naked oats grown in organic
or conventional conditions is close to optimal for human health.
Abstract: Polyaniline is an indispensible component in lightemitting
devices (LEDs), televisions, cellular telephones, automotive,
corrosion-resistant coatings, actuators etc. The electrical conductivity
properties was found be increased by introduction of metal nano
particles. In the present study, an attempt has been made to utilize
platinum nano particles to achieve the improved electrical properties.
Polyaniline and Pt-polyaniline composite are synthesized by
electrochemical routes. X-ray diffractometer confirms the amorphous
nature of polyaniline. The Bragg’s diffraction peaks correspond to
platinum nanoparticles in Pt-polyaniline composite and
thermogravimetric analyzer indicates its decomposition at certain
temperature. The Scanning Electron Micrographs of colloidal
platinum nanoparticles were spherical, uniform shape in the
composite. The current-voltage (I-V) characteristics of the PANI and
composites were also studied which indicate a significant decreasing
resistivity than PANI-Platinum after introduction of pt nanoparticles
in the matrix of polyaniline (PANI).
Abstract: In this paper, we present a new segmentation approach
for liver lesions in regions of interest within MRI (Magnetic
Resonance Imaging). This approach, based on a two-cluster Fuzzy CMeans
methodology, considers the parameter variable compactness
to handle uncertainty. Fine boundaries are detected by a local
recursive merging of ambiguous pixels with a sequential forward
floating selection with Zernike moments. The method has been tested
on both synthetic and real images. When applied on synthetic images,
the proposed approach provides good performance, segmentations
obtained are accurate, their shape is consistent with the ground truth,
and the extracted information is reliable. The results obtained on MR
images confirm such observations. Our approach allows, even for
difficult cases of MR images, to extract a segmentation with good
performance in terms of accuracy and shape, which implies that the
geometry of the tumor is preserved for further clinical activities (such
as automatic extraction of pharmaco-kinetics properties, lesion
characterization, etc.).
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: In recent research copper and manganese systems
were found to be the most active in CO and organic compounds
oxidation among the base catalysts. The mixed copper manganese
oxide has been widely studied in oxidation reactions because of their
higher activity at low temperatures in comparison with single oxide
catalysts. The results showed that the formation of spinel
CuxMn3−xO4 in the oxidized catalyst is responsible for the activity
even at room temperature. That is why the most of the investigations
are focused on the hopcalite catalyst (CuMn2O4) as the best coppermanganese
catalyst. Now it’s known that this is true only for CO
oxidation, but not for mixture of CO and VOCs. The purpose of this
study is to investigate the alumina supported copper-manganese
catalysts with different Cu/Mn molar ratio in terms of oxidation of
CO, methanol and dimethyl ether. The catalysts were prepared by impregnation of γ-Al2O3 with
copper and manganese nitrates and the catalytic activity
measurements were carried out in two stage continuous flow
equipment with an adiabatic reactor for simultaneous oxidation of all
compounds under the conditions closest possible to the industrial. Gas
mixtures on the input and output of the reactor were analyzed with a
gas chromatograph, equipped with FID and TCD detectors. The
texture characteristics were determined by low-temperature (- 196oС)
nitrogen adsorption in a Quantachrome Instruments NOVA 1200e
(USA) specific surface area & pore analyzer. Thermal, XRD and
TPR analyses were performed. It was established that the active component of the mixed Cu-
Mn/γ–alumina catalysts strongly depends on the Cu/Mn molar ratio.
Highly active alumina supported Cu-Mn catalysts for CO, methanol
and DME oxidation were synthesized. While the hopcalite is the best
catalyst for CO oxidation, the best compromise for simultaneous
oxidation of all components is the catalyst with Cu/Mn molar ratio
1:5.
Abstract: Mobil Producing Nigeria Unlimited (MPNU), a
subsidiary of ExxonMobil and the highest crude oil & condensate
producer in Nigeria has its operational base and an oil terminal, the
Qua Iboe terminal (QIT) located at Ibeno, Nigeria. Other oil
companies like Network Exploration and Production Nigeria Ltd,
Frontier Oil Ltd; Shell Petroleum Development Company Ltd; Elf
Petroleum Nigeria Ltd and Nigerian Agip Energy, a subsidiary of the
Italian ENI E&P operate onshore, on the continental shelf and in deep
offshore of the Atlantic Ocean, respectively with the coastal waters of
Ibeno, Nigeria as the nearest shoreline. This study was designed to
delineate the oil-polluted sites in Ibeno, Nigeria using
microbiological and physico-chemical characterization of soils,
sediments and ground and surface water samples from the study area.
Results obtained revealed that there have been significant recent
hydrocarbon inputs into this environment as observed from the high
counts of hydrocarbonoclastic microorganisms in excess of 1% at all
the stations sampled. Moreover, high concentrations of THC, BTEX
and heavy metals contents in all the samples analyzed corroborate the
high recent crude oil input into the study area. The results also
showed that the pollution of the different environmental media
sampled were of varying degrees, following the trend: ground water
> surface water > sediments > soils.
Abstract: We report herein the development and preliminary mechanical characterization of fully-dense multi-wall carbon nanotube (MWCNT)-reinforced ceramics and glasses based on a completely new methodology termed High Shear Compaction (HSC). The tubes are introduced and bound to the matrix grains by aid of polymeric binders to form flexible green bodies which are sintered and densified by spark plasma sintering to unprecedentedly high densities of 100% of the pure-matrix value. The strategy was validated across a PyrexTM glass / MWCNT composite while no identifiable factors limit application to other types of matrices. Nondestructive evaluation, based on ultrasonics, of the dynamic mechanical properties of the materials including elastic, shear and bulk modulus as well as Poisson’s ratio showed optimum property improvement at 0.5 %wt tube loading while evidence of nanoscalespecific energy dissipative characteristics acting complementary to nanotube bridging and pull-out indicate a high potential in a wide range of reinforcing and multifunctional applications.
Abstract: Knowledge of bone mechanical properties is important
for bone substitutes design and fabrication, and more efficient
prostheses development. The aim of this study is to characterize the
viscoelastic behavior of bone specimens, through stress relaxation
and fatigue tests performed to trabecular bone samples from bovine
femoral heads. Relaxation tests consisted on preloading the samples
at five different magnitudes and evaluate them for 1020 seconds,
adjusting the results to a KWW mathematical model. Fatigue tests
consisted of 700 load cycles and analyze their status at the end of the
tests. As a conclusion we have that between relaxation stress and
each preload there is linear relation and for samples with initial
Young´s modulus greater than 1.5 GPa showed no effects due fatigue
test loading cycles.
Abstract: Aluminium matrix composites with alumina
reinforcements give superior mechanical & physical properties. Their
applications in several fields like automobile, aerospace, defense,
sports, electronics, bio-medical and other industrial purposes are
becoming essential for the last several decades. In the present work,
fabrication of hybrid composite was done by Stir casting technique
using Al 6061 as a matrix with alumina and silicon carbide (SiC) as
reinforcement materials. The weight percentage of alumina is varied
from 2 to 4% and the silicon carbide weight percentage is maintained
constant at 2%. Hardness and wear tests are performed in the as cast
and heat treated conditions. Age hardening treatment was performed
on the specimen with solutionizing at 550°C, aging at two
temperatures (150 and 200°C) for different time durations. Hardness
distribution curves are drawn and peak hardness values are recorded.
Hardness increase was very sensitive with respect to the decrease in
aging temperature. There was an improvement in wear resistance of
the peak aged material when aged at lower temperature. Also
increase in weight percent of alumina, increases wear resistance at
lower temperature but opposite behavior was seen when aged at
higher temperature.
Abstract: This paper addresses a cutting edge method of
business demand forecasting, based on an empirical probability
function when the historical behavior of the data is random.
Additionally, it presents error determination based on the numerical
method technique ‘propagation of errors.’ The methodology was
conducted characterization and process diagnostics demand planning
as part of the production management, then new ways to predict its
value through techniques of probability and to calculate their mistake
investigated, it was tools used numerical methods. All this based on
the behavior of the data. This analysis was determined considering
the specific business circumstances of a company in the sector of
communications, located in the city of Bogota, Colombia. In
conclusion, using this application it was possible to obtain the
adequate stock of the products required by the company to provide its
services, helping the company reduce its service time, increase the
client satisfaction rate, reduce stock which has not been in rotation
for a long time, code its inventory, and plan reorder points for the
replenishment of stock.
Abstract: In order to address construction project requirements
and specifications, scholars and practitioners need to establish
taxonomy according to a scheme that best fits their need. While
existing characterization methods are continuously being improved,
new ones are devised to cover project properties which have not been
previously addressed. One such method, the Project Definition Rating
Index (PDRI), has received limited consideration strictly as a
classification scheme. Developed by the Construction Industry
Institute (CII) in 1996, the PDRI has been refined over the last two
decades as a method for evaluating a project's scope definition
completeness during front-end planning (FEP). The main
contribution of this study is a review of practical project classification
methods, and a discussion of how PDRI can be used to classify
projects based on their readiness in the FEP phase. The proposed
model has been applied to 59 construction projects in Ontario, and
the results are discussed.