Abstract: We present a gas-liquid microfluidic system as a
reactor to obtain magnetite nanoparticles with an excellent degree of
control regarding their crystalline phase, shape and size. Several
types of microflow approaches were selected to prevent nanomaterial
aggregation and to promote homogenous size distribution. The
selected reactor consists of a mixer stage aided by ultrasound waves
and a reaction stage using a N2-liquid segmented flow to prevent
magnetite oxidation to non-magnetic phases. A milli-fluidic reactor
was developed to increase the production rate where a magnetite
throughput close to 450 mg/h in a continuous fashion was obtained.
Abstract: The substantial development of the construction
industry has forced the cement industry, its major support, to focus
on achieving maximum productivity to meet the growing demand for
this material. This means that the reliability of a cement production
system needs to be at the highest level that can be achieved by good
maintenance. This paper studies the extent to which the
implementation of RCM is needed as a strategy for increasing the
reliability of the production systems component can be increased,
thus ensuring continuous productivity. In a case study of four Libyan
cement factories, 80 employees were surveyed and 12 top and middle
managers interviewed. It is evident that these factories usually
breakdown more often than once per month which has led to a
decline in productivity. In many times they cannot achieve the
minimum level of production amount. This has resulted from the
poor reliability of their production systems as a result of poor or
insufficient maintenance. It has been found that most of the factories’
employees misunderstand maintenance and its importance. The main
cause of this problem is the lack of qualified and trained staff, but in
addition it has been found that most employees are not found to be
motivated as a result of a lack of management support and interest. In
response to these findings, it has been suggested that the RCM
strategy should be implemented in the four factories. The results
show the importance of the development of maintenance strategies
through the implementation of RCM in these factories. The purpose
of it would be to overcome the problems that could secure the
reliability of the production systems. This study could be a useful
source of information for academic researchers and the industrial
organizations which are still experiencing problems in maintenance
practices.
Abstract: Masonry infill walls are inevitable in the selfsupporting
structures, but their contribution in the resistance to
earthquake loads is generally neglected in the structural analyses. The
principal aim of this work through a numerical study of masonry
infill walls behavior in structures subjected to horizontal load is to
propose by finite elements numerical modeling, a more reliable
approach, faster and close to reality. In this study, 3D Finite Element
Analysis was developed to study the behavior of masonry infill walls
in structures subjected to horizontal load; the finite element software
being used was ABAQUS, it is observed that more rigidity of the
masonry filling is significant, more the structure is rigid, we can so
conclude that the filling brings an additional rigidity to the structure
not to be neglected; it is also observed that when the framework is
subjected to horizontal loads, the framework separates from the
filling on the level of the tended diagonal.
Abstract: Computational fluid dynamics analysis of the burning
of syngas fuels derived from biomass and plastic solid waste mixture
through gasification process is presented in this paper. The syngas
fuel is burned in gas turbine can combustor. Gas turbine can
combustor with swirl is designed to burn the fuel efficiently and
reduce the emissions. The main objective is to test the impact of the
alternative syngas fuel compositions and lower heating value on the
combustion performance and emissions. The syngas fuel is produced
by blending palm kernel shell (PKS) with polyethylene (PE) waste
via catalytic steam gasification (fluidized bed reactor). High
hydrogen content syngas fuel was obtained by mixing 30% PE waste
with PKS. The syngas composition obtained through the gasification
process is 76.2% H2, 8.53% CO, 4.39% CO2 and 10.90% CH4. The
lower heating value of the syngas fuel is LHV = 15.98 MJ/m3. Three
fuels were tested in this study natural gas (100%CH4), syngas fuel
and pure hydrogen (100% H2). The power from the combustor was
kept constant for all the fuels tested in this study. The effect of syngas
fuel composition and lower heating value on the flame shape, gas
temperature, mass of carbon dioxide (CO2) and nitrogen oxides
(NOX) per unit of energy generation is presented in this paper. The
results show an increase of the peak flame temperature and NO mass
fractions for the syngas and hydrogen fuels compared to natural gas
fuel combustion. Lower average CO2 emissions at the exit of the
combustor are obtained for the syngas compared to the natural gas
fuel.
Abstract: This study focuses on a novel method for dispersion
and distribution of reinforcement under high intensive shear stress to
produce metal composites. The polyacrylonitrile (PAN)-based short
carbon fiber (Csf) and Nextel 610 alumina fiber were dispersed under
high intensive shearing at mushy zone in semi-solid of A356 by a
novel method. The bundles and clusters were embedded by
infiltration of slurry into the clusters, thus leading to a uniform
microstructure. The fibers were embedded homogenously into the
aluminum around 576-580°C with around 46% of solid fraction.
Other experiments at 615°C and 568°C which are contained 0% and
90% solid respectively were not successful for dispersion and
infiltration of aluminum into bundles of Csf. The alumina fiber has
been cracked by high shearing load. The morphologies and
crystalline phase were evaluated by SEM and XRD. The adopted
thixo-process effectively improved the adherence and distribution of
Csf into Al that can be developed to produce various composites by
thixomixing.
Abstract: Microbes have been used to solve environmental
problems for many years. The role of microorganism to sequester,
precipitate or alter the oxidation state of various heavy metals has
been extensively studied. Treatment using microorganism interacts
with toxic metal are very diverse. The purpose of this research is to
remove the mercury using Pseudomonas putida (P. putida), pure
culture ATTC 49128 at optimum growth parameters such as
techniques of culture, acclimatization time and speed of incubator
shaker. Thus, in this study, the optimum growth parameters of P.
putida were obtained to achieve the maximum of mercury removal.
Based on the optimum parameters of P. putida for specific growth
rate, the removal of two different mercury concentration, 1 ppm and
4 ppm were studied. From mercury nitrate solution, a mercuryresistant
bacterial strain which is able to reduce from ionic mercury
to metallic mercury was used to reduce ionic mercury. The overall
levels of mercury removal in this study were between 80% and 89%.
The information obtained in this study is of fundamental for
understanding of the survival of P. putida ATTC 49128 in mercury
solution. Thus, microbial mercury removal is a potential
bioremediation for wastewater especially in petrochemical industries
in Malaysia.
Abstract: In contrast with literal meaning of nano, researchers
have been achieved mega adventures in this area and every day more
nanomaterials are being introduced to the market. After long time
application of fossil-based plastics, nowadays accumulation of their
waste seems to be a big problem to the environment. On the other
hand, mankind has more attention to safety and living environment.
Replacing common plastic packaging materials with degradable ones
that degrade faster and convert to non-dangerous components like
water and carbon dioxide have more attractions; these new materials
are based on renewable and inexpensive sources of starch and
cellulose. However, the functional properties of them do not suitable
for packaging. At this point, nanotechnology has an important role.
Utilizing of nanomaterials in polymer structure will improve
mechanical and physical properties of them; nanocrystalline cellulose
(NCC) has this ability. This work has employed a chemical method to
produce NCC and starch bio nanocomposite containing NCC. X-Ray
Diffraction technique has characterized the obtained materials.
Results showed that applied method is a suitable one as well as
applicable one to NCC production.
Abstract: Five palm oil ether monoesters utilized as novel
biodiesels were synthesized and structurally identified in the paper.
The investigation was made on the effect of ether species on
physicochemical properties of the palm oil ether monoesters. The
results showed that density, kinematic viscosity, smoke point, and
solidifying point increase linearly with their –CH2 group number in
certain relationships. Cetane number is enhanced whereas heat value
decreases linearly with –CH2 group number. In addition, the
influencing regularities of the volumetric content of the palm oil ether
monoesters on the fuel properties were also studied when the ether
monoesters are used as diesel fuel additives.
Abstract: This paper deals with the study of reflection and
transmission characteristics of acoustic waves at the interface of a
semiconductor half-space and elastic solid. The amplitude ratios
(reflection and transmission coefficients) of reflected and transmitted
waves to that of incident wave varying with the incident angles have
been examined for the case of quasi-longitudinal wave. The special
cases of normal and grazing incidence have also been derived with
the help of Gauss elimination method. The mathematical model
consisting of governing partial differential equations of motion and
charge carriers’ diffusion of n-type semiconductors and elastic solid
has been solved both analytically and numerically in the study. The
numerical computations of reflection and transmission coefficients
has been carried out by using MATLAB programming software for
silicon (Si) semiconductor and copper elastic solid. The computer
simulated results have been plotted graphically for Si
semiconductors. The study may be useful in semiconductors,
geology, and seismology in addition to surface acoustic wave (SAW)
devices.
Abstract: This paper presents an optimization method for
reducing the number of input channels and the complexity of the
feed-forward NARX neural network (NN) without compromising the
accuracy of the NN model. By utilizing the correlation analysis
method, the most significant regressors are selected to form the input
layer of the NN structure. An application of vehicle dynamic model
identification is also presented in this paper to demonstrate the
optimization technique and the optimal input layer structure and the
optimal number of neurons for the neural network is investigated.
Abstract: Mammography is widely used technique for breast cancer
screening. There are various other techniques for breast cancer screening
but mammography is the most reliable and effective technique. The
images obtained through mammography are of low contrast which
causes problem for the radiologists to interpret. Hence, a high quality
image is mandatory for the processing of the image for extracting any
kind of information from it. Many contrast enhancement algorithms have
been developed over the years. In the present work, an efficient
morphology based technique is proposed for contrast enhancement of
masses in mammographic images. The proposed method is based on
Multiscale Morphology and it takes into consideration the scale of the
structuring element. The proposed method is compared with other stateof-
the-art techniques. The experimental results show that the proposed
method is better both qualitatively and quantitatively than the other
standard contrast enhancement techniques.
Abstract: Toddy sediment (TS) was cultured in a PDA medium
to determine initial yeast load, and also it was undergone sun, shade,
solar, dehumidified cold air (DCA) and hot air oven (at 400, 500 and
60oC) drying with a view to preserve viability of yeast. Thereafter,
this study was conducted according to two factor factorial design in
order to determine best preservation method. Therein the dried TS
from the best drying method was taken and divided into two portions.
One portion was mixed with 3: 7 ratio of TS: rice flour and the
mixture was divided in to two again. While one portion was kept
under in house condition the other was in a refrigerator. Same
procedure was followed to the rest portion of TS too but it was at the
same ratio of corn flour. All treatments were vacuum packed in triple
laminate pouches and the best preservation method was determined
in terms of leavening index (LI). The TS obtained from the best
preservation method was used to make foods (bread and hopper) and
organoleptic properties of it were evaluated against same of ordinary
foods using sensory panel with a five point hedonic scale.
Results revealed that yeast load or fresh TS was 58×106 CFU/g.
The best drying method in preserving viability of yeast was DCA
because LI of this treatment (96%) is higher than that of other three
treatments. Organoleptic properties of foods prepared from best
preservation method are as same as ordinary foods according to Duo
trio test.
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: Potassium borates, which are widely used in welding
and metal refining industry, as a lubricating oil additive, cement
additive, fiberglass additive and insulation compound, are one of the
important groups of borate minerals. In this study the production of a
potassium borate mineral via hydrothermal method is aimed. The
potassium source of potassium nitrate (KNO3) was used along with a
sodium source of sodium hydroxide (NaOH) and boron source of
boric acid (H3BO3). The constant parameters of reaction temperature
and reaction time were determined as 80°C and 1 h, respectively. The
molar ratios of 1:1:3 (as KNO3:NaOH:H3BO3), 1:1:4, 1:1:5, 1:1:6
and 1:1:7 were used. Following the synthesis the identifications of
the produced products were conducted by X-Ray Diffraction (XRD),
Fourier Transform Infrared Spectroscopy (FT-IR) and Raman
Spectroscopy. The results of the experiments and analysis showed in
the ratio of 1:1:6, the Santite mineral with powder diffraction file
number (pdf no.) of 01-072-1688, which is known as potassium
pentaborate (KB5O8·4H2O) was synthesized as best.
Abstract: This paper presents the results of an experimental
study undertaken to evaluate the local bond stress-slip response of
short embedment of reinforcing bars in normal concrete (NC) and
high performance fiber reinforced cement composites (HPFRCC)
blocks. Long embedment was investigated as well to gain insights on
the distribution of strain, slip, bar stress and bond stress along the bar
especially in post-yield range. A total of 12 specimens were tested,
by means of pull-out of the reinforcing bars from concrete blocks. It
was found that the enhancement of local bond strength can be
reached up to 50% and ductility of the bond behavior was improved
significantly if HPFRCC is used. Also, under a constant strain at
loaded end, HPFRCC has delayed yielding of bars at other location
from the loaded end. Hence, the reduction of bond stress was slower
for HPFRCC in comparison with NC. Due to the same reason, the
total slips at loaded end for HPFRCC was smaller than NC as
expected. Test results indicated that HPFRCC has better bond slip
behavior which makes it a suitable material to be employed in
anchorage zone such as beam-column joints.
Abstract: The effect of partially substitution of magnetic
impurity Fe for Cu to the magnetic and transport properties in
electron-doped superconducting cuprates of
Eu1.85+yCe0.15-yCu1-yFeyO4+α-δ (ECCFO) with y = 0, 0.010, 0.020, and
0.050 has been studied, in order to investigate the mechanism of
magnetic and transport properties of ECCFO in normal-state.
Magnetic properties are investigated by DC magnetic-susceptibility
measurements that carried out at low temperatures down to 2 K using a
standard SQUID magnetometer in a magnetic field of 5 Oe on field
cooling. Transport properties addressed to electron mobility, are
extracted from radius of electron localization calculated from
temperature dependence of resistivity. For y = 0, temperature
dependence of dc magnetic-susceptibility (χ) indicated the change of
magnetic behavior from paramagnetic to diamagnetic below 15 K.
Above 15 K, all samples show paramagnetic behavior with the values
of magnetic moment in every volume unit increased with increasing y.
Electron mobility decreased with increasing y.
Abstract: In this paper, a new concept of closed-loop design for a
product is presented. The closed-loop design model is developed by
integrating forward design and reverse design. Based on this new
concept, a closed-loop design model for sustainable manufacturing by
integrated evaluation of forward design, reverse design, and green
manufacturing using a fuzzy analytic network process is developed. In
the design stage of a product, with a given product requirement and
objective, there can be different ways to design the detailed
components and specifications. Therefore, there can be different
design cases to achieve the same product requirement and objective.
Subsequently, in the design evaluation stage, it is required to analyze
and evaluate the different design cases. The purpose of this research is
to develop a model for evaluating the design cases by integrated
evaluating the criteria in forward design, reverse design, and green
manufacturing. A fuzzy analytic network process method is presented
for integrated evaluation of the criteria in the three models. The
comparison matrices for evaluating the criteria in the three groups are
established. The total relational values among the three groups
represent the total relational effects. In applications, a super matrix
model is created and the total relational values can be used to evaluate
the design cases for decision-making to select the final design case. An
example product is demonstrated in this presentation. It shows that the
model is useful for integrated evaluation of forward design, reverse
design, and green manufacturing to achieve a closed-loop design for
sustainable manufacturing objective.
Abstract: This paper presents a method of evaluating the effect
of aggregate angularity on hot mix asphalt (HMA) properties and its
relationship to the Permanent Deformation resistance. The research
concluded that aggregate particle angularity had a significant effect
on the Permanent Deformation performance, and also that with an
increase in coarse aggregate angularity there was an increase in the
resistance of mixes to Permanent Deformation. A comparison
between the measured data and predictive data of permanent
deformation predictive models showed the limits of existing
prediction models. The numerical analysis described the permanent
deformation zones and concluded that angularity has an effect of the
onset of these zones. Prediction of permanent deformation help road
agencies and by extension economists and engineers determine the
best approach for maintenance, rehabilitation, and new construction
works of the road infrastructure.
Abstract: Some plants of genus Schinus have been used in the
folk medicine as topical antiseptic, digestive, purgative, diuretic,
analgesic or antidepressant, and also for respiratory and urinary
infections. Chemical composition of essential oils of S. molle and S.
terebinthifolius had been evaluated and presented high variability
according with the part of the plant studied and with the geographic
and climatic regions. The pharmacological properties, namely
antimicrobial, anti-tumoural and anti-inflammatory activities are
conditioned by chemical composition of essential oils. Taking into
account the difficulty to infer the pharmacological properties of
Schinus essential oils without hard experimental approach, this work
will focus on the development of a decision support system, in terms
of its knowledge representation and reasoning procedures, under a
formal framework based on Logic Programming, complemented with
an approach to computing centered on Artificial Neural Networks
and the respective Degree-of-Confidence that one has on such an
occurrence.
Abstract: The objective of this study is to conduct computational
fluid dynamic (CFD) simulations for evaluating the cooling efficacy
from vegetation implanted in a public park in the Taipei, Taiwan. To
probe the impacts of park renewal by means of adding three pavilions
and supplementary green areas on urban microclimates, the simulated
results have revealed that the park having a higher percentage of green
coverage ratio (GCR) tended to experience a better cooling effect.
These findings can be used to explore the effects of different greening
modifications on urban environments for achieving an effective
thermal comfort in urban public spaces.