Abstract: The use of magnesium alloys is limited due to their
susceptibility to corrosion although they have many attractive
physical and mechanical properties. To increase mechanical and
corrosion properties of these alloys, many deposition method and
coating types are used. Electroless Ni–B coatings have received
considerable interest recently due to its unique properties such as
cost-effectiveness, thickness uniformity, good wear resistance,
lubricity, good ductility and corrosion resistance, excellent
solderability and electrical properties and antibacterial property. In
this study, electroless Ni-B coating could been deposited on AZ91
magnesium alloy. The obtained coating exhibited a harder and
rougher structure than the substrate.
Abstract: The objective of the paper is a numerical study of heat
transfer between perforated metal plates and the surrounding air
flows. Different perforation structures can nowadays be found in
various industrial products. Besides improving the mechanical
properties, the perforations can intensify the heat transfer as well. The
heat transfer coefficient depends on a wide range of parameters such
as type of perforation, size, shape, flow properties of the surrounding
air etc. The paper was focused on three different perforation
structures which have been investigated from the point of the view of
the production in the previous studies. To determine the heat
coefficients and the Nusselt numbers, the numerical simulation
approach was adopted. The calculations were performed using the
OpenFOAM software. The three-dimensional, unstable, turbulent and
incompressible air flow around the perforated surface metal plate was
considered.
Abstract: NiFe2O4 (nickel ferrite), ZnFe2O4 (zinc ferrite) and
Ni0.5Zn0.5Fe2O4 (nickel-zinc ferrite) were prepared by
mechanochemical route in a planetary ball mill starting from mixture
of the appropriate quantities of the Ni(OH)2/Fe(OH)3,
Zn(OH)2/Fe(OH)3 and Ni(OH)2/Zn(OH)2/Fe(OH)3 hydroxide
powders. In order to monitor the progress of chemical reaction and
confirm phase formation, powder samples obtained after 25 h, 18 h
and 10 h of milling were characterized by X-ray diffraction (XRD),
transmission electron microscopy (TEM), IR, Raman and Mössbauer
spectroscopy. It is shown that the soft mechanochemical method, i.e.
mechanochemical activation of hydroxides, produces high quality
single phase ferrite samples in much more efficient way. From the IR
spectroscopy of single phase samples it is obvious that energy of
modes depends on the ratio of cations. It is obvious that all samples
have more than 5 Raman active modes predicted by group theory in
the normal spinel structure. Deconvolution of measured spectra
allows one to conclude that all complex bands in the spectra are made
of individual peaks with the intensities that vary from spectrum to
spectrum. The deconvolution of Raman spectra allows to separate
contributions of different cations to a particular type of vibration and
to estimate the degree of inversion.
Abstract: In present study, a large deposit of oolitic iron ore of
Late Carboniferous-Permotriassic-Lower Jurassic age was discovered
in Wadi Halfa and Argein areas, North Sudan. It seems that the iron
ore mineralization exists in the west and east bank of the River Nile
of the study area that are found on the Egyptian-Sudanese border.
The Carboniferous-Lower Jurassic age strata were covered by 67
sections and each section has been examined and carefully described.
The iron-ore in Wadi Halfa occurs as oolitic ironstone and contained
two horizons: (A) horizon and (B) horizon. Only horizon (A) was
observed in southern Argein area. The texture of the ore is variable
depending on the volume of the component. In thin sections, the
average of the ooids was ranged between 90%-80%. The matrix
varies between 10%-20% by volume and detritus quartz in other
component my reach up to 30% by volume in sandy massive ore.
Ooids size ranges from 0.2mm-1.00 mm on average in very coarse
ooids may attend up to 1 mm in size. The matrix around the ooids is
dominated by iron hydroxide, carbonate, fine, and amorphous silica.
The probable ore reserve estimate of 1.234 billion at a head grade of
41.29% Fe for the Wadi Halfa Oolitic Ironstone Formation. The iron
ore shows higher content of phosphorus ranges from 6.15% to 0.16%,
with mean 1.45%. The new technology Hatch–Ironstone Chloride
Segregation (HICS) can be used to produce commercial-quality of
iron and reduce phosphorus and silica to acceptable levels for steel
industry. The presence of infrastructures in addition to the presence
of massive quantities of iron ore would make exploitation
economically.
Abstract: At present, in China, the research about the urban
sustainability construction is still in the exploratory stage. The
ecological problems of the coastal area are more sensitive and
complicated. In the background of global warming with serious
ecological damage, this paper deeply researches on the main
characteristics of urban sustainability and measures how to build urban
sustainability. Through combining regional environmental with
economic ability along the coastal area, then authors put forward the
system planning framework, construction strategy and the evaluation
index system, in order to seek the way of building urban sustainability
along coastal area in China.
Abstract: The objective of this study was to synthesize and
characterize the poly(alkenoic acid)s with different molecular
structures, use these polymers to formulate a dental cement
restorative, and study the effect of molecular structures on reaction
kinetics, viscosity, and mechanical strengths of the formed polymers
and cement restoratives. In this study, poly(alkenoic acid)s with
different molecular structures were synthesized. The purified
polymers were formulated with commercial Fuji II LC glass fillers to
form the experimental cement restoratives. The reaction kinetics was
studied via 1HNMR spectroscopy. The formed restoratives were
evaluated using compressive strength, diametral tensile strength,
flexural strength, hardness and wear-resistance tests. Specimens were
conditioned in distilled water at 37oC for 24 h prior to testing. Fuji II
LC restorative was used as control. The results show that the higher
the arm number and initiator concentration, the faster the reaction
was. It was also found that the higher the arm number and branching
that the polymer had, the lower the viscosity of the polymer in water
and the lower the mechanical strengths of the formed restorative. The
experimental restoratives were 31-53% in compressive strength, 37-
55% in compressive modulus, 80-126% in diametral tensile strength,
76-94% in flexural strength, 4-21% in fracture toughness and 53-96%
in hardness higher than Fuji II LC. For wear test, the experimental
restoratives were only 5.4-13% of abrasive and 6.4-12% of attritional
wear depths of Fuji II LC in each wear cycle. The aging study also
showed that all the experimental restoratives increased their strength
continuously during 30 days, unlike Fuji II LC. It is concluded that
polymer molecular structures have significant and positive impact on
mechanical properties of dental cement restoratives.
Abstract: This paper presents the design and implementation
details of a complete unmanned aerial system (UAS) based
on commercial-off-the-shelf (COTS) components, focusing on
safety, security, search and rescue scenarios in GPS-denied
environments. In particular, The aerial platform is capable
of semi-autonomously navigating through extremely low-light,
GPS-denied indoor environments based on onboard sensors only,
including a downward-facing optical flow camera. Besides, an
additional low-cost payload camera system is developed to stream
both infra-red video and visible light video to a ground station in
real-time, for the purpose of detecting sign of life and hidden humans.
The total cost of the complete system is estimated to be $1150,
and the effectiveness of the system has been tested and validated
in practical scenarios.
Abstract: Hydraulic fracturing is one of the most important
stimulation techniques available to the petroleum engineer to extract
hydrocarbons in tight gas sandstones. It allows more oil and gas
production in tight reservoirs as compared to conventional means.
The main aim of the study is to optimize the hydraulic fracturing as
technique and for this purpose three multi-zones layer formation is
considered and fractured contemporaneously. The three zones are
named as Zone1 (upper zone), Zone2 (middle zone) and Zone3
(lower zone) respectively and they all occur in shale rock. Simulation was performed with Mfrac integrated software which
gives a variety of 3D fracture options. This simulation process
yielded an average fracture efficiency of 93.8%for the three
respective zones and an increase of the average permeability of the
rock system. An average fracture length of 909 ft with net height
(propped height) of 210 ft (average) was achieved. Optimum
fracturing results was also achieved with maximum fracture width of
0.379 inches at an injection rate of 13.01 bpm with 17995 Mscf of
gas production.
Abstract: Detecting changes in multiple images of the same
scene has recently seen increased interest due to the many
contemporary applications including smart security systems, smart
homes, remote sensing, surveillance, medical diagnosis, weather
forecasting, speed and distance measurement, post-disaster forensics
and much more. These applications differ in the scale, nature, and
speed of change. This paper presents an application of image
processing techniques to implement a real-time change detection
system. Change is identified by comparing the RGB representation of
two consecutive frames captured in real-time. The detection threshold
can be controlled to account for various luminance levels. The
comparison result is passed through a filter before decision making to
reduce false positives, especially at lower luminance conditions. The
system is implemented with a MATLAB Graphical User interface
with several controls to manage its operation and performance.
Abstract: The aim of this paper is to analyze the impact of
literature review software on researchers. The aim of this study was
achieved by analyzing models in terms of perceived usefulness,
perceived ease of use, and acceptance level. Collected data were
analyzed using WarpPLS 4.0 software. This study used two
theoretical frameworks, namely, Technology Acceptance Model and
the Training Needs Assessment Model. The study was experimental
and was conducted at a public university in South Africa. The results
of the study showed that acceptance level has a high impact on
research productivity followed by perceived usefulness and perceived
ease of use.
Abstract: Cesium molybdates with general formula
CsMIII(MoO4)2, where MIII = Bi, Dy, Pr, Er, exhibit rich
polymorphism, and crystallize in a layered structure. These properties
cause intensive studies on cesium molybdates. CsBi(MoO4)2 was synthesized by microwave method by using
cerium sulphate, bismuth oxide and molybdenum (VI) oxide in an
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/differantial thermal analysis (TG/DTA).
Abstract: Scheduled waste management is very important in
environmental and health aspects. In delivering services, highway
industry has been indirectly involved in producing scheduled wastes.
This paper aims to define the scheduled waste, to provide a
conceptual framework of the scheduled waste management in
highway industry, to highlight the effect of improper management of
scheduled waste and to encourage future researchers to identify and
share the present practice of scheduled waste management in their
country. The understanding on effective management of scheduled
waste will help the operators of highway industry, the academicians,
future researchers, and encourage a friendly environment around the
world. The study on scheduled waste management in highway
industry is very crucial as highway transverse and run along
kilometers crossing the various type of environment, residential and
schools. Using Environmental Quality (Scheduled Waste)
Regulations 2005 as a guide, this conceptual paper highlight several
scheduled wastes produced by highway industry in Malaysia and
provide a conceptual framework of scheduled waste management that
focused on the highway industry. Understanding on scheduled waste
management is vital in order to preserve the environment. Besides
that, the waste substances are hazardous to human being. Many
diseases have been associated with the improper management of
schedule waste such as cancer, throat irritation and respiration
problem.
Abstract: CuO thin films were deposited by spray ultrasonic
pyrolysis with different precursor solution. Two staring solution slats
were used namely: copper acetate and copper chloride. The influence
of these solutions on CuO thin films proprieties of is instigated. The
X rays diffraction (XDR) analysis indicated that the films deposed
with copper acetate are amorphous however the films elaborated with
copper chloride have monoclinic structure. UV- Visible transmission
spectra showed a strong absorbance of the deposited CuO thin films
in the visible region. Electrical characterization has shown that CuO
thin films prepared with copper acetate have a higher electrical
conductivity.
Abstract: A numerical study is made in a parallel-plate porous
channel subjected to an oscillating flow and an exothermic chemical
reaction on its walls. The flow field in the porous region is modeled
by the Darcy–Brinkman–Forchheimer model and the finite volume
method is used to solve the governing equations. The effects of the
modified Frank-Kamenetskii (FKm) and Damköhler (Dm) numbers,
the amplitude of oscillation (A), and the Strouhal number (St) are
examined. The main results show an increase of heat and mass
transfer rates with A and St, and their decrease with FKm and Dm.
Abstract: Software testing has become a mandatory process in
assuring the software product quality. Hence, test management is
needed in order to manage the test activities conducted in the
software test life cycle. This paper discusses on the challenges faced
in the software test life cycle, and how the test processes and test
activities, mainly on test cases creation, test execution, and test
reporting is being managed and automated using several test
automation tools, i.e. Jira, Robot Framework, and Jenkins.
Abstract: Electronic mediums such as websites, feeds, blogs and
social media sites are on a daily basis influencing our decision
making, are improving our productivity and are shaping futures of
many consumers and service/product providers. This research
identifies that both customers and business providers heavily rely on
smart phone applications. Based on this, mobile applications
available on iTunes store were studied. It was identified that fruit and
vegetable related applications used by consumers can broadly be
categorized into purchase applications, diaries, tracking health
applications, trip farm location and cooking applications. On the
other hand, applications used by farmers can broadly be classified as:
weather tracking, pests / fertilizer applications and general social
media applications such as Facebook. To blur this farmer-consumer
application divide, our research utilizes Context Specific
eTransformation Framework and based on it identifies characteristic
future consumer-farmer applications will need to have so that the
current divide can be narrowed and consequently better farmerconsumer
supply chain link established.
Abstract: This paper presents a model predictive control (MPC)
of a utility interactive three phase inverter (TPI) for a photovoltaic
(PV) system at commercial level. The proposed model uses phase
locked loop (PLL) to synchronize the TPI with the power electric
grid (PEG) and performs MPC control in a dq reference frame. TPI
model consists of a boost converter (BC), maximum power point
tracking (MPPT) control, and a three-leg voltage source inverter
(VSI). The operational model of VSI is used to synthesize the
sinusoidal current and track the reference. The model is validated
using a 35.7 kW PV system in Matlab/Simulink. Implementation
results show simplicity and accuracy, as well as reliability of the
model.
Abstract: Wheat is the first and the most important grain of the
world and its bakery property is due to glutenin and gliadin qualities.
Wheat seed proteins were divided into four groups according to
solubility including albumin, globulin, glutenin and prolamin or
gliadin. Gliadins are major components of the storage proteins in
wheat endosperm. It seems that little information is available about
gliadin genes in Iranian wild relatives of wheat. Thus, the aim of this
study was the evaluation of the wheat wild relatives collected from
different origins of Zagros Mountains in Iran, in terms of coding
gliadin genes using specific primers. For this, forty accessions of
Triticum boeoticum and Triticum urartu were selected for this study.
For each accession, genomic DNA was extracted and PCRs were
performed in total volumes of 15 μl. The amplification products were
separated on 1.5% agarose gels. In results, for Gli-2A locus three
allelic variants were detected by Gli-2As primer pairs. The sizes of
PCR products for these alleles were 210, 490 and 700 bp. Only five
(13%) and two accessions (5%) produced 700 and 490 bp fragments
when their DNA was amplified with the Gli.As.2 primer pairs.
However, 93% of the accessions carried allele 210 bp, and only 8%
did not any product for this marker. Therefore, these germplasm
could be used as rich gene pool to broaden the genetic base of bread
wheat.
Abstract: In this numerical study, effects of using Al2O3-water
nanofluid on the rate of heat transfer have been investigated. Physical
model is a square enclosure with insulated top and bottom horizontal
walls, while the vertical walls are kept at different constant
temperatures. Two appropriate models are used to evaluate the
viscosity and thermal conductivity of nanofluid. The governing
stream-vorticity equations are solved using a second order central
finite difference scheme, coupled to the conservation of mass and
energy. The study has been carried out for the nanoparticle diameter
30, 60 and 90 nm and the solid volume fraction 0 to 0.04. Results are
presented by average Nusselt number and normalized Nusselt number
in different range of φ and D for mixed convection dominated
regime. It is found that different heat transfer rate is predicted when
the effect of nanoparticle diameter is taken into account.
Abstract: Government reports and published research have
flagged and brought to public attention the deteriorating condition of
a large percentage of bridges in Canada and the United States. With
the increasing number of deteriorated bridges in the US, Canada, and
around the globe, condition assessment techniques of concrete
bridges are evolving. Investigation for bridges’ defects such as
cracks, spalls, and delamination and their level of severity are the
main objectives of condition assessment. Inspection and
rehabilitation programs are being implemented to monitor and
maintain deteriorated bridge infrastructure. This paper highlights the
state-of-the art of current practices being performed for concrete
bridge inspection. The information is gathered from the literature and
through a distributed questionnaire. The current practices in concrete
bridge inspection rely on the use of hummer sounding and chain
dragging tests. Non-Destructive Testing (NDT) techniques are not
being utilized fully in the process. Nonetheless, they are being
partially utilized by the recommendation of the bridge inspector after
conducting visual inspection. Lanes are usually closed during the
performance of visual inspection and bridge inspection in general.