Abstract: The substantial similarity of fatigue mechanism in a
new test rig for rolling contact fatigue (RCF) has been investigated. A
new reduced-scale test rig is designed to perform controlled RCF
tests in wheel-rail materials. The fatigue mechanism of the rig is
evaluated in this study using a combined finite element-fatigue
prediction approach. The influences of loading conditions on fatigue
crack initiation have been studied. Furthermore, the effects of some
artificial defects (squat-shape) on fatigue lives are examined. To
simulate the vehicle-track interaction by means of the test rig, a threedimensional
finite element (FE) model is built up. The nonlinear
material behaviour of the rail steel is modelled in the contact
interface. The results of FE simulations are combined with the critical
plane concept to determine the material points with the greatest
possibility of fatigue failure. Based on the stress-strain responses, by
employing of previously postulated criteria for fatigue crack initiation
(plastic shakedown and ratchetting), fatigue life analysis is carried
out. The results are reported for various loading conditions and
different defect sizes. Afterward, the cyclic mechanism of the test rig
is evaluated from the operational viewpoint. The results of fatigue
life predictions are compared with the expected number of cycles of
the test rig by its cyclic nature. Finally, the estimative duration of the
experiments until fatigue crack initiation is roughly determined.
Abstract: The crude oil in an oil well exists in various phases
such as gas, seawater, and sand, as well as oil. Therefore, a phase
separator is needed at the front of a single-phase pump for
pressurization and transfer. On the other hand, the application of a
multiphase pump can provide such advantages as simplification of the
equipment structure and cost savings, because there is no need for a
phase separation process. Therefore, the crude oil transfer method
using a multiphase pump is being applied to recently developed oil
wells. Due to this increase in demand, technical demands for the
development of multiphase pumps are sharply increasing, but the
progress of research into related technologies is insufficient, due to the
nature of multiphase pumps that require high levels of skills. This
study was conducted to verify the reliability of pump performance
evaluation using numerical analysis, which is the basis of the
development of a multiphase pump. For this study, a model was
designed by selecting the specifications of this study. The performance
of the designed model was evaluated through numerical analysis and
experiment. The results of the performance evaluation were compared
to verify the reliability of the result using numerical analysis.
Abstract: One of the biggest challenges facing Theological/
Religious Education in Nigeria is access to quality learning materials.
For instance at the Trinity (Union) Theological College, Umuahia, it
was difficult for lecturers to access suitable and qualitative materials
for instruction especially the ones that would suit the African context
and stimulate a deep rooted interest among the students. Some
textbooks written by foreign authors were readily available in the
School Library, but were lacking in the College bookshops for
students to own copies. Even when the College was able to order
some of the books from abroad, it did not usher in the needed
enthusiasm expected from the students because they were either very
expensive or very difficult to understand during private studies. So it
became necessary to develop contextual materials which were
affordable and understandable, though with little success. The
National Open University of Nigeria (NOUN)’s innovation in the
development and sharing of learning resources through its Open
Courseware is a welcome development and of great assistance to
students. Apart from NOUN students who could easily access the
materials, many others from various theological/religious institutes
across the nation have benefited immensely. So, the thesis of this
paper is that the promotion of open educational resources in
theological/religious education in Nigeria would facilitate a better
informed/equipped religious leadership, which would in turn impact
its adherents for a healthier society and national development.
Adopting a narrative and historical approach within the context of
Nigeria’s educational system, the paper discusses: educational
traditions in Nigeria; challenges facing theological/religious
education in Nigeria; and benefits of open educational resources. The
study goes further to making recommendations on how OER could
positively influence theological/religious education in Nigeria. It is
expected that theologians, religious educators, and ODL practitioners
would find this work very useful.
Abstract: Kigelia africana (Lam.) Benth. (Bignoniaceae) is a
reputed traditional remedy for various human ailments such as skin
diseases, microbial infections, melanoma, stomach troubles,
metabolic disorders, malaria and general pains. In spite of the fruit
being widely used for purposes related to its antibacterial and
antifungal properties, the chemical constituents associated with the
activity have not been fully identified. To elucidate the active
principles, we evaluated the antimicrobial activity of fruit extracts
and purified fractions against Staphylococcus aureus, Enterococcus
faecalis, Moraxella catarrhalis, Escherichia coli, Candida albicans
and Candida tropicalis. Shade-dried fruits were powdered and
extracted with hydroalcoholic (1:1) mixture by soaking at room
temperature for 72 h. The crude extract was further fractionated by
column chromatography, with successive elution using hexane,
dichloromethane, ethyl acetate, acetone and methanol. The
dichloromethane and ethyl acetate fractions were combined and
subjected to column chromatography to furnish a wax and oil from
the eluates of 20% and 40% ethyl acetate in hexane, respectively. The
GC-MS and GC×GC-MS results revealed that linoleic acid, linolenic
acid, palmitic acid, arachidic acid and stearic acid were the major
constituents in both oil and wax. The crude hydroalcoholic extract
exhibited the strongest activity with MICs of 0.125-0.5 mg/mL,
followed by the ethyl acetate (MICs = 0.125-1.0 mg/mL),
dichloromethane (MICs = 0.250-2.0 mg/mL), hexane (MICs = 0.25-
2.0 mg/mL), acetone (MICs = 0.5-2.0 mg/mL) and methanol (MICs =
1.0-2.0 mg/mL), whereas the wax (MICs = 2.0-4.0 mg/mL) and oil
(MICs = 4.0-8.0 mg/mL) showed poor activity. The study concludes
that synergistic interactions of chemical constituents could be
responsible for the antimicrobial activity of K. africana fruits, which
needs a more holistic approach to understand the mechanism of its
antimicrobial activity.
Abstract: Apps are today the most important possibility to adapt
mobile phones and computers to fulfill the special needs of their
users. Location- and context-sensitive programs are hereby the key to
support the interaction of the user with his/her environment and also
to avoid an overload with a plenty of dispensable information. The
contribution shows, how a trusted, secure and really bi-directional
communication and interaction among users and their environment
can be established and used, e.g. in the field of home automation.
Abstract: Robotics provides answers to amputees. The most
expensive solutions surgically connect the prosthesis to nerve endings.
There are also several types of non-invasive technologies that recover
nerve messages passing through the muscles. After analyzing these
messages, myoelectric prostheses perform the desired movement.
The main goal is to avoid all surgeries, which can be heavy and offer
cheaper alternatives. For an amputee, we use valid muscles to recover
the electrical signal involved in a muscle movement. EMG sensors
placed on the muscle allows us to measure a potential difference,
which our program transforms into control for a robotic arm with two
degrees of freedom. We have shown the feasibility of non-invasive
prostheses with two degrees of freedom. Signal analysis and an
increase in degrees of freedom is still being improved.
Abstract: Nations are still finding it quite difficult to win mega
sport competitions despite the major contribution of sport to society
in terms of social and economic development, personal health, and in
education. Even though the world of sports has been transformed into
a huge global economy, it is important to note that the first step of
sport is usually its introduction to children at school through physical
education or PE. In other words, nations who do not win mega sport
competitions also suffer from a weak and neglected PE system. This
problem of the neglect of PE systems is the main motivation of this
research aimed at examining the factors affecting the perceived
awareness of physical education teachers on the ICTs that are
adoptable for the teaching and learning of physical education. Two
types of research objectives will materialize this aim: relevant
theories will be identified in relation to the analysis of the perceived
ICT awareness of PE teachers and subsequent models will be
compiled and designed from existing literature; the empirical testing
of such theories and models will also be achieved through the survey
of PE teachers from the Camperdown magisterial district of the
KwaZulu-Natal province of South Africa. The main hypothesis at the
heart of this study is the relationship between the demographics of PE
teachers, their behavior both as individuals and as social entities, and
their perceived awareness of the ICTs that are adoptable for PE, as
postulated by existing literature; except that this study categorizes
human behavior under performance expectancy, computer attitude,
and social influence. This hypothesis was partially confirmed by the
survey conducted by this research in the sense that performance
expectancy and teachers’ age, gender, computer usage, and class size
were found to be the only factors affecting their awareness of ICTs
for physical education.
Abstract: In this paper, numerical solution of system of
Fredholm and Volterra integral equations by means of the Spline
collocation method is considered. This approximation reduces the
system of integral equations to an explicit system of algebraic
equations. The solution is collocated by cubic B-spline and the
integrand is approximated by the Newton-Cotes formula. The error
analysis of proposed numerical method is studied theoretically. The
results are compared with the results obtained by other methods to
illustrate the accuracy and the implementation of our method.
Abstract: It’s an era of high competition, dynamism and
complexities which have forced organizations to change dramatically
due to rising customer expectations. Marketers are under constant
pressure to deliver finest to their customers. With the advent of
technology, marketers have identified latest advertising media
options to reach out to target audience. But the conventional ways of
print advertisements still holds a deeper penetration and coverage.
Various researchers and practitioners have studied the area of print
media advertising and have tried to identify and implement
advertisement effectiveness enablers. The purpose of this paper is to
suggest select enablers for print media in Indian context using an
integrated approach of review of literature and investigative
interviews with academicians and experts from the area of
advertising.
Abstract: Due to the advancement of Internet technology, online
learning is widely used in higher education institutions. Online
learning offers several means of communication, including online
forum. Through online forum, students and instructors are able to
discuss and share their knowledge and expertise without having a
need to attend the face-to-face, ordinary classroom session. The
purposes of this study are to analyze the students’ levels of
participation and critical thinking, types of action and factors
influencing their participation in online forum. A total of 41
postgraduate students undertaking a course in educational technology
from a public university in Malaysia were involved in this study. In
this course, the students participated in a weekly online forum as part
of the course requirement. Based on the log data file extracted from
the online forum, the students’ type of actions (view, add, update,
delete posts) and their levels of participation (passive, moderate or
active) were identified. In addition, the messages posted in the forum
were analyzed to gauge their level of critical thinking. Meanwhile,
the factors that might influence their online forum participation were
measured using a 24-items questionnaire. Based on the log data, a
total of 105 posts were sent by the participants. In addition, the
findings show that (i) majority of the students are moderate
participants, with an average of two to three posts per person, (ii)
viewing posts are the most frequent type of action (85.1%), and
followed by adding post (9.7%). Furthermore, based on the posts
they made, the most frequent type of critical thinking observed was
justification (50 input or 19.0%), followed by linking ideas and
interpretation (47 input or 18%), and novelty (38 input or 14.4%).
The findings indicate that online forum allows for social interaction
and can be used to measure the students’ critical thinking skills. In
order to achieve this, monitoring students’ activities in the online
forum is recommended.
Abstract: This paper presents the design analysis of saddle
support of a horizontal pressure vessel. Since saddle have the vital
role to support the pressure vessel and to maintain its stability, it
should be designed in such a way that it can afford the vessel load
and internal pressure of the vessel due to liquid contained in the
vessel. A model of horizontal pressure vessel and saddle support is
created in ANSYS. Stresses are calculated using mathematical
approach and ANSYS software. The analysis reveals the zone of high
localized stress at the junction part of the pressure vessel and saddle
support due to operating conditions. The results obtained by both the
methods are compared with allowable stress value for safe designing.
Abstract: Most quality models have defined usability as a
significant factor that leads to improving product acceptability,
increasing user satisfaction, improving product reliability, and also
financially benefitting companies. Usability is also the best factor that
balances both the technical and human aspects of a software product,
which is an important aspect in defining quality during software
development process. A usability risk consist risk factors that could
impact the usability of a software product thereby contributing to
negative user experiences and causing a possible software product
failure. Hence, it is important to mitigate and reduce usability risks in
the software development process itself. By managing possible
usability risks in software development process, failure of software
product could be reduced. Therefore, this research uses the Delphi
method to identify mitigation plans for reducing potential usability
risks. The Delphi method is conducted with seven experts from the
field of risk management and software development.
Abstract: Multiwall carbon nanotubes, prepared by chemical
vapor deposition, have an average diameter of 60-100 nm as shown
by High Resolution Transmittance Electron Microscope, HR-TEM.
The Multiwall carbon nanotubes (MWCNTs) were further
characterized using X-ray Diffraction and Raman Spectroscopy.
Mercury uptake capacity of MWCNTs was studied using batch
adsorption method at different concentration ranges up to 150 ppm.
Mercury concentration (before and after the treatment) was measured
using cold vapor atomic absorption spectroscopy. The effect of time,
concentration, pH and adsorbent dose were studied. MWCNT were
found to perform complete absorption in the sub-ppm concentrations
(parts per billion levels) while for high concentrations, the adsorption
efficiency was 92% at the optimum conditions; 0.1 g of the adsorbent
at 150 ppm mercury (II) solution. The adsorption of mercury on
MWCNTs was found to follow the Freundlich adsorption isotherm
and the pseudo-second order kinetic model.
Abstract: The aim of this paper is to propose a novel technique
to guarantee Quality of Service (QoS) in a highly dynamic
environment. The MANET changes its topology dynamically as the
nodes are moved frequently. This will cause link failure between
mobile nodes. MANET cannot ensure reliability without delay. The
relay node is selected based on achieving QoS in previous
transmission. It considers one more factor Connection Existence
Period (CEP) to ensure reliability. CEP is to find out the period
during that connection exists between the nodes. The node with
highest CEP becomes a next relay node. The relay node is selected
dynamically to avoid frequent failure. The bandwidth of each link
changed dynamically based on service rate and request rate. This
paper proposes Active bandwidth setting up algorithm to guarantee
the QoS. The series of results obtained by using the Network
Simulator (NS-2) demonstrate the viability of our proposed
techniques.
Abstract: Fritillaria oranensis (Liliaceae) was described in 1874
by pomel from Algeria. Plant samples have been collected from the
mount of Tessala (Sidi-Bel-Abbes). The morphological features of
various organs of the plant are described in detail. In the
morphological part of the study, features of various organs of the
plants such as stem and leaf were determined and illustrated.
Ecological studies provide information about the physical and
chemical structure of soil types in Tessala Mountain. The aim of this
original investigation is to put forth ecological and anatomical
features of these species for the first time, but at the same time given
detailed account of the morphological characteristics of the stem and
leaf of Fritillaria oranensis.
Abstract: Natural gas, as one of the most important sources of
energy for many of the industrial and domestic users all over the
world, has a complex, huge supply chain which is in need of heavy
investments in all the phases of exploration, extraction, production,
transportation, storage and distribution. The main purpose of supply
chain is to meet customers’ need efficiently and with minimum cost.
In this study, with the aim of minimizing economic costs, different
levels of natural gas supply chain in the form of a multi-echelon,
multi-period fuzzy linear programming have been modeled. In this
model, different constraints including constraints on demand
satisfaction, capacity, input/output balance and presence/absence of a
path have been defined. The obtained results suggest efficiency of the
recommended model in optimal allocation and reduction of supply
chain costs.
Abstract: The phased-array ultrasound transducer types are
utilities for medical ultrasonography as well as optical imaging.
However, their discontinuity characteristic limits the applications due
to the artifacts contaminated into the reconstructed images. Because
of the effects of the ultrasound pressure field pattern to the echo
ultrasonic waves as well as the optical modulated signal, the side
lobes of the focused ultrasound beam induced by discontinuity of the
phased-array ultrasound transducer might the reason of the artifacts.
In this paper, a simple method in approach of numerical simulation
was used to investigate the limitation of discontinuity of the elements
in phased-array ultrasound transducer and their effects to the
ultrasound pressure field. Take into account the change of ultrasound
pressure field patterns in the conditions of variation of the pitches
between elements of the phased-array ultrasound transducer, the
appropriated parameters for phased-array ultrasound transducer
design were asserted quantitatively.
Abstract: The aim of present study was to monitor the presence
of Trichodina sp. in Rainbow trout, Oncorhynchus mykiss collected
from various fish farms in the western provinces of Iran during
January, 2013- January, 2014. Out of 675 sampled fish 335, (49.16%)
were infested with Trichodina. The highest prevalence was observed
in the spring and winter followed by autumn and summer. In general,
the intensity of infection was low except in cases where outbreaks of
Trichodiniasis endangered the survival of fish in some ponds. In light
infestation Trichodina is usually present on gills, fins and skin of
apparently healthy fish. Clinical signs of Trichodiniasis only appear
on fish with heavy infections and cases of moderate ones that are
usually exposed to one or more stress factors including, rough
handling during transportation from ponds, overcrowdness,
malnutrition, high of free ammonia and low of oxygen concentration.
Clinical signs of Trichodiniasis in sampled fish were sluggish
movement, loss of appetite, black coloration, necrosis and ulcer on
different parts of the body, detached scales and excessive
accumulation of mucous in gill pouches. The most obvious
histopathological changes in diseased fish were sloughing of the
epidermal layer, aggregation of leucocytes and melanine-carrying
cells (between the dermis and hypodermis) and proliferative changes
including hyperplasia and hypertrophy of the epithelial lining cells of
gill filaments which resulted in fusion of secondary lamellae. Control
of Trichodiniasis, has been achieved by formalin bath treatment at a
concentration of 250 ppm for one hour.
Abstract: Stress Corrosion Crack (SCC) in pipeline is a type of
environmentally assisted cracking (EAC), since its discovery in 1965
as a possible cause of failure in pipeline, SCC has caused, on
average, one of two failures per year in the U.S, According to the
NACE SCC DA a pipe line segment is considered susceptible to SCC
if all of the following factors are met: The operating stress exceeds
60% of specified minimum yield strength (SMYS), the operating
temperature exceeds 38°C, the segment is less than 32 km
downstream from a compressor station, the age of the pipeline is
greater than 10 years and the coating type is other than Fusion
Bonded Epoxy(FBE). In this paper as a practical experience in
NISOC, Direct Assessment (DA) Method is used for identification
SCC defect in unpiggable pipeline located downstream of
compressor station.
Abstract: Kuosheng nuclear power plant (NPP) is a BWR/6 type
NPP and located on the northern coast of Taiwan. First, Kuosheng
NPP TRACE model were developed in this research. In order to assess
the system response of Kuosheng NPP TRACE model, startup tests
data were used to evaluate Kuosheng NPP TRACE model. Second, the
overpressurization transient analysis of Kuosheng NPP TRACE model
was performed. Besides, in order to confirm the mechanical property
and integrity of fuel rods, FRAPTRAN analysis was also performed in
this study.