Abstract: Thermoacoustic refrigerator is a cooling device which
uses the acoustic waves to produce the cooling effect. The aim of this
paper is to explore the experimental and numerical feasibility of a
standing-wave thermoacoustic refrigerator. The effects of the stack
length, position of stack and operating frequency on the cooling
performance are carried out. The circular pore stacks are tested under
the atmospheric pressure. A low-cost loudspeaker is used as an
acoustic driver. The results show that the location of stack installed in
resonator tube has a greater effect on the cooling performance, than
the stack length and operating frequency, respectively. The
temperature difference across the ends of stack can be generated up
to 13.7°C, and the temperature of cold-end is dropped down by 5.3°C
from the ambient temperature.
Abstract: A seizure prediction method is proposed by extracting
global features using phase correlation between adjacent epochs for
detecting relative changes and local features using fluctuation/
deviation within an epoch for determining fine changes of different
EEG signals. A classifier and a regularization technique are applied
for the reduction of false alarms and improvement of the overall
prediction accuracy. The experiments show that the proposed method
outperforms the state-of-the-art methods and provides high prediction
accuracy (i.e., 97.70%) with low false alarm using EEG signals in
different brain locations from a benchmark data set.
Abstract: The purpose of the study is to investigate the level of
intrinsic motivation of trainers after attending a Continuous
Professional Development Course (CPD) organized by Institute of
Teacher Training Malaysia titled, “Transformation of Teaching and
Learning the Fun Way”. This study employed a survey whereby 96
teacher trainers were given Situational Intrinsic Motivational Scale
(SIMS) Instruments. Confirmatory factor analysis was carried out to
get the validity of this instrument in local setting. Data were analyzed
with SPSS for descriptive statistic. Semi- structured interviews were
also administrated to collect qualitative data on participants’
experiences after participating in the two-day fun-filled program. The
findings showed that the participants’ level of intrinsic motivation
showed higher mean than the amotivation. The results revealed that
the intrinsic motivation mean is 19.0 followed by Identified
regulation with a mean of 17.4, external regulation 9.7 and
amotivation 6.9. The interview data also revealed that the participants
were motivated after attending this training program. It can be
concluded that this program, which was organized by Institute of
Teacher Training Malaysia, was able to enhance participants’ level of
motivation. Self-Determination Theory (SDT) as a multidimensional
approach to motivation was utilized. Therefore, teacher trainers may
have more success using the “The fun way approach” in conducting
training program in future.
Abstract: The power electronic components within Electric Vehicles (EV) need to operate in several important modes. Some modes directly influence safety, while others influence vehicle performance. Given the variety of functions and operational modes required of the power electronics, it needs to meet efficiency requirements to minimize power losses. Another challenge in the control and construction of such systems is the ability to support bidirectional power flow. This paper considers the construction, operation, and feasibility of available converters for electric vehicles with feasible configurations of electrical buses and loads. This paper describes logic and control signals for the converters for different operations conditions based on the efficiency and energy usage bases.
Abstract: The transesterification of dimethyl malonate (DMM)
with phenol has been studied in vapour phase over cordierite
honeycomb coated with solid acid catalysts such as ZrO2,
Mo(VI)/ZrO2 and SO42-/ZrO2. The catalytic materials were prepared
honeycomb coated, powder forms, and characterized for their total
surface acidity by NH3-TPD and crystalinity by powder XRD
methods. Phenyl methyl malonate (PMM) and diphenyl malonate
(DPM) were obtained as the reaction products. A good conversion of
DMM (up to 82%) of MPM with 95% selectivity was observed when
the reactions were carried out at a catalyst bed temperature of 200 °C
and flow-rate of 10 mL/h in presence of Mo(VI)/ZrO2 as catalyst.
However, over SO4^2-/ZrO2 catalyst, the yield of DPM was found to be
higher. The results have been interpreted based on the variation of
acidic properties and powder XRD phases of zirconia on
incorporation of Mo(VI) or SO42– ions. Transesterification reactions
were also carried out over powder forms of the catalytic materials
and the yield of the desired phenyl ester products were compared
with that of the HC coated catalytic materials. The solid acids were
found to be reusable when used for at least 5 reaction cycles.
Abstract: A model to predict the plastic zone size for material
under plane stress condition has been developed and verified
experimentally. The developed model is a function of crack size,
crack angle and material property (dislocation density). Simulation
and validation results show that the model developed show good
agreement with experimental results. Samples of low carbon steel
(0.035%C) with included surface crack angles of 45o, 50o, 60o, 70o
and 90o and crack depths of 2mm and 4mm were subjected to low
strain rate between 0.48 x 10-3 s-1 – 2.38 x 10-3 s-1. The mechanical
properties studied were ductility, tensile strength, modulus of
elasticity, yield strength, yield strain, stress at fracture and fracture
toughness. The experimental study shows that strain rate has no
appreciable effect on the size of plastic zone while crack depth and
crack angle plays an imperative role in determining the size of the
plastic zone of mild steel materials.
Abstract: Production fluids are transported from the platform to
tankers or process facilities through transfer pipelines. Water being
one of the heavier phases tends to settle at the bottom of pipelines
especially at low flow velocities and this has adverse consequences
for pipeline integrity. On restart after a shutdown, this could result in
corrosion and issues for process equipment, thus the need to have the
heavier liquid dispersed into the flowing lighter fluid. This study
looked at the flow regime of low water cut and low flow velocity oil
and water flow using conductive film thickness probes in a large
diameter 4-inch pipe to obtain oil and water interface height and the
interface structural velocity. A wide range of 0.1–1.0 m/s oil and
water mixture velocities was investigated for 0.5–5% water cut. Two
fluid model predictions were used to compare with the experimental
results.
Abstract: The modelling of physical phenomena, such as the
earth’s free oscillations, the vibration of strings, the interaction of
atomic particles, or the steady state flow in a bar give rise to Sturm-
Liouville (SL) eigenvalue problems. The boundary applications of
some systems like the convection-diffusion equation, electromagnetic
and heat transfer problems requires the combination of Dirichlet and
Neumann boundary conditions. Hence, the incorporation of Robin
boundary condition in the analyses of Sturm-Liouville problem. This
paper deals with the computation of the eigenvalues and
eigenfunction of generalized Sturm-Liouville problems with Robin
boundary condition using the finite element method. Numerical
solution of classical Sturm–Liouville problem is presented. The
results show an agreement with the exact solution. High results
precision is achieved with higher number of elements.
Abstract: Global economy today is full of sophistication. All
over the world, business and marketing practices are undergoing
unprecedented transformation. In realization of this fact, the federal
government of Nigeria has put in place a robust transformation
agenda in order to put Nigeria in a better position to be a competitive
player and in the process transform all sectors of its economy. New
technologies, especially the Internet, are the driving force behind this
transformation. However, technology has inadvertently affected the
way businesses are done thus necessitating the acquisition of new
skills. In developing countries like Nigeria, citizens are still battling
with effective application of those technologies. Obviously, students
of business education need to acquire relevant business knowledge to
be able to transit into the world of work on graduation from school
and compete favorably in the labor market. Therefore, effective
utilization of social media by both teachers and students can help
extensively in empowering students with the needed skills. Social
media which is a group of Internet-based applications built on the
ideological foundations of Web 2.0, that allow the creation and
exchange of user generated content, and if incorporated into the
classroom experience may be the needed answer to unemployment
and poverty in Nigeria as beneficiaries can easily connect with
existing and potential enterprises and customers, engage with them
and reinforce mutual business benefits. Challenges and benefits of
social media use in education in Nigeria universities were revealed in
this study.
Abstract: This research was made during the 2015 growing
periods in the trial filed of "Research Station for Department of Field
Crops, Agricultural Faculty, Selcuk University" according to
“Randomized Blocks Design” with 3 replications. Research material
was the following pea lines; PS16, PS18, PS21, PS23, PS24, PS25,
PS36, PS47, PS49, PS51, PS54, PS58, PS67, PS69, PS71, PS73,
PS83, PS84, PS87 and PSKY and three cultivars and other 2
commercial varieties named as Bolero, Rondo and Ultrello. Some
agronomical characteristics such as plant height (cm) number of pod
per plant number of seed per pod number of seed per plant 100 seed
weight (g) and seed yield (kg ha-1) were determined. The highest seed
yield was obtained 2727.0 kg ha-1 in the PS71 line and the lowest
value was obtained 1238.0 kg ha-1 in the commercial variety of
Bolero. Results of the research implicated that the new developed
lines were superior compared with the control (commercial) varieties
by means of most of the characteristics. Nevertheless, similar
researches should be continued in different locations and years.
Abstract: This research aimed to investigate the relationship
between attitude towards marketing mix, brand image and consumer
behavior of the passengers of low-cost airlines service. This study
employed by quantitative research and the questionnaire was used to
collect the data from 400 sampled of the passengers who have ever
used the low-cost airline services based in Bangkok, Thailand. The
descriptive statistics and Pearson’s correlation analysis were used to
analyze data. The research results revealed that the attitude of the marketing mix
of the low-cost airline services including product, price, place,
promotion and process had related to the consumer behavior on the
aspects of duration of service and frequency of service. While, the
brand image of the low cost airline including the characteristics of
organization, service quality and company identity had related to the
consumer behavior on duration of service, frequency of service and
cost of service at the significant statistically acceptable levels.
Abstract: This study aims to examine the sensory quality of
meatballs made from Balinese beef and buffalo meat after the
addition of smoke powder prior to storage at the temperatures of 2-
5°C for 7 days. This study used meat from Longissimus dorsi muscle
of male Balinese cattle aged 3 years and of male buffalo aged 5 years
as the main raw materials, and smoke powder as a binder and
preservative in making meatballs. The study was based on completely
randomized design (CRD) of factorial pattern of 2 x 3 x 2 where
factors 1, 2 and 3 included the types of meat (cattle and buffalo),
types of smoke powder (oven dried, freeze dried and spray dried)
with a level of 2% of the weight of the meat (w/w), and storage
duration (0 and 7 days) with three replications, respectively. The
parameters measured were the meatball sensory quality (scores of
tenderness, firmness, chewing residue, and intensity of flavor). The
results of this study show that each type of meat has produced
different sensory characteristics. The meatballs made from buffalo
meat have higher tenderness and elasticity scores than the Balinese
beef. Meanwhile, the buffalo meatballs have a lower residue
mastication score than the Balinese beef. Each type of smoke
powders has produced a relatively similar sensory quality of
meatballs. It can be concluded that the smoke powder of 2% of the
weight of the meat (w/w) could maintain the sensory quality of the
meatballs for 7 days of storage.
Abstract: The aim of this study is to evaluate the effect of
supplementing broiler starter diet with different levels of an essential
oil blend (EOB) containing capsaicin, carvacrol and cinnamaldehyde
on the performance of broilers. A total of 300 day-old straight-run
Cobb broiler chicks were randomly assigned to three treatments after
7-day group brooding following a completely randomized design
(CRD). Birds assigned in treatment 1 were given starter basal diet
while those in treatments 2 and 3 were given starter basal diet with
400 mg/kg antibiotic growth promoter (AGP) and 150 mg/kg EOB,
respectively, until the 28th day. Basal finisher feed were given for all
the treatments until harvest. Following 37 d feeding, body weight
gain, feed consumption, feed efficiency, dressing percentage,
livability and jejunal villi height were determined. Results showed no
significant differences (P>0.05) in growth performance. However,
villi height and crypt depth was significantly lower for birds fed
EOB.
Abstract: In Algeria, the conditioning units of dates, generate
significant quantities of waste arising from sorting deviations. This
biomass, until then considered as a waste with high impact on the
environment can be transformed into high value added product. It is
possible to develop common dates of low commercial value, and put
on the local and international market a new generation of products
with high added values such as bio ethanol. Besides its use in
chemical synthesis, bio ethanol can be blended with gasoline to
produce a clean fuel while improving the octane.
Abstract: Geological and tectonic framework indicates that
Bangladesh is one of the most seismically active regions in the world.
The Bengal Basin is at the junction of three major interacting plates:
the Indian, Eurasian, and Burma Plates. Besides there are many
active faults within the region, e.g. the large Dauki fault in the north.
The country has experienced a number of destructive earthquakes due
to the movement of these active faults. Current seismic provisions of
Bangladesh are mostly based on earthquake data prior to the 1990.
Given the record of earthquakes post 1990, there is a need to revisit
the design provisions of the code. This paper compares the base shear
demand of three major cities in Bangladesh: Dhaka (the capital city),
Sylhet, and Chittagong for earthquake scenarios of magnitudes
7.0MW, 7.5MW, 8.0MW, and 8.5MW using a stochastic model. In
particular, the stochastic model allows the flexibility to input region
specific parameters such as shear wave velocity profile (that were
developed from Global Crustal Model CRUST2.0) and include the
effects of attenuation as individual components. Effects of soil
amplification were analysed using the Extended Component
Attenuation Model (ECAM). Results show that the estimated base
shear demand is higher in comparison with code provisions leading to
the suggestion of additional seismic design consideration in the study
regions.
Abstract: Rotary entrainment is a phenomenon in which the
interface of two immiscible fluids are subjected to external flux by
means of rotation. Present work reports the experimental study on
rotary motion of a horizontal cylinder between the interface of air and
water to observe the penetration of gas inside the liquid. Experiments
have been performed to establish entrainment of air mass in water
alongside the cylindrical surface. The movement of tracer and seeded
particles has been tracked to calculate the speed and path of the
entrained air inside water. Simplified particle image velocimetry
technique has been used to trace the movement of particles/tracers at
the moment they are injected inside the entrainment zone and
suspended beads have been used to replicate the particle movement
with respect to time in order to determine the flow dynamics of the
fluid along the cylinder. Present paper establishes a thorough experimental analysis of the
rotary entrainment phenomenon between air and water keeping in
interest the extent to which we can intermix the two and also to study
its entrainment trajectories.
Abstract: In this paper, we have reported birefringence
manipulation in regenerated high birefringent fiber Bragg grating
(RPMG) by using CO2 laser annealing method. The results indicate
that the birefringence of RPMG remains unchanged after CO2 laser
annealing followed by slow cooling process, but reduced after fast
cooling process (~5.6×10-5). After a series of annealing procedures
with different cooling rates, the obtained results show that slower the
cooling rate, higher the birefringence of RPMG. The volume, thermal
expansion coefficient (TEC) and glass transition temperature (Tg)
change of stress applying part in RPMG during cooling process are
responsible for the birefringence change. Therefore, these findings
are important to the RPMG sensor in high and dynamic temperature
environment. The measuring accuracy, range and sensitivity of
RPMG sensor is greatly affected by its birefringence value. This
work also opens up a new application of CO2 laser for fiber annealing
and birefringence modification.
Abstract: Unsteady flow and heat transfer from a circular
cylinder in cross-flow is studied numerically. The governing
equations are solved by using finite volume method. Reynolds
number varies in range of 50 to 200; in this range flow is considered
to be laminar and unsteady. Al2O3 nanoparticle with volume fraction
in range of 5% to 20% is added to pure water. Effects of adding
nanoparticle to pure water on lift and drag coefficient and Nusselt
number is presented. Addition of Al2O3 has inconsiderable effect on
the value of drags and lift coefficient. However, it has significant
effect on heat transfer; results show that heat transfer of Al2O3
nanofluid is about 9% to 36% higher than pure water.
Abstract: Monitoring the conditions of rotating machinery, such
as bearings, is important in order to improve the stability of work.
Acoustic Emission (AE) and vibration analysis are some of the most
accomplished techniques used for this purpose. Acoustic emission
has the ability to detect the initial phase of component degradation.
Moreover, it has been observed that vibration analysis is not as
successful at low rotational speeds (below 100 rpm). This because the
energy generated within this speed region is not detectable using
conventional vibration. From this perspective, this paper has
presented a brief review of using acoustic emission techniques for
monitoring bearing conditions.
Abstract: Internship is a supervised and structured learning
experience related to one’s field of study or career goal. Internship
allows students to obtain work experience and the opportunity to
apply skills learned during university. Internship is a valuable
learning experience for students; however, literature on employer
assessment is scarce on Malaysian student’s internship experience.
This study focuses on employer’s perspective on student’s
performances during their three months of internship. The results are
based on the descriptive analysis of 45 sets of question gathered from
the on-site supervisors of the interns. The survey of 45 on-site
supervisor’s feedback was collected through postal mail. It was found
that, interns have not met their on-site supervisor’s expectations in
many areas. The significance of this study is employer’s assessment
on the internship shall be used as feedback to improve on ways how
to prepare students for their internship and employments in future.