Abstract: This paper reveals the interaction between hydrogen
and surface stress in austenitic stainless steel by X-ray diffraction
stress measurement and thermal desorption analysis before and after
being charged with hydrogen. The surface residual stress was varied
by surface finishing using several disc polishing agents. The obtained
results show that the residual stress near surface had a significant
effect on hydrogen absorption behavior, that is, tensile residual stress
promoted the hydrogen absorption and compressive one did opposite.
Also, hydrogen induced equi-biaxial stress and this stress has a linear
correlation with hydrogen content.
Abstract: In this paper a novel design of aerostatic thrust bearing
is proposed and is analyzed numerically. The capillary restrictor and
bearing disk are made of elastomer like silicone and PU. The
viscoelasticity of elastomer helps the capillary expand for more air
flux and at the same time, allows conicity of the bearing surface to
form when the air pressure is enhanced. Therefore the bearing has the
better ability of passive compensation. In the present example, as
compared with the typical model, the new designs can nearly double
the load capability and offer four times static stiffness.
Abstract: This paper presents the electromagnetic interference
(EMI) shielding effectiveness of rice husk and carbon nanotubes
(RHCNTs) composites in the X-band region (8.2-12.4 GHz). The
difference weight ratio of carbon nanotubes (CNTs) were mix with
the rice husk. The rectangular waveguide technique was used to
measure the complex permittivity of the RHCNTs composites
materials. The complex permittivity is represented in terms of both
the real and imaginary parts of permittivity in X-band frequency. The
conductivity of RHCNTs shows increasing when the ratio of CNTs
mixture increases. The composites materials were simulated using
Computer Simulation Technology (CST) Microwave Studio
simulation software. The shielding effectiveness of RHCNTs and
pure rice husk was compared. The highest EMI SE of 30 dB is
obtained for RHCNTs composites of 10 wt % CNTs with 10mm
thickness.
Abstract: Supermarkets are the most electricity-intensive type of
commercial buildings. The unsuitable indoor environment of a
supermarket provided by abnormal HVAC operations incurs waste
energy consumption in refrigeration systems. This current study
briefly describes significantly solid backgrounds and proposes easyto-
use analysis terminology for investigating the impact of HVAC
operations on refrigeration power consumption using the field-test
data obtained from building automation system (BAS). With solid
backgrounds and prior knowledge, expected energy interactions
between HVAC and refrigeration systems are proposed through
Pearson’s correlation analysis (R value) by considering correlations
between equipment power consumption and dominantly independent
variables (driving force conditions).The R value can be conveniently
utilized to evaluate how strong relations between equipment
operations and driving force parameters are. The calculated R values
obtained from field data are compared to expected ranges of R values
computed by energy interaction methodology. The comparisons can
separate the operational conditions of equipment into faulty and
normal conditions. This analysis can simply investigate the condition
of equipment operations or building sensors because equipment could
be abnormal conditions due to routine operations or faulty
commissioning processes in field tests. With systematically solid and
easy-to-use backgrounds of interactions provided in the present
article, the procedures can be utilized as a tool to evaluate the proper
commissioning and routine operations of HVAC and refrigeration
systems to detect simple faults (e.g. sensors and driving force
environment of refrigeration systems and equipment set-point) and
optimize power consumption in supermarket buildings. Moreover,
the analysis will be used to further study the FDD research for
supermarkets in future.
Abstract: The development of the agricultural sector in Ghana
has been reliant on the use of irrigation systems to ensure food
security. However, the manual operation of these systems has not
facilitated their maximum efficiency due to human limitations.
This paper seeks to address this problem by designing and
implementing an efficient, cost effective automated system which
monitors and controls the water flow of irrigation through
communication with an authorized operator via text messages. The
automatic control component of the system is timer based with an
Atmega32 microcontroller and a real time clock from the SM5100B
cellular module. For monitoring purposes, the system sends periodic
notification of the system on the performance of duty via SMS to the
authorized person(s). Moreover, the GSM based Irrigation
Monitoring and Control System saves time and labour and reduces
cost of operating irrigation systems by saving electricity usage and
conserving water.
Field tests conducted have proven its operational efficiency and
ease of assessment of farm irrigation equipment due to its costeffectiveness
and data logging capabilities.
Abstract: Renewable energy is derived from natural processes
that are replenished constantly. Included in the definition is
electricity and heat generated from solar, wind, ocean, hydropower,
biomass, geothermal resources, and bio-fuels and hydrogen derived
from renewable resources. Each of these sources has unique
characteristics which influence how and where they are used. This
paper presents the modeling the simulation of solar and hydro hybrid
energy sources in MATLAB/SIMULINK environment. It simulates
all quantities of Hybrid Electrical Power system (HEPS) such as AC
output current of the inverter that injected to the load/grid, load
current, grid current. It also simulates power output from PV and
Hydraulic Turbine Generator (HTG), power delivered to or from grid
and finally power factor of the inverter for PV, HTG and grid. The
proposed circuit uses instantaneous p-q (real-imaginary) power
theory.
Abstract: Students’ achievement and motivation in learning
English in Malaysia is a worrying trend as it is lagging behind several
other countries in Asia. Thus, necessary actions have to be taken by
the parties concerned to overcome this problem. The purpose of this
research was to study the effects of drill and practice courseware on
students’ achievement and motivation in learning English language.
A multimedia courseware was developed for this purpose. The
independent variable was the drill and practice courseware while the
dependent variables were the students’ achievement and motivation.
Their achievement was measured using pre-test and post-test scores,
while motivation was measured using a questionnaire. A total of 60
students from three vernacular primary schools in a northern state in
Malaysia were randomly selected in this study. The findings indicate:
(1) a significant difference between the students’ pre-test and posttest
scores after using the courseware, (2) no significant difference in
the achievement score between male and female students after using
the courseware, (3) a significant difference in motivation score
between the female and the male students, and (4) while the female
students scored significantly higher than the male students in the
aspects of relevance, confidence and satisfaction, no significant
difference in terms of attention was observed between them. Overall,
the findings clearly indicate that although the female students are
significantly more motivated than their male students, they are
equally good in terms of achievement after learning from the
courseware. Through this study, the drill and practice courseware is
proven to influence the students’ learning and motivation.
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.
Abstract: Folic acid (FA) is known to be an important
supplement to prevent neural tube defect (NTD) in pregnant women.
Similar to some commercial formulations, sodium bicarbonate
solution is used as a solvent for FA. This work uses the antisolvent
vapour precipitation (AVP), incorporating ethanol vapour as the
convective drying medium in place of air to produce branch-like
micro-structure FA particles. Interestingly, the dissolution rate of the
resultant particle is 2-3 times better than the particle produce from
conventional air drying due to the higher surface area of particles
produced. The higher dissolution rate could possibly improve the
delivery and absorption of FA in human body. This application could
potentially be extended to other commercial products, particularly in
less soluble drugs to improve its solubility.
Abstract: The 1/f noise investigation in nanoscale light-emitting
diodes and lasers, based on GaAs and alloys, is presented here.
Leakage and additional (to recombination through quantum wells
and/or dots) nonlinear currents were detected and it was shown that
these currents are the main source of the 1/f noise in devices studied.
Abstract: Mech-Degla, Degla-Beida and Frezza are the date
(Phoenix dactylifera L.) common varieties with a more or less good
availability and feeble trade value. Some morphologic and
physicochemical factors were determined. Results show that the
whole date weight is significantly different (P= 95%) concerning
Mech-Degla and Degla-Beida which are more commercialized than
Frezza whereas the pulp mass proportion in relation to whole fruits is
highest for Frezza (88.28%). Moreover, there is a large variability
concerning the weights and densities of constitutive tissues in each
variety. The white tissue is dominant in Mech-Degla in opposite to
the two other varieties. The variance analyze showed that the
difference in weights between brown and white tissues is significant
(P = 95%) for all studied varieties. Some other morphologic and
chemical proprieties of the whole pulps and their two constitutive
parts (brown or pigmented and white) are also investigated. The
predominance of phenolics in Mech-Degla (4.01g/100g, w.b) and
Frezza (4.96 g/100g, w.b) pulps brown part is the main result
revealed in this study.
Abstract: Theoretical optimization of a copper-water negative
inclination heat pipe with internal composite wick structure had been
performed, regarding a new introduced parameter: the ratio between
the coarse mesh wraps and the fine mesh wraps of the composite
wick. Since in many cases, the design of a heat pipe matches specific
thermal requirements and physical limitations, this work
demonstrates the optimization of a 1m length, 8mm internal diameter
heat pipe without an adiabatic section, at a negative inclination angle
of -10º. The optimization is based on a new introduced parameter, LR:
the ratio between the coarse mesh wraps and the fine mesh wraps.
Abstract: Advances technology in the field of photogrammetry
replaces analog cameras with reflection on aircraft GPS/IMU system
with a digital aerial camera. In this system, when determining the
position of the camera with the GPS, camera rotations are also
determined by the IMU systems. All around the world, digital aerial
cameras have been used for the photogrammetry applications in the
last ten years. In this way, in terms of the work done in
photogrammetry it is possible to use time effectively, costs to be
reduced to a minimum level, the opportunity to make fast and
accurate.
Geo-referencing techniques that are the cornerstone of the GPS /
INS systems, photogrammetric triangulation of images required for
balancing (interior and exterior orientation) brings flexibility to the
process. Also geo-referencing process; needed in the application of
photogrammetry targets to help to reduce the number of ground
control points. In this study, the use of direct and indirect georeferencing
techniques on the accuracy of the points was investigated
in the production of photogrammetric mapping.
Abstract: Persea declinata (Bl.) Kosterm is a member of the
Lauraceae family, widely distributed in Southeast Asia. It is from the
same genus with avocado (Persea americana Mill), which is widely
consumed as food and for medicinal purposes. In the present study,
we examined the anticancer properties of Persea declinata (Bl.)
Kosterm bark methanolic crude extract (PDM). PDM exhibited a
potent antiproliferative effect in MCF-7 human breast cancer cells,
with an IC50 value of 16.68 .g/mL after 48h of treatment. We
observed that PDM caused cell cycle arrest and subsequent apoptosis
in MCF-7 cells, as exhibited by increased population at G0/G1 phase,
higher lactate dehydrogenase (LDH) release, and DNA
fragmentation. Mechanistic studies showed that PDM caused
significant elevation in ROS production, leading to perturbation of
mitochondrial membrane potential, cell permeability, and activation
of caspases-3/7. On the other hand, real-time PCR and Western blot
analysis showed that PDM treatment increased the expression of the
proapoptotic molecule, Bax, but decreased the expression of
prosurvival proteins, Bcl-2 and Bcl-xL, in a dose-dependent manner.
These findings imply that PDM could inhibit proliferation in MCF-7
cells via cell cycle arrest and apoptosis induction, indicating its
potential as a therapeutic agent worthy of further development.
Abstract: Opportunistic routing is used, where the network has
the features like dynamic topology changes and intermittent network
connectivity. In Delay tolerant network or Disruption tolerant
network opportunistic forwarding technique is widely used. The key
idea of opportunistic routing is selecting forwarding nodes to forward
data packets and coordination among these nodes to avoid duplicate
transmissions. This paper gives the analysis of pros and cons of
various opportunistic routing techniques used in MANET.
Abstract: This paper presents the design and analysis of Liquid
Crystal (LC) based tunable reflectarray antenna with different design
configurations within X-band frequency range. The effect of LC
volume used for unit cell element on frequency tunability and
reflection loss performance has been investigated. Moreover different
slot embedded patch element configurations have been proposed for
LC based tunable reflectarray antenna design with enhanced
performance. The detailed fabrication and measurement procedure
for different LC based unit cells has been presented. The waveguide
scattering parameter measured results demonstrated that by using the
circular slot embedded patch elements, the frequency tunability and
dynamic phase range can be increased from 180MHz to 200MHz and
120° to 124° respectively. Furthermore the circular slot embedded
patch element can be designed at 10GHz resonant frequency with a
patch volume of 2.71mm3 as compared to 3.47mm3 required for
rectangular patch without slot.
Abstract: Azadirachta excelsa or locally known as sentang are
frequently used as a traditional medicine by diabetes patients in
Malaysia. However, less attention has been given to their toxicity
effect. Thus, the study is an attempt to examine the protective effect
of A. excelsa on the pancreas and to determine possible toxicity
mediated by the extract. Diabetes was induced experimentally in rats
by high-fat-diet for 16 weeks followed by intraperitoneal injection of
streptozotocin at dosage of 35 mg/kg of body weight. Declination of
the fasting blood glucose level was observed after continuous
administration of A. excelsa for 14 days twice daily. This is due to the
refining structure of the pancreas. However, surprisingly, the plant
extract reduced the leukocytes, erythrocytes, hemoglobin, MCHC and
lymphocytes. In addition, the rat treated with the plant extract
exhibited increment in AST and eosinocytes level. Overall, the
finding shows that A. excelsa possesses antidiabetic activity by
improving the structure of pancreatic islet of Langerhans but
involved in ameliorating of hematology and biochemical parameters.
Abstract: In this study, six bacterial isolates of a slightly
thermophilic organism from the Sg. Klah hot spring, Malaysia were
successfully isolated and designated as M7T55D1, M7T55D2,
M7T55D3, M7T53D1, M7T53D2 and M7T53D3 respectively. The
bacterial isolates were screened for their cellulose hydrolytic ability
on Carboxymethlycellulose agar medium. The isolated bacterial
strains were identified morphologically, biochemically and
molecularly with the aid of 16S rDNA sequencing. All of the bacteria
showed their optimum growth at a slightly alkaline pH of 7.5 with a
temperature of 55°C. All strains were Gram-negative, non-spore
forming type, strictly aerobic, catalase-positive and oxidase-positive
with the ability to produce thermostable cellulase. Based on BLASTn
results, bacterial isolates of M7T55D2 and M7T53D1 gave the
highest homology (97%) with similarity to Tepidimonas ignava while
isolates M7T55D1, M7T55D3, M7T53D2 and M7T53D3 showed
their closest homology (97%-98%) with Tepidimonas thermarum.
These cellulolytic thermophiles might have a commercial potential to
produce valuable thermostable cellulase.
Abstract: This paper presents the design and analysis of Liquid
Crystal (LC) based tunable reflectarray antenna with different design
configurations within X-band frequency range. The effect of LC
volume used for unit cell element on frequency tunability and
reflection loss performance has been investigated. Moreover different
slot embedded patch element configurations have been proposed for
LC based tunable reflectarray antenna design with enhanced
performance. The detailed fabrication and measurement procedure
for different LC based unit cells has been presented. The waveguide
scattering parameter measured results demonstrated that by using the
circular slot embedded patch elements, the frequency tunability and
dynamic phase range can be increased from 180MHz to 200MHz and
120° to 124° respectively. Furthermore the circular slot embedded
patch element can be designed at 10GHz resonant frequency with a
patch volume of 2.71mm3 as compared to 3.47mm3 required for
rectangular patch without slot.