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: In this paper, the effect of admixtures on the tensional
strength of concrete in Urmia-lake water have been investigated. We
made different types of concretes with the ratio of w/c and replaced
different percentages of micro-silica, air-entraining, super plasticizer,
corrosion-inhibiting, and caulk with two types of cement I and II as
well as investigating in both ordinary water and Urmia-lake water.
The tensional strength was investigated on these samples.
Abstract: Cement-based grouts has been used successfully to
repair cracks in many concrete structures such as bridges, tunnels,
buildings and to consolidate soils or rock foundations. In the present
study the rheological characterization of cement grout with
water/binder ratio (W/B) is fixed at 0.5. The effect of the replacement
of cement by bentonite (2 to 10% wt) in presence of superplasticizer
(0.5% wt) was investigated. Several rheological tests were carried out
by using controlled-stress rheometer equipped with vane geometry in
temperature of 20°C. To highlight the influence of bentonite and
superplasticizer on the rheological behavior of grout cement, various
flow tests in a range of shear rate from 0 to 200 s-1 were observed.
Cement grout showed a non-Newtonian viscosity behavior at all
concentrations of bentonite. Three parameter model Herschel-
Bulkley was chosen for fitting of experimental data. Based on the
values of correlation coefficients of the estimated parameters, The
Herschel-Bulkley law model well described the rheological behavior
of the grouts. Test results showed that the dosage of bentonite
increases the viscosity and yield stress of the system and introduces
more thixotropy. While the addition of both bentonite and
superplasticizer with cement grout improve significantly the fluidity
and reduced the yield stress due to the action of dispersion of SP.
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 order to study the effect of drought stress on grain
yield, yield components and associated traits of durum wheat
cultivars, an experiment was done as split plot arrangement using
randomized complete block design with three replications in Ilam
province, Iran in 2009-2010 cropping season. Different levels of
irrigation (Full irrigation, drought stress at stem elongation,
Flowering and grain formation stages) were considered as a main plot
and three durum wheat cultivars (Yavaros, Seimareh and Karkheh)
were assigned as a sub plot. The results showed that drought stress
was significant on grain yield, spike.m-2, grain. Spike-1, 1000-grain
weight, biological yield, harvest index and protein content. Drought
stress at all stages caused a loss in grain yield and its components.
Full irrigation had the highest grain yield and yield components.
Drought stress at stem elongation, flowering and grain formation
stages caused a reduction in spike.m-2, grain.spike-1 and 1000-grain
weight, respectively. Protein content was significantly affected by
drought stress. The highest protein content was obtained from
drought stress at grain formation stage. Cultivars had an influence on
grain yield and yield components. Yavaros and Seimareh cultivars
had the highest and lowest grain yield, respectively. Interaction effect
between drought stress and cultivar had a significant effect on grain
and yield components. Full irrigation and Yavaros cultivar had the
highest grain yield and drought stress at grain formation stage and
Seimareh cultivar had the lowest grain yield, respectively.
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: Different services based on different switching
techniques in wireless networks leads to drastic changes in the
properties of network traffic. Because of these diversities in services,
network traffic is expected to undergo qualitative and quantitative
variations. Hence, assumption of traffic characteristics and the
prediction of network events become more complex for the wireless
networks. In this paper, the traffic characteristics have been studied
by collecting traces from the mobile switching centre (MSC). The
traces include initiation and termination time, originating node, home
station id, foreign station id. Traffic parameters namely, call interarrival
and holding times were estimated statistically. The results
show that call inter-arrival and distribution time in this wireless
network is heavy-tailed and follow gamma distributions. They are
asymptotically long-range dependent. It is also found that the call
holding times are best fitted with lognormal distribution. Based on
these observations, an analytical model for performance estimation is
also proposed.
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: In this paper a scheme is proposed for generating
a programmable current reference which can be implemented
in the CMOS technology. The current can be varied over a
wide range by changing an external voltage applied to one
of the control gates of FGMOS (Floating Gate MOSFET).
For a range of supply voltages and temperature, CMOS
current reference is found to be dependent, this dependence
is compensated by subtracting two current outputs with the
same dependencies on the supply voltage and temperature.
The system performance is found to improve with the
use of FGMOS. Mathematical analysis of the proposed
circuit is done to establish supply voltage and temperature
independence. Simulation and performance evaluation of the
proposed current reference circuit is done using TANNER
EDA Tools. The current reference shows the supply and
temperature dependencies of 520 ppm/V and 312 ppm/oC,
respectively. The proposed current reference can operate down
to 0.9 V supply.
Abstract: With advances in solid-state power electronic devices
and microprocessors, various pulse-width-modulation (PWM)
techniques have been developed for industrial applications. This
paper presents the comparison of two different PWM techniques, the
sinusoidal PWM (SPWM) technique and the space-vector PWM
(SVPWM) technique applied to two level VSI for micro grid
applications. These two methods are compared by discussing their
ease of implementation and by analyzing the output harmonic spectra
of various output voltages (line-to-neutral voltages, and line-to-line
voltages) and their total harmonic distortion (THD). The SVPWM
technique in the under-modulation region can increase the
fundamental output voltage by 15.5% over the SPWM technique.
Abstract: The current study explored the effect of economic
development, financial development and institutional quality on
environmental destruction in upper-middle income countries during
the time period of 1999-2011. The dependent variable is logarithm of
carbon dioxide emissions that can be considered as an index for
destruction or quality of the environment given to its effects on the
environment. Financial development and institutional development
variables as well as some control variables were considered. In order
to study cross-sectional correlation among the countries under study,
Pesaran and Friz test was used. Since the results of both tests show
cross-sectional correlation in the countries under study, seemingly
unrelated regression method was utilized for model estimation. The
results disclosed that Kuznets’ environmental curve hypothesis is
confirmed in upper-middle income countries and also, financial
development and institutional quality have a significant effect on
environmental quality. The results of this study can be considered by
policy makers in countries with different income groups to have
access to a growth accompanied by improved environmental quality.
Abstract: The objective of this study is to analyze the
prophylactic usage of low molecular weight heparin (LMWH) along
pregnancy and the correlation between their usage and month/week
of pregnancy, in the Department of Gynecology and Obstetrics, at
Clinical Hospital in Tetovo. A retrospective study was undertaken
during 01 January – 31 December 2012. Over of one year, the total
number of patients was 4636. Among the 1447 (32.21%) pregnant
women, 298 (20.59%) of them were prescribed LMWH. The majority
of patients given LMWH, 119 (39.93%) were diagnosed
hypercoagulable. The age group with the highest attendance was 25-
35, 141 patients (47.32%). For 195 (65.44%) patients, this was their
first pregnancy. Earliest stage of using LMWH was the second month
of pregnancy 4 (1.34%) cases. The most common patients were 70
women along the seventh month (23.49%), followed by 68 in the
ninth month of pregnancy (22.81%). Women in the 28th gestational
week, were found to be the most affected, a total of 55 (78.57%) were
in that week. Clexane 2000 and Fraxiparine 0.3 were the most
common for which low molecular weight heparin was prescribed.
The number of patients which received Clexane 2000 was 84
(28.19%), followed by those with Fraxiparine 0.3 81 (27.18%). The
administration of LMWH is associated with long hospitalization
(median 14,6 days).
Abstract: Since the emergence of e-Commerce, the world of
business has witnessed a radical shift in the way business activities
are conducted. However, the emergence of m-Commerce has further
pushed the boundaries of virtual commerce revolution. As a result,
there seems to be a growing blur in the distinction between e-
Commerce and m-Commerce. In addition, existing definitions for
both forms of commerce highlight characteristics (e.g. type of device
and activity conducted) that may be applicable to both concepts. The
aim of this paper is to identify the characteristics that help define and
delineate between e- and m- Commerce. The paper concludes that
characteristics of mobility, ubiquity and immediacy provide a clearer
and simpler template to distinguish between e-Commerce and m-
Commerce.
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: 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: The purpose of this study was to investigate graduate
students’ visual attention and perceptions of a Prezi presentation. Ten
postgraduate master students were presented with a Prezi presentation
at the Centre for Instructional Technology and Multimedia, Universiti
Sains Malaysia (USM). The eye movement indicators such as dwell
time, average fixation on the areas of interests, heat maps and focus
maps were abstracted to indicate the students’ visual attention.
Descriptive statistics was employed to analyze the students’
perception of the Prezi presentation in terms of text, slide design,
images, layout and overall presentation. The result revealed that the
students paid more attention to the text followed by the images and
sub heading presented through the Prezi presentation.
Abstract: The sub-task pattern in terms of deviations and defects
should be identified and understood in order to improve the quality of
practices in construction projects. Therefore, sub-task susceptibility
to exposure to deviations and defects has been evaluated and
classified via six classifications proposed in this study. Thirty-four
case studies of specific sub-tasks (from compression members in
constructed concrete structures) were collected from seven
construction projects in order to examine the study’s proposed
classifications. The study revealed that the sub-task has a high
sensitivity to deviation, where 91% of the cases were recorded as
deviations; however, only 19% of cases were recorded as defects.
Other findings were that the actual work during the execution process
is a high source of deviation for this sub-task (74%), while only 26%
of the source of deviation was due to both design documentation and
the actual work. These findings significantly imply that the study’s
proposed classifications could be used to determine the pattern of
each sub-task and develop proactive actions to overcome issues of
sub-task deviations and defects.
Abstract: Off-site construction methods have played an
important role in the construction sector in the past few decades. It is
increasingly becoming a major alternative technique and strategic
direction compared to traditional in-situ method. It produces a
significant amount of value for the construction industry and the
economy more generally. To date, an impressive number of studies
have been lunched on the perceived perception of off-site
construction. However, it seems that a quantifying benefit on the
offsite construction area is lacking. Therefore, this paper examines
the recent research literature on the benefits of off- site construction
and provides future direction. In the beginning, this paper provides a
brief history and current value of the off-site construction followed
by a detailed discussion on the benefit of off-site construction. These
benefits include but not limited to time saving, quality improvement,
relieving skills shortages, cost reduction and productivity
improvement. Toward this end, off-site construction should learn
from other productive industry similar to services or manufacturing
industry by applying operational management tools and techniques
with extensive focus on employee empowerment will shed the light
on future uptake of Off-site construction. This study is of value in
providing scholars have a clear picture of perceived benefit of off-site
construction research and give an opportunities for future uptake of
off-site method.
Abstract: This experimental study aims at studying the
conversion of macro-algae into bioethanol under several steps of
procedure: preparation, pre-treatment, fermentation, and distillation.
The main objective of this work was to investigate the role of buffer’s
type as a stabiliser of pH level and fermentation time on the yield of
ethanol. For this purpose, experiments were carried out on biomass
macro-algae to de-couple the pre-treatment and fermentation
processes from those associated with distillation process. β-
glucosidase was used as cellulose decomposer during hydrolysis step
and yeast was used during fermentation process. The species of
macro-algae utilised as energy feedstock was Ulva lactuca and it was
harvested from southern coast of Central of Java Island – Indonesia.
Experiments were conducted in a simple fermenter over a different
buffer: citrate buffer and acetic buffer, and over a range of
fermentation times between 5 to 20 days. The ethanol production was
found to be significantly affected by both variables. The optimum
time of fermentation was 10 days with citrate buffer; result in
0.88458% of ethanol, and the ethanol content after distillation
process was shown 0.985015%.
Abstract: Cloud service brokering is a new service paradigm that
provides interoperability and portability of application across multiple
Cloud providers. In this paper, we designed Cloud service brokerage
system, anyBroker, supporting integrated service provisioning and
SLA based service lifecycle management. For the system design, we
introduce the system concept and whole architecture, details of main
components and use cases of primary operations in the system. These
features ease the Cloud service provider and customer’s concern and
support new Cloud service open market to increase Cloud service
profit and prompt Cloud service echo system in Cloud computing
related area.