Abstract: This paper presents a grid synchronization technique based on adaptive notch filter for SPV (Solar Photovoltaic) system along with MPPT (Maximum Power Point Tracking) techniques. An efficient grid synchronization technique offers proficient detection of various components of grid signal like phase and frequency. It also acts as a barrier for harmonics and other disturbances in grid signal. A reference phase signal synchronized with the grid voltage is provided by the grid synchronization technique to standardize the system with grid codes and power quality standards. Hence, grid synchronization unit plays important role for grid connected SPV systems. As the output of the PV array is fluctuating in nature with the meteorological parameters like irradiance, temperature, wind etc. In order to maintain a constant DC voltage at VSC (Voltage Source Converter) input, MPPT control is required to track the maximum power point from PV array. In this work, a variable step size P & O (Perturb and Observe) MPPT technique with DC/DC boost converter has been used at first stage of the system. This algorithm divides the dPpv/dVpv curve of PV panel into three separate zones i.e. zone 0, zone 1 and zone 2. A fine value of tracking step size is used in zone 0 while zone 1 and zone 2 requires a large value of step size in order to obtain a high tracking speed. Further, adaptive notch filter based control technique is proposed for VSC in PV generation system. Adaptive notch filter (ANF) approach is used to synchronize the interfaced PV system with grid to maintain the amplitude, phase and frequency parameters as well as power quality improvement. This technique offers the compensation of harmonics current and reactive power with both linear and nonlinear loads. To maintain constant DC link voltage a PI controller is also implemented and presented in this paper. The complete system has been designed, developed and simulated using SimPower System and Simulink toolbox of MATLAB. The performance analysis of three phase grid connected solar photovoltaic system has been carried out on the basis of various parameters like PV output power, PV voltage, PV current, DC link voltage, PCC (Point of Common Coupling) voltage, grid voltage, grid current, voltage source converter current, power supplied by the voltage source converter etc. The results obtained from the proposed system are found satisfactory.
Abstract: The world crude oil demand is projected to rise to 108.5 million bbl/d by the year 2035. With reserves estimated at 869 billion tonnes worldwide, coal remains an abundant resource. The aim of this work was to produce a high value hydrocarbon liquid product using a Direct Coal Liquefaction (DCL) process at, relatively mild operating conditions. Via hydrogenation, the temperature-staged approach was investigated in a dual reactor lab-scale pilot plant facility. The objectives included maximising thermal dissolution of the coal in the presence of tetralin as the hydrogen donor solvent in the first stage with 2:1 and 3:1 solvent: coal ratios. Subsequently, in the second stage, hydrogen saturation, in particular, hydrodesulphurization (HDS) performance was assessed. Two commercial hydrotreating catalysts were investigated viz. NickelMolybdenum (Ni-Mo) and Cobalt-Molybdenum (Co-Mo). GC-MS results identified 77 compounds and various functional groups present in the first and second stage liquid product. In the first stage 3:1 ratios and liquid product yields catalysed by magnetite were favoured. The second stage product distribution showed an increase in the BTX (Benzene, Toluene, Xylene) quality of the liquid product, branched chain alkanes and a reduction in the sulphur concentration. As an HDS performer and selectivity to the production of long and branched chain alkanes, Ni-Mo had an improved performance over Co-Mo. Co-Mo is selective to a higher concentration of cyclohexane. For 16 days on stream each, Ni-Mo had a higher activity than Co-Mo. The potential to cover the demand for low–sulphur, crude diesel and solvents from the production of high value hydrocarbon liquid in the said process, is thus demonstrated.
Abstract: In this study, we demonstrate a high-resolution
refractive index sensor based on a Magnetic Photonic Crystal (MPC)
composed of a triangular lattice array of air holes embedded in Si
matrix. A microcavity is created by changing the radius of an air hole
in the middle of the photonic crystal. The cavity filled with gyrotropic
materials can serve as a refractive index sensor. The shift of the
resonant frequency of the sensor is obtained numerically using finite
difference time domain method under different ambient conditions
having refractive index from n = 1.0 to n = 1.1. The numerical results
show that a tiny change in refractive index of Δn = 0.0001 is
distinguishable. In addition, the spectral response of the MPC sensor is
studied while an external magnetic field is present. The results show
that the MPC sensor exhibits a dramatic improvement in resolution.
Abstract: In the past few years, high consumption of soft drinks
has attracted negative attention world-wide due to its possible
adverse effects, leading the health conscious people to find
alternative nutraceutical or herbal health drinks. In the present study,
a nutraceutical soft drink was developed utilizing some easily
available and well known traditional herbs having nutritional
potential. The key ingredients were selected as bael, amla, lemon
juice, ashwagandha and poppy seeds based on their household routine
use in the summer with proven refreshing, cooling and energetic
feeling since ages. After several trials made, the final composition of
nutraceutical summer soft drink was selected as most suitable
combination based on the taste, physicochemical, microbial and
organoleptic point of view. The physicochemical analysis of the
prepared drink found to contain optimum level of titratable acidity,
total soluble solids and pH which were in accordance of the
commercial recommendations. There were no bacterial colonies
found in the product therefore found within limits. During the nine
point’s hedonic scale sensory evaluation, the drink was strongly liked
for colour, taste, flavour and texture. The formulation was found to
contain flavonoids (80mg/100ml), phenolics (103mg/100ml), vitamin
C (250mg/100ml) and has antioxidant potential (75.52%) apart from
providing several other essential vitamins, minerals and healthy
components. The developed nutraceutical drink provides an
economical and feasible option for the consumers with very good
taste combined with potential health benefits. The present drink is
potentially capable to replace the synthetic soft drinks available in the
market.
Abstract: In this paper, we present a quantum statistical
mechanical formulation from our recently analytical expressions for
partial-wave transition matrix of a three-particle system. We report
the quantum reactive cross sections for three-body scattering
processes 1+(2,3)→1+(2,3) as well as recombination
1+(2,3)→1+(3,1) between one atom and a weakly-bound dimer. The
analytical expressions of three-particle transition matrices and their
corresponding cross-sections were obtained from the threedimensional
Faddeev equations subjected to the rank-two non-local
separable potentials of the generalized Yamaguchi form. The
equilibrium quantum statistical mechanical properties such partition
function and equation of state as well as non-equilibrium quantum
statistical properties such as transport cross-sections and their
corresponding transport collision integrals were formulated
analytically. This leads to obtain the transport properties, such as
viscosity and diffusion coefficient of a moderate dense gas.
Abstract: This paper presents the results of a Finite Element
based vibration analysis of a solar powered Unmanned Aerial
Vehicle (UAV). The purpose of this paper was to quantify the free
vibration, forced vibration response due to differing point inputs in
order to predict the relative response magnitudes and frequencies at
various wing locations of vibration induced power generators
(magnet in coil) excited by gust and/or control surface pulse-decays
used to help power the flight of the electric UAV. A Fluid Structure
Interaction (FSI) study was performed in order to ascertain pertinent
design stresses and deflections as well as aerodynamic parameters of
the UAV airfoil. The 10 ft span airfoil is modeled using Mylar as the
primary material. Results show that the free mode in bending is 4.8
Hz while the first forced bending mode is on range of 16.2 to 16.7 Hz
depending on the location of excitation. The free torsional bending
mode is 28.3 Hz, and the first forced torsional mode is range of 26.4
to 27.8 Hz, depending on the location of excitation. The FSI results
predict the coefficients of aerodynamic drag and lift of 0.0052 and
0.077, respectively, which matches hand-calculations used to validate
the Finite Element based results. FSI based maximum von Mises
stresses and deflections were found to be 0.282 MPa and 3.4 mm,
respectively. Dynamic pressures on the airfoil range from 1.04 to
1.23 kPa corresponding to velocity magnitudes in range of 22 to 66
m/s.
Abstract: A teeming set of doctors that graduated from various
universities within and outside Nigeria with the hope of practicing in
the country, has their hope shattered because of poor financing, lack
of medical equipments and a very weak healthcare systems. Such
hydra headed challenges, allows room for quackery which
increasingly contributes to the cause of mortality in Nigeria. With a
view of reversing the challenges of healthcare delivery and financing
in Nigeria, African Health Market for Equity (AHME), a project
funded by the Bill and Melinda Gates foundation [With contribution
from Department For International Development (DFID)] and
currently implemented in three African Countries (Nigeria, Kenya
and Ghana) over a Five (5) year period supports the healthcare sector
via Medical credit fund (MCF). The study examines the impact of
credit policy and medical credit funding on Nigerian health market.
Ordinary least square analysis, correlation and granger causality tests
were employed to measure the extent to which the Nigerian
healthcare market has been influenced. Medical credit fund
significantly and positively influenced average monthly turnover of
private healthcare providers and Commercial bank’s lending rate had
a weak relationship with access to credit/approved loans (13.46%).
The programme has so far made 13.91% progress, which is very
poor, considering the minimum targeted private health care providers
(437.6) and expected number of loan approvals (180.4) for the two
years. Medical credit policy in Nigeria should be revised to include
private healthcare providers in rural area for more positive impact
and increased returns. Good brand advert and sensitization of the
programme to stakeholders and health pressure group, and an
extension of the programme beyond five years is necessary to better
address the issues raised in the study.
Abstract: This study was undertaken at four different sites
(north polluted, south polluted, south healthy and north healthy) in
Tehran, in order to examine whether there was a relationship between
publicly available air quality data and the public’s perception of air
quality and to suggest some guidelines for reducing air pollution. A
total of 200 people were accidentally filled out the research
questionnaires at mentioned sites and air quality data were obtained
simultaneously from the Air Quality Control Department. Data was
analyzed in Excel and SPSS software’s. Clean air and job security
were of great importance to people comparing to other pleasant
aspect of life. Also air pollution and serious diseases were the most
important of people concerns. Street monitors and news paper
services on air quality were little used by the public as a means of
obtaining information on air pollution. Using public transportation
and avoiding inevitable journeys are the most important ways for
reducing air pollution. The results reveal that the public’s perception
of air quality is not a reliable indicator of the actual levels of air
pollution.
Abstract: Second generation military Filipino Amerasians
comprise a formidable contemporary segment of the estimated
250,000-plus biracial Amerasians in the Philippines today. Overall,
they are a stigmatized and socioeconomically marginalized diaspora;
historically, they were abandoned or estranged by U.S. military
personnel fathers assigned during the century-long Colonial, Post-
World War II and Cold War Era of permanent military basing (1898-
1992). Indeed, U.S. military personnel are assigned in smaller
numbers in the Philippines today. This inquiry is an outgrowth of two
recent small sample studies. The first surfaced the impact of the U.S.
military prostitution system on formation of the ‘Derivative
Amerasian Family Construct’ on first generation Amerasians; a
second, qualitative case study suggested the continued effect of the
prostitution systems' destructive impetuous on second generation
Amerasians. The intent of this current qualitative, multiple-case study
was to actively seek out second generation sex industry toilers. The
purpose was to focus further on this human phenomenon in the postbasing
and post-military prostitution system eras. As background, the
former military prostitution apparatus has transformed into a modern
dynamic of rampant sex tourism and prostitution nationwide. This is
characterized by hotel and resorts offering unrestricted carnal access,
urban and provincial brothels (casas), discos, bars and pickup clubs,
massage parlors, local barrio karaoke bars and street prostitution. A
small case study sample (N = 4) of female and male second
generation Amerasians were selected. Sample formation employed a
non-probability ‘snowball’ technique drawing respondents from the
notorious Angeles, Metro Manila, Olongapo City ‘AMO Amerasian
Triangle’ where most former U.S. military installations were sited
and modern sex tourism thrives. A six-month study and analysis of
in-depth interviews of female and male sex laborers, their families
and peers revealed a litany of disturbing, and troublesome
experiences. Results showed profiles of debilitating human poverty,
history of family disorganization, stigmatization, social
marginalization and the ghost of the military prostitution system and
its harmful legacy on Amerasian family units. Emerging were testimonials of wayward young people ensnared in a maelstrom of
deep economic deprivation, familial dysfunction, psychological
desperation and societal indifference. The paper recommends that
more study is needed and implications of unstudied psychosocial and
socioeconomic experiences of distressed younger generations of
military Amerasians require specific research. Heretofore apathetic or
disengaged U.S. institutions need to confront the issue and formulate
activist and solution-oriented social welfare, human services and
immigration easement policies and alternatives. These institutions
specifically include academic and social science research agencies,
corporate foundations, the U.S. Congress, and Departments of State,
Defense and Health and Human Services, and Homeland Security
(i.e. Citizen and Immigration Services) It is them who continue to
endorse a laissez-faire policy of non-involvement over the entire
Filipino Amerasian question. Such apathy, the paper concludes,
relegates this consequential but neglected blood progeny to the status
of humiliating destitution and exploitation. Amerasians; thus, remain
entrapped in their former colonial, and neo-colonial habitat.
Ironically, they are unwitting victims of a U.S. American homeland
that fancies itself geo-politically as a strong and strategic military
treaty ally of the Philippines in the Western Pacific.
Abstract: The aim of this study was to investigate the
photocatalytic activity of polycrystalline phases of bismuth tungstate
of formula Bi2WO6. Polycrystalline samples were elaborated using a
coprecipitation technique followed by a calcination process at
different temperatures (300, 400, 600 and 900°C). The obtained
polycrystalline phases have been characterized by X-ray diffraction
(XRD), scanning electron microscopy (SEM), and transmission
electron microscopy (TEM). Crystal cell parameters and cell volume
depend on elaboration temperature. High-resolution electron
microscopy images and image simulations, associated with X-ray
diffraction data, allowed confirming the lattices and space groups
Pca21. The photocatalytic activity of the as-prepared samples was
studied by irradiating aqueous solutions of Rhodamine B, associated
with Bi2WO6 additives having variable crystallite sizes. The
photocatalytic activity of such bismuth tungstates increased as the
crystallite sizes decreased. The high specific area of the
photocatalytic particles obtained at 300°C seems to condition the
degradation kinetics of RhB.
Abstract: Review of studies carried out on the use of bagasse
ash for the improvement of deficient soils in Nigeria, with emphasis
on lateritic and black cotton soils is presented. Although, the bagasse
ash is mostly used as additive to the conventional soil stabilizers
(cement and lime), the studies generally showed improvement in the
geotechnical properties of the soils, either modified or stabilized with
the ash. This showed the potentials of using this agricultural waste
(bagasse ash) in the improvement of geotechnical properties of
deficient soils, thus suggesting that using this material at large scale
level in geotechnical engineering practice could help in the provision
of stable and durable structures, reduce cost of soil improvement and
also reduces environmental nuisance caused by the unused waste in
Nigeria.
Abstract: Due to the interference effects, the intrinsic
aerodynamic parameters obtained from the individual component
testing are always fundamentally different than those obtained for
complete model testing. Consideration and limitation for such testing
need to be taken into account in any design work related to the
component buildup method. In this paper, the scaled model of a
straight rectangular canard of a hybrid buoyant aircraft is tested at 50
m/s in IIUM-LSWT (Low Speed Wind Tunnel). Model and its
attachment with the balance are kept rigid to have results free from
the aeroelastic distortion. Based on the velocity profile of the test
section’s floor; the height of the model is kept equal to the
corresponding boundary layer displacement. Balance measurements
provide valuable but limited information of overall aerodynamic
behavior of the model. Zero lift coefficient is obtained at -2.2o and
the corresponding drag coefficient was found to be less than that at
zero angle of attack. As a part of the validation of low fidelity tool,
plot of lift coefficient plot was verified by the experimental data and
except the value of zero lift coefficients, the overall trend has under
predicted the lift coefficient. Based on this comparative study, a
correction factor of 1.36 is proposed for lift curve slope obtained
from the panel method.
Abstract: The main idea of this work is to investigate the effect
of knitted fabrics characteristics on moisture management properties.
Wetting and transport properties of single jersey, Rib 1&1 and
English Rib fabrics made out of cotton and blended Cotton/Polyester
yarns were studied. The dynamic water sorption of fabrics was
investigated under same isothermal and terrestrial conditions at
20±2°C-65±4% by using the Moisture Management Tester (MMT)
which can be used to quantitatively measure liquid moisture transfer
in one step in a fabric in multidirections: Absorption rate, moisture
absorbing time of the fabric's inner and outer surfaces, one-way
transportation capability, the spreading/drying rate, the speed of
liquid moisture spreading on fabric's inner and outer surfaces are
measured, recorded and discussed. The results show that fabric’s
composition and knit’s structure have a significant influence on those
phenomena.
Abstract: This paper explores and provides substantiated
evidence on the usage patterns of Information and Communication
Technologies (ICTs) by female users at Vhembe District in Limpopo-
Province, South Africa. The study presents a comprehensive picture
on the usage of ICTs from female users’ perspective. The
significance of this study stems from the need to assess the role,
relevance and usage patterns of ICTs such as smartphones,
computers, laptops, and iPods, the internet and social networking
sites among females following the developments of new media
technologies in society. The objective of the study is to investigate
the usability and accessibility of ICTs to empower female users in
South Africa. The study used quantitative and qualitative research
methods to determine the major ideas, perceptions and usage patterns
of ICTs by users. Data collection involved the use of structured selfadministered
questionnaire from two groups of respondents who
participated in this study. Thus, (n=50) female students at the
University of Venda provided their ideas and perceptions about the
usefulness and usage patterns of ICTs such as smartphones, the
Internet and computers at the university level, whereas, the second
group were (n=50) learners from Makhado Comprehensive School
who provided their perceptions and ideas about the use of ICTs at the
high school level. The researcher also noted that the findings of the
study were useful as a guideline and model for ICT intervention that
could work as an empowerment to women in South Africa. It was
observed that the central purpose of ICTs among female users was to
search for information regarding assignment writing, conducting
research, dating, exchanging ideas and networking with friends and
relatives. This was demonstrated by a high number of females who
used ICTs for e-learning (62%) and social purposes (85%).
Therefore, the study revealed that most females used ICTs for social
purposes and accessing the internet rather than for entertainment, a
gesture that provides an opportune space to empower rural women in
South Africa.
Abstract: Current transformers are an integral part of power
system because it provides a proportional safe amount of current for
protection and measurement applications. However, when the power
system experiences an abnormal situation leading to huge current
flow, then this huge current is proportionally injected to the
protection and metering circuit. Since the protection and metering
equipment’s are designed to withstand only certain amount of current
with respect to time, these high currents pose a risk to man and
equipment. Therefore, during such instances, the CT saturation
characteristics have a huge influence on the safety of both man and
equipment and on the reliability of the protection and metering
system. This paper shows the effect of burden on the Accuracy Limiting
factor/ Instrument security factor of current transformers and the
change in saturation characteristics of the CT’s. The response of the
CT to varying levels of overcurrent at different connected burden will
be captured using the data acquisition software LabVIEW. Analysis
is done on the real time data gathered using LabVIEW. Variation of
current transformer saturation characteristics with changes in burden
will be discussed.
Abstract: Networked environments which provide platforms for
business organizations are configured in different forms depending
on many factors including life time, member characteristics,
communication structure, and business objectives, among others.
With continuing advances in digital technologies the distance has
become a less barrier for business minded collaboration among
organizations. With the need and ease to make business collaborate
nowadays organizations are sometimes forced to co-work with others
that are either unknown or less known to them in terms of history and
performance. A promising approach for sustaining established
collaboration has been establishment of trust relationship among
organizations based on assessed trustworthiness for each participating
organization. It has been stated in research that trust in organization is
dynamic and thus assessment of trust level must address such
dynamic nature. This paper assesses relevant aspects of trust and
applies the assessed concepts to propose a semi-automated system for
the management of Sustainability and Evolution of trust in
organizations participating in specific objective in a networked
organizations environment.
Abstract: In internet of things (IoT) system, the communication
scheme with reliability and low power is required to connect a
terminal. Cooperative communication can achieve reliability and
lower power than multiple-input multiple-output (MIMO) system.
Cooperative communication increases the reliability with low
power, but decreases a throughput. It has a weak point that the
communication throughput is decreased. In this paper, a novel scheme
is proposed to increase the communication throughput. The novel
scheme is a transmission structure that increases transmission rate.
A decoding scheme according to the novel transmission structure is
proposed. Simulation results show that the proposed scheme increases
the throughput without bit error rate (BER) performance degradation.
Abstract: We report the design and characterization of ultra high
quality factor filter based on one-dimensional photonic-crystal Thue-
Morse sequence structure. The behavior of aperiodic array of
photonic crystal structure is numerically investigated and we show
that by changing the angle of incident wave, desired wavelengths
could be tuned and a tunable filter is realized. Also it is shown that
high quality factor filter be achieved in the telecommunication
window around 1550 nm, with a device based on Thue-Morse
structure. Simulation results show that the proposed structure has a
quality factor more than 100000 and it is suitable for DWDM
communication applications.
Abstract: This paper discusses the question whether a person
diagnosed with dyslexia will necessarily have difficulty in reading
musical notes. The author specifies the characteristics of alphabet
reading in comparison to musical notation reading, and concludes
that there should be no contra-indication for teaching standard music
reading to children with dyslexia if an appropriate process is offered.
This conclusion is based on a long term case study and relies on two
main characteristics of music reading: (1) musical notation system is
a systematic, logical, relative set of symbols written on a staff; and
(2) music reading learning connected with playing a musical
instrument is a multi-sensory activity that combines sight, hearing,
touch, and movement. The paper describes music reading teaching
procedures, using soprano recorders, and provides unique teaching
methods that have been found to be effective for students who were
diagnosed with dyslexia. It provides theoretical explanations in
addition to guidelines for music education practices.
Abstract: Malaysia’s green building development is gaining
momentum and green buildings have become a key focus area,
especially within the commercial sector with the encouragement of
government legislation and policy. Due to the emerging awareness
among the market players’ views of the benefits associated with the
ownership of green buildings in Malaysia, there is a need for valuers
to incorporate consideration of sustainability into their assessments of
property market value to ensure the green buildings continue to
increase in the market. This paper analyses the valuers’ current
perception on the valuation practices with regard to the green issues
in Malaysia. The study was based on a survey of registered real estate
valuers and the experts whose work related to valuation in the Klang
Valley area to rate their view regarding the perception on valuation of
green building. The findings present evidence that even though
Malaysian valuers have limited knowledge of green buildings, they
recognise the importance of incorporating the green features in the
valuation process. The inclusion of incorporating the green features
in valuations in practice was hindered by the inadequacy of sufficient
transaction data in the market. Furthermore, valuers experienced
difficulty in identifying what are the various input parameters of
green building and how to adjust it in order to reflect the benefit of
sustainability features correctly in the valuation process. This paper
focuses on the present challenges confronted by Malaysian valuers
with regards to incorporating the green features in their valuation.