Abstract: The current statuses of lifetime test of LaB6 hollow
cathode at the Lanzhou Institute of Physics (LIP), China, was
described. 5A LaB6 hollow cathode was design for LIPS-200 40mN
Xenon ion thruster, and it could be used for LHT-100 80 mN Hall
thruster, too. Life test of the discharge and neutralizer modes of LHC-5
hollow cathode were stared in October 2011, and cumulative operation
time reached 17,300 and 16,100 hours in April 2015, respectively. The
life of cathode was designed more than 11,000 hours. Parameters of
discharge and key structure dimensions were monitored in different
stage of life test indicated that cathodes were health enough. The test
will continue until the cathode cannot work or operation parameter is
not in normally. The result of the endurance test of cathode
demonstrated that the LaB6 hollow cathode is satisfied for the required
of thruster in life and performance.
Abstract: The objective of this work is to carryout critical
comparison of different actuation mechanisms like electrostatic,
thermal, piezoelectric, and magnetic with reference to a micro
cantilever. The relevant parameters like force generated,
displacement are compared in actuation methods. With these results,
helps in choosing the best actuation method for a particular
application. In this study, Comsol/Multiphysics software is used.
Modeling and simulation is done by considering the micro cantilever
of same dimensions as an actuator using all the above mentioned
actuation techniques. In addition to their small size, micro actuators
consume very little power and are capable of accurate results. In this
work, a comparison of actuation mechanisms is done to decide the
efficient system in micro domain.
Abstract: Reduction of energy consumption in built
infrastructure, through the installation of energy-efficient
technologies, is a major approach to achieving sustainability. In
practice, the viability of energy efficiency projects strongly depends
on the cost reimbursement and profitability. These projects are
subject to failure if the actual cost savings do not reimburse the
project cost promptly. In such cases, refinancing could be a solution
to benefit from the long-term returns of the project, if implemented
wisely. However, very little is still known about the effect of
refinancing options on financial performance of energy efficiency
projects. In order to fill this gap, the present study investigates the
financial behavior of energy efficiency projects with focus on
refinancing options, such as Leveraged Loans. A System Dynamics
(SD) model is introduced, and the model application is presented
using an actual case-study data. The case study results indicate that
while high-interest start-ups make using Leveraged Loan inevitable,
refinancing can rescue the project and bring about profitability. This
paper also presents some managerial implications of refinancing
energy efficiency projects based on the case-study analysis. Results
of this study help to implement financially viable energy efficiency
projects so that the community could benefit from their
environmental advantages widely.
Abstract: Given the increase in the number of e-commerce sites,
the number of competitors has become very important. This means
that companies have to take appropriate decisions in order to meet the
expectations of their customers and satisfy their needs. In this paper,
we present a case study of applying LRFM (length, recency,
frequency and monetary) model and clustering techniques in the
sector of electronic commerce with a view to evaluating customers’
values of the Moroccan e-commerce websites and then developing
effective marketing strategies. To achieve these objectives, we adopt
LRFM model by applying a two-stage clustering method. In the first
stage, the self-organizing maps method is used to determine the best
number of clusters and the initial centroid. In the second stage, kmeans
method is applied to segment 730 customers into nine clusters
according to their L, R, F and M values. The results show that the
cluster 6 is the most important cluster because the average values of
L, R, F and M are higher than the overall average value. In addition,
this study has considered another variable that describes the mode of
payment used by customers to improve and strengthen clusters’
analysis. The clusters’ analysis demonstrates that the payment method is
one of the key indicators of a new index which allows to assess the
level of customers’ confidence in the company's Website.
Abstract: Numerical study of the static response of
homogeneous clay stratum considering a wide range of cohesion and
subject to foundation loads is presented. The linear elastic–perfectly
plastic constitutive relation with the von Mises yield criterion were
utilised to develop a numerically cost effective finite element model
for the soil while imposing a rigid body constrain to the foundation
footing. From the analyses carried out, estimate of the bearing
capacity factor, Nc as well as the ultimate load-carrying capacities of
these soils, effect of cohesion on foundation settlements, stress fields
and failure propagation were obtained. These are consistent with
other findings in the literature and hence can be a useful guide in
design of safe foundations in clay soils for buildings and other
structure.
Abstract: Cooperative groups through much research have been
recognized to churn remarkable achievements instead of solitary or
individualistic efforts. Based on Johnson and Johnson’s model of
cooperative learning, the five key components of cooperation are
positive interdependence, face-to-face promotive interaction,
individual accountability, social skills, and group processing. In
2011, the Malaysian Ministry of Higher Education (MOHE)
introduced the Holistic Student Development policy with the aim to
develop morally sound individuals equipped with lifelong learning
skills. The Community Service project was included in the
improvement initiative. The purpose of this study is to assess the
relationship of team-based learning in facilitating particularly
students’ positive interdependence and face-to-face promotive
interaction. The research methods involve in-depth interviews with
the team leaders and selected team members, and a content analysis
of the undergraduate students’ reflective journals. A significant
positive relationship was found between students’ progressive
outlook towards teamwork and the highlighted two components. The
key findings show that students have gained in their individual
learning and work results through teamwork and interaction with
other students. The inclusion of Community Service as a MOHE
subject resonates with cooperative learning methods that enhances
supportive relationships and develops students’ social skills together
with their professional skills.
Abstract: The analytical bright two soliton solution of the 3-
coupled nonlinear Schrödinger equations with variable coefficients in
birefringent optical fiber is obtained by Darboux transformation
method. To the design of ultra-speed optical devices, Soliton
interaction and control in birefringence fiber is investigated. Lax pair
is constructed for N coupled NLS system through AKNS method.
Using two-soliton solution, we demonstrate different interaction
behaviors of solitons in birefringent fiber depending on the choice of
control parameters. Our results shows that interactions of optical
solitons have some specific applications such as construction of logic
gates, optical computing, soliton switching, and soliton amplification
in wavelength division multiplexing (WDM) system.
Abstract: Broiler slaughter waste has become a major source of
pollution throughout the world. Utilization of broiler slaughter waste
by dry rendering process produced Rendered Chicken Oil (RCO), a
cheap raw material for biodiesel production and Carcass Meal a feed
ingredient for pets and fishes. Conversion of RCO into biodiesel may
open new vistas for generating wealth from waste besides controlling
the major havoc of environmental pollution. A two-step process to
convert RCO to good quality Biodiesel was invented. Acid catalysed
esterification of FFA followed by base catalysed transesterification of
triglycerides was carried out after meticulously standardizing the
methanol molar ratio, catalyst concentration, reaction temperature,
and reaction time to obtain the maximum biodiesel yield of 97.62%
and lowest glycerol yield of 6.96%. RCO biodiesel blend was tested
in a CRDI diesel engine. The results revealed that the blending of
commercial diesel with 20% RCO biodiesel (B20) lead to less engine
wear, a quieter engine and better fuel economy. The better lubricating
qualities of RCO B20 prevented over heating of engine, which
prolongs the engine life. RCO B20 can reduce the import of crude oil
and substantially reduce the engine emissions as proved by
significantly lower smoke levels, thus mitigating climatic changes.
Abstract: The main cause of Alzheimer disease (AD) was
believed to be mainly due to the accumulation of free radicals owing
to oxidative stress (OS) in brain tissue. The mechanism of the
neurotoxicity of Aluminum chloride (AlCl3) induced AD in
hippocampus Albino wister rat brain tissue, the curative & the
protective effects of Lipidium sativum group (LS) water extract were
assessed after 8 weeks by attenuated total reflection spectroscopy
ATR-IR and histologically by light microscope. ATR-IR results
revealed that the membrane phospholipid undergo free radical
attacks, mediated by AlCl3, primary affects the polyunsaturated fatty
acids indicated by the increased of the olefinic -C=CH sub-band area
around 3012 cm-1 from the curve fitting analysis. The narrowing in
the half band width (HBW) of the sνCH2 sub-band around 2852 cm-1
due to Al intoxication indicates the presence of trans form fatty acids
rather than gauch rotomer. The degradation of hydrocarbon chain to
shorter chain length, increasing in membrane fluidity, disorder, and
decreasing in lipid polarity in AlCl3 group indicated by the detected
changes in certain calculated area ratios compared to the control.
Administration of LS was greatly improved these parameters
compared to the AlCl3 group. Al influences the Aβ aggregation and
plaque formation, which in turn interferes to and disrupts the
membrane structure. The results also showed a marked increase in
the β-parallel and antiparallel structure, that characterize the Aβ
formation in Al-induced AD hippocampal brain tissue, indicated by
the detected increase in both amide I sub-bands around 1674, 1692
cm-1. This drastic increase in Aβ formation was greatly reduced in the
curative and protective groups compared to the AlCl3 group and
approached nearly the control values. These results supported too by
the light microscope. AlCl3 group showed significant marked
degenerative changes in hippocampal neurons. Most cells appeared
small, shrieked and deformed. Interestingly, the administration of LS
in curative and protective groups markedly decreases the amount of
degenerated cells compared to the non-treated group. In addition, the
intensity of congo red stained cells was decreased. Hippocampal
neurons looked more/or less similar to those of control. This study showed a promising therapeutic effect of Lipidium
sativum group (LS) on AD rat model that seriously overcome the
signs of oxidative stress on membrane lipid and restore the protein
misfolding.
Abstract: Lagos urban mini bus drivers play a critical role in the
transportation sector. The current major mode of transportation
within Lagos metropolis remains road transportation and this
confirms the relevance of urban mini-bus drivers in transporting the
populace to their various destinations. Other modes of transportation
such as the train and waterways are currently inadequate. Various
threats to the well-being of urban bus drivers include congested
traffic typical of modern day lifestyles, dwindling financial returns
due to long hours in traffic, fewer hours of sleep, inadequate diet,
time pressure, and assaults related to fare disputes. Several healthrelated
problems have been documented to be associated with urban
bus driving. For instance, greater rates of hypertension, obesity and
cholesterol level have been reported. Research studies are yet to
identify the influence of age and marital status on the well-being of
urban mini-bus drivers in Lagos metropolis. A study of this nature is
necessary as it is culturally perceived in Nigeria that older and
married people are especially influenced by family affiliation and
would behave in ways that would project positive outcomes. The
study sample consisted of 150 urban mini-bus drivers who were
conveniently sampled from six (6) different terminuses where their
journey begins and terminates. The well-being questionnaire was
administered to participants. The criteria for inclusion in the study
included the ability to read in English language and the confirmation
that interested participants were on duty and suited to be driving
mini-buses. Due to the nature of the job of bus driving, the researcher
administered the questionnaires on participants who were free and
willing to respond to the survey. All participants were males of
various age groups and of different marital statuses. Results of
analyses conducted revealed no significant influence of age and
marital status on the well-being of urban mini-bus drivers. This
indicates that the well-being of urban mini bus drivers is not
influenced by age or marital status. The findings of this study have
cultural implications. It negates the popularly held belief that older
and married people care more about their well-being than younger
and single people. It brings to fore the need to also identify and
consider other factors when certifying people for the job of urban bus
driving.
Abstract: Highly developed technology and highly competitive
global market highlight the important role of competitive advantages
and operation performances in sustainable company operation.
Activity-Based Costing (ABC) provides accurate operation cost and
operation performance information. Rich literatures provide relevant
research with cases study on Activity-Based Costing application, but
the research on cause relationship between key success factors and its
specific outcome, such as profitability or share market are few. These
relationships provide the ways to handle the key success factors to
achieve the specific outcomes for ensuring to promote the competitive
advantages and operation performances. The main purposes of this
research are exploring the key success paths by Key Success Paths
approach which will lead the ways to apply Activity-Base Costing.
The Key Success Paths is the innovative method which is exploring
the cause relationships and explaining what are the effects of key
success factors to specific outcomes of Activity-Based Costing
implementation. The cause relationships between key success factors
and successful specific outcomes are Key Success Paths (KSPs). KSPs
are the guidelines to lead the cost management strategies to achieve the
goals of competitive advantages and operation performances. The
research findings indicate that good management system design may
affect the well outcomes of Activity-Based Costing application and
achieve to outstanding competitive advantage, operating performance
and profitability as well by KSPs exploration.
Abstract: Various nanomaterials can be used as a drug delivery
vehicles in nanomedicine, called nanocarriers. They can either be
organic or inorganic, synthetic or natural-based. Although synthetic
nanocarriers are easier to produce, they can often be toxic for the
organism and thus not suitable for use in treatment. From naturalbased
nanocarriers, the most commonly used are protein cages or
viral capsids. In this work, virus bacteriophage λ was used for
delivery of different cytotoxic drugs (cisplatin, carboplatin,
oxaliplatin and doxorubicin). Large quantities of phage λ were
obtained from phage λ-producing strain of E. coli cultivated in
medium with 0.2% maltose. After killing of E. coli with chloroform
and its removal by centrifugation, the phage was concentrated by
ultracentrifugation at 130 000×g and 4°C for 3 h. The encapsulation
of the drugs was performed by infusion method and four different
concentrations of the drugs were encapsulated (200; 100; 50; 25
μg·mL-1). Free drug molecules were removed by filtration. The
encapsulation was verified using the absorbance for doxorubicin and
atomic absorption spectrometry for platinum cytostatics. The amount
of encapsulated drug linearly increased with the increasing
concentration of applied drug with the determination coefficient
R2=0.989 for doxorubicin; R2=0.967 for cisplatin; R2=0.989 for
carboplatin and R2=0.996 for oxaliplatin. The overall encapsulation
efficiency was calculated as 50% for doxorubicin; 8% for cisplatin;
6% for carboplatin and 10% for oxaliplatin.
Abstract: According to IR, 13C and 1H NMR, APT, 1D NOE,
2D heteronuclear 1H/13C HSQC and 2D DOSY experiments the main
chemical constituent of high-molecular preparations from Symphytum
asperum, S. caucasicum, S. officinale and Anchusa italica
(Boraginaceae) was found to be caffeic acid-derived polyether,
namely poly[3-(3,4-dihydroxyphenyl)glyceric acid] (PDPGA) or
poly[oxy-1-carboxy-2-(3,4-dihydroxyphenyl)ethylene]. Most
carboxylic groups of this polymer of A. italica are methylated.
Abstract: Millions of girls are forcibly married during the
transitional period between puberty and adulthood. At a stage of
vulnerability cultural practices, religious rights and social standards
place her in a position where she is catapult into womanhood. An
advocate against forced child marriage could argue that child rights,
cultural rights, religious rights, right to marry, right to life, right to
health, right to education, right to be free from slavery, right to be
free from torture, right to consent to marriage are all violated by the
practice of child marriage. The author is this advocate and this paper
will present how some of these rights are violated and establish the
need for change.
Abstract: Chatter vibrations, occurring during cutting process,
cause vibration between the cutting tool and workpiece, which
deteriorates surface roughness and reduces tool life. The purpose of
this study is to investigate the influence of cutting parameters and
tool construction on surface roughness and vibration in turning of
aluminum alloy AA2024. A new design of cutting tool is proposed,
which is filled up with epoxy granite in order to improve damping
capacity of the tool. Experiments were performed at the lathe using
carbide cutting insert coated with TiC and two different cutting tools
made of AISI 5140 steel. Taguchi L9 orthogonal array was applied to
design of experiment and to optimize cutting conditions. By the help
of signal-to-noise ratio and analysis of variance the optimal cutting
condition and the effect of the cutting parameters on surface
roughness and vibration were determined. Effectiveness of Taguchi
method was verified by confirmation test. It was revealed that new
cutting tool with epoxy granite has reduced vibration and surface
roughness due to high damping properties of epoxy granite in
toolholder.
Abstract: Noninvasive diagnostics of diseases via breath
analysis has attracted considerable scientific and clinical interest for
many years and become more and more promising with the rapid
advancements in nanotechnology and biotechnology. The volatile
organic compounds (VOCs) in exhaled breath, which are mainly
blood borne, particularly provide highly valuable information about
individuals’ physiological and pathophysiological conditions.
Additionally, breath analysis is noninvasive, real-time, painless, and
agreeable to patients. We have developed a wireless sensor array
based on single-stranded DNA (ssDNA)-functionalized single-walled
carbon nanotubes (SWNT) for the detection of a number of
physiological indicators in breath. Seven DNA sequences were used
to functionalize SWNT sensors to detect trace amount of methanol,
benzene, dimethyl sulfide, hydrogen sulfide, acetone, and ethanol,
which are indicators of heavy smoking, excessive drinking, and
diseases such as lung cancer, breast cancer, and diabetes. Our test
results indicated that DNA functionalized SWNT sensors exhibit
great selectivity, sensitivity, and repeatability; and different
molecules can be distinguished through pattern recognition enabled
by this sensor array. Furthermore, the experimental sensing results
are consistent with the Molecular Dynamics simulated ssDNAmolecular
target interaction rankings. Thus, the DNA-SWNT sensor
array has great potential to be applied in chemical or biomolecular
detection for the noninvasive diagnostics of diseases and personal
health monitoring.
Abstract: This research paper portrays a comparative analysis of
thermomechanical behaviour of Shielded Metal Arc Welding
(SMAW) and Gas Tungsten Arc Welding (GTAW) of low carbon
steel of AISI 1020 grade butt joints. The thermal history has been
obtained by experimental work. We have focused on temperature
dependent cooling rate as depicted by Adam’s two-dimensional
model. The effect of moving point heat source of SMAW and GTAW
on mechanical properties has been judged by optical and scanning
electron micrographs of different regions in weld joints. The
microhardness study has been carried to visualize the joint strength
due to formation of different phases.
Abstract: This paper discusses the thematic structure of Yoruba
popular music of Southwest Nigeria. It examines the use of themes
and variations in early and contemporary Juju music. The work is an
outcome of a research developed by the author in his doctoral studies
at the University of Lagos, Nigeria, with the aim of analyzing the
thematic and motivic developments in Yoruba popular genres.
Observations, interviews, live recordings and CDs were used as
methods for eliciting information. Field recordings and CDs of
selected musical samples were also transcribed and notated. The
research established the prevalent use of string of themes by Juju
musicians as a compositional technique in moving from one musical
section to another, as they communicate the verbal messages in their
song. These themes consist of the popular ‘call and response’ form
found in most African music, analogous to the western ‘subject and
answer’ style of the fugue or sonata form, although without the tonic–
dominant relations. Due to the short and repetitive form of African
melodies and rhythms, a theme is restated as a variation, where its
rhythmic and melodic motifs are stylistically developed and repeated,
but still retaining its recognizable core musical structure. The
findings of this study showed that Juju musicians generally often
employ a thematic plan where new themes are used to arrange the
songs into sections, and each theme is developed into variations in
order to further expand the music, eliminate monotony, and create
musical aesthetics, serving as hallmark of its musical identity. The
study established the musical and extra-musical attributes of the
genre, while recommending further research towards analyzing the
various compositional techniques employed in African popular
genres.
Abstract: The effects of the contact ball-lens on the soda lime
glass in laser thermal cleavage with a cw Nd-YAG laser were
investigated in this study. A contact ball-lens was adopted to generate
a bending force on the crack formation of the soda-lime glass in the
laser cutting process. The Nd-YAG laser beam (wavelength of 1064
nm) was focused through the ball-lens and transmitted to the soda-lime
glass, which was coated with a carbon film on the surface with a
bending force from a ball-lens to generate a tensile stress state on the
surface cracking. The fracture was controlled by the contact ball-lens
and a straight cutting was tested to demonstrate the feasibility.
Experimental observations on the crack propagation from the leading
edge, main section and trailing edge of the glass sheet were compared
with various mechanical and thermal loadings. Further analyses on the
stress under various laser powers and contact ball loadings were made
to characterize the innovative technology. The results show that the distributions of the side crack at the
leading and trailing edges are mainly dependent on the boundary
condition, contact force, cutting speed and laser power. With the
increase of the mechanical and thermal loadings, the region of the side
cracks might be dramatically reduced with proper selection of the
geometrical constrains. Therefore the application of the contact
ball-lens is a possible way to control the fracture in laser cleavage with
improved cutting qualities.
Abstract: The plastic industry plays very important role in the
economy of any country. It is generally among the leading share of
the economy of the country. Since metals and their alloys are very
rarely available on the earth. Therefore, to produce plastic products
and components, which finds application in many industrial as well
as household consumer products is beneficial. Since 50% plastic
products are manufactured by injection moulding process. For
production of better quality product, we have to control quality
characteristics and performance of the product. The process
parameters plays a significant role in production of plastic, hence the
control of process parameter is essential. In this paper the effect of
the parameters selection on injection moulding process has been
described. It is to define suitable parameters in producing plastic
product. Selecting the process parameter by trial and error is neither
desirable nor acceptable, as it is often tends to increase the cost and
time. Hence, optimization of processing parameter of injection
moulding process is essential. The experiments were designed with
Taguchi’s orthogonal array to achieve the result with least number of
experiments. Plastic material polypropylene is studied. Tensile
strength test of material is done on universal testing machine, which
is produced by injection moulding machine. By using Taguchi
technique with the help of MiniTab-14 software the best value of
injection pressure, melt temperature, packing pressure and packing
time is obtained. We found that process parameter packing pressure
contribute more in production of good tensile plastic product.