Abstract: Concurrent planning of project scheduling and
material ordering can provide more flexibility to the project
scheduling problem, as the project execution costs can be enhanced.
Hence, the issue has been taken into account in this paper. To do so, a
mixed-integer mathematical model is developed which considers the
aforementioned flexibility, in addition to the materials quantity
discount and space availability restrictions. Moreover, the activities
duration has been treated as decision variables. Finally, the efficiency
of the proposed model is tested by different instances. Additionally,
the influence of the aforementioned parameters is investigated on the
model performance.
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: In this paper, the unstable angle of attack of a
FOXTROT aircraft is controlled by using Genetic Algorithm based
flight controller and the result is compared with the conventional
techniques like Tyreus-Luyben (TL), Ziegler-Nichols (ZN) and
Interpolation Rule (IR) for tuning the PID controller. In addition, the
performance indices like Mean Square Error (MSE), Integral Square
Error (ISE), and Integral Absolute Time Error (IATE) etc. are
improved by using Genetic Algorithm. It was established that the
error by using GA is very less as compared to the conventional
techniques thereby improving the performance indices of the
dynamic system.
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: 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: High Performance Liquid Chromatography (HPLC)
method was developed and validated for simultaneous estimation of
6-Gingerol(6G) and 6-Shogaol(6S) in joint pain relief gel containing
ginger extract. The chromatographic separation was achieved by
using C18 column, 150 x 4.6mm i.d., 5μ Luna, mobile phase
containing acetonitrile and water (gradient elution). The flow rate
was 1.0 ml/min and the absorbance was monitored at 282 nm. The
proposed method was validated in terms of the analytical parameters
such as specificity, accuracy, precision, linearity, range, limit of
detection (LOD), limit of quantification (LOQ), and determined
based on the International Conference on Harmonization (ICH)
guidelines. The linearity ranges of 6G and 6S were obtained over 20-
60 and 6-18 μg/ml respectively. Good linearity was observed over the
above-mentioned range with linear regression equation Y= 11016x-
23778 for 6G and Y = 19276x-19604 for 6S (x is concentration of
analytes in μg/ml and Y is peak area). The value of correlation
coefficient was found to be 0.9994 for both markers. The limit of
detection (LOD) and limit of quantification (LOQ) for 6G were
0.8567 and 2.8555 μg/ml and for 6S were 0.3672 and 1.2238 μg/ml
respectively. The recovery range for 6G and 6S were found to be
91.57 to 102.36 % and 84.73 to 92.85 % for all three spiked levels.
The RSD values from repeated extractions for 6G and 6S were 3.43
and 3.09% respectively. The validation of developed method on
precision, accuracy, specificity, linearity, and range were also
performed with well-accepted results.
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: Internal circulation two-platen clamping system for
injection molding machine (IMM) has many potential advantages on
energy-saving. In order to estimate its properties, experiments were
carried out in this paper. Displacement and pressure of the components
were measured. In comparison, the model of hydraulic clamping
system was established by using AMESim. The related parameters as
well as the energy consumption could be calculated. According to the
analysis, the hydraulic system was optimized in order to reduce the
energy consumption.
Abstract: Green concrete are generally composed of recycling
materials as hundred or partial percent substitutes for aggregate,
cement, and admixture in concrete. To reduce greenhouse gas
emissions, efforts are needed to develop environmentally friendly
construction materials. Using of fly ash based geopolymer as an
alternative binder can help reduce CO2 emission of concrete. The
binder of geopolymer concrete is different from the ordinary Portland
cement concrete. Geopolymer Concrete specimens were prepared
with different concentration of NaOH solution M10, M14, and, M16
and cured at 60ºC in duration of 24 hours and 8 hours, in addition to
the curing in direct sunlight. Thus, it is necessary to study the effects
of the geopolymer binder on the behavior of concrete. Concrete is
made by using geopolymer technology is environmental friendly and
could be considered as part of the sustainable development. In this
study, the Local Alkaline Activator in Egypt and crashed stone as
coarse aggregate in fly ash based-geopolymer concrete was
investigated. This paper illustrates the development of mechanical
properties. Since the gained compressive strength for geopolymer
concrete at 28 days was in the range of 22.5MPa – 43.9MPa.
Abstract: Local steel slag is produced as a by-product during the
oxidation of steel pellets in an electric arc furnace. Using local steel
slag waste as a hundred substitutes of crashed stone in construction
materials would resolve the environmental problems caused by the
large-scale depletion of the natural sources of crashed stone. This
paper reports the experimental study to investigate the influence of a
hundred replacement of crashed stone as a coarse aggregate with
local steel slag, on the fresh and hardened geopolymer concrete
properties. The investigation includes traditional testing of hardening
concrete, for selected mixes of cement and geopolymer concrete. It
was found that local steel slag as a coarse aggregate enhanced the
slump test of the fresh state of cement and geopolymer concretes.
Nevertheless, the unit weight of concretes was affected. Meanwhile,
the good performance was observed when fly ash used as geopolymer
concrete based.
Abstract: Heat treatable aluminum alloys such as 7075 and
7055, because of high strength and low density, are used widely in
aircraft industry. For best mechanical properties, T6 heat treatment
has recommended for this regards, but this temper treatment is
sensitive to corrosion induced and Stress Corrosion Cracking (SCC)
damage. For improving this property, the over-aging treatment (T7)
applies to this alloy, but it decreases the mechanical properties up to
30 percent. Hence, to increase the mechanical properties, without any
remarkable decrease in SCC resistant, Retrogression and Re-Aging
(RRA) heat treatment is used. This treatment performs in a relatively
short time. In this paper, the RRA heat treatment was applied to 7055
aluminum alloy and then effect of RRA time on the mechanical
properties of 7055 has been investigated. The results show that the
40-minute time is suitable time for retrogression of 7055 aluminum
alloy and ultimate strength increases up to 625MPa.
Abstract: This study presents experimental and optimization of
nanoparticle mass concentration and heat input based on the total
thermal resistance (Rth) of loop heat pipe (LHP), employed for PCCPU
cooling. In this study, silica nanoparticles (SiO2) in water with
particle mass concentration ranged from 0% (pure water) to 1% is
considered as the working fluid within the LHP. The experimental
design and optimization is accomplished by the design of
experimental tool, Response Surface Methodology (RSM). The
results show that the nanoparticle mass concentration and the heat
input have significant effect on the Rth of LHP. For a given heat
input, the Rth is found to decrease with the increase of the
nanoparticle mass concentration up to 0.5% and increased thereafter.
It is also found that the Rth is decreased when the heat input is
increased from 20W to 60W. The results are optimized with the
objective of minimizing the Rth, using Design-Expert software, and
the optimized nanoparticle mass concentration and heat input are
0.48% and 59.97W, respectively, the minimum thermal resistance
being 2.66 (ºC/W).
Abstract: Polycyclic Aromatic Hydrocarbons (PAHs) are
formed mainly because of incomplete combustion of organic
materials during industrial, domestic activities or natural occurrence.
Their toxicity and contamination of terrestrial and aquatic ecosystem
have been established. However, with limited validity index, previous
research has focused on PAHs isomer pair ratios of variable
physicochemical properties in source identification. The objective of
this investigation was to determine the empirical validity of Pearson
Correlation Coefficient (PCC) and Cluster Analysis (CA) in PAHs
source identification along soil samples of different land uses.
Therefore, 16 PAHs grouped, as Endocrine Disruption Substances
(EDSs) were determined in 10 sample stations in top and sub soils
seasonally. PAHs was determined the use of Varian 300 gas
chromatograph interfaced with flame ionization detector. Instruments
and reagents used are of standard and chromatographic grades
respectively. PCC and CA results showed that the classification of
PAHs along pyrolitic and petrogenic organics used in source
signature is about the predominance PAHs in environmental matrix.
Therefore, the distribution of PAHs in the studied stations revealed
the presence of trace quantities of the vast majority of the sixteen
PAHs, which may ultimately inhabit the actual source signature
authentication. Therefore, factors to be considered when evaluating
possible sources of PAHs could be; type and extent of bacterial
metabolism, transformation products/substrates, and environmental
factors such as salinity, pH, oxygen concentration, nutrients, light
intensity, temperature, co-substrates, and environmental medium are
hereby recommended as factors to be considered when evaluating
possible sources of PAHs.
Abstract: In this study, the three-dimensional cavitating
turbulent flow in a complete Francis turbine is simulated using
mixture model for cavity/liquid two-phase flows. Numerical analysis
is carried out using ANSYS CFX software release 12, and standard k-ε
turbulence model is adopted for this analysis. The computational
fluid domain consist of spiral casing, stay vanes, guide vanes, runner
and draft tube. The computational domain is discretized with a threedimensional
mesh system of unstructured tetrahedron mesh. The
finite volume method (FVM) is used to solve the governing equations
of the mixture model. Results of cavitation on the runner’s blades
under three different boundary conditions are presented and
discussed. From the numerical results it has been found that the
numerical method was successfully applied to simulate the cavitating
two-phase turbulent flow through a Francis turbine, and also
cavitation is clearly predicted in the form of water vapor formation
inside the turbine. By comparison the numerical prediction results
with a real runner; it’s shown that the region of higher volume
fraction obtained by simulation is consistent with the region of runner
cavitation damage.
Abstract: The purpose of the study was to examine lifelong
education for teachers as a tool for achieving effective teaching and
learning. Lifelong education enhances social inclusion, personal
development, citizenship, employability, teaching and learning,
community and the nation. It is imperative that the teacher needs to
update his knowledge regularly to be able to perform optimally, since
he has a major position in the inculcation of desirable elements in
students, and the challenges of lifelong education were also
discussed. Descriptive survey design was adopted for the study. A
simple random sampling technique was used to select 80 teachers as
sample from a population of 105 senior secondary school teachers in
Makurdi Local Government Area of Benue State. A 20-item self
designed questionnaire subjected to expert validation and reliability
was used to collect data. The reliability Alpha coefficient of 0.87 was
established using Cronbach’s Alpha technique, mean scores and
standard deviation were used to answer the 2 research questions
while chi-square was used to analyse data for the 2 null hypotheses,
which states that lifelong education for teachers is not a significant
tool for achieving effective teaching and lifelong education for
teachers does not significantly impact on effective learning. The
findings of the study revealed that, lifelong education for teachers can
be used as a tool for achieving effective teaching and learning, and
the study recommended among others that government, organizations
and individuals should in collaboration put lifelong education
programmes for teachers on the priority list. The paper concluded
that the strategic position of lifelong education for teachers towards
enhanced teaching, learning and the production of quality manpower
in the society makes it imperative for all hands to be on “deck” to
support the programme financially and otherwise.
Abstract: Round addition differential fault analysis using
operation skipping for lightweight block ciphers with on-the-fly key
scheduling is presented. For 64-bit KLEIN, it is shown that only a pair
of correct and faulty ciphertexts can be used to derive the secret master
key. For PRESENT, one correct ciphertext and two faulty ciphertexts
are required to reconstruct the secret key. Furthermore, secret key
extraction is demonstrated for the LBlock Feistel-type lightweight
block cipher.
Abstract: In this study, a general approach to the reliability
based limit analysis of laterally loaded piles is presented. In
engineering practice the uncertainties play a very important role. The
aim of this study is to evaluate the lateral load capacity of free-head
and fixed-head long pile when plastic limit analysis is considered. In
addition to the plastic limit analysis to control the plastic behaviour
of the structure, uncertain bound on the complementary strain energy
of the residual forces is also applied. This bound has significant effect
for the load parameter. The solution to reliability-based problems is
obtained by a computer program which is governed by the reliability
index calculation.
Abstract: Temperature regulating system by gaseous nitrogen is
of importance to the space environment simulator, which keeps the
shrouds in the temperature range from -150°C to +150°C. Liquid
nitrogen spray equipment is one of the most critical parts in the
temperature regulating system by gaseous nitrogen. Y type jet
atomizer and internal mixing atomizer of the liquid nitrogen spray
equipment are studied in this paper, 2D/3D atomizer model was
established and grid division was conducted respectively by the
software of Catia and ICEM. Based on the above preparation,
numerical simulation on the spraying process of the atomizer by
FLUENT is performed. Using air and water as the medium,
comparison between the tests and numerical simulation was conducted
and the results of two ways match well. Hence, it can be conclude that
this atomizer model can be applied in the numerical simulation of
liquid nitrogen spray equipment.
Abstract: Cancer is still one of the serious diseases threatening
the lives of human beings. How to have an early diagnosis and
effective treatment for tumors is a very important issue. The animal
carcinoma model can provide a simulation tool for the studies of
pathogenesis, biological characteristics, and therapeutic effects.
Recently, drug delivery systems have been rapidly developed to
effectively improve the therapeutic effects. Liposome plays an
increasingly important role in clinical diagnosis and therapy for
delivering a pharmaceutic or contrast agent to the targeted sites.
Liposome can be absorbed and excreted by the human body, and is
well known that no harm to the human body. This study aimed to
compare the therapeutic effects between encapsulated (doxorubicin
liposomal, Lipodox) and un-encapsulated (doxorubicin, Dox)
anti-tumor drugs using magnetic resonance imaging (MRI).
Twenty-four New Zealand rabbits implanted with VX2 carcinoma at
left thighs were classified into three groups: control group (untreated),
Dox-treated group, and LipoDox-treated group, 8 rabbits for each
group. MRI scans were performed three days after tumor implantation.
A 1.5T GE Signa HDxt whole body MRI scanner with a high
resolution knee coil was used in this study. After a 3-plane localizer
scan was performed, three-dimensional (3D) fast spin echo (FSE)
T2-weighted Images (T2WI) was used for tumor volumetric
quantification. Afterwards, two-dimensional (2D) spoiled gradient
recalled echo (SPGR) dynamic contrast-enhanced (DCE) MRI was
used for tumor perfusion evaluation. DCE-MRI was designed to
acquire four baseline images, followed by contrast agent Gd-DOTA
injection through the ear vein of rabbit. A series of 32 images were
acquired to observe the signals change over time in the tumor and
muscle. The MRI scanning was scheduled on a weekly basis for a
period of four weeks to observe the tumor progression longitudinally.
The Dox and LipoDox treatments were prescribed 3 times in the first
week immediately after the first MRI scan; i.e. 3 days after VX2 tumor
implantation. ImageJ was used to quantitate tumor volume and time
course signal enhancement on DCE images. The changes of tumor size
showed that the growth of VX2 tumors was effectively inhibited for
both LipoDox-treated and Dox-treated groups. Furthermore, the tumor
volume of LipoDox-treated group was significantly lower than that of
Dox-treated group, which implies that LipoDox has better therapeutic effect than Dox. The signal intensity of LipoDox-treated group is
significantly lower than that of the other two groups, which implies
that targeted therapeutic drug remained in the tumor tissue. This study
provides a radiation-free and non-invasive MRI method for
therapeutic monitoring of targeted liposome on an animal tumor
model.
Abstract: Fires is one of the main types of disturbances that
shape ecosystems in the Mediterranean region. However nowadays,
climate alterations towards higher temperatures result on increased
levels of fire intensity, frequency and spread as well as difficulties for
natural regeneration to occur. Thasos Island is one of the Greek
islands that has experienced those problems. Since 1984, a series of
wildfires led to the reduction of forest cover from 61.6% to almost
20%. The negative impacts were devastating in many different
aspects for the island. The absence of plant cover, post-wildfire
precipitation and steep slopes were the major factors that induced
severe soil erosion and intense floods. That also resulted to serious
economic problems to the local communities and the inability of the
burnt areas to regenerate naturally. Despite the substantial amount of
published work regarding Thasos wildfires, there is no information
related to post-wildfire effects on factors such as soil erosion. More
research related to post-fire effects should help to an overall
assessment of the negative impacts of wildfires on land degradation
through processes such as soil erosion and flooding.