Abstract: In wastewater treatment processes, aeration introduces
air into a liquid. In these systems, air is introduced by different
devices submerged in the wastewater. Smaller bubbles result in more
bubble surface area per unit of volume and higher oxygen transfer
efficiency. Jet pumps are devices that use air bubbles and are widely
used in wastewater treatment processes. The principle of jet pumps is
their ability to transfer energy of one fluid, called primary or motive,
into a secondary fluid or gas. These pumps have no moving parts and
are able to work in remote areas under extreme conditions. The
objective of this work is to study experimentally the characteristics of
the jet pump and the size of air bubbles in the laboratory water tank.
The effect of flow rate ratio on pump performance is investigated in
order to have a better understanding about pump behavior under
various conditions, in order to determine the efficiency of receiving
air bubbles different sizes. The experiments show that we should take
care when increasing the flow rate ratio while seeking to decrease
bubble size in the outlet flow. This study will help improve and
extend the use of the jet pump in many practical applications.
Abstract: Many industrial materials like magnets need to be
tested for the radiation environment expected at linear colliders (LC)
where the accelerator and detectors will be subjected to large
influences of beta, neutron and gamma’s over their life Gamma
irradiation of the permanent sample magnets using a 60Co source was
investigated up to an absorbed dose of 700Mrad shows a negligible
effect on some magnetic properties of Nd-Fe-B. In this work it has
been tried to investigate the change of some important properties of
Barium hexa ferrite. Results showed little decreases of magnetic
properties at doses rang of 0.5 to 2.5 Mrad. But at the gamma
irradiation dose up to 10 Mrad it is showed a few increase of
properties. Also study of gamma irradiation of Nd-Fe-B showed
considerably increase of magnetic properties.
Abstract: Many factors influence the educational outcome of
students. Some of these have been studied by researchers with many
emphasizing the role of students, schools, governments, peer groups
and so on. More often than not, some of these factors influencing the
academic achievement of the students have been traced back to
parents and family; being the primary platform on which learning not
only begins but is nurtured, encouraged and developed which later
transforms to the performance of the students. This study not only
explores parental and related factors that predict academic
achievement through the review of relevant literatures but also,
investigates the influence of parental background on the academic
achievement of senior secondary school students in Ibadan North
Local Government Area of Oyo State, Nigeria. As one of the criteria
of the quality of education, students’ academic achievement was
investigated because it is most often cited as an indicator of school
effectiveness by school authorities and educationists. The data
collection was done through interviews and use of well-structured
questionnaires administered to one hundred students (100) within the
target local government. This was statistically analysed and the result
showed that parents’ attitudes towards their children’s education had
significant effect(s) on students’ self-reporting of academic
achievement. However, such factors as parental education and socioeconomic
background had no significant relationship with the
students’ self-reporting of academic achievement.
Abstract: The iron environment in Fe-doped Vycor Anode was
investigated with EXAFS using Brookhaven Synchrotron Light
Source. The iron-reducing Shewanella oneidensis culture was grown
in a microbial fuel cell under anaerobic respiration. The Fe bond
length was found to decrease and correlate with the amount of
biofilm growth on the Fe-doped Vycor Anode. The data suggests that
Fe-doped Vycor Anode would be a good substrate to study the
Shewanella oneidensis nanowire structure using EXAFS.
Abstract: The arsenic and iron environments in different growth
stages have been studied with EXAFS and XANES using
Brookhaven Synchrotron Light Source. Collard Greens plants were
grown and tissue samples were harvested. The project studied the
EXAFS and XANES of tissue samples using As and Fe K-edges. The
Fe absorption and the Fourier transform bond length information
were used as a control comparison. The Fourier transform of the
XAFS data revealed the coexistence of As (III) and As (V) in the As
bonding environment inside the studied plant tissue samples,
although the soil only had As (III). The data suggests that Collard
Greens has a novel pathway to handle arsenic absorption in soil.
Abstract: With the flourishing development of online shopping,
an increasing number of customers see online shopping as an
entertaining experience. Because the online consumer has a double
identity as a shopper and an Internet user, online shopping should offer
hedonic values of shopping and Internet usage. The purpose of this
study is to investigate hedonic online shopping motivations from the
perspectives of traditional hedonic value and flow theory.
The study adopted a focus group interview method, including two
online and two offline interviews. Four focus groups of shoppers
consisted of online professionals, online college students, offline
professionals and offline college students. The results of the study
indicate that traditional hedonic values and dimensions of flow theory
exist in the online shopping environment. The study indicated that
online shoppers seem to appreciate being able to learn things and grow
to become competitive achievers online. Comparisons of online
hedonic motivations between groups are conducted. This study serves
as a basis for the future growth of Internet marketing.
Abstract: A simple adaptive voice activity detector (VAD) is
implemented using Gabor and gammatone atomic decomposition of
speech for high Gaussian noise environments. Matching pursuit is
used for atomic decomposition, and is shown to achieve optimal
speech detection capability at high data compression rates for low
signal to noise ratios. The most active dictionary elements found by
matching pursuit are used for the signal reconstruction so that the
algorithm adapts to the individual speakers dominant time-frequency
characteristics. Speech has a high peak to average ratio enabling
matching pursuit greedy heuristic of highest inner products to isolate
high energy speech components in high noise environments. Gabor
and gammatone atoms are both investigated with identical
logarithmically spaced center frequencies, and similar bandwidths.
The algorithm performs equally well for both Gabor and gammatone
atoms with no significant statistical differences. The algorithm
achieves 70% accuracy at a 0 dB SNR, 90% accuracy at a 5 dB SNR
and 98% accuracy at a 20dB SNR using 30d B SNR as a reference
for voice activity.
Abstract: Fruit juices play important roles in human health as
being a key part of nutrition. Juice and nectar are two categories of
drinks with so many variations for consumers, regardless of age,
lifestyle and taste preferences, which they can find their favorites.
Juices contain 100% pulp when pulp content of ‘nectar’ changes
between 25%-50%. In this study, potassium (K), magnesium (Mg),
and phosphorus (P) contents in orange juice and nectar is determined
for conscious consumption. For this purpose inductively coupled
plasma optical emission spectrometry (ICP-OES) is used to find out
potassium (K), magnesium (Mg), and phosphorus (P) contents in
orange juices and nectar. Furthermore, the daily intake of elements
from orange juice and nectar that affects human health is also
investigated. From the results of experiments K, Mg and P contents
are found in orange juice as 1351; 73,25; 89,27 ppm and in orange
nectar as 986; 33,76; 51,30 respectively.
Abstract: Kidney cancer is the most lethal urological cancer
accounting for 3% of adult malignancies. VHL, a tumor-suppressor
gene, is best known to be associated with renal cell carcinoma
(RCC). The VHL functions as negative regulator of hypoxia inducible
factors. Recent sequencing efforts have identified several novel
frequent mutations of histone modifying and chromatin remodeling
genes in ccRCC (clear cell RCC) including PBRM1 and SETD2. The
PBRM1 gene encodes the BAF180 protein, which involved in
transcriptional activation and repression of selected genes. SETD2
encodes a histone methyltransferase, which may play a role in
suppressing tumor development. In this study, RNAs of 30 paired
tumor and normal samples that were grouped according to the types
of kidney cancer and clinical characteristics of patients, including
gender and average age were examined by RT-PCR, SSCP and
sequencing techniques. VHL, PBRM1 and SETD2 expressions were
relatively down-regulated. However, statistically no significance was
found (Wilcoxon signed rank test, p>0.05). Interestingly, no mutation
was observed on the contrary of previous studies. Understanding the
molecular mechanisms involved in the pathogenesis of RCC has
aided the development of molecular-targeted drugs for kidney cancer.
Further analysis is required to identify the responsible genes rather
than VHL, PBRM1 and SETD2 in kidney cancer.
Abstract: The atmospheres in many cities along the coastal lines
in the world have been rapidly changed to coastal-industrial
atmosphere. Hence, it is vital to investigate the corrosion behavior of
steel exposed to this kind of environment. In this present study,
Electrochemical Impedance Spectrography (EIS) and film thickness
measurement were applied to monitor the corrosion behavior of
weathering steel covered with a thin layer of the electrolyte in a
wet-dry cyclic condition, simulating a coastal-industrial environment
at 25oC and 60% RH. The results indicate that in all cycles, the
corrosion rate increases during the drying process due to an increase in
anion concentration and an acceleration of oxygen diffusion enhanced
by the effect of the thinning out of the electrolyte. During the wet-dry
cyclic corrosion test, the long-term corrosion behavior of this steel
depends on the periods of exposure. Corrosion process is first
accelerated and then decelerated. The decelerating corrosion process is
contributed to the formation of the protective rust, favored by the
wet-dry cycle and the acid regeneration process during the rusting
process.
Abstract: The problems arising from unbalanced data sets
generally appear in real world applications. Due to unequal class
distribution, many researchers have found that the performance of
existing classifiers tends to be biased towards the majority class. The
k-nearest neighbors’ nonparametric discriminant analysis is a method
that was proposed for classifying unbalanced classes with good
performance. In this study, the methods of discriminant analysis are
of interest in investigating misclassification error rates for classimbalanced
data of three diabetes risk groups. The purpose of this
study was to compare the classification performance between
parametric discriminant analysis and nonparametric discriminant
analysis in a three-class classification of class-imbalanced data of
diabetes risk groups. Data from a project maintaining healthy
conditions for 599 employees of a government hospital in Bangkok
were obtained for the classification problem. The employees were
divided into three diabetes risk groups: non-risk (90%), risk (5%),
and diabetic (5%). The original data including the variables of
diabetes risk group, age, gender, blood glucose, and BMI were
analyzed and bootstrapped for 50 and 100 samples, 599 observations
per sample, for additional estimation of the misclassification error
rate. Each data set was explored for the departure of multivariate
normality and the equality of covariance matrices of the three risk
groups. Both the original data and the bootstrap samples showed nonnormality
and unequal covariance matrices. The parametric linear
discriminant function, quadratic discriminant function, and the
nonparametric k-nearest neighbors’ discriminant function were
performed over 50 and 100 bootstrap samples and applied to the
original data. Searching the optimal classification rule, the choices of
prior probabilities were set up for both equal proportions (0.33: 0.33:
0.33) and unequal proportions of (0.90:0.05:0.05), (0.80: 0.10: 0.10)
and (0.70, 0.15, 0.15). The results from 50 and 100 bootstrap samples
indicated that the k-nearest neighbors approach when k=3 or k=4 and
the defined prior probabilities of non-risk: risk: diabetic as 0.90:
0.05:0.05 or 0.80:0.10:0.10 gave the smallest error rate of
misclassification. The k-nearest neighbors approach would be
suggested for classifying a three-class-imbalanced data of diabetes
risk groups.
Abstract: Press-hardened profiles are used e.g. for automotive
applications in order to improve light weight construction due to the
high reachable strength. The application of interior water-air spray
cooling contributes to significantly reducing the cycle time in the
production of heat-treated tubes. This paper describes a new
manufacturing method for producing press-hardened hollow profiles
by means of an additional interior cooling based on a water-air spray.
Furthermore, this paper provides the results of thorough
investigations on the properties of press-hardened tubes in
dependence of varying spray parameters.
Abstract: High density electrical prospecting has been widely
used in groundwater investigation, civil engineering and
environmental survey. For efficient inversion, the forward modeling
routine, sensitivity calculation, and inversion algorithm must be
efficient. This paper attempts to provide a brief summary of the past
and ongoing developments of the method. It includes reviews of the
procedures used for data acquisition, processing and inversion of
electrical resistivity data based on compilation of academic literature.
In recent times there had been a significant evolution in field survey
designs and data inversion techniques for the resistivity method. In
general 2-D inversion for resistivity data is carried out using the
linearized least-square method with the local optimization technique
.Multi-electrode and multi-channel systems have made it possible to
conduct large 2-D, 3-D and even 4-D surveys efficiently to resolve
complex geological structures that were not possible with traditional
1-D surveys. 3-D surveys play an increasingly important role in very
complex areas where 2-D models suffer from artifacts due to off-line
structures. Continued developments in computation technology, as
well as fast data inversion techniques and software, have made it
possible to use optimization techniques to obtain model parameters to
a higher accuracy. A brief discussion on the limitations of the
electrical resistivity method has also been presented.
Abstract: This study investigated the behavior of improved soft soils through the vibro replacement technique by considering their settlements and consolidation rates and the applicability of this technique in various types of soils and settlement and bearing capacity calculations.
Abstract: We investigated the structure and electronic properties
of the compound Mg1-xBixO with varying concentrations of 0, ¼, ½,
and ¾ x bismuth in the the cesium chloride (CsCl), zinc-blende
(ZnS), nickel arsenide (NiAs) NaCl (rock-salt) and WZ (wurtzite)
phases. We calculated. The calculations were performed using the
first-principles pseudo-potential method within the framework of spin
density functional theory (DFT).
Abstract: The effect of additional magnesium oxide (MgO) was
investigated by using the tungsten oxide supported on silica catalyst
(WOx/SiO2) physically mixed with MgO in a weight ratio 1:1. The
both fresh and spent catalysts were characterized by FT-Raman
spectrometer, UV-Vis spectrometer, X-Ray diffraction (XRD) and
temperature programmed oxidation (TPO). The results indicated that
the additional MgO could enhance the conversion of trans-2-butene
due to isomerization reaction. However, adding MgO would increase
the amount of coke deposit on the WOx/SiO2 catalyst. The TPO
profile presented two peaks when the WOx/SiO2 catalyst was
physically mixed with MgO. The further peak was suggested that
came from coke precursor could be produced by isomerization
reaction of undesired product. Then, the occurred coke precursor
could deposit and form coke on the acid catalyst.
Abstract: Heat transfer of leaves is a crucial factor in optimal
operation of metabolic functions in plants. In order to quantify this
phenomenon in different leaves and investigate the influence of leaf
shape on heat transfer, natural convection for pine, orange and olive
leaves was simulated as representatives of different groups of leaf
shapes. CFD techniques were used in this simulation with the
purpose to calculate heat transfer of leaves in similar environmental
conditions. The problem was simulated for steady state and threedimensional
conditions. From obtained results, it was concluded that
heat fluxes of all three different leaves are almost identical, however,
total rate of heat transfer have highest and lowest values for orange
leaves, and pine leaves, respectively.
Abstract: Ibeno, Nigeria hosts the operational base of Mobil
Producing Nigeria Unlimited (MPNU), a subsidiary of ExxonMobil
and the current highest oil & condensate producer in Nigeria. Besides
MPNU, other oil companies operate onshore, on the continental shelf
and deep offshore of the Atlantic Ocean in Ibeno, Nigeria. This study
was designed to delineate oil polluted sites in Ibeno, Nigeria using
geophysical methods of electrical resistivity (ER) and ground
penetrating radar (GPR). Results obtained revealed that there have
been hydrocarbon contaminations of this environment by past crude
oil spills as observed from high resistivity values and GPR profiles
which clearly show the distribution, thickness and lateral extent of
hydrocarbon contamination as represented on the radargram reflector
tones. Contaminations were of varying degrees, ranging from slight
to high, indicating levels of substantial attenuation of crude oil
contamination over time. Moreover, the display of relatively lower
resistivities of locations outside the impacted areas compared to
resistivity values within the impacted areas and the 3-D Cartesian
images of oil contaminant plume depicted by red, light brown and
magenta for high, low and very low oil impacted areas, respectively
confirmed significant recent pollution of the study area with crude
oil.
Abstract: An unconventional composite inorganic ceramic
membrane capable of enhancing carbon dioxide emission decline was
fabricated and tested at laboratory scale in conformism to various
environmental guidelines and also to mitigate the effect of global
warming. A review of the existing membrane technologies for carbon
capture including the relevant gas transport mechanisms is presented.
Single gas permeation experiments using silica modified ceramic
membrane with internal diameter 20mm, outside diameter 25mm and
length of 368mm deposited on a macro porous support was carried
out to investigate individual gas permeation behaviours at different
pressures at room temperature. Membrane fabrication was achieved
using after a dip coating method. Nitrogen, Carbon dioxide, Argon,
Oxygen and Methane pure gases were used to investigate their
individual permeation rates at various pressures. Results show that
the gas flow rate increases with pressure drop. However above a
pressure of 3bar, CO2 permeability ratio to that of the other gases
indicated control of a more selective surface adsorptive transport
mechanism.
Abstract: This study investigates the use of a time-series of
MODIS NDVI data to identify agricultural land cover change on an
annual time step (2007 - 2012) and characterize the trend. Following
an ISODATA classification of the MODIS imagery to selectively
mask areas not agriculture or semi-natural, NDVI signatures were
created to identify areas cereals and vineyards with the aid of
ancillary, pictometry and field sample data for 2010. The NDVI
signature curve and training samples were used to create a decision
tree model in WEKA 3.6.9 using decision tree classifier (J48)
algorithm; Model 1 including ISODATA classification and Model 2
not. These two models were then used to classify all data for the
study area for 2010, producing land cover maps with classification
accuracies of 77% and 80% for Model 1 and 2 respectively. Model 2
was subsequently used to create land cover classification and change
detection maps for all other years. Subtle changes and areas of
consistency (unchanged) were observed in the agricultural classes
and crop practices. Over the years as predicted by the land cover
classification. Forty one percent of the catchment comprised of
cereals with 35% possibly following a crop rotation system.
Vineyards largely remained constant with only one percent
conversion to vineyard from other land cover classes.