Abstract: Toxicity of copper (Cu), lead (Pb) and iron (Fe) to
Tilapia guinensis was carried out for 4 days with a view to
determining their effects on the liver and muscle tissues. Tilapia
guinensis samples of about 10 - 14cm length and 0.2 – 0.4kg weight
each were obtained from University of Calabar fish ponds and
acclimated for three (3) days before the experimental set up.
Survivors after the 96-hr LC50 test period were selected from test
solutions of the heavy metals for the histopathological studies.
Histological preparations of liver and muscle tissues were randomly
examined for histopathological lesions. Results of the histological
examinations showed gross abnormalities in the liver tissues due to
pathological and degenerative changes compared to liver and muscle
tissues from control samples (tilapia fishes from aquaria without
heavy metals). Extensive hepatocyte necrosis with chronic
inflammatory changes was observed in the liver of fishes exposed to
Cu solution. Similar but less damaging effects were observed in the
liver of fishes exposed to Pb and Fe. The extent of lesion observed
was therefore heavy metal-related. However, no pathologic changes
occurred in the muscle tissues.
Abstract: Boiling process is characterized by the rapid
formation of vapour bubbles at the solid–liquid interface (nucleate
boiling) with pre-existing vapour or gas pockets. Computational fluid
dynamics (CFD) is an important tool to study bubble dynamics. In
the present study, CFD simulation has been carried out to determine
the bubble detachment diameter and its terminal velocity. Volume of
fluid method is used to model the bubble and the surrounding by
solving single set of momentum equations and tracking the volume
fraction of each of the fluids throughout the domain. In the
simulation, bubble is generated by allowing water-vapour to enter a
cylinder filled with liquid water through an inlet at the bottom. After
the bubble is fully formed, the bubble detaches from the surface and
rises up during which the bubble accelerates due to the net balance
between buoyancy force and viscous drag. Finally when these forces
exactly balance each other, it attains a constant terminal velocity. The
bubble detachment diameter and the terminal velocity of the bubble
are captured by the monitor function provided in FLUENT. The
detachment diameter and the terminal velocity obtained are compared
with the established results based on the shape of the bubble. A good
agreement is obtained between the results obtained from simulation
and the equations in comparison with the established results.
Abstract: The main objective of this article is to examine the
impact of interest rates on investments in Poland in the context of
financial crisis. The paper also investigates the dependence of bank
loans to enterprises on interbank market rates. The article studies the
impact of interbank market rate on the level of investments in Poland.
Besides, this article focuses on the research of the correlation
between the level of corporate loans and the amount of investments
in Poland in order to determine the indirect impact of central bank
interest rates through the transmission mechanism of monetary policy
on the real economy. To achieve the objective we have used
econometric and statistical research methods like: econometric model
and Pearson correlation coefficient.
This analysis suggests that the central bank reference rate
inversely proportionally affects the level of investments in Poland
and this dependence is moderate. This is also important issue because
it is related to preparing of Poland to accession to euro area. The
research is important from both theoretical and empirical points of
view. The formulated conclusions and recommendations determine
the practical significance of the paper which may be used in the
decision making process of monetary and economic authorities of the
country.
Abstract: We investigate experimentally and theoretically the
dynamics of a capacitive resonator under mixed frequency excitation
of two AC harmonic signals. The resonator is composed of a proof
mass suspended by two cantilever beams. Experimental
measurements are conducted using a laser Doppler Vibrometer to
reveal the interesting dynamics of the system when subjected to twosource
excitation. A nonlinear single-degree-of-freedom model is
used for the theoretical investigation. The results reveal combination
resonances of additive and subtractive type, which are shown to be
promising to increase the bandwidth of the resonator near primary
resonance frequency. Our results also demonstrate the ability to shift
the combination resonances to much lower or much higher frequency
ranges. We also demonstrate the dynamic pull-in instability under
mixed frequency excitation.
Abstract: In this paper, we present a model-based regression test
suite reducing approach that uses EFSM model dependence analysis
and probability-driven greedy algorithm to reduce software regression
test suites. The approach automatically identifies the difference
between the original model and the modified model as a set of
elementary model modifications. The EFSM dependence analysis is
performed for each elementary modification to reduce the regression
test suite, and then the probability-driven greedy algorithm is adopted
to select the minimum set of test cases from the reduced regression test
suite that cover all interaction patterns. Our initial experience shows
that the approach may significantly reduce the size of regression test
suites.
Abstract: Academicians at the Arab Open University have
always voiced their concern about the efficacy of the blended
learning process. Based on 75% independent study and 25% face-toface
tutorial, it poses the challenge of the predisposition to
adjustment. Being used to the psychology of traditional educational
systems, AOU students cannot be easily weaned from being spoonfed.
Hence they lack the motivation to plunge into self-study. For
better involvement of AOU students into the learning practices, it is
imperative to diagnose the factors that impede or increase their
motivation. This is conducted through an empirical study grounded
upon observations and tested hypothesis and aimed at monitoring and
optimizing the students’ learning outcome. Recommendations of the
research will follow the findings.
Abstract: To construct the lumped spring-mass model
considering the occupants for the offset frontal crash, the SISAME
software and the NHTSA test data were used. The data on 56 kph 40%
offset frontal vehicle to deformable barrier crash test of a MY2007
Mazda 6 4-door sedan were obtained from NHTSA test database. The
overall behaviors of B-pillar and engine of simulation models agreed
very well with the test data. The trends of accelerations at the driver
and passenger head were similar but big differences in peak values.
The differences of peak values caused the large errors of the HIC36
and 3 ms chest g’s. To predict well the behaviors of dummies, the
spring-mass model for the offset frontal crash needs to be improved.
Abstract: Ontology validation is an important part of web
applications’ development, where knowledge integration and
ontological reasoning play a fundamental role. It aims to ensure the
consistency and correctness of ontological knowledge and to
guarantee that ontological reasoning is carried out in a meaningful
way. Existing approaches to ontology validation address more or less
specific validation issues, but the overall process of validating web
ontologies has not been formally established yet. As the size and the
number of web ontologies continue to grow, more web applications’
developers will rely on the existing repository of ontologies rather
than develop ontologies from scratch. If an application utilizes
multiple independently created ontologies, their consistency must be
validated and eventually adjusted to ensure proper interoperability
between them. This paper presents a validation technique intended to
test the consistency of independent ontologies utilized by a common
application.
Abstract: Designing cost-efficient, secure network protocols for
Wireless Sensor Networks (WSNs) is a challenging problem because
sensors are resource-limited wireless devices. Security services such
as authentication and improved pairwise key establishment are
critical to high efficient networks with sensor nodes. For sensor
nodes to correspond securely with each other efficiently, usage of
cryptographic techniques is necessary. In this paper, two key
predistribution schemes that enable a mobile sink to establish a
secure data-communication link, on the fly, with any sensor nodes.
The intermediate nodes along the path to the sink are able to verify
the authenticity and integrity of the incoming packets using a
predicted value of the key generated by the sender’s essential power.
The proposed schemes are based on the pairwise key with the mobile
sink, our analytical results clearly show that our schemes perform
better in terms of network resilience to node capture than existing
schemes if used in wireless sensor networks with mobile sinks.
Abstract: Under active stress conditions, a rigid cantilever
retaining wall tends to rotate about a pivot point located within the
embedded depth of the wall. For purely granular and cohesive soils, a
methodology was previously reported called minimization of moment
ratio to determine the location of the pivot point of rotation. The
usage of this new methodology is to estimate the rotational stability
safety factor. Moreover, the degree of improvement required in a
backfill to get a desired safety factor can be estimated by the concept
of the shear strength demand. In this article, the accuracy of this
method for another type of cantilever walls called Contiguous Bored
Pile (CBP) retaining wall is evaluated by using physical modeling
technique. Based on observations, the results of moment ratio
minimization method are in good agreement with the results of the
carried out physical modeling.
Abstract: This paper presents an approach for the classification of
an unstructured format description for identification of file formats.
The main contribution of this work is the employment of data mining
techniques to support file format selection with just the unstructured
text description that comprises the most important format features for
a particular organisation. Subsequently, the file format indentification
method employs file format classifier and associated configurations to
support digital preservation experts with an estimation of required file
format. Our goal is to make use of a format specification knowledge
base aggregated from a different Web sources in order to select file
format for a particular institution. Using the naive Bayes method,
the decision support system recommends to an expert, the file format
for his institution. The proposed methods facilitate the selection of
file format and the quality of a digital preservation process. The
presented approach is meant to facilitate decision making for the
preservation of digital content in libraries and archives using domain
expert knowledge and specifications of file formats. To facilitate
decision-making, the aggregated information about the file formats is
presented as a file format vocabulary that comprises most common
terms that are characteristic for all researched formats. The goal is to
suggest a particular file format based on this vocabulary for analysis
by an expert. The sample file format calculation and the calculation
results including probabilities are presented in the evaluation section.
Abstract: This paper presents a computational study of steady
state three dimensional very high turbulent flow and heat transfer
characteristics in a constant temperature-surfaced circular duct fitted
with 900 hemispherical inline baffles. The computations are based on
realizable k-ɛ model with standard wall function considering the
finite volume method, and the SIMPLE algorithm has been
implemented. Computational Study are carried out for Reynolds
number, Re ranging from 80000 to 120000, Prandtl Number, Pr of
0.73, Pitch Ratios, PR of 1,2,3,4,5 based on the hydraulic diameter of
the channel, hydrodynamic entry length, thermal entry length and the
test section. Ansys Fluent 15.0 software has been used to solve the
flow field. Study reveals that circular pipe having baffles has a higher
Nusselt number and friction factor compared to the smooth circular
pipe without baffles. Maximum Nusselt number and friction factor
are obtained for the PR=5 and PR=1 respectively. Nusselt number
increases while pitch ratio increases in the range of study; however,
friction factor also decreases up to PR 3 and after which it becomes
almost constant up to PR 5. Thermal enhancement factor increases
with increasing pitch ratio but with slightly decreasing Reynolds
number in the range of study and becomes almost constant at higher
Reynolds number. The computational results reveal that optimum
thermal enhancement factor of 900 inline hemispherical baffle is
about 1.23 for pitch ratio 5 at Reynolds number 120000.It also shows
that the optimum pitch ratio for which the baffles can be installed in
such very high turbulent flows should be 5. Results show that pitch
ratio and Reynolds number play an important role on both fluid flow
and heat transfer characteristics.
Abstract: Experts, enterprises and operators expect that the
bandwidth request will increase up to rates of 100 to 1,000 Mbps
within several years. Therefore the most important question is which
technology shall satisfy the future consumer broadband demands.
Currently the consensus is, that the fiber technology has the best
technical characteristics to achieve such the high bandwidth rates.
But fiber technology is so far very cost-intensive and resource
consuming. To avoid these investments, operators are concentrating
to upgrade the existing copper and hybrid fiber coax infrastructures.
This work presents a comparison of the copper and fiber
technologies including an overview about the current German
broadband market. Both technologies are reviewed in the terms of
demand, willingness to pay and economic efficiency in connection
with the technical characteristics.
Abstract: The aim of this investigation is to elaborate nearinfrared
methods for testing and recognition of chemical components
and quality in “Pannon wheat” allied (i.e. true to variety or variety
identified) milling fractions as well as to develop spectroscopic
methods following the milling processes and evaluate the stability of
the milling technology by different types of milling products and
according to sampling times, respectively. These wheat categories
produced under industrial conditions where samples were collected
versus sampling time and maximum or minimum yields. The changes
of the main chemical components (such as starch, protein, lipid) and
physical properties of fractions (particle size) were analysed by
dispersive spectrophotometers using visible (VIS) and near-infrared
(NIR) regions of the electromagnetic radiation. Close correlation
were obtained between the data of spectroscopic measurement
techniques processed by various chemometric methods (e.g. principal
component analysis [PCA], cluster analysis [CA]) and operation
condition of milling technology. It is obvious that NIR methods are
able to detect the deviation of the yield parameters and differences of
the sampling times by a wide variety of fractions, respectively. NIR
technology can be used in the sensitive monitoring of milling
technology.
Abstract: By the evolvement in technology, the way of
expressing opinions switched direction to the digital world. The
domain of politics, as one of the hottest topics of opinion mining
research, merged together with the behavior analysis for affiliation
determination in texts, which constitutes the subject of this paper.
This study aims to classify the text in news/blogs either as
Republican or Democrat with the minimum number of features. As
an initial set, 68 features which 64 were constituted by Linguistic
Inquiry and Word Count (LIWC) features were tested against 14
benchmark classification algorithms. In the later experiments, the
dimensions of the feature vector reduced based on the 7 feature
selection algorithms. The results show that the “Decision Tree”,
“Rule Induction” and “M5 Rule” classifiers when used with “SVM”
and “IGR” feature selection algorithms performed the best up to
82.5% accuracy on a given dataset. Further tests on a single feature
and the linguistic based feature sets showed the similar results. The
feature “Function”, as an aggregate feature of the linguistic category,
was found as the most differentiating feature among the 68 features
with the accuracy of 81% in classifying articles either as Republican
or Democrat.
Abstract: In this work, the Ictalurus punctatus species estimated
available physical habitat is compared with the estimated physical
habitat for the same but modified river reach, with the aim of creating
a linear park, along a length of 5 500 m.
To determine the effect of ecological park construction, on
physical habitat of the Lerma river stretch of study, first, the available
habitat for the Ictalurus punctatus species was estimated through the
simulation of the physical habitat, by using surveying, hydraulics,
and habitat information gotten at the river reach in its actual situation.
Second, it was estimated the available habitat for the above species,
upon the simulation of the physical habitat through the proposed
modification for the ecological park creation. Third, it is presented a
comparison between both scenarios in terms of available habitat
estimated for Ictalurus punctatus species, concluding that in cases of
adult and spawning life stages, changes in the channel to create an
ecological park would produce a considerable loss of potentially
usable habitat (PUH), while in the case of the juvenile life stage PUH
remains virtually unchanged, and in the case of life stage fry the PUH
would increase due to the presence of velocities and depths of lesser
magnitude, due to the presence of minor flow rates and lower volume
of the wet channel.
It is expected that habitat modification for linear park construction
may produce the lack of Ictalurus punktatus species conservation at
the river reach of the study.
Abstract: A pilot field study was conducted at the Jagjeetpur
Municipal Sewage treatment plant situated in the Haridwar town in
Uttarakhand state, India. The objectives of the present study were to
study the effect of treated wastewater on the production of various
paddy varieties (Sharbati, PR-114, PB-1, Menaka, PB1121 and PB
1509) and the emission of GHG gases (CO2, CH4 and N2O) as
compared to the same varieties grown in the control plots irrigated
with fresh water. Of late, the concept of water footprint assessment
has emerged, which explains enumeration of various types of water
footprints of an agricultural entity from its production to processing
stages. Paddy, the most water demanding staple crop of Uttarakhand
state, displayed a high green water footprint value of 2474.12 m3/
Ton. Most of the wastewater irrigated varieties displayed up to 6%
increase in production, except Menaka and PB-1121, which showed a
reduction in production (6% and 3% respectively), due to pest and
insect infestation. The treated wastewater was observed to be rich in
Nitrogen (55.94 mg/ml Nitrate), Phosphorus (54.24 mg/ml) and
Potassium (9.78 mg/ml), thus rejuvenating the soil quality and not
requiring any external nutritional supplements. A Percentage increase
of GHG gases of irrigation with treated municipal wastewater as
compared to control plots was observed as 0.4% - 8.6% (CH4), 1.1%
- 9.2% (CO2), and 0.07% - 5.8% (N2O). The variety, Sharbati,
displayed maximum production (5.5 ton/ha) and emerged as the most
resistant variety against pests and insects. The emission values of
CH4, CO2 and N2O were 729.31 mg/m2/d, 322.10 mg/m2/d and
400.21 mg/m2/d in water stagnant condition.
This study highlighted a successful possibility of reuse of
wastewater for non-potable purposes offering the potential for
exploiting this resource that can replace or reduce the existing use of
fresh water sources in agriculture sector.
Abstract: In this study, the experiments were carried out to
determine the best coolant for the quenching process among waterbased
silica, alumina, titania and copper oxide nanofluids (0.1 vol%).
A sphere made up off brass material was used in the experiments.
When the spherical test specimen was heated at high temperatures, it
was suddenly immersed into the nanofluids. All experiments were
carried out at saturated conditions and under atmospheric pressure.
After the experiments, the cooling curves were obtained by using the
temperature-time data of the specimen. The experimental results
showed that the cooling performance of test specimen depended on
the type of nanofluids. The silica nanoparticles enhanced the
performance of boiling heat transfer and it is the best coolant for the
quenching among other nanoparticles.
Abstract: As technology-based service industries grow
drastically worldwide; companies are recognizing the importance of
market preoccupancy and have made an effort to capture a large
market to gain the upper hand. To this end, a focus on patents can be
used to determine the properties of a technology, as well as to capture
advantages in technical skills, in comparison with the firm’s
competitors. However, technology-based services largely depend not
only on their technological value but also their economic value, due
to the recognized worth that is passed to a plurality of users. Thus, it
is important to determine whether there are any competitors in the
target areas and what services they provide in any field. Despite this
importance, little effort has been made to systematically benchmark
competitors in order to identify business opportunities. Thus, this
study aims to not only identify each position of technology-centered
service companies in complex market dynamics, but also to discover
new business opportunities. For this, we try to consider both
technology and market environments simultaneously by utilizing
patent data as a representative proxy for technology and trademark
dates as an index for a firm’s target goods and services. Theoretically,
this is one of the earliest attempts to combine patent data and
trademark data to analyze corporate strategies. In practice, the
research results are expected to be used as a decision criterion to
diagnose the economic value that companies can obtain by entering
the market, as well as the technological value to be passed onto their
customers. Thus, the proposed approach can be useful to support
effective technology and business strategies in a firm.
Abstract: Any signal transmitted over a channel is corrupted by noise and interference. A host of channel coding techniques has been proposed to alleviate the effect of such noise and interference. Among these Turbo codes are recommended, because of increased capacity at higher transmission rates and superior performance over convolutional codes. The multimedia elements which are associated with ample amount of data are best protected by Turbo codes. Turbo decoder employs Maximum A-posteriori Probability (MAP) and Soft Output Viterbi Decoding (SOVA) algorithms. Conventional Turbo coded systems employ Equal Error Protection (EEP) in which the protection of all the data in an information message is uniform. Some applications involve Unequal Error Protection (UEP) in which the level of protection is higher for important information bits than that of other bits. In this work, enhancement to the traditional Log MAP decoding algorithm is being done by using optimized scaling factors for both the decoders. The error correcting performance in presence of UEP in Additive White Gaussian Noise channel (AWGN) and Rayleigh fading are analyzed for the transmission of image with Discrete Cosine Transform (DCT) as source coding technique. This paper compares the performance of log MAP, Modified log MAP (MlogMAP) and Enhanced log MAP (ElogMAP) algorithms used for image transmission. The MlogMAP algorithm is found to be best for lower Eb/N0 values but for higher Eb/N0 ElogMAP performs better with optimized scaling factors. The performance comparison of AWGN with fading channel indicates the robustness of the proposed algorithm. According to the performance of three different message classes, class3 would be more protected than other two classes. From the performance analysis, it is observed that ElogMAP algorithm with UEP is best for transmission of an image compared to Log MAP and MlogMAP decoding algorithms.