Abstract: The aim of present study was to monitor the presence
of Trichodina sp. in Rainbow trout, Oncorhynchus mykiss collected
from various fish farms in the western provinces of Iran during
January, 2013- January, 2014. Out of 675 sampled fish 335, (49.16%)
were infested with Trichodina. The highest prevalence was observed
in the spring and winter followed by autumn and summer. In general,
the intensity of infection was low except in cases where outbreaks of
Trichodiniasis endangered the survival of fish in some ponds. In light
infestation Trichodina is usually present on gills, fins and skin of
apparently healthy fish. Clinical signs of Trichodiniasis only appear
on fish with heavy infections and cases of moderate ones that are
usually exposed to one or more stress factors including, rough
handling during transportation from ponds, overcrowdness,
malnutrition, high of free ammonia and low of oxygen concentration.
Clinical signs of Trichodiniasis in sampled fish were sluggish
movement, loss of appetite, black coloration, necrosis and ulcer on
different parts of the body, detached scales and excessive
accumulation of mucous in gill pouches. The most obvious
histopathological changes in diseased fish were sloughing of the
epidermal layer, aggregation of leucocytes and melanine-carrying
cells (between the dermis and hypodermis) and proliferative changes
including hyperplasia and hypertrophy of the epithelial lining cells of
gill filaments which resulted in fusion of secondary lamellae. Control
of Trichodiniasis, has been achieved by formalin bath treatment at a
concentration of 250 ppm for one hour.
Abstract: Stress Corrosion Crack (SCC) in pipeline is a type of
environmentally assisted cracking (EAC), since its discovery in 1965
as a possible cause of failure in pipeline, SCC has caused, on
average, one of two failures per year in the U.S, According to the
NACE SCC DA a pipe line segment is considered susceptible to SCC
if all of the following factors are met: The operating stress exceeds
60% of specified minimum yield strength (SMYS), the operating
temperature exceeds 38°C, the segment is less than 32 km
downstream from a compressor station, the age of the pipeline is
greater than 10 years and the coating type is other than Fusion
Bonded Epoxy(FBE). In this paper as a practical experience in
NISOC, Direct Assessment (DA) Method is used for identification
SCC defect in unpiggable pipeline located downstream of
compressor station.
Abstract: A noble low NOx combustion technology, based on
partial oxidation combustion concept in a fuel rich combustion zone, is
successfully applied in this research. The burner is designed such that
a portion of fuel is heated and pre-vaporized in the furnace then
injected into a fuel rich combustion zone so that a partial oxidation
reaction occurs. The effects of equivalence ratio, thermal load, and
fuel distribution ratio on the emissions of NOx and CO are
experimentally investigated. This newly developed combustion
technology showed very low NOx emission level, about 12 ppm, when
light oil is used as a fuel.
Abstract: In the present work, hydrogen gas sensor of modest
sensitivity utilizing functionalized multiwalled carbon nanotubes
partially decorated with tin oxide nanoparticles (F-MWCNTs/SnO2)
has been fabricated. This sensing material was characterized by
scanning electron microscopy (SEM). In addition, a remarkable
finding was that the F-MWCNTs/SnO2 sensor shows good sensitivity
as compared to F-MWCNTs for low concentration (0.05-1% by
volume) of H2 gas. The fabricated sensors show complete resistance
recovery and good repeatability when exposed to H2 gas at the room
temperature conditions.
Abstract: In this paper, snow samples containing dust particles
from several sampling points around the city of Ostrava were
analyzed. The pH values of sampled snow were measured and solid
particles analyzed. Particle size, zeta potential and content of selected
heavy metals were determined in solid particles. The pH values of
most samples lay in the slightly acid region. Mean values of particle
size ranged from 290.5 to 620.5 nm. Zeta potential values varied
between -5 and -26.5 mV. The following heavy metal concentration
ranges were found: copper 0.08-0.75 mg/g, lead 0.05-0.9 mg/g,
manganese 0.45-5.9 mg/g and iron 25.7-280.46 mg/g. The highest
values of copper and lead were found in the vicinity of busy
crossroads, and on the contrary, the highest levels of manganese and
iron were detected close to a large steelworks. The proportion
between pH values, zeta potentials, particle sizes and heavy metal
contents was established. Zeta potential decreased with rising pH
values and, simultaneously, heavy metal content in solid particles
increased. At the same time, higher metal content corresponded to
lower particle size.
Abstract: In this paper two approaches to joint signal detection,
time of arrival (ToA) and angle of arrival (AoA) estimation in
multi-element antenna array are investigated. Two scenarios were
considered: first one, when the waveform of the useful signal
is known a priori and, second one, when the waveform of the
desired signal is unknown. For first scenario, the antenna array
signal processing based on multi-element matched filtering (MF)
with the following non-coherent detection scheme and maximum
likelihood (ML) parameter estimation blocks is exploited. For second
scenario, the signal processing based on the antenna array elements
covariance matrix estimation with the following eigenvector analysis
and ML parameter estimation blocks is applied. The performance
characteristics of both signal processing schemes are thoroughly
investigated and compared for different useful signals and noise
parameters.
Abstract: The purpose of the present work is to review some
data for the management challenges that the aquaculture industry in
Greece is currently facing. The results indicate that Greek
aquaculture fish farms apply Human Resources Management (HRM)
practices which can increase motivation, commitment and job
satisfaction of their personnel. In turn, these practices can increase
the productivity of the business. The Greek fish farms appear to
invest in research and technological innovation with a good record in
research activities and the generation of patents. Interestingly, the
results of the present work were carried out during the period of the
recent economic crisis in Greece. Several sectors of the Greek
economy were severely affected by the financial problems of the
Greek government and the Greek banks. Under the adverse
economical conditions created by the Greek economic crisis, even the
Greek aquaculture industry, which historically is considered as a
thriving national exporting business sector, experienced harsh
economic and market conditions. As a result of the global, European
and national economic crisis, consumption of fish dropped while
companies had to hold most of their stocked fish in order to regulated
the flow to the market and the price. This occurred at a time where
Banks in Greece had their own financial crisis – banking crisis -
which resulted in limited access to lending for the all business sectors
of the national economy including the Greek aquaculture industry. In
spite of these economic conditions, the Greek aquaculture industry,
after a series of mergers and acquisitions, has now stabilized
production and exhibits very good prospects for future growth.
Evidently, the firms had to cut salaries and on some occasions even
pay their staff in arrears. Nevertheless, the results presented in this
paper indicate that during the economic crisis, the surveyed fish
farms maintained their HRM practices, investing in their human
capital and technological input. In fact, human capital and
technological input are the ticket for future success of companies in
any business sector.
Abstract: This paper explores the effects of gamification on
lower secondary school students’ motivation and engagement in the
classroom. Two-group posttest-only experimental design were
employed to study the influence of gamification teaching method
(GTM) when compared with conventional teaching method (CTM)
on 60 lower secondary school students. The Student Engagement
Instrument (SEI) and Intrinsic Motivation Inventory (IMI) were used
to assess students’ intrinsic motivation and engagement level towards
the respective teaching method. Finding indicates that students who
completed the GTM lesson were significantly higher in intrinsic
motivation to learn than those from the CTM. Although the result
were insignificant and only marginal difference in the engagement
mean, GTM still show better potential in raising student’s
engagement in class when compared with CTM. This finding proves
that the GTM is likely to solve the current issue of low motivation to
learn and low engagement in class among lower secondary school
students in Malaysia. On the other hand, despite being not significant,
higher mean indicates that CTM positively contribute to higher peer
support for learning and better teacher and student relationship when
compared with GTM. As a conclusion, gamification approach is
flexible and can be adapted into many learning content to enhance the
intrinsic motivation to learn and to some extent, encourage better
student engagement in class.
Abstract: A study was conducted to determine the diversity and
abundance of shorebird species habituating the mudflat area of Jeram
Beach and Remis Beach, Selangor, Peninsular Malaysia. Direct
observation technique (using binoculars and video camera) was
applied to record the presence of bird species in the sampling sites
from August 2013 until July 2014. A total of 32 species of shorebird
were recorded during both migratory and non-migratory seasons. Of
these, eleven species (48%) are migrants, six species (26%) have both
migrant and resident populations, four species (17%) are vagrants and
two species (9%) are residents. The compositions of the birds
differed significantly in all months (χ2 = 84.35, p < 0.001). There is a
significant difference in avian abundance between migratory and
non-migratory seasons (Mann-Whitney, t = 2.39, p = 0.036). The
avian abundance were differed significantly in Jeram and Remis
Beaches during migratory periods (t = 4.39, p = 0.001) but not during
non-migratory periods (t = 0.78, p = 0.456). Shorebird diversity was
also affected by tidal cycle. There is a significance difference
between high tide and low tide (Mann-Whitney, t = 78.0, p < 0.005).
Frequency of disturbance also affected the shorebird distribution
(Mann-Whitney, t = 57.0, p = 0.0134). Therefore, this study
concluded that tides and disturbances are two factors that affecting
temporal distribution of shorebird in mudflats area.
Abstract: Hot aqueous and methanol extracts of the two selected
herbal medicines such are Vellarugu chooranam (V.C) and
Amukkirai Chooranam (A.C) were examined for total phenolic and
flavonoid contents and in vitro antioxidant activity using four
different methods. The total phenolic and flavonoid contents in
methanol extract of V.C were found to be higher (44.41±1.26mg
GAE/g; 174.44±9.32mg QE/g) than in the methanol extract of A.C
(20.56±0.67mg GAE/g; 7.21±0.85mg QE/g). Hot methanol and
aqueous extracts of both medicines showed low antioxidant activity
in DPPH, ABTS, and FRAP methods and Iron chelating activity not
found at highest possible concentration. V.C contains higher
concentrations of total phenolic and flavonoid contents than A.C and
can also exert greater antioxidant activity than A.C, although the
activities demonstrated were lower than the positive control Trolox.
The in vitro antioxidant activity was not related with the total
phenolic and flavonoid contents of the methanol and aqueous extracts
of both herbal medicines (A.C and V.C).
Abstract: This paper presents a method for the efficient
implementation of a unidirectional or bidirectional DC/DC converter.
The DC/DC converter is used essentially for energy exchange
between the low voltage service battery and a high voltage battery
commonly found in Electric Vehicle applications. In these
applications, apart from cost, efficiency of design is an important
characteristic. A useful way to reduce the size of electronic
equipment in the electric vehicles is proposed in this paper. The
technique simplifies the mechanical complexity and maximizes the
energy usage using the latest converter control techniques. Moreover
a bidirectional battery charger for hybrid electric vehicles is also
implemented in this paper. Several simulations on the test system
have been carried out in Matlab/Simulink environment. The results
exemplify the robustness of the proposed design methodology in case
of a 1.5 KW DC-DC converter.
Abstract: This paper presents a comparison between using a
desktop web application and a mobile application for students
enrolling in courses at Rangsit University, Thailand. In addition,
Rangsit University has enhanced the enrollment process by
leveraging its information systems, which allows students to choose
to enroll in courses online. In order to use the system, students must
provide their identification and personal documents for registration.
The reason to have a mobile application is to support students’ ability
to access the system at anytime, anywhere and anyplace. The
objective of this paper was to: 1. Evaluate the success of developing a
user friendly mobile device system and 2. Measure user interest in
future mobile development.
Abstract: This study proposes the transformation of nonlinear
Magnetic Levitation System into linear one, via state and feedback
transformations using explicit algorithm. This algorithm allows
computing explicitly the linearizing state coordinates and feedback
for any nonlinear control system, which is feedback linearizable,
without solving the Partial Differential Equations. The algorithm is
performed using a maximum of N-1 steps where N being the
dimension of the system.
Abstract: Ancillary services are support services which are
essential for humanizing and enhancing the reliability and security of
the electric power system. Reactive power ancillary service is one of
the important ancillary services in a restructured electricity market
which determines the cost of supplying ancillary services and finding
of how this cost would change with respect to operating decisions.
This paper presents a new formation that can be used to minimize the
Independent System Operator (ISO)’s total payment for reactive
power ancillary service. The modified power flow tracing algorithm
estimates the availability of reserve reactive power for ancillary
service. In order to find optimum reactive power dispatch,
Biogeography based optimization method (BPO) is proposed. Market
Reactive Clearing Price (MRCP) is then estimated and it encourages
generator companies (GENCOs) to participate in an ancillary service.
Finally, optimal weighting factor and real time utilization factor of
reactive power give the minimum ISO’s total payment. The
effectiveness of proposed design is verified using IEEE 30 bus
system.
Abstract: In MANET, mobile nodes communicate with each
other using the wireless channel where transmission takes place with
significant interference. The wireless medium used in MANET is a
shared resource used by all the nodes available in MANET. Packet
reserving is one important resource management scheme which
controls the allocation of bandwidth among multiple flows through
node cooperation in MANET. This paper proposes packet reserving
and clogging control via Routing Aware Packet Reserving (RAPR)
framework in MANET. It mainly focuses the end-to-end routing
condition with maximal throughput. RAPR is complimentary system
where the packet reserving utilizes local routing information
available in each node. Path setup in RAPR estimates the security
level of the system, and symbolizes the end-to-end routing by
controlling the clogging. RAPR reaches the packet to the destination
with high probability ratio and minimal delay count. The standard
performance measures such as network security level,
communication overhead, end-to-end throughput, resource utilization
efficiency and delay measure are considered in this work. The results
reveals that the proposed packet reservation and clogging control via
Routing Aware Packet Reserving (RAPR) framework performs well
for the above said performance measures compare to the existing
methods.
Abstract: Recent concerns about the value of teaching cursive
handwriting in the classroom are based on the belief that cursive
handwriting or penmanship is an outdated and unnecessary skill in
today’s online world. The discussion of this issue begins with a
description of current initiatives to eliminate handwriting instruction
in schools. This is followed by a brief history of cursive writing
through the ages. Next considered is a description of its benefits as a
preliminary process for younger children as compared with
immediate instruction in keyboarding, particularly in the areas of
vision, cognition, motor skills and automatic fluency. Also
considered, is cursive’s companion, paper itself, and the impact of a
paperless, “screen and keyboard” environment. The discussion
concludes with a consideration of the unique contributions of cursive
and keyboarding as written forms of communication, along with their
respective surfaces, paper and screen. Finally, an assessment of the
practical utility of each skill is followed by an informal assessment of
what is lost and what remains as we move from a predominantly
paper and pen world of handwriting to texting and keyboarding in an
environment of screens.
Abstract: In this paper the effect of wall waviness of side walls
in a two-dimensional wavy enclosure is numerically investigated.
Two vertical wavy walls and straight top wall are kept isothermal and
the bottom wall temperature is higher and spatially varying with
cosinusoidal temperature distribution. A computational code based on
Finite-volume approach is used to solve governing equations and
SIMPLE method is used for pressure velocity coupling. Test is
performed for several different numbers of undulations. The Prandtl
number was kept constant and the Ra number denotes that the flow is
laminar. Temperature and velocity fields are determined. Therefore,
according to the obtained results a correlation is proposed for average
Nusselt number as a function of number of side wall waves. The
results indicate that the Nusselt number is highly affected by number
of waves and increasing it decreases the wavy walls Nusselt number;
although the Nusselt number is not highly affected by surface
waviness when the number of undulations is below one.
Abstract: This paper presents a 4-DOF nonlinear model of a
cracked de Laval rotor-stator system derived based on Energy
Principles. The model has been used to simulate coupled torsionallateral
response of the faulty system with multiple parametric
excitations; rotor-stator-rub, a breathing transverse crack, eccentric
mass and an axial force. Nonlinearity of a “breathing” crack is
incorporated in the model using a simple hinge mechanism suitable
for a shallow crack. Response of the system while passing via its
critical speed with intermittent rotor-stator rub is analyzed. Effects of
eccentricity with phase and acceleration are investigated. Features of
crack, rub and eccentricity in vibration response are explored for
condition monitoring. The presence of a crack and rub are observable
in the power spectrum despite excitations by an axial force and rotor
unbalance. Obtained results are consistent with existing literature and
could be adopted into rotor condition monitoring strategies.
Abstract: In this paper, design of solid-state battery/supercapacitor emulator based on dc-dc boost converter is described.
The emulator mimics charging behavior of any storage device based
on a predefined behavior set by the user. The device is operated by a
two-level control structure: high-level emulating controller and low-
level input voltage controller. Simulation and experimental results are
shown to demonstrate the emulator operation.
Abstract: Different strategies and tools are available at the oil
and gas industry for detecting and analyzing tension and possible
fractures in borehole walls. Most of these techniques are based on
manual observation of the captured borehole images. While this
strategy may be possible and convenient with small images and few
data, it may become difficult and suitable to errors when big
databases of images must be treated. While the patterns may differ
among the image area, depending on many characteristics (drilling
strategy, rock components, rock strength, etc.). In this work we
propose the inclusion of data-mining classification strategies in order
to create a knowledge database of the segmented curves. These
classifiers allow that, after some time using and manually pointing
parts of borehole images that correspond to tension regions and
breakout areas, the system will indicate and suggest automatically
new candidate regions, with higher accuracy. We suggest the use of
different classifiers methods, in order to achieve different knowledge
dataset configurations.