Abstract: In Croatia, the majority of cultured marine fish species are reared in net cages. The intensive production of the fish in net cages may generate the considerable amount of bio waste and change water quality especially in enclosed and semi-enclosed coastal areas. The aim of this paper is to assess the potential impact of sea bass (Dicentrarchus labrax L.) cage farm on water quality. The weak relationship between food supply and water quality parameters (nutrient content and phytoplankton biomass) was found, but significant changes in oxygen saturation was observed in the cages during the warmer period of a year especially in the morning (occasionally it dropped below 70 %). Despite of, satisfactory results of water quality parameters, it is necessary to establish comprehensive monitoring process, especially to include quality assessment of fouling communities.
Abstract: In a transcutanious inductive coupling of a biomedical
implant, a new formula is given for the study of the Radio Frequency
power attenuation by the biological tissue. The loss of the signal
power is related to its interaction with the biological tissue and the
composition of this one. A confrontation with the practical
measurements done with a synthetic muscle into a Faraday cage,
allowed a checking of the obtained theoretical results. The
supply/data transfer systems used in the case of biomedical implants,
can be well dimensioned by taking in account this type of power
attenuation.
Abstract: A submerged horizontal plate type breakwater is
pointed out as an efficient wave protection device for cage culture in
marine fishery. In order to reveal the wave elimination principle of this
type breakwater, boundary element method is utilized to investigate
this problem. The flow field and the trajectory of water particles are
studied carefully. The flow field analysis shows that: the interaction of
incident wave and adverse current above the plate disturbs the water
domain drastically. This can slow down the horizontal velocity and
vertical velocity of the water particles.
Abstract: There is a variety of inconsistencies in the differences
in alcohol use and related problems between male and female
genders. This study was aimed at analyzing the gender differences in
alcohol use and related problems among university students in
Minsk, Belarus. A total of 465 male (average age of 21) and 1030
female (average age of 20.5) students from four major universities in
Minsk, Belarus were administered WHO recommended standardized
screening instruments – AUDIT, MAST, CAGE questionnaire, as
well as other alcohol related questions. The male to female ratio for
the prevalence of alcohol problems according to the AUDIT was
3.34, while the ratio for alcohol users was 0.97. There are a wide
gender differences in the pattern of alcohol use and preference for
different alcoholic beverages, cause for drinking, and other alcohol
related problems like injuries and blackouts.
Abstract: This paper is proposed the dynamic simulation of
small power induction motor based on Mathematical modeling. The
dynamic simulation is one of the key steps in the validation of the
design process of the motor drive systems and it is needed for
eliminating inadvertent design mistakes and the resulting error in the
prototype construction and testing. This paper demonstrates the
simulation of steady-state performance of induction motor by
MATLAB Program Three phase 3 hp induction motor is modeled
and simulated with SIMULINK model.
Abstract: There is a paucity of data on the prevalence of alcohol
use and related problems among foreign students in Belarus. We
therefore screen for the prevalence of alcohol related problems
among the general foreign students- population in Minsk, Belarus.
Participants were 135 male university foreign students (average age –
21) from three major universities in Minsk, Belarus. All respondents
were administered questionnaire, containing the AUDIT, CAGE,
MAST and other alcohol related questions. Overall, 62.2% (n=84)
alcohol users and 31.1% (n=42) problem drinkers were identified on
the AUDIT. There was a significant increase (from 39.3% to 60.7%)
of the total alcohol users after arrival in Belarus (¤ç2 = 7.714, p
Abstract: This study was conducted to investigate the optimum
levels of glutamine (Gln) supplementation in broiler diets. A total of
32 one-day-old male chicks with initial body weight 41.5 g were
segregated into 4 groups (8 chicks per group) and subsequently
distributed to individual cages. Feed and water were provided ad
libitum for 21 days. Four dietary treatments were as follows: control
and supplemented Gln at 1, 2 and 3%, respectively. The results found
that the addition Gln had no negative effects on dry matter, organic
matter, ash digestibility or nitrogen retention. Birds fed with 1% Gln
had significantly higher villi wide and villi height : crypt depth ratio
in duodenum than the control chicks and 2 and 3% Gln chicks. It is
suggested that the addition of Gln at 1% indicated a beneficial effect
on improving small intestinal morphology, in addition Gln may
stimulate immune organ development of broiler chickens.
Abstract: Detection of squirrel cage induction motor (SCIM) broken bars has long been an important but difficult job in the detection area of motor faults. Early detection of this abnormality in the motor would help to avoid costly breakdowns. A new detection method based on particle swarm optimization (PSO) is presented in this paper. Stator current in an induction motor will be measured and characteristic frequency components of faylted rotor will be detected by minimizing a fitness function using pso. Supply frequency and side band frequencies and their amplitudes can be estimated by the proposed method. The proposed method is applied to a faulty motor with one and two broken bars in different loading condition. Experimental results prove that the proposed method is effective and applicable.
Abstract: The mineral having chemical compositional formula MgAl2O4 is called “spinel". The ferrites crystallize in spinel structure are known as spinel-ferrites or ferro-spinels. The spinel structure has a fcc cage of oxygen ions and the metallic cations are distributed among tetrahedral (A) and octahedral (B) interstitial voids (sites). The X-ray diffraction (XRD) intensity of each Bragg plane is sensitive to the distribution of cations in the interstitial voids of the spinel lattice. This leads to the method of determination of distribution of cations in the spinel oxides through XRD intensity analysis. The computer program for XRD intensity analysis has been developed in C language and also tested for the real experimental situation by synthesizing the spinel ferrite materials Mg0.6Zn0.4AlxFe2- xO4 and characterized them by X-ray diffractometry. The compositions of Mg0.6Zn0.4AlxFe2-xO4(x = 0.0 to 0.6) ferrites have been prepared by ceramic method and powder X-ray diffraction patterns were recorded. Thus, the authenticity of the program is checked by comparing the theoretically calculated data using computer simulation with the experimental ones. Further, the deduced cation distributions were used to fit the magnetization data using Localized canting of spins approach to explain the “recovery" of collinear spin structure due to Al3+ - substitution in Mg-Zn ferrites which is the case if A-site magnetic dilution and non-collinear spin structure. Since the distribution of cations in the spinel ferrites plays a very important role with regard to their electrical and magnetic properties, it is essential to determine the cation distribution in spinel lattice.
Abstract: The numerous qualities of squirrel cage induction
machines enhance their use in industry. However, various faults can
occur, such as stator short-circuits and rotor failures.
In this paper, we use a technique based on the spectral analysis of
stator current in order to detect the fault in the machine: broken rotor
bars. Thus, the number effect of the breaks has been highlighted. The
effect is highlighted by considering the machine controlled by the
Direct Torque Control (DTC). The key to fault detection is the
development of a simplified dynamic model of a squirrel cage
induction motor taking account the broken bars fault and the stator
current spectrum analysis (FFT).
Abstract: LDPC codes could be used in magnetic storage devices because of their better decoding performance compared to other error correction codes. However, their hardware implementation results in large and complex decoders. This one of the main obstacles the decoders to be incorporated in magnetic storage devices. We construct small high girth and rate 2 columnweight codes from cage graphs. Though these codes have low performance compared to higher column weight codes, they are easier to implement. The ease of implementation makes them more suitable for applications such as magnetic recording. Cages are the smallest known regular distance graphs, which give us the smallest known column-weight 2 codes given the size, girth and rate of the code.
Abstract: The impact of fixed speed squirrel cage type as well as
variable speed doubly fed induction generators (DFIG) on dynamic
performance of a multimachine power system has been investigated.
Detailed models of the various components have been presented and
the integration of asynchronous and synchronous generators has been
carried out through a rotor angle based transform. Simulation studies
carried out considering the conventional dynamic model of squirrel
cage asynchronous generators show that integration, as such, could
degrade to the AC system performance transiently. This article
proposes a frequency or power controller which can effectively
control the transients and restore normal operation of fixed speed
induction generator quickly. Comparison of simulation results
between classical cage and doubly-fed induction generators indicate
that the doubly fed induction machine is more adaptable to
multimachine AC system. Frequency controller installed in the DFIG
system can also improve its transient profile.
Abstract: In recent years, rehabilitation has been the subject of extensive research due to increased spending on building work and repair of built works. In all cases, it is absolutely essential to carry out methods of strengthening or repair of structural elements, and that following an inspection analysis and methodology of a correct diagnosis. The reinforced concrete columns are important elements in building structures. They support the vertical loads and provide bracing against the horizontal loads. This research about the behavior of reinforced concrete rectangular columns, rehabilitated by concrete liner, confinement FRP fabric, steel liner or cage formed by metal corners. It allows comparing the contributions of different processes used perspective section resistance elements rehabilitated compared to that is not reinforced or repaired. The different results obtained revealed a considerable gain in bearing capacity failure of reinforced sections cladding concrete, metal bracket, steel plates and a slight improvement to the section reinforced with fabric FRP. The use of FRP does not affect the weight of the structures, but the use of different techniques cladding increases the weight of elements rehabilitated and therefore the weight of the building which requires resizing foundations.
Abstract: The operational behavior of a six-phase squirrel cage
induction machine with faulted stator terminals is presented in this
paper. The study is carried out using the derived mathematical model
of the machine in the arbitrary reference frame. Tests are conducted
on a 1 kW experimental machine.
Steady-state and dynamic performance are analyzed for the
machine unloaded and loaded conditions. The results shows that with
one of the stator phases experiencing either an open- circuit or short
circuit fault the machine still produces starting torque, albeit the
running performance is significantly derated.
Abstract: The line start permanent magnet motor (LSPMM)
combines a permanent magnet rotor for a better motor efficiency
during synchronous running with an induction motor squirrel cage
rotor to permit the motor starting by direct coupling to power source.
In this paper effect of the rotor structure on a line start synchronous
permanent magnet motor (LSPMM) is analyzed. LSPMM motor with
three different structures for rotor is designed by using RMxprt
software; efficiency and line current of LSPMM motor for different
structures in full-load condition have been presented. The results
indicate that with correct choosing of rotor structure, maximum
efficiency can be found.