Abstract: The following article presents Technology Centre of
Ostrava (TCO) in the Czech Republic describing the structure and
main research areas realized by the project ENET - Energy Units for
Utilization of non Traditional Energy Sources. More details are
presented from the research program dealing with transformation,
accumulation and distribution of electric energy. Technology Centre
has its own energy mix consisting of alternative sources of fuel
sources that use of process gases from the storage part and also the
energy from distribution network. The article will be focus on the
properties and application possibilities SiC semiconductor devices for
power semiconductor converter for photovoltaic systems.
Abstract: This paper shows in detail the mathematical model of
direct and inverse kinematics for a robot manipulator (welding type)
with four degrees of freedom. Using the D-H parameters, screw
theory, numerical, geometric and interpolation methods, the
theoretical and practical values of the position of robot were
determined using an optimized algorithm for inverse kinematics
obtaining the values of the particular joints in order to determine the
virtual paths in a relatively short time.
Abstract: Moringa oleifera is a nutritious vegetable tree with
varieties of potential uses, as almost every part of the Moringa
oleifera tree can be used for food. This study was conducted in Oyo
State, Nigeria, to find out the level of acceptability of Moringa
oleifera diversified products among rural and urban dwellers.
Purposive sampling was used to select two local governments’ areas.
Stratified sampling technique was also used to select one community
each from rural and urban areas while snowball sampling technique
was used to select ten respondents each from the two communities,
making a total number of forty respondents. Data were analyzed
using frequencies, percentages, Chi-square, Pearson Product Moment
Correlation and regression analysis. Result from the study revealed
that majority of the respondents (80%) fell within the age range of
20-49 years and 55% of them were male, 55% were married, 70% of
them were Christians, 80% of them had tertiary education. The result
also showed that 85% were aware of the Moringa plant and (65%) of
them have consumed Moringa oleifera and the perception statements
on the benefits of Moringa oleifera indicated that (52.5%) of the
respondents rated Moringa oleifera to be favorable, most of them had
high acceptability for Moringa egusi soup, Moringa tea, Moringa pap
and yam pottage with Moringa. The result of the hypotheses testing
showed that there is a significant relationship between sex of the
respondents and acceptability of the diversified Moringa oleifera
products (x2=6.465, p = 0.011). There is also a significant
relationship between family size of the respondents level of
acceptability of the Moringa oleifera products (r = 0.327, p = 0.040).
Based on the level of acceptability of Moringa oleifera diversified
products; the plant is of great economic importance to the populace.
Therefore, there should be more public awareness through the media
to enlighten people on the beneficial effects of Moringa oleifera.
Abstract: Recently, there is a lot of interest in the field of under
water optical wireless communication for short range because of
its high bandwidth. But in most of the previous works line of
sight propagation or single scattering of photons only considered.
In practical case this is not applicable because of beam blockage in
underwater and multiple scattering also occurred during the photons
propagation through water. In this paper we consider a non-line
of sight underwater wireless optical communication system with
multiple scattering and examine the performance of the system using
monte carlo simulation. The distribution scattering angle of photons
are modeled by Henyey-Greenstein method. The average bit error
rate is calculated using on-off keying modulation for different water
types.
Abstract: Image compression based on fractal coding is a lossy
compression method and normally used for gray level images range
and domain blocks in rectangular shape. Fractal based digital image
compression technique provide a large compression ratio and in this
paper, it is proposed using YUV colour space and the fractal theory
which is based on iterated transformation. Fractal geometry is mainly
applied in the current study towards colour image compression
coding. These colour images possesses correlations among the colour
components and hence high compression ratio can be achieved by
exploiting all these redundancies. The proposed method utilises the
self-similarity in the colour image as well as the cross-correlations
between them. Experimental results show that the greater
compression ratio can be achieved with large domain blocks but more
trade off in image quality is good to acceptable at less than 1 bit per
pixel.
Abstract: Present paper describes method of obtaining clay
ceramic foam (CCF) and foam concrete (FC), by direct foaming with
high speed mixer-disperser (HSMD). Three foaming agents (FA) are
compared for the FC and CCF production: SCHÄUMUNGSMITTEL
W 53 FLÜSSIG (Zschimmer & Schwarz Gmbh, Germany), SCF-
1245 (Sika, test sample, Latvia) and FAB-12 (Elade, Latvija). CCF
were obtained at 950, 1000°C, 1150°C and 1150°C firing temperature
and have mechanical compressive strength 1.2, 2.55 and 4.3 MPa and
porosity 79.4, 75.1, 71.6%, respectively. Obtained FC has 6-14 MPa
compressive strength and porosity 44-55%. The goal of this work
was development of a sustainable and durable ceramic cellular
structures using HSMD.
Abstract: This paper proposes techniques like MT CMOS,
POWER GATING, DUAL STACK, GALEOR and LECTOR to
reduce the leakage power. A Full Adder has been designed using
these techniques and power dissipation is calculated and is compared
with general CMOS logic of Full Adder.
Simulation results show the validity of the proposed techniques is
effective to save power dissipation and to increase the speed of
operation of the circuits to a large extent.
Abstract: High pressure turbine (HPT) blades of DV – 2 jet
engines are made from Ni – based superalloy. This alloy was
originally manufactured in the Soviet Union and referred as ŽS6K.
For improving alloy’s high temperature resistance are blades coated
with Al – Si diffusion layer. A regular operation temperature of HPT
blades vary from 705°C to 750°C depending on jet engine regime.
An overcrossing working temperature range causes degradation of
the protective coating as well as base material which microstructure
is formed by the gamma matrix and strengthening phase gamma
prime (forming small particles in the microstructure). Diffusion
processes inside the material during exposition of the material to high
temperatures causes mainly coarsening of the gamma prime particles,
thus decreasing its strengthening effect. Degradation of the Al – Si
coating caused its thickness growth. All the microstructure changes
and coating layer thickness growth results in decreasing of the turbine
blade operation lifetime.
Abstract: The authors propose the identification, analysis and
prognosis of the quantitative and qualitative evolution of the elderly
population in the functional urban areas. The present paper takes into
account the analysis of some representative indicators (the weight of
the elderly population, ageing index, dynamic index of economic
ageing of productive population etc.) and the elaboration of an
integrated indicator that would help differentiate the population
ageing forms in the 48 functional urban areas that were defined based
on demographic and social-economic criteria for all large and
medium cities in Romania.
Abstract: A central element of higher education today is the
“core” or “general education” curriculum: that configuration of
courses that often encompasses the essence of liberal arts education.
Ensuring that such offerings reflect the mission and values of the
institution is a challenge faced by most college and universities, often
more than once. This paper presents an action model of program
planning designed to structure the processes of developing,
implementing and revising core curricula in a manner consistent with
key institutional goals and objectives. Through presentation of a case
study from a university in the United States, the elements of needs
assessment, stakeholder investment and collaborative compromise
are shown as key components of a planning strategy that can produce
a general education program that is comprehensive, academically
rigorous, assessable, and mission consistent. The paper concludes
with recommendations for both the implementation and evaluation of
such programs in practice.
Abstract: One of the crucial parameters of digital cryptographic
systems is the selection of the keys used and their distribution. The
randomness of the keys has a strong impact on the system’s security
strength being difficult to be predicted, guessed, reproduced, or
discovered by a cryptanalyst. Therefore, adequate key randomness
generation is still sought for the benefit of stronger cryptosystems.
This paper suggests an algorithm designed to generate and test
pseudo random number sequences intended for cryptographic
applications. This algorithm is based on mathematically manipulating
a publically agreed upon information between sender and receiver
over a public channel. This information is used as a seed for
performing some mathematical functions in order to generate a
sequence of pseudorandom numbers that will be used for
encryption/decryption purposes. This manipulation involves
permutations and substitutions that fulfill Shannon’s principle of
“confusion and diffusion”. ASCII code characters were utilized in the
generation process instead of using bit strings initially, which adds
more flexibility in testing different seed values. Finally, the obtained
results would indicate sound difficulty of guessing keys by attackers.
Abstract: DC motors have been widely used in the past
centuries which are proudly known as the workhorse of industrial
systems until the invention of the AC induction motors which makes
a huge revolution in industries. Since then, the use of DC machines
has been decreased due to enormous factors such as reliability,
robustness and complexity but it lost its fame due to the losses. In this
paper a new methodology is proposed to construct a DC motor
through the simulation in LabVIEW to get an idea about its real time
performances, if a change in parameter might have bigger
improvement in losses and reliability.
Abstract: Proposed paper dealt with the modelling and analysis of induction motor based on the mathematical expression using the graphical programming environment of Laboratory Virtual Instrument Engineering Workbench (LabVIEW). Induction motor modelling with the mathematical expression enables the motor to be simulated with the various required parameters. Owing to the invention of variable speed drives study about the induction motor characteristics became complex. In this simulation motor internal parameter such as stator resistance and reactance, rotor resistance and reactance, phase voltage, frequency and losses will be given as input. By varying the speed of motor corresponding parameters can be obtained they are input power, output power, efficiency, torque induced, slip and current.
Abstract: A total of 115 yeast strains isolated from local cassava
processing wastes were measured for crude protein content. Among
these strains, the strain MSY-2 possessed the highest protein
concentration (>3.5 mg protein/mL). By using molecular
identification tools, it was identified to be a strain of Pichia
kudriavzevii based on similarity of D1/D2 domain of 26S rDNA
region. In this study, to optimize the protein production by MSY-2
strain, Response Surface Methodology (RSM) was applied. The
tested parameters were the carbon content, nitrogen content, and
incubation time. Here, the value of regression coefficient (R2) =
0.7194 could be explained by the model which is high to support the
significance of the model. Under the optimal condition, the protein
content was produced up to 3.77 g per L of the culture and MSY-2
strain contains 66.8 g protein per 100 g of cell dry weight. These
results revealed the plausibility of applying the novel strain of yeast
in single-cell protein production.
Abstract: Non contact evaluation of the thickness of paint
coatings can be attempted by different destructive and nondestructive
methods such as cross-section microscopy, gravimetric mass
measurement, magnetic gauges, Eddy current, ultrasound or
terahertz. Infrared thermography is a nondestructive and non-invasive
method that can be envisaged as a useful tool to measure the surface
thickness variations by analyzing the temperature response. In this
paper, the thermal quadrupole method for two layered samples heated
up with a pulsed excitation is firstly used. By analyzing the thermal
responses as a function of thermal properties and thicknesses of both
layers, optimal parameters for the excitation source can be identified.
Simulations show that a pulsed excitation with duration of ten
milliseconds allows obtaining a substrate-independent thermal
response. Based on this result, an experimental setup consisting of a
near-infrared laser diode and an Infrared camera was next used to
evaluate the variation of paint coating thickness between 60 μm and
130 μm on two samples. Results show that the parameters extracted
for thermal images are correlated with the estimated thicknesses by
the Eddy current methods. The laser pulsed thermography is thus an
interesting alternative nondestructive method that can be moreover
used for nonconductive substrates.
Abstract: Turkish migrants constitute the largest group among
people with migration background living in Germany. Turkish
women’s labor market participation is of significant importance for
their social and economic integration to the German society. This
paper thus aims to investigate their labor market positions. Turkish
migrant women participate less in the labor market compared to men,
and are responsible for most of the housework, child care, and elderly
care. This is due to their traditional roles in the family, educational
level, insufficient knowledge of German language, and insufficient
professional experience. We strongly recommend that wide-reaching
integration policies for women are formulated, so as to encourage
participation of not only migrant women but also their husbands,
fathers and/or brothers, and natives.
Abstract: The paper presents a method for a simple and
immediate motion planning of a SCARA robot, whose end-effector
has to move along a given trajectory; the calculation procedure
requires the user to define in analytical form or by points the
trajectory to be followed and to assign the curvilinear abscissa as
function of the time. On the basis of the geometrical characteristics
of the robot, a specifically developed program determines the motion
laws of the actuators that enable the robot to generate the required
movement; this software can be used in all industrial applications for
which a SCARA robot has to be frequently reprogrammed, in order
to generate various types of trajectories with different motion times.
Abstract: Coal is an important non-renewable energy source of
and can be associated with radioactive elements. In Figueira city,
Paraná state, Brazil, it was recorded high uranium activity near the
coal mine that supplies a local thermoelectric power plant. In this
context, the radon activity (Rn-222, produced by the Ra-226 decay in
the U-238 natural series) was evaluated in groundwater, river water
and effluents produced from the acid mine drainage in the coal reject
dumps. The samples were collected in August 2013 and in February
2014 and analyzed at LABIDRO (Laboratory of Isotope and
Hydrochemistry), UNESP, Rio Claro city, Brazil, using an alpha
spectrometer (AlphaGuard) adjusted to evaluate the mean radon
activity concentration in five cycles of 10 minutes. No radon activity
concentration above 100 Bq.L-1, which was a previous critic value
established by the World Health Organization. The average radon
activity concentration in groundwater was higher than in surface
water and in effluent samples, possibly due to the accumulation of
uranium and radium in the aquifer layers that favors the radon
trapping. The lower value in the river waters can indicate dilution and
the intermediate value in the effluents may indicate radon absorption
in the coal particles of the reject dumps. The results also indicate that
the radon activities in the effluents increase with the sample
acidification, possibly due to the higher radium leaching and the
subsequent radon transport to the drainage flow. The water samples
of Laranjinha River and Ribeirão das Pedras stream, which,
respectively, supply Figueira city and receive the mining effluent,
exhibited higher pH values upstream the mine, reflecting the acid
mine drainage discharge. The radionuclides transport indicates the
importance of monitoring their activity concentration in natural
waters due to the risks that the radioactivity can represent to human
health.
Abstract: The emerging markets of post-USSR countries have
attracted Western multinational companies; however, weak
institutions and unstable host country environments have hindered the
implementation of successful management practices. The Ukrainian
market, in light of recent events, is particularly interesting to study
for its compatibility with Western businesses. This paper focuses on
factors that can facilitate or inhibit the transfer of human resource
management practices from Western headquarters to Ukrainian
subsidiaries. To explain the national context’s effects better, a
business systems approach has been applied to a qualitative study of
16 wholly owned Western subsidiaries, dissecting the reasons for a
weak integration of Western practices in Ukraine. Results show that
underdeveloped institutions have forced companies to develop
additional practices that compensate for national weaknesses, as well
as to adjust to a constantly changing environment. Flexibility and
local responsiveness were observed as vital for success in Ukraine.
Abstract: The efficiency of the actuation system of exoskeletons
and active orthoses for lower limbs is a significant aspect of the
design of such devices because it affects their efficacy. The F-IVT is
an innovative actuation system to power artificial knee joint with
energy recovery capabilities. Its key and non-conventional elements
are a flywheel that acts as a mechanical energy storage system, and
an Infinitely Variable Transmission (IVT). The design of the F-IVT
can be optimized for a certain walking condition, resulting in a heavy
reduction of both the electric energy consumption and of the electric
peak power. In this work, by means of simulations of level ground
walking at different speeds, it is demonstrated that the F-IVT is still
an advantageous actuator which permits to save energy consumption
and to downsize the electric motor even when it does not work in
nominal conditions.