Abstract: This paper aims to study the effect of cold work
condition on the microstructure of Cu-1.5wt%Ti, and Cu-3.5wt%Ti
and hence mechanical properties. The samples under investigation
were machined, and solution heat treated. X-ray diffraction technique
is used to identify the different phases present after cold deformation
by compression and also different heat treatment and also measuring
the relative quantities of phases present. The metallographic
examination is used to study the microstructure of the samples. The
hardness measurements were used to indicate the change in
mechanical properties. The results are compared with the mechanical
properties obtained by previous workers. Experiments on cold
compression followed by aging of Cu-Ti alloys have indicated that
the most efficient hardening of the material results from continuous
precipitation of very fine particles within the matrix. These particles
were reported to be β`-type, Cu4Ti phase. The β`-β transformation
and particles coarsening within the matrix as well as long grain
boundaries were responsible for the overaging of Cu-1.5wt%Ti and
Cu-3.5wt%Ti alloys. It is well known that plate-like particles are β –
type, Cu3Ti phase. Discontinuous precipitation was found to start at
the grain boundaries and expand into grain interior. At the higher
aging temperature, a classic Widmanstätten morphology forms giving
rise to a coarse microstructure comprised of α and the equilibrium
phase β. Those results were confirmed by X-ray analysis, which
found that a few percent of Cu3Ti, β precipitates are formed during
aging at high temperature for long time for both Cu- Ti alloys (i.e.
Cu-1.5wt%Ti and Cu-3.5wt%Ti).
Abstract: Current systems complexity has reached a degree that
requires addressing conception and design issues while taking into
account environmental, operational, social, legal and financial
aspects. Therefore, one of the main challenges is the way complex
systems are specified and designed. The exponential growing effort,
cost and time investment of complex systems in modeling phase
emphasize the need for a paradigm, a framework and an environment
to handle the system model complexity. For that, it is necessary to
understand the expectations of the human user of the model and his
limits. This paper presents a generic framework for designing
complex systems, highlights the requirements a system model needs
to fulfill to meet human user expectations, and suggests a graphbased
formalism for modeling complex systems. Finally, a set of
transformations are defined to handle the model complexity.
Abstract: Model transformation, as a pivotal aspect of Modeldriven
engineering, attracts more and more attentions both from
researchers and practitioners. Many domains (enterprise engineering,
software engineering, knowledge engineering, etc.) use model
transformation principles and practices to serve to their domain
specific problems; furthermore, model transformation could also be
used to fulfill the gap between different domains: by sharing and
exchanging knowledge. Since model transformation has been widely
used, there comes new requirement on it: effectively and efficiently
define the transformation process and reduce manual effort that
involved in. This paper presents an automatic model transformation
methodology based on semantic and syntactic comparisons, and
focuses particularly on granularity issue that existed in transformation
process. Comparing to the traditional model transformation
methodologies, this methodology serves to a general purpose: crossdomain
methodology. Semantic and syntactic checking
measurements are combined into a refined transformation process,
which solves the granularity issue. Moreover, semantic and syntactic
comparisons are supported by software tool; manual effort is replaced
in this way.
Abstract: Whey is the lactose rich by-product of the dairy
industry, having good amount of nutrient reservoir. Most abundant
nutrients are lactose, soluble proteins, lipids and mineral salts.
Disposing of whey by most of milk plants which do not have proper
pre-treatment system is the major issue. As a result of which, there
can be significant loss of potential food and energy source. Thus,
whey has been explored as the substrate for the synthesis of different
value added products such as enzymes. β-galactosidase is one of the
important enzymes and has become the major focus of research due
to its ability to catalyze both hydrolytic as well as
transgalactosylation reaction simultaneously. The enzyme is widely
used in dairy industry as it catalyzes the transformation of lactose to
glucose and galactose, making it suitable for the lactose intolerant
people. The enzyme is intracellular in both bacteria and yeast,
whereas for molds, it has an extracellular location. The present work
was carried to utilize the whey for the production of β-galactosidase
enzyme using both yeast and fungal cultures. The yeast isolate
Kluyveromyces marxianus WIG2 and various fungal strains have
been used in the present study. Different disruption techniques have
also been investigated for the extraction of the enzyme produced
intracellularly from yeast cells. Among the different methods tested
for the disruption of yeast cells, SDS-chloroform showed the
maximum β-galactosidase activity. In case of the tested fungal
cultures, Aureobasidium pullulans NCIM 1050 was observed to be
the maximum extracellular enzyme producer.
Abstract: The nanoindentation behaviour and phase
transformation of annealed single-crystal silicon wafers are examined.
The silicon specimens are annealed at temperatures of 250, 350 and
450ºC, respectively, for 15 minutes and are then indented to maximum
loads of 30, 50 and 70 mN. The phase changes induced in the indented
specimens are observed using transmission electron microscopy
(TEM) and micro-Raman scattering spectroscopy (RSS). For all
annealing temperatures, an elbow feature is observed in the unloading
curve following indentation to a maximum load of 30 mN. Under
higher loads of 50 mN and 70 mN, respectively, the elbow feature is
replaced by a pop-out event. The elbow feature reveals a complete
amorphous phase transformation within the indented zone, whereas
the pop-out event indicates the formation of Si XII and Si III phases.
The experimental results show that the formation of these crystalline
silicon phases increases with an increasing annealing temperature and
indentation load. The hardness and Young’s modulus both decrease as
the annealing temperature and indentation load are increased.
Abstract: WO3/SiO2 catalysts were modified by an ion exchange
method with sodium hydroxide or potassium hydroxide solution. The
performance of the modified catalysts was tested in the metathesis of
ethylene and trans-2-butene to propylene. During ion exchange,
sodium and potassium ions played different roles. Sodium modified
catalysts revealed constant trans-2-butene conversion and propylene
selectivity when the concentrations of sodium in the solution were
varied. In contrast, potassium modified catalysts showed reduction of
the conversion and increase of the selectivity. From these results,
potassium hydroxide may affect the transformation of tungsten oxide
active species, resulting in the decrease in conversion whereas
sodium hydroxide did not. Moreover, the modification of catalysts by
this method improved the catalyst stability by lowering the amount of
coke deposited on the catalyst surface.
Abstract: An important problem for the CaSO4/CaSO4･1/2H2O
Chemical heat pump (CHP) is that the material is deactivated through
repetitive reaction between hydration and dehydration in which the
crystal phase of the material is transformed from III-CaSO4 to
II-CaSO4. We investigated suppression on the phase change by adding
a sulfated compound. The most effective material was MgSO4. MgSO4
doping increased the durability of CaSO4 in the actual CHP repetitive
cycle of hydration/dehydration to 3.6 times that of undoped CaSO4.
The MgSO4-doped CaSO4 showed a higher phase transition
temperature and activation energy for crystal transformation from
III-CaSO4 to II-CaSO4. MgSO4 doping decreased the crystal lattice
size of CaSO4･1/2H2O and II-CaSO4 to smaller than that of undoped
CaSO4. Modification of the crystal structure is considered to be related
to the durability change in CaSO4 resulting from MgSO4 doping.
Abstract: The coaxial transformer-coupled push-pull circuitry
has been used widely in HF and VHF amplifiers for many decades
without significant changes in the topology of the transformers. Basic
changes over the years concerned the construction and turns ratio of
the transformers as has been imposed upon the newer technologies
active devices demands. The balun transmission line transformers
applied in push-pull amplifiers enable input/output impedance
transformation, but are mainly used to convert the balanced output
into unbalanced and the input unbalanced into balanced. A simple
and affordable alternative solution over the traditional coaxial
transformer is the coreless planar balun. A key advantage over the
traditional approach lies in the high specifications repeatability;
simplifying the amplifier construction requirements as the planar
balun constitutes an integrated part of the PCB copper layout. This
paper presents the performance analysis of a planar LDMOS
MRFE6VP5600 Push-Pull amplifier that enables robust operation in
Band III, DVB-T, DVB-T2 standards but functions equally well in
Band II, for DRM+ new generation transmitters.
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: The largest share of policy and money within the
European Union goes to agriculture. The Union’s Common
Agricultural Policy has undergone several transformations in the last
five decades, with the main change taking place in the 1990s. This
change influenced agriculture in the Czech Republic, inasmuch as the
fledgling republic was preparing to join the European Union and
adopt its policies. In the 1990s, Czech agriculture passed from
a centrally planned economy to a market economy and subsequently
adopted the terms of the Common Agricultural Policy. The Czech
Republic is also characterized by a significant diversification of
landscape sphere. Agricultural entrepreneurs in the Czech Republic
are still not accustomed to the possibility of grants from the European
Union. They focus rather on national or regional subsidies. Only half
of all agricultural entrepreneurs in the Czech Republic use European
subsidies. This article focuses on the introduction of the Common
Agricultural Policy to the Czech Republic and its subsequent
influence on Czech agriculture. It is demonstrated through the
implementation rate of the CAP in the EU Member States and
a closer focus on Czech integration.
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: This study is about the structural transformations of
aluminium examining with the Dynamic Mechanical Thermal
Analyzer (DMTA). It is a faster and simpler measuring method to
make consequence about the metal’s structural transformations. The
device measures the changing of the mechanical characteristics
depending on the heating rate, and concludes certain transformations.
This measuring method fast and shows clean-cut results comparing
the conventional ways.
Applying polymer measuring devices for metal investigations is
not widespread method. One of the adaptable ways is shown in this
study. The article compares the results of the small specimen test and
the DMTA method, considering the temperature and the forming
dependence of recrystallization temperature.
Abstract: We report the microstructural and magnetic properties
of Ni50Mn39Sn11 and Ni50Mn36Sn14 ribbon Heusler alloys.
Experimental results were obtained by differential scanning
calorymetry, X-ray diffraction and vibrating sample magnetometry
techniques. The Ni-Mn-Sn system undergoes a martensitic structural
transformation in a wide temperature range. For example, for
Ni50Mn39Sn11 the start and finish temperatures of the martensitic and
austenite phase transformation for ribbon alloy were Ms=336K,
Mf=328K, As=335K and Af=343K whereas no structural
transformation is observed for Ni50Mn36Sn14 alloys. Magnetic
measurements show the typical ferromagnetic behavior with Curie
temperature 207 K at low applied field of 50 Oe. The complex
behavior exhibited by these Heusler alloys should be ascribed to the
strong coupling between magnetism and structure, being their
magnetic behavior determined by the distance between Mn atoms.
Abstract: In this paper, the problem of steady laminar boundary
layer flow and heat transfer over a permeable exponentially
stretching/shrinking sheet with generalized slip velocity is
considered. The similarity transformations are used to transform the
governing nonlinear partial differential equations to a system of
nonlinear ordinary differential equations. The transformed equations
are then solved numerically using the bvp4c function in MATLAB.
Dual solutions are found for a certain range of the suction and
stretching/shrinking parameters. The effects of the suction parameter,
stretching/shrinking parameter, velocity slip parameter, critical shear
rate and Prandtl number on the skin friction and heat transfer
coefficients as well as the velocity and temperature profiles are
presented and discussed.
Abstract: The convective heat and mass transfer in nanofluid
flow through a porous media due to a permeable stretching sheet with
magnetic field, viscous dissipation, chemical reaction and Soret
effects are numerically investigated. Two types of nanofluids, namely
Cu-water and Ag-water were studied. The governing boundary layer
equations are formulated and reduced to a set of ordinary differential
equations using similarity transformations and then solved
numerically using the Keller box method. Numerical results are
obtained for the skin friction coefficient, Nusselt number and
Sherwood number as well as for the velocity, temperature and
concentration profiles for selected values of the governing
parameters. Excellent validation of the present numerical results has
been achieved with the earlier linearly stretching sheet problems in
the literature.
Abstract: The detection of moving objects from a video image
sequences is very important for object tracking, activity recognition,
and behavior understanding in video surveillance.
The most used approach for moving objects detection / tracking is
background subtraction algorithms. Many approaches have been
suggested for background subtraction. But, these are illumination
change sensitive and the solutions proposed to bypass this problem
are time consuming.
In this paper, we propose a robust yet computationally efficient
background subtraction approach and, mainly, focus on the ability to
detect moving objects on dynamic scenes, for possible applications in
complex and restricted access areas monitoring, where moving and
motionless persons must be reliably detected. It consists of three
main phases, establishing illumination changes invariance,
background/foreground modeling and morphological analysis for
noise removing.
We handle illumination changes using Contrast Limited Histogram
Equalization (CLAHE), which limits the intensity of each pixel to
user determined maximum. Thus, it mitigates the degradation due to
scene illumination changes and improves the visibility of the video
signal. Initially, the background and foreground images are extracted
from the video sequence. Then, the background and foreground
images are separately enhanced by applying CLAHE.
In order to form multi-modal backgrounds we model each channel
of a pixel as a mixture of K Gaussians (K=5) using Gaussian Mixture
Model (GMM). Finally, we post process the resulting binary
foreground mask using morphological erosion and dilation
transformations to remove possible noise.
For experimental test, we used a standard dataset to challenge the
efficiency and accuracy of the proposed method on a diverse set of
dynamic scenes.
Abstract: Everyday life is and will be influenced depending on
the developments that society undergoes throughout the history.
Particularly, countries undergoing transition from one system to
another sustain the greatest impact in trying to embrace the modern
system. Kosovo society had the fortune to experience a change,
which began in late 1999 to continue up to date. One of the
'developments' of the time with the evolution in Kosovo society was
the transition from the traditional education system into the modern
one. This transformation began immediately after the war, to
continue even today. It was started by internationals, which governed
and administered Kosovo society, including education. There was a
great 'evolution', because almost the entire system was 'changed'.
Among other things, for the first time it was enabled the opening of
private schools from the lowest level up to the colleges and
universities. This paper will address: how much was ready the society
to embrace such a 'cultural' change in education, respectively, how
much were prepared teachers for such changes; as it was actually
thought to be a modern education system, how much was it according
to international standards; what are the results and current situation in
Kosovo education.
Abstract: Agriculture is the backbone of economy of Pakistan
and cotton is the major agricultural export and supreme source of raw
fiber for our textile industry. To combat severe problems of insect
and weed, combination of three genes namely Cry1Ac, Cry2A and
EPSPS genes was transferred in locally cultivated cotton variety
MNH-786 with the use of Agrobacterium mediated genetic
transformation. The present study focused on the molecular screening
of transgenic cotton plants at T3 generation in order to confirm
integration and expression of all three genes (Cry1Ac, Cry2A and
EPSP synthase) into the cotton genome. Initially, glyphosate spray
assay was used for screening of transgenic cotton plants containing
EPSP synthase gene at T3 generation. Transgenic cotton plants which
were healthy and showed no damage on leaves were selected after 07
days of spray. For molecular analysis of transgenic cotton plants in
the laboratory, the genomic DNA of these transgenic cotton plants
were isolated and subjected to amplification of the three genes. Thus,
seventeen out of twenty (Cry1Ac gene), ten out of twenty (Cry2A
gene) and all twenty (EPSP synthase gene) were produced positive
amplification. On the base of PCR amplification, ten transgenic plant
samples were subjected to protein expression analysis through
ELISA. The results showed that eight out of ten plants were actively
expressing the three transgenes. Real-time PCR was also done to
quantify the mRNA expression levels of Cry1Ac and EPSP synthase
gene. Finally, eight plants were confirmed for the presence and active
expression of all three genes at T3 generation.
Abstract: The concept of urban transformation came about
through interventions aimed at bringing socially and economically
problematic areas of cities into use. The issue of urban transformation
arose frequently during the post-2000 period in particular, and legal
regulations on this matter were also developed in Turkey. Urban
transformation project would be a focal point for the formation of the
city in the near future. Izmir, which is third largest city of Turkey, is
an important trade and port city. But, assessment of the current
situation shows that, the majority of existing residential areas was
formed with squatters and unplanned settlements in Izmir city center.
Therefore an important part of these areas have significant problems
in terms of the quality of life, safety and environmental quality. In
this study, the central policies in Turkey and local policies in Đzmir
about urban transformation will be considered. In addition, urban
renewal projects that are being implemented in Izmir were discussed
and suggestions will be developed in accordance with this policy.
Abstract: An analysis is carried out to investigate the effect of
magnetic field and heat source on the steady boundary layer flow and
heat transfer of a Casson nanofluid over a vertical cylinder stretching
exponentially along its radial direction. Using a similarity
transformation, the governing mathematical equations, with the
boundary conditions are reduced to a system of coupled, non –linear
ordinary differential equations. The resulting system is solved
numerically by the fourth order Runge – Kutta scheme with shooting
technique. The influence of various physical parameters such as
Reynolds number, Prandtl number, magnetic field, Brownian motion
parameter, thermophoresis parameter, Lewis number and the natural
convection parameter are presented graphically and discussed for non
– dimensional velocity, temperature and nanoparticle volume
fraction. Numerical data for the skin – friction coefficient, local
Nusselt number and the local Sherwood number have been tabulated
for various parametric conditions. It is found that the local Nusselt
number is a decreasing function of Brownian motion parameter Nb
and the thermophoresis parameter Nt.