Abstract: Acoustic properties of polymeric liquids are high
sensitive to free gas traces in the form of fine bubbles. Their presence
is typical for such liquids because of chemical reactions, small
wettability of solid boundaries, trapping of air in technological
operations, etc. Liquid temperature influences essentially its
rheological properties, which may have an impact on the bubble
pulsations and sound propagation in the system. The target of the
paper is modeling of the liquid temperature effect on single bubble
dynamics and sound dispersion and attenuation in polymeric solution
with spherical gas bubbles. The basic sources of attenuation (heat
exchange between gas in microbubbles and surrounding liquid,
rheological and acoustic losses) are taken into account. It is supposed
that in the studied temperature range the interface mass transfer has a
minor effect on bubble dynamics. The results of the study indicate
that temperature raise yields enhancement of bubble pulsations and
increase in sound attenuation in the near-resonance range and may
have a strong impact on sound dispersion in the liquid-bubble
mixture at frequencies close to the resonance frequency of bubbles.
Abstract: Background subtraction and temporal difference are
often used for moving object detection in video. Both approaches are
computationally simple and easy to be deployed in real-time image
processing. However, while the background subtraction is highly
sensitive to dynamic background and illumination changes, the
temporal difference approach is poor at extracting relevant pixels of
the moving object and at detecting the stopped or slowly moving
objects in the scene. In this paper, we propose a simple moving object
detection scheme based on adaptive background subtraction and
temporal difference exploiting dynamic background updates. The
proposed technique consists of histogram equalization, a linear
combination of background and temporal difference, followed by the
novel frame-based and pixel-based background updating techniques.
Finally, morphological operations are applied to the output images.
Experimental results show that the proposed algorithm can solve the
drawbacks of both background subtraction and temporal difference
methods and can provide better performance than that of each method.
Abstract: Sodium formate is the chemical substance used for
food additive. Catalase is the important antioxidative enzyme in
protecting the cell from oxidative damage by reactive oxygen species
(ROS). The resultant level of oxidative stress in sodium formatetreated
lymphocytes was investigated. The sodium formate
concentrations of 0.05, 0.1, 0.2, 0.4 and 0.6 mg/mL were treated in
human lymphocytes for 12 hours. After 12 treated hours, catalase
activity change was measured in sodium formate-treated
lymphocytes. The results showed that the sodium formate
concentrations of 0.4 and 0.6 mg/mL significantly decreased catalase
activities in lymphocytes (P < 0.05). The change of catalase activity
in sodium formate-treated lymphocytes may be the oxidative damage
marker for detect sodium formate exposure in human.
Abstract: In light of the technological development and its
introduction into the field of education, an online course was
designed in parallel to the 'conventional' course for teaching the
''Qualitative Research Methods''. This course aimed to characterize
learning-teaching processes in a 'Qualitative Research Methods'
course studied in two different frameworks. Moreover, its objective
was to explore the difference between the culture of a physical
learning environment and that of online learning. The research
monitored four learner groups, a total of 72 students, for two years,
two groups from the two course frameworks each year. The courses
were obligatory for M.Ed. students at an academic college of
education and were given by one female-lecturer. The research was
conducted in the qualitative method as a case study in order to attain
insights about occurrences in the actual contexts and sites in which
they transpire. The research tools were open-ended questionnaire and
reflections in the form of vignettes (meaningful short pictures) to all
students as well as an interview with the lecturer. The tools facilitated
not only triangulation but also collecting data consisting of voices
and pictures of teaching and learning. The most prominent findings
are: differences between the two courses in the change features of the
learning environment culture for the acquisition of contents and
qualitative research tools. They were manifested by teaching
methods, illustration aids, lecturer's profile and students' profile.
Abstract: SARA is a common and serious metabolic disorder in
early lactation in dairy cattle and in finishing beef cattle, caused by
diets with high inclusion of cereal grain. This experiment was
performed to determine the efficacy of Megasphaera elsdenii, a
major lactate-utilizing bacterium in prevention/treatment of SARA in
vivo. In vivo experimentation, it was used eight ruminally cannulated
rams and it was applied the rapid adaptation with the mixture of grain
based on wheat (80% wheat, 20% barley) and barley (80% barley,
20% wheat). During the systematic adaptation, it was followed the
probability of SARA formation by being measured the rumen pH
with two hours intervals after and before feeding. After being
evaluated the data, it was determined the ruminal pH ranged from
5.2-5.6 on the condition of feeding with 60 percentage of grain
mixture based on barley and wheat, that assured the definite form of
subacute acidosis. In four days SARA period, M. elsdenii (1010 cfu
ml-1) was inoculated during the first two days. During the SARA
period, it was observed the decrease of feed intake with M. elsdenii
inoculation. Inoculation of M. elsdenii was caused to differentiation
of rumen pH (P
Abstract: The work aims to develop a robot in the form of
autonomous vehicle to detect, inspection and mapping of
underground pipelines through the ATmega328 Arduino platform.
Hardware prototyping is very similar to C / C ++ language that
facilitates its use in robotics open source, resembles PLC used in
large industrial processes. The robot will traverse the surface
independently of direct human action, in order to automate the
process of detecting buried pipes, guided by electromagnetic
induction. The induction comes from coils that send the signal to the
Arduino microcontroller contained in that will make the difference in
intensity and the treatment of the information, and then this
determines actions to electrical components such as relays and
motors, allowing the prototype to move on the surface and getting the
necessary information. This change of direction is performed by a
stepper motor with a servo motor. The robot was developed by
electrical and electronic assemblies that allowed test your application.
The assembly is made up of metal detector coils, circuit boards and
microprocessor, which interconnected circuits previously developed
can determine, process control and mechanical actions for a robot
(autonomous car) that will make the detection and mapping of buried
pipelines plates. This type of prototype can prevent and identifies
possible landslides and they can prevent the buried pipelines suffer an
external pressure on the walls with the possibility of oil leakage and
thus pollute the environment.
Abstract: The rapid growth of multimedia technology demands
the secure and efficient access to information. This fast growing lose
the confidence of unauthorized duplication. Henceforth the protection
of multimedia content is becoming more important. Watermarking
solves the issue of unlawful copy of advanced data. In this paper,
blind video watermarking technique has been proposed. A luminance
layer of selected frames is interlaced into two even and odd rows of
an image, further it is deinterlaced and equalizes the coefficients of
the two shares. Color watermark is split into different blocks, and the
pieces of block are concealed in one of the share under the wavelet
transform. Stack the two images into a single image by introducing
interlaced even and odd rows in the two shares. Finally, chrominance
bands are concatenated with the watermarked luminance band. The
safeguard level of the secret information is high, and it is
undetectable. Results show that the quality of the video is not
changed also yields the better PSNR values.
Abstract: Neural activity in the human brain starts from the
early stages of prenatal development. This activity or signals
generated by the brain are electrical in nature and represent not only
the brain function but also the status of the whole body. At the
present moment, three methods can record functional and
physiological changes within the brain with high temporal resolution
of neuronal interactions at the network level: the
electroencephalogram (EEG), the magnet oencephalogram (MEG),
and functional magnetic resonance imaging (fMRI); each of these has
advantages and shortcomings. EEG recording with a large number of
electrodes is now feasible in clinical practice. Multichannel EEG
recorded from the scalp surface provides very valuable but indirect
information about the source distribution. However, deep electrode
measurements yield more reliable information about the source
locations intracranial recordings and scalp EEG are used with the
source imaging techniques to determine the locations and strengths of
the epileptic activity. As a source localization method, Low
Resolution Electro-Magnetic Tomography (LORETA) is solved for
the realistic geometry based on both forward methods, the Boundary
Element Method (BEM) and the Finite Difference Method (FDM). In
this paper, we review the findings EEG- LORETA about epilepsy.
Abstract: Since 1920, the industry has almost completely
changed the rivets production techniques for the manufacture of
permanent welding join production of structures and manufacture of
other products. The welding arc is the process more widely used in
industries. This is accomplished by the heat of an electric arc which
melts the base metal while the molten metal droplets are transferred
through the arc to the welding pool, protected from the atmosphere
by a gas curtain. The GMAW (Gas metal arc welding) process is
influenced by variables such as: current, polarity, welding speed,
electrode: extension, position, moving direction; type of joint,
welder's ability, among others. It is remarkable that the knowledge
and control of these variables are essential for obtaining satisfactory
quality welds, knowing that are interconnected so that changes in one
of them requiring changes in one or more of the other to produce the
desired results. The optimum values are affected by the type of base
metal, the electrode composition, the welding position and the quality
requirements. Thus, this paper proposes a new methodology, adding
the variable vibration through a mechanism developed for GMAW
welding, in order to improve the mechanical and metallurgical
properties which does not affect the ability of the welder and enables
repeatability of the welds made. For confirmation metallographic
analysis and mechanical tests were made.
Abstract: While choosing insulating oil, characteristic features
such as thermal cooling, endurance, efficiency and being
environment-friendly should be considered. Mineral oils are referred
as petroleum-based oil. In this study, vegetable oils investigated as an
alternative insulating liquid to mineral oil. Dissipation factor,
breakdown voltage, relative dielectric constant and resistivity
changes with the frequency and voltage of mineral, rapeseed and nut
oils were measured. Experimental studies were performed according
to ASTM D924 and IEC 60156 standards.
Abstract: In this paper, an experiment was conducted to assess
the impact of online deliberation on citizens’ attitudes. Specifically,
this research compared pre and post deliberation opinions of
participants who deliberated online via an asynchronous platform
regarding the issue of political opinion polls. Results indicate that
online deliberation had a positive effect on citizens’ attitudes since it
was found that following deliberation participants changed their
views regarding public opinion polls. Specifically, online deliberation
improved discussants perceptions regarding the reliability of polls,
while suppressing their negative views about the misuse of polls by
media, polling organizations and politicians.
Abstract: In this study, one dimensional phase change problem
(a Stefan problem) is considered and a numerical solution of this
problem is discussed. First, we use similarity transformation to
convert the governing equations into ordinary differential equations
with its boundary conditions. The solutions of ordinary differential
equation with the associated boundary conditions and interface
condition (Stefan condition) are obtained by using a numerical
approach based on operational matrix of differentiation of shifted
second kind Chebyshev wavelets. The obtained results are compared
with existing exact solution which is sufficiently accurate.
Abstract: The paper provides a comprehensive analysis of the
sustainable development in the Belgrade Metropolitan Region - BMA
(level NUTS 2) preliminary evaluating the three chosen components:
1) economic growth and developmental changes; 2) competitiveness;
and 3) territorial concentration and industrial specialization. First, we
identified the main results of development changes and economic
growth by applying Shift-share analysis on the metropolitan level.
Second, the empirical evaluation of competitiveness in the BMA is
based on the analysis of absolute and relative values of eight
indicators by Spider method. Paper shows that the consideration of
the national share, industrial mix and metropolitan/regional share in
total Shift share of the BMA, as well as economic/functional
specialization of the BMA indicate very strong process of
deindustrialization. Allocative component of the BMA economic
growth has positive value, reflecting the above-average sector
productivity compared to the national average. Third, the important
positive role of metropolitan/regional component in decomposition of
the BMA economic growth is highlighted as one of the key results.
Finally, comparative analysis of the industrial territorial
concentration in the BMA in relation to Serbia is based on location
quotient (LQ) or Balassa index as a valid measure. The results
indicate absolute and relative differences in decrease of industry
territorial concentration as well as inefficiency of utilizing territorial
capital in the BMA. Results are important for the increase of regional
competitiveness and territorial distribution in this area as well as for
improvement of sustainable metropolitan and sector policies,
planning and governance on this level.
Abstract: A comparison of activity and stability of the as-formed
Pt/C, Pt-Co and Pt-Pd/C electrocatalysts, prepared by a combined
approach of impregnation and seeding, was performed. According to
the activity test in a single Proton Exchange Membrane (PEM) fuel
cell, the Oxygen Reduction Reaction (ORR) activity of the Pt-M/C
electrocatalyst was slightly lower than that of Pt/C. The j0.9 V and
E10 mA/cm2 of the as-prepared electrocatalysts increased in the order of
Pt/C > Pt-Co/C > Pt-Pd/C. However, in the medium-to-high current
density region, Pt-Pd/C exhibited the best performance. With regard to
their stability in a 0.5 M H2SO4 electrolyte solution, the
electrochemical surface area decreased as the number of rounds of
repetitive potential cycling increased due to the dissolution of the
metals within the catalyst structure. For long-term measurement, Pt-
Pd/C was the most stable than the other three electrocatalysts.
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: Haynes 25 alloy (also known as L-605 alloy) is cobalt
based super alloy which has widely applications such as aerospace
industry, turbine and furnace parts, power generators and heat
exchangers and petroleum refining components due to its excellent
characteristics. However, the workability of this alloy is more
difficult compared to normal steels or even stainless. In present work,
an experimental investigation was performed under cryogenic
cooling to determine cutting tool wear patterns and obtain optimal
cutting parameters in turning of cobalt based superalloy Haynes 25.
In experiments, uncoated carbide tool was used and cutting speed (V)
and feed rate (f) were considered as test parameters. Tool wear
(VBmax) were measured for process performance indicators.
Analysis of variance (ANOVA) was performed to determine the
importance of machining parameters.
Abstract: We used live E. coli containing synthetic genetic
oscillators to study how the degree of synchrony between the genetic
circuits of sister cells changes with temperature. We found that both
the mean and the variability of the degree of synchrony between the
fluorescence signals from sister cells are affected by temperature.
Also, while most pairs of sister cells were found to be highly
synchronous in each condition, the number of asynchronous pairs
increased with increasing temperature, which was found to be due to
disruptions in the oscillations. Finally we provide evidence that these
disruptions tend to affect multiple generations as opposed to
individual cells. These findings provide insight in how to design
more robust synthetic circuits and in how cell division can affect their
dynamics.
Abstract: This paper presents a rheological model for producing
shape-memory thermoplastic polymers. Shape-memory occurs as a
result of internal rearrangement of the structural elements of a
polymer. A non-linear viscoelastic model was developed that allows
qualitative and quantitative prediction of the stress-strain behavior of
shape-memory polymers during heating. This research was done to
develop a technique to determine the maximum possible change in
size of shape-memory products during heating. The rheological
model used in this work was particularly suitable for defining process
parameters and constructive parameters of the processing equipment.
Abstract: Mitigating soil erosion, especially in Mediterranean
countries such as Greece, is essential in order to maintain
environmental and agricultural sustainability. In this paper, scientific
publications related to soil erosion studies in Greece were reviewed
and categorized. To accomplish this, the online search engine of
Scopus was used. The key words were “soil”, “erosion” and
“Greece.” An analysis of the published articles was conducted at
three levels: i) type of publication, ii) chronologic and iii) thematic. A
hundred and ten publications published in scientific journals were
reviewed. The results showed that the awareness regarding the soil
erosion in Greece has increased only in the last decades. The
publications covered a wide range of thematic categories such as the
type of studied areas, the physical phenomena that trigger and
influence the soil erosion, the negative anthropogenic impacts on
them, the assessment tools that were used in order to examine the
threat and the proper management. The analysis of these articles was
significant and necessary in order to find the scientific gaps of soil
erosion studies in Greece and help enhance the sustainability of soil
management in the future.
Abstract: Today architecture has become as a powerful media
for introducing cultures to the world, which in turn brings about a
change in the global insight, power gaining, investment, and
development. Islamic architecture is based on the language of Koran
and shows the depth and richness of Islam through the spiritual soul.
This is in a way that belief in monotheism and faith in Islamic
teachings are manifested as Islam's aesthetic thought in Islamic
architecture. Unfortunately, Islamic architecture has been damaged a
lot due to the lack of the necessary information, and also successive
wars that have overtaken the Moslems as well as the dominance of
colonizing counties.
Islamic architecture is rooted in the history, culture and
civilization of Moslems, but its deficiencies and shortcomings should
be removed through systematizing the Islamic architecture
researchers. Islamic countries should act in a way that the art of
Islamic architecture shows its true place in different architecture eras
and makes everybody aware that Islamic architecture has a historical
root and is connected eternally to the genuineness, religious art, and
Moslems' culture and civilization.