Abstract: In this work new macroporous Ni electrodes modified
with Au nanoparticles for hydrogen production have been developed.
The supporting macroporous Ni electrodes have been obtained by
means of the electrodeposition at high current densities. Then, the Au
nanoparticles were synthesized and added to the electrode surface.
The electrocatalytic behaviour of the developed electrocatalysts was
studied by means of pseudo-steady-state polarization curves,
electrochemical impedance spectroscopy (EIS) and hydrogen
discharge curves. The size of the Au synthetized nanoparticles shows
a monomodal distribution, with a very sharp band between 10 and 50
nm. The characteristic parameters d10, d50 and d90 were 14, 20 and
31 nm respectively. From Tafel polarization data has been concluded
that the Au nanoparticles improve the catalytic activity of the
developed electrodes towards the HER respect to the macroporous Ni
electrodes. EIS permits to obtain the electrochemically active area by
means of the roughness factor value. All the developed electrodes
show roughness factor values in the same order of magnitude. From
the activation energy results it can be concluded that the Au
nanoparticles improve the intrinsic catalytic activity of the
macroporous Ni electrodes.
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: Interstitial free steels possess better formability and
have many applications in automotive industries. Forming limit
diagrams (FLDs) indicate the formability of materials which can be
determined by experimental and finite element (FE) simulations.
FLDs were determined experimentally by LDH test, utilizing optical
strain measurement system for measuring the strains in different
width specimens and by FE simulations in Interstitial Free (IF) and
Interstitial Free High Strength (IFHS) steels. In this study, the
experimental and FE simulated FLDs are compared and also the
stress based FLDs were investigated.
Abstract: The Chair of Thermal Engineering at Poznan
University of Technology has been conducted research works on the
possibilities of using carbon nanostructures in energy and mechanics
applications for a couple of years. Those studies have provided results in a form of co-operation with foreign research centres, numerous publications and patent
applications.
Authors of this paper have studied the influence of multi-walled
carbon nanostructures on changes in static friction arising when steel
surfaces were moved. Tests were made using the original test stand
consisting of automatically controlled inclined plane driven by
precise stepper motors. Computer program created in the LabView
environment was responsible for monitoring of the stand operation,
accuracy of measurements and archiving the obtained results. Such a
solution enabled to obtain high accuracy and repeatability of all
conducted experiments.
Tests and analysis of the obtained results allowed us to determine
how additional layers of carbon nanostructures influenced on changes
of static friction coefficients. At the same time, we analyzed the
potential possibilities of applying nanostructures under consideration
in mechanics.
Abstract: One of the functions of the commercial heavy vehicle
is to safely and efficiently transport goods and people. Due to its size
and carrying capacity, it is important to study the vehicle dynamic
stability during cornering. Study has shown that there are a number of
overloaded heavy vehicles or permissible Gross Vehicle Weight
(GVW) violations recorded at selected areas in Malaysia assigned by
its type and category. Thus, the objective of this study is to
investigate the correlation and effect of the GVW on heavy vehicle
stability during cornering event using simulation. Various selected
heavy vehicle types and category are simulated using IPG/Truck
Maker® with different GVW and road condition (coefficient of
friction of road surface), while the speed, driver characteristic, center
of gravity of load and road geometry are constant. Based on the
analysis, the relationship between GVW and lateral acceleration were
established. As expected, on the same value of coefficient of friction,
the maximum lateral acceleration would be increased as the GVW
increases.
Abstract: Remote arid areas of the vast expanses of the African
deserts hold huge subterranean reserves of brackish water resources
waiting for economic development. This work presents design
guidelines as well as initial performance data of new autonomous
solar desalination equipment which could help local communities
produce their own fresh water using solar energy only and, why not,
contribute to transforming desert lands into lush gardens. The output
of solar distillation equipments are typically low and in the range of 3
l/m2/day on the average. This new design with an integrated, water
based, environmentally-friendly solar heat storage system produced 5
l/m2/day in early spring weather. Equipment output during summer
exceeded 9 liters per m2 per day.
Abstract: Mobil Producing Nigeria Unlimited (MPNU), a
subsidiary of ExxonMobil and the highest crude oil & condensate
producer in Nigeria has its operational base and an oil terminal, the
Qua Iboe terminal (QIT) located at Ibeno, Nigeria. Other oil
companies like Network Exploration and Production Nigeria Ltd,
Frontier Oil Ltd; Shell Petroleum Development Company Ltd; Elf
Petroleum Nigeria Ltd and Nigerian Agip Energy, a subsidiary of the
Italian ENI E&P operate onshore, on the continental shelf and in deep
offshore of the Atlantic Ocean, respectively with the coastal waters of
Ibeno, Nigeria as the nearest shoreline. This study was designed to
delineate the oil-polluted sites in Ibeno, Nigeria using
microbiological and physico-chemical characterization of soils,
sediments and ground and surface water samples from the study area.
Results obtained revealed that there have been significant recent
hydrocarbon inputs into this environment as observed from the high
counts of hydrocarbonoclastic microorganisms in excess of 1% at all
the stations sampled. Moreover, high concentrations of THC, BTEX
and heavy metals contents in all the samples analyzed corroborate the
high recent crude oil input into the study area. The results also
showed that the pollution of the different environmental media
sampled were of varying degrees, following the trend: ground water
> surface water > sediments > soils.
Abstract: Land Use Land Cover (LULC) changes due to human
activities and natural causes have become a major environmental
concern. Assessment of temporal remote sensing data provides
information about LULC impacts on environment. Land Surface
Temperature (LST) is one of the important components for modeling
environmental changes in climatological, hydrological, and
agricultural studies. In this study, LULC changes (September 7, 1984
and July 8, 2014) especially in agricultural lands together with
population changes (1985-2014) and LST status were investigated
using remotely sensed and census data in South Marmara Watershed,
Turkey. LULC changes were determined using Landsat TM and
Landsat OLI data acquired in 1984 and 2014 summers. Six-band TM
and OLI images were classified using supervised classification
method to prepare LULC map including five classes including Forest
(F), Grazing Land (G), Agricultural Land (A), Water Surface (W),
Residential Area-Bare Soil (R-B) classes. The LST image was also
derived from thermal bands of the same dates.
LULC classification results showed that forest areas, agricultural
lands, water surfaces and residential area-bare soils were increased as
65751 ha, 20163 ha, 1924 ha and 20462 ha respectively. In
comparison, a dramatic decrement occurred in grazing land (107985
ha) within three decades. The population increased 29% between
years 1984-2014 in whole study area. Along with the natural causes,
migration also caused this increase since the study area has an
important employment potential. LULC was transformed among the
classes due to the expansion in residential, commercial and industrial
areas as well as political decisions. In the study, results showed that
agricultural lands around the settlement areas transformed to
residential areas in 30 years.
The LST images showed that mean temperatures were ranged
between 26-32°C in 1984 and 27-33°C in 2014. Minimum
temperature of agricultural lands was increased 3°C and reached to
23°C. In contrast, maximum temperature of A class decreased to
41°C from 44°C. Considering temperatures of the 2014 R-B class and
1984 status of same areas, it was seen that mean, min and max
temperatures increased by 2°C.
As a result, the dynamism of population, LULC and LST resulted
in increasing mean and maximum surface temperatures, living
spaces/industrial areas and agricultural lands.
Abstract: The use of hydroelectric pump-storage system at large
scale, MW-size systems, is already widespread around the world.
Designed for large scale applications, pump-storage station can be
scaled-down for small, remote residential applications. Given the cost
and complexity associated with installing a substation further than
100 miles from the main transmission lines, a remote, independent
and self-sufficient system is by far the most feasible solution. This
article is aiming at the design of wind and solar power generating
system, by means of pumped-storage to replace the wind and /or solar
power systems with a battery bank energy storage. Wind and solar
pumped-storage power generating system can reduce the cost of
power generation system, according to the user's electricity load and
resource condition and also can ensure system reliability of power
supply. Wind and solar pumped-storage power generation system is
well suited for remote residential applications with intermittent wind
and/or solar energy. This type of power systems, installed in these
locations, could be a very good alternative, with economic benefits
and positive social effects. The advantage of pumped storage power
system, where wind power regulation is calculated, shows that a
significant smoothing of the produced power is obtained, resulting in
a power-on-demand system’s capability, concomitant to extra
economic benefits.
Abstract: Today, there is a large number of political transcripts
available on the Web to be mined and used for statistical analysis,
and product recommendations. As the online political resources are
used for various purposes, automatically determining the political
orientation on these transcripts becomes crucial. The methodologies
used by machine learning algorithms to do an automatic classification
are based on different features that are classified under categories
such as Linguistic, Personality etc. Considering the ideological
differences between Liberals and Conservatives, in this paper, the
effect of Personality traits on political orientation classification is
studied. The experiments in this study were based on the correlation
between LIWC features and the BIG Five Personality traits. Several
experiments were conducted using Convote U.S. Congressional-
Speech dataset with seven benchmark classification algorithms. The
different methodologies were applied on several LIWC feature sets
that constituted by 8 to 64 varying number of features that are
correlated to five personality traits. As results of experiments,
Neuroticism trait was obtained to be the most differentiating
personality trait for classification of political orientation. At the same
time, it was observed that the personality trait based classification
methodology gives better and comparable results with the related
work.
Abstract: Perception, evaluation and representation of the
environment have been the subject of many disciplines including
psychology, geography and architecture. In environmental and social
psychology literature there are several evidences which suggest that
cognitive representations about a place consisted of not only
geographic items but also social and cultural. Mental representations
of residence area or a country are influenced and determined by
social-demographics, the physical and social context. Thus, all
mental representations of a given place are also social
representations. Cognitive maps are the main and common
instruments that are used to identify spatial images and the difference
between physical and subjective environments. The aim of the
current study is investigating the mental and social representations of
Turkey in university students’ minds. Data was collected from 249
university students from different departments (i.e. psychology,
geography, history, tourism departments) of Ege University.
Participants were requested to reflect Turkey in their mind onto the
paper drawing sketch maps. According to the results, cognitive maps
showed geographic aspects of Turkey as well as the context of
symbolic, cultural and political reality of Turkey. That is to say, these
maps had many symbolic and verbal items related to critics on social
and cultural problems, ongoing ethnic and political conflicts, and
actual political agenda of Turkey. Additionally, one of main
differentiations in these representations appeared in terms of the East
and West side of the Turkey, and the representations of the East and
West was varied correspondingly participants’ cultural background,
their ethnic values, and where they have born. The results of the
study were discussed in environmental and social psychological
perspective considering cultural and social values of Turkey and
current political circumstances of the country.
Abstract: Continuous upflow filters can combine the nutrient
(nitrogen and phosphate) and suspended solid removal in one unit
process. The contaminant removal could be achieved chemically or
biologically; in both processes the filter removal efficiency depends
on the interaction between the packed filter media and the influent. In
this paper a residence time distribution (RTD) study was carried out
to understand and compare the transfer behaviour of contaminants
through a selected filter media packed in a laboratory-scale
continuous up flow filter; the selected filter media are limestone and
white dolomite. The experimental work was conducted by injecting a
tracer (red drain dye tracer –RDD) into the filtration system and then
measuring the tracer concentration at the outflow as a function of
time; the tracer injection was applied at hydraulic loading rates
(HLRs) (3.8 to 15.2 m h-1). The results were analysed according to
the cumulative distribution function F(t) to estimate the residence
time of the tracer molecules inside the filter media. The mean
residence time (MRT) and variance σ2 are two moments of RTD that
were calculated to compare the RTD characteristics of limestone with
white dolomite. The results showed that the exit-age distribution of
the tracer looks better at HLRs (3.8 to 7.6 m h-1) and (3.8 m h-1) for
limestone and white dolomite respectively. At these HLRs the
cumulative distribution function F(t) revealed that the residence time
of the tracer inside the limestone was longer than in the white
dolomite; whereas all the tracer took 8 minutes to leave the white
dolomite at 3.8 m h-1. On the other hand, the same amount of the
tracer took 10 minutes to leave the limestone at the same HLR. In
conclusion, the determination of the optimal level of hydraulic
loading rate, which achieved the better influent distribution over the
filtration system, helps to identify the applicability of the material as
filter media. Further work will be applied to examine the efficiency
of the limestone and white dolomite for phosphate removal by
pumping a phosphate solution into the filter at HLRs (3.8 to 7.6 m h-1).
Abstract: Model predictive control is a kind of optimal feedback
control in which control performance over a finite future is optimized
with a performance index that has a moving initial time and a moving
terminal time. This paper examines the stability of model predictive
control for linear discrete-time systems with additive stochastic
disturbances. A sufficient condition for the stability of the closed-loop
system with model predictive control is derived by means of a linear
matrix inequality. The objective of this paper is to show the results
of computational simulations in order to verify the effectiveness of
the obtained stability condition.
Abstract: Background in music analysis: Traditionally, when we
think about a composer’s sketches, the chances are that we are
thinking in terms of the working out of detail, rather than the
evolution of an overall concept. Since music is a “time art,” it follows
that questions of a form cannot be entirely detached from
considerations of time. One could say that composers tend to regard
time either as a place gradually and partially intuitively filled, or they
can look for a specific strategy to occupy it. It seems that the one
thing that sheds light on Stockhausen’s compositional thinking is his
frequent use of “form schemas,” that is often a single-page
representation of the entire structure of a piece.
Background in music technology: Sonic Visualiser is a program
used to study a musical recording. It is an open source application for
viewing, analyzing, and annotating music audio files. It contains a
number of visualisation tools, which are designed with useful default
parameters for musical analysis. Additionally, the Vamp plugin
format of SV supports to provide analysis such as for example
structural segmentation.
Aims: The aim of paper is to show how SV may be used to obtain
a better understanding of the specific musical work, and how the
compositional strategy does impact on musical structures and musical
surfaces. It is known that “traditional” music analytic methods don’t
allow indicating interrelationships between musical surface (which is
perceived) and underlying musical/acoustical structure.
Main Contribution: Stockhausen had dealt with the most diverse
musical problems by the most varied methods. A characteristic which
he had never ceased to be placed at the center of his thought and
works, it was the quest for a new balance founded upon an acute
connection between speculation and intuition. In the case with
Mikrophonie I (1964) for tam-tam and 6 players Stockhausen makes
a distinction between the “connection scheme,” which indicates the
ground rules underlying all versions, and the form scheme, which is
associated with a particular version. The preface to the published
score includes both the connection scheme, and a single instance of a
“form scheme,” which is what one can hear on the CD recording. In
the current study, the insight into the compositional strategy chosen
by Stockhausen was been compared with auditory image, that is, with
the perceived musical surface. Stockhausen’s musical work is
analyzed both in terms of melodic/voice and timbre evolution.
Implications: The current study shows how musical structures
have determined of musical surface. The general assumption is this,
that while listening to music we can extract basic kinds of musical
information from musical surfaces. It is shown that interactive
strategies of musical structure analysis can offer a very fruitful way
of looking directly into certain structural features of music.
Abstract: This paper presents development results of usage of
C-OTDR monitoring systems for rail traffic management. The COTDR
method is based on vibrosensitive properties of optical fibers.
Analysis of Rayleigh backscattering radiation parameters changes
which take place due to microscopic seismoacoustic impacts on the
optical fiber allows to determine seismoacoustic emission source
positions and to identify their types. This approach proved successful
for rail traffic management (moving block system, weigh- in-motion
system etc.).
Abstract: Diagnostic enzymes like aspartate aminotransferase
(AST), alanine aminotransferase (ALT) and alkaline phosphatase
(ALP) were determined as indices of heavy metal pollution in Tilapia
guinensis. Three different sets of fishes treated with lead (Pb), iron
(Fe) and copper (Cu) were used for the study while a fourth group
with no heavy metal served as a control. Fishes in each of the groups
were exposed to 2.65mg/l of Pb, 0.85mg/l of Fe and 0.35 mg/l of Cu
in aerated aquaria for 96 hours. Tissue fractionation of the liver
tissues was carried out and the three diagnostic enzymes (AST, ALT,
and ALP) were estimated. Serum levels of the same diagnostic
enzymes were also measured. The mean values of the serum enzyme
activity for ALP in each experimental group were 19.5±1.62,
29.67±2.17 and 1.15±0.27 IU/L for Pb, Fe and Cu groups compared
with 9.99±1.34 IU/L enzyme activity in the control. This result
showed that Pb and Fe caused increased release of the enzyme into
the blood circulation indicating increased tissue damage while Cu
caused a reduction in the serum level as compared with the level in
the control group. The mean values of enzyme activity obtained in
the liver were 102.14±6.12, 140.17±2.06 and 168.23±3.52 IU/L for
Pb, Fe and Cu groups, respectively compared to 91.20±9.42 IU/L
enzyme activity for the control group. The serum and liver AST and
ALT activities obtained in Pb, Fe, Cu and control groups are
reported. It was generally noted that the presence of the heavy metal
caused liver tissues damage and consequent increased level of the
diagnostic enzymes in the serum.
Abstract: In this paper a new methodology for vendor selection
and supply quotas determination (VSSQD) is proposed. The problem
of VSSQD is solved by the model that combines revised weighting
method for determining the objective function coefficients, and a
multiple objective linear programming (MOLP) method based on the
cooperative game theory for VSSQD. The criteria used for VSSQD
are: (1) purchase costs and (2) product quality supplied by individual
vendors. The proposed methodology has been tested on the example
of flour purchase for a bakery with two decision makers.
Abstract: In recent years a new method of combination
treatment for cancer has been developed and studied that has led to
significant advancements in the field of cancer therapy. Hyperthermia
is a traditional therapy that, along with a creation of a medically
approved level of heat with the help of an alternating magnetic AC
current, results in the destruction of cancer cells by heat. This paper
gives details regarding the production of the spherical nanocomposite
PVA/γ-Fe2O3 in order to be used for medical purposes such as tumor
treatment by hyperthermia. To reach a suitable and evenly distributed
temperature, the nanocomposite with core-shell morphology and
spherical form within a 100 to 200 nanometer size was created using
phase separation emulsion, in which the magnetic nano-particles γ-
Fe2O3 with an average particle size of 20 nano-meters and with
different percentages of 0.2, 0.4, 0.5 and 0.6 were covered by
polyvinyl alcohol. The main concern in hyperthermia and heat
treatment is achieving desirable specific absorption rate (SAR) and
one of the most critical factors in SAR is particle size. In this project
all attempts has been done to reach minimal size and consequently
maximum SAR. The morphological analysis of the spherical
structure of the nanocomposite PVA/γ-Fe2O3 was achieved by SEM
analyses and the study of the chemical bonds created was made
possible by FTIR analysis. To investigate the manner of magnetic
nanocomposite particle size distribution a DLS experiment was
conducted. Moreover, to determine the magnetic behavior of the γ-
Fe2O3 particle and the nanocomposite PVA/γ-Fe2O3 in different
concentrations a VSM test was conducted. To sum up, creating
magnetic nanocomposites with a spherical morphology that would be
employed for drug loading opens doors to new approaches in
developing nanocomposites that provide efficient heat and a
controlled release of drug simultaneously inside the magnetic field,
which are among their positive characteristics that could significantly
improve the recovery process in patients.
Abstract: The degradation of concrete due to various hygrochemo-
mechanical actions is inevitable for the structures particularly
built to store water. Therefore, it is essential to determine the material
properties of dam-like structures due to ageing to predict the behavior
of such structures after a certain age. The degraded material
properties are calculated by introducing isotropic degradation index.
The predicted material properties are used to study the behavior of
aged dam at different ages. The dam is modeled by finite elements
and displacement and is considered as an unknown variable. The
parametric study reveals that the displacement is quite larger for
comparatively lower design life of the structure because the
degradation of elastic properties depends on the design life of the
dam. The stresses in dam cam be unexpectedly large at any age with
in the design life. The outcomes of the present study indicate the
importance of the consideration ageing effect of concrete exposed to
water for the safe design of dam throughout its life time.
Abstract: Biodiesel, as an alternative renewable fuel, has been
receiving increasing attention due to the limited supply of fossil fuels
and the increasing need for energy. Microalgae are promising source
for lipids, which can be converted to biodiesel. The biodiesel
production from microalgae lipids using lipase catalyzed reaction in
supercritical CO2 medium has several advantages over conventional
production processes. However, identifying the optimum microalgae
lipid extraction and transesterification conditions is still a challenge.
In this study, the quality of biodiesel produced from lipids extracted
from Scenedesmus sp. and their enzymatic transesterification using
supercritical carbon dioxide have been investigated. At the optimum
conditions, the highest biodiesel production yield was found to be
82%. The fuel properties of the produced biodiesel, without any
separation step, at optimum reaction condition, were determined and
compared to ASTM standards. The properties were found to comply
with the limits, and showed a low glycerol content, without any
separation step.