Abstract: Effect of sprue/metal head height on mould filling,
microstructure and mechanical properties of TWDI casting is studied.
Results show that metal/sprue height of 50 mm is not sufficient to
push the melt through the gating channel, but as it is increased from
100-350 mm, proper mould filling is achieved. However at higher
heights between 200 mm and 350 mm, defects associated with
incomplete solidification, carbide precipitation and turbulent flow are
evident. This research shows that superior UTS, hardness, nodularity
and nodule count are obtained at 100 mm sprue height.
Abstract: Ant Colony Optimization (ACO) is a promising
modern approach to the unused combinatorial optimization. Here
ACO is applied to finding the shortest during communication link
failure. In this paper, the performances of the prim’s and ACO
algorithm are made. By comparing the time complexity and program
execution time as set of parameters, we demonstrate the pleasant
performance of ACO in finding excellent solution to finding shortest
path during communication link failure.
Abstract: This work studies the effect of chemical composition
on the activity and selectivity of γ–alumina supported CuO/
MnO2/Cr2O3 catalysts toward deep oxidation of CO, dimethyl ether
(DME) and methanol. The catalysts were prepared by impregnation
of the support with an aqueous solution of copper nitrate, manganese
nitrate and CrO3 under different conditions. Thermal, XRD and TPR
analysis were performed. The catalytic measurements of single
compounds oxidation were carried out on continuous flow equipment
with a four-channel isothermal stainless steel reactor. Flow-line
equipment with an adiabatic reactor for simultaneous oxidation of all
compounds under the conditions that mimic closely the industrial
ones was used. The reactant and product gases were analyzed by
means of on-line gas chromatographs.
On the basis of XRD analysis it can be concluded that the active
component of the mixed Cu-Mn-Cr/γ–alumina catalysts consists of at
least six compounds – CuO, Cr2O3, MnO2, Cu1.5Mn1.5O4,
Cu1.5Cr1.5O4 and CuCr2O4, depending on the Cu/Mn/Cr molar ratio.
Chemical composition strongly influences catalytic properties, this
influence being quite variable with regards to the different processes.
The rate of CO oxidation rapidly decrease with increasing of
chromium content in the active component while for the DME was
observed the reverse trend. It was concluded that the best
compromise are the catalysts with Cu/(Mn + Cr) molar ratio 1:5 and
Mn/Cr molar ratio from 1:3 to 1:4.
Abstract: Currently, continuous two-phase decanter process
used for olive oil production is the more internationally widespread.
The wastewaters generated from this industry (OMW) are a real
environmental problem because of its high organic load. Among
proposed treatments for these wastewaters, advanced oxidation
technologies (Fenton, ozone, photoFenton, etc.) are the most
favourable. The direct application of these processes is somewhat
expensive. Therefore, the application of a previous stage based on a
flocculation-sedimentation operation is of high importance. In this
research five commercial flocculants (three cationic, and two anionic)
have been used to achieve the separation of phases (liquid clarifiedsludge).
For each flocculant, different concentrations (0-1000 mg/L)
have been studied. In these experiments, sludge volume formed and
the final water quality were determined. The final removal
percentages of total phenols (11.3-25.1%), COD (5.6-20.4%), total
carbon (2.3-26.5%), total organic carbon (1.50-23.8%), total nitrogen
(1.45-24.8%), and turbidity (27.9-61.4%) were determined. The
variation on electric conductivity reduction percentage (1-8%) was
also determined. Finally, the best flocculants with highest removal
percentages have been determined (QG2001 and Flocudex CS49).
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: In this paper, some limit properties for mixing random
variables sequences were studied and some results on weak law of
large number for mixing random variables sequences were presented.
Some complete convergence theorems were also obtained. The results
extended and improved the corresponding theorems in i.i.d random
variables sequences.
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: In this paper, the energy saving and human thermal
comfort in a typical office room are investigated. The impact of a
combined system of exhaust inlet air with light slots located at the
ceiling level in a room served by displacement ventilation system is
numerically modelled. Previous experimental data are used to
validate the Computational Fluid Dynamic (CFD) model. A case
study of simulated office room includes two seating occupants, two
computers, two data loggers and four lamps. The combined system is
located at the ceiling level above the heat sources. A new method of
calculation for the cooling coil load in Stratified Air Distribution
(STRAD) system is used in this study. The results show that 47.4%
energy saving of space cooling load can be achieved by combing the
exhaust inlet air with light slots at the ceiling level above the heat
sources.
Abstract: This study aims at developing a novel cold asphalt
concrete binder course mixture by using Ordinary Portland Cement
(OPC) as a replacement for conventional mineral filler (0%-100%)
with new by-product material (LJMU-A2) used as a supplementary
cementitious material. With this purpose, cold asphalt concrete binder
course mixtures with cationic emulsions were studied by means of
stiffness modulus whereas water sensitivity was assessed by
measuring the stiffness modulus ratio before and after sample
conditioning.
The results indicate that a substantial enhancement in the stiffness
modulus and a considerable improvement of water sensitivity
resistance is achieved by adding LJMU-A2 to the cold asphalt
mixtures as a supplementary cementitious material. Moreover, the
addition of LJMU-A2 to those mixtures leads to a stiffness modulus
after 2-day curing compared to that obtained with Portland cement,
which occurs after 7-day curing.
Abstract: The phatic function of communication is a vital
element of any conversation. This research paper looks into this
function with respect to personal blogs maintained by Indian
bloggers. This paper is a study into the phenomenon of phatic
communication maintained by bloggers through their blogs. Based on
a linguistic analysis of the posts of twenty eight Indian bloggers,
writing in English, studied over a period of three years, the study
indicates that though the blogging phenomenon is not conversational
in the same manner as face-to-face communication, it does make
ample provision for feedback that is conversational in nature.
Ordinary day to day offline conversations use conventionalized
phatic utterances; those on the social media are in a perpetual mode
of innovation and experimentation in order to sustain contact with its
readers. These innovative methods and means are the focus of this
study. Though the personal blogger aims to chronicle his/her personal
life through the blog, the socializing function is crucial to these
bloggers. In comparison to the western personal blogs which focus on
the presentation of the ‘bounded individual self’, we find Indian
personal bloggers engage in the presentation of their ‘social selves’.
These bloggers yearn to reach out to the readers on the internet and
the phatic function serves to initiate, sustain and renew social ties on
the blogosphere thereby consolidating the social network of readers
and bloggers.
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: 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: This paper presents the ‘Eye Ball Motion Controlled
Wheelchair using IR Sensors’ for the elderly and differently abled
people. In this eye tracking based technology, three Proximity
Infrared (IR) sensor modules are mounted on an eye frame to trace
the movement of the iris. Since, IR sensors detect only white objects;
a unique sequence of digital bits is generated corresponding to each
eye movement. These signals are then processed via a micro
controller IC (PIC18F452) to control the motors of the wheelchair.
The potential and efficiency of previously developed rehabilitation
systems that use head motion, chin control, sip-n-puff control, voice
recognition, and EEG signals variedly have also been explored in
detail. They were found to be inconvenient as they served either
limited usability or non-affordability. After multiple regression
analyses, the proposed design was developed as a cost-effective,
flexible and stream-lined alternative for people who have trouble
adopting conventional assistive technologies.
Abstract: Let us consider that the entire universe is composed of
a single hydrogen atom within which the electron is moving around
the proton. In this case, according to classical theories of physics,
radiation, photons respectively, should be absorbed by the electron.
Depending on the number of photons absorbed, the electron radius of
rotation around the proton is established. Until now, the principle of
photons absorption by electrons and the electron transition to a new
energy level, namely to a higher radius of rotation around the proton,
is not clarified in physics. This paper aims to demonstrate that
radiation, photons respectively, have mass and negative electrostatic
charge similar to electrons but infinitely smaller. The experiments
which demonstrate this theory are simple: thermal expansion,
photoelectric effect and thermonuclear reaction.
Abstract: This paper presents an application of Artificial Neural
Network (ANN) algorithm for improving power system voltage
stability. The training data is obtained by solving several normal and
abnormal conditions using the Linear Programming technique. The
selected objective function gives minimum deviation of the reactive
power control variables, which leads to the maximization of
minimum Eigen value of load flow Jacobian. The considered reactive
power control variables are switchable VAR compensators, OLTC
transformers and excitation of generators. The method has been
implemented on a modified IEEE 30-bus test system. The results
obtain from the test clearly show that the trained neural network is
capable of improving the voltage stability in power system with a
high level of precision and speed.
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: In this paper, we propose moving object detection
method which is helpful for driver to safely take his/her car out of
parking lot. When moving objects such as motorbikes, pedestrians,
the other cars and some obstacles are detected at the rear-side of host
vehicle, the proposed algorithm can provide to driver warning. We
assume that the host vehicle is just before departure. Gaussian
Mixture Model (GMM) based background subtraction is basically
applied. Pre-processing such as smoothing and post-processing as
morphological filtering are added. We examine “which color space
has better performance for detection of moving objects?” Three color
spaces including RGB, YCbCr, and Y are applied and compared, in
terms of detection rate. Through simulation, we prove that RGB
space is more suitable for moving object detection based on
background subtraction.
Abstract: HZSM-5 zeolites modified by iron and phosphorus
were applied in catalytic cracking of butene. N2 adsorption and
NH3-TPD were employed to measure the structure and acidity of
catalysts. The results indicate that increasing phosphorus loading
decreased surface area, pore volume and strong acidity of catalysts.
The addition of phosphorus significantly decreased butene conversion
and promoted propylene selectivity. The catalytic performance of
catalyst was strongly dependent on the reaction conditions.
Appropriate reaction conditions could suppress side reactions and
enhance propylene selectivity.
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: Durability of Membrane Electrode Assembly for
Proton Exchange Membrane Fuel Cells was evaluated in both steady
state and accelerated decay modes. Steady state mode was carried out
at constant current of 800mA/cm2 for 2500 hours using air as cathode
feed and pure hydrogen as anode feed. The degradation of the cell
voltage was 0.015V after such 2500 hrs operation. The degradation
rate was therefore calculated to be 6uV/hr. Continuously Vigorous
fluctuation of the cell voltage, which was switched between OCV and
0.2V, was employed for the accelerated decay mode. No obvious
change in performance of the MEA was observed after 10000 cycles
of such operation.