Abstract: Ceramic obtained on the base of aluminum oxide has
wide application range, because it has unique properties, for example,
wear-resistance, dielectric characteristics, and exploitation ability at
high temperatures and in corrosive atmosphere. Low temperature
synthesis of α-Al2O3 is energo-economical process and it is topical
for developing technologies of corundum ceramics fabrication. In the present work possibilities of low temperature transformation
of oxyhydroxides in α-Al2O3, during the presence of small amount of
rare–earth elements compounds (also Th, Re), have been discussed.
Aluminum unstable oxyhydroxides have been obtained by hydrolysis
of aluminium isopropoxide, nitrates, sulphate, and chloride in
alkaline environment at 80-90ºC temperatures. β-Al(OH)3 has been
received from aluminum powder by ultrasonic development. Drying
of oxyhydroxide sol has been conducted with presence of various
types seeds, which amount reaches 0,1-0,2% (mas). Neodymium,
holmium, thorium, lanthanum, cerium, gadolinium, disprosium
nitrates and rhenium carbonyls have been used as seeds and they
have been added to the sol specimens in amount of 0.1-0.2% (mas)
calculated on metals. Annealing of obtained gels is carried out at 70–
1100ºC for 2 hrs. The same specimen transforms in α-Al2O3 at
1100ºC. At this temperature in case of presence of lanthanum and
gadolinium transformation takes place by 70-85%. In case of
presence of thorium stabilization of γ-and θ-phases takes place. It is
established, that thorium causes inhibition of α-phase generation at
1100ºC, and at the time when in all other doped specimens α-phase is
generated at lower temperatures (1000-1050ºC). Synthesis of various
type compounds and simultaneous consolidation has developed in the
furnace of OXY-GON. Composite materials containing oxide and
non-oxide components close to theoretical data have been obtained in
this furnace respectively. During the work the following devices have
been used: X-ray diffractometer DRON-3M (Cu-Kα, Ni filter,
2º/min), High temperature vacuum furnace OXY-GON, electronic
scanning microscopes Nikon ECLIPSE LV 150, NMM-800TRF,
planetary mill Pulverisette 7 premium line, SHIMADZU Dynamic
Ultra Micro Hardness Tester, DUH-211S, Analysette 12 Dyna sizer.
Abstract: In the present study we have investigated axial
buckling characteristics of nanocomposite beams reinforced by
single-walled carbon nanotubes (SWCNTs). Various types of beam
theories including Euler-Bernoulli beam theory, Timoshenko beam
theory and Reddy beam theory were used to analyze the buckling
behavior of carbon nanotube-reinforced composite beams.
Generalized differential quadrature (GDQ) method was utilized to
discretize the governing differential equations along with four
commonly used boundary conditions. The material properties of the
nanocomposite beams were obtained using molecular dynamic (MD)
simulation corresponding to both short-(10,10) SWCNT and long-
(10,10) SWCNT composites which were embedded by amorphous
polyethylene matrix. Then the results obtained directly from MD
simulations were matched with those calculated by the mixture rule
to extract appropriate values of carbon nanotube efficiency
parameters accounting for the scale-dependent material properties.
The selected numerical results were presented to indicate the
influences of nanotube volume fractions and end supports on the
critical axial buckling loads of nanocomposite beams relevant to
long- and short-nanotube composites.
Abstract: This paper describes a subarray based low
computational design method of multiuser massive multiple
input multiple output (MIMO) system. In our previous works, use of
large array is assumed only in transmitter, but this study considers
the case both of transmitter and receiver sides are equipped with
large array antennas. For this aim, receive arrays are also divided
into several subarrays, and the former proposed method is modified
for the synthesis of a large array from subarrays in both ends.
Through computer simulations, it is verified that the performance
of the proposed method is degraded compared with the original
approach, but it can achieve the improvement in the aspect of
complexity, namely, significant reduction of the computational load
to the practical level.
Abstract: Recently, numerous documents including large
volumes of unstructured data and text have been created because of the
rapid increase in the use of social media and the Internet. Usually,
these documents are categorized for the convenience of users. Because
the accuracy of manual categorization is not guaranteed, and such
categorization requires a large amount of time and incurs huge costs.
Many studies on automatic categorization have been conducted to help
mitigate the limitations of manual categorization. Unfortunately, most
of these methods cannot be applied to categorize complex documents
with multiple topics because they work on the assumption that
individual documents can be categorized into single categories only.
Therefore, to overcome this limitation, some studies have attempted to
categorize each document into multiple categories. However, the
learning process employed in these studies involves training using a
multi-categorized document set. These methods therefore cannot be
applied to the multi-categorization of most documents unless
multi-categorized training sets using traditional multi-categorization
algorithms are provided. To overcome this limitation, in this study, we
review our novel methodology for extending the category of a
single-categorized document to multiple categorizes, and then
introduce a survey-based verification scenario for estimating the
accuracy of our automatic categorization methodology.
Abstract: An analytical 4-DOF nonlinear model of a de Laval
rotor-stator system based on Energy Principles has been used
theoretically and experimentally to investigate fault symptoms in a
rotating system. The faults, namely rotor-stator-rub, crack and
unbalance are modeled as excitations on the rotor shaft. Mayes
steering function is used to simulate the breathing behaviour of the
crack. The fault analysis technique is based on waveform signal,
orbits and Fast Fourier Transform (FFT) derived from simulated and
real measured signals. Simulated and experimental results manifest
considerable mutual resemblance of elliptic-shaped orbits and FFT
for a same range of test data.
Abstract: The hydrodynamic and thermal behaviors of fluid
flow in wavy microchannel are investigated numerically. Effects of
Reynolds number on the hydrodynamics and thermal behaviors are
investigated. Three cases of Reynolds number (580, 1244, and 1910)
are adopted in this study. It is found that the separation zone begin
appears when Reynolds number is greater than 1910 at the endsection
of the wave. Also it is found that dimensionless maximum
velocity at the mid-section of the wave decreases and becomes as a
turbulent behavior as Reynolds numbers increases. The maximum
temperature at the center line at the mid-section of the wave increases
as Reynolds number increases until it reaches the turbulent behavior
when Reynolds number is equal or greater than 1244, while this
behavior will be achieved at very high velocities at the end section of
the wave.
Abstract: Si-Ge solid solutions (bulk poly- and mono-crystalline
samples, thin films) are characterized by high perspectives for
application in semiconductor devices, in particular, optoelectronics
and microelectronics. From this point of view, complex studying of
structural state of the defects and structural-sensitive physical
properties of Si-Ge solid solutions depending on the contents of Si
and Ge components is very important. Present work deals with the
investigations of microstructure, microhardness, internal friction and
shear modulus of Si1-xGex(x≤0,02) bulk monocrystals conducted at
room temperature. Si-Ge bulk crystals were obtained by Czochralski
method in [111] crystallographic direction. Investigated
monocrystalline Si-Ge samples are characterized by p-type
conductivity and carriers’ concentration 5.1014-1.1015cm-3.
Microhardness was studied on Dynamic Ultra Micro hardness Tester
DUH-201S with Berkovich indenter. Investigate samples are characterized with 0,5x0,5x(10-15)mm3
sizes, oriented along [111] direction at torsion oscillations ≈1Hz,
multistage changing of internal friction and shear modulus has been
revealed in an interval of strain amplitude of 10-5-5.10-3. Critical
values of strain amplitude have been determined at which hysteretic
changes of inelastic characteristics and microplasticity are observed. The critical strain amplitude and elasticity limit values are also
determined. Dynamic mechanical characteristics decreasing trend is
shown with increasing Ge content in Si-Ge solid solutions. Observed
changes are discussed from the point of view of interaction of various
dislocations with point defects and their complexes in a real structure
of Si-Ge solid solutions.
Abstract: Urinary Tract Infections are considered as one of the
most common bacterial infections with an estimated annual global
incidence of 150 million. Antimicrobial drug resistance is one of the
major threats due to wide spread usage of uncontrolled antibiotics. In
this study, a total number of 9149 urine samples were collected from
R.H Patiala and processed in the Department of Microbiology G. M.
C Patiala (January 2013 to December 2013). Urine samples were
inoculated on MacConkey’s and blood agar plates and incubated at
370C for 24 hrs. The organisms were identified by colony characters,
Gram’s staining, and biochemical reactions. Antimicrobial
susceptibility of the isolates was determined against various
antimicrobial agents (Hi – Media Mumbai India) by Kirby Bauer
DISK diffusion method on Muller Hinton agar plates. Maximum patients were in the age group of 21-30 yrs followed by
31-40 yrs. Males (34%) are less prone to urinary tract infections than
females (66%). Culture was positive in 25% of the samples.
Escherichia coli was the most common isolate 60.3% followed by
Klebsiella pneumoniae 13.5%, Proteus spp. 9% and Staphylococcus
aureus 7.6%. Most of the urinary isolates were sensitive to,
carbepenems, Aztreonam, Amikacin, and Piperacillin + Tazobactum.
All the isolates showed a good sensitivity towards Nitrofurantoin
(82%). ESBL production was found to be 70.6% in Escherichia coli
and 29.4% in Klebsiella pneumonia. Susceptibility of ESBL
producers to Imipenem, Nitrofurantoin and Amikacin were found to
be 100%, 76%, and 75% respectively. Uropathogens are increasingly
showing resistance to many antibiotics making empiric management
of outpatient UTIs challenging. Ampicillin, Cotrimoxazole and
Ciprofloxacin should not be used in empiric treatment. Nitrofurantoin
could be used in lower urinary tract infection. Knowledge of
uropathogens and their antimicrobial susceptibility pattern in a
geographical region will help in appropriate and judicious antibiotic
usage in a health care setup.
Abstract: This research was conducted in an automotive company in Indonesia to overcome the problem of high logistics cost. The problem causes high of additional truck delivery. From the breakdown of the problem, chosen one route, which has the highest gap value, namely for RE-04. Research methodology will be started from calculating the ideal condition, making simulation, calculating the ideal logistic cost, and proposing an improvement. From the calculation of the ideal condition, box arrangement was done on the truck has efficiency with three trucks delivery per day. Route simulation making uses Tecnomatix Plant Simulation software as a visualization for the company about how the system is occurred on route RE-04 in ideal condition. The last step is proposing improvements on the area of route RE-04. The route arrangement is done by Saving Method and sequence of each supplier with the Nearest Neighbor. The results of the proposed improvements are three new route groups, where was expected to decrease logistics cost and increase the average of the truck efficiency per day.
Abstract: The effect of molybdate addition to chloride
environment on resistance of AISI 316Ti stainless steel to pitting
corrosion was studied. Potentiodynamic polarisation tests were
performed in 1 M and 0.1 M chloride acidified solutions with various
additions of sodium molybdate at room temperature. The presented
results compare the effect of molybdate anions on quality of passive
film (expressed by the pitting potential) in both chloride solutions.
The pitting potential increases with the increase inhibitor
concentration. The inhibitive effect of molybdate ions is stronger in
chloride solution of lower aggressiveness (0.1M).
Abstract: This paper studies a mathematical model based on the
integral equations for dynamic analyzes numerical investigations of a
non-uniform or multi-material composite beam. The beam is
subjected to a sub-tangential follower force and elastic foundation.
The boundary conditions are represented by generalized
parameterized fixations by the linear and rotary springs. A
mathematical formula based on Euler-Bernoulli beam theory is
presented for beams with variable cross-sections. The non-uniform
section introduces non-uniformity in the rigidity and inertia of beams
and consequently, more complicated equilibrium who governs the
equation. Using the boundary element method and radial basis
functions, the equation of motion is reduced to an algebro-differential
system related to internal and boundary unknowns. A generalized
formula for the deflection, the slope, the moment and the shear force
are presented. The free vibration of non-uniform loaded beams is
formulated in a compact matrix form and all needed matrices are
explicitly given. The dynamic stability analysis of slender beam is
illustrated numerically based on the coalescence criterion. A realistic
case related to an industrial chimney is investigated.
Abstract: The growing concerns for physical wellbeing and
health have been reflected in the way we choose food in our table.
Nowadays, we are all more informed consumers and choose healthier
foods. On the other hand, stroke, cancer and atherosclerosis may be
somehow minimized by the intake of some bioactive compounds
present in food, the so-called nutraceuticals and functional foods. The
aim of this work was to make a revision of the published studies
about the effects of some bioactive compounds, namely lycopene in
human health, in the prevention of diseases, thus playing the role of a
functional food. Free radical in human body can induce cell damage
and consequently can be responsible for the development of some
cancers and chronic diseases. Lycopene is one of the most powerful
antioxidants known, being the predominant carotenoid in tomato. The
respective chemistry, bioavailability, and its functional role in the
prevention of several diseases will be object of this work. On the
other hand, the inclusion of lycopene in some foods can also be made
by biotechnology and represents a way to recover the wastes in the
tomato industry with nutritional positive effects in health.
Abstract: Health of a person plays a vital role in the collective
health of his community and hence the well-being of the society as a
whole. But, in today’s fast paced technology driven world, health
issues are increasingly being associated with human behaviors – their
lifestyle. Social networks have tremendous impact on the health
behavior of individuals. Many researchers have used social network
analysis to understand human behavior that implicates their social
and economic environments. It would be interesting to use a similar
analysis to understand human behaviors that have health
implications. This paper focuses on concepts of those behavioural
analyses that have health implications using social networks analysis
and provides possible algorithmic approaches. The results of these
approaches can be used by the governing authorities for rolling out
health plans, benefits and take preventive measures, while the
pharmaceutical companies can target specific markets, helping health
insurance companies to better model their insurance plans.
Abstract: This paper describes a sliding mode controller for
autonomous underwater vehicles (AUVs). The dynamic of AUV
model is highly nonlinear because of many factors, such as
hydrodynamic drag, damping, and lift forces, Coriolis and centripetal
forces, gravity and buoyancy forces, as well as forces from thruster.
To address these difficulties, a nonlinear sliding mode controller is
designed to approximate the nonlinear dynamics of AUV and
improve trajectory tracking. Moreover, the proposed controller can
profoundly attenuate the effects of uncertainties and external
disturbances in the closed-loop system. Using the Lyapunov theory
the boundedness of AUV tracking errors and the stability of the
proposed control system are also guaranteed. Numerical simulation
studies of an AUV are included to illustrate the effectiveness of the
presented approach.
Abstract: The main issue in designing a wireless sensor network
(WSN) is the finding of a proper routing protocol that complies with
the several requirements of high reliability, short latency, scalability,
low power consumption, and many others. This paper proposes a
novel routing algorithm that complies with these design
requirements. The new routing protocol divides the WSN into several subnetworks
and each sub-network is divided into several clusters. This
division is designed to reduce the number of radio transmission and
hence decreases the power consumption. The network division may
be changed dynamically to adapt with the network changes and
allows the realization of the design requirements.
Abstract: The McEliece cryptosystem is an asymmetric type of
cryptography based on error correction code. The classical McEliece
used irreducible binary Goppa code which considered unbreakable
until now especially with parameter [1024, 524, and 101], but it is
suffering from large public key matrix which leads to be difficult to
be used practically. In this work Irreducible and Separable Goppa
codes have been introduced. The Irreducible and Separable Goppa
codes used are with flexible parameters and dynamic error vectors. A
Comparison between Separable and Irreducible Goppa code in
McEliece Cryptosystem has been done. For encryption stage, to get
better result for comparison, two types of testing have been chosen;
in the first one the random message is constant while the parameters
of Goppa code have been changed. But for the second test, the
parameters of Goppa code are constant (m=8 and t=10) while the
random message have been changed. The results show that the time
needed to calculate parity check matrix in separable are higher than
the one for irreducible McEliece cryptosystem, which is considered
expected results due to calculate extra parity check matrix in
decryption process for g2(z) in separable type, and the time needed to
execute error locator in decryption stage in separable type is better
than the time needed to calculate it in irreducible type. The proposed
implementation has been done by Visual studio C#.
Abstract: Predicting earnings management is vital for the capital
market participants, financial analysts and managers. The aim of this
research is attempting to respond to this query: Is there a significant
difference between the regression model and neural networks’
models in predicting earnings management, and which one leads to a
superior prediction of it? In approaching this question, a Linear
Regression (LR) model was compared with two neural networks
including Multi-Layer Perceptron (MLP), and Generalized
Regression Neural Network (GRNN). The population of this study
includes 94 listed companies in Tehran Stock Exchange (TSE)
market from 2003 to 2011. After the results of all models were
acquired, ANOVA was exerted to test the hypotheses. In general, the
summary of statistical results showed that the precision of GRNN did
not exhibit a significant difference in comparison with MLP. In
addition, the mean square error of the MLP and GRNN showed a
significant difference with the multi variable LR model. These
findings support the notion of nonlinear behavior of the earnings
management. Therefore, it is more appropriate for capital market
participants to analyze earnings management based upon neural
networks techniques, and not to adopt linear regression models.
Abstract: Structural failure is caused mainly by damage that
often occurs on structures. Many researchers focus on to obtain very
efficient tools to detect the damage in structures in the early state. In
the past decades, a subject that has received considerable attention in
literature is the damage detection as determined by variations in the
dynamic characteristics or response of structures. The study presents
a new damage identification technique. The technique detects the
damage location for the incomplete structure system using output
data only. The method indicates the damage based on the free
vibration test data by using ‘Two Points Condensation (TPC)
technique’. This method creates a set of matrices by reducing the
structural system to two degrees of freedom systems. The current
stiffness matrices obtain from optimization the equation of motion
using the measured test data. The current stiffness matrices compare
with original (undamaged) stiffness matrices. The large percentage
changes in matrices’ coefficients lead to the location of the damage. TPC technique is applied to the experimental data of a simply
supported steel beam model structure after inducing thickness change
in one element, where two cases consider. The method detects the
damage and determines its location accurately in both cases. In
addition, the results illustrate these changes in stiffness matrix can be
a useful tool for continuous monitoring of structural safety using
ambient vibration data. Furthermore, its efficiency proves that this
technique can be used also for big structures.
Abstract: This research studies the joint production,
maintenance and subcontracting control policy for an unreliable
deteriorating manufacturing system. Production activities are
controlled by a derivation of the Hedging Point Policy, and given that
the system is subject to deterioration, it reduces progressively its
capacity to satisfy product demand. Multiple deterioration effects are
considered, reflected mainly in the quality of the parts produced and
the reliability of the machine. Subcontracting is available as support
to satisfy product demand; also, overhaul maintenance can be
conducted to reduce the effects of deterioration. The main objective
of the research is to determine simultaneously the production,
maintenance and subcontracting rate, which minimize the total,
incurred cost. A stochastic dynamic programming model is
developed and solved through a simulation-based approach
composed of statistical analysis and optimization with the response
surface methodology. The obtained results highlight the strong
interactions between production, deterioration and quality, which
justify the development of an integrated model. A numerical example
and a sensitivity analysis are presented to validate our results.
Abstract: The Gezi Park protests of 2013 have significantly changed the Turkish agenda and its effects have been felt historically. The protests, which rapidly spread throughout the country, were triggered by the proposal to recreate the Ottoman Army Barracks to function as a shopping mall on Gezi Park located in Istanbul’s Taksim neighbourhood despite the oppositions of several NGOs and when trees were cut in the park for this purpose. Once the news that the construction vehicles entered the park on May 27 spread on social media, activists moved into the park to stop the demolition, against whom the police used disproportioned force. With this police intervention and the then prime-minister Tayyip Erdoğan's insistent statements about the construction plans, the protests turned into anti- government demonstrations, which then spread to the rest of the country, mainly in big cities like Ankara and Izmir. According to the Ministry of Internal Affairs’ June 23rd reports, 2.5 million people joined the demonstrations in 79 provinces, that is all of them, except for the provinces of Bayburt and Bingöl, while even more people shared their opinions via social networks. As a result of these events, 8 civilians and 2 security personnel lost their lives, namely police chief Mustafa Sarı, police officer Ahmet Küçükdağ, citizens Mehmet Ayvalıtaş, Abdullah Cömert, Ethem Sarısülük, Ali İsmail Korkmaz, Ahmet Atakan, Berkin Elvan, Burak Can Karamanoğlu, Mehmet İstif, and Elif Çermik, and 8163 more were injured. Besides being a turning point in Turkish history, the Gezi Park protests also had broad repercussions in both in Turkish and in global media, which focused on Turkey throughout the events. Our study conducts content analysis of three Turkish reporting newspapers with varying ideological standpoints, Hürriyet, Cumhuriyet ve Yeni Şafak, in order to reveal their basic approach to news casting in context of the Gezi Park protests. Headlines, news segments, and news content relating to the Gezi protests were treated and analysed for this purpose. The aim of this study is to understand the social effects of the Gezi Park protests through media samples with varying political attitudes towards news casting.