Abstract: In this study, we examine some spectral properties
of non-selfadjoint matrix-valued difference equations consisting of
a polynomial-type Jost solution. The aim of this study is to
investigate the eigenvalues and spectral singularities of the difference
operator L which is expressed by the above-mentioned difference
equation. Firstly, thanks to the representation of polynomial type Jost
solution of this equation, we obtain asymptotics and some analytical
properties. Then, using the uniqueness theorems of analytic functions,
we guarantee that the operator L has a finite number of eigenvalues
and spectral singularities.
Abstract: Friction stir welding and tungsten inert gas welding
techniques were employed to weld armor grade aluminum alloy to
investigate the effect of welding processes on tensile behavior of
weld joints. Tensile tests, Vicker microhardness tests and optical
microscopy were performed on developed weld joints and base metal.
Welding process influenced tensile behavior and microstructure of
weld joints. Friction stir welded joints showed tensile behavior better
than tungsten inert gas weld joints.
Abstract: This paper presents the influence of the vertical
seismic component on the non-linear dynamics analysis of three
different structures. The subject structures were analyzed and
designed according to recent codes. This paper considers three types
of buildings: 5-, 10-, and 15-story buildings. The non-linear
dynamics analysis of the structures with assuming elastic-perfectlyplastic
behavior was performed using RAM PERFORM-3D software;
the horizontal component was taken into consideration with and
without the incorporation of the corresponding vertical component.
Dynamic responses obtained for the horizontal component acting
alone were compared with those obtained from the simultaneous
application of both seismic components. The results show that the
effect of the vertical component of ground motion may increase the
axial load significantly in the interior columns and, consequently, the
stories. The plastic mechanisms would be changed. The P-Delta
effect is expected to increase. The punching base plate shear of the
columns should be considered. Moreover, the vertical component
increases the input energy when the structures exhibit inelastic
behavior and are taller.
Abstract: A large variety of pipe flange is required in marine
and construction industry. Pipe flanges are usually welded or screwed
to the pipe end and are connected with bolts. This approach is very
simple and widely used for a long time; however, it results in high
development cost and low productivity, and the productions made by
this approach usually have safety problem at the welding area. In this
research, a new approach of forming pipe flange based on cold
forging and floating die concept is presented. This innovative
approach increases the effectiveness of the material usage and save
the time cost compared with conventional welding method. To ensure the dimensional accuracy of the final product, the finite
element analysis (FEA) was carried out to simulate the process of
cold forging, and the orthogonal experiment methods were used to
investigate the influence of four manufacturing factors (pin die angle,
pipe flange angle, rpm, pin die distance from clamp jig) and predicted
the best combination of them. The manufacturing factors were
obtained by numerical and experimental studies and it shows that the
approach is very useful and effective for the forming of pipe flange,
and can be widely used later.
Abstract: Growing human population has placed increased
demands on water supplies and spurred a heightened interest in
desalination infrastructure. Key elements of the economics of
desalination projects are thermal and electrical inputs. With growing
concerns over use of fossil fuels to (indirectly) supply these inputs,
coupling of desalination with nuclear power production represents a
significant opportunity. Individually, nuclear and desalination
technologies have a long history and are relatively mature. For
desalination, Reverse Osmosis (RO) has the lowest energy inputs.
However, the economically driven output quality of the water
produced using RO, which uses only electrical inputs, is lower than the
output water quality from thermal desalination plants. Therefore,
modern desalination projects consider that RO should be coupled with
thermal desalination technologies (MSF, MED, or MED-TVC) with
attendant steam inputs to permit blending to produce various qualities
of water. A large nuclear facility is well positioned to dispatch large
quantities of both electrical and thermal power. This paper considers
the supply of thermal energy to a large desalination facility to examine
heat balance impact on the nuclear steam cycle. The APR1400 nuclear
plant is selected as prototypical from both a capacity and turbine cycle
heat balance perspective to examine steam supply and the impact on
electrical output. Extraction points and quantities of steam are
considered parametrically along with various types of thermal
desalination technologies to form the basis for further evaluations of
economically optimal approaches to the interface of nuclear power
production with desalination projects. In our study, the
thermodynamic evaluation will be executed by DE-TOP, an IAEA
sponsored program. DE-TOP has capabilities to analyze power
generation systems coupled to desalination plants through various
steam extraction positions, taking into consideration the isolation loop
between the nuclear and the thermal desalination facilities (i.e., for
radiological isolation).
Abstract: Optimizing the parameters in the controller plays a
vital role in the control theory and its applications. Optimizing the
PID parameters is finding out the best value from the feasible
solutions. Finding the optimal value is an optimization problem.
Inverted Pendulum is a very good platform for control engineers to
verify and apply different logics in the field of control theory. It is
necessary to find an optimization technique for the controller to tune
the values automatically in order to minimize the error within the
given bounds. In this paper, the algorithmic concepts of Harmony
search (HS) and Genetic Algorithm (GA) have been analyzed for the
given range of values. The experimental results show that HS
performs well than GA.
Abstract: Objectives: To determine the nutritional status and
risk factors associated with women practicing geophagia in QwaQwa,
South Africa. Materials and Methods: An observational epidemiological study
design was adopted which included an exposed (geophagia) and nonexposed
(control) group. A food frequency questionnaire, anthropometric measurements and blood sampling were applied to
determine nutritional status of participants. Logistic regression
analysis was performed in order to identify factors that were likely to
be associated with the practice of geophagia. Results: The mean total energy intake for the geophagia group (G)
and control group (C) were 10324.31 ± 2755.00 kJ and 10763.94 ±
2556.30 kJ respectively. Both groups fell within the overweight
category according to the mean Body Mass Index (BMI) of each
group (G= 25.59 kg/m2; C= 25.14 kg/m2). The mean serum iron
levels of the geophagia group (6.929 μmol/l) were significantly lower
than that of the control group (13.75 μmol/l) (p = 0.000). Serum
transferrin (G=3.23g/l; C=2.7054g/l) and serum transferrin saturation
(G=8.05%; C=18.74%) levels also differed significantly between
groups (p=0.00). Factors that were associated with the practice of
geophagia included haemoglobin (Odds ratio (OR):14.50), serumiron
(OR: 9.80), serum-ferritin (OR: 3.75), serum-transferrin (OR:
6.92) and transferrin saturation (OR: 14.50). A significant negative
association (p=0.014) was found between women who were wageearners
and those who were not wage-earners and the practice of
geophagia (OR: 0.143; CI: 0.027; 0.755). These findings seem to
indicate that a permanent income may decrease the likelihood of
practising geophagia. Key Findings: Geophagia was confirmed to be a risk factor for
iron deficiency in this community. The significantly strong
association between geophagia and iron deficiency emphasizes the
importance of identifying the practice of geophagia in women,
especially during their child bearing years.
Abstract: This work deals with the problem of MHD mixed
convection in a completely porous and differentially heated vertical
channel. The model of Darcy-Brinkman-Forchheimer with the
Boussinesq approximation is adopted and the governing equations are
solved by the finite volume method. The effects of magnetic field and
buoyancy force intensities are given by the Hartmann and Richardson
numbers respectively, as well as the Joule heating represented by
Eckert number on the velocity and temperature fields, are examined.
The main results show an augmentation of heat transfer rate with the
decrease of Darcy number and the increase of Ri and Ha when Joule
heating is neglected.
Abstract: Radical technological innovations enable companies
to reach strong market positions and are thus desirable. On the other
hand, the innovation process is related to significant costs and risks.
Hence, the knowledge of the factors that influence success is crucial
for technology driven companies. Taking a previously developed
framework of Critical Success Factors for radical technological
innovations as a reference model, we conducted a structured and
focused literature review of eleven standard books within the field of
technology and innovation management. With this approach we aim
to evaluate, expand, and clarify the set of Critical Success Factors
detailed in this framework. Overall, the set of factors and their
allocation to the main categories of the framework could be
confirmed. However, the factor organizational home is not
emphasized and discussed in most of the reviewed literature. On the
other hand, an additional factor that has not been part of the
framework is described to be important – strategy fit. Furthermore,
the factors strategic alliances and platform strategy appear in the
literature but in a different context compared to the reference model.
Abstract: Our sowing date experiment took place in the
Demonstration Garden of Institution of Plant Sciences, Centre for
Agricultural Sciences of University of Debrecen, in 2012-2014. The
paper contains data of test year 2014. Our purpose, besides several
other examinations, was to observe how sowing date influences the
leaf area index and the activity of photosynthesis of maize hybrids,
and how those factors affect fruiting. In the experiment we monitored
the change of the leaf area index and the photosynthesis of hybrids
with four different growing seasons. The results obtained confirm
that not only the environmental and agricultural factors in the
growing season have effect on the yield, but also other factors like
the leaf area index and the photosynthesis are determinative
parameters, and all those factors together, modifying the effects of
each other, develop average yields.
Abstract: The aim of this study is to examine the relationship
between organizational commitment which is defined as a strong
belief in and acceptance of the organization’s goals and values, and
burnout syndrome and organizational cynicism. Accordingly, a field
research based on survey method was conducted on the employees of
a health institution operating in the province of Konya. The findings
of the research show that there is a positive statistically significant
relationship between organizational cynicism and burnout while
there is a negative statistically significant relationship between
organizational commitment and burnout. Furthermore, it has been
also realized that there is a negative and statistically significant
relationship between organizational commitment and organizational
cynicism.
Abstract: This study and the field test comparisons were carried
out on the Algerian Derguna – Setif transmission systems. The
transmission line of normal voltage 225 kV is 65 km long,
transported and uses twin bundle conductors protected with two
shield wires of transposed galvanized steel. An iterative finite-element method is used to solve Poisons
equation. Two algorithms are proposed for satisfying the current
continuity condition and updating the space-charge density. A new approach to the problem of corona discharge in
transmission system has been described in this paper. The effect of
varying the configurations and wires number is also investigated. The
analysis of this steady is important in the design of HVDC
transmission lines. The potential and electric field have been
calculating in locations singular points of the system.
Abstract: This article presents an alternative collapse capacity
intensity measure in the three elements form which is influenced by
the spectral ordinates at periods longer than that of the first mode
period at near and far source sites. A parameter, denoted by β, is
defined by which the spectral ordinate effects, up to the effective
period (2T1), on the intensity measure are taken into account. The
methodology permits to meet the hazard-levelled target extreme
event in the probabilistic and deterministic forms. A MATLAB code
is developed involving OpenSees to calculate the collapse capacities
of the 8 archetype RC structures having 2 to 20 stories for regression
process. The incremental dynamic analysis (IDA) method is used to
calculate the structure’s collapse values accounting for the element
stiffness and strength deterioration. The general near field set
presented by FEMA is used in a series of performing nonlinear
analyses. 8 linear relationships are developed for the 8structutres
leading to the correlation coefficient up to 0.93. A collapse capacity
near field prediction equation is developed taking into account the
results of regression processes obtained from the 8 structures. The
proposed prediction equation is validated against a set of actual near
field records leading to a good agreement. Implementation of the
proposed equation to the four archetype RC structures demonstrated
different collapse capacities at near field site compared to those of
FEMA. The reasons of differences are believed to be due to
accounting for the spectral shape effects.
Abstract: This paper presents the result of an experimental
investigation regarding the use of Fe2O3 nanoparticles added to
kerosene as a working fluid, under magnetic field for Copper
Oscillating Heat pipe with inclination angle of 0°(horizontal), 15°,
30°,45°, 60°,75° and 90° (vertical). The following were examined;
measure the temperature distribution and heat transfer rate on
Oscillating Heat Pipe (OHP), with magnetic field under different
angles. Results showed that the addition of Fe2O3 nanoparticles under
magnetic field improved thermal performance of OHP especially in
75°.
Abstract: In this study, it has been studied to determine the
relationship between business performance and strategic flexibility,
which is defined to be the strategic choice that provides the ability of
rapidly responding the changes of the dynamic environment of the
companies, for having competitive advantages. In this context a field
study has been conducted over 56 companies, which are active in
informatics and electronics sectors in TEKNOKENT. As a result of
the study it has been determined that; strategic flexibility has an
effect on business performance and there is a positive and
statistically significant relationship between strategic flexibility and
business performance.
Abstract: Lyophilization, also called freeze-drying, is an
important dehydration technique mainly used for pharmaceuticals.
Food industry also uses lyophilization when it is important to retain
most of the nutritional quality, taste, shape and size of dried products
and to extend their shelf life. Vacuum-Induced during freezing cycle
(VI) has been used in order to control ice nucleation and,
consequently, to reduce the time of primary drying cycle of
pharmaceuticals preserving quality properties of the final product.
This procedure has not been applied in freeze drying of foods. The
present work aims to investigate the effect of VI on the lyophilization
drying time, final moisture content, density and reconstitutional
properties of mango (Mangifera indica L.) slices (MS) and mango
pulp-maltodextrin dispersions (MPM) (30% concentration of total
solids). Control samples were run at each freezing rate without using
induced vacuum. The lyophilization endpoint was the same for all
treatments (constant difference between capacitance and Pirani
vacuum gauges). From the experimental results it can be concluded
that at the high freezing rate (0.4°C/min) reduced the overall process
time up to 30% comparing process time required for the control and
VI of the lower freeze rate (0.1°C/min) without affecting the quality
characteristics of the dried product, which yields a reduction in costs
and energy consumption for MS and MPM freeze drying. Controls
and samples treated with VI at freezing rate of 0.4°C/min in MS
showed similar results in moisture and density parameters.
Furthermore, results from MPM dispersion showed favorable values
when VI was applied because dried product with low moisture
content and low density was obtained at shorter process time
compared with the control. There were not found significant
differences between reconstitutional properties (rehydration for MS
and solubility for MPM) of freeze dried mango resulting from
controls, and VI treatments.
Abstract: This paper presents comparative analysis of
photovoltaic systems (PVS) and propose practical techniques to
improve operational efficiency of the PVS. The best engineering and
construction practices for PVS are identified and field oriented
recommendation are made. Comparative analysis of central and
string inverter based, as well as 600 and 1000VDC PVS are
performed. In addition, direct current (DC) and alternating current
(AC) photovoltaic (PV) module based systems are compared.
Comparison shows that 1000V DC String Inverters based PVS is the
best choice.
Abstract: Carbon nanotubes (CNTs) are known for having high elastic properties with high surface area that promote them as good candidates for reinforcing polymeric matrices. In composite materials, CNTs lack chemical bonding with the surrounding matrix which decreases the possibility of better stress transfer between the components. In this work, a chemical treatment for activating the surface of the multi-wall carbon nanotubes (MWCNT) was applied and the effect of this functionalization on the elastic properties of the epoxy nanocomposites was studied. Functional amino-groups were added to the surface of the CNTs and it was evaluated to be about 34% of the total weight of the CNTs. Elastic modulus was found to increase by about 40% of the neat epoxy resin at CNTs’ weight fraction of 0.5%. The elastic modulus was found to decrease after reaching a certain concentration of CNTs which was found to be 1% wt. The scanning electron microscopic pictures showed the effect of the CNTs on the crack propagation through the sample by forming stress concentrated spots at the nanocomposite samples.
Abstract: The shielding ability of a shielding cavity with an
aperture will be greatly degraded at resonance frequencies, and the
resonance modes and frequencies are affected by aperture resonances
and aperture-cavity coupling, which are closely related with aperture
sizes. The equivalent circuit method and numerical method of
Transmission Line Matrix (TLM) are used to analyze the effects of
aperture resonances and aperture-cavity coupling on the
electromagnetic resonances of a cavity with an aperture in this paper.
Both analytical and numerical results show that the resonance modes
of a shielding cavity with an aperture consist of cavity resonance
modes and aperture resonance modes, and the resonance frequencies
will shift with the change of the aperture sizes because of the aperture
resonances and aperture-cavity coupling. Variation rules of
electromagnetic resonances with aperture sizes for a cavity with an
aperture are given, which will be useful for design of shielding
cavities.
Abstract: In this work, we attempt to associate firm
characteristics with innovative activity. We collect microdata from
listed firms of selected Eurozone Country-members, after the
beginning of 2007 financial crisis. The following literature, several
indicators of growth and performance were selected and tested for
their ability to interpret innovative activity. The main scope is to
examine the possible differences in performance and growth between
innovative and non-innovative firms, during a severe recession.
Additionally to that, a special focus will be held on whether
macroeconomic performance and national innovation system,
determines the extent of innovators' performance. Preliminary
findings, through correlation matrices and non-parametric tests,
strongly indicate the positive relation between innovative activity and
most of the measures used (profitability, size, employment),
confirming that even during a recessionary period, innovative firms
not only survive but also seem to succeed better economic results in
almost all indexes relative to non-innovative. However, even though
innovators seem to perform better in all economies examined, the
extent of that performance seems to be strongly affected by the
supportive mechanisms (financial and structural) that their country
provides. Thus, it is clear, that the technologically intensive 'gap'
between European South and North, during the economic crisis,
became chaotic, due to the harsh austerity measures and reduced
budgets in those countries, even in sectors with high potentials in
economic activity and employment, impairing the effects of crisis and
enhancing the vicious circle of recession.