Abstract: The ferrites ZnFe2O4, CdFe2O4 and CuFe2O4 are
synthesized in laboratory conditions using ceramic technology. Their
homogeneity and structure are proven by X-Ray diffraction analysis
and Mössbauer spectroscopy. The synthesized ferrites are subjected
to strong acid and high temperature leaching with solutions of H2SO4,
HCl and HNO3. The results indicate that the highest degree of
leaching of Zn, Cd and Cu from the ferrites is achieved by use of
HCl. The charging of five zinc sulfide concentrates was optimized using
the criterion of minimal amount of zinc ferrite produced when
roasting the concentrates in a fluidized bed. The results obtained are
interpreted in terms of the hydrometallurgical zinc production and
maximum recovery of zinc, copper and cadmium from initial zinc
concentrates after their roasting.
Abstract: The activation volume of 6082T6 aluminum is
investigated at different temperatures for grain size variants. The
deformation activation volume was computed on the basis of the
relationship between the Boltzmann’s constant k, the testing
temperatures, the material strain rate sensitivity and the material yield
stress grain size variants. The material strain rate sensitivity is
computed as a function of yield stress and strain rate grain size
variants. The effect of the material strain rate sensitivity and the
deformation activation volume of 6082T6 aluminum at different
temperatures of 3-D grain are discussed. It is shown that the strain rate sensitivities and activation volume
are negative for the grain size variants during the deformation of
nanostructured materials. It is also observed that the activation
volume vary in different ways with the equivalent radius, semi minor
axis radius, semi major axis radius and major axis radius. From the
obtained results it is shown that the variation of activation volume
increase and decrease with the testing temperature. It was revealed
that, increase in strain rate sensitivity led to decrease in activation
volume whereas increase in activation volume led to decrease in
strain rate sensitivity.
Abstract: Dead wood and habitat tree such as fallen logs, snags,
stumps and cracks and loos bark etc. are regarded as an important
ecological component of forests on which many forest dwelling
species depend on presence of them within forest ecosystems.
Meanwhile its relation to management history in Caspian forest has
gone unreported. The aim of research was to compare the amounts of
dead wood and habitat trees in the forests with historically different
intensities of management, including: forests with the long term
implication of management (PS), the short term implication of
management (NS) which were compared with semi virgin forest
(GS). The number of 405 individual dead and habitat trees were
recorded and measured at 109 sampling locations. ANOVA revealed
volume of dead tree in the form and decay classes significantly differ
within sites and dead volume in the semi virgin forest significantly
higher than managed sites. Comparing the amount of dead and
habitat tree in three sites showed that, dead tree volume related with
management history and significantly differ in three study sites.
Meanwhile, frequency of habitat trees was significantly different
within sites. The highest amount of habitat trees including cavities,
cracks and loose bark and fork split trees was recorded in virgin site
and lowest recorded in the sites with the long term implication of
management. It can be concluded that forest management cause
reduction of the amount of dead and habitat tree specially in a large
size, thus managing this forest according to ecological sustainable
principles require a commitment to maintaining stand structure that
allow, continued generation of dead trees in a full range of size.
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: 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: Processing of high-silicon bauxite on the base of the
traditional clinkering method is related to high power consumption
and capital investments, which makes production of alumina from
those ores non-competitive in terms of basic economic showings. For
these reasons, development of technological solutions enabling to
process bauxites with various chemical and mineralogical structures
efficiently with low level of thermal power consumption is important.
Flow sheet of the studies on washability of ores from the Timanskoe
and the Severo-Onezhskoe deposits is on the base of the flotation
method.
Abstract: The research explores the relationship between
management responsibility and corporate governance of listed
companies in Kazakhstan. This research employs firm level data of
selected listed non-financial firms and firm level data “operational”
financial sector, consisted from banking sector, insurance companies
and accumulated pension funds using multivariate regression analysis
under fixed effect model approach. Ownership structure includes
institutional ownership, managerial ownership and private investor’s
ownership. Management responsibility of the firm is expressed by the
decision of the firm on amount of leverage. Results of the cross
sectional panel study for non-financial firms showed that only
institutional shareholding is significantly negatively correlated with
debt to equity ratio. Findings from “operational” financial sector
show that leverage is significantly affected only by the CEO/Chair
duality and the size of financial institutions, and insignificantly
affected by ownership structure. Also, the findings show, that there is
a significant negative relationship between profitability and the debt
to equity ratio for non-financial firms, which is consistent with
pecking order theory. Generally, the found results suggest that
corporate governance and a management responsibility play
important role in corporate performance of listed firms in
Kazakhstan.
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: The purpose of this theoretical literature review is to
study the relevant academic literature on lack of cardiorespiratory
fitness and its effects on children. The total of thirty eight relevant
documents were identified and considered for this review which
nineteen of those were original research articles published in peer
reviewed journals. The other nineteen articles were statistical
documents. This literature review is structured to examine 5 effects
in deficiency of cardiorespiratory fitness in school aged children (A)
Relative Age Effect (RAE), (B) Obesity, (C) Inadequate fitness level
(D) Unhealthy life style, and (E) Academics. The categories provide
a theoretical framework for future studies where results are driven
from the literature review. The study discusses that regular physical fitness assists children
and adolescents to develop healthy physical activity behaviors which
can be sustained throughout adult life. Conclusion suggests that
advocacy for increasing physical activity and decreasing sedentary
behaviors at school and home are necessary.
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 describes three lumped parameters models
for the study of the dynamic behavior of a boom crane. The models
here proposed allows to evaluate the fluctuations of the load arising
from the rope and structure elasticity and from the type of the
motion command imposed by the winch. A calculation software
was developed in order to determine the actual acceleration of the
lifted mass and the dynamic overload during the lifting phase. Some
application examples are presented, with the aim of showing the
correlation between the magnitude of the stress and the type of the
employed motion command.
Abstract: An experimental study with four different types of bed
conditions was carried out to understand the effect of roughness in
open channel flow at two different Reynolds numbers. The bed
conditions include a smooth surface and three different roughness
conditions, which were generated using sand grains with a median
diameter of 2.46 mm. The three rough conditions include a surface
with distributed roughness, a surface with continuously distributed
roughness and a sand bed with a permeable interface. A commercial
two-component fibre-optic LDA system was used to conduct the
velocity measurements. The variables of interest include the mean
velocity, turbulence intensity, correlation between the streamwise and
the wall normal turbulence, Reynolds shear stress and velocity triple
products. Quadrant decomposition was used to extract the magnitude
of the Reynolds shear stress of the turbulent bursting events. The
effect of roughness was evident throughout the flow depth. The
results show that distributed roughness has the greatest roughness
effect followed by the sand bed and the continuous roughness.
Compared to the smooth bed, the streamwise turbulence intensity
reduces but the vertical turbulence intensity increases at a location
very close to the bed due to the introduction of roughness. Although
the same sand grain is used to create the three different rough bed
conditions, the difference in the turbulence intensity is an indication
that the specific geometry of the roughness has an influence on
turbulence structure.
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: Evaluation of the excavation-induced ground
movements is an important design aspect of support systems in urban
areas. Geological and geotechnical conditions of an excavation area
have significant effects on excavation-induced ground movements and
the related damage. This paper is aimed at studying the performance of
excavation walls supported by nails in jointed rock medium. The
performance of nailed walls is investigated based on evaluating the
excavation-induced ground movements. For this purpose, a set of
calibrated 2D finite element models are developed by taking into
account the nail-rock-structure interactions, the anisotropic properties
of jointed rock, and the staged construction process. The results of this
paper highlight effects of different parameters such as joint
inclinations, anisotropy of rocks and nail inclinations on deformation
parameters of excavation wall supported by nails.
Abstract: Nonlinear evolution of broadband ultrasonic pulses
passed through the rock specimens is studied using the apparatus
“GEOSCAN-02M”. Ultrasonic pulses are excited by the pulses of Qswitched
Nd:YAG laser with the time duration of 10 ns and with the
energy of 260 mJ. This energy can be reduced to 20 mJ by some light
filters. The laser beam radius did not exceed 5 mm. As a result of the
absorption of the laser pulse in the special material – the optoacoustic
generator–the pulses of longitudinal ultrasonic waves are excited with
the time duration of 100 ns and with the maximum pressure
amplitude of 10 MPa. The immersion technique is used to measure
the parameters of these ultrasonic pulses passed through a specimen,
the immersion liquid is distilled water. The reference pulse passed
through the cell with water has the compression and the rarefaction
phases. The amplitude of the rarefaction phase is five times lower
than that of the compression phase. The spectral range of the
reference pulse reaches 10 MHz. The cubic-shaped specimens of the
Karelian gabbro are studied with the rib length 3 cm. The ultimate
strength of the specimens by the uniaxial compression is (300±10)
MPa. As the reference pulse passes through the area of the specimen
without cracks the compression phase decreases and the rarefaction
one increases due to diffraction and scattering of ultrasound, so the
ratio of these phases becomes 2.3:1. After preloading some horizontal
cracks appear in the specimens. Their location is found by one-sided
scanning of the specimen using the backward mode detection of the
ultrasonic pulses reflected from the structure defects. Using the
computer processing of these signals the images are obtained of the
cross-sections of the specimens with cracks. By the increase of the
reference pulse amplitude from 0.1 MPa to 5 MPa the nonlinear
transformation of the ultrasonic pulse passed through the specimen
with horizontal cracks results in the decrease by 2.5 times of the
amplitude of the rarefaction phase and in the increase of its duration
by 2.1 times. By the increase of the reference pulse amplitude from 5
MPa to 10 MPa the time splitting of the phases is observed for the
bipolar pulse passed through the specimen. The compression and
rarefaction phases propagate with different velocities. These features
of the powerful broadband ultrasonic pulses passed through the rock
specimens can be described by the hysteresis model of Preisach-
Mayergoyz and can be used for the location of cracks in the optically
opaque materials.
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: Heart is the most important part in the body of living
organisms. It affects and is affected by any factor in the body.
Therefore, it is a good detector for all conditions in the body. Heart
signal is a non-stationary signal; thus, it is utmost important to study
the variability of heart signal. The Heart Rate Variability (HRV) has
attracted considerable attention in psychology, medicine and has
become important dependent measure in psychophysiology and
behavioral medicine. The standards of measurements, physiological
interpretation and clinical use for HRV that are most often used were
described in many researcher papers, however, remain complex
issues are fraught with pitfalls. This paper presents one of the nonlinear
techniques to analyze HRV. It discusses many points like, what
Poincaré plot is and how Poincaré plot works; also, Poincaré plot's
merits especially in HRV. Besides, it discusses the limitation of
Poincaré cause of standard deviation SD1, SD2 and how to overcome
this limitation by using complex correlation measure (CCM). The
CCM is most sensitive to changes in temporal structure of the
Poincaré plot as compared toSD1 and SD2.
Abstract: In this paper, we describe the use of formal methods
to model malware behaviour. The modelling of harmful behaviour
rests upon syntactic structures that represent malicious procedures
inside malware. The malicious activities are modelled by a formal
grammar, where API calls’ components are the terminals and the set
of API calls used in combination to achieve a goal are designated
non-terminals. The combination of different non-terminals in various
ways and tiers make up the attack vectors that are used by harmful
software. Based on these syntactic structures a parser can be
generated which takes execution traces as input for pattern
recognition.
Abstract: Environmental and functional conditions, sometimes,
necessitate the architectural plan of the building to be asymmetric,
and this result in an asymmetric structure. In such cases finding an
optimal pattern for locating the components of lateral load bearing
system, including shear walls, in the building’s plan is desired. In
case of shear wall in addition to the location the shape of the wall
cross-section is also an effective factor. Various types of shear walls
and their proper layout might come effective in better stiffness
distribution and more appropriate seismic response of the building.
Several studies have been conducted in the context of analysis and
design of shear walls; however, few studies have been performed on
making decisions for the location and form of shear walls in multistory
buildings, especially those with irregular plan. In this study, an
attempt has been made to obtain the most reliable seismic behavior of
multi-story reinforced concrete vertically chamfered buildings by
using more appropriate shear walls form and arrangement in 7-, 10-,
12-, and 15-stoy buildings. The considered forms and arrangements
include common rectangular walls and L-, T-, U- and Z-shaped plan,
located as the core or in the outer frames of the building structure.
Comparison of seismic behaviors of the buildings, including
maximum roof displacement and particularly formation of plastic
hinges and their distribution in the buildings’ structures, have been
done based on the results of a series of nonlinear time history
analyses, by using a set of selected earthquake records. Results show
that shear walls with U-shaped cross-section, placed as the building
central core, and also walls with Z-shaped cross-section, placed at the
corners give the building more reliable seismic behavior.