Abstract: Nanotechnology has become the world attention in
various applications including the solar cells devices due to the
uniqueness and benefits of achieving low cost and better
performances of devices. Recently, thin film solar cells such as
Cadmium Telluride (CdTe), Copper-Indium-Gallium-diSelenide
(CIGS), Copper-Zinc-Tin-Sulphide (CZTS), and Dye-Sensitized
Solar Cells (DSSC) enhanced by nanotechnology have attracted
much attention. Thus, a compilation of nanotechnology devices
giving the progress in the solar cells has been presented. It is much
related to nanoparticles or nanocrystallines, carbon nanotubes, and
nanowires or nanorods structures.
Abstract: This study was conducted to determine sex
differentiation of laboratory reared Elm nymphalid (Nymphalis
polychloros Linnaeus, 1758) by examining the morphological
structure of pupal stage. Laboratory colony of elm nymphalid, reared
on pear leaves, was used to set up experiments. It was performed
with 5 replications having 8 pupae for each replication. Dorsal,
ventral and lateral parts of external morphological structures of pupae
were examined by Olympus SZX9 stereozoom microscope and
photographed. When fully grown, mature larvae wander the highest
part of the rearing cage and pupae were formed hanging by
cremaster. After completing prepupa stage about 1.5±0.3 days, they
all pupated. Pupal stage was completed at 24±1°C about 4.38±1.20
days. Pupal weights were 0.483±0.05 g in females and 0.392±0.08 g
(n=40) in males respectively. Pupal emergence rate was 95%, with
22 females and 16 males. Examinations of ventral parts of 8th, 9th,
and 10th abdominal segments revealed that anal opening were found
at 10th abdominal segment in both sexes, 3 lumps were determined at
9th abdominal segments then the specific opening structure at 8th
segment was only found on female pupae.
Abstract: These Monolayer and multilayer coatings of CrN and
AlCrN deposited on 100Cr6 (AISI 52100) substrate by PVD
magnetron sputtering system. The microstructures of the coatings
were characterized using atomic force microscopy (AFM). The AFM
analysis revealed the presence of domes and craters that are
uniformly distributed over all surfaces of the various layers.
Nanoindentation measurement of CrN coating showed maximum
hardness (H) and modulus (E) of 14 GPa and 190 GPa, respectively.
The measured H and E values of AlCrN coatings were found to be 30
GPa and 382 GPa, respectively. The improved hardness in both the
coatings was attributed mainly to a reduction in crystallite size and
decrease in surface roughness. The incorporation of Al into the CrN
coatings has improved both hardness and Young’s modulus.
Abstract: Superabsorbent polymers received much attention and
are used in many fields because of their superior characters to
traditional absorbents, e.g., sponge and cotton. So, it is very
important but challenging to prepare highly and fast-swelling
superabsorbents. A reliable, efficient and low-cost technique for
removing heavy metal ions from wastewater is the adsorption using
bio-adsorbents obtained from biological materials, such as
polysaccharides-based hydrogels superabsorbents. In this study, novel multi-functional superabsorbent composites
type semi-interpenetrating polymer networks (Semi-IPNs) were
prepared via graft polymerization of acrylamide onto chitosan
backbone in presence of gelatin, CTS-g-PAAm/Ge, using potassium
persulfate and N,N’-methylene bisacrylamide as initiator and
crosslinker, respectively. These hydrogels were also partially
hydrolyzed to achieve superabsorbents with ampholytic properties
and uppermost swelling capacity. The formation of the grafted
network was evidenced by Fourier Transform Infrared Spectroscopy
(ATR-FTIR) and Thermogravimetric Analysis (TGA). The porous
structures were observed by Scanning Electron Microscope (SEM).
From TGA analysis, it was concluded that the incorporation of the Ge
in the CTS-g-PAAm network has marginally affected its thermal
stability. The effect of gelatin content on the swelling capacities of
these superabsorbent composites was examined in various media
(distilled water, saline and pH-solutions). The water absorbency was
enhanced by adding Ge in the network, where the optimum value was
reached at 2 wt. % of Ge. Their hydrolysis has not only greatly
optimized their absorption capacity but also improved the swelling
kinetic.These materials have also showed reswelling ability. We
believe that these super-absorbing materials would be very effective
for the adsorption of harmful metal ions from wastewater.
Abstract: Zn alloy and composite coatings are widely used in
buildings and structures, automobile and fasteners industries to
protect steel component from corrosion. In this paper, Zn-Ni-Al2O3
nanocomposite coatings were electrodeposited on mild steel using a
novel sol enhanced electroplating method. In this method, transparent
Al2O3 sol was added into the acidic Zn-Ni bath to produced Zn-Ni-
Al2O3 nanocomposite coatings. The effect of alumina sol on the
electrodeposition process, and coating properties was investigated
using cyclic voltammetry, XRD, ESEM and Tafel test. Results from
XRD tests showed that the structure of all coatings was single γ-
Ni5Zn21 phase. Cyclic voltammetry results showed that the
electrodeposition overpotential was lower in the presence of alumina
sol in the bath, and caused the reduction potential of Zn-Ni to shift to
more positive values. Zn-Ni-Al2O3 nanocomposite coatings produced
more uniform and compact deposits, with fine grained microstructure
when compared to Zn-Ni coatings. The corrosion resistance of Zn-Ni
coatings was improved significantly by incorporation of alumina
nanoparticles into the coatings.
Abstract: This study suggests the estimation method of stress
distribution for the beam structures based on TLS (Terrestrial Laser
Scanning). The main components of method are the creation of the
lattices of raw data from TLS to satisfy the suitable condition and
application of CSSI (Cubic Smoothing Spline Interpolation) for
estimating stress distribution. Estimation of stress distribution for the
structural member or the whole structure is one of the important
factors for safety evaluation of the structure. Existing sensors which
include ESG (Electric strain gauge) and LVDT (Linear Variable
Differential Transformer) can be categorized as contact type sensor
which should be installed on the structural members and also there are
various limitations such as the need of separate space where the
network cables are installed and the difficulty of access for sensor
installation in real buildings. To overcome these problems inherent in
the contact type sensors, TLS system of LiDAR (light detection and
ranging), which can measure the displacement of a target in a long
range without the influence of surrounding environment and also get
the whole shape of the structure, has been applied to the field of
structural health monitoring. The important characteristic of TLS
measuring is a formation of point clouds which has many points
including the local coordinate. Point clouds are not linear distribution
but dispersed shape. Thus, to analyze point clouds, the interpolation is
needed vitally. Through formation of averaged lattices and CSSI for
the raw data, the method which can estimate the displacement of
simple beam was developed. Also, the developed method can be
extended to calculate the strain and finally applicable to estimate a
stress distribution of a structural member. To verify the validity of the
method, the loading test on a simple beam was conducted and TLS
measured it. Through a comparison of the estimated stress and
reference stress, the validity of the method is confirmed.
Abstract: Since 1920, the industry has almost completely
changed the rivets production techniques for the manufacture of
permanent welding join production of structures and manufacture of
other products. The welding arc is the process more widely used in
industries. This is accomplished by the heat of an electric arc which
melts the base metal while the molten metal droplets are transferred
through the arc to the welding pool, protected from the atmosphere
by a gas curtain. The GMAW (Gas metal arc welding) process is
influenced by variables such as: current, polarity, welding speed,
electrode: extension, position, moving direction; type of joint,
welder's ability, among others. It is remarkable that the knowledge
and control of these variables are essential for obtaining satisfactory
quality welds, knowing that are interconnected so that changes in one
of them requiring changes in one or more of the other to produce the
desired results. The optimum values are affected by the type of base
metal, the electrode composition, the welding position and the quality
requirements. Thus, this paper proposes a new methodology, adding
the variable vibration through a mechanism developed for GMAW
welding, in order to improve the mechanical and metallurgical
properties which does not affect the ability of the welder and enables
repeatability of the welds made. For confirmation metallographic
analysis and mechanical tests were made.
Abstract: It is a major challenge to build a bridge superstructure
that has long-term durability and low maintenance requirements. A
solution to this challenge may be to use new materials or to
implement new structural systems. Fiber Reinforced Polymer (FRP)
composites have continued to play an important role in solving some
of persistent problems in infrastructure applications because of its
high specific strength, light weight, and durability. In this study, the
concept of the hybrid FRP-concrete structural systems is applied to a
bridge superstructure. The hybrid FRP-concrete bridge superstructure
is intended to have durable, structurally sound, and cost effective
hybrid system that will take full advantage of the inherent properties
of both FRP materials and concrete. In this study, two hybrid FRP-concrete
bridge systems were investigated. The first system consists
of trapezoidal cell units forming a bridge superstructure. The second
one is formed by arch cells. The two systems rely on using cellular
components to form the core of the bridge superstructure, and an
outer shell to warp around those cells to form the integral unit of the
bridge. Both systems were investigated analytically by using finite
element (FE) analysis. From the rigorous FE studies, it was
concluded that first system is more efficient than the second.
Abstract: Aging infrastructures became a serious social problem.
This brought out the increased need for the legislation of a new strict
guideline for infrastructure management. Although existing guidelines
provided basics of how to evaluate and manage the condition of
infrastructures, they needed improvements for their evaluation
procedures. Most guidelines mainly focused on the structural
condition of infrastructures and did not properly reflect service aspects
of infrastructures such as performance, public demand, capacity, etc.,
which were significantly valuable to public. Regardless of the
importance, these factors were often neglected in infrastructure
evaluations, because they were quite subjective and difficult to
quantify in rational manner. Thus, this study proposed a framework to
properly identify and evaluate the service indicators. This study
showed that service indicators could be grouped into two categories
and properly evaluated using AHP and Fuzzy. Overall, proposed
framework is expected to assist governmental agency in establishing
effective investment strategies for infrastructure improvements.
Abstract: Several parameters are established in order to measure
biodiesel quality. One of them is the iodine value, which is an
important parameter that measures the total unsaturation within a
mixture of fatty acids. Limitation of unsaturated fatty acids is
necessary since warming of higher quantity of these ones ends in
either formation of deposits inside the motor or damage of lubricant.
Determination of iodine value by official procedure tends to be very
laborious, with high costs and toxicity of the reagents, this study uses
artificial neural network (ANN) in order to predict the iodine value
property as an alternative to these problems. The methodology of
development of networks used 13 esters of fatty acids in the input
with convergence algorithms of back propagation of back
propagation type were optimized in order to get an architecture of
prediction of iodine value. This study allowed us to demonstrate the
neural networks’ ability to learn the correlation between biodiesel
quality properties, in this caseiodine value, and the molecular
structures that make it up. The model developed in the study reached
a correlation coefficient (R) of 0.99 for both network validation and
network simulation, with Levenberg-Maquardt algorithm.
Abstract: The goal of the paper is to highlight the effect of the
building design and epicentral distance on the storey lateral
displacements, for several reinforced concrete buildings (6, 9 and 12
stories). These structures are subjected to seismic accelerations from
the Boumerdes earthquake (Algeria, May 21st, Mw = 6.8). Using the
response spectrum method (modal spectral approach), the analysis is
performed in both longitudinal and transverse directions. The
building design is expressed through the fundamental period and
epicentral distance is used to represent the earthquake effect variation
on storey lateral displacements and interstory drift for the considered
buildings.
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: Background in music analysis: Traditionally, when we
think about a composer’s sketches, the chances are that we are
thinking in terms of the working out of detail, rather than the
evolution of an overall concept. Since music is a “time art,” it follows
that questions of a form cannot be entirely detached from
considerations of time. One could say that composers tend to regard
time either as a place gradually and partially intuitively filled, or they
can look for a specific strategy to occupy it. It seems that the one
thing that sheds light on Stockhausen’s compositional thinking is his
frequent use of “form schemas,” that is often a single-page
representation of the entire structure of a piece.
Background in music technology: Sonic Visualiser is a program
used to study a musical recording. It is an open source application for
viewing, analyzing, and annotating music audio files. It contains a
number of visualisation tools, which are designed with useful default
parameters for musical analysis. Additionally, the Vamp plugin
format of SV supports to provide analysis such as for example
structural segmentation.
Aims: The aim of paper is to show how SV may be used to obtain
a better understanding of the specific musical work, and how the
compositional strategy does impact on musical structures and musical
surfaces. It is known that “traditional” music analytic methods don’t
allow indicating interrelationships between musical surface (which is
perceived) and underlying musical/acoustical structure.
Main Contribution: Stockhausen had dealt with the most diverse
musical problems by the most varied methods. A characteristic which
he had never ceased to be placed at the center of his thought and
works, it was the quest for a new balance founded upon an acute
connection between speculation and intuition. In the case with
Mikrophonie I (1964) for tam-tam and 6 players Stockhausen makes
a distinction between the “connection scheme,” which indicates the
ground rules underlying all versions, and the form scheme, which is
associated with a particular version. The preface to the published
score includes both the connection scheme, and a single instance of a
“form scheme,” which is what one can hear on the CD recording. In
the current study, the insight into the compositional strategy chosen
by Stockhausen was been compared with auditory image, that is, with
the perceived musical surface. Stockhausen’s musical work is
analyzed both in terms of melodic/voice and timbre evolution.
Implications: The current study shows how musical structures
have determined of musical surface. The general assumption is this,
that while listening to music we can extract basic kinds of musical
information from musical surfaces. It is shown that interactive
strategies of musical structure analysis can offer a very fruitful way
of looking directly into certain structural features of music.
Abstract: Rapid Prototyping (RP) technologies enable physical
parts to be produced from various materials without depending on the
conventional tooling. Fused Deposition Modeling (FDM) is one of
the famous RP processes used at present. Tensile strength and
compressive strength resistance will be identified for different sample
structures and different layer orientations of ABS rapid prototype
solid models. The samples will be fabricated by a FDM rapid
prototyping machine in different layer orientations with variations in
internal geometrical structure. The 0° orientation where layers were
deposited along the length of the samples displayed superior strength
and impact resistance over all the other orientations. The anisotropic
properties were probably caused by weak interlayer bonding and
interlayer porosity.
Abstract: The degradation of concrete due to various hygrochemo-
mechanical actions is inevitable for the structures particularly
built to store water. Therefore, it is essential to determine the material
properties of dam-like structures due to ageing to predict the behavior
of such structures after a certain age. The degraded material
properties are calculated by introducing isotropic degradation index.
The predicted material properties are used to study the behavior of
aged dam at different ages. The dam is modeled by finite elements
and displacement and is considered as an unknown variable. The
parametric study reveals that the displacement is quite larger for
comparatively lower design life of the structure because the
degradation of elastic properties depends on the design life of the
dam. The stresses in dam cam be unexpectedly large at any age with
in the design life. The outcomes of the present study indicate the
importance of the consideration ageing effect of concrete exposed to
water for the safe design of dam throughout its life time.
Abstract: In this study free vibration analysis of aluminum
honeycomb sandwich structures were carried out experimentally and
numerically. The natural frequencies and mode shapes of sandwich
structures fabricated with different configurations for clamped-free
boundary condition were determined. The effects of lower and upper
face sheet thickness, the core material thickness, cell diameter, cell
angle and foil thickness on the vibration characteristics were
examined. The numerical studies were performed with ANSYS
package. While the sandwich structures were modeled in ANSYS the
continuum model was used. Later, the numerical results were
compared with the experimental findings.
Abstract: The future and the development of science is therefore
seen in interdisciplinary areas such as biomedical engineering. Selfassembled
structures, similar to stem cell niches would inhibit fast
division process and subsequently capture the stem cells from the
blood flow. By means of surface topography and the stiffness as well
as microstructure progenitor cells should be differentiated towards
the formation of endothelial cells monolayer which effectively will
inhibit activation of the coagulation cascade. The idea of the material
surface development met the interest of the clinical institutions,
which support the development of science in this area and are waiting
for scientific solutions that could contribute to the development of
heart assist systems. This would improve the efficiency of the
treatment of patients with myocardial failure, supported with artificial
heart assist systems. Innovative materials would enable the redesign,
in the post project activity, construction of ventricular heart assist.
Abstract: Riveting process is one of the important ways to keep
fastening the lap joints in aircraft structures. Failure of aircraft lap
joints directly depends on the stress field in the joint. An important
application of riveting process is in the construction of aircraft
fuselage structures. In this paper, a 3D finite element method is
carried out in order to optimize residual stress field in a riveted lap
joint and also to estimate its fatigue life. In continue, a number of
experiments are designed and analyzed using design of experiments
(DOE). Then, Taguchi method is used to select an optimized case
between different levels of each factor. Besides that, the factor which
affects the most on residual stress field is investigated. Such
optimized case provides the maximum residual stress field. Fatigue
life of the optimized joint is estimated by Paris-Erdogan law. Stress
intensity factors (SIFs) are calculated using both finite element
analysis and experimental formula. In addition, the effect of residual
stress field, geometry and secondary bending are considered in SIF
calculation. A good agreement is found between results of such
methods. Comparison between optimized fatigue life and fatigue life
of other joints has shown an improvement in the joint’s life.
Abstract: In the years followed independence, an economic
crisis and some conflicts led to the displacement of many people
inside Georgia. The growing poverty, unemployment, low income
and its unequal distribution limited access to basic social service have
had a clear direct impact on Georgian population dynamics and its
age-sex structure. Factors influencing the changing population age
structure and urbanization include mortality, fertility, migration and
expansion of urban. In this paper presents the main factors of
changing the distribution by urban and rural areas. How different are
the urban and rural age and sex structures? Does Georgia have the
same age-sex structure among their urban and rural populations since
1950s?
Abstract: The modeling lung respiratory system that has complex anatomy and biophysics presents several challenges including tissue-driven flow patterns and wall motion. Also, the pulmonary lung system because of that they stretch and recoil with each breath, has not static walls and structures. The direct relationship between air flow and tissue motion in the lung structures naturally prefers an FSI simulation technique. Therefore, in order to toward the realistic simulation of pulmonary breathing mechanics the development of a coupled FSI computational model is an important step. A simple but physiologically relevant three-dimensional deep long geometry is designed and fluid-structure interaction (FSI) coupling technique is utilized for simulating the deformation of the lung parenchyma tissue that produces airflow fields. The real understanding of respiratory tissue system as a complex phenomenon have been investigated with respect to respiratory patterns, fluid dynamics and tissue viscoelasticity and tidal breathing period.