Abstract: This paper presents a study the effect of nose radius
(Rz-mm) on cutting force components and temperatures during the
machining simulation in an orthogonal cutting process for titanium
alloy (Ti-6Al-4V). The cutting process was performed at various
nose radiuses (Rz-mm) while the depth of cut (d-mm), feed rate (fmm/
tooth) and cutting speed (vc-m/ min) were remained constant.
The main cutting force (Fc), feed cutting force (Ft) and temperatures
were estimated by using finite element modeling (FEM) through
ABAQUS/EXPLICIT software and the simulation was developed the
two-dimension via an orthogonal cutting process during machining
titanium alloy (Ti-6Al-4V). The results led to the conclusion that the
nose radius (Rz-mm) has affected directly on the cutting force
components. However, temperature gave no indication or has no
significant relation with nose radius during machining titanium alloy
(Ti-6Al-4V). Hence, any increase or decrease in the nose radius (Rzmm)
during machining operation led to effect on the cutting forces
and thus it will be effective on surface finish, quality, and quantity of
products.
Abstract: The material selection in the design of the sandwich
structures is very crucial aspect because of the positive or negative
influences of the base materials to the mechanical properties of the
entire panel. In the literature, it was presented that the selection of the
skin and core materials plays very important role on the behavior of
the sandwich. Beside this, the use of the correct adhesive can make
the whole structure to show better mechanical results and behavior.
In the present work, the static three-point bending tests were
performed on the sandwiches having an aluminum alloy foam core,
the skins made of three different types of fabrics and two different
commercial adhesives (flexible polyurethane and toughened epoxy
based) at different values of support span distances by aiming the
analyses of their flexural performance in terms of absorbed energy,
peak force values and collapse mechanisms. The main results of the
flexural loading are: force-displacement curves obtained after the
bending tests, peak force and absorbed energy values, collapse
mechanisms and adhesion quality. The experimental results presented
that the sandwiches with epoxy based toughened adhesive and the
skins made of S-Glass Woven fabrics indicated the best adhesion
quality and mechanical properties. The sandwiches with toughened
adhesive exhibited higher peak force and energy absorption values
compared to the sandwiches with flexible adhesive. The use of these
sandwich structures can lead to a weight reduction of the transport
vehicles, providing an adequate structural strength under operating
conditions.
Abstract: In this paper, the effects of fiber types and elevated
temperatures on compressive strength, modulus of rapture and the
bond characteristics of fiber reinforced concretes (FRC) are
presented. By using the three different types of fibers (steel fiber-SF,
polypropylene-PPF and polyvinyl alcohol-PVA), FRC specimens
were produced and exposed to elevated temperatures up to 800 ºC for
1.5 hours. In addition, a plain concrete (without fiber) was produced
and used as a control. Test results obtained showed that the steel fiber
reinforced concrete (SFRC) had the highest compressive strength,
modulus of rapture and bond stress values at room temperatures, the
residual bond, flexural and compressive strengths of both FRC and
plain concrete dropped sharply after exposure to high temperatures.
The results also indicated that the reduction of bond, flexural and
compressive strengths with increasing the exposed temperature was
relatively less for SFRC than for plain, and FRC with PPF and PVA.
Abstract: Dental porcelain composites reinforced and toughened
by 20 wt.% tetragonal zirconia (3Y-TZP) were processed by hot
pressing at 1000°C. Two types of particles were tested: yttriastabilized
zirconia (ZrO2–3%Y2O3) agglomerates and pre-sintered
yttria-stabilized zirconia (ZrO2–3%Y2O3) particles. The composites
as well as the reinforcing particles were analyzed by the means of
optical and Scanning Electron Microscopy (SEM), Energy Dispersion
Spectroscopy (EDS) and X-Ray Diffraction (XRD). The mechanical
properties were obtained by the transverse rupture strength test. Wear
tests were also performed on the composites and monolithic
porcelain. The best mechanical results were displayed by the
porcelain reinforced with the pre-sintered ZrO2–3%Y2O3
agglomerates.
Abstract: High performance turf reinforcement mat (HPTRM) is
one of the most advanced flexible armoring technologies for severe
erosion challenges. The effect of turbulence on the slope stability of
an earthen levee strengthened by high performance turf reinforcement
mat (HPTRM) is investigated in this study for combined storm surge
and wave overtopping conditions. The results show that turbulence
has strong influence on the slope stability during the combined storm
surge and wave overtopping conditions. Among the surge height,
peak wave force and turbulent force. The turbulent force has the
ability to stabilize the earthen levee at the large wave force the
turbulent force has strongest effect on the FS. The surge storm acts as
an independent force on the slope stability of the earthen levee. It just
adds to the effects of the turbulent force and wave force on the slope
stability of HPTRM strengthened levee.
Abstract: This paper presents effects of distilled water, seawater
and sustained bending strains of 30% and 50% ultimate strain at
room temperature, on the durability of unidirectional pultruded
carbon fiber reinforced polymer (CFRP) plates. In this study,
dynamic mechanical analyzer (DMA) was used to investigate the
synergic effects of the immersions and bending strains on the viscoelastic
properties of (CFRP) such as storage modulus, tan delta and
glass transition temperature. The study reveals that the storage
modulus and glass transition temperature increase while tan delta
peak decreases in the initial stage of both immersions due to the
progression of curing. The storage modulus and Tg subsequently
decrease and tan delta increases due to the matrix plasticization. The
blister induced damages in the unstrained seawater samples enhance
water uptake and cause more serious degradation of Tg and storage
modulus than in water immersion. Increasing sustained bending
decreases Tg and storage modulus in a long run for both immersions
due to resin matrix cracking and debonding. The combined effects of
immersions and strains are not clearly reflected due to the statistical
effects of DMA sample sizes and competing processes of molecular
reorientation and postcuring.
Abstract: The objective of this work is to study the effect of two
key factors - external magnetic field and applied current density
during template-based electrodeposition of nickel nanowires using an
electrode distance of 20 mm. Morphology, length, crystallite size and
crystallographic characterization of the grown nickel nanowires at an
electrode distance of 20mm are presented. For this electrode distance
of 20 mm, these two key electrodeposition factors when coupled was
found to reduce crystallite size with a higher growth length and
preferred orientation of Ni crystals. These observed changes can be
inferred to be due to coupled interaction forces induced by the
intensity of applied electric field (current density) and external
magnetic field known as magnetohydrodynamic (MHD) effect during
the electrodeposition process.
Abstract: The problem of toughening in brittle materials
reinforced by fibers is complex, involving all of the mechanical
properties of fibers, matrix and the fiber/matrix interface, as well as
the geometry of the fiber. Development of new numerical methods
appropriate to toughening simulation and analysis is necessary. In
this work, we have performed simulations and analysis of toughening
in brittle matrix reinforced by randomly distributed fibers by means
of the discrete elements method. At first, we put forward a
mechanical model of toughening contributed by random fibers. Then
with a numerical program, we investigated the stress, damage and
bridging force in the composite material when a crack appeared in the
brittle matrix. From the results obtained, we conclude that: (i) fibers
of high strength and low elasticity modulus are beneficial to
toughening; (ii) fibers of relatively high elastic modulus compared to
the matrix may result in substantial matrix damage due to spalling
effect; (iii) employment of high-strength synthetic fibers is a good
option for toughening. We expect that the combination of the discrete
element method (DEM) with the finite element method (FEM) can
increase the versatility and efficiency of the software developed. The
present work can guide the design of ceramic composites of high
performance through the optimization of the parameters.
Abstract: Fixed-geometry hydrodynamic journal bearings are
one of the best supporting systems for several applications of rotating
machinery. Cylindrical journal bearings present excellent loadcarrying
capacity and low manufacturing costs, but they are subjected
to the oil-film instability at high speeds. An attempt of overcoming
this instability problem has been the development of non-circular
journal bearings. This work deals with an analysis of oil-lubricated
elliptical journal bearings using the finite element method. Steadystate
and dynamic performance characteristics of elliptical bearings
are rendered by zeroth- and first-order lubrication equations obtained
through a linearized perturbation method applied on the classical
Reynolds equation. Four-node isoparametric rectangular finite
elements are employed to model the bearing thin film flow. Curves of
elliptical bearing load capacity and dynamic force coefficients are
rendered at several operating conditions. The results presented in this
work demonstrate the influence of the bearing ellipticity on its
performance at different loading conditions.
Abstract: In the past researchers have questioned the
effectiveness of ethics training in higher education. Also, there are
observations that support the view that ethical behaviour (range of
actions)/ethical decision making models used in the past make use of
vignettes to explain ethical behaviour. The understanding remains in
the perspective that these vignettes play a limited role in determining
individual intentions and not actions. Some authors have also agreed
that there are possibilities of differences in one’s intentions and
actions. This paper makes an attempt to fill those gaps by evaluating
real actions rather than intentions. In a way this study suggests the
use of an experiential methodology to explore Berlo’s model of
communication as an action along with orchestration of various
principles. To this endeavor, an attempt was made to use
conversational analysis in the pursuance of evaluating ethical
decision making behaviour among students and middle level
managers. The process was repeated six times with the set of an
average of 15 participants. Similarities have been observed in the
behaviour of students and middle level managers that calls for
understanding that both the groups of individuals have no cognizance
of their actual actions. The deliberations derived out of conversation
were taken a step forward for meta-ethical evaluations to portray a
clear picture of ethical behaviour among participants. This study
provides insights for understanding demonstrated unconscious human
behaviour which may fortuitously be termed both ethical and
unethical.
Abstract: The main purpose of this paper is to determine the
applicability of the constitutional social rights in the so-called
horizontal relations, i.e. the relations between private entities.
Nowadays the constitutional rights are more and more often violated
by private entities and not only by the state. The private entities
interfere with the privacy of individuals, limit their freedom of
expression or disturb their peaceful gatherings. International
corporations subordinate individuals in a way which may limit their
constitutional rights. These new realities determine the new role of
the constitution in protecting human rights.
The paper will aim at answering two important questions. Firstly,
are the private entities obliged to respect the constitutional social
rights of other private entities and can they be liable for violation of
these rights? Secondly, how the constitutional social rights can
receive horizontal effect? Answers to these questions will have a
significant meaning for the popularisation of the practice of applying
the Constitution among the citizens as well as for the courts which
settle disputes between them.
Abstract: R.C.C. buildings with dual structural system
consisting of shear walls (or braces) and moment resisting frames
have been widely used to resist lateral forces during earthquakes. The
dual systems are designed to resist the total design lateral force in
proportion to their lateral stiffness. The response of combination of
braces and shear walls has not yet been studied. The combination
may prove to be more effective to resist lateral forces during
earthquakes. This concept has been applied to regular R.C.C.
buildings provided with shear walls, braces and their combinations.
Abstract: Parabolic solar trough systems have seen limited
deployments in cold northern climates as they are more suitable for
electricity production in southern latitudes. A numerical dynamic
model is developed to simulate troughs installed in cold climates and
validated using a parabolic solar trough facility in Winnipeg. The
model is developed in Simulink and will be utilized to simulate a trigeneration
system for heating, cooling and electricity generation in
remote northern communities. The main objective of this simulation
is to obtain operational data of solar troughs in cold climates and use
the model to determine ways to improve the economics and address
cold weather issues.
In this paper the validated Simulink model is applied to simulate a
solar assisted absorption cooling system along with electricity
generation using Organic Rankine Cycle (ORC) and thermal storage.
A control strategy is employed to distribute the heated oil from solar
collectors among the above three systems considering the
temperature requirements. This modelling provides dynamic
performance results using measured meteorological data recorded
every minute at the solar facility location. The purpose of this
modeling approach is to accurately predict system performance at
each time step considering the solar radiation fluctuations due to
passing clouds. Optimization of the controller in cold temperatures is
another goal of the simulation to for example minimize heat losses in
winter when energy demand is high and solar resources are low.
The solar absorption cooling is modeled to use the generated heat
from the solar trough system and provide cooling in summer for a
greenhouse which is located next to the solar field.
The results of the simulation are presented for a summer day in
Winnipeg which includes comparison of performance parameters of
the absorption cooling and ORC systems at different heat transfer
fluid (HTF) temperatures.
Abstract: Morphological interaction of porcine cumulus-oocyte
complexes (pCOCs) was investigated on in vitro condition using
electron microscope (SEM and TEM). The totals of 1,923 oocytes
were round in shape, surrounded by Zona pellucida with layer of
cumulus cells ranging between 59.29-202.14 μm in size. They were
classified into intact-, multi-, partial cumulus cell layer oocyte, and
completely denuded oocyte, at the percentage composition of 22.80%
32.70%, 18.60%, and 25.90 % respectively. The pCOCs classified as
intact- and multi cumulus cell layer oocytes were further culturing at
37°C with 5% CO2, 95% air atmosphere and high humidity for 44 h
in M199 with Earle’s salts supplemented with 10% HTFCS, 2.2
mg/mL NaHCO3, 1 M Hepes, 0.25 mM pyruvate, 15 μg/mL porcine
follicle-stimulating hormone, 1 μg/mL LH, 1μg/mL estradiol with
ethanol, and 50 μg/mL gentamycin sulfate. On electron microscope
study, cumulus cells were found to stick their processes to secrete
substance from the sac-shape end into Zona pellucida of the oocyte
and also communicated with the neighboring cells through their
microvilli on the beginning of incubation period. It is believed that
the cumulus cells communicate with the oocyte by inserting the
microvilli through this gap and embedded in the oocyte cytoplasm
before secreting substance, through the sac-shape end of the
microvilli, to inhibit primary oocyte development at the prophase I.
Morphological changes of the complexes were observed after
culturing for 24-44 h. One hundred percentages of the cumulus layers
were expanded and cumulus cells were peeling off from the oocyte
surface. In addition, the round-shape cumulus cells transformed
themselves into either an elongate shape or a columnar shape, and no
communication between cumulus neighboring cells. After 44 h of
incubation time, diameter of oocytes surrounded by cumulus cells
was larger than 0 h incubation. The effect of hormones in culture
medium is exerted by their receptors present in porcine oocyte. It is
likely that all morphological changes of the complexes after hormone
treatment were to allow maturation of the oocyte. This study
demonstrated that the association of hormones in M199 could
promote porcine follicle activation in 44 h in vitro condition. This
culture system should be useful for studying the regulation of early
follicular growth and development, especially because these follicles represent a large source of oocytes that could be used in vitro for cell
technology.
Abstract: Machining of hard materials is a recent technology for
direct production of work-pieces. The primary challenge in
machining these materials is selection of cutting tool inserts which
facilitates an extended tool life and high-precision machining of the
component. These materials are widely for making precision parts for
the aerospace industry. Nickel-based alloys are typically used in
extreme environment applications where a combination of strength,
corrosion resistance and oxidation resistance material characteristics
are required. The present paper reports the theoretical and
experimental investigations carried out to understand the influence of
machining parameters on the response parameters. Considering the
basic machining parameters (speed, feed and depth of cut) a study has
been conducted to observe their influence on material removal rate,
surface roughness, cutting forces and corresponding tool wear.
Experiments are designed and conducted with the help of Central
Composite Rotatable Design technique. The results reveals that for a
given range of process parameters, material removal rate is favorable
for higher depths of cut and low feed rate for cutting forces. Low feed
rates and high values of rotational speeds are suitable for better finish
and higher tool life.
Abstract: Within the framework of this research, the regulatory
documents, which are in force in relation to this industry, were
analyzed. The main attention is turned to their modernization and
necessity of their compliance with European standards.
It is a current issue to direct the efforts of state policy on support
of business by implementing infrastructural projects, as well as by
development of human resources, which may be possible by
supporting the relevant higher and vocational studying-educational
programs.
Abstract: If teamwork is the key to organizational learning,
productivity and growth, then, why do some teams succeed in
achieving these, while others falter at different stages? Building
teams in higher education institutions has been a challenge and an
open-ended constructivist approach was considered on an
experimental basis for this study to address this challenge. For this
research, teams of students from the MBA program were chosen to
study the effect of teamwork in learning, the motivation levels among
student team members, and the effect of collaboration in achieving
team goals. The teams were built on shared vision and goals,
cohesion was ensured, positive induction in the form of faculty
mentoring was provided for each participating team and the results
have been presented with conclusions and suggestions.
Abstract: An experimental study was performed to investigate
the behavior and strength of proposed technique to connect
reinforced concrete (RC) beam to steel or composite columns. This
approach can practically be used in several types of building
construction. In this technique, the main beam of the frame consists
of a transfer part (part of beam; Tr.P) and a common reinforcement
concrete beam. The transfer part of the beam is connected to the
column, whereas the rest of the beam is connected to the transfer part
from each side. Four full-scale beam-column connections were tested
under static loading. The test parameters were the length of the
transfer part and the column properties. The test results show that
using of the transfer part technique leads to modify the deformation
capabilities for the RC beam and hence it increases its resistance
against failure. Increase in length of the transfer part did not
necessarily indicate an enhanced behavior. The test results contribute
to the characterization of the connection behavior between RC beam -
steel column and can be used to calibrate numerical models for the
simulation of this type of connection.
Abstract: In its efforts to utilize the information and
communication technology to enhance the quality of public service
delivery, national and local governments around the world are
competing to introduce more ICT applications as tools to automate
processes related to law enforcement or policy execution, increase
citizen orientation, trust, and satisfaction, and create one-stop-shops
for public services. In its implementation, e-Government ICTs need
to maintain transparency, participation, and collaboration. Due to this
diverse of mixed goals and requirements, e-Government systems
need to be designed based on special design considerations in order
to eliminate the risks of failure to compliance to government
regulations, citizen dissatisfaction, or market repulsion.
In this article we suggest a framework with guidelines for
designing government information systems that takes into
consideration the special requirements of the public sector. Then we
introduce two case studies and show how applying those guidelines
would result in a more solid system design.
Abstract: We are facing serious problems related to long-term
depopulation and an aging society with a falling birth rate in Japan. In
this situation, we are suffering from a shortfall in human resources as
well as a shortage of workforce in rural regions. In addition, we are
struggling with a protracted economic slump and excess concentration
of population in the Tokyo Metropolitan area. It is an urgent national
issue to consider how to live in this country and what kind of structure
of society and administration policy is needed. It is necessary to clarify
people’s desire for their way of living and social assistance to be
provided. The aim of this study is to clarify the characteristics of
regional issues and the degree of their seriousness in local
municipalities of Japan. We conducted a questionnaire survey about
regional agenda in all local municipalities in Japan. We obtained
responses concerning the degree of seriousness of regional issues and
degree of importance of policies. Based on the data gathered from the
survey, it is apparent that many local municipalities are facing an
aging population and declining population. We constructed a model to
analyze factors for declining population. Using the model, it was
clarified that a population’s age structure, job opportunities and
income level affect the decline of population. In addition, we showed
the way of the evaluation of state of local municipality.