Abstract: The objective of this research is to mitigate and prevent
the alkali silica reactivity (ASR) in highway construction projects.
ASR is a deleterious reaction initiated when the silica content of the
aggregate reacts with alkali hydroxides in cement in the presence of
relatively high moisture content. The ASR results in the formation of
an expansive white colored gel-like material which forms the
destructive tensile stresses inside hardened concrete. In this research, different types of local aggregates available in the
State of Arkansas were mixed and mortar bars were poured according
to the ASTM specifications. Mortar bars expansion was measured
versus time and aggregates with potential ASR problems were
detected. Different types of supplementary cementitious materials
(SCMs) were used in remixing mortar bars with highly reactive
aggregates. Length changes for remixed bars proved that different
types of SCMs can be successfully used in reducing the expansive
effect of ASR. SCMs percentage by weight is highly dependent on
the SCM type. The result of this study will help avoiding future
losses due to ASR cracking in construction project and reduce the
maintenance, repair, and replacement budgets required for highways
network.
Abstract: Digital technologies offer many opportunities in the
design and implementation of brand communication and advertising.
Augmented reality (AR) is an innovative technology in marketing
communication that focuses on the fact that virtual interaction with a
product ad offers additional value to consumers. AR enables
consumers to obtain (almost) real product experiences by the way of
virtual information even before the purchase of a certain product.
Aim of AR applications in relation with advertising is in-depth
examination of product characteristics to enhance product knowledge
as well as brand knowledge. Interactive design of advertising
provides observers with an intense examination of a specific
advertising message and therefore leads to better brand knowledge.
The elaboration likelihood model and the central route to persuasion
strongly support this argumentation. Nevertheless, AR in brand
communication is still in an initial stage and therefore scientific
findings about the impact of AR on information processing and brand
attitude are rare. The aim of this paper is to empirically investigate
the potential of AR applications in combination with traditional print
advertising. To that effect an experimental design with different
levels of interactivity is built to measure the impact of interactivity of
an ad on different variables o advertising effectiveness.
Abstract: The aim of this article is to identify the measures
companies undertake in order to adapt to the environment as well as
discussing their diversity and effectiveness. The research methods
used in the study include an in-depth analysis of the literature and a
case study, which helps to illustrate the issue in question. Referring to
the concept of agility, which is firmly embedded in the theory of
strategic management and has been developed with the aim of
adapting to the environment and its changes, the paper first examines
different types of adaptation measures for companies. Then the issue
under discussion is illustrated with the example of the company
Hortimex. This company is an eminent representative of the world’s
leading manufacturers of food additives and ingredients. The
company was established in 1988 and is a family business, which in
practice means that it conducts business in a responsible manner,
observing the law and respecting the interests of society and the
environment. The company’s mission is to develop a market in
Poland for the products and solutions offered by their partners and to
share their knowledge of additives in food production and
consumption.
Abstract: Effect of Zn addition on the microstructure and
mechanical properties of Mg-Zn alloys with Zn contents from 6 to 10
weight percent was investigated in this study. Through calculation of
phase equilibria of Mg-Zn alloys, carried out by using FactSage® and
FTLite database, solution treatment temperature was decided as
temperatures from 300 to 400oC, where supersaturated solid solution
can be obtained. Solid solution treatment of Mg-Zn alloys was
successfully conducted at 380oC and supersaturated microstructure
with all beta phase resolved into matrix was obtained. After solution
treatment, hot rolling was successfully conducted by reduction of
60%. Compression and tension tests were carried out at room
temperature on the samples as-cast, solution treated, hot-rolled and
recrystallized after rolling. After solid solution treatment, each alloy
was annealed at temperatures of 180 and 200oC for time intervals from
1 min to 48 hrs and hardness of each condition was measured by
micro-Vickers method. Peak aging conditions were deduced as at the
temperature of 200oC for 10 hrs. By addition of Zn by 10 weight
percent, hardness and strength were enhanced.
Abstract: Comparing with prior studies mainly focused on the
effect of a certain event (it may be the initial announcement of bad
news or the repeated announcements of identical bad news) on stock
price, the aim of this study is to explore how investors react to
subsequent bad news with identical content. Empirical results show
that as a result of behavioral pitfalls, investors underreact to the initial
announcement of the bad news (i.e., unknown bad news) and overreact
to the repeated announcements of the identical bad news (i.e., known
bad news).
Abstract: The Flexible AC Transmission System (FACTS)
technology is a new advanced solution that increases the reliability
and provides more flexibility, controllability, and stability of a power
system. The Unified Power Flow Controller (UPFC), as the most
versatile FACTS device for regulating power flow, is able to control
respectively transmission line real power, reactive power, and node
voltage. The main purpose of this paper is to analyze the effect of the
UPFC on the load flow, the power losses, and the voltage stability
using NEPLAN software modules, Newton-Raphson load flow is
used for the power flow analysis and the modal analysis is used for
the study of the voltage stability. The simulation was carried out on
the IEEE 14-bus test system.
Abstract: Autologous Chondrocyte Implantation (ACI) is used worldwide since 1998 to treat cartilage defect. GEL based ACI is a new tissue-engineering technique to treat full thickness cartilage defect with fibrin and thrombin as scaffold for chondrocytes. Purpose of this study is to see safety and efficacy of gel based ACI for knee cartilage defect in multiple centres with different surgeons. Gel-based Autologous Chondrocyte Implantation (GACI) has shown effectiveness in treating isolated cartilage defect of knee joint. Long term results are still needed to be studied. This study was followed-up up to two years and showed benefit to patients. All enrolled patients with a mean age of 28.5 years had an average defect size of3 square centimeters, and were grade IV as per ICRS grading. All patients were followed up several times and at several intervals at 6th week, 8th week, 11th week, 17th week, 29th week, 57th week after surgery. The outcomes were measured based on the IKDC (subjective and objective) and MOCART scores.
Abstract: Microstructure and fabric of soils play an important
role on structural properties e.g. stiffness and strength of compacted
earthwork. Traditional quality control monitoring based on moisturedensity
tests neither reflects the variability of soil microstructure nor
provides a direct assessment of structural property, which is the
ultimate objective of the earthwork quality control. Since stiffness
and strength are sensitive to soil microstructure and fabric, any
independent test methods that provide simple, rapid, and direct
measurement of stiffness and strength are anticipated to provide an
effective assessment of compacted earthen materials’ uniformity. In
this study, the soil stiffness gauge (SSG) and the dynamic cone
penetrometer (DCP) were respectively utilized to measure and
monitor the stiffness and strength in companion with traditional
moisture-density measurements of various earthen materials used in
Thailand road construction projects. The practical earthwork quality
control criteria are presented herein in order to assure proper
earthwork quality control and uniform structural property of
compacted earthworks.
Abstract: Community living adjacent to forests and Protected
Areas, especially in South Asian countries, have a common practice
in extracting resources for their living and livelihoods. This
extraction of resources, because the way it is done, destroys the biophysical
features of the area. Deforestation, wildlife poaching, illegal
logging, unauthorized hill cutting etc. are some of the serious issues
of concern for the sustainability of the natural resources that has a
direct impact on environment and climate as a whole. To ensure
community involvement in conservation initiatives of the state,
community based forest management, commonly known as Comanagement,
has been in practice in 6 South Asian countries. These
are -India, Nepal, Sri Lanka, Pakistan, Bhutan and Bangladesh.
Involving community in forestry management was initiated first in
Bangladesh in 1979 and reached as an effective co-management
approach through a several paradigm shifts. This idea of Comanagement
has been institutionalized through a Government Order
(GO) by the Ministry of Environment and Forests, Government of
Bangladesh on November 23, 2009. This GO clearly defines the
structure and functions of Co-management and its different bodies.
Bangladesh Forest Department has been working in association with
community to conserve and manage the Forests and Protected areas
of Bangladesh following this legal document. Demographically
young people constitute the largest segment of population in
Bangladesh. This group, if properly sensitized, can produce valuable
impacts on the conservation initiatives, both by community and
government. This study traced the major factors that motivate
community youths to work effectively with different tiers of comanagement
organizations in conservation of forests and Protected
Areas of Bangladesh. For the purpose of this study, 3 FGDs were
conducted with 30 youths from the community living around the
Protected Areas of Cox’s bazar, South East corner of Bangladesh,
who are actively involved in Co-management organizations. KII were
conducted with 5 key officials of Forest Department stationed at
Cox’s Bazar. 2 FGDs were conducted with the representatives of 7
Co-management organizations working in Cox’s Bazar region and
approaches of different community outreach activities conducted for
forest conservation by 3 private organizations and Projects have been
reviewed. Also secondary literatures were reviewed for the history
and evolution of Co-management in Bangladesh and six South Asian
countries. This study found that innovative community outreach
activities that are financed by public and private sectors involving
youths and community as a whole have played a pivotal role in
conservation of forests and Protected Areas of the region. This
approach can be replicated in other regions of Bangladesh as well as
other countries of South Asia where Co-Management exists in
practice.
Abstract: The rapid growth of the human population and the
environmental degradation associated with increased consumption of
resources raises concerns on sustainability. Social sustainability
constitutes one of the three dimensions of sustainability together with
environmental and economic dimensions. Even though there is not an
agreement on what social sustainability consists of, it is a well known
fact that it necessitates user participation. The fore, this study aims to
observe and analyze the role of user participation on social
sustainability. In this paper, the links between user participation and indicators of
social sustainability have been searched. In order to achieve this, first
of all a literature review on social sustainability has been done;
accordingly, the information obtained from researches has been used
in the evaluation of the projects conducted in the developing
countries considering user participation. These examples are taken as
role models with pros and cons for the development of the checklist
for the evaluation of the case studies. Furthermore, a case study over
the post earthquake residential settlements in Turkey have been
conducted. The case study projects are selected considering different building
scales (differing number of residential units), scale of the problem
(post-earthquake settlements, rehabilitation of shanty dwellings) and
the variety of users (differing socio-economic dimensions). Decisionmaking,
design, building and usage processes of the selected projects
and actors of these processes have been investigated in the context of
social sustainability. The cases include: New Gourna Village by
Hassan Fathy, Quinta Monroy dwelling units conducted in Chile by
Alejandro Aravena and Beyköy and Beriköy projects in Turkey
aiming to solve the problem of housing which have appeared after the
earthquake happened in 1999 have been investigated. Results of the
study possible links between social sustainability indicators and user
participation and links between user participation and the
peculiarities of place. Results are compared and discussed in order to find possible
solutions to form social sustainability through user participation.
Results show that social sustainability issues depend on communities'
characteristics, socio-economic conditions and user profile but user
participation has positive effects on some social sustainability
indicators like user satisfaction, a sense of belonging and social
stability.
Abstract: The exploitation of flow pulsation in micro- and
mini-channels is a potentially useful technique for enhancing cooling
of high-end photonics and electronics systems. It is thought that
pulsation alters the thickness of the hydrodynamic and thermal
boundary layers, and hence affects the overall thermal resistance
of the heat sink. Although the fluid mechanics and heat transfer
are inextricably linked, it can be useful to decouple the parameters
to better understand the mechanisms underlying any heat transfer
enhancement. Using two-dimensional, two-component particle image
velocimetry, the current work intends to characterize the heat transfer
mechanisms in pulsating flow with a mean Reynolds number of
48 by experimentally quantifying the hydrodynamics of a generic
liquid-cooled channel geometry. Flows circulated through the test
section by a gear pump are modulated using a controller to achieve
sinusoidal flow pulsations with Womersley numbers of 7.45 and
2.36 and an amplitude ratio of 0.75. It is found that the transient
characteristics of the measured velocity profiles are dependent on the
speed of oscillation, in accordance with the analytical solution for
flow in a rectangular channel. A large velocity overshoot is observed
close to the wall at high frequencies, resulting from the interaction
of near-wall viscous stresses and inertial effects of the main fluid
body. The steep velocity gradients at the wall are indicative of
augmented heat transfer, although the local flow reversal may reduce
the upstream temperature difference in heat transfer applications.
While unsteady effects remain evident at the lower frequency, the
annular effect subsides and retreats from the wall. The shear rate at
the wall is increased during the accelerating half-cycle and decreased
during deceleration compared to steady flow, suggesting that the flow
may experience both enhanced and diminished heat transfer during
a single period. Hence, the thickness of the hydrodynamic boundary
layer is reduced for positively moving flow during one half of the
pulsation cycle at the investigated frequencies. It is expected that the
size of the thermal boundary layer is similarly reduced during the
cycle, leading to intervals of heat transfer enhancement.
Abstract: In general, it is desirable to finish the weld quickly,
before a large volume of surrounding metal heats up and expands.
The welding process used, type, welding current and speed of travel,
thus, affect the degree of shrinkage and distortion of a weldment. The
use of mechanized welding equipment reduces welding time, metal
affected zone and consequently distortion. This article helps to define
what weld distortion is and then provide a practical understanding of
the causes of distortion, effects of shrinkage in butt joint welded
assemblies using TI6AL4VA and Aluminium AA2024 alloy sheet.
The beam offset position to the joint interface towards titanium and
aluminium side. The factors affecting distortion during welding is
also given. Test results reveal that welding speed is the significant
parameter to decide the extent of distortion. Also welding from Al
side reduces the distortion while Ti side increases the distortion.
Abstract: In this paper, we present the design of the
super-ellipsoidal potential function (SEPF), that can be used for
autonomous collision avoidance of an unmanned aerial vehicle (UAV)
in a 3-dimensional space. In the design of SEPF, we have the
full control over the shape and size of the potential function. In
particular, we can adjust the length, width, height, and the amount
of flattening at the tips of the potential function so that the collision
avoidance motion vector generated from the potential function can
be adjusted accordingly. Based on the idea of the SEPF, we also
propose an approach for the local autonomy of a UAV for its collision
avoidance when the UAV is teleoperated by a human operator. In
our proposed approach, a teleoperated UAV can not only avoid
collision autonomously with other surrounding objects but also track
the operator’s control input as closely as possible. As a result, an
operator can always be in control of the UAV for his/her high-level
guidance and navigation task without worrying too much about
the UAVs collision avoidance while it is being teleoperated. The
effectiveness of the proposed approach is demonstrated through a
human-in-the-loop simulation of quadrotor UAV teleoperation using
virtual robot experimentation platform (v-rep) and Matlab programs.
Abstract: The cumulative costs for O&M may represent as
much as 65%-90% of the turbine's investment cost. Nowadays the
cost effectiveness concept becomes a decision-making and
technology evaluation metric. The cost of energy metric accounts for
the effect replacement cost and unscheduled maintenance cost
parameters. One key of the proposed approach is the idea of
maintaining the WTs which can be captured via use of a finite state
Markov chain. Such a model can be embedded within a probabilistic
operation and maintenance simulation reflecting the action to be
done. In this paper, an approach of estimating the cost of O&M is
presented. The finite state Markov model is used for decision
problems with number of determined periods (life cycle) to predict
the cost according to various options of maintenance.
Abstract: This paper discusses the intake of combining multi-criteria
decision analysis (MCDA) with OLAP systems, to generate
an integrated analysis process dealing with complex multi-criteria
decision-making situations. In this context, a multi-agent modeling is
presented for decision support systems by combining multi-criteria
decision analysis (MCDA) with OLAP systems. The proposed
modeling which consists in performing the multi-agent system
(MAS) architecture, procedure and protocol of the negotiation model
is elaborated as a decision support tool for complex decision-making
environments. Our objective is to take advantage from the multi-agent
system which distributes resources and computational
capabilities across interconnected agents, and provide a problem
modeling in terms of autonomous interacting component-agents.
Thus, the identification and evaluation of criteria as well as the
evaluation and ranking of alternatives in a decision support situation
will be performed by organizing tasks and user preferences between
different agents in order to reach the right decision. At the end, an
illustrative example is conducted to demonstrate the function and
effectiveness of our MAS modeling.
Abstract: Strategic investment decisions are characterized by
high innovation potential and long-term effects on the
competitiveness of enterprises. Due to the uncertainty and risks
involved in this complex decision making process, the need arises for
well-structured support activities. A method that considers cost and
the long-term added value is the cost-benefit effectiveness estimation.
One of those methods is the “profitability estimation focused on
benefits – PEFB”-method developed at the Institute of Management
Cybernetics at RWTH Aachen University. The method copes with
the challenges associated with strategic investment decisions by
integrating long-term non-monetary aspects whilst also mapping the
chronological sequence of an investment within the organization’s
target system. Thus, this method is characterized as a holistic
approach for the evaluation of costs and benefits of an investment.
This participation-oriented method was applied to business
environments in many workshops. The results of the workshops are a
library of more than 96 cost aspects, as well as 122 benefit aspects.
These aspects are preprocessed and comparatively analyzed with
regards to their alignment to a series of risk levels. For the first time,
an accumulation and a distribution of cost and benefit aspects
regarding their impact and probability of occurrence are given. The
results give evidence that the PEFB-method combines precise
measures of financial accounting with the incorporation of benefits.
Finally, the results constitute the basics for using information
technology and data science for decision support when applying
within the PEFB-method.
Abstract: Reinforced earth structures are generally subjected to cyclic loading generated from earthquakes. This paper presents a summary of the results and analyses of a testing program carried out in a large-scale multi-function geosynthetic testing apparatus that accommodates soil samples up to 1.0 m3. This apparatus performs different shear and pullout tests under both static and cyclic loading. The testing program was carried out to investigate the controlling factors affecting soil/geogrid interaction under cyclic loading. The extensibility of the geogrids, the applied normal stresses, the characteristics of the cyclic loading (frequency, and amplitude), and initial static load within the geogrid sheet were considered in the testing program. Based on the findings of the testing program, the effect of these parameters on the pullout resistance of geogrids, as well as the displacement mobility under cyclic loading were evaluated. Conclusions and recommendations for the design of reinforced earth walls under cyclic loading are presented.
Abstract: The power buck converter is the most widely used
DC/DC converter topology. They have a very large application area
such as DC motor drives, photovoltaic power system which require
fast transient responses and high efficiency over a wide range of load
current. This work proposes, the modelling of DC/DC power buck
converter using state-space averaging method and the current-mode
control using a proportional-integral controller. The efficiency of the
proposed model and control loop are evaluated with operating point
changes. The simulation results proved the effectiveness of the linear
model of DC/DC power buck converter.
Abstract: The irradiation of polymeric materials has received
much attention because it can produce diverse changes in chemical
structure and physical properties. Thus, studying the chemical and
structural changes of polymers is important in practice to achieve
optimal conditions for the modification of polymers. The effect of
gamma irradiation on the crystalline structure of poly(vinylidene
fluoride) (PVDF) has been investigated using differential scanning
calorimetry (DSC) and X-ray diffraction techniques (XRD). Gamma
irradiation was carried out in atmosphere air with doses between 100
kGy at 3,000 kGy with a Co-60 source. In the melting thermogram of
the samples irradiated can be seen a bimodal melting endotherm is
detected with two melting temperature. The lower melting
temperature is attributed to melting of crystals originally present and
the higher melting peak due to melting of crystals reorganized upon
heat treatment. These results are consistent with those obtained by
XRD technique showing increasing crystallinity with increasing
irradiation dose, although the melting latent heat is decreasing.
Abstract: This paper investigates the effects of breaks in bonds,
breaks in the earthing system and breaks in earth wire on the rise of
the earth potential (EPR) in a substation and at the transmission tower
bases using various models of an L6 tower. Different approaches
were adopted to examine the integrity of the earthing system and the
terminal towers. These effects were investigated to see the associated
difference in the EPR magnitudes with respect to a healthy system at
various locations. Comparisons of the computed EPR magnitudes
were then made between the healthy and unhealthy system to detect
any difference. The studies were conducted at power frequency for a
uniform soil with different soil resistivities. It was found that full
breaks in the double bond of the terminal towers increase the EPR
significantly at the fault location, while they reduce EPR at the
terminal tower bases. A fault on the isolated section of the grid can
result in EPR values up to 8 times of those on a healthy system at
higher soil resistivities, provided that the extended earthing system
stays connected to the grid.