Abstract: This experimental study consists of a characterization
of epoxy grout where an amount of 2% of graphene nanoplatelets
particles were added to commercial epoxy resin to evaluate their
behavior regarding neat epoxy resin. Compressive tests, tensile tests
and flexural tests were conducted to study the effect of graphene
nanoplatelets on neat epoxy resin. By comparing graphene-based and
neat epoxy grout, there is no significant increase of strength due to
weak interface in the graphene nanoplatelets/epoxy composites.
From this experiment, the tension and flexural strength of graphenebased
epoxy grouts is slightly lower than ones of neat epoxy grout.
Nevertheless, the addition of graphene has produced more consistent
results according to a smaller standard deviation of strength.
Furthermore, the graphene has also improved the ductility of the
grout, hence reducing its brittle behaviour. This shows that the
performance of graphene-based grout is reliably predictable and able
to minimise sudden rupture. This is important since repair design of
damaged pipeline is of deterministic nature.
Abstract: Issues relating to the destructive phenomena that can
damage people and goods have returned to the centre of debate in
Italy with the increase in catastrophic episodes in recent years in a
country which is highly vulnerable to hydrological risk.
Environmental factors and geological and geomorphological
territorial characteristics play an important role in determining the
level of vulnerability and the natural tendency to risk. However, a
territory has also been subjected to the requirements of and
transformations of society and this brings other relevant factors. The
reasons for the increase in destructive phenomena are often to be
found in the territorial development models adopted. Stewardship of
the landscape and management of risk are related issues. This study aims to summarize the most relevant elements about
this connection and at the same time to clarify the role of
environmental risk assessment as a tool to aid in the sustainable
management of landscape. Finally, the study reflects on how regional
and urban planners deal with environmental risk and which aspects
should be monitored in order to adopt responsible and useful
interventions.
Abstract: The major environmental risk of soil pollution is the
contamination of groundwater by infiltration of organic and inorganic
pollutants which can cause a serious menace. To prevent this risk and
to protect the groundwater, we proceeded in this study to test the
reliability of a biosolid as barrier to prevent the migration of very
dangerous pollutants as ‘Cadmium’ through the different soil layers. In this study, we tried to highlight the effect of several parameters
such as: turbidity (different cycle of Hydration/Dehydration),
rainfall, effect of initial Cd(II) concentration and the type of soil.
These parameters allow us to find the most effective manner to
integrate this barrier in the soil. From the results obtained, we found a
significant effect of the barrier. Indeed, the recorded passing
quantities are lowest for the highest rainfall; we noted also that the
barrier has a better affinity towards higher concentrations; the most
retained amounts of cadmium has been in the top layer of the two
types of soil tested, while the lowest amounts of cadmium are
recorded in the bottom layers of soils.
Abstract: Hard coatings are widely used in cutting and forming
tool industries. Titanium Nitride (TiN) possesses good hardness,
strength, and corrosion resistance. The coating properties are
influenced by many process parameters. The coatings were deposited
on steel substrate by changing the process parameters such as
substrate temperature, nitrogen flow rate and target power in a D.C
planer magnetron sputtering. The structure of coatings were analysed
using XRD. The hardness of coatings was found using Micro
hardness tester. From the experimental data, a regression model was
developed and the optimum response was determined using Response
Surface Methodology (RSM).
Abstract: Rapid developments in technology in the present age
have made it necessary for communities to follow technological
developments and adapt themselves to these developments. One of
the fields that are most rapidly affected by these developments is
undoubtedly education. Determination of the attitudes of preservice
teachers, who live in an age of technology and get ready to raise
future individuals, is of paramount importance both educationally and
professionally. The purpose of this study was to analyze attitudes of
preservice teachers towards technology and some variables that
predict these attitudes (gender, daily duration of internet use, and the
number of technical devices owned). 329 preservice teachers
attending the education faculty of a large university in central Turkey
participated, on a volunteer basis, in this study, where relational
survey model was used as the research method. Research findings
reveal that preservice teachers’ attitudes towards technology are
positive and at the same time, the attitudes of male preservice
teachers towards technology are more positive than their female
counterparts. As a result of the stepwise multiple regression analysis
where factors predicting preservice teachers’ attitudes towards
technology, it was found that duration of daily internet use was the
strongest predictor of attitudes towards technology.
Abstract: The aim of this work is to study the numerical
implementation of the Hilbert Uniqueness Method for the exact
boundary controllability of Euler-Bernoulli beam equation. This study
may be difficult. This will depend on the problem under consideration
(geometry, control and dimension) and the numerical method used.
Knowledge of the asymptotic behaviour of the control governing the
system at time T may be useful for its calculation. This idea will
be developed in this study. We have characterized as a first step, the
solution by a minimization principle and proposed secondly a method
for its resolution to approximate the control steering the considered
system to rest at time T.
Abstract: Companies face increasing challenges in research due
to higher costs and risks. The intensifying technology complexity and
interdisciplinarity require unique know-how. Therefore, companies
need to decide whether research shall be conducted internally or
externally with partners. On the other hand, research institutes meet
increasing efforts to achieve good financing and to maintain high
research reputation. Therefore, relevant research topics need to be
identified and specialization of competency is necessary. However,
additional competences for solving interdisciplinary research projects
are also often required. Secured financing can be achieved by
bonding industry partners as well as public fundings. The realization
of faster and better research drives companies and research institutes
to cooperate in organized research networks, which are managed by
an administrative organization. For an effective and efficient
cooperation, necessary processes, roles, tools and a set of rules need
to be determined. Goal of this paper is to show the state-of-art
research and to propose a governance framework for organized
research networks.
Abstract: Contemporary metropolitan areas and large cities are
dynamic, rapidly growing and continuously changing. Thus, urban
transformations and mutations are not a new phenomenon, but rather
a continuous process. Basic factors of urban transformation are
related to development of technologies, globalisation, lifestyle, etc.,
which in combination with local factors have generated an extremely
great variety of urban development conditions. This article discusses
the main urbanisation processes in Lithuania during last 50-year
period and social factors affecting urban functional mutations.
Abstract: Zinc borates are used as a multi-functional flame
retardant additive for its high dehydration temperature. In this study,
the method of ultrasonic mixing was used in the synthesis of zinc
borates. The reactants of zinc oxide (ZnO) and boric acid (H3BO3)
were used at the constant reaction parameters of 90°C reaction
temperature and 55 min of reaction time. Several molar ratios of
ZnO:H3BO3 (1:1, 1:2, 1:3, 1:4 and 1:5) were conducted for the
determination of the optimum reaction ratio. Prior to synthesis the
characterization of the synthesized zinc borates were made by X-Ray
Diffraction (XRD) and Fourier Transform Infrared Spectroscopy
(FT-IR). From the results Zinc Oxide Borate Hydrate
[Zn3B6O12.3.5H2O], were synthesized optimum at the molar ratio of
1:3, with a reaction efficiency of 95.2%.
Abstract: Web Usage Mining is the application of data mining
techniques to find usage patterns from web log data, so as to grasp
required patterns and serve the requirements of Web-based
applications. User’s expertise on the internet may be improved by
minimizing user’s web access latency. This may be done by
predicting the future search page earlier and the same may be prefetched
and cached. Therefore, to enhance the standard of web
services, it is needed topic to research the user web navigation
behavior. Analysis of user’s web navigation behavior is achieved
through modeling web navigation history. We propose this technique
which cluster’s the user sessions, based on the K-medoids technique.
Abstract: The need to protect our cultural heritage was stressed
on revitalization of historical city centers in communities. The main
aim of this research is to attract finance and activities to the historical
city centers through the citizens and municipalities participation
while cities expanded their boundaries toward suburban areas. Today
the main problems which facing to the most historical city centers, is
loss of their centrality through effect of urbanization on any point of
the cities which is the most important issue on neglect and
abandonment of the historical central area by decentralizing living,
commerce and public areas. This article evaluate the ways in which
city center revitalization can be effect on vitality and viability of the
central area in case of Naghshe Jahan square which situated at the
center of Isfahan city, Iran. Constructed between 1598 and 1629, it is
now an important historical site, and one of UNESCO's World
Heritage Sites.
Abstract: The purpose of this study is to analyze the temporal
and spatial variability of thermal conditions in the Republic of
Armenia. The paper describes annual fluctuations in air temperature.
Research has been focused on case study region of Armenia and
surrounding areas, where long–term measurements and observations
of weather conditions have been performed within the National
Meteorological Service of Armenia and its surrounding areas. The
study contains yearly air temperature data recorded between 1961-
2012. Mann-Kendal test and the autocorrelation function were
applied to detect the change trend of annual mean temperature, as
well as other parametric and non-parametric tests searching to find
the presence of some breaks in the long term evolution of
temperature. The analysis of all records reveals a tendency mostly
towards warmer years, with increased temperatures especially in
valleys and inner basins. The maximum temperature increase is up to
1,5°C. Negative results have not been observed in Armenia. The
patterns of temperature change have been observed since the 1990’s
over much of the Armenian territory. The climate in Armenia was
influenced by global change in the last 2 decades, as results from the
methods employed within the study.
Abstract: This first-attempt study revealed that decolorized
intermediates of azo dyes could act as redox mediators to assist
wastewater (WW) decolorization due to enhancement of
electron-transport phenomena. Electrochemical impedance spectra
indicated that hydroxyl and amino-substituent(s) were functional
group(s) as redox-mediator(s). As azo dyes are usually multiple
benzene-rings structured, their derived decolorized intermediates are
likely to play roles of electron shuttles due to lower barrier of energy
gap for electron shuttling. According to cyclic voltammetric profiles,
redox mediating characteristics of decolorized intermediates of azo
dyes (e.g., RBu171, RR198, RR141, RBk5) were clearly disclosed.
With supplementation of biodecolorized metabolites of RR141 and
198, decolorization performance of could be evidently augmented.
This study also suggested the optimal modes of microbial fuel cell
(MFC)-assisted WW decolorization would be plug-flow or batch
mode of operation with no mix. Single chamber-MFCs would be more
favourable than double chamber MFCs due to non-mixing contacting
reactor scheme for operation.
Abstract: River Hindon is an important river catering the
demand of highly populated rural and industrial cluster of western
Uttar Pradesh, India. Water quality of river Hindon is deteriorating at
an alarming rate due to various industrial, municipal and agricultural
activities. The present study aimed at identifying the pollution
sources and quantifying the degree to which these sources are
responsible for the deteriorating water quality of the river. Various
water quality parameters, like pH, temperature, electrical
conductivity, total dissolved solids, total hardness, calcium, chloride,
nitrate, sulphate, biological oxygen demand, chemical oxygen
demand, and total alkalinity were assessed. Water quality data
obtained from eight study sites for one year has been subjected to the
two multivariate techniques, namely, principal component analysis
and cluster analysis. Principal component analysis was applied with
the aim to find out spatial variability and to identify the sources
responsible for the water quality of the river. Three Varifactors were
obtained after varimax rotation of initial principal components using
principal component analysis. Cluster analysis was carried out to
classify sampling stations of certain similarity, which grouped eight
different sites into two clusters. The study reveals that the
anthropogenic influence (municipal, industrial, waste water and
agricultural runoff) was the major source of river water pollution.
Thus, this study illustrates the utility of multivariate statistical
techniques for analysis and elucidation of multifaceted data sets,
recognition of pollution sources/factors and understanding
temporal/spatial variations in water quality for effective river water
quality management.
Abstract: Over the last two decades, externally bonded fiber
reinforced polymer (FRP) composites bonded to concrete substrates
has become a popular method for strengthening reinforced concrete
(RC) highway and railway bridges. Such structures are exposed to
severe cyclic loading throughout their lifetime often resulting in
fatigue damage to structural components and a reduction in the
service life of the structure. Since experimental and numerical results
on the fatigue performance of FRP-to-concrete joints are still limited,
the current research focuses on assessing the fatigue performance of
externally bonded FRP-to-concrete joints using a direct shear test.
Some early results indicate that the stress ratio and the applied cyclic
stress level have a direct influence on the fatigue life of the externally
bonded FRP. In addition, a calibrated finite element model is
developed to provide further insight into the influence of certain
parameters such as: concrete strength, FRP thickness, number of
cycles, frequency, and stiffness on the fatigue life of the FRP-toconcrete
joints.
Abstract: In the present work, forming limit diagrams and strain
distribution profile diagrams for extra deep drawing steel at room and
elevated temperatures have been determined experimentally by
conducting stretch forming experiments by using designed and
fabricated warm stretchforming tooling setup. With the help of
forming Limit Diagrams (FLDs) and strain, distribution profile
diagrams the formability of Extra Deep Drawing steel has been
analyzed and co-related with mechanical properties like strain
hardening COEFFICIENT (n) and normal anisotropy (r−). Mechanical
properties of EDD steel from room temperature to 4500C were
determined and discussed the impact of temperature on the properties
like work hardening exponent (n) anisotropy (r-) and strength
coefficient of the material. In addition, the fractured surfaces after
stretching have undergone the some metallurgical investigations and
attempt has been made to co-relate with the formability of EDD steel
sheets. They are co-related and good agreement with FLDs at various
temperatures.
Abstract: Context-aware technologies provide system
applications with the awareness of environmental conditions,
customer behaviours, object movements, etc. Further, with such
capability system applications can be smart to intelligently adapt their
responses to the changing conditions. In regard to business
operations, this promises businesses that their business processes can
run more intelligently, adaptively and flexibly, and thereby either
improve customer experience, enhance reliability of service delivery,
or lower operational cost, to make the business more competitive and
sustainable. Aiming at realising such context-aware business process
management, this paper firstly explores its potential benefit, and then
identifies some gaps between the current business process
management support and the expected. In addition, some preliminary
solutions are also discussed in regard to context definition, rule-based
process execution, run-time process evolution, etc. A framework is
also presented to give a conceptual architecture of context-aware
business process management system to guide system
implementation.
Abstract: Fluctuations of Schottky diode parameters in a
structure of the mixer are investigated. These fluctuations are
manifested in two ways. At the first, they lead to fluctuations in the
transfer factor that is lead to the amplitude fluctuations in the signal
of intermediate frequency. On the basis of the measurement data of
1/f noise of the diode at forward current, the estimation of a spectrum
of relative fluctuations in transfer factor of the mixer is executed.
Current dependence of the spectrum of relative fluctuations in
transfer factor of the mixer and dependence of the spectrum of
relative fluctuations in transfer factor of the mixer on the amplitude
of the heterodyne signal are investigated. At the second, fluctuations
in parameters of the diode lead to occurrence of 1/f noise in the
output signal of the mixer. This noise limits the sensitivity of the
mixer to the value of received signal.
Abstract: Sewage sludge is a biomass resource that can create a
solid fuel and electricity. Utilizing sewage sludge as a renewable
energy can contribute to the reduction of greenhouse gases. In Japan,
the "National Plan for the Promotion of Biomass Utilization" and the
“Priority Plan for Social Infrastructure Development" were approved
at cabinet meetings in December 2010 and August 2012, respectively,
to promote the energy utilization of sewage sludge. This study
investigated costs and greenhouse gas emission in different sewage
sludge treatments with technologies for energy from sewage sludge.
Expenses were estimated based on capital costs and O&M costs
including energy consumption of solid fuel plants and biogas power
generation plants for sewage sludge. Results showed that the cost of
sludge digestion treatment with solid fuel technologies was 8% lower
than landfill disposal. The greenhouse gas emission of sludge
digestion treatment with solid fuel technologies was also 6,390t as
CO2 smaller than landfill disposal. Biogas power generation reduced
the electricity of a wastewater treatment plant by 30% and the cost by
5%.
Abstract: A physical model for guiding the wave in
photorefractive media is studied. Propagation of cos-Gaussian beam
as the special cases of sinusoidal-Gaussian beams in photorefractive
crystal is simulated numerically by the Crank-Nicolson method in
one dimension. Results show that the beam profile deforms as the
energy transfers from the center to the tails under propagation. This
simulation approach is of significant interest for application in optical
telecommunication. The results are presented graphically and
discussed.