Abstract: The secondary alloy A226 is used for many
automotive casting produced by mould casting and high pressure die
casting. This alloy has excellent castability, good mechanical
properties and cost-effectiveness. Production of primary aluminium
alloys belong to heavy source fouling of life environs. The European
Union calls for the emission reduction and reduction in energy
consumption therefore increase production of recycled (secondary)
aluminium cast alloys. The contribution is deal with influence of
recycling on the quality of the casting made from A226 in automotive
industry. The properties of the casting made from secondary
aluminium alloys were compared with the required properties of
primary aluminium alloys. The effect of recycling on microstructure
was observed using combination different analytical techniques (light
microscopy upon black-white etching, scanning electron microscopy
- SEM upon deep etching and energy dispersive X-ray analysis -
EDX). These techniques were used for the identification of the
various structure parameters, which was used to compare secondary
alloy microstructure with primary alloy microstructure.
Abstract: Many factors influence the educational outcome of
students. Some of these have been studied by researchers with many
emphasizing the role of students, schools, governments, peer groups
and so on. More often than not, some of these factors influencing the
academic achievement of the students have been traced back to
parents and family; being the primary platform on which learning not
only begins but is nurtured, encouraged and developed which later
transforms to the performance of the students. This study not only
explores parental and related factors that predict academic
achievement through the review of relevant literatures but also,
investigates the influence of parental background on the academic
achievement of senior secondary school students in Ibadan North
Local Government Area of Oyo State, Nigeria. As one of the criteria
of the quality of education, students’ academic achievement was
investigated because it is most often cited as an indicator of school
effectiveness by school authorities and educationists. The data
collection was done through interviews and use of well-structured
questionnaires administered to one hundred students (100) within the
target local government. This was statistically analysed and the result
showed that parents’ attitudes towards their children’s education had
significant effect(s) on students’ self-reporting of academic
achievement. However, such factors as parental education and socioeconomic
background had no significant relationship with the
students’ self-reporting of academic achievement.
Abstract: The iron environment in Fe-doped Vycor Anode was
investigated with EXAFS using Brookhaven Synchrotron Light
Source. The iron-reducing Shewanella oneidensis culture was grown
in a microbial fuel cell under anaerobic respiration. The Fe bond
length was found to decrease and correlate with the amount of
biofilm growth on the Fe-doped Vycor Anode. The data suggests that
Fe-doped Vycor Anode would be a good substrate to study the
Shewanella oneidensis nanowire structure using EXAFS.
Abstract: This paper is aimed at proposing a rhombus shaped
wearable fractal antenna for wireless communication systems. The
geometrical descriptors of the antenna have been obtained using
bacterial foraging optimization (BFO) for wide band operation. The
method of moment based IE3D software has been used to simulate
the antenna and observed that miniaturization of 13.08% has been
achieved without degrading the resonating properties of the proposed
antenna. An analysis with different substrates has also been done in
order to evaluate the effectiveness of electrical permittivity on the
presented structure. The proposed antenna has low profile, light
weight and has successfully demonstrated wideband and multiband
characteristics for wearable electronic applications.
Abstract: Due to the increasing efforts on saving our natural
environment a change in the structure of energy resources can be
observed - an increasing fraction of a renewable energy sources.
In many countries traditional underground coal mining loses its
significance but there are still countries, like Poland or Germany, in
which the coal based technologies have the greatest fraction in a total
energy production. This necessitates to make an effort to limit the
costs and negative effects of underground coal mining. The longwall
complex is as essential part of the underground coal mining. The
safety and the effectiveness of the work is strongly dependent of the
diagnostic state of powered roof supports.
The building of a useful and reliable diagnostic system requires
a lot of data. As the acquisition of a data of any possible operating
conditions it is important to have a possibility to generate a demanded
artificial working characteristics. In this paper a new approach of
modelling a leg pressure in the single unit of powered roof support.
The model is a result of the analysis of a typical working cycles.
Abstract: The aim of this exploratory research is to understand
further how organisations can evaluate their activities, which
generate knowledge creation, to meet changing stakeholder
expectations. A Scale of Knowledge (SoK) Framework is proposed
which links knowledge management and organisational activities to
changing stakeholder expectations. The framework was informed by
the knowledge management literature, as well as empirical work
conducted via a single case study of a multi-site hospital organisation
in Saudi Arabia. Eight in-depth semi-structured interviews were
conducted with managers from across the organisation regarding
current and future stakeholder expectations, organisational
strategy/activities and knowledge management. Data were analysed
using thematic analysis and a hierarchical value map technique to
identify activities that can produce further knowledge and
consequently impact on how stakeholder expectations are met.
The SoK Framework developed may be useful to practitioners as
an analytical aid to determine if current organisational activities
produce organisational knowledge which helps them meet
(increasingly higher levels of) stakeholder expectations. The
limitations of the research and avenues for future development of the
proposed framework are discussed.
Abstract: High density electrical prospecting has been widely
used in groundwater investigation, civil engineering and
environmental survey. For efficient inversion, the forward modeling
routine, sensitivity calculation, and inversion algorithm must be
efficient. This paper attempts to provide a brief summary of the past
and ongoing developments of the method. It includes reviews of the
procedures used for data acquisition, processing and inversion of
electrical resistivity data based on compilation of academic literature.
In recent times there had been a significant evolution in field survey
designs and data inversion techniques for the resistivity method. In
general 2-D inversion for resistivity data is carried out using the
linearized least-square method with the local optimization technique
.Multi-electrode and multi-channel systems have made it possible to
conduct large 2-D, 3-D and even 4-D surveys efficiently to resolve
complex geological structures that were not possible with traditional
1-D surveys. 3-D surveys play an increasingly important role in very
complex areas where 2-D models suffer from artifacts due to off-line
structures. Continued developments in computation technology, as
well as fast data inversion techniques and software, have made it
possible to use optimization techniques to obtain model parameters to
a higher accuracy. A brief discussion on the limitations of the
electrical resistivity method has also been presented.
Abstract: In this study, we proposed two techniques to track the
maximum power point (MPPT) of a photovoltaic system. The first is
an intelligent control technique, and the second is robust used for
variable structure system. In fact the characteristics I-V and P–V of
the photovoltaic generator depends on the solar irradiance and
temperature. These climate changes cause the fluctuation of
maximum power point; a maximum power point tracking technique
(MPPT) is required to maximize the output power. For this we have
adopted a control by fuzzy logic (FLC) famous for its stability and
robustness. And a Siding Mode Control (SMC) widely used for
variable structure system. The system comprises a photovoltaic panel
(PV), a DC-DC converter, which is considered as an adaptation stage
between the PV and the load. The modelling and simulation of the
system is developed using MATLAB/Simulink. SMC technique
provides a good tracking speed in fast changing irradiation and when
the irradiation changes slowly or it is constant the panel power of
FLC technique presents a much smoother signal with less
fluctuations.
Abstract: We investigated the structure and electronic properties
of the compound Mg1-xBixO with varying concentrations of 0, ¼, ½,
and ¾ x bismuth in the the cesium chloride (CsCl), zinc-blende
(ZnS), nickel arsenide (NiAs) NaCl (rock-salt) and WZ (wurtzite)
phases. We calculated. The calculations were performed using the
first-principles pseudo-potential method within the framework of spin
density functional theory (DFT).
Abstract: This work assesses the cortical and the sub-cortical
neural activity recorded from rodents using entropy and mutual
information based approaches to study how hypothermia affects neural
activity. By applying the multi-scale entropy and Shannon entropy, we
quantify the degree of the regularity embedded in the cortical and
sub-cortical neurons and characterize the dependency of entropy of
these regions on temperature. We study also the degree of the mutual
information on thalamocortical pathway depending on temperature.
The latter is most likely an indicator of coupling between these highly
connected structures in response to temperature manipulation leading
to arousal after global cerebral ischemia.
Abstract: Polymer Electrolyte Membrane Fuel Cell (PEMFC) is
such a time-vary nonlinear dynamic system. The traditional linear
modeling approach is hard to estimate structure correctly of PEMFC
system. From this reason, this paper presents a nonlinear modeling of
the PEMFC using Neural Network Auto-regressive model with
eXogenous inputs (NNARX) approach. The multilayer perception
(MLP) network is applied to evaluate the structure of the NNARX
model of PEMFC. The validity and accuracy of NNARX model are
tested by one step ahead relating output voltage to input current from
measured experimental of PEMFC. The results show that the obtained
nonlinear NNARX model can efficiently approximate the dynamic
mode of the PEMFC and model output and system measured output
consistently.
Abstract: The aim of this research is to identify the key factors in shipping company’s port selection in order to providing their requirement. To identify and rank factors that play the main role in selecting port for providing the ship requirement, at the first step, data were collected via Semi-structured interviews, the aim was to generate knowledge on how shipping company select the port and suppliers for providing their needs. 37 port selection factors were chosen from the previous researches and field interviews and have been categorized into two groups of port's factor and the factors of services of suppliers companies. The current study adopts a questionnaire survey to the main shipping companies' operators in Iran. Their responses reveal that level of services of supplying companies and customs rules play the important role in selecting the ports. Our findings could affect decisions made by port authorities to consider that supporting the privet sections for ship chandelling business could have the best result in attracting ships.
Abstract: The structures obtained with the use of sandwich
technologies combine low weight with high energy absorbing
capacity and load carrying capacity. Hence, there is a growing and
markedly interest in the use of sandwiches with aluminum foam core
because of very good properties such as flexural rigidity and energy
absorption capability. In the current investigation, the static threepoint
bending tests were carried out on the sandwiches with
aluminum foam core and glass fiber reinforced polymer (GFRP)
skins at different values of support span distances aiming the analyses
of their flexural performance. The influence of the core thickness and
the GFRP skin type was reported in terms of peak load and energy
absorption capacity. For this purpose, the skins with two different
types of fabrics which have same thickness value and the aluminum
foam core with two different thicknesses were bonded with a
commercial polyurethane based flexible adhesive in order to combine
the composite sandwich panels. The main results of the bending tests
are: force-displacement curves, peak force values, absorbed energy,
collapse mechanisms and the effect of the support span length and
core thickness. The results of the experimental study showed that the
sandwich with the skins made of S-Glass Woven fabrics and with the
thicker foam core presented higher mechanical values such as load
carrying and energy absorption capacities. The increment of the
support span distance generated the decrease of the mechanical
values for each type of panels, as expected, because of the inverse
proportion between the force and span length. The most common
failure types of the sandwiches are debonding of the lower skin and
the core shear. The obtained results have particular importance for
applications that require lightweight structures with a high capacity
of energy dissipation, such as the transport industry (automotive,
aerospace, shipbuilding and marine industry), where the problems of
collision and crash have increased in the last years.
Abstract: The present study was carried out to investigate the
effect of alloying elements and thermo-mechanical treatment (TMT)
i.e. hot rolling and forging with different reduction ratios on the
hardness (HV) and impact toughness (J) of heat-treated low alloy
steels. An understanding of the combined effect of TMT and alloying
elements and by measuring hardness, impact toughness, resulting
from different heat treatment following TMT of the low alloy steels,
it is possible to determine which conditions yielded optimum
mechanical properties and high strength to weight ratio.
Experimental Correlations between hot work reduction ratio,
hardness and impact toughness for thermo-mechanically heat treated
low alloy steels are analyzed quantitatively, and both regression and
mathematical hardness and impact toughness models are developed.
Abstract: Big Data and analytics have gained a huge momentum
in recent years. Big Data feeds into the field of Learning Analytics
(LA) that may allow academic institutions to better understand the
learners’ needs and proactively address them. Hence, it is important
to have an understanding of Big Data and its applications. The
purpose of this descriptive paper is to provide an overview of Big
Data, the technologies used in Big Data, and some of the applications
of Big Data in education. Additionally, it discusses some of the
concerns related to Big Data and current research trends. While Big
Data can provide big benefits, it is important that institutions
understand their own needs, infrastructure, resources, and limitation
before jumping on the Big Data bandwagon.
Abstract: This work sets out to debate the tensions involved in
the processes of contamination and self-purification in the urban
space, particularly in the streams that run through the Buenos Aires
metropolitan area. For much of their course, those streams are piped;
their waters do not come into contact with the outdoors until they
have reached deeply impoverished urban areas with high levels of
environmental contamination. These are peripheral zones that, until
thirty years ago, were marshlands and fields. They are now densely
populated areas largely lacking in urban infrastructure.
The Cárcova neighborhood, where this project is underway, is in
the José León Suárez section of General San Martín county, Buenos
Aires province. A stretch of José León Suarez canal crosses the
neighborhood. Starting upstream, this canal carries pollutants due to
the sewage and industrial waste released into it. Further downstream,
in the neighborhood, domestic drainage is poured into the stream. In
this paper, we formulate a hypothesis diametrical to the one that
holds that these neighborhoods are the primary source of
contamination, suggesting instead that in the stretch of the canal that
runs through the neighborhood the stream’s waters are actually
cleaned and the sediments accumulate pollutants. Indeed, the
stretches of water that runs through these neighborhoods act as water
processing plants for the metropolis.
This project has studied the different organic-load polluting
contributions to the water in a certain stretch of the canal, the
reduction of that load over the course of the canal, and the
incorporation of pollutants into the sediments. We have found that
the surface water has considerable ability to self-purify, mostly due to
processes of sedimentation and adsorption. The polluting load is
accumulated in the sediments where that load stabilizes slowly by
means of anaerobic processes. In this study, we also investigated the
risks of sediment management and the use of the processes studied
here in controlled conditions as tools of environmental restoration.
Abstract: Due to rapid pressured of population growth, city has
started to lose its old tradition. City becomes congested with
uncomfortably living. Urban renewal refers orderly development of
settlements as well as land redevelopment. For this paper Chittagong
city has been selected as study area. It had a great tradition but it has
been losing its concord. Land use pattern of this place is also
haphazard due to lack of planning intervention. Renewal plan is
needed to ascertain suitable redevelopment and to recommend on
preservation of city heritage structure. The goal of this study is to
prepare a renewal plan using local planning approach. Social impact
methods have been used to achieve this goal. Both primary and
secondary data are used to achieve the goal. This study may find out
a complete solution for healthy living in old Part of city. This study
will help to preserve its tradition and makes urban lives more livable.
Abstract: This study presented to reduce earthquake damage and
emergency rehabilitation of critical structures such as schools, hightech
factories, and hospitals due to strong ground motions associated
with climate changes. Regarding recent trend, a strong earthquake
causes serious damage to critical structures and then the critical
structure might be influenced by sequence aftershocks (or tsunami)
due to fault plane adjustments. Therefore, in order to improve seismic
performance of critical structures, retrofitted or strengthening study
of the structures under aftershocks sequence after emergency
rehabilitation of the structures subjected to strong earthquakes is
widely carried out. Consequently, this study used composite material
for emergency rehabilitation of the structure rather than concrete and
steel materials because of high strength and stiffness, lightweight,
rapid manufacturing, and dynamic performance. Also, this study was
to develop or improve the seismic performance or seismic retrofit of
critical structures subjected to strong ground motions and earthquake
aftershocks, by utilizing GFRP-Corrugated Infill Panels (GCIP).
Abstract: Organizational tendencies towards computer-based
information processing have been observed noticeably in the
third-world countries. Many enterprises are taking major initiatives
towards computerized working environment because of massive
benefits of computer-based information processing. However,
designing and developing information resource management software
for small and mid-size enterprises under budget costs and strict
deadline is always challenging for software engineers. Therefore, we
introduced an approach to design mid-size enterprise software by
using the Waterfall model, which is one of the SDLC (Software
Development Life Cycles), in a cost effective way. To fulfill research
objectives, in this study, we developed mid-sized enterprise software
named “BSK Management System” that assists enterprise software
clients with information resource management and perform complex
organizational tasks. Waterfall model phases have been applied to
ensure that all functions, user requirements, strategic goals, and
objectives are met. In addition, Rich Picture, Structured English, and
Data Dictionary have been implemented and investigated properly in
engineering manner. Furthermore, an assessment survey with 20
participants has been conducted to investigate the usability and
performance of the proposed software. The survey results indicated
that our system featured simple interfaces, easy operation and
maintenance, quick processing, and reliable and accurate transactions.
Abstract: Public-private partnerships (PPP) arrangements have
been extensively used in Canada, where the participation of private
companies in financing and managing infrastructure projects has
increased significantly in the last decade, particularly in the
transportation sector. This paper analyses the evolution of the PPP
market for transportation projects in Canada and examines the
participation of Spanish developers in this market, which have been
particularly successful in winning PPP contracts during the last
decade.