Abstract: The dissimilar joint between aluminum/titanium
alloys (Al 6082 and Ti G2) were successfully achieved by CO2 laser
welding with a single pass and without filler material using the
overlap joint design. Laser welding parameters ranges combinations
were experimentally determined using Taguchi approach with the
objective of producing welded joint with acceptable welding profile
and high quality of mechanical properties. In this study a joining of
dissimilar Al 6082 / Ti G2 was resulted in three distinct regions
fusion area in the weldment. These regions are studied in terms of its
microstructural characteristics and microhardness which are directly
affecting the welding quality.
The weld metal was mainly composed of martensite alpha prime.
In two different metals in the two different sides of joint HAZ, grain
growth was detected. The microhardness of the joint distribution also
has shown microhardness increasing in the HAZ of two base metals
and a varying microhardness in fusion zone.
Abstract: The article deals with modelling of the fire
pragmatism in the area of military management and its experimental
verification. Potential approaches are based on the synergy of
mathematical and theoretical ideas, operational and tactical
requirements and the military decision-making process. This issue
has taken on importance in recent times, particularly with the
increasing trend of digitized battlefield, the development of C4ISR
systems and intention to streamline the command and control process
at the lowest levels of command. From fundamental and
philosophical point of view, these new approaches seek to
significantly upgrade and enhance the decision-making process of the
tactical commanders.
Abstract: Urban Search and Rescue (USAR) is a functional
capability that has been developed to allow the United Kingdom Fire
and Rescue Service to deal with ‘major incidents’ primarily involving
structural collapse. The nature of the work undertaken by USAR
means that staying out of a damaged or collapsed building structure is
not usually an option for search and rescue personnel. As a result
there is always a risk that they themselves could become victims. For
this paper, a systematic and investigative review using desk research
was undertaken to explore the role which structural engineering can
play in assisting search and rescue personnel to conduct structural
assessments when in the field. The focus is on how search and rescue
personnel can assess damaged and collapsed building structures, not
just in terms of structural damage that may been countered, but also
in relation to structural stability. Natural disasters, accidental
emergencies, acts of terrorism and other extreme events can vary
significantly in nature and ferocity, and can cause a wide variety of
damage to building structures. It is not possible or, even realistic, to
provide search and rescue personnel with definitive guidelines and
procedures to assess damaged and collapsed building structures as
there are too many variables to consider. However, understanding
what implications damage may have upon the structural stability of a
building structure will enable search and rescue personnel to better judge
and quantify risk from a life-safety standpoint. It is intended that this
will allow search and rescue personnel to make informed decisions
and ensure every effort is made to mitigate risk, so that they
themselves do not become victims.
Abstract: Over the years, it has been extensively established that
the practice of assuming a structure being fixed at base, leads to gross
errors in evaluation of its overall response due to dynamic loadings
and overestimations in design. The extent of these errors depends on
a number of variables; soil type being one of the major factor. This
paper studies the effect of Soil Structure Interaction (SSI) on multistorey
buildings with varying under-laying soil types after proper
validation of the effect of SSI. Analysis for soft, stiff and very stiff
base soils has been carried out, using a powerful Finite Element
Method (FEM) software package ANSYS v14.5. Results lead to
some very important conclusions regarding time period, deflection
and acceleration responses.
Abstract: The building sector is responsible, in many
industrialized countries, for about 40% of the total energy
requirements, so it seems necessary to devote some efforts in this
area in order to achieve a significant reduction of energy
consumption and of greenhouse gases emissions.
The paper presents a study aiming at providing a design
methodology able to identify the best configuration of the system
building/plant, from a technical, economic and environmentally point
of view.
Normally, the classical approach involves a building's energy
loads analysis under steady state conditions, and subsequent selection
of measures aimed at improving the energy performance, based on
previous experience made by architects and engineers in the design
team. Instead, the proposed approach uses a sequence of two wellknown
scientifically validated calculation methods (TRNSYS and
RETScreen), that allow quite a detailed feasibility analysis.
To assess the validity of the calculation model, an existing,
historical building in Central Italy, that will be the object of
restoration and preservative redevelopment, was selected as a casestudy.
The building is made of a basement and three floors, with a
total floor area of about 3,000 square meters.
The first step has been the determination of the heating and
cooling energy loads of the building in a dynamic regime by means,
which allows simulating the real energy needs of the building in
function of its use. Traditional methodologies, based as they are on
steady-state conditions, cannot faithfully reproduce the effects of
varying climatic conditions and of inertial properties of the structure.
With this model is possible to obtain quite accurate and reliable
results that allow identifying effective combinations building-HVAC
system.
The second step has consisted of using output data obtained as
input to the calculation model, which enables to compare different
system configurations from the energy, environmental and financial
point of view, with an analysis of investment, and operation and
maintenance costs, so allowing determining the economic benefit of
possible interventions.
The classical methodology often leads to the choice of
conventional plant systems, while our calculation model provides a
financial-economic assessment for innovative energy systems and
low environmental impact.
Computational analysis can help in the design phase, particularly
in the case of complex structures with centralized plant systems, by
comparing the data returned by the calculation model for different
design options.
Abstract: Cemented carbide balls are usually implemented in
industry under the environment of high speed, high temperature,
corrosiveness and strong collisions. However, its application is limited
due to high fabrication cost, processing efficiency and quality. A novel
eccentric lapping method with two rotatable lapping plates was
proposed in this paper. A mathematical model was constructed to
analyze the influence of each design parameter on this lapping method.
To validate this new lapping method, an orthogonal experiment was
conducted with cemented carbide balls (YG6). The simulation model
was verified and the optimal lapping parameters were derived. The
results show that the surface roundness of the balls reaches to 0.65um
from 2um in 1 hour using this lapping method. So, using this novel
lapping method, it can effectively improve the machining precision
and efficiency of cemented carbide balls.
Abstract: Knowledge is considered as an important asset which
can help organizations to create competitive advantage. The necessity
of taking care of these assets is more important in these days – in
days of turbulent changes in business environment. Knowledge could
facilitate adaption to constant changes. The aim of this paper is to
describe how the knowledge sharing can be supported in the
manufacturing companies. The methods of case studies and grounded
theory were used to present information gained by carrying out semistructured
interviews. Results show that knowledge sharing is
supported in very similar ways in respondent companies.
Abstract: Thin-walled elements with a matrix set on a base of
high-valuable Portland cement with dispersed reinforcement from
alkali-resistant glass fibres are used in a range of applications as
claddings of buildings and infrastructure constructions as well as
various architectural elements of residential buildings.
Even though their elementary thickness and therefore total weight
is quite low, architects and building companies demand on even
further decreasing of the bulk density of these fibre-cement elements
for the reason of loading elimination of connected superstructures
and easier assembling in demand conditions.
By the means of various kinds of light-weight aggregates it is
possible to achieve light-weighing of these composite elements.
From the range of possible fillers with different material properties
granulated expanded glass worked the best.
By the means of laboratory testing an effect of two fillers based on
expanded glass on the fibre reinforced cement composite was
verified.
Practical applicability was tested in the production of commonly
manufactured glass fibre reinforced concrete elements, such as
channels for electrical cable deposition, products for urban equipment
and especially various cladding elements.
Even though these are not structural elements, it is necessary to
evaluate also strength characteristics and resistance to environment
for their durability in certain applications.
Abstract: Offering a Product-Service System (PSS) is a
well-accepted strategy that companies may adopt to provide a set of
systemic solutions to customers. PSSs were initially provided in a
simple form but now take diversified and complex forms involving
multiple services, products and technologies. With the growing
interest in the PSS, frameworks for the PSS development have been
introduced by many researchers. However, most of the existing
frameworks fail to examine various relations existing in a complex
PSS. Since designing a complex PSS involves full integration of
multiple products and services, it is essential to identify not only
product-service relations but also product-product/ service-service
relations. It is also equally important to specify how they are related
for better understanding of the system. Moreover, as customers tend to
view their purchase from a more holistic perspective, a PSS should be
developed based on the whole system’s requirements, rather than
focusing only on the product requirements or service requirements.
Thus, we propose a framework to develop a complex PSS that is
coordinated fully with the requirements of both worlds. Specifically,
our approach adopts a multi-domain matrix (MDM). A MDM
identifies not only inter-domain relations but also intra-domain
relations so that it helps to design a PSS that includes highly desired
and closely related core functions/ features. Also, various dependency
types and rating schemes proposed in our approach would help the
integration process.
Abstract: Despite the highly touted benefits, emerging
technologies have unleashed pervasive concerns regarding unintended
and unforeseen social impacts. Thus, those wishing to create safe and
socially acceptable products need to identify such side effects and
mitigate them prior to the market proliferation. Various methodologies
in the field of technology assessment (TA), namely Delphi, impact
assessment, and scenario planning, have been widely incorporated in
such a circumstance. However, literatures face a major limitation in
terms of sole reliance on participatory workshop activities. They
unfortunately missed out the availability of a massive untapped data
source of futuristic information flooding through the Internet. This
research thus seeks to gain insights into utilization of futuristic data,
future-oriented documents from the Internet, as a supplementary
method to generate social impact scenarios whilst capturing
perspectives of experts from a wide variety of disciplines. To this end,
network analysis is conducted based on the social keywords extracted
from the futuristic documents by text mining, which is then used as a
guide to produce a comprehensive set of detailed scenarios. Our
proposed approach facilitates harmonized depictions of possible
hazardous consequences of emerging technologies and thereby makes
decision makers more aware of, and responsive to, broad qualitative
uncertainties.
Abstract: One of the best examples, in evolution of the public
procurement, from post-soviet countries are reforms carried out in
Georgia, which brought them close to international standards of
procurement. In Georgia, public procurement legislation started
functioning short after gaining independence. The reform has passed
several stages and came in the form as it is today. It should also be
noted, that countries with economy in transition, including Georgia,
implemented all the reforms in public procurement based on
recommendations and support of World Bank, the United Nations
and other international organizations.
The aim of first adopted law was regulation of the procurement
process of budget-organizations, transparency and creation of
competitive environment for private companies to access state funds
legally. The priorities were identified quite clearly in the wording of
the law, but operation/function of this law could not be reached on its
level, because of some objective and subjective reasons. The high
level of corruption in all levels of governance can be considered as a
main obstacle reason and of course, it is natural, that it had direct
impact on the procurement process, as well as on transparency and
rational use of state funds. These circumstances were the reasons that
reforms in this sphere continued, to improve procurement process, in
particular, the first wave of reforms began after several years. Public
procurement agency carried out reform with World Bank with main
purpose of smartening the procurement legislation and its
harmonization with international treaties and agreements. Also with
the support of World Bank various activities were carried out to raise
awareness of participants involved in procurement system.
Further major changes in the legislation were filed bit later, which
was also directed towards the improvement and smarten of the
procurement process. The third wave of the reform more or less
guaranteed the transparency of the procurement process, which later
became the basis for the rational spending of state funds. The reform
of the procurement system completely changed the procedures.
Carried out reform in Georgia resulted in introducing new
electronic tendering system, which benefit the transparency of the
process, after this became the basis for the further development of a
competitive environment, which become a prerequisite for the state
rational spending. Increased number of supplier organizations
participating in the procurement process resulted in reduction of the
estimated cost and the actual cost.
Assessment of the reforms in Georgia in the field of public
procurement can be concluded, that proper regulation of the sector
and relevant policy may proceed to rational and transparent spending
of the budget from country’s state institutions. Also, the business
sector has the opportunity to work in competitive market conditions
and to make a preliminary analysis, which is a prerequisite for future
strategy and development.
Abstract: Hurling a successful Construction and Demolition
Waste (C&DW) recycling operation around the globe is a challenge
today, predominantly because secondary materials markets are yet to
be integrated. Reducing, Reusing and recycling of (C&DW) have
been employed over the years, and various techniques have been
investigated. However, the economic and environmental viability of
its application seems limited. This paper discusses the costs and
benefits in using secondary materials and focus on investigating reuse
and recycling process for five major types of construction materials:
concrete, metal, wood, cardboard/paper and plasterboard. Data
obtained from demolition specialists and contractors are considered
and evaluated. The research paper found that construction material
recovery process fully incorporate a 3R’s principle contributing to
saving energy and natural resources. This scrutiny leads to the
empathy of grand challenges in construction material recovery
process. Recommendations to deepen material recovery process are
also discussed.
Abstract: The Malaysian government had consistently revived
its campaign for “Buy Malaysian Goods” from time to time. The
purpose of the campaign is to remind consumers to be ethnocentric
and patriotic when purchasing product and services. This is necessary
to ensure high demand for local products and services compared to
foreign products. However, the decline of domestic investment in
2012 has triggered concern for the Malaysian economy. Hence, this
study attempts to determine the drivers of actual purchasing behavior,
intention to purchase domestic products and ethnocentrism. The
study employs the cross-sectional primary data, self-administered on
household, selected using stratified random sampling in four
Malaysian regions. A nine factor driver of actual domestic purchasing
behavior (culture openness, conservatism, collectivism, patriotism,
control belief, interest in foreign travel, attitude, ethnocentrism and
intention) were measured utilizing 60 items, using 7-point Likertscale.
From 1000 questionnaires distributed, a sample of 486 were
returned representing 48.6 percent response rate. From the fit
generated structural model (SEM analysis), it was found that the
drivers of actual purchase behavior are collectivism, cultural
openness and patriotism; the drivers of intention to purchase
domestic product are attitude, control belief, collectivism and
conservatism; and drivers of ethnocentrism are cultural openness,
control belief, foreign travel and patriotism. It also shows that
Malaysian consumers scored high in ethnocentrism and patriotism.
The findings are discussed in the perspective of its implication to
Malaysian National Agenda.
Abstract: This work deals with parameter identification of
permanent magnet motors, a class of ac motor which is particularly
important in industrial automation due to characteristics like
applications high performance, are very attractive for applications
with limited space and reducing the need to eliminate because they
have reduced size and volume and can operate in a wide speed range,
without independent ventilation. By using experimental data and
genetic algorithm we have been able to extract values for both the
motor inductance and the electromechanical coupling constant, which
are then compared to measured and/or expected values.
Abstract: In this paper, the problem of fault detection and
isolation in the attitude control subsystem of spacecraft formation
flying is considered. In order to design the fault detection method, an
extended Kalman filter is utilized which is a nonlinear stochastic state
estimation method. Three fault detection architectures, namely,
centralized, decentralized, and semi-decentralized are designed based
on the extended Kalman filters. Moreover, the residual generation
and threshold selection techniques are proposed for these
architectures.
Abstract: This study is to fill up a research gap on examining the
differences in normative beliefs (namely acceptance of weaknesses,
acceptance of provoked aggression, and acceptance of unprovoked
aggression) among different subtypes of aggressors and
non-aggressors (reactive aggressors, proactive aggressors,
reactive-proactive aggressors, and non-aggressors). 2,236 students
(1,372 males and 864 females), aged from 11 to 18, completed a
self-reported questionnaire. Results revealed that (a) schoolchildren
with reactive-proactive aggression have the highest acceptance of
provoked aggression, the highest acceptance of unprovoked
aggression, and the lowest acceptance of weakness; (b) schoolchildren
with proactive aggression have higher acceptance of unprovoked
aggression and lower acceptance of weakness than reactive aggressors;
and (c) schoolchildren without aggression have the lowest acceptance
of provoked aggression, the lowest acceptance of unprovoked
aggression, and the highest acceptance of weakness.
Abstract: Over the past four decades, the fatigue behavior of
nickel-based alloys has been widely studied. However, in recent
years, significant advances in the fabrication process leading to grain
size reduction have been made in order to improve fatigue properties
of aircraft turbine discs. Indeed, a change in particle size affects the
initiation mode of fatigue cracks as well as the fatigue life of the
material. The present study aims to investigate the fatigue behavior of
a newly developed nickel-based superalloy under biaxial-planar
loading. Low Cycle Fatigue (LCF) tests are performed at different
stress ratios so as to study the influence of the multiaxial stress state
on the fatigue life of the material. Full-field displacement and strain
measurements as well as crack initiation detection are obtained using
Digital Image Correlation (DIC) techniques. The aim of this
presentation is first to provide an in-depth description of both the
experimental set-up and protocol: the multiaxial testing machine, the
specific design of the cruciform specimen and performances of the
DIC code are introduced. Second, results for sixteen specimens
related to different load ratios are presented. Crack detection, strain
amplitude and number of cycles to crack initiation vs. triaxial stress
ratio for each loading case are given. Third, from fractographic
investigations by scanning electron microscopy it is found that the
mechanism of fatigue crack initiation does not depend on the triaxial
stress ratio and that most fatigue cracks initiate from subsurface
carbides.
Abstract: The thermal behavior of a large-scale, phase change material (PCM) enhanced building envelope system was studied in regard to the need for pre-fabricated construction in subtropical regions. The proposed large-scale envelope consists of a reinforced aluminum skin, insulation core, phase change material and reinforced gypsum board. The PCM impact on an energy efficiency of an enveloped room was resolved by validation of the EnergyPlus numerical scheme and optimization of a smart material location in the core. The PCM location was optimized by a minimization method of a cooling energy demand. It has been shown that there is good agreement between the test and simulation results. The optimal location of the PCM layer in Hong Kong summer conditions has been then recomputed for core thicknesses of 40, 60 and 80 mm. A non-dimensional value of the optimal PCM location was obtained to be same for all the studied cases and the considered external and internal conditions.
Abstract: The development of allometric models is crucial to
accurate forest biomass/carbon stock assessment. The aim of this
study was to develop a set of biomass prediction models that will
enable the determination of total tree aboveground biomass for
savannah woodland area in Niger State, Nigeria. Based on the data
collected through biometric measurements of 1816 trees and
destructive sampling of 36 trees, five species specific and one site
specific models were developed. The sample size was distributed
equally between the five most dominant species in the study site
(Vitellaria paradoxa, Irvingia gabonensis, Parkia biglobosa,
Anogeissus leiocarpus, Pterocarpus erinaceous). Firstly, the
equations were developed for five individual species. Secondly these
five species were mixed and were used to develop an allometric
equation of mixed species. Overall, there was a strong positive
relationship between total tree biomass and the stem diameter. The
coefficient of determination (R2 values) ranging from 0.93 to 0.99 P
< 0.001 were realised for the models; with considerable low standard
error of the estimates (SEE) which confirms that the total tree above
ground biomass has a significant relationship with the dbh. F-test
values for the biomass prediction models were also significant at p
Abstract: Robotic surgery is used to enhance minimally invasive
surgical procedure. It provides greater degree of freedom for surgical
tools but lacks of haptic feedback system to provide sense of touch to
the surgeon. Surgical robots work on master-slave operation, where
user is a master and robotic arms are the slaves. Current, surgical
robots provide precise control of the surgical tools, but heavily rely
on visual feedback, which sometimes cause damage to the inner
organs. The goal of this research was to design and develop a realtime
Simulink based robotic system to study force feedback
mechanism during instrument-object interaction. Setup includes three
VelmexXSlide assembly (XYZ Stage) for three dimensional
movement, an end effector assembly for forceps, electronic circuit for
four strain gages, two Novint Falcon 3D gaming controllers,
microcontroller board with linear actuators, MATLAB and Simulink
toolboxes. Strain gages were calibrated using Imada Digital Force
Gauge device and tested with a hard-core wire to measure
instrument-object interaction in the range of 0-35N. Designed
Simulink model successfully acquires 3D coordinates from two
Novint Falcon controllers and transfer coordinates to the XYZ stage
and forceps. Simulink model also reads strain gages signal through
10-bit analog to digital converter resolution of a microcontroller
assembly in real time, converts voltage into force and feedback the
output signals to the Novint Falcon controller for force feedback
mechanism. Experimental setup allows user to change forward
kinematics algorithms to achieve the best-desired movement of the
XYZ stage and forceps. This project combines haptic technology
with surgical robot to provide sense of touch to the user controlling
forceps through machine-computer interface.