Abstract: The reheating furnace is used to reheat the steel slabs
before the hot-rolling process. The supported system includes the
stationary/moving beams, and the skid buttons which block some
thermal radiation transmitted to the bottom of the slabs. Therefore, it is
important to analyze the steel slab temperature distribution during the
heating period. A three-dimensional mathematical transient heat
transfer model for the prediction of temperature distribution within the
slab has been developed. The effects of different skid button height
(H=60mm, 90mm, and 120mm) and different gap distance between
two slabs (S=50mm, 75mm, and 100mm) on the slab skid mark
formation and temperature profiles are investigated. Comparison with
the in-situ experimental data from Steel Company in Taiwan shows
that the present heat transfer model works well for the prediction of
thermal behavior of the slab in the reheating furnace. It is found that
the skid mark severity decreases with an increase in the skid button
height. The effect of gap distance is important only for the slab edge
planes, while it is insignificant for the slab central planes.
Abstract: The aim of the performed work is to establish the 2D
and 3D model of direct unsteady task of sample heat treatment by
moving source employing computer model on the basis of finite
element method. Complex boundary condition on heat loaded sample
surface is the essential feature of the task. Computer model describes
heat treatment of the sample during heat source movement over the
sample surface. It is started from 2D task of sample cross section as a
basic model. Possibilities of extension from 2D to 3D task are
discussed. The effect of the addition of third model dimension on
temperature distribution in the sample is showed. Comparison of
various model parameters on the sample temperatures is observed.
Influence of heat source motion on the depth of material heat
treatment is shown for several velocities of the movement. Presented
computer model is prepared for the utilization in laser treatment of
machine parts.
Abstract: With the increasing population and intensive land use,
huge traffic demand is generating worldwide both in developing and
developed countries. As a developing country, Bangladesh is also
facing the same problem in recent years by producing huge numbers
of daily trips. As a matter of fact, extensive traffic demand is
increasing day by day. Also, transport system in Dhaka is
heterogeneous, reflecting the heterogeneity in the socio-economic
and land use patterns. Trips produced here are for different purposes
such as work, business, educational etc. Due to the significant
concentration of educational institutions a large share of the trips are
generated by educational purpose. And one of the major percentages
of educational trips is produced by university going students and
most of them are travelled by car, bus, train, taxi, rickshaw etc. The
aim of the study was to find out the university students’ perception on
public transit ridership. A survey was conducted among 330 students
from eight different universities. It was found out that 26% of the
trips produced by university going students are travelled by public
bus service and only 5% are by train. Percentage of car share is 16%
and 12% of the trips are travelled by private taxi. It has been
observed from the study, students those who prefer bus instead of
other options, 42 percent of their family resides outside Dhaka. And
those who prefer walking, of them, over 40 percent students’ family
reside outside of Dhaka and of them over 85 percent students have a
tendency to live in a mess. On the contrary, students travelling by car
represents, most of their family reside in Dhaka. The study also
revealed that the most important reason that restricts students not to
use public transit is poor service. Negative attitudes such as
discomfort, uneasiness in using public transit also reduces the usage
of public transit. The poor waiting area is another major cause of not
using public transit. Insufficient security also plays a significant role
in not using public transit. On the contrary, the fare is not a problem
for students those who use public transit as a mode of transportation.
Students also think stations are not far away from their home or
institution and they do not need to wait long for the buses or trains. It
was also found accessibility to public transit is moderate.
Abstract: The market competition is moving from the single
firm to the whole supply chain because of increasing competition and
growing need for operational efficiencies and customer orientation.
Supply chain management allows companies to look beyond their
organizational boundaries to develop and leverage resources and
capabilities of their supply chain partners. This creates competitive
advantages in the marketplace and because of this SCM has acquired
strategic importance. Lean Approach is a management strategy that focuses on reducing
every type of waste present in an organization. This approach is
becoming more and more popular among supply chain managers. The supply chain application of lean approach is not frequent. In
particular, it is not well studied which are the impacts of lean
approach principles in a supply chain context. In literature there are
only few studies aimed at understanding the qualitative impact of the
lean approach in supply chains. Therefore, the goal of this research
work is to study the impacts of lean principles implementation along
a supply chain. To achieve this, a simulation model of a threeechelon
multi-product supply chain has been built. Kanban system (and several priority policies) and setup time
reduction degrees are implemented in the lean-configured supply
chain to apply pull and lot-sizing decrease principles respectively. To
evaluate the benefits of lean approach, lean supply chain is compared
with an EOQ-configured supply chain. The simulation results show
that Kanban system and setup-time reduction improve inventory
stock level. They also show that logistics efforts are affected to lean
implementation degree. The paper concludes describing
performances of lean supply chain in different contexts.
Abstract: This work deals with the problem of MHD mixed
convection in a completely porous and differentially heated vertical
channel. The model of Darcy-Brinkman-Forchheimer with the
Boussinesq approximation is adopted and the governing equations are
solved by the finite volume method. The effects of magnetic field and
buoyancy force intensities are given by the Hartmann and Richardson
numbers respectively, as well as the Joule heating represented by
Eckert number on the velocity and temperature fields, are examined.
The main results show an augmentation of heat transfer rate with the
decrease of Darcy number and the increase of Ri and Ha when Joule
heating is neglected.
Abstract: Radical technological innovations enable companies
to reach strong market positions and are thus desirable. On the other
hand, the innovation process is related to significant costs and risks.
Hence, the knowledge of the factors that influence success is crucial
for technology driven companies. Taking a previously developed
framework of Critical Success Factors for radical technological
innovations as a reference model, we conducted a structured and
focused literature review of eleven standard books within the field of
technology and innovation management. With this approach we aim
to evaluate, expand, and clarify the set of Critical Success Factors
detailed in this framework. Overall, the set of factors and their
allocation to the main categories of the framework could be
confirmed. However, the factor organizational home is not
emphasized and discussed in most of the reviewed literature. On the
other hand, an additional factor that has not been part of the
framework is described to be important – strategy fit. Furthermore,
the factors strategic alliances and platform strategy appear in the
literature but in a different context compared to the reference model.
Abstract: In this paper, various methods of providing restricted
earth fault protection are discussed. The proper operation of high and
low impedance Restricted Earth Fault (REF) protection for various
applications has been discussed. The maloperation of a relay due to
improper placement of CTs has been identified and a simple/unique
solution has been proposed in this work with a case study. Moreover,
it is found that the proper placement of CT in high impedance method
will provide the same result with reduced CT. This methodology has
been successfully implemented in Al Takreer refinery for a 2000
KVA transformer. The outcome of the paper may be included in
IEEEC37.91 standard to give the proper guidance for protection
engineers to sort out the issues related to mal functioning of REF
relays.
Abstract: Since the last decade, there has been a rapid growth in
digital multimedia, such as high-resolution media files and threedimentional
movies. Hence, there is a need for large digital storage
such as Hard Disk Drive (HDD). As such, users expect to have a
quieter HDD in their laptop. In this paper, a jury test has been
conducted on a group of 34 people where 17 of them are students
who are the potential consumer, and the remaining are engineers who
know the HDD. A total 13 HDD sound samples have been selected
from over hundred HDD noise recordings. These samples are
selected based on an agreed subjective feeling. The samples are
played to the participants using head acoustic playback system, which
enabled them to experience as similar as possible the same
environment as have been recorded. Analysis has been conducted and
the obtained results have indicated different group has different
perception over the noises. Two neural network-based acoustic
annoyance models are established based on back propagation neural
network. Four psychoacoustic metrics, loudness, sharpness,
roughness and fluctuation strength, are used as the input of the
model, and the subjective evaluation results are taken as the output.
The developed models are reasonably accurate in simulating both
training and test samples.
Abstract: Rice Husk (RH) is the major byproduct in the
processing of paddy rice. The management of this waste has become
a big challenge to some of the rice producers, some of these wastes
are left in open dumps while some are burn in the open space, and
these two actions have been contributing to environmental pollution.
This study evaluates an alternative waste management of this
agricultural product for use as a civil engineering material. The RH
was burn in a controlled environment to form Rice Husk Ash (RHA).
The RHA was mix with lateritic clay at 0, 2, 4, 6, 8, and 10%
proportion by weight. Chemical test was conducted on the open burn
and controlled burn RHA with the lateritic clay. Physical test such as
particle size distribution, Atterberg limits test, and density test were
carried out on the mix material. The chemical composition obtained
for the RHA showed that the total percentage compositions of Fe2O3,
SiO2 and Al2O3 were found to be above 70% (class “F” pozzolan)
which qualifies it as a very good pozzolan. The coefficient of
uniformity (Cu) was 8 and coefficient of curvature (Cc) was 2 for the
soil sample. The Plasticity Index (PI) for the 0, 2, 4, 6, 8. 10% was
21.0, 18.8, 16.7, 14.4, 12.4 and 10.7 respectively. The work
concluded that RHA can be effectively used in hydraulic barriers and
as a stabilizing agent in soil stabilization.
Abstract: The purpose of this theoretical literature review is to
study the relevant academic literature on lack of cardiorespiratory
fitness and its effects on children. The total of thirty eight relevant
documents were identified and considered for this review which
nineteen of those were original research articles published in peer
reviewed journals. The other nineteen articles were statistical
documents. This literature review is structured to examine 5 effects
in deficiency of cardiorespiratory fitness in school aged children (A)
Relative Age Effect (RAE), (B) Obesity, (C) Inadequate fitness level
(D) Unhealthy life style, and (E) Academics. The categories provide
a theoretical framework for future studies where results are driven
from the literature review. The study discusses that regular physical fitness assists children
and adolescents to develop healthy physical activity behaviors which
can be sustained throughout adult life. Conclusion suggests that
advocacy for increasing physical activity and decreasing sedentary
behaviors at school and home are necessary.
Abstract: This paper presents the result of an experimental
investigation regarding the use of Fe2O3 nanoparticles added to
kerosene as a working fluid, under magnetic field for Copper
Oscillating Heat pipe with inclination angle of 0°(horizontal), 15°,
30°,45°, 60°,75° and 90° (vertical). The following were examined;
measure the temperature distribution and heat transfer rate on
Oscillating Heat Pipe (OHP), with magnetic field under different
angles. Results showed that the addition of Fe2O3 nanoparticles under
magnetic field improved thermal performance of OHP especially in
75°.
Abstract: Lyophilization, also called freeze-drying, is an
important dehydration technique mainly used for pharmaceuticals.
Food industry also uses lyophilization when it is important to retain
most of the nutritional quality, taste, shape and size of dried products
and to extend their shelf life. Vacuum-Induced during freezing cycle
(VI) has been used in order to control ice nucleation and,
consequently, to reduce the time of primary drying cycle of
pharmaceuticals preserving quality properties of the final product.
This procedure has not been applied in freeze drying of foods. The
present work aims to investigate the effect of VI on the lyophilization
drying time, final moisture content, density and reconstitutional
properties of mango (Mangifera indica L.) slices (MS) and mango
pulp-maltodextrin dispersions (MPM) (30% concentration of total
solids). Control samples were run at each freezing rate without using
induced vacuum. The lyophilization endpoint was the same for all
treatments (constant difference between capacitance and Pirani
vacuum gauges). From the experimental results it can be concluded
that at the high freezing rate (0.4°C/min) reduced the overall process
time up to 30% comparing process time required for the control and
VI of the lower freeze rate (0.1°C/min) without affecting the quality
characteristics of the dried product, which yields a reduction in costs
and energy consumption for MS and MPM freeze drying. Controls
and samples treated with VI at freezing rate of 0.4°C/min in MS
showed similar results in moisture and density parameters.
Furthermore, results from MPM dispersion showed favorable values
when VI was applied because dried product with low moisture
content and low density was obtained at shorter process time
compared with the control. There were not found significant
differences between reconstitutional properties (rehydration for MS
and solubility for MPM) of freeze dried mango resulting from
controls, and VI treatments.
Abstract: Ceramic obtained on the base of aluminum oxide has
wide application range, because it has unique properties, for example,
wear-resistance, dielectric characteristics, and exploitation ability at
high temperatures and in corrosive atmosphere. Low temperature
synthesis of α-Al2O3 is energo-economical process and it is topical
for developing technologies of corundum ceramics fabrication. In the present work possibilities of low temperature transformation
of oxyhydroxides in α-Al2O3, during the presence of small amount of
rare–earth elements compounds (also Th, Re), have been discussed.
Aluminum unstable oxyhydroxides have been obtained by hydrolysis
of aluminium isopropoxide, nitrates, sulphate, and chloride in
alkaline environment at 80-90ºC temperatures. β-Al(OH)3 has been
received from aluminum powder by ultrasonic development. Drying
of oxyhydroxide sol has been conducted with presence of various
types seeds, which amount reaches 0,1-0,2% (mas). Neodymium,
holmium, thorium, lanthanum, cerium, gadolinium, disprosium
nitrates and rhenium carbonyls have been used as seeds and they
have been added to the sol specimens in amount of 0.1-0.2% (mas)
calculated on metals. Annealing of obtained gels is carried out at 70–
1100ºC for 2 hrs. The same specimen transforms in α-Al2O3 at
1100ºC. At this temperature in case of presence of lanthanum and
gadolinium transformation takes place by 70-85%. In case of
presence of thorium stabilization of γ-and θ-phases takes place. It is
established, that thorium causes inhibition of α-phase generation at
1100ºC, and at the time when in all other doped specimens α-phase is
generated at lower temperatures (1000-1050ºC). Synthesis of various
type compounds and simultaneous consolidation has developed in the
furnace of OXY-GON. Composite materials containing oxide and
non-oxide components close to theoretical data have been obtained in
this furnace respectively. During the work the following devices have
been used: X-ray diffractometer DRON-3M (Cu-Kα, Ni filter,
2º/min), High temperature vacuum furnace OXY-GON, electronic
scanning microscopes Nikon ECLIPSE LV 150, NMM-800TRF,
planetary mill Pulverisette 7 premium line, SHIMADZU Dynamic
Ultra Micro Hardness Tester, DUH-211S, Analysette 12 Dyna sizer.
Abstract: The Radio Frequency Identification (RFID) technology
has a diverse base of applications, but it is also prone to security
threats. There are different types of security attacks which limit the
range of the RFID applications. For example, deploying the RFID
networks in insecure environments could make the RFID system
vulnerable to many types of attacks such as spoofing attack, location
traceability attack, physical attack and many more. Therefore, security
is often an important requirement for RFID systems. In this paper,
RFID mutual authentication protocol is implemented based on mobile
agent technology and timestamp, which are used to provide strong
authentication and integrity assurances to both the RFID readers and
their corresponding RFID tags. The integration of mobile agent
technology and timestamp provides promising results towards
achieving this goal and towards reducing the security threats in RFID
systems.
Abstract: This paper describes a subarray based low
computational design method of multiuser massive multiple
input multiple output (MIMO) system. In our previous works, use of
large array is assumed only in transmitter, but this study considers
the case both of transmitter and receiver sides are equipped with
large array antennas. For this aim, receive arrays are also divided
into several subarrays, and the former proposed method is modified
for the synthesis of a large array from subarrays in both ends.
Through computer simulations, it is verified that the performance
of the proposed method is degraded compared with the original
approach, but it can achieve the improvement in the aspect of
complexity, namely, significant reduction of the computational load
to the practical level.
Abstract: Recently, numerous documents including large
volumes of unstructured data and text have been created because of the
rapid increase in the use of social media and the Internet. Usually,
these documents are categorized for the convenience of users. Because
the accuracy of manual categorization is not guaranteed, and such
categorization requires a large amount of time and incurs huge costs.
Many studies on automatic categorization have been conducted to help
mitigate the limitations of manual categorization. Unfortunately, most
of these methods cannot be applied to categorize complex documents
with multiple topics because they work on the assumption that
individual documents can be categorized into single categories only.
Therefore, to overcome this limitation, some studies have attempted to
categorize each document into multiple categories. However, the
learning process employed in these studies involves training using a
multi-categorized document set. These methods therefore cannot be
applied to the multi-categorization of most documents unless
multi-categorized training sets using traditional multi-categorization
algorithms are provided. To overcome this limitation, in this study, we
review our novel methodology for extending the category of a
single-categorized document to multiple categorizes, and then
introduce a survey-based verification scenario for estimating the
accuracy of our automatic categorization methodology.
Abstract: For schools to be desirable places in which to work, it
is necessary for principals to recognise their teachers’ emotions, and
be sensitive to their needs. This necessitates that principals are
capable to correctly identify their emotionally intelligent behaviours
(EIBs) they need to use in order to be successful leaders. They also
need to have knowledge of their emotional intelligence and be able to
identify the factors and situations that evoke emotion at an
interpersonal level. If a principal is able to do this, then the control
and understanding of emotions and behaviours of oneself and others
could improve vastly. This study focuses on the interpersonal EIBS
of principals affecting the job satisfaction of teachers. The correlation
coefficients in this quantitative study strongly indicate that there is a
statistical significance between the respondents’ level of job
satisfaction, the rating of their principals’ EIBs and how they believe
their principals’ EIBs will affect their sense of job satisfaction. It can
be concluded from the data obtained in this study that there is a
significant correlation between the sense of job satisfaction of
teachers and their principals’ interpersonal EIBs. This means that the
more satisfied a teacher is at school, the more appropriate and
meaningful a principal’s EIBs will be. Conversely, the more
dissatisfied a teacher is at school the less appropriate and less
meaningful a principal’s interpersonal EIBs will be. This implies that
the leaders’ EIBs can be construed as one of the major factors
affecting the job satisfaction of employees.
Abstract: The knitted fabric suffers a deformation in its
dimensions due to stretching and tension factors, transverse and
longitudinal respectively, during the process in rectilinear knitting
machines so it performs a dry relaxation shrinkage procedure and
thermal action of prefixed to obtain stable conditions in the knitting.
This paper presents a dry relaxation shrinkage prediction of Bordeaux
fiber using a feed forward neural network and linear regression
models. Six operational alternatives of shrinkage were predicted. A
comparison of the results was performed finding neural network
models with higher levels of explanation of the variability and
prediction. The presence of different reposes is included. The models
were obtained through a neural toolbox of Matlab and Minitab
software with real data in a knitting company of Southern
Guanajuato. The results allow predicting dry relaxation shrinkage of
each alternative operation.
Abstract: Si-Ge solid solutions (bulk poly- and mono-crystalline
samples, thin films) are characterized by high perspectives for
application in semiconductor devices, in particular, optoelectronics
and microelectronics. From this point of view, complex studying of
structural state of the defects and structural-sensitive physical
properties of Si-Ge solid solutions depending on the contents of Si
and Ge components is very important. Present work deals with the
investigations of microstructure, microhardness, internal friction and
shear modulus of Si1-xGex(x≤0,02) bulk monocrystals conducted at
room temperature. Si-Ge bulk crystals were obtained by Czochralski
method in [111] crystallographic direction. Investigated
monocrystalline Si-Ge samples are characterized by p-type
conductivity and carriers’ concentration 5.1014-1.1015cm-3.
Microhardness was studied on Dynamic Ultra Micro hardness Tester
DUH-201S with Berkovich indenter. Investigate samples are characterized with 0,5x0,5x(10-15)mm3
sizes, oriented along [111] direction at torsion oscillations ≈1Hz,
multistage changing of internal friction and shear modulus has been
revealed in an interval of strain amplitude of 10-5-5.10-3. Critical
values of strain amplitude have been determined at which hysteretic
changes of inelastic characteristics and microplasticity are observed. The critical strain amplitude and elasticity limit values are also
determined. Dynamic mechanical characteristics decreasing trend is
shown with increasing Ge content in Si-Ge solid solutions. Observed
changes are discussed from the point of view of interaction of various
dislocations with point defects and their complexes in a real structure
of Si-Ge solid solutions.
Abstract: Research has shown that techno-entrepreneurship is
economically significant. Therefore, it is suggested that teaching
techno-entrepreneurship may be important because such programmes
would prepare current and future generations of learners to recognise
and act on high-technology opportunities. Education in technoentrepreneurship
may increase the knowledge of how to start one’s
own enterprise and recognise the technological opportunities for
commercialisation to improve decision-making about starting a new
venture; also it influence decisions about capturing the business
opportunities and turning them into successful ventures. Universities
can play a main role in connecting and networking technoentrepreneurship
students towards a cooperative attitude with real
business practice and industry knowledge. To investigate and answer
whether education for techno-entrepreneurs really helps, this paper
choses a comparison of literature reviews as its method of research.
After reviewing literature related to the impact of technoentrepreneurship
education on self-employment 6 studies which had
similar aim and objective to this paper were. These particular papers
were selected based on a keywords search and as their aim,
objectives, and gaps were close to the current research. In addition,
they were all based on the influence of techno-entrepreneurship
education in self-employment and intention of students to start new
ventures. The findings showed that teaching techno-entrepreneurship
education may have an influence on students’ intention and their
future self-employment, but which courses should be covered and the
duration of programmes, needs further investigation.