Abstract: Water spray cooling is a technique typically used in
heat treatment and other metallurgical processes where controlled
temperature regimes are required. Water spray cooling is used in
static (without movement) or dynamic (with movement of the steel
plate) regimes. The static regime is notable for the fixed position of
the hot steel plate and fixed spray nozzle. This regime is typical for
quenching systems focused on heat treatment of the steel plate. The
second application of spray cooling is the dynamic regime. The
dynamic regime is notable for its static section cooling system and
moving steel plate. This regime is used in rolling and finishing mills.
The fixed position of cooling sections with nozzles and the
movement of the steel plate produce nonhomogeneous water
distribution on the steel plate. The length of cooling sections and
placement of water nozzles in combination with the nonhomogeneity
of water distribution lead to discontinued or interrupted cooling
conditions. The impact of static and dynamic regimes on cooling
intensity and the heat transfer coefficient during the cooling process
of steel plates is an important issue.
Heat treatment of steel is accompanied by oxide scale growth. The
oxide scale layers can significantly modify the cooling properties and
intensity during the cooling. The combination of static and dynamic
(section) regimes with the variable thickness of the oxide scale layer
on the steel surface impact the final cooling intensity. The study of
the influence of the oxide scale layers with different cooling regimes
was carried out using experimental measurements and numerical
analysis. The experimental measurements compared both types of
cooling regimes and the cooling of scale-free surfaces and oxidized
surfaces. A numerical analysis was prepared to simulate the cooling
process with different conditions of the section and samples with
different oxide scale layers.
Abstract: Given the importance of ports as links in the global
supply chains and because they are key elements to induce
competitiveness in their hinterlands, the number of studies devoted to
port governance, management and operations has increased in the last
decades. Some of these studies address the port governance model as
an element to improve coordination among the actors of the portlogistics
chain and to generate a better port performance. In this
context, the present study analyzes the governance of Port of Santos
through individual interviews with port managers, based on a
conceptual model that considers the key dimensions associated with
port governance. The results reinforce the usefulness of the applied
model and highlight some existing improvement opportunities in the
port studied.
Abstract: Strong anion exchange resins with QN+OH-, have the
potential to be developed and employed as heterogeneous catalyst for
transesterification, as they are chemically stable to leaching of the
functional group. Nine different SIERs (SIER1-9) with QN+OH-were
prepared by suspension polymerization of vinylbenzyl chloridedivinylbenzene
(VBC-DVB) copolymers in the presence of n-heptane
(pore-forming agent). The amine group was successfully grafted into
the polymeric resin beads through functionalization with
trimethylamine. These SIERs are then used as a catalyst for the
transesterification of triacetin with methanol. A set of differential
equations that represents the Langmuir-Hinshelwood-Hougen-
Watson (LHHW) and Eley-Rideal (ER) models for the
transesterification reaction were developed. These kinetic models of
LHHW and ER were fitted to the experimental data. Overall, the
synthesized ion exchange resin-catalyzed reaction were welldescribed
by the Eley-Rideal model compared to LHHW models,
with sum of square error (SSE) of 0.742 and 0.996, respectively.
Abstract: In this paper, student admission process is studied to
optimize the assignment of vacant seats with three main objectives.
Utilizing all vacant seats, satisfying all programs of study admission
requirements and maintaining fairness among all candidates are the
three main objectives of the optimization model. Seat Assignment
Method (SAM) is used to build the model and solve the optimization
problem with help of Northwest Coroner Method and Least Cost
Method. A closed formula is derived for applying the priority of
assigning seat to candidate based on SAM.
Abstract: Operations research science (OR) deals with good
success in developing and applying scientific methods for problem
solving and decision-making. However, by using OR techniques, we
can enhance the use of computer decision support systems to achieve
optimal management for institutions. OR applies comprehensive
analysis including all factors that effect on it and builds mathematical
modeling to solve business or organizational problems. In addition, it
improves decision-making and uses available resources efficiently.
The adoption of OR by universities would definitely contributes to
the development and enhancement of the performance of OR
techniques. This paper provides an understanding of the structures,
approaches and models of OR in problem solving and decisionmaking.
Abstract: Factors affecting construction unit cost vary
depending on a country’s political, economic, social and
technological inclinations. Factors affecting construction costs have
been studied from various perspectives. Analysis of cost factors
requires an appreciation of a country’s practices. Identified cost
factors provide an indication of a country’s construction economic
strata. The purpose of this paper is to identify the essential factors
that affect unit cost estimation and their breakdown using artificial
neural networks. Twenty five (25) identified cost factors in road
construction were subjected to a questionnaire survey and employing
SPSS factor analysis the factors were reduced to eight. The 8 factors
were analysed using neural network (NN) to determine the
proportionate breakdown of the cost factors in a given construction
unit rate. NN predicted that political environment accounted 44% of
the unit rate followed by contractor capacity at 22% and financial
delays, project feasibility and overhead & profit each at 11%. Project
location, material availability and corruption perception index had
minimal impact on the unit cost from the training data provided.
Quantified cost factors can be incorporated in unit cost estimation
models (UCEM) to produce more accurate estimates. This can create
improvements in the cost estimation of infrastructure projects and
establish a benchmark standard to assist the process of alignment of
work practises and training of new staff, permitting the on-going
development of best practises in cost estimation to become more
effective.
Abstract: This paper presents a new structure of microstrip band
pass filter (BPF) based on coupled stepped impedance resonators.
Each filter consists of two coupled stepped impedance resonators
connected to microstrip feed lines. The coupled junction is utilized to
connect the two BPFs to the antenna. This two band pass filters are
designed and simulated to operate for the digital communication
system (DCS) and Industrial Scientific and Medical (ISM) bands at
1.8 GHz and 2.45 GHz respectively. The proposed circuit presents
good performances with an insertion loss lower than 2.3 dB and
isolation between the two channels greater than 21 dB. The prototype
of the optimized diplexer have been investigated numerically by
using ADS Agilent and verified with CST microwave software.
Abstract: In this study, attempt has been made to investigate the
relationship specifically the causal relation between fund unit prices
of Islamic equity unit trust fund which measure by fund NAV and the
selected macro-economic variables of Malaysian economy by using
VECM causality test and Granger causality test. Monthly data has
been used from Jan, 2006 to Dec, 2012 for all the variables. The
findings of the study showed that industrial production index,
political election and financial crisis are the only variables having
unidirectional causal relationship with fund unit price. However the
global oil price is having bidirectional causality with fund NAV.
Thus, it is concluded that the equity unit trust fund industry in
Malaysia is an inefficient market with respect to the industrial
production index, global oil prices, political election and financial
crisis. However the market is approaching towards informational
efficiency at least with respect to four macroeconomic variables,
treasury bill rate, money supply, foreign exchange rate, and
corruption index.
Abstract: The thermal conductivity of a fluid can be
significantly enhanced by dispersing nano-sized particles in it, and
the resultant fluid is termed as "nanofluid". A theoretical model for
estimating the thermal conductivity of a nanofluid has been proposed
here. It is based on the mechanism that evenly dispersed
nanoparticles within a nanofluid undergo Brownian motion in course
of which the nanoparticles repeatedly collide with the heat source.
During each collision a rapid heat transfer occurs owing to the solidsolid
contact. Molecular dynamics (MD) simulation of the collision
of nanoparticles with the heat source has shown that there is a pulselike
pick up of heat by the nanoparticles within 20-100 ps, the extent
of which depends not only on thermal conductivity of the
nanoparticles, but also on the elastic and other physical properties of
the nanoparticle. After the collision the nanoparticles undergo
Brownian motion in the base fluid and release the excess heat to the
surrounding base fluid within 2-10 ms. The Brownian motion and
associated temperature variation of the nanoparticles have been
modeled by stochastic analysis. Repeated occurrence of these events
by the suspended nanoparticles significantly contributes to the
characteristic thermal conductivity of the nanofluids, which has been
estimated by the present model for a ethylene glycol based nanofluid
containing Cu-nanoparticles of size ranging from 8 to 20 nm, with
Gaussian size distribution. The prediction of the present model has
shown a reasonable agreement with the experimental data available
in literature.
Abstract: Climate change confronts the built environment with
many new challenges in the form of more severe and frequent hydrometeorological
events. A series of strategies is proposed whereby the
various aspects of buildings and their sites can be made more resilient
to the effects of such events.
Abstract: Artificial Neural Network (ANN) can be trained using
back propagation (BP). It is the most widely used algorithm for
supervised learning with multi-layered feed-forward networks.
Efficient learning by the BP algorithm is required for many practical
applications. The BP algorithm calculates the weight changes of
artificial neural networks, and a common approach is to use a twoterm
algorithm consisting of a learning rate (LR) and a momentum
factor (MF). The major drawbacks of the two-term BP learning
algorithm are the problems of local minima and slow convergence
speeds, which limit the scope for real-time applications. Recently the
addition of an extra term, called a proportional factor (PF), to the
two-term BP algorithm was proposed. The third increases the speed
of the BP algorithm. However, the PF term also reduces the
convergence of the BP algorithm, and criteria for evaluating
convergence are required to facilitate the application of the three
terms BP algorithm. Although these two seem to be closely related,
as described later, we summarize various improvements to overcome
the drawbacks. Here we compare the different methods of
convergence of the new three-term BP algorithm.
Abstract: Developing young people’s employability is a key
policy issue for ensuring their successful transition to the labour
market and their access to career oriented employment. The youths of
today irrespective of their gender need to acquire the knowledge,
skills and attitudes that will enable them to create or find jobs as well
as cope with unpredictable labour market changes throughout their
working lives. In a study carried out to determine the influence of
gender on job-competencies requirements of chemical-based
industries and undergraduate-competencies acquisition by chemists
working in the industries, all chemistry graduates working in twenty
(20) chemical-based industries that were randomly selected from six
sectors of chemical-based industries in Lagos and Ogun States of
Nigeria were administered with Job-competencies required and
undergraduate-competencies acquired assessment questionnaire. The
data were analysed using means and independent sample t-test. The
findings revealed that the population of female chemists working in
chemical-based industries is low compared with the number of male
chemists; furthermore, job-competencies requirements are found not
to be gender biased while there is no significant difference in
undergraduate-competencies acquisition of male and female
chemists. This suggests that females should be given the same
opportunity of employment in chemical-based industries as their male
counterparts. The study also revealed the level of acquisition of
undergraduate competencies as related to the needs of chemicalbased
industries.
Abstract: In this study which has been conducted in Akçasu
Forest Range District of Devrek Forest Directorate; 3 methods (weed
control with labourer power, cover removal with Hitachi F20
Excavator, and weed control with agricultural equipment mounted on
a Ferguson 240S agriculture tractor) were utilized in weed control
efforts in regeneration of degraded oriental beech forests have been
compared. In this respect, 3 methods have been compared by
determining certain work hours and standard durations of unit areas
(1 hectare). For this purpose, evaluating the tasks made with human
and machine force from the aspects of duration, productivity and
costs, it has been aimed to determine the most productive method in
accordance with the actual ecological conditions of research field.
Within the scope of the study, the time studies have been conducted
for 3 methods used in weed control efforts. While carrying out those
studies, the performed implementations have been evaluated by
dividing them into business stages. Also, the actual data have been
used while calculating the cost accounts. In those calculations, the
latest formulas and equations which are also used in developed
countries have been utilized. The variance of analysis (ANOVA) was
used in order to determine whether there is any statistically
significant difference among obtained results, and the Duncan test
was used for grouping if there is significant difference. According to
the measurements and findings carried out within the scope of this
study, it has been found during living cover removal efforts in
regeneration efforts in demolished oriental beech forests that the
removal of weed layer in 1 hectare of field has taken 920 hours with
labourer force, 15.1 hours with excavator and 60 hours with an
equipment mounted on a tractor. On the other hand, it has been
determined that the cost of removal of living cover in unit area (1
hectare) was 3220.00 TL for labourer power, 1250 TL for excavator
and 1825 TL for equipment mounted on a tractor.
According to the obtained results, it has been found that the
utilization of excavator in weed control effort in regeneration of
degraded oriental beech regions under actual ecological conditions of
research field has been found to be more productive from both of
aspects of duration and costs. These determinations carried out
should be repeated in weed control efforts in degraded forest fields
with different ecological conditions, it is compulsory for finding the
most efficient weed control method. These findings will light the way
of technical staff of forestry directorate in determination of the most
effective and economic weed control method. Thus, the more actual
data will be used while preparing the weed control budgets, and there
will be significant contributions to national economy. Also the results of this and similar studies are very important for developing the policies for our forestry in short and long term.
Abstract: Over the last few decades, oilfield service rolling
equipment has significantly increased in weight, primarily because of
emissions regulations, which require larger/heavier engines, larger
cooling systems, and emissions after-treatment systems, in some
cases, etc. Larger engines cause more vibration and shock loads,
leading to failure of electronics and control systems.
If the vibrating frequency of the engine matches the system
frequency, high resonance is observed on structural parts and mounts.
One such existing automated control equipment system comprising
wire rope mounts used for mounting computers was designed
approximately 12 years ago. This includes the use of an industrialgrade
computer to control the system operation. The original
computer had a smaller, lighter enclosure. After a few years, a newer
computer version was introduced, which was 10 lbm heavier. Some
failures of internal computer parts have been documented for cases in
which the old mounts were used. Because of the added weight, there
is a possibility of having the two brackets impact each other under
off-road conditions, which causes a high shock input to the computer
parts. This added failure mode requires validating the existing mount
design to suit the new heavy-weight computer.
This paper discusses the modal finite element method (FEM)
analysis and experimental modal analysis conducted to study the
effects of vibration on the wire rope mounts and the computer. The
existing mount was modelled in ANSYS software, and resultant
mode shapes and frequencies were obtained. The experimental modal
analysis was conducted, and actual frequency responses were
observed and recorded.
Results clearly revealed that at resonance frequency, the brackets
were colliding and potentially causing damage to computer parts. To
solve this issue, spring mounts of different stiffness were modeled in
ANSYS software, and the resonant frequency was determined.
Increasing the stiffness of the system increased the resonant
frequency zone away from the frequency window at which the engine
showed heavy vibrations or resonance. After multiple iterations in
ANSYS software, the stiffness of the spring mount was finalized,
which was again experimentally validated.
Abstract: Many wireless sensor network applications require
K-coverage of the monitored area. In this paper, we propose a
scalable harmony search based algorithm in terms of execution
time, K-Coverage Enhancement Algorithm (KCEA), it attempts to
enhance initial coverage, and achieve the required K-coverage degree
for a specific application efficiently. Simulation results show that
the proposed algorithm achieves coverage improvement of 5.34%
compared to K-Coverage Rate Deployment (K-CRD), which achieves
1.31% when deploying one additional sensor. Moreover, the proposed
algorithm is more time efficient.
Abstract: With a long history, dual-task has become one of the
most intriguing research fields regarding human brain functioning
and cognition. However, findings considering effects of taskinterrelations
are limited (especially, in combined motor and
cognitive tasks). Therefore, we aimed at developing a measurement
system in order to analyse interrelation effects of cognitive and motor
tasks. On the one hand, the present study demonstrates the
applicability of the measurement system and on the other hand first
results regarding a systematisation of different task combinations are
shown. Future investigations should combine imagine technologies
and this developed measurement system.
Abstract: Cross flow water tube heat exchanger can be designed
and made operational using methods of model building and
simulation of the system. This paper projects the design and
development of a model of cross flow water tube heat-exchanger
system, simulation and validation of control analysis of different
tuning methods. Feedback and override control system is developed
using inputs acquired with the help of sensory system. A
mathematical model is formulated for analysis of system behaviour.
The temperature is regulated at the desired set point automatically.
Abstract: Systems Engineering plays a key role during industrial
product development of complex technical systems. The need for
systems engineers in industry is growing. But there is a gap between
the industrial need and the academic education. Normally the
academic education is focused on the domain specific design,
implementation and testing of technical systems. Necessary systems
engineering expertise like knowledge about requirements analysis,
product cost estimation, management or social skills are poorly
taught. Thus there is the need of new academic concepts for teaching
systems engineering skills. This paper presents a project-orientated
training concept to prepare students from different technical degree
programs for systems engineering activities. The training concept has
been initially implemented and applied in the industrial engineering
master program of the University of Applied Sciences Offenburg.
Abstract: Nowadays, Photovoltaic-PV Farms/ Parks and large
PV-Smart Grid Interface Schemes are emerging and commonly
utilized in Renewable Energy distributed generation. However, PVhybrid-
Dc-Ac Schemes using interface power electronic converters
usually has negative impact on power quality and stabilization of
modern electrical network under load excursions and network fault
conditions in smart grid. Consequently, robust FACTS based
interface schemes are required to ensure efficient energy utilization
and stabilization of bus voltages as well as limiting switching/fault
onrush current condition. FACTS devices are also used in smart grid-
Battery Interface and Storage Schemes with PV-Battery Storage
hybrid systems as an elegant alternative to renewable energy
utilization with backup battery storage for electric utility energy and
demand side management to provide needed energy and power
capacity under heavy load conditions. The paper presents a robust
interface PV-Li-Ion Battery Storage Interface Scheme for
Distribution/Utilization Low Voltage Interface using FACTS
stabilization enhancement and dynamic maximum PV power tracking
controllers.
Digital simulation and validation of the proposed scheme is done
using MATLAB/Simulink software environment for Low Voltage-
Distribution/Utilization system feeding a hybrid Linear-Motorized
inrush and nonlinear type loads from a DC-AC Interface VSC-6-
pulse Inverter Fed from the PV Park/Farm with a back-up Li-Ion
Storage Battery.
Abstract: TiO2 thin films have been prepared by the sol-gel dipcoating
technique in order to elaborate antireflective thin films for
monocrystalline silicon (mono-Si). The titanium isopropoxyde was
chosen as a precursor with hydrochloric acid as a catalyser for
preparing a stable solution. The optical properties have been tailored
with varying the solution concentration, the withdrawn speed, and the
heat-treatment. We showed that using a TiO2 single layer with 64.5
nm in thickness, heat-treated at 450°C or 300°C reduces the mono-Si
reflection at a level lower than 3% over the broadband spectral
domains [669-834] nm and [786-1006] nm respectively. Those latter
performances are similar to the ones obtained with double layers of
low and high refractive index glasses respectively.