Abstract: An aqueous methanol sensor for use in direct
methanol fuel cells (DMFCs) applications is demonstrated; the
methanol sensor is built using dispersed single-walled carbon
nanotubes (SWCNTs) with Nafion117 solution to detect the methanol
concentration in water. The study is aimed at the potential use of the
carbon nanotubes array as a methanol sensor for direct methanol fuel
cells (DMFCs). The concentration of methanol in the fuel circulation
loop of a DMFC system is an important operating parameter, because
it determines the electrical performance and efficiency of the fuel cell
system. The sensor is also operative even at ambient temperatures
and responds quickly to changes in the concentration levels of the
methanol. Such a sensor can be easily incorporated into the methanol
fuel solution flow loop in the DMFC system.
Abstract: Recently, several designs of single fed circularly
polarized microstrip antennas have been studied. Relatively, a few
designs for achieving circular polarization using triangular microstrip
antenna are available. Typically existing design of single fed
circularly polarized triangular microstrip antennas include the use of
equilateral triangular patch with a slit or a horizontal slot on the patch
or addition a narrow band stub on the edge or a vertex of triangular
patch.
In other word, with using a narrow band tune stub on middle of an
edge of triangle causes of facility to compensate the possible
fabrication error and substrate materials with easier adjusting the
tuner stub length. Even though disadvantages of this method is very
long of stub (approximate 1/3 length of triangle edge). In this paper,
instead of narrow band stub, a wide band stub has been applied,
therefore the length of stub by this method has been decreased
around 1/10 edge of triangle in addition changing the aperture angle
of stub, provides more facility for designing and producing circular
polarization wave.
Abstract: Simultaneous recovery of copper and DCA from
simulated MEUF concentrated stream was investigated. Effects of
surfactant (DCA) and metal (copper) concentrations, surfactant to
metal molar ratio (S/M ratio), electroplating voltage, EDTA
concentration, solution pH, and salt concentration on metal recovery
and current efficiency were studied. Electric voltage of -0.5 V was
shown to be optimum operation condition in terms of Cu recovery,
current efficiency, and surfactant recovery. Increasing Cu recovery and
current efficiency were observed with increases of Cu concentration
while keeping concentration of DCA constant. However, increasing
both Cu and DCA concentration while keeping S/M ratio constant at
2.5 showed detrimental effect on Cu recovery at DCA concentration
higher than 15 mM. Cu recovery decreases with increasing pH while
current efficiency showed an opposite trend. It is believed that
conductivity is the main cause for discrepancy of Cu recovery and
current efficiency observed at different pH. Finally, it was shown that
EDTA had adverse effect on both Cu recovery and current efficiency
while addition of NaCl salt had negative impact on current efficiency
at concentration higher than 8000 mg/L.
Abstract: A data warehouse (DW) is a system which has value and role for decision-making by querying. Queries to DW are critical regarding to their complexity and length. They often access millions of tuples, and involve joins between relations and aggregations. Materialized views are able to provide the better performance for DW queries. However, these views have maintenance cost, so materialization of all views is not possible. An important challenge of DW environment is materialized view selection because we have to realize the trade-off between performance and view maintenance cost. Therefore, in this paper, we introduce a new approach aimed at solve this challenge based on Two-Phase Optimization (2PO), which is a combination of Simulated Annealing (SA) and Iterative Improvement (II), with the use of Multiple View Processing Plan (MVPP). Our experiments show that our method provides a further improvement in term of query processing cost and view maintenance cost.
Abstract: Fisheries management all around the world is
hampered by the lack, or poor quality, of critical data on fish
resources and fishing operations. The main reasons for the chronic
inability to collect good quality data during fishing operations is the
culture of secrecy common among fishers and the lack of modern
data gathering technology onboard most fishing vessels. In response,
OLRAC-SPS, a South African company, developed fisheries datalogging
software (eLog in short) and named it Olrac. The Olrac eLog
solution is capable of collecting, analysing, plotting, mapping,
reporting, tracing and transmitting all data related to fishing
operations. Olrac can be used by skippers, fleet/company managers,
offshore mariculture farmers, scientists, observers, compliance
inspectors and fisheries management authorities. The authors believe
that using eLog onboard fishing vessels has the potential to
revolutionise the entire process of data collection and reporting
during fishing operations and, if properly deployed and utilised,
could transform the entire commercial fleet to a provider of good
quality data and forever change the way fish resources are managed.
In addition it will make it possible to trace catches back to the actual
individual fishing operation, to improve fishing efficiency and to
dramatically improve control of fishing operations and enforcement
of fishing regulations.
Abstract: Global Software Development (GSD) projects are
passing through different boundaries of a company, country and even
in other continents where time zone differs between both sites.
Beside many benefits of such development, research declared plenty
of negative impacts on these GSD projects. It is important to
understand problems which may lie during the execution of GSD
project with different time zones. This research project discussed and
provided different issues related to time delays in GSD projects. In
this paper, authors investigated some of the time delay factors which
usually lie in GSD projects with different time zones. This
investigation is done through systematic review of literature.
Furthermore, the practices to overcome these delay factors which
have already been reported in literature and GSD organizations are
also explored through literature survey and case studies.
Abstract: The main purpose of the dam is to control the surface
streams and rivers across the country. Dam construction and
formation of river and big water reservoirs and resources happen in
the glen is a big incident which would change its surrounding area
considerably. In fact, constructing a dam the glen width is close and
fishes don't migrate from upstream to downstream and ultimately it
would led to their death. To resolve this, it seems necessity to create a
passage for fishes during the construction of dam. It is provided
establishing a set of stepped pools overlooking each other as a fish
way or fish ladder a proper pathway for moving fishes. In this article
we first examine the surrounding environment and then Ghazal Ozon
River and preserving the aquatics.
Abstract: We have defined two suites of metrics, which cover
static and dynamic aspects of component assembly. The static
metrics measure complexity and criticality of component assembly,
wherein complexity is measured using Component Packing Density
and Component Interaction Density metrics. Further, four criticality
conditions namely, Link, Bridge, Inheritance and Size criticalities
have been identified and quantified. The complexity and criticality
metrics are combined to form a Triangular Metric, which can be used
to classify the type and nature of applications. Dynamic metrics are
collected during the runtime of a complete application. Dynamic
metrics are useful to identify super-component and to evaluate the
degree of utilisation of various components. In this paper both static
and dynamic metrics are evaluated using Weyuker-s set of properties.
The result shows that the metrics provide a valid means to measure
issues in component assembly. We relate our metrics suite with
McCall-s Quality Model and illustrate their impact on product
quality and to the management of component-based product
development.
Abstract: Faced with social and health system capacity
constraints and rising and changing demand for welfare services,
governments and welfare providers are increasingly relying on
innovation to help support and enhance services. However, the
evidence reported by several studies indicates that the realization of
that potential is not an easy task. Innovations can be deemed
inherently complex to implement and operate, because many of them
involve a combination of technological and organizational renewal
within an environment featuring a diversity of stakeholders. Many
public welfare service innovations are markedly systemic in their
nature, which means that they emerge from, and must address, the
complex interplay between political, administrative, technological,
institutional and legal issues. This paper suggests that stakeholders
dealing with systemic innovation in welfare services must deal with
ambiguous and incomplete information in circumstances of
uncertainty. Employing a literature review methodology and case
study, this paper identifies, categorizes and discusses different
aspects of the uncertainty of systemic innovation in public welfare
services, and argues that uncertainty can be classified into eight
categories: technological uncertainty, market uncertainty,
regulatory/institutional uncertainty, social/political uncertainty,
acceptance/legitimacy uncertainty, managerial uncertainty, timing
uncertainty and consequence uncertainty.
Abstract: Currently, the Malaysian construction industry is
focusing on transforming construction processes from conventional
building methods to the Industrialized Building System (IBS). Still,
research on the decision making of IBS technology adoption with the
influence of contextual factors is scarce. The purpose of this paper is
to explore how contextual factors influence the IBS decision making
in building projects which is perceived by those involved in
construction industry namely construction stakeholders and IBS
supply chain members. Theoretical background, theoretical
frameworks and literatures which identify possible contextual factors
that influence decision making towards IBS technology adoption are
presented. This paper also discusses the importance of contextual
factors in IBS decision making, highlighting some possible crossover
benefits and making some suggestions as to how these can be
utilized. Conclusions are drawn and recommendations are made with
respect to the perception of socio-economic, IBS policy and IBS
technology associated with building projects.
Abstract: Computer languages are usually lumped together
into broad -paradigms-, leaving us in want of a finer classification
of kinds of language. Theories distinguishing between -genuine
differences- in language has been called for, and we propose that
such differences can be observed through a notion of expressive mode.
We outline this concept, propose how it could be operationalized and
indicate a possible context for the development of a corresponding
theory. Finally we consider a possible application in connection
with evaluation of language revision. We illustrate this with a case,
investigating possible revisions of the relational algebra in order to
overcome weaknesses of the division operator in connection with
universal queries.
Abstract: Hydrogen is an important chemical in many industries
and it is expected to become one of the major fuels for energy
generation in the future. Unfortunately, hydrogen does not exist in its
elemental form in nature and therefore has to be produced from
hydrocarbons, hydrogen-containing compounds or water.
Above its critical point (374.8oC and 22.1MPa), water has lower
density and viscosity, and a higher heat capacity than those of
ambient water. Mass transfer in supercritical water (SCW) is
enhanced due to its increased diffusivity and transport ability. The
reduced dielectric constant makes supercritical water a better solvent
for organic compounds and gases. Hence, due to the aforementioned
desirable properties, there is a growing interest toward studies
regarding the gasification of organic matter containing biomass or
model biomass solutions in supercritical water.
In this study, hydrogen and biofuel production by the catalytic
gasification of 2-Propanol in supercritical conditions of water was
investigated. Pt/Al2O3and Ni/Al2O3were the catalysts used in the
gasification reactions. All of the experiments were performed under a
constant pressure of 25MPa. The effects of five reaction temperatures
(400, 450, 500, 550 and 600°C) and five reaction times (10, 15, 20,
25 and 30 s) on the gasification yield and flammable component
content were investigated.
Abstract: This paper solves the environmental/ economic dispatch
power system problem using the Non-dominated Sorting Genetic
Algorithm-II (NSGA-II) and its hybrid with a Convergence Accelerator
Operator (CAO), called the NSGA-II/CAO. These multiobjective
evolutionary algorithms were applied to the standard IEEE 30-bus
six-generator test system. Several optimization runs were carried out
on different cases of problem complexity. Different quality measure
which compare the performance of the two solution techniques were
considered. The results demonstrated that the inclusion of the CAO
in the original NSGA-II improves its convergence while preserving
the diversity properties of the solution set.
Abstract: A prototype for audio and video capture and compression in real time on a Linux platform has been developed. It is able to visualize both the captured and the compressed video at the same time, as well as the captured and compressed audio with the goal of comparing their quality. As it is based on free code, the final goal is to run it in an embedded system running Linux. Therefore, we would implement a node to capture and compress such multimedia information. Thus, it would be possible to consider the project within a larger one aimed at live broadcast of audio and video using a streaming server which would communicate with our node. Then, we would have a very powerful and flexible system with several practical applications.
Abstract: Irradiated material is a typical example of a complex
system with nonlinear coupling between its elements. During
irradiation the radiation damage is developed and this development
has bifurcations and qualitatively different kinds of behavior.
The accumulation of primary defects in irradiated crystals is
considered in frame work of nonlinear evolution of complex system.
The thermo-concentration nonlinear feedback is carried out as a
mechanism of self-oscillation development.
It is shown that there are two ways of the defect density evolution
under stationary irradiation. The first is the accumulation of defects;
defect density monotonically grows and tends to its stationary state
for some system parameters. Another way that takes place for
opportune parameters is the development of self-oscillations of the
defect density.
The stationary state, its stability and type are found. The
bifurcation values of parameters (environment temperature, defect
generation rate, etc.) are obtained. The frequency of the selfoscillation
and the conditions of their development is found and
rated. It is shown that defect density, heat fluxes and temperature
during self-oscillations can reach much higher values than the
expected steady-state values. It can lead to a change of typical
operation and an accident, e.g. for nuclear equipment.
Abstract: In this paper we have proposed a methodology to
develop an amperometric biosensor for the analysis of glucose
concentration using a simple microcontroller based data acquisition
system. The work involves the development of Detachable
Membrane Unit (enzyme based biomembrane) with immobilized
glucose oxidase on the membrane and interfacing the same to the
signal conditioning system. The current generated by the biosensor
for different glucose concentrations was signal conditioned, then
acquired and computed by a simple AT89C51-microcontroller. The
optimum operating parameters for the better performance were found
and reported. The detailed performance evaluation of the biosensor
has been carried out. The proposed microcontroller based biosensor
system has the sensitivity of 0.04V/g/dl, with a resolution of
50mg/dl. It has exhibited very good inter day stability observed up to
30 days. Comparing to the reference method such as HPLC, the
accuracy of the proposed biosensor system is well within ± 1.5%.
The system can be used for real time analysis of glucose
concentration in the field such as, food and fermentation and clinical
(In-Vitro) applications.
Abstract: In this paper we discuss the effect of unbounded particle interaction operator on particle growth and we study how this can address the choice of appropriate time steps of the numerical simulation. We provide also rigorous mathematical proofs showing that large particles become dominating with increasing time while small particles contribute negligibly. Second, we discuss the efficiency of the algorithm by performing numerical simulations tests and by comparing the simulated solutions with some known analytic solutions to the Smoluchowski equation.
Abstract: Partial discharge (PD) detection is an important
method to evaluate the insulation condition of metal-clad apparatus.
Non-intrusive sensors which are easy to install and have no
interruptions on operation are preferred in onsite PD detection.
However, it often lacks of accuracy due to the interferences in PD
signals. In this paper a novel PD extraction method that uses frequency
analysis and entropy based time-frequency (TF) analysis is introduced.
The repetitive pulses from convertor are first removed via frequency
analysis. Then, the relative entropy and relative peak-frequency of
each pulse (i.e. time-indexed vector TF spectrum) are calculated and
all pulses with similar parameters are grouped. According to the
characteristics of non-intrusive sensor and the frequency distribution
of PDs, the pulses of PD and interferences are separated. Finally the
PD signal and interferences are recovered via inverse TF transform.
The de-noised result of noisy PD data demonstrates that the
combination of frequency and time-frequency techniques can
discriminate PDs from interferences with various frequency
distributions.
Abstract: The emergence of blended learning has been
influenced by the rapid changes in Higher Education within the last
few years. However, there is a lack of studies that look into the future
of blended learning in the Saudi context. The most likely explanation
is that blended learning is relatively new and, with respect to learning
in general, under-researched. This study addresses this gap and
explores the views of lecturers and students towards the future of
blended learning in Saudi Arabia. This study was informed by the
interpretive paradigm that appears to be most appropriate to
understand and interpret the perceptions of students and instructors
towards a new learning environment. While globally there has been
considerable research on the perceptions of e-learning and blended
learning with its different models, there is plenty of space for further
research specifically in the Arab region, and in Saudi Arabia where
blended learning is now being introduced.
Abstract: When cars are released from the factory, strut noises are very small and therefore it is difficult to perceive them. As the use time and travel distance increase, however, strut noises get larger so as to cause users much uneasiness. The noises generated at the field include engine noises and flow noises and therefore it is difficult to clearly discern the noises generated from struts. This study developed a test method which can reproduce field strut noises in the lab. Using the newly developed noise evaluation test, this study analyzed the effects that insulator performance degradation and failure can have on car noises. The study also confirmed that the insulator durability test by the simple back-and-forth motion cannot completely reflect the state of the parts failure in the field. Based on this, the study also confirmed that field noises can be reproduced through a durability test that considers heat aging.