Abstract: During welding or flame cutting of metals, the
prediction of heat affected zone (HAZ) is critical. There is need to
develop a simple mathematical model to calculate the temperature
variation in HAZ and derivative analysis can be used for this purpose.
This study presents analytical solution for heat transfer through
conduction in mild steel plate. The homogeneous and nonhomogeneous
boundary conditions are single variables. The full field
analytical solutions of temperature measurement, subjected to local
heating source, are derived first by method of separation of variables
followed with the experimental visualization using infrared imaging.
Based on the present work, it is suggested that appropriate heat input
characteristics controls the temperature distribution in and around
HAZ.
Abstract: The study focused on the analysis of the Adjusted
Rorschach Comprehensive System’s responses. The objective of this
study is to analyse the participants’ response rate of the Adjusted
Rorschach Comprehensive System with regards to critical
psychology approach. The use of critical psychology theory in this
study was crucial because it responds to the current inadequate
western theory or practice in the field of psychology. The study
adopted a qualitative approach and a case study design. The study
was grounded on interpretivist paradigm. The sample size comprised
six learners (three boys and three girls, aged of 14 years) from
historically disadvantaged school in the Western Cape, South Africa.
The Adjusted Rorschach Comprehensive System (ARCS)
administration procedure, biographical information, semi-structured
interviews, and observation were used to collect data. Data was
analysed using thematic framework. The study found out that, factors
that increased the response rates during the administration of ARCS
were, language, seating arrangement, drawing, viewing, and
describing. The study recommended that, psychological test
designers take into consideration the philosophy or worldviews of the
local people for whom the test is designed to minimize low response
rates.
Abstract: This paper discusses the question whether a person
diagnosed with dyslexia will necessarily have difficulty in reading
musical notes. The author specifies the characteristics of alphabet
reading in comparison to musical notation reading, and concludes
that there should be no contra-indication for teaching standard music
reading to children with dyslexia if an appropriate process is offered.
This conclusion is based on a long term case study and relies on two
main characteristics of music reading: (1) musical notation system is
a systematic, logical, relative set of symbols written on a staff; and
(2) music reading learning connected with playing a musical
instrument is a multi-sensory activity that combines sight, hearing,
touch, and movement. The paper describes music reading teaching
procedures, using soprano recorders, and provides unique teaching
methods that have been found to be effective for students who were
diagnosed with dyslexia. It provides theoretical explanations in
addition to guidelines for music education practices.
Abstract: A sliding door system is used in commercial vehicles
and passenger cars to allow a larger unobstructed access to the
interior for loading and unloading. The movement of a sliding door
on vehicle body is ensured by mechanisms and tracks having special
cross-section which is manufactured by roll forming and stretch
bending process. There are three tracks and three mechanisms which
are called upper, central and lower on a sliding door system. There
are static requirements as strength on different directions, rigidity for
mechanisms, door drop off, door sag; dynamic requirements as high
energy slam opening-closing and durability requirement to validate
these products. In addition, there is a kinematic requirement to find
out force values from door handle during manual operating. In this
study, finite element analysis and physical test results which are
realized for sliding door systems will be shared comparatively.
Abstract: This paper will discuss how we optimize our physical
verification flow in our IC Design Department having various rule
decks from multiple foundries. Our ultimate goal is to achieve faster
time to tape-out and avoid schedule delay. Currently the physical
verification runtimes and memory usage have drastically increased
with the increasing number of design rules, design complexity, and
the size of the chips to be verified. To manage design violations, we
use a number of solutions to reduce the amount of violations needed
to be checked by physical verification engineers. The most important
functions in physical verifications are DRC (design rule check), LVS
(layout vs. schematic), and XRC (extraction). Since we have a
multiple number of foundries for our design tape-outs, we need a
flow that improve the overall turnaround time and ease of use of the
physical verification process. The demand for fast turnaround time is
even more critical since the physical design is the last stage before
sending the layout to the foundries.
Abstract: This study presents a hybrid metaheuristic algorithm
to obtain optimum designs for steel space buildings. The optimum
design problem of three-dimensional steel frames is mathematically
formulated according to provisions of LRFD-AISC (Load and
Resistance factor design of American Institute of Steel Construction).
Design constraints such as the strength requirements of structural
members, the displacement limitations, the inter-story drift and the
other structural constraints are derived from LRFD-AISC
specification. In this study, a hybrid algorithm by using teachinglearning
based optimization (TLBO) and harmony search (HS)
algorithms is employed to solve the stated optimum design problem.
These algorithms are two of the recent additions to metaheuristic
techniques of numerical optimization and have been an efficient tool
for solving discrete programming problems. Using these two
algorithms in collaboration creates a more powerful tool and
mitigates each other’s weaknesses. To demonstrate the powerful
performance of presented hybrid algorithm, the optimum design of a
large scale steel building is presented and the results are compared to
the previously obtained results available in the literature.
Abstract: Although there has been a growing interest in the
hybrid free-space optical link and radio frequency FSO/RF
communication system, the current literature is limited to results
obtained in moderate or cold environment. In this paper, using a soft
switching approach, we investigate the effect of weather
inhomogeneities on the strength of turbulence hence the channel
refractive index under Qatar harsh environment and their influence
on the hybrid FSO/RF availability. In this approach, either FSO/RF
or simultaneous or none of them can be active. Based on soft
switching approach and a finite state Markov Chain (FSMC) process,
we model the channel fading for the two links and derive a
mathematical expression for the outage probability of the hybrid
system. Then, we evaluate the behavior of the hybrid FSO/RF under
hazy and harsh weather. Results show that the FSO/RF soft switching
renders the system outage probability less than that of each link
individually. A soft switching algorithm is being implemented on
FPGAs using Raptor code interfaced to the two terminals of a
1Gbps/100 Mbps FSO/RF hybrid system, the first being implemented
in the region. Experimental results are compared to the above
simulation results.
Abstract: In many countries, governments have been promoting the involvement of private sector entities to enter into long-term agreements for the development and delivery of large infrastructure projects, with a focus on overcoming the limitations upon public fund of the traditional approach. The involvement of private sector through public private partnerships (PPP) brings in new capital investments, value for money and additional risks to handle. Worldwide research studies have shown that an objective, systematic, reliable and useroriented risk assessment process and an optimal allocation mechanism among different stakeholders is crucial to the successful completion. In this framework, this paper, which is the first stage of a research study, aims to identify the main risks for the delivery of PPP projects. A review of cross-countries research projects and case studies was performed to map the key risks affecting PPP infrastructure delivery. The matrix of mapping offers a summary of the frequency of factors, clustered in eleven categories: construction, design, economic, legal, market, natural, operation, political, project finance, project selection and relationship. Results will highlight the most critical risk factors, and will hopefully assist the project managers in directing the managerial attention in the further stages of risk allocation.
Abstract: Water resource systems modeling has constantly been
a challenge through history for human beings. As the innovative
methodological development is evolving alongside computer sciences
on one hand, researches are likely to confront more complex and
larger water resources systems due to new challenges regarding
increased water demands, climate change and human interventions,
socio-economic concerns, and environment protection and
sustainability. In this research, an automatic calibration scheme has
been applied on the Gilan’s large-scale water resource model using
mathematical programming. The water resource model’s calibration
is developed in order to attune unknown water return flows from
demand sites in the complex Sefidroud irrigation network and other
related areas. The calibration procedure is validated by comparing
several gauged river outflows from the system in the past with model
results. The calibration results are pleasantly reasonable presenting a
rational insight of the system. Subsequently, the unknown optimized
parameters were used in a basin-scale linear optimization model with
the ability to evaluate the system’s performance against a reduced
inflow scenario in future. Results showed an acceptable match
between predicted and observed outflows from the system at selected
hydrometric stations. Moreover, an efficient operating policy was
determined for Sefidroud dam leading to a minimum water shortage
in the reduced inflow scenario.
Abstract: Anammox is a novel and promising technology that has changed the traditional concept of biological nitrogen removal. The process facilitates direct oxidation of ammonical nitrogen under anaerobic conditions with nitrite as an electron acceptor without addition of external carbon sources. The present study investigated the feasibility of Anammox Hybrid Reactor (AHR) combining the dual advantages of suspended and attached growth media for biodegradation of ammonical nitrogen in wastewater. Experimental unit consisted of 4 nos. of 5L capacity AHR inoculated with mixed seed culture containing anoxic and activated sludge (1:1). The process was established by feeding the reactors with synthetic wastewater containing NH4-H and NO2-N in the ratio 1:1 at HRT (hydraulic retention time) of 1 day. The reactors were gradually acclimated to higher ammonium concentration till it attained pseudo steady state removal at a total nitrogen concentration of 1200 mg/l. During this period, the performance of the AHR was monitored at twelve different HRTs varying from 0.25-3.0 d with increasing NLR from 0.4 to 4.8 kg N/m3d. AHR demonstrated significantly higher nitrogen removal (95.1%) at optimal HRT of 1 day. Filter media in AHR contributed an additional 27.2% ammonium removal in addition to 72% reduction in the sludge washout rate. This may be attributed to the functional mechanism of filter media which acts as a mechanical sieve and reduces the sludge washout rate many folds. This enhances the biomass retention capacity of the reactor by 25%, which is the key parameter for successful operation of high rate bioreactors. The effluent nitrate concentration, which is one of the bottlenecks of anammox process was also minimised significantly (42.3-52.3 mg/L). Process kinetics was evaluated using first order and Grau-second order models. The first-order substrate removal rate constant was found as 13.0 d-1. Model validation revealed that Grau second order model was more precise and predicted effluent nitrogen concentration with least error (1.84±10%). A new mathematical model based on mass balance was developed to predict N2 gas in AHR. The mass balance model derived from total nitrogen dictated significantly higher correlation (R2=0.986) and predicted N2 gas with least error of precision (0.12±8.49%). SEM study of biomass indicated the presence of heterogeneous population of cocci and rod shaped bacteria of average diameter varying from 1.2-1.5 mm. Owing to enhanced NRE coupled with meagre production of effluent nitrate and its ability to retain high biomass, AHR proved to be the most competitive reactor configuration for dealing with nitrogen laden wastewater.
Abstract: Objective: Sharing devastating news with patients is
often considered the most difficult task of doctors. This study aimed
to explore patients’ perceptions of receiving bad news including
which features improve the experience and which areas need refining. Methods: A questionnaire was written based on the steps of the
SPIKES model for breaking bad new. 20 patients receiving treatment
for a hematological malignancy completed the questionnaire. Results: Overall, the results are promising as most patients praised
their consultation. ‘Poor’ was more commonly rated by women and
participants aged 45-64. The main differences between the ‘excellent’
and ‘poor’ consultations include the doctor’s sensitivity and checking
the patients’ understanding. Only 35% of patients were asked their
existing knowledge and 85% of consultations failed to discuss the
impact of the diagnosis on daily life. Conclusion: This study agreed with the consensus of existing
literature. The commended aspects include consultation set-up and
information given. Areas patients felt needed improvement include
doctors determining the patient’s existing knowledge and checking
new information has been understood. Doctors should also explore
how the diagnosis will affect the patient’s life. With a poorer
prognosis, doctors should work on conveying appropriate hope. The
study was limited by a small sample size and potential recall bias.
Abstract: Electrostatic interaction energy (ΔEEDL) is a part of the Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, which, together with van der Waals (ΔEVDW) and acid base (ΔEAB) interaction energies, has been extensively used to investigate the initial adhesion of bacteria to surfaces. Electrostatic or electrical double layer interaction energy is considerably affected by surface potential; however it cannot be determined experimentally and is usually replaced by zeta (ζ) potential via electrophoretic mobility. This paper focusses on the effect of ionic concentration as a function of pH and the effect of mineral grain size on ζ potential. It was found that both ionic strength and mineral grain size play a major role in determining the value of ζ potential for the adhesion of P. putida to hematite and quartz surfaces. Higher ζ potential values lead to higher electrostatic interaction energies and eventually to higher total XDLVO interaction energy resulting in bacterial repulsion.
Abstract: This study aimed to explore the practical experience
of child welfare caseworkers and professionalism in child case
management in Malaysia. This paper discussed the specific social
work practice competency and the challenges faced by child
caseworkers in the fieldwork. This research was qualitative with
grounded theory approach. Four sessions of focused group discussion
(FGD) were conducted involving a total of 27 caseworkers (child
protector and probation officers) in the Klang Valley. The study
found that the four basic principles of knowledge in child case
management namely: 1. knowledge in child case management; 2.
professional values of caseworkers towards children; 3. skills in
managing cases; and 4. culturally competent practice in child case
management. In addition, major challenges faced by the child case
manager are the capacity and commitment of the family in children’s
rehabilitation program, the credibility of caseworkers are being
challenged, and the challenges of support system from intra and interagency.
This study is important for policy makers to take into account
the capacity and the needs of the child’s caseworker in accordance
with the national social work competency framework. It is expected
that case management services for children will improve
systematically in line with national standards.
Abstract: In the present paper the design of plate heat exchangers
is formulated as an optimization problem considering two
mathematical modelling. The number of plates is the objective
function to be minimized, considering implicitly some parameters
configuration. Screening is the optimization method used to solve the
problem. Thermal and hydraulic constraints are verified, not viable
solutions are discarded and the method searches for the convergence to
the optimum, case it exists. A case study is presented to test the
applicability of the developed algorithm. Results show coherency with
the literature.
Abstract: The goal of the modern education system is to prepare
students to be able to adapt to ever-changing life situations. They
must be able to acquire required knowledge independently; apply
such knowledge in practice to solve various problems by using
modern technologies; think critically and creatively; competently use
information; be communicative, work in a team; and develop their
own moral values, intellect and cultural awareness. As a result, the
status of education significantly increases; new requirements to its
quality have been formed. In recent years the competency-based
approach in education has become of significant interest. This
approach is a strengthening of applied and practical characteristics of
a school education and leads to the forming of the key students’
competencies which define their success in future life. In this article,
the authors’ attention focuses on a range of key competencies,
educational, informational and communicative and on the possibility
to develop such competencies via STEM education. This research
shows the change in students’ attitude towards scientific disciplines
such as mathematics, general science, technology and engineering as
a result of STEM education. Two staged analyzed questionnaires
completed by students of forms II to IV in the republic of Trinidad
and Tobago allowed the authors to categorize students between two
levels that represent students’ attitude to various disciplines. The
significance of differences between selected levels was confirmed
with the use of Pearson’s chi-squared test. In summary, the analysis
of obtained data makes it possible to conclude that STEM education
has a great potential for development of core students’ competencies
and encourage the development of positive student attitude towards
the above mentioned above scientific disciplines.
Abstract: The paper presents an advanced control system for
tennis ball throwing machines to improve their accuracy according to
the ball impact points. A further advantage of the system is the much
easier calibration process involving the intelligent solution of the
automatic adjustment of the stroking parameters according to the ball
elasticity, the self-calibration, the use of the safety margin at very flat
strokes and the possibility to placing the machine to any position of
the half court. The system applies mathematical methods to
determine the exact ball trajectories and special approximating
processes to access all points on the aimed half court.
Abstract: The global demand for long-tailed macaques for
medical experimentation has continued to increase. Fulfillment of
Indonesian export demands has been mostly from natural habitats,
based on a harvesting quota. This quota has been determined
according to the total catch for a given year, and not based on
consideration of any demographic parameters or physical
environmental factors with regard to the animal; hence threatening
the sustainability of the various populations. It is therefore necessary
to formulate a method for calculating a sustainable harvesting quota,
based on population parameters in natural habitats. Considering the
possibility of variations in habitat characteristics and population
parameters, a time series observation of demographic and
physical/biotic parameters, in various habitats, was performed on 13
groups of long-tailed macaques, distributed throughout the West
Java, Lampung and Yogyakarta areas of Indonesia. These provinces
were selected for comparison of the influence of human/tourism
activities. Data on population parameters that was collected included
data on life expectancy according to age class, numbers of
individuals by sex and age class, and ‘ratio of infants to reproductive
females’. The estimation of population growth was based on a
population dynamic growth model: the Leslie matrix. The harvesting
quota was calculated as being the difference between the actual
population size and the MVP (minimum viable population) for each
sex and age class. Observation indicated that there were variations within group size
(24–106 individuals), gender (sex) ratio (1:1 to 1:1.3), life expectancy
value (0.30 to 0.93), and ‘ratio of infants to reproductive females’
(0.23 to 1.56). Results of subsequent calculations showed that
sustainable harvesting quotas for each studied group of long-tailed
macaques, ranged from 29 to 110 individuals. An estimation model
of the MVP for each age class was formulated as Log Y = 0.315 +
0.884 Log Ni (number of individual on ith age class). This study also
found that life expectancy for the juvenile age class was affected by
the humidity under tree stands, and dietary plants’ density at sapling,
pole and tree stages (equation: Y=2.296 – 1.535 RH + 0.002 Kpcg –
0.002 Ktg – 0.001 Kphn, R2 = 89.6% with a significance value of
0.001). By contrast, for the sub-adult-adult age class, life expectancy
was significantly affected by slope (equation: Y=0.377 = 0.012 Kml,
R2 = 50.4%, with significance level of 0.007). The infant-toreproductive-
female ratio was affected by humidity under tree stands,
and dietary plant density at sapling and pole stages (equation: Y = -
1.432 + 2.172 RH – 0.004 Kpcg + 0.003 Ktg, R2 = 82.0% with
significance level of 0.001). This research confirmed the importance
of population parameters in determining the minimum viable
population, and that MVP varied according to habitat characteristics
(especially food availability). It would be difficult therefore, to
formulate a general mathematical equation model for determining a
harvesting quota for the species as a whole.
Abstract: Sewer deposits have been identified as a major cause
of dysfunctions in combined sewer systems regarding sewer
management, which induces different negative consequents resulting
in poor hydraulic conveyance, environmental damages as well as
worker’s health. In order to overcome the problematics of
sedimentation, flushing has been considered as the most operative
and cost-effective way to minimize the sediments impacts and
prevent such challenges. Flushing, by prompting turbulent wave
effects, can modify the bed form depending on the hydraulic
properties and geometrical characteristics of the conduit. So far, the
dynamics of the bed-load during high-flow events in combined sewer
systems as a complex environment is not well understood, mostly due
to lack of measuring devices capable to work in the “hostile” in
combined sewer system correctly. In this regards, a one-episode
flushing issue from an opening gate valve with weir function was
carried out in a trunk sewer in Paris to understand its cleansing
efficiency on the sediments (thickness: 0-30 cm). During more than
1h of flushing within 5 m distance in downstream of this flushing
device, a maximum flowrate and a maximum level of water have
been recorded at 5 m in downstream of the gate as 4.1 m3/s and 2.1
m respectively. This paper is aimed to evaluate the efficiency of this
type of gate for around 1.1 km (from the point -50 m to +1050 m in
downstream from the gate) by (i) determining bed grain-size
distribution and sediments evolution through the sewer channel, as
well as their organic matter content, and (ii) identifying sections that
exhibit more changes in their texture after the flush. For the first one,
two series of sampling were taken from the sewer length and then
analyzed in laboratory, one before flushing and second after, at same
points among the sewer channel. Hence, a non-intrusive sampling
instrument has undertaken to extract the sediments smaller than the
fine gravels. The comparison between sediments texture after the
flush operation and the initial state, revealed the most modified zones
by the flush effect, regarding the sewer invert slope and hydraulic
parameters in the zone up to 400 m from the gate. At this distance,
despite the increase of sediment grain-size rages, D50 (median grainsize)
varies between 0.6 mm and 1.1 mm compared to 0.8 mm and 10
mm before and after flushing, respectively. Overall, regarding the
sewer channel invert slope, results indicate that grains smaller than
sands (< 2 mm) are more transported to downstream along about 400
m from the gate: in average 69% before against 38% after the flush
with more dispersion of grain-sizes distributions. Furthermore, high
effect of the channel bed irregularities on the bed material evolution
has been observed after the flush.
Abstract: In this article, we deal with a variant of the classical
course timetabling problem that has a practical application in many
areas of education. In particular, in this paper we are interested in
high schools remedial courses. The purpose of such courses is to
provide under-prepared students with the skills necessary to succeed
in their studies. In particular, a student might be under prepared in
an entire course, or only in a part of it. The limited availability
of funds, as well as the limited amount of time and teachers at
disposal, often requires schools to choose which courses and/or which
teaching units to activate. Thus, schools need to model the training
offer and the related timetabling, with the goal of ensuring the
highest possible teaching quality, by meeting the above-mentioned
financial, time and resources constraints. Moreover, there are some
prerequisites between the teaching units that must be satisfied. We
first present a Mixed-Integer Programming (MIP) model to solve
this problem to optimality. However, the presence of many peculiar
constraints contributes inevitably in increasing the complexity of
the mathematical model. Thus, solving it through a general-purpose
solver may be performed for small instances only, while solving
real-life-sized instances of such model requires specific techniques
or heuristic approaches. For this purpose, we also propose a heuristic
approach, in which we make use of a fast constructive procedure
to obtain a feasible solution. To assess our exact and heuristic
approaches we perform extensive computational results on both
real-life instances (obtained from a high school in Lecce, Italy) and
randomly generated instances. Our tests show that the MIP model is
never solved to optimality, with an average optimality gap of 57%.
On the other hand, the heuristic algorithm is much faster (in about the
50% of the considered instances it converges in approximately half of
the time limit) and in many cases allows achieving an improvement
on the objective function value obtained by the MIP model. Such an
improvement ranges between 18% and 66%.
Abstract: The purpose of this study is the discrimination of 28
postmenopausal with osteoporotic femoral fractures from an agematched
control group of 28 women using texture analysis based on
fractals. Two pre-processing approaches are applied on radiographic
images; these techniques are compared to highlight the choice of the
pre-processing method. Furthermore, the values of the fractal
dimension are compared to those of the fractal signature in terms of
the classification of the two populations. In a second analysis, the
BMD measure at proximal femur was compared to the fractal
analysis, the latter, which is a non-invasive technique, allowed a
better discrimination; the results confirm that the fractal analysis of
texture on calcaneus radiographs is able to discriminate osteoporotic
patients with femoral fracture from controls. This discrimination was
efficient compared to that obtained by BMD alone. It was also
present in comparing subgroups with overlapping values of BMD.