Abstract: This study investigates the suitability of using plastic,
such as polyethylene terephthalate (PET), as a partial replacement of
natural coarse and fine aggregates (for example, brick chips and
natural sand) to produce lightweight concrete for load bearing
structural members. The plastic coarse aggregate (PCA) and plastic
fine aggregate (PFA) were produced from melted polyethylene
terephthalate (PET) bottles. Tests were conducted using three
different water–cement (w/c) ratios, such as 0.42, 0.48, and 0.57,
where PCA and PFA were used as 50% replacement of coarse and
fine aggregate respectively. Fresh and hardened properties of
concrete have been compared for natural aggregate concrete (NAC),
PCA concrete (PCC) and PFA concrete (PFC). The compressive
strength of concrete at 28 days varied with the water–cement ratio for
both the PCC and PFC. Between PCC and PFC, PFA concrete
showed the highest compressive strength (23.7 MPa) at 0.42 w/c ratio
and also the lowest compressive strength (13.7 MPa) at 0.57 w/c
ratio. Significant reduction in concrete density was mostly observed
for PCC samples, ranging between 1977–1924 kg/m³. With the
increase in water–cement ratio PCC achieved higher workability
compare to both NAC and PFC. It was found that both the PCA and
PFA contained concrete achieved the required compressive strength
to be used for structural purpose as partial replacement of the natural
aggregate; but to obtain the desired lower density as lightweight
concrete the PCA is most suited.
Abstract: All the software engineering researches and best
industry practices aim at providing software products with high
degree of quality and functionality at low cost and less time. These
requirements are addressed by the Component Based Software
Engineering (CBSE) as well. CBSE, which deals with the software
construction by components’ assembly, is a revolutionary extension
of Software Engineering. CBSE must define and describe processes
to assure timely completion of high quality software systems that are
composed of a variety of pre built software components. Though
these features provide distinct and visible benefits in software design
and programming, they also raise some challenging problems. The
aim of this work is to summarize the pertinent issues and
considerations in CBSE to make an understanding in forms of
concepts and observations that may lead to development of newer
ways of dealing with the problems and challenges in CBSE.
Abstract: Alone with fast urbanization in world, traffic control
became a big issue in urban construction. Having an efficient and
reliable traffic control system is crucial to macro-traffic control.
Traffic signal is used to manage conflicting requirement by allocating
different sets of mutually compatible traffic movement during distinct
time interval. Many approaches have been made proposed to solve
this discrete stochastic problem. Recognizing the need to minimize
right-of-way impacts while efficiently handling the anticipated high
traffic volumes, the proposed alternative system gives effective
design. This model allows for increased traffic capacity and reduces
delays by eliminating a step in maneuvering through the freeway
interchange. The concept proposed in this paper involves
construction of bridges and ramps at intersection of four roads to
control the vehicular congestion and to prevent traffic breakdown.
Abstract: Microalgae Meyerella planktonica is a potential
biofuel source because it can grow in bulk in either autotrophic or
heterotrophic condition. However, the quantitative growth of this
algal type is still low as it tends to precipitates on the bottom.
Besides, the lipid concentration is still low when grown in
autotrophic condition. In contrast, heterotrophic condition can
enhance the lipid concentration. The combination of autotrophic
condition and agitation treatment was conducted to increase the
density of the culture. On the other hand, a heterotrophic condition
was set up to raise the lipid production. A two-stage experiment
was applied to increase the density at the first step and to increase
the lipid concentration in the next step. The autotrophic condition
resulted higher density but lower lipid concentration compared to
heterotrophic one. The agitation treatment produced higher density
in both autotrophic and heterotrophic conditions. The two-stage
experiment managed to enhance the density during the autotrophic
stage and the lipid concentration during the heterotrophic stage.
The highest yield was performed by using 0.4% v/v glycerol as a
carbon source (2.9±0.016 x 10^6 cells w/w) attained 7 days after the
heterotrophic stage began. The lipid concentration was stable
starting from day 7.
Abstract: In this article, the antibiogram and heavy metal
resistance profile of the bacteria isolated from total 34 studied
animals (Pelophylax ridibundus = 12; Mauremys rivulata = 14;
Natrix natrix = 8) captured around the Biga Stream, are described.
There was no database information on antibiogram and heavy metal
resistance profile of bacteria from these area’s amphibians and
reptiles.
A total of 200 bacteria were successfully isolated from cloaca and
oral samples of the aquatic amphibians and reptiles as well as from
the water sample. According to Jaccard’s similarity index, the degree
of similarity in the bacterial flora was quite high among the
amphibian and reptile species under examination, whereas it was
different from the bacterial diversity in the water sample. The most
frequent isolates were A. hydrophila (31.5%), B. pseudomallei
(8.5%), and C. freundii (7%). The total numbers of bacteria obtained
were as follows: 45 in P. ridibundus, 45 in N. natrix 30 in M.
rivulata, and 80 in the water sample. The result showed that
cefmetazole was the most effective antibiotic to control the bacteria
isolated in this study and that approximately 93.33% of the bacterial
isolates were sensitive to this antibiotic. The multiple antibiotic
resistances (MAR) index indicated that P. ridibundus (0.95) > N.
natrix (0.89) > M. rivulata (0.39). Furthermore, all the tested heavy
metals (Pb+2, Cu+2, Cr+3, and Mn+2) inhibit the growth of the bacterial
isolates at different rates. Therefore, it indicated that the water source
of the animals was contaminated with both antibiotic residues and
heavy metals.
Abstract: The material selection in the design of the sandwich
structures is very crucial aspect because of the positive or negative
influences of the base materials to the mechanical properties of the
entire panel. In the literature, it was presented that the selection of the
skin and core materials plays very important role on the behavior of
the sandwich. Beside this, the use of the correct adhesive can make
the whole structure to show better mechanical results and behavior.
In the present work, the static three-point bending tests were
performed on the sandwiches having an aluminum alloy foam core,
the skins made of three different types of fabrics and two different
commercial adhesives (flexible polyurethane and toughened epoxy
based) at different values of support span distances by aiming the
analyses of their flexural performance in terms of absorbed energy,
peak force values and collapse mechanisms. The main results of the
flexural loading are: force-displacement curves obtained after the
bending tests, peak force and absorbed energy values, collapse
mechanisms and adhesion quality. The experimental results presented
that the sandwiches with epoxy based toughened adhesive and the
skins made of S-Glass Woven fabrics indicated the best adhesion
quality and mechanical properties. The sandwiches with toughened
adhesive exhibited higher peak force and energy absorption values
compared to the sandwiches with flexible adhesive. The use of these
sandwich structures can lead to a weight reduction of the transport
vehicles, providing an adequate structural strength under operating
conditions.
Abstract: The main objective of this paper is to provide a new
methodology for road safety assessment in Oman through the
development of suitable accident prediction models. GLM technique
with Poisson or NBR using SAS package was carried out to develop
these models. The paper utilized the accidents data of 31 un-signalized
T-intersections during three years. Five goodness-of-fit
measures were used to assess the overall quality of the developed
models. Two types of models were developed separately; the flow-based
models including only traffic exposure functions, and the full
models containing both exposure functions and other significant
geometry and traffic variables.
The results show that, traffic exposure functions produced much
better fit to the accident data. The most effective geometric variables
were major-road mean speed, minor-road 85th percentile speed,
major-road lane width, distance to the nearest junction, and right-turn
curb radius.
The developed models can be used for intersection treatment or
upgrading and specify the appropriate design parameters of T-intersections.
Finally, the models presented in this thesis reflect the intersection
conditions in Oman and could represent the typical conditions in
several countries in the middle east area, especially gulf countries.
Abstract: Reliability allocation is quite important during early
design and development stages for a system to apportion its specified
reliability goal to subsystems. This paper improves the reliability
fuzzy allocation method, and gives concrete processes on determining
the factor and sub-factor sets, weight sets, judgment set, and
multi-stage fuzzy evaluation. To determine the weight of factor and
sub-factor sets, the modified trapezoidal numbers are proposed to
reduce errors caused by subjective factors. To decrease the fuzziness
in fuzzy division, an approximation method based on linear
programming is employed. To compute the explicit values of fuzzy
numbers, centroid method of defuzzification is considered. An
example is provided to illustrate the application of the proposed
reliability allocation method based on fuzzy arithmetic.
Abstract: This study examined how individuals in their
respective teams contributed to innovation performance besides
defining the term of innovation in their own respective views. This
study also identified factors that motivated University staff to
contribute to the innovation products. In addition, it examined
whether there is a significant relationship between professional
training level and the length of service among university staff
towards innovation and to what extent do the two variables
contributed towards innovative products. The significance of this
study is that it revealed the strengths and weaknesses of the
university staff when contributing to innovation performance.
Stratified-random sampling was employed to determine the samples
representing the population of lecturers in the study, involving 123
lecturers in one of the local universities in Malaysia. The method
employed to analyze the data is through categorizing into themes for
the open-ended questions besides using descriptive and inferential
statistics for the quantitative data. This study revealed that two types
of definition for the term “innovation” exist among the university
staff, namely, creation of new product or new approach to do things
as well as value-added creative way to upgrade or improve existing
process and service to be more efficient. This study found that the
most prominent factor that propels them towards innovation is to
improve the product in order to benefit users, followed by selfsatisfaction
and recognition. This implies that the staff in the
organization viewed the creation of innovative products as a process
of growth to fulfill the needs of others and also to realize their
personal potential. This study also found that there was only a
significant relationship between the professional training level and
the length of service of 4 - 6 years among the university staff. The
rest of the groups based on the length of service showed that there
was no significant relationship with the professional training level
towards innovation. Moreover, results of the study on directional
measures depicted that the relationship for the length of service of 4-
6 years with professional training level among the university staff is
quite weak. This implies that good organization management lies on
the shoulders of the key leaders who enlighten the path to be
followed by the staff.
Abstract: This paper presents a novel integrated hybrid
approach for fault diagnosis (FD) of nonlinear systems. Unlike most
FD techniques, the proposed solution simultaneously accomplishes
fault detection, isolation, and identification (FDII) within a unified
diagnostic module. At the core of this solution is a bank of adaptive
neural parameter estimators (NPE) associated with a set of singleparameter
fault models. The NPEs continuously estimate unknown
fault parameters (FP) that are indicators of faults in the system. Two
NPE structures including series-parallel and parallel are developed
with their exclusive set of desirable attributes. The parallel scheme is
extremely robust to measurement noise and possesses a simpler, yet
more solid, fault isolation logic. On the contrary, the series-parallel
scheme displays short FD delays and is robust to closed-loop system
transients due to changes in control commands. Finally, a fault
tolerant observer (FTO) is designed to extend the capability of the
NPEs to systems with partial-state measurement.
Abstract: Forward Osmosis (FO) polyamide thin-film composite
membranes have been prepared by interfacial polymerization using
commercial UF polyethersulfoneas membrane support. Different
interfacial polymerization times (10s, 30s and 60s) in the organic
solution containing trimesoyl chloride (TMC) at constant m-phenylenediamine
(MPD) concentration (2% w/v) were studied. The
synthesized polyamide membranes then tested for treatment of
natural organic matter (NOM) and compared to commercial Cellulose
TriAcetate (CTA) membrane. It was found that membrane prepared
with higher reaction time (30s and 60s) exhibited better membrane
performance (flux and humic acid removal) over commercial CTA
membrane.
Abstract: In this paper, the effects of fiber types and elevated
temperatures on compressive strength, modulus of rapture and the
bond characteristics of fiber reinforced concretes (FRC) are
presented. By using the three different types of fibers (steel fiber-SF,
polypropylene-PPF and polyvinyl alcohol-PVA), FRC specimens
were produced and exposed to elevated temperatures up to 800 ºC for
1.5 hours. In addition, a plain concrete (without fiber) was produced
and used as a control. Test results obtained showed that the steel fiber
reinforced concrete (SFRC) had the highest compressive strength,
modulus of rapture and bond stress values at room temperatures, the
residual bond, flexural and compressive strengths of both FRC and
plain concrete dropped sharply after exposure to high temperatures.
The results also indicated that the reduction of bond, flexural and
compressive strengths with increasing the exposed temperature was
relatively less for SFRC than for plain, and FRC with PPF and PVA.
Abstract: The aim of this paper is to present the optimization
methodology developed in the frame of a Coastal Transport
Information System. The system will be used for the effective design
of coastal transportation lines and incorporates subsystems that
implement models, tools and techniques that may support the design
of improved networks. The role of the optimization and decision
subsystem is to provide the user with better and optimal scenarios
that will best fulfill any constrains, goals or requirements posed. The
complexity of the problem and the large number of parameters and
objectives involved led to the adoption of an evolutionary method
(Genetic Algorithms). The problem model and the subsystem
structure are presented in detail, and, its support for simulation is also
discussed.
Abstract: High gain broadband plasmonic slot nano-antenna has
been considered. The theory of plasmonic slot nano-antenna (PSNA)
has been developed. The analytical model takes into account also the
electrical field inside the metal due to imperfectness of metal in
optical range, as well as numerical investigation based on finite
element method (FEM) has been realized. It should be mentioned that
Yagi-Uda configuration improves directivity in the plane of structure.
In contrast, in this paper the possibility of directivity improvement of
proposed PSNA in perpendicular plane of structure by using
reflection metallic surface placed under the slot in fixed distance has
been demonstrated. It is well known that a directivity improvement
brings to the antenna gain increasing. This method of diagram
improving is also well known from RF antenna design theory.
Moreover the improvement of directivity in the perpendicular plane
gives more flexibility in such application as improving the light and
atom, ion, molecule interactions by using such type of plasmonic slot
antenna. By the analogy of dipole type optical antennas the widening
of working wavelengths has been realized by using bowtie geometry
of slots, which made the antenna broadband.
Abstract: Verification of vented wooden façade system with
bonded joints is presented in this paper. The potential of bonded
joints is studied and described in more detail. The paper presents the results of an experimental and theoretical research about the effects of freeze cycling on the bonded joint. For the purpose of tests spruce
timber profiles were chosen for the load bearing substructure. Planks from wooden plastic composite and Siberian larch are representing facade cladding. Two types of industrial polyurethane adhesives intended for structural bonding were selected. The article is focused on the preparation as well as on the subsequent curing and conditioning of test samples. All test samples were subjected to 15 cycles that represents sudden temperature changes, i.e. immersion in a water bath at (293.15 ± 3) K for 6 hours and subsequent freezing to (253.15 ± 2) K for 18 hours. Furthermore, the retention of bond strength between substructure and cladding wastested and strength in shear was determined under tensile stress.Research data indicate that little, if any, damage to the bond results from freezingcycles. Additionally, the suitability of selected group of adhesives in combination with timber substructure was confirmed.
Abstract: Taking into account the significance of measuring the
daily use of the study space in the libraries in order to develop and
reorganize the space for enhancing the efficiency of the study space,
the current study aimed to apply GIS in analyzing the study halls of
the Central Library and Document Center of Tehran University in
order to determine how study desks and chairs were used by the
students. The study used a combination of survey-descriptive and
system design method. In order to gather the required data, surveydescriptive
method was used. For implementing and entering data
into ArcGIS and analyzing the data and displaying the results on the
maps of the study halls of the library, system design method was
utilized. The design of the spatial database of the use of the study
halls was measured through the extent of occupancy of the space by
the library users and the maps of the study halls of the central library
of Tehran University as the case study. The results showed that
Abooreyhan hall had the highest rate of occupancy of the desks and
chairs compared to the other halls. The Hall of Science and
Technology, with an average occupancy rate of 0.39 for the tables
represented the lowest number of users and Rashid al-Dins hall, and
Science and Technology hall with an average occupancy rate (0.40)
had the lowest number of users for seats. In this study, the
comparison of the space occupied at different periods in the morning,
evenings, afternoons, and several months was performed through
GIS. This system analyzed the space relationships effectively and
efficiently. The output of this study would be used by administrators
and librarians to determine the exact extent of use of the equipment
of the study halls and librarians can use the output map to design the
space more efficiently at the library.
Abstract: Experimental production methods of Chevreul’s salt
being an intermediate stage product in copper recovery were
investigated on this article. Chevreul’s salt, Cu2SO3.CuSO3.2H2O,
being a mixed valence copper sulphite compound, has been obtained
by using different methods and reagents. Chevreul’s salt has an
intense brick-red color. It is highly stable and expensive. The
production of Chevreul’s salt plays a key role in hydrometallurgy.
Thermodynamic tendency on precipitation of Chevreul’s salt is
related to pH and temperature. Besides, SO2 gaseous is a versatile
reagent for precipitating of copper sulphites, Using of SO2 for
selective precipitation can be made by appropriate adjustments of pH
and temperature. Chevreul’s salt does not form in acidic solutions if
those solutions contains considerable amount of sulfurous acid. It is
necessary to maintain between pH 2–4.5, because, solubility of
Chevreul’s salt increases with decreasing of pH values. Also, the
region which Chevreul’s salt is stable can be seen from the potentialpH
diagram.
Abstract: The paper presents an innovative networked radar
system for detection of obstacles in a railway level crossing scenario.
This Monitoring System (MS) is able to detect moving or still
obstacles within the railway level crossing area automatically,
avoiding the need of human presence for surveillance. The MS is also
connected to the National Railway Information and Signaling System
to communicate in real-time the level crossing status. The
architecture is compliant with the highest Safety Integrity Level
(SIL4) of the CENELEC standard. The number of radar sensors used
is configurable at set-up time and depends on how large the level
crossing area can be. At least two sensors are expected and up four
can be used for larger areas. The whole processing chain that
elaborates the output sensor signals, as well as the communication
interface, is fully-digital, was designed in VHDL code and
implemented onto a Xilinx Virtex 6.
Abstract: The mechanisms underlying the association between
obesity and asthma may be related to a decreased immunological
tolerance induced by a defective function of regulatory T cells
(Tregs). The aim of this study is to establish the potential link
between these diseases and CD4+, CD25+ FoxP3+ Tregs as well as T
helper cells (Ths) in children. This is a prospective case control
study. Obese (n:40), asthmatic (n:40), asthmatic obese (n:40) and
healthy children (n:40), who don't have any acute or chronic diseases,
were included in this study. Obese children were evaluated according
to WHO criteria. Asthmatic patients were chosen based on GINA
criteria. Parents were asked to fill up the questionnaire. Informed
consent forms were taken. Blood samples were marked with CD4+,
CD25+ and FoxP3+ in order to determine Tregs and Ths by flow
cytometric method. Statistical analyses were performed. p≤0.05 was
chosen as meaningful threshold. Tregs exhibiting anti-inflammatory
nature were significantly lower in obese (0,16%; p≤0,001), asthmatic
(0,25%; p≤0,01) and asthmatic obese (0,29%; p≤0,05) groups than
the control group (0,38%). Ths were counted higher in asthma group
than the control (p≤0,01) and obese (p≤0,001) groups. T cell
immunity plays important roles in obesity and asthma pathogeneses.
Decreased numbers of Tregs found in obese, asthmatic and asthmatic
obese children may help to elucidate some questions in
pathophysiology of these diseases. For HOMA-IR levels, any
significant difference was not noted between control and obese
groups, but statistically higher values were found for obese
asthmatics. The values obtained in all groups were found to be below
the critical cut off points. This finding has made the statistically
significant difference observed between Tregs of obese, asthmatic,
obese asthmatic and control groups much more valuable. These
findings will be useful in diagnosis and treatment of these disorders
and future studies are needed. The production and propagation of
Tregs may be promising in alternative asthma and obesity treatments.
Abstract: Increasing prevalence of childhood obesity has
increased the interest in early and late indicators of gaining weight.
Cell blood counts may be indicators of pro-inflammatory states. The
aim was to evaluate associations of hematological parameters,
including hematocrit (HTC), hemoglobin, blood cell counts and their
indices with the degree of obesity in pediatric population. A total of
249; -139 morbidly obese (MO), 82 healthy normal weight (NW) and
28 overweight (OW) children were included into the scope of the
study. WHO BMI-for age percentiles were used to form age- and sexmatched
groups. Informed consent forms and the Ethics Committee
approval were obtained. Anthropometric measurements were
performed. Hematological parameters were determined. Statistical
analyses were performed using SPSS. The degree for statistical
significance was p≤0.05. Significant differences (p=0.000) between
waist-to-hip ratios and head-to- neck ratios (hnrs) of MO and NW
children were detected. A significant difference between hnrs of OW
and MO children (p=0.000) was observed. Red cell distribution width
(RDW) was higher in OW children than NW group (p=0.030). Such
finding couldn’t be detected between MO and NW groups. Increased
RDW was prominent in OW children. The decrease in mean
corpuscular hemoglobin concentration (MCHC) values in MO
children was sharper than the values in OW children (p=0.006 vs
p=0.042) compared to those in NW group. Statistically higher HTC
levels were observed between MO-NW (p=0.014), but none between
OW-NW. Though the cause-effect relationship between obesity and
erythrocyte indices still needs further investigation, alterations in
RDW, HTC, MCHC during obesity may be of significance in the
early life.