Abstract: Composites depending on the nature of their
constituents and mode of production are regarded as one of the
advanced materials that drive today’s technology. This paper
attempts a short review of the subject matter with a general aim of
pushing to the next level the frontier of knowledge as it impacts the
technology of nano-particles manufacturing. The objectives entail an
effort to; aggregate recent research efforts in this field, analyse
research findings and observations, streamline research efforts and
support industry in taking decision on areas of fund deployment. It is
envisaged that this work will serve as a quick hand-on compendium
material for researchers in this field and a guide to relevant
government departments wishing to fund a research whose outcomes
have the potential of improving the nation’s GDP.
Abstract: Objective of this study is to explore the recent trends,
patterns and the structural changes in the labour migration from Sri
Lanka to Middle East countries and to discuss the possible impacts of
those changes on the remittance flow. Study uses secondary data
published by Sri Lanka Bureau of Foreign Employment and Central
Bank. Thematic analysis of the secondary data revealed that the
migration for labour has increased rapidly during past decades.
Parallel with that the gender and the skill composition of the
migration flow has been changing. Similarly, the destinations for
male migration have changed over the period. These show positive
implications on the international remittance receipts to the country.
Abstract: Magnetic powder of Sr-ferrite was prepared by
conventional and sol-gel auto-combustion methods. In conventional
method, strontium carbonate and ferric oxide powders were mixed
together and then mixture was calcined. In sol-gel auto-combustion
method, a solution containing strontium nitrate, ferric nitrate and
citric acid was heated until the combustion took place automatically;
then, as-burnt powder was calcined. Thermal behavior, phase
identification, morphology and magnetic properties of powders
obtained by these two methods were compared by DTA, XRD, SEM
and VSM techniques. According to the results of DTA analysis,
formation temperature of Sr-ferrite obtained by conventional and solgel
auto-combustion methods were 1300°C and 1000°C, respectively.
XRD results confirmed the formation of pure Sr-ferrite at the
mentioned temperatures. Plate and hexagonal-shape particles of Srferrite
were observed using SEM. The Sr-ferrite powder obtained by
sol-gel auto-combustion method had saturation magnetization of
66.03 emu/g and coercivity of 5731 Oe in comparison with values of
58.20 emu/g and 4378 Oe obtained by conventional method.
Abstract: A series of polystyrene (PS) nanoparticles were
prepared by grafting polystyrene from both aggregated silica and
colloidally dispersed silica nanoparticles using atom-transfer radical
polymerisation (ATRP). Cross-linking and macroscopic gelation
were minimised by using a miniemulsion system. The thermal and
mechanical behaviour of the nanocomposites have been examined by
differential scanning calorimetry (DSC) and dynamic mechanical
thermal analysis (DMTA).
Abstract: This paper focuses on the contemporary phenomenon
of Anti-Gypsyism which diffused widely throughout social
representations of the so called “Gypsies”. In Europe and especially
in Italy, the media tends to reproduce racist stereotypes and
prejudices through a xenophobic depiction of this ethnic group, often
offering an ethnocentric point of view. From an anthropological
perspective, Roma people are a minority group facing diasporic
phenomena across Europe, produced by the host societies.
Abstract: In an urban area the location allocation of emergency
services mobile units, such as ambulances, police patrol cars must be
designed so as to achieve a prompt response to demand locations.
In this paper the partition of a given urban network into distinct
sub-networks is performed such that the vertices in each component
are close and simultaneously the sums of the corresponding
population in the sub-networks are almost uniform. The objective
here is to position appropriately in each sub-network a mobile
emergency unit in order to reduce the response time to the demands.
A mathematical model in framework of graph theory is developed.
In order to clarify the corresponding method a relevant numerical
example is presented on a small network.
Abstract: Assertion-Based software testing has been shown to
be a promising tool for generating test cases that reveal program
faults. Because the number of assertions may be very large for
industry-size programs, one of the main concerns to the applicability
of assertion-based testing is the amount of search time required to
explore a large number of assertions. This paper presents a new
approach for assertions exploration during the process of Assertion-
Based software testing. Our initial exterminations with the proposed
approach show that the performance of Assertion-Based testing may
be improved, therefore, making this approach more efficient when
applied on programs with large number of assertions.
Abstract: Series of laboratory tests were carried out to study the
extent of scour caused by a three-dimensional wall jets exiting from a
square cross-section nozzle and into a non-cohesive sand beds.
Previous observations have indicated that the effect of the tail water
depth was significant for densimetric Froude number greater than ten.
However, the present results indicate that the cut off value could be
lower depending on the value of grain size-to-nozzle width ratio.
Numbers of equations are drawn out for a better scaling of numerous
scour parameters. Also suggested the empirical prediction of scour to
predict the scour centre line profile and plan view of scour profile at
any particular time.
Abstract: Reduction of CO2 emissions has become a priority for
several countries due to increasing concerns about global warming
and climate change, especially in the developed countries. Residential
sector is considered one of the most important sectors for
considerable reduction of CO2 emissions since it represents a
significant amount of the total consumed energy in those countries. A
significant CO2 reduction cannot be achieved unless some initiatives
have been adopted in the policy of these countries. Introducing micro
combined heat and power (!CHP) systems into residential energy
systems is one of these initiatives, since such a technology offers
several advantages. Moreover, !CHP technology has the opportunity
to be operated not only by natural gas but it could also be operated by
renewable fuels. However, this technology can be operated by
different operation strategies. Each strategy has some advantages and
disadvantages.
This paper provides a review of different operation strategies of
such a technology used for residential energy systems, especially for
single dwellings. The review summarizes key points that outline the
trend of previous research carried out in this field.
Abstract: Weed suppression and weeding are necessary measures
for rice cultivation. Weed suppression precedes the process of
weeding. It means suppressing the growth of young weeds and
creating a weed-less environment. If we suppress the growth of weeds,
we can reduce the number of weeds in a paddy field. This would result
in a reduction of the weeding work load.
In this paper, we will show how we developed a weed suppression
robot for the purpose of reducing the weeding work load. The robot
has a laser range finder for autonomous mobility and a robot arm for
weed suppression. It travels along the rice rows without stepping on
and injuring the rice plants in a paddy field. The robot arm applies
force to the weed seedlings and thereby suppresses the growth of
weeds. This paper will explain the methodology of the autonomous
mobile, the experiment in weed suppression, and the method of
controlling the robot’s posture on uneven ground.
Abstract: Calcium phosphate cement (CPC) is one of the most
attractive bioceramics due to its moldable and shape ability to fill
complicated bony cavities or small dental defect positions. In this
study, CPC was produced by using mixture of tetracalcium phosphate
(TTCP, Ca4O(PO4)2) and dicalcium phosphate anhydrous (DCPA,
CaHPO4) in equimolar ratio (1/1) with aqueous solutions of acetic
acid (C2H4O2) and disodium hydrogen phosphate dehydrate
(Na2HPO4.2H2O) in combination with sodium alginate in order to
improve theirs moldable characteristic. The concentration of the
aqueous solutions and sodium alginate were varied to investigate the
effect of different aqueous solutions and alginate on properties of the
cements. The cement paste was prepared by mixing cement powder
(P) with aqueous solution (L) in a P/L ratio of 1.0g/0.35ml. X-ray
diffraction (XRD) was used to analyses phase formation of the
cements. Setting time and compressive strength of the set CPCs were
measured using the Gilmore apparatus and Universal testing
machine, respectively.
The results showed that CPCs could be produced by using both
basic (Na2HPO4.2H2O) and acidic (C2H4O2) solutions. XRD results
show the precipitation of hydroxyapatite in all cement samples. No
change in phase formation among cements using difference
concentrations of Na2HPO4.2H2O solutions. With increasing
concentration of acidic solutions, samples obtained less
hydroxyapatite with a high dicalcium phosphate dehydrate leaded to
a shorter setting time. Samples with sodium alginate exhibited higher
crystallization of hydroxyapatite than that of without alginate as a
result of shorten setting time in a basic solution but a longer setting
time in an acidic solution. The stronger cement was attained from
samples using the acidic solution with sodium alginate; however the
strength was lower than that of using the basic solution.
Abstract: The main objective of the study is focused in
producing slag based geopolymer concrete obtained with the addition
of alkali activator. Test results indicated that the reaction of silicates
in slag is based on the reaction potential of sodium hydroxide and the
formation of alumino-silicates. The study also comprises on the
evaluation of the efficiency of polymer reaction in terms of the
strength gain properties for different geopolymer mixtures.
Geopolymer mixture proportions were designed for different binder
to total aggregate ratio (0.3 & 0.45) and fine to coarse aggregate ratio
(0.4 & 0.8). Geopolymer concrete specimens casted with normal
curing conditions reported a maximum 28 days compressive strength
of 54.75 MPa. The addition of glued steel fibres at 1.0% Vf in
geopolymer concrete showed reasonable improvements on the
compressive strength, split tensile strength and flexural properties of
different geopolymer mixtures. Further, comparative assessment was
made for different geopolymer mixtures and the reinforcing effects of
steel fibres were investigated in different concrete matrix.
Abstract: Heightened concerns over the amount of carbon
emitted from coal-related processes are generating shifts to the
application of biomass. In co-gasification, where coal is gasified
along with biomass, the biomass may be fed together with coal (cofeeding)
or an independent biomass gasifier needs to be integrated
with the coal gasifier. The main aim of this work is to evaluate the
biomass introduction methods in coal co-gasification. This includes
the evaluation of biomass concentration input (B0 to B100) and its
gasification performance. A process model is developed and
simulated in Aspen HYSYS, where both coal and biomass are
modelled according to its ultimate analysis. It was found that the
syngas produced increased with increasing biomass content for both
co-feeding and independent schemes. However, the heating values
and heat duties decreases with biomass concentration as more CO2
are produced from complete combustion.
Abstract: Medical imaging produces human body pictures in
digital form. Since these imaging techniques produce prohibitive
amounts of data, compression is necessary for storage and
communication purposes. Many current compression schemes
provide a very high compression rate but with considerable loss of
quality. On the other hand, in some areas in medicine, it may be
sufficient to maintain high image quality only in region of interest
(ROI). This paper discusses a contribution to the lossless
compression in the region of interest of Scintigraphic images based
on SPIHT algorithm and global transform thresholding using
Huffman coding.
Abstract: Since the marine environmental conditions are
extremely different from the other ones, marine actinomycetes might
produce novel bioactive compounds. Therefore, actinomycete strains
were screened from marine water and sediment samples collected
from the coastal areas of Northern Vietnam. Ninety-nine
actinomycete strains were obtained on starch-casein agar media by
dilution technique, only seven strains, named HP112, HP12, HP411,
HPN11, HP 11, HPT13 and HPX12, showed significant antibacterial
activity against both gram-positive and gram-negative bacteria
(Bacillus subtilis ATCC 6633, Staphylococcus epidemidis ATCC
12228, Escherichia coli ATCC 11105). Further studies were carried
out with the most active HP411 strain against Candida albicans
ATCC 10231. This strain could grow rapidly on starch casein agar
and other media with high salt containing 7-10% NaCl at 28-30oC.
Spore-chain of HP411 showed an elongated and circular shape with
10 to 30 spores/chain. Identification of the strain was carried out by
employing the taxonomical studies including the 16S rRNA
sequence. Based on phylogenetic and phenotypic evidence it is
proposed that HP411 to be belongs to species Streptomyces
variabilis. The potent of the crude extract of fermentation broth of
HP411 that are effective against wide range of pathogens: both grampositive,
gram-negative and fungi. Further studies revealed that the
crude extract HP411 could obtain the anticancer activity for cancer
cell lines: Hep-G2 (liver cancer cell line); RD (cardiac and skeletal
muscle letters cell line); FL (membrane of the uterus cancer cell line).
However, the actinomycetes from marine ecosystem will be useful
for the discovery of new drugs in the future.
Abstract: Inland Waterway Transportation (IWT) is playing an
important role in national transport systems, water transportation is
considered to be safe, energy efficient and environmentally friendly
mode of transport, all benefits of IWT cause national awareness
increase, for instance the Colombian government is planning to
restore the navigability of the most important river of the country, the
Magdalena’s River navigability, embrace waterway transportation in
Colombia could strength competitiveness while reduce most of the
transport externalities. However, the current situation of the
Magdalena is deplorable, the most important river of Colombia has
been abandoned for decades and the solution is beyond of a single
administrative entity. This paper analyzes the outcomes of the
Navigation And Inland Waterway Action and Development in
Europe program (NAIADES) as a prospective to develop a similar
program in Colombia with similar objectives and guidelines,
considering sustainability, guarantying the long-term future results
and adaptability of the program. Identifying stakeholders and policy
experts, a set of individual interviews were carried out; findings
support the idea of lack of integration within governmental
institutions and lack of importance in marketing promotion as
possible drawbacks on the implementation of IWT projects.
Abstract: Climate warming would increase rainfall by shifting
precipitation falling form from snow to rain, and would accelerate
snow cover disappearing by increasing snowpack. Using temperature
and precipitation data in the temperature-index snowmelt model, we
evaluated variability of snowfall and continuous snow cover duration
(CSCD) during 1944-2010 over Pelso, central Finland. Mann-
Kendall non-parametric test determined that annual precipitation
increased by 2.69 (mm/year, p
Abstract: Climate change would cause mean sea level to rise +1
m by 2100. To prevent coastal floods resulting from the sea level
rising, different flood control structures have been built, with
acceptable protection levels. Gothenburg with the River Göta älv
located on the southwest coast of Sweden is a vulnerable city to the
accelerated rises in mean sea level. We evaluated using a sea barrage
in the River Göta älv to protect Gothenburg during this century. The
highest sea level was estimated to 2.95 m above the current mean sea
level by 2100. To verify flood protection against such high sea levels,
both barriers have to be closed. To prevent high water level in the
River Göta älv reservoir, the barriers would be open when the sea
level is low. The suggested flood control structures would
successfully protect the city from flooding events during this century.
Abstract: Time and cost are the main goals of the construction
project management. The first schedule developed may not be a
suitable schedule for beginning or completing the project to achieve
the target completion time at a minimum total cost. In general, there
are trade-offs between time and cost (TCT) to complete the activities
of a project. This research presents genetic algorithms (GAs) multiobjective
model for project scheduling considering different
scenarios such as least cost, least time, and target time.
Abstract: Using ETABS software, this study analyzed 23
buildings to evaluate effects of mistakes during construction phase on
buildings structural behavior. For modelling, two different loadings
were assumed: 1) design loading and 2) loading due to the effects of
mistakes in construction phase. Research results determined that
considering traditional construction methods for buildings resulted in
a significant increase in dead loads and consequently intensified the
displacements and base-shears of buildings under seismic loads.