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: 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: 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.
Abstract: Food contamination occurs during post process
handling. This leads to spoilage and growth of pathogenic
microorganisms in the food, thereby reducing its shelf life or
spreading of food borne diseases. Several methods are tried and one
of which is use of antimicrobial packaging. Here, papain, a protease
enzyme, is covalently immobilized with the help of glutarldehyde on
polyurethane and used as a food wrap to protect food from microbial
contamination. Covalent immobilization of papain was achieved at a
pH of 7.4; temperature of 4°C; glutaraldehyde concentration of 0.5%;
incubation time of 24h; and 50mg of papain. The formation of -C=Nobserved
in the Fourier transform infrared spectrum confirmed the
immobilization of the enzyme on the polymer. Immobilized enzyme
retained higher activity than the native free enzyme. The modified
polyurethane showed better reduction of Staphylococcus aureus
biofilm than bare polymer film (eight folds reduction in live colonies,
two times reduction in protein and 6 times reduction in
carbohydrates). The efficacy of this was studied by wrapping it over
S. aureus contaminated cottage cheese (paneer) and cheese and
stored at a temperature of 4°C for 7days. The modified film reduced
the bacterial contamination by eight folds when compared to the bare
film. FTIR also indicated reduction in lipids, sugars and proteins in
the biofilm.
Abstract: South Africa has some regions which are susceptible
to moderate seismic activity. A peak ground acceleration of between
0.1g and 0.15g can be expected in the southern parts of the Western
Cape. Unreinforced Masonry (URM) is commonly used as a
construction material for 2 to 5 storey buildings in underprivileged
areas in and around Cape Town. URM is typically regarded as the
material most vulnerable to damage when subjected to earthquake
excitation. In this study, a three-storey URM building was analysed
by applying seven earthquake time-histories, which can be expected
to occur in South Africa using a finite element approach.
Experimental data was used to calibrate the in- and out-of-plane
stiffness of the URM. The results indicated that tensile cracking of
the in-plane piers was the dominant failure mode. It is concluded that
URM buildings of this type are at risk of failure especially if
sufficient ductility is not provided. The results also showed that
connection failure must be investigated further.
Abstract: Columns have traditionally been constructed of
reinforced concrete or structural steel. Much attention was allocated
to estimate the axial capacity of the traditional column sections to the
detriment of other forms of construction. Other forms of column
construction such as Concrete Filled Double Skin Tubes received
little research attention, and almost no attention when subjected to
eccentric loading. This paper investigates the axial capacity of
columns when subjected to eccentric loading. The experimental axial
capacities are compared to other established theoretical formulae on
concentric loading to determine a possible relationship. The study
found a good correlation between the reduction in axial capacity for
different column lengths and hollow section ratios.
Abstract: Preparation of nanoparticles of cerium oxide and
adsorption of bovine serum albumin on them were studied. Particle
size distribution and influence of pH on zeta potential of prepared
CeO2 were determined. Average size of prepared cerium oxide
nanoparticles was 9 nm. The simultaneous measurements of the
bovine serum albumin adsorption and zeta potential determination of
the (adsorption) suspensions were carried out. The adsorption
isotherms were found to be of typical Langmuir type; values of the
bovine serum albumin adsorption capacities were calculated.
Increasing of pH led to decrease of zeta potential and decrease of
adsorption capacity of cerium oxide nanoparticles. The maximum
adsorption capacity was found for strongly acid suspension (am =
118 mg/g). The samples of nanoceria with positive zeta potential
adsorbed more bovine serum albumin on the other hand, the samples
with negative zeta potential showed little or no protein adsorption.
Surface charge or better say zeta potential of CeO2 nanoparticles
plays the key role in adsorption of proteins on such type of materials.
Abstract: Electricity is recognized as fundamental to
industrialization and improving the quality of life of the people.
Harnessing the immense untapped hydropower potential in Tripura
region opens avenues for growth and provides an opportunity to
improve the well-being of the people of the region, while making
substantial contribution to the national economy. Gumti hydro power
plant generates power to mitigate the crisis of power in Tripura,
India. The first unit of hydro power plant (5MW) was commissioned
in June 1976 & another two units of 5 MW was commissioned
simultaneously. But out of 15MW capacity at present only 8MW-
9MW power is produced from Gumti hydro power plant during rainy
season. But during lean season the production reduces to 0.5MW due
to shortage of water. Now, it is essential to implement some
mitigation measures so that the further atrocities can be prevented
and originality will be possible to restore. The decision making
ability of the Analytic Hierarchy Process (AHP) and Concordance
Analysis Techniques (CAT) are utilized to identify the better decision
or solution to the present problem. Some related attributes are
identified by the method of surveying within the experts and the
available reports and literatures. Similar criteria are removed and
ultimately seven relevant ones are identified. All the attributes are
compared with each other and rated accordingly to their importance
over the other with the help of Pair wise Comparison Matrix. In the
present investigation different mitigation measures are identified and
compared to find the best suitable alternative which can solve the
present uncertainties involving the existence of the Gumti Hydro
Power Plant.
Abstract: Paper presents a study about dynamic effects obtained
from the dynamic load testing of the city highway bridges in Latvia
carried out from 2005 to 2012. 9 prestressed concrete bridges and 4
composite bridges were considered. 11 of 13 bridges were designed
according to the Eurocodes but two according to the previous
structural codes used in Latvia (SNIP 2.05.03-84). The dynamic
properties of the bridges were obtained by heavy vehicle passing the
bridge roadway with different driving speeds and with or without
even pavement. The obtained values of the Dynamic amplification
factor (DAF) and the bridge natural frequency were analyzed and
compared to the values of built-in traffic load models provided in
Eurocode 1. The actual DAF values for even bridge pavement in the
most cases are smaller than the value adopted in Eurocode 1. Vehicle
speed for uneven pavements significantly influence Dynamic
amplification factor values.
Abstract: The thermo-mechanical behaviour of concrete energy
pile foundations with different single and double U-tube shapes
incorporated was analysed using the Comsol Multi-physics package.
For the analysis, a 3D numerical model in real scale of the concrete
pile and surrounding soil was simulated regarding actual operation of
ground heat exchangers (GHE) and the surrounding ambient
temperature. Based on initial ground temperature profile measured in
situ, tube inlet temperature was considered to range from 6oC to 0oC
(during the contraction process) over a 30-day period. Extra thermal
stresses and deformations were calculated during the simulations and
differences arising from the use of two different systems (single-tube
and double-tube) were analysed. The results revealed no significant
difference for extra thermal stresses at the centre of the pile in either
system. However, displacements over the pile length were found to
be up to 1.5-fold higher in the double-tube system than the singletube
system.
Abstract: There are pending discussions over the mapping of
country export potential in order to refocus export strategy of firms
and its evidence-based promotion by the Export Credit Agencies
(ECAs) and other permitted vehicles of governments.
In this paper we develop our version of an applied model that
offers “stepwise” elimination of unattractive markets. We modify and
calibrate the model for the particular features of the Czech Republic
and specific pilot cases where we apply an individual approach to
each sector.
Abstract: The use of information and communication
technologies such as computers, mobile phones and the Internet is
becoming prevalent in today’s world; and it is facilitating access to a
vast amount of data, services and applications for the improvement of
people’s lives. However, this prevalence of ICTs is hampered by the
problem of low income levels in developing countries to the point
where people cannot timeously replace or repair their ICT devices
when damaged or lost; and this problem serves as a motivation for
this study whose aim is to examine the perceptions of teachers on the
reliability of cellphones when used for teaching and learning
purposes. The research objectives unfolding this aim are of two
types: Objectives on the selection and design of theories and models,
and objectives on the empirical testing of these theories and models.
The first type of objectives is achieved using content analysis in an
extensive literature survey: and the second type of objectives is
achieved through a survey of high school teachers from the ILembe
and UMgungundlovu districts in the KwaZulu-Natal province of
South Africa. Data collected from this questionnaire based survey is
analysed in SPSS using descriptive statistics and Pearson correlations
after checking the reliability and validity of the questionnaires. The
main hypothesis driving this study is that there is a relationship
between the demographics and the attribution identity of teachers on
one hand, and their perceptions on the reliability of cellphones on the
other hand, as suggested by existing literature; except that attribution
identities are considered in this study under three angles: intention,
knowledge and ability, and action. The results of this study confirm
that the perceptions of teachers on the reliability of cellphones for
teaching and learning are affected by the school location of these
teachers, and by their perceptions on learners’ cellphones usage
intentions and actual use.
Abstract: The handwriting is a physical demonstration of a
complex cognitive process learnt by man since his childhood. People
with disabilities or suffering from various neurological diseases are
facing so many difficulties resulting from problems located at the
muscle stimuli (EMG) or signals from the brain (EEG) and which
arise at the stage of writing. The handwriting velocity of the same
writer or different writers varies according to different criteria: age,
attitude, mood, writing surface, etc. Therefore, it is interesting to
reconstruct an experimental basis records taking, as primary
reference, the writing speed for different writers which would allow
studying the global system during handwriting process. This paper
deals with a new approach of the handwriting system modeling based
on the velocity criterion through the concepts of artificial neural
networks, precisely the Radial Basis Functions (RBF) neural
networks. The obtained simulation results show a satisfactory
agreement between responses of the developed neural model and the
experimental data for various letters and forms then the efficiency of
the proposed approaches.