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: 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: Collapsible soils go through radical rearrangement of
their particles when triggered by water, stress or/and vibration,
causing loss of volume. This loss of volume in soil as seen in
foundation failures has caused millions of dollars’ worth of damages
to public facilities and infrastructure and so has an adverse effect on
the society and people. Despite these consequences and the several
studies that are available, more research is still required in the study
of soil collapsibility. Discerning the pedogenesis (formation) of soils
and investigating the combined effects of the different geological soil
properties is key to elucidating and quantifying soils collapsibility.
This study presents a novel laboratory testing regime that would be
undertaken on soil samples where the effects of soil type, compactive
variables (moisture content, density, void ratio, degree of saturation)
and loading are analyzed. It is anticipated that results obtained would
be useful in mapping the trend of the combined effect thus the basis
for evaluating soil collapsibility or collapse potentials encountered in
construction with volume loss problems attributed to collapse.
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: Pavement surface unevenness plays a pivotal role on
roughness index of road which affects on riding comfort ability.
Comfort ability refers to the degree of protection offered to vehicle
occupants from uneven elements in the road surface. So, it is
preferable to have a lower roughness index value for a better riding
quality of road users. Roughness is generally defined as an
expression of irregularities in the pavement surface which can be
measured using different equipments like MERLIN, Bump integrator,
Profilometer etc. Among them Bump Integrator is quite simple and
less time consuming in case of long road sections. A case study is
conducted on low volume roads in West District in Tripura to
determine roughness index (RI) using Bump Integrator at the
standard speed of 32 km/h. But it becomes too tough to maintain the
requisite standard speed throughout the road section. The speed of
Bump Integrator (BI) has to lower or higher in some distinctive
situations. So, it becomes necessary to convert these roughness index
values of other speeds to the standard speed of 32 km/h. This paper
highlights on that roughness index conversional model. Using SPSS
(Statistical Package of Social Sciences) software a generalized
equation is derived among the RI value at standard speed of 32 km/h
and RI value at other speed conditions.
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: This paper discusses about the findings of preliminary
survey on MATLAB software learning among power electronics
students. One of the main focuses of power electronics course is on
DC to DC boost convertors, because boost convertors are generally
used in different industrial and non industrial applications. Population
samples of this study were randomly selected final year bachelor of
electronics and electrical engineering students from University Tun
Hussein Onn Malaysia (UTHM).As per the results from the survey
questioner analysis, almost eighty percent students are facing
problem and difficulties in Dc to Dc boost convertors experimental
understanding without using MATLAB simulink package. As per
finding of this study it is clear that MATLAB play an effective and
efficient function for better understanding of boost convertors
experimental work among power electronics learners.
Abstract: This paper explains about the voltage output for DC to
DC boost converter between open loop, PID controller and fuzzy
logic controller through Matlab Simulink. Simulink input voltage was
set at 12V and the voltage reference was set at 24V. The analysis on
the deviation of voltage resulted that the difference between reference
voltage setting and the output voltage is always lower. Comparison
between open loop, PID and FLC shows that, the open loop circuit
having a bit higher on the deviation of voltage. The PID circuit
boosts for FLC has a lesser deviation of voltage and proved that it is
such a better performance on control the deviation of voltage during
the boost mode.
Abstract: The bean (Phaseolus vulgaris L.) is one of the best
known of the legumes, and it has a long cultivation tradition in Italy.
The territory of “Subappennino Dauno” (southern Italy) is at around
700 m a.s.l. and is predominantly grown with cereals, olive trees and
grapevines. Ecotypes of white beans to eat dry (such as cannellini
beans) are also grown, which are sought for their palatability, high
digestibility, and ease of cooking. However, these are not easy to find
on the market due to their low production in relatively small areas
and on small family farms that use seeds handed down from
generation to generation. The introduction of these ecotypes in plain
areas of the Puglia region would provide an opportunity to promote
the diffusion of this type of bean. To investigate the adaptability of
these ecotypes in plain environments (Cerignola, in southern Italy) a
comparative trial was carried out between three ‘Monti Dauni’
ecotypes (E1, E2, E3) that are native to mountain areas and the
similar commercial variety, ‘Cannellini’. The data provide useful
information about the quantitative and qualitative characteristics of
these ecotypes when grown in lowland environments. Ecotype E3
provided the greatest bean production (2.34 t ha-1) compared to
‘Cannellini’ (1.28 t ha-1) and the other ecotypes (0.55 and 0.40 t ha-1,
for E1 and E2, respectively), due to its greater plant growth and the
larger size of the seed (and thickness, in particular). Finally, ecotype
E2 provided the greatest protein content (31.2%), although not
significantly different from the commercial cultivar ‘Cannellini’
(32.1%).
Abstract: The connection between past travel experience and
tourists’ revisit behavioral intentions has not been widely explored
but the existing studies suggest a close relationship between them.
Destination image can equally be construed as having effects on the
attitudes of the tourists at the end of their actual visitation and the
satisfaction of a tourist with his or her travel experiences contributes
to a revisit intention towards a particular destination. With strong
marketing efforts, UAE is not only considered to be successful in
attracting foreign investors, but is becoming the most popular tourism
destination in the Arab region. UAE is seriously developing its
tourism image and taking serious initiatives to attract new or repeat
visitations from the international tourists. This study empirically
investigates the causal relationships between tourism destination
image, tourist satisfaction and revisit intention using UAE as a
contextual study setting. A very clear picture emerged which
provides a host country with potential implications for its tourism
industry practitioners, Department of Tourism and Commerce
Marketing and the travel agencies who act as the intermediaries
between the potential tourists and the hotel operators.
Abstract: This paper presents a study on Proportional Resonant
(PR) current control with additional PR harmonic compensators for
Grid Connected Photovoltaic (PV) Inverters. Both simulation and
experimental results will be presented. Testing was carried out on a
3kW Grid-Connected PV Inverter which was designed and
constructed for this research.
Abstract: The effective development of a geoscience education
and training program takes account of the rapidly changing
environment in the geoscience market, includes information about
resource-rich countries which have international education demands.
In this paper, we introduce the geoscience program run by the
International School for Geoscience Resources at the Korea Institute
of Geoscience and Mineral Resources (IS-Geo of KIGAM), and show
its remarkable performance. To further effective geoscience program
planning and operation, we present recommendations for strategic
management for customer-oriented operation with a more favorable
program format and advanced training aids. Above all, the IS-Geo of
KIGAM should continue improve through ‘plan-do-see-feedback’
activities based on the recommendations.
Abstract: An investigation into the effect of countersunk depth,
plate thickness, countersunk angle and plate width on the stress
concentration around countersunk hole is carried out with the help of
finite element analysis. The variation of stress concentration with
respect to these parameters is studied for three types of loading viz.
uniformly distributed load, uniformly varying load and functionally
distributed load. The results of the finite element analysis are
interpreted and some conclusions are drawn. The distribution of
stress concentration around countersunk hole in isotropic plates
simply supported at all the edges is found similar and is independent
of loading. The maximum stress concentration also occurs at a
particular point irrespective of the loading conditions.
Abstract: In the present work, the finite element formulation for
the investigation of the effects of a localized interfacial degeneration
on the dynamic behavior of the [90°/0°] laminated composite plate
employing the state-space technique is performed. The stiffness of
the laminate is determined by assembling the stiffnesses of subelements.
This includes an introduction of an interface layer adopting
the virtually zero-thickness formulation to model the interfacial
degeneration. Also, the kinematically consistent mass matrix and
proportional damping have been formulated to complete the free
vibration governing expression. To simulate the interfacial
degeneration of the laminate, the degenerated areas are defined from
the center propagating outwards in a localized manner. It is found
that the natural frequency, damped frequency and damping ratio of
the plate decreases as the degenerated area of the interface increases.
On the contrary, the loss factor increases correspondingly.
Abstract: Drying behavior of blanched sweet potato in a cabinet
dryer using different five air temperatures (40-80°C) and ten sweet
potato varieties sliced to 5mm thickness were investigated. The
drying data were fitted to eight models. The Modified Henderson and
Pabis model gave the best fit to the experimental moisture ratio data
obtained during the drying of all the varieties while Newton (Lewis)
and Wang and Singh models gave the least fit. The values of Deff
obtained for Bophelo variety (1.27 x 10-9 to 1.77 x 10-9 m2/s) was
the least while that of S191 (1.93 x 10-9 to 2.47 x 10-9 m2/s) was the
highest which indicates that moisture diffusivity in sweet potato is
affected by the genetic factor. Activation energy values ranged from
0.27-6.54 kJ/mol. The lower activation energy indicates that drying
of sweet potato slices requires less energy and is hence a cost and
energy saving method. The drying behavior of blanched sweet potato
was investigated in a cabinet dryer. Drying time decreased
considerably with increase in hot air temperature. Out of the eight
models fitted, the Modified Henderson and Pabis model gave the best
fit to the experimental moisture ratio data on all the varieties while
Newton, Wang and Singh models gave the least. The lower activation
energy (0.27 - 6.54 kJ/mol) obtained indicates that drying of sweet
potato slices requires less energy and is hence a cost and energy
saving method.
Abstract: The postharvest quality management of tomatoes is
important to limit the amount of losses that occur due to deterioration
between harvest and consumption. This study was undertaken to
investigate the effects of pre- and postharvest integrated agrotechnologies,
involving greenhouse microclimate and postharvest
storage conditions, on the postharvest quality attributes of four
tomato cultivars. Tomato fruit firmness, colour (hue angle (h°) and
L* value), pH and total soluble solids for the cultivars Bona,
Star 9037, Star 9009 and Zeal, grown in a fan-pad evaporativelycooled
and an open-ended naturally-ventilated tunnel, were harvested
at the mature-green stage. The tomatoes were stored for 28 days
under cold storage conditions, with a temperature of 13°C and RH of
85%, and under ambient air conditions, with a temperature of 23±
2°C and RH of 52± 4%. This study has provided information on the
effect of integrated pre-harvest and postharvest agro-technologies,
involving greenhouse microclimate and postharvest storage
environment on the postharvest quality attributes of four of the
tomato cultivars in South Africa. NVT-grown tomatoes retained
better textural qualities, but ripened faster by changing from green to
red faster, although these were reduced under cold storage conditions.
FPVT-grown tomatoes had lower firmness, but ripened slowly with
higher colour attributes. With cold storage conditions, the firmness of
FPVT-grown tomatoes was maintained. Cultivar Bona firmness and
colour qualities depreciated the fastest, but it had higher TSS content
and lower pH values. Star 9009 and Star 9037 presented better
quality, by retaining higher firmness and ripening slowly, but they
had the lowest TSS contents and high pH values, especially
Star 9037. Cold storage improved the firmness of tomato cultivars
with poor textural quality and faster colour changes.