Abstract: Dissimilar joining of Titanium and Aluminum thin
sheets has potential applications in aerospace and automobile
industry which can reduce weight and cost and improve strength,
corrosion resistance and high temperature properties. However
successful welding of Titanium/Aluminium sheets is of challenge due
to differences in physical, chemical and metallurgical properties
between the two. This paper describes research results of Laser Beam
Welding (LBW) of Ti/Al thin sheets in which many researchers have
recently performed and critically reviewed from different
perspectives. Also some of notable works in the field of laser welding
with changes in mechanical properties, crack propagation, diffusion
behavior, chemical potential, interfacial reaction and the
microstructure are reported.
Abstract: Wireless sensor network is vulnerable to a wide range
of attacks. Recover secrecy after compromise, to develop technique
that can detect intrusions and able to resilient networks that isolates
the point(s) of intrusion while maintaining network connectivity for
other legitimate users. To define new security metrics to evaluate
collaborative intrusion resilience protocol, by leveraging the sensor
mobility that allows compromised sensors to recover secure state
after compromise. This is obtained with very low overhead and in a
fully distributed fashion using extensive simulations support our
findings.
Abstract: In this paper, the influence of upstream structures on the flow patternaround and inside the wind-catcher is experimentally investigated by smoke flow visualization techniques. Wind-catchers are an important part of natural ventilation in residential buildings or public places such as shopping centers, libraries, etc. Wind-catchers might be also used in places of high urban densities; hence their potential to provide natural ventilation is dependent on the presence of upstream structures. In this study, the two-sided wind-catcher model was based on a real wind-catcher observed in the city of Yazd, Iran. The present study focuses on the flow patterns around and inside the isolated two-sided wind-catcher, and on a two-sided wind-catcher in the presence of an upstream structure. The results show that the presence of an upstream structure influences the airflow pattern force and direction. Placing a high upstream structure reverses the airflow direction inside the wind-catcher.
Abstract: The hydrogenated amorphous carbon films (α-C:H)
were deposited on p-type Si (100) substrates at different thicknesses by
radio frequency plasma enhanced chemical vapor deposition
technique (rf-PECVD). Raman spectra display asymmetric
diamond-like carbon (DLC) peaks, representative of the α-C:H films.
The decrease of intensity ID/IG ratios revealed the sp3 content arise at
different thicknesses of the α-C:H films. In terms of mechanical
properties, the high hardness and elastic modulus values showed the
elastic and plastic deformation behaviors related to sp3 content in
amorphous carbon films. Electrochemical properties showed that the
α-C:H films exhibited excellent corrosion resistance in air-saturated
3.5 wt.% NaCl solution for pH 2 at room temperature. Thickness
increasing affected the small sp2 clusters in matrix, restricting the
velocity transfer and exchange of electrons. The deposited α-C:H films
exhibited excellent mechanical properties and corrosion resistance.
Abstract: Many studies have revealed the fact of the complexity
of ontology building process. Therefore there is a need for a new
approach which one of that addresses the socio-technical aspects in the
collaboration to reach a consensus. Meta-design approach is
considered applicable as a method in the methodological model of
socio-technical ontology engineering. Principles in the meta-design
framework are applied in the construction phases of the ontology. A
web portal is developed to support the meta-design principles
requirements. To validate the methodological model semantic web
applications were developed and integrated in the portal and also used
as a way to show the usefulness of the ontology. The knowledge based
system will be filled with data of Indonesian medicinal plants. By
showing the usefulness of the developed ontology in a semantic web
application, we motivate all stakeholders to participate in the
development of knowledge based system of medicinal plants in
Indonesia.
Abstract: This review summarizes the potential of starch
agroindustrial residues as substrate for biohydrogen production.
Types of potential starch agroindustrial residues, recent developments
and bio-processing conditions for biohydrogen production will be
discussed. Biohydrogen is a clean energy source with great potential
to be an alternative fuel, because it releases energy explosively in
heat engines or generates electricity in fuel cells producing water as
only by-product. Anaerobic hydrogen fermentation or dark
fermentation seems to be more favorable, since hydrogen is yielded
at high rates and various organic waste enriched with carbohydrates
as substrate result in low cost for hydrogen production. Abundant
biomass from various industries could be source for biohydrogen
production where combination of waste treatment and energy
production would be an advantage. Carbohydrate-rich nitrogendeficient
solid wastes such as starch residues can be used for
hydrogen production by using suitable bioprocess technologies.
Alternatively, converting biomass into gaseous fuels, such as
biohydrogen is possibly the most efficient way to use these
agroindustrial residues.
Abstract: This paper reveals the interaction between hydrogen
and surface stress in austenitic stainless steel by X-ray diffraction
stress measurement and thermal desorption analysis before and after
being charged with hydrogen. The surface residual stress was varied
by surface finishing using several disc polishing agents. The obtained
results show that the residual stress near surface had a significant
effect on hydrogen absorption behavior, that is, tensile residual stress
promoted the hydrogen absorption and compressive one did opposite.
Also, hydrogen induced equi-biaxial stress and this stress has a linear
correlation with hydrogen content.
Abstract: In recent decades with the development of technology
and lack of food sources, sewage sludge in production of human
foods is inevitable. Various sources of municipal and industrial
sewage sludge that is produced can provide the requirement of plant
nutrients. Soils in arid, semi-arid climate of central Iran that most
affected by water drainage, iron and zinc deficiencies, using of
sewage sludge is helpful. Therefore, the aim of this study is
investigation of sewage sludge and manure application on Ni, Pb and
Cd uptake by Savory. An experiment in a randomized complete block
design with three replications was performed. Sewage sludge
treatments consisted of four levels, control, 15, 30, 80 tons per
hectares; the manure was used in four levels of control, 20, 40 and 80
tons per hectare. Results showed that the wet and dry weights was not
affected by sewage sludge using, while, manure has significant effect
on them. The effect of sewage sludge on the cadmium and lead
concentrations were significant. Interactions of sewage sludge and
manure on dry weight values were not significant. Compare mean
analysis showed that increasing the amount of sewage sludge had no
significant effect on cadmium concentration and it reduced when
sewage sludge usage increased. This is probably due to increased
plant growth and reduced concentrations of these elements in the
plant.
Abstract: In this paper a novel design of aerostatic thrust bearing
is proposed and is analyzed numerically. The capillary restrictor and
bearing disk are made of elastomer like silicone and PU. The
viscoelasticity of elastomer helps the capillary expand for more air
flux and at the same time, allows conicity of the bearing surface to
form when the air pressure is enhanced. Therefore the bearing has the
better ability of passive compensation. In the present example, as
compared with the typical model, the new designs can nearly double
the load capability and offer four times static stiffness.
Abstract: This paper represents performance of particle swarm
optimisation (PSO) algorithm based integral (I) controller and
proportional-integral controller (PI) for interconnected hydro-thermal
automatic generation control (AGC) with generation rate constraint
(GRC) and Thyristor controlled phase shifter (TCPS) in series with
tie line. The control strategy of TCPS provides active control of
system frequency. Conventional objective function integral square
error (ISE) and another objective function considering square of
derivative of change in frequencies of both areas and change in tie
line power are considered. The aim of designing the objective
function is to suppress oscillation in frequency deviations and change
in tie line power oscillation. The controller parameters are searched
by PSO algorithm by minimising the objective functions. The
dynamic performance of the controllers I and PI, for both the
objective functions, are compared with conventionally optimized I
controller.
Abstract: In a highly competitive environment, it becomes more
important to shorten the whole business process while delivering or
even enhancing the business value to the customers and suppliers.
Although the workflow management systems receive much attention
for its capacity to practically support the business process enactment,
the effective workflow modeling method remain still challenging and
the high degree of process complexity makes it more difficult to gain
the short lead time. This paper presents a workflow structuring method
in a holistic way that can reduce the process complexity using
activity-needs and formal concept analysis, which eventually enhances
the key performance such as quality, delivery, and cost in business
process.
Abstract: This paper presents a hybrid fuzzy logic control
strategy for a unicycle trajectory following robot on irregular terrains.
In literature, researchers have presented the design of path tracking
controllers of mobile robots on non-frictional surface. In this work,
the robot is simulated to drive on irregular terrains with contrasting
frictional profiles of peat and rough gravel. A hybrid fuzzy logic
controller is utilised to stabilise and drive the robot precisely with the
predefined trajectory and overcome the frictional impact. The
controller gains and scaling factors were optimised using spiral
dynamics optimisation algorithm to minimise the mean square error
of the linear and angular velocities of the unicycle robot. The robot
was simulated on various frictional surfaces and terrains and the
controller was able to stabilise the robot with a superior performance
that is shown via simulation results.
Abstract: Two tragic tsunamis that devastated the west coast of
Sumatra Island, Indonesia in 2004 and North East Japan in 2011 had
damaged bridges to various extents. Tsunamis have resulted in the
catastrophic deterioration of infrastructures i.e. coastal structures,
utilities and transportation facilities. A bridge structure performs vital
roles to enable people to perform activities related to their daily needs
and for development. A damaged bridge needs to be repaired
expeditiously. In order to understand the effects of tsunami forces on
bridges, experimental tests are carried out to measure the
characteristics of hydrodynamic force at various wave heights.
Coastal bridge models designed at a 1:40 scale are used in a 24.0 m
long hydraulic flume with a cross section of 1.5 m by 2.0 m. The
horizontal forces and uplift forces in all cases show that forces
increase nonlinearly with increasing wave amplitude.
Abstract: Marine Protected Areas can benefit from nature based
tourism, monitoring environmental impacts and also become target
for human presence. From more than 3 million tourists visiting
Cozumel Island every year, an average of 2,8 million arrive by cruise
ship, and 41% are estimated to have motivation for water activities.
The destination is relying so much on the tourism activity, that scuba
diving and snorkeling in the National Park Reef of Cozumel sustain
the major economic activity. In order to achieve the sustainable
development indicator designed for regional environmental
development, the PNAC offers a training course to tourism providers
to access the protected area. This way, the update of the last 5 years
of such training is directed to diving staff, boat crew and
professionals, making them able to assist in managing the natural
resource. Moreover, the case study is an example to be used for
raising awareness among tourists visiting protected areas.
Abstract: Asphaltic concrete for pavement construction in India
are produced by using crushed stone, gravels etc. as aggregate. In
north-Eastern region of India, there is a scarcity of stone aggregate.
Therefore the road engineers are always in search of an optional
material as aggregate which can replace the regularly used material.
The purpose of this work was to evaluate the utilization of
substandard or marginal aggregates in flexible pavement
construction. The investigation was undertaken to evaluate the effects
of using lower quality aggregates such as over burnt brick aggregate
on the preparation of asphalt concrete for flexible pavements. The
scope of this work included a review of available literature and
existing data, a laboratory evaluation organized to determine the
effects of marginal aggregates and potential techniques to upgrade
these substandard materials, and a laboratory evaluation of these
upgraded marginal aggregate asphalt mixtures. Over burnt brick
aggregates are water susceptible and can leads to moisture damage.
Moisture damage is the progressive loss of functionality of the
material owing to loss of the adhesion bond between the asphalt
binder and the aggregate surface. Hence zycosoil as an anti striping
additive were evaluated in this study. This study summarizes the
results of the laboratory evaluation carried out to investigate the
properties of asphalt concrete prepared with zycosoil modified over
burnt brick aggregate. Marshall specimen were prepared with stone
aggregate, zycosoil modified stone aggregate, over burnt brick
aggregate and zycosoil modified over burnt brick aggregate. Results
show that addition of zycosoil with stone aggregate increased
stability by 6% and addition of zycosoil with over burnt brick
aggregate increased stability by 30%.
Abstract: The power converter that feeds high-frequency, highvoltage
transformers must be carefully designed due to parasitic
components, mainly the secondary winding capacitance and the
leakage inductance, that introduces resonances in relatively lowfrequency
range, next to the switching frequency. This paper
considers applications in which the load (resistive) has an
unpredictable behavior, changing from open to short-circuit condition
faster than the output voltage control loop could react. In this context,
to avoid overvoltage and over current situations, that could damage
the converter, the transformer or the load, it is necessary to find an
operation point that assure the desired output voltage in spite of the
load condition. This can done adjusting the frequency response of the
transformer adding an external inductance, together with selecting the
switching frequency to get stable output voltage independently of the
load.
Abstract: Nanostructured catalysts were successfully prepared
by acidification of diatomite and regeneration of FCC spent catalysts.
The obtained samples were characterized by IR, XRD, SEM, EDX,
MAS-NMR (27Al and 29Si), NH3-TPD and tested in catalytic
pyrolysis of biomass (rice straw). The results showed that the similar
bio-oil yield of 41.4% can be obtained by pyrolysis with catalysts at
450oC as compared to that of the pyrolysis without catalyst at 550oC.
The bio-oil yield reached a maximum of 42.55% at the pyrolysis
temperature of 500oC with catalytic content of 20%. Moreover, by
catalytic pyrolysis, bio-oil quality was better as reflected in higher
ratio of H/C, lower ratio of O/C. This clearly indicated high
application potential of these new nanostructured catalysts in the
production of bio-oil with low oxygenated compounds.
Abstract: This paper evaluates the performance of a multi-lane
four legged modern roundabout operating in Muscat using SIDRA
model. The performance measures include Degree of Saturation
(DOS), average delay, and queue lengths. The geometric and traffic
data were used for model preparation. Gap acceptance parameters,
critical gap and follow up headway, were used for calibration of
SIDRA model. The results from the analysis showed that currently
the roundabout is experiencing delays up to 610 seconds per vehicle
with DOS 1.67 during peak hour. Further, sensitivity analysis for
general and roundabout parameters was performed, amongst lane
width, cruise speed, inscribed diameter, entry radius and entry angle
showed that inscribed diameter is most crucial factor affecting delay
and DOS. Up gradation of roundabout to fully signalized junction
was found as the suitable solution which will serve for future years
with LOS C for design year having DOS of 0.9 with average control
delay of 51.9 seconds per vehicle.
Abstract: The present study involved analysis of certain
characteristics of the perennial ryegrass (Lolium perenne L.)
genotypes collected from the natural flora of Ankara, and explores a
correlation among them. In order to evaluate the plants for breeding
purpose as per Turkey's environmental conditions, the perennial
ryegrass plants were collected from natural pasture of Ankara in 2004
and were utilized for the study. Seeds of the collected plants were
sown in pots and seedlings were prepared in a greenhouse. In 2005,
the seedlings were transplanted at 50 × 50 cm2 intervals in
Randomized Complete Blocks Design in an experimental field. In
2007 and 2008, data were recorded from the observations and
measurements of 568 perennial ryegrasses. The plant characteristics,
which were investigated, included re-growth time in spring, color,
density, growth habit, tendency to form inflorescence, time of
inflorescence, plant height, length of upper internode, spike length,
leaf length, leaf width, leaf area, leaf shape, number of spikelets per
spike, seed yield per spike and 1000 grain weight and the correlation
analyses were made using this data. Correlation coefficients were
estimated between all paired combinations of the studied traits. The
yield components exhibited varying trends of association among
themselves. Seed yield per spike showed significant and positive
association with the number of spikelets per spike, 1000 grain weight,
plant height, length of upper internode, spike length, leaf length, leaf
width, leaf area and color, but significant and negative association
with the growth habit and re-growth time in spring.
Abstract: This work presents the result of investigations aimed
at determining the hardness of the welded Chromoly (A 4130) steel
plate of 2” thickness. Multi pass welding for the thick sections was
carried out and analyzed for the Chromoly alloy steel plates. The
study of hardness at the weld metal reveals that there is the presence
of different micro structure products which yields diverse properties.
The welding carried out using GMAW with ER70s-2 electrode.
Single V groove design was selected for the butt joint configuration.
The presence of hydrogen has been suppressed by selecting low
hydrogen electrode. Preheating of the plate prior to welding reduces
the cooling rate which also affects the weld metal microstructure. The
shielding gas composition used in this analysis is 80% Ar-20% CO2.
The experimental analysis gives the detailed study of the hardness of
the material.