Abstract: This paper presents the design, fabrication and
evaluation of magneto-rheological damper. Semi-active control
devices have received significant attention in recent years because
they offer the adaptability of active control devices without requiring
the associated large power sources. Magneto-Rheological (MR)
dampers are semi- active control devices that use MR fluids to
produce controllable dampers. They potentially offer highly reliable
operation and can be viewed as fail-safe in that they become passive
dampers if the control hardware malfunction. The advantage of MR
dampers over conventional dampers are that they are simple in
construction, compromise between high frequency isolation and
natural frequency isolation, they offer semi-active control, use very
little power, have very quick response, has few moving parts, have a
relax tolerances and direct interfacing with electronics. Magneto-
Rheological (MR) fluids are Controllable fluids belonging to the
class of active materials that have the unique ability to change
dynamic yield stress when acted upon by an electric or magnetic
field, while maintaining viscosity relatively constant. This property
can be utilized in MR damper where the damping force is changed by
changing the rheological properties of the fluid magnetically. MR
fluids have a dynamic yield stress over Electro-Rheological fluids
(ER) and a broader operational temperature range. The objective of
this papert was to study the application of an MR damper to vibration
control, design the vibration damper using MR fluids, test and
evaluate its performance. In this paper the Rheology and the theory
behind MR fluids and their use on vibration control were studied.
Then a MR vibration damper suitable for vehicle suspension was
designed and fabricated using the MR fluid. The MR damper was
tested using a dynamic test rig and the results were obtained in the
form of force vs velocity and the force vs displacement plots. The
results were encouraging and greatly inspire further research on the
topic.
Abstract: Pressures for urban redevelopment are intensifying in
all large cities. A new logic for urban development is required –
green urbanism – that provides a spatial framework for directing
population and investment inwards to brownfields and greyfields
precincts, rather than outwards to the greenfields. This represents
both a major opportunity and a major challenge for city planners in
pluralist liberal democracies. However, plans for more compact
forms of urban redevelopment are stalling in the face of community
resistance. A new paradigm and spatial planning platform is required
that will support timely multi-level and multi-actor stakeholder
engagement, resulting in the emergence of consensus plans for
precinct-level urban regeneration capable of more rapid
implementation. Using Melbourne, Australia as a case study, this
paper addresses two of the urban intervention challenges – where and
how – via the application of a 21st century planning tool ENVISION
created for this purpose.
Abstract: Conflicts identification among non-functional requirements is often identified intuitively which impairs conflict analysis practices. This paper proposes a new model to identify conflicts among non-functional requirements. The proposed model uses the matrix mechanism to identify the quality based conflicts among non-functional requirements. The potential conflicts are identified through the mapping of low level conflicting quality attributes to low level functionalities using the matrices. The proposed model achieves the identification of conflicts among product and process requirements, identifies false conflicts, decreases the documentation overhead, and maintains transparency of identified conflicts. The attributes are not concomitantly taken into account by current models in practice.
Abstract: Plants are rich sources of bioactive compounds. In this study the photochemical screening of hexane, ethanolic and aqueous extracts of roots and latex of jojoba (Simmondsia chinensis) plant revealed the presence of saponins, tannins, alkaloids, steroids and glycosides. Ethanolic extract was found to be richer in these metabolites than hexane, aqueous extracts and latex. The extracts and latex displayed effective antimicrobial activity against Salmonella typhimurium, Bacillus cereus, Clostridium perfringens, Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus flavus. The increase in volume of the extracts and latex caused more activity, as shown by zones of inhibition. Candida albicans growth was inhibited only by hexane extract. Jojoba latex was not effective against Candida albicans at 0.1 and 0.5 ml extracts concentration but showed 5mm zone of inhibition at (1.0 ml). Lower volume (0.1ml) of latex encouraged Aspergillus flavus growth, while at (1.00 ml) reduced its mycelial growth. Thus, jojoba root extracts and latex can be of potential natural antimicrobial agents.
Abstract: MRAM technology provides a combination of fast
access time, non-volatility, data retention and endurance. While a
growing interest is given to two-terminal Magnetic Tunnel Junctions
(MTJ) based on Spin-Transfer Torque (STT) switching as the
potential candidate for a universal memory, its reliability is
dramatically decreased because of the common writing/reading path.
Three-terminal MTJ based on Spin-Orbit Torque (SOT) approach
revitalizes the hope of an ideal MRAM. It can overcome the
reliability barrier encountered in current two-terminal MTJs by
separating the reading and the writing path. In this paper, we study
two possible writing schemes for the SOT-MTJ device based on
recently fabricated samples. While the first is based on precessional
switching, the second requires the presence of permanent magnetic
field. Based on an accurate Verilog-A model, we simulate the two
writing techniques and we highlight advantages and drawbacks of
each one. Using the second technique, pioneering logic circuits based
on the three-terminal architecture of the SOT-MTJ described in this
work are under development with preliminary attractive results.
Abstract: This is the first report from India on a beverage resulting from alcoholic fermentation of the juice of sea buckthorn (Hippophae rhamnoides L) using lab isolated yeast strain. The health promoting potential of the product was evaluated based on its total phenolic content. The most important finding was that under the present fermentation condition, the total phenolic content of the wine product was 689 mg GAE/L. Investigation of influence of bottle ageing on the sea buckthorn wine showed a slight decrease in the phenolic content (534 m mg GAE/L). This study also includes the comparative analysis of the phenolic content of wines from other selected fruit juices like grape, apple and black currant. KeywordsAlcoholic fermentation, Hippophae, Total phenolic content, Wine
Abstract: Chitosan is an attractive polysaccharide obtained by
deacetylation of an abundant natural biopolymer called chitin. Chitin
and chitosan are excellent materials. To improve the potential of
chitin and chitosan modification is needed. In the present study,
grafting of maleic acid on to chitosan by cerium ammonium nitrate in
acetic acid solution was investigated with use of a microwave and
reflux system. The grafted chitosan was characterized by using a
Fourier-transform infrared spectrometry. The solubility and swelling
behavior of grafted chitosans were determined in acetate buffer (pH
3.6), citrophosphate buffer (pH 5.6 and pH 7.0), and boric buffer (pH
9.2) solutions. The sample obtained by microwave system with use of
a chitosan/maleic anhydride/ceric ammonium nitrate 0.2/3.922/0.99
gram of raw material within 30 minute showed the maximum
swelling ratio (13.6) in boric buffer solution.
Abstract: A new target detection technique is presented in this
paper for the identification of small boats in coastal surveillance. The
proposed technique employs an adaptive progressive thresholding (APT) scheme to first process the given input scene to separate any
objects present in the scene from the background. The preprocessing
step results in an image having only the foreground objects, such as
boats, trees and other cluttered regions, and hence reduces the search
region for the correlation step significantly. The processed image is then fed to the shifted phase-encoded fringe-adjusted joint transform
correlator (SPFJTC) technique which produces single and delta-like
correlation peak for a potential target present in the input scene. A
post-processing step involves using a peak-to-clutter ratio (PCR) to determine whether the boat in the input scene is authorized or unauthorized. Simulation results are presented to show that the
proposed technique can successfully determine the presence of an authorized boat and identify any intruding boat present in the given input scene.
Abstract: Optical properties of sputter-deposited ZnS thin films
were investigated as potential replacements for CBD(chemical bath
deposition) CdS buffer layers in the application of CIGS solar cells.
ZnS thin films were fabricated on glass substrates at RT, 150oC, 200oC,
and 250oC with 50 sccm Ar gas using an RF magnetron sputtering
system. The crystal structure of the thin film is found to be zinc blende
(cubic) structure. Lattice parameter of ZnS is slightly larger than CdS
on the plane and thus better matched with that of CIGS. Within a
400-800 nm wavelength region, the average transmittance was larger
than 75%. When the deposition temperature of the thin film was
increased, the blue shift phenomenon was enhanced. Band gap energy
of the ZnS thin film tended to increase as the deposition temperature
increased. ZnS thin film is a promising material system for the CIGS
buffer layer, in terms of ease of processing, low cost, environmental
friendliness, higher transparency, and electrical properties
Abstract: Expression data analysis is based mostly on the
statistical approaches that are indispensable for the study of
biological systems. Large amounts of multidimensional data resulting
from the high-throughput technologies are not completely served by
biostatistical techniques and are usually complemented with visual,
knowledge discovery and other computational tools. In many cases,
in biological systems we only speculate on the processes that are
causing the changes, and it is the visual explorative analysis of data
during which a hypothesis is formed. We would like to show the
usability of multidimensional visualization tools and promote their
use in life sciences. We survey and show some of the
multidimensional visualization tools in the process of data
exploration, such as parallel coordinates and radviz and we extend
them by combining them with the self-organizing map algorithm. We
use a time course data set of transitional cell carcinoma of the bladder
in our examples. Analysis of data with these tools has the potential to
uncover additional relationships and non-trivial structures.
Abstract: Natural organic matter (NOM) is heterogeneous
mixture of organic compounds that enter the water media from
animal and plant remains, domestic and industrial wastes.
Researches showed that NOM is likely precursor material for
disinfection by products (DBPs). Chlorine very commenly used for
disinfection purposes and NOM and chlorine reacts then
Trihalomethane (THM) and Haloacetic acids (HAAs) which are
cancerogenics for human health are produced. The aim of the study is
to search NOM removal by enhanced coagulation from drinking
water source of Eskisehir which is supplied from Porsuk Dam.
Recently, Porsuk dam water is getting highly polluted and therefore
NOM concentration is increasing. Enhanced coagulation studies were
evaluated by measurement of Dissolved Organic Carbon (DOC), UV
absorbance at 254 nm (UV254), and different trihalomethane
formation potential (THMFP) tests. Results of jar test experiments
showed that NOM can be removed from water about 40-50 % of
efficiency by enhanced coagulation. Optimum coagulant type and
coagulant dosages were determined using FeCl3 and Alum.
Abstract: Scalability poses a severe threat to the existing
DRAM technology. The capacitors that are used for storing and
sensing charge in DRAM are generally not scaled beyond 42nm.
This is because; the capacitors must be sufficiently large for reliable
sensing and charge storage mechanism. This leaves DRAM memory
scaling in jeopardy, as charge sensing and storage mechanisms
become extremely difficult. In this paper we provide an overview of
the potential and the possibilities of using Phase Change Memory
(PCM) as an alternative for the existing DRAM technology. The
main challenges that we encounter in using PCM are, the limited
endurance, high access latencies, and higher dynamic energy
consumption than that of the conventional DRAM. We then provide
an overview of various methods, which can be employed to
overcome these drawbacks. Hybrid memories involving both PCM
and DRAM can be used, to achieve good tradeoffs in access latency
and storage density. We conclude by presenting, the results of these
methods that makes PCM a potential replacement for the current
DRAM technology.
Abstract: Gas chromatography (GC) is the most widely used
technique in analytical chemistry. However, GC has high initial cost
and requires frequent maintenance. This paper examines the
feasibility and potential of using a neural network model as an
alternative whenever GC is unvailable. It can also be part of system
verification on the performance of GC for preventive maintenance
activities. It shows the performance of MultiLayer Perceptron (MLP)
with Backpropagation structure. Results demonstrate that neural
network model when trained using this structure provides an
adequate result and is suitable for this purpose. cm.
Abstract: New lead-free ferroelectric relaxor ceramics were
prepared by conventional solid-state synthesis in the BaTiO3-Bi2O3-
Y2O3 systems. Some of these ceramics present a ferroelectric relaxor
with transition temperature close to room temperature. These new
materials are very interesting for applications and can replace leadbased
ceramic to prevent the toxic pollutions during the preparation
state. In the other hand, the energy band diagram shows the
potentiality of these compounds for the solar energy conversion.
Thus, some compositions have been tested successfully for H2
production upon visible light. The best activity occurs in alkaline
media with a rate evolution of about 0.15 mL g-1 mn-1 and a quantum
yield of 1% under polychromatic light.
Abstract: The effect of porous medium on the capillary instability of a cylindrical interface in the presence of axial electric field has been investigated using viscous potential flow theory. In viscous potential flow, the viscous term in Navier-Stokes equation vanishes as
vorticity is zero but viscosity is not zero. Viscosity enters through normal stress balance in the viscous potential flow theory and tangential stresses are not considered. A dispersion relation that accounts for the growth of axisymmetric waves is derived and stability is discussed theoretically as well as numerically. Stability criterion is given by critical value of applied electric field as well as critical wave number. Various graphs have been drawn to show the effect of various physical parameters such as electric field, viscosity ratio, permittivity ratio on the stability of the system. It has been observed that the axial electric field and porous medium both have stabilizing effect on the stability of the system.
Abstract: The purpose of this research was to demonstrate
prevalence of post-exposure preventive measures (PEP) after needlestick
injuries and its relationship with locus of control beliefs in a
sample of medical students. In this cross-sectional study, 300 medical
students with history of having experienced needle stick injuries
(NSI) for at least once filled in a questionnaire to determine if they
perceived themselves to be responsible and effective in preventing
blood born infections after NSI. About 38% of students did not seek
any professional consult or PEP after NSI due to lack of enough time
or access, anxiety about tests results, belief in uselessness of followup
and not being able to change destiny. These 114 students were not
different from others regarding their scores on NSI specific scale of
locus of health control. Thus, the potentiality of NSI locus of control
beliefs in predicting PEP was not seen in this study.
Abstract: Computerized lip reading has been one of the most
actively researched areas of computer vision in recent past because
of its crime fighting potential and invariance to acoustic environment.
However, several factors like fast speech, bad pronunciation,
poor illumination, movement of face, moustaches and beards make
lip reading difficult. In present work, we propose a solution for
automatic lip contour tracking and recognizing letters of English
language spoken by speakers using the information available from
lip movements. Level set method is used for tracking lip contour
using a contour velocity model and a feature vector of lip movements
is then obtained. Character recognition is performed using modified
k nearest neighbor algorithm which assigns more weight to nearer
neighbors. The proposed system has been found to have accuracy
of 73.3% for character recognition with speaker lip movements as
the only input and without using any speech recognition system in
parallel. The approach used in this work is found to significantly
solve the purpose of lip reading when size of database is small.
Abstract: Solid waste can be considered as an urban burden or
as a valuable resource depending on how it is managed. To meet the
rising demand for energy and to address environmental concerns, a
conversion from conventional energy systems to renewable resources
is essential. For the sustainability of human civilization, an
environmentally sound and techno-economically feasible waste
treatment method is very important to treat recyclable waste. Several
technologies are available for realizing the potential of solid waste as
an energy source, ranging from very simple systems for disposing of
dry waste to more complex technologies capable of dealing with
large amounts of industrial waste. There are three main pathways for
conversion of waste material to energy: thermo chemical,
biochemical and physicochemical. This paper investigates the thermo
chemical conversion of solid waste for energy recovery. The
processes, advantages and dis-advantages of various thermo chemical
conversion processes are discussed and compared. Special attention
is given to Gasification process as it provides better solutions
regarding public acceptance, feedstock flexibility, near-zero
emissions, efficiency and security. Finally this paper presents
comparative statements of thermo chemical processes and introduces
an integrated waste management system.
Abstract: Built environments have a large impact on environmental sustainability and if it is not considered properly can negatively affect our planet. The application of transformable intelligent building systems that automatically respond to environmental conditions is one of the best ways that can intelligently assist us to create sustainable environment. The significance of this issue is evident as energy crisis and environmental changes has made the sustainability the main concerns in many societies. The aim of this research is to review and evaluate the importance and influence of transformable intelligent structure on the creation of sustainable architecture. Intelligent systems in current buildings provide convenience through automatically responding to changes in environmental conditions, reducing energy dissipation and increase of the lifecycle of buildings. This paper by analyzing significant intelligent building systems will evaluate the potentials of transformable intelligent systems in the creation of sustainable architecture and environment.
Abstract: Multiphasing of dc-dc converters has been known to give technical and economical benefits to low voltage high power buck regulator modules. A major advantage of multiphasing dc-dc converters is the improvement of input and output performances in the buck converter. From this aspect, a potential use would be in renewable energy where power quality plays an important factor. This paper presents the design of a 2-phase 200W boost converter for battery charging application. Analysis of results from hardware measurement of the boost converter demonstrates the benefits of using multiphase. Results from the hardware prototype of the 2-phase boost converter further show the potential extension of multiphase beyond its commonly used low voltage high current domains.