Abstract: With the drastically growth in optical communication
technology, a lossless, low-crosstalk and multifunction optical switch
is most desirable for large-scale photonic network. To realize such a
switch, we have introduced the new architecture of optical switch
that embedded many functions on single device. The asymmetrical
architecture of OXADM consists of 3 parts; selective port, add/drop
operation, and path routing. Selective port permits only the interest
wavelength pass through and acts as a filter. While add and drop
function can be implemented in second part of OXADM architecture.
The signals can then be re-routed to any output port or/and perform
an accumulation function which multiplex all signals onto single path
and then exit to any interest output port. This will be done by path
routing operation. The unique features offered by OXADM has
extended its application to Fiber to-the Home Technology (FTTH),
here the OXADM is used as a wavelength management element in
Optical Line Terminal (OLT). Each port is assigned specifically with
the operating wavelengths and with the dynamic routing management
to ensure no traffic combustion occurs in OLT.
Abstract: The process for predicting the ballistic properties of a liquid rocket engine is based on the quantitative estimation of idealized performance deviations. In this aim, an equilibrium chemistry procedure is firstly developed and implemented in a Fortran routine. The thermodynamic formulation allows for the calculation of the theoretical performances of a rocket thrust chamber. In a second step, a computational fluid dynamic analysis of the turbulent reactive flow within the chamber is performed using a finite volume approach. The obtained values for the “quasi-real" performances account for both turbulent mixing and chemistryturbulence coupling. In the present work, emphasis is made on the combustion efficiency performance for which deviation is mainly due to radial gradients of static temperature and mixture ratio. Numerical values of the characteristic velocity are successfully compared with results from an industry-used code. The results are also confronted with the experimental data of a laboratory-scale rocket engine.
Abstract: A series of Ti based shape memory alloys with
composition of Ti50Ni49Cr1, Ti50Ni47Cr3 and Ti50Ni45Cr5 were
developed by vacuum arc-melting under a purified argon atmosphere.
The histometric and corrosion evaluation of Ti-Ni-Cr shape memory
alloys have been considered in this research work. The alloys were
developed by vacuum arc melting and implanted subcutaneously in
rabbits for 4, 8 and 12 weeks. Metallic implants were embedded in
order to determine the outcome of implantation on histometric and
corrosion evaluation of Ti-Ni-Cr metallic strips. Encapsulating
membrane formation around the alloys was minimal in the case of all
materials. After histomorphometric analyses it was possible to
demonstrate that there were no statistically significant differences
between the materials. Corrosion rate was also determined in this
study which is within acceptable range. The results showed the Ti-
Ni-Cr alloy was neither cytotoxic, nor have any systemic reaction on
living system in any of the test performed. Implantation shows good
compatibility and a potential of being used directly in vivo system.
Abstract: Martensitic stainless steels have been extensively used for their good corrosion resistance and better mechanical properties. Heat treatment was suggested as one of the most excellent ways to this regard; hence, it affects the microstructure, mechanical and corrosion properties of the steel. In the current research work the microstructural changes and corrosion behavior in an AISI 420A stainless steel exposed to temperatures in the 980-1035oC range were investigated. The heat treatment is carried out in vacuum furnace within the said temperature range. The quenching of the samples was carried out in oil, brine and water media. The formation and stability of passive film was studied by Open Circuit Potential, Potentiodynamic polarization and Electrochemical Scratch Tests. The Electrochemical Impedance Spectroscopy results simulated with Equivalent Electrical Circuit suggested bilayer structure of outer porous and inner barrier oxide films. The quantitative data showed thick inner barrier oxide film retarded electrochemical reactions. Micrographs of the quenched samples showed sigma and chromium carbide phases which prove the corrosion resistance of steel alloy.
Abstract: The nanofiber sheet of Multiwall Cabon Nanotube
(MWCNTs)/Polyacylonitile (PAN) composites was fabricated from
electrospun nanofiber. Firstly the surface of MWCNTs was
chemically modified, comparing two different techniques consisting
of admicellar polymerization and functionalization to improve the
dispersion and prevent the aggregation in the PAN matrix. The
modified MWCNTs were characterized by the dispersion in
dimethylformamide (DMF) solvent, Laser particle size, and FTRaman.
Lastly, DSC, SEM and mechanical properties of the
nanofiber sheet were examined. The results show that the mechanical
properties of the nanofiber sheet prepared from admicellar
polymerization-modified MWCNTs were higher than those of the
others.
Abstract: Effective cooling of electronic equipment has emerged
as a challenging and constraining problem of the new century. In the
present work the feasibility and effectiveness of jet impingement
cooling on electronics were investigated numerically and
experimentally. Studies have been conducted to see the effect of the
geometrical parameters such as jet diameter (D), jet to target
spacing (Z) and ratio of jet spacing to jet diameter (Z/D) on the heat
transfer characteristics. The values of Reynolds numbers considered
are in the range 7000 to 42000. The results obtained from the
numerical studies are validated by conducting experiments. From the
studies it is found that the optimum value of Z/D ratio is 5. For a
given Reynolds number, the Nusselt number increases by about 28%
if the diameter of the nozzle is increased from 1mm to 2mm.
Correlations are proposed for Nusselt number in terms of Reynolds
number and these are valid for air as the cooling medium.
Abstract: The aims of this paper are to study the efficacy of
chitosan nanoparticles in stimulating specific antibody against
A/H1N1 influenza antigen in mice. Chitosan nanoparticles (CSN)
were characterized by TEM. The results showed that the average size
of CSN was from 80nm to 106nm. The efficacy of A/H1N1 influenza
vaccine loaded on the surface of CSN showed that loading efficiency
of A/H1N1 influenza antigen on CSN was from 93.75 to 100%. Safe
property of the vaccine were tested. In 10 days post vaccination,
group of CSN 30 kDa and 300 kDa loaded A/H1N1 influenza antigen
were the rate of immune response on mice to be 100% (9/9) higher
than Al(OH)3 and other adjuvant. 100% mice in the experiment of all
groups had immune response in 20 days post vaccination. The results
also showed that HI titer of the group using CSN 300 kDa as an
adjuvant increased significantly up to 3971 HIU, over three-fold
higher than the Al(OH)3 adjuvant, chitosan (CS), and one hundredfold
than the A/H1N1 antigen only. Stability of the vaccine
formulation was investigated.
Abstract: We estimate snow velocity and snow drift density on hilly terrain under the assumption that the drifting snow mass can be represented using a micro-continuum approach (i.e. using a nonclassical mechanics approach assuming a class of fluids for which basic equations of mass, momentum and energy have been derived). In our model, the theory of coupled stress fluids proposed by Stokes [1] has been employed for the computation of flow parameters. Analyses of bulk drift velocity, drift density, drift transport and mass transport of snow particles have been carried out and computations made, considering various parametric effects. Results are compared with those of classical mechanics (logarithmic wind profile). The results indicate that particle size affects the flow characteristics significantly.
Abstract: In distributed resource allocation a set of agents must assign their resources to a set of tasks. This problem arises in many real-world domains such as distributed sensor networks, disaster rescue, hospital scheduling and others. Despite the variety of approaches proposed for distributed resource allocation, a systematic formalization of the problem, explaining the different sources of difficulties, and a formal explanation of the strengths and limitations of key approaches is missing. We take a step towards this goal by using a formalization of distributed resource allocation that represents both dynamic and distributed aspects of the problem. In this paper we present a new idea for target tracking in sensor networks and compare it with previous approaches. The central contribution of the paper is a generalized mapping from distributed resource allocation to DDCSP. This mapping is proven to correctly perform resource allocation problems of specific difficulty. This theoretical result is verified in practice by a simulation on a realworld distributed sensor network.
Abstract: This research investigates the factors that influence moral judgments when dealing with ethical dilemmas in the organizational context. It also investigates the antecedents of individual ethical ideology (idealism and relativism). A mixed method study, which combines qualitative (field study) and quantitative (survey) approaches, was used in this study. An initial model was developed first, which was then fine-tuned based on field studies. Data were collected from managers in Malaysian large organizations. The results of this study reveal that in-group collectivism culture, power distance culture, parental values, and religiosity were significant as antecedents of ethical ideology. However, direct effects of these variables on moral judgment were not significant. Furthermore, the results of this study confirm the significant effects of ethical ideology on moral judgment. This study provides valuable insight into evaluating the validity of existing theory as proposed in the literature and offers significant practical implications.
Abstract: Field mapping activity for an active volcano mainly in
the Torrid Zone is usually hampered by several problems such as steep
terrain and bad atmosphere conditions. In this paper we present a
simple solution for such problem by a combination Synthetic Aperture
Radar (SAR) and geostatistical methods. By this combination, we
could reduce the speckle effect from the SAR data and then estimate
roughness distribution of the pyroclastic flow deposits. The main
purpose of this study is to detect spatial distribution of new pyroclastic
flow deposits termed as P-zone accurately using the β°data from two
RADARSAT-1 SAR level-0 data. Single scene of Hyperion data and
field observation were used for cross-validation of the SAR results.
Mt. Merapi in central Java, Indonesia, was chosen as a study site and
the eruptions in May-June 2006 were examined. The P-zones were
found in the western and southern flanks. The area size and the longest
flow distance were calculated as 2.3 km2 and 6.8 km, respectively. The
grain size variation of the P-zone was mapped in detail from fine to
coarse deposits regarding the C-band wavelength of 5.6 cm.
Abstract: Phase locked loops (PLL) and delay locked loops (DLL) play an important role in establishing coherent references (phase of carrier and symbol timing) in digital communication systems. Fully digital receiver including digital carrier synchronizer and symbol timing synchronizer fulfils the conditions for universal multi-mode communication receiver with option of symbol rate setting over several digit places and long-term stability of requirement parameters. Afterwards it is necessary to realize PLL and DLL in synchronizer in digital form and to approach to these subsystems as a discrete representation of analog template. Analysis of discrete phase locked loop (DPLL) or discrete delay locked loop (DDLL) and technique to determine their characteristics based on analog (continuous-time) template is performed in this posed paper. There are derived transmission response and error function for 1st order discrete locked loop and resulting equations and graphical representations for 2nd order one. It is shown that the spectrum translation due to sampling takes effect at frequency characteristics computing for specific values of loop parameters.
Abstract: Coagulation of water involves the use of coagulating
agents to bring the suspended matter in the raw water together for
settling and the filtration stage. Present study is aimed to examine the
effects of aluminum sulfate as coagulant in conjunction with Moringa
Oleifera Coagulant Protein as coagulant aid on turbidity, hardness,
and bacteria in turbid water. A conventional jar test apparatus was
employed for the tests. The best removal was observed at a pH of 7
to 7.5 for all turbidities. Turbidity removal efficiency was resulted
between % 80 to % 99 by Moringa Oleifera Coagulant Protein as
coagulant aid. Dosage of coagulant and coagulant aid decreased with
increasing turbidity. In addition, Moringa Oleifera Coagulant Protein
significantly has reduced the required dosage of primary coagulant.
Residual Al+3 in treated water were less than 0.2 mg/l and meets the
environmental protection agency guidelines. The results showed that
turbidity reduction of % 85.9- % 98 paralleled by a primary
Escherichia coli reduction of 1-3 log units (99.2 – 99.97%) was
obtained within the first 1 to 2 h of treatment. In conclusions,
Moringa Oleifera Coagulant Protein as coagulant aid can be used for
drinking water treatment without the risk of organic or nutrient
release. We demonstrated that optimal design method is an efficient
approach for optimization of coagulation-flocculation process and
appropriate for raw water treatment.
Abstract: In this work we develop an object extraction method
and propose efficient algorithms for object motion characterization.
The set of proposed tools serves as a basis for development of objectbased
functionalities for manipulation of video content. The
estimators by different algorithms are compared in terms of quality
and performance and tested on real video sequences. The proposed
method will be useful for the latest standards of encoding and
description of multimedia content – MPEG4 and MPEG7.
Abstract: The importance of nurturing, accumulating, and efficiently deploying knowledge resources through formal structures and organisational mechanisms is well understood. Recent trends in knowledge management (KM) highlight that the effective creation and transfer of knowledge can also rely upon extra-organisational channels, such as, informal networks. The perception exists that the role of informal networks in knowledge creation and performance has been underestimated in the organisational context. Literature indicates that many managers fail to comprehend and successfully exploit the potential role of informal networks to create value for their organisations. This paper investigates: 1) whether managers share work-specific knowledge with informal contacts within and outside organisational boundaries; and 2) what do they think is the importance of this knowledge collaboration in their learning and work outcomes.
Abstract: Located within the tropical belt region, there are
certain rules which should implemented in creating a passive
sustainable housing design in Malaysia. Traditional Malay house
possess a strong character with certain special spaces to create a
sustainable house which suit to the tropical climate in Malaysia. One
of the special space known as verandah or serambi gantung, create
various advantages in solving various issues. However, this special
space is not extremely being applied currently which produce major
issues in term of social and environmental aspects. Hence, this
phenomena create a negative impact to the occupant while Malaysia
already has a best housing design previously. Therefore, this paper
aims to explore both of the main issues mentioned above and reveal
the advantages of implementing verandah into passive sustainable
housing design in Malaysia. A systematic literature review is the
main methodology in this research to identify the various advantages
about verandah.. The study reveals that verandah is the best solution
in term of social and environmental issues and should be
implemented in current housing design in Malaysia.
Abstract: The restoration of extinct ponds is considered as one
of ways to gain new retention capacities for water which is getting
much more important issue with respect to expected impacts of a
climate change. However, there are also other pressures on the
landscape which must be all taken into consideration when making a
decision on the possible restoration of extinct ponds. The research
presented here focuses besides others on the restoration of former
ponds which could be important for both the flood protection and
drought impacts prevention. The first step of the methodology
development for the assessment of such areas is the assessment of
their present state. In this paper, the results of land use types
assessment for 22 localities are presented. These results confirm the
assumption that the most present land use type in such areas is the
permanent grassland. However, the spectra of land use types present
in extinct pond areas is very diverse and include besides others also
airport areas and industry.
Abstract: PCMs have always been viewed as a suitable
candidate for off peak thermal storage, particularly for refrigeration
systems, due to the high latent energy densities of these materials.
However, due to the need to have them encapsulated within a
container this density is reduced. Furthermore, PCMs have a low
thermal conductivity which reduces the useful amount of energy
which can be stored. To consider these factors, the true energy
storage density of a PCM system was proposed and optimised for
PCMs encapsulated in slabs. Using a validated numerical model of
the system, a parametric study was undertaken to investigate the
impact of the slab thickness, gap between slabs and the mass flow
rate. The study showed that, when optimised, a PCM system can
deliver a true energy storage density between 53% and 83% of the
latent energy density of the PCM.
Abstract: Semantic Web services will enable the semiautomatic
and automatic annotation, advertisement, discovery,
selection, composition, and execution of inter-organization business
logic, making the Internet become a common global platform where
organizations and individuals communicate with each other to carry
out various commercial activities and to provide value-added
services. There is a growing consensus that Web services alone will
not be sufficient to develop valuable solutions due the degree of
heterogeneity, autonomy, and distribution of the Web. This paper
deals with two of the hottest R&D and technology areas currently
associated with the Web – Web services and the Semantic Web. It
presents the synergies that can be created between Web Services and
Semantic Web technologies to provide a new generation of eservices.
Abstract: The mechanical properties including flexural and
tensile of neat vinyl ester and polymer based on layered silicate
nanocomposite materials are discussed. The addition of layered
silicate into the polymer matrix increased the tensile and flexural
modulus up to 1 wt.% clay loading. The incorporation of more clay
resulted in decreasing the mechanical properties which was traced to
the existence of aggregation layers. Likewise, up to 1 wt.% clay
loading, the thermal behaviour showed significant improvements and
at higher clay loading the thermal pattern was reduced. The
aggregation layers imparted a negative impact on the overall
mechanical and thermal properties. Wide Angle X-ray Diffraction,
Scanning Electron Microscopy and Transmission Electron
Microscopy were utilised in order to characterise the interlamellar
structure of nanocomposites.