Abstract: Air quality in Setapak district of Kuala Lumpur was
studied by analysing the rainwater chemical composition using ion
chromatography method. Twelve sampling sites were selected and
120 rainwater samples were collected in the period of 10 weeks. The
results of this study were compared to the earlier published data and
the evaluation showed that the NO3
- ion concentration increased from
0.41 to 3.32 ppm, while SO4
2- ion concentration increased from 0.39
to 3.26 ppm over the past two decades that is mostly due to rapid
urban development of the city. However, it was found that the
chemical composition for both residential and industrial areas does
not have significant difference. Most of the rainwater samples
showed alkaline pH (pH > 5.6). The possible factors for such alkaline
pH in rainwater samples are assumed to be the marine sources,
biomass burning and alkaline character of soil particles.
Abstract: In this research, effect of combustion reaction
mechanism on direct initiation of detonation has been studied
numerically. For this purpose, reaction mechanism has been
simulated by using a three-step chemical kinetics model. The reaction
scheme consists sequentially of a chain-initiation and chainbranching
step, followed by a temperature -independent chaintermination.
In a previous research, the effect of chain-branching on
the direct initiation of detonation is studied. In this research effect of
chain-initiation on direct initiation of detonation is investigated. For
the investigation, first a characteristic time (τ) for each step of
mechanism, which includes effect of different kinetics parameters, is
defined. Then the effect of characteristic time of chain-initiation (τI)
on critical initiation energy is studied. It is seen that increasing τI,
causes critical initiation energy to be increased. Drawing detonation's
shock pressure diagrams for different cases, shows that in small value
of τI , kinetics has more important effect on the behavior of the wave.
Abstract: This study investigates CO2 mitigation by methanol
synthesis from flue gas CO2 and H2 generation through water
electrolysis. Electrolytic hydrogen generation is viable provided that
the required electrical power is supplied from renewable energy
resources; whereby power generation from renewable resources is yet
commercial challenging. This approach contribute to zero-emission,
moreover it produce oxygen which could be used as feedstock for
chemical process. At ZPC, however, oxygen would be utilized
through partial oxidation of methane in autothermal reactor (ATR);
this makes ease the difficulties of O2 delivery and marketing. On the
other hand, onboard hydrogen storage and consumption; in methanol
plant; make the project economically more competitive.
Abstract: We study the problem of reconstructing a three dimensional binary matrices whose interiors are only accessible through few projections. Such question is prominently motivated by the demand in material science for developing tool for reconstruction of crystalline structures from their images obtained by high-resolution transmission electron microscopy. Various approaches have been suggested to reconstruct 3D-object (crystalline structure) by reconstructing slice of the 3D-object. To handle the ill-posedness of the problem, a priori information such as convexity, connectivity and periodicity are used to limit the number of possible solutions. Formally, 3Dobject (crystalline structure) having a priory information is modeled by a class of 3D-binary matrices satisfying a priori information. We consider 3D-binary matrices with periodicity constraints, and we propose a polynomial time algorithm to reconstruct 3D-binary matrices with periodicity constraints from two orthogonal projections.
Abstract: Evaporator is an important and widely used heat
exchanger in air conditioning and refrigeration industries. Different
methods have been used by investigators to increase the heat transfer
rates in evaporators. One of the passive techniques to enhance heat
transfer coefficient is the application of microfin tubes. The
mechanism of heat transfer augmentation in microfin tubes is
dependent on the flow regime of two-phase flow. Therefore many
investigations of the flow patterns for in-tube evaporation have been
reported in literatures. The gravitational force, surface tension and
the vapor-liquid interfacial shear stress are known as three dominant
factors controlling the vapor and liquid distribution inside the tube. A
review of the existing literature reveals that the previous
investigations were concerned with the two-phase flow pattern for
flow boiling in horizontal tubes [12], [9]. Therefore, the objective of
the present investigation is to obtain information about the two-phase
flow patterns for evaporation of R-134a inside horizontal smooth and
microfin tubes. Also Investigation of heat transfer during flow
boiling of R-134a inside horizontal microfin and smooth tube have
been carried out experimentally The heat transfer coefficients for
annular flow in the smooth tube is shown to agree well with Gungor
and Winterton-s correlation [4]. All the flow patterns occurred in the
test can be divided into three dominant regimes, i.e., stratified-wavy
flow, wavy-annular flow and annular flow. Experimental data are
plotted in two kinds of flow maps, i.e., Weber number for the vapor
versus weber number for the liquid flow map and mass flux versus
vapor quality flow map. The transition from wavy-annular flow to
annular or stratified-wavy flow is identified in the flow maps.
Abstract: The soil ecology of the organic and mineral soil layers
of laurel-leaved and Cryptomeria japonica forest in the Kasuga-yama
Hill Primeval Forest (Nara, Japan) was assessed. The number of
bacteria obtained by the dilution plate count method was less than
0.05% of those counted by the direct microscopic count. We therefore
found that forest soil contains large numbers of non-culturable
bacteria compared with agricultural soils. The numbers of bacteria and
fungi obtained by both the dilution plate count and the direct
microscopic count were larger in the deeper horizons (F and H) of the
organic layer than in the mineral soil layer. This suggests that active
microbial metabolism takes place in the organic layer. The numbers of
bacteria and the length of fungal hyphae obtained by the direct count
method were greater in the H horizon than in the F horizon. The direct
microscopic count revealed numerous non-culturable bacteria and
fungi in the soil. The ratio of fungal to bacterial biomass was lower in
the laurel-leaved forest soil. The fungal biomass was therefore
relatively low in the laurel-leaved forest soil due to differences in
forest vegetation.
Abstract: This paper presents a novel algorithm for path planning of mobile robots in known 3D environments using Binary Integer Programming (BIP). In this approach the problem of path planning is formulated as a BIP with variables taken from 3D Delaunay Triangulation of the Free Configuration Space and solved to obtain an optimal channel made of connected tetrahedrons. The 3D channel is then partitioned into convex fragments which are used to build safe and short paths within from Start to Goal. The algorithm is simple, complete, does not suffer from local minima, and is applicable to different workspaces with convex and concave polyhedral obstacles. The noticeable feature of this algorithm is that it is simply extendable to n-D Configuration spaces.
Abstract: Since supply chains highly impact the financial
performance of companies, it is important to optimize and analyze
their Key Performance Indicators (KPI). The synergistic combination
of Particle Swarm Optimization (PSO) and Monte Carlo simulation is
applied to determine the optimal reorder point of warehouses in
supply chains. The goal of the optimization is the minimization of the
objective function calculated as the linear combination of holding and
order costs. The required values of service levels of the warehouses
represent non-linear constraints in the PSO. The results illustrate that
the developed stochastic simulator and optimization tool is flexible
enough to handle complex situations.
Abstract: Electronic Systems are the core of everyday lives.
They form an integral part in financial networks, mass transit,
telephone systems, power plants and personal computers. Electronic
systems are increasingly based on complex VLSI (Very Large Scale
Integration) integrated circuits. Initial electronic design automation is
concerned with the design and production of VLSI systems. The next
important step in creating a VLSI circuit is Physical Design. The
input to the physical design is a logical representation of the system
under design. The output of this step is the layout of a physical
package that optimally or near optimally realizes the logical
representation. Physical design problems are combinatorial in nature
and of large problem sizes. Darwin observed that, as variations are
introduced into a population with each new generation, the less-fit
individuals tend to extinct in the competition of basic necessities.
This survival of fittest principle leads to evolution in species. The
objective of the Genetic Algorithms (GA) is to find an optimal
solution to a problem .Since GA-s are heuristic procedures that can
function as optimizers, they are not guaranteed to find the optimum,
but are able to find acceptable solutions for a wide range of
problems. This survey paper aims at a study on Efficient Algorithms
for VLSI Physical design and observes the common traits of the
superior contributions.
Abstract: In studying the possibility of using plants as
rhizoremediators, barley and grass mixture which showed resistance
to various concentrations of oil were selected. The minimum
inhibitory effect of oil on these plants by morphological parameters
such as survival of plants, length and biomass of shoot and root
compared with the control was showed. In determining physiological
parameters, a slight decrease in the number of chlorophyll a and b in
the leaves of plants was noted. The differences in the ratio of the total
surface of the roots to the work surface with the growth of plants in
soil with oil in the study of adsorption of the root surface were
showed.
Abstract: The global chaos synchronization for a class of time-delayed power systems is investigated via observer-based approach. By employing the concepts of quadratic stability theory and generalized system model, a new sufficient criterion for constructing an observer is deduced. In contrast to the previous works, this paper proposes a theoretical and systematic design procedure to realize chaos synchronization for master-slave power systems. Finally, an illustrative example is given to show the applicability of the obtained scheme.
Abstract: The objective of this paper is to present the
development of the frame of Chulalongkorn University team in TSAE
Auto Challenge Student Formula and Student Formula SAE
Competition of Japan. Chulalongkorn University's SAE team, has
established since year 2003, joined many competitions since year 2006
and became the leading team in Thailand. Through these 5 years, space
frame was the most selected and developed year by year through six
frame designs. In this paper, the discussions on the conceptual design
of these frames are introduced, focusing on the mass and torsional
stiffness improvement. The torsional stiffness test was performed on
the real used frames and the results are compared. It can be seen that
the 2010-2011 frame is firstly designed based on the analysis and
experiment that considered the required mass and torsional stiffness.
From the torsional stiffness results, it can be concluded that the frames
were developed including the decreasing of mass and the increasing
torsional stiffness by applying many techniques.
Abstract: This paper maps the structure of the social network of
the 2011 class ofsixty graduate students of the Masters of Science
(Knowledge Management) programme at the Nanyang Technological
University, based on their friending relationships on Facebook. To
ensure anonymity, actual names were not used. Instead, they were
replaced with codes constructed from their gender, nationality, mode
of study, year of enrollment and a unique number. The relationships
between friends within the class, and among the seniors and alumni
of the programme wereplotted. UCINet and Pajek were used to plot
the sociogram, to compute the density, inclusivity, and degree,
global, betweenness, and Bonacich centralities, to partition the
students into two groups, namely, active and peripheral, and to
identify the cut-points. Homophily was investigated, and it was
observed for nationality and study mode. The groups students formed
on Facebook were also studied, and of fifteen groups, eight were
classified as dead, which we defined as those that have been inactive
for over two months.
Abstract: We describe a novel method for removing noise (in wavelet domain) of unknown variance from microarrays. The method is based on a smoothing of the coefficients of the highest subbands. Specifically, we decompose the noisy microarray into wavelet subbands, apply smoothing within each highest subband, and reconstruct a microarray from the modified wavelet coefficients. This process is applied a single time, and exclusively to the first level of decomposition, i.e., in most of the cases, it is not necessary a multirresoltuion analysis. Denoising results compare favorably to the most of methods in use at the moment.
Abstract: This paper presents a model for the characterization
and selection of beeswaxes for use as base substitute tissue for the
manufacture of objects suitable for external radiotherapy using
megavoltage photon beams. The model of characterization was
divided into three distinct stages: 1) verification of aspects related to
the origin of the beeswax, the bee species, the flora in the vicinity of
the beehives and procedures to detect adulterations; 2) evaluation of
physical and chemical properties; and 3) evaluation of beam
attenuation capacity. The chemical composition of the beeswax
evaluated in this study was similar to other simulators commonly
used in radiotherapy. The behavior of the mass attenuation coefficient
in the radiotherapy energy range was comparable to other simulators.
The proposed model is efficient and enables convenient assessment
of the use of any particular beeswax as a base substitute tissue for
radiotherapy.
Abstract: The aim of this study was to estimate the frequency of
EBV infection in Hodgkin's lymphoma (HL) and non-Hodgkin's
lymphoma (NHL) occurring in Jordanian patients. A total of 55
patients with lymphoma were examined in this study. Of 55 patients,
30 and 25 were diagnosed as HL and NHL, respectively. The four
HL subtypes were observed with the majority of the cases exhibited
the mixed cellularity (MC) subtype followed by the nodular sclerosis
(NS). The high grade was found to be the commonest subtype of
NHL in our sample, followed by the low grade. The presence of EBV
virus was detected by immunostating for expression of latent
membrane protein-1 (LMP-1). The frequency of LMP-1 expression
occurred more frequent in patients with HL (60.0%) than in patients
with NHL (32.0%). The frequency of LMP-1 expression was also
higher in patients with MC subtype (61.11%) than those patients with
NS (28.57%). No age or gender difference in occurrence of EBV
infection was observed among patient with HL. By contrast, the
prevalence of EBV infection in NHL patients aged below 50 was
lower (16.66%) than in NHL patients aged 50 or above (46.15%). In
addition, EBV infection was more frequent in females with NHL
(38.46%) than in male with NHL (25%). In NHL cases, the
frequency of EBV infection in intermediate grade (60.0%) was high
when compared with frequency of low (25%) or high grades (25%).
In conclusion, analysis of LMP-1 expression indicates an important
role for this viral oncogene in the pathogenesis of EBV-associated
malignant lymphomas. These data also support the previous findings
that people with EBV may develop lymphoma and that efforts to
maintain low lymphoma should be considered for people with EBV
infection.
Abstract: We consider a Principal-Agent model with the
Principal being a seller who does not know perfectly how much the
buyer (the Agent) is willing to pay for the good. The buyer-s
preferences are hence his private information. The model corresponds
to the nonlinear pricing problem of Maskin and Riley. We assume
there are three types of Agents. The model is solved using
“informational rents" as variables. In the last section we present the
main characteristics of the optimal contracts in asymmetric
information and some possible extensions of the model.
Abstract: The use of renewable energy sources incl. biogas has become topical in accordance with the increasing demand for energy, decrease of fossil energy resources and the efforts to reduce greenhouse gas emissions as well as to increase energy independence from the territories where fossil energy resources are available.
As the technologies of biogas production from agricultural biomass develop, risk assessment and risk management become necessary for farms producing such a renewable energy. The need for risk assessments has become particularly topical when discussions on changing the biogas policy in the EU take place, which may influence the development of the sector in the future, as well as the operation of existing biogas facilities and their income level.
The current article describes results of the risk assessment for farms producing biomass from agriculture biomass in Latvia, the risk assessment system included 24 risks, that affect the whole biogas production process and the obtained results showed the high significance of political and production risks.
Abstract: The analytical solutions for geodesic acoustic
eigenmodes in tokamak plasmas with circular concentric magnetic
surfaces are found. In the frame of ideal magnetohydrodynamics the
dispersion relation taking into account the toroidal coupling between
electrostatic perturbations and electromagnetic perturbations with
poloidal mode number |m| = 2 is derived. In the absence of such
a coupling the dispersion relation gives the standard continuous
spectrum of geodesic acoustic modes. The analysis of the existence
of global eigenmodes for plasma equilibria with both off-axis
and on-axis maximum of the local geodesic acoustic frequency is
performed.
Abstract: This paper reports a new approach on identifying the
individuality of persons by using parametric classification of multiple
mental thoughts. In the approach, electroencephalogram (EEG)
signals were recorded when the subjects were thinking of one or
more (up to five) mental thoughts. Autoregressive features were
computed from these EEG signals and classified by Linear
Discriminant classifier. The results here indicate that near perfect
identification of 400 test EEG patterns from four subjects was
possible, thereby opening up a new avenue in biometrics.