Abstract: Several different cements have been tested to evaluate
their potential to leach calcium, chromium and aluminum ions in soft
water environment. The research allows comparing some different
cements in order to the potential risk of water contamination. This
can be done only in the same environment. To reach the results in
reasonable short time intervals and to make heavy metals
measurements with high accuracy, demineralized water was used. In
this case the conditions of experiments are far away from the water
supply practice, but short time experiments and measurably high
concentrations of elements in the water solution are an important
advantage. Moreover leaching mechanisms can be recognized, our
experiments reported here refer to this kind of cements evaluation.
Abstract: In spite of the advent of new materials, clay bricks
remain, arguably, the most popular construction materials today.
Nevertheless the low cost and versatility of clay bricks cannot always
be associated with high environmental and sustainable values,
especially in terms of raw material sources and manufacturing
processes. At the same time, the worldwide agricultural footprint is
fast growing, with vast agricultural land cultivation and active
expansion of the agro-based industry. The resulting large quantities of
agricultural wastes, unfortunately, are not always well managed or
utilised. These wastes can be recycled, such as by retrieving fibres
from disposed leaves and fruit bunches, and then incorporated in
brick-making. This way the clay bricks are made a 'greener' building
material and the discarded natural wastes can be reutilised, avoiding
otherwise wasteful landfill and harmful open incineration. This study
examined the physical and mechanical properties of clay bricks made
by adding two natural fibres to a clay-water mixture, with baked and
non-baked conditions. The fibres were sourced from pineapple leaves
(PF) and oil palm fruit bunch (OF), and added within the range of
0.25-0.75 %. Cement was added as a binder to the mixture at 5-15 %.
Although the two fibres had different effects on the bricks produced,
cement appeared to dominate the compressive strength. The
non-baked bricks disintegrated when submerged in water, while the
baked ones displayed cement-dependent characteristics in
water-absorption and density changes. Interestingly, further increase
in fibre content did not cause significant density decrease in both the
baked and non-baked bricks.
Abstract: The combustion of liquid fuel in the porous burner
(PB) was experimented to investigate evaporation mechanism and
combustion behavior. The diesel oil was used as fuel and the pebbles
carefully chosen in the same size like the solid sphere homogeneously
was adopted as the porous media. Two structures of the liquid porous
burner, i.e. the PB without and with installation of porous emitter
(PE), were performed. PE was installed by lower than PB with
distance of 20 cm. The pebbles having porosity (φ) of 0.45 and 0.52
were, respectively, used in PB and PE. The fuel was supplied dropwise
from the top through the PB and the combustion was occurred between
PB and PE. Axial profiles of temperature along the burner length were
measured to clarify the evaporation and combustion phenomena. The
pollutant emission characteristics were monitored at the burner exit.
From the experiment, it was found that the temperature profiles of both
structures decreased with the three ways swirling air flows (QA)
increasing. On the other hand, the temperature profiles increased with
fuel heat input (QF). Obviously, the profile of the porous burner
installed with PE was higher than that of the porous burner without
PE
Abstract: Sensor network applications are often data centric and
involve collecting data from a set of sensor nodes to be delivered
to various consumers. Typically, nodes in a sensor network are
resource-constrained, and hence the algorithms operating in these
networks must be efficient. There may be several algorithms available
implementing the same service, and efficient considerations may
require a sensor application to choose the best suited algorithm. In
this paper, we present a systematic evaluation of a set of algorithms
implementing the data gathering service. We propose a modular
infrastructure for implementing such algorithms in TOSSIM with
separate configurable modules for various tasks such as interest
propagation, data propagation, aggregation, and path maintenance.
By appropriately configuring these modules, we propose a number
of data gathering algorithms, each of which incorporates a different
set of heuristics for optimizing performance. We have performed
comprehensive experiments to evaluate the effectiveness of these
heuristics, and we present results from our experimentation efforts.
Abstract: The use of composite materials in offshore engineering for deep sea oil production riser systems has drawn considerable interest due to the potential weight savings and improvement in durability. The design of composite risers consists of two stages: (1) local design based on critical local load cases, and (2) global analysis of the full length composite riser under global loads and assessment of critical locations. In the first stage, eight different material combinations were selected and their laminate configurations optimised under local load considerations. Stage two includes a final local stress analysis of the critical sections of the riser under the combined loads determined in the global analysis. This paper describes two design methodologies of the composite riser to provide minimum structural weight and shows that the use of off angle fibre orientations in addition to axial and hoop reinforcements offer substantial weight savings and ensure the structural capacity.
Abstract: A series of 1-(1H-benzimidazol-2-yl)-3-(substituted phenyl)-2-propen-1-one were allowed to react with hydrazine hydrate and phenyl hydrazine in submitted reactions to get pyrazoline and phenyl pyrazoline derivatives. All the compounds entered for screening at the Tuberculosis Antimicrobial Acquisition and Coordinating Facility (TAACF) for their in vitro antibacterial activity against Mycobacterium tuberculosis H37Rv strain (ATCC 27294) using Microplate Alamar Blue Assay (MABA) susceptibility test. The results expressed as MIC (minimum inhibitory concentration) in μg/mL. Among the fifteen compounds, eight compounds were found to have MIC values less than 10 μg/mL. These were subjected for cytotoxicity assay in VERO cells to determine CC50 (cytotoxic concentration 50%) values and finally SI (Selectivity Index) were calculated. Compound (XV) 2-[5-(4- fluorophenyl)-1-phenyl-4,5-dihydro-1H-3-pyrazolyl]-1Hbenzimidazole was considered the best candidate of the series that could be a good starting point to develop new lead compounds in the fight against tuberculosis.
Abstract: This paper presents a new approach for automatic
document categorization. Exploiting the logical structure of the
document, our approach assigns a HTML document to one or more
categories (thesis, paper, call for papers, email, ...). Using a set of
training documents, our approach generates a set of rules used to
categorize new documents. The approach flexibility is carried out
with rule weight association representing your importance in the
discrimination between possible categories. This weight is
dynamically modified at each new document categorization. The
experimentation of the proposed approach provides satisfactory
results.
Abstract: Enzymatic hydrolysis of starch from natural sources
finds potential application in commercial production of alcoholic
beverage and bioethanol. In this study the effect of starch
concentration, temperature, time and enzyme concentration were
studied and optimized for hydrolysis of cassava (Manihot esculenta)
starch powder (of mesh 80/120) into glucose syrup by immobilized
(using Polyacrylamide gel) a-amylase using central composite
design. The experimental result on enzymatic hydrolysis of cassava
starch was subjected to multiple linear regression analysis using
MINITAB 14 software. Positive linear effect of starch concentration,
enzyme concentration and time was observed on hydrolysis of
cassava starch by a-amylase. The statistical significance of the model
was validated by F-test for analysis of variance (p < 0.01). The
optimum value of starch concentration temperature, time and enzyme
concentration were found to be 4.5% (w/v), 45oC, 150 min, and 1%
(w/v) enzyme. The maximum glucose yield at optimum condition
was 5.17 mg/mL.
Abstract: In this paper we consider the problem of change
detection and non stationary signals tracking. Using parametric
estimation of signals based on least square lattice adaptive filters we
consider for change detection statistical parametric methods using
likelihood ratio and hypothesis tests. In order to track signals
dynamics, we introduce a compensation procedure in the adaptive
estimation. This will improve the adaptive estimation performances
and fasten it-s convergence after changes detection.
Abstract: This paper deals with under actuator dynamic systems such as spring-mass-damper system when the number of control variable is less than the number of state variable. In order to apply optimal control, the controllability must be checked. There are many objective functions to be selected as the goal of the optimal control such as minimum energy, maximum energy and minimum jerk. As the objective function is the first priority, if one like to have the second goal to be applied; however, it could not fit in the objective function format and also avoiding the vector cost for the objective, this paper will illustrate the problem of under actuator dynamic systems with the easiest to deal with comparing between minimum energy and minimum jerk.
Abstract: A universal current-mode biquad is described which
represents an economical variant of well-known KHN (Kerwin,
Huelsman, Newcomb) voltage-mode filter. The circuit consists of
two multiple-output OTAs and of two grounded capacitors. Utilizing
simple splitter of the input current and a pair of jumpers, all the basic
2nd-order transfer functions can be implemented. The principle is
verified by Spice simulation on the level of a CMOS structure of
OTAs.
Abstract: The load frequency control problem of power systems has attracted a lot of attention from engineers and researchers over the years. Increasing and quickly changing load demand, coupled with the inclusion of more generators with high variability (solar and wind power generators) on the network are making power systems more difficult to regulate. Frequency changes are unavoidable but regulatory authorities require that these changes remain within a certain bound. Engineers are required to perform the tricky task of adjusting the control system to maintain the frequency within tolerated bounds. It is well known that to minimize frequency variations, a large proportional feedback gain (speed regulation constant) is desirable. However, this improvement in performance using proportional feedback comes about at the expense of a reduced stability margin and also allows some steady-state error. A conventional PI controller is then included as a secondary control loop to drive the steadystate error to zero. In this paper, we propose a robust controller to replace the conventional PI controller which guarantees performance and stability of the power system over the range of variation of the speed regulation constant. Simulation results are shown to validate the superiority of the proposed approach on a simple single-area power system model.
Abstract: In this paper we propose a novel RF LDMOS structure which employs a thin strained silicon layer at the top of the channel and the N-Drift region. The strain is induced by a relaxed Si0.8 Ge0.2 layer which is on top of a compositionally graded SiGe buffer. We explain the underlying physics of the device and compare the proposed device with a conventional LDMOS in terms of energy band diagram and carrier concentration. Numerical simulations of the proposed strained silicon laterally diffused MOS using a 2 dimensional device simulator indicate improvements in saturation and linear transconductance, current drivability, cut off frequency and on resistance. These improvements are however accompanied with a suppression in the break down voltage.
Abstract: Using of natural lighting has come into prominence in
constructed buildings, especially in last ten years, under scope of
energy efficiency. Natural lighting methods are one of the methods
that aim to take advantage of day light in maximum level and
decrease using of artificial lighting. Increasing of day light amount in
buildings by using suitable methods will give optimum result in
terms of comfort and energy saving when the daylight-artificial light
integration is ensured with a suitable control system. Using of natural
light in places that require lighting will ensure energy saving in great
extent. With this study, it is aimed to save energy used for purpose of
lighting. Under this scope, lighting of a scanning laboratory of a
hospital was realized by using a lighting automation containing
natural and artificial lighting. In natural lighting, light pipes were
used and in artificial lighting, dimmable power LED modules were
used. Necessity of lighting was followed with motion sensors. The
lighting automation containing natural and artificial light was ensured
with fuzzy logic control. At the scanning laboratory where this
application was realized, energy saving in lighting was obtained.
Abstract: The objectives of this research are to search the
management pattern of Bang Khonthi lodging entrepreneurs for
sufficient economy ways, to know the threat that affects this sector
and design fit arrangement model to sustain their business with
Samut Songkram style. What will happen if they do not use this
approach? Will they have a financial crisis? The data and information
are collected by informal discussions with 8 managers and 400
questionnaires. A mixed methods of both qualitative research and
quantitative research are used. Bent Flyvbjerg-s phronesis is utilized
for this analysis. Our research will prove that sufficient economy can
help small business firms to solve their problems. We think that the
results of our research will be a financial model to solve many
problems of the entrepreneurs and this way will can be a model for
other provinces of Thailand.
Abstract: This paper presents a constrained valley detection
algorithm. The intent is to find valleys in the map for the path planning
that enables a robot or a vehicle to move safely. The constraint to the
valley is a desired width and a desired depth to ensure the space for
movement when a vehicle passes through the valley. We propose an
algorithm to find valleys satisfying these 2 dimensional constraints.
The merit of our algorithm is that the pre-processing and the
post-processing are not necessary to eliminate undesired small valleys.
The algorithm is validated through simulation using digitized
elevation data.
Abstract: This paper presents a portable robot that is to use for
welding process in shipbuilding yard. It has six degree of freedom and
3kg payload capability. Its weight is 21.5kg so that human workers can
carry it to the work place. Its body mainly made of magnesium alloy
and aluminum alloy for few parts that require high strength. Since the
distance between robot and controller should be 50m at most, the robot
controller controls the robot through EtherCAT. RTX and KPA are
used for real time EtherCAT control on Windows XP. The
performance of the developed robot was satisfactory, in welding of U
type cell in shipbuilding yard.
Abstract: CIM is the standard formalism for modeling management
information developed by the Distributed Management Task
Force (DMTF) in the context of its WBEM proposal, designed to
provide a conceptual view of the managed environment. In this
paper, we propose the inclusion of formal knowledge representation
techniques, based on Description Logics (DLs) and the Web Ontology
Language (OWL), in CIM-based conceptual modeling, and then we
examine the benefits of such a decision. The proposal is specified
as a CIM metamodel level mapping to a highly expressive subset
of DLs capable of capturing all the semantics of the models. The
paper shows how the proposed mapping provides CIM diagrams with
precise semantics and can be used for automatic reasoning about the
management information models, as a design aid, by means of newgeneration
CASE tools, thanks to the use of state-of-the-art automatic
reasoning systems that support the proposed logic and use algorithms
that are sound and complete with respect to the semantics. Such a
CASE tool framework has been developed by the authors and its
architecture is also introduced. The proposed formalization is not
only useful at design time, but also at run time through the use of
rational autonomous agents, in response to a need recently recognized
by the DMTF.
Abstract: The development of many measurement and inspection systems of products based on real-time image processing can not be carried out totally in a laboratory due to the size or the temperature of the manufactured products. Those systems must be developed in successive phases. Firstly, the system is installed in the production line with only an operational service to acquire images of the products and other complementary signals. Next, a recording service of the image and signals must be developed and integrated in the system. Only after a large set of images of products is available, the development of the real-time image processing algorithms for measurement or inspection of the products can be accomplished under realistic conditions. Finally, the recording service is turned off or eliminated and the system operates only with the real-time services for the acquisition and processing of the images. This article presents a systematic performance evaluation of the image compression algorithms currently available to implement a real-time recording service. The results allow establishing a trade off between the reduction or compression of the image size and the CPU time required to get that compression level.
Abstract: The study applied a combination of organisational learning models (Senge, 1994: Pedler, Burgoyne and Boydell, 1991) and later adopted fifteen organisational learning principles with one of the biggest energy providers in South East Asia. The purposes of the current study were to: a) investigate the company-s practices on fifteen organisational learning principles; b) explore the perceptions and expectations of its employees in relations to the principles; and c) compare the perceptions and expectations between management and non-management staff toward the fifteen factors. One hundred and ten employees responded on a designed questionnaire and the results indicated that the company was practicing activities that associated with organisational learning principles. Also, according to the T-test results, significant differences between management and non-management respondents were found. Research implications are also provided.