Abstract: In the last decade, carbohydrates have attracted great
attention as renewable resources for the chemical industry.
Carbohydrates are abundantly found in nature in the form of
monomers, oligomers and polymers, or as components of
biopolymers and other naturally occurring substances. As natural
products, they play important roles in conferring certain physical,
chemical, and biological properties to their carrier molecules.The
synthesis of this particular carbohydrate glycomonomer is part of our
work to obtain biodegradable polymers. Our current paper describes
the synthesis and characterization of a novel carbohydrate
glycomonomer starting from D-glucose, in several synthesis steps,
that involve the protection/deprotection of the D-glucose ring via
acetylation, tritylation, then selective deprotection of the aromaticaliphatic
protective group, in order to obtain 1,2,3,4-tetra-O-acetyl-
6-O-allyl-β-D-glucopyranose. The glycomonomer was then obtained
by the allylation in drastic conditions of 1,2,3,4-tetra-O-acetyl-6-Oallyl-
β-D-glucopyranose with allylic alcohol in the presence of
stannic chloride, in methylene chloride, at room temperature. The
proposed structure of the glycomonomer, 2,3,4-tri-O-acetyl-1,6-di-
O-allyl-β-D-glucopyranose, was confirmed by FTIR, NMR and
HPLC-MS spectrometry. This glycomonomer will be further
submitted to copolymerization with certain acrylic or methacrylic
monomers in order to obtain competitive plastic materials for
applications in the biomedical field.
Abstract: The setting agent Ca(OH)2 for activation of slag
cement is used in the proportions of 0%, 2%, 4%, 6%, 8% and 10%
by various methods (substitution and addition by mass of slag
cement). The physical properties of slag cement activated by the
calcium hydroxide at anhydrous and hydrated states (fineness,
particle size distribution, consistency of the cement pastes and setting
times) were studied. The activation method by the mineral activator
of slag cement (latent hydraulicity) accelerates the hydration process
and reduces the setting times of the cement activated.
Abstract: This paper presents the modeling and simulation of a hybrid proton exchange membrane fuel cell (PEMFC) with an energy storage system for use in a stand-alone distributed generation (DG) system. The simulation model consists of fuel cell DG, lead-acid battery, maximum power point tracking and power conditioning unit which is modeled in the MATLAB/Simulink platform. Poor loadfollowing characteristics and slow response to rapid load changes are some of the weaknesses of PEMFC because of the gas processing reaction and the fuel cell dynamics. To address the load-tracking issues in PEMFC, a hybrid PEMFC and battery storage system is considered and modelled. The model utilizes PEMFC as the main energy source whereas the battery functions as energy storage to compensate for the limitations of PEMFC.Simulation results are given to show the overall system performance under light and heavyloading conditions.
Abstract: Charging and discharging phenomenon on the surface
of materials can be found in plasma display panel, spacecraft
charging, high voltage insulator, etc. This report gives a simple
explanation on this phenomenon. A scanning electron microscope
was used not only as a tool to produce energetic electron beam to
charge an insulator without metallic coating and to produce a surface
discharging (surface breakdown/flashover) but also to observe the
visible charging and discharging on the sample surface. A model of
electric field distribution on the surface was developed in order to
explain charging and discharging phenomena. Since charging and
discharging process involves incubation time, therefore this process
can be used to evaluate the insulation property of materials under
electron bombardment.
Abstract: The concept of the new government should focus on
forming a new relationship between public servants and citizens of
the state, formed on the principles of transparency, accountability,
protection of citizens' rights. These principles are laid down in the
problem of administrative reform in the Republic of Kazakhstan.
Also, this wish arises, contributing to the improvement of the system
of political management in our country. For the full realization of the
goals is necessary to develop a special state program designed to
improve the regulatory framework for public service, improving
training, retraining and advanced training of civil servants, forming a
system of incentives in public service and other activities aimed at
achieving the efficiency of the entire system government.
Abstract: Bubble columns have a variety of applications in
absorption, bio-reactions, catalytic slurry reactions, and coal
liquefaction; because they are simple to operate, provide good heat
and mass transfer, having less operational cost. The use of
Computational Fluid Dynamics (CFD) for bubble column becomes
important, since it can describe the fluid hydrodynamics on both local
and global scale. Euler- Euler two-phase fluid model has been used to
simulate two-phase (air and water) transient up-flow in bubble
column (15cm diameter) using FLUENT6.3. These simulations and
experiments were operated over a range of superficial gas velocities
in the bubbly flow and churn turbulent regime (1 to16 cm/s) at
ambient conditions. Liquid velocity was varied from 0 to 16cm/s. The
turbulence in the liquid phase is described using the standard k-ε
model. The interactions between the two phases are described
through drag coefficient formulations (Schiller Neumann). The
objectives are to validate CFD simulations with experimental data,
and to obtain grid-independent numerical solutions. Quantitatively
good agreements are obtained between experimental data for hold-up
and simulation values. Axial liquid velocity profiles and gas holdup
profiles were also obtained for the simulation.
Abstract: Fossil fuel-firing power plants dominate electric
power generation in Taiwan, which are also the major contributor to
Green House gases (GHG). CO2 is the most important greenhouse
gas that cause global warming. This paper penetrates the relationship
between carbon trading for GHG reduction and power generation
expansion planning (GEP) problem for the electrical utility. The
Particle Swarm Optimization (PSO) Algorithm is presented to deal
with the generation expansion planning strategy of the utility with
independent power providers (IPPs). The utility has to take both the
IPPs- participation and environment impact into account when a new
generation unit is considering expanded from view of supply side.
Abstract: This article gives a short preview of the new software
created especially for palletizing process in automated production
systems. Each chapter of this article is about problem solving in
development of modules in Java programming language. First part
describes structure of the software, its modules and data flow
between them. Second part describes all deployment methods, which
are implemented in the software. Next chapter is about twodimensional
editor created for manipulation with objects in each
layer of the load and gives calculations for collision control. Module
of virtual reality used for three-dimensional preview and creation of
the load is described in the fifth chapter. The last part of this article
describes communication and data flow between control system of
the robot, vision system and software.
Abstract: A two-parameter fatigue model explicitly accounting for the cyclic as well as the mean stress was used to fit static and fatigue data available in literature concerning carbon fiber reinforced composite laminates subjected tension-tension fatigue. The model confirms the strength–life equal rank assumption and predicts reasonably the probability of failure under cyclic loading. The model parameters were found by best fitting procedures and required a minimum of experimental tests.
Abstract: This paper describes about dynamic reconfiguration to
miniaturize arithmetic circuits in general-purpose processor. Dynamic
reconfiguration is a technique to realize required functions by
changing hardware construction during operation. The proposed
arithmetic circuit performs floating-point arithmetic which is
frequently used in science and technology. The data format is
floating-point based on IEEE754. The proposed circuit is designed
using VHDL, and verified the correct operation by simulations and
experiments.
Abstract: In this manuscript, we discuss the problem of determining the optimum stratification of a study (or main) variable based on the auxiliary variable that follows a uniform distribution. If the stratification of survey variable is made using the auxiliary variable it may lead to substantial gains in precision of the estimates. This problem is formulated as a Nonlinear Programming Problem (NLPP), which turn out to multistage decision problem and is solved using dynamic programming technique.
Abstract: This paper describes a newly designed decentralized
nonlinear control strategy to control a robot manipulator. Based on the
concept of the nonlinear state feedback theory and decentralized
concept is developed to improve the drawbacks in previous works
concerned with complicate intelligent control and low cost effective
sensor. The control methodology is derived in the sense of Lyapunov
theorem so that the stability of the control system is guaranteed. The
decentralized algorithm does not require other joint angle and velocity
information. Individual Joint controller is implemented using a digital
processor with nearly actuator to make it possible to achieve good
dynamics and modular. Computer simulation result has been
conducted to validate the effectiveness of the proposed control scheme
under the occurrence of possible uncertainties and different reference
trajectories. The merit of the proposed control system is indicated in
comparison with a classical control system.
Abstract: This paper presents a new methodology to select test
cases from regression test suites. The selection strategy is based on
analyzing the dynamic behavior of the applications that written in
any programming language. Methods based on dynamic analysis are
more safe and efficient. We design a technique that combine the code
based technique and model based technique, to allow comparing the
object oriented of an application that written in any programming
language. We have developed a prototype tool that detect changes
and select test cases from test suite.
Abstract: The Reverse Monte Carlo (RMC) simulation is applied in the study of an aqueous electrolyte LiCl6H2O. On the basis of the available experimental neutron scattering data, RMC computes pair radial distribution functions in order to explore the structural features of the system. The obtained results include some unrealistic features. To overcome this problem, we use the Hybrid Reverse Monte Carlo (HRMC), incorporating an energy constraint in addition to the commonly used constraints derived from experimental data. Our results show a good agreement between experimental and computed partial distribution functions (PDFs) as well as a significant improvement in pair partial distribution curves. This kind of study can be considered as a useful test for a defined interaction model for conventional simulation techniques.
Abstract: The objective of this work was to investigate flow
properties of powdered infant formula samples. Samples were
purchased at a local pharmacy and differed in composition. Lactose
free infant formula, gluten free infant formula and infant formulas
containing dietary fibers and probiotics were tested and compared
with a regular infant formula sample which did not contain any of
these supplements. Particle size and bulk density were determined
and their influence on flow properties was discussed. There were no
significant differences in bulk densities of the samples, therefore the
connection between flow properties and bulk density could not be
determined. Lactose free infant formula showed flow properties
different to standard supplement-free sample. Gluten free infant
formula with addition of probiotic microorganisms and dietary fiber
had the narrowest particle size distribution range and exhibited the
best flow properties. All the other samples exhibited the same
tendency of decreasing compaction coefficient with increasing flow
speed, which means they all become freer flowing with higher flow
speeds.
Abstract: Paced Auditory Serial Addition Test (PASAT) has
been used as a common research tool for different neurological
disorders like Multiple Sclerosis. Recently, technology let
researchers to introduce a new versions of the visual test, the paced
visual serial addition test (PVSAT). In this paper, the computerized
version of these two tests is introduced. Beside the number of true
responses are interpreted, the reaction time of subjects are calculated
by the software. We hypothesize that paying attention to the reaction
time may be valuable. For this purpose, sixty eight female normal
subjects and fifty eight male normal subjects are enrolled in the
study. We investigate the similarity between the PASAT3 and
PVSAT3 in number of true responses and the new criterion (the
average reaction time of each subject). The similarity between two
tests were rejected (p-value = 0.000) which means that these two test
differ. The effect of sex in the tests were not approved since the pvalues
of different between PASAT3 and PVSAT3 in both sex is the
same (p-value = 0.000) which means that male and female subjects
performed the tests at no different level of performance. The new
criterion shows a negative correlation with the age which offers aged
normal subjects may have the same number of true responses as the
young subjects but they have latent responses. This will give prove
for the importance of reaction time.
Abstract: Prickly pear (Opuntia spp) fruit has received renewed
interest since it contains a betalain pigment that has an attractive
purple colour for the production of juice. Prickly pear juice was
prepared by homogenizing the fruit and treating the pulp with 48 g of
pectinase from Aspergillus niger. Titratable acidity was determined
by diluting 10 ml prickly pear juice with 90 ml deionized water and
titrating to pH 8.2 with 0.1 N NaOH. Brix was measured using a
refractometer and ascorbic acid content assayed
spectrophotometrically. Colour variation was determined
colorimetrically (Hunter L.a.b.). Hunter L.a.b. analysis showed that
the red purple colour of prickly pear juice had been affected by juice
treatments. This was indicated by low light values of colour
difference meter (CDML*), hue, CDMa* and CDMb* values. It was
observed that non-treated prickly pear juice had a high (colour
difference meter of light) CDML* of 3.9 compared to juice
treatments (range 3.29 to 2.14). The CDML* significantly (p
Abstract: In this paper, the melting of a semi-infinite body as a
result of a moving laser beam has been studied. Because the Fourier
heat transfer equation at short times and large dimensions does not
have sufficient accuracy; a non-Fourier form of heat transfer
equation has been used. Due to the fact that the beam is moving in x
direction, the temperature distribution and the melting pool shape are
not asymmetric. As a result, the problem is a transient threedimensional
problem. Therefore, thermophysical properties such as
heat conductivity coefficient, density and heat capacity are functions
of temperature and material states. The enthalpy technique, used for
the solution of phase change problems, has been used in an explicit
finite volume form for the hyperbolic heat transfer equation. This
technique has been used to calculate the transient temperature
distribution in the semi-infinite body and the growth rate of the melt
pool. In order to validate the numerical results, comparisons were
made with experimental data. Finally, the results of this paper were
compared with similar problem that has used the Fourier theory. The
comparison shows the influence of infinite speed of heat propagation
in Fourier theory on the temperature distribution and the melt pool
size.
Abstract: Managers as the key employees have a very important role in maintaining the workforce performance which is critical to the
construction companies- success in the future. If motivated employees start with motivated managers probably it would seem
plausible if the de-motivated ones start with de-motivated managers. This study aims to analyze the importance of motivated managers to
their successes and construction companies- successes. In this study,
a quantitative method was used and the study area was in Medan, North Sumatera. Questionnaire survey was distributed directly to
construction companies in Medan which are listed in the
Construction Services Development Board. A total of 60 managers responded and the completed questionnaires were analyzed using the
descriptive analysis. The results indicated that the respondents acknowledge the importance of motivation among themselves to the
projects and construction companies- success, implying that it is vital o maintain the motivation and good performance of the workforce.
Abstract: Checkpointing is one of the commonly used techniques to provide fault-tolerance in distributed systems so that the system can operate even if one or more components have failed. However, mobile computing systems are constrained by low bandwidth, mobility, lack of stable storage, frequent disconnections and limited battery life. Hence, checkpointing protocols having lesser number of synchronization messages and fewer checkpoints are preferred in mobile environment. There are two different approaches, although not orthogonal, to checkpoint mobile computing systems namely, time-based and index-based. Our protocol is a fusion of these two approaches, though not first of its kind. In the present exposition, an index-based checkpointing protocol has been developed, which uses time to indirectly coordinate the creation of consistent global checkpoints for mobile computing systems. The proposed algorithm is non-blocking, adaptive, and does not use any control message. Compared to other contemporary checkpointing algorithms, it is computationally more efficient because it takes lesser number of checkpoints and does not need to compute dependency relationships. A brief account of important and relevant works in both the fields, time-based and index-based, has also been included in the presentation.