Abstract: Polymers are one of the most widely used materials in our every day life. The subject of renewable resources has attracted great attention in the last period of time. New polymeric materials derived from renewable resources, like carbohydrates draw attention to public eye especially because of their biocompatibility and biodegradability. The aim of our paper was to obtain environmentally compatible polymers from monosaccharides. Novel glycopolymers based on D-glucose have been obtained from copolymerization of a new monomer carrying carbohydrate moiety with methyl methacrylate (MMA) via free radical bulk polymerization. Differential scanning calorimetry (DSC) was performed in order to study the copolymerization process of the monomer into the chosen co-monomer; the activation energy of this process was evaluated using Ozawa method. The copolymers obtained were characterized using ATR-FTIR spectroscopy. The thermal stability of the obtained products was studied by thermogravimetry (TG).
Abstract: The effect of chemical treatment in CdCl2 and thermal
annealing in 400°C, on the defect structures of potentially useful
ZnS\CdS solar cell thin films deposited onto quartz substrate and
prepared by vacuum deposition method was studied using the
Thermoluminesence (TL) techniques. A series of electron and hole
traps are found in the various deposited samples studied. After
annealing, however, it was observed that the intensity and activation
energy of TL signal increases with loss of the low temperature
electron traps.
Abstract: Sulphur dioxide is a harmful gaseous product that
needs to be minimized in the atmosphere. This research work
investigates the use of zeolite as a possible additive that can improve
the sulphur dioxide capture in wet flue gas desulphurisation
dissolution process. This work determines the effect of temperature,
solid to liquid ratio, acid concentration and stirring speed on the
leaching of zeolite using a pH stat apparatus. The atomic absorption
spectrometer was used to measure the calcium ions from the solution.
It was found that the dissolution rate of zeolite decreased with
increase in solid to liquid ratio and increases with increase in
temperature, stirring speed and acid concentration. The activation
energy for the dissolution rate of zeolite in hydrochloric acid was
found to be 9.29kJ/mol. and therefore the product layer diffusion was
the rate limiting step.
Abstract: The design of a complete expansion that allows for
compact representation of certain relevant classes of signals is a
central problem in signal processing applications. Achieving such a
representation means knowing the signal features for the purpose of
denoising, classification, interpolation and forecasting. Multilayer
Neural Networks are relatively a new class of techniques that are
mathematically proven to approximate any continuous function
arbitrarily well. Radial Basis Function Networks, which make use of
Gaussian activation function, are also shown to be a universal
approximator. In this age of ever-increasing digitization in the
storage, processing, analysis and communication of information,
there are numerous examples of applications where one needs to
construct a continuously defined function or numerical algorithm to
approximate, represent and reconstruct the given discrete data of a
signal. Many a times one wishes to manipulate the data in a way that
requires information not included explicitly in the data, which is
done through interpolation and/or extrapolation.
Tidal data are a very perfect example of time series and many
statistical techniques have been applied for tidal data analysis and
representation. ANN is recent addition to such techniques. In the
present paper we describe the time series representation capabilities
of a special type of ANN- Radial Basis Function networks and
present the results of tidal data representation using RBF. Tidal data
analysis & representation is one of the important requirements in
marine science for forecasting.
Abstract: The production of activated carbon from low or zero cost of agricultural by-products or wastes has received great attention from academics and practitioners due to its economic and environmental benefits. In the production of bamboo furniture, a significant amount of bamboo waste is inevitably generated. Therefore, this research aimed to prepare activated carbons from bamboo furniture waste by chemical (KOH) activation and determine their properties and adsorption capacities for water treatment. The influence of carbonization time on the properties and adsorption capacities of activated carbons was also investigated. The finding showed that the bamboo-derived activated carbons had microporous characteristics. They exhibited high tendency for the reduction of impurities present in effluent water. Their adsorption capacities were comparable to the adsorption capacity of a commercial activated carbon regarding to the reduction in COD, TDS and turbidity of the effluent water.
Abstract: Potassium monopersulfate has been decomposed in
aqueous solution in the presence of Co(II). The effect of the main
operating variables has been assessed. Minimum variations in pH
exert a considerable influence on the process kinetics. Thus, when no
pH adjustment is considered, the actual effect of variables like initial
monopersulfate and/or catalyst concentration may be hindered. As
expected, temperature enhances the monopersulfate decomposition
rate by following the Arrhenius law. The activation energy in the
proximity of 85 kJ/mol has been obtained. Amongst the different
solids tested in the monopersulfate decomposition, only the
perovskite LaTi0.15Cu0.85O3 has shown a significant catalytic activity.
Abstract: The pyrolysis characteristics and kinetics of seven marine biomass, which are fixed Enteromorpha clathrata, floating Enteromorpha clathrata, Ulva lactuca L., Zosterae Marinae L., Thallus Laminariae, Asparagus schoberioides kunth and Undaria pinnatifida (Harv.), were studied with thermogravimetric analysis method. Simultaneously, cornstalk, which is a grass biomass, and sawdust, which is a lignocellulosic biomass, were references. The basic pyrolysis characteristics were studied by using TG- DTG-DTA curves. The results showed that there were three stages (dehydration, dramatic weight loss and slow weight loss) during the whole pyrolysis process of samples. The Tmax of marine biomass was significantly lower than two kinds of terrestrial biomass. Zosterae Marinae L. had a relatively high stability of pyrolysis, but floating Enteromorpha clathrata had lowest stability of pyrolysis and a good combustion characteristics. The corresponding activation energy E and frequency factor A were obtained by Coats-Redfern method. It was found that the pyrolysis reaction mechanism functions of three kinds of biomass are different.
Abstract: It is shown that the relationship of tick-borne
encephalitis virus with the human body comes in two ways, the
development of acute infection with the outcome in convalescence
and long stay by the virus in the body, its persistence in the nervous
tissue with periodic reactivation and prolonged circulating
immunoglobulin M. In spite of the fact that tick-borne encephalitis
virus has a tropism for nerve tissue, involvement in the process of
blood cells is an integral component of the infection. Comprehensive
study of the relation of factors of innate and adaptive immunity in the
tick-borne encephalitis providing insight into the features of chronic
disease.
Abstract: With getting older in the whole population, the
prevalence of stroke and its residual disability is getting higher and
higher recently in Taiwan. The functional electrical stimulation
cycling system (FESCS) is useful for hemiplegic patients. Because
that the muscle of stroke patients is under hybrid activation. The raw
electromyography (EMG) represents the residual muscle force of
stroke subject whereas the peak-to-peak of stimulus EMG indicates the
force enhancement benefiting from ES. It seems that EMG signals
could be used for a parameter of feedback control mechanism. So, we
design the feedback control protocol of FESCS, it includes
physiological signal recorder, FPGA biomedical module, DAC and
electrical stimulation circuit. Using the intensity of real-time EMG
signal obtained from patients, as a feedback control method for the
output voltage of FES-cycling system.
Abstract: The use of bioindicators plants (lichens, bryophytes
and Sphagnum....) in monitoring pollution by heavy metals has been
the subject of several works. However, few studies have addressed
the impact of specific type-s pollutants (fertilizers, pesticides.) on
these organisms.
We propose in this work to make the highlighting effect of NPKs
(NPK: nitrogen-phosphate-potassium-sulfate (NP2O5K2O) (15,15,15),
at concentrations of 10, 20, 30 , 40 and 50mM/L) on the activity of
detoxification enzymes (GSH/GST, CAT, APX and MDA) of plant
bioindicators (mosses and lichens) after treatment for 3 and 7 days.
This study shows the important role of the defense system in the
accumulation and tolerance to chemical pollutants through the
activation of enzymatic (GST (glutathione-S-transferase, APX
(ascorbat peroxidase), CAT (catalase)) and nonenzymatic biomarkers
(GSH (glutathione), MDA (malondialdehyde)) against oxidative
stress generated by the NPKs.
Abstract: Bones are dynamic and responsive organs, they
regulate their strength and mass according to the loads which they are subjected. Because, the Wnt/β-catenin pathway has profound
effects on the regulation of bone mass, we hypothesized that mechanical loading of bone cells stimulates Wnt/β-catenin signaling, which results in the generation of new bone mass.
Mechanical loading triggers the secretion of the Wnt molecule, which after binding to transmembrane proteins, causes GSK-3β (Glycogen synthase kinase 3 beta) to cease the phosphorylation of β-catenin. β-catenin accumulation in the cytoplasm, followed by its
transport into the nucleus, binding to transcription factors (TCF/LEF)
that initiate transcription of genes related to bone formation. To test this hypothesis, we used TOPGAL (Tcf Optimal Promoter
β-galactosidase) mice in an experiment in which cyclic loads were
applied to the forearm. TOPGAL mice are reporters for cells effected
by the Wnt/β-catenin signaling pathway. TOPGAL mice are genetically engineered mice in which transcriptional activation of β-
catenin, results in the production of an enzyme, β-galactosidase. The
presence of this enzyme allows us to localize transcriptional
activation of β-catenin to individual cells, thereby, allowing us to quantify the effects that mechanical loading has on the Wnt/β-catenin pathway and new bone formation. The ulnae of loaded TOPGAL
mice were excised and transverse slices along different parts of the
ulnar shaft were assayed for the presence of β-galactosidase.
Our results indicate that loading increases β-catenin transcriptional
activity in regions where this pathway is already primed (i.e. where basal activity is already higher) in a load magnitude dependent
manner. Further experiments are needed to determine the temporal and spatial activation of this signaling in relation to bone formation.
Abstract: The conjugate gradient optimization algorithm
usually used for nonlinear least squares is presented and is
combined with the modified back propagation algorithm yielding
a new fast training multilayer perceptron (MLP) algorithm
(CGFR/AG). The approaches presented in the paper consist of
three steps: (1) Modification on standard back propagation
algorithm by introducing gain variation term of the activation
function, (2) Calculating the gradient descent on error with
respect to the weights and gains values and (3) the determination
of the new search direction by exploiting the information
calculated by gradient descent in step (2) as well as the previous
search direction. The proposed method improved the training
efficiency of back propagation algorithm by adaptively modifying
the initial search direction. Performance of the proposed method
is demonstrated by comparing to the conjugate gradient algorithm
from neural network toolbox for the chosen benchmark. The
results show that the number of iterations required by the
proposed method to converge is less than 20% of what is required
by the standard conjugate gradient and neural network toolbox
algorithm.
Abstract: Modeling and simulation of fixed bed three-phase
catalytic reactors are considered for wet air catalytic oxidation of
phenol to perform a comparative numerical analysis between tricklebed
and packed-bubble column reactors. The modeling involves
material balances both for the catalyst particle as well as for different
fluid phases. Catalyst deactivation is also considered in a transient
reactor model to investigate the effects of various parameters
including reactor temperature on catalyst deactivation. The
simulation results indicated that packed-bubble columns were
slightly superior in performance than trickle beds. It was also found
that reaction temperature was the most effective parameter in catalyst
deactivation.