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The aim of this study was to develop a pH-sensitive ternary system of chitosan, κ-carrageenan, and carboxymethylcellulose sodium salt (CMC) that can serve as a controlled release system. Encapsulation of curcumin in chitosan was achieved by transforming the present colloidal suspension into hydrogels via cryotropic gel formation. The frozen hydrogel specimens (cryogels) were freeze-dried for preservation and investigation. It was reported that, when the ratio of κ-carrageenan to NaCMC was kept constant, the cooling rate was found to determine the type of release between burst type and controlled first-order-rate type [1]. The microstructural morphology of freeze-dried specimens was observed with a Scanning Electron Microscope (SEM) to be affected by the cooling rate. The faster cooling rate produced specimens with slightly larger pore size and, as a result, higher amount of curcumin released at 2 days. Swelling tests of the hydrogels in buffer solutions of different pH values showed that acidic media had a pronounced effect on swelling compared to the neutral and alkaline media. The faster cooling rate produced specimens that had higher structural strength against swelling despite the fact that the specimens had larger pore size and faster controlled release rate.

Plasma treatment of activated carbon (AC) was found to be an efficient method to enhance phenol removal by ozonation in a three-phase fluidized-bed reactor. The plasma treatment extended porous structure, changed surface morphologies, and produced oxygen functional groups on the surface of AC. Plasma-treated activated carbon together with O3 gave the best removal result, in which phenol was completely decomposed within 10 min (with pseudo first-order rate constant k = 0.286 min1), while untreated AC without O3 showed the worst result (k = 0.024 min1). Consequently, AC modified by plasma was shown to be a good material for removal of organic pollutants and yield superb performance in an integrated process with ozone in a fluidized-bed reactor.

Cryogel based oil encapsulation was attempted with a ternary system of colloidal chitosan, κ-carrageenan, and carboxymethylcellulose sodium salt (NaCMC). Favourable formulations of this ternary system that caused irreversible sol-gel transition by freezing (cryogelation) were found in this study, and the oil phase that contained a selected model food ingredient (curcumin) was successfully encapsulated in this prepared cryogel matrix. The encapsulation yields were found to vary from ca 89 to 99%, and the values were influenced by the cooling protocol used during freezing, thereby indicating that the gel formation kinetics was intimately related to the degree of encapsulation. The release behaviours of the ingredient were investigated in aqueous systems. The release curves showed that both a burst release and a first order release were achieved simply by changing the freezing condition. Freezing could modify the gel formation of the present cryogel, and the resulting structural modification evidently controlled the oil encapsulation manner. The prepared cryogels were found to be sensitive to the ambient pH. It was suggested that the ternary system of chitosan, κ-carrageenan, and NaCMC is an interesting matrix for designing controlled release system.

Cryogel based encapsulation was attempted to entrap oil phase (containing curcumin) with a ternary system of colloidal chitosan, κ-carrageenan, and carboxy methylcellulose sodium salt (NaCMC). The cryotropic gel formation was investigated by varying the cooling rate during freezing and type of polymer suspension. The microstructure of the resulting curcumin cryogels revealed oil droplets entrapped in the cryogel matrix. The encapsulation yield for two types of suspension was found to vary from 83.89 to 99.37%. Controlled release of the curcumin in an aqueous system could be maintained for 4 days, and the released amount of curcumin was found to vary from 41.1-59.9%. The encapsulation yield as well as the released pattern and amount of curcumin were influenced by the cooling protocol used during freezing. The release patterns were found to be sensitive to the ambient aqueous pH and, interestingly, either a burst release or a first order release was achievable simply by changing the freezing condition. These results suggested that freezing could modify the gel formation of the present cryogel, and the resulting structural modification evidently controlled the oil encapsulation manner. The present ternary system (chitosan, κ- carrageenan, and NaCMC) is an interesting matrix for designing controlled release system in a food system.

Abstract: Typical rice mills generally generate tonnes of biomass which is rice husks and a significant quantity of coarse and fine dusts from the paddy, resulting in public health concern. Instead of normal air cyclones which are not efficient for collecting fine soft-hair (detached pubescence) particles smaller than a few microns, a new system using packed beds of rice husks was developed for collection fine dusts. It was found that the rice-husk packed beds could exhibit an effective performance in capturing fine dusts at various dust loadings with collection efficiency higher than 85% by mass. The filtrating phenomenon could be observed as an integrated effect of cake and deep-bed filtrations due to the heavy dust loads, agglomeration of dusts, and cohesion between the dusts and bed of irregularly shaped rice husks. Both the pressure drop across the bed and the overall filtration efficiency remarkably increased at the initial clean stage, then increased more slowly due to the recurrent fracture of the dust cake layer. [Copyright &y& Elsevier]

Abstract: The titanate nanostructures with high UV absorption characteristics could be fabricated by hydrothermal method within a temperature range of 90–150°C. TEM, XRD, BET analyses, and UV–vis spectroscopy were employed to elucidate the synthesized titanate nanostructure characteristics which were microstructure, phase transformation, specific surface area, and band gap energy, respectively. With an increase in the hydrothermal treating temperature from 90 to 120°C, the specific surface area of titanate nanostructures was increased from 83 to 258m2/g, while the band gap energy of titanate nanostructures was increased from 3.44 to 3.84eV and then slightly decreased to 3.81eV at 150°C. The fabricated titanate nanostructures could exhibit higher UV adsorption capability but lower photocatalytic activity when compared with that of commercial TiO2 powders. [Copyright &y& Elsevier]

Abstract: Selective synthesis of well aligned multi-walled carbon nanotubes (MW-CNT) and multi-shelled carbon nanocapsule (MS-CNC) using pyrolysis of naphthalene with the presence of ferrocene was experimentally examined. With higher mole fraction of naphthalene to ferrocene, more MW-CNTs could be synthesized due to higher concentration of carbonaceous precursors emerging from the decomposed naphthalene. Based on kinetic analysis, at lower temperature, MW-CNTs could preferably be synthesized due to the controlled supply of carbonaceous clusters to get onto the surface of Fe clusters. On the other hand, at temperature higher than 900°C the Fe clusters become more active to catalyze carbonaceous precursors to undergo self assembling process of MS-CNCs. With cheaper cost of naphthalene compared with other high-value hydrocarbons, usage of naphthalene would provide an advantage of reasonably economical synthesis of MW-CNT or MS-CNC. [Copyright &y& Elsevier]

Abstract: Influence of fluidizing air velocity, temperature and atomizing air pressure, as well as types of raw materials on the size distribution, shape and flow properties of pharmaceutical granules, which were tabletized using a single punch tableting machine, was experimentally investigated. The granules prepared at the fluidizing air velocity of 0.8m/s had average particle size larger than those obtained at higher air velocity. Meanwhile the fluidizing air temperature had moderate effect on the average particle size of the granules. However, an increase in the atomizing air pressure resulted in an increase in amount of fine particles, leading to the smaller mean particle size. From microscopic analysis, a primary lactose particle wetted by binder had several contact points with other particles inside the prepared granules. Based on granule morphology, it can be implied that the granules are formed by the so-called snowballing mechanism, leading to the relatively spherical structure. In tabletization, the granules with higher average particle size provided tablets with the less weight variation and friability. Meanwhile, the tablets produced from lactose–corn starch mixture had shorter disintegration time than those of lactose powder only. [Copyright &y& Elsevier]

Abstract: Rawhide split was hydrolysed separately by two proteolytic enzymes, papain and neutrase. The effects of enzymatic conditions of the hydrolysis reaction were investigated. During the first 10min of the enzymatic hydrolysis, the yield of the hydrolysed protein increased sharply, then it slowly increased or became essentially constant due to the limited availability of the substrate. The optimum hydrolysis conditions of papain and neutrase for highest protein yield are at 70°C, pH 6–7 and 40–50°C, pH 6–7, respectively. The product from papain hydrolysis is a gelatin with low gel strength and viscosity, while that from neutrase hydrolysis is collagen hydrolysate with viscosity as low as water. This is considered to indicate that longer fragments of protein are obtained from papain hydrolysis than that from neutrase implying different mechanisms of papain and neutrase hydrolysis. [Copyright &y& Elsevier]

Highly filled systems prepared by compression molding of Hevea brasiliensis woodflour filled polybenzoxazine composites with high mechanical properties and reduced water uptake has been developed. The effects of percent filler content and particle size of woodflour on the obtained composite's properties were examined. The low melt viscosity of BA‐a type polybenzoxazine allows substantial amount of woodflour to be easily incorporated into the composites. The results showed that mechanical properties from dynamic mechanical analysis and flexural test at filler content below the optimum filler packing show approximately linear relationship with filler loading. The outstanding compatibility between the woodflour and the polybenzoxazine matrix is evidently seen from the large improvement in the composite's Tg and char yield. Scanning electron micrographs of the composite also reveals substantially strong interface between the woodflour filler and the polybenzoxazine matrix. Water absorption of the composites is greatly reduced with increasing the amount of polybenzoxazine due to the inherent low water absorption of the matrix. The polybenzoxazine is; therefore, a highly attractive candidate as high performance lignocellulosic binder or adhesive and other related applications. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1240–1253, 2006

Most conventional methods of process design ignore the stochastic nature of the process and its param eters ; only deterministic models are employed, and the solutions obtained are at best only approxima tions. To allow for the uncertainty of designs based on such a procedure, gross safety factors must be added to the design variables based on the deterministic models.An alternative approach is to introduce stochastic variability directly into the process model and to use stochastic simulation to estimate the process outputs and design parameters. By using stochastic simulations which incorporate random inputs and ran dom parameters, one can obtain sample estimates of the expected values and expected variances of the output variables. From these and the characteristics of the probability distributions of the output vari ables, one can show when the expected values of the outputs of stochastic process models differ from those of deterministic models in which the random variables are replaced by their expected values and what safety factors are necessary for a satisfactorydesign.As an example, we have developed a stochastic dynamic mathematical model for a wastewater treatment plant. The output of the plant was simulated for a period of several days under different random input conditions and different probability distributions of parameters. Differences between the deterministic and stochastic responses of the model are described, as is the effect of frequency of fluctuations of the stochastic inputs on responses of the model and on their variances.Of particular interest is the use of the results of the simulations, stochastic and deterministic, to estimate safety (overdesign) factors that should be used in designs based on deterministic models. The validity of the propagation-of-variance formula- i.e., the relation used to compute the sample vari ances of the outputs of a nonlinear stochastic model in the unsteady state from the sample variances of the inputs and parameters - is demonstrated. With the aid of this relation, overdesign factors can be esti mated from the magnitudes of the standard deviations of the outputs.Although stochastic analysis cannot reduce the uncer tainty in design, it can provide a more quantitative assessment of the uncertainty than can deterministic design and so can lead to better designs of process plants.

Air flow through a porous refractory was experimentally studied at a large mean free path region and the resulting pressure drop across the porous medium was measured to evaluate the three-dimensional complexity of the refractory. A new method to evaluate the pore structure of a porous medium has been proposed. It is composed of the measurement of pressure drop and the determination of the effective specific surface area of the medium at the same mass flow rate but at a different absolute gas pressure and the evaluation of the pore structure through fractal analysis. This approach is can be used to measure any pore structure.

Monte Carlo simulation techniques have been used to characterize the stochastic responses of the components of a solar heated and cooled house. Random variables with specified ensemble means, standard deviations, and probability distributions were introduced as inputs and parameters into the model equations for the house, and the equations solved repeatedly to provide samples of the component outputs. The character of the frequency distributions of the outputs, their means and standard deviations, and time statistics are discussed as well as implications with respect to the design of similar systems.