The developing behavior of toners (maximum 150000 particles) in a two-component development system was simulated to find out the correlation between experimental results and simulated ones by using the large-scale Discrete Element Method (DEM). The effect of bias voltage, development gap or circumferential speed of a photoreceptor on the developed toner mass per area (DMA) was discussed both in experimental and simulation works. DMA increased with increasing offset voltage due to an increase in the development field, and it decreased with increasing the development gap because of the weakening of the electric field or reduction of a development nip. It also decreased with increasing circumferential speed of the photoreceptor, because the toners had less chances to contact the latent image, and the image was damaged by the magnetic brush under the high speed. The similar tendency was observed both in experimental and simulation works, and the simulation results correlates with experimental ones. Therefore, this simulation method is useful for the analysis of the developing behavior in electrophotographic system and the optimization or designing of this system will be possible.
Estimation of the activities or solubility of small molecules in polymers is essential in a number of process applications such as the mixture separation by polymeric membrane, polymeric membrane preparation, polymer preparation, especially, the selection of membrane material for a predefined separation process. The VTPR EoS-GE group contribution model has been used to predict the activities of water, alkane, and aromatic small molecules in poly(vinyl alcohol), poly(dimethyl siloxane), and polyisobutylene polymeric membrane materials. The influence of temperature and the molar mass of polymer on the activities of small molecules in the polymeric membrane are discussed. It has been shown that the results predicted by the VTPR EoS-GE model are good agreement with the experimental ones, and the total average deviation between the experimental and the calculated is no more than 3%. It should be expected that the VTPR EoS-GE group contribution model could be applied to the polymeric membrane material selection, to the polymeric membrane preparation processes and to the polymeric material preparation processes.
A solid phase of a fatty acid mixture (lauric acid + myristic acid) on a rotating cold cylinder from the binary melt was formed in an annular cylindrical vessel. The growth rate of the solid phase was kept constant by cooling the rotating cold cylinder. The shape of the solid phase formed on the rotating cold cylinder depended on the hydrodynamics of Taylor vortices in the melt phase. The solid phase consisted of a concave part and convex part. We observed the detail structures of the surface and the inside of the solid phase under a microscope, and analyzed the crystallinity of the solid phase by using X-ray diffraction. We measured the weight fraction of myristic acid from the thin slices of the solid phase by gas chromatography. The growth rate of the solid phase decreased as the rotation speed increased or as the temperature of the hot cylinder increased. When the growth rate decreased, the crystalline part of the solid phase obviously increased. The effective distribution coefficient of lauric acid between the solid phase and melt phase increased according to the crystalline of the solid phase. The effective distribution could be well correlated with the growth rate by using our interfacial distribution model.
A lithium silicate (Li4SiO4) absorbent has been developed as a new CO2 absorbent at high temperatures, which emits CO2 at temperatures above 993 K in pure CO2 at 101 kPa. This temperature is approximately 200 K lower than that for well-known CaO. It was used in CH4 steam reforming experiments and higher CH4 conversion was observed for a mixture of a catalyst and an Li4SiO4 pellet, than for a catalyst alone, at around 873 K. In this study, the emission temperature and reproducibility of an Li4SiO4 pellet (5 mm, spherical) in N2 was examined from the viewpoint of building a high-efficiency H2 production system, since the CO2 emission temperature is lower than that in pure CO2. The pellet completely emitted CO2 within 1 h at 873 K, and within 0.5 h at 923 K, and showed high reproducibility, exhibiting almost the same absorption property for 5 cycles.
It has been found that catalytic activity can be promoted with the sintering of some platinum catalysts in some VOCs’ catalytic combustion reactions. Hence, the pre-treatment for these catalysts is always carried out in reactant gas for several hours. Effects of pre-treatment atmosphere, the pre-treatment temperature and the reaction atmosphere on the sintering process were studied in this paper. The results show that the sintering can be observed at high reaction temperature (>523 K) in the reaction conditions. Water steam and reactant substance also plays an important role in the sintering. Moreover, the reaction kinetics parameters for the fresh and the used catalysts in the toluene combustion reaction were calculated with the Mars van Krevelen mechanism.
A high heat resistance plate catalyst, Ni-Al2O3/alloy clad catalyst, made by anodization technology, was applied to a methane steam reforming system. In this work, a two-dimensional coaxial model was proposed to simulate a cylinder methane steam reformer by using this novel catalyst. For the momentum balance, the two widely used models, the Navier–Stokes (NS) and plug flow (PF) models were both validated by the experimental data. All the results indicate that the NS model is in good agreement with the experimental values while the PF model works well in a limited range. On the basis of the model, the effects of catalyst thermal conductivity, channel height, reaction temperature and the length of the catalyst bed on the reactor performance were also discussed.
A reducing method for a detailed reaction mechanism is presented. In the reducing procedure, a reduced mechanism is systematically constructed in three steps by using the parameters obtained in the computation of reaction kinetics. The reducing method is applied to the reduction of the detailed mechanism for NO formation from the oxidation of pyridine. The calculated results with the reduced mechanism obtained by the present method are in good agreement with those obtained by the detailed mechanism. The computational time is significantly shorter than that with the detailed mechanism, although the computational time for the reaction kinetics with the reduced mechanism by the present method is larger than that using the conventional method. Furthermore, the computational time required for the construction of the reduced mechanism by the present method is about one tenth of that required by the conventional method. Therefore, the present reducing method is a powerful tool for the construction of the reduced mechanism.
In order to develop a reaction rate equation for the high concentration CO2, the regeneration reaction of CaCO3 was examined for the corresponding pressure condition in the temperature range 1123–1193 K. It was observed that the reaction rate was controlled by CO2 diffusion during the initial period and thereafter by the chemical reaction. In this study, the reaction rate equation was determined for the reaction-controlled period, which occupies the major part of the entire reaction. The reaction orders for the conversion process and pressure condition were obtained as 0.35 and 2.0, respectively. The reaction rate constant was also obtained, and the activation energy was estimated to be 102.68 kJ/mol.
Linear epitopes of sperm whale myoglobin for a rabbit polyclonal anti-myoglobin antibody were determined from a random-peptide displayed phage library by biopanning using antibody-coupled liposomes (AB-MLVs). Two kinds of positive phages displaying peptides (RNFGADAQ and YDLDIGAD) homological to the myoglobin sequence were obtained after 4 rounds of biopanning. Binding affinities of antibodies, which were fractionated from the anti-myoglobin antibody by specificity to both the peptides, were higher than that of an antibody fraction specific to the peptide that was screened by biopanning using an antibody-coated polystyrene tube (AB-Tube). The epitope identified in this study, N(D)FGADAQ has not been reported as an epitope of the rabbit anti-myoglobin antibody. These results suggest that biopanning using AB-MLVs shows much higher selectivity to recover phages displaying peptides with high affinity and specificity than that using the AB-Tube.
Ergosterol was crystallized from hexane solution by using a novel continuous column crystallizer equipped with a water feeding system. The water feeding system was used to control the water concentration of the crystallization solution at a ppm-level. Precipitates recovered from the bottom of the crystallizer were agglomerates that were a mixture of amorphous solid and monohydrate micro crystals. The water concentration of the crystallization solution played an important role for the size and the crystallinity of the precipitates. Large precipitates having a good filtration property were recovered when the water concentration of the solution was 162 ppm, namely when the mole ratio of water to ergosterol was 0.89.
Biomass is the third largest primary energy resource in the world after coal and oil. Due to its huge potential, the renewable and the corresponding positive role for CO2 reduction, the use of carbonized biomass for energy purpose is expected to increase. The carbonized biomass comes from agricultural waste and forest by-product. Carbonized plant and carbonized coconut cell biomass were mixed with water to study the possibilities of slurry preparation as a carbonized biomass water mixture (CBWM). Beside that, the upgraded coal by an upgraded brown coal (UBC) process was also studied to produce a UBC water mixture (UBCWM) with high coal concentration. The rheological characteristics of CBWM and UBCWM have been conducted by using a stress controlled rheometer. The results indicate that the maximum concentrations of the carbonized plant, carbonized coconut cell biomass, and UBC were 35.9, 51.2, and 61.5 wt%, when respectively using 0.3 wt% of naphthalene sulfonic acid (NSF), polymethacrylate (PMA), and NSF as dispersing additives, and 0.1 wt% of carboxyl methyl cellulose (CMC) as a stabilizing additive.
The process of ozonation is optimized when the gaseous ozone is efficiently dissolved into the liquid to be treated. The characteristics of microbubbles, such as high specific interfacial area, slow rising velocity and high inner pressure, suggest their desirability for the mass transfer of gas. In this study, a new microbubble generation system was developed and applied to an ozone contactor, and its characteristics were investigated in a semi-batch bubble column at different gas and water flow rates. The volumetric mass transfer coefficient increases with the increase of both induced-gas and water flow rates. High ozone transfer efficiency was obtained at low gas flow rates, which indicates that the present gas-induced ozone contactor using microbubbles is a desirable device for the dissolution of ozone at high concentrations.