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941.
Mi-Sug Kim Jong Ho Kim Hyeon-Soo Park Yle Shik Sun Hong-Seok Kim Kyung Hee Choi Jongheop Yi 《Korean Journal of Chemical Engineering》2006,23(6):919-924
Based on methodologies developed by US EPA, European EMEP/CORINAIR, and Australian NPI, and the former emission inventory
in Korea, two methods were applied to 151 villages in northeastern Seoul, Korea to estimate emission of VOCs from line and
area vehicle sources depending on vehicle types with different fuel types. A discharge coefficient method for the line source
on the Eastern main road was calculated by multiplying the emission amounts per unit of mileage, and a fuel exhaust coefficient
method for the area vehicle sources on other roads was determined as multiplying the emission rates by the actual consumption
of excess fuel. Results indicated the methods could be adequate for estimating the amounts of mobile emissions when limited
information on mobile emission is available. The methods can be used to develop the emission model for all VOCs emission sources
(point and non-point sources), which provides input data of atmospheric models. 相似文献
942.
The row‐nucleated lamellar crystalline structure of high‐density polyethylene (HDPE) films was prepared by applying elongation stress to HDPE melt during T‐die cast film extrusion and subsequently annealing the extruded films. This unusual crystalline structure was analyzed in terms of lamellar crystalline orientation, long‐period lamellar spacing, crystallite size, and degree of crystallinity. The contribution of melt‐extension represented by draw‐down‐ratio (DDR) to the overall orientation was found to be most noticeable than other processing variables. Meanwhile, the long‐period lamellar spacing, the crystallite size, and the degree of crystallinity were influenced predominantly by the annealing temperature. Finally, the processing (melt extension and annealing temperature) – structure (lamellar crystalline structure) – property (hard elasticity) relationship of HDPE films was investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3326–3333, 2007 相似文献
943.
The removal of hydrogen sulfide (H2S) from simulated gas was carried out in a batch type fluidized-bed reactor using natural manganese ore (NMO), which consists
of several metal oxides (MnOx: 51.85%, FeOy: 3.86%, CaO: 0.11%). The H2S breakthrough curves were obtained by changing temperature, gas velocity, initial H2S concentration, and aspect ratio. Moreover, the effects of the particle size and the particle-mixing fraction on H2S removal were investigated in a binary system of different particle size. From this study, H2S removal efficiency increased with increasing temperature but decreased with increasing excess gas velocity. The breakthrough
time for H2S decreased as the gas velocity increased, which leads to reducing gas-solid contacting due to gas bypassing in a fluidized
bed reactor. Improvement of H2S removal efficiency in continuous process can be expected from the results of the binary particle system with different size
in a batch experiment. The NMO could be considered as a potential sorbent in H2S removal. 相似文献
944.
Native corn starch‐ and hydroxypropylated starch (HPS‐) based plastic films were prepared using the short pulp fiber as the reinforcement and the glycerol as the plasticizer. The results of tensile test showed that the strain and stress at break and elastic modulus increased with pulp content. With glycerol content, the strain at break increased considerably, but the breaking stress and elastic modulus decreased. And the stress–strain curves showed that the brittleness problem of films was overcome by the pulp, glycerol, and water content. The hydroxypropyl starch films showed results similar to those of the native starch films. The results of the three‐point bending test showed that maximum deflection, flexural strength, and specific work increased with pulp content, but the flexural modulus was the highest at a pulp content of 20%. And with the glycerol content, the maximum deflection and specific work of rupture increased, but the bending elastic modulus decreased. The hydroxypropyl starch films showed results similar to those of native starch films as far as the maximum deflection and flexural strength were concerned, but the bending elastic modulus and specific work of the hydroxypropyl starch films were considerably lower than those of starch films. So it was concluded that the flexibility of films was improved by the hydroxypropylation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2108–2117, 2003 相似文献
945.
Man-Hee HanJung-Whan Kim Jinwon KimJung Yoon Ko Jules J. MagdaIn Suk Han 《Polymer》2003,44(16):4541-4546
The acrylic comonomers hydroxypropyl methacrylate (HPMA) and N,N-dimethylaminoethyl methacrylate (DMA) have been used in several earlier studies to produce pH-responsive hydrogels. However, these same monomers can also be used to prepare hydrogels that are highly responsive to temperature. One manifestation of this temperature sensitivity is a sharp decrease in hydrogel optical transparency that occurs when the temperature exceeds a critical transition value. For example, a hydrogel that exhibits a swelling transition at the physiological pH value of 7.4 has a transition temperature of about 45 °C when the environmental salt concentration is 0.15 M. The value of the transparency transition temperature is shown to depend on hydrogel synthesis parameters such as comonomer mole ratio, crosslinker mole ratio, and even initiator concentration. By reducing the mole ratio of the crosslinker tetraethylene glycol dimethacrylate (TEGDMA), the transition temperature can be lowered by as much as 15 °C. Environmental salt concentration and solvent polarity are also shown to influence the transition temperature. 相似文献
946.
The interphase between a polyimide and a metal substrate was modeled by depositing phthalic anhydride (PA) onto a silver substrate pretreated with meta-aminothiophenol (m-ATP) and then curing in a mixture of acetic anhydride and pyridine or triethylamine. Surface-enhanced Raman scattering (SERS) and reflection-absorption infrared spectroscopy (RAIR) were used to determine the molecular structure of the interphase. It was found that m-ATP was adsorbed dissociatively onto silver substrates through the thiol groups. The tilt angle for m-ATP molecules adsorbed on silver substrates was determined using RAIR to be approximately 39°. However, there was no preferred rotational angle of the adsorbed APDS molecules about the molecular axes. When PA was deposited onto m-ATP pretreated silver substrates, anhydride groups of PA reacted with amino groups of m-ATP to form amic acids. When PA/m-ATP/Ag samples were chemically cured in acetic anhydride and pyridine or triethylamine, isoimide was the predominant product regardless of the use of pyridine or triethylamine as catalyst. These results were different from those obtained from PA/APDS/Au systems in which imide was the major product in the presence of triethylamine. These differences in the relative composition of cured products between two model systems were explained by the effect of substituents attached to APDS and m-ATP benzene rings. 相似文献
947.
This study is to investigate the factors influencing the alcohol production byKluyveromyces fragilis using the juice of Jerusalem Artichoke tubers.
The cell growth rate and ethanol production rate were stimulated by aeration and by the addition of unsaturated fatty acids
and the cell mass production and the ethanol production were substantially improved.
It was found that oxygen and unsaturated fatty acids added played a decisive role on the increase of alcohol tolerance of
yeast. 相似文献
948.
Byoung Chul Kim Hyun Woog Kang Young Han Kim 《Korean Journal of Chemical Engineering》2006,23(5):789-794
A crystallization monitoring system using a quartz crystal oscillator was utilized to predict different shapes of crystal
formation by measuring crystal growth rate and to measure supersaturation. Applying different rates of cooling, crystal formation
of different shapes was induced, and the frequency variation of the oscillator and the crystal shape observed with an SEM
were compared to determine how the frequency variation can be interpreted for the prediction of produced crystal shape. The
experimental results obtained from the crystallization of potassium nitrate and cupric sulfate solutions showed that the proposed
frequency measurement technique could be applied in the prediction of crystal shape of cooling crystallization processes.
In addition, supersaturation was determined from the measurements of solution and coolant temperatures. 相似文献
949.
Haiqing?Liu S.?Kay?ObendorfEmail author Michael?J.?Leonard Timothy?J.?Young Michael?J.?Incorvia 《Journal of surfactants and detergents》2005,8(4):311-317
The adsorption of aroma chemicals on cotton fabric was studied relative to the surfactant concentration, surfactant type,
water solubility, and fiber morphology. The adsorption increased with increasing surfactant concentration to a maximum near
the critical micelle concentration, then decreased with further increases in surfactant concentration. The adsorption also
was found to be highly dependent on the fiber surface area and pore structure; dramatic differences were observed between
untreated and mercerized cotton fabric and are believed to be due to morphological differences. Cationic and anionic surfactants
increased the aroma chemical adsorption, which varied with surfactant type, with cetyltrimethylammonium chloride (CTAC)>sodium
dodecyl sulfate (SDS)>H2O. Water solubility also influenced adsorption; in most cases, adsorption increased with water solubility. In addition, adsorption
was also influenced by chemical structure and hydrophobic interactions. The adsorption of aroma chemicals on cotton fabric
can be attributed to the aqueous solution being physically held in capillaries and pore structures within the fibular structure
of cotton fiber and also to molecular interactions among the aroma chemical molecules, surfactants, and cotton substrate. 相似文献
950.
The interfaces between metal organic chemical vapor deposited PbTiO3 thin films and various diffusion barrier layers deposited on Si substrates were investigated by transmission electron microscopy. Several diffusion barrier thin films such as polycrystalline TiO2 , amorphous TiO2 , ZrO2 , and TiN were deposited between the PbTiO3 thin film and Si substrate, because the deposition of PbTiO3 thin films on bare Si substrates produced Pb silicate layers at the interface irrespective of the deposition conditions. The TiO2 films were converted to PbTiO3 by their reaction with diffused Pb and O ions during PbTiO3 deposition at a gubstrate temperature of 410°C. Further diffusion of Pb and O induces formation of a Pb silicate layer at the interface. ZrO2 did not seem to react with Pb and O during PbTiO3 deposition at the same temperature, but the Pb and O ions that diffused through the ZrO2 layer formed a Pb silicate layer between the ZrO2 and Si substrate. The TiN films did not seem to react with Pb and O ions during the deposition of PbTiO3 at 410°C, but reacted with PbTiO3 to form a lead-deficient pyrochlore during postdeposition rapid thermal annealing at 700°C. However, TiN could effectively block the diffusion of Pb and O ions into the Si substrate and the formation of Pb silicate at the interface. 相似文献