排序方式: 共有25条查询结果,搜索用时 0 毫秒
1.
Blown films from poly(butylene adipate‐co‐terephthalate) and poly(lactide) (PLA) blends were investigated. The blends were prepared in a twin‐screw extruder, in the presence of small amounts of dicumyl peroxide (DCP). The influence of DCP concentration on film blowing, rheological, mechanical, and thermal properties of the blends is reported in this article. Rheological results showed a marked increase in polymer melt strength and elasticity with the addition of DCP. As a consequence, the film homogeneity and the stability of the bubble were improved. The modified blend films, compared with the unmodified blend, showed an improvement in tensile strength and modulus with a slight loss in elongation. Fourier transform infrared and gel results revealed that chain scission and branching were more significant than crosslinking when the DCP loadings in the blends were not higher than 0.7%. A reduction in melt temperatures of PLA was observed due to difficulty in chain crystallization. The concentrations of DCP strongly affected the melting temperatures but had an insignificant effect on the decomposition behavior of the blends. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
2.
3,12-Dimethoxy-7,8-dicyano-[5]helicene as a novel emissive material for organic light-emitting diode
Somboon Sahasithiwat Tipwan Mophuang Laongdao Menbangpung Siriporn Kamtonwong Thanasat Sooksimuang 《Synthetic Metals》2010,160(11-12):1148-1152
3,12-Dimethoxy-7,8-dicyano-[5]helicene (DDH) was introduced as a novel emissive material for organic light-emitting diode. It shown good thermal stability and no glass transition temperature was observed. The LUMO, HOMO and energy band gap (?3.3, ?5.9 and 2.6 eV) of this compound were determined using cyclic voltammetry technique. Fluorescence quantum yield of DDH in chloroform is 0.27. The turn-on voltage of OLEDs with a configuration of ITO/PEDOT:PSS/DDH/Ca/Al was not a function of DDH thickness in a range of 60–100 nm. The best OLED, in which DDH thickness was 100 nm, exhibited a turn-on voltage of 3.7 V with maximum brightness of 1587 cd/m2 at 8.0 V and 281 mA/cm2. The maximum current efficiency and power efficiency were 0.64 cd/A and 0.29 lm/W, respectively. The CIE coordinates of the OLED electroluminescence, however, appeared to depend on the applied voltage as they were (0.38,0.47) at 5.0 V and (0.51,0.44) at 8.0 V. 相似文献
3.
Somkiat Prachayawarakorn Somchart Soponronnarit Somboon Wetchacama Donrudee Jaisut 《Drying Technology》2002,20(3):669-684
Desorption isotherms for shrimp were determined at the temperatures of 50, 60, 70 and 80°C. Amongst the moisture equilibrium predictions between the BET and GAB models, the latter has a better predictable capability. The GAB parameters are correlated with the temperatures by the Arrhenius expression. Drying characteristics of shrimp in drying media at the temperature range of 120-180°C for superheated steam and of 70-140°C for hot air have been examined. Drying rate and effective diffusion coefficient are used to quantify quantitatively the difference between the superheated steam and the hot air dryings. The temperature is more important effect on drying rate and effective diffusion coefficient in the superheated steam than in the hot air. Inversion temperature exists between 140 and 150°C. Comparing to the hot air, the shrimp dried by the superheated steam shows a lower degree of shrimp shrinkage. In addition, product colours are slightly different to those from the commercial sources. 相似文献
4.
5.
6.
Wanwisa Skolpap Somboon Nuchprayoon Jeno M. Scharer Nurak Grisdanurak Peter L. Douglas Murray Moo-Young 《Korean Journal of Chemical Engineering》2008,25(4):646-655
A modified Markov Chain Monte Carlo (MCMC) searching procedure was developed to search for an optimal set of decision variables
and optimal feed rate trajectories for recombinant α-amylase expression by Bacillus subtilis ATCC 6051a. The bacterium also synthesizes proteases as undesirable products in fed-batch culture that need to be minimized.
To maximize α-amylase productivity, a 14th-order fed-batch model was optimized by integrating Pontryagin’s maximum principle with the Luedeking-Piret equation. The number of iterations and simulations of the proposed searching procedure were statistically examined for accuracy
and acceptability of the results. It can be concluded that the proposed searching procedure increased the parameter selection
opportunity near the tail ends of redefined triangular distribution. By applying a modified MCMC searching procedure with
1,500 iterations, the predicted α-amylase productivity was improved by 18% in comparison with near-optimum experimental results. This productivity was 3.5%
higher than predicted by conventional MCMC optimization. 相似文献
7.
改变MOFs材料的中心金属能影响其气体的亲和性和双组份气体的吸附选择性(如比表面积,孔道结构,内部电场等),本文合成并表征了M-DABCO系列(M=Ni, Co, Cu, Zn) MOFs材料。并应用理想吸附溶液理论(Ideal Adsorbed Solution Theory,简称IAST)量化模拟了环境条件下双组分混合气体(组分比CO2:CH4=40%:60%)的吸附选择性。 Ni-DABCO材料具有良好的CO2吸附性能和在环境条件下对CO2/CH4混合气体的吸附选择性。本文通过实验、表征及计算等来讨论中心金属对M-DABCO系列吸附位点的影响。 相似文献
8.
Nikom Sae‐Ma Piyasan Praserthdam Joongjai Panpranot Somboon Chaemchuen Siraprpha Dokjamp Kongkiat Suriye Garry L. Rempel 《应用聚合物科学杂志》2010,117(5):2862-2869
Color improvement of commercial C9 hydrocarbon resin (c‐C9HR) and prepared C9 hydrocarbon resin (p‐C9HR) has been investigated under various hydrogenation conditions over 2% Pd/γ‐alumina catalysts. The degrees of aromatic rings hydrogenation (DHs) and molecular structure of resin were determined from nuclear magnetic resonance of 1H and 13C (1H‐NMR and 13C‐NMR) and Fourier transform infrared spectroscopy (FTIR) analyses. The starting c‐C9HR presented in yellow color (Gardner color No. 8.4). Under the hydrogenation conditions used (H2 pressure 70 bar, 250°C, and 8 h), the ethylenic proton in c‐C9HR was completely removed, but the aromatic rings content remained unaltered and very little change in resin color was observed (Gardner color No.8.1). On the other hand, the starting p‐C9HR contained only unsaturated aromatic proton with Gardner color No.17.1. Under similar conditions, aromatic rings in p‐C9HR were converted to alicyclic rings, and its color was reduced to Gardner color No.5.7. By varying the DH of aromatics in p‐C9HR, two‐step decolorization was observed in which at lower DH (≤10%) the color decreased sharply from 17.1 to 9.3, while further color reduction to 5.7 was obtained when the DH was increased to 94%. It is suggested that both color body and aromatic rings were the main sources contributing to C9HR color. Nevertheless, color stability of the resin during heat treatment was significantly improved by hydrogenation especially at DH ≥ 50%. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
9.
Somchart Sopanronnarit Wathanyoo Rordprapat Somboon Wetchacama 《Drying Technology》1998,16(7):1501-1513
The objectives of this research are to design, construct and test a mobile fluidized bed paddy dryer with a drying capacity of 2.5-4.0 t/h. Suitable drying conditions are recommended as follows : drying capacity 3.8 t/h, bed velocity 2.8 m/s, average drying air temperature 144 °C, bed height 13.5 cm, fraction of air recycled 0.8. Residence time of paddy was approximately 1.3 minutes. Test results showed that moisture content of paddy was reduced from 32.6 % dry-basis to 25.8 % dry-basis. Consumption of electrical power and diesel fuel was 12.9 kW and 21.71 1/h respectively. Primary energy consumption was 910.9 MJ/h. The dryer could evaporate water 218.8 kg/h. Specific primary energy consumption was 4.2 MJ/kg-water evaporated. Cost of paddy drying was 1.48 baht/kg-water evaporated of which 0.53 was fixed cost and 0.95 was energy cost (US$1 =34baht). 相似文献
10.
Somchart Soponronnarit Somboon Wetchacama Thanit Swasdisevi Nattapol Poomsa-ad 《Drying Technology》1999,17(1):335-343
This paper describes a strategy for reducing moisture in paddy by fluidized bed drying, tempering and ambient air cooling. Experimental results showed that after the three processes, moisture content was reduced from 33 % to 16.5 % dry-basis within approximately 53 minutes. During the first process, a fluidized-bed dryer was used to reduce the moisture content of paddy down to 19.5 % dry-basis within 3 minutes. Then the paddy was tempered for 30 minutes. Finally, it was cooled by ambient air (temperature and relative humidity of 30 °C and 55-60% respectively) with air velocity of 0.15 m/s for 20 minutes. Quality of paddy in terms of head rice yield and whiteness was acceptable. 相似文献