Facile modifications of polyimide via chloromethylation: II. Synthesis and characterization of thermocurable transparent polyimide having methylene acrylate side groups

From chloromethylated polyimide, a useful starting material for modification of aromatic polyimides, a thermocurable transparent polyimide having acrylate side groups was prepared. In the presence of 1,8‐diazabicyclo[5,4,0]undec‐7‐ene, chloromethylated polyimide was esterified with acrylic acid to synthesize poly(imide methylene acrylate). The polymer was soluble in organic solvent, which makes it possible to prepare a planar film by spin coating. The polymer film became insoluble after thermal treatment at 230 °C for 30 min. Optical transparency of the film at 400 nm (for 1 µm thickness) was higher than 98 % and not affected by further heating at 230 °C for 250 min. Adhesion properties measured by the ASTM D3359‐B method ranged from 4B to 5B. Preliminary results of planarization testing showed a high degree of planarization (DOP) value (>0.53). These properties demonstrate that poly(imide methylene acrylate) could be utilized as a thermocurable transparent material in fabricating display devices such as TFT‐LCD. Copyright © 2004 Society of Chemical Industry     

Holographic polymer‐dispersed liquid crystal fabrication under electric field

The transmission mode of holographic polymer‐dispersed liquid crystals (HPDLCs) was developed an under electric field. It is reported that orientation of LC molecules under an electric field induces orientation of oligomer molecules giving rise to low off‐state diffraction and small grating shrinkage. Copyright © 2005 Society of Chemical Industry     

ACAT inhibitors derived from hetero-Diels-Alder cycloadducts of thioaldehydes

Acyl-CoA:cholesterol acyltransferase (ACAT) is the enzyme largely responsible for intracellular cholesterol esterification. A systemic inhibitor of ACAT is believed to be able to slow or even reverse the atherosclerotic process. Towards that goal, a series of cyclic sulfides, derived from the hetero-Diels-Alder reaction of thioaldehydes with 1,3-dienes, and bearing carboxamide substituents, were prepared and evaluated for in vitro (in several tissues and species) and ex vivo ACAT inhibition. Minor changes in subsequent structure were found to have a significant effect in optimization of the biological activity of this series of compounds.     

The lived experience of nursing students in caring for suffering individuals

Most nursing school curricula address the pathologic nature of illness, the nursing care of clients who are ill, the prevention of illness, and the promotion of health. There seems to be minimal discussion, however, both in nursing curricula and in textbooks, of the alleviation of suffering or of how nurses know that someone is suffering. The article describes a phenomenologic analysis of 12 nursing students' lived experiences of caring for individuals who were suffering. The voices of the students as they chronicled their experiences are exemplars of clinical scholarship as described in the literature.     

Haemolytic activity of Aeromonas species isolated in Libya

Twenty seven Aeromonas strains (5A. hydrophila, 8A. sobria and 14A. caviae) isolated from children with diarrhoea and 34 Aeromonas strains (9A. hydrophila, 7A. sobria an 18A. caviae) isolated from children without diarrhoea were tested from haemolysin production. The results obtained showed that haemolysin production using human, horse or sheep erythrocytes was significantly associated with A.hydrophila and A sobria but not with A.caviae, regardless of whether these strains were isolated from children with or without diarrhoea. Human or horse rather than sheep erythrocytes are recommended for use in the haemolysin assay.     

Analysis of a 2(9) full factorial chemical library

Robotic synthesis is making possible the synthesis of large, systematically designed sets of compounds. We analyze a 512-compound set that is a 2(9) full factorial experimental design using a recursive partitioning algorithm, FIRM, and a high-dimension visualization tool, TempleMVV. These techniques are used to quickly and easily identify the main trends in the data set and also identify unusual observations. We show that analytical and visualization methods can be used synergistically to analyze a large, complex, high-dimensional data set. We also show that a fractional factorial design of 128 compounds would give essentially the same information.     

Droplet de-entrainment by inertial impaction on vertical rods in an air-droplet mixture flow

We experimentally investigate the de-entrainment of droplets by inertial impaction on an array of vertical rods in an air-droplet mixture flow. The de-entrainment efficiencies are measured for a single rod, for a single row of rods, and for a multi-row of rods. We investigate the effects of the droplet mass flux (0.5–5.4 kg/m² s), the droplet Weber number (3000–8000), the air velocity (0–6 m/s), the rod geometry, and the surface roughness on the de-entrainment, and the rod diameter-to-pitch ratio effect on the de-entrainment. The results for a single rod show that the de-entrainment efficiency decreases slightly as the droplet mass flux increases; however, in our experimental ranges, there is negligible dependence on the droplet Weber number, the air velocity, and the surface roughness. The rod geometry affects the de-entrainment efficiency. The results for a single row of rods show that the existence of neighboring rods promotes de-entrainment due to droplet splashing, and we develop a correlation to show the effect of diameter-to-pitch ratio on the de-entrainment. Using information on the de-entrainment efficiencies of a single rod and those of a single row of rods, we propose a correlation that predicts the de-entrainment efficiency for a multi-row of rods with a staggered array. The RMS errors of the correlation from the de-entrainment efficiencies experimentally obtained are within 13.5%.     

悬浮床加氢裂化油溶性催化剂与沥青质的作用

在高压釜反应器中对添加了油溶性 Ni 催化剂(UPC-O)和水溶性 Ni 催化剂(UPC-W)的辽河稠油常压渣油(LHAR)进行了悬浮床加氢裂化实验。通过元素分析和傅里叶变换红外光谱(FTIR)分析对抑制反应生焦效果好的 UPC-O 与 LHAR 沥青质的作用进行了研究。元素分析结果显示,在 LHAR 中加入 UPC-O1000μg/g,沥青质和脱沥青质油中 Ni 含量分别出476μg/g和110μg/g 增加到7 559μg/g 和1 024μg/g,表明 UPC-O 在沥青质中有富集的趋势。FTIR 表征结果显示,UPC-O 和沥青质发生了相互作用。UPC-O 可在沥青质原位硫化为活性组分,对沥青质在悬浮床加氢裂化反应中的缩合起到好的抑制作用。