Progress in the development of polymer cholesteric liquid crystal flakes for display applications

Polymer cholesteric liquid crystal (PCLC) flake technology is being developed as an alternative display technology for flexible, reflective particle displays. The motion of PCLC flakes suspended in a host fluid can be controlled with an electric field, creating a way to electrically control the flakes' ability to brightly reflect light that is circularly polarized. The PCLC flake/host fluid dispersion has been successfully microencapsulated both in a polymer matrix and in gelatin micro-capsules. Microencapsulation will not only expand the applications scope of the technology, but also may aid in addressing some potential problem areas that are inherent to many forms of particle display technology. A second important development in PCLC flake technology involves the manufacture of shaped flakes based on soft lithography techniques. The size and shape of a flake impact its reorientation, and uniformly shaped flakes respond in a similar manner. The unique reflective properties of PCLC flakes also provide possible applications in areas such as optics and photonics, switchable ‘smart windows’ or conformal coatings, and information displays such as ‘electronic paper.’     

DS-CDMA卫星通信系统线性多用户检测算法性能比较

CDMA是新一代移动通信系统的关键技术,现代卫星移动通信也采用CDMA技术。多址干扰(MAI)的存在严重影响了CDMA系统的性能,需要采用多用户检测技术进行抑制。本文分析了卫星移动通信系统的模型,将线性多用户检测算法用于卫星移动通信系统,并对传统检测器、解相关检测器、MMSE检测器等线性检测器进行了性能比较。计算机仿真结果表明采用线性多用户检测技术使卫星移动通信系统的性能得到了明显的改善。     

Impact of Posttraumatic Stress Disorder on early smoking lapse and relapse during a self-guided quit attempt among community-recruited daily smokers

The present investigation examined whether daily smokers with posttraumatic stress disorder (PTSD), as compared to daily smokers with either anxiety psychopathology or no current Axis I psychopathology, have decreased success in the early phases of a self-guided smoking quit attempt. Participants were 140 daily smokers (81 women; M (age) = 29.5; SD = 11.9; range = 18-65 years); approximately one-third of the sample met criteria for current PTSD (n = 47), one-third met criteria for other current anxiety disorders (without PTSD; n = 33), and one-third did not meet criteria for any current Axis I disorder (n = 60). Consistent with prediction, membership in the PTSD group, compared to membership in the other anxiety disorders group and the group with no current Axis I psychopathology, was associated with increased risk of lapse during the first week following quit day. Additionally, daily smokers with PTSD and other anxiety disorders were at significantly increased risk of relapse during the first week post-cessation compared to persons without Axis I psychopathology. However, the PTSD group and the other anxiety disorders group did not differ from one another in terms of relapse. Results suggest that PTSD is associated with increased risk of smoking lapse and relapse compared to smokers with no current Axis I psychiatric problems, and increased risk of early smoking lapse but not relapse, as compared to those with other anxiety disorders. Findings provide novel evidence that PTSD, and perhaps anxiety disorders more generally, may be important factors in reducing the odds of successful unaided quit attempts in the early phases of cessation.     

Investigations on the self‐ignition of deposits containing combustibles

Self‐ignition of deposited combustibles is a possible reason for excessive fires occurring on deposits for recycling materials or on waste dumps. Two series of experiments were performed to assess the hazard of self‐ignition: hot storage tests with different homogeneous mixtures of combustible material and inert material and tests with pockets of combustible material embedded in inert matter. In the first test series considerable exothermicity (ΔT>60K) was observed for mass fractions of combustible material as low as 2.5%. In the second series it could be shown that the heat transfer from a pocket of burning material through the inert matter can ignite a second pocket of combustible matter. Based on the experimental data, numerical simulations were performed to predict self‐ignition on real‐scale waste deposits. For a deposit of specific size and shape, the influence of the ambient temperature on the occurrence of self‐ignition has been investigated. Copyright © 2008 John Wiley & Sons, Ltd.     

Optimization of furfural production from millet husk using response surface methodology

Biomass has been recognized as a viable source for energy and bio-based chemicals. This study reported furfural production from millet husk via simultaneous hydrolysis and dehydration processes. Effect of reaction variables such as temperature (120–200°C), resident time (15–45 min), and acid concentration (5–10%) was studied using central composite design. Furfural yield (71.55%) was achieved at 184°C, 39 min, and 9% acid concentration. FT-IR spectrum of the produced furfural showed absorption at 1,697 and 2,880 cm^?1 indicating a conjugated carbonyl functional group and aldehydic hydrogen. The results revealed that millet husk could be a potential substrate for furfural production.     

Anxiety sensitivity and smoking motives and outcome expectancies among adult daily smokers: replication and extension.

The present investigation examined the incremental validity of anxiety sensitivity in the context of distress intolerance in terms of predicting smoking motives and outcome expectancies. Participants were a community sample of 144 daily smokers (85 women, M (age) = 29.72 years, SD = 11.96). Results indicated that above and beyond discomfort intolerance, Axis I diagnoses, gender, volume of alcohol consumption, and average number of cigarettes smoked per day, anxiety sensitivity significantly incrementally predicted habitual, addictive, and negative affect reduction motives to smoke, as well as negative reinforcement outcome expectancies. No such incremental effects were similarly evident for distress intolerance. Findings are discussed in relation to the role of anxiety sensitivity in smoking motives and outcome expectancies.     

Fresh from the Ornamental Garden: Hips of Selected Rose Cultivars Rich in Phytonutrients

Morphological parameters (size, weight, color), the content of sugars, organic acids, lycopene, β‐carotene, and phenolics were determined in hips of Rosa canina (RCA), Rosa sweginzowii (RSW), Rosa rugosa (RUG), and selected ornamental Rosa cultivars Fru Dagmar Hastrup (FDH), Repandia (REP), Veilchenblau (RVB), Aloha (RAL), Bonica (BON), and Golden Gate (RGG). Although traditionally used RCA hips contained the highest amount of cyanidin‐3‐glucoside (83 μg/g DW) and were the reddest (h° = 17.5), they did not stand out in other analyzed parameters. RGG climber had the biggest hips (8.86 g), which also contained highest sugar levels (50.9 g/100 g DW). RAL stood out as the cultivar rich in organic acids (33.9 g/100 g DW), mainly because of high quinic acid content (17.6 g/100g DW). FDH and RSW hips were characterized by particularly high ascorbic acid levels (4325 mg/100 g DW and 4711 mg/100 g DW). Other ornamental cultivars contained low amounts of ascorbic acid compared to the analyzed species. The phenolic profile was species/cultivars‐specific. The greatest diversity of phenolic compounds was detected in RUG and FDH hips (55 and 54 different tentatively identified compounds with HPLC/MS). Flavanols represented the main phenolic class in most of the investigated species/cultivars and RGG hips contained the highest amount of catechin and proanthocyandin derivatives (15855 μg/g DW). Altogether RAL hips contained the highest quantity of phenolics (44746 μg/g DW) mainly due to high levels of hydrolysable tannins compared to other species/cultivars. Although small, hips of BON and REP were most abundant regarding β‐carotene and lycopene content, respectively.     

Posttraumatic stress disorder and anxious and fearful reactivity to bodily arousal: A test of the mediating role of nicotine withdrawal severity among daily smokers in 12-hr nicotine deprivation.

Posttraumatic stress disorder (PTSD) is associated with high rates of smoking and fear of bodily perturbation. The current study examined the role of nicotine withdrawal in the association between PTSD and responding to bodily arousal among 52 participants (27 women; Mage = 30.50 years). Compared to participants without current axis I psychopathology, persons with current PTSD responded to a 3-min voluntary hyperventilation procedure with greater increases in anxiety and more intense cognitive and physical panic symptoms, despite no group differences in physiological arousal. Nicotine withdrawal demonstrated significant mediational effects in the relations between diagnostic group and panic symptoms elicited by the hyperventilation procedure. Findings suggest nicotine withdrawal is an important factor to consider in terms of better understanding the nature of fear responding to bodily sensations among persons with PTSD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anxiety sensitivity, acute nicotine withdrawal symptoms, and anxious and fearful responding to bodily sensations: A laboratory test.

The present investigation examined the moderating role of anxiety sensitivity (AS) in regard to the relation between acute nicotine withdrawal and anxious and fearful responding to a 10% carbon dioxide-enriched air (CO2) procedure. Ninety daily smokers (35 women; Mage = 28.87, SD = 12.12) were assigned randomly to one of two groups (12-hr nicotine deprivation or smoking “as usual”) and subsequently underwent a 10% CO2 provocation challenge. Partially consistent with prediction, results indicated that the AS by nicotine withdrawal (group status) interaction was significantly predictive of peri-challenge anxiety ratings (anxiety during the challenge), but not skin conductance reactivity. Findings are discussed in the context of the role of AS in amplifying smoking-based fear responses to bodily sensations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)