Rheology of poly(vinyl chloride) blends

PVC/EVA blends were studied with an extrusion plastometer in order to examine the effect of EVA on the processability of PVC. The melt flow of PVC/EVA blends containing from 4 to 30 weight percent EVA follows a simple power law between 160 and 180°C. EVA reduced the melt viscosity and enhanced processability. Blends of PVC and EVA were morphologically incompatible. The molecular weight of extruded PVC in the blends was unchanged.     

Aerodynamics and aerosol particle deaggregation phenomena in model oral-pharyngeal cavities

The results of numerical simulations of the aerodynamics and of solid aerosol deaggregation phenomena arising in the process of airflow through various model human oropharyngeal cavities are reported. Special attention is given to the relevance of these simulations to the inhalation of dry-powder therapeutic aerosols. Several two- and three-dimensional mouth and throat geometries (terminating just beyond the larynx) are considered. Cross-sectional area-averaged viscous stress values are numerically determined as a function of distance from the mouth opening. These values, ranging from approximately 10 to 500 dyn cm⁻², are compared with estimates of Van der Waals attractive forces per unit area of particle-particle contact so as to evaluate the ability of the flowing airstream to deaggregate aerosol particles that enter the mouth in an aggregated state (held together principally by Van der Waals attractive forces). Estimates of airstream viscous stress differ markedly depending on whether the geometry is two- or three-dimensional. Quantitative differences between flow in a 90°-bend model and an oropharyngeal geometry numerically reconstructed from a cast of a human mouth and throat are especially significant in regards to the ability of the airstream to break apart particle agglomerates. For all geometries it is observed that increasingly smaller particle agglomerates may potentially be separated as the airflow rate increases from 30 to 2001 min⁻¹. At the highest airflows, aggregated particles of diameter near to or even below 1 μm may potentially be separated by the airflow. If separation of particle agglomerates is to occur, it appears far more likely to take place in the throat than in the mouth. This is especially apparent for the more physiologically faithful oropharyngeal geometries considered.     

Interactive Visual User Interfaces: A Survey

Following a short survey of input data types onwhich to construct interactive visual userinterfaces, we report on a new and recentimplementation taking concept hierarchies asinput data. The visual user interfacesexpress domain ontologies which are based onthese concept hierarchies. We detail aweb-based implementation, and show examples ofusage. An appendix surveys related systems,many of them commercial.     

LUREC(R)工艺——冶炼烟气制酸装置经济运营之关键

介绍奥图泰公司开发的LUREC(R)工艺的操作原理、通用流程、各种工艺方案的技术条件及经济和环境评审.LUREC(R)工艺能够直接处理ψ(SO2)高达25%的冶炼烟气,而不必像常规硫酸工艺那样需用大量的空气稀释.在LUREC(R)工艺中,将硫酸装置(例如)三段出口的部分SO3气体再循环到一段,以抑制进口SO2的氧化反应,从而使一段出气温度限制在可接受的水平.LUREC(R)工艺可用于新建装置,也可作为一个插件式模块用于现有装置的扩能改造.在现代高浓度冶炼烟气制酸装置中应用LUREC(R)工艺,可大大减小气体处理设备的单位尺寸,节约相关投资和操作成本.     

The analysis of PM2.5 and associated elements and their indoor/outdoor pollution status in an urban area

In this study, elemental composition of PM2.5 and the status of indoor/outdoor pollution were investigated in a commercial building near a roadside area in Daejeon, Korea. A total of 60 parallel PM2.5 samples were collected both on the roof (outdoor) and in an indoor office of a building near a highly congested road during the spring and fall of 2008. The concentrations of 23 elements were analysed from these PM2.5 samples using instrumental neutron activation analysis. PM2.5 levels in indoor environment (47.6 ± 16.5 μg/m(3)) were noticeably higher than the outdoor levels (37.7 ± 17.2 μg/m(3)) with the I/O concentration ratio of 1.37 ± 0.33 [correlation coefficient (r) = 0.89, P < 0.001]. Principal component analysis results coincidently showed the predominance of sources such as soil dust, traffic, oil/coal combustion and road dust for both indoor and outdoor microenvironments. An isolated source in the indoor environment was assigned to environmental tobacco smoke (ETS) with high factor loading of Ce, Cl, I, K, La and Zn. The overall results of our study indicate that the sources of indoor constituents were strongly dependent on outdoor processes except for the ones affected by independent sources such as ETS. PRACTICAL IMPLICATIONS: An improved understanding of the factors affecting the indoor PM2.5 concentration levels can lead to the development of an efficient management strategy to control health risks from exposure to indoor PM2.5 and related toxic components. A comparison of our comprehensive data sets indicated that most indoor PM2.5 and associated elemental species were strongly enriched by indoor source activities along with infiltration of ambient outdoor air for a naturally ventilated building.     

Ecdysteroids fromPycnogonum litorale (Arthropoda,Pantopoda) act as chemical defense againstCarcinus maenas (Crustacea,Decapoda)

Pycnogonum litorale (Ström) is unpalatable to the common shore crabCarcinus maenas, a generalist predator in the pycnogonid's habitat. A feeding bioassay reveals that the crabs are deterred by ecdysteroids that occur in high levels in all developmental stages ofP. litorale. The total ecdysteroids in the pycnogonids reach 5.9×10^–4 M. The 20-hydroxyecdysone 22-acetate (20E22A), which is the predominant ecdysteroid in the pycnogonids, and 20-hydroxyecdysone (20E), the arthropod molting hormone, were tested for their antifeedant effect onC. maenas. When contained in food pellets in homogeneous concentrations, 20E and 20E22A significantly reduced food consumption at 1.25×10^–4 and 5.0×10^–4 molar levels, respectively. The present results demonstrate for the first time chemical defense in arthropods in a marine predator-prey relationship. Furthermore, they provide evidence that ES contained in one animal can act as feeding deterrents on another animal.     

Lactobacillus gasseri [corrected] CHO-220 and inulin reduced plasma total cholesterol and low-density lipoprotein cholesterol via alteration of lipid transporters

This randomized, double-blind, placebo-controlled, and parallel-designed study was conducted to investigate the effect of a synbiotic product containing Lactobacillus acidophilus CHO-220 and inulin on lipid profiles of hypercholesterolemic men and women. Thirty-two hypercholesterolemic men and women with initial mean plasma cholesterol levels of 5.7 ± 0.32 mmol/L were recruited for the 12-wk study. The subjects were randomly allocated to 2 groups; namely the treatment group (synbiotic product) and the control group (placebo), and each received 4 capsules of synbiotic or placebo daily. Our results showed that the mean body weight, energy, and nutrient intake of the subjects did not differ between the 2 groups over the study period. The supplementation of synbiotic reduced plasma total cholesterol and low-density lipoprotein (LDL)-cholesterol by 7.84 and 9.27%, respectively, compared with the control over 12 wk. Lipoproteins were subsequently subfractionated and characterized. The synbiotic supplementation resulted in a lower concentration of triglycerides in the very low, intermediate, low, and high-density lipoprotein particles compared with the control over 12 wk. The concentration of triglycerides in lipoproteins is positively correlated with an increased risk of atherosclerosis. Our results showed that the synbiotic might exhibit an atheropreventive characteristic. Cholesteryl ester (CE) in the high-density lipoprotein particles of the synbiotic group was also higher compared with the control, indicating greater transport of cholesterol in the form of CE to the liver for hydrolysis. This may have led to the reduced plasma total cholesterol level of the synbiotic group. The supplementation of synbiotic also reduced the concentration of CE in the LDL particles compared with the control, leading to the formation of smaller and denser particles that are more easily removed from blood. This supported the reduced LDL-cholesterol level of the synbiotic group compared with the control. Our present study showed that the synbiotic product improved plasma total- and LDL-cholesterol levels by modifying the interconnected pathways of lipid transporters. In addition, although Lactobacillus acidophilus CHO-220 could deconjugate bile, our results showed a statistically insignificant difference in the levels of conjugated, deconjugated, primary, and secondary bile acids between the synbiotic and control groups over 12 wk, indicating safety from bile-related toxicity.     

Preparation of low-fat uptake doughnut by dry particle coating technique

ABSTRACT:  Soybean hull–wheat flour composites were prepared and used a doughnut formulation in order to decrease fat uptake during deep-fat frying. Soybean hulls were microparticulated by jet milling, and wheat flour was air-classified into coarse and fine fraction by an air classifying system. The coarse fraction of wheat flour was dry-coated with the microparticulated soybean hulls by a hybridization system. To investigate the effect on fat uptake, 4 different types of composites were prepared, which contained 0%, 1%, 5%, and 10% of soybean hulls. Doughnuts containing 1%, 5%, and 10% of microparticulated hulls decreased fat contents of 11.5%, 13.6%, and 35.8%, respectively. As soybean hulls content increased, hardness and crispiness increased. However, sensory evaluations demonstrated that there were no significant differences in appearance, flavor, crispiness, taste, and general liking ( P < 0.05). Inner crust structures of doughnut showed slight reductions in cell size and improved cellular integrity with shrinkage in the cell membrane as the content of soybean hulls increased. These results show that microparticulated soybean hulls may form a protective layer during frying process, and this process could be used by the food industry for preparing doughnuts with reduced fat uptake.     

The Telemedicine benchmark--a general tool to measure and compare the performance of video conferencing equipment in the telemedicine area.

In this paper, we describe the 'Telemedicine Benchmark' (TMB), which is a set of standard procedures, protocols and measurements to test reliability and levels of performance of data exchange in a telemedicine session. We have put special emphasis on medical imaging, i.e. digital image transfer, joint viewing and editing and 3D manipulation. With the TMB, we can compare the aptitude of different video conferencing software systems for telemedicine issues and the effect of different network technologies (ISDN, xDSL, ATM, Ethernet). The evaluation criteria used are length of delays and functionality. For the application of the TMB, a data set containing radiological images and medical reports was set up. Considering the Benchmark protocol, this data set has to be exchanged between the partners of the session. The Benchmark covers file transfer, whiteboard usage, application sharing and volume data analysis and compression. The TMB has proven to be a useful tool in several evaluation issues.