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The action mechanism for aggressive and highly pure media on fluoropolymer constructional elements is assumed to consist of two basic microeffects: destructive changes in the fluoropolymer and contamination of the environment. Our approach to a quantitative estimation of the physicochemical stability is based on logic similar to that of a thermodynamic model of a two‐component system. A fluoropolymer and changes in its microstructure are considered the first component of the system. The second component is composed of liquid media contaminated with fluoroorganic compounds extracted from the fluoropolymer. The proposed methods for delivering aggressive and highly pure fluids to consumers allow the exclusion of pollution from working areas with gaseous products through an exception to a number of intermediate stages of product transport. The discussed principles allow the creation of a modern, highly effective, and safe (with respect to the ecology and raw materials) production of aggressive liquid chemicals for consumers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 906–910, 2002 相似文献
124.
《Drying Technology》2007,25(1):75-84
This article proposes a multiscale computational model able to calculate energy consumption in a batch lumber kiln. A dual-scale computational model of wood drying deals with the boards/stack interaction and serves as a basis for the present work. A new module was added here that calculates heat losses through kiln walls (convection, condensation) and the energy used by each kiln component (fans, heating elements, humidifier, vacuum pump, etc.). The corresponding mathematical formulation is presented and then theoretical results are compared to those collected in an industrial vacuum kiln. As application example, the effect of air reversal, air velocity, and kiln insulation are exhibited, which depicts the great potential and prospects of this new tool for energy savings in relation to the product quality. 相似文献
125.
Economic ideas and processes are becoming increasingly integrated with more traditional engineering and hydrologic models
of water management problems. Combining economic management concepts and performance indicators with an engineering-level
of understanding of a hydrologic system can provide results and insights more directly relevant for water management decisions
and policies. When such models are developed and used with involvement of stakeholders, they can become a basis for shared
understanding of water problems as a foundation for negotiated management and policy solutions. When implemented with optimization
software, integrated hydro-economic models also can suggest promising innovative solutions for policy-makers to consider.
Their applications to river basin management problems are reviewed. Economic and integrated economic-engineering-hydrologic
modeling is then discussed in the context of the evolving European Water Framework Directive. Relevant items are cost recovery
and water pricing, cost-effectiveness of water management measures, and public participation in decision processes. 相似文献
126.
127.
ARMA噪声中的正弦波检测 总被引:2,自引:1,他引:1
本文提出一种ARMA噪声中正弦波检测的方法,本方法先用改进的Prony法估计可能存在的正弦波,然后利用一种综合考虑衰减因子以及MUSIC值的准则从估计结果中区分正统率波的真伪。数值例子表明,本文方法比Prong方法及MUSIC方法具有更高的分辨力。 相似文献
128.
三维地震资料的处理与解释往往都需要三维正演模型给予验证,以得到准确的处理、解释结果。本文提出的三维正演方法是一种偏移算法的逆运算方法-有限差分反偏移法。这一算法具有算法简单、运算量小及深度方向分辨率高的特点,是一种快速、高精度的正演算法。反偏移法虽是偏移算法的逆运算法,却出现常规偏移算法中所没有的很多问题。为此,本文进行了三种不同反偏移方法试验,并采用了一种新的浮动坐标变换,使正演结果精度得到很大 相似文献
129.
数值地形图的生成及其水文地貌特征评价 总被引:17,自引:2,他引:15
数值地形图(DEM)是利用地理信息系统(GIS)进行流域水文模拟的基础, 其精度直接影响模拟结果在没有现成的数值地形图时, 应用人员往往利用传统的地形图来生成它. 本文分别采用Arc/Info地理信息系统软件提供的哈奇逊法和不规则三角网五次插值法, 对一个实验流域的高程取样点进行插值, 生成了4种不同的数值地形图, 从凹洼分布、流域界定、河网提取、地面坡度和地形指数、以及地面径流汇成等方面, 对它们的水文地貌精度进行了比较. 结果表明, 两种方法都能生成由高程点群所反映的地形, 然而由于哈奇逊法能够结合流域的河网结构及其具有物理基础的水文地貌加强法来处理凹洼问题, 因此大大地提高了其所生成的流域数值地形图水文地貌特征精度. 相似文献
130.
We modeled nisin's anticlostridial activity and assessed the antagonistic or potentiating influences of food ingredients. The model systems contained yeast extract, proteose peptone, and glucose; were supplemented with protein (0.075, 0.75, 7.5% w/v), phospholipid (0.075, 0.75, 7.5% w/v), or soluble starch (5, 17.5, 30% w/v); and were adjusted to pH 5.5, 6.0, or 6.5. Samples inoculated with 104/mL spores were incubated at 15, 25, or 35°C. Statistical analysis developed an equation (r2= 0.76) that modeled the response and identified temperature as the most significant (α 0.001) variable. Nisin lost effectiveness with increasing temperature. Nisin concentration had significant positive and phospholipid negative, linear effects. Many interactive effects were significant (α 0.20). Nisin inhibited C. botulinum until its residual level dropped below a threshold, which decreased from 154 IU/mL at 35°C to 12 IU/mL at 15°C. 相似文献