Macrocell corrosion of steel in concrete: Characterization of anodic behavior in relation to the chloride content

This study presents the determination of electrochemical properties of active steel in mortar, based on inverse numerical modeling that focuses on their dependency on chloride content. An experimental campaign, consisting of galvanic coupling tests between anode samples contaminated with different chloride concentrations and cathode samples without chlorides, was carried out. Cathode polarization tests allowed for directly determining passive steel electrochemical parameters. Anode polarization tests coupled with a numerical optimization were then performed for quantifying active steel parameters and focusing on chloride's effect on the iron anodic Tafel coefficient. Furthermore, the steel electrochemical properties were successfully used as input parameters to model the galvanic experiments.     

Effect of iron compounds (oxide,salt, or complexes) on poly(vinyl chloride) thermal and photochemical stability

The color requirements for vinyl siding have drastically evolved over the last decade and have moved toward medium to dark colors. Therefore, manufacturers are exploring new ways to modify their formulations in order to improve weather-ability of these challenging colors. Examination of some of the PVC additives typically used in these formulations has led to some interesting revelations about the performance of iron-containing pigments, which are extensively used in darker colors. A quick weathering test was designed to evaluate the effect of iron in PVC formulations, and this test clearly demonstrates the correlation between iron content and PVC photodegradation.     

Diffusion coefficients of additives in polymers. I. Correlation with geometric parameters

Diffusion coefficients of a broad range of molecules with molecular weight ranging from 100 to 800 g/mol have been measured in polypropylene, by solid/solid contact methods (without liquid contact), at 40°C. The behaviors of the different molecules are compared to those of linear alkanes. The diffusion coefficients are correlated to parameters describing size, shape, and flexibility of the molecules. The concept of weighted fractionated volume is introduced using molecular modeling. It enables the classification of the molecules according to modes of molecule displacement (crawling, jumps, or dual mode). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2422–2433, 2001     

METHODS FOR PROCESSING EXPERIMENTAL DRYING KINETICS DATA

This paper provides a review of methods for processing the data obtained from drying kinetics rigs and pilot-plant trials. Different methods for fitting and smoothing drying curves are compared, aiming to generate curves that are usable in industrial design without losing vital information by oversmoothing. Generally, plots of drying rate need more smoothing than moisture content data. Special care is needed at low drying rates and moisture contents. It is shown that some popular methods of processing data, including use of smoothing programs or fitting to equations, may generate drying curves which are seriously in error. Recommendations are made for reliable methods of processing data; cubic splines have been found to be effective for moisture-time curves. It is important to retain the original raw experimental data as a cross-check, as smoothing can conceal valuable information.     

Water levels in the Amazon basin derived from the ERS 2 and ENVISAT radar altimetry missions

This study sets out to analyze the stages of water bodies in the Amazon basin derived from the processing of ERS-2 and ENVISAT satellite altimetry data. For ENVISAT, GDR measurements for both Ice-1 and Ice-2 tracking algorithms were tested. For ERS-2, the Ice-2 data produced by the OSCAR project was used. Water level time series over river segments of very different width, from several kilometers to less than a hundred of meters, were studied. The water level time series that can be derived from narrow riverbeds are enhanced by off-nadir detections. Conversely, the off-nadir effect may degrade the series over large bodies if not properly accounted for. Comparison at crossovers and with in situ gauges shows that the quality of the series can be highly variable, from 12 cm in the best cases and 40 cm in most cases to several meters in the worse cases. Cautious data selection is clearly a key point to achieve high quality series. Indeed, low quality series mostly result from inclusion of outliers in the data set finally retained for the computation of the series. Ice-2 and Ice-1 tracking algorithms in the ENVISAT data perform almost equally well. ENVISAT altimetry is clearly an improvement on ERS-2 altimetry.     

在加强型学习系统中用伪熵进行不确定性估计

加强型学习系统是一种与没有约束的，未知的环境相互作用的系统，学习系统的目标在大最大可能地获取累积奖励信号，这个奖励信号在有限，未知的生命周期由系统所处的环境中得到，对于一个加强型学习系统，困难之一在于奖励信号非常稀疏，尤其是对于只有时延信号的系统，已有的加强型学习方法以价值函数的形式贮存奖励信号，例如著名的Ｑ－学习。本文提出了一个基于状态的不生估计模型的方法，这个算法对有利用存贮于价值函数中的奖励     

Call-by-Value {lambda}-calculus and LJQ

LJQ is a focused sequent calculus for intuitionistic logic,with a simple restriction on the first premiss of the usualleft introduction rule for implication. In a previous paperwe discussed its history (going back to about 1950, or beyond)and presented its basic theory and some applications; here wediscuss in detail its relation to call-by-value reduction inlambda calculus, establishing a connection between LJQ and theCBV calculus _C of Moggi. In particular, we present an equationalcorrespondence between these two calculi forming a bijectionbetween the two sets of normal terms, and allowing reductionsin each to be simulated by reductions in the other.     

Mobile agents and intellectual property protection

Technical enforcemment of intellectual property (IP) rights often conflicts with the ability to use the IP. This is especially true when the IP is data, which may eaisly be copied while it is being accessed. As electronic commerce of data becomes more widespread, traditional approaches will prove increasingly problematic. In this paper, we show that the mobile agent architecture is an ideal solution to this dilemma: by providing full access to the data but charging for the transmission of results back to the user-reslts-based billing-we resulve the access versus protection conflict. We define new requirements for agent frameworks to implement results-based billing: data-aware accounting and data-tight sandboxing, which, along with the common requirements such as authentication, authorisation, agen self-monitoring, and efficiency, provide the mechanisms by which database owners can effectively grant users access to their intellectual property.