High- and low- temperature behaviors of La0.6Sr0.4Co0.2Fe0.8O3−δ cathode operating under CO2/H2O-containing atmosphere

High- and low- temperature behaviors of La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ (LSCF) cathode for solid oxide fuel cells operating under CO₂/H₂O-containing atmosphere are investigated. LSCF shows different stability against CO₂ and H₂O at high and low temperature. LSCF has excellent electrochemical performance and high stability against the corrosion of CO₂ and H₂O at 750 °C due to weak reactivity of LSCF with CO₂. LSCF shows a serious degradation at 600 °C under operation with O₂–CO₂(2.83%)–H₂O(2.64%), which is ascribed to the impeded oxygen activation and oxygen surface diffusion by surface carbonates and SrCO₃ phases on LSCF surface. Under CO₂(5%)–H₂O(2.81%)–He, LSCF reacts with CO₂ to yield SrCO₃ phases in 400–680 °C, and H₂O aggravates the chemical reaction between CO₂ and LSCF. Taking into account of SrCO₃ phase formation on LSCF, LSCF cathode is stable under operation with O₂–CO₂(2.83%)–H₂O(2.64%) in 680–800 °C, whereas it is unstable below 680 °C. LSCF can be subject to degradation caused by CO₂ and H₂O in air during long-term operation below 680 °C.     

加固需求度评价在龙滩水电站左岸边坡加固 工程中的应用

 边坡加固效果的评价是边坡加固的关键环节之一,边坡加固效果的评价方法大致可分为两类：第一类是工程地质条件分析和岩石力学研究的定性或半稳定性方法,其不足在于在预测和评价准确度上很难得到保证;第二类是基于现场监测分析的定量评价方法,其缺点是在测点安装并作监测之后才有可能根据监测数据做出判断。加固需求度(DRD)是一种新提出的评价方法,由于可将基于工程地质条件岩石力学研究评价和基于现场监测的评价进行综合集成,发挥两类方法的长处并弥补各自的不足,具有独特优势。广西龙滩水电站左岸开挖形成的组合坡高达435 m,边坡的变形和稳定直接关系着工程建设的成败,以左岸A区边坡为例进行加固需求度评价的应用研究,结果表明其加固效果较好,与监测数据及现场调查的情况相符。     

Sequential enzymatic quantification of two sugars in a single microchannel

This paper presents the implementation of a multiple analyte enzyme assay, based on the sequential injection of the different enzyme solutions, in an electrokinetic driven microfluidic chip. The assay methodology for the simultaneous quantification of d-glucose and d-fructose was reported in previous publications but here the real integration of both enzyme assays was achieved. When assays were executed separately, good reproducibility was observed with average CV values of 5.2% and 4.5% for the d-glucose and d-fructose assay, respectively. Next, the assays for the quantification of d-glucose and d-fructose were integrated simultaneously on chip, where each assay was executed consecutively in the same microreactor by applying a specific sequence of potentials at the reservoirs. This article proves the integration of a sequential based quantification approach in continuous microfluidic chips with electrokinetic actuation.     

Renewable linear alpha olefins by selective ethenolysis of decarboxylated unsaturated fatty acids

A two‐step concept for the production of linear alpha olefins from biomass is reported. As a starting material an internally unsaturated C17 alkene was used, which was obtained by the decarboxylation of oleic acid. Here, we report on the ethenolysis of this bio‐based product, using commercially available metathesis catalysts. The desired alpha olefin products, 1‐nonene and 1‐decene, were obtained in excellent yield (96%) and selectivity (96%). Practical applications: The two‐step conversion described in this contribution, starting from unsaturated fatty acids, provides a method for the production of industrially important linear alpha olefins. These valuable products are widely used as starting materials for the production of surfactants and polymers such as linear low density polyethylene (LLDPE).     

Self-sacrificial leadership and follower self-esteem: When collective identification matters.

In the present research, we examine whether leader's self-sacrifice positively influences followers' self-esteem and whether followers' identification with the collective plays a role in this process. It was predicted that leader self-sacrifice would influence followers' self-esteem, but particularly so when followers exhibited strong (vs. weak) collective identification. Results from an organizational survey showed that leader self-sacrifice and collective identification interacted in predicting follower self-esteem, such that followers' self-esteem was higher when they identified strongly with the collective and when the leader was self-sacrificial (vs. self-benefiting). An experimental scenario study replicated this interactive effect between collective identification and leader's self-sacrifice on followers' self-esteem and also showed that this effect was (at least partly) mediated by followers' perceptions of whether the leader respected and valued the group. Implications with respect to the relationship between self-sacrifice and self-esteem are outlined, and possible integrations of leader self-sacrifice, identity, and empowerment are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unity through diversity: Value-in-diversity beliefs, work group diversity, and group identification.

Research on work group diversity has more or less neglected the possibility that reactions to diversity may be informed by individuals' beliefs about the value of diversity (vs. homogeneity) for their work group. We studied the role of such diversity beliefs as a moderator of the relationship between work group diversity and individuals' identification with the work group across 2 studies. Study 1 was a cross-sectional survey that focused on gender diversity and gender diversity beliefs. Study 2 was a laboratory experiment in which work group diversity and diversity beliefs were manipulated. Results of both studies support the prediction that work group diversity and group identification are more positively related the more individuals believe in the value of diversity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Controlling droplet size variability of a digital lab-on-a-chip for improved bio-assay performance

Although several applications of electrowetting on dielectric digital lab-on-a-chips are reported in literature, there is still a lack of knowledge about the influence of operational and design parameters on the performance of an analytical assay. This paper investigates how droplet size variability, introduced by droplet dispensing and splitting, influences the assay performance with respect to repeatability and accuracy and presents a novel method to reduce this variability. Both a theoretical and experimental approach were followed. Monte Carlo simulations were applied to study the cumulative effect of the variability caused by different droplet manipulations on the final assay performance. It is shown that a highly controllable droplet generation and manipulation is achieved with respect to droplet size variability through an accurate control of actuation voltage, activation time, relaxation time, and electrode size. As a case study, it is illustrated that through optimization of these parameters a complete on-chip calibration curve is obtained for a d-glucose assay with an average CV-value of 2%. These new insights aim to bring the digital lab-on-a-chip technology closer to researchers in the field of diagnostics offering them a valuable and accessible alternative to standard analysis platforms.     

Learning directed probabilistic logical models: ordering-search versus structure-search

We discuss how to learn non-recursive directed probabilistic logical models from relational data. This problem has been tackled before by upgrading the structure-search algorithm initially proposed for Bayesian networks. In this paper we show how to upgrade another algorithm for learning Bayesian networks, namely ordering-search. For Bayesian networks, ordering-search was found to work better than structure-search. It is non-obvious that these results carry over to the relational case, however, since there ordering-search needs to be implemented quite differently. Hence, we perform an experimental comparison of these upgraded algorithms on four relational domains. We conclude that also in the relational case ordering-search is competitive with structure-search in terms of quality of the learned models, while ordering-search is significantly faster.