Operating Modes of Sandwiched Light‐Emitting Electrochemical Cells

Light‐emitting electrochemical cells (LECs) are promising lighting devices in which the redistribution of ionic charges allows for double electronic carrier injection from air‐stable electrodes. Uncertainties about the mode of operation are limiting the progress of these devices. Using fast (with respect to the current growth time) but resolutive electrical measurement techniques, the electronic transport mechanism in state‐of‐the‐art sandwiched devices can be monitored as a function of the operation time. The results indicate the formation of doped transport layers adjacent to the electrodes that reduces the extent of the central neutral light‐emitting layer where electronic transport is limited by space‐charge. Prolonged growth of the doped regions beyond that required for efficient injection should be prevented, as this decreases the efficiency and leads to low luminance devices.     

Evaluation of two control strategies for a sequencing batch reactor degrading high concentration peaks of 4-chlorophenol

The operation of a sequencing batch reactor (SBR) exposed to high concentration peaks (shock loads) of a toxic compound (4-chlorophenol, 4CP) was evaluated. Two control strategies based on on-line measurements of the dissolved oxygen concentration were tested. The first strategy, called variable timing control (VTC), detects the end of the reaction period to stop it. In the second control strategy, called observer-based time optimal control (OB-TOC), the automated system tries to maintain the critical specific growth rate by controlling the feed rate, i.e. the maximum growth rate when the substrate is toxic. The system operating under the VTC strategy presented a stable and efficient operation when the acclimated microorganisms (to an initial concentration of 350 mg 4CP/L) were exposed to punctual concentration peaks of 700 mg 4CP/L. A 4CP concentration peak higher than or equal to 1050 mg/L disturbed the system (1 month to recover). A 1400 mg/L peak caused strong inhibition that shut down the metabolic activity of the microorganisms, leading to reactor failure. With the OB-TOC strategy, the system was stable and worked efficiently when punctual concentration peaks of 700, 1050 and 1400 mg 4CP/L were fed. The system controlled by the OB-TOC strategy treated 1400 mg 4CP/L in less than 8h without affecting the operation of the reactor. The conclusion is that the OB-TOC strategy is more efficient than the VTC strategy to control a bioreactor when there are variations of concentrations of toxic organic compounds.     

A framework for decision-making in investment alternatives selection

Investment alternatives selection involves a variety of criteria that should be evaluated to provide a solid basis for decision-making. Some prior research has proposed methodologies and frameworks to support such alternatives selection. However, many of them present intrinsic limitations related to their applicability and complexity. Thus, this paper presents a framework for decision-making concerning investment alternatives that are usually related to equipment selection for a manufacturing process, technology selection for product development, product portfolio selection, and production strategy selection, among others. The framework is based on a multi-criteria approach that considers three main criteria: (i) strategy, which considers company market competitiveness; (ii) quality, which considers client requirements; and (iii) economic aspects, considering the overall financial benefits of the investment. These criteria are evaluated with the support of well-known tools from traditional management engineering such as SWOT, QFD, NPV and Payback. The results obtained through the use of these tools are rated using the MAUT method. Two major contributions are offered by this framework: (i) the integration of three key criteria for decision-making that enables to obtain a balanced analysis of the investment alternatives and (ii) the intrinsic easy-to-implement characteristic of the framework – based on the use of traditional tools. The proposed framework was applied in a tailor-made furniture company to support a make-or-buy decision, and the obtained results are discussed.     

Eco-sustainable routing in optical networks

It is quite easy to foresee that in the next years, the future generation ultra-high speed network infrastructures and equipments will be no longer constrained only by their pure transport capacity, but also by their energy consumption costs and environmental effects. In particular, large network infrastructures are now widely recognized to play a fundamental role in the emission of greenhouse gases in the atmosphere, significantly affecting the environmental sustainability of new evolutions in network architectures as well as technological developments in communication devices. In this paper, a novel eco-sustainable routing and wavelength assignment algorithm, based on shortest path routing with an adaptive link weighting function relying on an extension of the OSPF-TE protocol to convey carbon footprint information, has been proposed to decrease the network ecological impact while balancing the traffic load and maintaining acceptable connection-blocking rate. The trade-off between load balancing and carbon footprint is also analyzed to evaluate the effectiveness of the proposed strategy within the context of a real world network.     

Effects of apple and pear varieties and pH on patulin accumulation by Penicillium expansum

BACKGROUND: Accumulation of patulin in apples and pears and subsequently in their by‐products is caused mostly by Penicillium expansum which causes blue mould. Fruit pH and other parameters are sometimes characteristic of a certain variety and thus the use of particular varieties might affect patulin content in the final products. The aim of this study was to evaluate the influence of fruit variety and pH on patulin accumulation. Patulin accumulation in both apple and pear juices at different pH and also in different apple varieties (Golden, Gala and Fuji) and pear varieties (Blanquilla and Conference) was assessed. RESULTS: The pH of juices significantly influenced patulin accumulation, especially in apple juice in which the highest amounts of patulin were detected at pH 3.5. In fruits, the pH values of the substrate were determinant only under cold storage. Thus, Golden apples, which presented a lower pH, accumulated more patulin at 1 °C. However, this trend was not observed at other temperatures in which varieties with higher amounts of organic acids (Golden and Fuji apples) accumulated most patulin. In the pear varieties, significant differences in pH did not lead to significant differences in patulin accumulation. CONCLUSION: Although pH influences patulin accumulation, other factors such as organic acid content may play an important role. Concerning the apple and pear varieties we studied, it seems that rather than variety, other parameters like pH or acidic content may be more important. These parameters vary significantly depending on the degree of ripeness of the fruit. Gala apple, which is used in Spanish juice production, was the only variety that accumulated dramatically higher amounts of patulin. Copyright © 2008 Society of Chemical Industry     

Randomised double-blind study comparing tropisetron alone and in combination with dexamethasone in the prevention of acute and delayed cisplatin-induced emesis

In order to determine whether infection with Schistosoma japonicum is related to a higher rate of infection with hepatitis B virus and/or to a higher probability of HBsAg chronic carriage, a population based survey was carried out in China in which HBV markers were studied in 112 subjects with long-lasting S. japonicum infection, and 93 subjects with no S. japonicum infection 37.5% of the cases and 40.9% of controls showed no markers of HBV infection. The prevalence rate of HBsAg was 12.5% in the cases and 12.9% in the controls. For anti-HBc and anti-HBs the figures were 59.8% and 59.8%, and 27.9% and 35.0%, respectively. These data do not support the hypothesis of an interaction between infection with hepatitis B virus and S. japonicum.     

Combining Embeddings of Input Data for Text Classification

Neural Processing Letters - The problem of automatic text classification is an essential part of text analysis. The improvement of text classification can be done at different levels such as a...     

A formal verification framework for static analysis

Static analysis tools, such as resource analyzers, give useful information on software systems, especially in real-time and safety-critical applications. Therefore, the question of the reliability of the obtained results is highly important. State-of-the-art static analyzers typically combine a range of complex techniques, make use of external tools, and evolve quickly. To formally verify such systems is not a realistic option. In this work, we propose a different approach whereby, instead of the tools, we formally verify the results of the tools. The central idea of such a formal verification framework for static analysis is the method-wise translation of the information about a program gathered during its static analysis into specification contracts that contain enough information for them to be verified automatically. We instantiate this framework with costa, a state-of-the-art static analysis system for sequential Java programs, for producing resource guarantees and KeY, a state-of-the-art verification tool, for formally verifying the correctness of such resource guarantees. Resource guarantees allow to be certain that programs will run within the indicated amount of resources, which may refer to memory consumption, number of instructions executed, etc. Our results show that the proposed tool cooperation can be used for automatically producing verified resource guarantees.