The properties of electroactive ruthenium oxide coatings supported by titanium-based ternary carbides

Electroactive oxide coatings on titanium, known in industrial chlorine production as dimensionally stable anodes (DSA), are of limited service life owing to the dissolution of active oxide, but also due to low corrosion stability of titanium, at high anodic potentials and elevated temperatures. In order to improve the anode stability, ternary carbide, Ti₃SiC₂, could be a promising material for the coating support, since chemical corrosion stability of Ti₃SiC₂ is significantly higher if compared to Ti. In this work, the possibility of the sol-gel preparation of RuO₂-TiO₂ coating on Ti₃SiC₂ is investigated and comparison of the basic characteristics of sol-gel processed oxide coating, Ru_0.5Ti_0.5O₂, applied onto Ti₃SiC₂ and Ti, is reported. Microscopic investigation of the coating surface showed that considerably less cracked coating is formed onto the Ti₃SiC₂ support. Slightly higher voltammetric currents are registered for Ti₃SiC₂-supported coating in H₂SO₄ and NaCl solution. The activity for chlorine evolution is higher, while the currents of oxygen evolution reaction are lower for Ru_0.5Ti_0.5O₂/Ti₃SiC₂ anode in comparison to Ru_0.5Ti_0.5O₂/Ti anode. Even though these preliminary results on the basic electrochemical properties of Ru_0.5Ti_0.5O₂/Ti₃SiC₂ anode and chemical stability of Ti₃SiC₂ are promising, the accelerated stability test in NaCl solution showed that coated Ti₃SiC₂ is not anodically stable and lasts considerably shorter than Ru_0.5Ti_0.5O₂/Ti anode prepared and tested under the same conditions.     

A semantic framework for automatic generation of computational workflows using distributed data and component catalogues

Computational workflows are a powerful paradigm to represent and manage complex applications, particularly in large-scale distributed scientific data analysis. Workflows represent application components that result in individual computations as well as their interdependences in terms of dataflow. Workflow systems use these representations to manage various aspects of workflow creation and execution for users, such as the automatic assignment of execution resources. This article describes an approach to automating a new aspect of the process: the selection of application components and data sources. We present a novel approach that enables users to specify varying degrees of detail and amount of constraints in a workflow request, including the specification of constraints on input, intermediate or output data in the workflow, abstract workflow component classes rather than specific component implementations, and generic reusable workflow templates that express a pre-defined combination of components. The algorithm elaborates the user request into a set of fully ground workflows with specific choices of data sources and codes to be used so that they can be submitted for mapping and execution. The algorithm searches through the space of possible candidate workflows by creating increasingly more specialized versions of the original template and eliminating candidates that violate constraints cumulated in the candidate workflow as components and data sources are selected. A novel feature of our approach is that it assumes a distributed architecture where data and component catalogues are separate from the workflow system. The algorithm explicitly poses queries to external catalogues, and therefore any reasoning regarding data or component properties is not assumed to occur within the workflow system. We describe our implementation of this approach in the Wings workflow system. This implementation uses the W3C Web Ontology Language and associated reasoners to implement the workflow system as well as the data and component catalogues. This research demonstrates the use of artificial intelligence techniques to support the kinds of automation envisioned by the scientific community for large-scale distributed scientific data analysis.     

Extragenital donovanosis of the foot

Kartagener's syndrome (KS) usually includes mirror-image dextrocardia. The incidence of congenital heart disease in KS is comparable with that in the general population. This paper reports on a case of Kartagener's syndrome associated with dextrocardia, corrected transposition of the great arteries (I,D,D), ventricular septal defect, and valvar pulmonary stenosis in an 8-year-old girl.     

Computer-based learning of neuroanatomy: A longitudinal study of learning, transfer, and retention.

A longitudinal experiment was conducted to evaluate the effectiveness of new methods for learning neuroanatomy with computer-based instruction. Using a three-dimensional graphical model of the human brain and sections derived from the model, tools for exploring neuroanatomy were developed to encourage adaptive exploration. This is an instructional method that incorporates graphical exploration in the context of repeated testing and feedback. With this approach, 72 participants learned either sectional anatomy alone or whole anatomy followed by sectional anatomy. Sectional anatomy was explored either with perceptually continuous navigation through the sections or with discrete navigation (as in the use of an anatomical atlas). Learning was measured longitudinally to a high performance criterion. Subsequent tests examined transfer of learning to the interpretation of biomedical images and long-term retention. There were several clear results of this study. On initial exposure to neuroanatomy, whole anatomy was learned more efficiently than sectional anatomy. After whole anatomy was mastered, learners demonstrated high levels of transfer of learning to sectional anatomy and from sectional anatomy to the interpretation of complex biomedical images. Learning whole anatomy prior to learning sectional anatomy led to substantially fewer errors overall than learning sectional anatomy alone. Use of continuous or discrete navigation through sectional anatomy made little difference to measured outcomes. Efficient learning, good long-term retention, and successful transfer to the interpretation of biomedical images indicated that computer-based learning using adaptive exploration can be a valuable tool in instruction of neuroanatomy and similar disciplines. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Ferroelectric Properties of Tungsten Bronze Morphotropic Phase Bounary Systems

Tungsten bronze ferroelectrics which have a morphotropic phase boundary (MPB) can have a number of enhanced dielectric, piezoelectric, and electrooptic properties compared to more conventional ferroelectric materials. The structural and ferroelectric properties of several MPB bronze systems are presented, including data from sintered and hot-pressed ceramics, epitaxial thin films, and bulk single crystals. Included among these are three systems which had not been previously identified as morphotropic. The potential advantages and limitations of these MPB systems are discussed, along with considerations of the appropriate growth methods for their possible utilization in optical, piezoelectric, or pyroelectric device applications.     

Investigations on Buckling Behaviour of Laminated Curved Composite Stiffened Panels

In Industrial applications structural efficiency is primary concern, this brings about the need of strong and lightweight materials. Due to their high specific strength, fibre reinforced polymers find wide application in these areas. Panels made of composite materials are widely used in aerospace structures, automobile, civil, marine and biomedical industries because of their good mechanical properties, impact resistance, excellent damage tolerance and also low fabrication cost. In this Paper, buckling and post-buckling analysis was performed on composite stiffened panel to obtain the critical load and modes of failures, with different parameters like ply-orientation, different composite materials, and stiffeners and by changing the number of stiffeners was derived. To analyze the post buckling behaviour of composite stiffened panels the nonlinear finite element analysis is employed and substantial investigations are undertaken using finite element (FE) model. Effect of critical parameters on buckling behaviour is studied and parametric studies were conducted with analytical tool to understand the structural behaviour in the post buckling range.