WOx/ZrO2 catalysts: Part 3. Surface coverage as investigated by low temperature CO adsorption: FT-IR and volumetric studies

The adsorption of CO at 77 K on zirconia-supported tungsten oxide (ZW) samples prepared by equilibrium adsorption or by impregnation and with tungsten content up to 12.4 W atoms nm⁻² was studied with the aim of determining the coverage of ZrO₂ surface by the supported tungsten oxospecies. As an essential background for quantitative volumetric measurements, ZW samples were investigated by FT-IR spectroscopy to identify the surface sites responsible for the CO adsorption. FT-IR showed that CO adsorbed selectively and irreversibly on Zr_cus⁴⁺ centers of the support surface, but not on W_cus⁶⁺ sites. By volumetric determinations, the coverage of the zirconia surface by tungsten oxospecies was about 50% at maximum, irrespective of the preparation procedure and of the support crystallographic modification (monoclinic or tetragonal). Zirconia coverage remained significantly unchanged after leaching with a NH₃ solution that removed tungsten oxospecies not directly interacting with the zirconia surface. This finding indicates that ZrO₂ support coverage depends mainly on the tungsten species strongly anchored to the zirconia surface.     

The ethnic unconscious and its role in transference, resistance, and countertransference: An introduction.

Introduces the Special Section "Ethnicity and psychoanalysis." The authors address how psychoanalytic formulations focus in the main on the study of the individual's internal structure, the study of the mind as a theater of conflict without much concern with the possible influence of ethnic components in psychic structure. Their interest is to extend the study of the mind as a theater of conflict to include the issue of ethnicity and ethnic tension. The authors further discuss providing a psychoanalytic perspective on ethnic tension, the ethnic unconscious, cultural background factors, and the psychological mechanism of ethnic tension in relation to the articles of the special section. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A method for identifying Web applications

Web applications are ubiquitous in today’s businesses. The security of these applications is of utmost importance since security breaches might negatively impact good reputation, and even result in bankruptcy. There are different methods of assessing security of Web applications, mainly based on some automated method of scanning. One type of scan method feeds random data to the application and monitors its behavior. The other type uses a database with predefined vulnerabilities that are checked one by one until either a vulnerability is found, or it can be claimed that the application does not have any known vulnerabilities. The important step in latter type of scan process is the identification of the application since in this case we are narrowing number of checks and, as a consequence, the scan process is faster. This paper describes a method for Web application identification based on a black box principle. Our method is based on the invariance of certain characteristics of Web applications. We experimentally tested and confirmed the usefulness of this approach.     

A Finite Element Method on Convex Polyhedra

We present a method for animating deformable objects using a novel finite element discretization on convex polyhedra. Our finite element approach draws upon recently introduced 3D mean value coordinates to define smooth interpolants within the elements. The mathematical properties of our basis functions guarantee convergence. Our method is a natural extension to linear interpolants on tetrahedra: for tetrahedral elements, the methods are identical. For fast and robust computations, we use an elasticity model based on Cauchy strain and stiffness warping. This more flexible discretization is particularly useful for simulations that involve topological changes, such as cutting or fracture. Since splitting convex elements along a plane produces convex elements, remeshing or subdivision schemes used in simulations based on tetrahedra are not necessary, leading to less elements after such operations. We propose various operators for cutting the polyhedral discretization. Our method can handle arbitrary cut trajectories, and there is no limit on how often elements can be split.     

A channelized digital receiver design for UWB systems in a multi-path indoor environment

Due to the very wide bandwidth of UWB system, it is hard if not impossible to design high speed and high resolution ADCs with today’s technology. This problem can be solved if the received UWB signal is split into a number of subbands by power splitters, analog low-pass filters, mixers and digital filters. By doing this, each of subbands can be sampled at a fraction of effective sampling frequency. In this paper, we present a simpler channelized receiver architecture for UWB systems than previously published work. Moreover, we present a new, though more complex, channelized receiver design for UWB systems in a multipath propagation environment. We also show through simulation that this new receiver achieves very good BER performance.     

Self-propagating combustion synthesis of intermetallic matrix composites in the ISS

Combustion Synthesis experiments have been performed on the ISS (International Space Station) during the Belgian taxi-flight mission ODISSEA in November 2002, in the framework of the ESA-coordinated project COSMIC (Combustion Synthesis under Microgravity Conditions). The main objective of the experiments was to investigate the general physico-chemical mechanisms of combustion synthesis processes and the formation of products microstructure. Within the combustion zone, a number of gravity-dependent phenomena occur, while other phenomena are masked by gravity. Under certain conditions, gravity-dependent secondary processes may also occur in the heat-affected zone after combustion. To study the influence of gravity, a specially dedicated reactor ensemble was designed and used in the Microgravity Science Glovebox (MSG) onboard the ISS. In this work, the experiment design is first discussed in terms of the experimental functionality and reactor ensemble integration in the MSG. To investigate microstructure formation, a sample constituted by a cylindrical portion followed by a conical one, the latter being inserted inside a massive copper block, is used. The experiment focused on the synthesis of intermetallic matrix composites (IMCs) based on the Al-Ti-B system. Depending on the composition, different intermetallic compounds (TiAl and TiAl₃) can be formed as matrix phase while TiB2 represents the reinforcing particulate phase. During the ISS mission, six samples with a relatively high green density of 65%TD have successfully been processed. The influence of the composition on the combustion process will be examined.     

完全可视化技术为ASIC验证带来革命性变化

针对FPGA原型验证系统开发的完全可视化技术能够大幅提高ASIC和系统验证工作的效率,Synplicity公司开发的TotalRecall技术就实现了这种突破。该技术采用最新的电路设计与综合方法,充分发挥FPGA原型验证技术的各种优势,如低成本、高速及高效等,从而实现了真正全面的信号可视性。     

Posttraumatic intrusion, avoidance, and social functioning: A 20-year longitudinal study.

The study assesses posttraumatic intrusion, avoidance, and social functioning among 214 Israeli combat veterans from the first Lebanon War with and without combat stress reaction (CSR) 1, 2, 3, and 20 years after the war. CSR veterans reported higher intrusion and avoidance than did non-CSR veterans. With time, there was a decline in these symptoms. In addition, intrusion and avoidance were associated with problems in social functioning on a given year, and they longitudinally predicted social dysfunction 2, 3, and 20 years after the war. CSR veterans presented stronger temporal covariations between intrusion-avoidance and social functioning. The findings suggest that CSR is a marker for future psychopathology and point to the role of avoidance in social dysfunction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing the Value of a Second Opinion: the Role and Structure of Exchangeability

This paper displays the productive role of the judgment of exchangeability and even conditional exchangeability that should replace the misleading assertion of independence of various experts' opinions regarding uncertain situations. The application is technically rather complicated, and a basic understanding of exchangeability in its simple applications is presumed. One component of the analysis is novel. It suggests how we might specify a likelihood function that allows us to learn about one exchangeable sequence of events from the outcomes of another exchangeable sequence. The substantive content of the the paper concerns the use of personal probabilities by two experts in assessing the sex of human skulls found in anthropological investigations. Although we initially value the two experts' assertions exchangeably, we learn to value one of the expert's assertions more than the other's. Moreover we identify precisely how much to value the elicitation from a second expert after we have already learned the assertion of the first. Valuation is based on a decision theoretic procedure assessing reduction in risk.     

A vision-based, 3D reconstruction technique for scanning electron microscopy: direct comparison with atomic force microscopy

High-resolution, detailed 3D reconstructions of biological specimens obtained from scanning electron microscopy stereo-micrographs and proprietary software were compared with Tapping-Mode AFM datasets of the same fields. The reconstruction software implements several original solutions including a neural adaptive point-matching technique, the ability to build an irregular triangulated mesh rather than a regular orthogonal grid, and the ability to re-map one of the original images exactly onto the reconstructed surface. The technique was applied to human nerve tissue to obtain 1,424 x 968-pixel, texture-mapped datasets, which were subsequently compared against 512 x 512-pixel AFM datasets from the same viewfields. Accounting for the inherent differences of the two techniques, direct comparison revealed an excellent visual match. The correspondence was also quantified by calculating the cross-correlation coefficient between corresponding altimetric profiles in SEM and AFM data, which consistently exceeded a figure of 0.9, with a rate of point mismatch in the order of 0.01%. Research is still underway to improve the robustness of the technique when applied to arbitrary images