POLITICAL ELECTIONS FOR MARKETERS

SrFe12O19 coatings, intended as electromagnetic wave absorbers, were produced by atmospheric plasma spraying (APS) using two different kindsof feedstock powders: spray-dried agglomerates of micrometric SrFe12O19 particles (type-A) or spray-dried agglomerates of raw materials (SrCO3,Fe2O3), reactively sintered at 1100 ◦C (type-B).During spraying, type-A agglomerates either remain unmelted, producing porous coating regions where crystalline hexaferrite is retained, orare disrupted into smaller granules which melt completely, resulting in dense coating regions with no crystalline hexaferrite.The sintered type-B agglomerates possess higher cohesive strength and do not fall apart: the finer ones melt completely, whereas, in the largerones, the outer region melts and infiltrates the porous unmelted core which retains crystalline hexaferrite. Dense coatings can therefore be obtainedwhile preserving high amounts of crystalline hexaferrite even inside the dense areas. Such coatings show magnetic properties that are promisingfor electromagnetic wave absorption applications

Development of matte finishes in electrostatic (EFB) and conventional hot dipping (CHDFB) fluidized bed coating process

This study focuses on the correlation between the thermo-rheological properties of a thermosetting powder coating system with its surface structure build-up. Epoxy powder coating systems, which displayed surface matting and surface wrinkling, were examined. Firstly, the evolution of the complex viscosity was correlated with the cure kinetic. Secondly, the structure build-up on the surface of the coatings was investigated with a combined SEM-CLA profilometry analysis at different stages of curing process for both EFB and CHDFB coating processes. Different finishes were found to characterize the films applied by using EFB and CHDFB coating processes as a result of the different way the film is heated by. Finally, a strict relationship of film morphology to the degree of conversion and to the evolution of the complex viscosity was found out for both EFB and CHDFB coating processes. The surface structure is built up after gelation point and continues to evolve after gelation with a full development of the film fine structure. Differences were observed in the surface structure build-up when different curing temperature was used, thereby indicating an influence of minimum viscosity on achievable finishing. These experimental results lead to further advances in a better understanding of the formation of surface topography and morphology of polymeric films. They also provide important indications for the settings of curing parameters in both EFB and CHDFB coating processes as well as for the development of new powder coating formulations. © 2007 Elsevier B.V. All rights reserved

A Block-Based Union-Find Algorithm to Label Connected Components on GPUs

In this paper, we introduce a novel GPU-based Connected Components Labeling algorithm: the Block-based Union Find. The proposed strategy significantly improves an existing GPU algorithm, taking advantage of a block-based approach. Experimental results on real cases and synthetically generated datasets demonstrate the superiority of the new proposal with respect to state-of-the-art

Improving the Performance of Thinning Algorithms with Directed Rooted Acyclic Graphs

In this paper we propose a strategy to optimize the performance of thinning algorithms. This solution is obtained by combining three proven strategies for binary images neighborhood exploration, namely modeling the problem with an optimal decision tree, reusing pixels from the previous step of the algorithm, and reducing the code footprint by means of Directed Rooted Acyclic Graphs. A complete and open-source benchmarking suite is also provided. Experimental results confirm that the proposed algorithms clearly outperform classical implementations

Microstructural and tribological comparison of HVOF-sprayed and post-treated M-Mo-Cr-Si (M = Co, Ni) alloy coatings

High velocity oxygen-fuel (HVOF)-sprayed wear resistant Co-28%Mo-17%Cr-3%Si and Ni-32%Mo-15%Cr-3%Si coatings, both as-sprayed and after heat treatments at 600 degrees C for 1 h, have been studied. Particularly, their dry sliding wear behaviour has been compared by ball-on-disk tests against different counterbodies (100Cr6 steel and sintered alumina), and differences were discussed based on microstructural characteristics and micromechanical properties (Vickers microindentation and scratch test responses). As-sprayed coatings contain oxide stringers, are mostly amorphous and display rather low Vickers microhardness (about 7.4 GPa for the Co-based and 6.2 GPa for the Ni-based), toughness and elastic modulus. Heat-treated ones display sub-micrometric crystalline intermetallics, improving hardness (9.6 GPa and 7.4 GPa, respectively) and elastic modulus. Scratch tests indicate greater brittleness of the Ni-based alloy (higher tendency to cracking). Due to low hardness and toughness, both as-sprayed coatings undergo wear loss against steel and alumina counterparts. The more plastic Co-based alloy undergoes higher adhesive wear against steel and lower abrasive wear against alumina; the situation is reversed for the Ni-based alloy. After heat treatment, the wear loss against steel is very low for both coatings; abrasive wear still occurs against alumina. (c) 2007 Elsevier B.V. All rights reserved

Optimal client recommendation for market makers in illiquid financial products

The process of liquidity provision in financial markets can result in prolonged exposure to illiquid instruments for market makers. In this case, where a proprietary position is not desired, pro-actively targeting the right client who is likely to be interested can be an effective means to offset this position, rather than relying on commensurate interest arising through natural demand. In this paper, we consider the inference of a client profile for the purpose of corporate bond recommendation, based on typical recorded information available to the market maker. Given a historical record of corporate bond transactions and bond meta-data, we use a topic-modelling analogy to develop a probabilistic technique for compiling a curated list of client recommendations for a particular bond that needs to be traded, ranked by probability of interest. We show that a model based on Latent Dirichlet Allocation offers promising performance to deliver relevant recommendations for sales traders.Comment: 12 pages, 3 figures, 1 tabl

EFFETTO DELLO SPESSORE SULLA RESISTENZA AD USURA E CORROSIONE DI RIVESTIMENTI WC-COCR DEPOSITATI SU LEGA DI AL TRAMITE TERMOSPRUZZATURA HVOF

Si sono esaminati gli effetti dello spessore e della presenza/assenza di un sottile bond coat in Ni sulla resistenza ad usura e a corrosione di rivestimenti in materiale cermet WC-CoCr, depositati tramite termospruzzatura HVOF su piastre in lega di alluminio AA 6082T6. Riporti con quattro diversi spessori, compresi nell’intervallo 50 ?m – 150 ?m, sono stati prodotti eseguendo, rispettivamente, un totale di 2, 3, 4 e 5 scansioni consecutive della torcia davanti al substrato. All’aumentare del numero di scansioni, la porosità del rivestimento cermet (sia con, sia senza bond coat) diminuisce; il cambiamento più sensibile si verifica fra i riporti depositati con 2 e 3 passaggi della torcia. Per spiegare questo fenomeno, si sono analizzati i meccanismi di deposizione di singole lamelle di WC-CoCr, esaminandole con tecnica Focused Ion Beam (FIB). All’aumento di densità del rivestimento corrispondono un incremento di microdurezza, un miglioramento della resistenza all’usura per strisciamento (misurata mediante test ball-on-disk) ed una maggior protezione del substrato contro la corrosione (valutata mediante spettroscopia di impedenza elettrochimica e monitoraggio del potenziale di libera corrosione). Rispetto a strati anodizzati, prodotti sulle stesse piastre, tutti riporti WC-CoCr (indipendentemente dallo spessore) sono molto più resistenti ad usura ma meno protettivi contro la corrosione del substrato

Influence of MAX-Phase Deformability on Coating Formation by Cold Spraying

As solid-state deposition technique avoiding oxidation, cold gas spraying is capable of retaining feedstock material properties in the coatings, but typically fails to build up coatings of brittle materials. Ceramic MAX phases show partial deformability in particular lattice directions and may thus successfully deposit in cold spraying. However, deformation mechanisms under high strain rate, as necessary for cohesion and adhesion, are not fully clear yet. A MAX-phase deposit only builds up, if the specific mechanical properties of the MAX phase allow for, and if suitable spray parameter sets get realized. To investigate the influence of material properties and deposition conditions on coating microstructure and quality, three MAX phases, Ti3SiC2, Ti2AlC and Cr2AlC, were selected. Up to ten passes under different spray parameters yielded Ti2AlC and Cr2AlC coatings with thicknesses of about 200-500 \ub5m. In contrast, Ti3SiC2 only forms a monolayer, exhibiting brittle laminar failure of the impacting particles. In all cases, the crystallographic structure of the MAX-phase powders was retained in the coatings. Thicker coatings show rather low porosities (< 2%), but some laminar cracks. The deposition behavior is correlated with individual mechanical properties of the different MAX-phase compositions and is discussed regarding the particular, highly anisotropic deformation mechanisms

Un'esperienza di catalogazione di risorse elettroniche: la Biblioteca italiana telematica

The Italian Telematic Library (Biblioteca Italiana Telematica, BIT) came into being in 1997 as an inter-university research project of national interest. Its aim was to make texts of Italian culture available in digital form through the work of about twenty research groups, in different subject fields, of fifteen universities, who had formed the CiBit consortium (Interuniversity Centre for the Italian Telematic Library), with headquarters in Pisa. The BIT is a digital library of texts of Italian culture that date from the Middle Ages to the twentieth century. They are mainly literary texts “of controlled origin”. This means that they are digitized, marked up and controlled by specialized teams following strict philological criteria, organized within a coherent library architecture with bibliographical and cataloguing standards that are accepted at national and international level. The analysis and implementation of library features and, more specifically, of the catalogue structure of the BIT have been entrusted to one of the research units of the University of Pisa, coordinated by A. Petrucciani. The unit was also responsible for the digitization of a selection of “classical” works of Italian bibliography and librarianship from the Eighteenth to the Twentieth Century. Thanks to cooperation with the Institute of Computational Linguistics of the National Research Council (CNR) of Pisa, the DBT (Textual Data Base) programme developed by Eugenio Picchi in the Applet Java version was used in the first stage of the project; for the sake of standardization a software program for the automatic conversion of the DBT coding into SGML/TEI markup was written and tested. The Web site of the Italian Telematic Library with DBT software was accessible until the Autumn of 2002 at the URL <http://cibit.humnet. unipi.it>. However, in 2002 the structure of the site was reconsidered in the light of recent developments and it was agreed to change from the DBT software and markup to newer and better options. The new site is accessible since May 2003 at the URL , with a search engine of new conception developed at the Computer Science Department of the University of Pisa. It was also decided to adopt the XML/TEI markup. Moreover, for the catalogue functions of the BIT (identification and selection of one or more texts with given characteristics, e.g. type, genre, period, etc.) it was realized that there was a need for a modern and powerful library system that would use a standard format (UNIMARC) and that would be able to overcome the limits of a search engine or of an ad hoc database application, typical of most “digital libraries”. The choice of a standard format for bibliographic data is seen as a qualifying element of the BIT programme