Extension of belief functions to infinite-valued events

We generalise belief functions to many-valued events which are represented by elements of Lindenbaum algebra of infinite-valued ?ukasiewicz propositional logic. Our approach is based on mass assignments used in the Dempster–Shafer theory of evidence. A generalised belief function is totally monotone and it has Choquet integral representation with respect to a unique belief measure on Boolean events.     

Current oscillations in austenitic stainless steel induced by the presence of chloride ions

The conditions for current oscillations in austenitic stainless steel (AISI Type 303) in 1M H₂SO₄ containing Cl^? ions are given. The periodic oscillations are produced in a close potential range determined at the active-passive transition region. It requires a non-homogeneous distribution of inclusions and carbides at the metal surface and a concentration range of Cl^? ion where active and passive areas coexist on the metal surface. The constraints at the surface determining these two regions are related to the Cl^? ion competitive adsorption and the local accumulation of corrosion products. Electrochemical data and SEM observations are correlated.     

Polylactide films formed by immersion precipitation: Effects of additives,nonsolvent, and temperature

The influence of nonsolvent, crystallinity of the polymer film, and addition of dodecane (a poor solvent for the polymer and for the nonsolvent) on the morphology of polylactides films has been investigated and was related to phase separation behavior. Both amorphous poly‐DL ‐lactide (PDLLA) and crystalline poly‐L ‐lactide (PLLA) were dissolved in dichloromethane, and subsequently films were made by immersion in nonsolvent baths. PDLLA gave dense films without any internal structure, since the structure was not solidified by crystallization or glassification. PLLA films show varying structure depending on the nonsolvent. With methanol, asymmetric morphologies were observed as a result from combined liquid‐liquid demixing and crystallization, while with water symmetric spherulitic structures were formed. As a next step, dodecane was added, which is not miscible with the nonsolvent, and we found it to have a strong influence on the morphology of the films. The PDLLA films with dodecane did not collapse: a closed cell structure was obtained. In PLLA films, dodecane speeds up phase separation and induces faster crystallization in the films, and the porosity, size of the pores, and interconnectivity increased. When the PLLA solutions were subjected to a heat pretreatment, crystallization could be postponed, which yielded a cellular structure around dodecane, which did not contain spherulites anymore. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 959–971, 2007     

Determination of the solubility parameter of poly(ethylene oxide) at 25°C by gas-liquid chromatography

The solubility parameter of poly(ethylene oxide) at 25°C has been determined using the method developed by DiPaola-Baranyi and Guillet, by the extrapolation of the values of the interaction parameter χ, at high temperatures, ranging from 70°–90°, 90°–110° and 110°–130°C down to 25°C. The values of the solubility parameter obtained, depending on the temperature ranges employed, are 9.8, 9.9 and 10.1, respectively.     

Surface Areas of Nitrated Hydrotalcites

Hydrotalcites in the nitrate form were prepared using microwave irradiation in the hydrotreatment step. The surface area (BET) of nitrated hydrotalcites was evaluated. Solids were characterized by atomic absorption, X-ray diffraction and BET analysis. Thermal pretreatment temperature determined the surface area of the hydrotalcites.     

Near-Surface Deformation in an Alumina–Silicon Carbide-Whisker Composite due to Surface Machining

Deformation due to two different surface-machining conditions—grinding (126 μm diamond) and polishing (3 μm diamond)—in an uniaxial hot-pressed Al₂O₃–30%-SiC-whisker composite has been investigated. A Warren–Averbach analysis of grazing incidence X-ray diffractometry data shows that the deformation is localized to the very top surface zone. The cell size and the root mean square of the strain show a gradient in the deformed layer. Transmission electron microscopy studies, in cross-sectional view, also show a near-surface deformation zone containing dislocations, twins, and cracks. This is seen for both machining procedures, but the depth of the zone and the degree of deformation, in terms of dislocation density and number of cracks, is much higher in the roughly ground specimen than in the polished one. For comparison, a monolithic Al₂O₃ sample also has been studied after grinding. The deformation zone is very similar to the Al₂O₃–SiC sample with the same grinding condition, but cracks and dislocations are present at a slightly larger depth. The deformation depth for the polished Al₂O₃–SiC sample is ∼50 nm. In the ground Al₂O₃–SiC sample, the deformation depth is 1–1.5 μm and corresponds to the grain size. The deformation zone in the ground monolithic Al₂O₃ sample is 1.5–2 μm deep. The observed grain-boundary cracks are almost parallel to the surface and may originate from nonaccommodated plastic flow between grains.     

Nature-Inspired Meta-Heuristics on Modern GPUs: State of the Art and Brief Survey of Selected Algorithms

Graphic processing units (GPUs) emerged recently as an exciting new hardware environment for a truly parallel implementation and execution of Nature and Bio-inspired Algorithms with excellent price-to-power ratio. In contrast to common multicore CPUs that contain up to tens of independent cores, the GPUs represent a massively parallel single-instruction multiple-data devices that can nowadays reach peak performance of hundreds and thousands of giga floating-point operations per second. Nature and Bio-inspired Algorithms implement parallel optimization strategies in which a single candidate solution, a group of candidate solutions (population), or multiple populations seek for optimal solution or set of solutions of given problem. Genetic algorithms (GA) constitute a family of traditional and very well-known nature-inspired populational meta-heuristic algorithms that have proved its usefulness on a plethora of tasks through the years. Differential evolution (DE) is another efficient populational meta-heuristic algorithm for real-parameter optimization. Particle swarm optimization (PSO) can be seen as nature-inspired multiagent method in which the interaction of simple independent agents yields intelligent collective behavior. Simulated annealing (SA) is global optimization algorithm which combines statistical mechanics and combinatorial optimization with inspiration in metallurgy. This survey provides a brief overview of the latest state-of-the-art research on the design, implementation, and applications of parallel GA, DE, PSO, and SA-based methods on the GPUs.     

Parameter Identification in Photothermal Imaging

We propose a technique to reconstruct the geometry of inclusions and their material parameters in thermal scattering near surfaces. The imaging problem is reformulated as a constrained optimization problem with a finite number of stationary constraints. The unknown domains and their parameters are the design variables. A descent method combining topological derivative analysis to find improved guesses of the objects and gradient iterations to correct their material parameters provides reasonable reconstructions.     

Effects of the nitrification inhibitor N-Serve on the utilization of fall-applied urea by wheat

Four-year microplot tests were performed to study the utilization by wheat, in the presence and absence of the nitrification inhibitor N-Serve, of¹⁵N labeled urea spread in fall. The percentages of fertilizer nitrogen taken up by winter wheat (grains and straw) were 18 to 37 percent when urea was spread in fall, 33 to 45 percent when urea plus N-Serve was applied in fall, and 36 to 49 percent when urea was spread in spring. In the 0–30 cm layer of soil there were found, for the treatments listed above, 15 to 23 percent, 24 to 45 percent, and 15 to 47 percent of urea nitrogen after the harvesting of winter wheat. Application of urea plus N-Serve in fall and of urea alone in spring resulted in similar amounts of fertilizer nitrogen being taken up by spring wheat to those taken up by winter wheat. Of the urea nitrogen applied in fall, 20 to 28 percent and 47 to 50 percent were not recovered from the plants and 0–30 cm soil layer with and without additional N-Serve treatment, respectively. The utilization by winter wheat of urea nitrogen spread, with no additional N-Serve, in fall from mid-October onward was considerably lower in those cases where, after fertilizing, weather conditions were such as to favour both nitrification and leaching. On heavy and loamy soil such influences of weather were offset by application of N-Serve.     

Experimental observation of temperature gradients occurring in a single zeolite pellet

An experimental study has been made of temperature profiles incident within a zeolite adsorbent particle in the course of adsorption of n-heptan. Using thermocouple wires 0.1 mm in diameter it has been possible to measure simultaneously the temperatures of the surface and in the centre. It was observed that temperature differences between center of the pellet and ambient stagnant gas may be more than 20°C. The results of this work indicate that the overheating of an adsorbent particle is a very rapid process which is followed by a slow cooling of the hot particle. Experimental data are compared with predictions calculated from the theoretical model.