Flow Properties of Ultrahigh-Molecular-Weight Poly(Methyl Methacrylate) in Semidilute Solutions

The article presents some Theological results obtained on a large domain of shear rates for semidilute solutions of ultrahigh-molecular-weight poly(methyl methacrylate) at different concentrations. The observed unusual behavior was explained as being due to the flow instabilities of long-chain polymers in an entangled state.     

Co-Magneli phases electrocatalysts for hydrogen/oxygen evolution

The subject of this work is the use of non-stoichiometric titanium oxides – Magneli phases as support material of Co-based electrocatalysts aimed for hydrogen/oxygen evolution reaction. Commercial micro-scaled Ebonex (Altraverda, UK) was mechanically treated for 4, 8, 12, 16 and 20 h and further Co metallic phase was grafted by sol-gel method. Morphology of Co/Ebonex electrocatalysts was observed by means of TEM and SEM microscopy, while electrochemical behavior by means of cyclic voltammetry and steady-state galvanostatic method.     

Setting up a competition framework for the evaluation of structure extraction from OCR-ed books

This paper describes the setup of the Book Structure Extraction competition run at ICDAR 2009. The goal of the competition was to evaluate and compare automatic techniques for deriving structure information from digitized books, which could then be used to aid navigation inside the books. More specifically, the task that participants faced was to construct hyperlinked tables of contents for a collection of 1,000 digitized books. This paper describes the setup of the competition and its challenges. It introduces and discusses the book collection used in the task, the collaborative construction of the ground truth, the evaluation measures, and the evaluation results. The paper also introduces a data set to be used freely for research evaluation purposes.     

Damage of heat-resistant castings in a carburizing furnace

The study reviews typical damages occurring in heat-resistant castings used in box-type carburizing furnaces. The analysis was mainly based on a visual examination of elements withdrawn from operation. Furnace heat-resistant equipment can be divided into construction elements installed permanently in a furnace chamber (e.g. radiant tubs, fans, rollers) and elements utilized to set or load and unload parts to be carburized (e.g. grates, fixtures, basket). Depending on the function performed by a particular casting, its degradation process varies. The final consequence of the wear and tear of a casting is above all a decohesion of its walls that results from an influence of carburizing atmosphere, or from the combined effect of carburizing atmosphere and thermal fatigue. The effect of creep, that may occur in castings during their use as a result of the load of the structure or/and of the carburized parts, was not observed to be a direct cause of the damages.     

Mechanisms for formation,chlorination, dechlorination and destruction of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs)

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) constitute a group of persistent organic pollutants that form almost inexorably in all thermal and combustion operations. This review focuses on mechanisms that govern their formation, chlorination, dechlorination and destruction. As a consequence of their extreme toxicity and propensity to bioaccumulate, PCDD/Fs have been subjected to much scientific research, designed to understand mechanisms and conditions that govern their emission rates and congener distribution (fingerprints). Consensus of opinions in the literature points to heterogeneous pathways contributing substantially more in the total yield of PCDD/Fs in combustion systems than the gas phase pathway. However, in our view, a great complexity of both homogeneous and heterogeneous routes and uncertainties in many thermochemical and rate parameters enable no conclusive statement about the contribution of each route. Chlorination patterns of precursors appear to play a major role in final congener profiles of PCDD/F emissions. According to the most recent theoretical studies, these congener profiles seem consistent with thermodynamic stabilities of dioxins and furans produced in thermal processes, however, further theoretical investigations at more accurate levels are needed to clarify this matter further. Theoretical studies along with experimental findings reveal that the PCDD/PCDF ratio remains very sensitive to the operating conditions, with pyrolytic conditions favouring the formation of PCDFs. A number of reaction mechanisms has been proposed to answer many of the most intriguing questions about the formation of PCDD/Fs. These mechanisms include models of gaseous and heterogeneous reactions, often inferred from theoretical quantum chemical calculations studies, which incorporate steps responsible for formation, chlorination, dechlorination and destruction of dioxins and furans. The review identifies gaps in our present understanding of the reaction mechanisms and suggests that further progress in the field needs to be facilitated by development of reliable mechanistic models for (i) catalytic pathways, (ii) chlorination/dechlorination reactions including the Deacon reaction and the direct transfer of chlorine from solid surfaces into the aromatic moieties, and (iii) formation of PCDD/Fs from precursors other than chlorophenols, especially pesticides.     

Synthesis and optical properties of water-soluble poly(vinylpyrrolidone) - modified fullerene C<Subscript>60</Subscript>

Summary  The effect of fullerene on the radical polymerization of N-vinylpyrrolidone with lauroyl peroxide in toluene was investigated kinetically. C₆₀ was found to act both as inhibitor and as retarder because the polymerization rate and the molecular weight of resulting poly(vinylpyrrolidone) is decreasing with the increase of the fullerene concentration (0-6.94 x 10^-4 mol l^-1). The water-soluble poly(vinylpyrrolidone)-modified fullerene C₆₀ compound was characterized by differential scanning calorimetric, Infrared and Raman spectroscopy, UV absorption and photoluminescence. Based on the results obtained by optical measurements, it is argued that by the covalent attachment of the polymeric radicals to fullerene cage the extended electronic conjugation system of the C₆₀ is broken leading to the appearance of a polyene structure.     

Beliefs about birth rank and their reflection in reality.

Beliefs about birth rank reflect what the society regards as social reality, and they may also influence that reality. Three studies found that people believe those with different birth ranks differ in their personalities, that higher birth ranks are likely to attain higher occupational prestige, and that the personality characteristics attributed to the various birth ranks favor the actual attainment of higher occupational prestige. In one example of such beliefs, firstborns were rated as most intelligent but least creative whereas the opposite was true of last-borns. The 4th study found that those with higher birth ranks in fact attain more prestigious occupations and actually do complete more years of schooling. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

THE DISCIPLE–RKF LEARNING AND REASONING AGENT

Over the years we have developed the Disciple theory, methodology, and family of tools for building knowledge-based agents. This approach consists of developing an agent shell that can be taught directly by a subject matter expert in a way that resembles how the expert would teach a human apprentice when solving problems in cooperation. This paper presents the most recent version of the Disciple approach and its implementation in the Disciple–RKF (rapid knowledge formation) system. Disciple–RKF is based on mixed-initiative problem solving , where the expert solves the more creative parts of the problem and the agent solves the more routine ones, integrated teaching and learning , where the agent helps the expert to teach it, by asking relevant questions, and the expert helps the agent to learn, by providing examples, hints, and explanations, and multistrategy learning , where the agent integrates multiple learning strategies, such as learning from examples, learning from explanations, and learning by analogy, to learn from the expert how to solve problems. Disciple–RKF has been applied to build learning and reasoning agents for military center of gravity analysis, which are used in several courses at the US Army War College.     

Turing machines with access to history

We study remembering Turing machines, that is Turing machines with the capability to access freely the history of their computations. These devices can detect in one step via the oracle mechanism whether the storage tapes have exactly the same contents at the moment of inquiry as at some past moment in the computation. The s(n)-space-bounded remembering Turing machines are shown to be able to recognize exactly the languages in the time-complexity class determined by bounds exponential in s(n). This is proved for deterministic, non-deterministic, and alternating Turing machines.