Abnormal Grain Growth in Alumina: Synergistic Effects of Yttria and Silica

Abnormal grain growth without strong anisotropy or faceting of the grains has been observed in high-purity yttria-doped alumina specimens, often starting at the surface and spreading right through the bulk at higher sintering temperatures. This appears to occur because of an interaction between Si contamination from sintering and the yttria doping; no such effect is seen for undoped samples. Similar microstructures were observed after deliberate Y/Si codoping. Analytical STEM showed that some grain boundaries bordering on large grains contained more Si than Y. HRTEM and diffuse dark-field imaging revealed thin (0.5–0.9 nm) disordered layers at some boundaries bordering large grains. It appears that Si impurities are accumulating at some boundaries and together with the Y inducing a grain boundary structural transformation that accounts for the dramatically increased mobility of these boundaries.     

The capacitated transshipment location problem with stochastic handling utilities at the facilities

The problem consists in finding a transshipment facilities location that maximizes the total net utility when the handling utilities at the facilities are stochastic variables, under supply, demand, and lower and upper capacity constraints. The total net utility is given by the expected total shipping utility minus the total fixed cost of the located facilities. Shipping utilities are given by a deterministic utility for shipping freight from origins to destinations via transshipment facilities plus a stochastic handling utility at the facilities, whose probability distribution is unknown. After giving the stochastic model, by means of some results of the extreme values theory, the probability distribution of the maximum stochastic utilities is derived and the expected value of the optimum of the stochastic model is found. An efficient heuristics for solving real‐life instances is also given. Computational results show a very good performance of the proposed methods both in terms of accuracy and efficiency.     

The Vault of the H?tel de Ville in Arles

The vault of the Arles City Hall, or H?tel de Ville, represents the architect’s revenge on the corporations of masons. Completed in 1676, the relationship of span to rise of the vault make it the boldest work of masonry in Europe, and while this complex vault appears to be a unitary structure, two vaults actually share the work, leaning against each other on the big arch. Bibliographic and archival research showed that surveys of the vault were missing; the only ancient survey was lost in the 1970s. A recent survey campaign made an analysis possible, leading to a hypothesis about the architect Mansart’s choices, based on hypothetical solutions to resolve the formal construction issues of the vault. A connoisseur of geometry and optics, Mansart knew that the human eye was unable to perceive the exact geometry of a surface. Knowing that he couldn’t control the intersections of vault portions and then the joints of the rows in the space, he introduced a solution that involved drawing the intersections in plan and then projecting them on the vault to obtain the spatial intersections. No further constructions of the bold type followed the vaulted space in the H?tel de ville, because the spatial research that linked the new discipline (stereotomy) to the quality of architectural space had by then come to an end.

La vo?te de l’H?tel de ville d’Arles est le chef d’oeuvre de la stéréotomie fran?aise [Perouse de Montclos 1983: 123-126]     

The role of the environment in agreement technologies

The notion of Multi-Agent System environment is currently considered as a mediating entity, functioning as enabler but possibly also as a manager and constrainer of agent actions, perceptions, and interactions. In this paper, we analyze how the environment could be a first class abstraction to support the building, the development and the management of Agreements in decentralized and open systems between autonomous agents. To this aim we analyze the synergies between the environment and the foundational dimensions of agreement technologies such as semantics, norms, organizations, argumentation & negotiation, trust.     

Reconstitution and anchoring of cytoskeleton inside giant unilamellar vesicles

Among the requirements for all life forms is the ability to self-replicate. In eukaryotic cellular systems, this division is achieved through cytokinesis, and is facilitated by the (re)arrangement and interaction of cytoskeletal proteins with lipids and other proteins localized to the plasma membrane. A fascinating challenge of modern synthetic biology is the bottom-up reconstitution of such processes for the generation of an artificial cell. One crucial step towards this goal is the functional reconstitution of the protein-anchoring machinery to facilitate cytokinesis into lipid vesicles. True to the ideal of a minimal cell-like system, we here describe the formation of an actin-based cytoskeleton within giant unilamellar vesicles (GUVs) made from porcine brain lipid extracts. We demonstrate that the actin filaments are localised and anchored to the interior walls of the GUVs through the spectrin/ankyrin proteins, and produce tightly packed actin bundles. These studies allow for the examination of cytoskeletal rearrangements within a cell-like model membrane system and represent important first steps in reconstituting the minimal machinery required for the division of an artificial cell. In addition, the study of such minimal systems can shed light on protein functions that are commonly unobservable or hidden within the overwhelming complexity of cells.     

Introduction to the Special Inaugural Issue

This first issue of Language Resources and Evaluation is dedicated to the memory of Antonio Zampolli, whom few would dispute is the one person who has led the way in promoting and establishing the development of language resources (LR) of all kinds for the past four decades. In this inaugural issue, we have attempted to bring together articles by major figures in the field in order to provide an overview of the history, state of the art, and the future of the creation, annotation, exploitation, evaluation, and distribution of LR. Hopefully, this collection of articles will serve not only as a tribute to Antonio, but also as a framework out of which this journal – which almost certainly would not have existed were it not for him – can grow.     

Bridge pier scour under pressure flow conditions

The probability of pressurized flow conditions occurring in existing bridges is forecast to increase due to possible changes in extreme precipitation, storm surges, and flooding predicted under climate change scenarios. The presence of a pressure flow is generally associated with scouring processes in proximity to the bridge. Scouring can also occur around bridge piers, possibly causing infrastructure failure. Although there is a vast literature on bridge pier scour and pressure flow scour, only a few studies have investigated their combined effect. This study will provide a new overview of the main features of bridge pier scour under pressurized flow conditions, based on laboratory experiences. Special focus is placed on the analysis of the flow features under pressure and free surface conditions and to the temporal evolution of the scour. A comparison with existing literature data is also conducted. The results highlight the nonlinear nature of scour processes and the need to consider pressurized flow conditions during structural design, as the interaction between pressure flow and the bridge pier strongly influences scour features and leads to scour depths much greater than the sum of the individual scours created only by pressure flow or pier presence.     

A first pilot study to produce a food antioxidant from sunflower seed shells (Helianthus annuus)

This article explains a laboratory procedure to produce an antioxidant from grinded, dehulled and partially defatted sunflower seeds. Initially, a solvent suitable to extract phenols was searched among different solutions of water mixed with ethanol, methanol and acetone at 40% (vol/vol) (each tested at pH 5, 7 and 9). Both the ethanol/water 60:40 (vol/vol) and the acetone/water 60:40 (vol/vol) mixtures proved to be suitable for the dephenolization of sunflower seed shells, but in the next steps of this research, the mixture ethanol/water 60:40 (vol/vol) at pH 5 was used. Secondly, the procedure to obtain the antioxidant product was defined, which consisted in hydrolysis of sunflower seed phenols with 1.25 N NaOH at room temperature for 60 min and finally the recovery of caffeic acid formed from chlorogenic acid with ethyl acetate. From 25 g of partially defatted sunflower shells, around 90 mg of powdery antioxidant product, consisting of 58% caffeic acid, was obtained. The antioxidant product, the caffeic acid standard and propyl gallate were added to different edible fats at the same dose of 240 AU (antioxidant units) per kg fat. A Rancimat test, at 130 °C and an air flow of 20 L h^?1, demonstrated that the effectiveness of the sunflower antioxidant product was essentially similar to that of the caffeic acid standard, but 15–20% lower than that of propyl gallate. In conclusion, dephenolization of sunflower seeds could be economically convenient, not only because a useful antioxidant can be produced, but also because the raw material composition can be improved for other uses.     

Anaerobic co‐digestion of potato processing wastewater with pig slurry and abattoir wastewater

BACKGROUND: Small‐scale experimental investigations were carried out on the anaerobic digestion of potato processing wastewater and its co‐digestion with pig slurry and/or abattoir wastewater. A simple and rapid procedure was used to determine the suitability of these wastes for digestion. RESULTS: During the initial 5‐day acclimation phase, the seed (digested brewery waste) was replaced by the test waste before allowing the tests to incubate without further addition, where methanogenesis was measured. Although potato processing wastewater has low pH, with high fat content treatment via anaerobic digestion was still feasible in spite of low methane production. Co‐digestion with pig slurry and abattoir wastewater was therefore investigated to enhance the process. Pig slurry improved the process, which, when co‐digested with potato processing wastewater in equal ratio achieved 72% volatile solids removal, 35 mL average daily biogas production and 32% maximum methane content in 22 days (following the acclimation period). Co‐digestion with abattoir wastewater did not improve the digestion process due to poor buffering and low pH value. CONCLUSION: Anaerobic co‐digestion may be a feasible treatment option for industrial bio‐wastes and livestock wastes produced in Cyprus and indeed in similar other countries of comparable market size and activities. Copyright © 2008 Society of Chemical Industry