All-fibre Lyot filters based on 45° tilted gratings UV-inscribed in PM fibre

We report all-fibre Lyot filters formed by concatenating fibre gratings with structure tilted at 45° UV-inscribed in PM fibre. Such polarisation filters exhibit distinct transmission property for potential application in fibre lasers and sensors. © 2012 OSA.

Rotor retaining sleeve design for a 1.12-MW high-speed PM machine

Permanent-magnet (PM) synchronous machines (PMSMs) can provide excellent performance in terms of torque density, energy efficiency, and controllability. However, PMs on the rotor are prone to centrifugal force, which may break their physical integrity, particularly at high-speed operation. Typically, PMs are bound with carbon fiber or retained by alloy sleeves on the rotor surface. This paper is concerned with the design of a rotor retaining sleeve for a 1.12-MW 18-kr/min PM machine; its electromagnetic performance is investigated by the 2-D finite-element method (FEM). Theoretical and numerical analyses of the rotor stress are carried out. For the carbon fiber protective measure, the stresses of three PM configurations and three pole filler materials are compared in terms of operating temperature, rotor speed, retaining sleeve thickness, and interference fit. Then, a new hybrid protective measure is proposed and analyzed by the 2-D FEM for operational speeds up to 22 kr/min (1.2 times the rated speed). The rotor losses and machine temperatures with the carbon fiber retaining sleeve and the hybrid retaining sleeve are compared, and the sleeve design is refined. Two rotors using both designs are prototyped and experimentally tested to validate the effectiveness of the developed techniques for PM machines. The developed retaining sleeve makes it possible to operate megawatt PM machines at high speeds of 22 kr/min. This opens doors for many high-power high-speed applications such as turbo-generator, aerospace, and submarine motor drives.

Investigating the origin of PM2.5 in Baltimore using highly time-resolved organic molecular markers measured during the Baltimore PM-supersite

The detailed organic composition of atmospheric fine particles with an aerodynamic diameter smaller than or equal to 2.5 micrometers (PM2.5) is an integral part of the knowledge needed in order to fully characterize its sources and transformation in the environment. For the study presented here, samples were collected at 3-hour intervals. This high time resolution allows gaining unique insights on the influence of short- and long-range transport phenomena, and dynamic atmospheric processes. A specially designed sequential sampler was deployed at the 2002-2003 Baltimore PM-Supersite to collect PM2.5 samples at a 3-hourly resolution for extended periods of consecutive days, during both summer and winter seasons. Established solvent-extraction and GC-MS techniques were used to extract and analyze the organic compounds in 119 samples from each season. Over 100 individual compounds were quantified in each sample. For primary organics, averaging the diurnal ambient concentrations over the sampled periods revealed ambient patterns that relate to diurnal emission patterns of major source classes. Several short-term releases of pollutants from local sources were detected, and local meteorological data was used to pinpoint possible source regions. Biogenic secondary organic compounds were detected as well, and possible mechanisms of formation were evaluated. The relationships between the observed continuous variations of the concentrations of selected organic markers and both the on-site meteorological measurements conducted parallel to the PM2.5 sampling, and the synoptic patterns of weather and wind conditions were also examined. Several one-to-two days episodes were identified from the sequential variation of the concentration observed for specific marker compounds and markers ratios. The influence of the meteorological events on the concentrations of the organic compounds during selected episodes was discussed. It was observed that during the summer, under conditions of pervasive influence of air masses originated from the west/northwest, some organic species displayed characteristics consistent with the measured PM2.5 being strongly influenced by the aged nature of these long-traveling background parcels. During the winter, intrusions from more regional air masses originating from the south and the southwest were more important.

Investigating the origin of PM2.5 in Baltimore using highly time-resolved organic molecular markers measured during the Baltimore PM-supersite

The detailed organic composition of atmospheric fine particles with an aerodynamic diameter smaller than or equal to 2.5 micrometers (PM 2.5) is an integral part of the knowledge needed in order to fully characterize its sources and transformation in the environment. For the study presented here, samples were collected at 3-hour intervals. This high time resolution allows gaining unique insights on the influence of short- and long-range transport phenomena, and dynamic atmospheric processes. A specially designed sequential sampler was deployed at the 2002-2003 Baltimore PM Supersite to collect PM2.5 samples at a 3-hourly resolution for extended periods of consecutive days, during both summer and winter seasons. Established solvent-extraction and GC-MS techniques were used to extract and analyze the organic compounds in 119 samples from each season. Over 100 individual compounds were quantified in each sample. For primary organics, averaging the diurnal ambient concentrations over the sampled periods revealed ambient patterns that relate to diurnal emission patterns of major source classes. Several short-term releases of pollutants from local sources were detected, and local meteorological data was used to pinpoint possible source regions. Biogenic secondary organic compounds were detected as well, and possible mechanisms of formation were evaluated. The relationships between the observed continuous variations of the concentrations of selected organic markers and both the on-site meteorological measurements conducted parallel to the PM2.5 sampling, and the synoptic patterns of weather and wind conditions were also examined. Several one-to-two days episodes were identified from the sequential variation of the concentration observed for specific marker compounds and markers ratios. The influence of the meteorological events on the concentrations of the organic compounds during selected episodes was discussed. It was observed that during the summer, under conditions of pervasive influence of air masses originated from the west/northwest, some organic species displayed characteristics consistent with the measured PM2.5 being strongly influenced by the aged nature of these long-traveling background parcels. During the winter, intrusions from more regional air masses originating from the south and the southwest were more important.

High-dimensional Z-stable AH algebras

Peer reviewed

High-dimensional Z-stable AH algebras

Peer reviewed

High-dimensional Z-stable AH algebras

Peer reviewed

Ah' quest'amplesso, o cara: scena e duetto nella Cleopatra / manuscript, [approximately 1800]

del Sig:re Sebastiano Nasolini :

"Llovió y llovió hasta que quedó cielo y tierra... y todo se terminó ahí" : Discurso e identidad en la comunidad de Asampay, Catamarca

El objetivo del presente trabajo es realizar una aproximación al análisis de aquellas prácticas sociales que dentro de la comunidad de Asampay -ubicada en el departamento de Belén, provincia de Catamarca (Argentina)- otorgan un sentido de pertenencia y de devenir a sus habitantes en tanto grupo social. Por consiguiente, nuestro objetivo específico será examinar la construcción de sentido de determinados fenómenos sociales que son significativos dentro de la comunidad. El marco metodológico a ser utilizado será aquel proveniente del análisis del discurso y de la semiótica cognitiva (Courtine 1981, Magariños de Morentín 1996) -sobre la base de los fundamentos establecidos por Foucault (1970,1971)-, así como también, ciertos lineamientos teóricos y método lógicos procedentes de los trabajos de Lévi-Strauss (1996, 1984, 983)

"Llovió y llovió hasta que quedó cielo y tierra... y todo se terminó ahí" : Discurso e identidad en la comunidad de Asampay, Catamarca

El objetivo del presente trabajo es realizar una aproximación al análisis de aquellas prácticas sociales que dentro de la comunidad de Asampay -ubicada en el departamento de Belén, provincia de Catamarca (Argentina)- otorgan un sentido de pertenencia y de devenir a sus habitantes en tanto grupo social. Por consiguiente, nuestro objetivo específico será examinar la construcción de sentido de determinados fenómenos sociales que son significativos dentro de la comunidad. El marco metodológico a ser utilizado será aquel proveniente del análisis del discurso y de la semiótica cognitiva (Courtine 1981, Magariños de Morentín 1996) -sobre la base de los fundamentos establecidos por Foucault (1970,1971)-, así como también, ciertos lineamientos teóricos y método lógicos procedentes de los trabajos de Lévi-Strauss (1996, 1984, 983)

"Llovió y llovió hasta que quedó cielo y tierra... y todo se terminó ahí" : Discurso e identidad en la comunidad de Asampay, Catamarca

El objetivo del presente trabajo es realizar una aproximación al análisis de aquellas prácticas sociales que dentro de la comunidad de Asampay -ubicada en el departamento de Belén, provincia de Catamarca (Argentina)- otorgan un sentido de pertenencia y de devenir a sus habitantes en tanto grupo social. Por consiguiente, nuestro objetivo específico será examinar la construcción de sentido de determinados fenómenos sociales que son significativos dentro de la comunidad. El marco metodológico a ser utilizado será aquel proveniente del análisis del discurso y de la semiótica cognitiva (Courtine 1981, Magariños de Morentín 1996) -sobre la base de los fundamentos establecidos por Foucault (1970,1971)-, así como también, ciertos lineamientos teóricos y método lógicos procedentes de los trabajos de Lévi-Strauss (1996, 1984, 983)

A comparative study of the corrosion resistance of incoloy MA 956 and PM 2000 superalloys

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

"Pegar primero: he ahí la ley" : Estereotipos de género en una obra de Oscar Castro

En el siguiente estudio se analiza la novela La vida simplemente del escritor chileno Oscar Castro publicada póstumamente en 1951. El fin de nuestra investigación es estudiar la existencia de estereotipos de género en la obra y cómo estos se reproducen o bien son desafiados en la novela. La interpretación hecha se basa principalmente en la teoría de las dicotomías (Hirdman, 2001), la cual pone énfasis en las cualidades que, históricamente, se le han atribuido a los respectivos géneros. Aplicamos un análisis crítico de texto para identificar cómo el lenguaje usado por el escritor contribuye a reproducirlos o los desafía. Para limitar nuestro trabajo hemos decidido concentrarnos en tres personajes de la obra: Berta, Roberto y la madre de Roberto. El resultado muestra que la obra de Castro tiende a contribuir a la reproducción y el mantenimiento de los estereotipos de género típicos de las dicotomías de las cuales problematiza Hirdman a excepción del personaje femenino representado por la madre de Roberto que los desafía en cierta forma.

Contributo e caracterização de PM da ressuspensão rodoviária

Nos últimos anos, tem-se assistido a um crescimento no interesse do estudo da ressuspensão de pó de estrada, dado o reconhecimento da importância que esta fração representa para os níveis de partículas atmosféricas em ambiente urbano. Dada a prematuridade deste tema e, de forma a compreender e conhecer a sua contribuição e caracterização, realizou-se um estudo sobre a ressuspensão de pó de estrada urbano para as cidades do Porto e Braga. No âmbito do projeto AIRUSE e URBE, realizaram-se amostragens de PM10 no terreno com um dispositivo de amostragem móvel e em ambiente laboratorial com uma câmara de ressuspensão, sendo posteriormente analisado o seu conteúdo carbonoso por um sistema de análise termo-ótico de transmitância e, os elementos por ICP-MS e ICP-AES. Da campanha in situ resultaram cargas de PM10 compreendidas entre 0.190 e 49.5 mg.m-2 para a cidade do Porto e 0.577 mg.m-2 para o túnel rodoviário em Braga. As amostras caracterizam-se por serem dominadas pelos elementos Al, Fe, K, e Ca e conterem enriquecimentos de Sb, Fe, Cu, Sn e Zn, fruto da contaminação antropogénica da atividade rodoviária. No que respeita às amostragens em laboratório, utilizou-se uma câmara de ressuspensão e o dispositivo móvel aplicado na campanha anteriormente descrita para estudar e caracterizar a fração PM10 do pó de estrada urbano proveniente do Túnel Avenida da Liberdade (Braga). Os resultados obtidos para as duas metodologias foram de um modo geral similares, com o carbono total a representar cerca de 6% da massa total de PM10. Esta última é composta maioritariamente por Al, Fe, Ca e K, elementos característicos da crosta terrestre. Quanto ao fatores de enriquecimento calculados, denotou-se a presença de Sb, Zn, Cu e Sn, tendo-se associando ao desgaste dos travões e pneus.