A meta-model framework for grinding simulation

When considering the mechanics of grinding, several physical phenomena have to be modeled, each one having effect on the resulting grinding forces, wheel and workpiece geometry. Depending on the analyzed problem, some dependencies can be neglected to privilege some aspects instead of others. Nevertheless, all models essentially start considering wheel-workpiece engagement and the corresponding material removal (both wheel and workpiece side), deriving the forces by means of energy balances and/or shear mechanics. The meta-model proposed in this paper represents a general framework conceived for providing a time-domain simulation engine based on a dexel representation of wheel and workpiece, capable to “host” all the semi-empirical models existing in literature, where the overall grinding force is the result of the integration of the force contributions associated to the local removal along wheel-workpiece engagement arc. A cascade approach is adopted to solve for forces and displacements the DAEs set describing the dynamic interactions between wheel and workpiece, whereas all the algebraic relationships pertaining to the various specific models are solved in a pre-processing phase, yielding a set of response surfaces that are queried during time integration. Finally, the meta-model framework is instantiated for a model of traverse roll grinding with force-dependent wheel wear

De "vagos y malentretenidos" a sectores subalternos : Una aproximación a las representaciones artísticas y discursivas en torno a los sectores populares en Buenos Aires durante la primera mitad del siglo XIX

La Revolución de Mayo fue considerada por la historiografía liberal argentina como una instancia de ruptura con las prácticas y las representaciones políticas y sociales del pasado colonial, quizás en un fuerte paralelismo –forzado hasta el extremismo- de comprender a las revoluciones latinoamericanas- como resultado de un proceso a escala atlántica generado por la doble revolución europea. Generándose desde esta postura liberal el mito de los orígenes de la nacionalidad argentina, nacionalidad no obstante, que tardaría varias décadas en concretarse y no con pocos avances y retroceso. A pesar de la fuerza de este paradigma el entramado histórico cultural que sustentaba esta interpretación de los hechos fue cambiando y desplazó su eje de atención en por lo menos dos cuestiones: relativizó las consecuencias sociales y culturales del proceso haciendo hincapié en las continuidades y en el largo plazo; en segundo lugar trajo a escena a nuevos actores que habían quedado opacados por la trascendencia de los “grandes hombres”. En definitiva se estaba en presencia de una nueva manera de hacer Historia en donde entraron en escena el gaucho, el negro, el miliciano, es decir aquellos personajes que conformaban los sectores populares en una sociedad jerarquizada y estratificada como la rioplatense en la aurora del siglo XIX. (Párrafo extraído del texto a modo de resumen)Facultad de Bellas Arte

Test on the effects of reconstituted soil on emergency speed and root growth in maize

Summary Reconstitution is a pedotechnique to counter land degradation and desertification. The reconstitution, patented by the research laboratory m.c.m. Ecosistemi, applies chemical-mechanical actions to a mixture of degraded soil and matrices (such as waste sludge) in order to produce reconstituted soil, a very high fertility soil. This paper is about a pot study in a greenhouse to investigate how reconstituted soil affects emergence speed and seminal roots development of Zea mays L. seedlings, in comparison with a Technosol. 200 seedlings are monitored up to the 16th day after the seeding. The emergence percentage is 98% on reconstituted soil and 91% on Technosol. Average length and weight of fresh seminal roots are higher on reconstituted soil

Application of the floristic-vegetational indexes system for the evaluation of the environmental quality of a semi-natural area of the Po Valley (Piacenza, Italy)

The floristic-vegetational indexes proposed by Taffetani and Rismondo (2009) and updated by Rismondo et al. (2011) were used to assess the environmental quality of a semi-natural located on the outskirts of Piacenza (Emilia Romagna, Italy), the site of a closed landfill of Municipal Solid Waste (MSW). This method was created and perfected to analyze the ecological functionality of afro-ecosystem and permits simp and rapid measurement of the ecological characteristics and grade of dynamic evolution of then phtocoenoses. These indexes were applied to the vegetation of the different sectors that make up the study area ad from the results obtained t was possible to identify those with the worst environmental quality and to formulate some proposes for action aimed at improving them environmentally. In particular an interruption in the evolution of the landfill vegetation was found, due to the chemical-physical characteristics of the cover sol which is compacted and of limited depth. The application of the Taffetani and Rismondo (2009) indexes to a real case has also allowed evaluation of their practicality and the information content obtained

The reconstitution: environmental restoration assessment by means of LCC and FCC

The reconstitution is a pedotecnique producing environmental proper and fertile Technosols, applying chemical-mechanical treatment to alluvial sediments, degraded soils and pedomaterials included waste by different productive processes. By means of reconstitution, the environmental restoration of the covering degraded soil of a closed landfill near Piacenza is made (LIFE10 ENV/IT/000400 NEW LIFE). In order to assess this environmental restoration, LCC and FCC are calculated on 5 soil samples before and after reconstitution. The results, which highlight the transition from worst to best LCC and FCC classes show how reconstitution was able to convert the environmental and agronomic conditions from soil have very severe limitations that restrict the choice of plants or require very careful management, and that limit or restrict its use mainly to pasture, range, forestland, or wildlife food and cover, to soil have moderate limitations that restrict the choice of plants or that require moderate conservation practices or have optimum fertility

Trees and Shrubs Monitoring Using an Ecological Approach: The Conclusion of the Restoration Project of Borgotrebbia Landfill (Northern Italy)

Plants growth monitoring in restored landfills are poorly available in literature. These data might be of critical importance for the evaluation and improvement of current and future restoration projects. Our study was focused on the plant\u2019s growth monitoring during a Life project (LIFE10 ENV/IT/000400 NEW LIFE), designed to restore a closed landfill (located in Northern Italy) using reconstituted soils. The growth monitoring was conducted on mortality rate, stress symptoms and phenological cycle completion of 10 plant species (trees and shrubs). Data were acquired during the 12 months following the end of the restoration with an ecological approach, using Landolt\u2019s indices and CSR functional strategy. It was observed that the stress-tolerant and the heliphilous ruderal species were the ones that best adapt to the restored environment (dead plants: 0 - 39%; unhealthy plants: 24 - 42%), whereas the most competitive species were the ones with highest mortality (17 - 43%) and stress symptoms (43 - 51%)

Imaginarios e imágenes: representaciones sociales y manifestaciones iconográficas y audiovisuales de la pobreza

A través del tiempo las representaciones del pobre y el ethos de la pobreza han ido variando y esto ha llevado a diversas categorizaciones de la misma, y desde allí a la implementación de prácticas desde distintas entidades, tanto civiles como eclesiásticas y estatales; con el objetivo de paliar, remediar y controlar a los sectores y/o grupos sociales que son considerados pobres. Estas «disposiciones» mentales se encuentran atravesadas por el binomio ideológico que constituye el gesto de dar una limosna y la amenaza de la represión a los mendigos. Así, daremos cuenta de las imágenes «guía» que sobre la pobreza se encarnan a través del tiempo, puntualmente desde el siglo XVI hasta la crisis del Estado de Bienestar; tanto desde su aspecto teórico a través de un análisis de los planteos ideológicos predominantes como también de las cristalizaciones que de los mismos ha generado la producción iconográfica de cada período o marco ideológico a referirnos; atendiendo al contraste continuo de la teoría y de la praxis de la caridad con la realidad social del pauperismo. Es bueno resaltar que esta indagación es el resultado del trabajo interdisciplinario entre profesores y un conjunto de alumnas del Instituto Universitario Nacional del Arte.Mesa 2Facultad de Bellas Arte

Imaginarios e imágenes: representaciones sociales y manifestaciones iconográficas y audiovisuales de la pobreza

A través del tiempo las representaciones del pobre y el ethos de la pobreza han ido variando y esto ha llevado a diversas categorizaciones de la misma, y desde allí a la implementación de prácticas desde distintas entidades, tanto civiles como eclesiásticas y estatales; con el objetivo de paliar, remediar y controlar a los sectores y/o grupos sociales que son considerados pobres. Estas «disposiciones» mentales se encuentran atravesadas por el binomio ideológico que constituye el gesto de dar una limosna y la amenaza de la represión a los mendigos. Así, daremos cuenta de las imágenes «guía» que sobre la pobreza se encarnan a través del tiempo, puntualmente desde el siglo XVI hasta la crisis del Estado de Bienestar; tanto desde su aspecto teórico a través de un análisis de los planteos ideológicos predominantes como también de las cristalizaciones que de los mismos ha generado la producción iconográfica de cada período o marco ideológico a referirnos; atendiendo al contraste continuo de la teoría y de la praxis de la caridad con la realidad social del pauperismo. Es bueno resaltar que esta indagación es el resultado del trabajo interdisciplinario entre profesores y un conjunto de alumnas del Instituto Universitario Nacional del Arte.Mesa 2Facultad de Bellas Arte

Confronto tra dati produttivi di mais coltivato su terre ricostituite e terre naturali

Le tematiche della desertificazione, del degrado del suolo e del risparmio idrico sono oggi trattate da numerosi studi e attraverso diverse strategie. Frequentemente le impostazioni di studio sono finalizzate soprattutto all\u2019indagine dei processi di degrado del suolo e sugli effetti della desertificazione, raramente, invece, vengono verificate e analizzate le tecnologie che si occupano del trattamenti di suoli degradati per il loro ripristino. Il presente lavoro \ue8 indirizzato a verificare le caratteristiche relative al consumo idrico da parte dei suoli ricostituiti, ovvero, terreni risultanti da un trattamento di suoli degradati mediante una tecnologia di recente realizzazione. Questo trattamento \u2013 coperto da due brevetti sul sistema di trattamento, sul metodo e sul modello concettuale \u2013 si basa su un processo di tipo chimico e meccanico applicato ai suoli mediante una disgregazione meccanica, un\u2019integrazione controllata di matrici ammendanti, un\u2019azione di policondensazione con acidi umici e un\u2019azione meccanica di ricostituzione finale. Tali operazioni consentono una mirata incorporazione di sostanza organica realizzando dei neoaggregati di suolo a partire dal terreno degradato sottoposto al trattamento. Vengono cio\ue8 realizzate le azioni che permettono di produrre un suolo differente da quello originario con propriet\ue0 di interesse ambientale ed agronomico. Questa tecnologia \ue8 stata ritenuta di interesse e finanziata dall\u2019Unione Europea con lo strumento LIFE+ 2010 mediante un\u2019opera dimostrativa della durata di cinque anni, tutt\u2019ora in corso, per il ripristino di un suolo degradato della provincia di Piacenza. Diverse prove sperimentali sono state eseguite per valutare le propriet\ue0 dei terreni ricostituiti, prodotti da questo sistema, rispetto ai suoli degradati. In questo specifico studio, come sopra accennato, viene valutata la propriet\ue0 del suolo ricostituito di possedere maggiore disponibilit\ue0 idrica rispetto ai suoli naturali. A questo scopo sono stati valutati i dati produttivi di mais coltivato su campi situati presso un\u2019azienda agricola sita a Gossolengo, Piacenza, localit\ue0 C\ue0 Matta, dove si trova l\u2019impianto di produzione di terre ricostituite di propriet\ue0 dell\u2019azienda MCM Ecosistemi srl. I due campi, tra loro confinanti, si trovano rispettivamente su un appezzamento di terreno naturalmente presente nell\u2019area ed un appezzamento realizzato, per 60 cm di spessore agrario, con terre ricostituite derivate da trattamento di ricostituzione di quest\u2019area agricola, improduttiva e degradata, a causa di pesanti interventi estrattivi e di erronee operazioni di ripristino agronomico. I due campi sono stati gestiti con le stesse dosi di concime ma con differenti quantitativi di acqua di irrigazione, in modo da restituire per il suolo ricostituito il 45% di acqua in meno rispetto a quello naturale. Le elaborazioni sui dati produttivi hanno permesso di verificare l\u2019efficacia del trattamento di ricostituzione in termini di risparmio idrico. Le produzioni, infatti, cos\uec come altri parametri indagati, seppur non mostrando in certi casi differenze significative tra i due suoli, hanno portato a concludere come le terre ricostituite permettono di coltivare una coltura come il mais risparmiando acqua

Status of the SOLEIL femtosecond X-ray source

http://accelconf.web.cern.ch/AccelConf/FEL2012/papers/wepd04.pdfInternational audienceAn electron bunch slicing setup is presently under construction on the SOLEIL storage ring for delivering 100 fs (rms) long photon pulses to two undulator-based beamlines providing soft (TEMPO) and hard X-rays (CRISTAL). Thanks to the non-zero dispersion function present in all straight sections of the storage ring, the sliced bunches can be easily separated from the core bunches. The modulator is a wiggler composed of 20 periods of 164.4 mm. It produces a magnetic field of 1.8 T at a minimum gap of 14.5 mm. To modulate the kinetic energy of the electrons in the wiggler, a Ti:Sa laser will be used, which produces 50 fs pulses at 800 nm with a repetition rate of 2.5 kHz. The laser beam is splitted into two branches in order to provide 2 mJ to the modulator and 0.5 mJ as pump pulse for the CRISTAL and TEMPO end stations. Focusing optics and beam path, from the laser hutch to the inside of the storage ring tunnel are presently under finalization. In this paper, we will report on the specificities of the SOLEIL setup, the status of its installation and the expected performances