247 research outputs found

    Surface Wave Analysis in Laterally Varying Media

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    This work studies the possibility of using surface wave analysis as a tool for a robust estimation of the S-wave velocity behaviour in laterally varying media. The surface wave method, in fact, can be effectively adopted for different purposes and at different scales, but I focused on the geo-engineering and geotechnical applications of surface wave analysis and also on the production of near-surface models for deep exploration: in both cases the aim is to retrieve the trend of the S-wave velocity in the first tens up to hundreds meters of depth of the subsoil. The surface wave method exploits the geometric dispersion proper of surface waves: in a non-homogeneous medium every frequency is characterized by a different phase velocity, as every frequency component travels through a portion of medium whose thickness is proportional to its wavelength. The curve associating every frequency component to its phase velocity is called dispersion curve, and it constitutes the experimental datum one uses for the solution of an inverse problem to estimate the behaviour of S-wave velocity in the subsurface. The inversion is performed by assuming a 1D forward modelling simulation and suffers from equivalence problems, leading to the non uniqueness of the solution. Despite its great ductility, the main limitation of surface wave method is constituted by its 1D approach, which has proved to be unsatisfactory or even misleading in case of presence of lateral variations in the subsoil. The aim of the present work is to provide data processing tools able to mitigate such limitation, so that the surface wave method can be effectively applied in laterally varying media. As far as the inadequacy of surface wave method in case of 2D structures in the subsoil, I developed two separate strategies to handle smooth and gradual lateral variations and abrupt subsurface heterogeneities. In case of smooth variations, the approach I adopted aims at "following" the gradual changes in subsoil materials properties. I therefore propose a procedure to extract a set of neighbouring dispersion curves from a single multichannel seismic record by applying a suitable spatial windowing of the traces. Each curve corresponds to a different subsoil portion, so that gradual changes in subsoil seismic parameters can be reconstructed through the inversion of dispersion curves. The method was tested on synthetic and real datasets, but proved its reliability in processing the data from a small scale seismic experiment as well. In the context of characterizing smooth 2D structures in the subsurface via the surface wave method, I also developed a procedure to quantitatively estimate the (gradual) lateral variability of model parameters by comparing the shape of local dispersion curves, without the need to solve a formal inverse problem. The method is based on a sensitivity analysis and on the applications of the scale properties of surface wave. The procedure can be devoted to different applications: I exploited it to extend a priori local information to subsoil portions for which an experimental dispersion curve is available and for an estimation of the lateral variability of model parameters for a set of neighboring dispersion curves. The method was successfully applied to synthetic and real datasets. To characterize sudden and abrupt lateral variations in the subsurface, I adopted another strategy: the aim is to estimate the location and embedment depth of sharp heterogeneities, to process separately the seismic traces belonging to quasi-1D subsoil portions. I adapted several methods, already available in literature but developed for different purposes and scales, to the detection of sudden changes in subsoil seismic properties via the analysis of anomalies in surface wave propagation. I got the most promising results when adapting these methods, originally developed for single shot configurations, to multifold seismic lines, exploiting their data redundancy to enhance the robustness of the analyses. The outcome of the thesis is therefore a series of processing tools that improve the reliability and the robustness of surface wave method when applied to the near surface characterization of laterally varying medi

    Taste, Freshness and Nutrients Information to Retailers regarding Control of Quality and Safety in Organic Production Chains

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    This leaflet provides a practical overview for retailers of what is done to secure the quality and taste of seven types of organically produced foods, where improvements are possible, and what the retailers can do to support improvements and ensure the best possible food quality. Other leaflets for retailers cover authenticity and fraud or safety and contamination, and separate leaflets aim at consumers or at production of specific commodities

    Taste, Freshness and Nutrients Information to Consumers regarding Control of Quality and Safety in Organic Production Chains

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    This leaflet provides a practical overview for consumers of what is done to secure the quality and taste of 7 types of organically produced foods, where improvements are possible and what the consumer can do to support improvements and to preserve the food quality after purchase. Other leaflets for consumers cover authenticity and fraud or safety and contamination, and separate leaflets aim at retailers or at production of specific commodities

    Processing of Wheat to Bread Control of Quality and Safety in Organic Production Chains

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    This leaflet provides a practical overview for millers, bakers and others involved in production of flour and bread, on what can be done at these steps to improve the quality and safety of organically produced bread, in addition to certification and general food safety requirements. A separate leaflet covers the wheat production and grain storage steps, and other leaflets cover other commodities or aim at consumers and retailers

    Sabor, Frescura, e Nutrientes Informação aos Consumidores visando o Controlo da Qualidade e Segurança Alimentar em Cadeias de Produção Biológica

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    Este desdobrável destina-se a consumidores, fornece uma visão prática acerca do que se tem feito para garantir a qualidade e o sabor de 7 tipos de produtos biológicos onde melhorias são possíveis e, o que os consumidores podem efectuar para apoiar as melhorias e preservar a qualidade dos alimentos após a sua compra. Outros desdobráveis para consumidores cobrem a autenticidade e fraude ou segurança e contaminação havendo ainda desdobráveis variados que visam os retalhistas ou a produção específica de determinados produtos

    Produção de Leite Controlo da Qualidade e Segurança em Cadeias de Produção Biológica

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    Este desdobrável destina-se a produtores e outros agentes envolvidos na produção e distribuição de leite biológico, sobre o que se pode fazer nas várias etapas da cadeia de produção de forma a melhorar a qualidade e a segurança do leite biológico, de acordo com os requisitos gerais da certificação da segurança alimentar. Foram também preparados desdobráveis para outros produtos, bem como desdobráveis dirigidos aos consumidores e retalhistas

    Sabor, Frescor y Contenido en Nutrientes Información a los consumidores de los controles de Calidad y Seguridad en cadenas de producción orgánica de los alimentos

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    Este catálogo proporciona una descripción práctica a los consumidores de lo que se hace para asegurar la calidad y el sabor de los productos orgánicos en toda la cadena de producción hasta que el producto alcance al consumidor, y lo que el consumidor puede hacer para apoyar esos esfuerzos y preservar el valor nutritivo después de la compra. Otros catálogos destinados a los consumidores cubren “la autenticidad y fraude” y “la seguridad y contaminación”. También hay otros catálogos específicos destinados a los vendedores (minoristas) y a la producción de productos específicos

    Producción de Leche Control de la Calidad y Seguridad en las Cadenas de Producción Orgánica

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    Este catálogo se destina a productores y otros agentes envueltos en la producción y distribución de leche orgánica, e pretende dar una visión práctica sobre lo que se puede hacer en varias etapas de la cadena de producción para a mejorar la calidad y la seguridad de la leche orgánica, de acuerdo con los requisitos generales de la certificación de la seguridad alimenticia. Fueron también preparados catálogos para otros productos, así como catálogos dirigidos a los consumidores y minoristas

    Geschmack, Frische und Nährstoffe Information für Konsumentinnen und Konsumenten zur Überwachung von Qualität und Sicherheit in biologischen Lebensmittelketten

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    Dieses Informationsblatt gibt Konsumentinnen und Konsumenten einen praktischen Überblick über Massnahmen zur Sicherung von Qualität und Geschmack biologisch erzeugter Lebensmittel entlang der gesamten Produktionskette. Es zeigt auf, wie Konsumenten diese Bemühungen unterstützen und die Produktqualität nach dem Einkauf bewahren können. Weitere Informationsblätter für Konsumenten informieren über «Authentizität und Betrug» sowie «Sicherheit und Kontamination». Zusätzliche Informationsblätter sprechen den Handel und die Produzierenden an
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