896 resultados para Arsenic mobility


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Tracking activities during daily life and assessing movement parameters is essential for complementing the information gathered in confined environments such as clinical and physical activity laboratories for the assessment of mobility. Inertial measurement units (IMUs) are used as to monitor the motion of human movement for prolonged periods of time and without space limitations. The focus in this study was to provide a robust, low-cost and an unobtrusive solution for evaluating human motion using a single IMU. First part of the study focused on monitoring and classification of the daily life activities. A simple method that analyses the variations in signal was developed to distinguish two types of activity intervals: active and inactive. Neural classifier was used to classify active intervals; the angle with respect to gravity was used to classify inactive intervals. Second part of the study focused on extraction of gait parameters using a single inertial measurement unit (IMU) attached to the pelvis. Two complementary methods were proposed for gait parameters estimation. First method was a wavelet based method developed for the estimation of gait events. Second method was developed for estimating step and stride length during level walking using the estimations of the previous method. A special integration algorithm was extended to operate on each gait cycle using a specially designed Kalman filter. The developed methods were also applied on various scenarios. Activity monitoring method was used in a PRIN’07 project to assess the mobility levels of individuals living in a urban area. The same method was applied on volleyball players to analyze the fitness levels of them by monitoring their daily life activities. The methods proposed in these studies provided a simple, unobtrusive and low-cost solution for monitoring and assessing activities outside of controlled environments.

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In this thesis, we extend some ideas of statistical physics to describe the properties of human mobility. By using a database containing GPS measures of individual paths (position, velocity and covered space at a spatial scale of 2 Km or a time scale of 30 sec), which includes the 2% of the private vehicles in Italy, we succeed in determining some statistical empirical laws pointing out "universal" characteristics of human mobility. Developing simple stochastic models suggesting possible explanations of the empirical observations, we are able to indicate what are the key quantities and cognitive features that are ruling individuals' mobility. To understand the features of individual dynamics, we have studied different aspects of urban mobility from a physical point of view. We discuss the implications of the Benford's law emerging from the distribution of times elapsed between successive trips. We observe how the daily travel-time budget is related with many aspects of the urban environment, and describe how the daily mobility budget is then spent. We link the scaling properties of individual mobility networks to the inhomogeneous average durations of the activities that are performed, and those of the networks describing people's common use of space with the fractional dimension of the urban territory. We study entropy measures of individual mobility patterns, showing that they carry almost the same information of the related mobility networks, but are also influenced by a hierarchy among the activities performed. We discover that Wardrop's principles are violated as drivers have only incomplete information on traffic state and therefore rely on knowledge on the average travel-times. We propose an assimilation model to solve the intrinsic scattering of GPS data on the street network, permitting the real-time reconstruction of traffic state at a urban scale.

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Efficient energy storage and conversion is playing a key role in overcoming the present and future challenges in energy supply. Batteries provide portable, electrochemical storage of green energy sources and potentially allow for a reduction of the dependence on fossil fuels, which is of great importance with respect to the issue of global warming. In view of both, energy density and energy drain, rechargeable lithium ion batteries outperform other present accumulator systems. However, despite great efforts over the last decades, the ideal electrolyte in terms of key characteristics such as capacity, cycle life, and most important reliable safety, has not yet been identified. rnrnSteps ahead in lithium ion battery technology require a fundamental understanding of lithium ion transport, salt association, and ion solvation within the electrolyte. Indeed, well-defined model compounds allow for systematic studies of molecular ion transport. Thus, in the present work, based on the concept of ‘immobilizing’ ion solvents, three main series with a cyclotriphosphazene (CTP), hexaphenylbenzene (HBP), and tetramethylcyclotetrasiloxane (TMS) scaffold were prepared. Lithium ion solvents, among others ethylene carbonate (EC), which has proven to fulfill together with pro-pylene carbonate safety and market concerns in commercial lithium ion batteries, were attached to the different cores via alkyl spacers of variable length.rnrnAll model compounds were fully characterized, pure and thermally stable up to at least 235 °C, covering the requested broad range of glass transition temperatures from -78.1 °C up to +6.2 °C. While the CTP models tend to rearrange at elevated temperatures over time, which questions the general stability of alkoxide related (poly)phosphazenes, both, the HPB and CTP based models show no evidence of core stacking. In particular the CTP derivatives represent good solvents for various lithium salts, exhibiting no significant differences in the ionic conductivity σ_dc and thus indicating comparable salt dissociation and rather independent motion of cations and ions.rnrnIn general, temperature-dependent bulk ionic conductivities investigated via impedance spectroscopy follow a William-Landel-Ferry (WLF) type behavior. Modifications of the alkyl spacer length were shown to influence ionic conductivities only in combination to changes in glass transition temperatures. Though the glass transition temperatures of the blends are low, their conductivities are only in the range of typical polymer electrolytes. The highest σ_dc obtained at ambient temperatures was 6.0 x 10-6 S•cm-1, strongly suggesting a rather tight coordination of the lithium ions to the solvating 2-oxo-1,3-dioxolane moieties, supported by the increased σ_dc values for the oligo(ethylene oxide) based analogues.rnrnFurther insights into the mechanism of lithium ion dynamics were derived from 7Li and 13C Solid- State NMR investigations. While localized ion motion was probed by i.e. 7Li spin-lattice relaxation measurements with apparent activation energies E_a of 20 to 40 kJ/mol, long-range macroscopic transport was monitored by Pulsed-Field Gradient (PFG) NMR, providing an E_a of 61 kJ/mol. The latter is in good agreement with the values determined from bulk conductivity data, indicating the major contribution of ion transport was only detected by PFG NMR. However, the μm-diffusion is rather slow, emphasizing the strong lithium coordination to the carbonyl oxygens, which hampers sufficient ion conductivities and suggests exploring ‘softer’ solvating moieties in future electrolytes.rn

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Die Verwendung von Metallen zur Entwicklung der heutigen fortschrittlichen technologischenrnGesellschaft lässt auf eine lange Geschichte zurück blicken. Im Zuge des letzten Jahrhundertsrnwurde realisiert, dass die chemischen und radioaktiven Eigenschaften von Metallen einernernsthafte Bedrohung für die Menschheit darstellen können. In der modernen Geochemie ist esrnallgemein akzeptiert, dass die spezifischen physikochemische Formen entscheidender sind, alsrndas Verhalten der gesamten Konzentration der Spurenmetalle in der Umwelt. Die Definition derrnArtbildung kann grob als die Identifizierung und Quantifizierung der verschiedenen Formen oderrnPhasen für ein Element zugeordnet werden. Die chemische Extraktion ist eine gemeinsamernSpeziierungstechnik bei der die Fraktionierung des Gesamtmetallgehaltes zur Analyse der Quellernanthropogener Metallkontamination und zur Vorhersage der Bioverfügbarkeit von verschiedenenrnMetallformen dient. Die Philosophie der partiellen und sequenziellen Extraktionsmethodernbesteht darin, dass insbesondere das Extraktionsmittel phasenspezifisch unter chemischemrnAngriff unterschiedlicher Mischungsformen steht. Die Speziation von Metall ist wichtig bei derrnBestimmung der Toxizität, Mobilität, Bioverfügbarkeit des Metalls und damit ihr Schicksal inrnder Umwelt und biologischem System. Die Artenbildungsanalyse kann für das Verständnis derrnAuswirkung auf die menschliche Gesundheit und bei ökologischen Risiken durch diernQuantifizierung von Metallspezies bei einem Untersuchungs-standort angewendet werden undrnanschließend können Sanierungsstrategien für den Standort umgesetzt werden. Mit Hilfe derrnSpezifizierung wurden Arsen und Kupfer in landwirtschaftlichem Kalkdünger und Thallium inrnkontaminierten Böden untersucht und in den folgenden Abschnitten im Einzelnen dargestellt.

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Although the period of the historic “Celtic migrations” is archaeologically extensively studied, the long-lasting question whether mass migration or increased individual mobility caused the expansion of the La Tène culture throughout continental Europe persist. Strontium (Sr) and in part oxygen (O) isotope analysis of human remains from the early La Tène cemeteries of Nebringen (Germany), Münsingen-Rain (Switzerland), Monte Bibele (Italy) and the Czech cemeteries of Radovesice I, Radovesice II and Kutná Hora was, therefore, carried out to investigate the importance of residential changes during this time period. These isotope analyses showed that most analysed individuals either came from the area they were buried in or from the surrounding area of the cemetery. An exception was formed by the Czech cemeteries, where almost a quarter of the studied individuals appeared non-local. Together with Nebringen, these cemeteries also had the most varied Sr isotope ratios, which suggest highly mobile communities in which individuals regularly changed their residency. The isotopic ratios of the cemeteries of Münsingen-Rain and Monte Bibele appeared far less varied. In part, these differences might be explained by the community structures of these cemeteries. Morphological kinship analysis in Münsingen-Rain demonstrated biological relatedness among most of the analysed individuals. These related individuals also shared similar isotope signatures, which suggest an origin from the surrounding Aar Valley. In the vicinity of the cemetery of Monte Bibele, an associated settlement site was discovered. The deceased presumably not only shared this settlement, but also cultivated the same land plots. Dispersed settlement structures were suggested for Nebringen, Radovesice and Kutná Hora, as these agriculturally favourable landscapes were densely populated during prehistoric times. Connected to these community structures are the prevailing geological conditions in these areas. Both Münsingen-Rain and Monte Bibele are located in a region where homogeneous geological conditions prevail, whereas the landscapes of Nebringen, Radovesice and Kutná Hora are characterised by complex heterogeneous geological conditions. As the majority of individuals in Nebringen and the Czech cemeteries correspond to the expected isotope values for the studied areas, regularly changing land plots might have contributed to the observed variation. Although mass migration as depicted by the historical sources was not observed individual mobility of a small part of these studied communities certainly played a role. Males appeared, thereby, to have slightly more often a non-local birthplace or moved during childhood. Male mobility was, however, not always associated with burial as a warrior. Females, on the other hand, originated more often from the region. Patrilocal residential patterns, with the exception of the Czech cemeteries, were nevertheless not observed. Objects and ideas also seem to have been exchanged freely, as there are no indications that individuals with particular grave goods came from specific areas. It rather appears that the individuals buried with them were either local or had different places of origin. This can be explained by the fact that the exact origin of grave goods is difficult to establish and the occurrence of similar 87Sr/86Sr values in different areas. This study provided important new insights on the period of the “Celtic migrations” and the way of life of these prehistoric people.

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This dissertation document deals with the development of a project, over a span of more than two years, carried out within the scope of the Arrowhead Framework and which bears my personal contribution in several sections. The final part of the project took place during a visiting period at the university of Luleå. The Arrowhead Project is an European project, belonging to the ARTEMIS association, which aims to foster new technologies and unify the access to them into an unique framework. Such technologies include the Internet of Things phe- nomenon, Smart Houses, Electrical Mobility and renewable energy production. An application is considered compliant with such framework when it respects the Service Oriented Architecture paradigm and it is able to interact with a set of defined components called Arrowhead Core Services. My personal contribution to this project is given by the development of several user-friendly API, published in the project's main repository, and the integration of a legacy system within the Arrowhead Framework. The implementation of this legacy system was initiated by me in 2012 and, after many improvements carried out by several developers in UniBO, it has been again significantly modified this year in order to achieve compatibility. The system consists of a simulation of an urban scenario where a certain amount of electrical vehicles are traveling along their specified routes. The vehicles are con-suming their battery and, thus, need to recharge at the charging stations. The electrical vehicles need to use a reservation mechanism to be able to recharge and avoid waiting lines, due to the long recharge process. The integration with the above mentioned framework consists in the publication of the services that the system provides to the end users through the instantiation of several Arrowhead Service Producers, together with a demo Arrowhead- compliant client application able to consume such services.

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Lo scopo che questa tesi ha è di inserirsi nell’ambito della Smart Mobility, in particolare nell'ambito dell’accessibilità urbana. Obiettivo primario è di offrire un software capace di adattarsi alle capacità dell’utente nel muoversi nell’ambiente urbano, in particolare riguardo alle barriere architettoniche che lo ostacolano. Quello che il programma deve fare è offrire percorsi per l’utente, personalizzati rispetto alle sue richieste. Affinché sia possibile tutto ciò, sono necessarie delle fondamenta, nella fattispecie una fonte di dati geografici e uno strumento che permetta di ricercare percorsi da essi e di essere modificato per includere le modifiche volute. La fonte di dati geografici scelta è stata OpenStreetMap, un progetto di crowdsourcing che punta a creare una mappa globale completamente accessibile fino al suo livello più basso e utilizzabile da chiunque, purché sia rispettata la sua licenza. Da questa scelta, derivano i software utilizzabili per calcolare i percorsi: la tesi ne esplorerà in particolare due GraphHopper e OpenTripPlanner, entrambi progetti open source. L’ultimo, ma non meno importante, scopo della tesi è effettivamente implementare un algoritmo di routing capace di considerare le preferenze degli utenti. Queste preferenze, infatti, non devono solo permettere di escludere percorsi con una barriera/architettonica cui l’utente non può accedere, ma anche di favorire percorsi con le facility che l’utente preferisce e di sfavorire quelli con facility che l’utente non preferisce.

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Nel corso degli ultimi decenni la fisica sperimentale ha raggiunto notevoli traguardi nel campo della manipolazione di sistemi di atomi freddi, riaccendendo l'interesse della ricerca su sistemi a lungo studiati teoricamente, ma fino a poco tempo fa impossibili da realizzare sperimentalmente. Questa riaccesa attenzione ha permesso di sfruttare le moderne capacità di calcolo per studiare sistemi quantistici che ancora risultano di difficile realizzazione. In questo contesto si inserisce il rinnovato interesse per i sistemi quantistici monodimensionali caratterizzati dalla presenza di potenziale disordinato. Questi presentano proprietà di trasporto particolari e sotto particolari condizioni sono oggetto di una transizione di localizzazione. La maggior parte degli studi in questo campo rivolgono la loro attenzione a sistemi di particelle fermioniche interagenti. In questo lavoro di tesi analizziamo, invece, sistemi quantistici fermionici non interagenti, mettendo in luce quanto già noto e proponendo strumenti di analisi derivati dallo studio dei sistemi interagenti. In particolare, proponiamo un'analisi statistica dei livelli energetici e poniamo le basi per futuri studi a riguardo.

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La tesi si occupa della creazione di una piattaforma virtuale, composta da un sito web e da una applicazione Android, a supporto di persone con handicap motori. La piattaforma e composta da una mappa interattiva che permette agli utenti di inserire nuovi locali o di commentarne esistenti, e di fare lo stesso per le barriere architettoniche. Per questi motivi il progetto e dettato da una continua comunicazione tra client e server, rendendo la piattaforma aggiornata e dinamica, anche alla vista degli utenti. La parte web viene implementata attraverso Spring MVC, utilizzando delle View .jsp ed AJAX per la comunicazione remota con il server. La parte mobile e stata implementata basandosi principalmente sulle classi di geolocalizzazione di Android, oltre alle librerie osmdroid ed osmbonuspack, fornendo compatitiblita con OSM. Questa fornisce anche un servizio di calcolo del percorso, cercando di evitare il numero maggiore di ostacoli. L'applicazione Android appoggia le proprie comunicazioni sulla libreria Robospice. La parte di persistenza e stata implementata adottando un approccio ad alto livello, grazie ad Hibernate e JPA.

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Mobility of naturally occurring U-238 and U-234 radionuclides was studied in a low permeability, reducing claystone formation (Opalinus Clay) near its contact with an overlying oxidising aquifer (Dogger Limestones) at Mont Terri, Switzerland. Our data point to a limited redistribution of U in some of the studied samples. Observed centimetre-scale U mobility is explained by slow diffusive transport of U-234 in the pore waters of the Opalinus Clay driven by spatially variable in situ supply (by alpha-recoil) of U-234 from the rock matrix. Metre-scale mobility is interpreted as a result of infiltration of meteoric water into the overlying aquifer which developed gradients of U concentration across the two rock formations. This triggered a slow in-diffusion of U with (U-234/U-238) > 1 into the Opalinus Clay as attested by a clear-cut pattern of decreasing bulk rock (U-234/U-238) inwards the Opalinus Clay, away from the Dogger Limestones.