13 research outputs found

    Tritium analytics by beta induced X-ray spectrometry

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    The aim of the Karlsruhe Tritium Neutrino (KATRIN) experiment is a neutrino mass measurement with a sensitivity of 0.2 eV/c2 (90% C.L.) by the investigation of the tritium beta-spectrum. This requires continuous activity monitoring of the windowless gaseous tritium source on the 0.1 % stability level. In this work, the suitability of the beta induced X-ray spectrometry (BIXS) method for high stability and high sensitivity activity monitoring of gaseous tritium sources has been shown

    Diffusion in a crowded adsorbate layer

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    Diffusion in a crowded adsorbate layer

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    SPATIAL TRANSFORMATION PATTERN DUE TO COMMERCIAL ACTIVITY IN KAMPONG HOUSE

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    ABSTRACT Kampung houses are houses in kampung area of the city. Kampung House oftenly transformed into others use as urban dynamics. One of the transfomation is related to the commercial activities addition by the house owner. It make house with full private space become into mixused house with more public spaces or completely changed into full public commercial building. This study investigate the spatial transformation pattern of the kampung houses due to their commercial activities addition. Site observations, interviews and questionnaires were performed to study the spatial transformation. This study found that in kampung houses, the spatial transformation pattern was depend on type of commercial activities and owner perceptions, and there are several steps of the spatial transformation related the commercial activity addition. Keywords: spatial transformation pattern; commercial activity; owner perception, kampung house; adaptabilit

    Electronic structure, morphology and chemical reactivity of nanoclusters and low-dimensional systems: fast photoemission spectroscopy studies

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    2008/2009L'obiettivo di questa tesi è l'applicazione della spettroscopia di fotoemissione allo studio di nanoparticelle supportate e di sistemi a bassa dimensionalità. Ad una primo periodo dedicato allo sviluppo del rivelatore e del software per un nuovo analizzatore d'energia per elettroni installato presso la linea di luce SuperESCA ad Elettra, è seguita una fase durante la quale ho eseguito una serie di esperimenti mirati ad esplorare le potenzialità del nuovo apparato sperimentale. Il primo risultato ottenuto riguarda la comprensione della relazione che intercorre tra le variazioni della reattività chimica del sistema Pd/Ru(0001) e il numero degli strati di Pd cresciuti in modo pseudomorfico sul substrato di rutenio. La risoluzione temporale raggiunta con la nuova strumentazione ci ha permesso di studiare processi dinamici su una scala temporale fino ad ora inaccessibile per la spettroscopia di fotoemissione dai livelli di core: in particolare abbiamo studiato la crescita del grafene ad alta temperatura sulla superficie (111) dell'iridio e la reattività chimica di nanocluster di Pt supportati su MgO. Nel primo caso abbiamo messo in evidenza come la formazione del grafene proceda attraverso la nucleazione di nano-isole di carbonio che assumono una peculiare forma di cupola. Nel secondo caso siamo riusciti a seguire sia la dinamica del processo di adsorbimento di CO, sia la reazione CO + 1/2 O2 -> CO2 sulle nanoparticelle di Pt depositate su un film ultra-sottile di ossido di magnesio. Infine, abbiamo caratterizzato la morfologia di nanoparticelle di Pd, Pt, Rh e Au cresciute su diversi substrati a base di carbonio, in particolare grafite, nanotubi a parete singola e grafene. Tra i vari risultati abbiamo compreso come l'interazione metallo-substrato dipenda dalla dimensione delle nano-particelle e abbiamo evidenziato il ruolo centrale dei difetti del substrato nei processi di nucleazione e intercalazione.The objective of this thesis is the application of photoelectron spectroscopy for the investigation of supported nanoclusters and low-dimensional systems. After a first stage devoted to the development of the detector and the software for the electron energy analyser installed on the SuperESCA beamline at Elettra, during the PhD project I've performed a series of experiments aimed to explore the capabilities of the new experimental apparatus. One of the first results concerns the understanding of the relation between the modifications in the chemical reactivity of the Pd/Ru(0001) system and the thickness of the pseudomorphically grown Pd overlayer. The temporal resolution achieved with the new experimental set-up allowed us to study dynamical processes on a new time scale, in particular the graphene growth process at high temperature on the Ir(111) surface and the chemical reactivity of Pt nanoclusters supported on MgO. In the former case, we discovered that graphene formation proceeds via preliminary nucleation of dome-shaped C nano-islands. In the second case, we succeded in following both the dynamics of CO adsorption process and the CO + 1/2 O2 -> CO2 reaction on Pt nanoclusters grown on a ultra-thin film of magnesium oxide. Finally, the morphology of Pd, Pt, Rh and Au nanoclusers grown on different carbon-based substrates (namely graphite, single-walled carbon nanotubes and graphene) has been characterized. Among the results we report the understanding of the dependence of the metal-substrate interaction on the cluster size and the role of defects in the nucleation and intercalation processes.XXII Ciclo197

    Application of Parametric Optimization and Control in The Smart Manufacturing of Hydrogen Systems

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    The main objective of this dissertation is to develop and deploy and test explicit model predictive control feedback strategy on hydrogen systems using the PARametric Optimization and Control framework (PAROC). In line with the Smart Manufacturing initiative, our endeavor explores a new model based embedded control architecture that can enable the flexibility and adaptability of hydrogen process system to artificial intelligent algorithms. First a hydrogen supply chain model is developed to identify sustainable hydrogen technologies and then explicit model predictive control is developed using the PAROC framework. Both in silico and laboratory implementations are considered towards a smart prototype system application and demonstration. In silico PAROC considerations include the development and validation of high-fidelity models based on which the application of the multi-parametric programming techniques results in the derivation of explicit optimal feedback design strategy through the solution of a receding horizon optimization problem formulation. The derived explicit parametric control strategy is validated first in silico and then in real-time. Thus, laboratory scale experimental prototypes have been designed and built. The prototypes include: (i) a metal hydride hydrogen storage system (MHSS) and (ii) a PEM Water Electrolysis (PEMWE). The MHSS is designed to replicate the refueling process of a Fuel Cell Electric Vehicle (FCEV) in a hydrogen gas station while the PEMWE is designed as a module in a large scale modular hydrogen production process. Integration of the explicit MPC feedback control strategy and the online implementation on the prototype systems create smart hydrogen energy technologies. Both prototypes are tested using the explicit model predictive control strategies developed and the results obtained from the real-time implementation of the explicit feedback strategy demonstrates the potential of the proposed strategy and effective control design that meets the desired control objectives

    New Light Source (NLS) project: conceptual design report

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