3D Particle Track Reconstrution in a Single Layer Cadmium-Telluride Hybrid Active Pixel Detector

In the past 20 years the search for neutrinoless double beta decay has driven many developements in all kind of detector technology. A new branch in this field are highly-pixelated semiconductor detectors - such as the CdTe-Timepix detectors. It compromises a cadmium-telluride sensor of 14 mm x 14 mm x 1 mm size with an ASIC which has 256 x 256 pixel of 55 \textmu m pixel pitch and can be used to obtain either spectroscopic or timing information in every pixel. In regular operation it can provide a 2D projection of particle trajectories; however, three dimensional trajectories are desirable for neutrinoless double beta decay and other applications. In this paper we present a method to obtain such trajectories. The method was developed and tested with simulations that assume some minor modifications to the Timepix ASIC. Also, we were able to test the method experimentally and in the best case achieved a position resolution of about 90 \textmu m with electrons of 4.4 GeV.Comment: 10 pages, 15 figure

Age and gender differences in health-related quality of life of children and adolescents in Europe: a multilevel analysis

Objectives: To determine age and gender differences in health-related quality of life (HRQOL) in children and adolescents across 12 European countries using a newly developed HRQOL measure (KIDSCREEN). Methods: The KIDSCREEN-52 questionnaire was filled in by 21,590 children and adolescents aged 8-18 from 12 countries. We used multilevel regression analyses to model the hierarchical structure of the data. In addition, effect sizes were computed to test for gender differences within each age group. Results: Children generally showed better HRQOL than adolescents (P<0.001). While boys and girls had similar HRQOL at young age, girls' HRQOL declined more than boys' (P<0.001) with increasing age, depending on the HRQOL scale. There was significant variation between countries both at the youngest age and for age trajectories. Conclusions: For the first time, gender and age differences in children's and adolescents' HRQOL across Europe were assessed using a comprehensive and standardised instrument. Gender and age differences exist for most HRQOL scales. Differences in HRQOL across Europe point to the importance of national contexts for youth's well-bein

The search for high-energy neutrinos coincident with fast radio bursts with the ANTARES neutrino telescope

In the past decade, a new class of bright transient radio sources with millisecond duration has been discovered. The origin of these so-called fast radio bursts (FRBs) is still a mystery, despite the growing observational efforts made by various multiwavelength and multimessenger facilities. To date, many models have been proposed to explain FRBs, but neither the progenitors nor the radiative and the particle acceleration processes at work have been clearly identified. In this paper, we assess whether hadronic processes may occur in the vicinity of the FRB source. If they do, FRBs may contribute to the high-energy cosmic-ray and neutrino fluxes. A search for these hadronic signatures was carried out using the ANTARES neutrino telescope. The analysis consists in looking for high-energy neutrinos, in the TeV–PeV regime, that are spatially and temporally coincident with the detected FRBs. Most of the FRBs discovered in the period 2013–2017 were in the field of view of the ANTARES detector, which is sensitive mostly to events originating from the Southern hemisphere. From this period, 12 FRBs were selected and no coincident neutrino candidate was observed. Upper limits on the per-burst neutrino fluence were derived using a power-law spectrum, dN/dE¿¿E-¿¿¿, for the incoming neutrino flux, assuming spectral indexes ¿ = 1.0, 2.0, 2.5. Finally, the neutrino energy was constrained by computing the total energy radiated in neutrinos, assuming different distances for the FRBs. Constraints on the neutrino fluence and on the energy released were derived from the associated null resultsPeer ReviewedPostprint (published version

Psychosoziale Bedürfnisse von ehemaligen Kinderkrebspatienten

Kein Abstract vorhanden

Three dimensional photograph of single electron tracks through a scintillator

The reconstruction of particle trajectories makes it possible to distinguish between different types of charged particles. In high-energy physics, where trajectories are rather long, large size trackers must be used to achieve sufficient position resolution. However, in low-background experiments tracks are rather short and three dimensional trajectories could only be resolved in time-projection chambers so far. For detectors of large volume and therefore large drift distances, which are inevitable for low-background experiments, this technique is limited by diffusion of charge carriers. In this work we present a "proof-of-principle" experiment for a new method for the three dimensional tracking of charged particles by scintillation light: We used a setup consisting of a scintillator, mirrors, lenses and a novel imaging device (the hybrid photo detector) in order to image two projections of electron tracks through the scintillator. We took data at the T-24 beam-line at DESY with relativistic electrons with a kinetic energy of 5 GeV and from this data successfully reconstructed their three dimensional propagetion path in the scintillator. With our setup we achieved a position resolution of about 28 mum in the best case.Comment: 9 pages, 13 figures, 1 tabl

Siza Vieira em Évora: revisitar uma experimentação

O projecto experimental de Siza em Évora- o Bairro da Malagueira (casas em banda com telhado em terraço) -, pela sua dimensão (1200 casas), duração (1977 -2000), inovação em termos de tipologias de habitat e morfologia urbana, e consequentes implicações ideológicas e políticas, é objecto de uma pesquisa e avaliação sócio-arquitectónica. Os resultados desta pesquisa revelam que, entre uma posição racionalista e um cuidado pela arquitectura da casa, o compromisso de Siza permitiu, por um lado, criar um bairro com uma forte identidade e, por outro, respeitar os modos de habitar numa casa. Apesar da sua densidade e contiguidade, as casas da Malagueira possuem dois dos pré-requisitos que distinguem o habitat individual do habitat colectivo: uma entrada autónoma e ausência de vizinhos, quer em cima quer em baixo. Esta pesquisa salienta igualmente a importância, nesta habitação, de uma variável de importância aparentemente menor: o muro do pátio. A variação da sua altura opõe dois tipos de pátio: de um muro elevado resulta um pátio fechado e íntimo voltado para a casa, enquanto que um muro baixo dá origem a um pátio aberto que expõe a casa à rua. Em contrapartida, a rudeza do acabamento do "aqueduto" (galerias de infra-estruturas- às quais Siza quis conferir um papel simbólico na unificação do bairro) e a não conclusão dos espaços públicos e equipamentos inicialmente projectados por Siza consumam algumas fragilidades, diminuindo o prestígio de um bairro que permanece um complexo residencial periférico.Fundação para a Ciência e a TecnologiaMinistério da CulturaInstituto Português do Livro e das Biblioteca

Detection of non-classical space-time correlations with a novel type of single-photon camera

During the last decades, multi-pixel detectors have been developed capable of registering single photons. The newly developed Hybrid Photon Detector camera has a remarkable property that it has not only spatial but also temporal resolution. In this work, we use this device for the detection of non-classical light from spontaneous parametric down-conversion and use two-photon correlations for the absolute calibration of its quantum efficiency

Modelling and condition-based control of a flexible and hybrid disassembly system with manual and autonomous workstations using reinforcement learning

Remanufacturing includes disassembly and reassembly of used products to save natural resources and reduce emissions. While assembly is widely understood in the field of operations management, disassembly is a rather new problem in production planning and control. The latter faces the challenge of high uncertainty of type, quantity and quality conditions of returned products, leading to high volatility in remanufacturing production systems. Traditionally, disassembly is a manual labor-intensive production step that, thanks to advances in robotics and artificial intelligence, starts to be automated with autonomous workstations. Due to the diverging material flow, the application of production systems with loosely linked stations is particularly suitable and, owing to the risk of condition induced operational failures, the rise of hybrid disassembly systems that combine manual and autonomous workstations can be expected. In contrast to traditional workstations, autonomous workstations can expand their capabilities but suffer from unknown failure rates. For such adverse conditions a condition-based control for hybrid disassembly systems, based on reinforcement learning, alongside a comprehensive modeling approach is presented in this work. The method is applied to a real-world production system. By comparison with a heuristic control approach, the potential of the RL approach can be proven simulatively using two different test cases