31 research outputs found
Expression and autonomy through assistive interfaces and digital games : a cartographic perspective
Orientador: Hermes Renato HildebrandTese (doutorado) - Universidade Estadual de Campinas, Instituto de ArtesResumo: IndivÃduos que possuem graves limitações motoras ou cognitivas raramente têm oportunidade de vivenciar experiências plenas, em que possam se expressar autonomamente ao tomarem suas próprias decisões. Neste contexto, busquei identificar possibilidades de desenvolvimento de interfaces assistivas que oferecessem condições necessárias para este tipo de experiência a um grupo de jovens alunos em situações restritivas. O objetivo está voltado a oferecer uma interface interativa que possibilite a estes sujeitos experimentarem a autonomia na tomada de decisões e a reflexão sobre os efeitos causados, permitindo que tenham total controle sobre o ambiente, o que não ocorre no mundo real devido à s suas condições de dependência de terceiros. Para tal, integrei um equipamento de leitura de pupila com um jogo Pong, ambos assistivos, elementos, propondo, implementando e testando melhorias na interatividade e balanceamento do jogo. Este projeto emergiu a partir de uma pesquisa sobre tecnologias assistivas comunicacionais, no momento que identifiquei a relevância da autonomia e necessidade de expressão para o grupo de foco. Assim, sem uma predefinição dos objetivos e atividades a serem realizadas, esta pesquisa não teve planejamento formal nem conclusão, sendo voltado para o processo de construção e avaliação da interface. Por este motivo, optei pelo Método Cartográfico como metodologia de pesquisa, pela perspectiva dinâmica aderente ao processo de design que realizei. Assim, defini um conjunto de dispositivos cartográficos a serem aplicados na pesquisa como mecanismo para apoiar a avaliação do processo. O conjunto trÃade de dispositivos que proponho permite o acompanhamento do decurso do trabalho pelas óticas de seus Valores, PrincÃpios e Práticas, e foram posteriormente desdobradas de maneira dicotômica para suportar sua aplicação. A interface assistiva articulada com o jogo posteriormente polido e balanceado se mostraram oportunas para criar o ambiente autônomo, independente das restrições motoras do grupo de foco. Da mesma forma, os dispositivos cartográficos que proponho apresentaram compatibilidade com o Método Cartográfico e promoveram a explicitação dos elementos envolvidos no complexo processo da pesquisaAbstract: Individuals who have a severe motor or cognitive limitations rarely have the opportunity to experience full experiences in which they can express themselves autonomously when making their own decisions. In this context, I tried to identify possibilities for the development of assistive interfaces that offered the necessary conditions for this type of experience to a group of young students in restrictive situations. The objective is to provide an interactive interface that enables these subjects to experience autonomy in decision making, and reflection on the effects caused, allowing them to have total control over the environment, which does not occur in the real world due to their conditions of dependence. For that, I integrated a pupil reading equipment with a Pong game, both assistive, elements, proposing, implementing and testing improvements in interactivity and game balancing. This project emerged from the research on communicational assistive technologies, at which point I identified the relevance of the autonomy and need for expression for the focus group. Thus, without a preset of the objectives and activities to be carried out, this research did not have formal planning nor conclusion, being directed to the process of construction and evaluation of the interface. For this reason, I opted for the Cartographic Method as research methodology, for the dynamic perspective adherent to the design process that I performed. Thus, I defined a set of cartographic devices to be applied in the research as a mechanism to support the evaluation of the process. The trial set of tools that I propose allows the follow-up of the course of work through the optics of its Values, Principles, and Practices, and were later deployed in a dichotomous way to support its application. The assistive interface articulated with the game later polished and balanced were shown to be opportune to create the free environment, independent of the motor restrictions of the focus group. In the same way, the cartographic devices that I propose presented compatibility with the Cartographic Method and promoted the explicitation of the elements involved in the complex process of the researchDoutoradoArtes VisuaisDoutor em Artes Visuai
Boron concentration profiling by high angle annular dark field-scanning transmission electron microscopy in homoepitaxial delta-doped diamond layers
To develop further diamond related devices, the concentration and spatial location of dopants should be controlled down to the nanometer scale. Scanning transmission electron microscopy using the high angle annular dark field mode is shown to be sensitive to boron doping in diamond epilayers. An analytical procedure is described, whereby local boron concentrations above 1020 cm-3 were quantitatively derived down to nanometer resolution from the signal dependence on thickness and
boron content. Experimental boron local doping profiles measured on diamond p-/p++/p- multilayers are compared to macroscopic profiles obtained by secondary ion mass spectrometry, avoiding reported artefacts.4 page
TEM study of homoepitaxial diamond layers scheduled for high power devices: FIB method of sample preparation
Homoepitaxial diamond structure observation by transmission electron microscopy (TEM) is still a very hard job due to the difficulty in preparing electron transparent samples for the further observation. The present contribution details the experimental operations with their respective conditions step by step. Finally high resolution TEM (HREM) observations of a CVD grown epilayer on a unnintentionally doped HPHT (001) oriented substrate are present to show the high quality of the sample preparation method.4 page
A microstructural study of superconductive nanocrystalline diamond
A transmission electron microscopy (TEM) study of superconducting nanocrystalline diamond (NCD) continuous layers is reported. The high resolution transmission electron microscopy (HREM) and the diffraction contrast modes of observations are used to reveal the nanograins configuration. Three types of them are observed: first, close to the interface with the Si/SiO2 substrate, 10 to 20 nm-sized diamond
16 seeds resulting from the 5nm size diamond powder deposition before growth that show some regrowth during CVD process, second a diamond overgrown layer, quasi-epitaxially by coalesced columnar NCD grains, and finally, up to the free surface, a thin disordered region composed of nanocrystallites smaller than 6 nm. This last layer was not nominally expected and is attributed to a renucleated-like (RND) diamond layer embedding ultra nanocrystalline grains. Diffraction contrast observations confirm this HREM observed behaviour.6 page
Cross sectional evaluation of boron doping and defect distribution in homoepitaxial diamond layers
In some diamond-based semiconducting devices, large variations of doping level are required over short distances. Tools to determine doping level and defects distribution should therefore be developed. The present contribution shows the capabilities of electron microscopy in this field. Focused ion beam (FIB-dual beam) cross section preparations allowed evaluating doping level in highly boron doped sample with doping transition down to some nm by diffraction contrast mode of transmission electron microscopy (CTEM) and by high angle annular dark field mode of scanning transmission electron microscopy (HAADF-STEM). The sensibility of the latter is around 1019cm-3 and, thus, cathodoluminescence (CL)is required for lower doping levels. Cross sectional analysis on FIB prepared lamella allowed to separate the epilayer behaviour from that of the substrate. Mid-gap centers involving boron, hydrogen and, for some peaks, also nitrogen are revealed. sp2 bonds are also present in the grown epilayer. These transitions make difficult the
observation of excitonic recombinations in the cross section configuration.5 page
Influence of the substrate type on CVD grown homoepitaxial diamond layer quality by cross sectional TEM and CL analysis
To assess diamond-based semiconducting devices, a reduction of point defect levels and an accurate control of doping are required as well as the control of layer thickness. Among the analyses required to improve such parameters, cross sectional studies should take importance in the near future. The present contribution shows
how FIB (focused ion beam) preparations followed by electron microscopy related techniques as TEM or CL allowed to performanalysis versus depth in the layer, doping and point defect levels. Three samples grown along the sameweek in the same machinewith identical growth conditions but on different substrates (CVD-IIIa (110)
oriented, CVD-optical grade (100) oriented and a HPHT-Ib (100) oriented) are studied. Even though A-band is observed by CL, no dislocation is observed by CTEM. Point defect type and level are shown to substantially change with respect to the substrate type as well as the boron doping levels that vary within an order of magnitude. H3 present in the epilayer grown on HPHT type of substrate is replaced by T1 and NE3 point defects for epilayers grown on the CVD type one. An increase of excitonic transitions through LO phonons is also shown to take place near the surface while only TO ones are detected deeper in the epilayer. Such results highlight the importance of choosing the correct substrate.5 page
Dislocation generation mechanisms in heavily boron-doped diamond epilayers
Doping diamond layers for electronic applications has become straightforward during the last two decades. However, dislocation generation in diamond during the microwave plasma enhanced chemical vapor deposition growth process is still not fully understood. This is a truly relevant topic to avoid for an optimal performance of any device, but, usually, it is not considered when designing diamond structures for electronic devices. The incorporation of a dopant, here boron, into a lattice as close as that of diamond, can promote the appearance of dislocations in the epilayer. The present contribution analyzes the different processes that can take place in this epilayer and gives some rules to avoid the formation of dislocations, based on the comparison of the different dislocation generation mechanisms. Indeed, competitive mechanisms, such as doping atom proximity effect and lattice strain relaxation, are here quantified for heavily boron-doped diamond epilayers. The resulting growth condition windows for defect-free heavily doped diamond are here deduced, introducing the diamond parameters and its lattice expansion in several previously published critical thickness (h(c)) and critical doping level relationships for different doping levels and growth conditions. Experimental evidence supports the previously discussed thickness-doping-growth condition relationships. Layers with and without dislocations reveal that not only the thickness but also other key factors such as growth orientation and growth parameters are important, as dislocations are shown to be generated in epilayers with a thickness below the People and Bean critical thickness
Para Todxs: Natal - uma introdução à lógica formal
Livro-texto de introdução à lógica, com (mais do que) pitadas de filosofia da lógica, produzido como uma versão revista e ampliada do livro Forallx: Calgary. Trata-se de uma versão rascunho, (0.7), em fase de revisão, e que deverá estar pronta para publicação até o final de 2021. Comentários, crÃticas, correções e sugestões são muito bem-vindos
Convalescent plasma for COVID-19 in hospitalised patients : an open-label, randomised clinical trial
Background: The effects of convalescent plasma (CP) therapy in hospitalised patients with coronavirus disease 2019 (COVID-19) remain uncertain. This study investigates the effect of CP on clinical improvement in these patients. Methods: This is an investigator-initiated, randomised, parallel arm, open-label, superiority clinical trial. Patients were randomly (1:1) assigned to two infusions of CP plus standard of care (SOC) or SOC alone. The primary outcome was the proportion of patients with clinical improvement 28 days after enrolment. Results: A total of 160 (80 in each arm) patients (66.3% critically ill, 33.7% severely ill) completed the trial. The median (interquartile range (IQR)) age was 60.5 (48–68) years; 58.1% were male and the median (IQR) time from symptom onset to randomisation was 10 (8–12) days. Neutralising antibody titres >1:80 were present in 133 (83.1%) patients at baseline. The proportion of patients with clinical improvement on day 28 was 61.3% in the CP+SOC group and 65.0% in the SOC group (difference −3.7%, 95% CI −18.8–11.3%). The results were similar in the severe and critically ill subgroups. There was no significant difference between CP+SOC and SOC groups in pre-specified secondary outcomes, including 28-day mortality, days alive and free of respiratory support and duration of invasive ventilatory support. Inflammatory and other laboratory marker values on days 3, 7 and 14 were similar between groups. Conclusions: CP+SOC did not result in a higher proportion of clinical improvement on day 28 in hospitalised patients with COVID-19 compared to SOC alone