Hollow Cathode and Low-Thrust Extraction Grid Analysis for a Miniature Ion Thruster

Miniature ion thrusters are well suited for future space missions that require high efficiency, precision thrust, and low contamination in the mN to sub-mN range. JPL’s miniature xenon Ion (MiXI) thruster has demonstrated an efficient discharge and ion extraction grid assembly using filament cathodes and the internal conduction (IC) cathode. JPL is currently preparing to incorporate a miniature hollow cathode for the MiXI discharge. Computational analyses anticipate that an axially upstream hollow cathode location provides the most favorable performance and beam profile; however, the hot surfaces of the hollow cathode must be sufficiently downstream to avoid demagnetization of the cathode magnet at the back of the chamber, which can significantly reduce discharge performance. MiXI’s ion extraction grids are designed to provide >3mN of thrust; however, previous to this effort, the low-thrust characteristics had not been investigated. Experimental results obtained with the MiXI-II thruster (a near replica or the original MiXI thruster) show that sparse average discharge plasma densities of ∼5×10^15–5×10^16 m^−3 allow the use of very low beamlet focusing extraction voltages of only ∼250–500 V, thus providing thrust levels as low as 0.03 mN for focused beamlet conditions. Consequently, the thrust range thus far demonstrated by MiXI in this and other tests is 0.03–1.54 mN

Novel natural and synthetic compounds for treating hormone resistant tumors

Cancer is a leading cause of mortality worldwide. Despite significant advances in medical research, deaths due to cancer are continuously increase. Data from 2010 has shown the colorectal, breast, prostate and lung cancer as the most common in Portugal. Considering the North Region, prostate cancer and breast cancer are the most incident in men and women, respectively. Despite all the improvement in cancer early detection and treatment, the high mortality rates challenges the discovery of new anticancer agents. In the last years, several team members were involved in the study of the bioactive potential of natural and synthetic compounds at the Health and Environment Research Centre at School of Health of the Polytechnic Institute of Porto (CISA ESS—P.Porto). From previous works, extracts isolated from plants and synthetic compounds, such as ionic liquids and quinoxalines, revealed an interesting bioactive potential as cancer drug. Following these previous approaches and considering the background of the team members in cancer research, the main goal of this project is to infer about the potential of these natural and synthetic compounds as anti-cancer drugs to common North Portugal cancer hormone-resistant tumors, namely castration-resistant prostate tumors and estrogen-independent breast tumors.info:eu-repo/semantics/publishedVersio

Quantum Confinement in Hydrogen Bond of DNA and RNA

The hydrogen bond is a fundamental ingredient to stabilize the DNA and RNA macromolecules. The main contribution of this work is to describe quantitatively this interaction as a consequence of the quantum confinement of the hydrogen. The results for the free and confined system are compared with experimental data. The formalism to compute the energy gap of the vibration motion used to identify the spectrum lines is the Variational Method allied to Supersymmetric Quantum Mechanics.Comment: 8 pages, 3 figures. To appear in The Proceedings of the 30th International Colloquium on Group Theoretical Methods in Physics (Group30), Ghent, Belgiu

Activities as a research resource

Activities play a guiding central role in occupational therapy, articulating to its utilization, the understanding and assessment of its capabilities in numerous and different interventions arising from this field. In this study, we aim to present the use of activities as a research methodology resource. Considering the pathways studied in a master’s research followed by a PhD work, some applications of this resource are reported as a powerful strategy of investigation for the occupational therapy researcher. It is about structuring, systematizing, and analyzing the activities proposed in professional practice by the theoretical and methodological rigor used in the research works. It emphasizes how the use of these activities can be considered important data, records, instruments and sources for different research methods, especially for qualitative analyses. Workshop activities were offered in the above mentioned studies; they were used as communication instruments and expressions of personal and collective experiences, supplying data to understand the actions of subjects and collectives. Furthermore, this strategy was applied as spaces of experimentation, learning and expression, where each participant was conceived as an active being of the process, in a way that the proposal could result in democratic experiences that reflected greater interest and participation, and a more complex presentation of the research data. It is worth mentioning that other methodological procedures, which substantiated the analyses and interpretation of the data collected, were also used. It was possible to conclude that activities, mainly as a qualitative research resource, constituted materialities in different languages and expressions that enriched the analyses arising from micro-realities, producing a repertoire of information that supported the interpretations required for the investigative processes

Proton Profile Function at 52.8 GeV

We present the results of a novel model-independent fit to elastic proton-proton differential cross section data at $\sqrt s$ = 52.8 GeV. Taking into account the error propagation from the fit parameters, we determine the scattering amplitude in the impact parameter space (the proton profile function) and its statistical uncertainty region. We show that both the real and imaginary parts of the profile are consistent with two dynamical contributions, one from a central dense region, up to roughly 1 fm and another from a peripheral evanescent region from 1 to 3 fm.Comment: Published in Int. J. Mod. Phys.

ANÁLISE DE CENÁRIOS E IDENTIFICAÇÃO DE TENDÊNCIAS EM JOGOS DE EMPRESAS: TOMADA DE DECISÕES BASEADA EM ESTUDO E PERCEPÇÃO

Este estudo analisará como a análise de cenários, juntamente com estudo e percepção, pode contribuir para uma apropriada tomada de decisões, diminuindo a incerteza e o risco do gestor. O modelo de gestão seguido no estudo é o modelo de Peter Schwartz, que combina o levantamento de dados, resultando em informações analisadas segundo a percepção do estrategista, que é afetada por variáveis como conhecimento, comportamento e formação individual. Terá como ambiente de estudo um simulador organizacional, que possui rodadas de jogos de empresa, onde retrata situações e variáveis econômicas que influenciam diretamente na tomada de decisão. Por meio desse estudo, é identificado que um planejamento prévio por análise de cenários pode ser de grande ajuda para a identificação de tendências com maior grau de acerto ao gestor e aliado a conhecimentos adicionais e formação podem complementar a diminuição do risco e aumento da possibilidade de êxito

Gestação múltipla na maternidade do Hospital Santa Isabel.

Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Departamento de Tocoginecologia, Curso de Medicina, Florianópolis, 198

Importância da avaliação da função tireoidiana em pacientes com diabetes mellitus

Universidade Federal de São Paulo (UNIFESP) Disciplina de EndocrinologiaUNIFESP, Disciplina de EndocrinologiaSciEL

Nefrite lúpica no Hospital Santa Isabel: análise de 12 casos.

Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Departamento de Clínica Médica, Curso de Medicina, Florianópolis, 198