Integrated optical polarizer based on the cross strip interferometer configuration.

A bimodal segment of specific length and thickness between two single mode sections of a planar waveguide can serve as a simple interferometer. The configuration can be realized by etching a wide strip from a dielectric film and forcing a — vertically guided, laterally unguided — beam of light to traverse the strip perpendicularly. A TE-pass polarizer designed on the basis of this concept achieves more that 30dB polarization discrimination with a total length of only 5 micrometers, for air covered Silicon-Oxide/Nitride waveguides at a wavelength of 650 nanometers

Papers, Please as Critical Making: A Review

This article examines Lucas Pope’s independent game Papers, Please as an instantiation of critical making within the discipline of the digital humanities. By confronting the player with moral decisions in their capacity as an immigration officer allowing or denying entry to immigrants within a totalitarian state, the game introduces an expressive form of game design in which conceptual practices are used to examine political and social realities. This type of critical media practice introduces a political ethic to the digital humanities that is arguably scarce within the discipline

Universidade e Empresas Juniores: Parceiras na Formação

Apresentamos nesta comunicação, um breve mas sólido conteúdo sobre as relações das Universidades com as Empresas Juniores (U2jr), sob a ótica da pedagogia empresarial ou seja, uma parceria desejada pelas partes envolvidas, na construção e formação profissional do discente. Estas parcerias muitas vezes completamente desvinculadas de avaliações formativas , podem e devem ser motivos de discussão para alavancar novas didáticas de instrumentar conteúdos. Em 1967, quando surgiu o Movimento Júnior (MJ) na “L`Ecole Supériore des Sciences Economiques et Comerciales” (ESSEC), ainda não se tinha introjetado os possíveis desdobramentos conseqüentes desta inovadora forma de parceria universitária. O Mj inicialmente preocupava-se com os discentes com o olhar da adequação à práxis inerentes à profissão escolhida. Do MJ nasce a Empresa Júnior (EJ). Estas organizações aprendentes são embriões dos novos processos de gestão. Norteadas pela a competência profissional, apresentam-se como uma das possibilidades para solucionar criativamente problemas organizacionais e de empregabilidade (psico-sócio-econômico). Empresa Júnior é uma associação civil sem fins lucrativos, mas com fins educativos, e com prazo de duração indeterminado, com sede e foro normalmente nos limites físicos da universidade, centro, faculdade a que se vincula.(Melo,2002.pg 163). Dentro do conceito Junior, as EJ fazem também, mas não só, consultorias. Estas consultorias são totalmente supervisionadas por professores orientadores. Entre os serviços oferecidos constam Capacitação de Pessoa,l Definição de Recursos, Diagnóstico Empresarial, Analise Ambiental, Geração de Alternativas, entre tantas outras possíveis.(FEJEMG,2002). Hoje encontramos EJ exportadoras, apoiada continuamente por seus clientes que majoritariamente são pequenas e media empresas (pyme)

Space weather radiation effects on geostationary satellite solid-state power amplifiers

In order to understand and mitigate the effects of space weather on the performance of geostationary (GEO) communications satellites, we analyze 16 years of archived telemetry data from Inmarsat, the UK-based telecommunications company. We compare 665,112 operational hours of housekeeping telemetry from two generations of satellites, designated as Fleet A and Fleet B. Each generation experienced 13 solid-state power amplifier (SSPA) anomalies for a total of 26 anomalies from 1996 to 2012. We compare telemetry from the Inmarsat anomalies with space weather observations, including data from the OMNI2 database, Geostationary Operational Environmental Satellites, the Advanced Composition Explorer Satellite, and Los Alamos National Laboratory (LANL) GEO observations; the evolution of the sunspot number; and the Kp index. Most SSPA anomalies for Fleet A occur as solar activity declines; Fleet B has not yet experienced a full solar cycle. For both fleets, the average value of Kp remained <2 over time periods of 2 days, 3 days, and 2 weeks around the time of anomaly, which suggests that the anomalies occurred at times of relatively quiet geomagnetic activity and that they were probably not solely caused by surface charging. From 1996 to 2009, the average of the 1.8-3.5MeV electron flux was 1.98 #/(cm(2)s st keV). Five of the 26 anomalies, unfortunately, do not have corresponding science observations (specifically, electron flux data in the LANL data set), so part of this study focuses on the 21 anomalies when science observations were available. Six out of 21 anomalies experienced a high-energy electron flux greater than 1.5 standard deviations above the mean of the log(10) of the flux between 7 and 14days prior to the anomaly. By contrast, a Monte Carlo simulation finds that on average, only 2.8 out of 21 (13%) of randomly assigned anomalies occur between 7 and 14days after an electron flux greater than 1.5 standard deviations above the mean. Our observations suggest that internal charging from either past elevated radiation belt fluxes or some conditions related to relativistic electron enhancements (either causally or accidentally) is most likely responsible for the SSPA anomalies. We next consider the timing of these anomalies with respect to the local time (LT) and season. Anomalies occur at all LT sectors with 46% (Fleet A) and 38.5% (Fleet B) in the midnight to dawn sector and 54% (Fleet A) and 46% (Fleet B) in the local noon to dusk sector. From the local time distribution, surface charging does not appear to be the sole causative agent of the anomalies. Understanding the connection between the space weather conditions and anomalies on subsystems and specific components on identical and similar geostationary communications satellites for periods of time longer than a solar cycle will help guide design improvements and provide insight on their operation during space weather events

Communication satellite power amplifiers: current and future SSPA and TWTA technologies

This study captures the state of current satellite transponder technology, specifically, solid-state power amplifiers (SSPAs) and traveling wave tube amplifiers (TWTAs), and describes expected future advances, including GaN SSPAs. The findings of five previous SSPA and TWTA studies, including the 1991 European Space and Technology Center study, the 1993 National Aeronautics and Space Administration study, and three Boeing studies conducted in 2005, 2008, and 2013, are tabulated and summarized. The results of these studies are then compared with new analyses of two validated sources of amplifier data: a commercially licensed database, Seradata's Spacetrak, and a publicly available database, Gunter's Space Page. The new analyses consider a total of 18,902 amplifiers (6428 TWTAs, 2158 SSPAs, and 10,316 unspecified amplifiers) onboard 565 communications satellites launched from 1982 to 2016. This new study contains the largest number of satellites and amplifiers to date and compares output power, redundancy, and bandwidth capabilities. We find an increase in output power from the 1993 study of >200% for Ku-band TWTAs and C-band SSPAs, and >1000% increase for C-band TWTAs. The ratio of operational to redundant amplifiers is 10 times higher for TWTAs than SSPAs, and the majority of amplifiers over the past 30 years operate with bandwidth less than 100 MHz. A second analysis is conducted using failure records and telemetry of 16 geostationary satellites equipped with 659 amplifiers: 535 SSPAs and 124 TWTAs. We find that <2% of TWTAs and 5% of SSPAs experience anomalies. Overall, this research was performed to update and clarify how the power and bandwidth needs and redundancy trends of the SatCom community have evolved over the past 30 years

Skin TLR7 triggering promotes accumulation of respiratory dendritic cells and natural killer cells.

The TLR7 agonist imiquimod has been used successfully as adjuvant for skin treatment of virus-associated warts and basal cell carcinoma. The effects of skin TLR7 triggering on respiratory leukocyte populations are unknown. In a placebo-controlled experimental animal study we have used multicolour flow cytometry to systematically analyze the modulation of respiratory leukocyte subsets after skin administration of imiquimod. Compared to placebo, skin administration of imiquimod significantly increased respiratory dendritic cells (DC) and natural killer cells, whereas total respiratory leukocyte, alveolar macrophages, classical CD4+ T helper and CD8+ T killer cell numbers were not or only moderately affected. DC subpopulation analyses revealed that elevation of respiratory DC was caused by an increase of respiratory monocytic DC and CD11b(hi) DC subsets. Lymphocyte subpopulation analyses indicated a marked elevation of respiratory natural killer cells and a significant reduction of B lymphocytes. Analysis of cytokine responses of respiratory leukocytes after stimulation with Klebsiella pneumonia indicated reduced IFN-γ and TNF-α expression and increased IL-10 and IL-12p70 production after 7 day low dose skin TLR7 triggering. Additionally, respiratory NK cytotoxic activity was increased after 7d skin TLR7 triggering. In contrast, lung histology and bronchoalveolar cell counts were not affected suggesting that skin TLR7 stimulation modulated respiratory leukocyte composition without inducing overt pulmonary inflammation. These data suggest the possibility to modulate respiratory leukocyte composition and respiratory cytokine responses against pathogens like Klebsiella pneumonia through skin administration of a clinically approved TLR7 ligand. Skin administration of synthetic TLR7 ligands may represent a novel, noninvasive means to modulate respiratory immunity

Causal relationships between solar proton events and single event upsets for communication satellites

In this work, we analyze a historical archive of single event upsets (SEUs) maintained by Inmarsat, one of the world's leading providers of global mobile satellite communications services. Inmarsat has operated its geostationary communication satellites and collected extensive satellite anomaly and telemetry data since 1990. Over the course of the past twenty years, the satellites have experienced more than 226 single event upsets (SEUs), a catch-all term for anomalies that occur in a satellite's electronics such as bit-flips, trips in power supplies, and memory changes in attitude control systems. While SEUs are seemingly random and difficult to predict, we correlate their occurrences to space weather phenomena, and specifically show correlations between SEUs and solar proton events (SPEs). SPEs are highly energetic protons that originate from solar coronal mass ejections (CMEs). It is thought that when these particles impact geostationary (GEO) satellites they can cause SEUs as well as solar array degradation. We calculate the associated statistical correlations that each SEU occurs within one day, one week, two weeks, and one month of 10 MeV SPEs between 10 - 10,000 particle flux units (pfu). However, we find that SPEs are most prevalent at solar maximum and that the SEUs on Inmarsat's satellites occur out of phase with the solar maximum. Ultimately, this suggests that SPEs are not the primary cause of the Inmarsat SEUs. A better understanding of the causal relationship between SPEs and SEUs will help the satellite communications industry develop component and operational space weather mitigation techniques as well as help the space weather community to refine radiation models.International Maritime Satellite OrganizationNational Science Foundation (U.S.)Massachusetts Institute of Technolog

MEDIDA SOCIOEDUCATIVA EM MEIO ABERTO: desafios à execução na Política de Assistência Social

RESUMO: O objetivo deste artigo é discutir como têm sido executadas as medidas socioeducativas em meio aberto (Liberdade Assistida e Prestação de Serviço à Comunidade) pela Política de Assistência Social. Foi realizado um estudo empírico, no segundo semestre de 2016, no CREAS do município de Tijucas de abordagem qualitativa, por meio de entrevista semiestruturada realizada com seis sujeitos da política de assistência social no município, representantes do Conselho Municipal dos Direitos da Criança e do Adolescente e com um(a) juiz(a) de direito, além da análise de documentos institucionais. Os dados sugerem importantes desafios técnicos, políticos e operacionais no cotidiano do acompanhamento aos adolescentes a serem superados – entre eles o da articulação intersetorial entre as políticas publicas – tendo em vista que esses tem dificultado o cumprimento da medida socioeducativa pelo adolescente autor de ato infracional, conforme determina o SINASE (Lei nº 12.594/2012)

Quantifying the average and the likelihood of increases in space weather indices and in situ measurements during Solar Cycles 20–23

It is known that space weather harshly affects spacecraft performance, yet spacecraft operations and understanding the cause of anomalies can be challenging due to the complexity of environmental metrics. In this work, we analyse five metrics and in-situ measurements (Kp, Dst, and AE index, and high-energy proton and electron flux) throughout Solar Cycles 20–23 (1964 to 2008), and provide a baseline for the environment during the phases of the solar cycles (maximum, minimum, declining or ascending). We define increased activity as activity greater than two median absolute deviations (MADs) above the average activity for each phase. MAD is used, rather than standard deviation, because it is more resilient to outliers. The average and MAD values are tabulated in Table 3 to Table 6. We determine the probability that increased activity occurs 3, 14 or 30 days before a random day to distinguish between increased/quiet activities and to aid in correlating intensifications of the environment and anomalous satellite performance