331 research outputs found

    Interactive computer graphics system for structural sizing and analysis of aircraft structures

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    A computerized system for preliminary sizing and analysis of aircraft wing and fuselage structures was described. The system is based upon repeated application of analytical program modules, which are interactively interfaced and sequence-controlled during the iterative design process with the aid of design-oriented graphics software modules. The entire process is initiated and controlled via low-cost interactive graphics terminals driven by a remote computer in a time-sharing mode

    Ion beam micromachining of integrated optics components

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    Thin film integrated optics components such as light guides, modulators, directional couplers, and polarizers demand high quality edge smoothness and high resolution pattern formation in dimensions down to submicrometer size. Fabrication techniques combining holographic and scanning electron beam lithography with ion beam micromachining have produced planar phase gratings with intervals as small as 2800 Å, guiding channel couplers in GaAs, and also wire- grid polarizers for 10.6-µm radiation

    Channel Optical Waveguides and Directional Couplers in GaAs -- Imbedded and Ridged

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    Two-channel imbedded directional couplers were fabricated with proton implantation, yielding complete light transfer in 2 mm. Ridged channel guides were fabricated by ion-micromachining epitaxial layers, and a method of directional coupling was demonstrated

    Theory and fabrication of integrated optics directional couplers in GaAs

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    Channel optical waveguide couplers will be discussed, citing the fabrication of closely-spaced waveguides by proton implantation. Coupling was observed at 1.15ÎĽ and 1.06ÎĽ

    Cascading the use of Web 2.0 technology in secondary schools in the United Kingdom: identifying the barriers beyond pre-service training

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    This paper reports on research that took place at Nottingham Trent University and Sheffield Hallam University, United Kingdom, over two years. The research focuses on the use of Web 2.0 technology, specifically web logs, with pre-service teachers, both during their university programme and the first year of teaching as full-time newly qualified teachers (NQTs). The purpose of this research was to add a developing body of knowledge by identifying whether technology used by pre-service teachers during their training course can be cascaded into their practice once qualified. Key findings identify a number of enablers and barriers to cascading technology in the classroom; these include curriculum time, pupil skills and support. The research concludes that early professional support and development should be on-going and assumptions about new teachers as champions of cascading innovative use of Web 2 technologies into their practice as NQTs may be over optimisti

    Behavioral and Emotional Disorders in Children during the COVID-19 Epidemic.

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    Since December 2019, health systems around the globe have struggled with an increasing number of cases of a viral respiratory syndrome that emerged in China. The cause is a new strain in the coronavirus family, provisionally named 2019 novel coronavirus (2019-nCoV), SARS-CoV-2 or COVID-19.The European Paediatric Association–Union of National European Paediatric Societies and Associations (EPA-UNEPSA) has established a collaborative working group with key Chinese academic institutions and medical centers with the purpose of facilitating the reciprocal exchange of information and sharing scientific knowledge. The aim of this commentary by the China-EPA-UNEPSA working group is to raise awareness regarding children’s psychological needs during epidemics and report early data collected in the COVID19–affected areas in China during the current outbreak, emphasizing the role of families and caregivers in the timely recognition and management of negative emotions

    Advocating for Children Trapped in the Midst of Armed Conflicts.

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    Natural and human-made disasters, including civil unrest, terrorism, biological and chemical threats, and war, have affected the world on a recurring basis. These events have caused suffering and misery to populations and have revealed a low degree of self-sufficiency and a high degree of unpreparedness on the part of governments to deal with the consequences.1 Natural and human-made adversity typically generate public health crises and economic instability, with lasting negative effects on the socioeconomic status of populations of all ages. These adverse effects affect children, who are among the most marginalized and vulnerable members of society and rarely consulted when communities make decisions that directly affect them. War is one of the world's most devastating events, requiring short-term interventions and complex long-term recovery planning, articulated in 4 phases—mitigation, preparedness, response and recovery—that focus on the rights of children who are in vulnerable circumstances and, therefore, at greater risk of harm. This commentary, authored by members of the board of directors of the European Pediatric Association–Union of National Pediatric Societies and Associations (EPA-UNEPSA), briefly discusses the plight of children exposed to situations of terror and horror during war, including severe loss and disruption in their lives, which can result in the lasting effects of post-traumatic stress disorder. Our goal is to raise awareness among pediatricians and public health authorities of the importance of developing programs directed toward the rehabilitation of children affected by war, including social healing and peace culture education, as a key approach to primary prevention of the recurrence of war

    Pertussis infection in fully vaccinated children in day-care centers, Israel.

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    We tested 46 fully vaccinated children in two day-care centers in Israel who were exposed to a fatal case of pertussis infection. Only two of five children who tested positive for Bordetella pertussis met the World Health Organization's case definition for pertussis. Vaccinated children may be asymptomatic reservoirs for infection

    Channel optical waveguides and directional couplers in GaAs - Imbedded and ridged

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