10 research outputs found

    Microfabricated pinholes for high contrast imaging testbeds

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    In order to reach contrast ratios of 10810^{-8} and beyond, coronagraph testbeds need source optics that reliably emulate nearly-point-like starlight, with microfabricated pinholes being a compelling solution. To verify, a physical optics model of the Space Coronagraph Optical Bench (SCoOB) source optics, including a finite-difference time-domain (FDTD) pinhole simulation, was created. The results of the FDTD simulation show waveguide-like behavior of pinholes. We designed and fabricated microfabricated pinholes for SCoOB made from an aluminum overcoated silicon nitride film overhanging a silicon wafer substrate, and report characterization of the completed pinholes.Comment: Submitted to SPIE Optical Engineering + Applications (OP23O

    Status and prospects for renewable energy using wood pellets from the southeastern United States

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    The ongoing debate about costs and benefits of wood-pellet based bioenergy production in the southeastern United States (SE USA) requires an understanding of the science and context influencing market decisions associated with its sustainability. Production of pellets has garnered much attention as US exports have grown from negligible amounts in the early 2000s to 4.6 million metric tonnes in 2015. Currently, 98% of these pellet exports are shipped to Europe to displace coal in power plants. We ask, ‘How is the production of wood pellets in the SE USA affecting forest systems and the ecosystem services they provide?’ To address this question, we review current forest conditions and the status of the wood products industry, how pellet production affects ecosystem services and biodiversity, and what methods are in place to monitor changes and protect vulnerable systems. Scientific studies provide evidence that wood pellets in the SE USA are a fraction of total forestry operations and can be produced while maintaining or improving forest ecosystem services. Ecosystem services are protected by the requirement to utilize loggers trained to apply scientifically based best management practices in planning and implementing harvest for the export market. Bioenergy markets supplement incomes to private rural landholders and provide an incentive for forest management practices that simultaneously benefit water quality and wildlife and reduce risk of fire and insect outbreaks. Bioenergy also increases the value of forest land to landowners, thereby decreasing likelihood of conversion to nonforest uses. Monitoring and evaluation are essential to verify that regulations and good practices are achieving goals and to enable timely responses if problems arise. Conducting rigorous research to understand how conditions change in response to management choices requires baseline data, monitoring, and appropriate reference scenarios. Long-term monitoring data on forest conditions should be publicly accessible and utilized to inform adaptive management

    Антикризисное управление

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    Учебно-методический комплекс (УМК) по учебной дисциплине «Ан-тикризисное управление» создан в соответствии с требованиями Положения об учебно-методическом комплексе на уровне высшего образования, утвер-жденного постановлением Министерства образования Республики Беларусь от 26.07.2011 № 167, предназначен для реализации содержания образова-тельной программы для обучающихся первой ступени высшего образования для студентов специальности 1-26 02-02 «Менеджмент». Содержание разделов УМК соответствует образовательному стандарту высшего образования данной специальности. Главная цель УМК – оказание методической помощи магистрантам в освоении и систематизации учебного материала в процессе обучения и под-готовки к аттестации по дисциплине «Антикризисное управление». УМК включает: 1. Теоретический раздел (конспект лекций, аннотированный перечень основных учебных и научно-практических изданий). 2. Практический раздел (тематика практических занятий по дисци-плине в соответствии с учебным планом и учебной программой). 3. Контроль работы обучающихся (материалы для текущей аттестации, позволяющие определить соответствие учебной деятельности обучающихся требованиям образовательного стандарта высшего образования и учебно-программной документации, в т.ч. вопросы для подготовки к зачету). 4. Вспомогательный раздел (содержание учебного материала учебной дисциплины; методические рекомендации по организации самостоятельной работы магистрантов; информационно-аналитические материалы: список ре-комендуемой литературы, перечень электронных ресурсов и их адреса; при-мерный перечень тем для написания рефератов). Работа с УМК должна включать на первом этапе ознакомление с со-держанием учебного материала учебной дисциплины, посредством которого можно получить информацию о тематике лекций и практических занятий, перечнях рассматриваемых вопросов и рекомендуемой для их изучения ли-тературы. Для подготовки к практическим занятиям необходимо использо-вать материалы, представленные в Теоретическом и Практическом разделах. В основу структуры программы легла учебная программа «Антикри-зисное управление» Белорусского государственного университета для выс-ших учебных заведений по специальности Э.01.03.00 «Экономика и управле-ния на предприятии» (регистрационный № ТД-182/баз.)

    Status and prospects for renewable energy using wood pellets from the southeastern United States

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    The ongoing debate about costs and benefits of wood-pellet based bioenergy production in the southeastern United States (SE USA) requires an understanding of the science and context influencing market decisions associated with its sustainability. Production of pellets has garnered much attention as US exports have grown from negligible amounts in the early 2000s to 4.6 million metric tonnes in 2015. Currently, 98% of these pellet exports are shipped to Europe to displace coal in power plants. We ask, 'How is the production of wood pellets in the SE USA affecting forest systems and the ecosystem services they provide?' To address this question, we review current forest conditions and the status of the wood products industry, how pellet production affects ecosystem services and biodiversity, and what methods are in place to monitor changes and protect vulnerable systems. Scientific studies provide evidence that wood pellets in the SE USA are a fraction of total forestry operations and can be produced while maintaining or improving forest ecosystem services. Ecosystem services are protected by the requirement to utilize loggers trained to apply scientifically based best management practices in planning and implementing harvest for the export market. Bioenergy markets supplement incomes to private rural landholders and provide an incentive for forest management practices that simultaneously benefit water quality and wildlife and reduce risk of fire and insect outbreaks. Bioenergy also increases the value of forest land to landowners, thereby decreasing likelihood of conversion to nonforest uses. Monitoring and evaluation are essential to verify that regulations and good practices are achieving goals and to enable timely responses if problems arise. Conducting rigorous research to understand how conditions change in response to management choices requires baseline data, monitoring, and appropriate reference scenarios. Long-term monitoring data on forest conditions should be publicly accessible and utilized to inform adaptive management

    Progression of Geographic Atrophy in Age-related Macular Degeneration

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