352 research outputs found

    Evaluasi Kinerja Bangunan Berlubang Dengan Metode Direct Displacement-based Design

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    Banyak penelitian mengenai kinerja Direct Displacement Based Design (DDBD) dan Force Based Design (FBD) telah dilakukan sebelumnya. Penelitian-penelitian sebelumnya menunjukkan bahwa DDBD menghasilkan performa struktur yang lebih mendekati target desain. Namun, penelitian terhadap bangunan berlubang belum pernah dilakukan sebelumnya. Konfigurasi struktur dengan void memiliki kekakuan portal yang bervariasi diaman hal ini mempengaruhi distribusi gaya pada setiap portal. Distribusi gaya pada bagian yang memiliki void akan mengalami perpindahan yang lebih besar daripada bagian yang tidak memiliki void khususnya jika pelat lantai diasumsikan semi rigid. Penelitian ini membandingkan kinerja FBD dan DDBD pada bangunan yang didesain berlubang atau memiliki void dengan asumsi desain bangunan tanpa lubang dan gaya geser dasar didistribusikan secara merata. Penelitian akan dievaluasi terhadap wilayah beresiko gempa tinggi dan rendah di Indonesia. Struktur yang didesain diuji dengan analisis non-linear dinamis time history. Hasil dari penelitian ini menunjukkan bahwa struktur bangunan yang didesain dengan DDBD memberikan kinerja yang lebih baik daripada FBD baik dalam drift ratio ataupun failure mechanism. Selain itu, prosedur DDBD lebih efektif dan efisien karena hasil desain mendekati target desain dan durasi desain sangat singkat. Satu-satunya kelemahan dari DDBD adalah biaya yang lebih mahal karena hasil desain yang menggunakan lebih banyak materia

    Performance Testing of a Novel Off-plane Reflection Grating and Silicon Pore Optic Spectrograph at PANTER

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    An X-ray spectrograph consisting of radially ruled off-plane reflection gratings and silicon pore optics was tested at the Max Planck Institute for extraterrestrial Physics PANTER X-ray test facility. The silicon pore optic (SPO) stack used is a test module for the Arcus small explorer mission, which will also feature aligned off-plane reflection gratings. This test is the first time two off-plane gratings were actively aligned to each other and with a SPO to produce an overlapped spectrum. The gratings were aligned using an active alignment module which allows for the independent manipulation of subsequent gratings to a reference grating in three degrees of freedom using picomotor actuators which are controllable external to the test chamber. We report the line spread functions of the spectrograph and the actively aligned gratings, and plans for future development.Comment: Draft Version March 19, 201

    Performance Testing of a Large-Format Reflection Grating Prototype for a Suborbital Rocket Payload

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    The soft X-ray grating spectrometer on board the Off-plane Grating Rocket Experiment (OGRE) hopes to achieve the highest resolution soft X-ray spectrum of an astrophysical object when it is launched via suborbital rocket. Paramount to the success of the spectrometer are the performance of the >250>250 reflection gratings populating its reflection grating assembly. To test current grating fabrication capabilities, a grating prototype for the payload was fabricated via electron-beam lithography at The Pennsylvania State University's Materials Research Institute and was subsequently tested for performance at Max Planck Institute for Extraterrestrial Physics' PANTER X-ray Test Facility. Bayesian modeling of the resulting data via Markov chain Monte Carlo (MCMC) sampling indicated that the grating achieved the OGRE single-grating resolution requirement of Rg(λ/Δλ)>4500R_{g}(\lambda/\Delta\lambda)>4500 at the 94% confidence level. The resulting RgR_g posterior probability distribution suggests that this confidence level is likely a conservative estimate though, since only a finite RgR_g parameter space was sampled and the model could not constrain the upper bound of RgR_g to less than infinity. Raytrace simulations of the system found that the observed data can be reproduced with a grating performing at Rg=R_g=\infty. It is therefore postulated that the behavior of the obtained RgR_g posterior probability distribution can be explained by a finite measurement limit of the system and not a finite limit on RgR_g. Implications of these results and improvements to the test setup are discussed.Comment: 25 pages, 16 figures, preprint of an article accepted for publication in the Journal of Astronomical Instrumentation \copyright 2020 [copyright World Scientific Publishing Company] [https://www.worldscientific.com/worldscinet/jai

    'Reaching the hard to reach' - lessons learned from the VCS (voluntary and community Sector). A qualitative study.

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    Background The notion 'hard to reach' is a contested and ambiguous term that is commonly used within the spheres of social care and health, especially in discourse around health and social inequalities. There is a need to address health inequalities and to engage in services the marginalized and socially excluded sectors of society. Methods This paper describes a pilot study involving interviews with representatives from eight Voluntary and Community Sector (VCS) organisations . The purpose of the study was to explore the notion of 'hard to reach' and perceptions of the barriers and facilitators to accessing services for 'hard to reach' groups from a voluntary and community sector perspective. Results The 'hard to reach' may include drug users, people living with HIV, people from sexual minority communities, asylum seekers, refugees, people from black and ethnic minority communities, and homeless people although defining the notion of the 'hard to reach' is not straight forward. It may be that certain groups resist engaging in treatment services and are deemed hard to reach by a particular service or from a societal stance. There are a number of potential barriers for people who may try and access services, including people having bad experiences in the past; location and opening times of services and how services are funded and managed. A number of areas of commonality are found in terms of how access to services for 'hard to reach' individuals and groups could be improved including: respectful treatment of service users, establishing trust with service users, offering service flexibility, partnership working with other organisations and harnessing service user involvement. Conclusions: If health services are to engage with groups that are deemed 'hard to reach' and marginalised from mainstream health services, the experiences and practices for engagement from within the VCS may serve as useful lessons for service improvement for statutory health services

    Optical design of the Off-plane Grating Rocket Experiment

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    The Off-plane Grating Rocket Experiment (OGRE) is a soft X-ray spectroscopy suborbital rocket payload scheduled for launch in Q3 2020 from Wallops Flight Facility. The payload will serve as a testbed for several key technologies which can help achieve the desired performance increases for the next generation of X-ray spectrographs and other space-based missions: monocrystalline silicon X-ray mirrors developed at NASA Goddard Space Flight Center, reflection gratings manufactured at The Pennsylvania State University, and electron-multiplying CCDs developed by the Open University and XCAM Ltd. With these three technologies, OGRE hopes to obtain the highest-resolution on-sky soft X-ray spectrum to date. We discuss the optical design of the OGRE payload

    The Off-plane Grating Rocket Experiment (OGRE) system overview

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    The Off-plane Grating Rocket Experiment (OGRE) is a sub-orbital rocket payload that will make the highest spectral resolution astronomical observation of the soft X-ray Universe to date. Capella, OGRE’s science target, has a well-defined line emission spectrum and is frequently used as a calibration source for X-ray observatories such as Chandra. This makes Capella an excellent target to test the technologies on OGRE, many of which have not previously flown. Through the use of state-of-the-art X-ray optics, co-aligned arrays of off-plane reflection gratings, and an X-ray camera based around four Electron Multiplying CCDs, OGRE will act as a proving ground for next generation X-ray spectrometers
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