43 research outputs found

    Изучение электрохимического поведения иридия (+4) методом полярографии с накоплением

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    Целью нашей работы было выяснить возможность применения метода пленочной полярографии с накоплением (ППН) для определения микрограммовых количеств ирридия. В литературе подобные исследования не описаны. Пики анодного электрорастворения иридия при потенциалах +0,7 отн. нас, к. э. с поверхности графитового электрода, полученные на фоне 1 м НСl с добавлением ионов ртути, имеют удобную для измерений форму и линейно растут с увеличением концентрации ионов иридия в исследуемом растворе, что позволяет применять метод ППН для определения иридия в интервале изученных концентраций 0,0000001-0,00001 моль/л

    Innovation in airport design

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    This article discusses the issue of innovation in airport design which is supported by aviation project management. This is why the decision making process on innovation in an airport’s design should correlate with future perspectives in aviation. This process influences a decrease in time and money lost during the period of leading an aviation project. A good result is obtained through selected essential information and analysis of the airport management process in order to achieve efficiency in aircraft operation. What is more, the innovation in airport design is closely related with the safety of aircraft and security of passengers

    Detectors for the James Webb Space Telescope Near-Infrared Spectrograph I: Readout Mode, Noise Model, and Calibration Considerations

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    We describe how the James Webb Space Telescope (JWST) Near-Infrared Spectrograph's (NIRSpec's) detectors will be read out, and present a model of how noise scales with the number of multiple non-destructive reads sampling-up-the-ramp. We believe that this noise model, which is validated using real and simulated test data, is applicable to most astronomical near-infrared instruments. We describe some non-ideal behaviors that have been observed in engineering grade NIRSpec detectors, and demonstrate that they are unlikely to affect NIRSpec sensitivity, operations, or calibration. These include a HAWAII-2RG reset anomaly and random telegraph noise (RTN). Using real test data, we show that the reset anomaly is: (1) very nearly noiseless and (2) can be easily calibrated out. Likewise, we show that large-amplitude RTN affects only a small and fixed population of pixels. It can therefore be tracked using standard pixel operability maps.Comment: 55 pages, 10 figure

    JWST Near-Infrared Detectors: Latest Test Results

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    The James Webb Space Telescope, an infrared-optimized space telescope being developed by NASA for launch in 2013, will utilize cutting-edge detector technology in its investigation of fundamental questions in astrophysics. JWST's near infrared spectrograph, NIRSpec utilizes two 2048 x 2048 HdCdTe arrays with Sidecar ASIC readout electronics developed by Teledyne to provide spectral coverage from 0.6 microns to 5 microns. We present recent test and calibration results for the NIRSpec flight arrays as well as data processing routines for noise reduction and cosmic ray rejection

    Detector Arrays for the James Webb Space Telescope Near-Infrared Spectrograph

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    The James Webb Space Telescope's (JWST) Near Infrared Spectrograph (NIRSpec) incorporates two 5 micron cutoff (lambda(sub co) = 5 microns) 2048x2048 pixel Teledyne HgCdTe HAWAII-2RG sensor chip assemblies. These detector arrays, and the two Teledyne SIDECAR application specific integrated circuits that control them, are operated in space at T approx. 37 K. In this article, we provide a brief introduction to NIRSpec, its detector subsystem (DS), detector readout in the space radiation environment, and present a snapshot of the developmental status of the NIRSpec DS as integration and testing of the engineering test unit begins

    Detectors for the James Webb Space Telescope Near-Infrared Spectrograph I: Readout Mode, Noise Model, and Calibration Considerations

    Get PDF
    We describe how the James Webb Space Telescope (JWST) Near-Infrared Spectrograph's (NIRSpec's) detectors will be read out, and present a model of how noise scales with the number of multiple non-destructive reads sampling-up-the-ramp. We believe that this noise model, which is validated using real and simulated test data, is applicable to most astronomical near-infrared instruments. We describe some non-ideal behaviors that have been observed in engineering grade NIRSpec detectors, and demonstrate that they are unlikely to affect NIRSpec sensitivity, operations, or calibration. These include a HAWAII-2RG reset anomaly and random telegraph noise (RTN). Using real test data, we show that the reset anomaly is: (1) very nearly noiseless and (2) can be easily calibrated out. Likewise, we show that RTN affects only a small and fixed population of pixels. It can therefore be tracked using standard pixel operability maps

    James Webb Space Telescope Near-Infrared Spectrograph: Dark Performance of the First Flight Candidate Detector Arrays

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    The James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec) incorporates two 5 micron cutoff (lambda(sub co) = 5 micron) 2048x2048 pixel Teledyne HgCdTe HAWAII-2RG sensor chip assemblies. These detector arrays, and the two Teledyne SIDECAR application specific integrated circuits that control them, are operated in space at T approx. 37 K. This article focuses on the measured performance of the first flight-candidate, and near-flight candidate, detector arrays. These are the first flight-packaged detector arrays that meet NIRSpec's challenging 6 e(-) rms total noise requirement

    Cause of Cambrian Explosion - Terrestrial or Cosmic?

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    We review the salient evidence consistent with or predicted by the Hoyle-Wickramasinghe (H-W) thesis of Cometary (Cosmic) Biology. Much of this physical and biological evidence is multifactorial. One particular focus are the recent studies which date the emergence of the complex retroviruses of vertebrate lines at or just before the Cambrian Explosion of ∼500 Ma. Such viruses are known to be plausibly associated with major evolutionary genomic processes. We believe this coincidence is not fortuitous but is consistent with a key prediction of H-W theory whereby major extinction-diversification evolutionary boundaries coincide with virus-bearing cometary-bolide bombardment events. A second focus is the remarkable evolution of intelligent complexity (Cephalopods) culminating in the emergence of the Octopus. A third focus concerns the micro-organism fossil evidence contained within meteorites as well as the detection in the upper atmosphere of apparent incoming life-bearing particles from space. In our view the totality of the multifactorial data and critical analyses assembled by Fred Hoyle, Chandra Wickramasinghe and their many colleagues since the 1960s leads to a very plausible conclusion - life may have been seeded here on Earth by life-bearing comets as soon as conditions on Earth allowed it to flourish (about or just before 4.1 Billion years ago); and living organisms such as space-resistant and space-hardy bacteria, viruses, more complex eukaryotic cells, fertilised ova and seeds have been continuously delivered ever since to Earth so being one important driver of further terrestrial evolution which has resulted in considerable genetic diversity and which has led to the emergence of mankind

    Large malignant phyllodes tumor of the breast with metastases to the lungs

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    Phyllodes tumors of the breast account for less than 0.5% of breast cancers and present most commonly in women 45 to 49 years old. The importance in managing fibroepithelial lesions lies in distinguishing fibroadenomas, which are benign, from phyllodes tumors, which can be malignant and require complete surgical excision. We report the case of a 56-year-old female who presented with a rapidly enlarging mass in her right breast 18 cm in maximum dimension that completely effaced the breast and distorted the nipple. The patient underwent a successful total mastectomy after core biopsy revealed a diagnosis of phyllodes tumor. Surgical resection is the primary treatment modality; neoadjuvant and adjuvant therapies remain controversial. Here, we report the case of a large malignant phyllodes tumor metastatic to the lungs, review the literature, and discuss diagnostic modalities and adjunct nonsurgical therapies
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