摘要 :
NIST produces large-format, dual-polarization-sensitive detector arrays for a broad range of frequencies (30-1400 GHz). Such arrays enable a host of astrophysical measurements. Detectors optimized for cosmic microwave background o...
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NIST produces large-format, dual-polarization-sensitive detector arrays for a broad range of frequencies (30-1400 GHz). Such arrays enable a host of astrophysical measurements. Detectors optimized for cosmic microwave background observations are monolithic, polarization-sensitive arrays based on feedhorn and planar Nb antenna-coupled transition-edge superconducting (TES) bolometers. Recent designs achieve multiband, polarimetric sensing within each spatial pixel. In this proceeding, we describe our multichroic, feedhorn-coupled design; demonstrate performance at 70-380 GHz; and comment on current developments for implementation of these detector arrays in the advanced Atacama Cosmology Telescope receiver
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摘要 :
ACTPol is the polarization-sensitive receiver on the Atacama Cosmology Telescope. ACTPol enables sensitive millimeter wavelength measurements of the temperature and polarization anisotropies of the Cosmic Microwave Background (CMB...
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ACTPol is the polarization-sensitive receiver on the Atacama Cosmology Telescope. ACTPol enables sensitive millimeter wavelength measurements of the temperature and polarization anisotropies of the Cosmic Microwave Background (CMB) at arcminute angular scales. These measurements are designed to explore the process of cosmic structure formation, constrain or determine the sum of the neutrino masses, probe dark energy, and provide a foundation for a host of other cosmological tests. We present an overview of the first season of ACTPol observations focusing on the optimization and calibration of the first detector array as well as detailing the on-sky performance.
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摘要 :
The purpose of this project is to develop a biological process for the production of liquid fuels from coal-derived synthesis gas feedstocks. A two-stage, anaerobic bioconversion process is proposed, where in the first stage the c...
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The purpose of this project is to develop a biological process for the production of liquid fuels from coal-derived synthesis gas feedstocks. A two-stage, anaerobic bioconversion process is proposed, where in the first stage the carbon monoxide (CO) gas is converted to butyric and acetic acids by the CO strain of Butyribacterium methylotrophicum. In the second state, these acids along with the hydrogen (H(sub 2)) gas are converted to butanol, ethanol, and acetone by an acid utilizing mutant of Clostridium acetobutylicum. During this third quarter, our efforts were focused on fermentation optimization studies for each stage of the process. Studies included batch fermentation to determine acid and alcohol tolerance of B. methylotrophicum, continuous fermentations with cell recycle to identify optimal conditions for production of butanol and butyrate by B. methylotrophicum, and optimization of pH and temperature for conversion of acids to alcohols by C. acetobutylicum. 5 figs., 11 tabs.
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