6,967 research outputs found
The Land Shall Be Deluged in Blood: A New History of the Nat Turner Revolt
The Nat Turner uprising in Virginia in August 1831 was, in its consequences if not in the actual numbers involved, the most significant slave revolt in U.S. history. As Patrick Breen writes in his new study, it contributed mightily to the radicalization of American politics
UCD Candidates in the Hydra Cluster
NGC 3311, the giant cD galaxy in the Hydra cluster (A1060), has one of the
largest globular cluster systems known. We describe new Gemini GMOS (g',i')
photometry of the NGC 3311 field which reveals that the red, metal-rich side of
its globular cluster population extends smoothly upward into the mass range
associated with the new class of Ultra-Compact Dwarfs (UCDs). We identify 29
UCD candidates with estimated masses > 6x10^6 solar masses and discuss their
characteristics. This UCD-like sequence is the most well defined one yet seen,
and reinforces current ideas that the high-mass end of the globular cluster
sequence merges continuously into the UCD sequence, which connects in turn to
the E galaxy structural sequence.Comment: 5 pages, 3 figures. Accepted for publication in ApJ Letter
An analysis of depot level repairables carcass management and position controls under the Advanced Traceability and Control (ATAC) program
Repairables are components andor sub assemblies which can be repaired if they become unserviceable. Repairables are typically high cost, long procurement leadtime items. Because of these characteristics, significant economies can be achieved by repairing these items rather than discarding them when they become unserviceable. Historically, these carcasses have been difficult to manage because, when they broke, maintenance personnel were primarily concerned with replacing them with ready-for-issue units; what happened to the carcass was of little concern. Defense Management Review Decision (DMRD) 901's objective to reduce supply system costs includes an initiative to achieve savings by retaining retrograde carcasses returned from the fleet at the first turn-in point rather than shipping them immediately to the repair depot or designated storage site. This thesis analyzes the operation of the ATAC Program to determine a 'ship or hold' decision for returned carcasses. A thorough study of ATAC's background, current management controls and operating procedures, and results from previous studies were combined with on-site hub observations to show how and why the ATAC system works. Because of ATAC, the DMRD 901 initiative to retain carcasses at their first turn-in point is not cost effective except for those items experiencing rapid phase-out or numerous upgrades. Detailed indicators to measure and monitor ATAC cost and performance effectiveness need to be implemented.http://archive.org/details/annalysisofdepot1094527594Lieutenant Commander, United States NavyLieutenant, United States NavyApproved for public release; distribution is unlimited
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