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Robotics for waste storage inspection: A user`s perspective (open access)

Robotics for waste storage inspection: A user`s perspective

Self-navigating robotic vehicles are now commercially available, and the technology supporting other important system components has also matured. Higher reliability and the obtainability of system support now make it practical to consider robotics as a way of addressing the growing operational requirement for the periodic inspection and maintenance of radioactive, hazardous, and mixed waste inventories. This paper describes preparations for the first field deployment of an autonomous container inspection robot at a Department of Energy (DOE) site. The Stored Waste Autonomous Mobile Inspector (SWAMI) is presently being completed by engineers at the Savannah River Technology Center (SRTC). It is a modified version of a commercially available robot. It has been outfitted with sensor suites and cognition that allow it to perform inspections of drum inventories and their storage facilities.
Date: June 23, 1994
Creator: Hazen, F. B.
System: The UNT Digital Library
Application of x-rays lasers as imaging and plasma diagnostics (open access)

Application of x-rays lasers as imaging and plasma diagnostics

This report describes utilization of multilayer mirrors and beam splitters to develop x-ray laser interferometry, radiography, and deflectometry to probe high-density laser plasmas.
Date: March 23, 1994
Creator: Wan, A. S.; Da Silva, L. B. & Barbee, T. W.
System: The UNT Digital Library
A high-power switch-mode dc power supply for dynamic loads (open access)

A high-power switch-mode dc power supply for dynamic loads

High-voltage dc power supplies are often required to operate with highly dynamic loads, such as arcs. A switch-mode dc power supply can offer significant advantages over conventional thyristor-based dc power supplies under such conditions. It can quickly turn off the supply to extinguish the arc, and it can quickly recover after the arc. It has a relatively small output filter capacitance, which results in small stored energy available to the arc. A 400-kW, 50-kV switch-mode dc power supply for an electron-beam gun that exploits these advantages was designed and tested. It uses four 100-kW, current-source-type dc-dc converters with inputs in parallel and outputs in series. The dc-dc converters operate at 20 kHz in the voltage regulator part and 10 kHz in the inverter, transformer, and output rectifier part of the circuit. Insulated gate bipolar transistors (IGBTs) are used as the power switches. Special techniques are used to protect the power supply and load against arcs and hard shorts. The power supply has an efficiency of 93%, an output voltage ripple of 1%, and fast dynamic response. In addition, it is nearly one-third the size of conventional power supplies.
Date: June 23, 1994
Creator: Shimer, D. W.; Lange, A. C. & Bombay, J. N.
System: The UNT Digital Library
Cosmic Bombardment IV: Averting catastrophe in the here-and-now (open access)

Cosmic Bombardment IV: Averting catastrophe in the here-and-now

At the present time, it is at least arguable that large-scale cosmic bombardment has been a major driver of the evolution of the terrestrialbiosphere. The fundamental motivation of the present paper is the (high) likelihood that the advent and rise of the human species hasn`t coincided with the cessation of soft and hard collisions in the Asteroid Belt or in the Oort Cloud, and that we will either stop the cosmic bombardment or it will eventually stop us. In the foregoing, briefly reviewed the prospects for active planetary defenses against cosmic bombardment in the very near-term, employing only technologies which exist now and could be brought-to-bear in a defensive system on a one-decade time-scale. We sketch various means and mechanisms from a physicist`s viewpoint by which such defensive systems might detect threat objects, launch interdiction machinery toward them and operate such machinery in their vicinity to alternately deflect, disperse or vaporize objects in the 0.1-10 km-diameter range, the ones whose size and population constitute the greatest threats to our biosphere. We conclude that active defenses of all types are readily feasible against 0.1 kmdiameter incoming cosmic bomblets and that even complete vaporization-class defenses are feasible against 1 km-diameter class objects …
Date: September 23, 1994
Creator: Wood, L.; Hyde, R.; Ishikawa, M. & Ledebuhr, A.
System: The UNT Digital Library
Lithium intercalation in porous carbon anodes (open access)

Lithium intercalation in porous carbon anodes

Carbon foams derived from the phase separation of polyacrylonitrile/solvent mixtures were investigated as lithium intercalation anodes for rechargeable lithium-ion batteries. The carbon foams have a bulk density of 0.35--0.5 g/cm{sup 3}, low surface area (< 50 m{sup 2}/g), and an average cell size of 5--10 {mu}m. Polyacrylonitrile-based carbon foams doped with phosphoric acid had capacity as high as 450 mAh/g. Carbon capacity increased with increasing phosphoric acid concentration in the doping solution. The doped porous carbon anodes exhibited good cyclability and excellent coulombic efficiency.
Date: November 23, 1994
Creator: Tran, T. D.; Pekala, R. W. & Mayer, S. T.
System: The UNT Digital Library