PLASMA WINDOW FOR VACUUM - ATMOSPHERE INTERFACE AND FOCUSING LENS OF SOURCES FOR NON-VACUUM MATERIAL MODIFICATION. (open access)

PLASMA WINDOW FOR VACUUM - ATMOSPHERE INTERFACE AND FOCUSING LENS OF SOURCES FOR NON-VACUUM MATERIAL MODIFICATION.

Material modifications by ion implantation, dry etching, and micro-fabrication are widely used technologies, all of which are performed in vacuum, since ion beams at energies used in these applications are completely attenuated by foils or by long differentially pumped sections, which ate currently used to interface between vacuum and atmosphere. A novel plasma window, which utilizes a short arc for vacuum-atmosphere interface has been developed. This window provides for sufficient vacuum atmosphere separation, as well as for ion beam propagation through it, thus facilitating non-vacuum ion material modification.
Date: September 7, 1997
Creator: Hershcovitch, A.
Object Type: Article
System: The UNT Digital Library
Implementing RCRA during facility deactivation (open access)

Implementing RCRA during facility deactivation

RCRA regulations require closure of permitted treatment, storage and disposal (TSD) facilities within 180 days after cessation of operations, and this may essentially necessitate decommissioning to complete closure. A more cost effective way to handle the facility would be to significantly reduce the risk to human health and the environment by taking it from its operational status to a passive, safe, inexpensive-to-maintain surveillance and maintenance condition (deactivation) prior to decommissioning. This paper presents an innovative approach to the cost effective deactivation of a large, complex chemical processing facility permitted under RCRA. The approach takes into account risks to the environment posed by this facility in comparison to risks posed by neighboring facilities at the site. The paper addresses the manner in which: 1) stakeholders and regulators were involved; 2) identifies a process by which the project proceeds and regulators and stakeholders were involved; 3) end points were developed so completion of deactivation was clearly identified at the beginning of the project, and 4) innovative practices were used to deactivate more quickly and cost effectively.
Date: September 7, 1997
Creator: Lebaron, G.J.
Object Type: Article
System: The UNT Digital Library
A study of multistage/multifunction column for fine particle seperation (open access)

A study of multistage/multifunction column for fine particle seperation

The objective if this program is to explore the potential application of a multistage column equipped with concentric draft- tubes (multistage column) for fine coal cleaning. The aim is to identify design parameters of the separation process. In the last quarter we conducted the gas holdup measurement which is an essential part of the hydrodynamic experiments for establishing a process model for engineering design and scale-up.
Date: September 7, 1997
Creator: Chiang, S.
Object Type: Report
System: The UNT Digital Library
Status of solubility data for selected elements (U, Mp, Pu, Am, Te, Ni, and Zr) (open access)

Status of solubility data for selected elements (U, Mp, Pu, Am, Te, Ni, and Zr)

This report is an evaluation of solubility data for U, Np, Pu, Am, Tc, Ni and Zr compounds at ambient and elevated temperatures. We review the status of such data in light of the most recently reported experimental results. The focus is on the solid phases that may control solubilities under expected conditions in and near a potential nuclear waste repository at Yucca Mountain, Nevada. Solubility data or reliable predictions over the temperature range 20 to 150{degrees}C will be used in geochemical modeling studies of the Yucca Mountain Project [96PAL].
Date: September 7, 1997
Creator: Moll, H.; Brachmann, A.; Wruck, D. & Palmer, C.
Object Type: Report
System: The UNT Digital Library