Benchmark field study of deep neutron penetration (open access)

Benchmark field study of deep neutron penetration

A unique benchmark neutron field has been established at the Lawrence Livermore National Laboratory (LLNL) to study deep penetration neutron transport. At LLNL, a tandem accelerator is used to generate a monoenergetic neutron source that permits investigation of deep neutron penetration under conditions that are virtually ideal to model, namely the transport of mono-energetic neutrons through a single material in a simple geometry. General features of the Lawrence Tandem (LATAN) benchmark field are described with emphasis on neutron source characteristics and room return background. The single material chosen for the first benchmark, LATAN-1, is a steel representative of Light Water Reactor (LWR) Pressure Vessels (PV). Also included is a brief description of the Little Boy replica, a critical reactor assembly designed to mimic the radiation doses from the atomic bomb dropped on Hiroshima, and its us in neutron spectrometry. 18 refs.
Date: June 10, 1991
Creator: Morgan, J. F.; Sale, K. (Lawrence Livermore National Lab., CA (USA) ); Gold, R.; Roberts, J. H. & Preston, C. C. (Metrology Control Corp., Richland, WA (USA) )
Object Type: Article
System: The UNT Digital Library
Chasing the x sub f dependence of J/. Psi. production (open access)

Chasing the x sub f dependence of J/. Psi. production

We discuss the combined effects of hard scattering processes and intrinsic heavy-quark components in the hadron wavefunction on the x{sub f} dependence of J/{psi} production. The A dependence arises from nuclear absorption, comover interactions, shadowing of parton distributions, and intrinsic heavy quarks. 9 refs., 1 fig.
Date: June 10, 1991
Creator: Vogt, R.
Object Type: Article
System: The UNT Digital Library
Novel macrocyclic carriers for proton-coupled liquid membrane transport (open access)

Novel macrocyclic carriers for proton-coupled liquid membrane transport

The objective of our research program is to elucidate the chemical principles which are responsible for the cation selectivity and permeability of liquid membranes containing macrocyclic carriers. Several new macrocyclic carriers were synthesized during the last three year period, including selenium-containing macrocycles, new crown-4 structures, and several new crown structures containing nitrogen based heterocycles as substituents in the principal macrocyclic ring. The cation binding properties of these macrocycles were investigated by potentiometric titration, calorimetric titration, solvent extraction, and NMR techniques. In addition, hydrophobic macrocycles were incorporated into dual hollow fiber membrane systems to investigate their membrane performance, especially in the proton-coupled transport mode. It was found that the dual hollow fiber system maintains the cation selectivity and permeability of supported liquid membranes, while enhancing membrane stability. The diffusion limited transport model was expanded to account for membrane solvent effects. Furthermore, Eu{sup 2+} transport was found to be similar to that of strontium and much higher than that of the lanthanides, in supported liquid membrane systems.
Date: June 10, 1991
Creator: Lamb, J.D.
Object Type: Report
System: The UNT Digital Library
Phytochrome from green plants: Assay, purification, and characterization (open access)

Phytochrome from green plants: Assay, purification, and characterization

This funding period was directed at developing an in-depth molecular analysis of the low-abundance, 118,000 M{sub r} green-tissue phytochrome that had at that time been relatively recently identified as being distinct from the better characterized 124,000 M{sub r} phytochrome abundant in etiolated tissue. The specific objectives as stated in the original proposal were: (1) To generate monoclonal antibodies specific to the 118,000 M{sub r} green-tissue phytochrome. (2) To develop additional and improved procedures to permit progress toward the ultimate goal of purifying green-tissue phytochrome to homogeneity. (3) To initiate an alternative approach to determining the structural properties of green-tissue phytochrome by isolating and sequencing cDNA cones representing the 118,000 M{sub r} green-tissue polypeptide in Avena. This approach is based on and will test hypothesis that the 118,000 M{sub r} polypeptide is encoded by a gene(s) distinct from those encoding etiolated-tissue 124,000 M{sub r} phytochrome. (4) To utilize any such 118,000 M{sub r} phytochrome specific cDNA clones as hybridization probes to begin to investigate the structure, organization, and regulation of the corresponding gene(s) in Avena. (5) To begin to investigate the possible presence in other higher plant and algal species of sequences homologous to the 118,000 M{sub r} Avena polypeptide using …
Date: June 10, 1991
Creator: Quail, P.H. (California Univ., Berkeley, CA (United States). Dept. of Plant and Soil Biology Agricultural Research Service, Albany, CA (United States). Plant Gene Expression Center)
Object Type: Report
System: The UNT Digital Library
Novel macrocyclic carriers for proton-coupled liquid membrane transport. Progress report, 1 December 1988--31 May 1991 (open access)

Novel macrocyclic carriers for proton-coupled liquid membrane transport. Progress report, 1 December 1988--31 May 1991

The objective of our research program is to elucidate the chemical principles which are responsible for the cation selectivity and permeability of liquid membranes containing macrocyclic carriers. Several new macrocyclic carriers were synthesized during the last three year period, including selenium-containing macrocycles, new crown-4 structures, and several new crown structures containing nitrogen based heterocycles as substituents in the principal macrocyclic ring. The cation binding properties of these macrocycles were investigated by potentiometric titration, calorimetric titration, solvent extraction, and NMR techniques. In addition, hydrophobic macrocycles were incorporated into dual hollow fiber membrane systems to investigate their membrane performance, especially in the proton-coupled transport mode. It was found that the dual hollow fiber system maintains the cation selectivity and permeability of supported liquid membranes, while enhancing membrane stability. The diffusion limited transport model was expanded to account for membrane solvent effects. Furthermore, Eu{sup 2+} transport was found to be similar to that of strontium and much higher than that of the lanthanides, in supported liquid membrane systems.
Date: June 10, 1991
Creator: Lamb, J. D.
Object Type: Report
System: The UNT Digital Library
Radiation Studies in the Antiproton Source (open access)

Radiation Studies in the Antiproton Source

Experiment E760 has a lead glass (Pb-G) calorimeter situated in the antiproton source tunnel in the accumulator ring at location A50. This location is exposed to radiation from several sources during antiproton stacking operations. A series of radiation studies has been performed over the last two years to determine the sources of this radiation and as a result, some shielding has been installed in the antiproton source in order to protect the lead glass from radiation damage.
Date: June 10, 1991
Creator: Church, Mike
Object Type: Report
System: The UNT Digital Library
Historical river flow rates for dose calculations (open access)

Historical river flow rates for dose calculations

Annual average river flow rates are required input to the LADTAP Computer Code for calculating offsite doses from liquid releases of radioactive materials to the Savannah River. The source of information on annual river flow rates used in dose calculations varies, depending on whether calculations are for retrospective releases or prospective releases. Examples of these types of releases are: Retrospective - releases from routine operations (annual environmental reports) and short term release incidents that have occurred. Prospective - releases that might be expected in the future from routine or abnormal operation of existing or new facilities (EIS`s, EID`S, SAR`S, etc.). This memorandum provides historical flow rates at the downstream gauging station at Highway 301 for use in retrospective dose calculations and derives flow rate data for the Beaufort-Jasper and Port Wentworth water treatment plants.
Date: June 10, 1991
Creator: Carlton, W. H.
Object Type: Report
System: The UNT Digital Library