scholarly journals Low-Level Gas Proportional Counting in An Underground Laboratory

Radiocarbon ◽  
1980 ◽  
Vol 22 (2) ◽  
pp. 461-469 ◽  
Author(s):  
H H Loosli ◽  
Martin Heimann ◽  
Hans Oeschger
Keyword(s):  
Construction Material ◽  
Volume Effect ◽  
Underground Laboratory ◽  
Counting System ◽  
Low Level ◽  
Background Values ◽  
Selection Of ◽  
Gas Pressures

Results of measurements in an underground laboratory, 70m of water equivalent below surface, are given. Background values of proportional gas counters with volumes between 16cc and 1.5L are lower by a factor of 2—4.5 compared to the values in the previously used laboratory (7m w.e.). High counting gas pressures, up to 5 at CH4 and up to 36 at P-10, enable the use of relatively small counters with correspondingly small background contributions from the walls. A separation of the residual background into different components is attempted, distinguishing a pressure dependent volume effect and surface correlated contributions. It can be shown that the selection of radioactively pure counter construction material is very important for a good low level counting system.

Identification of Possible High Integrity Containers for Low-Level Nuclear Waste Disposal

1981 ◽  
Vol 6 ◽  
Author(s):  
Jeffrey D. Williams
Keyword(s):  
South Carolina ◽  
Structural Integrity ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Economic Factors ◽  
Burial Site ◽  
Low Level ◽  
High Integrity ◽  
Low Level Radioactive Waste ◽  
Selection Of

ABSTRACTIncreased concern by the State of South Carolina over the condition and capacity of the low-level radioactive waste burial site at Barnwell has prompted them to promulgate new regulations on waste burial containers. As of September 30, 1981, ion exchange resin and filter media waste with an activity of 1 μCi/cc or greater and with isotopes with halflives greater than five years disposed at Barnwell shall be solidified or confined in a “high integrity container”. The materials and designs of these containers are required to provide waste isolation from the environment for a period of 300 years and provide the structural integrity specified in 49 CFR 173.398(b). HITTMAN has been active in the design and development of containers suitable for this purpose with this paper detailing the analyses involved. Material selections were limited to stainless steel, fiberglass, and polyethylenes. Structural concerns focused on overpressure requirements, drop-testing requirements, and lifting capabilities. With a lifetime dose of up to 108 rads, the possibilities of radiation damage were considered. Preliminary selection of polyethylene was based on satisfactory resolution of these issues and economic factors.

Failed predation in Late Ordovician gastropods (Mollusca) from Manitoulin Island, Ontario, CanadaThis article is one of a selection of papers published in this Special Issue on the theme The dynamic reef and shelly communities of the Paleozoic. This Special is in honour of our colleague and friend Paul Copper.

2008 ◽  
Vol 45 (2) ◽  
pp. 231-241 ◽  
Author(s):  
Jan Ove R. Ebbestad ◽  
Christopher A. Stott
Keyword(s):  
Success Rate ◽  
Late Ordovician ◽  
Size Class ◽  
Low Energy ◽  
Special Issue ◽  
Georgian Bay ◽  
Low Level ◽  
Shell Repair ◽  
Number Of Individuals ◽  
Selection Of

Shell repairs resulting from presumed failed predation are documented in gastropods from the Late Ordovician (Cincinnatian; Richmondian) mid-to-upper Kagawong Submember of the Georgian Bay Formation on Manitoulin Island, Ontario, Canada. The bryozoan–mollusc biota and associated sediments generally suggest nearshore, shallow (<10 m), low energy (lagoonal), and perhaps mesotrophic to eutrophic conditions. Two sample sets from this unit have been studied for shell repair. One of the more commonly applied estimates of shell repair frequencies involves division of the number of individuals with at least one scar by the total number of individuals in the sample (the Individuals with scars method). Using this calculation, 207 specimens of Lophospira trilineata Ulrich and Scofield yielded a shell repair frequency of 4.8%; in 28 specimens of Trochonemella sp. the shell repair frequency was 35.7%. Repairs in Trochonemella occur primarily in the larger size class, suggesting that a size refuge was achieved by this species. Low repair frequencies in L. trilineata suggest predation with a higher success rate or fewer encounters. This study demonstrates that the paradigm of a standardized low level of shell repair in Ordovician and Silurian gastropods is oversimplistic and a range of frequency rates can be expected.

Rapid determination of Sr-89/Sr-90 in radwaste by low-level background beta counting system

1994 ◽  
Vol 45 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Chu-Fang Wang ◽  
Jeng-Horng Lee ◽  
Horng-Jye Chiou
Keyword(s):  
Rapid Determination ◽  
Counting System ◽  
Low Level ◽  
Beta Counting

Improvements of a low-level gamma-ray spectrometry system at the underground laboratory “UDO”

2009 ◽  
Vol 67 (5) ◽  
pp. 726-730 ◽  
Author(s):  
S. Neumaier ◽  
M. Wojcik ◽  
H. Dombrowski ◽  
D. Arnold
Keyword(s):  
Gamma Ray ◽  
Underground Laboratory ◽  
Gamma Ray Spectrometry ◽  
Low Level

scholarly journals Material Origins of Accelerated Operational Wear of RD-33 Engine Blades

2020 ◽  
Author(s):  
Adam Kozakiewicz ◽  
Stanislaw Jóźwiak ◽  
Przemysław Jóźwiak ◽  
Stanisław Kachel
Keyword(s):  
Chemical Composition ◽  
Construction Material ◽  
Operating Conditions ◽  
Design Stage ◽  
Strength Analysis ◽  
Jet Engine ◽  
Emergency Situations ◽  
Low Pressure Turbine ◽  
Propulsion Unit ◽  
Selection Of

The structural and strength analysis of the material used to construct such an important engine element as the turbine is of great significance, both at the design stage as well as during tests and expertises related to emergency situations. Bearing in mind the conditions above mentioned, the paper presents the results of research on the chemical composition, morphology and phased structure of the metallic construction material used to produce the blades of the high and low pressure turbine of the RD-33 jet engine, which is the propulsion unit of the MiG-29 aircraft. The data obtained as a result of the material tests of the blades allowed, on the basis of the analysis of chemical composition and phased structure, to determine the grade of the alloy used to construct the tested elements of the jet engine turbine. The structural stability of the material was found to be lower in comparison with engine operating conditions, which manifested itself as a clear decrease in the resistance properties of the blade material. The results obtained can be used as a basis for analyzing the life span of an object or a selection of material replacements, which enable to produce the analyzed engine element.

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