L A Currie
Dados Biográficos
| ID | 5597703 |
|---|---|
| NOME | L A Currie |
| PRENOMES | L A |
| SOBRENOME | Currie |
| ASSINATURA | CURRIE L A |
| VERIFICADO | Não |
| TOTAL DE OBRAS | 10 |
| TOTAL DE CITAÇÕES | 19 |
| TOTAL COMO AUTOR | 10 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 1963 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2000 |
| ÍNDICE H | 3 |
Evolution and Multidisciplinary Frontiers of 14 C Aerosol Science
A review is given of some critical events in the development of radiocarbon aerosol science, and the profound influence of radiocarbon accelerator mass spectrometry (AMS) on its current applications and future prospects. The birth of this discipline occurred shortly after the initial development of 14 C dating. Unlike dating, which is founded on the continual decay of 14 C and the resulting full range of 14 C/ 12 C ratios in once-living matter, 1…
On the Validity of the Poisson Hypothesis for Low-Level Counting
Does radioactive decay follow the Poisson distribution?—a fundamental question, to which the theoretical answer seems to be, Yes. On the practical side, the answer to this question impacts the best achievable precision in well-controlled counting experiments. There have been some noteworthy experimental tests of the Poisson assumption, using systems carefully designed for the analysis of individual pulses from stable radioactive sources; thus far…
The Pursuit of Isotopic and Molecular Fire Tracers in the Polar Atmosphere and Cryosphere
We present an overview of recent multidisciplinary, multi-institutional efforts to identify and date major sources of combustion aerosol in the current and paleoatmospheres. The work was stimulated, in part, by an atmospheric particle “sample of opportunity” collected at Summit, Greenland in August 1994, that bore the 14 C imprint of biomass burning. During the summer field seasons of 1995 and 1996, we collected air filter, surface snow and snowp…
AMS and Microprobe Analysis of Combusted Particles in Ice and Snow
Ice cores and snow pits of the cryosphere contain particles that detail the history of past atmospheric air compositions. Some of these particles result from combustion processes and have undergone long-range transport to arrive in the Arctic. Recent research has focused on the separation of particulate matter from ice and snow, as well as the subsequent analysis of the separated particles for 14 C with accelerator mass spectrometry (AMS) and for…
Urban Atmospheric 14 CO and 14 CH 4 Measurements by Accelerator Mass Spectrometry
Atmospheric gas samples (0.1m 3 ) were collected at ground level during January/February 1984 in Las Vegas, Nevada for 14 C/ 13 C accelerator mass spectrometry and total abundance measurements of CO and CH 4 . During winter months in this locale, CO concentrations can occur at 10 to 100 times background, occasionally exceeding the National Ambient Air Quality Standard (NAAQS). Methane concentrations show a slight enhancement (∼24%) above the back…
The Power of 14 C Measurements Combined with Chemical Characterization for Tracing Urban Aerosol in Norway
Changing fuel patterns and increased awareness of health effects from combustion aerosols have generated considerable interest in the use of 14 C as a biogenic-fossil aerosol source discriminator. Prior studies in the US demonstrated the importance of 14 C measurement for estimating the wood-burning contribution to urban aerosols. The present work treats a specific air-pollution problem in the town of Elverum, Norway where large wintertime concen…
On the Origin of Carbonaceous Particles in American Cities
During the past three years radiocarbon assay has emerged as a primary tool in the quantitative assignment of sources of urban and rural particulate pollution. Its use in several major field studies has come about because of its excellent (fossil/biogenic) discriminating power, because of advances in 14 C measurements of small samples, and because of the increased significance of carbonaceous particles in the atmosphere. The problem is especially…
Miniature Signals and Miniature Counters
When 14 C signals approach background levels, the validity of assumptions concerning Poisson counting statistics and measurement system stability becomes crucial in interpreting the resultant low-level counting observations. This has been demonstrated in our previous work on detection limits for non-Poisson error and it is critical in our current studies of carbonaceous pollutants, where the 14 C signal from just 5 mg C is comparable to that of t…
Anthropogenic Changes in Organic Carbon and Trace Metal Input to Lake Washington
An example of how man's contaminants are introduced, deposited, and retained in sediments giving a chronological record of events has been developed for Lake Washington, Seattle. Significant amounts of both inorganic and organic compounds in the environment originate from fossil fuel sources, such as power plants and motor vehicles. Many organic compounds are introduced also from contemporary biogenic materials. Through the combined carbon isotop…
Pretreatment of Wood and Char Samples
It has been shown that contamination from humic acids, chitin, fungal products, etc., contributing young carbon, and from bitumen and carbonate, contributing old carbon, may not be completely removed from wood and char samples by the usual hydrochloric acid and sodium hydroxide pretreatments of the samples. A procedure is offered for the isolation of a pure chemical substance from such samples, cellulose from wood and uncombined carbon from char,…
Evolution and Multidisciplinary Frontiers of 14 C Aerosol Science
A review is given of some critical events in the development of radiocarbon aerosol science, and the profound influence of radiocarbon accelerator mass spectrometry (AMS) on its current applications and future prospects. The birth of this discipline occurred shortly after the initial development of 14 C dating. Unlike dating, which is founded on the continual decay of 14 C and the resulting full range of 14 C/ 12 C ratios in once-living matter, 1…
Miniature Signals and Miniature Counters
When 14 C signals approach background levels, the validity of assumptions concerning Poisson counting statistics and measurement system stability becomes crucial in interpreting the resultant low-level counting observations. This has been demonstrated in our previous work on detection limits for non-Poisson error and it is critical in our current studies of carbonaceous pollutants, where the 14 C signal from just 5 mg C is comparable to that of t…
AMS and Microprobe Analysis of Combusted Particles in Ice and Snow
Ice cores and snow pits of the cryosphere contain particles that detail the history of past atmospheric air compositions. Some of these particles result from combustion processes and have undergone long-range transport to arrive in the Arctic. Recent research has focused on the separation of particulate matter from ice and snow, as well as the subsequent analysis of the separated particles for 14 C with accelerator mass spectrometry (AMS) and for…
The Pursuit of Isotopic and Molecular Fire Tracers in the Polar Atmosphere and Cryosphere
We present an overview of recent multidisciplinary, multi-institutional efforts to identify and date major sources of combustion aerosol in the current and paleoatmospheres. The work was stimulated, in part, by an atmospheric particle “sample of opportunity” collected at Summit, Greenland in August 1994, that bore the 14 C imprint of biomass burning. During the summer field seasons of 1995 and 1996, we collected air filter, surface snow and snowp…
On the Validity of the Poisson Hypothesis for Low-Level Counting
Does radioactive decay follow the Poisson distribution?—a fundamental question, to which the theoretical answer seems to be, Yes. On the practical side, the answer to this question impacts the best achievable precision in well-controlled counting experiments. There have been some noteworthy experimental tests of the Poisson assumption, using systems carefully designed for the analysis of individual pulses from stable radioactive sources; thus far…
Urban Atmospheric 14 CO and 14 CH 4 Measurements by Accelerator Mass Spectrometry
Atmospheric gas samples (0.1m 3 ) were collected at ground level during January/February 1984 in Las Vegas, Nevada for 14 C/ 13 C accelerator mass spectrometry and total abundance measurements of CO and CH 4 . During winter months in this locale, CO concentrations can occur at 10 to 100 times background, occasionally exceeding the National Ambient Air Quality Standard (NAAQS). Methane concentrations show a slight enhancement (∼24%) above the back…
On the Origin of Carbonaceous Particles in American Cities
During the past three years radiocarbon assay has emerged as a primary tool in the quantitative assignment of sources of urban and rural particulate pollution. Its use in several major field studies has come about because of its excellent (fossil/biogenic) discriminating power, because of advances in 14 C measurements of small samples, and because of the increased significance of carbonaceous particles in the atmosphere. The problem is especially…
Pretreatment of Wood and Char Samples
It has been shown that contamination from humic acids, chitin, fungal products, etc., contributing young carbon, and from bitumen and carbonate, contributing old carbon, may not be completely removed from wood and char samples by the usual hydrochloric acid and sodium hydroxide pretreatments of the samples. A procedure is offered for the isolation of a pure chemical substance from such samples, cellulose from wood and uncombined carbon from char,…
On the Origin of Carbonaceous Particles in American Cities
During the past three years radiocarbon assay has emerged as a primary tool in the quantitative assignment of sources of urban and rural particulate pollution. Its use in several major field studies has come about because of its excellent (fossil/biogenic) discriminating power, because of advances in 14 C measurements of small samples, and because of the increased significance of carbonaceous particles in the atmosphere. The problem is especially…
Miniature Signals and Miniature Counters
When 14 C signals approach background levels, the validity of assumptions concerning Poisson counting statistics and measurement system stability becomes crucial in interpreting the resultant low-level counting observations. This has been demonstrated in our previous work on detection limits for non-Poisson error and it is critical in our current studies of carbonaceous pollutants, where the 14 C signal from just 5 mg C is comparable to that of t…
Anthropogenic Changes in Organic Carbon and Trace Metal Input to Lake Washington
An example of how man's contaminants are introduced, deposited, and retained in sediments giving a chronological record of events has been developed for Lake Washington, Seattle. Significant amounts of both inorganic and organic compounds in the environment originate from fossil fuel sources, such as power plants and motor vehicles. Many organic compounds are introduced also from contemporary biogenic materials. Through the combined carbon isotop…
Urban Atmospheric 14 CO and 14 CH 4 Measurements by Accelerator Mass Spectrometry
Atmospheric gas samples (0.1m 3 ) were collected at ground level during January/February 1984 in Las Vegas, Nevada for 14 C/ 13 C accelerator mass spectrometry and total abundance measurements of CO and CH 4 . During winter months in this locale, CO concentrations can occur at 10 to 100 times background, occasionally exceeding the National Ambient Air Quality Standard (NAAQS). Methane concentrations show a slight enhancement (∼24%) above the back…
The Power of 14 C Measurements Combined with Chemical Characterization for Tracing Urban Aerosol in Norway
Changing fuel patterns and increased awareness of health effects from combustion aerosols have generated considerable interest in the use of 14 C as a biogenic-fossil aerosol source discriminator. Prior studies in the US demonstrated the importance of 14 C measurement for estimating the wood-burning contribution to urban aerosols. The present work treats a specific air-pollution problem in the town of Elverum, Norway where large wintertime concen…
On the Validity of the Poisson Hypothesis for Low-Level Counting
Does radioactive decay follow the Poisson distribution?—a fundamental question, to which the theoretical answer seems to be, Yes. On the practical side, the answer to this question impacts the best achievable precision in well-controlled counting experiments. There have been some noteworthy experimental tests of the Poisson assumption, using systems carefully designed for the analysis of individual pulses from stable radioactive sources; thus far…
The Pursuit of Isotopic and Molecular Fire Tracers in the Polar Atmosphere and Cryosphere
We present an overview of recent multidisciplinary, multi-institutional efforts to identify and date major sources of combustion aerosol in the current and paleoatmospheres. The work was stimulated, in part, by an atmospheric particle “sample of opportunity” collected at Summit, Greenland in August 1994, that bore the 14 C imprint of biomass burning. During the summer field seasons of 1995 and 1996, we collected air filter, surface snow and snowp…
AMS and Microprobe Analysis of Combusted Particles in Ice and Snow
Ice cores and snow pits of the cryosphere contain particles that detail the history of past atmospheric air compositions. Some of these particles result from combustion processes and have undergone long-range transport to arrive in the Arctic. Recent research has focused on the separation of particulate matter from ice and snow, as well as the subsequent analysis of the separated particles for 14 C with accelerator mass spectrometry (AMS) and for…
Evolution and Multidisciplinary Frontiers of 14 C Aerosol Science
A review is given of some critical events in the development of radiocarbon aerosol science, and the profound influence of radiocarbon accelerator mass spectrometry (AMS) on its current applications and future prospects. The birth of this discipline occurred shortly after the initial development of 14 C dating. Unlike dating, which is founded on the continual decay of 14 C and the resulting full range of 14 C/ 12 C ratios in once-living matter, 1…
Chemistry (8 obras) · Geology (7 obras) · Environmental Science (6 obras) · Atmospheric chemistry and aerosols (5 obras) · Atmospheric sciences (5 obras) · Carbon fibers (5 obras) · Environmental Chemistry (5 obras) · Materials Science (5 obras) · Particulates (5 obras) · Aerosol (4 obras)