Tamás Vargas
Dados Biográficos
| ID | 4456837 |
|---|---|
| NOME | Tamás Vargas |
| PRENOMES | Tamás |
| SOBRENOME | Vargas |
| ASSINATURA | VARGAS T |
| ORCID | 0000-0002-2735-1375 |
| VERIFICADO | Sim |
| TOTAL DE OBRAS | 13 |
| TOTAL DE CITAÇÕES | 41 |
| TOTAL COMO AUTOR | 13 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 2018 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2025 |
| ÍNDICE H | 4 |
Investigating the impact of Covid-19 on the atmospheric 14C trend and fossil carbon load at urban and background sites in Hungary
The study analyses in situ CO 2 mole fraction, 14 CO 2 , and fossil based excess CO 2 mole fraction (C foss ) data at Hegyhátsál (HUN) rural monitoring station (Central Europe) supplemented by passive monitoring of 14 C content of tree-rings. Through the observed period (2014–2020) we focused on revealing trends in atmospheric CO 2 and 14 C levels, particularly during the year of the first COVID lockdown, in comparison to the preceding five years…
Novel dissolved organic 14C analyses method applied in a case study at a Lilw waste repository
A routine chemical procedure was developed at the Ede Hertelendi Laboratory of Environmental Studies (HEKAL), in Debrecen which can measure the dissolved organic radiocarbon content of groundwater as well as the inorganic and total fraction. The typical background of this non-purgeable dissolved organic radiocarbon preparation is 0.73 ± 0.14 percent modern carbon (pMC), using a carbon contamination correction on fossil dissolved material (potassi…
The Potential of Biogenic Fraction Analysis by Radiocarbon in Food, Drug, and Cosmetic Products
Biobased content analysis is a well-established, analytically independent, standardized method to determine the biobased content of fuels and plastics, based on differences of the specific radiocarbon ( 14 C) activity of fossil and recent biogenic compounds. This biogenic content analysis can be useful for the producers as a quality assurance tool, for the customers as feedback about the truly biobased products and for the control organizations a…
Intercomparison Exercise on Fuel Samples for Determination of Biocontent Ratio by 14 C Accelerator Mass Spectrometry
The method of determining the biobased carbon content in liquid fuel samples is standardized, but different laboratories use different protocols during sample preparation and perform the measurements using different machines. The accelerator mass spectrometry (AMS) laboratories use different combustion, preparation, and graphitization methods for the graphite production for the spectrometric measurements. As a result, the intercomparison between …
Soil Organic Carbon Dating of Paleosoils of Alluvial Fans in a Blown Sand Area (Nyírség, Hungary)
The most widely used dating techniques in quaternary research are the radiocarbon ( 14 C) and optically stimulated luminescence (OSL) dating methods. In some environments, the investigated sediments do not contain enough material for 14 C dating. In these cases, 14 C dating of bulk sediment may be used as a last resort. The major aim of the present study was to determine the reliability and limitations of the different fractions of the soil organ…
Gas Ion Source Performance of the Environmicadas at Hekal Laboratory, Debrecen, Hungary
A coupled accelerator mass spectrometer–gas interface system has been successfully operating at the Hertelendi Laboratory of Environmental Studies, Debrecen, Hungary, since 2013. Over the last 6 years more than 500 gas targets were measured below 100 μg carbon content for carbon isotopic composition. The system was tested with blanks, OxII, IAEA-C1, IAEA-C2, and IAEA-C7 standards. The performance of our instrumentation shows good agreement with o…
An Intercomparison Project on 14 C From Single-Year Tree Rings
A laboratory intercomparison project was carried out on 20 annually resolved late-wood samples from the Danish oak record. The project included the following three laboratories: (1) the University of Arizona AMS Laboratory, University of Arizona, USA (AA); (2) HEKAL AMS Laboratory, MTA Atomki, Hungary (DeA); and (3) Aarhus AMS Centre (AARAMS), Aarhus University, Denmark (AAR). The large majority of individual data points (96%) lie within ±2σ of t…
Spatial Distribution of 14 C in Tree Leaves from Bali, Indonesia
The increase of fossil-fuel-derived CO 2 in the atmosphere has led to the dilution of the atmospheric radiocarbon concentration, but due to the costly instrumentation, the continuous atmospheric 14 C/ 12 C data is incomplete in developing countries, such as in Indonesia. These data give useful information about the level of local and regional fossil emissions. In this study, 14 C AMS measurements of local vegetation and woody plant species sample…
Can the 14 C Production in 1055 Ce Be Affected by Sn1054
Annually resolved radiocarbon ( 14 C) measurements on tree rings led to the discovery of abrupt variations in 14 C production attributed to large solar flares. We present new results of annual and subannual 14 C fluctuations in tree rings from a middle-latitude sequoia (California) and a high-latitude pine (Finland), analyzed for the period 1030–1080 CE, to trace a possible impact of the Crab supernova explosion, occurring during the Oort minimum…
Variation of 14 C in Japanese Tree Rings Related to the Fukushima Nuclear Accident
Radiocarbon ( 14 C) analysis was performed on Japanese cedar (Cryptomeria japonica) tree rings from Koriyama, Fukushima prefecture. Our primary aim was to detect any 14 C release from the Fukushima Dai-ichi nuclear power plant accident on 11 March 2011. We also completed and assessed the 14 C level in Japanese tree rings for the period of 1990–2014 because of the lack of environmental 14 C results in the Japanese island that time. For this reason…
Fossil Carbon Load in Urban Vegetation for Debrecen, Hungary
Deciduous tree leaf and grass samples were collected in Debrecen, the second largest city in Hungary. The aim of the study was to determine the rate of fossil fuel-derived carbon in urban vegetation. At the locations sampled, C3 and C4 plants close to roads were collected in September 2017. In total, 82 tree and grass leaf samples were gathered at 36 different sampling points all over the city of Debrecen. The radiocarbon ( 14 C) results of the s…
More Rapid 14 C Excursions in the Tree-Ring Record
Two radiocarbon ( 14 C) excursions are caused by an increase of incoming cosmic rays on a short time scale found in the Late Holocene (AD 774–775 and AD 993–994), which are widely explained as due to extreme solar proton events (SPE). In addition, a larger event has also been reported at 5480 BC (Miyake et al. 2017a), which is attributed to a special mode of a grand solar minimum, as well as another at 660 BC (Park et al. 2017). Clearly, other ev…
High-Precision Biogenic Fraction Analyses of Liquid Fuels by 14 C AMS at Hekal
The biocomponent ratio in liquid fuels as well as the usage of renewable resources for fuel consumption in the transport sector needs to be increased as a result of EU directive 2003/30/EC. Based on radiocarbon ( 14 C) measurements, it should be relatively simple and fast to measure the weight percentage of the fossil and biological sources by accelerator mass spectrometry (AMS) as recommended in the ASTM D 6866-12 and EN 16640 standards. In this…
More Rapid 14 C Excursions in the Tree-Ring Record
Two radiocarbon ( 14 C) excursions are caused by an increase of incoming cosmic rays on a short time scale found in the Late Holocene (AD 774–775 and AD 993–994), which are widely explained as due to extreme solar proton events (SPE). In addition, a larger event has also been reported at 5480 BC (Miyake et al. 2017a), which is attributed to a special mode of a grand solar minimum, as well as another at 660 BC (Park et al. 2017). Clearly, other ev…
Fossil Carbon Load in Urban Vegetation for Debrecen, Hungary
Deciduous tree leaf and grass samples were collected in Debrecen, the second largest city in Hungary. The aim of the study was to determine the rate of fossil fuel-derived carbon in urban vegetation. At the locations sampled, C3 and C4 plants close to roads were collected in September 2017. In total, 82 tree and grass leaf samples were gathered at 36 different sampling points all over the city of Debrecen. The radiocarbon ( 14 C) results of the s…
High-Precision Biogenic Fraction Analyses of Liquid Fuels by 14 C AMS at Hekal
The biocomponent ratio in liquid fuels as well as the usage of renewable resources for fuel consumption in the transport sector needs to be increased as a result of EU directive 2003/30/EC. Based on radiocarbon ( 14 C) measurements, it should be relatively simple and fast to measure the weight percentage of the fossil and biological sources by accelerator mass spectrometry (AMS) as recommended in the ASTM D 6866-12 and EN 16640 standards. In this…
Gas Ion Source Performance of the Environmicadas at Hekal Laboratory, Debrecen, Hungary
A coupled accelerator mass spectrometer–gas interface system has been successfully operating at the Hertelendi Laboratory of Environmental Studies, Debrecen, Hungary, since 2013. Over the last 6 years more than 500 gas targets were measured below 100 μg carbon content for carbon isotopic composition. The system was tested with blanks, OxII, IAEA-C1, IAEA-C2, and IAEA-C7 standards. The performance of our instrumentation shows good agreement with o…
Can the 14 C Production in 1055 Ce Be Affected by Sn1054
Annually resolved radiocarbon ( 14 C) measurements on tree rings led to the discovery of abrupt variations in 14 C production attributed to large solar flares. We present new results of annual and subannual 14 C fluctuations in tree rings from a middle-latitude sequoia (California) and a high-latitude pine (Finland), analyzed for the period 1030–1080 CE, to trace a possible impact of the Crab supernova explosion, occurring during the Oort minimum…
Soil Organic Carbon Dating of Paleosoils of Alluvial Fans in a Blown Sand Area (Nyírség, Hungary)
The most widely used dating techniques in quaternary research are the radiocarbon ( 14 C) and optically stimulated luminescence (OSL) dating methods. In some environments, the investigated sediments do not contain enough material for 14 C dating. In these cases, 14 C dating of bulk sediment may be used as a last resort. The major aim of the present study was to determine the reliability and limitations of the different fractions of the soil organ…
Spatial Distribution of 14 C in Tree Leaves from Bali, Indonesia
The increase of fossil-fuel-derived CO 2 in the atmosphere has led to the dilution of the atmospheric radiocarbon concentration, but due to the costly instrumentation, the continuous atmospheric 14 C/ 12 C data is incomplete in developing countries, such as in Indonesia. These data give useful information about the level of local and regional fossil emissions. In this study, 14 C AMS measurements of local vegetation and woody plant species sample…
Intercomparison Exercise on Fuel Samples for Determination of Biocontent Ratio by 14 C Accelerator Mass Spectrometry
The method of determining the biobased carbon content in liquid fuel samples is standardized, but different laboratories use different protocols during sample preparation and perform the measurements using different machines. The accelerator mass spectrometry (AMS) laboratories use different combustion, preparation, and graphitization methods for the graphite production for the spectrometric measurements. As a result, the intercomparison between …
More Rapid 14 C Excursions in the Tree-Ring Record
Two radiocarbon ( 14 C) excursions are caused by an increase of incoming cosmic rays on a short time scale found in the Late Holocene (AD 774–775 and AD 993–994), which are widely explained as due to extreme solar proton events (SPE). In addition, a larger event has also been reported at 5480 BC (Miyake et al. 2017a), which is attributed to a special mode of a grand solar minimum, as well as another at 660 BC (Park et al. 2017). Clearly, other ev…
High-Precision Biogenic Fraction Analyses of Liquid Fuels by 14 C AMS at Hekal
The biocomponent ratio in liquid fuels as well as the usage of renewable resources for fuel consumption in the transport sector needs to be increased as a result of EU directive 2003/30/EC. Based on radiocarbon ( 14 C) measurements, it should be relatively simple and fast to measure the weight percentage of the fossil and biological sources by accelerator mass spectrometry (AMS) as recommended in the ASTM D 6866-12 and EN 16640 standards. In this…
Variation of 14 C in Japanese Tree Rings Related to the Fukushima Nuclear Accident
Radiocarbon ( 14 C) analysis was performed on Japanese cedar (Cryptomeria japonica) tree rings from Koriyama, Fukushima prefecture. Our primary aim was to detect any 14 C release from the Fukushima Dai-ichi nuclear power plant accident on 11 March 2011. We also completed and assessed the 14 C level in Japanese tree rings for the period of 1990–2014 because of the lack of environmental 14 C results in the Japanese island that time. For this reason…
Fossil Carbon Load in Urban Vegetation for Debrecen, Hungary
Deciduous tree leaf and grass samples were collected in Debrecen, the second largest city in Hungary. The aim of the study was to determine the rate of fossil fuel-derived carbon in urban vegetation. At the locations sampled, C3 and C4 plants close to roads were collected in September 2017. In total, 82 tree and grass leaf samples were gathered at 36 different sampling points all over the city of Debrecen. The radiocarbon ( 14 C) results of the s…
Spatial Distribution of 14 C in Tree Leaves from Bali, Indonesia
The increase of fossil-fuel-derived CO 2 in the atmosphere has led to the dilution of the atmospheric radiocarbon concentration, but due to the costly instrumentation, the continuous atmospheric 14 C/ 12 C data is incomplete in developing countries, such as in Indonesia. These data give useful information about the level of local and regional fossil emissions. In this study, 14 C AMS measurements of local vegetation and woody plant species sample…
Can the 14 C Production in 1055 Ce Be Affected by Sn1054
Annually resolved radiocarbon ( 14 C) measurements on tree rings led to the discovery of abrupt variations in 14 C production attributed to large solar flares. We present new results of annual and subannual 14 C fluctuations in tree rings from a middle-latitude sequoia (California) and a high-latitude pine (Finland), analyzed for the period 1030–1080 CE, to trace a possible impact of the Crab supernova explosion, occurring during the Oort minimum…
Gas Ion Source Performance of the Environmicadas at Hekal Laboratory, Debrecen, Hungary
A coupled accelerator mass spectrometer–gas interface system has been successfully operating at the Hertelendi Laboratory of Environmental Studies, Debrecen, Hungary, since 2013. Over the last 6 years more than 500 gas targets were measured below 100 μg carbon content for carbon isotopic composition. The system was tested with blanks, OxII, IAEA-C1, IAEA-C2, and IAEA-C7 standards. The performance of our instrumentation shows good agreement with o…
An Intercomparison Project on 14 C From Single-Year Tree Rings
A laboratory intercomparison project was carried out on 20 annually resolved late-wood samples from the Danish oak record. The project included the following three laboratories: (1) the University of Arizona AMS Laboratory, University of Arizona, USA (AA); (2) HEKAL AMS Laboratory, MTA Atomki, Hungary (DeA); and (3) Aarhus AMS Centre (AARAMS), Aarhus University, Denmark (AAR). The large majority of individual data points (96%) lie within ±2σ of t…
Soil Organic Carbon Dating of Paleosoils of Alluvial Fans in a Blown Sand Area (Nyírség, Hungary)
The most widely used dating techniques in quaternary research are the radiocarbon ( 14 C) and optically stimulated luminescence (OSL) dating methods. In some environments, the investigated sediments do not contain enough material for 14 C dating. In these cases, 14 C dating of bulk sediment may be used as a last resort. The major aim of the present study was to determine the reliability and limitations of the different fractions of the soil organ…
The Potential of Biogenic Fraction Analysis by Radiocarbon in Food, Drug, and Cosmetic Products
Biobased content analysis is a well-established, analytically independent, standardized method to determine the biobased content of fuels and plastics, based on differences of the specific radiocarbon ( 14 C) activity of fossil and recent biogenic compounds. This biogenic content analysis can be useful for the producers as a quality assurance tool, for the customers as feedback about the truly biobased products and for the control organizations a…
Intercomparison Exercise on Fuel Samples for Determination of Biocontent Ratio by 14 C Accelerator Mass Spectrometry
The method of determining the biobased carbon content in liquid fuel samples is standardized, but different laboratories use different protocols during sample preparation and perform the measurements using different machines. The accelerator mass spectrometry (AMS) laboratories use different combustion, preparation, and graphitization methods for the graphite production for the spectrometric measurements. As a result, the intercomparison between …
Novel dissolved organic 14C analyses method applied in a case study at a Lilw waste repository
A routine chemical procedure was developed at the Ede Hertelendi Laboratory of Environmental Studies (HEKAL), in Debrecen which can measure the dissolved organic radiocarbon content of groundwater as well as the inorganic and total fraction. The typical background of this non-purgeable dissolved organic radiocarbon preparation is 0.73 ± 0.14 percent modern carbon (pMC), using a carbon contamination correction on fossil dissolved material (potassi…
Investigating the impact of Covid-19 on the atmospheric 14C trend and fossil carbon load at urban and background sites in Hungary
The study analyses in situ CO 2 mole fraction, 14 CO 2 , and fossil based excess CO 2 mole fraction (C foss ) data at Hegyhátsál (HUN) rural monitoring station (Central Europe) supplemented by passive monitoring of 14 C content of tree-rings. Through the observed period (2014–2020) we focused on revealing trends in atmospheric CO 2 and 14 C levels, particularly during the year of the first COVID lockdown, in comparison to the preceding five years…
Environmental Science (11 obras) · Radiocarbon dating (10 obras) · Geology (8 obras) · Carbon fibers (6 obras) · Chemistry (6 obras) · Environmental Chemistry (6 obras) · Geography (6 obras) · Isotope Analysis in Ecology (6 obras) · Paleontology (6 obras) · Physics (6 obras)