Results 71 to 80 of about 158,813 (385)

Assessing fossil fuel CO2 emissions in California using atmospheric observations and models

Environmental Research Letters, 2018
Analysis systems incorporating atmospheric observations could provide a powerful tool for validating fossil fuel CO _2 (ffCO _2 ) emissions reported for individual regions, provided that fossil fuel sources can be separated from other CO _2 sources or ...
H Graven, M L Fischer, T Lueker, S Jeong, T P Guilderson, R F Keeling, R Bambha, K Brophy, W Callahan, X Cui, C Frankenberg, K R Gurney, B W LaFranchi, S J Lehman, H Michelsen, J B Miller, S Newman, W Paplawsky, N C Parazoo, C Sloop, S J Walker   +20 more
doaj   +1 more source

Towards a radiocarbon chronology of the Late-Glacial: Sample selection strategies [PDF]

, 2001
This paper outlines a dating program designed to test the reproducibility of radiocarbon dates on different materials of Late-Glacial age (plant macrofossils, fossil beetle remains, and the "humic" and "humin" chemical fractions of limnic sediments ...
Bengtsson, Coope, Coope, Donahue, Harkness, Hodgins, Lowe, Lowe, Lowe, Moore, Pennington, Pennington, Southon, Sutherland, Switsur   +14 more
core   +1 more source

Reanalysis of the Atmospheric Radiocarbon Calibration Record from Lake Suigetsu, Japan

Radiocarbon: An International Journal of Cosmogenic Isotope Research, 2020
Terrestrial plant macrofossils from the sedimentary record of Lake Suigetsu, Japan, provide the only quasi-continuous direct atmospheric record of radiocarbon (14C) covering the last 50 ka cal BP (Bronk Ramsey et al. 2012). Since then, new high precision
C. Bronk Ramsey, T. Heaton, G. Schlolaut, R. Staff, C. Bryant, A. Brauer, H. Lamb, M. Marshall, T. Nakagawa   +8 more
semanticscholar   +1 more source

Tallinn Radiocarbon Dates I [PDF]

Radiocarbon, 1973
Preparations for determining absolute age by the radiocarbon method were started at the Institute of Geology, Academy of Sciences of the Estonian SSR in 1971. Dating of samples has been carried out since 1972.
J M Punning, T Kakum, R Rajamäe
openaire   +3 more sources

Is the Sun a Long Period Variable [PDF]

, 1990
The inventory of atmospheric radiocarbon exhibits quasi-periodic variations of mean period of bar-lambda=269 years over the entire 9000 year record. But the period is inconstant and subject to random variability (sigma m exp. 1/2 = 119 years).
Sonett, Charles P.
core   +1 more source

Autonomous Machine Learning‐Based Classification and Arrangement of Submillimeter Objects Using a Capillary Force Gripper

Advanced Intelligent Discovery, EarlyView.
This study presents an automated system integrating a capillary force gripper and machine learning‐based object detection for sorting and placing submillimeter objects. The system achieved stable and simultaneous manipulation of four object types, with an average task time of 86.0 seconds and a positioning error of 157 ± 84 µm, highlighting its ...
Satoshi Ando, Naoto Watanabe, Chihiro Sekine, Shogen Sekiguchi, Ohmi Fuchiwaki   +4 more
wiley   +1 more source

Spring buds of European woody plants have old 14C age

Heliyon
Trees and shrubs maintain carbon reserves to support their functions during periods when metabolic demand exceeds carbon supply, such as during the dormant season.
Tamás Varga, Dominik Nagy, Mihály Molnár, A.J. Timothy Jull, István Futó, Zsuzsa Lisztes-Szabó   +5 more
doaj   +1 more source

Radiocarbon dates from the Oxford AMS system: archaeometry datelist 35 [PDF]

, 2014
This is the 35th list of AMS radiocarbon determinations measured at the Oxford Radiocarbon Accelerator Unit (ORAU). Amongst some of the sites included here are the latest series of determinations from the key sites of Abydos, El Mirón, Ban Chiang, Grotte
Baker, D., Brock, F., Bronk Ramsey, C., Ditchfield, P., Higham, T. F. G., Staff, R. A.   +5 more
core   +1 more source

Mediterranean radiocarbon offsets and calendar dates for prehistory

Science Advances, 2020
Intra-annual offsets in Northern Hemisphere atmospheric radiocarbon levels challenge and complicate Old World radiocarbon dating. A single Northern Hemisphere calibration curve has formed the basis of radiocarbon dating in Europe and the Mediterranean ...
S. Manning, B. Kromer, M. Cremaschi, M. Dee, R. Friedrich, Carol B. Griggs, Carla S. Hadden   +6 more
semanticscholar   +1 more source

Origin, evolution and biogeographic dynamics of the European rabbit (Oryctolagus cuniculus) in Southwestern Europe

The Anatomical Record, EarlyView.
Abstract The Pleistocene is a key period for understanding the evolutionary history and palaeobiogeography of the European rabbit (Oryctolagus cuniculus). The species was first documented in southeastern Iberia at the beginning of the Middle Pleistocene and appears to have rapidly spread throughout Southwestern Europe, where it was found in numerous ...
Maxime Pelletier
wiley   +1 more source