scholarly journals The Ocean Bomb Radiocarbon Inventory Revisited

Radiocarbon ◽  
2013 ◽  
Vol 55 (3) ◽  
pp. 1580-1594 ◽  
Author(s):  
Anne Mouchet
Keyword(s):  
Model Calibration ◽  
Isotopic Ratio ◽  
Piston Velocity ◽  
Modeling Studies ◽  
C Cycle ◽  
Bomb Radiocarbon ◽  
Insight Into ◽  
Simplified Form

Large discrepancies exist among data-based estimates and model reconstructions of the ocean bomb radiocarbon inventory. In order to resolve this gap, it has been proposed that the CO2 piston velocity should be revised downward (Sweeney et al. 2007; Müller et al. 2008). This article compares the transient 14C distributions in the ocean obtained with different formulations of the isotopic ratio commonly used in modeling studies. It is found that both the CO2 increase and the air-sea CO2 flux significantly contribute to the 1990 ocean bomb 14C inventory, by around 10% each. Moreover, these 2 processes explain more than 25% of the inventory difference between 1974 and 1990. These results imply that, as already argued by Naegler (2009), inventories based on observations that lack information about CO2 invasion are underestimated. Further, this work provides insight into the reasons for discrepancies among model results. It suggests that while a comprehensive isotopic formulation is needed when addressing the global 14C cycle, a simplified form is more relevant for model calibration and piston velocity assessment based on currently available bomb 14C inventories.

Pipe Ovalization Prediction for the Pipe-Laying Ocean System

2018 ◽  
Author(s):  
Matěj Bartecký ◽  
Radim Halama
Keyword(s):  
Plastic Deformation ◽  
Cross Section ◽  
Process Simulation ◽  
Model Calibration ◽  
Material Model ◽  
Pure Bending ◽  
Pipe Cross Section ◽  
Technical Practice ◽  
Chaboche Model ◽  
Insight Into

This contribution brings a new insight into pipe cross section ovalisation due to plastic deformation during pipe-lying process to the seabed. Firstly, the influence of material model calibration on ovalization prediction is presented on pure bending case including the Prager model, the Chaboche model and the modified Abdel-Karim–Ohno model. The mechanism responsible for cross section ovalisation was identified as the phenomenon of the accumulation of plastic deformation, the so-called ratcheting. The next part of this contribution presents main results of the pipe-laying process simulation. The pipe cross-section behavior during passing the considered pipe-laying system is studied in detail. A macro based solution makes possible to do a parametric study and to easily apply the offshore standard DNV-OS-F101 in technical practice.

scholarly journals Leaf and root pectin methylesterase activity and 13C/12C stable isotopic ratio measurements of methanol emissions give insight into methanol production in Lycopersicon esculentum

2011 ◽  
Vol 191 (4) ◽  
pp. 1031-1040 ◽  
Author(s):  
Patricia Yoshino Oikawa ◽  
Brian M. Giebel ◽  
Leonel da Silveira Lobo O’Reilly Sternberg ◽  
Lei Li ◽  
Michael P. Timko ◽  
...  
Keyword(s):  
Lycopersicon Esculentum ◽  
Isotopic Ratio ◽  
Pectin Methylesterase ◽  
Methanol Production ◽  
Stable Isotopic ◽  
Stable Isotopic Ratio ◽  
Insight Into

Interaction of different prototropic species of an anticancer drug ellipticine with HSA and IgG proteins: multispectroscopic and molecular modeling studies

2015 ◽  
Vol 17 (26) ◽  
pp. 16937-16946 ◽  
Author(s):  
Raina Thakur ◽  
Anupam Das ◽  
Vandna Sharma ◽  
Chandan Adhikari ◽  
Kalyan Sundar Ghosh ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Blood Serum ◽  
Anticancer Drug ◽  
Carrier Proteins ◽  
Physiological Conditions ◽  
Modeling Studies ◽  
Molecular Modeling Studies ◽  
Insight Into

Studies on interactions between an anticancer alkaloid, ellipticine, and various carrier proteins in blood serum show tangible results to gain insight into the solubility and transport of the drug under physiological conditions.

Car-Following Model Calibration and Analysis of Intra-Driver Heterogeneity

2010 ◽  
Vol 108-111 ◽  
pp. 805-810 ◽  
Author(s):  
Hao Wang ◽  
Wei Wang ◽  
Jun Chen
Keyword(s):  
Model Calibration ◽  
Optimization Method ◽  
Acceleration Process ◽  
Trajectory Data ◽  
Car Following ◽  
Car Following Model ◽  
Vehicle Trajectory ◽  
Best Fit ◽  
Insight Into ◽  
Selection Of

This paper presents a methodology for car-following models calibration with vehicle trajectory data. A two-step optimization method is performed for searching the best-fit parameters of two popular car-following models, namely, the Helly model and the IDM model. The model calibration results verify the validity of the optimization method. Based on the results of calibrations, the intra-driver heterogeneity of driving behavior between the acceleration process and the deceleration process is studied. It is found that obvious intra-driver heterogeneities exist in driving behaviours between acceleration processes and deceleration processes of car-following. Besides, some criteria are proposed for the selection of sub-trajectories corresponding to both the acceleration and the deceleration processes of car-following. This work not only develops a general approach for car-following model calibration with vehicle trajectory data, but also provides insight into the intra-driver heterogeneity in car-following behaviours.

A new insight into mushroom tyrosinase inhibitors: docking, pharmacophore-based virtual screening, and molecular modeling studies

2014 ◽  
Vol 33 (3) ◽  
pp. 487-501 ◽  
Author(s):  
Kowsar Bagherzadeh ◽  
Faezeh Shirgahi Talari ◽  
Amirhossein Sharifi ◽  
Mohammad Reza Ganjali ◽  
Ali Akbar Saboury ◽  
...  
Keyword(s):  
Molecular Modeling ◽  
Virtual Screening ◽  
Mushroom Tyrosinase ◽  
Modeling Studies ◽  
Molecular Modeling Studies ◽  
Tyrosinase Inhibitors ◽  
Insight Into

scholarly journals Local and global trace plutonium contributions in fast breeder legacy soils

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chris Tighe ◽  
Maxi Castrillejo ◽  
Marcus Christl ◽  
Claude Degueldre ◽  
Jeremy Andrew ◽  
...  
Keyword(s):  
Structural Change ◽  
Isotopic Ratio ◽  
Fast Neutrons ◽  
Fast Breeder Reactor ◽  
Trace Level ◽  
Plutonium Concentration ◽  
Local Contribution ◽  
Specific Activities ◽  
Insight Into ◽  
Mass Concentrations

AbstractTrace-level plutonium in the environment often comprises local and global contributions, and is usually anthropogenic in origin. Here, we report estimates of local and global contributions to trace-level plutonium in soil from a former, fast-breeder reactor site. The measured 240Pu/239Pu ratio is anomalously low, as per the reduced 240Pu yield expected in plutonium bred with fast neutrons. Anomalies in plutonium concentration and isotopic ratio suggest forensic insight into specific activities on site, such as clean-up or structural change. Local and global 239Pu contributions on-site are estimated at (34 ± 1)% and (66 ± 3)%, respectively, with mass concentrations of (183 ± 6) fg g−1 and (362 ± 13) fg g−1. The latter is consistent with levels at undisturbed and distant sites, (384 ± 44) fg g−1, where no local contribution is expected. The 240Pu/239Pu ratio for site-derived material is estimated at 0.05 ± 0.04. Our study demonstrates the multi-faceted potential of trace plutonium assay to inform clean-up strategies of fast breeder legacies.

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