Stellarator-pinch: a composite fusion concept

2005 ◽  
Vol 47 (2) ◽  
pp. 241-248
Author(s):  
A K Sen
Keyword(s):  
Fusion Concept

scholarly journals Constraining a complex biogeochemical model for CO<sub>2</sub> and N<sub>2</sub>O emission simulations from various land uses by model–data fusion

2017 ◽  
Vol 14 (14) ◽  
pp. 3487-3508 ◽  
Author(s):  
Tobias Houska ◽  
David Kraus ◽  
Ralf Kiese ◽  
Lutz Breuer
Keyword(s):  
Data Fusion ◽  
Arable Land ◽  
Shallow Groundwater ◽  
Scale Model ◽  
Biogeochemical Model ◽  
N2o Emissions ◽  
Model Errors ◽  
Model Data ◽  
Validation Data ◽  
Fusion Concept

Abstract. This study presents the results of a combined measurement and modelling strategy to analyse N2O and CO2 emissions from adjacent arable land, forest and grassland sites in Hesse, Germany. The measured emissions reveal seasonal patterns and management effects, including fertilizer application, tillage, harvest and grazing. The measured annual N2O fluxes are 4.5, 0.4 and 0.1 kg N ha−1 a−1, and the CO2 fluxes are 20.0, 12.2 and 3.0 t C ha−1 a−1 for the arable land, grassland and forest sites, respectively. An innovative model–data fusion concept based on a multicriteria evaluation (soil moisture at different depths, yield, CO2 and N2O emissions) is used to rigorously test the LandscapeDNDC biogeochemical model. The model is run in a Latin-hypercube-based uncertainty analysis framework to constrain model parameter uncertainty and derive behavioural model runs. The results indicate that the model is generally capable of predicting trace gas emissions, as evaluated with RMSE as the objective function. The model shows a reasonable performance in simulating the ecosystem C and N balances. The model–data fusion concept helps to detect remaining model errors, such as missing (e.g. freeze–thaw cycling) or incomplete model processes (e.g. respiration rates after harvest). This concept further elucidates the identification of missing model input sources (e.g. the uptake of N through shallow groundwater on grassland during the vegetation period) and uncertainty in the measured validation data (e.g. forest N2O emissions in winter months). Guidance is provided to improve the model structure and field measurements to further advance landscape-scale model predictions.

On-line multi-slice computed tomography interactive overlay with conventional X-ray: A new and advanced imaging fusion concept

2009 ◽  
Vol 133 (3) ◽  
pp. e101-e105 ◽  
Author(s):  
Joel A. Garcia ◽  
Shyam Bhakta ◽  
Joseph Kay ◽  
Kak-Chen Chan ◽  
Onno Wink ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Advanced Imaging ◽  
X Ray ◽  
On Line ◽  
Fusion Concept

scholarly journals Z pinches—A historical view

2001 ◽  
Vol 19 (4) ◽  
pp. 509-525 ◽  
Author(s):  
R.B. SPIELMAN ◽  
J.S. DE GROOT
Keyword(s):  
Recent Progress ◽  
18Th Century ◽  
Nuclear Fusion ◽  
Energy Gain ◽  
Fusion Program ◽  
Historical View ◽  
Negative Results ◽  
The World ◽  
Fusion Concept ◽  
Varied History

Z pinches have a long and varied history. Beginning in the 18th century, z pinches have been used to heat plasmas very efficiently. Early in the nuclear fusion program, it was realized that modest currents are required to confine plasma that could produce energy gain. The instability of the confined plasma was convincingly demonstrated in experiments in the 1950s that were performed around the world. These uniformly negative results led to z pinches being dropped as a fusion concept. Recent progress in fast z pinches has reinvigorated the field. We review the field and highlight the recent advances that point the way to a bright future for z pinches.

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