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| 2. |
- Mantsinen, M. J., et al.
(author)
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Bulk Ion Heating with ICRF Waves in Tokamaks
- 2015
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In: RADIOFREQUENCY POWER IN PLASMAS. - : American Institute of Physics (AIP). - 9780735413368
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Conference paper (peer-reviewed)abstract
- Heating with ICRF waves is a well-established method on present-day tokamaks and one of the heating systems foreseen for ITER. However, further work is still needed to test and optimize its performance in fusion devices with metallic high-Z plasma facing components (PFCs) in preparation of ITER and DEMO operation. This is of particular importance for the bulk ion heating capabilities of ICRF waves. Efficient bulk ion heating with the standard ITER ICRF scheme, i.e. the second harmonic heating of tritium with or without He-3 minority, was demonstrated in experiments carried out in deuterium-tritium plasmas on JET and TFTR and is confirmed by ICRF modelling. This paper focuses on recent experiments with He-3 minority heating for bulk ion heating on the ASDEX Upgrade (AUG) tokamak with ITER-relevant all-tungsten PFCs. An increase of 80% in the central ion temperature T-i from 3 to 5.5 keV was achieved when 3 MW of ICRF power tuned to the central He-3 ion cyclotron resonance was added to 4.5 MW of deuterium NBI. The radial gradient of the Ti profile reached locally values up to about 50 keV/m and the normalized logarithmic ion temperature gradients R/L-Ti of about 20, which are unusually large for AUG plasmas. The large changes in the Ti profiles were accompanied by significant changes in measured plasma toroidal rotation, plasma impurity profiles and MHD activity, which indicate concomitant changes in plasma properties with the application of ICRF waves. When the He-3 concentration was increased above the optimum range for bulk ion heating, a weaker peaking of the ion temperature profile was observed, in line with theoretical expectations.
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| 4. |
- Walker, M. J. C., et al.
(author)
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Formal Subdivision of the Holocene Series/Epoch
- 2014
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In: STRATI 2013. - Cham : Springer International Publishing. - 2197-9545. - 9783319043630 ; , s. 983-987
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Conference paper (peer-reviewed)abstract
- This proposal, by a Working Group of Integration of ice-core, marine, and terrestrial records (INTIMATE) and the Subcommission on Quaternary Stratigraphy (SQS) of the International Commission on Stratigraphy (ICS), is for a formal subdivision of the Holocene Series/Epoch. Although previous attempts to subdivide the Holocene have proved inconclusive, recent developments in Quaternary stratigraphy, notably the definition of the Pleistocene-Holocene boundary and the emergence of formal subdivisions of the Pleistocene Series/Epoch, mean that it may be timely to revisit this matter. The Quaternary literature reveals a widespread but variable informal usage of a tripartite division of the Holocene ("early", "middle" or "mid-", and "late"), and we propose that this de facto subdivision should now be formalised to ensure consistency in stratigraphic terminology. We advocate a formal Early-Middle Holocene boundary at 8200 a BP and a formal Middle-Late Holocene boundary at 4200 a BP, each of which is linked to a Global Stratotype Section and Point (GSSP).
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| 5. |
- Buker, O., et al.
(author)
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Metrological support for LNG custody transfer and transport
- 2016
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In: Proceedings of the 17th International Flow Measurement Conference (FLOMEKO 2016).
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Conference paper (peer-reviewed)abstract
- In the framework of the ongoing EMRP Joint Research Project (JRP) ENG 60 “Metrology for LNG” (2014-2017), co-funded by the European Union, a number of metrological challenges associated with custody transfer and transport of LNG will be faced. The project consists of four technical work packages (WP), whereby the main objective is to reduce the measurement uncertainty of LNG custody transfer by a factor two. The focus in WP1 is the design and development of a traceable mid-scale calibration standard for LNG mass and volume flow. The goal is to provide traceable mass and volume flow calibrations up to 400 m3/h (180000 kg/h). In WP2, the emphasis is on the development and validation of a LNG sampling and composition measurement reference standard, consisting of sampler, vaporizer, gas standards, and gas chromatography (GC), which will be used to test and calibrate commercially available LNG sampling and composition measurement systems. The priority in WP3 is given to the development and validation of a method for the determination of the methane number, including correlations based on the LNG composition and corrections for traces of nitrogen and higher hydrocarbons. Since physical properties and quantities play an important role in LNG custody transfer, WP4 comprises reference quality density measurements of LNG to validate and improve models for LNG density predictions, the uncertainty evaluation of enthalpy and calorific value calculations and the development of a novel cryogenic sensor for the simultaneous measurement of speed-of-sound and density. The present paper gives an overview of recently achieved objectives within the project and provides an outlook to future activities.
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| 7. |
- Frischknecht, R., et al.
(author)
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Comparison of the greenhouse gas emissions of a high-rise residential building assessed with different national LCA approaches - IEA EBC Annex 72
- 2020
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In: IOP Conference Series. - : IOP Publishing. ; , s. 022029-
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Conference paper (peer-reviewed)abstract
- Introduction: The international research project IEA EBC Annex 72 investigates the life cycle related environmental impacts caused by buildings. The project aims inter alia to harmonise LCA approaches on buildings. Methods: To identify major commonalities and discrepancies among national LCA approaches, reference buildings were defined to present and compare the national approaches. A residential high-rise building located in Tianjin, China, was selected as one of the reference buildings. The main construction elements are reinforced concrete shear walls, beams and floor slabs. The building has an energy reference area of 4566 m2 and an operational heating energy demand of 250 MJ/m2a. An expert team provided information on the quantities of building materials and elements required for the construction, established a BIM model and quantified the operational energy demand. Results: The greenhouse gas emissions and environmental impacts of the building were quantified using 17 country-specific national assessment methods and LCA databases. Comparisons of the results are shown on the level of building elements as well as the complete life cycle of the building. Conclusions: The results of these assessments show that the main differences lie in the LCA background data used, the scope of the assessment and the reference study period applied. Despite the variability in the greenhouse gas emissions determined with the 17 national methods, the individual results are relevant in the respective national context of the method, data, tool and benchmark used. It is important that environmental benchmarks correspond to the particular LCA approach and database of a country in which the benchmark is applied. Furthermore, the results imply to include building technologies as their contribution to the overall environmental impacts is not negligible. Grant support: The authors thank the IEA for its organizational support and the funding organizations in the participating countries for their financial support.
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| 10. |
- Tala, T., et al.
(author)
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Dimensionless collisionality scans for core particle transport in JET
- 2015
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In: 42nd European Physical Society Conference on Plasma Physics, EPS 2015.
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Conference paper (peer-reviewed)abstract
- Density peaking increases in the inner core (r/a=0.3) from 0.3 to 2.7 and in the outer core (r/a=0.8) from 1.6 to 3.5 when ν∗ decreases from 0.47 to 0.09 in JET H-mode plasmas while density peaking does not depend on ν∗ in JET L-mode plasma. For this particular scan, experimental evidence indicates that a dominant part of this peaking originates from NBI fuelling and inward pinch is a subdominant fraction. This is supported by the simple linear runs with GYRO although much more work is needed here to make a conclusion. More discharges are needed to quantify more precisely the fractions of these two contributions and also much more work is required on the modelling front to make exact comparisons.
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