| 1. |
- Albert, Damien, et al.
(författare)
-
A Decade with VAMDC : Results and Ambitions
- 2020
-
Ingår i: Atoms. - : MDPI. - 2218-2004. ; 8:4
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents an overview of the current status of the Virtual Atomic and Molecular Data Centre (VAMDC) e-infrastructure, including the current status of the VAMDC-connected (or to be connected) databases, updates on the latest technological development within the infrastructure and a presentation of some application tools that make use of the VAMDC e-infrastructure. We analyse the past 10 years of VAMDC development and operation, and assess their impact both on the field of atomic and molecular (A&M) physics itself and on heterogeneous data management in international cooperation. The highly sophisticated VAMDC infrastructure and the related databases developed over this long term make them a perfect resource of sustainable data for future applications in many fields of research. However, we also discuss the current limitations that prevent VAMDC from becoming the main publishing platform and the main source of A&M data for user communities, and present possible solutions under investigation by the consortium. Several user application examples are presented, illustrating the benefits of VAMDC in current research applications, which often need the A&M data from more than one database. Finally, we present our vision for the future of VAMDC.
|
|
| 2. |
- Roth, Lorenz, et al.
(författare)
-
An attempt to detect transient changes in Io's SO2 and NaCl atmosphere
- 2020
-
Ingår i: Icarus. - : Elsevier BV. - 0019-1035 .- 1090-2643. ; 350
-
Tidskriftsartikel (refereegranskat)abstract
- Io's atmosphere is predominately SO2 that is sustained by a combination of volcanic outgassing and sublimation. The loss from the atmosphere is the main mass source for Jupiter's large magnetosphere. Numerous previous studies attributed various transient phenomena in Io's environment and Jupiter's magnetosphere to a sudden change in the mass loss from the atmosphere supposedly triggered by a change in volcanic activity. Since the gas in volcanic plumes does not escape directly, such causal correlation would require a transient volcano-induced change in atmospheric abundance, which has never been observed so far. Here we report four observations of atmospheric SO2 and NaCl from the same hemisphere of Io, obtained with the IRAM NOEMA interferometer on 11 December 2016, 14 March, 6 and 29 April 2017. These observations are compared to measurements of volcanic hot spots and Io's neutral and plasma environment. We find a stable NaCl column density in Io's atmosphere on the four dates. The SO2 column density derived for December 2016 is about 30% lower compared to the SO2 column density found in the period of March to April 2017. This increase in SO2 from December 2016 to March 2017 might be related to increasing volcanic activity observed at several sites in spring 2017, but the stability of the volcanic trace gas NaCl and resulting decrease in NaCl/SO2 ratio do not support this interpretation. Observed dimmings in both the sulfur ion torus and Na neutral cloud suggest rather a decrease in mass loading in the period of increasing SO2 abundance. The dimming Na brightness and stable atmospheric NaCl furthermore dispute an earlier suggested positive correlation of the sodium cloud and the hot spot activity at Loki Patara, which considerably increased in this period. The environment of Io overall appears to be in a rather quiescent state, preventing further conclusions. Only Jupiter's aurora morphology underwent several short-term changes, which are apparently unrelated to Io's quiescent environment or the relatively stable atmosphere.
|
|
| 3. |
- Torstensson, Peter, 1981, et al.
(författare)
-
Rail corrugation growth on small radius curves—Measurements and validation of a numerical prediction model
- 2013
-
Ingår i: Wear. - : Elsevier BV. - 0043-1648. ; 303:1-2, s. 381-396
-
Tidskriftsartikel (refereegranskat)abstract
- The development of low rail corrugation (rutting corrugation) on a 120 m radius curve on the Stockholm metro is studied by field measurements, laboratory measurements and numerical simulations. The corrugation develops exclusively on the low rail with wavelengths of about 5 cm and 8 cm. It is concluded by field measurements that the application of friction modification effectively mitigates the corrugation growth on the curve. For the low rail, high levels of lateral acceleration and plastic material flow in the surface layer orientated towards the field side indicate large magnitude lateral creep forces generated by the curving vehicles. A time-domain model for prediction of roughness growth on small radius curves is applied to obtain an improved understanding of the wheel rail interaction leading to rutting corrugation. The model is validated by comparison of predicted long-term rail roughness growth against measured data, and it is concluded that the corrugation is generated by the low rail contact of the leading wheelset of passing bogies. The corrugation wavelengths observed on the curve are related to excitation of the first symmetric and first antisymmetric bending eigenmodes of the leading wheelsets. Important parameters for the identified wavelength-fixing mechanisms are investigated.
|
|
