| 1. |
- Aartsen, M. G., et al.
(författare)
-
South Pole glacial climate reconstruction from multi-borehole laser particulate stratigraphy
- 2013
-
Ingår i: Journal of Glaciology. - 0022-1430 .- 1727-5652. ; 59:218, s. 1117-1128
-
Tidskriftsartikel (refereegranskat)abstract
- The IceCube Neutrino Observatory and its prototype, AMANDA, were built in South Pole ice, using powerful hot-water drills to cleanly bore >100 holes to depths up to 2500 m. The construction of these particle physics detectors provided a unique opportunity to examine the deep ice sheet using a variety of novel techniques. We made high-resolution particulate profiles with a laser dust logger in eight of the boreholes during detector commissioning between 2004 and 2010. The South Pole laser logs are among the most clearly resolved measurements of Antarctic dust strata during the last glacial period and can be used to reconstruct paleoclimate records in exceptional detail. Here we use manual and algorithmic matching to synthesize our South Pole measurements with ice-core and logging data from Dome C, East Antarctica. We derive impurity concentration, precision chronology, annual-layer thickness, local spatial variability, and identify several widespread volcanic ash depositions useful for dating. We also examine the interval around similar to 74 ka recently isolated with radiometric dating to bracket the Toba (Sumatra) supereruption.
|
|
| 2. |
- Kehoe, Laura, et al.
(författare)
-
Make EU trade with Brazil sustainable
- 2019
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 3. |
- Moritz, J., et al.
(författare)
-
Functional integration approaches via laser powder bed processing
- 2019
-
Ingår i: Journal of laser applications. - : Laser Institute of America. - 1042-346X .- 1938-1387. ; 31:2
-
Tidskriftsartikel (refereegranskat)abstract
- Additive manufacturing design rules are different from those of conventional fabrication techniques. These allow geometries that would not be possible to achieve otherwise. One example of application is the integration of functional parts as part of the manufacturing process. Conceivable applications range from mechanical functions like integration of moving parts or thermodynamic functions, for example, cooling channels or incorporation of electric circuits for electrical functionalization [J. Glasschroeder, E. Prager, and M. F. Zaeh, Rapid Prototyping J. 21, 207–215 (2015)]. Nevertheless, the potential of functional integration using powder-bed processes is far from being exhausted. The present approach addresses the generation of inner cavities and internal structures of titanium-based parts or components by the use of selective laser melting. This paper focusses on the investigation of voids and cavities regarding their capabilities to add new functions to the material. To this end, comprehensive characterization is performed using destructive as well as nondestructive testing methods. These include 3D scanning, computed tomography, and surface roughness measurements as well as microscopic analysis. Voids and cavities were filled with different thermoplastic materials, followed by the qualitative assessment of the mold filling and resulting material properties. Finally, applications are derived and evaluated with respect to the field of lightweight design or damping structures.
|
|
| 4. |
- Ashkenov, N., et al.
(författare)
-
Infrared dielectric functions and phonon modes of high-quality ZnO films
- 2003
-
Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 93:1, s. 126-133
-
Tidskriftsartikel (refereegranskat)abstract
- A study was performed on the phonon modes and infrared dielectric functions of high-quality ZnO thin films. The pulsed laser deposition technique was used to deposit the ZnO films on c-plane sapphire substrates and were investigated by high-resolution transmission electron microscopy, high-resolution x-ray diffraction and Rutherford backscattering experiments. The accurate long-wavelength dielectric constant limits of the films were also obtained and were compared with near-band-gap index-of-refraction data upon the Lyddane-Sachs-Teller relation for both film and bulk samples. It was found that the phonon modes of the film were highly consistent with those of the bulk sample.
|
|
