| 1. |
- Berthelsen, A., et al.
(författare)
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Recording marine airgun shots at offsets between 300 and 700 km
- 1991
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 18:4, s. 645-648
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Tidskriftsartikel (refereegranskat)abstract
- This paper demonstrates that - under favorable conditions - by using multichannel recording and subsequent stacking of adjacent records marine airgun shots have been detected at offset distances up to 700 km, the maximum offset at which the authors attempted to record data.^Besides a powerful airgun array, a low noise environment at the recording site and the elimination of static shifts are the prerequisites to obtain refracted and reflected arrivals from the crust and upper mantle at such large offsets.^Primary arrivals detected at offsets between 400 and 700 km image the upper mantle from 70 to about 120 km depth.^Stacking of neighboring shots and/or receivers successfully increases the signal-to-noise ratio, if the traces have been corrected for offset differences, which requires knowledge of the apparent phase velocities.^The data presented here were collected in autumn 1989 during the BABEL Project on the Baltic Shield.
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| 2. |
- Doeleman, S., et al.
(författare)
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86 GHz Global VLBI Progress Report
- 1993
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Ingår i: VLBI Technology. - Tokyo : Terrapub. - 4887041128 ; , s. 89-92
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Bokkapitel (refereegranskat)
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| 3. |
- Hobbs, R. W., et al.
(författare)
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Integrated seismic studies of the Baltic shield using data in the Gulf of Bothnia region
- 1993
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Ingår i: Geophysical Journal International. - 0956-540X .- 1365-246X. ; 112:3, s. 305-324
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Tidskriftsartikel (refereegranskat)abstract
- In the autumn of 1989 a co-operative experiment involving 12 research institutions in northwestern Europe collected 2268 km of deep seismic reflection profiles in the Gulf of Bothnia and the Baltic Sea. the 121 litre airgun array used for this profiling was also recorded by 62 muiticomponent land stations to provide coincident refraction surveys, fan-spreads, and 3-D seismic coverage of much of the Gulf of Bothnia. We thus have potentially both high-resolution impedance contrast images as well as more regional 3-D velocity models in both P- and S-waves. In the Bothnian Bay a south-dipping, non-reflective zone coincides with the conductive Archaean-Proterozoic boundary onshore in Finland. Between the Bothnian Bay and Bothnian Sea observed reflectivity geometries and velocity models at Moho depths suggest structures inherited from a 1.9Ga subduction zone; the upper crust here appears to have anomalously low velocity. Within the Bothnian Sea, reflectivity varies considerably beneath the metasedimentary/granitoid rocks of the Central Svecofennian Province (CSP) and the surrounding metavolcanic-arc rocks. Numerous dipping reflectors appear throughout the metavolcanic crust, whereas the CSP has little reflectivity. Wide-angle reflections indicate that the metasedimentary crust of the Bothnian Basin is 10 km thicker than the neighbouring Svecofennian subprovinces. Near the Åland archipelago Rapakivi granite plutons exhibit bright reflections, a contrast to the usual non-reflective plutons elsewhere in western Europe. Additional dipping reflections deep in the crust of this area may support models of rifting and crustal thinning during emplacement of the 1.70-1.54 Ga Rapakivi granites. Coeval gabbroic/anorthositic magmatism may explain the high reflectivity and high velocity of these plutons. the c. 1.25 Ga mafic sills and feeder dykes of the Central Scandinavian Dolerite Group also produce clear reflections on both near- and far-offset seismic sections. Continued modelling will produce better velocity models of the crust and better constrained contour maps of crustal thickness in this part of the Baltic shield.
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| 4. |
- Dannetun, Per, et al.
(författare)
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New Results on Metal-Polymer Interfaces
- 1993
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Ingår i: Molecular Crystals and Liquid Crystals. - : Taylor & Francis. - 1542-1406 .- 1563-5287. ; 228:1, s. 43-48
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Tidskriftsartikel (refereegranskat)abstract
- New results on studies of the early stages of formation of the aluminum-poly(p-phenylenevinylene) interface are presented.
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| 5. |
- Dannetun, Per, et al.
(författare)
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Proceedings of the International Conference on Science and Technology of Synthetic Metals The chemical and electronic structure of the interface between aluminum and conjugated polymers or molecules
- 1993
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Ingår i: Synthetic metals. - : Elsevier. - 0379-6779 .- 1879-3290. ; 55:1, s. 212-217
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Tidskriftsartikel (refereegranskat)abstract
- The interaction between aluminum and α-ω-diphenyltetradecaheptaenee (DP7), α-sexithienyl (6T), and poly(p-phenylenevinylene) (PPV), respectively have been studied using both X-ray Photoelectron Spectroscopy (XPS) and Ultraviolet Photoelectron Spectroscopy (UPS). The UPS valence band spectra, are interpreted with the help of quantum chemical calculations based upon Modified Neglect of Diatomic Overlap (MNDO), Valence Effective Hamitonian (VEH) and ab initio Hartree-Fock methods. DP7 is a model molecule for polyacetylene, while 6T is a model molecule (an oligomer) of polythiophene. The results indicate that aluminum reacts strongly with the surfaces of all of the materials studied. The π-electronic structure of each material was strongly modified. Furthermore, aluminum reacts preferentially with the polyene partof DP7, with the vinylene part of PPV, and with the α-carbons of the thiophene nits of 6T.
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| 6. |
- McNurlan, Margaret A., et al.
(författare)
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Response of protein synthesis in human skeletal muscle to insulin : an investigation with L[2H5]phenylalanine
- 1994
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Ingår i: American Journal of Physiology. - : American Physiological Society. - 0002-9513 .- 2163-5773. ; 67:Part 1, s. E102-E108
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Tidskriftsartikel (refereegranskat)abstract
- The role of insulin in the regulation of muscle protein synthesis in adult humans has been investigated with intravenous infusion of insulin at levels comparable with those observed after normal feeding. Glucose was also infused to maintain euglycemia. Muscle protein synthesis was measured in six healthy subjects before and during insulin and glucose infusion from the incorporation of L-[H-2(5)]phenylalanine into the protein of vastus lateralis sampled by percutaneous biopsy. L-[H-2(5)]phenylalanine was given as a single injection of a flooding amount (45 mg/kg). The relatively low levels of enrichment of phenylalanine in protein (0.005 atom%) were measured by modified gas chromatography-mass spectrometry and verified by comparison with incorporation of L-[2,6-H-3]phenylalanine. Similarity of enrichment in tissue-free and plasma pools (flooding) and linear incorporation over the period of measurement were also verified. The fractional rate of muscle protein synthesis in the group of postabsorptive subjects was 1.65 +/- 0.11% (SE)/day. The rate was unaltered by insulin and glucose infusion, 1.66 +/- 0.16%/day.
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| 7. |
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| 8. |
- Standke, K. J., et al.
(författare)
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High Sensitivity VLBI at 86 GHz : First Fringes with the 100 m Radio Telescope at Effelsberg
- 1993
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Ingår i: VLBI Technology. - Tokyo : Terra Scientific. - 4887041128 ; , s. 75-85
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Bokkapitel (refereegranskat)abstract
- Inclusion of large and sensitive antennas is of essential importance to further improve the imaging capabilities of VLBI at 3.5 mm wavelength. The combination of the 100 m radio telescope at Effelsberg (illuminated diameter ~60 m at lambda = 3.5 mm) with the 30 m radio telescope at Pico Veleta presently allows the detection of compact flux down to a level of 0.2 Jy (for τ=360 seconds integration time). Fringes have been found for 23 radio sources many of them not observed previously with VLBI at 86 GHz. On European baselines to Effelsberg the SNR typically was 10 to 30 (and ranged up to 107 for 3C279), facilitating model fitting for the brightest sources. Even in spite of chaning weather conditions during the observations (coherence times ranged between 10 to 100 seconds) and a still non-optimum pointing model for the 100 m antenna for observations at high frequencies, these results demonstrate that the 100 m radio telescope can be successfully incorporated in global VLBI experiments at 3.5 mm wavelength.
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