Search

Your search keyword '"Seppä, H."' showing total 232 results
Start Over Author "Seppä, H."
232 results on '"Seppä, H."'

1. Superconducting transition detector in power amplification mode: a tool for cryogenic multiplexing

Author

Helistö, P., Hassel, J., Luukanen, A., and Seppä, H.

Subjects
Condensed Matter - Superconductivity, Physics - Instrumentation and Detectors
Abstract

We demonstrate that substantial power gain can be obtained with superconducting transition detectors. We describe the properties of the detector as a power amplifier theoretically. In our first experiments power gain of 23 was reached in a good agreement with the theory. The gain facilitates noise matching of the readout circuit to the detectors in the case of time division multiplexing., Comment: 4 pages, 3 figures

Published
2008

2. The Bloch Oscillating Transistor

Author

Seppä, H. and Hassel, J.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We introduce a new mesoscopic transistor, which consists of a superconducting island connected to superconducting and normal electrodes via two mesoscopic tunnel junctions. Furthermore, the island is being charged through a resistor. The interplay between Bloch oscillations, single-electron effects and ohmic current leads to a device having a high current gain. The operation and characteristics of the transistor are analyzed with a numerical model., Comment: 3 pages, 5 pictures

Published
2003

3. Testing the Effect of Relative Pollen Productivity on the REVEALS Model: A Validated Reconstruction of Europe-Wide Holocene Vegetation

Author

Serge, M., primary, Mazier, F., additional, Fyfe, R., additional, Gaillard, M.-J., additional, Klein, T., additional, Lagnoux, A., additional, Galop, D., additional, Githumbi, E., additional, Mindrescu, M., additional, Nielsen, A., additional, Trondman, A.-K., additional, Poska, A., additional, Sugita, S., additional, Woodbridge, J., additional, Abel-Schaad, D., additional, Åkesson, C., additional, Alenius, T., additional, Ammann, B., additional, Andersen, S., additional, Anderson, R., additional, Andrič, M., additional, Balakauskas, L., additional, Barnekow, L., additional, Batalova, V., additional, Bergman, J., additional, Birks, H., additional, Björkman, L., additional, Bjune, A., additional, Borisova, O., additional, Broothaerts, N., additional, Carrion, J., additional, Caseldine, C., additional, Christiansen, J., additional, Cui, Q., additional, Currás, A., additional, Czerwiński, S., additional, David, R., additional, Davies, A., additional, De Jong, R., additional, Di Rita, F., additional, Dietre, B., additional, Dörfler, W., additional, Doyen, E., additional, Edwards, K., additional, Ejarque, A., additional, Endtmann, E., additional, Etienne, D., additional, Faure, E., additional, Feeser, I., additional, Feurdean, A., additional, Fischer, E., additional, Fletcher, W., additional, Franco-Múgica, F., additional, Fredh, E., additional, Froyd, C., additional, Garcés-Pastor, S., additional, García-Moreiras, I., additional, Gauthier, E., additional, Gil-Romera, G., additional, González-Sampériz, P., additional, Grant, M., additional, Grindean, R., additional, Haas, J., additional, Hannon, G., additional, Heather, A.-J., additional, Heikkilä, M., additional, Hjelle, K., additional, Jahns, S., additional, Jasiunas, N., additional, Jiménez-Moreno, G., additional, Jouffroy-Bapicot, I., additional, Kabailienė, M., additional, Kamerling, I., additional, Kangur, M., additional, Karpińska-Kołaczek, M., additional, Kasianova, A., additional, Kołaczek, P., additional, Lagerås, P., additional, Latalowa, M., additional, Lechterbeck, J., additional, Leroyer, C., additional, Leydet, M., additional, Lindbladh, M., additional, Lisitsyna, O., additional, López-Sáez, J.-A., additional, Lowe, John, additional, Luelmo-Lautenschlaeger, R., additional, Lukanina, E., additional, Macijauskaitė, L., additional, Magri, D., additional, Marguerie, D., additional, Marquer, L., additional, Martinez-Cortizas, A., additional, Mehl, I., additional, Mesa-Fernández, J., additional, Mighall, T., additional, Miola, A., additional, Miras, Y., additional, Morales-Molino, C., additional, Mrotzek, A., additional, Sobrino, C., additional, Odgaard, B., additional, Ozola, I., additional, Pérez-Díaz, S., additional, Pérez-Obiol, R., additional, Poggi, C., additional, Rego, P., additional, Ramos-Román, M., additional, Rasmussen, P., additional, Reille, M., additional, Rösch, M., additional, Ruffaldi, P., additional, Goni, M., additional, Savukynienė, N., additional, Schröder, T., additional, Schult, M., additional, Segerström, U., additional, Seppä, H., additional, Vives, G., additional, Shumilovskikh, L., additional, Smettan, H., additional, Stancikaite, M., additional, Stevenson, A., additional, Stivrins, N., additional, Tantau, I., additional, Theuerkauf, M., additional, Tonkov, S., additional, van der Knaap, W., additional, van Leeuwen, J., additional, Vecmane, E., additional, Verstraeten, G., additional, Veski, S., additional, Voigt, R., additional, Von Stedingk, H., additional, Waller, M., additional, Wiethold, J., additional, Willis, K., additional, Wolters, S., additional, and Zernitskaya, V., additional

Published
2023
Full Text
View/download PDF

6. Collagenous Matrices as Determinants of Cell Function

Author

Kleinman, H. K., primary, Rohrbach, D. H., additional, Terranova, V. P., additional, Varner, H. H., additional, Hewitt, A. T., additional, Grotendorst, G. R., additional, Wilkes, C. M., additional, Martin, G. R., additional, Seppä, H., additional, and Schiffmann, E., additional

Published
2018
Full Text
View/download PDF

7. 14 MHz Micromechanical Oscillator

Author

Mattila, T., Jaakkola, O., Kiihamäki, J., Karttunen, J., Lamminmäki, T., Rantakari, P., Oja, A., Seppä, H., Kattelus, H., Tittonen, I., and Obermeier, Ernst, editor

Published
2001
Full Text
View/download PDF

37. Theory of the Bloch oscillating transistor.

Author

Hassel, J. and Seppä, H.

Subjects
*JOSEPHSON junctions, *TRANSISTORS, *SEMICONDUCTORS, *ELECTRONICS, *JOSEPHSON effect, *QUANTUM tunneling, *SUPERCONDUCTORS
Abstract

The Bloch oscillating transistor (BOT) is a device in which single electron current through a normal tunnel junction enhances Cooper pair current in a mesoscopic Josephson junction, leading to signal amplification. In this article we develop a theory in which the BOT dynamics is described as a two-level system. The theory is used to predict current–voltage characteristics and small-signal response. The transition from stable operation into the hysteretic regime is studied. By identifying the two-level switching noise as the main source of fluctuations, the expressions for equivalent noise sources and the noise temperature are derived. The validity of the model is tested by comparing the results with simulations and experiments. [ABSTRACT FROM AUTHOR]

Published
2005
Full Text
View/download PDF

38. Control of Coulomb blockade in a mesoscopic Josephson junction using single electron tunneling.

Author

Hassel, J., Seppä, H., Delahaye, J., and Hakonen, P.

Subjects
*ELECTRONS, *JOSEPHSON junctions, *MESOSCOPIC phenomena (Physics), *ENERGY bands, *TRANSISTORS
Abstract

Focuses on the use of single electron tunneling method in determining the effects of Coulomb blockade in mesoscopic Josephson junctions. Formation of energy bands; Awareness on the noise properties of the devices; Characterization of the transistors.

Published
2004
Full Text
View/download PDF

39. How robust are Holocene treeline simulations? A model–data comparison in the European Arctic treeline region

Author

Fang, K., Morris, J.L., Salonen, S., Miller, P.A., Renssen, H., Sykes, M.T., Seppä, H., Earth and Climate, and Amsterdam Global Change Institute

Subjects
SDG 13 - Climate Action
Abstract

Treeline encroachments and retractions can provide global-scale feedbacks to the climate system, and treeline dynamics are therefore of great relevance for understanding global climate variability. To assess the accuracy of long-term treeline simulations based on the generalized dynamic vegetation model LPJ-GUESS, we simulate European Arctic treeline dynamics over the past 9000 years and compare the results with fossil-based reconstructions. The results show that while LPJ-GUESS is limited in its ability to capture species-level current treeline patterns and past dynamics, it is generally able to realistically simulate the Holocene coniferous treeline changes with a cutoff biomass carbon of 2Ckg m

Published
2013

44. Pollen‐based quantitative reconstructions of Holocene regional vegetation cover (plant‐functional types and land‐cover types) in Europe suitable for climate modelling

Author

Trondman, A.‐K., primary, Gaillard, M.‐J., additional, Mazier, F., additional, Sugita, S., additional, Fyfe, R., additional, Nielsen, A. B., additional, Twiddle, C., additional, Barratt, P., additional, Birks, H. J. B., additional, Bjune, A. E., additional, Björkman, L., additional, Broström, A., additional, Caseldine, C., additional, David, R., additional, Dodson, J., additional, Dörfler, W., additional, Fischer, E., additional, Geel, B., additional, Giesecke, T., additional, Hultberg, T., additional, Kalnina, L., additional, Kangur, M., additional, Knaap, P., additional, Koff, T., additional, Kuneš, P., additional, Lagerås, P., additional, Latałowa, M., additional, Lechterbeck, J., additional, Leroyer, C., additional, Leydet, M., additional, Lindbladh, M., additional, Marquer, L., additional, Mitchell, F. J. G., additional, Odgaard, B. V., additional, Peglar, S. M., additional, Persson, T., additional, Poska, A., additional, Rösch, M., additional, Seppä, H., additional, Veski, S., additional, and Wick, L., additional

Published
2014
Full Text
View/download PDF

46. Flora, vegetation and climate near Sokli, northern Fennoscandia, during the Weichselian Middle Pleniglacial: palynological and macrofossil investigations

Author

Bos, J.A.A., Helmers, K.F., Bohncke, S.J.P., Seppä, H., Birks, H.J.B., and Climate Change and Landscape Dynamics

Subjects
SDG 14 - Life Below Water
Abstract

A 2 m thick laminated lacustrine deposit of silt and clay recovered from the high-latitudinal site at Sokli (northern Finland) provides a unique mid-Weichselian fossil record for Fennoscandia. High-resolution botanical and zoological analyses of the lacustrine deposit allow detailed reconstruction of the regional vegetational development and of the history of the lake and the wetland ecosystem within the Sokli basin during the early part of the Weichselian Middle Pleniglacial (= equivalent to Marine Isotope Stage (MIS) 3). The inferred terrestrial vegetation represented by the Sokli MIS 3 sequence (so-called Tulppio Interstadial) was probably low-arctic tundra, treeless but with shrub elements including juniper, willow, dwarf birch, ericoids, lycopods and a rich herb flora with a variety of arctic-alpine taxa and heliophilous, pioneer elements. The presence of herbs such as Rubus chamaemorus, Epilobium palustre, Potentilla palustris and Sphagnum, Drepanocladus and other mosses suggests that the lake was fringed by wet meadows and peatlands or peaty telmatic communities. The distributional ranges of pine and tree birch were probably only a few hundred kilometres south or southeast of Sokli. This is concordant with evidence for the presence of boreal tree taxa during the MIS 3 in the Baltic countries and further east in Europe, but contradicts with the commonly inferred treeless tundra or grass-dominated steppe conditions in central Europe. © 2008 The Authors, Journal compilation © 2008 The Boreas Collegium.

Published
2009

48. Arctic Holocene proxy climate database – new approaches to assessing geochronological accuracy and encoding climate variables

Author

Sundqvist, H. S., primary, Kaufman, D. S., additional, McKay, N. P., additional, Balascio, N. L., additional, Briner, J. P., additional, Cwynar, L. C., additional, Sejrup, H. P., additional, Seppä, H., additional, Subetto, D. A., additional, Andrews, J. T., additional, Axford, Y., additional, Bakke, J., additional, Birks, H. J. B., additional, Brooks, S. J., additional, de Vernal, A., additional, Jennings, A. E., additional, Ljungqvist, F. C., additional, Rühland, K. M., additional, Saenger, C., additional, Smol, J. P., additional, and Viau, A. E., additional

Published
2014
Full Text
View/download PDF

50. Regional climate model simulations for Europe at 6 and 0.2 k BP: sensitivity to changes in anthropogenic deforestation

Author

Strandberg, G., primary, Kjellström, E., additional, Poska, A., additional, Wagner, S., additional, Gaillard, M.-J., additional, Trondman, A.-K., additional, Mauri, A., additional, Davis, B. A. S., additional, Kaplan, J. O., additional, Birks, H. J. B., additional, Bjune, A. E., additional, Fyfe, R., additional, Giesecke, T., additional, Kalnina, L., additional, Kangur, M., additional, van der Knaap, W. O., additional, Kokfelt, U., additional, Kuneš, P., additional, Lata\\l owa, M., additional, Marquer, L., additional, Mazier, F., additional, Nielsen, A. B., additional, Smith, B., additional, Seppä, H., additional, and Sugita, S., additional

Published
2014
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results