uu.seUppsala University Publications
Change search
Refine search result
345678 251 - 300 of 366
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 251.
    O'Hare, Paschal
    et al.
    Lund Univ, Dept Geol Quaternary Sci, S-22362 Lund, Sweden.
    Mekhaldi, Florian
    Lund Univ, Dept Geol Quaternary Sci, S-22362 Lund, Sweden.
    Adolphi, Florian
    Lund Univ, Dept Geol Quaternary Sci, S-22362 Lund, Sweden;Univ Bern, Phys Inst, Climate & Environm Phys & Oeschger Ctr Climate Ch, CH-3012 Bern, Switzerland.
    Raisbeck, Grant
    Univ Paris Saclay, CNRS, Ctr Sci Nucl & Sci Matiere, F-91405 Orsay, France.
    Aldahan, Ala
    United Arab Emirates Univ, Dept Geol, Al Ain, U Arab Emirates.
    Anderberg, Emma
    Lund Univ, Dept Geol Quaternary Sci, S-22362 Lund, Sweden.
    Beer, Jurg
    Swiss Fed Inst Aquat Sci & Technol, Dept Surface Waters, CH-8600 Dubendorf, Switzerland.
    Christl, Marcus
    Swiss Fed Inst Technol, Lab Ion Beam Phys, CH-8093 Zurich, Switzerland.
    Fahrni, Simon
    Swiss Fed Inst Technol, Lab Ion Beam Phys, CH-8093 Zurich, Switzerland.
    Synal, Hans-Arno
    Swiss Fed Inst Technol, Lab Ion Beam Phys, CH-8093 Zurich, Switzerland.
    Park, Junghun
    Korea Inst Geosci & Mineral Resources, Daejeon 34132, South Korea.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Southon, John
    Univ Calif Irvine, Keck Accelerator Mass Spectrometry AMS Lab, Irvine, CA 92697 USA.
    Bard, Edouard
    Aix Marseille Univ, CNRS, Inst Natl Rech Agron, Coll France,CEREGE,IRD,UMR 34, F-13545 Aix En Provence, France.
    Muscheler, Raimund
    Lund Univ, Dept Geol Quaternary Sci, S-22362 Lund, Sweden.
    Multiradionuclide evidence for an extreme solar proton event around 2,610 BP (similar to 660 BC)2019In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 116, no 13, p. 5961-5966Article in journal (Refereed)
    Abstract [en]

    Recently, it has been confirmed that extreme solar proton events can lead to significantly increased atmospheric production rates of cosmogenic radionuclides. Evidence of such events is recorded in annually resolved natural archives, such as tree rings [carbon-14 (C-14)] and ice cores [beryllium-10 (Be-10), chlorine-36 (Cl-36)]. Here, we show evidence for an extreme solar event around 2,610 years B.P. (similar to 660 BC) based on high-resolution Be-10 data from two Greenland ice cores. Our conclusions are supported by modeled C-14 production rates for the same period. Using existing Cl-36 ice core data in conjunction with Be-10, we further show that this solar event was characterized by a very hard energy spectrum. These results indicate that the 2,610-years B.P. event was an order of magnitude stronger than any solar event recorded during the instrumental period and comparable with the solar proton event of AD 774/775, the largest solar event known to date. The results illustrate the importance of multiple ice core radionuclide measurements for the reliable identification of short-term production rate increases and the assessment of their origins.

  • 252.
    Olovsson, I., Ptasiewicz-Bak, H., Gustafsson, T. and Majerz, I.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Asymmetric hydrogen bonds in centrosymmetric environment: Neutron study of very short hydrogen bonds in potassium hydrogen dichloromaleate2002In: Acta Cryst., Vol. B57, p. 311-316Article in journal (Refereed)
  • 253.
    Olovsson, Ivar
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Ptasiewicz-Bak, H.
    Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Gustafsson, Torbjörn
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Majerz, I.
    Asymmetric hydrogen bonds in a centrosymmetric environment. II:Neutron study of the very short hydrogen bonds in potassium hydrogen dichloromaleate at 90 K and 170 K.2002In: Acta Cryst., Vol. B58, p. 627-631Article in journal (Refereed)
  • 254.
    Omeltchenko, A
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Bachlechner, ME
    Nakano, A
    Kalia, RK
    Vashishta, P
    Ebbsjo, I
    Madhukar, A
    Messina, P
    Stress domains in Si(111)/a-Si3N4 nanopixel: Ten-million-atom molecular dynamics simulations on parallel computers2000In: PHYSICAL REVIEW LETTERS, ISSN 0031-9007, Vol. 84, no 2, p. 318-321Article in journal (Refereed)
    Abstract [en]

    Parallel molecular dynamics simulations are performed to determine atomic-level stresses in Si(111)/Si3N4(0001) and Si(111)/a-Si3N4 nanopixels. Compared to the crystalline case, the stresses in amorphous Si3N4 are highly inhomogeneous in the plane of the

  • 255.
    Palm, Ola
    et al.
    Swedish Institute for Agricultural and Environmental Engineering, JTI, Uppsala, Sweden.
    Jakobsson, Christine
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Uppsala Centre for Sustainable Development, The Baltic University Programme.
    20 Sewage Sludge Management in Relation to EU-requirements2012In: Sustainable Agriculture / [ed] Christine Jakobsson, Uppsala: Baltic University Press , 2012, 1500, p. 150-158Chapter in book (Other (popular science, discussion, etc.))
  • 256.
    Peng, RL
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Odén, M
    Wang, YD
    Johansson, S
    Intergranular strains and plastic deformation of an austenitic stainless steel2002In: Mater. Sci. Eng. A, Vol. in pressArticle in journal (Refereed)
  • 257.
    Peng, RL
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Rode, N
    Odén, M
    Gibmeier, J
    Scholtes, B
    Characterisation of residual stress distribution in clinched joints by diffraction methods2002In: Mater. Sci. Tech., Vol. submittedArticle in journal (Refereed)
  • 258.
    Persson, S.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Afimov, V.
    Hou, X.
    I-129 Variability in precipitation over Europe2007In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 259, no 1, p. 508-512Article in journal (Refereed)
    Abstract [en]

    We present results and an overview of studies on I-129 in precipitation over Europe during the last decade, covering latitudes 37-70 degrees N. The data show about three orders of magnitude variability in concentrations but without specific correlation to latitude when all Europe is considered. The total amount of I-129 provided annually by precipitation over Europe composes only a tiny portion of the annual marine discharge but a significant portion of the gaseous discharges from the nuclear reprocessing facilities. Contribution of gaseous releases seems to be significant, although difficult to estimate. As shown by this study, a unified sampling procedure and systematic measurements of I-129 in precipitation throughout Europe are needed to achieve a coherent picture about the loading and sources of I-129 in precipitation and the atmosphere.

  • 259. Petersson, P.
    et al.
    Rubel, M.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Brezinsek, S.
    Kreter, A.
    Moeller, S.
    Hakola, A.
    Mayer, M.
    Miettunen, J.
    Airila, M. I.
    Makkonen, T.
    Neu, R.
    Rohde, V.
    Overview of nitrogen-15 application as a tracer gas for material migration and retention studies in tokamaks2014In: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896, Vol. T159, p. 014042-Article in journal (Refereed)
    Abstract [en]

    Experimental and analytical procedures related to the application of nitrogen-15 isotope for material migration studies have been developed and used for tracer experiments in the TEXTOR and ASDEX-Upgrade tokamaks in order to assess the retention of nitrogen in plasma-facing components made of graphite and tungsten. The surface study was performed by time-of-flight heavy ion elastic recoil detection analysis and by means of nuclear reaction analysis based on the N-15(p, gamma alpha)C-12 process. In both tokamaks nitrogen retention has exceeded 10% of the injected gas. In ASDEX-Upgrade the largest fraction of N-15 has been detected on protruding parts near the injection port, while around 4% has been found in the divertor. The ASDEX-Upgrade results have also been modeled. Helium trapping has been measured in deposits containing tungsten and nitrogen.

  • 260. Petersson, P.
    et al.
    Rubel, M.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy. Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Brezinsek, S.
    Pegourie, B.
    Nuclear reaction and heavy ion ERD analysis of wall materials from controlled fusion devices: Deuterium and nitrogen-15 studies2012In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 273, p. 113-117Article in journal (Refereed)
    Abstract [en]

    Time-of-flight HIERDA (26 MeV I-127(7+)) and micro-NRA (2.5 MeV He-3) were used to determine the composition of graphite and tungsten plasma-facing components (PFC) exposed at the TEXTOR and Tore Supra tokamaks. High sensitivity and resolution of HIERDA allowed, for the first time, for studies of nitrogen-15 showing that the gas injected during tokamak discharges is trapped on PFC, 3-7 x 10(15) N cm(-2). Also helium retention in tungsten has been identified: up to 8 x 10(15) He cm(-2). Deuterium distribution on the main limiters of Tore Supra is not uniform on tiles extracted from the erosion- and deposition-dominated areas. This is measured both on macro- (points 5 mm apart) and micro-scale (30 gm). The mapping with mu-NRA revealed the D content variation by a factor 40-50 in regions 1 x 2 mm(2): 1.2-40 x 10(17) D cm(-2) and 4-230 x 10(18) D cm(-2) in the erosion and deposition zones, respectively. In summary, the measurements of N-15 contributed to material mixing studies and improved understanding of deuterium retention on PFC.

  • 261.
    Petersson, Per
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Ion Physics. Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Bergsåker, H.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Ion Physics. Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Coad, J. P.
    Koivuranta, S.
    Likonen, J.
    Ion beam micro analysis of deposits at tokamak divertor surfaces2010In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 268, no 11-12, p. 1838-1841Article in journal (Refereed)
  • 262.
    Petersson, Per
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Bergsåker, H.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Coad, J. P.
    Likonen, J.
    Koivuranta, S.
    Hakola, A.
    Cross sections of deposited layers investigated by micronuclear reaction analysis2011In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 415, no 1, p. S262-S265Article in journal (Refereed)
    Abstract [en]

    Cross sections of deposited layers from the divertor of the Joint European Torus (JET) have been investigated, microscopically and by ion microbeam analysis. The thickness of these layers on the studied samples varies between about 50 mu m and 800 mu m depending on the exposure time and poloidal location of the sample. For most of the thicker layers a laminar structure is observed. In some locations changes, such as gaps, are also observed along the laminar structure as well as more complex structures. The possibility to use the layers as historical reference was also investigated.

  • 263.
    Petrykin, V., Kakihana, M., Tanaka,Y., Yasuoka, H., Abe, M. and Eriksson, S.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Ferromagnetic and superconducting properties of pure RuCe0.5Eu1.5Sr2Cu2O10 samples prepared by polymerizable complex method2002In: Physica, Vol. C 378-381, p. 47-Article in journal (Refereed)
  • 264. Pham, M. K.
    et al.
    Betti, M.
    Povinec, P. P.
    Alfimov, V.
    Biddulph, D.
    Gastaud, J.
    Kieser, W. E.
    Gutierrez, J. M. Lopez
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Sanchez-Cabeza, J. A.
    Suzuki, T.
    Certified reference material IAEA-418: 129I in Mediterranean Sea water2010In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 286, no 1, p. 121-127Article in journal (Refereed)
    Abstract [en]

    A certified reference material designed for the determination of I-129 in seawater, IAEA-418 (Mediterranean Sea water) is described and the results of certification are presented. The median of I-129 concentration with 95% confidence interval was chosen as the most reliable estimates of the true value. The median, given as the certified value, is 2.28 x 10(8) atom L-1 (95% confidence interval is (2.16-2.73) 10(8) atom L-1), or 3.19 x 10(-7) Bq L-1 (95% confidence interval is (3.02-3.82) x 10(-7) Bq L-1). The material is intended to be used for standardization procedures applied in accelerator mass spectrometric laboratories. It is available in 1 L units and may be ordered via IAEA web side (www.iaea.org).

  • 265.
    Podolyak, Zs., P.M.Walker, H.Mach, G.de France, G.Sletten, F.Azaiez, J.M.Casandjian, B.Cederwall, D.M.Cullen, Zs.Dombradi, G.D.Dracoulis, L.M.Fraile, S.Franchoo, H.Fynbo, M.Gorska, Y.Kopatch, G.J.Lane, S.Mandal, L.Milechina, J.Molnar, C.O'Leary, W.Plocien
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    g-ray spectroscopy with a 8He beam2003In: Nucl.Instrum.Methods Phys.Res. A, Vol. 511, p. 354-Article in journal (Refereed)
  • 266.
    Possnert, Göran
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics. Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Kulan, A
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Berggren, Ann-Marie
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Environment and Landscape Dynamics. Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Beryllium isotopes in aerosols over Sweden2006Conference paper (Refereed)
  • 267.
    Povic, Mirjana
    et al.
    Ethiopian Space Sci & Technol Inst, Addis Ababa, Ethiopia;Inst Astrofis Andalucia CSIC, Granada, Spain.
    Backes, Michael
    Univ Namibia, Dept Phys, Windhoek, Namibia;North West Univ, Ctr Space Res, Potchefstroom, South Africa.
    Baki, Paul
    Tech Univ Kenya, Nairobi, Kenya.
    Baratoux, David
    Univ Toulouse, Geosci Environm Toulouse, French Natl Res Inst Sustainable Dev, Toulouse, France.
    Tessema, Solomon Belay
    Ethiopian Space Sci & Technol Inst, Addis Ababa, Ethiopia.
    Benkhaldoun, Zouhair
    Oukaimeden Observ & Cadi Ayyad Univ, Marrakech, Morocco.
    Bode, Michael
    Botswana Int Univ Sci & Technol, Palapye, Botswana.
    Klutse, Nana A. Browne
    Ghana Space Sci & Technol Inst, Accra, Ghana.
    Charles, Phil
    Univ Southampton, Southampton, Hants, England.
    Govender, Kevin
    Off Astron Dev IAU, Cape Town, South Africa;South African Astron Observ, Cape Town, South Africa.
    van Groningen, Ernst
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, International Science Programme (ISP).
    Jurua, Edward
    Mbarara Univ Sci & Technol, Mbarara, Uganda.
    Mamo, Alemiye
    Ethiopian Space Sci & Technol Inst, Addis Ababa, Ethiopia;ESSTI, East African Reg Off Astron Dev, Addis Ababa, Ethiopia.
    Manxoyi, Sivuyile
    South African Astron Observ, Cape Town, South Africa.
    McBride, Vanessa
    Off Astron Dev IAU, Cape Town, South Africa;South African Astron Observ, Cape Town, South Africa.
    Mimouni, Jamal
    Mentouri Univ, LPMPS, Constantine 1, Constantine, Algeria.
    Nemaungani, Takalani
    Dept Sci & Technol, Pretoria, South Africa.
    Nkundabakura, Pheneas
    Univ Rwanda, Kigali, Rwanda.
    Okere, Bonaventure
    NASRDA, Ctr Basic Space Sci, West African Reg Off Astron Dev, Nsukka, Nigeria.
    Saad, Somaya
    Natl Res Inst Astron & Geophys, Cairo, Egypt.
    Simpemba, Prospery C.
    Copperbelt Univ, Southern African Reg Off Astron Dev, Kitwe, Zambia.
    Walwa, Tefera
    Ethiopian Space Sci Soc, Addis Ababa, Ethiopia.
    Yilma, Abdissa
    Ethiopian Space Sci & Technol Inst, Addis Ababa, Ethiopia.
    Development in astronomy and space science in Africa2018In: NATURE ASTRONOMY, ISSN 2397-3366, Vol. 2, no 7, p. 507-510Article in journal (Other academic)
  • 268.
    Powell, DH
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Pitteloud, C
    Benmore, CJ
    Soper, AK
    Delaplane, RG
    Neutron diffraction studies of clays: the structure of interlayer water in Na- and Li- Wyoming montmorillonite at ambient and low temperatures2001In: Mineralogical Magazine, Vol. in pressArticle in journal (Refereed)
  • 269.
    Prieto, C
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Sánchez-Soria, D
    Muñoz-Martin, A
    Vila, M
    Delaplane, RG
    Zetterström, P
    Traverse, A
    Structural order and chemical disorder in the mechanically alloyed Fe-Co-Cu nano-crystalline system2001In: Recent Res. Devel. Non-Crystalline Solids, ISSN 81-7895-028-6, Vol. 1, p. 151-169Article in journal (Refereed)
    Abstract [en]

    In this paper we present a structural study of the formation of a metastable Fe-Co-Cu alloy that can be prepared by mechanical alloying. Several steps in the alloy formation are described by using three different techniques: X-ray absorption spectroscopy,

  • 270.
    Pusztai, L
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    McGreevy, RL
    The structure of molten ZnCl2 and MgCl22001In: JOURNAL OF PHYSICS-CONDENSED MATTER, ISSN 0953-8984, Vol. 13, no 33, p. 7213-7222Article in journal (Refereed)
    Abstract [en]

    The structures of molten MgCl2 and ZnCl2 have been modelled using the reverse Monte Carlo method, based on neutron and x-ray diffraction data. We show that, although the structures are similar in terms of two-body correlations (e.g. partial radial distrib

  • 271. Qiao, Jixin
    et al.
    Hansen, Violeta
    Hou, Xiaolin
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Speciation analysis of 129I, 137Cs, 232Th, 238U, 239Pu and 240Pu in environmental soil and sediment2012In: Applied Radiation and Isotopes, ISSN 0969-8043, E-ISSN 1872-9800, Vol. 70, no 8, p. 1698-1708Article in journal (Refereed)
    Abstract [en]

    The environmental mobility and bioavailability of radionuclides are related to their physicochemical forms, namely species. We here present a speciation analysis of important radionuclides including I-129 (also I-127), Cs-137, Th-232, U-238 and plutonium isotopes (Pu-239 and Pu-240) in soil (IAEA-375) and sediment (NIST-4354) standard reference materials and two fresh sediment samples from Ovre Heimdalsvatnet Lake, Norway. A modified sequential extraction protocol was used for the speciation analysis of these samples to obtain fractionation information of target radionuclides. Analytical results reveal that the partitioning behaviour, and thus the potential mobility and bioavailability, are exclusively featured for the individual radionuclide. Iodine is relatively mobile and readily binds to organic matter, while plutonium is mainly bound to both organic matter and nitric acid leachable fractions. Thorium is predominated in nitric acid leachable fraction and caesium is primarily observed in nitric acid and aqua regia leachable fractions and residue. Our analytical results reveal that around 50% of uranium might still remain in the residue which could not be extracted with aggressive acid, namely, aqua regia.

  • 272.
    Rahman, Mahbubur
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Cooray, Vernon
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy. Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Efficiencies for production of nitrogen oxides by proton impact in air2013In: Journal of Atmospheric and Solar-Terrestrial Physics, ISSN 1364-6826, E-ISSN 1879-1824, Vol. 94, p. 1-4Article in journal (Refereed)
    Abstract [en]

    We present present the first laboratory measurements of nitrogen oxides generated by proton impact in air. Experiments were conducted at the Tandem Laboratory of Uppsala University. A proton beam with known current and energy was injected into an air tight ionising chamber for a fixed time duration and the resulting nitrogen oxides were measured by the method of chemiluminescence. The data are presented in terms of number of produced NOX (NO+NO2) molecules for different proton energy, proton beam current and duration. The efficiency for NOX production by proton impact in air can on average be estimated to about 0.2 NOX molecules per ion-pair based on 1 cm diameter proton beam with energies from 2 to 4 MeV and varied currents from 0.1 to 10 nA. 

  • 273. Reu, Pedro
    et al.
    Mold, Jeff
    Michaelsson, Jakob
    Salehpour, Mehran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Frisen, Jonas
    Human T cell lifespan2013In: Journal of Immunology, ISSN 0022-1767, E-ISSN 1550-6606, Vol. 190, p. P1284-Article in journal (Other academic)
  • 274.
    Rino, JP
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Chatterjee, A
    Ebbsjö, I
    Kalia, RK
    Nakano, A
    Shimojo, F
    Vashishta, P
    Pressure induced structural transformation in gallium arsenide: A molecular dynamics study2001In: Phys. Rev. B, Vol. submittedArticle in journal (Refereed)
  • 275.
    Rydén, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Uppsala Centre for Sustainable Development.
    Governing a Common Sea: Environmental Policies in the Baltic Sea Region2010In: Journal of Baltic Studies, ISSN 0162-9778, E-ISSN 1751-7877, Vol. 41, no 3, p. 408-410Article, book review (Other academic)
  • 276.
    Salehpour, Mehran
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Håkansson, Karl
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy. Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy. Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Accelerator mass spectrometry of ultra-small samples with applications in the biosciences2013In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 294, p. 97-103Article in journal (Refereed)
    Abstract [en]

    An overview is presented covering the biological accelerator mass spectrometry activities at Uppsala University. The research utilizes the Uppsala University Tandem laboratory facilities, including a 5 MV Pelletron tandem accelerator and two stable isotope ratio mass spectrometers. In addition, a dedicated sample preparation laboratory for biological samples with natural activity is in use, as well as another laboratory specifically for C-14-labeled samples. A variety of ongoing projects are described and presented. Examples are: (1) Ultra-small sample AMS. We routinely analyze samples with masses in the 5-10 mu g C range. Data is presented regarding the sample preparation method, (2) bomb peak biological dating of ultra-small samples. A long term project is presented where purified and cell-specific DNA from various part of the human body including the heart and the brain are analyzed with the aim of extracting regeneration rate of the various human cells, (3) biological dating of various human biopsies, including atherosclerosis related plaques is presented. The average built up time of the surgically removed human carotid plaques have been measured and correlated to various data including the level of insulin in the human blood, and (4) In addition to standard microdosing type measurements using small pharmaceutical drugs, pre-clinical pharmacokinetic data from a macromolecular drug candidate are discussed.

  • 277.
    Salehpour, Mehran
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Håkansson, Karl
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy. Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Small sample Accelerator Mass Spectrometry for biomedical applications2015In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 361, p. 43-47Article in journal (Refereed)
    Abstract [en]

    The Accelerator Mass Spectrometry activities at Uppsala University include a group dedicated to the biomedical applications, involving natural level samples, as well as C-14-labeled substances requiring separate handling and preparation. For most applications sufficient sample amounts are available but many applications are limited to samples sizes in the mu g-range. We have developed a preparation procedure for small samples biomedical applications, where a few mu g C can be analyzed, albeit with compromised precision. The latest results for the small sample AMS method are shown and some of the biomedical activities at our laboratory are presented.

  • 278.
    Salehpour, Mehran
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Håkansson, Karl
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Wacker, L.
    ETH, Ion Phys, Otto Stern Weg 5, CH-8093 Zurich, Switzerland..
    Synal, H-A
    ETH, Ion Phys, Otto Stern Weg 5, CH-8093 Zurich, Switzerland..
    Performance report for the low energy compact radiocarbon accelerator mass spectrometer at Uppsala University2016Conference paper (Refereed)
    Abstract [en]

    A range of ion beam analysis activities are ongoing at Uppsala University, including Accelerator Mass Spectrometry (AMS). Various isotopes are used for AMS but the isotope with the widest variety of applications is radiocarbon. Up until recently, only the 5 MV Pelletron tandem accelerator had been used at our site for radiocarbon AMS, ordinarily using 12 MeV C-14,13,12(3+) ions. Recently a new radiocarbon AMS system, the Green-MICADAS, developed at the ion physics group at ETH Zurich, was installed. The system has a number of outstanding features which will be described. The system operates at a terminal voltage of 175 kV and uses helium stripper gas, extracting singly charged carbon ions. The low- and high energy mass spectrometers in the system are stigmatic dipole permanent magnets (0.42 and 0.97 T) requiring no electrical power nor cooling water. The system measures both the C-14/C-12 and the C-13/C-12 ratios on-line. Performance of the system is presented for both standard mg samples as well as mu g-sized samples.

  • 279.
    Sanchez, D., Alonso, J. A., Garcia-Hernandez, M., Martinez-Lope,M. J., Martinez J. L., and Mellergård, A.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Neutron-diffraction magnetic scattering in ordered and disordered Sr2FeMoO62002In: Appl. Phys., Vol. A74, p. 1752-1754Article in journal (Refereed)
  • 280.
    Sanchez, D., Alonso, J. A., Garcia-Hernandez, M., Martinez-Lope, M. J., Martinez, J. L., and Mellergård, A.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Origin of neutron magnetic scattering in antisite-disordered Sr2 FeMoO6 double perovskites, Modelling of atomic and magnetic structures from powder diffraction data: recent developments of the RMCPOW method2002In: Phys. Rev. B, Vol. 65, p. 104426-Article in journal (Refereed)
  • 281.
    Sanchez, D., Garcia-Hernandez, M., Martinez, J.L., Alonso, J.A. Martinez-Lope, M.J., Casais, M.T., Mellergard, A.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    The effect of substitutional mis-site disorder on the structural, magnetic and electronic transport properties of Sr2FeMoO6 double perovskites2002In: J. Magn. Magn. Mater., Vol. 242, p. 729-731Article in journal (Refereed)
  • 282.
    Sapota, Tomasz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Peck, John
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    King, John
    Prokopenko, Alexander
    Kuzmin, Mikhail
    A late Cenozoic Earth’s crust and climate dynamics record from Lake Baikal2004In: Journal of Paleolimnology, ISSN 0921-2728, E-ISSN 1573-0417, Vol. 32, no 4, p. 341-349Article in journal (Refereed)
    Abstract [en]

    The sedimentary record from Lake Baikal (Siberia, Russia) has been an important source of information about paleoclimatic variability in the northern hemisphere and dynamics of continental rift development. A lack of reliable chronology has, however, been a major obstacle to fully utilizing the Baikal archive for time scales beyond about 4-5 Myr. In this paper we use the distribution of 10Be to establish a new chronology for the longest core drilled in Lake Baikal so far. The 10Be-based chronology spans the last 8 Myr and provides better constraints on sedimentation rates and consequently on an east-west tectonic extension in the lake, which has been apparently coeval with other rifts in Asia that are related to the Tibetan plateau uplift. Our data also show higher 10Be flux in the sediment section older then 5 Myr compared with the younger period. This can be explained partly by warm and humid climatic conditions of the Miocene and partly by a high cosmic ray flux to the Earth resulting from possible low geomagnetic field intensity during that time.

  • 283.
    Sawicka, M., J.M.Daugas, H.Grawe, S.Cwiok, D.L.Balabanski, R.Beraud, C.Bingham, C.Borcea, M.La Commara, G.de France, G.Georgiev, M.Gorska, R.Grzywacz, M.Hass, M.Hellstrom, Z.Janas, M.Lewitowicz, H.Mach, I.Matea, G.Neyens, C.O'Leary, F.de Oliveira Santos,
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Isomeric decay of 67Fe -- Evidence for deformation2003In: Eur.Phys.J. A, Vol. 16, p. 51-Article in journal (Refereed)
  • 284.
    Sawicka, S., R.Grzywacz, I.Matea, H.Grawe, M.Pfutzner, J.M.Daugas, M.Lewitowicz, D.L.Balabanski, F.Becker, G.Belier, C.Bingham, C.Borcea, E.Bouchez, A.Buta, M.La Commara, E.Dragulescu, G.de France, G.Georgiev, J.Giovinazzo, M.Gorska, F.Hammache, M.Hass, M
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Low energy levels in 72Ni2003In: Phys.Rev. C, Vol. 68, p. 044304-Article in journal (Other scientific)
  • 285. Shaheen, R.
    et al.
    Bashir, J.
    Rundlöf, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Rennie, Adrian
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    The crystal structure of CaLaMnFeOdouble perovskite2005In: Materials letters (General ed.), ISSN 0167-577X, E-ISSN 1873-4979, Vol. 59, no 18, p. 2296-2299Article in journal (Refereed)
  • 286. Shaheen, R.
    et al.
    Bashir, J.
    Siddique, M.
    Rundlöf, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Rennie, Adrian
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Crystal structure of ALaMnFeO(6) (A = Ca, Sr, Ba)2006In: Physica. B, Condensed matter, ISSN 0921-4526, E-ISSN 1873-2135, Vol. 385, p. 103-105Article in journal (Refereed)
    Abstract [en]

    The crystal structures of perovskites of the formula ALaMnFeO(6) (A = Ca, Sr, Ba) have been characterised by powder X-ray, neutron powder diffraction and Mossbauer spectroscopy. Both CaLaMnFeO6 and BaLaMnFeO6 were found to crystallise in orthorhombic symmetry (space group Pbnm), whereas SrLaMnFeO6 was rhombohedral (space group R (3) over barc). No evidence of phase transformation or magnetic structure was noticed in the low-temperature (10K) neutron diffraction measurements. The Mossbauer parameters indicate that iron is present in Fe3+ high-spin (d(5) configuration) state in octahedral coordination.

  • 287.
    Shergur J, Brown BA, Fedoseyev V, Koster U, Kratz KL, Sweryniak D, Walters WB, Wohr A, Fedorov D, Hannawald M, Hjorth-Jensen M, Mishin V, Pfeiffer B, Ressler JJ, Fynbo HOU, Hoff P, Mach H, Nilsson T, Wilhelmsen-Rolander K, Simon H, Bickley A and the ISOLD
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Beta-Decay Studies of 135-137Sn using Selective Resonance Laser Ionization Techniques2002In: Phys. Rev., Vol. C65, p. 34313-Article in journal (Refereed)
  • 288.
    Shimojo, F
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Ebbsjo, I
    Kalia, RK
    Nakano, A
    Rino, JP
    Vashishta, P
    Molecular dynamics simulation of structural transformation in silicon carbide under pressure2000In: PHYSICAL REVIEW LETTERS, ISSN 0031-9007, Vol. 84, no 15, p. 3338-3341Article in journal (Refereed)
    Abstract [en]

    Pressure-induced structural transformation in cubic silicon carbide is studied with the isothermal-iosbaric molecular-dynamics method using a new interatomic potential scheme. The reversible transformation between the fourfold coordinated zinc-blende stru

  • 289. Sijinkumar, A. V.
    et al.
    Nath, B. Nagender
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Pulleniatina Minimum Events in the Andaman Sea (NE Indian Ocean): Implications for winter monsoon and thermocline changes2011In: Marine Micropaleontology, ISSN 0377-8398, E-ISSN 1872-6186, Vol. 81, no 3-4, p. 88-94Article in journal (Refereed)
    Abstract [en]

    The late Quaternary record of Pulleniatina obliquiloculata was investigated from two well dated sediment cores from the Andaman Sea (NE Indian Ocean) to examine its paleoceanographic significance and the presence of the Pulleniatina Minimum Events (PME) in the western North Pacific. As in the Pacific, our study shows that PMEs exist in the Indian Ocean albeit with a lower intensity. The Holocene PME occurs between 4.5 and 3.0 cal ka BP with a considerable reduction in P. obliquiloculata abundance, and which matches well with the Pacific records influenced by the Kuroshio Current. Additionally, two significant minimum events of P. obliquiloculata are also seen during the Younger Dryas (YD) and late Last Glacial Maximum (LGM, 20-18 cal ka BP). Overall, the PMEs of the Andaman Sea are not current driven events like in the western Pacific margin either by the weakening of the Kuroshio Current or reduced winter SSTs. The PMEs of the Andaman Sea are characterised by lower abundances of thermocline species indicating the increased depth of the thermocline (DOT) and reduced winter SSTs mainly during the minimum events of the YD and late LGM. The high SSTs during the Holocene PME make this event a mystery. However, the presence of PMEs in the Andaman Sea suggests that these events are not confined to areas influenced by the Kuroshio Current but may be responding to a broad scale oceanographic-climatic process or mechanism which needs to be explored with a detailed study.

  • 290. Sjunneskog, Charlotte
    et al.
    Scherer, R.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Be-10 in glacial marine sediment of the Ross Sea, Antarctica, a potential tracer of depositional environment and sediment chronology2007In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 259, no 1, p. 576-583Article in journal (Refereed)
    Abstract [en]

    Beryllium isotopes (9Be and 10Be) distribution in Holocene and late Pleistocene glacial ice and sediment facies from sub-ice stream and sub-ice shelf settings of the Ross sector of the West Antarctic Ice Sheet (WAIS) and from the open Ross Sea are presented, to assess the temporal and spatial variability of these tracers. Significant variation is detected (>one order of magnitude) among Holocene post-glacial deposits. Late Pleistocene diamictons from bathymetric lows in the Ross Sea show depleted concentrations that are less variable among sites and distinctly lower than bank deposits of similar age. In general, sub-ice shelf and ice stream sediments are the most depleted in 10Be. 10Be with its longer half-life and different pathways compared apparant to 14C is found to be a sensitive marker for evaluating the complex spatial and temporal relationships between texturally similar sediments formed by different depositional processes.

  • 291. Snyder, Glen
    et al.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Global distribution and long-term fate of anthropogenic I-129 in marine and surface water reservoirs2010In: Geochemistry Geophysics Geosystems, ISSN 1525-2027, E-ISSN 1525-2027, Vol. 11, p. Q04010-Article in journal (Refereed)
    Abstract [en]

    Since the advent of the nuclear age in the mid-1940s, the mass of radioactive I-129 (t(1/2) = 15.7 Myr) circulating in the Earth's hydrosphere has increased nearly fortyfold from its natural background level of 140 kg. Nuclear fuel reprocessing has been by far the major contributor, responsible for releasing 5400 kg of I-129, primarily into the North Atlantic Ocean. Regional and global trends in the distribution of the I-129 inventory are elucidated from an examination of more than 600 determinations of I-129 in environmental samples from around the world. Because the major point sources are located in Europe and the United States, more than 99% of the present I-129 reservoir is distributed in the Northern Hemisphere, where both I-129 concentrations and I-129/I ratios in rivers, lakes, and shallow seawater are several orders of magnitude above the preanthropogenic background. Downwelling in the North Atlantic presently provides a major sink for marine I-129; however, marine upwelling along the margins of the Pacific will eventually return part of this anthropogenic input to the ocean surface, where it will find its way back into surface waters and the atmosphere. Iodine-129 has a long half-life (15.7 Myr), and consequently, there is also the possibility that climate change will influence the dynamics of iodine transfer in surface reservoirs. We model the effect of a collapse in thermohaline circulation and project a concentration increase of more than 3 orders of magnitude in shallow oceans over the 10,000 years that follow if nuclear reprocessing is to continue at the present rate.

  • 292. Sorby, M. H.
    et al.
    Mellergård, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Hauback, B. C.
    Fjellvåg, H.
    Delaplane, Robert G.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Reverse Monte Carlo investigation of the temperature dependent deuterium distribution in ZrCr2D42008In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 457, no 1-2, p. 225-232Article in journal (Refereed)
    Abstract [en]

    Short-range correlations in ZrCr2D4 have been investigated with total neutron scattering and Reverse Monte Carlo (RMC) modelling. Data were collected for the deuteride with a disordered deuterium lattice at 298 K, a partly ordered deuterium lattice at 248 K and a fully ordered deuterium lattice at 150 K. Short-range order (SRO) prevents occupation of interstitial sites closer than 2 angstrom from deuterium atoms in the disordered and partly ordered samples in agreement with the Switendick criterion and earlier investigations. The deuterium configurations at 298 and 248 K resemble those found in the fully ordered phase at length scales up to about 4 angstrom. There is no appreciable difference in the short-range deuterium correlations or the extent of the SRO at 248 K as compared to at 298 K. The differences and similarities with the previously investigated compound VD0.8 are discussed.

  • 293. Spalding, Kl
    et al.
    Bergmann, O.
    Alkass, K.
    Buchholz, B.
    Salehpour, Mehran
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Liebl, J.
    Steier, P.
    Kutschera, W.
    Bernard, S.
    Druid, H.
    Frisen, J.
    Radiocarbon analysis of neurogenesis in the adult human brain2013In: Journal of Molecular Neuroscience, ISSN 0895-8696, E-ISSN 1559-1166, Vol. 51, no S1, p. S117-S117Article in journal (Other academic)
  • 294. Spaulding, Kirsty
    et al.
    Bergmann, Olaf
    Alkass, Kanar
    Bernard, Samuel
    Salehpour, Mehran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Huttner, Hagen
    Boström, Emil
    Westerlund, Isabelle
    Vial, Céline
    Buchholz, Bruce
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Mash, Deborah
    Druid, Henrik
    Frisén, Jonas
    Dynamics of Hippocampal Neurogenesis in Adult Humans2013In: Cell, ISSN 0092-8674, E-ISSN 1097-4172, Vol. 153, no 6, p. 1219-1227Article in journal (Refereed)
    Abstract [en]

    Adult-born hippocampal neurons are important for cognitive plasticity in rodents. There is evidence for hippocampal neurogenesis in adult humans, although whether its extent is sufficient to have func- tional significance has been questioned. We have assessed the generation of hippocampal cells in humans by measuring the concentration of nuclear- bomb-test-derived 14C in genomic DNA, and we present an integrated model of the cell turnover dy- namics. We found that a large subpopulation of hip- pocampal neurons constituting one-third of the neu- rons is subject to exchange. In adult humans, 700 new neurons are added in each hippocampus per day, corresponding to an annual turnover of 1.75% of the neurons within the renewing fraction, with a modest decline during aging. We conclude that neu- rons are generated throughout adulthood and that the rates are comparable in middle-aged humans and mice, suggesting that adult hippocampal neuro- genesis may contribute to human brain function.

  • 295.
    Ström, E., Zhang, J., Eriksson, S., Li, C. and Deng, D.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    The influence of alloying elements on phase constitution and microstructures on Mo3M2Si3 (M= Cr, Ti, Nb, Ni, or Co)2002In: Materials Science and Engineering, Vol. A329-331, p. 289-Article in journal (Refereed)
  • 296.
    Ström, Petter
    et al.
    KTH Royal Inst Technol, Sch Elect Engn, Dept Fus Plasma Phys, SE-10044 Stockholm, Sweden..
    Petersson, Per
    KTH Royal Inst Technol, Sch Elect Engn, Dept Fus Plasma Phys, SE-10044 Stockholm, Sweden..
    Rubel, Marek
    KTH Royal Inst Technol, Sch Elect Engn, Dept Fus Plasma Phys, SE-10044 Stockholm, Sweden..
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics. Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    A combined segmented anode gas ionization chamber and time-of-flight detector for heavy ion elastic recoil detection analysis2016In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 87, no 10, article id 103303Article in journal (Refereed)
    Abstract [en]

    A dedicated detector system for heavy ion elastic recoil detection analysis at the Tandem Laboratory of Uppsala University is presented. Benefits of combining a time-of-flight measurement with a segmented anode gas ionization chamber are demonstrated. The capability of ion species identification is improved with the present system, compared to that obtained when using a single solid state silicon detector for the full ion energy signal. The system enables separation of light elements, up to Neon, based on atomic number while signals from heavy elements such as molybdenum and tungsten are separated based on mass, to a sample depth on the order of 1 mu m. The performance of the system is discussed and a selection of material analysis applications is given. Plasma-facing materials from fusion experiments, in particular metal mirrors, are used as a main example for the discussion. Marker experiments using nitrogen-15 or oxygen-18 are specific cases for which the described improved species separation and sensitivity are required. Resilience to radiation damage and significantly improved energy resolution for heavy elements at low energies are additional benefits of the gas ionization chamber over a solid state detector based system.

  • 297.
    Sturevik-Storm, Anna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Berggren, Ann-Marie
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Muscheler, Raimund
    Dahl-Jensen, Dorthe
    Vinther, Bo M.
    Usoskin, Ilya
    Be-10 climate fingerprints during the Eemian in the NEEM ice core, Greenland2014In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 4, p. 6408-Article in journal (Refereed)
    Abstract [en]

    Several deep Greenland ice cores have been retrieved, however, capturing the Eemian period has been problematic due to stratigraphic disturbances in the ice. The new Greenland deep ice core from the NEEM site (77.456 degrees N, 51.066 degrees W, 2450 m.a.s.l) recovered a relatively complete Eemian record. Here we discuss the cosmogenic Be-10 isotope record from this core. The results show Eemian average 10Be concentrations about 0.7 times lower than in the Holocene which suggests a warmer climate and approximately 65-90% higher precipitation in Northern Greenland compared to today. Effects of shorter solar variations on 10Be concentration are smoothed out due to coarse time resolution, but occurrence of a solar maximum at 115.26-115.36 kyr BP is proposed. Relatively high 10Be concentrations are found in the basal ice sections of the core which may originate from the glacial-interglacial transition and relate to a geomagnetic excursion about 200 kyr BP.

  • 298.
    Sundin, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, International Science Programme (ISP).
    International Science Programme (ISP): Annual Report to Sida 20102011Report (Other (popular science, discussion, etc.))
    Abstract [en]

    ISP provides long‐term support to Research Groups and Scientific Networks. The work is carried out in close cooperation with research groups at more advanced host institutions. Although Uppsala University is the base of the operation, ISP functions as an international program and host laboratories may be at other Swedish universities, in other Nordic and European countries, and in the regions. This is to meet the requests from developing countries on their own terms. ISP also handles other research programs, organised by Sida.

    In 2010, 28 Research Groups were supported in 10 African and 4 Asian countries; 5 groups in Kenya, 4 in Sri Lanka, 3 each in Laos and Zimbabwe, 2 each in Bangladesh, Burkina Faso, Cambodia, and Malawi, and 1 each in Ghana, Mali, Nigeria, Senegal and Zambia. In addition, 15 regional Scientific Networks were supported, 12 in Africa, 2 in Asia, and 1 in Latin America.

    A total of 117 PhD students (12% of which were female) were active in ISP‐supported research groups and scientific networks in 2010, of which 57% on a sandwich basis. During the year, 25 students graduated on the PhD level, about half of them participating in sandwich programs. The number Master students were 232, of which 26% were female and 10% participated in sandwich programs.

    Regarding dissemination of scientific findings in 2010 it can be noted that most (66%) of the in total 83 publications in international scientific journals were in high ranking journals listed with ISI impact factors. International publications clearly dominated over publication in regional (15) and national (2) journals. In addition, 18 contributions were made in the form of books, chapters, popular publications andtechnical reports.

  • 299.
    Sundin, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, International Science Programme (ISP).
    International Science Programme (ISP): Annual Report to Sida 20112012Report (Other (popular science, discussion, etc.))
    Abstract [en]

    ISP provides long-term support to Research Groups and Scientific Networks. The work is carried out in close cooperation with research groups at more advanced host institutions. Although Uppsala University is the base of the operation, ISP functions as an international program and host laboratories may be at other Swedish universities, in other Nordic and European countries, and in the regions. This is to meet the requests from developing countries on their own terms. ISP also handles other research programs, organised by Sida.

    In 2011, ISP provided support to 31 research groups and 14 regional networks. The supported groups are located in ten countries in Asia and Africa; Bangladesh, Burkina Faso, Cambodia, Ethiopia, Kenya, Laos, Mali, Uganda, Zambia, and Zimbabwe. Supported regional networks are coordinated from countries in Asia, Africa and Latin America. Groups and networks together utilized about 19 million SEK.

    A total of 185 PhD students (24% of which were female) were active in ISP-supported research groups and scientific networks in 2011, of which 54% on a sandwich basis. During the year, 19 students graduated on the PhD level, about a third of them participating in sandwich programs. The number Master students was 319, of which 27% were female, and 12% participated in sandwich programs. Of the 96 graduating, only 1 participated on a sandwich basis.

    Regarding dissemination of scientific findings in 2011 it can be noted that 44% of the in total 148 publications in international scientific journals were in high-ranking journals listed with ISI impact factors. In addition, 23 contributions were made in the form of books, chapters, popular publications and technical reports. Furthermore, 183 contributions were made to scientific conferences, 41% at the international, 33% at the regional, and 26% at the national level, and 42 scientific events were arranged.

  • 300.
    Sundin, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, International Science Programme (ISP).
    Support to the Basic Sciences in Developing Countries: Importance of Scientific Networks2011In: Asian Biotechnology and Development Review, ISSN 0972-7566, Vol. 13, no 3, p. 125-129Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    The International Science Programme (ISP) at Uppsala University, Sweden, since 1961 has been devoted to long-term support for building capacity in scientific research and higher education in developing countries in the Basic sciences. An increased domestic capacity for research and higher education in the Basic sciences has a long-term impact on development. In the larger perspective support to the Basic sciences is generally low or neglected, despite their importance for sustaining applied sciences and quality science education. Regional and interregional cooperation may be a fruitful approach to overcome many constraints, adding value to participating scientists and their institutions. Therefore, ISP support to regional collaboration and the formation of scientific networks was initiated already in the early 1980s. Currently, nine chemistry networks are supported, in the fields of analytical chemistry, biotechnology, environmental chemistry, natural products chemistry, and technical and analytical support and training. The activities carried out by the networks are diverse. For support to networks to continue in the future the demands will increase to demonstrate benefits, added value, achievements, impacts, and sustainability.

345678 251 - 300 of 366
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf