uu.seUppsala University Publications
Change search
Refine search result
1234567 1 - 50 of 360
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.
  • 1. Abbuehl, Luca M.
    et al.
    Norton, Kevin P.
    Schlunegger, Fritz
    Kracht, Oliver
    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.
    El Niño forcing on 10Be-based surface denudation rates in the northwestern Peruvian Andes?2010In: Geomorphology, ISSN 0169-555X, E-ISSN 1872-695X, Vol. 123, no 3-4, p. 257-268Article in journal (Refereed)
    Abstract [en]

    High magnitude precipitation events provide large contributions to landscape formation and surface denudation in arid environments. Here, we quantify the precipitation-dependent geomorphic processes within the Rio Piura drainage basin located on the Western Escarpment of the northern Peruvian Andes at 5 degrees S latitude. In this region, monsoonal easterly winds bring precipitation to the >3000 m asl high headwaters, from where the annual amount of precipitation decreases downstream toward the Pacific coast. Denudation rates are highest in the knickzones near the headwaters, similar to 200-300 mm ky(-1), and sediment discharge is limited by the transport capacity of the channel network. Every few years, this situation is perturbed by westerly, wind-driven heavy precipitation during El Nino events and results in supply-limited sediment discharge as indicated by bedrock channels. The detailed analysis of the stream-long profiles of two river basins within the Rio Piura catchment reveals a distinct knickzone in the transition zone between the easterly and westerly climatic influences, suggesting an En Nino forcing on the longitudinal channel profiles over at least Holocene timescales. Measured trunk stream catchment-wide denudation rates are up to ca. 300 mm ky(-1) and decrease successively downstream along the river profiles. Denudation rates of tributary rivers are ca. 200 mm ky(-1) near the plateau and show a stronger downstream decreasing trend than trunk stream rates. This suggests that the landscape is in a transient stage of local relief growth, which is driven by fluvial incision. This corroborates the results of paleoclimate studies that point towards higher El Nino frequencies during the past ca. 3000 years, leading to higher runoff and more erosion in the trunk channel compared to the hillslopes and thus growth of local relief. Downstream increases in channel gradient spatially coincide with the reaches of highest precipitation rates during El Nino events, we therefore interpret that Holocene landscape evolution has largely been controlled by climate. The ky-timescale of the Be-10 data together with the transience of the landscape implies that El Nino events in northwestern Peru have occurred since at least the Holocene, and that adjustment to channel incision is still taking place.

  • 2. Abbühl, Luca M.
    et al.
    Norton, Kevin P.
    Jansen, John D.
    Schlunegger, Fritz
    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.
    Erosion rates and mechanisms of knickzone retreat inferred from (10)Be measured across strong climate gradients on the northern and central Andes Western Escarpment2011In: Earth Surface Processes and Landforms, ISSN 0197-9337, E-ISSN 1096-9837, Vol. 36, no 11, p. 1464-1473Article in journal (Refereed)
    Abstract [en]

    A steep escarpment edge, deep gorges and distinct knickzones in river profiles characterize the landscape on the Western Escarpment of the Andes between similar to 5 degrees S and similar to 18 degrees S (northern Peru to northern Chile). Strong north-south and east-west precipitation gradients are exploited in order to determine how climate affects denudation rates in three river basins spanning an otherwise relatively uniform geologic and geomorphologic setting. Late Miocene tectonics uplifted the Meseta/Altiplano plateau (similar to 3000 m a.s.l.), which is underlain by a series of Tertiary volcanic-volcanoclastic rocks. Streams on this plateau remain graded to the Late Miocene base level. Below the rim of the Meseta, streams have responded to this ramp uplift by incising deeply into fractured Mesozoic rocks via a series of steep, headward retreating knickzones that grade to the present-day base level defined by the Pacific Ocean. It is found that the Tertiary units on the plateau function as cap-rocks, which aid in the parallel retreat of the sharp escarpment edge and upper knickzone tips. (10)Be-derived catchment denudation rates of the Rio Piura (5 degrees S), Rio Pisco (13 degrees S) and Rio Lluta (18 degrees S) average similar to 10 mm ky(-1) on the Meseta/Altiplano, irrespective of precipitation rates; whereas, downstream of the escarpment edge, denudation rates range from 10 mm ky(-1) to 250 mm ky(-1) and correlate positively with precipitation rates, but show no strong correlation with hillslope angles or channel steepness. These relationships are explained by the presence of a cap-rock and climate-driven fluvial incision that steepens hillslopes to near-threshold conditions. Since escarpment retreat and the precipitation pattern were established at least in the Miocene, it is speculated that the present-day distribution of morphology and denudation rates has probably remained largely unchanged during the past several millions of years as the knickzones have propagated headward into the plateau.

  • 3.
    Abrahamsson, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Accelerator mass spectrometry group.
    Tuning of the Excited State Properties of Ruthenium(II)-Polypyridyl Complexes2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Processes where a molecule absorbs visible light and then converts the solar energy into chemical energy are important in many biological systems, such as photosynthesis and also in many technical applications e.g. photovoltaics. This thesis describes a part of a multidisciplinary project, aiming at a functional mimic of the natural photosynthesis, with the overall goal of production of a renewable fuel from sun and water. More specific, the thesis is focused on design and photophysical characterization of new photosensitizers, i.e. light absorbers that should be capable of transferring electrons to an acceptor and be suitable building blocks for supramolecular rod-like donor-photosensitizer-acceptor arrays.

    The excited state lifetime, the excited state energy and the geometry are important properties for a photosensitizer. The work presented here describes a new strategy to obtain longer excited state lifetimes of the geometrically favorable Ru(II)-bistridentate type complexes, without a concomitant substantial decrease in excited state energy. The basic idea is that a more octahedral coordination around the Ru will lead to longer excited state lifetimes. In the first generation of new photosensitizers a 50-fold increase of the excited state lifetime was observed, going from 0.25 ns for the model complex to 15 ns for the best photosensitizer. The second generation goes another step forward, to an excited state lifetime of 810 ns. Furthermore, the third generation of new photosensitizers show excited state lifetimes in the 0.45 - 5.5 microsecond region at room temperature, a significant improvement. In addition, the third generation of photosensitizers are suitable for further symmetric attachment of electron donor and acceptor motifs, and it is shown that the favorable properties are maintained upon the attachment of anchoring groups. The reactivity of the excited state towards light-induced reactions is proved and the photostability is sufficient so the new design strategy has proven successful.

    List of papers
    1. A tridentate Ligand for Preparation of Bisterpyridine-like Ruthenium(II) Complexes with an Increased Excited State Lifetime
    Open this publication in new window or tab >>A tridentate Ligand for Preparation of Bisterpyridine-like Ruthenium(II) Complexes with an Increased Excited State Lifetime
    Show others...
    2004 (English)In: Inorganic Chemistry Communications, ISSN 1387-7003, E-ISSN 1879-0259, Vol. 7, no 3, p. 337-340Article in journal (Refereed) Published
    Abstract [en]

    A new tridentate polypyridine ligand, 6-(2-picolyl)-2,2-bipyridine, as well as its homoleptic Ru(II) complex has been prepared. Photophysical studies show a prolonged lifetime of the excited state compared to [Ru(tpy)2]2+, where tpy is 2,2:6,2″-terpyridine.

    Place, publisher, year, edition, pages
    Elsevier, 2004
    National Category
    Inorganic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-95083 (URN)10.1016/j.inoche.2003.12.007 (DOI)
    Available from: 2006-11-09 Created: 2006-11-09 Last updated: 2017-12-14Bibliographically approved
    2. A New Strategy for the Improvement of Photophysical Properties in Ruthenium(II) Polypyridyl Complexes: Synthesis and Photophysical and Electrochemical Characterization of Six Mononuclear Ruthenium(II) Bisterpyridine-Type Complexes
    Open this publication in new window or tab >>A New Strategy for the Improvement of Photophysical Properties in Ruthenium(II) Polypyridyl Complexes: Synthesis and Photophysical and Electrochemical Characterization of Six Mononuclear Ruthenium(II) Bisterpyridine-Type Complexes
    Show others...
    2005 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 44, no 9, p. 3215-3225Article in journal (Refereed) Published
    Place, publisher, year, edition, pages
    ACS, 2005
    National Category
    Inorganic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-95084 (URN)10.1021/ic048247a (DOI)15847430 (PubMedID)
    Available from: 2006-11-09 Created: 2006-11-09 Last updated: 2017-12-14Bibliographically approved
    3. Steric influence on the excited-state lifetimes of ruthenium complexes with bipyridyl-alkanylene-pyridyl ligands.
    Open this publication in new window or tab >>Steric influence on the excited-state lifetimes of ruthenium complexes with bipyridyl-alkanylene-pyridyl ligands.
    Show others...
    2008 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 47, no 9, p. 3540-3548Article in journal (Refereed) Published
    Abstract [en]

    The structural effect on the metal-to-ligand charge transfer (MLCT) excited-state lifetime has been investigated in bis-tridentate Ru(II)-polypyridyl complexes based on the terpyridine-like ligands [6-(2,2'-bipyridyl)](2-pyridyl)methane (1) and 2-[6-(2,2'-bipyridyl)]-2-(2-pyridyl)propane (2). A homoleptic ([Ru(2)(2)](2+)) and a heteroleptic complex ([Ru(ttpy)(2)](2+)) based on the new ligand 2 have been prepared and their photophysical and structural properties studied experimentally and theoretically and compared to the results for the previously reported [Ru(1)(2)](2+). The excited-state lifetime of the homoleptic Ru-II complex with the isopropylene-bridged ligand 2 was found to be 50 times shorter than that of the corresponding homoleptic Ru-II complex of ligand 1, containing a methylene bridge. A comparison of the ground-state geometries of the two homoleptic complexes shows that steric interactions involving the isopropylene bridges make the coordination to the central Ru-II ion less octahedral in [Ru(2)(2)](2+) than in [Ru(1)(2))(2+). Calculations indicate that the structural differences in these complexes influence their ligand field splittings as well as the relative stabilities of the triplet metal-to-ligand charge transfer ((MLCT)-M-3) and metal-centered ((MC)-M-3) excited states. The large difference in measured excited-state lifetimes for the two homoleptic Ru-II complexes is attributed to a strong influence of steric interactions on the ligand field strength, which in turn affects the activation barriers for thermal conversion from (MLCT)-M-3 states to short-lived (MC)-M-3 states.

    Place, publisher, year, edition, pages
    ACS, 2008
    National Category
    Inorganic Chemistry Analytical Chemistry
    Research subject
    Analytical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-95085 (URN)10.1021/ic7019457 (DOI)000255380500018 ()18402440 (PubMedID)
    Available from: 2006-11-09 Created: 2006-11-09 Last updated: 2017-12-14Bibliographically approved
    4. Six-membered Ring Chelate Complexes of Ru(II): Structural and photophysical effects
    Open this publication in new window or tab >>Six-membered Ring Chelate Complexes of Ru(II): Structural and photophysical effects
    Show others...
    2007 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 46, no 24, p. 10354-10364Article in journal (Refereed) Published
    Abstract [en]

    The structural and photophysical properties of Ru(II)−polypyridyl complexes with five- and six-membered chelate rings were studied for two bis-tridentate and two tris-bidentate complexes. The photophysical effect of introducing a six-membered chelate ring is most pronounced for the tridentate complex, leading to a room-temperature excited-state lifetime of 810 ns, a substantial increase from 180 ns for the five-membered chelate ring model complex. Contrasting this, the effect is the opposite in tris-bidentate complexes, in which the lifetime decreases from 430 ns to around 1 ns in going from a five-membered to six-membered chelate ring. All of the complexes were studied spectroscopically at both 80 K and ambient temperatures, and the temperature dependence of the excited-state lifetime was investigated for both of the bis-tridentate complexes. The main reason for the long excited-state lifetime in the six-membered chelate ring bis-tridentate complex was found to be a strong retardation of the activated decay via metal-centered states, largely due to an increased ligand field splitting due to the complex having a more-octahedral geometry.

    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-95086 (URN)10.1021/ic7011827 (DOI)000251109500039 ()17975915 (PubMedID)
    Available from: 2006-11-09 Created: 2006-11-09 Last updated: 2017-12-14Bibliographically approved
    5. A 3.0 mu s room temperature excited state lifetime of a bistridentate Ru-II-polypyridine complex for rod-like molecular arrays
    Open this publication in new window or tab >>A 3.0 mu s room temperature excited state lifetime of a bistridentate Ru-II-polypyridine complex for rod-like molecular arrays
    Show others...
    2006 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 128, no 39, p. 12616-12617Article in journal (Refereed) Published
    Abstract [en]

    A bistridentate RuII-polypyridine complex [Ru(bqp)2]2+ (bqp = 2,6-bis(8'-quinolinyl)pyridine) has been prepared, which has a coordination geometry much closer to a perfect octahedron than the typical Ru(terpyridine)2-type complex. Thus, the complex displays a 3.0 mus lifetime of the lowest excited metal-to-ligand charge transfer (3MLCT) state at room temperature. This is, to the best of our knowledge, the longest MLCT state lifetime reported for a RuII-polypyridyl complex at room temperature. The structure allows for the future construction of rod-like, isomer-free molecular arrays by substitution of donor and acceptor moieties on the central pyridine units. This makes it a promising photosensitizer for applications in molecular devices for artificial photosynthesis and molecular electronics.

    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-95087 (URN)10.1021/ja064262y (DOI)000240795000014 ()17002333 (PubMedID)
    Available from: 2006-11-09 Created: 2006-11-09 Last updated: 2017-12-14Bibliographically approved
    6. Bistridentate Ruthenium(II)polypyridyl-Type Complexes with Microsecond 3MLCT State Lifetimes: Sensitizers for Rod-Like Molecular Arrays
    Open this publication in new window or tab >>Bistridentate Ruthenium(II)polypyridyl-Type Complexes with Microsecond 3MLCT State Lifetimes: Sensitizers for Rod-Like Molecular Arrays
    Show others...
    2008 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 130, no 46, p. 15533-15542Article in journal (Refereed) Published
    Abstract [en]

    A series of bistridentate ruthenium(II) polypyridyl-type complexes based on the novel 2,6-di(quinolin-8-yl)pyridine (dqp) ligand have been synthesized and their photophysical properties have been studied. The complexes are amenable to substitution in the 4-position of the central pyridine with conserved quasi-C2v symmetry, which allows for extension to isomer-free, rod-like molecular arrays for vectorial control of electron and energy transfer. DFT calculations performed on the parent [Ru(dqp) 2](2+) complex (1) predicted a more octahedral structure than in the typical bistridentate complex [Ru(tpy)2](2+) (tpy is 2,2':6',2"-terpyridine) thanks to the larger ligand bite angle, which was confirmed by X-ray crystallography. A strong visible absorption band, with a maximum at 491 nm was assigned to a metal-to-ligand charge transfer (MLCT) transition, based on time-dependent DFT calculations. 1 shows room temperature emission (Phi = 0.02) from its lowest excited ((3)MLCT) state that has a very long lifetime (tau = 3 micros). The long lifetime is due to a stronger ligand field, because of the more octahedral structure, which makes the often dominant activated decay via short-lived metal-centered states insignificant also at elevated temperatures. A series of complexes based on dqp with electron donating and/or accepting substituents in the 4-position of the pyridine was prepared and the properties were compared to those of 1. An unprecedented (3)MLCT state lifetime of 5.5 micros was demonstrated for the homoleptic complex based on dqpCO2Et. The favorable photosensitizer properties of 1, such as a high extinction coefficient, high excited-state energy and long lifetime, and tunable redox potentials, are maintained upon substitution. In addition, the parent complex 1 is shown to be remarkably photostable and displays a high reactivity in light-induced electron and energy transfer reactions with typical energy and electron acceptors and donors: methylviologen, tetrathiofulvalene, and 9,10-diphenylanthracene. This new class of complexes constitutes a promising starting point for the construction of linear, rod-like molecular arrays for photosensitized reactions and applications in artificial photosynthesis and molecular electronics.

    Place, publisher, year, edition, pages
    ACS, 2008
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-95088 (URN)10.1021/ja804890k (DOI)000263311300058 ()19006410 (PubMedID)
    Available from: 2006-11-09 Created: 2006-11-09 Last updated: 2017-12-14Bibliographically approved
    7. Modulation of the lowest metal-to-ligand charge-transfer state in [Ru(bpy)(2)(N-N)](2+) systems by changing the N-N from hydrazone to azine: Photophysical Consequences
    Open this publication in new window or tab >>Modulation of the lowest metal-to-ligand charge-transfer state in [Ru(bpy)(2)(N-N)](2+) systems by changing the N-N from hydrazone to azine: Photophysical Consequences
    Show others...
    2006 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 45, no 23, p. 9580-9586Article in journal (Refereed) Published
    Abstract [en]

    Two Ru( II) complexes, [ Ru( bpy) L-2]( ClO4) 2 ( 1) and [ Ru( bpy)(2)L']( BF4) 2 ( 2), where bpy is 2,2'-bipyridine, L is diacetyl dihydrazone, and L' 1: 2 is the condensate of L and acetone, are synthesized. From X-ray crystal structures, both are found to contain distorted octahedral RuN62+ cores. NMR spectra show that the cations in 1 and 2 possess a C-2 axis in solution. They display the expected metal-to-ligand charge transfer ( (MLCT)-M-1) band in the 400 - 500 nm region. Complex 1 is nonemissive at room temperature in solution as well as at 80 K. In contrast, complex 2 gives rise to an appreciable emission upon excitation at 440 nm. The room-temperature emission is centered at 730 nm ( lambda(max)(em)) with a quantum yield ( em) of 0.002 and a lifetime ( tau(em)) of 42 ns in an air-equilibrated methanol - ethanol solution. At 80 K, Phi(em) = 0.007 and tau(em)= 178 ns, with a lambda(max)(em) of 690 nm, which is close to the 0 - 0 transition, indicating an (MLCT)-M-3 excited-state energy of 1.80 eV. The radiative rate constant ( 5 x 10(4) s(-1)) at room temperature and 80 K is almost temperature independent. From spectroelectrochemistry, it is found that bpy is easiest to reduce in 2 and that L is easiest in 1. The implications of this are that in 2 the lowest (MLCT)-M-3 state is localized on a bpy ligand and in 1 it is localized on L. Transient absorption results also support these assignments. As a consequence, even though 2 shows a fairly strong and long-lived emission from a Ru( II) -> bpy CT state, the Ru( II) -> L CT state in 1 shows no detectable emission even at 80 K.

    National Category
    Inorganic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-95089 (URN)10.1021/ic061116k (DOI)000241778900057 ()
    Available from: 2006-11-09 Created: 2006-11-09 Last updated: 2017-12-14Bibliographically approved
    8. Structural and Spectral Investigation of Ruthenium(II) Polypyridyl Complexes by DFT Calculations
    Open this publication in new window or tab >>Structural and Spectral Investigation of Ruthenium(II) Polypyridyl Complexes by DFT Calculations
    Show others...
    (English)In: Inorganic ChemistryArticle in journal (Refereed) Submitted
    Identifiers
    urn:nbn:se:uu:diva-95090 (URN)
    Available from: 2006-11-09 Created: 2006-11-09 Last updated: 2013-05-17Bibliographically approved
  • 4.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Accelerator mass spectrometry group. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Jäger, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Kumar, Rohan J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Österman, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Persson, Petter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Becker, Hans-Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Johansson, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Bistridentate Ruthenium(II)polypyridyl-Type Complexes with Microsecond 3MLCT State Lifetimes: Sensitizers for Rod-Like Molecular Arrays2008In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 130, no 46, p. 15533-15542Article in journal (Refereed)
    Abstract [en]

    A series of bistridentate ruthenium(II) polypyridyl-type complexes based on the novel 2,6-di(quinolin-8-yl)pyridine (dqp) ligand have been synthesized and their photophysical properties have been studied. The complexes are amenable to substitution in the 4-position of the central pyridine with conserved quasi-C2v symmetry, which allows for extension to isomer-free, rod-like molecular arrays for vectorial control of electron and energy transfer. DFT calculations performed on the parent [Ru(dqp) 2](2+) complex (1) predicted a more octahedral structure than in the typical bistridentate complex [Ru(tpy)2](2+) (tpy is 2,2':6',2"-terpyridine) thanks to the larger ligand bite angle, which was confirmed by X-ray crystallography. A strong visible absorption band, with a maximum at 491 nm was assigned to a metal-to-ligand charge transfer (MLCT) transition, based on time-dependent DFT calculations. 1 shows room temperature emission (Phi = 0.02) from its lowest excited ((3)MLCT) state that has a very long lifetime (tau = 3 micros). The long lifetime is due to a stronger ligand field, because of the more octahedral structure, which makes the often dominant activated decay via short-lived metal-centered states insignificant also at elevated temperatures. A series of complexes based on dqp with electron donating and/or accepting substituents in the 4-position of the pyridine was prepared and the properties were compared to those of 1. An unprecedented (3)MLCT state lifetime of 5.5 micros was demonstrated for the homoleptic complex based on dqpCO2Et. The favorable photosensitizer properties of 1, such as a high extinction coefficient, high excited-state energy and long lifetime, and tunable redox potentials, are maintained upon substitution. In addition, the parent complex 1 is shown to be remarkably photostable and displays a high reactivity in light-induced electron and energy transfer reactions with typical energy and electron acceptors and donors: methylviologen, tetrathiofulvalene, and 9,10-diphenylanthracene. This new class of complexes constitutes a promising starting point for the construction of linear, rod-like molecular arrays for photosensitized reactions and applications in artificial photosynthesis and molecular electronics.

  • 5.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Accelerator mass spectrometry group. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Jäger, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Österman, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Eriksson, Lars
    Persson, Petter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Quantum Chemistry.
    Becker, Hans-Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Johansson, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Photochemistry and Molecular Science.
    A 3.0 mu s room temperature excited state lifetime of a bistridentate Ru-II-polypyridine complex for rod-like molecular arrays2006In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 128, no 39, p. 12616-12617Article in journal (Refereed)
    Abstract [en]

    A bistridentate RuII-polypyridine complex [Ru(bqp)2]2+ (bqp = 2,6-bis(8'-quinolinyl)pyridine) has been prepared, which has a coordination geometry much closer to a perfect octahedron than the typical Ru(terpyridine)2-type complex. Thus, the complex displays a 3.0 mus lifetime of the lowest excited metal-to-ligand charge transfer (3MLCT) state at room temperature. This is, to the best of our knowledge, the longest MLCT state lifetime reported for a RuII-polypyridyl complex at room temperature. The structure allows for the future construction of rod-like, isomer-free molecular arrays by substitution of donor and acceptor moieties on the central pyridine units. This makes it a promising photosensitizer for applications in molecular devices for artificial photosynthesis and molecular electronics.

  • 6.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Accelerator mass spectrometry group. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    Wolpher, Henriette
    Johansson, Olof
    Larsson, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    Kritikos, Mikael
    Eriksson, Lars
    Norrby, Per-Ola
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry, Analytical Chemistry.
    Sun, Licheng
    Åkermark, Björn
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical Chemistry.
    A New Strategy for the Improvement of Photophysical Properties in Ruthenium(II) Polypyridyl Complexes: Synthesis and Photophysical and Electrochemical Characterization of Six Mononuclear Ruthenium(II) Bisterpyridine-Type Complexes2005In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 44, no 9, p. 3215-3225Article in journal (Refereed)
  • 7. Adolphi, Florian
    et al.
    Muscheler, Raimund
    Svensson, Anders
    Aldahan, Ala
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Beer, Jurg
    Sjolte, Jesper
    Bjorck, Svante
    Matthes, Katja
    Thieblemont, Remi
    Persistent link between solar activity and Greenland climate during the Last Glacial Maximum2014In: Nature Geoscience, ISSN 1752-0894, E-ISSN 1752-0908, Vol. 7, no 9, p. 662-666Article in journal (Refereed)
    Abstract [en]

    Changes in solar activity have previously been proposed to cause decadal- to millennial-scale fluctuations in both the modern and Holocene climates(1). Direct observational records of solar activity, such as sunspot numbers, exist for only the past few hundred years, so solar variability for earlier periods is typically reconstructed from measurements of cosmogenic radionuclides such as Be-10 and C-14 from ice cores and tree rings(2,3). Here we present a high-resolution Be-10 record from the ice core collected from central Greenland by the Greenland Ice Core Project (GRIP). The record spans from 22,500 to 10,000 years ago, and is based on new and compiled data(4-6). Using C-14 records(7,8) to control for climate-related influences on Be-10 deposition, we reconstruct centennial changes in solar activity. We find that during the Last Glacial Maximum, solar minima correlate with more negative delta O-18 values of ice and are accompanied by increased snow accumulation and sea-salt input over central Greenland. We suggest that solar minima could have induced changes in the stratosphere that favour the development of high-pressure blocking systems located to the south of Greenland, as has been found in observations and model simulations for recent climate(9,10). We conclude that the mechanism behind solar forcing of regional climate change may have been similar under both modern and Last Glacial Maximum climate conditions.

  • 8.
    Ahmad, Noor Azlinda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology.
    Baharudin, Zikri Abadi
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter.
    Cooray, Vernon
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter.
    Fernando, Mahendra
    Department of Physics.
    Radiation Field Spectra of Long-duration Cloud FlashesIn: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187XArticle in journal (Refereed)
    Abstract [en]

    The radiation electric fields produced by long-duration cloud flashes have been Fourier analyzed to determined the frequency spectrum in the range of 10 kHz to 10 MHz. The flashes were recorded within a distance of less than 20 km. The spectrum was normalized to 50 km distance and it shows a f-1 dependence within the entire frequency range.

  • 9.
    Ahmad, Noor Azlinda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology.
    Baharudin, Zikri Abadi
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter.
    Cooray, Vernon
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter.
    Fernando, Mahendra
    Some features of electric field waveform of Narrow Bipolar PulsesIn: Atmospheric research, ISSN 0169-8095, E-ISSN 1873-2895Article in journal (Refereed)
    Abstract [en]

    Narrow Bipolar Pulses (NBPs) are generated by intra-cloud discharge processes and they are of interest due to their strong broadband and high frequency (HF) emissions. In this study, we present some features of electric field waveform of NBPs which have not been reported in the literature.  The HF emission was observed to begin simultaneously with the onset of NBPs indicating no streamers or stepped-leader process was taking place before the initiation of NBPs. The electric field waveforms of NBPs were characterized by many fine peaks embedded intermittently on the rising and decaying edge of NBPs suggesting that some small scale electrical discharges were involved during the formation of NBPs.

     

  • 10.
    Albertini, G. Giuliani, A. Lin Peng, R. Manescu, A., Ponzetti, A.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Determination of the residual stress in a centrifuge bowl by neutron diffraction2002In: Applied Physics, Vol. A75, no 1Article in journal (Refereed)
  • 11.
    Albertini, G
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Peng, RL
    Manescu, A
    Ponzetti, A.
    Neutron diffraction measurement of residual stress in a centrifugal bowl of duplex steel2001In: J. Neutron Research, Vol. 9, p. 305-Article in journal (Other scientific)
  • 12.
    Aldahan, Ala Adin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Morad, Sadoon
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Ion Physics.
    Sturesson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    ElSaiy, A.
    10Be in rhodochrosite nodules from Neogene sediments along the Galapagos Ridge, equatorial Pacific2010In: 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 7-8, p. 1253-1256Article in journal (Refereed)
    Abstract [en]

    Microcrystalline, calcian rhodochrosite occurs as nodules around burrows in late Neogene pelagic sediments from the Galapagos Ridge in the Guatemala Basin, eastern equatorial Pacific (DSDP Leg 68; Site 503). Be-10 isotope revealed that the rhodochrosite nodules have formed under growth conditions much faster than those reported for Fe-Mn nodules. The overall REE patterns of the nodules and host pelagic sediments indicate element derivation mainly from marine pore water. However, variations in the shale normalised Eu values suggest influx of hydrothermal fluids into mounds area at Galapagos, which is also evidenced by the similar minor and major element contents in the nodules and host sediments.

  • 13.
    Aldahan, Ala
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Hedfors, Jim
    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. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics.
    Kulan, Abdulhadi
    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.
    Söderström, C.
    FOI, Swedish Defence Research Agency, Stockholm, Sweden.
    Atmospheric impact on beryllium isotopes as solar activity proxy2008In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 35, no L21812Article in journal (Refereed)
    Abstract [en]

    Reconstructing solar activity variability beyond the time scale of actual measurements provides invaluable data for modeling of past and future climate change. The 10 Be isotope has been a primary proxy archive of past solar activity and cosmic ray intensity, particularly for the last millennium. There is, however, a lack of direct high-resolution atmospheric time series on 10 Be that enable estimating atmospheric modulation on the production signal. Here we report quasi-weekly data on 10 Be and 7 Be isotopes covering the periods 1983-2000 and 1975-2006 respectively, that show, for the first time, coherent variations reflecting both atmospheric and production effects. Our data indicate intrusion of stratosphere/upper troposphere air masses that can modulate the isotopes production signal, and may induce relative peaks in the natural 10 Be archives (i.e., ice and sediment). The atmospheric impact on the Be-isotopes can disturb the production signals and consequently the estimate of past solar activity magnitude. Citation: Aldahan, A., J. Hedfors, G. Possnert, A. Kulan, A.-M. Berggren, and C. Soderstrom (2008), Atmospheric impact on beryllium isotopes as solar activity proxy, Geophys. Res. Lett., 35, L21812, doi: 10.1029/2008GL035189.

  • 14.
    Aldahan, Ala
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Persson, S
    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, Technology, Department of Engineering Sciences, Ion Physics.
    Hou, Xiaolin
    Distribution of I-127 and I-129 in preciptitation at high European latitudes2009In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 36, p. L11805-Article in journal (Refereed)
    Abstract [en]

     We here present the most extensive data set on the distribution of   I-127 and I-129 in precipitation (rain and snow) covering the period   2000-2006 and European latitudes 55 degrees N-68 degrees N. Our results   indicate a wide variation in the concentrations and fluxes of the two   isotopes associated with generally higher values at near coastal sites   compared to the inland ones. Total wet-related annual deposition of   I-127 and I-129 on Sweden and Denmark is estimated at about 1.2 x 10(9)   g and 60 g respectively. The average annual I-129 wet deposition   accounts for <1% and <0.05% of the total annual gaseous and liquid,   respectively, discharges from the Sellafiled and La Hague Facilities.   The I-127 annual wet deposition represents < 1% of the estimated global   oceanic iodine flux. Air mass trajectories suggest that events of   enhanced I-129 in precipitation are closely related to southwesterly weather fronts from regions of elevated concentrations.

  • 15.
    Aldahan, Ala
    et al.
    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.
    Alfimov, V.
    Cato, I.
    Sveriges geologiska undersökning.
    Kekli, Aziz
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Anthropogenic I-129 in the Baltic Sea2007In: 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. 491-495Article in journal (Refereed)
    Abstract [en]

    We report here data on the distribution of I-129 in water of the Baltic Sea and Skagerrak-Kattegat basins obtained through sampling campaigns during the years 2000 and 2001. I-129 in the water of the Skagerrak-Kattegat shows persistently high concentrations in both the surface and deep parts. A decreasing trend in surface water I-129 concentration is observed away from the Kattegat basin and into the Baltic Sea. Inventory calculations indicate that at least 95%of the isotope supply to the Baltic Sea is from the North Sea marine water via Skagerrak-Kattegat and only minor part is from riverine inflow and the Chernobyl accident. As the discharges from the nuclear reprocessing facilities were not decreased during the last decade, it is expected that more I-129 will accumulate in the Baltic Sea and related basins in the future. Consequently, systematic sampling is needed to reevaluate the concentration levels not only in the water, but also in the sediments and biota of the region.

  • 16.
    Aldahan, Ala
    et al.
    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.
    El Saiy, A.
    Abdelghany, O.
    Particle-bound Be-10 from a low latitude arid region2014In: Journal of Radioanalytical and Nuclear Chemistry, ISSN 0236-5731, E-ISSN 1588-2780, Vol. 299, no 3, p. 1709-1713Article in journal (Refereed)
    Abstract [en]

    The Be-10 isotope is widely used in geochronology, climate and environmental analyses and astrophysics where atmospheric deposition model estimate plays a vital role for the initial concentration. Data from arid regions have not been well constrained because of sparse measurement and here we present Be-10 concentration in samples of dust, soil, marine sediments and paleosol collected from an arid to semi-arid low latitude region. These results indicate concentrations that are about a factor of three lower than values expected from latitude zonal models, but are comparable with global atmospheric depositional model. The agreement and discrepancy between model and measured data are rather vital for establishing accurate initial Be-10 in the Earth's surface environment for reconstruction of paleoclimatic variability (precipitation rates and temperature).

  • 17.
    Aldahan, Ala
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Scherer, Reed
    Sjunneskog, C
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Ion Physics.
    Berggren, A-M
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Cosmogenic 10Be as an environmental tracer in subglacial Antarctic Lake2006In: SALE advanced Science and Technology Workshop, 24-26 April, Grenoble, France,, 2006, p. 2-3Conference paper (Refereed)
  • 18. Alfimov, Vasily
    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.
    Water masses and I-129 distribution in the Nordic Seas2013In: 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. 542-546Article in journal (Refereed)
    Abstract [en]

    The application of the radioactive isotope iodine-129 as a tracer of water circulation in the oceans has provided interesting information with respect to sources and mixing of different water masses. We here present results of I-129 distribution in water profiles located in the Nordic Seas and use the isotope to fingerprint water masses in the region. The samples were collected by the US research vessel Knorr in May-June 2002. I-129 signatures along the Norwegian Sea reflect a mixing of I-129-rich surface water along the Scandinavian continental slope and I-129-poor North Atlantic surface water. These two water masses become less segregated along the Fram Strait where apparent I-129 enrichment penetrates the return Arctic flow into the East Greenland Current. The I-129 data further suggest existence of a water mass that is not entirely labeled with respect to origin at the Denmark Strait bottom water. This water parcel probably originates from the Iceland Sea. I-129 data also shed light on the major deep water outflow from the Nordic Seas located at the Faeroe Bank Channel.

  • 19.
    Alfimov, Vasily
    et al.
    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.
    Aldahan, Ala
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Air and Water Science.
    Measurements of Cl-36 with a gas-filled magnet at the Uppsala tandem laboratory2007In: 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. 199-203Article in journal (Refereed)
    Abstract [en]

    The performance of a gas-filled magnet combined with a gas ionization detector for measurements of Cl-36 was systematically studied at the Uppsala tandem laboratory. Our tests were conducted at a terminal voltage of 4,6 MV using gas-foil stripping and a 37 MeV Cl-36(+7) ion beam. An optimal suppression of the interfering isobar S-36 in the stand-alone gas-filled magnet (2 mbar N-2 gas pressure) was found to be >= 300, and an additional >= 300 times reduction was achieved by the Eresidual signal of the two-anode gas ionization detector. The overall suppression in the order of >= 10(5) permits analysis of samples with a sulfur content of <= 5 ppm and Cl-36/Cl ratios of >= 10(-15). We have successfully measured samples with Cl-36/Cl ratios in the range of 10(-12)-10(-15) demonstrating the use of a mediumsized tandem accelerator system (similar to 1 MeV/amu) for Cl-36 AMS.

  • 20.
    Almer, J. , U Lienert, R. L. Peng, C. Schlauer and M. Odén
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Strain and texture analysis of coatings using high-energy x-rays2003In: Journal of Applied Physics., Vol. 94(1), p. 697-702Article in journal (Refereed)
  • 21.
    Andersson, Rebecca
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, International Science Programme (ISP).
    The Sandwich Model: A Successful Case of Capacity Building2017In: Internationalisation of Higher Education - A Handbook, Vol. 1, p. 54-64, article id D2.8Article in journal (Other academic)
    Abstract [en]

    Based on the experiences of the International Science Programme (ISP) at Uppsala University, Sweden, this article describes and analyses the sandwich (PhD) model, where students from lower income countries spend part of their training at their home university and part at a better resourced university abroad. The model does more than provide scholarships; it includes long-term collaboration and commitment between partners, and improvement of research environments at students’ home institutions. By maintaining the connections to the home institutions throughout their training, conducting research of local relevance, and benefiting from enhanced research opportunities, graduates are facilitated to return home and continue their research after graduation.

  • 22.
    Andersson, Rebecca
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, International Science Programme (ISP).
    Marta, Zdravkovic
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, International Science Programme (ISP). Örebro universitet.
    The International Science Programme in Sri Lanka and Thailand: Three decades of research cooperation2017 (ed. 1)Book (Other (popular science, discussion, etc.))
    Abstract [en]

    Developing capacity for research and higher education takes time, especially in resource scarce environments. Equipping laboratories, building human capacity, and establishing research cultures at teaching oriented universities are complex and slow processes. This book focuses on the long-term cooperation with chemistry and physics research groups at universities in Sri Lanka and Thailand, provided by the International Science Programme (ISP) at Uppsala University, Sweden. It traces and gathers experiences from graduated students and other collaborating partners from supported groups. It addresses questions of if, and how, capacity for research and higher education has developed over the decades of ISP support, and the possible effects, efficiency, sustainability and improvements of it.

  • 23.
    Andersson, Rebecca
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, International Science Programme (ISP).
    Sundin, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, International Science Programme (ISP).
    Tracing ISP Graduates 2008-20132016Report (Other (popular science, discussion, etc.))
    Abstract [en]

    The International Science Programme (ISP) at Uppsala University, Sweden, aims to contribute to the growth of scientific knowledge in Africa, Asia and Latin America. The ISP model is designed to prevent brain drain by improving local facilities and conditions for research and by promoting local postgraduate training. When local training is not possible, sandwich postgraduate training is employed, where students spend part of their training at their home university and part at a more resourceful scientific host institution abroad, in the North or in the region.

    The focus of this report is PhD graduates from ISP supported research groups and networks during the granting period 2008-2013, to trace where they are today and what they are doing.

    Most of the 154 traced PhD graduates (92%) are currently working in their home countries (126) or regions (16), most as Lecturers or Senior Lecturers at universities or research institutes. Twelve graduates are currently living in OECD countries, all but two of them employed in academia. A slightly higher share of students trained locally have stayed in their home countries or relocated within the regions, compared to sandwich students.

  • 24.
    Andersson, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Uppsala Centre for Sustainable Development, Centre for Environment and Development Studies.
    Att samverka för hållbar utveckling: Om Cemus mötesplats och universitetets ansvar att inspirera till förändring2010In: Över gränserna: om Cemus utbildning för förändring / [ed] Hald, Matilda, Uppsala: CEMUS/CSD Uppsala , 2010, p. 39-47Chapter in book (Other (popular science, discussion, etc.))
  • 25. Andreasson, Jakob
    et al.
    Holmlund, Joakim
    Knee, Christopher S.
    Käll, Mikael
    Börjesson, Lars
    Naler, Stefan
    Bäckström, Joakim
    Ruebhausen, Michael
    Azad, Abul Kalam
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Eriksson, Sten-G.
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Franck-Condon higher order lattice excitations in the LaFe1-xCrxO3 (x=0, 0.1, 0.5, 0.9, 1.0) perovskites due to Fe-Cr charge transfer effects2007In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 75, no 10, p. 103402-Article in journal (Refereed)
    Abstract [en]

    First and higher order lattice excitations in the B-site disordered perovskites LaFe1-xCrxO3 (x=0, 0.1, 0.5, 0.9, and 1) and La0.835Sr0.165Fe0.5Cr0.5O3-delta are investigated using temperature dependent and polarized inelastic light scattering [lambda=515 nm (2.41 eV) and 676 nm (1.83 eV)] on oriented crystallites. A peak at approximately 2.4 eV in the imaginary part of the dielectric function of LaFe0.5Cr0.5O3 is assigned to a charge transfer from Fe3+ (d(5)) to Cr3+ (d(3)) ions, coupled with the appearance of an intense A(g)-like mode at approximately 700 cm(-1) in the Raman data. This excitation is identified as a symmetric oxygen breathing mode activated by the Fe-Cr charge transfer through an orbital coupling mechanism. Higher order scattering (up to seventh order) of the intrinsic Raman active symmetric breathing mode is also explained by an orbital-mediated electron-phonon coupling, similar to the Franck-Condon effect observed in the Jahn-Teller active-perovskite-structured manganite LaMaO(3). These results show that the Franck-Condon mechanism is a more common mechanism for resonant higher order scattering in solids than previously believed and propose the LaFe1-xCrxO3 system as a model system for electron-phonon coupling and higher order Raman scattering in solids.

  • 26. Ansell, Nicola
    et al.
    Robson, Elsbeth
    Hajdu, Flora
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Uppsala Centre for Sustainable Development.
    van Blerk, Lorraine
    Chipeta, Lucy
    The new variant famine hypothesis: moving beyond the household in exploring links between AIDS and food insecurity in southern Africa2009In: Progress in Development Studies, ISSN 1464-9934, E-ISSN 1477-027X, Vol. 9, no 3, p. 187-207Article in journal (Refereed)
    Abstract [en]

    A number of southern African countries have experienced food crises during recent years. The fact that the scale of these crises has been disproportionate to the apparent triggers of climatic adversity or production decline has led to the suggestion that they are more closely related to the AIDS pandemic, which is at its most extreme in many of the same countries. This hypothesis, developed by de Waal and Whiteside (2003), has been termed 'New Variant Famine'(NVF). The New Variant Famine hypothesis is helpful in drawing attention to the effects of AIDS in diminishing both food production and capacity to purchase food, but it focuses more intensely on the household level than many other theories that seek to explain food insecurity, which tend to emphasise the integration of peasants into a capitalist market economy, and the functioning of markets and institutions. The household level focus also characterises much research on the impacts of AIDS. In this article we argue that the effects of AIDS on food security are not confined to the household level, and that an NVF analysis should also consider processes operating within and beyond the household including social relationships, relations of age and gender, colonial inheritance and contemporary national and international political economy. Recognition of these processes and how they interact with AIDS may offer greater scope for political mobilisation rather than technocratic responses.

  • 27. Ansell, Nicola
    et al.
    van Blerk, Lorraine
    Hajdu, Flora
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Uppsala Centre for Sustainable Development.
    Robson, Elsbeth
    Spaces, times, and critical moments: a relational time-space analysis of the impacts of AIDS on rural youth in Malawi and Lesotho2011In: Environment and planning A, ISSN 0308-518X, E-ISSN 1472-3409, Vol. 43, no 3, p. 525-544Article in journal (Refereed)
    Abstract [en]

    Southern Africa's AIDS epidemic is profoundly spatially and temporally structured; so too are the lives of the young people whose families it blights. In this paper we draw on qualitative research with AIDS-affected young people in Malawi and Lesotho, and recent work theorising time space in human geography, to examine how time spaces of AIDS-related sickness and death intersect with the time spaces of young people and, importantly, those of their relations with others to produce differentiated outcomes for young people. We also explore the time spaces of those outcomes and of young people's responses to them. We conclude that a relational time space analysis of the impacts of AIDS on young people helps explain the diversity of those young people's experiences and allows AIDS to be contextualised more adequately in relation to everyday life and young people's wider lifecourses and their relationships with others. Moreover, the research points to the significance of the time space structuring of society in shaping the outcomes of familial sickness and death for young people.

  • 28.
    Apel, Jan
    et al.
    Lund Univ LUX, Dept Archaeol & Ancient Hist, Box 192, Lund, Sweden.;Stockholm Univ, Dept Archaeol & Class Studies, Osteoarchaeol Res Lab, Stockholm, Sweden..
    Wallin, Paul
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Department of Archaeology and Ancient History, Archaeology.
    Stora, Jan
    Stockholm Univ, Dept Archaeol & Class Studies, Osteoarchaeol Res Lab, Stockholm, Sweden..
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory.
    Early Holocene human population events on the island of Gotland in the Baltic Sea (9200-3800 cal. BP)2018In: Quaternary International, ISSN 1040-6182, E-ISSN 1873-4553, Vol. 465, p. 276-286Article in journal (Refereed)
    Abstract [en]

    The summed probability distribution of 162 radiocarbon dates from Gotland was analysed with reference to archaeological and environmental data in order to evaluate possible variations in settlement intensity on the island. The data indicated variations in demographic development on the island, with probably several different colonization events and external influences; the pioneer settlement reached the island around 9200 cal. BP. After the initial colonization, the radiocarbon dates were rather evenly distributed until around 7700-7600 cal. BP, then there was a drop in the number of dates between 8300 and 8000 cal. BP that may be associated with the 8200 cold event. A marked decline in the number of dates between 7600 and 6000 cal. BP may be associated initially with the Littorina I transgression, but this transgression cannot explain why the Late Mesolithic period is not well represented on Gotland: the climatic development was favourable but did not result in increased human activity. The number of radiocarbon dates indicated that the population size remained low until around 6000 cal. BP, after which there was a gradual increase that reached a first 'threshold' after 5600 cal. BP and a second 'threshold' after 4500 cal. BP. The first apparent population increase was associated with the appearance of the Funnel Beaker Culture (FBC) and the second with Pitted Ware Culture (PWC) complexes. A decline in the number of dates occurred after 4300 cal. BP, i.e. towards the Late Neolithic. There was an association between the frequency distributions of the radiocarbon dates and the number of stray finds from different time periods but any correlation was not straightforward. (C) 2017 Elsevier Ltd and INQUA. All rights reserved.

  • 29.
    Azad, A. K. , S.-G. Eriksson
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Formation of a cubic Sr2MnWO6 phase at elevated temperature: a neutron powder diffraction study2003In: Solid State Communication, Vol. 126, p. 503-Article in journal (Refereed)
  • 30.
    Azad, A. K. , S.-G. Eriksson, S.A. Ivanov, J. Eriksen, H. Rundlöf
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Structural studies of the spinel system GaxCoFe1-xCrO4 (0 £ x £ 1) by neutron powder diffraction2003In: Materials Science Forum, 2003, Vol. 443-444, p. 325-Conference paper (Refereed)
  • 31.
    Azad, A. K., S.- G. Eriksson, S. A. Ivanov, H. Rundlöf, J. Eriksen, R. Mathieu, and P. Svedlindh
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Synthesis, Structure and Magnetic properties of Ca2-xSrxMnWO6 (x = 0.0, 0.5, 1.0, 1.5, 2.0)2003In: Materials Science Forum, 2003, Vol. 443-444, p. 375-Conference paper (Refereed)
  • 32.
    Azad, A. K., S.- G. Eriksson, S. M. Yunus, J. Eriksen, H. Rundlöf
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Synthesis, cation distribution and crystal structure of the spinel type solid solution GaxCoFe1-xCrO4 (0 < x < 1)2003In: Physica B, Vol. 327, p. 1-Article in journal (Refereed)
  • 33.
    Azad, A.K., Eriksson, S.-G., Mellergård, A. Ivanov, S.A., Eriksen, J. Rundlöf, H.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    A study on the nuclear and magnetic structure of the double perovskite A2FeWO6 (A = Sr, Ba) by neutron diffraction and reverse Monte Carlo modeling2002In: Materials Research Bulletin, Vol. 37, p. 1797-1813Article in journal (Refereed)
  • 34.
    Azad, AK
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Eriksson, S-G
    Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Materials Science.
    Ivanov, H
    Rundlöf, H
    Eriksen, J
    Mathieu, R
    Svedlindh, P.
    Structural and magnetic characterisatrion of the double perovskite A2MnWO6 (AA'=Ba2, BaSr, Sr2, SrCa and Ca2)2001In: Ferroelectrics, Vol. in pressOther (Other scientific)
  • 35.
    Azad, A.K., Eriksson, S.-G., Ivanov, S.A., Rundlöf, H., Eriksen, J. Mathieu, R., Svedlindh, P.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory.
    Structural and magnetic characterization of the double perovskites AA´MnWO6 (AA´= Ba2, SrBa, Sr2, SrCa and Ca2)2002In: Ferroelectrics, Vol. 269, p. 105-110Article in journal (Refereed)
  • 36.
    Azad, AK
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory. Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Eriksson, S-G
    Mellergård, A
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Ivanov, SA
    Eriksen, J
    Rundlöf, Håkan
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    A study on the nuclear and magnetic structure of the double perovskite A1FeWO6 (A=Sr, Ba) by neutron diffraction and reverse Monte Carlo modelling2001In: J. Phys.; Condensed Matter, Vol. submittedArticle in journal (Refereed)
  • 37.
    Azad, AK
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory. Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Eriksson, S-G
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Yunus, SM
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Eriksen, J
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Rundlöf, Håkan
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Synthesis, cation distribution and crystal structure of the spinel type solid solution GaxCoFe1-xCrO4 (0<x<1)2003In: Physica B, Vol. B 327, p. 1-8Article in journal (Refereed)
  • 38.
    Azad, AK
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory. Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Ivanov, SA
    Eriksson, SG
    Technology, Department of Materials Science. Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Eriksen, J
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Rundlöf, Håkan
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Mathieu, R
    Svedlindh, P
    Nuclear and magnetic structure of Ca2MnWO6: A neutron powder diffraction study2001In: MATERIALS RESEARCH BULLETIN, ISSN 0025-5408, Vol. 36, no 13-14, p. 2485-2496Article in journal (Refereed)
    Abstract [en]

    The nuclear and magnetic structures of the double provskite compound Ca2MnWO6 have been determined by neutron powder diffraction. Rietveld refinement shows that the compound adopts a monoclinic crystal structure with P2(1)/n symmetry. Magnetic refinement

  • 39.
    Azad, AK
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory. Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Ivanov, SA
    Eriksson, S-G
    Eriksen, J
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Rundlöf, Håkan
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Mathieu, R
    Svedlindh, P
    Structural and magnetic properties of the double perovskite Sr2MnWO62001In: J. Magnetism and Magnetic Materials, Vol. 237, p. 124-Article in journal (Refereed)
  • 40.
    Azad, AK
    et al.
    Uppsala University, Interfaculty Units, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, The Studsvik Neutron Research Laboratory. Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Ivanov, SA
    Eriksson, SG
    Technology, Department of Materials Science. Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Eriksen, J
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Rundlöf, Håkan
    Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Materials Chemistry, Structural Chemistry. strukturkemi.
    Mathieu, R
    Svedlindh, P