| 1. |
|
|
| 2. |
|
|
| 3. |
- Johansson, Erik M .J., et al.
(författare)
-
Interfacial properties of photovoltaic TiO2/dye/PEDOT-PSS heterojunctions
- 2005
-
Ingår i: Synthetic metals. - : Elsevier BV. - 0379-6779 .- 1879-3290. ; 149:03-feb, s. 157-167
-
Tidskriftsartikel (refereegranskat)abstract
- Systems comprising a dense TiO2 film electrode, a ruthenium polypyridine dye and a PEDOT-PSS (poly(3,4-ethylenedioxythiophene)-poly(4-styrenesulphonate)) film were prepared. The heterojunctions were shown to have photovoltaic properties, with the dye absorbing the light, the TiO2 acting as an electron conducting material and PEDOT-PSS acting as a hole transport material. A series of dyes was used to investigate their influence on the photocurrent and the photovoltage characteristics of the heterojunction. These results were compared to a photoelectrochemical system in which the PEDOT-PSS was replaced by a liquid electrolyte containing triiodide/iodide redox-couple. Photoelectron spectroscopy (PES) was used to monitor the interfacial properties of the heterojunction and the investigation points out effects of importance when assembling the materials together to a functional unit. Specifically, it was concluded that the interaction with the dye clearly affects the structure of PEDOT-PSS, both with respect to the surface composition of PSS relative to PEDOT and with respect to the chemical state of the sulphur in the polymers. Moreover, a comparison of the Ru3d and the valence band spectra of the two different interfaces (dye/TiO2 and dye/PEDOT-PSS) indicates that the energy level structure of the dyes compared to the substrate is different for the two surfaces. Thus, in the combined energy level picture under dark conditions, the energy levels in TiO2 relative to the energy levels in PEDOT-PSS depend on the dye.
|
|
| 4. |
- Richter, Jan Hinnerk, et al.
(författare)
-
Phase separation and charge localization in UHV-lithiated anatase TiO2 nanoparticles
- 2005
-
Ingår i: Physical Review B. - 1098-0121. ; 71:23, s. 235419-
-
Tidskriftsartikel (refereegranskat)abstract
- The insertion of lithium in anatase TiO2 nanoparticles under ultrahigh vacuum (UHV) conditions is studied using x-ray absorption spectroscopy (XAS) and resonant photoelectron spectroscopy (RPES) at the Ti L2,3 edge. It is demonstrated that XAS can be used to monitor the separation into an anatase phase and a lithium titanate phase of formal stoichiometry Li0.5TiO2. The initial state properties of the Ti 3d states of the lithium titanate phase are investigated using ab initio electronic structure calculations. The calculations show a correlation driven separation of Ti 3d states from the conduction band in agreement with previous studies. It is shown that Ti in different oxidation states (Ti3+ and Ti4+) is formed as a direct consequence of the electron-electron interaction. RPES and XAS spectra confirm the presence of electronically inequivalent Ti sites. The site-sensitivity of the RPES spectra at selected electron binding energies is found to be consistent with the calculations.
|
|
| 5. |
- Siikanen, Jonathan, et al.
(författare)
-
An anesthetic method compatible with (18)F-FDG-PET studies in mice.
- 2015
-
Ingår i: American journal of nuclear medicine and molecular imaging. - 2160-8407. ; 5:3, s. 270-277
-
Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to establish an experimental setting and an anesthetic method compatible with future sequential studies using (18)F-FDG-PET single scans, i.e. autoradiographic measurements, for the estimation of metabolic rate of glucose (MRglc) in mice. In this study we had no access to a small animal PET scanner and therefore focus was on the anesthetic setting and optimization of the input function as a preparation for the future tumor metabolic studies. Initially, four combinations of intraperitoneal (ip) anesthesia were tested on tumor bearing mice. Fentanyl-fluanisone plus diazepam yielded low and stable blood glucose levels and kept the animals sedated for approximately 2 h. The anesthesia was also tested in a longitudinal (18)F-FDG study, where tumor bearing mice were anesthetized, injected with (18)F-FDG, and sampled for blood, before, one day after, and 8 days after treatment with cisplatin. The animals were in good condition during the entire study period. To validate the method, average MRglc of whole brain and cerebellum in mice were calculated and compared with the literature. The average MRglc in the whole brain and cerebellum were 46.2±4.4 and 39.0±3.1 µmol 100g(-1) min(-1). In the present study, we have shown that an ip anesthesia with a combination of fentanyl-fluanisone and diazepam is feasible and provides stable and low blood glucose levels after a fasting period of 4 h in experiments in nude mice with xenografted human tumors. We have also verified that (18)F-FDG, intraperitoneally administrated, results in an expected plasma activity uptake and clearance. The method doesn't alter the uptake in brain which is an indirect indication that the anesthesia doesn't alter the uptake in other organs. In combination with meticulous animal handling this set-up is reliable and future sequential tumor studies of early metabolic effects with calculation of MRglc following cytotoxic therapy are made possible.
|
|
| 6. |
- Adler, Jan-Olof, et al.
(författare)
-
A broad range tagging spectrometer for the MAX-laboratory
- 1997
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 388:1-2, s. 17-26
-
Tidskriftsartikel (refereegranskat)abstract
- A broad range tagging spectrometer together with a new beam transport system for photonuclear experiments at the MAX-laboratory in Lund is described. The spectrometer consists of a quadrupole followed by an Elbek-type dipole and has a large momentum acceptance. It can produce both polarized and unpolarized tagged photons in the energy range 10–80 MeV with an energy resolution of about 300 keV.
|
|
| 7. |
- Adler, Jan-Olof, et al.
(författare)
-
The upgraded photon tagging facility at the MAX IV Laboratory
- 2013
-
Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 715, s. 1-10
-
Tidskriftsartikel (refereegranskat)abstract
- A description is given of the upgraded photon tagging facility at the MAX IV Laboratory. Two magnetic spectrometers are used to momentum analyze post-bremsstrahlung electrons. The tagged photon range extends from 10 to 180 MeV with an energy resolution of about 300 keV. The system has been operated at rates up to 4 x 10(6) photons s(-1) MeV (-1). Different diagnostic tools are described as well as the experimental program.
|
|
| 8. |
- Agnarsson, Björn, 1977-
(författare)
-
Surface studies on α–sapphire for potential use in GaN epitaxial growth
- 2009
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This Licentiate thesis summarizes the work carried out by the author the years 2004 to 2008 at the University of Iceland and the Royal Institute of Technology (KTH) in Sweden. The aim of the project was to investigate the structure of sapphire (alpha-Al2O3) surfaces, both for pure scientific reasons and also for potential use as substrate for GaN-growth by molecular beam epitaxy. More generally the thesis describes some surface science methods used for investigating the substrates; the general physical back ground, the experi- mental implementation and what information they can give. The described techniques are used for surface analysis on sapphire substrates which have been treated variously in order to optimize them for use as templates for epi- taxial growth of GaN or related III-V compounds. The thesis is based on three published papers. The first paper focuses on the formation a thin AlN layer on sapphire, which may act as a buffer layer for potential epitaxial growth of GaN or any related III-V materials. Two types of sapphire substrates (reconstructed and non- reconstructed) were exposed to ammonia resulting in the formation of AlN on the surface. The efficiency of the AlN formation (nitridation efficiency) for the two surfaces was then compared as a function of substrate temperature through photoelectron spectroscopy and low electron energy diffraction. The reconstructed surface showed a much higher nitridation efficiency than the non-reconstructed surface. In the second paper, the affect of different annealing processes on the sapphire morphology, and thus its capability to act as a template for GaN growth, was studied. Atomic force microscopy, X-ray diffraction analysis together with ellipsometry measurements showed that annealing in H2 ambient and subse- quent annealing at 1300 °C in O2 for 11 hours resulted in high quality and atomically flat sapphire surface suitable for III-V epitaxial growth. The third paper describes the effect of argon sputtering on cleaning GaN surfaces and the possibility of using indium as surfactant for establishing a clean and stoichiometric GaN surface, after such sputtering. Soft sputtering, followed by deposition of 2 ML of indium and subsequent annealing at around 500 °C resulted in a well ordered and clean GaN surface while hard sputtering introduced defects and incorporated both metallic gallium and indium in the surface.
|
|
| 9. |
- Akkurt, I, et al.
(författare)
-
Photoneutron yields from tungsten in the energy range of the giant dipole resonance
- 2003
-
Ingår i: Physics in Medicine and Biology. - : IOP Publishing. - 1361-6560 .- 0031-9155. ; 48:20, s. 3345-3352
-
Tidskriftsartikel (refereegranskat)abstract
- Photoneutron production on the nuclei of high-Z components of medical accelerator heads can lead to a significant secondary dose during a course of bremsstrahlung radiotherapy, However, a quantitative evaluation of secondary neutron dose requires improved data on the photoreaction yields. These have been measured as a function of photon energy, neutron energy and neutron angle for W-nat, using tagged photons at the MAX-Lab photonuclear facility in Sweden. This work presents neutron yields for W-nat(gamma, n) and compares these with the predictions of the Monte Carlo code MCNP-GN, developed specifically to simulate photoneutron production at medical accelerators.
|
|
| 10. |
- Alfredsson, Ylvi, 1973-
(författare)
-
Electronic and Structural Properties of Thin Films of Phthalocyanines and Titanium Dioxide
- 2005
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is based on experimental studies in chemical physics. Titanium dioxide (TiO2) and phthalocyanine’s (Pc’s), interesting in many future perspectives, have been deposited as thin films and studied as follows. Information has been obtained on e.g. molecular orientation, crystal structure, depth profile of the chemical composition, electrochemical properties and electronic structure. This has been achieved by means of a combination of techniques: X-ray photoelectron spectroscopy (XPS), near edge x-ray absorption fine structure (NEXAFS), density functional theory calculations (DFT), UV-visible absorption spectroscopy (UVVIS) and cyclic voltammetry (CV).Metal-free phthalcyanine (H2Pc) has been shown to form films with different crystal structure and molecular orientation depending on deposition method, evaporation/sublimation or powder deposition, on commercial conducting glass (fluorine doped tin oxide, FTO), which is used e.g. in solar cells and organic light emitting devices (OLEDs). The unoccupied molecular orbitals are divided in x, y and z space coordinates of the molecule and also divided in inequivalent nitrogen components.The electronic structure is also studied for a sublimated titanyl phthalocyanine (TiOPc) film and related to the metal-free phthalocyanine. The ligand field around the titanium atom in TiOPc is compared with that of TiO2 to delineate the unoccupied levels recorded by means of x-ray absorption spectroscopy.Nanostructured TiO2 films were manufactured by screen printing/doctor blading on FTO. Such films were additionally covered with lutetium diphthalocyanine (LuPc2) by means of surface assembly from solution. LuPc2-, LuPc2+ and LuPc2H were identified and the stability of the electrochromic reactions in this system was monitored.Chemical vapor deposition (CVD) has been used to grow nanometer sized anatase TiO2 crystals on pre-oxidized Si (111) without formation of interfacial carbon and with an interface layer of the size of 15- 25Å. The interface layer was found to be amorphous TiSixOy with graded stoichiometry.
|
|
| 11. |
- Alfredsson, Ylvi, et al.
(författare)
-
Electronic structure of a vapor-deposited metal-free phthalocyanine thin film
- 2005
-
Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 122:21
-
Tidskriftsartikel (refereegranskat)abstract
- The electronic structure of a vapor-sublimated thin film of metal-free phthalocyanine (H2Pc) is studied experimentally and theoretically. An atom-specific picture of the occupied and unoccupied electronic states is obtained using x-ray-absorption spectroscopy (XAS), core- and valence-level x-ray photoelectron spectroscopy (XPS), and density-functional theory (DFT) calculations. The DFT calculations allow for an identification of the contributions from individual nitrogen atoms to the experimental N1s XAS and valence XPS spectra. This comprehensive study of metal-free phthalocyanine is relevant for the application of such molecules in molecular electronics and provides a solid foundation for identifying modifications in the electronic structure induced by various substituent groups.
|
|
| 12. |
- Alfredsson, Ylfi, et al.
(författare)
-
Phase and molecular orientation in H2Pc on conducting glass : characterization of two deposition methods
- 2005
-
Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 493:1-2, s. 13-19
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, metal-free phthalocyanine has been deposited on a conducting glass surface by two methods: by spreading the molecular powder directly on the substrate in air and by vapor sublimation under ultra-high vacuum conditions (evaporation). The films have been characterized by means of core level X-ray Photoemission Spectroscopy, X-ray Absorption Spectroscopy (XAS) and Ultra Violet and Visible absorption spectroscopy (UV-Vis). Our results show that the two deposition methods produce molecular overlayers in different polymorphic phases; the UV-Vis measurements indicate that the film obtained by powder deposition is of x-phase type whereas sublimation leads to an α-polymorph structure. The XAS results show that in the powder deposited film the molecules are mainly oriented parallel to the surface. This is opposite to the case of the vapor deposited film, where the molecules mainly are oriented orthogonal to the surface.
|
|
| 13. |
|
|
| 14. |
- Amft, Martin, et al.
(författare)
-
A Molecular Mechanism for the Water-Hydroxyl Balance during Wetting of TiO2
- 2013
-
Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 117:33, s. 17078-17083
-
Tidskriftsartikel (refereegranskat)abstract
- We show that the formation of the wetting layer and the experimentally observed continuous shift of the H2O-OH balance toward molecular water at increasing coverage on a TiO2(110) surface can be rationalized on a molecular level. The mechanism is based on the initial formation of stable hydroxyl pairs, a repulsive interaction between these pairs, and an attractive interaction with respect to water molecules. The experimental data are obtained by synchrotron radiation photoelectron spectroscopy and interpreted with the aid of density functional theory calculations and Monte Carlo simulations.
|
|
| 15. |
- Avendano, Esteban, et al.
(författare)
-
Coloration Mechanism in Proton-Intercalated Electrochromic Hydrated NiOy and Ni1-xVxOy Thin Films
- 2009
-
Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 156:8, s. p132-p138
-
Tidskriftsartikel (refereegranskat)abstract
- Electrochromic (EC) films of nickel oxide, with and without vanadium, were prepared by reactive dc magnetron sputtering. They were characterized by electrochemical and optical measurements and studied by X-ray photoelectron spectroscopy (PES) using synchrotron radiation. The films were analyzed under as-deposited conditions and after bleaching/coloration by insertion/extraction of protons from a basic solution and ensuing charge stabilization. Optical measurements were consistent with a coloration process due to charge-transfer transitions from Ni2+ to Ni3+ states. The PES measurements showed a higher concentration of Ni3+ in the colored films. Moreover, two peaks were present in the O 1s spectra of the bleached film and pointed to contributions of Ni(OH)(2) and NiO. The changes in the O 1s spectra upon coloration treatment indicate the presence of Ni2O3 in the colored film and necessitated an extension of the conventional model for the mechanism of EC coloration. The model involves not only proton extraction from nickel hydroxide to form nickel oxyhydroxide but also participation of NiO in the coloration process to form Ni2O3.
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
- Brun, Eva, et al.
(författare)
-
Early prediction of treatment outcome in head and neck cancer with 2-18FDG PET
- 1997
-
Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 36:7, s. 741-747
-
Tidskriftsartikel (refereegranskat)abstract
- The development of alternative treatment regimens in clinical oncology has increased the need for early prediction of cancer therapy outcome. The aim of this study was, early in the treatment phase, to identify patients with advanced head and neck cancer, responding or not responding to initiated therapy. The tumour metabolic rate of glucose (MRgl) examined by 2-18FDG-PET was determined in 17 patients before and after the first weeks of either radiotherapy (16-35 Gy) or one course of combination chemotherapy. Metabolic values uptake values normalized to plasma activity integrals--were correlated to loco-regional outcome, as evaluated 5-6 weeks after completion of treatment. Initial low tumour MRgl (<20 micromol/min/100 g tissue), in primary lesions or regional metastases, predicted a local complete response. When a high initial tumour MRgl was found, the magnitude of the reduction of MRgl in the second PET examination might be an adjunct in predicting local tumour response.
|
|
| 20. |
- Brun, Eva, et al.
(författare)
-
FDG PET studies during treatment: Prediction of therapy outcome in head and neck squamous cell carcinoma.
- 2002
-
Ingår i: Head and Neck. - : Wiley. - 1043-3074. ; 24:2, s. 127-135
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Positron emission tomography (PET) provides metabolic information of tissues in vivo. The purpose of this study was to assess the value of PET with 2-[(18) F] fluoro-2-deoxy-D-glucose (FDG) in prediction of therapy outcome (tumor response, survival, and locoregional control) in locally advanced HNSCC. METHODS: Between 1993 and 1999 47 patients underwent PET before (PET(1)) and after (PET(2)) 1 to 3 weeks of radical treatment with evaluation of metabolic rate (MR) and standardized uptake value (SUV) of FDG. All patients received radiotherapy, and 10 also received neoadjuvant chemotherapy. Median follow-up time was 3.3 years. RESULTS: Low and high MR FDG at PET(2), with median value as cutoff, was associated with complete remission in 96% and 62% (p =.007), with 5-year overall survival in 72% and 35% (p =.0042) and with local control in 96% and 55% (p =.002), respectively. CONCLUSIONS: FDG PET in the early phase of treatment of HNSCC is associated with tumor response, survival, and local control. Copyright 2002 John Wiley & Sons, Inc.
|
|
| 21. |
|
|
| 22. |
- Cappel, Ute B, et al.
(författare)
-
Electronic structure dynamics in a low bandgap polymer studied by time-resolved photoelectron spectroscopy.
- 2016
-
Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry. - 1463-9076 .- 1463-9084. ; 18:31, s. 21921-9
-
Tidskriftsartikel (refereegranskat)abstract
- Means to measure the temporal evolution following a photo-excitation in conjugated polymers are a key for the understanding and optimization of their function in applications such as organic solar cells. In this paper we study the electronic structure dynamics by direct pump-probe measurements of the excited electrons in such materials. Specifically, we carried out a time-resolved photoelectron spectroscopy (TRPES) study of the polymer PCPDTBT by combining an extreme ultraviolet (XUV) high harmonic generation source with a time-of-flight spectrometer. After excitation to either the 1st excited state or to a higher excited state, we follow how the electronic structure develops and relaxes on the electron binding energy scale. Specifically, we follow a less than 50 fs relaxation of the higher exited state and a 10 times slower relaxation of the 1st excited state. We corroborate the results using DFT calculations. Our study demonstrates the power of TRPES for studying photo-excited electron energetics and dynamics of solar cell materials.
|
|
| 23. |
|
|
| 24. |
- Dorkhan, Marjan, et al.
(författare)
-
Crystalline anatase-rich titanium can reduce adherence of oral streptococci
- 2014
-
Ingår i: Biofouling (Print). - : Informa UK Limited. - 0892-7014 .- 1029-2454. ; 30:6, s. 751-759
-
Tidskriftsartikel (refereegranskat)abstract
- Dental implant abutments that emerge through the mucosa are rapidly covered with a salivary protein pellicle to which bacteria bind, initiating biofilm formation. In this study, adherence of early colonizing streptococci, Streptococcus gordonii, Streptococcus oralis, Streptococcus mitis and Streptococcus sanguinis to two saliva-coated anodically oxidized surfaces was compared with that on commercially pure titanium (CpTi). Near edge X-ray absorption (NEXAFS) showed crystalline anatase was more pronounced on the anodically oxidized surfaces than on the CpTi. As revealed by fluorescence microscopy, a four-species mixture, as well as individual bacterial species, exhibited lower adherence after 2 h to the saliva-coated, anatase-rich surfaces than to CpTi. Since wettability did not differ between the saliva-coated surfaces, differences in the concentration and/or configuration of salivary proteins on the anatase-rich surfaces may explain the reduced bacterial binding effect. Anatase-rich surfaces could thus contribute to reduced overall biofilm formation on dental implant abutments through diminished adherence of early colonizers.
|
|
| 25. |
- Farstad, M. H., et al.
(författare)
-
Oxidation and Reduction of TiOx Thin Films on Pd(111) and Pd(100)
- 2018
-
Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 122:2, s. 688-694
-
Tidskriftsartikel (refereegranskat)abstract
- Thin films of TiOx on Pd(100) and Pd(111) have been investigated with respect to their properties after oxidation and reduction cycles. High-resolution photoemission spectroscopy (HRPES) and low energy electron diffraction (LEED) have been applied to characterize the thin film oxidation states and structure before and after oxidation and reduction under ultrahigh vacuum conditions. Fully oxidized TiO2 films were formed on both surfaces. These structures display Moiré patterns in LEED, in one dimension for Pd(100) and in two dimensions for Pd(111), and they have previously not been reported for TiO2/Pd. The oxidation process causes strong reduction in the interaction between the oxide thin film and the Pd substrate, most significantly for Pd(111). Reversible oxidation/reduction cycling of TiOx thin films on Pd(111) and Pd(100) was possible.
|
|
| 26. |
|
|
| 27. |
|
|
| 28. |
- Farstad, M. H., et al.
(författare)
-
Water Adsorption on TiOx Thin Films Grown on Au(111)
- 2015
-
Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 119:12, s. 6660-6669
-
Tidskriftsartikel (refereegranskat)abstract
- High resolution photoelectron spectroscopy has been used to investigate water adsorption on four different TiOx ultrathin film structures, grown on Au(111) by chemical vapor deposition. Two of the structures are reduced TiOx single layer phases, forming a honeycomb (HC) and a pinwheel (PW) structure, respectively. The other two phases have TiO2 stoichiometry, one in the form of islands and one in the form of a TiO2(B)(001) extended layer. Partial water dissociation is observed for all phases but the HC phase, and the dissociation propensity and adsorbate thermal stability structure result from interplay between the atomic structure of the particular TiOx phase and defects formed in the preparation. The dissociation on the TiO2(B) film is mainly related to different types of defect sites. The TiO2 islands, interpreted as surface reconstructed rutile TiO2(100), generate the highest amount of hydroxyls with a behavior consistent with reconstruction into a mixed (100) and (110) termination. Water dissociation on the PW layer can be assigned to particular sites of the structure and it stands out by leading to oxidation of Ti species.
|
|
| 29. |
- Forsberg, Anton, et al.
(författare)
-
Low background and high contrast PET imaging of amyloid-β with [11C]AZD2995 and [11C]AZD2184 in Alzheimer's disease patients
- 2013
-
Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer-Verlag New York. - 1619-7070 .- 1619-7089. ; 40:4, s. 580-593
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to evaluate AZD2995 side by side with AZD2184 as novel PET radioligands for imaging of amyloid-β in Alzheimer's disease (AD).METHODS: In vitro binding of tritium-labelled AZD2995 and AZD2184 was studied and compared with that of the established amyloid-β PET radioligand PIB. Subsequently, a first-in-human in vivo PET study was performed using [(11)C]AZD2995 and [(11)C]AZD2184 in three healthy control subjects and seven AD patients.RESULTS: AZD2995, AZD2184 and PIB were found to share the same binding site to amyloid-β. [(3)H]AZD2995 had the highest signal-to-background ratio in brain tissue from patients with AD as well as in transgenic mice. However, [(11)C]AZD2184 had superior imaging properties in PET, as shown by larger effect sizes comparing binding potential values in cortical regions of AD patients and healthy controls. Nevertheless, probably due to a lower amount of nonspecific binding, the group separation of the distribution volume ratio values of [(11)C]AZD2995 was greater in areas with lower amyloid-β load, e.g. the hippocampus.CONCLUSION: Both AZD2995 and AZD2184 detect amyloid-β with high affinity and specificity and also display a lower degree of nonspecific binding than that reported for PIB. Overall [(11)C]AZD2184 seems to be an amyloid-β radioligand with higher uptake and better group separation when compared to [(11)C]AZD2995. However, the very low nonspecific binding of [(11)C]AZD2995 makes this radioligand potentially interesting as a tool to study minute levels of amyloid-β. This sensitivity may be important in investigating, for example, early prodromal stages of AD or in the longitudinal study of a disease modifying therapy.
|
|
| 30. |
- Fredman, Peter, et al.
(författare)
-
Friluftsliv i förändring – ett forskningsprogram
- 2013
-
Ingår i: Friluftsliv i förändring. Resultat från ett forskningsprogram, Slutrapport. Naturvårdsverket rapport 6547. - Stockholm : Naturvårdsverket. - 9789162065478 ; , s. 11-24
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
|
|
| 31. |
- Fredman, Peter, et al.
(författare)
-
Friluftsliv i förändring. Resultat från ett forskningsprogram, Slutrapport : Naturvårdsverket Rapport 6547
- 2013
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Friluftsliv i förändring är den hittills största samlade satsningen på forskning kring friluftsliv och naturturism i Sverige. Detta är forskningsprogrammets slutrapport där huvudsakliga resultat av sex års forskning redovisas. Rapporten består av 15 fristående kapitel som var och ett fördjupar sig inom olika teman som programmet har fokuserat på. I rapportens inledning ges en en kort bakgrund till friluftsliv som forskningsområde, programmets tematiska inriktning, vårt sätt att organisera verksamheten samt samverkan med omgivande aktörer. Vi ger också några goda råd till framtida forskningsprogram. Avslutningsvis summeras några av de viktigaste resultaten jämte våra reflektioner kring programmets bidrag till ny kunskap. Vi redogör här för några huvudsakliga ställningstaganden när det gäller framtida forskningsstrukturer för friluftsliv och naturturism i Sverige, diskuterar samhällsutmaningar och ger förslag på forskningsbehov, samt sätter in svensk friluftslivsforskning i ett internationellt perspektiv.
|
|
| 32. |
-
Friluftsliv explored : An environmental and outdoor teaching approach for knowledge, emotions and quality of life
- 2021
-
Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- Friluftsliv explored doesn’t only include nature knowledge, techniques in the outdoors and outdoor pedagogics but also covers ecology, human ecology, geography, environmental and societal questions, history, health, biology, craft and lots of practical activities -both for urban and rural friluftsliv. In this translation to English of the revised fifth edition of the Swedish book there are many activities and the text is suitable for the modern day.Friluftsliv embraces the feeling around the campfire, paddling along winding rivers and walking towards the distant blue mountains. But, it is also to whittle a stick, to remember your waterproofs and to find your way home.Knowledge emerges when you combine imagination with facts and the glint in your eyes, using all our outdoor environments: forests, water, the coast, mountains and the nature close at hand.Emotion is to swim in crystal clear water far out in the archipelago and to see the clouds gliding across the sky. But also, to be able to present other sides of yourself, to be fascinated by your own body, the struggling ant and the sight of frost on trees.Quality of life is to experience friluftsliv – as it happens!
|
|
| 33. |
|
|
| 34. |
- Grennberg, Anders, et al.
(författare)
-
Estimation of subsample time delay differences in narrowband ultrasonic echoes using the Hilbert correlation
- 1994
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In many areas the time delay of arrival (TDOA) is desired. Conventional estimators usually have the property of breaking down for low SNR. In the case of narrowbanded signals we propose a fast and simple method to estimate the small time delays. The method is shown to have the same accuracy as conventional methods for small delays and high SNR while it performs better for low SNR. It is based on using the Hilbert transform in correlation between two signals. Apart from using it for better resolution in TDOA, it may also be used in applications with narrowbanded signals where the measurements are repeatable, such as ultrasonic imaging and ECG. In ultrasonic applications, due to fluctuations in the insonified media, a small random time shift may be present causing the signals to be misaligned in time. Averaging signals under these conditions will result in a distortion of the signal shape. We propose an averaging method to avoid this and to accomplish a higher SNR without the distortion. Simulations and experiments from ultrasonic applications are presented.
|
|
| 35. |
- Grennberg, Anders, et al.
(författare)
-
Estimation of subsample time delay differences in narrowband ultrasonic echoes using the Hilbert transform correlation
- 1994
-
Ingår i: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-3010 .- 1525-8955. ; 41:5, s. 588-595
-
Tidskriftsartikel (refereegranskat)abstract
- In many areas the time delay of arrival (TDOA) is desired. In the case of narrowband signals we propose a fast and simple method to estimate small time delays. This method is shown to have the same or better accuracy as the cross correlation methods for small delays in the order of fractions of the sample interval. It is based on using the Hilbert transform in correlation between two signals and consists of only one scalar product, which makes it fast. It may also be used in applications with narrowband signals where the measurements are repeatable, such as ultrasonic imaging and nondestructive testing. In ultrasonic applications, due to fluctuations in the insonified media, a small random time shift may be present causing the signals to be misaligned in time. Averaging signals under these conditions will result in a distortion of the signal shape. We propose an averaging method to avoid this and to accomplish a higher SNR without the distortion. Simulations and experiments from ultrasonic applications are presented.
|
|
| 36. |
- Grennberg, Anders, et al.
(författare)
-
Experimental determination of the single point echo of an ultrasonic transducer using a tomographic approach
- 1992
-
Ingår i: Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society. - Piscataway, NJ : IEEE Communications Society. ; , s. 2151-2152
-
Konferensbidrag (refereegranskat)abstract
- The impulse response method is often used to study the ultrasonic field radiated by planar or gently curved transducers. This, however, requires one transmitting and one receiving transducer which has to be placed with great accuracy in the ultrasonic field. Here we propose a measuring method with only one transducer which acts both as transmitter and receiver. Echoes from sliding halfplanes are registered and by using tomographic methods, the echo from a single point in the same plane as the halfplanes can then be calculated. Beside the ultrasonic field, these calculations will yield us the transducer's characteristics. These can be used to extract further information from an echo of an arbitrary surface, such as the gradient of the surface
|
|
| 37. |
- Grennberg, Anders, et al.
(författare)
-
Experimental determination of the ultrasonic echo from a pointlike reflector using a tomographic approach
- 1992
-
Ingår i: Proceedings. - Piscataway, NJ : IEEE Communications Society. - 0780305620 ; , s. 639-642
-
Konferensbidrag (refereegranskat)abstract
- One important parameter for an ultrasonic transducer is the echo it yields from a pointlike reflector. It can be measured directly but there are however certain problems connected with this. This reflector must have such a size that it can be considered a point, which results in a very weak echo and consequently a low SNR. We propose an alternative method to calculate the echo from a pointlike reflector by measuring the echoes from sliding halfplanes. Using a tomographic way of reasoning, we can calculate the single point echo from these measurements. Our approach was to find basis functions that are suitable for the inversion of the measurements. These basis functions depend on which norm and weight function you choose. Numerical solutions are given for chosen weight functions and the inversion is shown for the measurements.
|
|
| 38. |
- Hahlin, Maria, 1975-
(författare)
-
Electronic and Molecular Surface Structures of Dye-Sensitized TiO2 Interfaces
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The dye-sensitized solar cell is a promising solar cell technology. In these systems the key process for light to electricity conversion is molecular in nature and is initiated in dye molecules adsorbed at a semiconducting surface. This thesis focuses on the electronic and molecular surface structure of the dye/TiO2 interface, and the experimental results were obtained from surface sensitive X-ray based electron spectroscopic methods. Two families of dyes, triarylamine based organic dyes and ruthenium based inorganic dyes, were investigated. The effect of dye structural modications on the interfacial properties was studied, such as the surface concentrations, dye molecular surface orientation, molecular interactions, and energy level matching. Also, the impact of additional parameters such as the incorporation of coadsorbents and the solvents used for dye sensitization were studied and complementary photoelectrochemical characterization was used to demonstrate functional properties corresponding to changes in the molecular layers. The experiments provided information on how specic structural modications change the frontier electronic structure. The results also showed that the adsorption of the organic dye leads to submolecular electronic changes, and that the dye surface orientations in general favor effcient energy conversion. Moreover, effects of solvents and coadsorbents, on both energy level matching between the dye and the TiO2 substrate and the surfacemolecular structure were quantied.
|
|
| 39. |
|
|
| 40. |
|
|
| 41. |
|
|
| 42. |
|
|
| 43. |
- Hilling, Axel, et al.
(författare)
-
Lagen är lika för alla, men är alla verkligen lika inför lagen? : En studie av Skatteverkets processföring i PwC-målet
- 2018
-
Ingår i: Förvaltningsrättslig tidskrift. - 0015-8585. ; :2, s. 269-286
-
Tidskriftsartikel (refereegranskat)abstract
- För korrekt beskattning i komplicerade mål är det viktigt att Skatteverket kan utvärdera och presentera sakomständigheter på ett kvalificerat sätt. Skattebetalare med hög kompetens har annars större möjligheter att hävda sin rätt jämfört med skattebetalare som saknar sådan kompetens, vilket står i konflikt med likabehandlingsprincipen. I artikeln illustreras vikten av en kvalificerad förvaltningsmyndighet för att rättssäkerhet ska säkerställas. Det sker genom en studie av det s.k. PwC-målet, där sakfrågan rör marknadsvärdering av finansiella instrument. Artikeln visar att sakfrågan i målet inte kom att prövas av domstol som följd av att Skatteverket inte presenterade sakomständigheterna på ett övertygande och prövningsbart sätt. En motpart med stora ekonomiska resurser hade möjlighet att visa på bristerna i Skatteverkets argumentation, något som inte nödvändigtvis en motpart med mindre resurser hade kunnat göra. Lagen är då förvisso lika för alla, men alla är inte lika inför lagen.
|
|
| 44. |
- Hilling, Axel, et al.
(författare)
-
Land-för-landrapportering av skatter – en ur hållbarhetsvinkel missad möjlighet
- 2022
-
Ingår i: Balans Fördjupning. ; 2022:1
-
Tidskriftsartikel (populärvet., debatt m.m.)abstract
- I den här artikeln redogör Axel Hilling, Niklas Sandell, Amanda Sonnerfeldt och Anders Vilhelmsson för utvecklingen av offentlig land-förlandrapportering av skatter inom EU. Författarna analyserar hur den aktuella regleringen förhåller sig till EU:s nya direktiv för hållbarhetsrapportering, Corporate Sustainability Reporting Directive, CSRD.
|
|
| 45. |
- Hilling, Axel, et al.
(författare)
-
Tax avoidance and state ownership : The case of Sweden
- 2021
-
Ingår i: Economics Letters. - : Elsevier BV. - 0165-1765. ; 208
-
Tidskriftsartikel (refereegranskat)abstract
- We propose a simple theoretical model for how a company with both private and state shareholders decides on its optimal tax policy. The model predicts that even in the absence of state shareholding, a company will not always pick a tax policy that minimizes taxes. Conversely, majority state ownership will generally not result in zero tax avoidance. Using panel regressions on the entire population of state-owned as well as publicly listed Swedish companies from 2000–2019, we find that a one standard deviation increase in state ownership increases corporate tax payments by around 14%.
|
|
| 46. |
|
|
| 47. |
- Hilling, Axel, et al.
(författare)
-
The development of a multidimensional meaning of tax: From unfair tax to fair
- 2023
-
Ingår i: Discourse & Communication. - : SAGE Publications. - 1750-4813 .- 1750-4821. ; 17:1, s. 57-76
-
Tidskriftsartikel (refereegranskat)abstract
- Historically, companies have communicated taxes as a burden, as the benefits provided by governments are not perceived to be in proportion to their payments. With sustainable development becoming central in many policy areas, new discourses including ‘fair’ or ‘sustainable’ tax have become omnipresent in public talk on taxes. This paper analyzes tax discourses in corporate annual reports within this changing context to examine the use of language in the construction of the meaning of tax. By analyzing tax reporting by a state-owned multinational company over two decades, we observe that the communication of taxes increased in both number and types of discourses. Importantly, this highlights the shift in tax discourses from one dominated by codified accounting discourse reinforcing the monolithic representation of tax as an unfair expense, to one where tax is given a multidimensional meaning within a broader discursive context, where tax is a meaningful corporate responsibility to society.
|
|
| 48. |
- Hilling, Axel, et al.
(författare)
-
The Pricing of Financial Instruments in Tax Disputes
- 2019
-
Ingår i: Derivatives & Financial Instruments. - 1389-1863. ; 21:2
-
Forskningsöversikt (övrigt vetenskapligt/konstnärligt)abstract
- The pricing of uncertainties, when establishing the market value of financial instruments, is problematic in tax litigation since the outcome of the litigation is binary. Different values can be equally correct, depending on the choice of models, assumptions regarding model parameters and forecasting techniques. The purpose of this article is to illustrate the challenges for tax administrations and courts in terms of the need and ability to price uncertainties in the market valuation of financial instruments. The authors illustrate the complexities with a case based on a publicly traded instrument, which gives a lower limit of the uncertainty associated with valuation. The authors then problematize the valuation of over-the-counter traded and non-publicly traded instruments, which, due to uncertainty, tends to create leeway for tax arbitrage. This illustration shows the necessity to further understand the manner in which courts reason, the dependency on experts and the use of models.
|
|
| 49. |
- Jacobse, Peter H., et al.
(författare)
-
One Precursor but Two Types of Graphene Nanoribbons : On-Surface Transformations of 10,10'-Dichloro-9,9'-bianthryl on Ag(111)
- 2019
-
Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 123:14, s. 8892-8901
-
Tidskriftsartikel (refereegranskat)abstract
- On-surface synthesis has emerged in the last decade as a method to create graphene nanoribbons (GNRs) with atomic precision. The underlying premise of this bottom-up strategy is that precursor molecules undergo a well-defined sequence of inter- and intramolecular reactions, leading to the formation of a single product. As such, the structure of the GNR is encoded in the precursors. However, recent examples have shown that not only the molecule, but also the coinage metal surface on which the reaction takes place, plays a decisive role in dictating the nanoribbon structure. In this work, we use scanning probe microscopy and X-ray photoelectron spectroscopy to investigate the behavior of 10,10'-dichloro-9,9'-bianthryl (DCBA) on Ag(111). Our study shows that Ag(111) can induce the formation of both seven-atom wide armchair GNRs (7-acGNRs) and 3,1-chiral GNRs (3,1-cGNRs), demonstrating that a single molecule on a single surface can react to different nanoribbon products. We additionally show that coadsorbed dibromoperylene can promote surface-assisted dehydrogenative coupling in DCBA, leading to the exclusive formation of 3,1-cGNRs.
|
|
| 50. |
- Johansson, Erik, 1977-
(författare)
-
Interfaces in Dye-Sensitized Oxide / Hole-Conductor Heterojunctions for Solar Cell Applications
- 2006
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Nanoporous dye-sensitized solar cells (DSSC) are promising devices for solar to electric energy conversion. In this thesis photoelectron spectroscopy (PES), x-ray absorption spectroscopy (XAS) and photovoltaic measurements are used for studies of the key interfaces in the DSSC.Photovoltaic properties of new combinations of TiO2/dye/hole-conductor heterojunctions were demonstrated and their interfacial structures were studied. Three different types of hole-conductor materials were investigated: Triarylamine derivatives, a conducting polymer and CuI. The difference in photocurrent and photovoltage properties of the heterojunction due to small changes in the hole-conductor material was followed. Also a series of dye molecules were used to measure the influence of the dye on the photovoltaic properties. Differences in both the energy-level matching and the geometric structure of the interfaces in the different heterojunctions were studied by PES. This combination of photovoltaic and PES measurements shows the possibility to link the interfacial electronic and molecular structure to the functional properties of the device.Three effective dyes used in the DSSC, Ru(dcbpy)2(NCS)2, Ru(tcterpy)(NCS)3 and an organic dye were studied in detail using PES and XAS and resonant core hole decay spectroscopy. The results gave information of the frontier electronic structure of the dyes and how the dyes are bonded to the TiO2 surface.Finally, the hole-conductor mechanism in a conducting polymer was investigated theoretically using semi-empirical and ab-initio methods.
|
|
