| 11. |
- Ahnesjö, Anders, et al.
(författare)
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Detector response modeling
- 2009
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Patent (populärvet., debatt m.m.)abstract
- A detector response correction arrangement and method is proposed for online determination of correction factors for arbitrary positions from arbitrary incident fluence distributions. As modern radiotherapy utilizes more of the available degrees of freedom of radiation machines, dosimetry has to be able to present reliable measurements for all these degrees of freedom. To determine correction factors online during measurement, Monte Carlo technique is used to precalculate fluence pencil kernels from a monodirectional beam to fully describe the particle fluence in an irradiated medium. Assuming that the particle fluence is not significantly altered by the introduction of a small detector volume, the fluence pencil kernels (212) can be integrated (214), and correction factors (216) determined, e.g. by Cavity Theory, in different positions for the detector material.
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| 12. |
- Alami, Jones, et al.
(författare)
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Phase tailoring of Ta thin films by highly ionized pulsed magnetron sputtering
- 2007
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Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 515:7-8, s. 3434-3438
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Tidskriftsartikel (refereegranskat)abstract
- Ta thin films were grown on Si substrates at different inclination angles with respect to the sputter source using high power impulse magnetron sputtering (HIPIMS), an ionized physical vapor deposition technique. The ionization allowed for better control of the energy and directionality of the sputtered species, and consequently for improved properties of the deposited films. Depositions were made on Si substrates with the native oxide intact. The structure of the as deposited films was investigated using X-ray diffraction, while a four-point probe setup was used to measure the resistivity. A substrate bias process-window for growth of bcc-Ta was observed. However, the process-window position changed with changing inclination angles of the substrate. The formation of this low-resistivity bcc-phase could be understood in light of the high ion flux from the HIPIMS discharge.
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| 13. |
- Ali, Sharafat, Associate Professor, 1976-, et al.
(författare)
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Optical and mechanical properties of amorphous Mg-Si-O-N thin films deposited by reactive magnetron sputtering
- 2019
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Ingår i: Surface & Coatings Technology. - : Elsevier. - 0257-8972 .- 1879-3347. ; 372:25, s. 9-15
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Tidskriftsartikel (refereegranskat)abstract
- In this work, amorphous thin films in Mg-Si-O-N system typically containing >15 at.% Mg and 35 at.% N were prepared in order to investigate especially the dependence of optical and mechanical properties on Mg composition. Reactive RF magnetron co-sputtering from magnesium and silicon targets were used for the deposition of Mg-Si-O-N thin films. Films were deposited on float glass, silica wafers and sapphire substrates in an Ar, N2 and O2 gas mixture. X-ray photoelectron spectroscopy, atomic force microscopy, scanning electron microscopy, spectroscopic ellipsometry, and nanoindentation were employed to characterize the composition, surface morphology, and properties of the films. The films consist of N and Mg contents up to 40 at.% and 28 at.%, respectively and have good adhesion to substrates and are chemically inert. The thickness and roughness of the films increased with increasing content of Mg. Both hardness (16–21 GPa) and reduced elastic modulus (120–176 GPa) are strongly correlated with the amount of Mg content. The refractive index up to 2.01 and extinction coefficient up to 0.18 were found to increase with Mg content. The optical band gap (3.1–4.3) decreases with increasing the Mg content. Thin film deposited at substrate temperature of 100 °C shows a lower value of hardness (10 GPa), refractive index (1.75), and higher values of reduced elastic modulus (124 GPa) as compared to the thin film deposited at 310 °C and 510 °C respectively, under identical synthesis parameters.
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| 14. |
- Alijan Farzad Lahiji, Faezeh, et al.
(författare)
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Growth and optical properties of NiO thin films deposited by pulsed dc reactive magnetron sputtering
- 2023
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : A V S AMER INST PHYSICS. - 0734-2101 .- 1520-8559. ; 41:6
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Tidskriftsartikel (refereegranskat)abstract
- NiO thin films with varied oxygen contents are grown on Si(100) and c-Al2O3 at a substrate temperature of 300 degrees C using pulsed dc reactive magnetron sputtering. We characterize the structure and optical properties of NiO changes as functions of the oxygen content. NiO with the cubic structure, single phase, and predominant orientation along (111) is found on both substrates. X-ray diffraction and pole figure analysis further show that NiO on the Si(100) substrate exhibits fiber-textured growth, while twin domain epitaxy was achieved on c-Al2O3, with NiO(111) k Al2O3(0001) and NiO[1 (1) over bar0]k Al2O3[10 (1) over bar0] or NiO[(1) over bar 10]k Al2O3[2 (1) over bar(1) over bar0] epitaxial relationship. The oxygen content in NiO films did not have a significant effect on the refractive index, extinction coefficient, and absorption coefficient. This suggests that the optical properties of NiO films remained unaffected by changes in the oxygen content.
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| 15. |
- Andersson, Bengt Olof, et al.
(författare)
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The reference step method for DC voltage at 1 mV and 10 mV
- 2014
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Ingår i: CPEM Digest (Conference on Precision Electromagnetic Measurements). - : Institute of Electrical and Electronics Engineers Inc.. - 9781479952052 ; , s. 520-521
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Konferensbidrag (refereegranskat)abstract
- We have investigated the performance of a method called the Reference Step Method at low voltage levels. The method has been evaluated earlier at voltage levels from 0.1 V to 1 kV with excellent results. The advantages of this method are that it uses commonly available equipment and can be fully automated. We have made comparisons with three other low-voltage methods and the differences show that the uncertainties can be less than 30 μV/V at 1 mV and 3 μV/V at 10 mV, making it possible to use this method to perform automated calibration of calibrators with sufficient accuracy for calibration of high-end instruments.
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| 16. |
- Andersson, Magnus, et al.
(författare)
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Structural Dynamics of Light-Driven Proton Pumps
- 2009
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Ingår i: Structure. - : Elsevier BV. - 0969-2126 .- 1878-4186. ; 17:9, s. 1265-1275
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Tidskriftsartikel (refereegranskat)abstract
- Bacteriorhodopsin and proteorhodopsin are simple heptahelical proton pumps containing a retinal chromophore covalently bound to helix G via a protonated Schiff base. Following the absorption of a photon, all-trans retinal is isomerized to a 13-cis conformation, initiating a sequence of conformational changes driving vectorial proton transport. In this study we apply time-resolved wide-angle X-ray scattering to visualize in real time the helical motions associated with proton pumping by bacteriorhodopsin and proteorhodopsin. Our results establish that three conformational states are required to describe their photocycles. Significant motions of the cytoplasmic half of helix F and the extracellular half of helix C are observed prior to the primary proton transfer event, which increase in amplitude following proton transfer. These results both simplify the structural description to emerge from intermediate trapping studies of bacteriorhodopsin and reveal shared dynamical principles for proton pumping.
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| 17. |
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| 18. |
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| 19. |
- Bengtson, Per, et al.
(författare)
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Serum transferrin carrying the xeno-tetrasaccharide NeuAc-Gal-GlcNAc2 is a biomarker of ALG1-CDG.
- 2016
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Ingår i: Journal of Inherited Metabolic Disease. - : Wiley. - 0141-8955 .- 1573-2665. ; 39:1, s. 107-114
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Tidskriftsartikel (refereegranskat)abstract
- ALG1-CDG (formerly CDG-Ik) is a subtype of congenital disorders of glycosylation (CDG) where the genetic defect disrupts the synthesis of the lipid-linked oligosaccharide precursor required for N-glycosylation. The initial step in the investigation for these disorders involves the demonstration of hypoglycosylated serum transferrin (TF). There are no specific biomarkers of this CDG subtype known to date. An LC/MS approach was used to analyze sera from patients with ALG1-CDG, PMM2-CDG, suspected CDG, and individuals with alcohol abuse. We show mass spectrometric data combined with data from enzymatic digestions that suggest the presence of a tetrasaccharide consisting of two N-acetylglucosamines, one galactose, and one sialic acid, appearing on serum TF, is a biomarker of this particular CDG subtype. This is the first time analysis of serum TF can suggest a specific CDG type I subtype and we suggest this tetrasaccharide be used in the clinic to guide the ALG1-CDG diagnostic process.
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| 20. |
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