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  • 1.
    Afanasiev, Sergey V.
    et al.
    Joint Institute for Nuclear Research Joliot-Curie 6.
    Afonin, Alexander G.
    Institute of High Energy Physics - Moscow Region.
    Ambrosi, Giovanni
    INFN Sezione di Perugia.
    Azzarello, Philipp
    INFN Sezione di Perugia.
    Baranov, Vladimir T.
    Institute of High Energy Physics - Moscow Region.
    Baricordi, Stefano
    INFN Sezione di Ferrara.
    Battiston, Roberto
    INFN Sezione di Perugia.
    Bertucci, Bruna
    INFN Sezione di Perugia.
    Bolognini, Davide
    Università dell'Insubria.
    Burger, William J.
    INFN Sezione di Perugia.
    Carnera, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Cavoto, Gianluca
    INFN Sezione di Roma.
    Chesnokov, Yury A.
    Institute of High Energy Physics - Moscow Region.
    Dalpiaz, Pietro
    INFN Sezione di Ferrara.
    Mea, Gianantonio Della
    INFN Laboratori Nazionali di Legnaro.
    Denisov, Alexander S.
    Petersburg Nuclear Physics Institute.
    Salvador, Davide De
    INFN Laboratori Nazionali di Legnaro.
    Fiorini, Massimiliano
    INFN Sezione di Ferrara.
    Foggetta, Luca
    Università dell'Insubria.
    Gavrikov, Yury A.
    Petersburg Nuclear Physics Institute.
    Guidi, Vincenzo
    INFN Sezione di Ferrara.
    Hasan, Said
    Università dell'Insubria.
    Ionica, Maria
    INFN Sezione di Perugia.
    Ivanov, Yuri M.
    Petersburg Nuclear Physics Institute.
    Ivochkin, Vladimir G.
    Petersburg Nuclear Physics Institute.
    Vomiero, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Zuccon, Paolo
    INFN Sezione di Perugia.
    Experimental apparatus to study crystal channeling in an external SPS beamline2007Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6634Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For the new generation of high intensity hadronic machines as, for instance, LHC, halo collimation is a necessary issue for the accelerator to operate at the highest possible luminosity and to prevent the damage of superconductor magnets.1 We propose an experiment aimed to systematic study of the channeling phenomenology and of the newly observed "volume reflection" effect. This experiment will be performed for an external SPS beamline and will make use of a primary proton beam with 400 GeV/c momentum and very small (∼ 3 μrad) divergence. The advantage of a proposed experiment is precise tracking of particles that interacted with a crystal, so that to determine the single-pass efficiency for all the processes involved. For this purpose, a telescope equipped with high-resolution silicon microstrip detectors will be used. New generation silicon crystals and an extra-precise goniometer are mandatory issues. Main goal of the experiment is to get the precise information on channeling of relativistic particles and, ultimately, on the feasibility of such technique for halo collimation at LHC. In this contribution we review the status of the setting-up of experimental apparatus and its future development in sight of the planned run in September 2006.

  • 2.
    Alfredson, J.
    FOI, Swedish Defence Research Agency, P.O. Box 1165, SE-581 11 Linkoping, Sweden.
    Individual differences in visual behaviour in simulated flight2002Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 4662, s. 494-502Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Flying an aircraft is highly visually demanding. It is very important to map pilot visual behaviour, both for the purpose of evaluating the cockpit interface and to effectively integrate it with future adaptive interfaces and decision support systems. Pilots' visual behaviour was studied in two experiments. In the first experiment commercial aviation pilots were flying a commercial aviation scenario and eye point of gaze, and eye blinks were collected. In the second experiment military pilots were flying an air-to-air combat scenario and the visual behaviour was video recorded. In both of the experiments the results show individual differences in the pilots' visual behaviour. In the second experiment two different categories of eye blinks were found that might help explain the individual differences in visual behaviour. One category can be related to the systematic eye blinks found to occur when the eye point of gaze was changed between head-up/head-down and head-down/head-up. The other category could be related to other reasons, such as, mental workload or visual demands.

  • 3.
    Andersson, I.
    et al.
    Saab Bofors Dynamics, S-581 88 Linkoping, Sweden.
    Haglund, L.
    Saab Bofors Dynamics, S-581 88 Linkoping, Sweden.
    Ronnqvist, E.
    Rönnqvist, E., Saab Bofors Dynamics, S-581 88 Linkoping, Sweden.
    Increasing spatial resolution by using an image sequence2001Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 4380, s. 542-551Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    In this paper we present two methods for increasing the spatial resolution of images using image sequences where all frames contain the same static scene with unknown shifts. Because of the subpixel shifts, aliased frequencies appear in a slightly different way in all images, making it possibly to reconstruct frequencies above the Nyqvist frequency, thus improving the resolution. To this end, we estimate parameters in the affine transform relating the images to each other from the sequence. To show the applicability of the algorithms, many experiments have been carried out mainly using image sequences captured by a TV-camera and not only using synthetic image sequences. The results from one TV-camera sequence are presented in this report. Measurements of PSF and MTF have been carried out and the results show that we can increase the spatial resolution by almost a factor of two. This technique can be used for target identification/recognition as well as for visualization. The second method (interpolation) is possible to implement in real time.

  • 4.
    Banaem, Hossein Y
    et al.
    Tehran University of Medical Science.
    Ahmadian, Alireza
    Tehran University of Medical Science.
    Saberi, Hooshangh
    Tehran University of Medical Science.
    Daneshmehr, Alireza
    University of Tehran.
    Khodadad, Davood
    Tehran University of Medical Science.
    Brain tumor modeling: glioma growth and interaction with chemotherapy2011Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 8285Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In last decade increasingly mathematical models of tumor growths have been studied, particularly on solid tumors which growth mainly caused by cellular proliferation. In this paper we propose a modified model to simulate the growth of gliomas in different stages. Glioma growth is modeled by a reaction-advection-diffusion. We begin with a model of untreated gliomas and continue with models of polyclonal glioma following chemotherapy. From relatively simple assumptions involving homogeneous brain tissue bounded by a few gross anatomical landmarks (ventricles and skull) the models have been expanded to include heterogeneous brain tissue with different motilities of glioma cells in grey and white matter. Tumor growth is characterized by a dangerous change in the control mechanisms, which normally maintain a balance between the rate of proliferation and the rate of apoptosis (controlled cell death). Result shows that this model closes to clinical finding and can simulate brain tumor behavior properly.

  • 5.
    Benckert, Lars
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Jonsson, Mikael
    Molin, Nils-Erik
    Measuring 3-D displacement of a surface using the white light speckle technique1986Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, s. 207-210Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    When measuring in plane surface deformation using white light speckle photography, errors will arise if an out of plane displacement is present. Here it is shown that stereoscopic photography resolves this problem and makes the measurement of true in plane displacements possible. A rigid body translation is also introduced to determine unambiguously the direction of the displacement

  • 6.
    Bjorstrom, Cecilia M.
    et al.
    Karlstad University.
    Nilsson, Svante
    Karlstad University.
    Magnusson, Kjell O.
    Karlstad University.
    Moons, Ellen
    Karlstad University.
    Bernasik, Andrzej
    AGH-Univ. of Science and Technology .
    Rysz, Jakub
    Jagiellonian Univ.
    Budkowski, Andrzej
    Jagiellonian Univ.
    Zhang, Fengling
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Andersson, Mats R.
    Chalmers.
    Influence of solvents and substrates on the morphology and the performance of low-bandgap polyfluorene: PCBM photovoltaic devices - art. no. 61921X2006Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6192, s. X1921-X1921Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Spin-coated thin films of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)] (APFO-3) blended with [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) are used as the active material in polymer photovoltaic cells. Such blends are known for their tendency to phase separate during film formation. Tuning the morphology of the blend in a controlled way is one possible road towards higher efficiency. We studied the effect of adding chlorobenzene to chloroform-based blend solutions before spin-coating on the conversion efficiency of APFO-3:PCBM photodiodes, and related that to the lateral and vertical morphology of thin films of the blend. The lateral morphology is imaged by atomic force microscopy (AFM) and the vertical compositional profile is obtained by dynamic secondary ion mass spectrometry (SIMS). The profiles reveal compositional variations consisting of multilayers of alternating polymer-rich and PCBM-rich domains in the blend film spin-coated from chloroform. The vertical compositional variations are caused by surface-directed spinodal waves and are frozen in during the rapid evaporation of a highly volatile solvent. With addition of the low-vapour pressure solvent chlorobenzene, a more homogeneous vertical composition is found. The conversion efficiency for solar cells of this blend was found to be optimal for chloroform: chlorobenzene mixtures with a volume-ratio of 80:1. We have also investigated the role of the substrate on the morphology. We found that blend films spin-coated from chloroform solutions on PEDOT:PSS-coated ITO show a similar compositional structure as the films on silicon, and that changing the substrate from silicon to gold only affects the vertical phase separation in a region close to the substrate interface.

  • 7.
    Björström, Cecilia M.
    et al.
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för fysik och elektroteknik.
    Nilsson, Svante
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för fysik och elektroteknik.
    Magnusson, Kjell
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för fysik och elektroteknik. Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Materialvetenskap.
    Moons, Ellen
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för fysik och elektroteknik.
    Bernasik, Andrzej
    Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Poland.
    Rysz, Jakub
    Institute of Physics, Jagiellonian University, Poland.
    Budkowski, Andrzej
    Institute of Physics, Jagiellonian University, Poland.
    Zhang, Fengling
    Department of Physics, Linköping University, Sweden.
    Inganäs, Olle
    Department of Physics, Linköping University, Sweden.
    Andersson, Mats R.
    Department of Materials and Surface Chemistry / Polymer Technology, Chalmers University of Technology, Gothenburg, Sweden.
    Influence of solvents and substrates on the morphology and the performance of low-bandgap polyfluorene:PCBM photovoltaic devices2006Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6192, s. 61921X-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Spin-coated thin films of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (APFO-3) blended with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) are used as the active material in polymer photovoltaic cells. Such blends are known for their tendency to phase separate during film formation. Tuning the morphology of the blend in a controlled way is one possible road towards higher efficiency. We studied the effect of adding chlorobenzene to chloroform-based blend solutions before spin-coating on the conversion efficiency of APFO-3:PCBM photodiodes, and related that to the lateral and vertical morphology of thin films of the blend. The lateral morphology is imaged by atomic force microscopy (AFM) and the vertical compositional profile is obtained by dynamic secondary ion mass spectrometry (SIMS). The profiles reveal compositional variations consisting of multilayers of alternating polymer-rich and PCBM-rich domains in the blend film spin-coated from chloroform. The vertical compositional variations are caused by surface-directed spinodal waves and are frozen in during the rapid evaporation of a highly volatile solvent. With addition of the low-vapour pressure solvent chlorobenzene, a more homogeneous vertical composition is found. The conversion efficiency for solar cells of this blend was found to be optimal for chloroform:chlorobenzene mixtures with a volume-ratio of 80:1. We have also investigated the role of the substrate on the morphology. We found that blend films spin-coated from chloroform solutions on PEDOT:PSS-coated ITO show a similar compositional structure as the films on silicon, and that changing the substrate from silicon to gold only affects the vertical phase separation in a region close to the substrate interface

  • 8.
    Blomquist, Mats
    et al.
    Luleå tekniska universitet.
    Wernersson, Åke
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Range camera on conveyor belts: estimating size distribution and systematic errors due to occlusion1999Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 118, s. 118-126Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    When range cameras are used for analyzing irregular material on a conveyor belt there will be complications such as missing segments caused by occlusion. Also, a number of range discontinuities will be present. In the framework towards stochastic geometry, conditions are found for the cases when range discontinuities take place. The test objects are pellets for the steel industry. An illuminating laser plane will give range discontinuities at the edges of each individual object. These discontinuities are used to detect and measure the chord created by the intersection of the laser plane and the object. From the measured chords we derive the average diameter and its variance. An improved method is to use a pair of parallel illuminating light planes to extract two chords. The estimation error for this method is not larger than the natural shape fluctuations (the difference in diameter) for the pellets. The laser-camera optronics is sensitive enough both for material on a conveyor belt and free falling material leaving the conveyor.

  • 9.
    Brandell, Daniel
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Strukturkemi.
    Ainla, Alar
    Liivat, Anti
    Aabloo, Alvo
    Molecular Dynamics Simulations of Li- and Na-Nafion Membranes2006Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6168, s. 61680G-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract
  • 10.
    Brandell, Daniel
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Strukturkemi.
    Kasemägi, Heiki
    Citérin, Johann
    Vidal, Frédéric
    Chevrot, Claude
    Aabloo, Alvo
    Molecular Dynamics studies of interpenetrated polymer networks for actuator devices2008Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6927Artikkel i tidsskrift (Fagfellevurdert)
  • 11.
    Chen, Daru
    et al.
    Centre for Optical and Electromagnetic Research, Department of Optical Engineering, Zhejiang University.
    Yu, Zhangwei
    Centre for Optical and Electromagnetic Research, Department of Optical Engineering, Zhejiang University.
    Qin, Shan
    Centre for Optical and Electromagnetic Research, Department of Optical Engineering, Zhejiang University.
    He, Sailing
    Centre for Optical and Electromagnetic Research, Department of Optical Engineering, Zhejiang University.
    Some switchable dual-wavelength fibre lasers based on fibre Bragg grating feedback2006Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6351, s. U864-U872Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two methods to achieve dual-wavelength switching in a fibre laser are proposed and two corresponding switchable dual-wavelength fibre lasers based on fibre Bragg grating (FBG) feedback are demonstrated in this paper. In one proposed fibre laser, both Raman and Erbium-doped fibre (EDF) pumps are employed and the dual-wavelength switching is achieved by controlling the power of the Raman pump. In the other proposed fibre laser, an injection technique is used and the dual-wavelength switching is realized by controlling the power of the injection laser. The detailed behavior of the dual-wavelength switching in the two fibre lasers is experimentally studied and the principle is explained physically.

  • 12.
    Chen, Han
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Medicinsk bildfysik.
    Danielsson, Mats
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Medicinsk bildfysik.
    Cederström, Björn
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Medicinsk bildfysik.
    On imaging with or without grid in digital mammography2014Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 9033, s. 903346-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The grids used in digital mammography to reduce scattered radiation from the breast are not perfect and lead to partial absorption of primary radiation at the same time as not all of the scattered radiation is absorbed. It has therefore lately been suggested to remove the grids and correct for effects of scattered radiation by post-processing the images. In this paper, we investigated the dose reduction that might be achieved if the gird were to be removed. Dose reduction is determined as a function of PMMA thickness by comparing the contrast-to-noise ratios (CNRs) of images acquired with and without grid at a constant exposure. We used a theoretical model validated with Monte Carlo simulations and phantom studies. To evaluate the CNR, we applied aluminum filters of two different sizes, 4x8 cm2 and 1x1 cm 2. When the large Al filter was used, the resulting CNR value for the grid-less images was overestimated as a result of a difference in amount of scattered radiation in the background region and of the region covered by the filter, a difference that could be eliminated by selecting a region of interest close to the edge of the filter. The optimal CNR when the PMMA thickness was above about 4 cm was obtained with a grid, whereas removing the grid leaded to a dose saving in thinner PMMAs. The results suggest not removing grids in breast cancer screening.

  • 13.
    Chen, Jiajia
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Chen, Bao
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    A Novel Joint Scheduling Algorithm for Multiple Services in 10G EPON2008Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 7137Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    In this paper, we propose and evaluate a novel joint scheduling algorithm for multiple services which can support differentiated services and bandwidth allocation with global priority of different traffic such as Triple-play: voice, video and Internet services. Simulation results show that for the higher priority traffic better delay and jitter performance can be achieved compared with the lower priority traffic.

  • 14.
    Edin, Benoni B
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Trulsson, Mats
    Neural network analysis of the information content in population responses from human periodontal receptors1992Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 1710, s. 257-266Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Understanding of the information processing in some sensory systems is hampered for several reasons. First, some of these systems may depend on several receptor types with different characteristics, and the crucial features of natural stimuli encoded by the receptors are rarely known with certainty. Second, the functional output of sensory processing is often not well defined. The human tooth is endowed with several types of sensory receptors. Among these, the mechanoreceptors located in the periodontal ligaments have been implicated in force encoding during chewing and biting. Individual receptors cannot, however, code unambiguously either the direction or the magnitude of the applied forces. Neuronal responses recorded in single human nerve fibers from periodontal receptors were fed to multi-layered feed-forward networks. The networks were trained with error back-propagation to identify specific features of the force stimuli that evoked the receptor responses. It was demonstrated that population responses in periodontal receptors contain information about both the point of attack and the direction of applied forces. It is concluded that networks may provide a powerful tool to investigate the information content in responses from biological receptor populations. As such, specific hypotheses with respect to information processing may be tested using neural networks also in sensory systems less well understood than, for instance, the visual system.

  • 15. Eldada, L. A.
    et al.
    Lee, E. -H
    He, S.
    Introduction2014Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 8989, s. IX-X, artikkel-id 898901Artikkel i tidsskrift (Fagfellevurdert)
  • 16.
    Elsharif Zainelabdin, Ahmed
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Nur, Omer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Amin, Gul
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Zaman, Siama
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Metal Oxide Nanostructures and White Light Emission2012Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 8263, nr 82630NArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on white light emission from zinc oxide nanostructures chemically grown on paper substrates. The effect of the growth solution pH on the morphology is discussed. The light emission form light emitting diodes based on ZnO nanorods/organic polymer hybrids on paper substrate is presented. Further copper oxide was grown on the walls of zinc oxide nanorods and the optical properties were investigated.

  • 17. Enochsson, Ola
    et al.
    Täljsten, Björn
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Olofsson, Thomas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Structural health monitoring of a concrete bridge in Sweden2006Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6176, nr 18Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Over the past decade the interests in upgrading, assessment and maintenance of our ageing infrastructure has grown avalanche-like. The main reason is economical aspects but also reasons due to accessibility environmental consideration play a vital role. Recently the Swedish and Norwegian Railway Association decided to upgrade the Iron Ore Line "Malmbanan", a railway line for transportation of iron from northern Sweden to the coasts of Norway and Sweden. Here the owner wanted to increase the axle loads from 25 to 30 tons to reduce the transportation costs. In one of the cases, the Luossajokk Bridge, a recalculation according to design codes showed that the increased axle loads would exceed the yield limit in the reinforcement. Before any decision was taken regarding strengthening or replacing the bridge an assessment with probabilistic methods was used. It appeared that the bridge could carry the higher load with a safety index β ≥ 4.7 for reasonable assumptions of the load distributions. A measurement system was installed to check the real worst placement of the new iron ore locomotive (IORE), and the actually level of strains in the reinforcement for the worst load case1. It was shown that the strain level was far from critical and that the evaluated worst placement of the locomotive was almost correct2. To assure a reliable transportation a long term monitoring program was arranged to check the development of strains with time. Examples from the probabilistic evaluation and the monitoring of the bridge are given and discussed.

  • 18.
    Eriksson, Fredrik
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik.
    Johansson, G.A.
    Hertz, H.M.
    Birch, Jens
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tunnfilmsfysik.
    Enhanced soft x-ray reflectivity of Cr/Sc multilayers by ion assisted sputter deposition2001Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 4506, s. 84-92Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Cr/Sc multilayers have been grown on Si substrates using DC magnetron sputtering. The multilayers are intended as condenser mirrors in a soft x-ray microscope operating at the wavelength 3.374 nm. They were designed for normal reflection of the first and second order with multilayer periods of 1.692 nm and 3.381 nm, and layer thickness ratios of 0.471 and 0.237, respectively. At-wavelength soft x-ray reflectivity measurements were carried out using a reflectometer with a compact soft x-ray laser-plasma source. The multilayers were irradiated during growth with Ar ions, varying both in energy (9-113 eV) and flux, in order to stimulate the ad-atom mobility and improve the interface flatness. It was found that to obtain a maximum soft x-ray reflectivity with a low flux (Cr=0.76, Sc=2.5) of Ar ions a rather high energy of 53 eV was required. Such energy also caused intermixing of the layers. By the use of a solenoid surrounding the substrate, the arriving ion-to-metal flux ratio could be increased 10 times and the ion energy could be decreased. A high flux (Cr=7.1, Sc=23.1) of low energy (9 eV) Ar ions founded the most favourable growth condition in order to limit the intermixing with a subsistent surface flatness.

  • 19. Fazio, Valentina
    et al.
    Örtegren, Jonas
    Koelsch, Patrick
    Andersen, Audree
    Wantke, Dieter
    Möhwald, Helmut
    Motschmann, Hubert
    New insights in static and dynamic properties of soluble monolayers2003Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 5223, s. 38-49Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Abstract In this paper we discuss selected equilibrium and dynamic properties of adsorp-tion layers of soluble surfactants. The surface state has been investigated by nonlinearoptical techniques based on second order χ(2)effects which exhibit a high surface specificityand suppress bulk contributions. The surface tension isotherm σ(c) of the homologousseries of n-alkyldimethylphosphine (n =8 − 12) can be described by Frumkin’s equation ofstate which yields the surface interaction parameter, surface coverage and the correspondingarea per molecule A. The comparison of the surface tension σ at a given area per moleculeA reveals a strong alternation within the homologous series. Odd C2n±1 layers show alower surface tension than the adjacent even members C2n of the homologous series. Thiseffect is also present at low surface coverage (A =1.4nm2) and cannot be attributed to adifferences in the chain-packing within a crystalline state. Infrared-Visible Sum-FrequencyGeneration Spectroscopy (SFGS) has been used to monitor the orientation and chain orderwithin the aliphatic tail. SFGS spectra have been recorded for different chain lengths andat different areas per molecule. The analysis of the spectra yields an order parameterG which is proportional to the number of gauche defects within the aliphatic tail. Theodd-even effect in the surface tension turned out to be accompanied by an odd-even effectin the order parameter G. The data suggest that an ordered structure has a bigger impacton the surface tension than an unordered structure. The odd-even effect is also observedin the orientation of the terminating methyl group as retrieved by polarization dependentSFGS measurements. The data shed some light in the relation between molecular andmacroscopic properties. Furthermore surface dilatational viscoelastic properties of afluorinated amphiphile have been measured by a novel version of the oscillating bubble.The oscillating bubble method generates a non-equilibrium state by a harmonic compressionand expansion of the surface layer formed at the tip of a capillary. The surface state ismonitored by Surface Second Harmonic Generation (SHG). This technique is highly surfacespecific and discriminates between monolayer and subsurface coverage. Our set-up allowsto measure the monolayer coverage under dynamic conditions and to relate this to surfacedilatational viscosity and elasticity. For a purely elastic surface layer the prediction of theLucassen van den Temple model (LvdT) are fulfilled.

  • 20.
    Forssell, G.
    et al.
    Swedish Defence Research Agency, FOI, P.O. Box 1165, SE-581 11 LinkÖping, Sweden.
    Hedborg-Karlsson, E.
    Swedish Defence Research Agency, FOI, P.O. Box 1165, SE-581 11 LinkÖping, Sweden.
    Measurements of polarization properties of camouflaged objects and of the denial of surfaces covered with cenospheres2003Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 5075, s. 246-258Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Camouflaged objects in a background, which are not possible to observe with conventional IR measurements without polarization, can be seen in polarization measurements.. In this paper will be shown that polarization measurements increase the possibility to detect covered objects.The denial of polarization measurements of a covered object has earlier been achieved by construction of a surface covered with cenospheres. The emissivity as a function of angle of incidence has also been investigated on this newly developed surface, which can be designed to have emission properties decided in advance. The results indicate that it is possible to use the surface materiel as a means to adapt an object to a certain optical signature. It has also been shown that the surface almost completely depolarises the emitted radiation, which makes it more difficult to observe with a polarization measurement. These properties make the surface suitable as a reference surface for polarization measurements. A more systematic development of these surfaces and investigation are reported here.

  • 21.
    Fredriksson, Ingemar
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Larsson, Marcus
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Strömberg, Tomas
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Absolute flow velocity components in laser Doppler flowmetry2006Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6094, s. 60940A-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A method to separate a Doppler power spectrum into a number of flow velocity components, measured in absolute units (mm/s), is presented. A Monte Carlo software was developed to track each individual Doppler shift, to determine the probability, p(n), for a photon to undergo n Doppler shifts. Given this shift distribution, a mathematical relationship was developed and used to calculate a Doppler power spectrum originating from a certain combination of velocity components. The non linear Levenberg-Marquardt optimization method could thus be used to fit the calculated and measured Doppler power spectra, giving the true set of velocity components in the measured sample. The method was evaluated using a multi tube flow phantom perfused with either polystyrene microspheres or undiluted/diluted human blood (hct = 0.45). It estimated the velocity components in the flow phantom well, during both low and high concentrations of moving scatterers (microspheres or blood). Thus, further development of the method could prove to be a valuable clinical tool to differentiate capillary blood flow.

  • 22.
    Fridolin, Ivo
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Magnusson, M.
    Lindberg, Lars-Göran
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    Measurement of solutes in dialysate using UV absorption2001Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 4263, s. 40-47Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The aim of this work was to describe a new method for optical monitoring of solutes in a spent dialysate. The method utilizes UV light absorption employing a commercially available spectrophotometer. Measurements were performed both on collected dialysate samples and on-line. The concentration of several removed solutes and electrolytes in the serum and in the dialysate was determined simultaneously using standard laboratory techniques. During on-line monitoring the spectrophotometer was connected to the fluid outlet of the dialysis machine. On-line measurements during a single hemodialysis session demonstrated a possibility to monitor deviations in the dialysator performance (e.g. dialysator in bypass). The experimental results indicated a good correlation between UV absorption and several removed solutes (urea, creatinine) in the spent dialysate. The correlation coefficient for urea and creatinine concentrations in the dialysate was very high for every individual treatment. The UV absorbance correlates well to the concentrations of several solutes thought to be uremic toxins. The results indicate that the technique can be used as a continuous, on-line method for monitoring deviations in the dialysator performance and may estimate the removal of the overall toxins. In the future, the new method will be used to evaluate parameters describing delivery of the prescribed treatment dose such as KT/V and Urea Reduction Rate (URR).

  • 23.
    Funke, Bernd
    et al.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    López-Puertas, M.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Stiller, G.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Clarmann, T. Von
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Martin-Torres, Javier
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    New non-LTE retrieval method for atmospheric parameters from MIPAS/ENVISAT emission spectra at 5.3 μm2002Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 4539, s. 396-405Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Atmospheric emissions at 5.3 μm will be measured by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), a high-resolution limb sounder on board the European polar platform ENVISAT, scheduled to be launched in 2001. Measured spectra at 5.3 μm contain information on important atmospheric quantities such as NO volume mixing ratio, thermospheric temperature, and chemical NO production rates. However, the scientific analysis of this spectral region has to deal with complex non-local thermodynamic equilibrium (non-LTE) effects. A conventional non-LTE retrieval approach using ab initio vibrational temperatures cannot be applied due to rotational and spin-orbit non-LTE of NO in the thermosphere, and the dependence of NO state populations on the NO abundance itself caused by chemical excitations. An innovative non-LTE retrieval method enabling the treatment of vibrational, rotational, and spin non-LTE as well as a dependence of the non-LTE state distribution on the retrieval target quantities has thus been developed for the MIPAS data analysis. The ability of the developed non-LTE inversion tool to retrieve NO abundance profiles, thermospheric temperature profiles, and NO mean production rates by NO2 photolysis in the stratosphere and N+O2 combination in the thermosphere is demonstrated by means of a feasibility study.

  • 24.
    Garbe, C.S.
    et al.
    Interdisc. Ctr. for Sci. Computing, University of Heidelberg, Heidelberg, Germany, Digital Image Processing, Interdisc. Ctr. for Sci. Computing, University of Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg, Germany.
    Spies, H.
    Jahne, B.
    Jähne, B., Interdisc. Ctr. for Sci. Computing, University of Heidelberg, Heidelberg, Germany.
    Estimation of complex motion from thermographic image sequences2003Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 5073, s. 303-317Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    In this contribution a novel technique for computing complex motion involving heat transport processes will be presented. The proposed technique is a local gradient based approach, combining transport models with motion analysis. It allows for the simultaneous estimation of both motion and parameter of an underlying transport model. Since the analysis is based on thermal image sequences, estimates are computed to a high temporal and spatial resolution, limited only by the resolution and frame rate of the employed IR camera. This novel technique was utilized on exchange processes at the atmosphere/ocean boundary, where significant parameters of heat transfer could be measured and a transport model verified. Using the presented algorithms, surface flows as well as convergences and divergences on air-water interfaces can be measured accurately. Apart from applications in oceanography and botany, relevant benefits of the proposed technique to NDT will be presented. It is possible to compensate for motion to reach accuracies much better than 1/10th of a pixel. Through the direct estimation of locally resolved diffusivities in materials, insights can be gained about defects present. By estimating not only isotropic diffusion but also the whole matrix of anisotropic diffusion, the technique is highly relevant to measurements of composite materials.

  • 25.
    Gaudiuso, Caterina
    et al.
    Istituto di Fotonica e Nanotecnologie (IFN)-CNR U.O.S. Bari, Via Amendola 173, Bari, Italy.
    Giannuzzi, Giuseppe
    Istituto di Fotonica e Nanotecnologie (IFN)-CNR U.O.S. Bari, Via Amendola 173, Bari, Italy.
    Choquet, Isabelle
    Högskolan Väst, Institutionen för ingenjörsvetenskap, Avdelningen för svetsteknologi (SV).
    Lugarà, Pietro Mario
    Istituto di Fotonica e Nanotecnologie (IFN)-CNR U.O.S. Bari, Via Amendola 173, Bari, Italy.
    Ancona, Antonio
    Högskolan Väst, Institutionen för ingenjörsvetenskap, Avdelningen för produktionssystem (PS).
    Incubation effect in burst mode fs-laser ablation of stainless steel samples2018Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 10520, artikkel-id 105200AArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report on an experimental study of the incubation effect during irradiation of stainless steel targets with bursts of femtosecond laser pulses at 1030 nm wavelength and 100 kHz repetition rate. The bursts were generated by splitting the pristine 650-fs laser pulses using an array of birefringent crystals which provided time separations between sub-pulses in the range from 1.5 ps to 24 ps. We measured the threshold fluence in Burst Mode, finding that it strongly depends on the bursts features. The comparison with Normal Pulse Mode revealed that the existing models introduced to explain the incubation effect during irradiation with trains of undivided pulses has to be adapted to describe incubation during Burst Mode processing. In fact, those models assume that the threshold fluence has a unique value for each number of impinging pulses in NPM, while in case of BM we observed different values of threshold fluence for fixed amount of sub-pulses but different pulse splitting. Therefore, the incubation factor coefficient depends on the burst features. It was found that incubation effect is higher in BM than NPM and that it increases with the number of sub-pulses and for shorter time delays within the burst. Two-Temperature-Model simulations in case of single pulses and bursts of up to 4 sub-pulses were performed to understand the experimental results. © Copyright SPIE.

  • 26.
    Haj-Hosseini, Neda
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Kistler, Benjamin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan. University of Applied Sciences in Northwest Switzerland.
    Wårdell, Karin
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Development and characterization of a brain tumor mimicking fluorescence phantom   2014Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 8945, s. 1-6, artikkel-id 894505Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fluorescence guidance using 5-aminolevulinic acid (5-ALA) for brain tumor resection is a recent technique applied to the highly malignant brain tumors. Five-ALA accumulates as protoporphyrin IX fluorophore in the tumor cells in different concentrations depending on the tumor environment and cell properties. Our group has developed a fluorescence spectroscopy system used with a hand-held probe intra-operatively. The system has shown improvement of fluorescence detection and allows quantification that preliminarily correlates with tumor malignancy grade during surgery. However, quantification of fluorescence is affected by several factors including the initial fluorophore concentration, photobleaching due to operating lamps and attenuation from the blood. Accordingly, an optical phantom was developed to enable controlled fluorescence measurements and evaluation of the system outside of the surgical procedure. The phantom mimicked the optical properties of glioma at the specific fluorescence excitation wavelength when different concentrations of the fluorophore were included in the phantom. To allow evaluation of photobleaching, kinetics of fluorophore molecules in the phantom was restricted by solidifying the phantoms. Moreover, a model for tissue autofluorescence was added. The fluorescence intensity’s correlation with fluorophore concentration in addition to the photobleaching properties were investigated in the phantoms and were compared to the clinical data measured on the brain tumor.

  • 27. Hejll, Arvid
    et al.
    Täljsten, Björn
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Carolin, Anders
    Structural health monitoring of the Gröndals bridge in Sweden: the behaviour of CFRP strengthening in cold temperature2006Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6176, nr 17Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To obtain a better knowledge of existing structures behaviour monitoring can be used. The use of monitoring in bridge structures by the use of instruments to assess the integrity of structures is not new and there are reports from structures tested as early as in the 19th century according to ISIS Canada1 However, the term SHM (Structural Health Monitoring) is relatively new to civil engineering and the driving force to implement SHM comes from recognising the limitations of conventional visual inspections and evaluations using conservative codes of practice. The possibilities to monitor existing structures with help of the rapidly evolving Information Technology are to day carried out. The objective of SHM is to monitor the in-situ behaviour of a structure accurately and efficiently, to assess its performance under various service conditions, to detect damage or deterioration, and to determine the health or condition of the structure1. In Sweden strengthening and periodic monitoring of a large freivorbau bridge (pre-stresed concrete box girder bridge) has been carried out, the Gröndals Bridge. The bridge is located in Stockholm and is approximately 400 m in length with a free span of 120 m. It was opened to tram traffic in year 2000. Just after opening cracks were noticed in the webs, these cracks have then increased, the size of the largest cracks exceeded 0.5 mm, and at the end of year 2001 the bridge was temporarily strengthened. This was carried out with externally placed prestressed steel stays. The reason for cracking is quite clear but the responsibility is still debated. Nevertheless, it was evidently that the bridge needed to be strengthened. The strengthening methods used were CFRP plates in the Service Limit State (SLS) and prestressed dywidag stays in the Ultimate Limit State (ULS). The strengthening was carried out during year 2002. At the same time monitoring of the bridge commenced, using LVDT crack gauges as well as optical fibre sensors. This monitoring was carried out during the summer period. In addition to this a winter monitoring was carried out in the beginning of 2005. This paper presents the background to strengthening and a comparison between summer and winter monitoring where the strengthening behaviour between the two seasons is enlightened. The result from the monitoring is very interesting; it would have been preferable to strengthen the bridge during the winter.

  • 28.
    Henriksson, Markus
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Laserfysik.
    Sjökvist, Lars
    FOI.
    Strömqvist, Gustav
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Laserfysik.
    Pasiskevicius, Valdas
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Laserfysik.
    Laurell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Laserfysik.
    Tandem PPKTP and ZGP OPO for mid-infrared generation2008Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 7115, s. 71150O1-10Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Efficient laser sources in the 3-5 μrn wavelength range are needed for directed infrared countermeasures, but also have applications in remote-sensing, medicine and spectroscopy. We present new results on our tandem optical parametric oscillator (OPO) scheme for converting the radiation from a 1.06 μm Nd3+-laser to the mid-infrared. Multi Watt level output power in the 3-5 μm range at 20 kHz pulse repetition frequency is reported. Our setup uses a type I quasi phasematched PPKTP crystal in a near degenerate OPO to generate 2.13 μm radiation. A volume Bragg grating resonant close to, but not exactly at the degenerate wavelength, is used as a cavity mirror to reduce the bandwidth and ensure singly resonant operation. Both signal and idler from the PPKTP OPO are used to pump a ZGP OPO generating high power radiation in the 3-5μm region. Using this scheme for each pump photon it is possible to generate four photons for each pump photon, all in the interesting wavelength range, thus enabling high efficiency conversion.

  • 29.
    Henriksson, Markus
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Laserfysik. Dept. of Laser Systems, Swedish Defence Research Agency, FOI, Sweden.
    Sjöqvist, L.
    Gustafsson, O.
    Experimental study of mid-IR laser beam wander close to a jet engine exhaust2006Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6397Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An increasing interest in lasers placed on aircrafts for active countermeasures and active imaging is observed. There remain unsolved issues regarding the propagation effects close to the jet engine exhaust and the possibilities of compensating them with adaptive optics. Laser beam propagation experiments parallel to the exhaust of a downscaled jet engine test rig have been performed. The experiments were carried out with nanosecond laser pulses at 1.6 and 3.5 μm wavelength. The laser spots were projected on a screen and the centroid motion were imaged by cameras. Root mean square magnitudes of the beam wander between 50 and 150 μrad were observed for different engine conditions and geometries. The 3.5 μm system had a frame rate of 607 Hz and could partly resolve the time variation of the beam wander. A correlation time (50 %) of 3.5 ms was observed for the beam wander. Deflections of several hundred μrad due to the average gradients in temperature and pressure were also found when the engine was turned on. In addition to beam wander intensity scintillations has been studied.

  • 30.
    Johansson, Anders
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för medicinsk teknik, Fysiologisk mätteknik.
    A neural network for photoplethysmographic respiratory rate monitoring2001Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 4434, s. 109-118Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The photoplethysmographic signal (PPG) includes respiratory components seen as frequency modulation of the heart rate (respiratory sinus arrhythmia, RSA), amplitude modulation of the cardiac pulse, and respiratory induced intensity variations (RIIV) in the PPG baseline. The aim of this study was to evaluate the accuracy of these components in determining respiratory rate, and to combine the components in a neural network for improved accuracy. The primary goal is to design a PPG ventilation monitoring system. PPG signals were recorded from 15 healthy subjects. From these signals, the systolic waveform, diastolic waveform, respiratory sinus arrhythmia, pulse amplitude and RIIV were extracted. By using simple algorithms, the rates of false positive and false negative detection of breaths were calculated for each of the five components in a separate analysis. Furthermore, a simple neural network (NN) was tried out in a combined pattern recognition approach. In the separate analysis, the error rates (sum of false positives and false negatives) ranged from 9.7% (pulse amplitude) to 14.5% (systolic waveform). The corresponding value of the NN analysis was 9.5-9.6%.

  • 31. Jonsson, P.
    et al.
    Kullander, F.
    Vahlberg, C.
    Jelger, Pär
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Laserfysik.
    Tiihonen, Mikael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Laserfysik.
    Wästerby, P.
    Tjärnhage, T.
    Lindgren, M.
    Spectral detection of ultraviolet laser induced fluorescence from individual bioaerosol particles2006Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6398Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present results of a measurement system designed for detecting the fluorescence spectrum of individual aerosol particles of biological warfare agents excited with laser pulses at wavelengths around 290 or 340 nm. The biological aerosol is prepared and directed into a narrow air beam. A red laser is focused on the aerosol beam and a trigger photomultiplier tube monitor the presence of individual particles by measuring the scattered light. When a particle is present in the detection volume, a laser pulse is triggered from an ultraviolet laser and the fluorescence spectrum is acquired with a spectrometer based on a diffraction grating and a 32 channels photomultiplier tube array with single-photon sensitivity. The spectrometer measures the fluorescence spectra in the wavelength region from 300 to 800 nm. In the experiment we used different simulants of biological warfare agents. These bioaerosol particles were excited by a commercial available gas laser (337 nm), or a laser (290 nm) that we have developed based on an optical parametric oscillator with intracavity sum-frequency mixing. In the analysis of the experiments we compare the measured signals (fluorescence spectra, total fluorescence energy and the scattered energy) from the individual bioaerosol particles excited with the two different ultraviolet wavelengths.

  • 32.
    Kanciurzewska, Anna
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Dobruchowska, Ewa
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Baranzahi, Amir
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Carlegrim, Elin
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Fahlman, Ana
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Fahlman, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Girtu, Mihai A.
    Dye sensitized solar cells with a plastic counter electrode of poly(3,4-ethylene dioxythiophene)-poly(styrenesulfonate) - art. no. 6656112007Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6656, s. 65611-65611Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    n/a

  • 33. Karlsson, G.
    et al.
    Pasiskevicius, Valdas
    Fragemann, A.
    Laurell, Fredrik
    Generation of 100 kW-level pulses at 1.53 µm in the diode-pumped Er-Yb:glass laser - PPKTP optical parametric amplifier system2002Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 5137, s. 37-43Artikkel i tidsskrift (Fagfellevurdert)
  • 34.
    Karlsson, Gunnar
    et al.
    KTH, Skolan för teknikvetenskap (SCI).
    Pasiskevicius, Valdas
    KTH, Skolan för teknikvetenskap (SCI).
    Fragemann, Anna
    KTH, Skolan för teknikvetenskap (SCI).
    Laurell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI).
    Generation of 100 kW-level pulses at 1.53 µm in the diode-pumped Er-Yb:glass laser - PPKTP optical parametric amplifier system2003Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 5137, s. 37-42Artikkel i tidsskrift (Fagfellevurdert)
  • 35.
    Khodadad, Davood
    et al.
    Tehran University of Medical Science.
    Ahmadian, Alireza Alireza
    Tehran University of Medical Science.
    Ay, Mohammadreza
    Tehran University of Medical Science.
    Esfahani, Armaghan Fard
    Tehran University of Medical Science.
    Banaem, Hossein Yousefi
    Zaidi, Habib
    Geneva University Hospital.
    B-spline based Free Form Deformation Thoracic non-rigid registration of CT and PET images2011Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 8285Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Accurate attenuation correction of emission data is mandatory for quantitative analysis of PET images. One of the main concerns in CT-based attenuation correction(CTAC) of PET data in multimodality PET/CT imaging is misalignment between PET and CT images. The aim of this study, is to proposed a hybrid method which is simple, fast and accurate, for registration of PET and CT data which affected from respiratory motion in order to improve the quality of CTAC. The algorithm is composed of three methods: First, using B-spline Free Form Deformation to describe both images and deformation field. Then applying a pre-filtering on both PET and CT images before segmentation of structures in order to reduce the respiratory related attenuation correction artifacts of PET emission data. In this approach, B-spline using FFD provide more accurate adaptive transformation to align the images, and structure constraints obtained from prefiltering applied to guide the algorithm to be more fast and accurate. Also it helps to reduce the radiation dose in PET/CT by avoiding repetition of CT imaging. These advances increase the potential of the method for routine clinical application.

  • 36.
    Khrennikov, Andrei
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Matematiska och systemtekniska institutionen. matematik.
    Can the mathematical formalism of quantum mechanics be applied to psychology?2008Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 7023, nr Article ID: 702308Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We show that (in contrast to rather common opinion) the domain of applications of the mathematical formalism of quantum mechanics is not restricted to physics. This formalism can be applied to the description of various quantum-like (QL) information processing. In particular, the calculus of quantum (and more general QL) probabilities can be used to explain some paradoxical statistical data which was obtained in psychology and cognitive science. We consider the QL description of prisoners dilemma (PD) and so called disjunction effect (violation of Savage's sure thing principle which plays the fundamental role in modern economics).

  • 37.
    Khrennikov, Andrei
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Matematiska och systemtekniska institutionen. matematik.
    Quantum averages from Gaussian random fields at the Planck length scale2008Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 7023, nr Article ID: 702309Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We show that the mathematical formalism of quantum mechanics can be interpreted as a method for approximation of classical (measure-theoretic) averages of functions f : L 2(R3) → R. These are classical physical variables in our model with hidden variables - Prequantum Classical Statistical Field Theory (PCSFT). In this paper we provide a simple stochastic picture of such a quantum approximation procedure. In the probabilistic terms this is nothing else than the approximative method for computation of averages for functions of random variables. Since in PCSFT the space of hidden variables is L 2(R3), the role of a classical random variable is played by a random field. In PCSFT we consider Gaussian random fields representing random fluctuations at the prequantum length scale. Quantum mechanical expression for the average (given by the von Neumann trace formula) is obtained through moving from the prequantum length scale to the quantum one (the scale at that we are able to perform measurements).

  • 38. Klasen, L.
    et al.
    Li, H.
    Forchheimer, Robert
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik.
    Evaluation of a method for invariant and automated detection and tracking of objects from video2001Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 4232, s. 455-463Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Video generates a rich set of image information and often the useful information is only a very limited set of the available information. Another well-known fact is that visually reviewing of long video recordings is a time demanding task. In combination with the continuously increasing number of video surveillance systems, this leads to an increasing need for automated analysis of long image sequences. The goal for this work is to develop and evaluate a method for automatic detection and tracking of events recorded onto a surveillance video, such as appearance of persons or vehicles in a surveyed area, to evaluate the usefulness for forensic applications and real time applications. One core problem is the fact that both the background and the objects move, where only the physical motion of moving objects are of interest and needs to be separated from the camera motion. Another core problem in many of the video processing algorithms is parameter estimation despite invariance for accurate modeling of the desired features. Varying scale, color, lightning conditions and occlusion of the object of interest can for example cause invariance. The technical approaches for this work is to separate global and local motion by analyzing the optical flow constraints. To overcome the problem caused by such feature and object invariance, all pixels are considered independently and no feature parameters are needed. If the basic optical flow constraint is satisfied, the motion is classified as global motion. If not, the motion is considered caused by local motion, noise or other phenomena. An object that undergoes local motion can then be detected and tracked as is forms a trace in the temporal domain, while the noise appears on an intermittent basis and will be disregarded. The results from applying this method on several image sequences were compared and the robustness and ability to deal with invariance has been evaluated. The result clearly shows that in realistic situations, where visual reviewing can be quite a difficult task, computer based methods for automatic detection are useful to detected moving objects in long video recordings.

  • 39.
    Laurell, Fredrik
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Laserfysik.
    Arvidsson, G.
    Jaskorzynska, B.
    Periodicstructures for phase-matching in second harmonic generation in titanium lithiumniobate waveguides1986Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756XArtikkel i tidsskrift (Fagfellevurdert)
  • 40.
    Leahy, M.J.
    et al.
    Department of Physics, University of Limerick, Limerick, Ireland.
    De, Mul F.F.M.
    De Mul, F.F.M., Department of Applied Physics, University of Twente, Enschede, Netherlands.
    Nilsson, G.E.
    Department of Biomedical Engineering, University of Linkoping, Linkoping, Sweden.
    Maniewski, R.
    Inst. of Biocybernet./Biomed. Eng., Warsaw, Poland.
    Liebert, A.
    Inst. of Biocybernet./Biomed. Eng., Warsaw, Poland.
    Developments in laser Doppler blood perfusion monitoring2002Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 4876, nr 1, s. 128-139Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    This paper reviews the development and use of laser Doppler perfusion monitors and imagers. Despite their great success and almost universal applicability in microcirculation research, they have had great difficulty in converting to widespread clinical application. The enormous interest in microvascular blood perfusion coupled with the 'ease of use' of the technique has led to 2000+ publications citing its use. However, useful results can only be achieved with an understanding of the basic principles of the instrumentation and its application in the various clinical disciplines. The basic technical background is explored and definitions of blood perfusion and laser Doppler perfusion are established. The calibration method is then described together with potential routes to standardisation. A guide to the limitations in application of the technique gives the user a clear indication of what can be achieved in new studies as well as possible inadequacy in some published investigations. Finally some clinical applications have found acceptability and these will be explored.

  • 41.
    Li, Qiang
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Wang, Shanshan
    Chen, Yiting
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Yan, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Tong, Limin
    Qiu, Min
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Fotonik och optik, Fotonik.
    Silver nanowire based plasmon propagation, coupling and splitting at 1.55 mu m wavelength2011Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 7986Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We experimentally demonstrate silver nanowire based plasmonic devices at optical communication wavelength 1.55 mu m. The plasmon propagation loss in a 300 nm diameter silver nanowire is measured to be 0.3 dB/mu m. Two types of plasmonic functional devices based on the coupling between two silver nanowires, nano-couplers and nano-splitters, are realized.

  • 42.
    Lindbergh, Tobias
    et al.
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Larsson, Marcus
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Fredriksson, Ingemar
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Strömberg, Tomas
    Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk instrumentteknik. Linköpings universitet, Tekniska högskolan.
    Reduced scattering coefficient determination by non-contact oblique angle illumination: methodological considerations2007Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6435, s. 64350I-1-64350I-12Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The reduced scattering coefficient, µs, was determined using oblique angle illumination and imaging backscattered light intensity. The distance r between the point of light incidence (hot-spot) and the circular symmetric diffuse reflectance centre, is ~1/µ. Previously, r was obtained analyzing a 1D strip aligned with the laser beam. We improved this method by calculating a 2D intensity image with extended dynamic range by assessing camera linearity, superimposing images with multiple integration times, and compensating for lens vignetting. The hot-spot algorithm utilises several images to minimize speckle variations and account for laser beam shape. Diffuse centre position is obtained by filtering the superimposed image with decreasing thresholds using momentum analysis to determine circular symmetry. The method was evaluated on 18 optical liquid phantoms with µs[1.5, 3.0] mm-1 and µs[0.01, 0.16] mm-1. The 2D method had better linearity with µs and smaller variations due to more stable hot-spot detection, than the 1D method. The anisotropy factor g was obtained by fitting measured and Monte Carlo simulated spatially resolved intensity decays and verified with a laser Doppler flowmetry technique. With an optimal compensation for the µa dependence, the rms error in µ estimation was 2.9%.

  • 43. Linderhed, A.
    et al.
    Lundberg, M.
    Department of Signals and System, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Nyberg, S.
    Sjokvist, S.
    Uppsall, M.
    Analysis of optical measurements on real minefields2002Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 4742, nr I, s. 160-171Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    This paper presents preliminary analysis of the data from measurements on a minefield in Croatia done in the international cooperation project Airborne Minefield Area Reduction (ARC). Temperature differences above and around suspected mines and minefield indicators, were recorded with a long wave IR camera in 8-9 µm, over a time of several days, capturing data under different weather conditions. The data are compared to simulations of land mines, minefield indicators and other objects using a themodynamic FEM model, developed at FOI. Different detection methods are presented and applied to the data.

  • 44.
    López-Puertas, M.
    et al.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Funke, B.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    López-Valverde, M. Á
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Martin-Torres, Javier
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Clarmann, T. Von
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Stiller, G.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Oelhaf, H.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Fischer, H.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Flaud, J. M.
    Instituto de Astrofísica de Andalucía CSIC, Granada.
    Non-LTE studies for the analysis of MIPAS/ENVISAT data2002Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 4539, s. 381-395Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is a high-resolution limb sounder on board the European polar platform ENVISAT, scheduled for launch late in 2001. Three main characteristics converge in MIPAS which make it a very useful instrument for non-LTE studies: its wide spectral coverage (4.15-14.6 μm or 680-2275 cm-1); high spectral resolution (0.03 cm-1), and high sensitivity; all of this in addition to its global spatial coverage. In this paper we present an overview of the non-LTE studies that have been carried out in preparation for the analysis of MIPAS data, including the evaluation of non-LTE effects in the operational processing, focussed in the stratosphere, and the retrieval of species that normally emit under non-LTE conditions. The current mission plan for measuring the non-LTE upper atmosphere is described, as well as the general purpose non-LTE retrieval scheme developed for analyzing those measurements.

  • 45. Maguire Jr., Gerald Q.
    et al.
    Zeleznik, Michael P.
    Horii, Steven C.
    New York University.
    Schimpf, James H.
    New York University.
    Noz, Marilyn E.
    New York University.
    Image-processing Requirements in Hospitals and an Integrated Systems-approach1982Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 318, s. 206-213Artikkel i tidsskrift (Fagfellevurdert)
  • 46.
    Marcks von Würtemberg, Rickard
    et al.
    KTH, Tidigare Institutioner, Mikroelektronik och informationsteknik, IMIT.
    Sundgren, Petrus
    KTH, Tidigare Institutioner, Mikroelektronik och informationsteknik, IMIT.
    Berggren, Jesper
    KTH, Tidigare Institutioner, Mikroelektronik och informationsteknik, IMIT.
    Hammar, Mattias
    KTH, Tidigare Institutioner, Mikroelektronik och informationsteknik, IMIT.
    Ghisoni, Marco
    Zarlink Semiconductor AB.
    Oscarsson, Vilhelm
    Zarlink Semiconductor AB.
    Ödling, Elsy
    Zarlink Semiconductor AB.
    Malmquist, Jessica
    Zarlink Semiconductor AB.
    Fabrication and performance of 1.3-μm vertical cavity surface emitting lasers with InGaAs quantum well active regions grown on GaAs substrates2004Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 5443, s. 229-239Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We describe the development of long-wavelength InGaAs/GaAs vertical-cavity surface emitting lasers (VCSELs). Using highly strained double-quantum wells (DQWs) in combination with negative gain-cavity detuning we have been able to realise such VCSELs with emission wavelength up to 1300 nm. High-performance device characteristics include mW-range output power, mA-range threshold currents, 10 Gbit/s data transmission and very good temperature stability with continuous-wave operation up to at least 140degreesC. Singlemode emission is realised using an integrated mode filter consisting of a patterned silicon layer on the out-coupling mirror surface, yielding output power and threshold currents for 1270-nm devices of 1.2 - 0.5 mW and 2.3 - 0.6 mA, respectively, over a temperature interval of 10 - 140degreesC. Multimode devices have been found to deliver more than 2 mW at 1290 nm. Preliminary lifetime measurements do not reveal any intrinsic reliability problems related to the highly strained quantum wells.

  • 47. McConnell, M. L.
    et al.
    Baring, M.
    Bloser, P.
    Dwyer, J. F.
    Emslie, A. G.
    Ertley, C. D.
    Greiner, J.
    Harding, A. K.
    Hartmann, D. H.
    Hill, J. E.
    Kaaret, P.
    Kippen, R. M.
    Mattingly, D.
    McBreen, S.
    Pearce, M.
    Produit, Nicolas
    KTH, Skolan för teknikvetenskap (SCI), Fysik.
    Ryan, J. M.
    Ryde, F.
    Sakamoto, T.
    Toma, K.
    Vestrand, W. T.
    Zhang, B.
    POET: A SMEX mission for gamma ray burst polarimetry2014Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 9144Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Polarimeters for Energetic Transients (POET) is a mission concept designed to t within the envelope of a NASA Small Explorer (SMEX) mission. POET will use X-ray and gamma-ray polarimetry to uncover the energy release mechanism associated with the formation of stellar-mass black holes and investigate the physics of extreme magnetic ields in the vicinity of compact objects. Two wide-FoV, non-imaging polarimeters will provide polarization measurements over the broad energy range from about 2 keV up to about 500 keV. A Compton scatter polarimeter, using an array of independent scintillation detector elements, will be used to collect data from 50 keV up to 500 keV. At low energies (215 keV), data will be provided by a photoelectric polarimeter based on the use of a Time Projection Chamber for photoelectron tracking. During a two-year baseline mission, POET will be able to collect data that will allow us to distinguish between three basic models for the inner jet of gamma-ray bursts.

  • 48. Milz, Mathias
    et al.
    Clarmann, Thomas von
    Automated quality control of scene and residual FTIR spectra1999Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 3821, s. 404-415Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Spectrally high-resolved infrared spectra from Fourier transform experiments are often used to determine atmospheric parameters. Reliability of results depends on the quality of the measured spectra and on the successful fit of modeled spectra to the measured ones. Algorithms are presented which enable automated quality control of measured spectra as well as the differences between measured and the calculated spectra, so-called residual spectra. The measured scene spectrum is checked for successful phase correction, the compliance of given maximum and minimum envelope functions, spectral patterns in the variance spectrum, which is calculated during coaddition of several spectra, if applicable. The symmetry of isolated lines, the consistence of expected and real noise, and the plausibility of the magnitude of background radiation are assessed.The quality of the spectral fit first is assessed by means of the X2-test and, is checked for superimposed functions, periodicities, spectral signatures, and conspicuous determine possible calculated spectra.

  • 49. Milz, Mathias
    et al.
    Clarmann, Thomas von
    Stiller, Gabriele
    Fischer, Herbert
    Retrieval of water vapour in the upper troposphere/lower stratosphere from mipas envisat limb emission spectra1999Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 3756, s. 536-543Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Global Measurements of water vapor in the upper troposphere and lower stratosphere (UT/LS) are required to assess its influence on the radiation budget of the Earth and for its use as a suitable tracer for the study of troposphere-stratosphere exchange processes(STE). MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) is a Fourier transform spectrometer measuring limb emission spectra. The field of view of the satellite-borne MIPAS/Envisat is rather wide compared to horizontal and vertical structures in real water vapor distributions (e.g. hygropause). Our aim is to derive UT/LS water vapor profiles from MIPAS/Envisat data with optimized spatial resolution and accuracy. The retrieval errors and vertical resolution were assessed in an altitude- range 5 - 25 km with respect to a MIPAS standard observation scenario and the retrieval of the water vapor profile to be performed on the measurement grid. As target parameters we used water vapor and continuum in the first case and water vapor, temperature and continuum in the second scenario. Improvements by joint retrieval of water vapor and temperature are investigated, in particular for saturated H2O- signatures originating fromthe troposphere. The vertical resolution was estimated by the use of so-called averaging kernels. 

  • 50. Miroshnikova, N.
    et al.
    Yalukova, O.
    Sjödahl, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Sarady, Istvan
    Study of the interaction mechanisms between different materials and pulses from CO2- and Nd:YAG-lasers using digital speckle photography2004Inngår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 5506, s. 42-50Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Pulsed irradiation from CO2- and Nd:YAG lasers focused on the front side of different plates produces nearly instantaneous surface changes on the rear side of the plate. The responses of the materials depend on physical parameters such as pulse energy and duration, photon energy, the absorption and mechanical characteristics of the target material. The equipment built up for visualization of these phenomena consists of a cw. He-Ne laser, a digital CCD camera and a fast computer. The analysis is done using Digital Speckle Photography (DSP). Using focused and defocused laser speckle patterns, DSP enables measurement of in-plane strain fields, Brownian motion and residual micro-structural changes in the material caused by a laser pulse. Results are obtained at the frame rate of the digital camera and allow the creation of animated real-time or "movie" sequences. Results from CO2- and Nd:YAG pulse interaction on Al2O3 ceramics and steel plates will be presented. The Brownian motion during the relaxation phase is more or less localized to the impacted area for both materials and both wavelengths but the relaxation times differ significantly. Steel also exhibits some residual material changes and doesn't recover completely while Al2O3 returns to its initial state some time after the impact

12 1 - 50 of 82
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