Change search
Refine search result
1234567 51 - 100 of 915
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 51.
    Ansari, Farhan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Sjöstedt, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Larsson, Per Tomas
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Hierarchical wood cellulose fiber/epoxy biocomposites: Materials design of fiber porosity and nanostructure2015In: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 74, p. 60-68Article in journal (Refereed)
    Abstract [en]

    Delignified chemical wood pulp fibers can be designed to have a controlled structure of cellulose fibril aggregates to serve as porous templates in biocomposites with unique properties. The potential of these fibers as reinforcement for an epoxy matrix (EP) was investigated in this work. Networks of porous wood fibers were impregnated with monomeric epoxy and cured. Microscopy images from ultramicrotomed cross sections and tensile fractured surfaces were used to study the distribution of matrix inside and around the fibers - at two different length scales. Mechanical characterization at different relative humidity showed much improved mechanical properties of biocomposites based on epoxy-impregnated fibers and they were rather insensitive to surrounding humidity. Furthermore, the mechanical properties of cellulose-fiber biocomposites were compared with those of cellulose-nanofibril (CNF) composites; strong similarities were found between the two materials. The reasons for this, some limitations and the role of specific surface area of the fiber are discussed.

  • 52. Ansebo, L.
    et al.
    Coracini, M. D. A.
    Bengtsson, M.
    Liblikas, Ilme
    KTH, Superseded Departments, Chemistry.
    Ramirez, M.
    KTH, Superseded Departments, Chemistry.
    Borg-Karlson, Anna-Karin
    KTH, Superseded Departments, Chemistry.
    Tasin, M.
    Witzgall, P.
    Antennal and behavioural response of codling moth Cydia pomonella to plant volatiles2004In: Journal of applied entomology, ISSN 0931-2048, E-ISSN 1439-0418, Vol. 128, no 7, p. 488-493Article in journal (Refereed)
    Abstract [en]

    Identification of host volatile compounds attractive to codling moth Cydia pomonella, a most important insect of apple, will contribute to the development of safe control techniques. Synthetic apple volatiles in two doses were tested for antennal and behavioural activity in codling moth. Female antennae strongly responded to (Z)3-hexenol, (Z)3-hexenyl benzoate, (Z)3-hexenyl hexanoate, (+/-)-linalool and E,E-alpha-farnesene. Two other compounds eliciting a strong antennal response were the pear ester, ethyl (E,Z)-2,4-decadienoate, and its corresponding aldehyde, E,E-2,4-decadienal, which is a component of the larval defence secretion of the European apple sawfly. Attraction of codling moth to compounds eliciting a strong antennal response was tested in a wind tunnel. Male moths were best attracted to a blend of (E,E)-alpha-farnesene, (E)-beta-farnesene and ethyl (E,Z)-2,4-decadienoate. The aldehyde E,E-2,4-decadienal had an antagonistic effect when added to the above mixture.

  • 53.
    Araujo, C. Moysés
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Kapilashrami, Mukes
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Jun, Xu
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Jayakumar, Onattu D.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Nagar, Sandeep
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Wu, Yan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Århammar, Cecilia
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Johansson, Börje
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Belova, Lyubov
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Gehring, Gillian A.
    Rao, K. Venkat
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Room temperature ferromagnetism in pristine MgO thin films2010In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 96, no 23Article in journal (Refereed)
    Abstract [en]

    Robust ferromagnetic ordering at, and well above room temperature is observed in pure transparent MgO thin films (<170 nm thick) deposited by three different techniques. Careful study of the wide scan x-ray photoelectron spectroscopy rule out the possible presence of any magnetic contaminants. In the magnetron sputtered films, we observe magnetic phase transitions as a function of film thickness. The maximum saturation magnetization of 5.7 emu/cm(3) is measured on a 170 nm thick film. The films above 500 nm are found to be diamagnetic. Ab initio calculations suggest that the ferromagnetism is mediated by cation vacancies.

  • 54.
    Araújo, José
    et al.
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. KTH, School of Electrical Engineering (EES), Automatic Control.
    Teixeira, André
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Henriksson, Erik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl H.
    KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. KTH, School of Electrical Engineering (EES), Automatic Control.
    A down-sampled controller to reduce network usage with guaranteed closed-loop performance2014In: Decision and Control (CDC), 2014 IEEE 53rd Annual Conference on, IEEE conference proceedings, 2014, p. 6849-6856Conference paper (Refereed)
    Abstract [en]

    We propose and evaluate a down-sampled controller which reduces the network usage while providing a guaranteed desired linear quadratic control performance. This method is based on fast and slow sampling intervals, as the closed-system benefits by being brought quickly to steady-state conditions while behaving satisfactorily when being actuated at a slow rate once at those conditions. This mechanism is shown to provide large savings with respect to network usage when compared to traditional periodic time-triggered control and other aperiodic controllers proposed in the literature.

  • 55.
    Arnell, Fredrik
    et al.
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP.
    Petersson, Lars
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP.
    Fast object segmentation from a moving camera2005In: 2005 IEEE Intelligent Vehicles Symposium Proceedings, NEW YORK, NY: IEEE , 2005, p. 136-141Conference paper (Refereed)
    Abstract [en]

    Segmentation of the scene is a fundamental component in computer vision to find regions of interest. Most systems that aspire to run in real-time use a fast segmentation stage that considers the whole image, and then a more costly stage for classification. In this paper we present a novel approach to segment moving objects from images taken with a moving camera. The segmentation algorithm is based on a special representation of optical flow, on which u-disparity is applied. The u-disparity is used to indirectly find and mask out the background flow in the image, by approximating it with a quadratic function. Robustness in the optical flow calculation is achieved by contrast content filtering. The algorithm successfully segments moving pedestrians from a moving vehicle with few false positive segments. Most false positive segments are due to poles and organic structures, such as trees. Such false positives are, however, easily rejected in a classification stage. The presented segmentation algorithm is intended to be used as a component in a detection/classification framework.

  • 56. Arslanov, Temirlan R.
    et al.
    Mollaev, Akhmedbek Yu.
    Kamilov, Ibragimkhan K.
    Arslanov, Rasul K.
    Kilanski, Lukasz
    Minikaev, Roman
    Reszka, Anna
    Lopez-Moreno, Sinhue
    Romero, Aldo H.
    Ramzan, Muhammad
    Panigrahi, Puspamitra
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Trukhan, Vladimir M.
    Chatterji, Tapan
    Marenkin, Sergey F.
    Shoukavaya, Tatyana V.
    Pressure control of magnetic clusters in strongly inhomogeneous ferromagnetic chalcopyrites2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, p. 7720-Article in journal (Refereed)
    Abstract [en]

    Room-temperature ferromagnetism in Mn-doped chalcopyrites is a desire aspect when applying those materials to spin electronics. However, dominance of high Curie-temperatures due to cluster formation or inhomogeneities limited their consideration. Here we report how an external perturbation such as applied hydrostatic pressure in CdGeP2:Mn induces a two serial magnetic transitions from ferromagnet to non-magnet state at room temperature. This effect is related to the unconventional properties of created MnP magnetic clusters within the host material. Such behavior is also discussed in connection with ab initio density functional calculations, where the structural properties of MnP indicate magnetic transitions as function of pressure as observed experimentally. Our results point out new ways to obtain controlled response of embedded magnetic clusters.

  • 57.
    Ashitani, T.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. Yamagata University, Japan.
    Garboui, S. S.
    Schubert, F.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Vongsombath, C.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. National University of Laos (NOUL), Laos.
    Liblikas, I.
    Pålsson, K.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Borg-Karlson, Anna-Karin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. Institute of Technology, Estonia.
    Activity studies of sesquiterpene oxides and sulfides from the plant Hyptis suaveolens (Lamiaceae) and its repellency on Ixodes ricinus (Acari: Ixodidae)2015In: Experimental & applied acarology, ISSN 0168-8162, E-ISSN 1572-9702Article in journal (Refereed)
    Abstract [en]

    Hyptis suaveolens (Lamiaceae), a plant traditionally used as a mosquito repellent, has been investigated for repellent properties against nymphs of the tick Ixodesricinus. Essential oils and volatile compounds of fresh and dried leaves, from plants originating from Laos and Guinea-Bissau, were identified by GC–MS and tested in a tick repellency bioassay. All the essential oils were strongly repellent against the ticks, even though the main volatile constituents differed in their proportions of potentially tick repellent chemicals. (+)/(−)-sabinene were present in high amounts in all preparations, and dominated the emission from dry and fresh leaves together with 1,8-cineol and α-phellandrene. 1,8-Cineol and sabinene were major compounds in the essential oils from H. suaveolens from Laos. Main compounds in H. suaveolens from Guinea-Bissau were (−)-sabinene, limonene and terpinolene. Among the sesquiterpene hydrocarbons identified, α-humulene exhibited strong tick repellency (96.8 %). Structure activity studies of oxidation or sulfidation products of germacrene D, α-humulene and β-caryophyllene, showed increased tick repellent activity: of mint sulfide (59.4 %), humulene-6,7-oxide (94.5 %) and caryophyllene-6,7-oxide (96.9 %). The substitution of oxygen with sulfur slightly lowered the repellency. The effects of the constituents in the oils can then be regarded as a trade off between the subsequently lower volatility of the sesquiterpene derivatives compared to the monoterpenes and may thus increase their potential usefulness as tick repellents.

  • 58. Ashley, S. F.
    et al.
    Linnemann, A.
    Jolie, J.
    Regan, P. H.
    Andgren, Karin
    KTH, School of Engineering Sciences (SCI), Physics. University of Surrey, United Kingdom .
    Dewald, A.
    McCutchan, E. A.
    Melon, B.
    Moeller, O.
    Zamfir, N. V.
    Amon, L.
    Boelaert, N.
    Cakirli, R. B.
    Casten, R. F.
    Clark, R. M.
    Fransen, C.
    Gelletly, W.
    Gurdal, G.
    Heidemann, M.
    Keyes, K. L.
    Erduran, M. N.
    Meyer, D. A.
    Papenberg, A.
    Plettner, C.
    Rainovski, G.
    Ribas, R. V.
    Thomas, Nathaniel J.
    KTH, School of Engineering Sciences (SCI), Physics.
    Vinson, J.
    Warner, D. D.
    Werner, V.
    Williams, E.
    Zell, K. O.
    Lifetime determination of excited states in Cd-1062007In: Acta Physica Polonica B, ISSN 0587-4254, E-ISSN 1509-5770, Vol. 38, no 4, p. 1385-1388Article in journal (Refereed)
    Abstract [en]

    Two separate experiments using the Differential Decay Curve Method have been performed to extract mean lifetimes of excited states in 106 Cd. The inedium-spin states of interest were populated by the Mo-98(C-12, 4n) Cd-106 reaction performed at the Wright Nuclear Structure Lab., Yale University. From this experiment, two isomeric state mean lifetimes have been deduced. The low-lying states were populated by the Mo-96(C-13, 3n)Cd-106 reaction performed at the Institut fur Kernphysik, Universitat zu Koln. The mean lifetime of the I-pi = 2(1)(+) state was deduced, tentatively, as 16.4(9) ps. This value differs from the previously accepted literature value from Coulomb excitation of 10.43(9) ps.

  • 59.
    Asplund, G
    et al.
    KTH, Superseded Departments, Pulp and Paper Technology.
    Norman, Bo
    KTH, Superseded Departments, Pulp and Paper Technology.
    Fibre orientation anisotropy profile over the thickness of a headbox jet2004In: Journal of Pulp and Paper Science (JPPS), ISSN 0826-6220, Vol. 30, no 8, p. 217-221Article in journal (Refereed)
    Abstract [en]

    The fibre orientation anisotropy at various levels of the jet from a model headbox has been investigated. Stiff nylon fibres, 3 mm long, were added at extremely low concentrations to make it possible to observe also the centre of the jet. This meant that fibre interactions, such as floc forming, could not take place. Transparent, parallel walls enclosed the jet where fibre orientation was measured. A thin laser sheet illuminated the jet from the side and a video camera captured the light reflected perpendicularly from the fibres. Using image analysis, the orientation of the fibres was evaluated. A central vane was mounted in the headbox nozzle so the effects of the vane wake could be studied. The results show that the effect a the boundary layers, at the walls of a headbox and at the surface of a vane, was to locally reduce fibre orientation anisotropy. Depending on the vane tip shape, fibre orientation anisotropy could be additionally decreased. Overall, the fibre orientation anisotropy was weakly affected by changes inflow rate and strongly dependent on the contraction ratio in the nozzle; low speed and large contractions produced more anisotropic orientations.

  • 60.
    Aulin, Christian
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. Innventia AB, Sweden.
    Johansson, Erik
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Structure and Properties of Layer-by-Layer Films from Combinations of Cellulose Nanofibers, Polyelectrolytes and Colloids2014In: HANDBOOK OF GREEN MATERIALS, VOL 3: SELF - AND DIRECT - ASSEMBLING OF BIONANOMATERIALS, World Scientific, 2014, p. 57-77Chapter in book (Refereed)
    Abstract [en]

    The formation of nanometer-thin films of cellulose nanofibers (CNFs), polyelectrolytes, and/or nanoparticles has opened up new possibilities of manufacturing interactive devices with controlled mechanical properties. By controlling the charge of the CNF and the charge and 3D structure of the polyelectrolytes, it is possible to control the buildup, i.e., the thickness, the adsorbed amount, and the immobilized water of layer-by-layer (LbL) films of these materials. The charge balance between the components is not the only factor controlling the LbL formation. The structure of these adsorbed layers in combination with the properties of the constituent components will in turn control how these layers interact with, for example moist air. The mechanical properties of the LbLs can be tuned by combining the high-modulus CNF with different components. This has been shown by using a microbuckling technique where the mechanical properties of ultra-thin films can be measured. In combination with, for example, moisture-sensitive poly(ethylene imine) (PEI), the Young's modulus of CNF/PEI films can be changed by one order of magnitude when the humidity is increased from 0% RH to 50% RH. The incorporation of high-modulus nanoparticles such as SiO2 particles can also be used to prepare LbLs with a higher modulus. Examples are also given where it is shown that the color of an LbL film can be used as a non-contact moisture sensor since the thickness is related to the amount of adsorbed moisture. By chemical modification of the CNF, it is also possible to tailor the interaction between the CNF and multivalent metal ions, enabling a specific interaction between multivalent for example metal surfaces in water and modified CNF.

  • 61.
    Azeem, Muhammad
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. Department of Chemistry, COMSATS Institute of Information Technology, Abbottabad, Pakistan.
    Terenius, Olle
    Rajarao, Gunaratna Kuttuva
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Nagahama, Kazuhiro
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. Sojo University, Faculty of Biotechnology and Life Science, Department of Applied Microbial Technology, 4-22-1 Ikeda, Nishi-ku, Kumamoto, Japan.
    Nordenhem, Henrik
    Nordlander, Goran
    Borg-Karlson, Anna-Karin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. Tartu University, Institute of Technology, Division of Organic Chemistry, Tartu, Estonia.
    Chemodiversity and biodiversity of fungi associated with the pine weevil Hylobius abietis2015In: Fungal Biology, ISSN 1878-6146, E-ISSN 1878-6162, Vol. 119, no 8, p. 738-46Article in journal (Refereed)
    Abstract [en]

    The pine weevil Hylobius abietis is a severe pest of conifer seedlings in reforestation areas. Weevils lay eggs in the root bark or in the soil near roots of recently dead trees and cover the eggs with frass (feces combined with chewed bark), possibly to avoid conspecific egg predation. The aim of the present investigation focused on isolation, identification, and volatile production of fungi from pine-weevil feces and frass. Fungi were isolated from weevil frass and feces separately, followed by identification based on ITS sequencing. Fifty-nine isolates belonging to the genera Penicillium, Ophiostoma, Mucor, Leptographium, Eucasphaeria, Rhizosphaera, Debaryomyces, and Candida were identified. Volatile organic compounds (VOCs) produced by the fungal community and fungal isolates cultured on weevil-frass broth were identified by SPME-GCMS. Major VOCs emitted from the fungal community and pure isolates were species- and strain specific and included isopentylalcohol, styrene, 3-octanone, 6-protoilludene, methyl salicylate, 3-methylanisole, 2-methoxyphenol, and phenol. Some of these are known to influence the orientation of pine weevils when tested among highly attractive newly planted conifer seedlings.

  • 62. Badran, H.
    et al.
    Scholey, C.
    Auranen, K.
    Grahn, T.
    Greenlees, P. T.
    Herzan, A.
    Jakobsson, U.
    KTH. Univeristy of Helsinki, Finland.
    Julin, R.
    Juutinen, S.
    Konki, J.
    Leino, M.
    Mallaburn, M.
    Pakarinen, J.
    Papadakis, P.
    Partanen, J.
    Peura, P.
    Rahkila, P.
    Sandzelius, M.
    Saren, J.
    Sorri, J.
    Stolze, S.
    Uusitalo, J.
    Confirmation of the new isotope Pb-1782016In: PHYSICAL REVIEW C, ISSN 2469-9985, Vol. 94, no 5, article id 054301Article in journal (Refereed)
    Abstract [en]

    The extremely neutron-deficient isotope Pb-178 has been produced. The GREAT spectrometer at the focal plane position of the gas-filled separator RITU was used to study the alpha decay of Pb-178 and its alpha-decay chain through alpha-alpha correlations. The alpha decay was measured to have an energy and half-life of E-alpha = 7610(30) keV and t(1/2) = 0.21(-0.08)(+0.21) ms, respectively. The half-life is consistent with recent theoretical calculations using the Coulomb and proximity potential model. The alpha-decay reduced width and hindrance factor for Pb-178 were deduced and correspond to an unhindered Delta l = 0 transition. In addition, the mass excess of Pb-178 and the alpha-decay Q value were calculated from the experimental results and compared to theoretical values.

  • 63.
    Bagampadde, Umaru
    et al.
    Makerere University, Kampala.
    Karlsson, R.
    KTH.
    Laboratory studies on stripping at bitumen/substrate interfaces using FTIR-ATR2007In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 42, no 9, p. 3197-3206Article in journal (Refereed)
    Abstract [en]

    A technique based on Fourier Transform Infrared Spectroscopy-Attenuated Total Reflectance (FTIR-ATR) was developed and used to study movement of water into bitumen/substrate interfaces, as well as to characterize stripping. Bitumens from different sources were used and applied on various substrates (silicon, germanium and zinc selenide) as thin films. The influence of bitumen type, substrate type, temperature, film thickness and modification with amines, on water damage was studied. The technique gave information on water flow into interfaces and how stripping possibly occurs. It distinguished between stripping and non-stripping bitumens. At least one of three processes occurred, namely water diffusion, film fracture, and bitumen displacement by water, respectively. The diffusion of water did not obey Fick's law. Stripping was influenced by bitumen source when silicon and germanium substrates were used. Notching the films made the process of water entry almost occur immediately. Additives significantly reduced stripping in the moisture-sensitive bitumen on silicon and germanium substrates, even after film notching. Although, good agreement was observed between tests for the bitumens that did not strip, the tests on stripping bitumens showed poor agreement.

  • 64.
    Bakari, Jabiri Kuwe
    et al.
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    Tarimo, Charles N.
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    Magnusson, Christer
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    Yngstrom, Louise
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    Bridging the gap between general management and technicians - A case study in ICT security2006In: Security and Privacy in Dynamic Environments / [ed] FischerHubner, S; Rannenberg, K; Yngstrom, L; Lindskog, S, NEW YORK, NY: SPRINGER , 2006, Vol. 201, p. 442-447Conference paper (Refereed)
    Abstract [en]

    The lack of planning, business re-engineering, and coordination in the whole process of computerisation, is the most pronounced problem facing organisations in developing countries. These problems often lead to a discontinuous link between. technology. and the business processes. As a result, the introduced technology poses some critical risks to the organisations due to the different perceptions of the management and technical staff in viewing the ICT security problem. Ibis paper discusses a practical experience of bridging the gap between the general management and ICT technicians.

  • 65.
    Bandmann, Nina
    KTH, School of Biotechnology (BIO).
    Rational and combinatorial genetic engineering approaches for improved recombinant protein production and purification2007Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The bacterium Escherichia coli (E. coli) is in many situations an ideal host for production of recombinant proteins, since it generally provides a rapid and economical means to achieve sufficiently high product quantities. However, there are several factors that may limit this host’s ability to produce large amounts of heterologous proteins in a soluble and native form. For many applications a high purity of the recombinant protein is demanded, which implies a purification strategy where the product efficiently can be isolated from the complex milieu of host cell contaminants. In this thesis, different strategies based on both rational and combinatorial genetic engineering principles have been investigated, aiming at improving and facilitating recombinant E. coli protein production and purification.

    One objective was to improve the PEG/salt aqueous two-phase system (ATPS) purification process of the lipase cutinase, by increasing the selectivity of the protein for the system top-phase. Peptide tags, with varying properties, were designed and genetically fused to the C-terminal end of ZZ-cutinase. Greatly increased partitioning values were observed for purified protein variants fused to tryptophan containing peptide tags, particularly a (WP)4 peptide. The partitioning properties of the ZZ-cutinase-(WP)4 protein were also retained when added to the ATPS directly from an E. coli total cell disintegrate, emphasizing the applicability of this genetic engineering strategy for primary protein purification in ATPSs.

    Further on, a combinatorial library approach using phage display technology was investigated as a tool for identification of peptide tags capable of improving partitioning properties of ZZ-cutinase in an ATPS. Repeated ATPS-based partitioning-selection cycles of a large phagemid (pVIII) peptide library, resulted in isolation of phage particles preferentially decorated with peptides rich in tyrosine and proline residues. Both a peptide corresponding to a phage library derived peptide sequence as well as peptides designed based on information of amino acid appearance frequencies in later selection rounds, were shown to improve partitioning several-fold when genetically fused to the C-terminal end of ZZ-cutinase. From the two- to four–fold increased production yields observed for these fusion proteins compared to ZZ-cutinase-(WP)4, it was concluded that the selection system used allowed for selection of desired peptide properties related to both partitioning and E. coli protein production parameters.

    Bacterial protein production is affected by several different mRNA and protein sequence-related features. Attempts to address single parameters in this respect are difficult due to the inter-dependence of many features, for example between codon optimization and mRNA secondary structure effects. Two combinatorial expression vector libraries (ExLib1 and ExLib2) were constructed using a randomization strategy that potentially could lead to variations in many of these sequence-related features and which would allow a pragmatic search of vector variants showing positive net effects on the level of soluble protein production. ExLib1 was constructed to encode all possible synonymous codons of an eight amino acid N-terminal extension of protein Z, fused to the N-terminal of an enhanced green fluorescent reporter protein (EGFP). In ExLib2, the same eight positions were randomized using an (NNG/T) degeneracy code, which could lead to various effects on both the nucleotide and protein level, through the introduction of nucleotide sequences functional as e.g. alternative ribosome binding or translation initiation sites or as translated codons for an Nterminal extension of the target protein by a peptide sequence. Flow cytometric analyses and sorting of library cell cultures resulted in isolation of clones displaying several-fold increases in whole cell fluorescence compared to a reference clone. SDS-PAGE and western blot analyses verified that this was a result of increases (up to 24-fold) in soluble intracellular ZEGFP product protein content. Both position specific codon bias effects and the appearance of new ribosomal binding sites in the library sequences were concluded to have influenced the protein production.

    To explore the possibility of applying the same combinatorial library strategy for improving soluble intracellular production of heterologous proteins proven difficult to express in E. coli, three proteins with either bacterial (a transcriptional regulator (DntR)) or human (progesterone receptor ligand binding domain (PRLBD) and 11-β Hydroxysteroid dehydrogenase type I (11-β)) origin, were cloned into the ExLib2 library. Flow cytometric sorting of libraries resulted in isolation of DntR library clones showing increased soluble protein production levels and PR-LBD library clones with up to ten-fold increases in whole cell fluorescence, although the product under these conditions co-separated with the insoluble cell material.

  • 66.
    Bandmann, Nina
    et al.
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Nygren, Per-Åke
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Combinatorial expression vector engineering for tuning of recombinant protein production in Escherichi coli2007In: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 35, no 5Article in journal (Refereed)
    Abstract [en]

    The complex and integrated nature of both genetic and protein level factors influencing recombinant protein production in Escherichia coli makes it difficult to predict the optimal expression strategy for a given protein. Here, two combinatorial library strategies were evaluated for their capability of tuning recombinant protein production in the cytoplasm of E. coli. Large expression vector libraries were constructed through either conservative (ExLib1) or free (ExLib2) randomization of a seven-amino-acid window strategically located between a degenerated start codon and a sequence encoding a fluorescently tagged target protein. Flow cytometric sorting and analyses of libraries, subpopulations or individual clones were followed by SDS-PAGE, western blotting, mass spectrometry and DNA sequencing analyses. For ExLib1, intracellular accumulation of soluble protein was shown to be affected by codon specific effects at some positions of the common N-terminal extension. Interestingly, for ExLib2 where the same sequence window was randomized via seven consecutive NN(G/T) tri-nucleotide repeats, high product levels (up to 24-fold higher than a reference clone) were associated with a preferential appearance of novel SID-like sequences. Possible mechanisms behind the observed effects are discussed.

  • 67. Banwart, Steven A.
    et al.
    Berg, Astrid
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Inorganic Chemistry.
    Beerling, David J.
    Process-based modeling of silicate mineral weathering responses to increasing atmospheric CO2 and climate change2009In: Global Biogeochemical Cycles, ISSN 0886-6236, E-ISSN 1944-9224, Vol. 23, p. GB4013-Article in journal (Refereed)
    Abstract [en]

    A mathematical model describes silicate mineral weathering processes in modern soils located in the boreal coniferous region of northern Europe. The process model results demonstrate a stabilizing biological feedback mechanism between atmospheric CO2 levels and silicate weathering rates as is generally postulated for atmospheric evolution. The process model feedback response agrees within a factor of 2 of that calculated by a weathering feedback function of the type generally employed in global geochemical carbon cycle models of the Earth's Phanerozoic CO2 history. Sensitivity analysis of parameter values in the process model provides insight into the key mechanisms that influence the strength of the biological feedback to weathering. First, the process model accounts for the alkalinity released by weathering, whereby its acceleration stabilizes pH at values that are higher than expected. Although the process model yields faster weathering with increasing temperature, because of activation energy effects on mineral dissolution kinetics at warmer temperature, the mineral dissolution rate laws utilized in the process model also result in lower dissolution rates at higher pH values. Hence, as dissolution rates increase under warmer conditions, more alkalinity is released by the weathering reaction, helping maintain higher pH values thus stabilizing the weathering rate. Second, the process model yields a relatively low sensitivity of soil pH to increasing plant productivity. This is due to more rapid decomposition of dissolved organic carbon (DOC) under warmer conditions. Because DOC fluxes strongly influence the soil water proton balance and pH, this increased decomposition rate dampens the feedback between productivity and weathering. The process model is most sensitive to parameters reflecting soil structure; depth, porosity, and water content. This suggests that the role of biota to influence these characteristics of the weathering profile is as important, if not more important, than the role of biota to influence mineral dissolution rates through changes in soil water chemistry. This process-modeling approach to quantify the biological weathering feedback to atmospheric CO2 demonstrates the potential for a far more mechanistic description of weathering feedback in simulations of the global geochemical carbon cycle.

  • 68.
    Barrientos, Javier
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Lualdi, Matteo
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Suarez Paris, Rodrigo
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Montes, V.
    Boutonnet, Magali
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Jaras, S.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    CO methanation over TiO2-supported nickel catalysts: A carbon formation study2015In: Applied Catalysis A: General, ISSN 0926-860X, E-ISSN 1873-3875, Vol. 502, p. 276-286Article in journal (Refereed)
    Abstract [en]

    A systematic study on titania-supported nickel catalysts was performed in order to evaluate the effect of different process conditions on catalyst stability. Reaction tests and temperature-programmed-hydrogenation analyses were used in order to evaluate the effect of temperature, feed composition, water and reduction conditions on catalyst deactivation and carbon deposition. It was shown that high H-2/CO ratios and syngas partial pressures decrease the rate of carbon formation. Moreover, increasing temperature enhanced the formation of more stable carbon species and thus catalyst deactivation. The temperature-programmed hydrogenation analyses also revealed that water reduces the rate of carbon deposition. However, water enhanced catalyst deactivation when the catalysts were reduced at high temperatures. This negative effect of water is probably due to a progressive destruction of the strong-metal-support interaction characteristic of titania-supported nickel catalysts reduced at high temperatures. (C) 2015 Elsevier B.V. All rights reserved.

  • 69. Baryshnikov, G. V.
    et al.
    Minaev, Boris F.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Minaeva, V. A.
    Ning, Zhijun
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Zhang, Qiong
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Structure and Spectral Properties of Truxene Dye S52012In: Optics and Spectroscopy, ISSN 0030-400X, E-ISSN 1562-6911, Vol. 112, no 2, p. 168-174Article in journal (Refereed)
    Abstract [en]

    On the ground of functional theory with the B3LYP and BMK functionals, we have studied the structure and optical properties of a truxene dye sensitizer S5 for photoelectric transducers. Based on the calculations of the vertical excitations energy of the dye molecule and accounting the influence of the solvent, we have revealed a positive solvatochromic effect that is weak compared to results obtained in the vacuum approximation. We have studied new features describing stabilization of the planar structure of the cyanothiophene-acrylic fragment of the S5 dye.

  • 70.
    Baryshnikov, Gleb V.
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. Bogdan Khmelnitsky Natl Univ.
    Valiev, Rashid R.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. Tomsk State Univ; Tomsk Polytech Univ.
    Karaush, Nataliya N.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Minaeva, Valentina A.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Sinelnikov, Alexandr N.
    Pedersen, Stephan K.
    Pittelkow, Michael
    Minaev, Boris F.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Benzoannelated aza-, oxa- and azaoxa[8]circulenes as promising blue organic emitters2016In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, no 40, p. 28040-28051Article in journal (Refereed)
    Abstract [en]

    In the present work, we studied the synergetic effect of benzoannelation and NH/O-substitution for enhancing the absorption intensity in a series of novel designed benzoannelated aza- and oxa[8]circulenes. Semi-empirical estimations of the fluorescence rate constants allowed us to determine the most promising fluorophores among all the possible benzoannelated aza-, oxa- and mixed azaoza[8]circulenes. Among them, para-dibenzoannelated [8]circulenes demonstrated the most intense light absorption and emission due to the prevailing role of the linear acene chromophore. Calculated phi(fl) values are in complete agreement with experimental data for a number of already synthesized circulenes. Thus, we believe that the most promising circulenes designed in this study can demonstrate an intensive fluorescence in the case of their successful synthesis, which in turn could be extremely useful for the fabrication of future blue OLEDs. Special attention is devoted to the aromaticity features and peculiarities of the absorption spectra for the two highly-symmetrical (D-4h ground state symmetry) pi-isoelectronic species as well as the so-called tetrabenzotetraaza[8]circulene and tetrabenzotetraoxa[8]circulene molecules. Both of them are characterized by rich electronic spectra, which can be assigned only by taking into account the vibronic coarse structure of the first electronic absorption band; the 0-1 and 0-2 transitions were found to be active in the absorption spectrum in complete agreement with experimental data obtained for both energy and intensity. The corresponding promotive vibrational modes have been determined and their vibronic activity estimated using the Franck-Condon approximation.

  • 71.
    Basylko, S. A.
    et al.
    KTH, Superseded Departments, Physics.
    Onischouk, V. A.
    Rosengren, Anders
    KTH, Superseded Departments, Physics.
    ac conductivity of a Coulomb glass from computer simulations2004In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 70, no 2, p. 024201-Article in journal (Refereed)
    Abstract [en]

    A method for calculating the photon-induced hopping ac conductivity of a Coulomb glass by computer simulation is proposed. Results obtained by using an effective relaxation algorithm for two three-dimensional models of a Coulomb glass are reported. ac conductance data clearly demonstrate the transition from super-linear to a sub-quadratic power law. We argue that the same qualitative behavior should be expected for compensated semiconductors. It is shown that the transition is driven by the Coulomb energy of sites forming resonant pairs and not by the width of the Coulomb gap.

  • 72. Bavarsad, Ehsan
    et al.
    Stahl, Clement
    KTH.
    Xue, She-Sheng
    Scalar current of created pairs by Schwinger mechanism in de Sitter spacetime2016In: PHYSICAL REVIEW D, ISSN 2470-0010, Vol. 94, no 10, article id 104011Article in journal (Refereed)
    Abstract [en]

    We consider a charged scalar field in a D-dimensional de Sitter spacetime and investigate pair creation by a Schwinger mechanism in a constant electric field background. Using a semiclassical approximation the current of the created pairs has been estimated. We find that the semiclassical current of the created pairs in the strong electric field limit responds as E-D/2. Going further but restricting to D = 3 dimensional de Sitter spacetime, the quantum expectation value of the spacelike component of the induced current has been computed in the in-vacuum state by applying an adiabatic subtraction scheme. We find that, in the strong electric field limit, the current responds as E-3/2. In the weak electric field limit the current has a linear response in E and an inverse dependence on the mass of the scalar field. In the case of a massless scalar field, the current varies with E-1 which leads to a phenomenon of infrared hyperconductivity. A new relation between infrared hyperconductivity, tachyons, and conformality is discussed, and a scheme to avoid an infrared hyperconductivity regime is proposed. In D dimension, we eventually presented some first estimates of the backreaction of the Schwinger pairs to the gravitational field, and we find a decrease of the Hubble constant due to the pair creation.

  • 73. Begue, D.
    et al.
    Iyyani, Shabnam
    KTH, School of Engineering Sciences (SCI), Physics. Stockholm University, Sweden.
    Transparency parameters from relativistically expanding outflows2014In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 792, no 1, p. 42-Article in journal (Refereed)
    Abstract [en]

    In many gamma-ray bursts a distinct blackbody spectral component is present, which is attributed to the emission from the photosphere of a relativistically expanding plasma. The properties of this component (temperature and flux) can be linked to the properties of the outflow and have been presented in the case where there is no sub-photospheric dissipation and the photosphere is in coasting phase. First, we present the derivation of the properties of the outflow for finite winds, including when the photosphere is in the accelerating phase. Second, we study the effect of localized sub-photospheric dissipation on the estimation of the parameters. Finally, we apply our results to GRB 090902B. We find that during the first epoch of this burst the photosphere is most likely to be in the accelerating phase, leading to smaller values of the Lorentz factor than the ones previously estimated. For the second epoch, we find that the photosphere is likely to be in the coasting phase.

  • 74. Bekiroglu, Y.
    et al.
    Damianou, A.
    Detry, Renaud
    KTH, School of Computer Science and Communication (CSC), Centres, Centre for Autonomous Systems, CAS. University of Liège.
    Stork, Johannes A.
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP.
    Kragic, Danica
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP. KTH, School of Computer Science and Communication (CSC), Centres, Centre for Autonomous Systems, CAS.
    Ek, Carl Henrik
    KTH, School of Computer Science and Communication (CSC), Centres, Centre for Autonomous Systems, CAS. University of Bristol.
    Probabilistic consolidation of grasp experience2016In: Proceedings - IEEE International Conference on Robotics and Automation, IEEE conference proceedings, 2016, p. 193-200Conference paper (Refereed)
    Abstract [en]

    We present a probabilistic model for joint representation of several sensory modalities and action parameters in a robotic grasping scenario. Our non-linear probabilistic latent variable model encodes relationships between grasp-related parameters, learns the importance of features, and expresses confidence in estimates. The model learns associations between stable and unstable grasps that it experiences during an exploration phase. We demonstrate the applicability of the model for estimating grasp stability, correcting grasps, identifying objects based on tactile imprints and predicting tactile imprints from object-relative gripper poses. We performed experiments on a real platform with both known and novel objects, i.e., objects the robot trained with, and previously unseen objects. Grasp correction had a 75% success rate on known objects, and 73% on new objects. We compared our model to a traditional regression model that succeeded in correcting grasps in only 38% of cases.

  • 75.
    Ben Slimane, Slimane
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Zhou, Bo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Li, Xuesong
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Delay Optimization in Cooperative Relaying with Cyclic Delay Diversity2008In: EURASIP Journal on Advances in Signal Processing, ISSN 1687-6172, E-ISSN 1687-6180, p. 736818-Article in journal (Refereed)
    Abstract [en]

    Cooperative relaying has recently been recognized as an alternative to MIMO in a typical multicellularenvironment. Inserting random delays at the nonregenerative fixed relays further improve the system performance.However, random delays result in limited performance gain from multipath diversity. In this paper, two promisingdelay optimization schemes are introduced for a multicellular OFDM system with cooperative relaying withstationary multiple users and fixed relays. Both of the schemes basically aim to take the most advantages ofthe potential frequency selectivity by inserting predetermined delays at the relays, in order to further improve thesystem performance (coverage and throughput). Evaluation results for different multipath fading environments showthat the system performance with delay optimization increases tremendously compared with the case of randomdelay.

  • 76. Benisty, H.
    et al.
    Weisbuch, C.
    Olivier, S.
    Houdré, R.
    Ferrini, R.
    Leuenberger, D.
    Wild, B.
    Lombardet, B.
    Qiu, Min
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Anand, Srinivasan
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Mulot, Mikael
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Karlsson, Anders
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Swillo, Marcin
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jazkorzynska, B.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Agio, M.
    Kafesaki, M.
    Soukoulis, C. M.
    Talneau, A.
    Kamp, M.
    Forchel, A.
    Moosburger, J.
    Happ, T.
    Duan, G. -H
    Cuisin, C.
    Chandouineau, J. -P
    Drisse, O.
    Gaborit, F.
    Legouézigou, L.
    Legouézigou, O.
    Lelarge, F.
    Poingt, F.
    Pommereau, F.
    Thedrez, B.
    Low-loss photonic-crystal and monolithic InP integration: Bands, bends, lasers, filters2004In: Photonic Crystal Materials and Devices II, SPIE - International Society for Optical Engineering, 2004, p. 119-128Conference paper (Refereed)
    Abstract [en]

    Practical realizations of 2D (planar) photonics crystal (PhC) are either on a membrane or etched through a conventional heterostructure. While fascinating objects can emerge from the first approach, only the latter approach lends itself to a progressive integration of more compact PhC's towards monolithic PICs based on InP. We describe in this talk the various aspects from technology to functions and devices, as emerged from the European collaboration "PCIC". The main technology tour de force is deep-etching with aspect ratio of about 10 and vertical sidewall, achieved by three techniques (CAIBE, ICP-RIE, ECR-RIE). The basic functions explored are bends, splitters/combiners, mirrors, tapers, and the devices are filters and lasers. At the end of the talk, I will emphasize some positive aspects of "broad" multimode PhC waveguides, in view of compact add-drop filtering action, notably.

  • 77.
    Bergholtz, Maria
    et al.
    KTH, Superseded Departments, Computer and Systems Sciences, DSV.
    Jayaweera, Prasad
    KTH, Superseded Departments, Computer and Systems Sciences, DSV.
    Johannesson, Paul
    KTH, Superseded Departments, Computer and Systems Sciences, DSV.
    Wohed, Petia
    A pattern and dependency based approach to the design of process models2004In: CONCEPTUAL MODELING: ER 2004, PROCEEDINGS, BERLIN: SPRINGER , 2004, Vol. 3288, p. 724-739Conference paper (Refereed)
    Abstract [en]

    In this paper an approach for building process models for e-commerce is proposed. It is based on the assumption that the process modeling task can be methodologically supported by a designers assistant. Such a foundation provides justifications, expressible in business terms, for design decisions made in process modeling, thereby facilitating communication between systems designers and business users. Two techniques are utilized in the designers assistant, namely process patterns and action dependencies. A process pattern is a generic template for a set of interrelated activities between two agents, while an action dependency expresses a sequential relationship between two activities.

  • 78.
    Berglund, Per
    et al.
    KTH, School of Biotechnology (BIO), Biochemistry (closed 20130101).
    Högfeldt, Anna-Karin
    KTH, School of Education and Communication in Engineering Science (ECE), Learning.
    Karlsson, Sara
    KTH.
    Klasén, Ida
    KTH, School of Education and Communication in Engineering Science (ECE).
    Sandberg, Teresia
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Utvärdering för utveckling: KTH:s samtliga utbildningar under belysning2011Conference paper (Other academic)
  • 79.
    Bergman, Anders
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Skubic, B
    Hellsvik, J
    Nordstrom, L
    Delin, Anna
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Eriksson, O
    Ultrafast switching in a synthetic antiferromagnetic magnetic random-access memory device2011In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 83, no 22Article in journal (Refereed)
    Abstract [en]

    The dynamics of a synthetic antiferromagnet (a metallic trilayer) have been explored and are shown to exhibit ultrafast switching on a time scale of tens of ps. This conclusion is based on first-principles, atomistic spin dynamics simulations. The simulations are performed at finite temperature, as well as at T = 0 K (the macrospin limit), and we observe a marked temperature dependence of the switching phenomenon. It is shown that, to reach very high switching speeds, it is important that the two ferromagnetic components of the synthetic antiferromagnet have oppositely directed external fields to one another. Then a complex collaboration between precession switching of an internal exchange field and the damping switching of the external field occurs, which considerably accelerates the magnetization dynamics. We discuss a possible application of this fast switching as a magnetic random access memory device, which has as a key component intrinsic antiferromagnetic couplings and an applied Oersted field.

  • 80.
    Bergman, Anders
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Taroni, Andrea
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Bergqvist, Lars
    Uppsala University, Sweden.
    Hellsvik, Johan
    Hjörvarsson, Björgvin
    Eriksson, Olle
    Magnon softening in a ferromagnetic monolayer: A first-principles spin dynamics study2010In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 81, no 14, p. 144416-Article in journal (Refereed)
    Abstract [en]

    We study the Fe/W(110) monolayer system through a combination of first-principles calculations and atomistic spin dynamics simulations. We focus on the dispersion of the spin-waves parallel to the [001] direction. Our results compare favorably with the experimental data of Prokop et al. [Phys. Rev. Lett. 102, 177206 (2009)] and correctly capture a drastic softening of the magnon spectrum, with respect to bulk bcc Fe. The suggested shortcoming of the itinerant electron model, in particular that given by density functional theory, is refuted. We also demonstrate that finite-temperature effects are significant, and that atomistic spin dynamics simulations represent a powerful tool with which to include these.

  • 81.
    Bergman, J.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Engman, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Sidén, J.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Tetra-and higher-valent (hypervalent) derivatives of selenium and tellurium2010In: Organic Selenium and Tellurium Compounds (1986), John Wiley & Sons, 2010, Vol. 1, p. 517-558Chapter in book (Other academic)
  • 82. Bergström, L.
    et al.
    Edlund, C.
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA. Stockholm University, Sweden.
    Fairbairn, M.
    Järemo, Anna Karin
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    Kreiss, Gunilla
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    Pieri, L.
    Signals of WIMP annihilation into electrons at the galactic center2005In: Proceedings of the 29th International Cosmic Ray Conference, Vol 4: OG 2.1, 2.2 & 2.3, Tata Institute of Fundamental Research , 2005, p. 57-60Conference paper (Refereed)
    Abstract [en]

    Photons from the annihilation of dark matter in the center of our Galaxy are expected to provide a promising way to find out the nature and distribution of the dark matter itself. These photons can be either produced directly and/or through successive decays of annihilation products, or radiated from electrons and positrons. This ends up in a multi-wavelength production of photons whose expected intensity can be compared to observational data. Assuming that the Lightest Supersymmetric Particle makes the dark matter, we derive the expected photon signal from a given dark matter model and compare it with present available data.

  • 83.
    Bergström, Rasmus
    et al.
    KTH.
    Crimella, Matteo
    KTH.
    Ivchenko, Nickolay
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Karlsson, Alexander
    KTH.
    Lindberg, Hannah
    KTH.
    Persson, Linnea
    KTH.
    Schlatter, Nicola
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Tibert, Gunnar
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Westerlund, Simon
    KTH.
    SCATTERING OF RADAR WAVES ON AEROSOLS IN PLASMAS2015In: EUROPEAN ROCKET AND BALLOON: PROGRAMMES AND RELATED RESEARCH, 2015, p. 87-94Conference paper (Refereed)
    Abstract [en]

    To study the physical mechanisms of phenomena such as polar mesospheric summer echoes, the SCRAP (Scattering of Radar waves on Aerosols in Plasmas) experiment aimed to validate theories on density fluctuations in dusty plasmas. The SCRAP team developed two identical free falling units (FFUs) designed to create a cloud of copper particles once they eject from the REXUS17 sounding rocket 124 seconds after launch. By using the EISCAT incoherent scatter radar system to observe the cloud, the SCRAP experiment proposed to relate theoretical predictions to a controlled object. The SCRAP experiment was launched from ESRANGE on March the 17th 2015. The FFUs GPS signal was lost during launch and the units were therefore not found. Moreover, no backscattering from the copper cloud was observed by the radar.

  • 84.
    Berns, Tomas
    et al.
    KTH.
    Lantz, Ann
    KTH, School of Computer Science and Communication (CSC), Human - Computer Interaction, MDI (closed 20111231).
    Toomingas, Allan
    Karolinska Institutet.
    Special issue of Behavioural and Information Technology with key note lectures and selected papers from the 8th international conference on Work With Computing Systems 2007 - WWCS 2007 - in Stockholm May 21st-24th 2007 - Foreword2008In: Behavior and Information Technology, ISSN 0144-929X, E-ISSN 1362-3001, Vol. 27, no 4, p. 283-284Article in journal (Refereed)
  • 85.
    Bhat, P.
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Brandenburg, Axel
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Hydraulic effects in a radiative atmosphere with ionization2016In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 587, article id A90Article in journal (Refereed)
    Abstract [en]

    Context. In his 1978 paper, Eugene Parker postulated the need for hydraulic downward motion to explain magnetic flux concentrations at the solar surface. A similar process has also recently been seen in simplified (e.g., isothermal) models of flux concentrations from the negative effective magnetic pressure instability (NEMPI). Aims. We study the effects of partial ionization near the radiative surface on the formation of these magnetic flux concentrations. Methods. We first obtain one-dimensional (1D) equilibrium solutions using either a Kramers-like opacity or the H-opacity. The resulting atmospheres are then used as initial conditions in two-dimensional (2D) models where flows are driven by an imposed gradient force that resembles a localized negative pressure in the form of a blob. To isolate the effects of partial ionization and radiation, we ignore turbulence and convection. Results. Because of partial ionization, an unstable stratification always forms near the surface. We show that the extrema in the specific entropy profiles correspond to the extrema in the degree of ionization. In the 2D models without partial ionization, strong flux concentrations form just above the height where the blob is placed. Interestingly, in models with partial ionization, such flux concentrations always form at the surface well above the blob. This is due to the corresponding negative gradient in specific entropy. Owing to the absence of turbulence, the downflows reach transonic speeds. Conclusions. We demonstrate that, together with density stratification, the imposed source of negative pressure drives the formation of flux concentrations. We find that the inclusion of partial ionization affects the entropy profile dramatically, causing strong flux concentrations to form closer to the surface. We speculate that turbulence effects are needed to limit the strength of flux concentrations and homogenize the specific entropy to a stratification that is close to marginal.

  • 86. Bider, Ilia
    et al.
    Johansson, Lena
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    Perjons, Erik
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    Striy, Alexey
    Activation of knowledge in an integrated business Process Support/Knowledge Management System2006In: Practical Aspects of Knowledge Management, Proceedings / [ed] Reimer, U; Karagiannis, D, 2006, Vol. 4333, p. 13-24Conference paper (Refereed)
    Abstract [en]

    The paper is devoted to the issue of activation of knowledge in automated Knowledge Management Systems (KMS). According to the authors, activation of knowledge means that a system, based on the knowledge stored in it, automatically suggests a solution appropriate for a task at hand and/or guards against the user invoking inappropriate solutions. The paper discusses activation of knowledge, first, in general, and then, in a more specific manner, while applying general concepts to an integrated Business Process Support and Knowledge Management System (BPS/KMS) that is based on the state-oriented view on business processes. Activation of knowledge in such a system is done through rules of planning. The paper presents a classification of such rules, which is based on deontic logic concepts, and shows how rules of different categories can be used for activation of knowledge. The discussion is illustrated by an example already implemented in a working system. Some details of the current implementation of rules of planning are also presented in the paper.

  • 87.
    Birgersson, F.
    et al.
    KTH, Superseded Departments, Vehicle Engineering.
    Finnveden, Svante
    KTH, Superseded Departments, Vehicle Engineering.
    Robert, G.
    Modelling turbulence-induced vibration of pipes with a spectral finite element method2004In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 278, no 05-apr, p. 749-772Article in journal (Refereed)
    Abstract [en]

    The vibration of pipes is studied here using the Arnold-Warburton theory for thin shells and a simplified theory valid in a lower frequency regime. The vibrational response is described numerically with the spectral finite element method (SFEM), which uses the exact solutions of the equations of motion as basis functions. For turbulence excitation, the set of basis functions was extended to include particular solutions, which model a spatially distributed excitation. An efficient numerical solution to homogeneous random excitation is presented and the results compare favourably with wind tunnel measurements.

  • 88. Bisping, R.
    et al.
    Dickson, Crispin
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Khan, Shafiq
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Psychometric analysis of stationary aircraft sounds2006In: 13th International Congress on Sound and Vibration 2006, 2006, p. 3658-3664Conference paper (Refereed)
    Abstract [en]

    The acoustical properties of aircraft sounds dynamically change during the time-history of the fly-over. It is therefore difficult to determine the relationship between the human perception of aircraft sounds and these acoustical changes. One option could be to use time continuous judgment to find relationships between acoustical and perceptual data, e.g. by applying cross-correlation methods. Since aircraft sounds comprise many acoustical features which might change simultaneously this method has a limited range of validity. To overcome such problem in the present study synthesized stationary aircraft sounds were used instead of the natural aircraft sounds. This allows the experimental variation of just one feature of interest at a given time. The sounds were generated to represent three different angles of the aircrafts flyover position relative to the observer at 78, 7°, 90° and 101, 3°. These three positions were found to cover a significant part of the acoustical phenomena which may occur during flyover, e.g. tonal components, fan noise, low-versus high frequency broadband effects, etc. Synthesis was performed based on the measurements of six different aircrafts and two flight conditions (take-off & arrival). All the sounds were equalized to have the same EPNL-level. The sounds were judged by 25 subjects using a multidimensional scale having five different attributes: loudness, annoyance, hardness, power and pitch. The statistical analysis of the data showed highly significant differences between the acoustical phenomena and all chosen perceptual attributes. The paper will present the applied methods and the results.

  • 89.
    Biswas, Anis
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Shirong, Wang
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Nagar, Sandeep
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Belova, Liubov
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Rao, K. Venkat
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    The effect of oxygen partial pressure during deposition in the magnetic properties of ZnO thin film2011In: Mater Res Soc Symp Proc, 2011, p. 117-122Conference paper (Refereed)
    Abstract [en]

    We have studied the magnetic properties of 100 nm thick ZnO thin films prepared by magnetron sputtering in different oxygen partial pressures (ratio of oxygen pressure to total pressure in deposition chamber, P Oxy). Only the films fabricated at P Oxy below ∼ 0.5 show room temperature ferromagnetism. The saturation magnetization at room temperature is initially found to increase as P Oxy increases and reaches maximum value of ∼ 5 emu/gm at P Oxy ∼ 0.3 and then starts to decrease and becomes diamagnetic for P Oxy &gt; 0.5. From small angle XRD study of structural properties of the films, we find that the lattice stress developed in the film along c-axis also exhibits a similar behavior with the variation of P Oxy. Thus, both the room temperature ferromagnetism and lattice stress appear to originate from the intrinsic defects present in the sample.

  • 90.
    Björk, Folke
    et al.
    KTH, Superseded Departments, Civil and Architectural Engineering.
    Oba, Koichi
    KTH, Superseded Departments, Civil and Architectural Engineering.
    Fogningsteknik för Mekaniskt Infästa Taktäckningar av Polymermodifierad Bitumen1995Report (Other academic)
  • 91.
    Björk, Jennie
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Knowledge Domain Spanners in Ideation2012In: Creativity and Innovation Management, ISSN 0963-1690, E-ISSN 1467-8691, Vol. 21, no 1, p. 17-27Article in journal (Refereed)
    Abstract [en]

    Ideation is increasingly receiving attention as a management issue, and we can at present witness the emergence and diffusion of a range of different proactive approaches towards ideation. This development is hardly surprising in the light of the changed nature of innovation activities, including a higher reliance also on external sources for innovation and more focus on non-technological types of innovation, such as business model innovations. Firms need to handle both a larger number of sources for innovation and more different types of innovations. This article investigates how spanning different knowledge domains influences individuals' ideation performance. A study has been performed using data on all ideas created within an organization during three years. From this data, two broad set of knowledge domains are identified and the influence on ideation of the individuals spanning these domains the knowledge domain spanners in ideation are investigated. The empirical results show that knowledge domain spanners in ideation have higher ideation performance than individuals engaged in only one knowledge domain.

  • 92.
    Björklund, Johan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Miki, Takahiro
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Andersson, Margareta
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Jönsson, Pär
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Effect of Temperature on Oxygen Activity during Ladle Treatment2008In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 48, no 4, p. 438-445Article in journal (Refereed)
    Abstract [en]

    The effect of temperature on oxygen activity in steel was studied in plant trials where temperature and oxygen activity were measured at two depths and at the same time during different parts of ladle refining. The results show that large temperature gradients exist towards the surface of the steel melt for the sampling occasion when no slag is present on the steel surface, as can be expected. It was also observed that the oxygen activity is higher in the lower measurement position than in the upper during the majority of the ladle refining. This is explained by the oxygen activity's temperature dependence. By using the data from this study and previously reported plant trials it was shown that Si-SiO2 or Al-Al2O3 equilibrium controls the oxygen activity.

  • 93.
    Björkman, Gunnar
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Sommestad, Teodor
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Ekstedt, Mathias
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Hadeli, Hadeli
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Zhu, Kun
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Chenine, Moustafa
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    SCADA system architectures2010Other (Other academic)
    Abstract [en]

    The aim of deliverable 2.3 in the VIKING is to catalogue architecture patterns or reference architectures, i.e. commonly deployed solutions, for SCADA systems. These patterns are represented as a set of descriptions that capture the vast majority of SCADA systems’ architecture on a high level. The patterns developed in this report focus on: - Software services in SCADA systems and software services which SCADA systems exchange data with. - Data flows among these services. - How services are placed in different security zones (network zones). The purpose of the SCADA architecture patterns is to clarify how SCADA systems are commonly designed by employing a stringent model framework. Internal in the project the SCADA patterns will be used to develop SCADA system design models that reflect some typical systems deployed in industry. These models will be used in other work packages and deliverables in the VIKING project.

  • 94.
    Björsell, Niclas
    et al.
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Isaksson, Magnus
    KTH, School of Electrical Engineering (EES), Signal Processing.
    Händel, Peter
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Rönnow, Daniel
    Kautz-Volterra modelling of an analogue-to-digital converter using a stepped three-tone excitation2007In: 12th IMEKO TC-4 International Workshop on ADC MODELLING AND TESTING, 2007, p. 107-112Conference paper (Refereed)
    Abstract [en]

    In many test and measurement applications, the analogue-to-digital converter (ADC) is the limiting component. Using post-correction methods can improve the performance of the component as well as the over all measurement system. In this paper an ADC is characterised by a Kautz-Volterra (KV) model, which utilises a model-based post-correction of the ADC with general properties and a reasonable number of parameters. Results that are based on measurements on a high-speed 12-bit ADC, shows good results for a third order model.

  • 95. Blinge, Magnus
    et al.
    Finnveden, Göran
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Environmental Strategies Research (fms).
    Höijer, Mattias
    KTH, School of Computer Science and Communication (CSC), Centres, School of Architecture and the Built Environment (ABE), Centres, Centre for Sustainable Communications, CESC.
    Isaksson, Karolina
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Roth, Anders
    Sprei, Frances
    Sterner, Tomas
    Åkerman, Jonas
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Environmental Strategies Research (fms).
    Trafikverket på kollisionskurs med klimatmålen2015In: Göteborgsposten, ISSN 1103-9345Article in journal (Other (popular science, discussion, etc.))
  • 96.
    Blomberg, C
    KTH.
    Aspects of fluctuations in non-linear biological systems - Motion in bistable potentials and selection equations2004In: SIMPLICITY BEHIND COMPLEXITY / [ed] Klonowski, W, LENGERICH: PABST SCIENCE PUBLISHERS , 2004, Vol. 3, p. 25-60Conference paper (Refereed)
    Abstract [en]

    Two rather different topics are discussed with one common factor: they are driven by irregular influences. The first part considers the stochastic transition between potential minima over a maximum (barrier), and is treated as a Brownian motion description of reaction rates. We also discuss the related problem of "stochastic resonance", in which a small oscillating force synchronises transitions. In both these cases, the emphasis is on the formalism, and the relations between the two problems are stressed. The other type of problem considers growth and competition equations of macromolecules, relevant for early molecular evolution on the path to the first life. Selection rates are simple and straightforward as long as competition essentially concerns limited resources. The situation gets more complex, when molecules are considered co-operative, e.g. they can catalyse growth processes. This corresponds to the hypercycle concept of Eigen, and is also a scenario for a RNA world. Components that use the support from other components may thrive, but can lead to the extermination of an entire system as the supporters may decline in the competition. As in the first part, the emphasis is on the formalism. We also take up probability aspects and problems that appear together with small probabilities and possibilities of exponential growth. Finally, the possibility of saving the co-operativity by spatial structures are discussed.

  • 97.
    Blomberg, Lars G.
    et al.
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Eriksson, Stefan
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Cumnock, Judy A.
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Yamauchi, M.
    Clemmons, J. H.
    Marklund, Göran T.
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Lindqvist, Per-Arne
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Karlsson, Tomas
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Lundin, R.
    Solar windmagnetosphere-ionosphere coupling: an event study based on Freja data2004In: Journal of Atmospheric and Solar-Terrestrial Physics, ISSN 1364-6826, E-ISSN 1879-1824, Vol. 66, no 5, p. 375-380Article in journal (Refereed)
    Abstract [en]

    Freja data are used to study the relative contributions from the high-latitude (reconnection/direct entry) and low-latitude (viscous interaction) dynamos to the cross-polar potential drop. Convection streamlines which are connected to the high-latitude dynamo may be identified from dispersed magnetosheath ions not only in the cusp/cleft region itself but also several degrees poleward of it. This fact, together with Freja's orbital geometry allows us to infer the potential drop from the high-latitude dynamo as well as to obtain a lower limit to the potential drop from the low-latitude dynamo for dayside Freja passes. All cases studied here are for active magnetospheric conditions. The Freja data suggest that under these conditions at least one third of the potential is generated in the low-latitude dynamo. These observations are consistent with earlier observations of the potential across the low-latitude boundary layer if we assume that the low-latitude dynamo region extends over several tens of Earth radii in the antisunward direction along the tail flanks, and that the majority of the potential drop derives from the sun-aligned component of the electric field rather than from its cross-boundary component, or equivalently, that the centre of the dynamo region is located quite far down tail. A possible dynamo geometry is illustrated.

  • 98.
    Blomberg, Lars G.
    et al.
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Marklund, Göran T.
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Lindqvist, Per-Arne
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Primdahl, F.
    Brauer, P.
    Bylander, Lars
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics. KTH, Superseded Departments, Alfvén Laboratory.
    Cumnock, Judy
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics. KTH, Superseded Departments, Alfvén Laboratory.
    Eriksson, Stefan
    KTH, Superseded Departments, Alfvén Laboratory.
    Ivchenko, Nickolay V.
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Karlsson, Tomas
    KTH, Superseded Departments, Alfvén Laboratory. KTH, School of Electrical Engineering (EES), Space and Plasma Physics.
    Kullen, Anita
    KTH, School of Electrical Engineering (EES), Space and Plasma Physics. KTH, Superseded Departments, Alfvén Laboratory.
    Merayo, J. M. G.
    Pedersen, E. B.
    Petersen, J. R.
    EMMA - the electric and magnetic monitor of the aurora on Astrid-22004In: Annales Geophysicae, ISSN 0992-7689, E-ISSN 1432-0576, Vol. 22, no 1, p. 115-123Article in journal (Refereed)
    Abstract [en]

    The Astrid-2 mission has dual primary objectives. First, it is an orbiting instrument platform for studying auroral electrodynamics. Second, it is a technology demonstration of the feasibility of using micro-satellites for innovative space plasma physics research. The EMMA instrument, which we discuss in the present paper, is designed to provide simultaneous sampling of two electric and three magnetic field components up to about 1 kHz. The spin plane components of the electric field are measured by two pairs of opposing probes extended by wire booms with a separation distance of 6.7 m. The probes have titanium nitride (TiN) surfaces. which has proved to be a material with excellent properties for providing good electrical contact between probe and plasma. The wire booms are of a new design in which the booms in the stowed position are wound around the exterior of the spacecraft body. The boom system was flown for the first time on this mission and worked flawlessly. The magnetic field is measured by a tri-axial fluxgate sensor located at the tip of a rigid. hinged boom extended along the spacecraft spin axis and facing away from the Sun. The new advanced-design fluxgate magnetometer uses digital signal processors for detection and feedback, thereby reducing the analogue circuitry to a minimum. The instrument characteristics as well as a brief review of the science accomplished and planned are presented.

  • 99.
    Blomstergren, Anna
    KTH, Superseded Departments, Biotechnology.
    Strategies for de novo DNA sequencing2003Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    The development of improved sequencing technologies hasenabled the field of genomics to evolve. Handling andsequencing of large numbers of samples require an increasedlevel of automation in order to obtain high throughput andconsistent quality. Improved performance has lead to thesequencing of numerous microbial genomes and a few genomes fromhigher eukaryotes and the benefits of comparing sequences bothwithin and between species are now becoming apparent. Thisthesis describes both the development of automated purificationmethods for DNA, mainly sequencing products, and a comparativesequencing project.

    The initially developed purification technique is dedicatedto single stranded DNA containing vector specific sequences,exemplified by sequencing products. Specific capture probescoupled to paramagnetic beads together with stabilizing modularprobes hybridize to the single stranded target. After washing,the purified DNA can be released using water. When sequencingproducts are purified they can be directly loaded onto acapillary sequencer after elution. Since this approach isspecific it can be applied to multiplex sequencing products.Different probe sets are used for each sequencing product andthe purifications are performed iteratively.

    The second purification approach, which can be applied to anumber of different targets, involves biotinylated PCR productsor sequencing products that are captured using streptavidinbeads. This has been described previously, buthere theinteraction between streptavidin and biotin can be disruptedwithout denaturing the streptavidin, enabling the re-use of thebeads. The relatively mild elution conditions also enable therelease of sensitive biotinylated molecules.

    Another project described in this thesis is the comparativesequencing of the 40 kbcagpathogenicity island (PAI) in fourHelicobacter pyloristrains. The results included thediscovery of a novel gene, present in approximately half of theSwedish strains tested. In addition, one of the strainscontained a major rearrangement dividing thecagPAI into two parts. Further, information about thevariability of different genes could be obtained.

    Keywords:DNA sequencing, DNA purification, automation,solid-phase, streptavidin, biotin, modular probes,Helicobacter pylori,cagPAI.

  • 100.
    Blomstergren, Anna
    et al.
    KTH, Superseded Departments, Biotechnology.
    Lundin, A.
    Nilsson, C.
    Engstrand, L.
    Lundeberg, Joakim
    KTH, Superseded Departments, Biotechnology.
    Comparative analysis of the complete cag pathogenicity island sequence in four Helicobacter pylori isolates2004In: Gene, ISSN 0378-1119, E-ISSN 1879-0038, Vol. 328, p. 85-93Article in journal (Refereed)
    Abstract [en]

    The cytotoxin-associated gene (cag) pathogenicity island (PAI) is important for the virulence of Helicobacter pylori. In this study, we have compared the complete nucleotide sequence of the cag PAI in four clinical isolates. These isolates were selected from patients matched for age and sex from the same geographical region. The patients suffered from either gastric cancer (Ca52 and Ca73) or duodenal ulcer (Du23:2 and Du52:2). All four strains induced an interleukin (IL)-8 response in AGS cells and translocated CagA into host cells where the protein was tyrosine phosphorylated, and thus harboured a functional type W secretion system encoded by the cag PAL The cagA gene contains a variable region close to its 3' end. Different compositions of this region has been proposed to exert various degrees of morphological changes in cultured gastric epithelial cells, and there are indications that the structure of the repetitive region is connected to the severity of disease. One of the studied strains (Du23:2) possessed five Westem-type repeat regions while the other three strains harboured one Western-type repeat. Strain Du23:2 also contained a major rearrangement or large insertion/ duplication in the intergenic region between HP0546 and HP0547 (cagA). Sequence similar to that of genes HP0510 and HP0509 was found in the 5' end of this region. The 3' end was-similar to the corresponding region of strain ATCC 43504, including a mini IS605 element and a duplication of the 3' end of the cag PAL Finally, a novel gene was identified in the cag PAI in three of the sequenced strains at the position of HP0521. This gene, HP0521B, is present in approximately half of Swedish H. pylori isolates.

1234567 51 - 100 of 915
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf