Change search
Refine search result
45678910 301 - 350 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.
  • 301.
    Guo, Wenhua
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Holmberg, Patrik
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Laurell, Fredrik
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Fokine, Michael
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Fabrication of long-period fiber gratings through periodic ablation using a focused CO2-laser beam2015In: Optical Materials Express, ISSN 2159-3930, E-ISSN 2159-3930, Vol. 5, no 11, p. 2702-2714Article in journal (Refereed)
    Abstract [en]

    Fabrication of long period gratings in optical fibers through periodic ablation using a focused CO2 laser beam has been studied. During the thermal ablation process most of the energy is absorbed at the glass surface, due to the high extinction coefficient of silica at the laser wavelength, resulting in rapid increase in temperature. Subsequent heat dissipation occurs through vaporization and ejection of molten material, heat conduction axially along the fiber, radiation and through convection. The high surface temperatures involved during ablation can result in a significant increase in temperature of the fiber itself, causing unwanted off-resonance background losses during grating fabrication. In order to minimize losses the temperature needs to be sufficiently low to avoid micro-bending and core deformation, triggered by the decrease in viscosity, while at the same time enabling strong grating formation through laser induced modification of the glass. In this work we have used short-period fiber Bragg gratings in order to assess the temperature dynamics within the fiber during ablation. Using a single grating written into the core, positioned below the point of ablation, we measure the peak temperature within the core of the fiber. When ablation was performed between two gratings, forming a short Fabry-Perot cavity, a different and faster response was recorded, which we ascribe to thermally induced stress and strain caused by the thermal expansion of the surface during ablation. By identifying suitable processing parameters we successfully fabricate strong long-period gratings with background losses of 0.5 dB to 1 dB when periodically ablating the fiber with up to 50 pulses. Experimental results indicate that the maximum core temperatures during ablation under these conditions are limited to within 600 degrees C to 1000 degrees C.

  • 302.
    Gustafson, Per
    KTH.
    Computer-assisted development of high-speed steels2008In: The SGTE Casebook: Thermodynamics At Work, Elsevier, 2008, 2, p. 91-97Chapter in book (Refereed)
  • 303.
    Gustafsson, David
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630), Environmental Physics.
    Magnusson, Jan
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630), Environmental Physics.
    Grelle, Achim
    Swedish University of Agricultural Sciences.
    Lundberg, Angela
    Luleå University of Technology.
    Impact of snow interception on water and energy balance of a forest stand in northern Sweden: combining measurements with impulse radar and eddy-correlation with numerical modelling2007Conference paper (Other academic)
  • 304.
    Gustafsson, Jon Petter
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630), Environmental Geochemistry and Ecotechnology.
    Renman, Agnieszka
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630).
    Renman, Gunno
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630).
    Poll, Katarina
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630).
    Phosphate removal by mineral-based sorbents used in filters for small-scale wastewater treatment2008In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 42, no 1-2, p. 189-197Article in journal (Refereed)
    Abstract [en]

    The mineral-based sorbents Filtra P, Polonite (R), natural wollastonite and water-cooled blast furnace slag (WCBFS) were studied in terms of their PO4 removal performance. Results from a long-term column experiment showed that both Filtra P and Polonite (R) removed > 95% of PO4 from the applied synthetic solution, and that the used filter materials had accumulated several (1.9-19) g kg(-1) P. Phosphorus was removed also by natural wollastonite and WCBFS, but these materials were less efficient. Batch experiments on the used materials showed that the solubility PO4 was considerably larger than the one expected for crystalline Ca phosphates such as hydroxyapatite, and results from investigations with attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) on the Filtra P material showed that the formed P phase was not crystalline. These evidence suggest that a soluble amorphous tricalcium phosphate (ATCP) was formed in the mineral-based sorbents; the apparent solubility constant on dissolution was estimated to log K-s = -27.94 ( 0.31) at 21 degrees C. However, since only up to 18% of the accumulated PO4 was readily dissolved in the experiments, it cannot be excluded that part of the phosphorus had crystallized to slightly less soluble phases. In conclusion, Filtra P and Polonite are two promising mineral-based sorbents for phosphorus removal, and at least part of the accumulated phosphorus is present in a soluble form, readily available to plants.

  • 305.
    Gustafsson, Pia
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Huldt, Jakob
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Löfgren, Henrik
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Improving the Value Assessment of IT Investments: A Case Study2009In: PROCEEDINGS OF PICMET: 09TECHNOLOGY MANAGEMENT IN THE AGE OF FUNDAMENTAL CHANGE / [ed] Kocaoglu DF; Anderson TR; Daim TU; Jetter A; Weber CM, NEW YORK: IEEE , 2009, p. 3083-3091Conference paper (Refereed)
    Abstract [en]

    A recent survey showed that 90 % of the studied companies claimed that they have full control of their IT-costs but less than 10 % have the same control of the value the IT adds. Even though the Figures can be questioned they show of a large uncertainty within the companies regarding IT value. The lack of processes and methods to support follow up of the investments lead to that companies fail to perceive if the benefits are realized or not. In order to take smarter investment decisions, companies must have better control of their investments through a proper evaluation of benefits. This work presents a framework that describes a method and suggested tools of how the business values of an IT investment can be assessed within a company. The framework combines existing methods for practitioners within the area of investment evaluation together with research findings. In a case study a gap analysis were performed between five different IT projects of different sizes and the framework. The case study show in which areas the projects fail in their value assessment work.

  • 306.
    Gustafsson, Roland
    et al.
    KTH, Superseded Departments, Pulp and Paper Technology.
    Freysoldt, Julia
    KTH, Superseded Departments, Pulp and Paper Technology.
    Teder, Ants
    KTH, Superseded Departments, Pulp and Paper Technology.
    Influence of the alkalinity in polysulphide pretreatment on results of cooking with normal liquor-to-wood ratios2004In: Paperi ja puu, ISSN 0031-1243, Vol. 86, no 3, p. 169-173Article in journal (Refereed)
    Abstract [en]

    The effect of alkalinity in a polysulphide pretreatment on the delignification rate, pulp yield and the pulp viscosity in the following kraft cook was investigated. The results were compared to those with reference pretreatments with a corresponding concentrations of hydroxide and hydrogen sulphide ions. The experiments were carried out at liquor-to-wood ratio of 4:1, and the alkalinity in the pretreatments was varied from 0 to 2.5 mole hydroxide/litre. It was found that when the polysulphide preteatment is performed at very high initial hydroxide concentrations, > 1.5 mole/litre, the delignification rate in the cook is increased. The pulp viscosity was higher than that achieved with the sulphide reference when the pulping was extended to low kappa numbers and when the initial hydroxide ion concentration in the pretreatment was high.

  • 307.
    Gustavsson, Catrin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    On the Interrelation Between Kraft Cooking Conditions and Pulp Composition2006Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    In the early 1990’s, a lot of work was focused on extending the kraft cook to a low lignin content (low kappa number). The driving force was the need to further reduce the environmental impact of the bleaching, as less delignification work would be needed there. However, the delignification during the residual phase of a kraft cook is very slow and, due to its poor selectivity, it is a limiting factor for the lignin removal. If the amount of lignin reacting according to the residual phase could be reduced, it would be possible to improve the selectivity of the kraft cook. In the work described in this thesis, special attention has been given to the activation energy of the slowly reacting residual phase of a kraft cook on softwood raw material and to the influence of different cooking parameters on the amount of the residual phase lignin.

    The activation energy of the residual phase delignification of the kraft cook was shown to be higher than that of the bulk phase delignification. In order to decrease the amount of residual phase lignin, it was essential to have a high concentration of hydrogen sulphide ions when cooking with a low hydroxide concentration. It was also important to avoid a high sodium ion concentration when cooking with low hydroxide and low hydrogen sulphide ion concentrations. Furthermore, it was demonstrated that dissolved wood components had a positive effect on the delignification rate in the bulk phase of a kraft cook.

    The influence of different cooking parameters in the extended softwood kraft process on the bleachability (i.e. the ease with which the pulps can be bleached to a target brightness) of the manufactured pulp was also investigated. If variations in bleachability were seen, an attempt would also be made to find chemical reasons to explain the differences. It was difficult to establish clear relationships between the chemical structures of the residual lignin and the bleachability of the pulp. However, it was seen that the higher the content of β-aryl ether structures in the residual lignin after cooking, the better was the QPQP*-bleachability.

    In the middle/end of the 1990’s, the focus moved from extended cooking to efficient utilisation of the wood raw material, e.g. by interrupting the kraft cook at higher kappa number levels and choosing appropriate cooking conditions to maximise the cooking yield. A high cooking yield often leads to a somewhat higher hexenuronic acid (HexA) content of the pulp at a given kappa number. Therefore additional attention was devoted to how the HexA content and carbohydrate composition were affected, e.g. by a set of cooking parameters. Performing these studies it was also important to investigate the effects of a low HexA (after cooking) strategy on such vital factors as the cooking yield, the bleachability and the yellowing characteristics of the pulp obtained. It proved to be difficult to significantly reduce the HexA content in a kraft pulp by altering the cooking conditions for both softwood and the hardwood Eucalyptus Globulus. A reduction in HexA content can be achieved by extending the cook to lower kappa numbers, or by using a high hydroxide concentration, a low hydrogen sulphide concentration or a high sodium ion concentration. However, neither of these strategies is attractive for industrial implementation since they would result in an extensive loss of yield, viscosity and strength.

  • 308.
    Haettner, E.
    et al.
    KTH.
    Iwase, H.
    Schardt, D.
    Experimental fragmentation studies with (12)C therapy beams2006In: Radiation Protection Dosimetry, ISSN 0144-8420, E-ISSN 1742-3406, Vol. 122, no 1-4, p. 485-487Article in journal (Refereed)
    Abstract [en]

    High-energy beams of (12)C ions in the range of 80-430 MeV u(-1) delivered by the heavy-ion synchrotron SIS-18 are used for radiotherapy of deep-seated localized tumors at the treatment unit at GSI Darmstadt. In order to improve the physical database, the fragmentation characteristics along the penetration path in tissue were investigated experimentally by using a water phantom as tissue-equivalent absorber. Measurements were performed at specific energies of 200 and 400 MeV u(-1) of the incident (12)C ions and at six different depths before and behind the Bragg peak. Secondary fragments with nuclear charges Z(f) = 1-5 were identified by scintillation detectors using AE-E and time-of-flight techniques. The preliminary results include energy- and angular distributions, fragment yields, build-up curves and attenuation of the primary carbon projectiles.

  • 309.
    Hagnell, Mathilda Karlsson
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Åkermo, M.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Cost modelling of composite structures2015In: JEC Composites Magazine, ISSN 1639-965X, Vol. 52, no 96, p. 28-29Article in journal (Refereed)
    Abstract [en]

    In aeronautics, composite materials are weight-efficient but difficult and often costly to produce. To study this contrast, the authors are working on a methodology where the costs of composite manufacture and assembly are estimated as a function of structure geometry, complexity and manufacturing approach.

  • 310.
    Hagrot, Erika
    et al.
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Oddsdóttir, Hildur Aesa
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.), Optimization and Systems Theory.
    Hosta, Joan Gonzalez
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Jacobsen, Elling W.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Chotteau, Veronique
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Poly-pathway model, a novel approach to simulate multiple metabolic states by reaction network-based model - Application to amino acid depletion in CHO cell culture2016In: Journal of Biotechnology, ISSN 0168-1656, E-ISSN 1873-4863, Vol. 228, p. 37-49Article in journal (Refereed)
    Abstract [en]

    Mammalian cell lines are characterized by a complex and flexible metabolism. A single model that could describe the variations in metabolic behavior triggered by variations in the culture conditions would be a precious tool in bioprocess development. In this paper, we introduce an approach to generate a poly-pathway model and use it to simulate diverse metabolic states triggered in response to removal, reduction or doubling of amino acids in the culture medium of an antibody-producing CHO cell line. Macro-reactions were obtained from a metabolic network via elementary flux mode enumeration and the fluxes were modeled by kinetic equations with saturation and inhibition effects from external medium components. Importantly, one set of kinetic parameters was estimated using experimental data of the multiple metabolic states. A good fit between the model and the data was obtained for the majority of the metabolites and the experimentally observed flux variations. We find that the poly-pathway modeling approach is promising for the simulation of multiple metabolic states.

  • 311.
    Halonen, Lena
    et al.
    KTH, Superseded Departments, Numerical Analysis and Computer Science, NADA.
    Andersson, S.
    KTH, Superseded Departments, Numerical Analysis and Computer Science, NADA.
    Stenberg, J.
    A study of mailroom runnability and the occurrence of unplanned Stops2004Conference paper (Refereed)
    Abstract [en]

    The different causes of mailroom stops, downtime, and reduced production speed in the mailroom are discussed. It is stated that inserting and stacker stops might cause longer down time in the mailroom that force the press to be stopped. Stops in the packaging lines can be handled to the production through increased personnel efforts by the production staff in the mailroom. The total downtime for the press caused by the mailroom varies from 8 to about 21 minutes. Additional studies are needed to support any further conclusions on minor stops.

  • 312.
    Halonen, Lena
    et al.
    KTH, Superseded Departments, Numerical Analysis and Computer Science, NADA.
    Andersson, Sara
    KTH, Superseded Departments, Numerical Analysis and Computer Science, NADA.
    Stenberg, Johan
    KTH, Superseded Departments, Numerical Analysis and Computer Science, NADA.
    A study of mailroom runnability and the occurence of unplanned stops2004In: TAGA 2004 proceedings, 2004, p. 578-591Conference paper (Refereed)
    Abstract [en]

    It is notable how inserting in newspapers has increased in the Nordic countries in the last 10 years. The days without inserting are becoming less frequent, and multiple inserts are used several days a week. The newspaper product structure is becoming more complex and this makes high demands on the printing plant and especially on the mailroom operations. Many companies today have older mailroom equipment and are planning new investments. Earlier studies, based on data collected from printing press systems, show that mailroom stops belong to one of the four main reasons for press downtime. But this data only gives information about the stops in the mailroom that cause the press to stop. Manual reports from the mailroom mostly give the same data as the press control system. Another study shows that in the inserting operation, it is the winding and unwinding of inserts that cause the most problems. Interviews with production staff have indicated that inserting and stacker operations are considered being the main problem areas. This paper focuses on the different causes of mailroom stops, downtime, and reduced production speed in the mailroom and on how inserts affect the production. Two different studies were carried out at two newspaper printing plants in Sweden. One of the studies examines the minor mailroom stops that never get registered in any system, the other focuses on the reported stops and on interviews about mailroom disturbances. Interviews with technical managers and mailroom managers at several other printing plants were also conducted. The studies indicate that inserting and stacker stops might cause longer down time in the mailroom that force the press to be stopped. Stops in the packaging lines can be handled in parallel to the production through increased personnel efforts by the production staff in the mailroom.

  • 313.
    Han, S.
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Din, I.
    Lee, B. C.
    Kim, H.
    An efficient spectrum sharing for throughput enhancement in heterogeneous networks2014In: Proceedings of the International Symposium on Consumer Electronics, ISCE, 2014Conference paper (Refereed)
    Abstract [en]

    Spectrum sharing has been considered as one of candidate technologies for enhancing spectral efficiency in wireless networks. Efficient cooperation among multiple radio access networks and proper system parameter setting regarding spectrum sharing are required in order to accomplish improvement on the system performance through spectrum sharing in such heterogeneous networks. This paper proposes a spectrum sharing scheme among access networks utilizing licensed and unlicensed band with an objective of enhancing system throughput while satisfying the user quality of service (QoS) under a simple condition of user deployment. A problem formulation to achieve the objective is suggested which enhances the system' spectral efficiency.

  • 314.
    Han, Zhanghua
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wang, Fei
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Forsberg, Erik
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Cao, Xia
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Synthesis and characterization InP and Ga(2)O(3) nanowires2005In: SEMICONDUCTOR AND ORGANIC OPTOELECTRONIC MATERIALS AND DEVICES / [ed] Zah, CE; Lou, Y; Tsuji, S, 2005, Vol. 5624, p. 378-386Conference paper (Refereed)
    Abstract [en]

    We report on the synthesis and characterization of crystalline InP and Ga(2)O(3) nanowires. The nanowires are synthesized using a simple method based on vapor-liquid-solid (VLS) growth; a method we believe could form the basis of cheap and simple fabrication of crystalline nanowires of a broad range of semiconductor materials, including III-IV compounds and semiconductor oxides. The reported InP nanowires have an average diameter of 30nm and the Ga(2)O(3) nanowires diameters down to 100nm. Characterization data including SEM, XRD, TEM and PL are presented.

  • 315.
    Hansson, B. A. M.
    et al.
    KTH, Superseded Departments, Physics.
    Hemberg, O.
    KTH, Superseded Departments, Physics.
    Hertz, Hans M.
    KTH, Superseded Departments, Physics.
    Berglund, Magnus
    KTH, Superseded Departments, Physics.
    Choi, H. J.
    KTH, Superseded Departments, Physics.
    Jacobsson, Björn
    KTH, Superseded Departments, Physics.
    Janin, E.
    KTH, Superseded Departments, Physics.
    Mosesson, Sofia
    KTH, Superseded Departments, Physics.
    Rymell, L.
    KTH, Superseded Departments, Physics.
    Thoresen, J.
    KTH, Superseded Departments, Physics.
    Wilner, M.
    KTH, Superseded Departments, Physics.
    Characterization of a liquid-xenon-jet laser-plasma extreme-ultraviolet source2004In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 75, no 6, p. 2122-2129Article in journal (Refereed)
    Abstract [en]

    A liquid-xenon-jet laser-plasma source for extreme-ultraviolet (EUV) and soft-x-ray generation has been characterized. Being a source candidate for EUV lithography (EUVL), we especially focus on parameters important for the integration of the source in EUVL systems. The deep-ultraviolet (DUV) out-of-band radiation (lambda=120-400 nm) was quantified, to within a factor of two, using a flying-circus tool together with a transmission-grating spectrograph resulting in a total DUV conversion efficiency (CE) of similar to0.33%/2pisr. The size and the shape of the xenon plasma was investigated using an in-band-only EUV microscope, based on a spherical Mo/Si multilayer mirror and a charge-coupled device detector. Scalability of the source size from 20-270 mum full width at half maximum was shown. The maximum repetition-rate sustainable by the liquid-xenon-jet target was simulated by a double-pulse experiment indicating feasibility of >17 kHz operation. The xenon-ion energy distribution from the plasma was determined in a time-of-flight experiment with a Faraday-cup detector showing the presence of multi-kilo-electron-volt ions. Sputtering of silicon witness plates exposed to the plasma was observed, while a xenon background of >1 mbar was shown to eliminate the sputtering. It is concluded that the source has potential to meet the requirements of future EUVL systems.

  • 316.
    Hansson, Björn
    et al.
    KTH, Superseded Departments, Physics.
    Berglund, Magnus
    KTH, Superseded Departments, Physics.
    Hemberg, Oscar
    KTH, Superseded Departments, Physics.
    Hertz, Hans M.
    KTH, Superseded Departments, Physics.
    Stabilization of liquified-inert-gas jets for laser-plasma generation2004In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 95, no 8, p. 4432-4437Article in journal (Refereed)
    Abstract [en]

    We investigate the hydrodynamic properties of liquified-inert-gas jets in a vacuum with a special emphasis on their stability. Such jets have applications as targets for laser-plasma generation of soft-x-ray and extreme-ultraviolet (EUV) radiation. An important example is the liquid-xenon-jet laser-plasma source, one of the source candidates for EUV lithography. A simple hydrodynamic model in not sufficient to explain experimental observations of jet stability. Evaporation-induced cooling explains observed in-flight freezing of the jet and may be a key factor influencing jet stability. It is shown how the jet stability, and, thus, the stability of the laser-plasma x-ray and EUV emission, are improved by applying localized heating to the tip of the jet-generating nozzle.

  • 317.
    Hansson, Karin
    KTH, Superseded Departments, Computer and Systems Sciences, DSV.
    The importance of pre mitigation strategies in development planning2004In: RISK ANALYSIS IV / [ed] Brebbia, CA, 2004, Vol. 9, p. 713-723Conference paper (Refereed)
    Abstract [en]

    Natural hazards destroy vital rural infrastructure. In Asia, which accounts for approximately half the number of the natural catastrophes in the world, and 70% of all floods, the average annual cost of floods over the past decade is approximately 15 billion USD [1]. Recovery from disasters is hard to cope with, especially for developing countries. To reduce rural poverty, effective infrastructure projects related to agriculture have proven to be an essential policy tool. In particular, infrastructure development for transportation, irrigation, and electricity plays an important role. Rural infrastructure loss in the developing world has severely affected the activities of the world's international lending institutions. For instance, the World Bank loan to developing countries in the last 20 years, for damages from natural disasters, has been estimated to be 14 billion USD [2]. It is assumed to be financially beneficial for a poor region to be provided with aid as a risk reduction measure instead of post disaster relief. That is, as a pre mitigation strategy in order to reduce the impact of a hazard and reduce risk. However, evaluations of preparedness actions are seldom performed and hard to find. In this article we present a framework for evaluating the possible benefits of a pre mitigation strategy. The framework is based on an earlier performed flood mitigation project in Hungary [3], and extensive literature studies. It must be emphasised that we do not suggest that no aid should be provided after a hazardous event. Instead, hopefully, less aid should be needed since precautions should have been taken before the event.

  • 318.
    Hansson, Karin
    et al.
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    Danielson, Mats
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    Ekenberg, Love
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    A framework for evaluation of flood management strategies2008In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 86, no 3, p. 465-480Article in journal (Refereed)
    Abstract [en]

    The resulting impact of disasters on society depends on the affected country's economic strength prior to the disaster. The larger the disaster and the smaller the economy, the more significant is the impact. This is clearest seen in developing countries, where weak economics become even weaker afterwards. Deliberate strategies for the sharing of losses from hazardous events may aid a country or a community in efficiently using scarce prevention and mitigation resources, thus being better prepared for the effects of a disaster. Nevertheless, many governments lack an adequate institutional system for applying cost effective and reliable technologies for disaster prevention, early warnings, and mitigation. Modelling by event analyses and strategy models is one way of planning ahead, but these models have so far not been linked together. An approach to this problem was taken during a large study in Hungary, the Tisza case study, where a number of policy strategies for spreading of flood loss were formulated. In these strategies, a set of parameters of particular interest were extracted from interviews with stakeholders in the region. However, the study was focused on emerging economies, and, in particular, on insurance strategies. The scope is now extended to become a functional framework also for developing countries. In general, they have a higher degree of vulnerability. The paper takes northern Vietnam as an example of a developing region. We identify important parameters and discuss their importance for flood strategy formulations. Based on the policy strategies in the Tisza case, we extract data from the strategies and propose a framework for loss spread in developing and emerging economics. The parameter set can straightforwardly be included in a simulation and decision model for policy formulation and evaluation, taking multiple stakeholders into account.

  • 319.
    He, Sailing
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Cui, Yanxia
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Ye, Yuqian
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Zhang, Pu
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Jin, Yi
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Optical nano-antennas and metamaterials2009In: MATERIALS TODAY, ISSN 1369-7021, Vol. 12, no 12, p. 16-24Article in journal (Refereed)
    Abstract [en]

    We review some recent approaches to transmission enhancement and light harvesting based on optical nano-antennas and metamaterials. Nano-cavity antennas are used to enhance the extraordinary transmission of TM-polarized light through vertical nano-slits in a metal film. The enhanced transmission of TE-polarized waves through an array of subwavelength-slits in a thin metal film at low frequencies (including microwave) is also investigated. Light harvesting with a metamaterial cloaking shell is also demonstrated.

  • 320.
    He, Sailing
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. KTH, Superseded Departments, Alfvén Laboratory.
    Ruan, Zhichao
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Chen, Long
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Shen, Jianqi
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Focusing properties of a photonic crystal slab with negative refraction2004In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 70, no 11, p. 115113-Article in journal (Refereed)
    Abstract [en]

    A layered Korringa-Kohn-Rostoker method is exploited to study the subwavelength imaging through a slab of rods-in-air photonic crystal. Both the intensity and phase spectra of transmission are investigated. The high transmission of evanescent waves arises due to the excitation of some slab-guided bound modes and the high coupling between the incident evanescent field and some bulk-guided Bloch modes. Through a study of the phase spectrum of transmission, it is shown that the self-collimation effect occurs at smaller incident angles whereas the negative refraction effect occurs at relatively larger incident angles. The existence of imaging aberrations is also explained with the phase spectrum. The focusing properties of the photonic crystal slab are mainly due to the negative-refraction effect for large incident angles, rather than the self-collimation effect.

  • 321.
    He, Sailing
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Ye, Yuqian
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Jin, Yi
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Cui, Yanxia
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Transmission enhancement, perfect absorption and field squeezing with nano-antennas and metamaterials2009In: THEORETICAL AND COMPUTATIONAL NANOPHOTONICS: (TACONA-PHOTONICS 2009) / [ed] Chigrin DN, 2009, Vol. 1176, p. 18-20Conference paper (Refereed)
    Abstract [en]

    We report some of our recent progress in enhancing the extraordinary optical transmission (EOT), perfect absorption and field squeezing. Based on the excitation of surface plasmon waves in optical nano-antennas, the extraordinary transmission of light through a vertical nano-slit in a metal film is realized. Omni-directional, broadband and polarization-insensitive absorption of light is achieved in a thin metamaterial absorber which consists of cross-antennas and a metal ground. A dielectric split ring inside a permeability-near-zero metamaterial is used to squeeze electromagnetic energy and obtain strong magnetic field at the gap without using any resonance mechanism.

  • 322.
    He, Sailing
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Yin, Yuan
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Dai, Daoxin
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Shi, Yaocheng
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wang, Qian
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Some progress in integrated photonics2005In: OPTOELECTRONIC DEVICES AND INTEGRATION, 2005, no PART 1, p. 405-413Conference paper (Refereed)
    Abstract [en]

    A review is presented on some progress we have made recently in planar integrated photonics including arrayed-waveguide gratings (AWGs) and etched diffraction gratings (EDGs), multimode interference (MMI) couplers/splitters, and spot-size converters. Some novel structures and design methods are summarized and presented.

  • 323.
    Hedberg, Yolanda
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Hedberg, Jonas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Liu, Yi
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Odnevall Wallinder, Inger
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Complexation- and ligand-induced metal release from 316L particles: importance of particle size and crystallographic structure2011In: Biometals, ISSN 0966-0844, E-ISSN 1572-8773, Vol. 24, no 6, p. 1099-1114Article in journal (Refereed)
    Abstract [en]

    Iron, chromium, nickel, and manganese released from gas-atomized AISI 316L stainless steel powders (sized < 45 and < 4 mu m) were investigated in artificial lysosomal fluid (ALF, pH 4.5) and in solutions of its individual inorganic and organic components to determine its most aggressive component, elucidate synergistic effects, and assess release mechanisms, in dependence of surface changes using atomic absorption spectroscopy, Raman, XPS, and voltammetry. Complexation is the main reason for metal release from 316L particles immersed in ALF. Iron was mainly released, while manganese was preferentially released as a consequence of the reduction of manganese oxide on the surface. These processes resulted in highly complexing media in a partial oxidation of trivalent chromium to hexavalent chromium on the surface. The extent of metal release was partially controlled by surface properties (e.g., availability of elements on the surface and structure of the outermost surface) and partially by the complexation capacity of the different metals with the complexing agents of the different media. In general, compared to the coarse powder (< 45 mu m), the fine (< 4 mu m) powder displayed significantly higher released amounts of metals per surface area, increased with increased solution complexation capacity, while less amounts of metals were released into non-complexing solutions. Due to the ferritic structure of lower solubility for nickel of the fine powder, more nickel was released into all solutions compared with the coarser powder.

  • 324.
    Hedenqvist, Mikael S.
    et al.
    KTH, Superseded Departments, Polymer Technology.
    Ritums, Janis
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Conde-Brana, M.
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Bergman, Gunnar
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Structure and properties of poly(ethylene-co-chlorotrifluoroethylene) and polyvinylidene fluoride exposed to water, hydrochloric acid, hydrobromic acid and tetrachloroethylene2004In: Polymer Engineering and Science, ISSN 0032-3888, E-ISSN 1548-2634, Vol. 44, no 1, p. 113-122Article in journal (Refereed)
    Abstract [en]

    The transport of water, hydrochloric acid. hydrobromic acid and tetrachloroethylene in poly(ethylene-co-chlorotrifluoroethylene) and polyvinylidene fluoride were studied at 70degreesC by the sorption/desorption technique. The effects on the structure and mechanical properties were studied using size-exclusion chromatography, infrared spectroscopy, differential scanning calorimetry and tensile testing. Solute concentrations in the polymers indicated that both the water and HCl/HBr components diffused into the polymers on exposure to acid solutions. The calculated water contents of the diffusing acids generally differed from the water content in the solution. The ratio of water content in the diffusing acid to that in the surrounding acid solution was generally a function of the relative vapor activity of water and HCl/HBr. It was possible to describe the 35% HCl and 47% HBr desorption data using a two-component model. It was assumed that the water and HCl/HBr diffused separately, each having its own constant diffusion coefficient. The water diffusivity was obtained from the pure water system, and this allowed the HCl/HBr diffusivity to be calculated. It was found that the diffusivity decreased, in a non-simple way, as a function of solute size. The exposure to solute did not lower the molar mass of the polyvinylidene fluoride. Differential scanning calorimetry indicated the development of low-melting point polyvinylidene fluoride crystals during the exposure to all solutes. This seemed to be a consequence of the long-term exposure (175 to 376 days) at 70degreesC. The long-term exposure stiffened several of the polyvinylidene fluoride resins and occasionally made them less ductile. The poly(ethylene-co-chlorotrifluoroethylene) also became stiffer, but it was otherwise unaffected as far as observation by the other available techniques was concerned.

  • 325.
    Hedin, Björn
    et al.
    KTH, School of Computer Science and Communication (CSC), Media Technology and Graphic Arts, Media (closed 20111231).
    Lindgren, Erik
    KTH, School of Computer Science and Communication (CSC), Media Technology and Graphic Arts, Media (closed 20111231).
    A Comparison of Presentation Methods for Reading on Mobile Phones2007In: IEEE Distributed Systems Online, ISSN 1541-4922, E-ISSN 1541-4922, Vol. 8, no 6, p. 0706-Article in journal (Refereed)
    Abstract [en]

    A study was conducted to compare traditional scroll-based methods for reading text-based content on mobile phones, with Rapid Serial Visual Presentation (RSVP), a method that displays words sequentially. The RSVP text-reading method presents one word or a few words at a rapid sequence, without using page or scroll-based layouts, such as books or Web pages. It was found that reading speed and comprehension level on small screen displays, such as mobile phones equaled speed and comprehension level of reading books, using the RSVP text-reading method. It was also found that the RSVPM method can be a better platform for text-based mobile-learning, when readability, comprehensibility, and preference rating are sufficient. It was also observed that the use of the RSVP text-reading method eliminates the need for eye movements between fixations that resulted in increasing reading speed of text from mobile phones.

  • 326.
    Hedström, Andreas
    et al.
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    Christensen, Henrik I.
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    Lundberg, Carl
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    A wearable GUI for field robots2006In: Field and Service Robotics / [ed] Corke, P; Sukkarieh, S, BERLIN: SPRINGER-VERLAG BERLIN , 2006, Vol. 25, p. 367-376Conference paper (Refereed)
    Abstract [en]

    In most search and rescue or reconnaissance missions involving field robots the requirements of the operator being mobile and alert to sudden changes in the near environment, are just as important as the ability to control the robot proficiently. This implies that the GUI platform should be light-weight and portable, and that the GUI itself is carefully designed for the task at hand. In this paper different platform solutions and design of a user-friendly GUI for a packbot will be discussed. Our current wearable system will be presented along with some results from initial field tests in urban search and rescue facilities.

  • 327.
    Hellström, Jonas
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Henricsson, H.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Pasiskevicius, Valdas
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Exploiting conical refraction in Yb-doped double tungstate lasers [invited]2010Conference paper (Refereed)
  • 328.
    Hellström, Per-Erik
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Edholm, J.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Östling, Mikael
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Olsen, S.
    O'Neill, A.
    Lyutovich, K.
    Oehme, M.
    Kasper, E.
    Strained-Si NMOSFETs on thin 200 nm virtual substrates2005Conference paper (Refereed)
  • 329. Helsing, Johan
    et al.
    Jonsson, Anders
    KTH, Superseded Departments, Mechanics.
    A Seventh-Order Accurate and Stable Algorithm for the Computation of Stress Inside Cracked Rectangular Domains2004In: International Journal for Multiscale Computational Engineering, ISSN 1543-1649, Vol. 2, no 1, p. 47-68Article in journal (Refereed)
    Abstract [en]

    A seventh-order accurate and extremely stable algorithm for the rapid computation of stress fields inside cracked rectangular domains is presented. The algorithm is seventh-order accurate since it incorporates basis functions, taking the asymptotic shape of the stress fields close to crack tips and corners into account at least up to order six. The algorithm is stable since it is based on a Predholm integral equation of the second kind. The particular form of the integral equation represents the solution as the limit of a function which is analytic inside the domain. This allows for an efficient implementation. In an example, involving 112 discretization points on an elastic square with a center crack, values of normalized stress intensity factors and T-stress with a relative error of 10(-6) are computed in seconds on a workstation. More points reduce the relative error down to 10(-15), where it saturates in double precision arithmetic. A large-scale setup with up to 1024 cracks in an elastic square is also studied, using up to 740,000 discretization points. The algorithm is intended as a basic building block in general-purpose solvers for fracture mechanics. It can also be used as a substitute for benchmark tables.

  • 330.
    Henriksson, Gunnar
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Lawoko, Martin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Eugenia Eugenio Martin, Maria
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Gellerstedt, Göran
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    The lignin-carbohydrate network in wood and pulps: a determinant for reactivity2006In: Ninth European Workshop on Lignocellulosict and pulp, 2006, p. 99-105Conference paper (Refereed)
  • 331. Herest, D.
    et al.
    Voolless, F.
    KTH, Superseded Departments, Biotechnology.
    Manifestation of nano-sized effects in photoinduced nonlinear optics of CdI2-Cu layered single crystals2004In: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 42, no 1, p. 85-89Article in journal (Refereed)
    Abstract [en]

    The infrared (IR) induced second harmonic generation in the thin CdI2-Cu crystalline layers was discovered. With decreasing thickness of the CdI2-Cu Crystals Lip to several nanometers value of second-order nonlinear optical susceptibility d(14) (at wavelength chi = 2.76 mum) for the output IR-induced SHG significantly increases. For the Cu content about 0.4% the output SHG signal achieves its maximum at the sample thickness below 2 nm. It is important that for the samples with larger film thickness the corresponding changes have substantially different properties. Limitation of the d(14) at the larger concentration is probably caused by formation of the Cu Clusters limiting the enhancement of the hyperpolarizability for particular cluster Lis well as total nonlinear dielectric susceptibility.

  • 332. Herzáň, A.
    et al.
    Juutinen, S.
    Auranen, K.
    Grahn, T.
    Greenlees, P. T.
    Hauschild, K.
    Jakobsson, Ulrika
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics. University of Jyvaskyla, Department of Physics, P.O. Box 35, Jyvaskyla, Finland.
    Jones, P.
    Julin, R.
    Ketelhut, S.
    Leino, M.
    Lopez-Martens, A.
    Nieminen, P.
    Nyman, M.
    Peura, P.
    Rahkila, P.
    Rinta-Antila, S.
    Ruotsalainen, P.
    Sandzelius, M.
    Sarén, J.
    Scholey, C.
    Sorri, J.
    Uusitalo, J.
    Detailed spectroscopy of Bi 1932015In: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 92, no 4Article in journal (Refereed)
    Abstract [en]

    An experiment aiming to study shape coexistence in Bi193 has been performed. Due to its transitional character, it has an exceptionally large number of structures identified close to the yrast line. Many new states have been found, significantly extending the previously known level scheme of Bi193, including several new rotational bands. The πi13/2 band was extended to Iπ=45/2+. The Iπ=31/2+ member of the πi13/2 band was found to de-excite also to a long-lived isomeric state. This isomeric state is located at 2350 keV and has a spin and parity of 29/2+. The half-life of the isomeric state was measured to be 85(3) μs and it decays via the emission of an 84 keV E2 transition. A level structure feeding this isomeric state was constructed. A low-energy, 49 keV transition has been identified to depopulate the (29/2-) isomeric state, which places it at an energy 2405 keV in the level scheme. This is the first time such a decay has been observed in the neutron-deficient Bi isotopes. A superdeformed band almost identical to that present in the neighboring isotope Bi191, based on the 1/2[651] Nilsson orbital, has also been identified.

  • 333.
    Hjelm, Mats
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT. Department of Information Technology and Media, Mid-Sweden University, Sweden .
    Nilsson, H. E.
    Martinez, A.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Critical evaluation of scattering models within the full band monte carlo simulation framework2005In: Recent Advances in Multidisciplinary Applied Physics: Proceedings of the First International Meeting on Applied Physics (APHYS-2003) October 13-18th 2003, Badajoz, Spain, Elsevier, 2005, p. 305-311Conference paper (Refereed)
    Abstract [en]

    The full band Monte Carlo (MC) simulation framework is regarded as the most accurate method available to study high-field carrier transport in semiconductors. Its potential has been demonstrated in a large number of studies over the years. In this work we focus on how the quantum mechanical uncertainty at high scattering rates affects the validity of Fermi’s Golden Rule, which traditionally is the basis for the scattering handling in the MC method. Considering the uncertainty is important in for instance silicon carbide, which at moderate energies exhibits a scattering rate exceeding 1014 s- 1. The expression for time-dependent scattering rate is presented together with calculated rates for some initial states with acoustic as well as polar-optical phonon interaction. A first-order time-dependent algorithm for handling of scattering events in MC simulators is proposed.

  • 334. Hoeijmakers, Maarten
    et al.
    Kornilov, Viktor
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Arteaga, Ines Lopez
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    de Goey, Philip
    Nijmeijer, Henk
    Flame dominated thermoacoustic instabilities in a system with high acoustic losses2016In: Combustion and Flame, ISSN 0010-2180, E-ISSN 1556-2921, Vol. 169, p. 209-215Article in journal (Refereed)
    Abstract [en]

    The thermoacoustic stability behaviour of a flame is experimentally investigated in the presence of large acoustic losses. Recently it has become clear that under such conditions an instability can occur due to an intrinsic local feedbackloop at the heat source. The experimental results confirm that despite significant acoustic losses, thermoacoustic instabilities can still be present. These findings imply that the effectiveness of passive thermoacoustic damping devices is limited by the intrinsic stability properties of the flame. (C) 2016 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  • 335.
    Hofverberg, Petter
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Johansson, H.
    KTH, School of Engineering Sciences (SCI), Physics.
    Pearce, Mark
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Rydström, Stefan
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    First results from the Stockholm Educational Air Shower Array (SEASA)2005In: Proceedings of the 29th International Cosmic Ray Conference Vol 8: HE 1.5, 2005, p. 271-274Conference paper (Refereed)
    Abstract [en]

    The 'Stockholm Educational Air Shower Array' (SEASA) project is establishing a network of time-synchronised scintillator detector stations at high-schools in the Stockholm region. High school students are contributing to the construction, installation, testing and running of the detector station placed on the roof of their school. This initiative aims to increase the students' interest in science and technology subjects by exposing them to modem research. Each station is equipped with three plastic scintillator detectors (each 0.3 m(2)) arranged in a triangular formation. Signals from GPS satellites are used to time-synchronise signals from the widely separated detector stations, allowing cosmic ray air showers to be identified and studied. A low-cost and highly scalable data acquisition system has been produced using embedded Linux processors which communicate station trigger and monitoring data to a central database. Air shower data and the performance of each detector station can be visualised in real-time via a web browser. The status of the project is presented along with first results from the observation of air showers over Stockholm.

  • 336.
    Hofverberg, Petter
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Johansson, H.
    KTH, School of Engineering Sciences (SCI), Physics.
    Pearce, Mark
    KTH, School of Engineering Sciences (SCI), Physics.
    Rydström, Stefan
    KTH, School of Engineering Sciences (SCI), Physics.
    Wikström, Christian
    KTH, School of Engineering Sciences (SCI), Physics.
    The data acquisition system of the Stockholm educational air shower array2005Conference paper (Refereed)
    Abstract [en]

    The Stockholm Educational Air Shower Array (SEASA) project is deploying an array of plastic scintillator detector stations on school roofs in the Stockholm area. Signals from GPS satellites are used to time synchronise signals from the widely separated detector stations, allowing cosmic ray air showers to be identified and studied. A low-cost and highly scalable data acquisition system has been produced using embedded Linux processors which communicate station data to a central server running a MySQL database. Air shower data can be visualised in real-time using a Java-applet client. It is also possible to query the database and manage detector stations from the client. In this paper, the design and performance of the system are described.

  • 337.
    Hofverberg, Petter
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Johansson, H.
    KTH, School of Engineering Sciences (SCI), Physics.
    Pearce, Mark
    KTH, School of Engineering Sciences (SCI), Physics.
    Rydström, Stefan
    KTH, School of Engineering Sciences (SCI), Physics.
    Wikström, Christian
    KTH, School of Engineering Sciences (SCI), Physics.
    The data acquisition system of the Stockholm Educational Air Shower Array2005In: IEEE Transactions on Nuclear Science, ISSN 0018-9499, E-ISSN 1558-1578, Vol. 52, no 6, p. 2801-2809Article in journal (Refereed)
    Abstract [en]

    The Stockholm Educational Air Shower Array (SEASA) project is deploying an array of plastic scintillator detector stations on school roofs in the Stockholm area. Signals from GPS satellites are used to time synchronise signals from the widely separated detector stations, allowing cosmic ray air showers to be identified and studied. A low-cost and highly scalable data acquisition system has been produced using embedded Linux processors which communicate station data to a central server running a MySQL database. Air shower data can be visualised in real-time using a Java-applet client. It is also possible to query the database and manage detector stations from the client. In this paper, the design and performance of the system are described.

  • 338.
    Holmberg, Andreas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Centres, Competence Center for Gas Exchange (CCGEx).
    Kierkegaard, Axel
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL.
    Weng, Chenyang
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Marcus Wallenberg Laboratory MWL. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    A frequency domain linearized Navier-Stokes method including acoustic damping by eddy viscosity using RANS2015In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 346, p. 229-247Article in journal (Refereed)
    Abstract [en]

    In this paper, a method for including damping of acoustic energy in regions of strong turbulence is derived for a linearized Navier-Stokes method in the frequency domain. The proposed method is validated and analyzed in 2D only, although the formulation is fully presented in 3D. The result is applied in a study of the linear interaction between the acoustic and the hydrodynamic held in a 2D T-junction, subject to grazing flow at Mach 0.1. Part of the acoustic energy at the upstream edge of the junction is shed as harmonically oscillating disturbances, which are conveyed across the shear layer over the junction, where they interact with the acoustic field. As the acoustic waves travel in regions of strong shear, there is a need to include the interaction between the background turbulence and the acoustic field. For this purpose, the oscillation of the background turbulence Reynolds stress, due to the acoustic Field, is modeled using an eddy Newtonian model assumption. The time averaged flow is first solved for using RANS along with a k-epsilon turbulence model. The spatially varying turbulent eddy viscosity is then added to the spatially invariant kinematic viscosity in the acoustic set of equations. The response of the 2D T-junction to an incident acoustic field is analyzed via a plane wave scattering matrix model, and the result is compared to experimental data for a T-junction of rectangular ducts. A strong improvement in the agreement between calculation and experimental data is found when the modification proposed in this paper is implemented. Discrepancies remaining are likely due to inaccuracies in the selected turbulence model, which is known to produce large errors e.g. for flows with significant rotation, which the grazing flow across the T-junction certainly is A natural next step is therefore to test the proposed methodology together with more sophisticated turbulence models.

  • 339.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Yuan, Jun
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Qiu, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Bratkovsky, Alexander M.
    Hewlett-Packard Laboratories.
    Application of metal nanoparticle arrays as a metamaterial for nanooptical directional couplers2010Conference paper (Refereed)
  • 340.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Yuan, Jun
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Qiu, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Bratkovsky, Alexander M.
    Hewlett-Packard Laboratories.
    Passive and active plasmonic nanoarray devices2011In: Metamaterials VI / [ed] Kuzmiak, Markos, Szoplik, SPIE - International Society for Optical Engineering, 2011, p. 80700T-1-80700T-6Conference paper (Refereed)
    Abstract [en]

    Metal nanoparticle arrays offer the possibility to considerably surpass the optical field confinement of silicon waveguides. The properties of directional couplers composed of such plasmonic nanoarrays are analyzed theoretically, while neglecting material losses. It is found that it is possible to generate very compact, submicron length, high fieldconfinement and functionality devices with very low switch energies. We further perform a study of spatial losses in Ag nanoparticle arrays by obtaining the group velocity and the lifetime of the surface plasmon polaritons. The losses are determined for different host permittivities, polarizations, and for spherical and spheroidal particles, with a minimum loss of 12 dB/μm. The possibilities to compensate the losses using gain materials, and the added noise associated with that, is briefly discussed.

  • 341.
    Holmström, Petter
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Yuan, Jun
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101). Xidian University, China.
    Qiu, Min
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Thylén, Lars
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101). Hewlett-Packard Laboratories, United States.
    Bratkovsky, Alexander M.
    Hewlett-Packard Laboratories, United States.
    Theoretical study of nanophotonic directional couplers comprising near-field-coupled metal nanoparticles2011In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 19, no 8, p. 7885-7893Article in journal (Refereed)
    Abstract [en]

    The properties of integrated-photonics directional couplers composed of near-field- coupled arrays of metal nanoparticles are analyzed theoretically. It is found that it is possible to generate very compact, submicron length, high field-confinement and functionality devices with very low switch energies. The analysis is carried out for a hypothetical lossless silver to demonstrate the potential of this type of circuits for applications in telecom and interconnects. Employing losses of real silver, standalone devices with the above properties are still feasible in optimized metal nanoparticle structures.

  • 342.
    Hope, H
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology (moved 20130630).
    Messmann, S
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology (moved 20130630).
    Olsson, Monika
    Brandt, Nils
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology (moved 20130630).
    Water Operation Lifelong Learning: An European Approach2006In: Proceedings of the 2nd International IWA Conference on Sewer Operation and Maintenance. October 26-28, 2006, Vienna, Austria., 2006Conference paper (Other academic)
  • 343.
    Hu, Lei
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Schaufelberger, Fredrik
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Zhang, Yan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Efficient asymmetric synthesis of lamivudine through enzymatic dynamic kinetic resolution2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247Article in journal (Other academic)
  • 344.
    Hu, Li
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Cai, Yangjian
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Analytical formula for a circular flattened Gaussian beam propagating through a misaligned paraxial ABCD optical system2006In: Physics Letters A, ISSN 0375-9601, E-ISSN 1873-2429, Vol. 360, no 2, p. 394-399Article in journal (Refereed)
    Abstract [en]

    Based on the generalized diffraction integral formula for treating the propagation of a laser beam through a misaligned paraxial ABCD optical system in the cylindrical coordinate system, analytical formula for a circular flattened Gaussian beam propagating through such optical system is derived. Furthermore, an approximate analytical formula is derived for a circular flattened Gaussian beam propagating through an apertured misaligned ABCD optical system by expanding the hard aperture function as a finite sum of complex Gaussian functions. Numerical examples are given.

  • 345.
    Hu, R.
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Qin, Yajie
    KTH, School of Information and Communication Technology (ICT).
    Tian, Y.
    KTH, School of Information and Communication Technology (ICT).
    Hong, Z.
    KTH, School of Information and Communication Technology (ICT).
    Yang, Geng
    KTH, School of Information and Communication Technology (ICT), Industrial and Medical Electronics.
    Zheng, Lirong
    KTH, School of Information and Communication Technology (ICT), Industrial and Medical Electronics. Fudan University, China .
    Jia, J.
    KTH, School of Information and Communication Technology (ICT).
    Yang, C.
    KTH, School of Information and Communication Technology (ICT).
    Wu, X.
    KTH, School of Information and Communication Technology (ICT).
    Wang, Y.
    KTH, School of Information and Communication Technology (ICT).
    Biofeedback neuromuscular electrical stimulation front-end for dysphagia treatment2014In: IEEE 2014 Biomedical Circuits and Systems Conference, BioCAS 2014 - Proceedings, IEEE Press, 2014, p. 612-615Conference paper (Refereed)
    Abstract [en]

    A dedicated front-end for biofeedback neuromuscular electrical stimulation (NESM) system is proposed. For controllable dysphagia treatment, the integrated circuit (IC) provides a stimulator front-end with programmable stimulation parameters (2μA-1mA current amplitude, DC-2KHz frequency, and variable duty cycle) and an electromyogram/impedance (EMG/ETI) readout front-end with programmable gain and bandwidth (42-80dB, 0.1Hz-1.2KHz) for biofeedback. Area-efficient, low-power but high precision current controlling is achieved by inducing the sigma-delta modulator technique in the stimulation channel. The measured impedance and EMG signal are used to determine the stimulation parameters, enabling a closed loop optimized treatment. The proposed front-end is fabricated in a 0.18 μm standard CMOS process technology and dissipates a peak power of 2.3 mW at the supply voltage of 1.8 V. Measurement results on a live person are also provided to validate the system's effectiveness.

  • 346.
    Hu, Shaolin
    et al.
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS. Nanjing University of Science and Technology, China .
    Meinke, Karl
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Chen, R.
    Fault-tolerant design of computer cyclic check and control system2007In: Proceedings of the 26th Chinese Control Conference, CCC 2007, 2007, p. 426-430Conference paper (Refereed)
    Abstract [en]

    Computer Cyclic Check is widely used in many different fields. Some limitations as well as bugs of classical algorithms in the computer cyclic check system are analyzed in detailed. In order to overcome these advantages, two series of new algorithms are set up in this paper, one of which is built for the computer cyclic check system with fixed reference value and the other for the computer cyclic check under operation steering with variant directive trajectory. Theoretical analysis and simulation result shows that these new algorithms are fault-tolerant and safe. These new algorithms can be widely used in engineering to improve safety of computer cyclic check system.

  • 347.
    Hu, Shaolin
    et al.
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Meinke, Karl
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Chen, Rushan
    Huajiang, Ouyang
    Iterative estimators of parameters in linear models with partially variant coefficients2007In: International Journal of Applied Mathematics and Computer Sciences, ISSN 1307-6906, Vol. 17, no 2, p. 179-187Article in journal (Refereed)
    Abstract [en]

    A new kind of linear model with partially variant coefficients is proposed and a series of iterative algorithms are introduced and verified. The new generalized linear model includes the ordinary linear regression model as a special case. The iterative algorithms efficiently overcome some difficulties in computation with multidimensional inputs and incessantly appending parameters. An important application is described at the end of this article, which shows that this new model is reasonable and applicable in practical fields.

  • 348.
    Huang, Shuo
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Li, Wei
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Li, Xiaoqing
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Schönecker, Stephan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Bergqvist, Lars
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Holmström, E.
    Varga, L. K.
    Vitos, Levente
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics. Wigner Research Centre for Physics, Hungary; Uppsala University, Sweden.
    Mechanism of magnetic transition in FeCrCoNi-based high entropy alloys2016In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 103, p. 71-74Article in journal (Refereed)
    Abstract [en]

    First-principles alloy theory and Monte-Carlo simulations are performed to investigate the magnetic properties of FeCrCoNiAlx high entropy alloys. Results show that face-centered-cubic (fcc) and body-centered-cubic (bcc) structures possess significantly different magnetic behaviors uncovering that the alloy's Curie temperature is controlled by the stability of the Al-induced single phase or fcc-bcc dual-phase. We show that the appearance of the bcc phase with increasing Al content brings about the observed transition from the paramagnetic state for FeCrCoNi to the ferromagnetic state for FeCrCoNiAl at room-temperature. Similar mechanism is predicted to give rise to room-temperature ferromagnetism in FeCrCoNiGa high entropy alloy.

  • 349.
    Hultén, Per
    et al.
    KTH, Superseded Departments, Infrastructure and Planning.
    Karlström, M.
    Bagge, Lars
    KTH, Superseded Departments, Infrastructure.
    Fuel cells in a medium-sized city in the year 20202004In: URBAN TRANSPORT X: URBAN TRANSPORT AND THE ENVIRONMENT IN THE 21ST CENTURY / [ed] Wadhwa, LC, 2004, Vol. 16, p. 593-605Conference paper (Refereed)
    Abstract [en]

    History of technology tells us that new technologies not only replace older ones, but that quite new patterns of possibilities may also arise. Fuel cell technology is developing fast and many new concepts for the use of fuel cells must be proposed and analysed, since we are facing enormous challenges when defending liveability and quality of life within available resources. The aim of the present article is to describe a vision of how fuel cell technology used in all the municipal vehicles serving a middle-sized urban center might bring us closer to both urban quality and help to fulfil our commitments regarding the climate. This paper is part I of a double-paper, where part II (named "Preliminary assessment of a fuel cell public transport system for a medium sized city in the year 2020") [1] is presented at the same WIT-conference in Dresden (May, 2004). The basic functions of this new public transport system are presented in part I (this paper), with particular focus on those functional qualities figured in the assessment in part-II. The climatic goal for a medium sized city in the year 2020 (in this case: 30 percent less CO2-emissions compared to the level of 1990) may be reached if at least one quarter of the vehicle fleet consists of fuel cell cars or if an advanced system of fuel cell-driven local public transport is installed. A combination would be the very best alternative to prepare the city to face the even tougher climatic goals to come. The city may also substitute its part of the national nuclear power program: if about half of the fuel cell car fleet mentioned above is generating electricity about half of the time the cars are parked. The precondition for local sustainability in this respect is that the initially waste- and bio-based hydrogen production is succeeded by renewable hydrogen production methods, working together. New built up areas may be climatically customised (heated, air conditioned etc.) by heat left over from parked fuel cell cars - while generating electricity - if these buildings are well designed for energy economising and adapted synergy.

  • 350.
    Hungria-Garcia, Rosane
    et al.
    KTH, Superseded Departments, Real Estate and Construction Management.
    Lind, Hans
    KTH, Superseded Departments, Real Estate and Construction Management.
    Karlsson, Björn
    KTH, Superseded Departments, Real Estate and Construction Management.
    Property yields as tools for valuation and analysis2004Report (Other academic)
    Abstract [en]

    This project was started in order to get an overview of conceptual problems, measurement problems, theories of determinants of yields, the use of yields in different contexts and how the actors on the Swedish market looked upon yields. Important issues discussed in the report is the need for:

    - Conceptual clarity: A number of different yield terms exist on the market and it is very important to be clear about how the specific terms are defined.

    - Operational clarity: There are measurement problems both concerning rental incomes, operating and maintenance costs and property values. This means that reported yields can be “manipulated” by choosing suitable operationalisations and pushing estimations of uncertain factors in directions that are favourable to the actor in question.

    - Specify the purpose for which the yield should be used. The most important distinction is between using yields/income returns for valuation purposes and using yields as benchmarks or bubble indicators. In the first case various types of normalization of the net operating income can be rational. In the second case it is important that the figure reflects “actual” incomes and costs, and that the concept is standardized and in such a way that the room for manipulation is small.

    - A clear view about how yields/income returns should develop according to different theories, e.g how the relate to the real return on other investments, inflation levels, risks and expectations about the development of the net operating income. Theories can always be questioned but they give a framework that are helpful in getting a perspective on what is happening on a specific market, and evaluate e.g. if property prices develop in a way that could be a bubble on the market.

45678910 301 - 350 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