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  • 101. Boella, G.
    et al.
    van der Torre, L.
    Verhagen, Harko
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    Introduction to normative multiagent systems2006In: Computational and mathematical organization theory, ISSN 1381-298X, E-ISSN 1572-9346, Vol. 12, no 2-3 SPEC. ISS., p. 71-79Article in journal (Refereed)
    Abstract [en]

    This article introduces the research issues related to and definition of normative multiagent systems. It also describes the papers selected from NorMAS05 that are part of this double special issue and relates the papers to each other.

  • 102. Bokhari, S H
    et al.
    Ahmed, M
    bin Sohail, S
    Khan, R H
    Mirza, J A
    Ali, Muhammad
    KTH, Superseded Departments, Electronics.
    A networking laboratory for the developing world2004In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 42, no 2, p. 106-113Article in journal (Refereed)
    Abstract [en]

    Internet-based communication is assuming an increasingly important role in the developing world. It is thus crucial that students be exposed to contemporary networking equipment in a realistic setting, in order to connect theoretical material taught in lecture courses with the realities of physical hardware. To this end, a large computer networking laboratory has been set up to provide a realistic environment for teaching internetworking concepts. This laboratory provides university-level students with a testbed to experiment with fundamental issues of internetworking in a way that cannot be provided by simulators and to a degree of rigor not possible with the commonly available laboratory setups designed for technicians. We describe the motivations for setting up the laboratory, its network structure and equipment, and the type of experiments students conduct. The laboratory structure is influenced heavily by the limited funds-at our disposal - a common problem in the developing world. Many of the problems we faced in setting up our equipment (such as the crucial impact of proper electrical grounding on system performance) are not ordinarily encountered in developed nations. Our experiences are thus likely to be of value to others in the developing world who are contemplating setting up experimental facilities for teaching networking.

  • 103.
    Boon, Edward
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Veligurska, Olga
    KTH.
    DIFFERENTIATION BETWEEN BUSINESS SCHOOL RESPONSIBILITY EFFORTS ACROSS REGIONS: A CONTENT ANALYSIS OF PRME SHARING INFORMATION ON PROGRESS REPORTS2015In: IDEAS IN MARKETING: FINDING THE NEW AND POLISHING THE OLD, Springer, 2015, p. 680-683Conference paper (Refereed)
  • 104. Bora, D. K.
    et al.
    Cheng, X.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. Lawrence Berkeley National Laboratory, United States; University of Science and Technology of China, China.
    Kapilashrami, M.
    Glans, P. A.
    Luo, Yi
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. University of Science and Technology of China, China.
    Guo, J. -H
    Influence of crystal structure, ligand environment and morphology on Co L-edge XAS spectral characteristics in cobalt compounds2015In: Journal of Synchrotron Radiation, ISSN 0909-0495, E-ISSN 1600-5775, Vol. 22, p. 1450-1458Article in journal (Refereed)
    Abstract [en]

    The electronic structure of a material plays an important role in its functionality for different applications which can be probed using synchrotron-based spectroscopy techniques. Here, various cobalt-based compounds, differing in crystal structure, ligands surrounding the central metal ion and morphology, have been studied by soft X-ray absorption spectroscopy (XAS) at the Co L-edge in order to measure the effect of these parameters on the electronic structure. A careful qualitative analysis of the spectral branching ratio and relative intensities of the L 3 and L 2 peaks provide useful insight into the electronic properties of compounds such as CoO/Co(OH)2, CoCl2.6H2O/CoF2.4H2O, CoCl2/CoF2, Co3O4 (bulk/nano/micro). For further detailed analysis of the XAS spectra, quantitative analysis has been performed by fitting the spectral profile with simulated spectra for a number of cobalt compounds using crystal field atomic multiplet calculations.

  • 105. Borg, Erik
    et al.
    Edquist, Gertrud
    Reinholdson, Anna-Clara
    Risberg, Arne
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH.
    McAllister, Bob
    Speech and language development in a population of Swedish hearing-impaired pre-school-children, a cross-sectional study2007In: International Journal of Pediatric Otorhinolaryngology, ISSN 0165-5876, E-ISSN 1872-8464, Vol. 71, no 7, p. 1061-1077Article in journal (Refereed)
    Abstract [en]

    Objective: There is little information on speech and language development in preschool children with mild, moderate or severe hearing impairment. The primary aim of the study is to establish a reference material for clinical use covering various aspects of speech and language functions and to relate test values to pure tone audiograms and parents' judgement of their children's hearing and language abilities. Methods: Nine speech and language tests were applied or modified, both classical tests and newly developed tests. Ninety-seven children with normal hearing and 156 with hearing impairment were tested. Hearing was 80 dB HL PTA or better in the best ear. Swedish was their strongest language. None had any additional diagnosed major handicaps. The children were 4-6 years of age. The material was divided into 10 categories of hearing impairment, 5 conductive and 5 sensorineural: unilateral; bilateral 0-20; 21-40; 41-60; 61-80 dB HL PTA. The tests, selected on the basis of a three component language model, are phoneme discrimination; rhyme matching; Peabody Picture Vocabulary Test (PPVT-III, word perception); Test for Reception of Grammar (TROG, grammar perception); prosodic phrase focus; rhyme construction; Word Finding Vocabulary Test (word production); Action Picture Test (grammar production); oral motor test. Results: Only categories with sensorineural toss showed significant differences from normal. Word production showed the most marked delay for 21-40 dB HL: 5 and 6 years p < 0.01; for 41-60 dB: 4 years p < 0.01 and 6 years p < 0.01 and 61-80 dB: 5 years p < 0.05. Phoneme discrimination 21-40 dB HL: 6 years p < 0.05; 41-60 dB: 4 years p < 0.01; 61-80 dB: 4 years p < 0.001, 5 years p < 0.001. Rhyme matching: no significant difference as compared to normal data. Word perception: sensorineural 41-60 dB HL: 6 years p < 0.05; 61-80 dB: 4 years p < 0.05; 5 years p < 0.01. Grammar perception: sensorineural 41-60 dB HL: 6 years p < 0.05; 61-80 dB: 5 years p < 0.05. Prosodic phrase focus: 41-60 dB HL: 5 years p < 0.01. Rhyme construction: 41-60 dB HL: 4 years p < 0.05. Grammar production: 61-80 dB HL: 5 years p < 0.01. Oral motor function: no differences. The Word production test showed a 1.5-2 years delay for sensorineural impairment 41-80 dB HL through 4-6 years of age. There were no differences between hearing-impaired boys and girls. Extended data for the screening test [E. Borg, A. Risberg, B. McAllister, B.M. Undemar, G. Edquist, A.C. Reinholdsson, et at., Language development in hearing-impaired children. Establishment of a reference material for a "Language test for hearing-impaired children", Int. J. Pediatr. Otorhinolaryngot. 65 (2002) 15-26] are presented. Conclusions: Reference values for expected speech and language development are presented that cover nearly 60% of the studied population. The effect of the peripheral hearing impairment is compensated for in many children with hearing impairment up to 60 dB HL. Above that degree of impairment, language delay is more pronounced, probably due to a toss of acuity. The importance of central cognitive functions, speech reading and signing for compensation of peripheral limitations is pointed out.

  • 106.
    Borg, Tessie
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Danielsson, Jakob
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Mohiti, Maziar
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Restorp, Per
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Somfai, Peter
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Diastereoselective Nucleophilic Addition to Aldehydes with Polar alpha- and alpha,beta-Substituents2011In: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 353, no 11-12, p. 2022-2036Article in journal (Refereed)
    Abstract [en]

    The stereoselectivities obtained in Lewis acid-promoted Mukaiyama aldol additions and Sakurai allylations of mono-, and syn- and anti-disubstituted aldehydes possessing various polar alpha- and beta-substituents under non-chelating conditions are presented. The stereochemical outcome in the nucleophilic addition to alpha-substituted aldehydes containing an alpha-benzyloxy, alpha-fluoro or alpha-sulfonamide substituent are accurately predicted by current stereoinduction models. In contrast, the selectivitites obtained from addition of sterically demanding nucleophiles to alpha-chloro-substituted aldehydes cannot be rationalized by the same models and an alternative is discussed. The stereochemichal outcome in the additions to alpha, beta-disubstituted aldehydes is more complex and cannot be predicted using current models.

  • 107.
    Bornefalk, Hans
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Hemmendorff, Magnus
    KTH, School of Engineering Sciences (SCI), Physics.
    Hjarn, Torbjorn
    Dual-energy imaging using a digital scanned multi-slit system for mammography: evaluation of a differential beam filtering technique - art. no. 61422O2006In: Medical Imaging 2006: Physics of Medical Imaging, Pts 1-3 / [ed] Flynn, MJ; Hsieh, J, BELLINGHAM, WA: SPIE-INT SOC OPTICAL ENGINEERING , 2006, Vol. 6142, p. O1422-O1422Conference paper (Refereed)
    Abstract [en]

    This paper describes a method for single exposure contrast-enhanced dual-energy imaging of tumors utilizing a scanned multi-slit system for digital mammography. This photon counting system employs an array of silicon strip detectors in an edge-on geometry. In the multi-slit setup, the line detectors and pre-collimator slits are aligned orthogonal to the scan direction. This geometry is advantageous to dual-energy imaging, since it allows differential filtering of the x-ray beam in the pre-collimator slits. A high-energy image is constructed from those lines where the filter material has been chosen to harden the x-ray beam and the low-energy image from the lines with a filter producing softer beams. Both images are obtained in the same scan, eliminating the need to change tube voltages and anode materials and minimizing the risk of motion artifacts. The method is illustrated on a purpose-built phantom and logarithmic subtraction of the images produces images essentially free of anatomical clutter with the contrast-enhanced targets clearly visible.

  • 108.
    Brena, Barbara
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Palmgren, Pål
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Nilson, Katharina
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Yu, Shun
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Hennies, F.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Agnarsson, Björn
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Önsten, Anneli
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Månsson, Martin
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Göthelid, Mats
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    InSb-TiOPc interfaces: Band alignment, ordering and structure dependent HOMO splitting2009In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 603, no 20, p. 3160-3169Article in journal (Refereed)
    Abstract [en]

    Thin films of titanyl phthalocyanine (TiOPc) have been adsorbed on InSb(1 1 1) (3 x 3) and InSb(1 0 0) c(8 x 2) surfaces and studied with respect to their electronic structure using photoemission (PES), density functional theory (DFT) and scanning tunneling microscopy (STM). The interface chemical interaction is weak in both cases; no adsorbate induced surface band bending is observed and the energy level alignment across the interface is determined by the original position of the substrate Fermi level and the charge neutrality level of the molecule. Room temperature adsorption results in disordered films on both surfaces. The behaviors after annealing are different; on InSb(1 0 0) well-ordered molecular chains form along and on top of the In-rows, whereas on (1 1 1) no long range order is observed. The disorder leads to intermolecular interactions between the titanyl group and neighboring benzene rings leading to a split of TiOPc HOMO (highest occupied molecular orbital) by as much as 0.8 eV.

  • 109.
    Brethouwer, Gert
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics.
    Matsuo, Y.
    KTH, School of Engineering Sciences (SCI), Mechanics.
    DNS of rotating homogeneous shear flow and scalar mixing2006In: Direct and Large-Eddy Simulation VI / [ed] Lamballais, E; Friedrich, R; Geurts, BJ; Metais, O, DORDRECHT: SPRINGER , 2006, Vol. 10, p. 225-232Conference paper (Refereed)
  • 110. Brocke, R. G.
    et al.
    Cao, J.
    Fontaine, N. K.
    Ji, C.
    Chubun, N.
    Olsson, Fredrik
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Lourdudoss, Sebastian
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Kolner, B. H.
    Heritage, J. P.
    Yoo, S. J. B.
    Phase characterization of an InP based Optical-CDMA encoder using Frequency-Resolved Optical Gating (FROG)2005In: 2005 IEEE LEOS Annual Meeting Conference Proceedings (LEOS), 2005, p. 123-124Conference paper (Refereed)
    Abstract [en]

    We demonstrate the optical phase characterization of a monolithically integrated InP optical-CDMA encoder/decoder chip using frequency-resolved optical gating.

  • 111.
    Brodin, Jane M.
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Centres, Stockholm International Toy Research Center, SITREC.
    Lindstrand, Peg
    KTH, School of Industrial Engineering and Management (ITM), Centres, Stockholm International Toy Research Center, SITREC.
    Are computers the solution to support development in children in need of special support?2004In: Technology and Disability, ISSN 1055-4181, E-ISSN 1878-643X, Vol. 16, no 3, p. 137-145Article in journal (Refereed)
    Abstract [en]

    This article is based on several studies conducted in the ICT field focussing on children with severe disabilities and their computer use. Topics of interest include how computers are used by children in general, and especially by children with severe disabilities. How effective is technology as support for child development and in daily activities? The main focus is on play and communication/social interaction for child development. The key question is if and how computers are the solution to support development in children in need of special support.

  • 112.
    Brouwers, Lisa
    et al.
    KTH, Superseded Departments, Computer and Systems Sciences, DSV.
    Ekenberg, Love
    KTH, Superseded Departments, Computer and Systems Sciences, DSV.
    Hansson, Karin
    KTH, Superseded Departments, Computer and Systems Sciences, DSV.
    Danielson, Mats
    Multi-criteria decision-making of policy strategies with public-private re-insurance systems2004In: Risk, Decision, and Policy, ISSN 1357-5309, E-ISSN 1466-4534, Vol. 9, no 1, p. 23-45Article in journal (Refereed)
    Abstract [en]

    This article describes an integrated flood catastrophe model as well as some results of a case study made in the Upper Tisza region in north-eastern Hungary: the Palad-Csecsei basin. The background data was provided through the Hungarian Academy of Sciences and complemented by interviews with different stakeholders in the region. Based on these data, for which a large degree of uncertainty is prevailing, we demonstrate how an implementation of a simulation and decision analytical model can provide insights into the effects of imposing different policy options for a flood risk management program in the region. We focus herein primarily on general options for designing a public-private insurance and reinsurance system for Hungary. Obviously, this is a multi-criteria and multi-stakeholder problem and cannot be solved using standard approaches. It should, however, be emphasised that the main purpose of this article is not to provide any definite recommendations, but rather to explore a set of policy packages that could gain a consensus among the stakeholders.

  • 113.
    Brown, Nils
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Bai, Wei
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Björk, Folke
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Malmqvist, Tove
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Environmental Strategies.
    Molinari, Marco
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    Sustainability assessment of Renovation for Increased End-use Energy Efficiency for Multi-family Buildings in Sweden2011In: Proceedings of 6th World Sustainable Building Conference, SB11, 2011Conference paper (Refereed)
  • 114.
    Bruce, Carl
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Nilsson, Camilla
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Fogelström, Linda
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malmström, Eva
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Paper sheets and laminates based on PCL- and PLLA-grafted fibers2011Conference paper (Refereed)
  • 115.
    Bruce, Carl
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Nilsson, Camilla
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Fogelström, Linda
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Paper-sheet biocomposites based on wood pulp grafted with poly(epsilon-caprolactone)2015In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 132, no 23, article id 42039Article in journal (Refereed)
    Abstract [en]

    Kraft pulp fibers were used as substrates for the grafting of poly(epsilon-caprolactone) (PCL) from available hydroxyl groups through ring-opening polymerization, targeting three different chain lengths (degree of polymerization): 120, 240, and 480. In a paper-making process, paper-sheet biocomposites composed of grafted fibers and neat pulp fibers were prepared. The paper sheets possessed both the appearance and the tactility of ordinary paper sheets. Additionally, the sheets were homogenous, suggesting that PCL-grafted fibers and neat fibers were compatible, as demonstrated by both Fourier transform infrared spectroscopy microscopy and through dye-labeling of the PCL-grafted fibers. Finally, it was shown that the paper-sheet biocomposites could be hot-pressed into laminate structures without the addition of any matrix polymer; the adhesive joint produced could even be stronger than the papers themselves. This apparent and sufficient adhesion between the layers was thought to be due to chain entanglements and/or co-crystallization of adjacent grafted PCL chains within the different paper sheets. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42039.

  • 116.
    Brunet, Philippe
    KTH, School of Engineering Sciences (SCI), Mechanics.
    Stabilized Kuramoto-Sivashinsky equation: A useful model for secondary instabilities and related dynamics of experimental one-dimensional cellular flows2007In: PHYSICAL REVIEW E, ISSN 1539-3755, Vol. 76, no 1, p. 017204-Article in journal (Refereed)
    Abstract [en]

    We report numerical simulations of one-dimensional cellular solutions of the stabilized Kuramoto-Sivashinsky equation. This equation offers a range of generic behavior in pattern-forming instabilities of moving interfaces, such as a host of secondary instabilities or transition toward disorder. We compare some of these collective behaviors to those observed in experiments. In particular, destabilization scenarios of bifurcated states are studied in a spatially semi-extended situation, which is common in realistic patterns, but has been barely explored so far.

  • 117.
    Brunet, Philippe
    et al.
    KTH, Superseded Departments, Mechanics.
    Limat, L
    Defects and spatiotemporal disorder in a pattern of falling liquid columns2004In: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics: Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, ISSN 1063-651X, E-ISSN 1095-3787, Vol. 70, no 4, p. 046207-Article in journal (Refereed)
    Abstract [en]

    Disordered regimes of a one-dimensional pattern of liquid columns hanging below an overflowing circular dish are investigated experimentally. The interaction of two basic dynamical modes (oscillations and drift) combined with the occurrence of defects (birth of new columns, disappearances by coalescences of two columns) leads to spatiotemporal chaos. When the flow rate is progressively increased, a continuous transition between transient and permanent chaos is pointed into evidence. We introduce the rate of defects as the sole relevant quantity to quantify this "turbulence" without ambiguity. Statistics on both transient and endlessly chaotic regimes enable to define a critical flow rate around which exponents are extracted. Comparisons are drawn with other interfacial pattern-forming systems, where transition towards chaos follows similar steps. Qualitatively, careful examinations of the global dynamics show that the contamination processes are nonlocal and involve the propagation of blocks of elementary laminar states (such as propagative domains or local oscillations), emitted near the defects, which turn out to be essential ingredients of this self-sustained disorder.

  • 118.
    Brunsell, Per
    et al.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Olofsson, K. Erik J.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Frassinetti, Lorenzo
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Menmuir, Sheena
    KTH, School of Engineering Sciences (SCI), Physics.
    Cecconello, Marco
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Yadikin, D.
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Kuldkepp, Mattias
    KTH, School of Engineering Sciences (SCI), Physics.
    Drake, James Robert
    KTH, School of Electrical Engineering (EES), Fusion Plasma Physics.
    Rachlew, Elisabethth
    KTH, School of Engineering Sciences (SCI), Physics.
    Resistive wall mode feedback control experiments in EXTRAP T2R2007In: 34th EPS Conference on Plasma Physics 2007, EPS 2007 - Europhysics Conference Abstracts, 2007, p. 544-547Conference paper (Refereed)
    Abstract [en]

    Experiments in EXTRAP T2R on RWM stabilization using intelligent shell feedback with a P-controller showed that mode suppression improves with increasing gain up to the system stability limit. A PD-controller gives faster response and allows operation with higher gain. The PI-controller is useful for suppression of modes driven by external resonant field error. Best mode suppression was in the present study achieved with a PID-controller.

  • 119. Buchert, T.
    et al.
    Carfora, M.
    Ellis, G. F. R.
    Kolb, E. W.
    MacCallum, M. A. H.
    Ostrowski, J. J.
    Rasanen, S.
    Roukema, B. F.
    Andersson, Lars Erik
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.).
    Coley, A. A.
    Wiltshire, D. L.
    Is there proof that backreaction of inhomogeneities is irrelevant in cosmology?2015In: Classical and quantum gravity, ISSN 0264-9381, E-ISSN 1361-6382, Vol. 32, no 21, article id 215021Article in journal (Refereed)
    Abstract [en]

    No. In a number of papers, Green and Wald argue that the standard FLRW model approximates our Universe extremely well on all scales, except close to strong-field astrophysical objects. In particular, they argue that the effect of inhomogeneities on average properties of the Universe (backreaction) is irrelevant. We show that this latter claim is not valid. Specifically, we demonstrate, referring to their recent review paper, that (i) their two-dimensional example used to illustrate the fitting problem differs from the actual problem in important respects, and it assumes what is to be proven; (ii) the proof of the trace-free property of backreaction is unphysical and the theorem about it fails to be a mathematically general statement; (iii) the scheme that underlies the trace-free theorem does not involve averaging and therefore does not capture crucial non-local effects; (iv) their arguments are to a large extent coordinate-dependent, and (v) many of their criticisms of backreaction frameworks do not apply to the published definitions of these frameworks. It is therefore incorrect to infer that Green and Wald have proven a general result that addresses the essential physical questions of backreaction in cosmology.

  • 120.
    Bégué, D.
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Pe'er, A.
    Poynting-flux-dominated jets challenged by their photospheric emission2015In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 802, no 2, article id 134Article in journal (Refereed)
    Abstract [en]

    One of the key open question in the study of jets, in general, and jets in gamma-ray bursts (GRBs), in particular, is the magnetization of the outflow. Here we consider the photospheric emission of Poynting-flux-dominated outflows, when the dynamics is mediated by magnetic reconnection. We show that thermal three-particle processes, responsible for the thermalization of the plasma, become inefficient at a radius of rsup ∼ 109.5 cm, far below the photosphere, at ∼1011.5 cm. Conservation of the total photon number above rsup combined with Compton scattering below the photosphere enforces kinetic equilibrium between electrons and photons. This, in turn, leads to an increase in the observed photon temperature, which reaches ≳8 MeV (observed energy) when decoupling the plasma at the photosphere. This result is weakly dependent on the free model parameters. We show that in this case, the expected thermal luminosity is a few percent of the total luminosity, and could therefore be detected. The predicted peak energy is more than an order of magnitude higher than the observed peak energy of most GRBs, which puts strong constraints on the magnetization of these outflows.

  • 121.
    Börjesson, Maria
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering. KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Harry, Flam
    Mörth, Ulrika
    Jan-Eric, Nilsson
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Traffic Research, CTR. VTI.
    Infrastrukturbeslut måste grundas på samhällsekonomiska kalkyler: DN Debatt2016In: Dagens nyheter, ISSN 1101-2447, no 2016-02-17Article, book review (Other (popular science, discussion, etc.))
  • 122.
    Cai, Yangjian
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Wang, Fei
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Lensless imaging with partially coherent light2007In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 32, no 3, p. 205-207Article in journal (Refereed)
    Abstract [en]

    Based on the fourth-order correlation of light, lensless imaging with incoherent or partially coherent light is investigated theoretically by use of classical optical coherence theory. A novel lensless optical system for implementing imaging is proposed. The visibility and quality of the image are influenced by the coherence and transverse size of the light source. The results suggest useful imaging applications in x-ray, gamma-ray, or other wavelengths where no effective lens is available, and they have potential applications in optical metrology and holography.

  • 123.
    Cai, Yangjian
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Wang, Fei
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Lensless optical implementation of the coincidence fractional Fourier transform2006In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 31, no 15, p. 2278-2280Article in journal (Refereed)
    Abstract [en]

    A lensless optical system for implementing the coincidence fractional Fourier transform (FRT) is proposed. The conditions for the lensless optical system to implement the coincidence FRT with incoherent light and entangled photon pairs are discussed. The results offer a novel scheme for FRTs and thus suggest useful applications.

  • 124. Calles, Karin
    et al.
    Eriksson, Ulrika
    KTH, School of Biotechnology (BIO), Bioprocess Technology (closed 20130101).
    Häggström, Lena
    KTH, School of Biotechnology (BIO), Bioprocess Technology (closed 20130101).
    Effect of conditioned medium factors on productivity and cell physiology in Trichoplusia ni insect cell cultures.2006In: Biotechnology progress (Print), ISSN 8756-7938, E-ISSN 1520-6033, Vol. 22, no 3, p. 653-659Article in journal (Refereed)
    Abstract [en]

    The influence of conditioned medium (CM) on cell physiology and recombinant protein production in Trichoplusia ni insect cells (T. ni, BTI-Tn-5B1-4) has been investigated. Cell cycle analysis showed that a high proportion of the cell population (80-90%) was in G1 during the whole culture, indicating that the S and G2/M phases are short relative to the G1 phase. Directly after inoculation, a rapid decrease of the S-phase population occurred, which could be observed as a lag-phase. The following increase in the number of cells in S occurred after 7 h of culture for cells in fresh medium, whereas for cells with the addition of CM it occurred at an earlier time point (5 h) and these cells had therefore a shorter lag-phase. The initial changes in the S-phase population were also affected by the inoculum cell density, as higher seeding cell densities resulted in a more rapid increase in the S-phase population after inoculation. These changes in cell cycle distribution were reflected in the cell size, and the CM-cells were smaller than the cells in fresh medium. Recombinant protein production in T. ni cells was improved by the addition of CM. The specific productivity was increased by 30% compared to cells in fresh medium. This beneficial effect was seen between 20 and 72 h of culture. In contrast, the highest specific productivity was obtained already at 7 h for the cells in fresh medium and then decreased rapidly. The total product concentration was around 30% higher in the culture with CM compared to the culture in fresh medium, and the maximum product concentration was obtained on day 2 compared to day 3 for the cells in fresh medium. Our results indicate that the positive effect on productivity by CM is related to its growth-promoting effect, suggesting that the proliferation potential of the culture determines the productivity.

  • 125. Camara, Alexandre R.
    et al.
    Pereira, Joao M. B.
    Tarasenko, Oleksandr
    Margulis, Walter
    Acreo Swedish ICT.
    Carvalho, Isabel C. S.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Optical creation and erasure of the linear electrooptical effect in silica fiber2015In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 23, no 14, p. 18060-18069Article in journal (Refereed)
    Abstract [en]

    We study the creation and erasure of the linear electrooptical effect in silicate fibers by optical poling. Carriers are released by exposure to green light and displaced with simultaneous application of an internal dc field. The second order nonlinear coefficient induced grows with poling bias. The field recorded (similar to 10(8) V/m) is comparable to that obtained through classical thermal poling of fibers. In the regime studied here, the second-order nonlinearity induced (similar to 0.06 pm/V) is limited by the field applied during poling (1.2 x 10(8) V/m). Optical erasure with high-power green light alone is very efficient. The dynamics of the writing and erasing process is discussed, and the two dimensional (2D) field distribution across the fiber is simulated. (C) 2015 Optical Society of America

  • 126.
    Carlborg, Carl Fredrik
    et al.
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Gylfason, Kristinn Björgvin
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Kazmierczak, Andrzej
    Dortu, Fabian
    Banuls Polo, Maria Jose
    Maquieira Catala, Angel
    Kresbach, Gerhard
    Sohlström, Hans
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Moh, Thomas
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    Vivien, Laurent
    Popplewell, Jon
    Ronan, Gerry
    Barrios, Carlos Angulo
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Microsystem Technology (Changed name 20121201).
    A packaged optical slot-waveguide ring resonator sensor array for multiplex label-free assays in labs-on-chips2010In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 10, no 3, p. 281-290Article in journal (Refereed)
    Abstract [en]

    We present the design, fabrication, and characterisation of an array of optical slot-waveguide ring resonator sensors, integrated with microfluidic sample handling in a compact cartridge, for multiplexed real-time label-free biosensing. Multiplexing not only enables high throughput, but also provides reference channels for drift compensation and control experiments. Our use of alignment tolerant surface gratings to couple light into the optical chip enables quick replacement of cartridges in the read-out instrument. Furthermore, our novel use of a dual surface-energy adhesive film to bond a hard plastic shell directly to the PDMS microfluidic network allows for fast and leak-tight assembly of compact cartridges with tightly spaced fluidic interconnects. The high sensitivity of the slot-waveguide resonators, combined with on-chip referencing and physical modelling, yields a volume refractive index detection limit of 5 x 10(-6) refractive index units (RIUs) and a surface mass density detection limit of 0.9 pg mm(-2), to our knowledge the best reported values for integrated planar ring resonators.

  • 127.
    Carling, Pär
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering (name changed to Building Service and Energy Systems 2012-03-01).
    Isaksson, Per O.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering (name changed to Building Service and Energy Systems 2012-03-01).
    Wetterström, Per
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering (name changed to Building Service and Energy Systems 2012-03-01).
    IT-stöd ger rationell besiktning av energi- och VVS-funktioner2005In: Husbyggaren : organ för Svenska byggnadsingenjörers riksförbund, SBR, ISSN 0018-7968Article in journal (Other academic)
  • 128.
    Carling, Pär
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering (name changed to Building Service and Energy Systems 2012-03-01).
    Isaksson, Per O.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering (name changed to Building Service and Energy Systems 2012-03-01).
    Wetterström, Per
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering (name changed to Building Service and Energy Systems 2012-03-01).
    Rumstemperaturer samlas in för glastornet i Kista2007In: Husbyggaren : organ för Svenska byggnadsingenjörers riksförbund, SBR, ISSN 0018-7968, no 6, p. 22-27Article in journal (Other academic)
  • 129.
    Carlsson, Per-Olof
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering (name changed to Building Service and Energy Systems 2012-03-01).
    Erlandsson, Martin
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering (name changed to Building Service and Energy Systems 2012-03-01).
    Andersson, Johnny
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering (name changed to Building Service and Energy Systems 2012-03-01).
    Lindholm, Torbjörn
    Malmström, Tor-Göran
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Services Engineering (name changed to Building Service and Energy Systems 2012-03-01).
    Miljöklassning av byggnader: Test av preliminära klassningsindikatorer2006Report (Other academic)
  • 130. Carroll, R. J.
    et al.
    Andgren, Karin
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Cederwal, Bo
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Doncel, Maria
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Hadinia, Baharak
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics. Department of Physics, University of Guelph, Guelph, ON, Canada.
    Jacobsson, Ulrika
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics. University of Jyväskylä, Department of Physics, Jyväskylä, Finland.
    Sandzelius, Mikael
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Taylor, M. J.
    Thornthwaite, A.
    et al.,
    Excited states in the proton-unbound nuclide Ta-1582016In: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 93, no 3, article id 034307Article in journal (Refereed)
    Abstract [en]

    Excited states in the neutron-deficient odd-odd proton-unbound nuclide Ta-158 have been investigated in two separate experiments. In the first experiment, Ir-166 nuclei were produced in the reactions of 380 MeV Kr-78 ions with an isotopically enriched Mo-92 target. The alpha-decay chain of the 9(+) state in Ir-166 was analyzed. Fine structure in the a decay of the 9(+) state in Re-162 established a 66 keV difference in excitation energy between the lowest-lying 9(+) and 10(+) states in Ta-158. Higher-lying states in Ta-158 were populated in the reactions of 255 MeV Ni-58 ions with an isotopically enriched Pd-102 target. Gamma-ray decay paths that populate, depopulate, and bypass a 19(-) isomeric state have been identified. The general features of the deduced level scheme are discussed and the prospects for observing proton emission branches from excited states are considered.

  • 131.
    Cats, Oded
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering. Delft University of Technology, Netherlands.
    Wang, Q.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Zhao, Y.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Identification and classification of public transport activity centres in Stockholm using passenger flows data2015In: Journal of Transport Geography, ISSN 0966-6923, E-ISSN 1873-1236, Vol. 48, p. 10-22, article id 1735Article in journal (Refereed)
    Abstract [en]

    Urban geography could be characterized by analysing the patterns that describe the flows of people and goods. Measuring urban structures is essential for supporting an evidence-based spatial planning policy. The objective of this study is to examine how the spatial-temporal distribution of public transport passenger flow could be used to reveal urban structure dynamics. A methodology to identify and classify centres based on mobility data was applied to Metropolitan Stockholm in Sweden using multi-modal public transport passenger flows. Stockholm is known for its long-term monocentric planning with a dominant central core and radial public transport system. Strategic nodes along its radial public transport system have been a focus for development of sub-centres. Although the regional planning policy embraces a shift towards a polycentric planning policy, the results indicate that this has not been realized insofar.

  • 132.
    Cha, Y.
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Olofsson, Ulf
    KTH, School of Industrial Engineering and Management (ITM).
    Gustafsson, M.
    Johansson, C.
    On particulate emissions from individual trains in tunnel environments2016In: Civil-Comp Proceedings, ISSN 1759-3433, Vol. 110Article in journal (Refereed)
    Abstract [en]

    In order to detect the concentrations and size distributions of airborne particles that were generated by individual moving trains on an underground railway platform, a series of real-time measurements were undertaken. The measurement range covered the ultrafine (less than 100 nm) and partly the fine (100 nm to 2.5 μm), but not the coarse fraction (2.5 to 10 μm). The results show that the individual trains with stop and start at the platform elevate substantially the particulate number concentrations with a diameter size greater than 100 nm. Two size modes of the particulate number concentrations are obtained. One mode peaks around 170 nm when a train stopped/started, while the other is around 30 nm when no train operated in the station. By using principal component analysis, four components are extracted from the thirty two-analyzed particulate sizes, indicating four different contributors in those detected particles. It is revealed from this study that the particulate matter released by individual moving trains (mainly through mechanical wear and turbulent resuspension) is a key contributing source of the fine particles on underground railway platforms, which can be separated from the background by their different size distributions. © Civil-Comp Press, 2016.

  • 133.
    Chacholski, Wojciech
    et al.
    KTH, Superseded Departments, Mathematics.
    Parent, Paul-Eugene
    KTH, Superseded Departments, Mathematics.
    Stanley, D.
    Cellular generators2004In: Proceedings of the American Mathematical Society, ISSN 0002-9939, E-ISSN 1088-6826, Vol. 132, no 11, p. 3397-3409Article in journal (Refereed)
    Abstract [en]

    The aim of this paper is twofold. On the one hand, we show that the kernelof the Bousfield periodization functor P-A is cellularly generated by a space B, i.e., we construct a space B such that the smallest closed class C( B) containing B is exactly C( A). On the other hand, we show that the partial order (Spaces, much greater than) is a complete lattice, where B much greater than A if B is an element of C(A). Finally, as a corollary we obtain Bousfield's theorem, which states that (Spaces, >) is a complete lattice, where B > A if B is an element of.

  • 134.
    Chacinski, Marek
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Schatz, Richard
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Westergren, Urban
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Photonics (Closed 20120101).
    Berggren, Jesper
    Yu, X.
    KTH.
    Marcks Von Würtemberg, Richard
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Hammar, Mattias
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Dynamic properties of electrically p-n confined, epitaxially regrown 1.27 μm InGaAs single-mode vertical-cavity surface-emitting lasers2009In: IET optoelectronics, ISSN 1751-8768, Vol. 3, no 3, p. 163-167Article in journal (Refereed)
    Abstract [en]

    The dynamic performance including chirp measurements of 1.27 mu m single-mode InGaAs/GaAs vertical-cavity surface-emitting lasers (VCSELs) with a large gain-cavity offset is presented. The VCSELs are based on a novel p-n confinement structure with selective area epitaxial regrowth. A resonance frequency of 9.11 GHz, a slope efficiency of 0.25 W/A and an alpha-factor of 5.7 were measured. The modulation bandwidth is limited by electrical parasitics. Eye diagrams at 5 Gb/s with 7 dB extinction ratio and Q-factor around 5 were obtained. The results are compared with the performance of oxide-confined VCSELs with similar active layer and negative gain-cavity detuning.

  • 135. Chan, H. K.
    et al.
    Zhou, Y.
    KTH, School of Engineering Sciences (SCI).
    Lam, C. H.
    Shin, F. G.
    Theory of time-dependent space-charge-limited conduction2007In: 2007 IEEE International Conference on Solid Dielectrics, Vols 1 and 2, IEEE , 2007, p. 35-38Conference paper (Refereed)
    Abstract [en]

    We have developed a theory of time-dependent space-charge-limited conduction in recent years to understand a hysteresis-shift phenomenon of graded ferroelectric films. The theory is a generalization of the conventional steady-state space-charge-limited conduction model to include (i) two carrier types (p-type and n-type), (ii) intrinsic conductivity and (iii) time dependence. Later, the theory was also applied to understand the hysteresis behaviour of homogeneous ferroelectric films. In this paper, a full and updated version of the theory is presented. At the limit of zero intrinsic conductivity, the theory implies the dominance of either carrier type. Accordingly, the independent assumptions of (i) a single carrier type and (ii) a negligible intrinsic conductivity in the conventional steady-state conduction model are interrelated.

  • 136.
    Charoenrat, Theppanya
    et al.
    KTH, School of Biotechnology (BIO).
    Ketudat-Cairns, M.
    Stendahl-Andersen, Helle
    KTH, School of Biotechnology (BIO).
    Jahic, Mehmedalija
    KTH, School of Biotechnology (BIO).
    Enfors, Sven-Olof
    KTH, School of Biotechnology (BIO), Bioprocess Technology (closed 20130101).
    Oxygen-limited fed-batch process: an alternative control for Pichia pastoris recombinant protein processes2005In: Bioprocess and biosystems engineering (Print), ISSN 1615-7591, E-ISSN 1615-7605, Vol. 27, no 6, p. 399-406Article in journal (Refereed)
    Abstract [en]

    An oxygen-limited fed-batch technique (OLFB) was compared to traditional methanol-limited fed-batch technique (MLFB) for the production of recombinant Thai Rosewood beta-glucosidase with Pichia pastoris. The degree of energy limitation, expressed as the relative rate of respiration (q(O)/q(O,max)), was kept similar in both the types of processes. Due to the higher driving force for oxygen transfer in the OLFB, the oxygen and methanol consumption rates were about 40% higher in the OLFB. The obligate aerobe P. pastoris responded to the severe oxygen limitation mainly by increased maintenance demand, measured as increased carbon dioxide production per methanol, but still somewhat higher cell density (5%) and higher product concentrations (16%) were obtained. The viability was similar, about 90-95%, in both process types, but the amount of total proteins released in the medium was much less in the OLFB processes resulting in substantially higher (64%) specific enzyme purity for input to the downstream processing.

  • 137.
    Chatti, Sami
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Syrou, Meni
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Kleiner, Matthias
    Lindström, Bo
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    New-transnational curricula for BSc/MSc programs in production engineering2005In: Journal of manufacturing systems, ISSN 0278-6125, E-ISSN 1878-6642, Vol. 24, no 3, p. 145-152Article in journal (Refereed)
    Abstract [en]

    The paper describes the curricula of two new international programs in production engineering-one a tri-national master of science in "industrial design and manufacturing" (IDM) program and the other an international bachelor of science program. The IDM master's program has been developed at the University of Dortmund in cooperation with the University of Twente in the Netherlands. Since 2004, the third partner in the IDM program is the University of Strathclyde in the UK. The IDM program provides an integrated, holistic, and internationally oriented graduate education in mechanical engineering that keeps the balance between theory and practice. For the development of the bachelor's program, the pilot project EPRODE (European Production Engineer) was initiated in 2003. It has been granted by the European Union (EU) program Leonardo da Vinci and aims at specifying a standardized European curriculum. Partners of EPRODE are institutes from universities and the industry sector in Sweden, Germany, Poland, and Spain.

  • 138. Chavez, Hector
    et al.
    Hezamsadeh, Mohammad Reza
    KTH, School of Electrical Engineering (EES).
    Carlsson, Fredrik
    A Simplified Model for Predicting Primary Control Inadequacy for Nonresponsive Wind Power2016In: IEEE Transactions on Sustainable Energy, ISSN 1949-3029, E-ISSN 1949-3037, Vol. 7, no 1, p. 271-278Article in journal (Refereed)
    Abstract [en]

    The integration of wind power (WP) into power systems has led to concerns on the adequacy of primary frequency control. Such concerns have currently arisen in interconnections with high penetration of WP and may appear in other systems where high penetration of WP is planned. This paper proposes a method for predicting the level of WP penetration that may lead to primary frequency control inadequacy, considering a empirically-validated model of primary frequency control, worst-case scenario conditions and no frequency response from WP machines. The NORDEL interconnection is considered as a case study.

  • 139.
    Chen, C
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Bissal, Ara
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Salinas, E
    Numerical modelling and experimental testing of eddy-current dampers2014In: ACTUATOR14, Bremen: MESSE BREMEN , 2014Conference paper (Refereed)
    Abstract [en]

    A contact system driven by a high energetic Thomson actuator requires to be decelerated from full speed down to zero. The forces originated from the interaction between a stationary copper tube and a moving array of magnets combined with plastic separators or ferromagnetic material are used to generate eddy-current damping. Five different configurations of small but strong neodymium magnets and spacers were benchmarked for simple free-fall damping. A comparison between experimental results and simulations (using COMSOL) shows that the most effective damping is reached by two consecutive permanent magnets with opposite magnetization directions, separated by low-carbon content steel concentrators. The proposed damper design is the result of the balance between various parameters such as magnet orientation topology in the array, spacer material and its dimensions, copper tube thickness and the air gap between copper tube and array. Furthermore, the design was scaled up and an actuator-drive system was added to perform more realistic tests, which demonstrated the damping effectiveness on a fast moving armature actuated by a Thomson coil energized by a capacitor bank. The results of these tests validated the numerical model with a good degree of accuracy.

  • 140.
    Chen, Cheng
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Cheng, Ming
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Liu, Peng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Gao, Jiajia
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Application of benzodithiophene based A-D-A structured materials in efficient perovskite solar cells and organic solar cells2016In: Nano Energy, ISSN 2211-2855, Vol. 23, p. 40-49Article in journal (Refereed)
    Abstract [en]

    In this work, we have designed and synthesized a novel molecular material, BDT-C1, in which the core unit, benzodithiophene (BDT), was functionalized by thiophene (TP) and benzo-[c][1,2,5]-thiadiazole (BTZ) derivatives to generate extended pi-conjugation. BDT-C1 shows high hole mobility and high conductivity in its pristine form, in combination with appropriate energy level alignment with respect to [CH3NH3]PbI3 and PC70BM, qualifying the material as a good candidate for application both in perovskite solar cells (PSCs) as dopant-free hole transport material (HTM) and in OSCs as donor material. The champion PSCs based on BDT-C1 show an average conversion efficiency (PCE) of 13.4% (scan forward: 13.9%; scan backward: PCE=12.9%, scan rate: 10 mV/s). Although the average efficiency obtained is slightly lower than that of reference devices based on the well-known doped HTM Spiro-OMeTAD (13.7%), the BDT-C1 based devices exhibit better stability. Moreover, BDT-C1 as a donor material in OSCs also shows good performance in combination with PC70BM as acceptor material, and an efficiency of 6.1% was obtained. The present results demonstrate that BDT-C1 works well as both donor material in OSCs as well as dopant-free HTMs for efficient PSCs.

  • 141.
    Chen, Danfang
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Kjellberg, Torsten
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Svensson, Robert
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Sivard, Gunilla
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Production pilot for co-operation in factory development2011In: Enabling Manufacturing Competitiveness and Economic Sustainability: Proceedings of the 4th International Conference on Changeable, Agile, Reconfigurable and Virtual production (CARV2011), Montreal, Canada, 2-5 October 2011 / [ed] Hoda A. El Maraghy, Springer , 2011, p. 636-641Conference paper (Refereed)
    Abstract [en]

    This paper is dedicated to the factory development where management of established knowledge and company practiceis a big challenge because its process involves many competence domains such as process planning, productioninvestment and building construction, etc. This article presents an in-house developed production pilot for a better cooperationand support in factory development. Details about methodologies and the thinking behind the pilot will bepresented in the paper. The pilot aims to ease the sharing and reuse of knowledge and experiences, create a valueaddingworking process, and ease the collaboration and semantic interpretation between disciplines within factorydevelopment.

  • 142.
    Chen, Daru
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Stable multi-wavelength erbium-doped fiber laser based on a photonic crystal fiber Sagnac loop filter2007In: LASER PHYSICS LETTERS, ISSN 1612-2011, Vol. 4, no 6, p. 437-439Article in journal (Refereed)
    Abstract [en]

    A multi-wavelength erbium-doped fiber laser based on a Sagnac loop fiber which is formed by a birefringent and highly nonlinear photonic crystal fiber (PCF), a 3-dB optical coupler and two polarization controllers is proposed. The PCF Sagnac loop filter is used as comb filter and power-stabilizing and equilibrizing component in the multi-wavelength erbium-doped fiber laser. Stable multi-wavelength lasing at room temperature is achieved, owing to the contributions of both the birefringent property and the four-wave mixing effect of the PCF.

  • 143.
    Chen, Daru
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Fu, Hongyan
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Liu, W.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Single-longitudinal-mode erbium-doped fiber laser based on a fiber Bragg grating Fabry-Perot filter2007In: Laser physics, ISSN 1054-660X, E-ISSN 1555-6611, Vol. 17, no 10, p. 1246-1248Article in journal (Refereed)
    Abstract [en]

    A novel single-longitudinal-mode (SLM) erbium-doped fiber laser with a simple linear cavity based on a fiber Bragg grating Fabry-Perot filter (FBG-FPF) and a narrowband (similar to 0.06 nm) FBG is proposed and demonstrated experimentally. Two uniform FBGs form the FBG-FPF, which has two ultranarrow transmission bands with a bandwidth of 0.12 pm and a wavelength spacing of 0.095 nm. By slightly tuning the central wavelength of the narrowband FBG, SLM lasing at 1549.658 or 1549.563 nm (corresponding to the two transmission peaks of the FBG-FPF) is achieved with a laser output power of similar to 4 mW, when the pump power is similar to 75 mW.

  • 144.
    Chen, Daru
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Qin, Shan
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Gao, Ying
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Gao, Shiming
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wavelength-spacing continuously tunable multiwavelength erbium-doped fibre laser based on DSF and MZI2007In: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 43, no 9, p. 524-525Article in journal (Refereed)
    Abstract [en]

    A novel multiwavelength erbium-doped fibre laser is proposed by incorporating a section of dispersion-shifted fibre (DSF) and a Mach-Zehnder interferometer (MZI). The wavelength spacing of the fibre laser can be continuously tuned by adjusting an optical variable delay line in the MZI-based comb filter. Stable multiwavelength lasing at room temperature with the standard ITU (International Telecommunication Union) channel spacing of 0.2 nm (25 GHz), 0.4 nm (50 GHz), 0.8 nm (100 GHz) or 1.6 nm (200 GHz) is demonstrated.

  • 145.
    Chen, Daru
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Qin, Shan
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Yu, Zhangwei
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    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.
    Tunable and injection-switchable erbium-doped fiber laser of line structure2007In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 49, no 4, p. 765-768Article in journal (Refereed)
    Abstract [en]

    A tunable and injection-switchable erbium-doped fiber (EDF) laser is proposed based on a line structure formed by a fiber Sagnac loop reflector and an fiber Bragg grating (FBG). Wavelength switching is achieved by controlling the power of the tunable injection laser. The self-seeded wavelength corresponding to the Bragg wavelength of the FBG can be tuned by, for example, heating the FBG, and the injection wavelength can be tuned over a wide range of about 50 nm. The characteristics of the wavelength switching for different levels of the EDF pump power and different wavelengths of the injection laser are studied experimentally. The present fiber laser has the advantages of tunability, stability, low amplified spontaneous emission noise, and high injection efficiency when compared with a fiber ring laser. Rapid wavelength switching is expected and the transient switching response of the laser is also studied.

  • 146.
    Chen, Daru R.
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Fu, H.
    Ou, H.
    Qin, Shan
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wavelength-spacing continuously tunable multi-wavelength SOA-fiber ring laser based on Mach-Zehnder interferometer2008In: Optics and Laser Technology, ISSN 0030-3992, Vol. 40, no 2, p. 278-281Article in journal (Refereed)
    Abstract [en]

    A Mach-Zehnder interferometer (MZI) which is used as a wavelength-spacing tunable comb filter in a fiber ring laser is built by employing an optical variable delay line (OVDL). Stable multi-wavelength semiconductor optical amplifier (SOA)-fiber ring laser based on an SOA and the MZI comb filter is achieved. Wavelength spacing can be continuously tuned by adjusting the OVDL and, as an example, multi-wavelength lasing with the wavelength spacing of 0.4, 0.8, or 1.6 nm is demonstrated. The output of the proposed multi-wavelength SOA-fiber ring laser is quite stable at room temperature and the output spectrum can be adjusted by controlling the bias current of the SOA.

  • 147.
    Chen, Daru
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Shen, L.
    Switchable and tunable Erbium-doped fiber ring laser incorporating a birefringent and highly nonlinear photonic crystal fiber2007In: LASER PHYSICS LETTERS, ISSN 1612-2011, Vol. 4, no 5, p. 368-370Article in journal (Refereed)
    Abstract [en]

    A birefringent and highly nonlinear photonic crystal fiber is employed in an Erbium doped fiber ring laser, which can operate with dual-wavelength lasing or single-wavelength lasing. Both stable dual-wavelength lasing and tunable single-wavelength lasing are achieved by adjusting a polarization controller in the ring cavity. The experimental results show that the output of the proposed fiber ring laser is rather stable at two different operation modes.

  • 148.
    Chen, Daru
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Shen, Linfang
    Ultrahigh bireffingent photonic crystal fiber with ultralow confinement loss2007In: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 19, no 2-4, p. 185-187Article in journal (Refereed)
    Abstract [en]

    A photonic crystal fiber (PCF) with circular air holes in the fiber cladding and elliptical air holes in the fiber core is proposed. According to calculation, both ultrahigh birefringence (larger than 0.01) and ultralow confinement loss (less than 0.001 dB/km) can be achieved simultaneously over a large wavelength range for a PCF with only four rings of circular air holes in the fiber cladding. The confinement loss in this PCF can be effectively reduced while the birefringence almost remains the same. The proposed design of the PCF is a solution to the tradeoff between the birefringence and the confinement loss for the originally reported highly birefringent elliptical-hole PCF. Moreover, an approach to modify the effective index of fiber core is also suggested in this letter.

  • 149.
    Chen, Daru
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Yu, Zhangwei
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Qin, S.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    He, Sailing
    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. KTH, School of Electrical Engineering (EES), Centres, Alfvén Laboratory Centre for Space and Fusion Plasma Physics.
    Switchable dual-wavelength Raman erbium-doped fibre laser2006In: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 42, no 4, p. 202-204Article in journal (Refereed)
    Abstract [en]

    A fibre Bragg grating feedback fibre laser with both Raman and erbium-doped fibre pumps is proposed. Dual-wavelength switching is achieved by controlling the power of the Raman pump. The characteristics of the dual-wavelength switching are studied experimentally, and the mechanism is explained physically.

  • 150.
    Chen, Guanying
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Ohulchanskyy, Tymish Y.
    Law, Wing Cheung
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Prasad, Paras N.
    Monodisperse NaYbF4: Tm3+/NaGdF4 core/shell nanocrystals with near-infrared to near-infrared upconversion photoluminescence and magnetic resonance properties2011In: NANOSCALE, ISSN 2040-3364, Vol. 3, no 5, p. 2003-2008Article in journal (Refereed)
    Abstract [en]

    We report core/shell NaYbF4 : Tm3+/NaGdF4 nanocrystals to be used as probes for bimodal near infrared to near infrared (NIR-to-NIR) upconversion photoluminescence (UCPL) and magnetic resonance (MR) imaging. The NaYbF4 : Tm3+ nanocrystals were previously reported to produce the intense NIR-to-NIR UCPL peaked at similar to 800 nm under excitation at similar to 975 nm. We have found that the growth of a NaGdF4 shell on surface of the NaYbF4 : Tm3+ nanocrystals results in the increase in the intensity of UCPL of Tm3+ ions by about 3 times. Unlike biexponential PL decay of NaYbF4 : Tm3+ nanocrystals, the PL decay of NaYbF4 : Tm3+/NaGdF4 core/shell nanocrystals is single exponential and of longer lifetime due to the suppression of surface quenching effects for Tm3+ PL. The growth of a NaGdF4 shell on surface of the NaYbF4 : Tm3+ nanocrystals also provides high MR relaxivity from paramagnetic Gd3+ ions contained in the shell. The T1-weighted MR signal of the (NaYbF4:2% Tm3+)/NaGdF4 nanoparticles was measured to be about 2.6 mM(-1)s(-1). Due to the combined presence of efficient optical and MR imaging capabilities, nanoprobes based on NaYbF4 : Tm3+/NaGdF4 fluoride nanophosphors can be considered as a promising platform for simultaneous bimodal PL and MR bioimaging.

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