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  • 151.
    Chen, Jiajia
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Gong, Yu
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Fiorani, Matteo
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    High Capacity and Energy Efficient Optical Interconnects at Top of the Rack in Datacentres2014Conference paper (Refereed)
  • 152.
    Chen, Jiajia
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Li, Jun
    KTH.
    Efficient Mobile Backhaul Architecture Offering Ultra-Short Latency for Handovers2016In: 2016 18TH INTERNATIONAL CONFERENCE ON TRANSPARENT OPTICAL NETWORKS (ICTON), IEEE, 2016Conference paper (Refereed)
  • 153.
    Chen, Xue-Wen
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Choy, Wallace C. H.
    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.
    Simulation of light emission from a semiconductor nanowire/nanotube2007In: 2007 IEEE LEOS ANNUAL MEETING CONFERENCE PROCEEDINGS, 2007, p. 411-412Conference paper (Refereed)
  • 154.
    Chen, Zhihui
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry (closed 20110512).
    Hellström, Staffan
    KTH, School of Biotechnology (BIO), Theoretical Chemistry (closed 20110512).
    Ning, Zhijun
    KTH, School of Biotechnology (BIO), Theoretical Chemistry (closed 20110512).
    Yu, Z-Y
    Fu, Ying
    KTH, School of Biotechnology (BIO), Theoretical Chemistry (closed 20110512).
    Exciton Polariton Contribution to the Stokes Shift in Colloidal Quantum Dots2011In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 115, no 13, p. 5286-5293Article in journal (Refereed)
    Abstract [en]

    We study the exciton polariton contribution to the Stokes shift in colloidal quantum dots (QDs). By detailed quantum mechanical description of light-matter interaction and temporal analysis of incident electromagnetic field across the QD using the finite-difference time-domain method, we have shown that the optical excitation of an exciton in the QD and its coupling with the excitation radiation (i.e., exciton polariton) induce strong variations in the dielectric constant of the QD which contribute significantly to the Stokes shift and cause modifications 50 in the absorption spectrum that agrees well with experiments.

  • 155.
    Cheng, Lihua
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Song, Jun
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wang, Jian
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Design of wavelength division demultiplexers based on holographic gratings with a low polarization dependent loss2006In: Guangzi Xuebao/Acta Photonica Sinica, ISSN 1004-4213, Vol. 35, no 11, p. 1667-1671Article in journal (Refereed)
    Abstract [en]

    An optimizing method of main structure parameters (e. g. , the thickness of the crystal) and writing conditions (e. g., the incident angle) is presented for a holographic grating wavelength division demultiplexer based on photorefractive LiNbO3 crystals. The key performance parameters of the demultiplexer, such as the loss and the polarization dependent loss (PDL), are optimized by selecting favourite structure parameters using a rigorous coupled wave analysis method. Numerical results show that a low loss and a low PDL can be achieved by using the optimal crystal thickness and incident angle. The designed demultiplexer obtains the favourite synthetical performance for an actual application. The experimental method of the grating recorded is also introduced in the present paper. The experimental results accorded with theoretical computation commendably by testing the three different specimens.

  • 156.
    Cheng, Ming
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Aitola, Kerttu
    Chen, Cheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Zhang, Fuguo
    Liu, Peng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Sveinbjornsson, Kari
    Hua, Yong
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Boschloo, Gerrit
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. Dalian Univ Technol.
    Acceptor Donor Acceptor type ionic molecule materials for efficient perovskite solar cells and organic solar cells2016In: NANO ENERGY, ISSN 2211-2855, Vol. 30, p. 387-397Article in journal (Refereed)
    Abstract [en]

    Perovskite solar cells (PSCs) have attracted significant interest and hole transporting materials (HTMs) play important roles in achieving high efficiency. Here, we report additive free ionic type HTMs that are based on 2-ethylhexyloxy substituted benzodithiophene (BDT) core unit. With the ionization of end-capping pyridine units, the hole mobility and conductivity of molecular materials are greatly improved. Applied in PSCs, ionic molecular material M7-TFSI exhibits the highest efficiency of 17.4% in the absence of additives [lithium bis(trifluor-omethanesulfonyl)imide and 4-tert-butylpyridine]. The high efficiency is attributed to a deep highest occupied molecular orbital (HOMO) energy level, high hole mobility and high conductivity of M7-TFSI. Moreover, due to the higher hydrophobicity of M7-TFSI, the corresponding PSCs showed better stability than that of Spiro-OMeTAD based ones. In addition, the strong absorption and suitable energy levels of materials (M6, M7-13r and M7-TFSI) also qualify them as donor materials in organic solar cells (OSCs) and the devices containing M7-TFSI as donor material displayed an efficiency of 6.9%.

  • 157.
    Cheng, Ming
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Chen, Cheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Xu, Bo
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Hua, Yong
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Zhang, Fuguo
    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. Dalian University of Technology (DUT), China.
    A novel phenoxazine-based hole transport material for efficient perovskite solar cell2015In: Journal of Energy Challenges and Mechanics, ISSN 2095-4956, E-ISSN 2056-9386, Vol. 24, no 6, p. 698-706Article in journal (Refereed)
    Abstract [en]

    Based on the previous research work in our laboratory, we have designed and synthesized a small-molecule, hole transport material (HTM) POZ6-2 using phenoxazine (POZ) as central unit and dicyanovinyl units as electron-withdrawing terminal groups. Through the introduction of a 2-ethyl-hexyl bulky chain into the POZ core unit, POZ6-2 exhibits good solubility in organic solvents. In addition, POZ6-2 possesses appropriate energy levels in combination with a high hole mobility and conductivity in its pristine form. Therefore, it can readily be used as a dopant-free HTM in perovskite solar cells (PSCs) and a conversion efficiency of 10.3% was obtained. The conductivity of the POZ6-2 layer can be markedly enhanced via doping in combination with typical additives, such as 4-tert-butylpyridine (TBP) and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI). Correspondingly, the efficiency of the PSCs was further improved to 12.3% using doping strategies. Under the same conditions, reference devices based on the well-known HTM Spiro-OMeTAD show an efficiency of 12.8%.

  • 158. Chiodaroli, M.
    et al.
    Guenaydin, M.
    Johansson, H.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Roiban, R.
    Complete Construction of Magical, Symmetric, and Homogeneous N=2 Supergravities as Double Copies of Gauge Theories2016In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 117, no 1, article id 011603Article in journal (Refereed)
    Abstract [en]

    We show that scattering amplitudes in magical, symmetric or homogeneous N = 2 Maxwell-Einstein supergravities can be obtained as double copies of two gauge theories, using the framework of color-kinematics duality. The left-hand copy is N = 2 super-Yang-Mills theory coupled to a hypermultiplet, whereas the right-hand copy is a nonsupersymmetric theory that can be identified as the dimensional reduction of a D-dimensional Yang-Mills theory coupled to P fermions. For generic D and P, the double copy gives homogeneous supergravities. For P = 1 and D = 7, 8, 10, 14, it gives the magical supergravities. We compute explicit amplitudes, discuss their soft limits, and study the UV behavior at one loop.

  • 159.
    Cho, Sung-Woo
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Gällstedt, Mikael
    Johansson, E.va
    Hedenqvist, Mikael S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Injection-molded nanocomposites and materials based on wheat gluten2011In: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 48, no 1, p. 146-152Article in journal (Refereed)
    Abstract [en]

    This is, to our knowledge, the first study of the injection molding of materials where wheat gluten (WG) is the main component. In addition to a plasticizer (glycerol), 5 wt.% natural montmorillonite clay was added. X-ray indicated intercalated clay and transmission electron microscopy indicated locally good clay platelet dispersion. Prior to feeding into the injection molder, the material was first compression molded into plates and pelletized. The filling of the circular mold via the central gate was characterized by a divergent flow yielding, in general, a stronger and stiffer material in the circumferential direction. It was observed that 20-30 wt.% glycerol yielded the best combination of processability and mechanical properties. The clay yielded improved processability, plate homogeneity and tensile stiffness. IR spectroscopy and protein solubility indicated that the injection molding process yielded a highly aggregated structure. The overall conclusion was that injection molding is a very promising method for producing WG objects.

  • 160. Choi, S. G.
    et al.
    Zhao, H. Y.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Persson, Clas
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Perkins, C. L.
    Donohue, A. L.
    To, B.
    Norman, A. G.
    Li, J.
    Repins, I. L.
    Dielectric function spectra and critical-point energies of Cu2ZnSnSe4 from 0.5 to 9.0 eV2012In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 111, no 3, p. 033506-Article in journal (Refereed)
    Abstract [en]

    We present dielectric function epsilon=epsilon(1) + i epsilon(2) spectra and critical-point energies of Cu2ZnSnSe4 determined by spectroscopic ellipsometry from 0.5 to 9.0 eV. We reduce artifacts from surface overlayers to the maximum extent possible by performing chemical-mechanical polishing and wet-chemical etching of the surface of a Cu2ZnSnSe4 thin film. Ellipsometric data are analyzed by the multilayer model and the epsilon spectra are extracted. The data exhibit numerous spectral features associated with critical points, whose energies are obtained by fitting standard lineshapes to second energy derivatives of the data. The experimental results are in good agreement with the a spectra calculated within the GW quasi-particle approximation, and possible origins of the pronounced critical-point structures are identified.

  • 161. Chorus, Caspar G.
    et al.
    de Jong, Gerard C.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Modeling experienced accessibility for utility-maximizers and regret-minimizers2011In: Journal of Transport Geography, ISSN 0966-6923, E-ISSN 1873-1236, Vol. 19, no 6, p. 1155-1162Article in journal (Refereed)
    Abstract [en]

    This paper argues that there is a discrepancy between what Logsum-measures of accessibility aim to measure (experienced-utility) and what they actually measure (decision-utility). The latter type of utility refers to the evaluation of an alternative with the aim of making a decision, while the former refers to the evaluation of a chosen alternative after the choice has been made. We argue that accessibility should preferably be conceptualized and operationalized in terms of experienced-utility, but that this type of utility is difficult to measure. Motivated by these observations we show, taking the Logsurn as a starting point, how its building blocks (parameters estimated from choice patterns) can be used to construct closed-form and easy to compute accessibility-measures that provide an approximation of experienced-utility. We distinguish between decision-making based on utility-maximization and regret-minimization premises. Using a small-scale case-study building on departure time-choice data, we illustrate the working of the developed accessibility-measures and highlight how they differ from the Logsum-approach.

  • 162.
    Chu, Liliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Wang, Shaowei
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Li, Kanghui
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Xi, Wang
    Zhao, Xinyuan
    Qian, Jun
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Biocompatible near-infrared fluorescent nanoparticles for macro and microscopic in vivo functional bioimaging2014In: Biomedical Optics Express, ISSN 2156-7085, E-ISSN 2156-7085, Vol. 5, no 11, p. 4076-4088Article in journal (Refereed)
    Abstract [en]

    Near-infrared (NIR) imaging technology has been widely used for biomedical research and applications, since it can achieve deep penetration in biological tissues due to less absorption and scattering of NIR light. In our research, polymer nanoparticles with NIR fluorophores doped were synthesized. The morphology, absorption/emission features and chemical stability of the fluorescent nanoparticles were characterized, separately. NIR fluorescent nanoparticles were then utilized as bright optical probes for macro in vivo imaging of mice, including sentinel lymph node (SLN) mapping, as well as distribution and excretion monitoring of nanoparticles in animal body. Furthermore, we applied the NIR fluorescent nanoparticles in in vivo microscopic bioimaging via a confocal microscope. Under the 635 nm-CW excitation, the blood vessel architecture in the ear and the brain of mice, which were administered with nanoparticles, was visualized very clearly. The imaging depth of our one-photon microscopy, which was assisted with NIR fluorescent nanoprobes, can reach as deep as 500 mu m. Our experiments show that NIR fluorescent nanoparticles have great potentials in various deep-tissue imaging applications.

  • 163.
    Chung, Sunjae
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF. Univ Gothenburg, Sweden.
    Eklund, Anders
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Iacocca, Ezio
    Mohseni, Seyed Majid
    Sani, Sohrab R.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Bookman, Lake
    Hoefer, Mark A.
    Dumas, Randy K.
    Åkerman, Johan
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics. Univ Gothenburg, Sweden.
    Magnetic droplet nucleation boundary in orthogonal spin-torque nano-oscillators2016In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 7, article id 11209Article in journal (Refereed)
    Abstract [en]

    Static and dynamic magnetic solitons play a critical role in applied nanomagnetism. Magnetic droplets, a type of non-topological dissipative soliton, can be nucleated and sustained in nanocontact spin-torque oscillators with perpendicular magnetic anisotropy free layers. Here, we perform a detailed experimental determination of the full droplet nucleation boundary in the current-field plane for a wide range of nanocontact sizes and demonstrate its excellent agreement with an analytical expression originating from a stability analysis. Our results reconcile recent contradicting reports of the field dependence of the droplet nucleation. Furthermore, our analytical model both highlights the relation between the fixed layer material and the droplet nucleation current magnitude, and provides an accurate method to experimentally determine the spin transfer torque asymmetry of each device.

  • 164.
    Chung, Sunjae
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF. University of Gothenburg, Sweden.
    Majid Mohseni, S.
    Eklund, Anders
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Dürrenfeld, P.
    Ranjbar, M.
    Redjai Sani, Sohrab
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Anh Nguyen, T. N.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics. Vietnam Academy of Science and Technology, Viet Nam.
    Dumas, R. K.
    Åkerman, Johan
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF. University of Gothenburg, Sweden.
    Magnetic droplet solitons in orthogonal spin valves2015In: Fizika Nizkih Temperatur, ISSN 0132-6414, E-ISSN 1816-0328, Vol. 41, no 10, p. 1063-1068Article in journal (Refereed)
    Abstract [en]

    We review the recent experimental advancements in the realization and understanding of magnetic droplet solitons generated by spin transfer torque in orthogonal nanocontact based spin torque nanooscillators (STNOs) fabricated on extended spin valves and spin valve nanowires. The magnetic droplets are detected and studied using the STNO microwave signal and its resistance, the latter both quasistatically and time-resolved. The droplet nucleation current is found to have a minimum at intermediate magnetic field strengths and the nature of the nucleation changes gradually from a single sharp step well above this field, mode-hopping around the minimum, and continuous at low fields. The mode-hopping and continuous transitions are ascribed to droplet drift instability and re-nucleation at different time scales, which is corroborated by time-resolved measurements. We argue that the use of tilted anisotropy fixed layers could reduce the nucleation current further, move the nucleation current minimum to lower fields, and potentially remove the need for an applied magnetic field altogether. Finally, evidence of an edge mode droplet in a nanowire is presented.

  • 165.
    Chung, Sunjae
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF. University of Gothenburg, Sweden.
    Mohseni, S. M.
    Eklund, Anders
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Dürrenfeld, P.
    Ranjbar, M.
    Sani, Redjai Sohrab
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Anh Nguyen, T. N.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics. Vietnam Academy of Science and Technology, Viet Nam.
    Dumas, R. K.
    Åkerman, Johan
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics. University of Gothenburg, Sweden.
    Magnetic droplet solitons in orthogonal spin valves2015In: Low temperature physics (Woodbury, N.Y., Print), ISSN 1063-777X, E-ISSN 1090-6517, Vol. 41, no 10, p. 833-837Article in journal (Refereed)
    Abstract [en]

    We review the recent experimental advancements in the realization and understanding of magnetic droplet solitons generated by spin transfer torque in orthogonal nanocontact based spin torque nanooscillators (STNOs) fabricated on extended spin valves and spin valve nanowires. The magnetic droplets are detected and studied using the STNO microwave signal and its resistance, the latter both quasistatically and time-resolved. The droplet nucleation current is found to have a minimum at intermediate magnetic field strengths and the nature of the nucleation changes gradually from a single sharp step well above this field, mode-hopping around the minimum, and continuous at low fields. The mode-hopping and continuous transitions are ascribed to droplet drift instability and re-nucleation at different time scales, which is corroborated by time-resolved measurements. We argue that the use of tilted anisotropy fixed layers could reduce the nucleation current further, move the nucleation current minimum to lower fields, and potentially remove the need for an applied magnetic field altogether. Finally, evidence of an edge mode droplet in a nanowire is presented.

  • 166. Claesson, A.
    et al.
    Fredman, D.
    Svensson, L.
    Ringh, M.
    Hollenberg, J.
    Nordberg, P.
    Rosenqvist, M.
    Djarv, T.
    Österberg, S.
    Lennartsson, J.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Ban, Yifang
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Unmanned aerial vehicles (drones) in out-of-hospital-cardiac-arrest2016In: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, ISSN 1757-7241, E-ISSN 1757-7241, Vol. 24, no 1, article id 124Article in journal (Refereed)
    Abstract [en]

    Background: The use of an automated external defibrillator (AED) prior to EMS arrival can increase 30-day survival in out-of-hospital cardiac arrest (OHCA) significantly. Drones or unmanned aerial vehicles (UAV) can fly with high velocity and potentially transport devices such as AEDs to the site of OHCAs. The aim of this explorative study was to investigate the feasibility of a drone system in decreasing response time and delivering an AED. Methods: Data of Global Positioning System (GPS) coordinates from historical OHCA in Stockholm County was used in a model using a Geographic Information System (GIS) to find suitable placements and visualize response times for the use of an AED equipped drone. Two different geographical models, urban and rural, were calculated using a multi-criteria evaluation (MCE) model. Test-flights with an AED were performed on these locations in rural areas. Results: In total, based on 3,165 retrospective OHCAs in Stockholm County between 2006-2013, twenty locations were identified for the potential placement of a drone. In a GIS-simulated model of urban OHCA, the drone arrived before EMS in 32 % of cases, and the mean amount of time saved was 1.5 min. In rural OHCA the drone arrived before EMS in 93 % of cases with a mean amount of time saved of 19 min. In these rural locations during (n = 13) test flights, latch-release of the AED from low altitude (3-4 m) or landing the drone on flat ground were the safest ways to deliver an AED to the bystander and were superior to parachute release. Discussion: The difference in response time for EMS between urban and rural areas is substantial, as is the possible amount of time saved using this UAV-system. However, yet another technical device needs to fit into the chain of survival. We know nothing of how productive or even counterproductive this system might be in clinical reality. Conclusions: To use drones in rural areas to deliver an AED in OHCA may be safe and feasible. Suitable placement of drone systems can be designed by using GIS models. The use of an AED equipped drone may have the potential to reduce time to defibrillation in OHCA.

  • 167.
    Claesson, P. M.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry (closed 20081231).
    Dedinaite, A.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry (closed 20081231).
    Mészáros, R.
    Varga, I.
    Association between Polyelectrolytes and Oppositely Charged Surfactants in Bulk and at Solid/Liquid Interfaces2010In: Colloids and Interface Science Series, Wiley-Blackwell, 2010, Vol. 3, p. 337-395Chapter in book (Other academic)
    Abstract [en]

    Mixtures of polyelectrolytes and oppositely charged surfactants find applications in many processes and products that are used in our daily life. Such systems also show many interesting features from a scientific point of view. Due to the combined technological relevance and scientific challenge, considerable research efforts have been made in this area in recent years. This has resulted in new theoretical approaches, the development of simulation methods and new experimental techniques and, of course, a large body of new findings. Together, these efforts have increased the understanding significantly, especially during the last 5 years. This chapter reviews some aspects of this topic, focusing on bulk association and association at solid/liquid interfaces. The review is focused on developments during the 21st century, even though in some cases a historical perspective is also offered.

  • 168. Clark, C J
    et al.
    Larsson, Stefan
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Li, L.
    KTH.
    Yassine, M.
    et al.,
    PSR J1906+0722: AN ELUSIVE GAMMA-RAY PULSAR2015In: Astrophysical Journal Letters, ISSN 2041-8205, E-ISSN 2041-8213, Vol. 809, no 1, article id L2Article in journal (Refereed)
    Abstract [en]

    We report the discovery of PSR J1906+0722, a gamma-ray pulsar detected as part of a blind survey of unidentified Fermi Large Area Telescope (LAT) sources being carried out on the volunteer distributed computing system, Einstein@Home. This newly discovered pulsar previously appeared as the most significant remaining unidentified gamma-ray source without a known association in the second Fermi-LAT source catalog (2FGL) and was among the top 10 most significant unassociated sources in the recent third catalog (3FGL). PSR J1906+0722 is a young, energetic, isolated pulsar, with a spin frequency of 8.9 Hz, a characteristic age of 49 kyr, and spin-down power 1.0 x 10(36) erg s(-1). In 2009 August it suffered one of the largest glitches detected from a gamma-ray pulsar (Delta f/f approximate to 4.5 x 10(-6)). Remaining undetected in dedicated radio follow-up observations, the pulsar is likely radio-quiet. An off-pulse analysis of the gamma-ray flux from the location of PSR J1906+0722 revealed the presence of an additional nearby source, which may be emission from the interaction between a neighboring supernova remnant and a molecular cloud. We discuss possible effects which may have hindered the detection of PSR J1906+0722 in previous searches and describe the methods by which these effects were mitigated in this survey. We also demonstrate the use of advanced timing methods for estimating the positional, spin and glitch parameters of difficult-to-time pulsars such as this.

  • 169.
    Cornelius, Hugo
    et al.
    KTH, Superseded Departments, Numerical Analysis and Computer Science, NADA.
    Sara, Radim
    Martinec, Daniel
    KTH, Superseded Departments, Numerical Analysis and Computer Science, NADA.
    Pajdla, Tomas
    KTH, Superseded Departments, Numerical Analysis and Computer Science, NADA.
    Chum, Ondrej
    KTH, Superseded Departments, Numerical Analysis and Computer Science, NADA.
    Matas, Jiri
    KTH, Superseded Departments, Numerical Analysis and Computer Science, NADA.
    Towards complete free-form reconstruction of complex 3D scenes from an unordered set of uncalibrated images2004In: STATISTICAL METHODS IN VIDEO PROCESSING / [ed] Comaniciu, D; Kanatani, K; Mester, R; Suter, D, BERLIN: SPRINGER , 2004, Vol. 3247, p. 1-12Conference paper (Refereed)
    Abstract [en]

    This paper describes a method for accurate dense reconstruction of a complex scene from a small set of high-resolution unorganized still images taken by a hand-held digital camera. A fully automatic data processing pipeline is proposed. Highly discriminative features are first detected in all images. Correspondences are then found in all image pairs by wide-baseline stereo matching and used in a scene structure and camera reconstruction step that can cope with occlusion and outliers. Image pairs suitable for dense matching are automatically selected, rectified and used in dense binocular matching. The dense point cloud obtained as the union of all pairwise reconstructions is fused by local approximation using oriented geometric primitives. For texturing, every primitive is mapped on the image with the best resolution. The global structure reconstruction in the first step allows us to work with an unorganized set of images and to avoid error accumulation. By using object-centered geometric primitives we are able to preserve the flexibility of the method to describe complex free-form structures, preserve the possibility to build the dense model in an incremental way, and to retain the possibility to refine the cameras and the dense model by bundle adjustment. Results are demonstrated on partial models of a circular church and a Henri de Miller's sculpture. We observed spatial resolution in the range of centimeters on objects of about 20 m in size.

  • 170. Corrigan, S.
    et al.
    Zon, G. D. R.
    Maij, A.
    McDonald, Nick J.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics.
    Mårtensson, Lena K.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    An approach to collaborative learning and the serious game development2015In: Cognition, Technology & Work, ISSN 1435-5558, E-ISSN 1435-5566, Vol. 17, no 2, p. 269-278Article in journal (Refereed)
    Abstract [en]

    This paper presents the overall learning process that evolved during the MASCA project (MAnaging System Change in Aviation—EU FP7 funded project (2010–2013), specifically focusing on the one of the key elements of the overall learning approach, the development of a serious game (SKYBOARD) and the role the game played in supporting the implementation of airport collaborative decision-making (A-CDM) in a major European airport. The underlying principles of the learning process was based on ongoing and collaborative learning in the workplace, with each phase of learning involving preparation and guidance, collaborative learning, consolidation of that learning and practically focused next steps that can be deployed to support overall change management. The aim of SKYBOARD was to aid communication and collaboration when introducing A-CDM, and thereby supporting the cultural change that comes with this introduction. The development of SKYBOARD was based upon an initial training needs analysis and an iterative development and implementation approach at a major European airport. The research demonstrated that we are at the beginning of a fundamental shift in the way both learning and working is happening in organisations. Therefore, the establishment of a collaborative learning process and integrated learning package needs to focus on supporting continuous performance improvement and learning (competency and capability at all levels) and to ensure this overall learning is fully aligned to the overall strategic blueprint of the organisation. The evaluation of SKYBOARD demonstrated that serious games can support collaborative learning and enhanced communication and that such games should be key resource in any learning environment and proved to be a highly effective support to the implementation of A-CDM in this case.

  • 171. Cui, Y. X.
    et al.
    Hu, Jun
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    He, Sailing
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Nanocavity antenna array for enhancing extraordinary optical transmission of light through a metallic nanoslit2009In: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 26, no 11, p. 2131-2135Article in journal (Refereed)
    Abstract [en]

    The transmission of light through a single nanoslit milled in the metallic film is enhanced by using an array of nanocavity antennas. It is shown that transmission efficiency through a 25-nm-wide silver nanoslit can be enhanced to eta = 151 when six pairs of nanostrips are placed 50 nm away from the input surface of the silver film at wavelength lambda(0) = 1 mu m. The influences of both the nanoslit position and the slit-to-strip distance on the extraordinary transmission are investigated, and the physical mechanism is explained.

  • 172.
    Cui, Yanxia
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP.
    Fung, Kin Hung
    Xu, Jun
    Ma, Hyungjin
    Jin, Yi
    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.
    Fang, Nicholas X.
    Ultrabroadband Light Absorption by a Sawtooth Anisotropic Metamaterial Slab2012In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 12, no 3, p. 1443-1447Article in journal (Refereed)
    Abstract [en]

    We present an ultrabroadband thin-film infrared absorber made of sawtoothed anisotropic metamaterial. Absorptivity of higher than 95% at normal incidence is supported in a wide range of frequencies, where the full absorption width at half-maximum is about 86%. Such property is retained well at a very wide range of incident angles too. Light of shorter wavelengths are harvested at upper parts of the sawteeth of smaller widths, while light of longer wavelengths are trapped at lower parts of larger tooth widths. This phenomenon is explained by the slowlight modes in anisotropic metamaterial waveguide. Our study can be applied in the field of designing photovoltaic devices and thermal emitters.

  • 173.
    Cui, Yanxia
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Zhejiang-KTH Joint Research Center of Photonics, JORCEP. KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Xu, Jun
    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.
    Fang, Nicholas X.
    Plasmon-Assisted Optical Curtains2010In: PLASMONICS, ISSN 1557-1955, Vol. 5, no 4, p. 369-374Article in journal (Refereed)
    Abstract [en]

    We predict an optical curtain effect, i.e., formation of a spatially invariant light field as light emerges from a set of periodic metallic nano-objects. The underlying physical mechanism of generation of this unique optical curtain can be explained in both the spatial domain and the wave-vector domain. In particular, in each period, we use one metallic nanostrip to equate the amplitudes of lights impinging on the openings of two metallic nanoslits and also shift their phases by pi difference. We elaborate the influence on the output effect from some geometrical parameters like the periodicity, the slit height, and so on. By controlling the light illuminated on metallic subwavelength apertures, it is practical to generate optical curtains of arbitrary forms, which may open new routes of plasmonic nanolithography.

  • 174. Da Silva, A. F.
    et al.
    Dantas, N. S.
    Da Silva Jr., E. F.
    Pepe, I.
    Torres, M. O.
    Persson, Claus
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Lindgren, T.
    De Almeida, J. S.
    Ahuja, R.
    Electronic and optical properties of TiO22005Conference paper (Refereed)
    Abstract [en]

    The electronic and optical properties of the rutile titanium dioxide compound have been investigated experimentally by absorption measurements and theoretically by a full-potential linearized augmented plane wave (FPLAPW) method within the local density approximation (LDA). The thin films for the absorption measurements were prepared by DC magnetron sputtering. The theoretical results for the absorption compared qualitatively well with the experimental findings. The dielectric functions and band-structure have also been calculated, and the LDA band-gap energy is corrected by an on-site Coulomb potential.

  • 175. da Silva, Aderson Miranda
    et al.
    Mocellin, Alexandra
    Monti, Susanna
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Li, Cui
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Marinho, Ricardo R. T.
    Medina, Aline
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Carravetta, Vincenzo
    de Brito, Arnaldo Naves
    Surface-Altered Protonation Studied by Photoelectron Spectroscopy and Reactive Dynamics Simulations2015In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 6, no 5, p. 807-811Article in journal (Refereed)
    Abstract [en]

    The extent to which functional groups are protonated at aqueous interfaces as compared to bulk is deemed essential to several areas in chemistry and biology. The origin of such changes has been the source of intense debate. We use X-ray photoelectron spectroscopy and all-atom reactive molecular dynamics simulations as two independent methods to probe, at the molecular scale, both bulk and surface distributions of protonated species of cysteine in an aqueous solution. We show that the distribution of the cysteine species at the surface is quite different from that in the bulk. We argue that this finding, however, cannot be simply related to a change in the extent of proton sharing between the two conjugate acid/base pairs that may occur between these two regions. The present theoretical simulations identify species at the surface that are not present in the bulk.

  • 176.
    Dahlin, Jon-Erik
    et al.
    KTH, School of Electrical Engineering (EES), Centres, Alfvén Laboratory Centre for Space and Fusion Plasma Physics.
    Scheffel, Jan
    KTH, School of Electrical Engineering (EES), Centres, Alfvén Laboratory Centre for Space and Fusion Plasma Physics.
    Anderson, Jay
    KTH, School of Electrical Engineering (EES), Centres, Alfvén Laboratory Centre for Space and Fusion Plasma Physics.
    Numerical studies of active current profile control in the reversed-field pinch2007In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, E-ISSN 1361-6587, Vol. 49, no 2, p. 183-195Article in journal (Refereed)
    Abstract [en]

    Quenching of the reversed-field pinch (RFP) dynamo is observed in numerical simulations using current profile control. A novel algorithm employing active feedback of the dynamo field has been utilized. The quasi-steady state achieved represents an important improvement as compared with earlier numerical work and may indicate a direction for the design of future experiments. Both earlier and the novel schemes of feedback control result in quasi-single helicity states. The energy confinement time and poloidal beta are observed to be substantially increased, as compared with the conventional RFP, in both the cases. Different techniques for experimental implementation are discussed.

  • 177. Daly, Andrew
    et al.
    Hess, Stephane
    de Jong, Gerard
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Calculating errors for measures derived from choice modelling estimates2012In: Transportation Research Part B: Methodological, ISSN 0191-2615, E-ISSN 1879-2367, Vol. 46, no 2, p. 333-341Article in journal (Refereed)
    Abstract [en]

    The calibration of choice models produces a set of parameter estimates and an associated covariance matrix, usually based on maximum likelihood estimation. However, in many cases, the values of interest to analysts are in fact functions of these parameters rather than the parameters themselves. It is thus also crucial to have a measure of variance for these derived quantities and it is preferable that this can be guaranteed to have the maximum likelihood properties, such as minimum variance. While the calculation of standard errors using the Delta method has been described for a number of such measures in the literature, including the ratio of two parameters, these results are often seen to be approximate calculations and do not claim maximum likelihood properties. In this paper, we show that many measures commonly used in transport studies and elsewhere are themselves maximum likelihood estimates and that the standard errors are thus exact, a point we illustrate for a substantial number of commonly used functions. We also discuss less appropriate methods, notably highlighting the issues with using simulation for obtaining the variance of a function of estimates.

  • 178.
    Danielsson, Sverker
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Kisara, Koki
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Lindström, Mikael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Kinetic study of Hexenuronic and Methylglucuronic acid reactions in pulp and in dissolved xylan during kraft pulping of hardwood2006In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 45, no 7, p. 2174-2178Article in journal (Refereed)
    Abstract [en]

    During kraft pulping, the side group in the xylan backbone, 4-O-methyl-D-glucuronic acid, is partly converted to hexenuronic acid. Simultaneously, degradation reactions of these side groups take place. The rates of these reactions were studied during the kraft pulping of hardwood and were shown to be strongly affected by the location of the x Ian; dissolved xylan had markedly higher methylglucuronic acid and hexenuronic acid contents than pulp xylan did. The degree of substitution of methyl-lucuronic acid in dissolved xylan was found to be higher at reduced cooking temperatures; no such change was seen for pulp xylan. A kinetic model was developed that included the energies of activation for formation (129 U/mol) and degradation (143 U/mol) of hexenuronic acid and dearadation (141 kJ/mol) of methylglucuronic acid and bulk delignification (118 kJ/mol, in accordance with earlier studies). Decreased cooking temperatures thus increase the number of acidic charged groups in the pulp and in dissolved xylan.

  • 179.
    Darko-Ampem, Sakyibea
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Katsoufi, M.
    Giambiagi, Pablo
    Swedish Institute of Computer Science, Sweden.
    Secure negotiation in virtual organizations2006In: Proceedings - 2006 10th IEEE International Enterprise Distributed Object Computing Conference Workshops, 2006Conference paper (Refereed)
    Abstract [en]

    Virtual organizations are dynamic associations of business partners that join forces to achieve a common goal. Because partners live in very competitive environments and they do not fully trust each other, they establish contractual agreements to help reduce the risk of participating in the virtual organization. This naturally puts severe demands on the security of the process leading to the establishment of a contract, including negotiation of terms and conditions. The open context in which virtual organizations are created raises further security concerns. This papers discusses the security requirements over contract negotiation that arise in this context, examines current negotiation protocols and proposes enhancements to one of them.

  • 180. De Moor, K.
    et al.
    Andrén, B.
    Guo, Yi
    KTH. Acreo Swedish ICTAB, Sweden.
    Brunnström, K.
    Wang, Kun
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab). Acreo Swedish ICTAB, Sweden.
    Drott, A.
    Hermann, D.
    Influence of high ambient illuminance and display luminance on readability and subjective preference2015In: Proceedings of SPIE - The International Society for Optical Engineering, 2015Conference paper (Refereed)
    Abstract [en]

    Many devices, such as tablets, smartphones, notebooks, fixed and portable navigation systems are used on a (nearly) daily basis, both in in- and outdoor environments. It is often argued that contextual factors, such as the ambient illuminance in relation to characteristics of the display (e.g., surface treatment, screen reflectance, display luminance...) may have a strong influence on the use of such devices and corresponding user experiences. However, the current understanding of these influence factors is still rather limited. In this work, we therefore focus in particular on the impact of lighting and display luminance on readability, visual performance, subjective experience and preference. A controlled lab study (N=18) with a within-subjects design was performed to evaluate two car displays (one glossy and one matte display) in conditions that simulate bright outdoor lighting conditions. Four ambient luminance levels and three display luminance settings were combined into 7 experimental conditions. More concretely, we investigated for each display: (1) whether and how readability and visual performance varied with the different combinations of ambient luminance and display luminance and (2) whether and how they influenced the subjective experience (through self-reported valence, annoyance, visual fatigue) and preference. The results indicate a limited, yet negative influence of increased ambient luminance and reduced contrast on visual performance and readability for both displays. Similarly, we found that the self-reported valence decreases and annoyance and visual fatigue increase as the contrast ratio decreases and ambient luminance increases. Overall, the impact is clearer for the matte display than for the glossy display. © 2015 SPIE-IS&T.

  • 181.
    de Pablo, A. D.
    KTH.
    Preservation of Franco’s social housing estates in Madrid2015In: Urbanism and Dictatorship: A European Perspective, Birkhauser Boston , 2015, p. 135-147Chapter in book (Other academic)
  • 182.
    Dekki Shalaly, Nancy
    et al.
    KTH, School of Biotechnology (BIO), Protein Technology.
    Ria, Massimiliano
    Johansson, Ulrika
    KTH, School of Biotechnology (BIO), Protein Technology.
    Avall, Karin
    Berggren, Per-Olof
    Hedhammar, My
    KTH, School of Biotechnology (BIO), Protein Technology.
    Silk matrices promote formation of insulin-secreting islet-like clusters2016In: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 90, p. 50-61Article in journal (Refereed)
    Abstract [en]

    Ex vivo expansion of endocrine cells constitutes an interesting alternative to be able to match the unmet need of transplantable pancreatic islets. However, endocrine cells become fragile once removed from their extracellular matrix (ECM) and typically become senescent and loose insulin expression during conventional 2D culture. Herein we develop a protocol where 3D silk matrices functionalized with ECM derived motifs are used for generation of insulin-secreting islet-like clusters from mouse and human primary cells. The obtained clusters were shown to attain an islet-like spheroid shape and to maintain functional insulin release upon glucose stimulation in vitro. Furthermore, in vivo imaging of transplanted murine clusters showed engraftment with increasing vessel formation during time. There was no sign of cell death and the clusters maintained or increased in size throughout the period, thus suggesting a suitable cluster size for transplantation.

  • 183. Delion, D. S.
    et al.
    Litta, R. J.
    KTH.
    Wyss, Ramon
    KTH, School of Engineering Sciences (SCI), Physics, Nuclear Physics.
    Decay rules in proton emission2007In: Proton Emitting Nuclei and Related Topics, American Institute of Physics (AIP), 2007, p. 47-52Conference paper (Refereed)
    Abstract [en]

    We give a simple relation, connecting the logarithm of the half-life, corrected by the centrifugal barrier, with the Coulomb parameter in proton decay processes. The reduced experimental data lie on two straight lines as a result of a sudden change in the nuclear shape, marking two regions of deformation, divided by the charge number Z = 68. This feature provides a powerful tool to assign experimentally quantum numbers in proton emitters.

  • 184. Denker, B.
    et al.
    Galagan, B.
    Ivleva, L.
    Osiko, V.
    Sverchkov, S.
    Voronina, I.
    Hellström, Jonas E.
    KTH, Superseded Departments, Physics.
    Karlsson, Gunnar
    KTH, Superseded Departments, Physics.
    Laurell, Fredrik
    KTH, Superseded Departments, Physics.
    New crystalline material for 1.5 μm lasers: Yb,Er - Activated GdCa 4O(BO3)32004In: Advanced Solid-State Photonics: Proceedings volume, Optics Info Base, Optical Society of America, 2004, Vol. 94, p. 430-434Conference paper (Refereed)
    Abstract [en]

    A new crystalline medium for 1.5 μm Yb-Er lasers is proposed: GdCa 4O(BO3)3 (GdCOB). Its melting point allows crystal growth using platinum instead of iridium crucibles. Spectroscopic and laser tests of the new material are described. A maximum CW output power of 80 mW was achieved in a monolithic microchip cavity under laser diode pumping.

  • 185. Denker, B.
    et al.
    Galagan, B.
    Ivleva, L.
    Sverchkov, S.
    Hellström, Jonas
    KTH, School of Engineering Sciences (SCI), Physics.
    Laurell, Fredrik
    KTH, School of Engineering Sciences (SCI), Physics.
    Pasiskevicius, Valdas
    KTH, School of Engineering Sciences (SCI), Physics.
    Diode-pumped 1.54 μm Er-Yb:GdCOB lasers2005Conference paper (Refereed)
  • 186. Denker, B.
    et al.
    Sverchkov, S.
    Galagan, B.
    Ivleva, L.
    Hellström, Jonas E.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Karlsson, Gunnar
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Pasiskevicius, Valdas
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Laurell, Fredrik
    KTH, School of Engineering Sciences (SCI), Applied Physics, Laser Physics.
    Passive Q-switching-at 1.54-micrometer of a Er-Yb:GdCa4O(BO 3)3 laser with a Co :MgAl2O4 saturable absorber2005In: OSA Trends in Optics and Photonics Series, Volume 98, Optical Society of America, 2005, p. 364-366Conference paper (Refereed)
    Abstract [en]

    A train of Q-switched pulses is formed in a diode-pumped microchip laser consisting of an Er-Yb:GdCa4O(BC3)3 active and Co2+:MgAl2C4:Co passive element. The pulses' durations were in the range of 1.6-6 ns and maximum output power was 88.2 mW at 928 mW of absorbed power.

  • 187.
    DesAutels, Philip
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial marketing.
    Berthon, Pierre
    Caruana, Albert
    Pitt, Leyland F.
    The impact of country connectedness and cultural values on the equity of a country's workforce A cross-country investigation2015In: Cross Cultural Management, ISSN 1352-7606, E-ISSN 1758-6089, Vol. 22, no 1, p. 2-20Article in journal (Refereed)
    Abstract [en]

    Purpose - The purpose of this paper is to focus on the impact that country connectedness and cultural values have on the equity afforded to a country's workforce in today's global economy. Design/methodology/approach - Drawing upon a number of large international surveys of national-level metrics, e-readiness is identified as a proxy measure for country connectedness. Cultural variables are proxied by the World Values Survey's national-level scores on "survival/self-expression" and "traditional/secular-rational" values. Workforce equity is captured via three measures: per capita Gross National Income (GNI) based on purchasing power parity (PPP), a Gini-coefficient, and the prevalence of child labor. Stepwise regression analysis is employed to investigate expected relationships. Findings - Results suggest an interesting link between the constructs investigated. A negative and significant effect of e-readiness and a negative and significant effect of traditional/secular-rational values on workforce equity are reported. In addition, the impact of e-readiness appears to be absolutely larger while thee impact of survival/self-expression values on the workforce equity is not found to be significant. Research limitations/implications - The research is primarily exploratory in nature thereby providing a foundation but not an end product. Next, the data used in the research is aggregate-level data providing broad generalizations about each country. Does a country have a single culture? Is the connectivity of a country a valid measure of the regions within? The authors chose to use an analysis at a single point in time. A longitudinal study could provide more insight and thus help to highlight causality. The data utilized was repurposed from third-party sources. Finally, only 37 observations are used and a broader data set could help strengthen findings further. Social implications - The rapid march of country connectedness across the globe is eroding firms' ability to shade their actions through the distance afforded by global supply chains. A country's culture values has a significant impact on workforce equity but country connectedness has a stronger impact, thus companies operating in more traditional and less developed countries will face significant impacts as these countries get connected. Rather than a threat, companies may see country connectedness and workforce equity as an opportunity. Firms that treat their workers well will see vast new markets open for them as evermore of the world's population becomes economically active. Originality/value - Uses an innovative data capture methodology that allows the investigation of an interesting and unexplored research question.

  • 188.
    Desta, Adey F.
    et al.
    KTH, School of Biotechnology (BIO), Environmental Microbiology (closed September 2009).
    Dalhammer, Gunnel
    KTH, School of Biotechnology (BIO), Environmental Microbiology (closed September 2009).
    Kittuva, Gunatrana R.
    KTH, School of Biotechnology (BIO), Environmental Microbiology (closed September 2009).
    A modified culture-based study of bacterial community composition in a tannery wastewater treatment plant2010In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 62, no 11, p. 2543-2549Article in journal (Refereed)
    Abstract [en]

    Though culture-independent methods have been used in preference to traditional isolation techniques for characterization of microbial community of wastewater treatment plants, it is difficult to widely apply this approach in resource-poor countries. The present study aimed to develop a test to identify the culturable portion of bacterial community in a high-strength wastewater. Wastewater samples were collected from nitrification-denitrification and settling tanks of the treatment plant of Elmo Leather AB tannery located in Boras, Sweden. After cultivating on nutrient agar with the optimal dilution (10(-2)), phenotypic and biochemical identification of the bacteria were done with colony morphology, Gram reaction, growth on MacConkey, phenylethanol media, triple sugar Iron agar slants, catalase and oxidase tests. Biochemical grouping of the isolates was done based on their test results for MacConkey, phenylethanol media, triple sugar Iron agar and oxidase test reaction. From the biochemical groups, isolates were randomly selected for API test and 16SrRNA gene sequencing. The isolates from the denitrification, nitrification tank were identified to be Paracoccus denitrificans (67%), Azoarcus spp (3%) and Spingomonas wittichii (1%). From the settling tank, Paracoccus denitrificans (22%), Corynebacterium freneyi (20%) and Bacillus cereus (1%) were identified. The grouping based on biochemical test results as well as the identification based on sequencing has shown coherence except for discrepancies with the API test. The preliminary implications of the grouping based on culture-based characteristics and its potential application for resource-limited environmental microbial studies is discussed.

  • 189. Di Gregorio, S.
    et al.
    Umeton, R.
    Bicocchi, A.
    Evangelisti, A.
    Gonzalez, Meliza Contreras
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Highway traffic model based on cellular automata: Preliminary simulation results with congestion pricing considerations2008In: Eur. Model. Simul. Symp., EMSS, 2008, p. 665-674Conference paper (Refereed)
    Abstract [en]

    Cellular Automata are a reputable formal support for traffic modelling and simulation. STRATUNA is a Cellular Automata model for simulating the evolution of two/three lane highways. It encodes the wide specification of driver's response to the events in his sight range. Encouraging comparison between simulated events and their corresponding in the reality bring to the specification of a theoretical general model characterized by an increased expression power and a significantly deeper forecasting potential, whose application fields are numerous and varied. Fair results in flow forecasting lead to the implementation of an established cost system in which simulation directly provides cost forecasting in terms of congestion toll.

  • 190.
    Ding, Zong-Hai
    et al.
    KTH, Superseded Departments, Materials Science and Engineering.
    Huml, Pavel
    KTH, Superseded Departments, Materials Science and Engineering.
    Yang, W.
    KTH, Superseded Departments, Materials Science and Engineering.
    Evaluation of strain hardening parameters2004In: Journal of Iron and Steel Research International, ISSN 1006-706X, E-ISSN 2210-3988, Vol. 11, no 4, p. 38-46Article in journal (Refereed)
    Abstract [en]

    The plane-strain compression test for three kinds of materials was carried out in a temperature range between room temperature and 400 degreesC. The sigma-epsilon curves and strain-hardening rate at different temperatures were simulated and a reasonable fit to the experimental data was obtained. A modified model created by data inference and computer simulation was developed to describe the strain hardening at a large deformation, and the predicted strain hardening are in a good agreement with that observed in a large range of stress. The influences of different parameters on strain hardening behaviour under large deformation were analysed. The temperature increase within the test temperatures for stainless steel 18/8 Ti results in dropping of flow stress and strain-hardening rate. For favourable gamma-fibre texture to obtain high r, the cold rolling was applied at large reduction. In the experimental procedure, the X-ray diffraction test was carried out to compare the strain hardening and microstructure under large deformation for a bcc steel (low carbon steel SS-1142). The results indicate that the high strain-hardening rate possibly occurs when the primary slip plane 110 is parallel to the rolling plane and the strain-hardening rate decreases when lots of 110 plane rotate out from the orientation {110}//RP.

  • 191.
    Dong, Zhihua
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics. Chongqing University, China.
    Li, Wei
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Long, Mujun
    Gui, Lintao
    Chen, Dengfu
    Huang, Yunwei
    Vitos, Levente
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics. Uppsala University, Sweden.
    Effect of Temperature Reversion on Hot Ductility and Flow Stress-Strain Curves of C-Mn Continuously Cast Steels2015In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 46, no 4, p. 1885-1894Article in journal (Refereed)
    Abstract [en]

    The influence of temperature reversion in secondary cooling and its reversion rate on hot ductility and flow stress-strain curve of C-Mn steel has been investigated. Tensile specimens were cooled at various regimes. One cooling regime involved cooling at a constant rate of 100 degrees C min(-1) to the test temperature, while the others involved temperature reversion processes at three different reversion rates before deformation. After hot tensile test, the evolution of mechanical properties of steel was analyzed at various scales by means of microstructure observation, ab initio prediction, and thermodynamic calculation. Results indicated that the temperature reversion in secondary cooling led to hot ductility trough occurring at higher temperature with greater depth. With increasing temperature reversion rate, the low temperature end of ductility trough extended toward lower temperature, leading to wider hot ductility trough with slightly reducing depth. Microstructure examinations indicated that the intergranular fracture related to the thin film-like ferrite and (Fe, Mn)S particles did not changed with varying cooling regimes; however, the Widmanstatten ferrite surrounding austenite grains resulted from the temperature reversion process seriously deteriorated the ductility. In addition, after the temperature reversion in secondary cooling, the peak stress on the flow curve slightly declined and the peak of strain to peak stress occurred at higher temperature. With increasing temperature reversion rate, the strain to peak stress slightly increased, while the peak stress showed little variation. The evolution of plastic modulus and strain to peak stress of austenite with varying temperature was in line with the theoretical prediction on Fe.

  • 192. d'Ortoli, Thibault Angles
    et al.
    Sjöberg, Nils A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Vasiljeva, Polina
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Lindman, Jonas
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Widmalm, Göran
    Bergenstråhle-Wohlert, Malin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Wohlert, Jakob
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Temperature Dependence of Hydroxymethyl Group Rotamer Populations in Cellooligomers2015In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 119, no 30, p. 9559-9570Article in journal (Refereed)
    Abstract [en]

    Empirical force fields for computer simulations of carbohydrates are often implicitly assumed to be valid also at temperatures different from room temperature for which they were optimited: Herein, the temperature dependence of the hydroxymethyl group rotamer populations in short oligogaccharides is invegtigated using Molecular dynamics simulations and NMR spectroscopy. Two oligosaccharides, methyl beta-cellobioside and beta-cellotetraose were simulated using three different carbohydrate force fields (CHARMM C35, GLYCAM06, and GROMOS 56A(carbo)) in combination with different water models (SPC, SPC/E, and TIP3P) using replica exchange molecular dynamics simulations. For comparison, hydroxymethyl group rotamer populations were investigated for methyl beta-cellobioside and cellopentaose based- on measured NMR (3)J(H5,H6) coupling constants, in the latter case by using a chemical shift selective NMR-filter. Molecular dynamics simulations in combination with NMR spectroscopy show that the temperature dependence of the hydroxymethyl rotamer population in these short cellooligomers, in the range 263-344 K, generally becomes exaggerated in simulations when compared to experimental data, but also that it is dependent on simulation conditions, and most notably properties of the water model.

  • 193.
    Duan, Lele
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Xu, Yunhua
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Zhang, Pan
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Wang, Mei
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Visible Light-Driven Water Oxidation by a Molecular Ruthenium Catalyst in Homogeneous System2010In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 49, no 1, p. 209-215Article in journal (Refereed)
    Abstract [en]

    Discovery of an efficient catalyst bearing low overpotential toward water oxidation is a key step for light-driven water splitting into dioxygen and dihydrogen. A mononuclear ruthenium complex, Ru(II)L(pic)(2) (1) (H2L = 2,2'-bipyridine-6,6'-dicarboxylic acids pic = 4-picoline), was found capable of oxidizing water eletrochemically at a relatively low potential and promoting light-driven water oxidation using a three-component system composed of a photosensitizer, sacrificial electron acceptor, and complex 1. The detailed electrochemical properties of 1 were studied, and the onset potentials of the electrochemically catalytic curves in pH 7.0 and pH 1.0 solutions are 1.0 and 1.5 V, respectively. The low catalytic potential of 1 under neutral conditions allows the use of [Ru(bpy)(3)](2+) and even [Ru(dmbpy)(3)](2+) as a photosensitizer for photochemical water oxidation. Two different sacrificial electron acceptors, [Co(NH3)(5)Cl]Cl-2 and Na2S2O8, were used to generate the oxidized state of ruthenium tris(2,2'-bipyridyl) photosensitizers. In addition, a two-hour photolysis of I in a pH TO phosphate buffer did not lead to obvious degradation, indicating the good photostability of our catalyst. However, under conditions of light-driven water oxidation, the catalyst deactivates quickly. In both solution and the solid state under aerobic conditions, complex 1 gradually decomposed via oxidative degradation of its ligands, and two of the decomposed products, sp(3) C-H bond oxidized Ru complexes, were identified. The capability of oxidizing the sp(3) C-H bond implies the presence of a highly oxidizing Ru species, which might also cause the final degradation of the catalyst.

  • 194.
    Duo, Xinzhong
    et al.
    KTH, Superseded Departments, Electronic Systems Design.
    Torikka, Tommi
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Zheng, Li-Rong
    KTH, Superseded Departments, Electronic Systems Design.
    Ismail, Mohammed
    Tenhunen, Hannu
    KTH, Superseded Departments, Electronic Systems Design.
    On-chip versus off-chip passives in multi-band radio design2004In: ESSCIRC 2004: PROCEEDINGS OF THE 30TH EUROPEAN SOLID-STATE CIRCUITS CONFERENCE / [ed] Steyaert, M; Claeys, CL, NEW YORK: IEEE , 2004, p. 327-330Conference paper (Refereed)
    Abstract [en]

    This paper presents on-chip versus off-chip passives in multi-band radio design. The analysis is demonstrated through several multi-band low noise amplifiers designs in SiGe BiCMOS and GaAs PHEMT. Cost-performance trade-off analysis shows that when on-chip passives are moved off chip, performance of RF circuits is always improved. However, simple RF circuits do not show obvious cost-benefits, whereas complex RF circuits such as multi-band radio can have significant cost savings by using off-chip passives.

  • 195. Dussauge, I.
    et al.
    Gribbe, Johan
    Philosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, History of Science, Technology and Environment.
    Kaijser, Arne
    Philosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, History of Science, Technology and Environment.
    Lundin, Per
    Philosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, History of Science, Technology and Environment.
    Peralta, Julia
    Philosophy and History, KTH, School of Architecture and the Built Environment (ABE), Philosophy and History of Technology, History of Science, Technology and Environment.
    Sjöblom, G.
    Thodenius, B.
    Precursors of the IT Nation: Computer use and control in swedish society, 1955–19852011In: 3rd IFIP WG 9.7 Conference on History of Nordic Computing, HiNC 2010, Springer-Verlag New York, 2011, p. 425-432Conference paper (Refereed)
    Abstract [en]

    This paper is a presentation of a research project that aims at writing the history of computing in Sweden in the mainframe age from a user perspective. Rather than beginning with the history of hardware, this project takes as its point of departure the way in which actors in different sectors of society used computer technology in order to achieve a higher degree of control over crucial processes, whether through electronic data processing systems, process control or technical/scientific computation.

  • 196. Dutta, Amit Kumar
    et al.
    Hari, K. V. S.
    KTH. Indian Institute of Science, India.
    Hanzo, Lajos
    Minimum-Error-Probability CFO Estimation for Multiuser MIMO-OFDM Systems2015In: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 64, no 7, p. 2804-2818Article in journal (Refereed)
    Abstract [en]

    We consider carrier frequency offset (CFO) estimation in the context of multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) systems over noisy frequency-selective wireless channels with both single- and multiuser scenarios. We conceived a new approach for parameter estimation by discretizing the continuous-valued CFO parameter into a discrete set of bins and then invoked detection theory, analogous to the minimum-bit-error-ratio optimization framework for detecting the finite-alphabet received signal. Using this radical approach, we propose a novel CFO estimation method and study its performance using both analytical results and Monte Carlo simulations. We obtain expressions for the variance of the CFO estimation error and the resultant BER degradation with the single- user scenario. Our simulations demonstrate that the overall BER performance of a MIMO-OFDM system using the proposed method is substantially improved for all the modulation schemes considered, albeit this is achieved at increased complexity.

  • 197.
    Dzougoutov, Anna
    et al.
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    Moon, Kyoung-Sook
    Department of Mathematics, University of Maryland.
    von Schwerin, Erik
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    Szepessy, Anders
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA. KTH, School of Engineering Sciences (SCI), Mathematics (Dept.).
    Tempone, Raul
    ICES, The University of Texas at Austin.
    Adaptive Monte Carlo Algorithms for Stopped Diffusion2005In: Multiscale Methods in Science and Engineering, Berlin: Springer-Verlag , 2005, 44, p. 59-88Chapter in book (Other academic)
    Abstract [en]

    We present adaptive algorithms for weak approximation of stopped diffusion using the Monte Carlo Euler method. The goal is to compute an expected value of a given function g depending on the solution X of an Itô stochastic differential equation and on the first exit time τ from a given domain.

    The main steps in the extension to stopped diffusion processes are to use a conditional probability to estimate the first exit time error and introduce difference quotients to approximate the initial data of the dual solutions.

  • 198.
    Ekengård, Johan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Jönsson, Pär
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Process Metallurgy.
    Dioszegi, Attila
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Jönköping University.
    A STUDY OF OXYGEN ACTIVITIES BEFORE THE START OF SOLIDIFICATION OF CAST IRONS2016In: International Journal of metalcasting, ISSN 1939-5981, E-ISSN 2163-3193, Vol. 10, no 4Article in journal (Refereed)
    Abstract [en]

    Focus in this work was to study dissolved oxygen content and oxygen activities in different cast irons. Plant trials were performed at three occasions for lamellar, compacted and nodular iron melts. The results show that at temperatures close to the liquidus temperature the oxygen activities ranged from 0.03-0.1 ppm for LGI, around 0.02 ppm for CGI and 0.001ppm for SGI. In addition, it was found that as oxygen activities increase with time after an Mg treatment, the ability to form compacted graphite or nodular graphite in Mg-treated iron melts was lowered. Also, oxygen activity differences up to 0.07 ppm were found for different hypoeutectic iron compositions for lamellar graphite iron at the liquidus temperature. Overall, the observed differences in the dissolved oxygen levels are believed to influence how graphite particles are incorporated into the austenite matrix and how the graphite morphology will be in the cast product.

  • 199.
    Ekeroth, Ella
    et al.
    KTH, Superseded Departments, Chemistry.
    Jonsson, Mats.
    KTH, Superseded Departments, Chemistry.
    Eriksen, Trygve
    KTH, Superseded Departments, Chemistry.
    Ljungqvist, Kristina
    KTH, Superseded Departments, Chemistry.
    Kovacs, Sandor
    Puigdomenech, Ignasi
    Reduction of UO22+ by H-22004In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 334, no 1, p. 35-39Article in journal (Refereed)
    Abstract [en]

    The reactivity of H, towards UO22+ has been studied experimentally using a PEEK coated autoclave where the UO22+ concentration in aqueous solution containing 2 mM carbonate was measured as a function of time at p(H2) similar to 40 bar. The experiments were performed in the temperature interval 74-100 degreesC. In addition, the suggested catalytic activity of UO2 on the reduction of UO22+ by H-2 was investigated. The results clearly show that H-2 is capable of reducing UO22+ to UO2 without the presence of a catalyst. The reaction is of first order with respect to UO22+. The activation energy for the process is 130 +/- 24 U mol(-1) and the rate constant is k(298K) = 3.6 x 10(-9) l mol(-1) s(-1). The activation enthalpy and entropy for the process was determined to 126 kJ mol(-1) and 16.5 J mol(-1) K-1, respectively. Traces of oxygen were shown to inhibit the reduction process. Hence, the suggested catalytic activity of freshly precipitated U02 on the reduction of UO22+ by H-2 could not be confirmed.

  • 200.
    Ekström, Henrik
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Hanarp, Per
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Gustavsson, Marie
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Fridell, Erik
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lundblad, Anders
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    A Novel Approach for Measuring Catalytic Activity of Planar Model Catalysts in the Polymer Electrolyte Fuel Cell Environment2006In: Journal of the Electrochemical Society, ISSN 0013-4651, Vol. 153, no 4, p. A724-A730Article in journal (Refereed)
    Abstract [en]

    The electrochemical oxygen reduction reaction on nanostructured supported platinum electrodes is measured using a newly developed solid-state polymer electrolyte electrochemical cell. Measurements were made on three types of catalytic surfaces on glassy carbon supports: nanostructured model electrodes prepared by colloidal lithography, a thin thermally evaporated Pt film, and a pure glassy carbon surface. Measurements in nitrogen and oxygen at several different humidities were performed at 60 degrees C in a fuel-cell-like environment. Lowering humidity showed a higher Tafel slope at high potentials for oxygen reduction on the nanostructured catalyst. Good agreement between the electrochemical active area from the hydrogen adsorption peaks and the catalytic area determined from scanning electron microscopy images was found. No significant change of the electrochemically active area with humidity could be found. Double-layer capacitance and oxygen reduction currents increased with increased humidification temperatures.

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