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  • 901.
    Zhu, Bin
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Liu, Qinghua
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Qin, Haiying
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Zhu, Zhigang
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Fan, Liangdong
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Singh, Manish
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Lund, Peter
    A new energy conversion technology joining electrochemical and physical principles2012In: RSC Advances, ISSN 2046-2069, Vol. 2, no 12, p. 5066-5070Article in journal (Refereed)
    Abstract [en]

    We report a new energy conversion technology joining electrochemical and physical principles. This technology can realize the fuel cell function but built on a different scientific principle. The device consists of a single component which is a homogenous mixture of ceria composite with semiconducting materials, e.g. LiNiCuZn-based oxides. The test devices with hydrogen and air operation delivered a power density of 760mWcm(-2) at 550 degrees C. The device has demonstrated a multi-fuel flexibility and direct alcohol and biogas operations have delivered 300-500 mW cm(-2) at the same temperature. Device physics reveal a key principle similar to solar cells realizing the function based on an effective separation of electronic and ionic conductions and phases within the single-component. The component material multi-functionalities: ion and semi-conductions and bi-catalysis to H-2 or alcohol (methanol and ethanol) and air (O-2) enable this device realized as a fuel cell.

  • 902.
    Zhu, Kun
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Yuan, Xu
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Honeth, Nicholas
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Data Volume Estimation for CIM based Information Exchange2011Conference paper (Refereed)
    Abstract [en]

    IEC 61970 and 61968, which are commonly referred as Common Information Model (CIM), are proposed to facilitate integration of EMS applications and information exchange between EMS systems with propitiatory data structures. To use communication network in an optimized manner, it is necessary to partition the potentially voluminous data into subsets given their sources, expected exchange frequency, and subscribing applications. In response to these requirements, the concept of CIM profiles is brought up by CIMug. In this paper, functions illustrating the dependency between exchange data volume and basic grid parameters for each data profile are presented. A CIM/XML/RDF file for a generally available 40 bus test system (CIM 13) and examples provided by standards are used as references. The method is validated by estimating the data sizes of similarly available 100bus and 60bus test systems that are modeled according to CIM 13 as well. The contribution of this paper is that it provides ICT system designers with a means to estimate the corresponding requirements for various CIM/XML based data exchange patterns. The estimations are performed based on commonly known grid parameters such as number of buses, branches, generators, transformers and loads together with execution frequency of particular grid planning and operation applications.

  • 903.
    Zhu, Weizhen
    et al.
    Chalmers, Sweden.
    Westman, Gunnar
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. Chalmers, Sweden.
    Theliander, Hans
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. Chalmers, Sweden.
    Lignin separation from kraft black liquor by combined ultrafiltration and precipitation: a study of solubility of lignin with different molecular properties2016In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 31, no 2, p. 270-278Article in journal (Refereed)
    Abstract [en]

    Lignin from wood is by far the largest source of bio-based aromatic raw material. Today a vast amount of lignin is processes and incinerated in kraft pulp mills around the world. One possible option to utilize the energy surplus in a modern kraft pulp mill is to extract lignin from black liquor. Precipitation of lignin is one important step in an extraction process. This study investigates how the molecular size and functional groups of lignin influenced the precipitation yield. Cross-flow filtration was applied to fractionate lignin with different molecular weights from a black liquor, precipitation studies was made on the different fractions. The precipitated lignin was characterized by GPC, HPAEC-PAD and NMR analysis. The results show that it was possible to obtain a more homogenous lignin by fractionation using cross-flow filtration. It was found that the molecular properties of kraft lignin, i.e. molecular weight and functional groups, influenced the yield of lignin precipitation: at the same precipitation condition, lignin fraction with higher molecular weight has higher precipitation yield. Lignin fraction with lower molecular weight contains less amount of carbohydrates and methoxyl groups but higher amount of phenolic groups.

  • 904.
    Zou, Dapeng
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Andersson, Samir
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Zhang, Rong
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Sun, Shiguo
    Åkermark, Björn
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Selective binding of cucurbit 7 uril and beta-cyclodextrin with a redox-active molecular triad Ru(bpy)(3)-MV2+-naphthol2007In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, no 45, p. 4734-4736Article in journal (Refereed)
    Abstract [en]

    A 1:1:1 inclusion complex is formed by the binding interactions among beta-CD, CB[ 7] hosts, and Ru(bpy)(3)-terminated viologen naphthalene guest in aqueous solution, in which the positions of both CB[7] and beta-CD are closer to the Ru stopper than in the respective 1:1 inclusion complexes, forming a tightened nut on bolt'' structural mode.

  • 905.
    Zou, Dapeng
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Andersson, Samir
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Zhang, Rong
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Sun, Shiguo
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Åkerrnark, Björn
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    A host-induced intramolecular charge-transfer complex and light-driven radical cation formation of a molecular triad with cucurbit 8 uril2008In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 73, no 10, p. 3775-3783Article in journal (Refereed)
    Abstract [en]

    The host-guest chemistry of systems containing a molecular triad Ru(bpy)(3)-MV2+-naphthol complex (denoted as Ru2+-MV2+-Np, 1) and cucurbit[8]uril (CB[8]) is investigated by NMR, EST-MS, UV-vis, and electrochemistry. The Ru2+-MV2+-Np guest and CB [8] host can form a stable 1:1 inclusion complex, in which the naphthalene residue is back-folded and inserted together with the viologen residue into the cavity of CB[8]. The selective binding of Ru2+-MV2+-Np guest with beta-CD and CB[8] host is also investigated. We find that CB[8] binds the Ru2+-MV2+-Np guest stronger than beta-CD. Upon light irradiation, a MV+center dot radical cation stabilized in the cavity of CB[8] accompanied by the naphthalene residue has been observed. This novel system may open a new way for design and synthesis of photoactive molecular devices.

  • 906. Zou, Yidong
    et al.
    Wang, Xiangxue
    Ai, Yuejie
    Liu, Yunhai
    Ji, Yongfei
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Wang, Hongqing
    Hayat, Tasawar
    Alsaedi, Ahmed
    Hu, Wenping
    Wang, Xiangke
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    beta-Cyclodextrin modified graphitic carbon nitride for the removal of pollutants from aqueous solution: experimental and theoretical calculation study2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 37, p. 14170-14179Article in journal (Refereed)
    Abstract [en]

    A novel beta-cyclodextrin modified, multifunctional, layer-by-layer graphitic carbon nitride (g-C3N4/beta-CD) was successfully synthesized and applied as an effective adsorbent for the removal of methyl orange (MO) and Pb(II) from aqueous solutions under various environmental conditions (e.g., solution pH, solid content, contact time and temperature). The kinetic results indicated that the adsorption was dominated by chemisorption, and the higher adsorption capacity of g-C3N4/beta-CD was attributed to it having more oxygen-containing functional groups than g-C3N4. The Langmuir, Freundlich and Sips models were applied to simulate the adsorption isotherms of MO and Pb(II), and the results demonstrated that the adsorption of MO was attributed to multilayer adsorption, while the coverage adsorption of Pb(II) on the g-C3N4/beta-CD was monolayer adsorption. The thermodynamic parameters showed that the adsorption of both MO and Pb(II) was spontaneous and endothermic. The DFT calculations further evidenced the surface complexation and electrostatic interaction of Pb(II) on the g-C3N4 and g-C3N4/beta-CD, whereas, the interaction of MO with g-C3N4 and g-C3N4/beta-CD was mainly attributed to hydrogen bonds and strong pi-pi interactions. The results demonstrated that g-C3N4/beta-CD is a promising material for the efficient removal of organic and inorganic pollutants in environmental pollution remediation.

  • 907.
    Ågren, Jonas
    KTH, Superseded Departments, Alfvén Laboratory.
    The analytical continuation bias in geoid determination using potential coefficients and terrestrial gravity data2004In: Journal of Geodesy, ISSN 0949-7714, E-ISSN 1432-1394, Vol. 78, no 4-5, p. 314-332Article in journal (Refereed)
    Abstract [en]

    One important application of an Earth Gravity Model (EGM) is to determine the geoid. Since an EGM is represented by an external-type series of spherical harmonics, a biased geoid model is obtained when the EGM is applied inside the masses in continental regions. In order to convert the downward-continued height anomaly to the corresponding geoid undulation, a correction has to be applied for the analytical continuation bias of the geoid height. This technique is here called the geoid bias method. A correction for the geoid bias can also be utilised when an EGM is combined with terrestrial gravity data, using the combined approach to topographic corrections. The geoid bias can be computed either by a strict integral formula, or by means of one or more terms in a binomial expansion. The accuracy of the lowest binomial terms is studied numerically. It is concluded that the first term (of power H-2) can be used with high accuracy up to degree 360 everywhere on Earth. If very high mountains are disregarded, then the use of the H-2 term can be extended up to maximum degrees as high as 1800. It is also shown that the geoid bias method is practically equal to the technique applied by Rapp, which utilises the quasigeoid-to-geoid separation. Another objective is to carefully consider how the combined approach to topographic corrections should be interpreted. This includes investigations of how the above-mentioned H-2 term should be Computed. as well as how it can be improved by a correction for the residual geoid bias. It is concluded that the computation of the combined topographic effect is efficient in the case that the residual geoid bias can be neglected, since the computation of the latter is very time consuming. It is nevertheless important to be able to Compute the residual bias for individual stations. For reasonable maximum degrees, this can be used to check the quality of the H-2 approximation in different situations.

  • 908.
    Ågren, Jonas
    et al.
    KTH, Superseded Departments, Infrastructure.
    Sjöberg, Lars Erik
    KTH, Superseded Departments, Infrastructure.
    Comparison of some methods for modifying stokes' formula in the GOCE ERA2004Conference paper (Refereed)
    Abstract [en]

    The dedicated satellite gravity mission GOCE will drastically improve our knowledge of the long to medium wavelengths of the Earth's gravity field. In order to determine the finest details in regional geoid determination, however, we still have to utilise gravity data. It is the purpose of this paper to study three modifications of Stokes' formula numerically, using error propagations with simulated standard errors for the GOCE potential coefficients. The methods tested are the standard remove-compute-restore, the least squares, and the low-degree GOCE-only modifications. In the latter technique it is required that only GOCE information must influence the determination of the lowest degrees. It is concluded that of the modifications tested, the least squares method is most suitable to be used with a GOCE satellite-only model. This is the case also when pessimistic weights are used for the gravity anomalies. The main fault with the standard remove-compute-restore method is its sensitivity to long-wavelength errors in the gravity anomalies, while a very large truncation error is the most serious problem for the low-degree GOCE-only technique.

  • 909. Åkeson, M.
    et al.
    Nordberg, Markus
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Ehlerding, Anneli
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Nilsson, L. -E
    Östmark, H.
    Strömbeck, P.
    Picosecond laser pulses improves sensitivity in standoff explosive detection2011In: Proc SPIE Int Soc Opt Eng, 2011Conference paper (Refereed)
    Abstract [en]

    Portendo has in collaboration with FOI, the Swedish Defence Research Agency, developed a world-leading technique of trace detection of explosives at standoff distance using Raman spectroscopy. The technology is further developed in order to enhance the sensitivity of the method and to be able to extend the field of applications. Raman scattering is a well-established technique able to detect substances down to single micrograms at standoff distances, however, one of the obstacles limiting the detection possibilities is interfering fluorescence, originating either from the substance itself or from the surrounding material. One main challenge for this technology is thus to either omit the excitation of the fluorescent process altogether or to be able to separate the two processes and only detect the Raman signal. Due to the difference in the temporal behavior of the two processes - Raman scattering occurs in the order of femtoseconds while fluorescence typically has a lifetime in the order of nanoseconds - one way to theoretically separate them is to limit the measurement to as short time as possible, cutting off most of the emitted fluorescence. The improvement depends on how much of the fluorescence can be omitted without decreasing the Raman signal. Experimentally, we have verified this improvement in signal to noise ratio when using a laser with picosecond pulses instead of nanosecond pulses, which has resulted in an improvement in SNR of up to 7 times for bulk ANFO. These results verify the predicted signal enhancement and suggest higher sensitivity for standoff detection in future systems.

  • 910. Åsbogård, M.
    et al.
    Johannesson, L.
    Angervall, D.
    Johansson, Peter
    KTH.
    Improving system design of a hybrid powertrain using stochastic drive cycles and dynamic programming2007In: SAE technical paper series, ISSN 0148-7191Article in journal (Refereed)
    Abstract [en]

    A new approach for system design of hybrid powertrains was demonstrated in a case study. The method is based on the following presumptions: The performance of a Hybrid Powertrain Concept (HPC) is evaluated using computer simulation; a HPC cannot be correctly evaluated without an Energy Management Strategy (EMS) for the energy buffer; the optimal EMS is different for each HPC. Dynamic programming was used to generate EMSs that were optimal for the vehicles intended traffic environment and for each given HPC, enabling evaluation of a large number of HPCs. Over-adaptation of the EMSs was avoided by using a stochastic drive cycle model. The final delivery is a competitive powertrain component sizing and the corresponding optimal EMS.

  • 911.
    Åström, Joachim
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Granberg, Mikael
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Khakee, Abdul
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Apple Pie-Spinach Metaphor: Shall e-Democracy make Participatory Planning More Wholesome?2011In: Planning Practice & Research, ISSN 0269-7459, Vol. 26, no 5, p. 571-586Article in journal (Refereed)
    Abstract [en]

    Despite claims that planners' attitude towards public participation has not always been enthusiastic, there have been genuine attempts to devolve powers through participation-although seldom with success. In this paper we discuss several major attempts to improve participation in Sweden including case studies of e-participation. Despite great expectations on information and communication technologies, Swedish experience indicates that the status quo between planners and people remains.

  • 912.
    Öman, Cecilia B.
    et al.
    KTH.
    Klutsé, A.
    Rabbani, G.
    Edward, Rumila
    KTH.
    Strategy for strengthening scientific capacity in developing countries on water and sanitation related issues2009In: Desalination, ISSN 0011-9164, E-ISSN 1873-4464, Vol. 248, no 1-3, p. 658-665Article in journal (Refereed)
    Abstract [en]

    It is generally accepted that scientific research offers a tool for meeting the development demands in the area of water and sanitation. It is stressed by the authors that research should be performed by researchers in the countries most affected, on topics identified by these researchers and in their own environment. For researchers in developing countries the resources and scientific infrastructure constitutes a hindrance to scientific research. To address the situation this paper presents a strategy for scientific capacity strengthening. The strategy builds on a number of activities including; training courses on scientific methodology, literature review, fundraising, sampling, laboratory practices, statistical methods, experimental designs, participatory approaches, oral presentation, posters and manuscript development, as well as thematic workshops, workshop for revision of proposals, contacts with end-users, research grants, networks, purchasing and maintaining scientific equipment and scientific conferences. The strategy builds heavily on collaboration with local organisations. It has been concluded through assessments of activities arranged in Bangladesh, Benin, Burkina Faso, Cameroon, Ivory Coast, Ghana, Mali, Niger, Nigeria, Nepal, Sri Lanka and Togo that the strategy has been successful.

  • 913.
    Österberg, Elena
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Revealing of age-related deterioration of prestressed reinforced concrete containments in nuclear power plants: Requirements and NDT methods2004Licentiate thesis, monograph (Other academic)
  • 914.
    Östling, Mikael
    et al.
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Ghandi, Reza
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Malm, Bengt Gunnar
    KTH, School of Information and Communication Technology (ICT).
    Buono, Benedetto
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Zetterling, Carl-Mikael
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Silicon carbide bipolar power devices2011In: ECS Transactions, 2011, no 8, p. 189-200Conference paper (Refereed)
    Abstract [en]

    This paper reviews the current state of the art in active switching device performance for SiC BJTs. In addition, some results from simulations are shown with particular attention on temperature and design dependence of the current gain. A design to improve conductivity modulation is also suggested. Finally, performance of a 2.8 kV BJT are illustrated. This device demonstrates high current gain of 52, low on-resistance of 6.8 mΩcm 2, fast switching, and no bipolar degradation.

  • 915.
    Östman, Leif E.
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    A pragmatist theory of design: The impact of the pragmatist philosophy of John Dewey on architecture and design2005Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    This study is an inquiry into design-theoretical aspects of architectural design in Finland based mainly on the pragmatist philosophy of John Dewey. The study comprises two case studies. The . rst case deals with a young family designing their future home – a detached house built from prefabricated components – in cooperation with an architect. The second case deals with the design process of a leading Finnish architect, Professor Ilmari Lahdelma, as he prepares his proposal for an architectural competition for a new city library in Lohja, a competition he eventually wins. The case describes and interprets Lahdelma’s design process, the processes of other competition entries made by the of. ce staff, as well as the process of the jury’s evaluation of the competition entries. The two cases are analysed and interwoven with aspects from three different theoretical perspectives: existing design theories, Pierre Bourdieu’s . eld theory and John Dewey’s thinking regarding art and research. In the study I argue that Dewey’s philosophy can provide a framework for a design-theoretical epistemology. I also arrive at conclusions regarding the interpretation of some key design-theoretical concepts and the position of design theory and its structures. I further argue that the Finnish architectural competition system is a strong tool for generating developments in the production of the architectural avant-garde, which acts as the leading light for the rest of the . eld of architecture. The present study also highlights the gap between ‘high-’ and ‘low culture’ in the . eld of architecture, yet points out that the design of a simple family house – assumedly a case of ‘low culture’ – is by no means trivial to the family itself, and is indeed . lled with moments of aesthetic experiences, which is a central issue in Dewey’s description of creative processes.

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