Ändra sökning
Avgränsa sökresultatet
12 51 - 84 av 84
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 51.
    Mittal, Nitesh
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Kaldéus, Tahani
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Effect of cellulose nanofibril morphology on the strength and stiffness of macroscopic filaments2017Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 253Artikel i tidskrift (Övrigt vetenskapligt)
  • 52.
    Mittal, Nitesh
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Hedhammar, My
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Flow-assisted organization of nanostructured bio-based materials2018Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Artikel i tidskrift (Övrigt vetenskapligt)
  • 53.
    Ohm, Wiebke
    et al.
    DESY, Hamburg, Germany..
    Rothkirch, Andre
    DESY, Hamburg, Germany..
    Pandit, Pallavi
    DESY, Hamburg, Germany..
    Koerstgens, Volker
    Tech Univ Munich, Garching, Germany..
    Mueller-Buschbaum, Peter
    Tech Univ Munich, Garching, Germany..
    Rojas, Ramiro
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Yu, Shun
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Brett, Calvin
    KTH, Skolan för teknikvetenskap (SCI), Mekanik, Strömningsfysik.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik, Strömningsfysik.
    Roth, Stephan V.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer. DESY, Hamburg, Germany..
    Morphological and crystalline properties of airbrush spray-deposited enzymatic cellulose thin films2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 54.
    Oliveira de Castro, Danielle
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Karim, Zoheb
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Medina, Lilian
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer.
    Svedberg, A.
    Wågberg, Lars
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Berglund, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Scale up of nanocellulose/hybrid inorganic films using a pilot web former2017Ingår i: International Conference on Nanotechnology for Renewable Materials 2017, TAPPI Press , 2017, s. 408-418Konferensbidrag (Refereegranskat)
  • 55.
    Rosén, Tomas
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. SUNY Stony Brook.
    Brouzet, Christophe
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Roth, Stephan V.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. DESY.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Three-Dimensional Orientation of Nanofibrils in Axially Symmetric Systems Using Small-Angle X-ray Scattering2018Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, nr 12, s. 6889-6899Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The increased availability and brilliance of new X-ray facilities have in the recent years opened up the possibility to characterize the alignment of dispersed anisotropic nanoparticles in various microfluidic applications, from hydrodynamic self-assemblies to flows in complex geometries. In such applications, it is vital to study the alignment of the nanoparticles in the flow, as this in turn affects the final properties of the self-assembled superstructures or those of the flow itself. Small-angle X-ray scattering (SAXS) is a well-suited characterization technique for this but typically provides the alignment in a projected plane perpendicular to the beam direction. In this work, we demonstrate a simple method to reconstruct the full three-dimensional orientation distribution function from a SAXS experiment through the assumption that the azimuthal angle of the nanoparticles around the flow direction is distributed uniformly, an assumption that is valid for a large range of nanoparticle flow processes. For demonstration purposes, the experimental results from previous works on hydrodynamic self-assembly of cellulose nanofibrils (CNFs) into filaments have been revised, resulting in a small correction to the presented order parameters. The results are then directly compared with simple numerical models to describe the increased alignment of CNFs both in the flowing system and during the drying of the filament. The proposed reconstruction method will allow for further improvements of theoretical or numerical simulations and consequently open up new possibilities for optimizing assembly processes, which include flow alignment of elongated nanoparticles.

  • 56.
    Rosén, Tomas
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Roth, Stephan V.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Evaluating alignment of elongated particles in cylindrical flows through small angle scattering experimentsManuskript (preprint) (Övrigt vetenskapligt)
  • 57.
    Rosén, Tomas
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Mittal, Nitesh
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Gowda V., Krishne
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Roth, Stephan V.
    Zhang, Peng
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Measuring rotary diffusion of dispersed cellulose nanofibrils using Polarized Optical MicroscopyManuskript (preprint) (Övrigt vetenskapligt)
  • 58.
    Rosén, Tomas
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Mittal, Nitesh
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Nordenström, Malin
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Håkansson, Karl M. O.
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Yu, Shun
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Roth, Stephan
    Zhang, Peng
    Iwamoto, Hiroyuki
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    On the applicability of time-resolved synchrotron X-ray techniques for studying rotary diffusion of dispersed cellulose nanofibrilsManuskript (preprint) (Övrigt vetenskapligt)
  • 59. Silva, R.
    et al.
    Garcia, F. A. P.
    Faia, P. M.
    Krochak, Paul
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Rasteiro, M. G.
    Validating dilute settling suspensions numerical data through MRI, UVP and EIT measurements2016Ingår i: Flow Measurement and Instrumentation, ISSN 0955-5986, E-ISSN 1873-6998, Vol. 50, s. 35-48Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The measurement of fluid dynamic quantities are of great interest both for extending the range of validity of current correlations to be used in equipment design and for verification of fundamental hydrodynamic models. Studies where comparisons are made between imaging techniques serve to provide confidence on the validity of each technique for the study of multiphase flow systems. The advantage of cross-validation is that it can help establish the limitations of each technique and the necessary steps towards improvement. A small amount of comparative studies are found in the literature and none of them reports the study of settling particles suspension flow using simultaneously Ultrasonic Velocity Profiling (UVP), Magnetic Resonance Imaging (MRI) and Electrical Impedance Tomography (EIT), at least not to the best of the authors knowledge. In the present paper the authors report efforts made on the characterization of dilute suspensions of glass particles in turbulent flow, with increasing flow velocities and particles concentrations, in a pilot rig at a laboratorial scale, using both MRI, EIT and UVP: direct comparisons of EIT, MRI and UVP measurements acquired and mixture model numerical simulations are presented and the level of agreement explored.

  • 60.
    Söderberg, Daniel
    KTH, Tidigare Institutioner                               , Mekanik.
    A comparison between the flow from a paper machine headbox and a low Reynolds number water jet1999Ingår i: Tappi Engineering Conference, Anaheim, 1999, 1999, s. 1155-1172Konferensbidrag (Övrigt vetenskapligt)
  • 61.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. STFI-Packforsk, Sweden.
    A new technique for stratified forming2008Ingår i: TAPPI Press - Paper Conference and Trade Show, PaperCon '08, 2008, s. 3529-3563Konferensbidrag (Refereegranskat)
    Abstract [en]

    A new technique for stratified forming has been developed where a thin passive liquid layer (a liquid vane or "Aq-vane") is injected in the between neighbouring pulp streams through a narrow hollow channel, thereby preventing mixing between the layers. The Aq-vanes have been implemented in extensive pilot scale trials where the technical solution has been tested and evaluated. In addition, the impact of this new technique and sheet stratification on product properties has been evaluated.

  • 62.
    Söderberg, Daniel
    KTH, Tidigare Institutioner                               , Mekanik.
    A visual study of the dynamics of a headbox jet2000Ingår i: Engineering Conference, 2000, TAPPI, Atlanta, GA., 2000Konferensbidrag (Övrigt vetenskapligt)
  • 63.
    Söderberg, Daniel
    KTH, Tidigare Institutioner                               , Mekanik.
    Absolute and convective instability of a relaxational plane liquid jet2003Ingår i: Journal of Fluid Mechanics, ISSN 0022-1120, E-ISSN 1469-7645, Vol. 493, s. 89-119Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The stability of a plane relaxational liquid jet has been studied theoretically and experimentally through linear stability analysis and flow visualizations. The relaxational liquid jet is obtained by the outflow of a liquid from a plane channel with an upstream fully developed Poiseuille flow into an ambient stagnant gas. Linear spatial stability calculations show that there are five convectively unstable modes, three sinuous and two dilatational. The spatial stability calculations are compared to experimental results for wavenumber variation and the growth of waves found in the visualizations. These variations have been quantified with a wavelet transform and through a comparison with the spatial stability results the type of mode observed in the visualizations has been determined. For this type of mode the calculated wavenumber variation is in good agreement with the experimental results. Also, in the experiments the breakup of the jet has been observed when the Reynolds number reaches a certain value, and as the Reynolds number increases this breakup moves closer to the channel exit. This upstream movement of the breakup can be explained by the linear stability results. Finally the relaxational liquid jet is shown to be absolutely unstable for a certain parameter region. Close to the nozzle both a sinuous mode and a dilatational mode are shown to be absolutely unstable. As the jet profile relaxes to uniform, the sinuous mode is shown to be the only unstable mode. This occurs for Weber numbers We < 1, which is in agreement with the theory for liquid jets with uniform velocity profile. The frequency selection for the observed waves is believed to be related to the region of absolute instability located closest to the channel exit.

  • 64.
    Söderberg, Daniel
    KTH, Tidigare Institutioner                               , Mekanik.
    Experimental and theoretical studies of plane liquid jets1997Licentiatavhandling, monografi (Övrigt vetenskapligt)
  • 65.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. Innventia AB.
    Fluid dynamic challenges of future nano cellulose fiber processes2011Ingår i: Pap. Conf. Trade Show, PaperCon, 2011, s. 323-346Konferensbidrag (Refereegranskat)
  • 66.
    Söderberg, Daniel
    KTH, Tidigare Institutioner                               , Mekanik.
    Hydrodynamics of plane liquid jets aimed at applications in paper manufacturing1999Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Process industries are in general depending, in one way or the other, on fluid mechanics.Specifically, paper manufacturing, which probably is the dominant processindustry in Sweden, is depending on the flow of cellulose fibres suspended in water.As a part of the process the suspension, consisting of fibres in water, is spread out onor between two moving permeable weaves, i.e. wires. The speed of this is usually 10–30 m/s and the suspension is spread out by a plane jet issuing from a headbox nozzle.It has been show that the conditions in the headbox and jet have a large influence onthe quality of the final paper sheet. Primarily, streaks in the paper sheet are believedto be the result of streamwise streaks in the headbox jet.The thesis is aimed at the flow phenomena which occur in the headbox jet. Theinvestigations have been made with numerical calculations, stability theory and modelexperiments using water, as well as experiments with a real paper machine headboxand fibre suspension. In the thesis an introduction to the hydrodynamics of planeliquid jets is presented together with a description of the paper forming process andthe fluid mechanics of headbox flow.The basic flow and stability of a two-dimensional plane liquid jet has been investigatedby numerical calculations, stability theory and experiments. The calculationsof the laminar basic flow is successfully compared to pitot-tube measurements of thestreamwise velocity profile. By visualisations of the flow it is found that wave disturbanceson the jet has a severe effect on the flow. These waves can be predicted bylinear stability theory, which shows the presence of five convectively unstable modes.These can be divided into three types and by comparison with the experiments thetype of the visible waves is determined. These waves seem to initiate a break-up ofthe jet, which leads to strong streamwise streaks inside the jet.By flow visualisation of headbox flow of an experimental paper machine, togetherwith analysis of the resulting paper structure using the wavelet method the correspondencebetween flow disturbances and paper quality was investigated. It was shownthat the wave instability, which is present on the low Reynolds number water jet, alsocan be found in the real the headbox jet. It is shown that these waves play an importantrole in the dynamics of the headbox jet and also have an influence on the final papersheet.

  • 67.
    Söderberg, Daniel
    et al.
    KTH, Tidigare Institutioner                               , Mekanik.
    Alfredsson, Henrik
    KTH, Tidigare Institutioner                               , Mekanik.
    Experimental and theoretical stability investigations of plane liquid jets1998Ingår i: European journal of mechanics. B, Fluids, ISSN 0997-7546, E-ISSN 1873-7390, Vol. 17, nr 5, s. 689-737Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The present investigation has been undertaken in order to better understand the development of free, plane liquid jets. Both the development of the basic laminar flow as well as its stability have been investigated theoretically and experimentally. The velocity field and free surface location of a liquid jet emanating from a plane channel was calculated numerically and the velocity and surface relaxation lengths were determined. Calculated velocity profile distributions were in good agreement with Pitot tube measurements. Temporal linear stability calculations were performed using the calculated velocity distributions. The calculations showed five unstable modes, three sinuous and two dilatational. Four of these modes have been reported earlier and one of the sinuous modes is considered to be 'new'. The linear stability calculations include surface tension as well as viscosity in the liquid and gas. Hot wire anemometry measurements of controlled forced disturbances showed that waves in the experimental jet also were sinuous and that the amplitude distribution was in fair agreement with theoretical results. Shadowgraph visualisations showed the evolution of the waves on the surface of the jet and it was found that the waves break up downstream the nozzle. This break-up was visualized by particle visualisations, which showed that it creates strong streamwise streaks in the jet.

  • 68.
    Söderberg, Daniel
    et al.
    KTH, Tidigare Institutioner                               , Mekanik.
    Alfredsson, Henrik
    KTH, Tidigare Institutioner                               , Mekanik.
    Observation of streaky structures in a plane water jet1997Ingår i: TAPPI Engineering conference, Oct. 6-9, 1997, Nashville, USA, 1997Konferensbidrag (Övrigt vetenskapligt)
  • 69.
    Söderberg, Daniel
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Hedhammar, My
    KTH, Skolan för bioteknologi (BIO), Centra, Centrum för Bioprocessteknik, CBioPT. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Proteinteknologi.
    Mittal, Nitesh
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Jansson, Ronnie
    Spiber AB, Stockholm, Sweden..
    Widhe, Mona
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap.
    Benselfelt, Tobias
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Håkansson, Karl
    RISE Bioecon, Stockholm, Sweden..
    Lundell, Fredrik
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Bioactive composites of cellulose nanofibrils and recombinant silk proteins2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 70. Söderberg, Daniel
    et al.
    Lucisano, M.
    Drotz, M.
    Rosen, F.
    Comparison between forming strategies regarding their effect on paper properties2013Ingår i: Pap. Conf. Trade Show, PaperCon, 2013, s. 773-790Konferensbidrag (Refereegranskat)
    Abstract [en]

    Extensive trials have been performed at the FEX machine at Innventia in Stockholm in order to determine fundamental relations between several process parameters. The goal with these has been to set up a matrix for further research aimed at the formation-retention-strength relations. The trials covered a total of five weeks at the FEX machine. Three of those were aimed at twin-wire forming and two at Fourdrinier forming. The results from these five weeks clearly show the difference between twin-wire and Fourdrinier forming. For the Fourdrinier case there is a linear relation between small-scale (0.3-3 mm) formation and large-scale (3-30 mm) formation, a higher value for the small-scale formation also gives a higher large-scale value. Furthermore, there is a direct relation between formation and retention; an increased retention gives a higher formation value. In addition, it is shown that a better formation gives a higher tensile index value. In comparison, it is shown that twin-wire forming does not have these clear relations. Hence, the twin-wire forming process seems to allow de-coupling of many of these relations.

  • 71.
    Söderberg, Daniel
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. STFI-Packforsk, Sweden.
    Tammisola, Outi
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    The fundamental mechanism behind headbox jet break-up2008Ingår i: TAPPI Press - Paper Conference and Trade Show, PaperCon '08, 2008, s. 3564-3596Konferensbidrag (Refereegranskat)
    Abstract [en]

    It has previously been shown that MD streaks are created in the headbox jet, which is closely connected to the appearance of waves on the jet surface. The fundamental mechanism behind this break-up is presented. This has been achieved by implementing state-of-the-art methods for determining the characteristics and evolution of hydrody-namic instabilities. The methodology also allows the headbox slice to be designed in order to minimise jet break-up. This possibility has been evaluated in pilot-scale.

  • 72.
    Söderberg, Daniel
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. Innventia, Sweden.
    Wiberg, A.
    Grussenmeyer, H.
    Ersson, H.
    Resource efficiency through top-down development2014Ingår i: Paper Conference and Trade Show, PaperCon 2014, TAPPI Press, 2014, s. 52-62Konferensbidrag (Refereegranskat)
    Abstract [en]

    Resource efficiency is one of the keys to future papermaking. This paper present a project where a top-down approach has been applied in order to identify, evaluate and combine a set of technologies for application on an existing paper machine. The paper describes the background and outline of the so-called Future SC-paper project that was performed 2010-2013 with a focus of developing a new manufacturing process for SC-paper generally and the PM8 production unit in Kvarnsveden, Sweden, specifically. The specific objective of the project was to develop a concept for SC-Paper production that would give lower environmental impact as well as reduced production costs. The project considered stock-preparation and the paper machine forming section. The research and development was made in pilot-scale as well as in mill-scale. The papermaking mill was the project owner and the work was performed in cooperation with machine and chemical suppliers including extensive work performed by a research institute. The project was partly funded by the European Community. Examples of technologies that were evaluated are fiber fractionation, stratified forming and advanced chemical adjuvants. The top-down approach, where the original list of ideas was reduced to final process solutions, i.e. a Future Manufacturing Concept. For the specific mill this gave the potential of reducing fiber raw material demand by 23% by using fillers and a reduction of energy demand by 20% at maintained product properties. Apart from being a specific result for the mill the technologies can be used more generally and the project approach would be of good use for other production units. It should also be noted that all technologies that used in the Future Manufacturing Concept are available on the market today.

  • 73.
    Söderberg, L. Daniel
    et al.
    KTH, Tidigare Institutioner                               , Mekanik.
    Alfredsson, P. Henrik
    KTH, Tidigare Institutioner                               , Mekanik.
    Experiments concerning the origin of streaky structures inside a plane water jet2000Ingår i: Journal of Pulp and Paper Science (JPPS), ISSN 0826-6220, Vol. 26, nr 11, s. 395-400Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is believed that the characteristics of a headbox jet are of vital importance for the formation in the final paper sheet. To better understand the physics of free, plane liquid jets, experiments have been made with wafer emanating from two different nozzles: a plane channel flow nozzle where viscous effects are of importance; and a slid nozzle, which closely approximates art inviscid jet. Both types of flow have been visualized and the visualization of the jet emanating from a channel showed that a strong streamwise streaky structure was created inside the jet a distance downstream the nozzle. These streaks do not originate from the nozzle but instead from the break-lip of two-dimensional waves on the jet travelling in the streamwise direction. This streaky structure could not be found at any velocity (<15 m/s) in the jet from the slit nozzle.

  • 74.
    Tammisola, Outi
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Schlatter, Philipp
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Wehrfritz, Armin
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Söderberg, Daniel
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Global linear and nonlinear stability of viscous confined plane wakes with co-flow2011Ingår i: Journal of Fluid Mechanics, ISSN 0022-1120, E-ISSN 1469-7645, Vol. 675, s. 397-434Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The global stability of confined wakes is studied numerically, using two-dimensionallinear global modes and nonlinear direct numerical simulations (DNS).The wake inflow velocity is varied between different amounts of co-flow (basebleed), while the density and viscosity are assumed to be constant everywherein the flow domain. In accordance with previous studies, we find that thefrequencies of both the most unstable linear and the saturated nonlinear globalmode increase with confinement. Here, we also find that for wake Reynoldsnumber Re = 100, the confinement is stabilising. It decreases both the growthrate of the linear and the saturation amplitude of the nonlinear modes. Weconclude that the dampening effect is connected to the streamwise developmentof the base flow, and for higher Reynolds numbers this effect decreases, sincethe flow becomes more parallel. The linear analysis reveals that the criticalwake velocities below which the flow becomes unstable are almost identicalfor unconfined and confined wakes at Re ≈ 400. Also, the present resultsare compared with literature data for an inviscid parallel wake due to thesimilarity of inflow profile. The confined wake is found to be more stable thanits inviscid counterpart, while the unconfined wake is more unstable than theinviscid wake. The main reason to both can be explained by the base flowdevelopment. A detailed comparison of the linear and nonlinear results revealsthat the most unstable linear global mode gives an excellent prediction of theinitial nonlinear behaviour and therefore the stability boundary, in all cases.However, the nonlinear saturated state is quite different in particular for higherReynolds numbers. For Re = 100, the saturated frequency also differs less than5% from the linear frequency, and trends regarding confinement observed in thelinear analysis are confirmed.141

  • 75.
    Tammisola, Outi
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Global linear stability of confined wakes with co-flowManuskript (Övrigt vetenskapligt)
    Abstract [en]

    The global stability of confined wakes is studied numerically, using 2D global modes. The wake inlet velocity is varied, and the main focus lies in wakes with co-flow (base bleed). The density and viscosity are assumed to be constant in and outside the wake. We find that for wake Reynolds number 100, the confinement is stabilising in general. The frequency of the unstable mode increases, and wavelength decreases with confinement. By comparing with an artificial, more slowly developing wake, we conclude that the dampening effect is due to the mean flow development. For higher Reynolds numbers this effect decreases. The critical inlet velocities for which the wake becomes unstable are almost identical for unconfined and confined wakes at $Re=400$. Also, the present results are compared with results for an inviscid parallel wake found in literature, since the inlet profile is very similar to the inviscid profile. The confined wake is found to be more stable than its inviscid counterpart, while the unconfined wake is more unstable than the inviscid wake. The reason to both can be explained by the mean flow development.

     

     

     

  • 76.
    Tammisola, Outi
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    On the global stability of a plane liquid jet surrounded by gas: problem formulation and preliminary resultsManuskript (Övrigt vetenskapligt)
    Abstract [en]

    The global stability of a liquid sheet in gas is studied. The global 3D stability problem for a 2D base flow is formulated, including surface tension of the interface, and the viscosity and density of both phases. The implementational requirements are clarified, and met by using a parallel code for eigenvalue computations based on the mathematical software libraries PARPACK and ScaLAPACK. Preliminary eigenvalue spectra and eigenmodes are presented for the case of water jet surrounded by air.

     

  • 77.
    Tammisola, Outi
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Sasaki, Atsushi
    Matsubara, Masaharu
    Global stability of a plane liquid jet surrounded by gas2010Ingår i: SEVENTH IUTAM SYMPOSIUM ON LAMINAR-TURBULENT TRANSITION / [ed] Schlatter P; Henningson DS, 2010, Vol. 18, s. 403-408Konferensbidrag (Refereegranskat)
    Abstract [en]

    The global stability of a liquid sheet in gas is studied. The global 3D stability problem for a 2D base flow is formulated, including surface tension of the interface, and the viscosity and density of both phases. The implementational requirements are clarified, and met by using a parallel code for eigenvalue computations based on the mathematical software libraries PARPACK and ScaLAPACK. Preliminary eigenvalue spectra and eigenmodes are presented for the case of a water jet surrounded by air.

  • 78.
    Tammisola, Outi
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Söderberg, L. Daniel
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Effect of surface tension on global modes of confined wake flows2011Ingår i: Physics of fluids, ISSN 1070-6631, E-ISSN 1089-7666, Vol. 23, nr 1, s. 014108-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Many wake flows are susceptible to self-sustained oscillations, such as the well-known von Karman vortex street behind a cylinder that makes a rope beat against a flagpole at a distinct frequency on a windy day. One appropriate method to study these global instabilities numerically is to look at the growth rates of the linear temporal global modes. If all growth rates for all modes are negative for a certain flow field then a self-sustained oscillation should not occur. On the other hand, if one growth rate for one mode is slightly positive, the oscillation will approximately obtain the frequency and shape of this global mode. In our study, we first introduce surface tension between two fluids to the wake-flow problem. Then we investigate its effects on the global linear instability of a spatially developing wake with two co-flowing immiscible fluids. The inlet profile consists of two uniform layers, which makes the problem easily parametrizable. The fluids are assumed to have the same density and viscosity, with the result that the interface position becomes dynamically important solely through the action of surface tension. Two wakes with different parameter values and surface tension are studied in detail. The results show that surface tension has a strong influence on the oscillation frequency, growth rate, and shape of the global mode(s). Finally, we make an attempt to confirm and explain the surface-tension effect based on a local stability analysis of the same flow field in the streamwise position of maximum reverse flow.

  • 79.
    Tammisola, Outi
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Söderberg, L. Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Surface tension-induced global instability of planar jets and wakes2012Ingår i: Journal of Fluid Mechanics, ISSN 0022-1120, E-ISSN 1469-7645, Vol. 713, s. 632-658Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effect of surface tension on global stability of co-flow jets and wakes at a moderate Reynolds number is studied. The linear temporal two-dimensional global modes are computed without approximations. All but one of the flow cases under study are globally stable without surface tension. It is found that surface tension can cause the flow to be globally unstable if the inlet shear (or, equivalently, the inlet velocity ratio) is strong enough. For even stronger surface tension, the flow is restabilized. As long as there is no change of the most unstable mode, increasing surface tension decreases the oscillation frequency. Short waves appear in the high-shear region close to the nozzle, and their wavelength increases with increasing surface tension. The critical shear (the weakest inlet shear at which a global instability is found) gives rise to antisymmetric disturbances for the wakes and symmetric disturbances for the jets. However, at stronger shear, the opposite symmetry can be the most unstable one, in particular for wakes at high surface tension. The results show strong effects of surface tension that should be possible to reproduce experimentally as well as numerically.

  • 80.
    Tammisola, Outi
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Sasaki, Atsushi
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Matsubara, Masaharu
    Söderberg, L. Daniel
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Stabilizing effect of surrounding gas flow on a plane liquid sheet2011Ingår i: Journal of Fluid Mechanics, ISSN 0022-1120, E-ISSN 1469-7645, Vol. 672, s. 5-32Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The stability of a plane liquid sheet is studied experimentally and theoretically, with an emphasis on the effect of the surrounding gas. Co-blowing with a gas velocity of the same order of magnitude as the liquid velocity is studied, in order to quantify its effect on the stability of the sheet. Experimental results are obtained for a water sheet in air at Reynolds number Re-t = 3000 and Weber number We = 300, based on the half-thickness of the sheet at the inlet, water mean velocity at the inlet, the surface tension between water and air and water density and viscosity. The sheet is excited with different frequencies at the inlet and the growth of the waves in the streamwise direction is measured. The growth rate curves of the disturbances for all air flow velocities under study are found to be within 20% of the values obtained from a local spatial stability analysis, where water and air viscosities are taken into account, while previous results from literature assuming inviscid air overpredict the most unstable wavelength with a factor 3 and the growth rate with a factor 2. The effect of the air flow on the stability of the sheet is scrutinized numerically and it is concluded that the predicted disturbance growth scales with (i) the absolute velocity difference between water and air (inviscid effect) and (ii) the square root of the shear from air on the water surface (viscous effect).

  • 81.
    Tammisola, Outi
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Sasaki, Atsushi
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Matsubara, Masaharu
    Stabilisation of a plane liquid sheet by gas flow: experiments and theoryManuskript (Övrigt vetenskapligt)
    Abstract [en]

    The stability of a plane liquid jet is studied experimentally and theoretically. The main emphasis is on the effect of the surrounding air. Co-blowing with a gas velocity of the same order of magnitude as the liquid velocity is studied. Experimental results are obtained and the growth rates of the disturbances are found to be within 20\% of the values obtained from local spatial stability analysis. The effect of different parameters of the gas flow on the stability of the jet is scrutinized and it is concluded that the predicted disturbance growth is mostly sensitive to the shear from the air on the liquid surface and the velocity difference between the water and the air.

    The overall disturbance growth and wavelength scales with the difference between the gas and liquid velocity.

     

     

  • 82.
    Vijayakumar, Krishnegowda
    et al.
    KTH, Skolan för teknikvetenskap (SCI).
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik, Strömningsfysik.
    Lundell, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. Royal Inst Technol, KTH Mech, Stockholm, Sweden..
    Orientation and alignment of cellulose nanofibrils in shear and extensional flows2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 83. Yan, H. W.
    et al.
    Söderberg, L. Daniel
    Two-dimensional wavelet flocculation analysis of fibre suspensions and paper sheets2006Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 21, nr 1, s. 13-18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An image analysis method is described, based on a two-dimensional continuous wavelet transform, for the study of fibre Suspension flocculation. Images of a fibre Suspension are cross-correlated with two-dimensional Mexican hat wavelets. The inner fibre floc structure information can be obtained by comparing the signals after the transforms using different scales of the two-dimensional Mexican hat wavelets. Centres of fibre floes can be obtained by finding the local maximum signal peaks in the transform. Simulated floes images and real fibre suspension images are analysed with the wavelet transform as well as quantification of sheet structure in paper sheets. Some applications of this image analysis method are also discussed.

  • 84.
    Zhu, Hongli
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Träkemi och massateknologi.
    Helander, Mikaela
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Moser, Carl
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Ståhlkranz, Adam
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Henriksson, Gunnar
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    A novel nano cellulose preparation method and size fraction by cross flow ultra- filtration2012Ingår i: Current organic chemistry, ISSN 1385-2728, E-ISSN 1875-5348, Vol. 16, nr 16, s. 1871-1875Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A novel energy-efficient method called nanopulping (patent pending) to produce nanocellulose from chemical pulp, and a novel cross-flow ultra-filtration method to separate nanofibrils fractions of different size were applied in this study. Pretreatment with endoglucanase or 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation seems to enhance the nanopulping process. Results were evaluated with atomic force microscope and ultrafiltration. The nanopulping produced a relatively inhomogeneous material with larger particles/ fibers in addition to nanofibers. However, by ultrafiltration of the material it was possible to obtain more homogeneous material in different dimensions with methods industrially acceptable.

12 51 - 84 av 84
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf