Change search
Refine search result
2533253425352536253725382539 126751 - 126800 of 127252
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 126751.
    Örlü, Ramis
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Low Reynolds number Zero Pressure-Gradient Equilibrium Turbulent Boundary-Layer ExperimentsManuscript (preprint) (Other academic)
  • 126752.
    Örlü, Ramis
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    On the determination of the wall position in wall-bounded turbulent flowsManuscript (preprint) (Other academic)
  • 126753.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences (SCI), Mechanics.
    Alfredsson, Henrik
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences (SCI), Mechanics.
    The life of a vortex in an axisymmetric jet2011In: Journal of Visualization, ISSN 1343-8875, E-ISSN 1875-8975, Vol. 14, no 1, p. 5-6Article in journal (Refereed)
    Abstract [en]

    An axisymmetric jet is produced whenever a fluid is ejected from a round nozzle. The internal and external disturbances present in and surrounding the jet will trigger the formation of Kelvin–Helmoltz waves that are amplified and grow until they saturate and roll up in discrete vortices undergoing different processes such as (vortex) pairing and tearing until they collapse generating a complete turbulent flow. Concerning the evolution of the vortices within the axisymmetric shear layer, a typical scenario, describing the stages in a life of a vortex, is well represented by the flow visualization sequences shown in Fig. 1 as well as the movie in Online Resource 1.

  • 126754.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Alfredsson, P. Henrik
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics.
    An experimental study of the near-field mixing characteristics of a swirling jet2008In: Flow Turbulence and Combustion, ISSN 1386-6184, E-ISSN 1573-1987, Vol. 80, no 3, p. 323-350Article in journal (Refereed)
    Abstract [en]

    The present experimental investigation is devoted to the mixing charac- teristics of a passive scalar in the near-field region of a moderately swirling jet issuing from a fully developed axially rotating pipe flow. Instantaneous streamwise and azimuthal velocity components as well as the temperature were simultaneously accessed by means of a combined X-wire and cold-wire probe. The results indicate a modification of the turbulence structures to that effect that the swirling jet spreads, mixes and evolves faster compared to its non-swirling counterpart. The high correlation between streamwise velocity and temperature fluctuations as well as the streamwise passive scalar flux are even more enhanced due to the addition of swirl, which in turn shortens the distance and hence time needed to mix the jet with the ambient air.

  • 126755.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Alfredsson, P. Henrik
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    BINORMAL COOLING ERRORS IN SINGLE HOT-WIRE MEASUREMENTS2016In: JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN 1429-2955, Vol. 54, no 1, p. 305-310Article in journal (Refereed)
    Abstract [en]

    In single-wire hot-wire measurements, velocity fluctuations acting normal to the hot-wire and its prongs will cause additional heat transfer known as binormal cooling. With respect to wall turbulence, the influence of this additional cooling is well-studied for crossed wires, while it is commonly ignored in single hot-wire measurements. The latter view is challenged in the recent work by Drozdz and Elsner (2014) that claims significant errors in variance measurements when using single-wire probes in turbulent boundary layers. This short communication revisits these claims and quantifies binormal cooling errors through an expansion of the effective-velocity concept and utilisation of direct numerical simulation data. Results support the common habit that binormal cooling errors can safely be ignored in single hot-wire measurements.

  • 126756.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Alfredsson, P. Henrik
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Comment on the scaling of the near-wall streamwise variance peak in turbulent pipe flows2013In: Experiments in Fluids, ISSN 0723-4864, E-ISSN 1432-1114, Vol. 54, no 1, p. 1431-Article in journal (Refereed)
    Abstract [en]

    Apparent contradictory results regarding the Reynolds number (Re) scaling of the near-wall peak of the streamwise velocity variance distribution in turbulent pipe flows (Ng et al. Exp Fluids 51, 1261 and Vallikivi et al. Exp. Fluids 51, 1521) are discussed. Conclusions from the Princeton University/ONR Superpipe published between 2010 and 2012 are examined, doubts are raised, and recent numerical and experimental results are supplemented. The compiled results support the view that the inner-scaled peak amplitude increases with Re (at least to a Kármán number (R+) of 3,000) in contrast to the view put forward by several publications based on results from the Superpipe. Consequently, there is a need for further experimental results for R+ > 3,000 to ascertain the trend at higher Re.

  • 126757.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Alfredsson, P. Henrik
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    On spatial resolution issues related to time-averaged quantities using hot-wire anemometry2010In: Experiments in Fluids, ISSN 0723-4864, E-ISSN 1432-1114, Vol. 49, no 1, p. 101-110Article in journal (Refereed)
    Abstract [en]

    The effect of spatial resolution on streamwise velocity measurements with single hot-wires is targeted in the present study, where efforts have been made to distinguish between spatial resolution and Reynolds number effects. The basis for measurements to accurately determine the mean velocity and higher order moments is that the probability density distribution is measured correctly. It is well known that the turbulence intensity is increasingly attenuated with increasing wire length. Here, it is also shown (probably for the first time) that besides the probability density distribution and hence the higher order moments, even the mean velocity is affected, albeit to subtle extent, but with important consequences in studies of concurrent wall-bounded turbulence.

  • 126758.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Alfredsson, P. Henrik
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Passive scalar flux measurements in the near-field region of a swirling jet2008In: Heat Transfer Research, ISSN 1064-2285, E-ISSN 2162-6561, Vol. 39, no 7, p. 597-607Article in journal (Refereed)
    Abstract [en]

    The present experimental investigation is devoted to the heat flux characteristics of a passive scalar in the near-field region of a swirling jet issuing from a fully developed axially rotating pipe flow. A combined X-wire and cold-wire probe made it possible to access the instantaneous streamwise and azimuthal velocity components as well as the temperature simultaneously. Results indicate that the addition of swirl increases the integral scales and entrainment and thereby the streamwise passive scalar flux and shortens the distance and hence time needed to mix the jet with the ambient air.

  • 126759.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences (SCI), Mechanics.
    Fiorini, T.
    Segalini, Antonio
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences (SCI), Mechanics.
    Bellani, G.
    Talamelli, Alessandro
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences (SCI), Mechanics. Università di Bologna, Italy.
    Alfredsson, P Henrik
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences (SCI), Mechanics. Università di Bologna, Italy.
    Reynolds stress scaling in pipe flow turbulence-first results from CICLoPE2017In: Philosophical Transactions. Series A: Mathematical, physical, and engineering science, ISSN 1364-503X, E-ISSN 1471-2962, Vol. 375, no 2089, article id 20160187Article in journal (Refereed)
    Abstract [en]

    This paper reports the first turbulence measurements performed in the Long Pipe Facility at the Center for International Cooperation in Long Pipe Experiments (CICLoPE). In particular, the Reynolds stress components obtained from a number of straight and boundary-layer-type single-wire and X-wire probes up to a friction Reynolds number of 3.8 x 10(4) are reported. In agreement with turbulent boundary-layer experiments as well as with results from the Superpipe, the present measurements show a clear logarithmic region in the streamwise variance profile, with a Townsend-Perry constant of A(2) approximate to 1.26. The wall-normal variance profile exhibits a Reynolds-number-independent plateau, while the spanwise component was found to obey a logarithmic scaling over a much wider wall-normal distance than the other two components, with a slope that is nearly half of that of the Townsend-Perry constant, i.e. A(2,w) approximate to A(2)/2. The present results therefore provide strong support for the scaling of the Reynolds stress tensor based on the attached-eddy hypothesis. Intriguingly, the wall-normal and spanwise components exhibit higher amplitudes than in previous studies, and therefore call for follow-up studies in CICLoPE, as well as other large-scale facilities. This article is part of the themed issue 'Toward the development of high-fidelity models of wall turbulence at large Reynolds number'.

  • 126760.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Fransson, Jens H. M.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Alfredsson, P. Henrik
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    On imperfect hot-wire resolution issues and their effect on mean quantities2009In: ADVANCES IN TURBULENCE XII: PROCEEDINGS OF THE 12TH EUROMECH EUROPEAN TURBULENCE CONFERENCE / [ed] Eckhardt, B., 2009, Vol. 132, p. 605-608Conference paper (Refereed)
  • 126761.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Industrial Engineering and Management (ITM), Centres, Competence Center for Gas Exchange (CCGEx).
    Kalpakli Vester, Athanasia
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Industrial Engineering and Management (ITM), Centres, Competence Center for Gas Exchange (CCGEx).
    Flow visualization of an oblique impinging jet: vortices like it downhill, not uphill2015In: Journal of Visualization, ISSN 1343-8875, E-ISSN 1875-8975Article in journal (Refereed)
  • 126762.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Malizia, Fabio
    Cimarelli, Andrea
    Schlatter, Philipp
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Talamelli, Alessandro
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. Univ Bologna, Italy.
    The influence of temperature fluctuations on hot-wire measurements in wall-bounded turbulence2014In: Experiments in Fluids, ISSN 0723-4864, E-ISSN 1432-1114, Vol. 55, no 7, p. 1781-Article in journal (Refereed)
    Abstract [en]

    There are no measurement techniques for turbulent flows capable of reaching the versatility of hot-wire probes and their frequency response. Nevertheless, the issue of their spatial resolution is still a matter of debate when it comes to high Reynolds number near-wall turbulence. Another, so far unattended, issue is the effect of temperature fluctuations-as they are, e. g. encountered in non-isothermal flows-on the low and higher-order moments in wall-bounded turbulent flows obtained through hot-wire anemometry. The present investigation is dedicated to document, understand, and ultimately correct these effects. For this purpose, the response of a hot-wire is simulated through the use of velocity and temperature data from a turbulent channel flow generated by means of direct numerical simulations. Results show that ignoring the effect of temperature fluctuations, caused by temperature gradients along the wall-normal direction, introduces-despite a local mean temperature compensation of the velocity reading-significant errors. The results serve as a note of caution for hot-wire measurements in wall-bounded turbulence, and also where temperature gradients are more prevalent, such as heat transfer measurements or high Mach number flows. A simple correction scheme involving only mean temperature quantities (besides the streamwise velocity information) is finally proposed that leads to a substantial bias error reduction.

  • 126763.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Schlatter, Philipp
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Comparison of experiments and simulations for zero pressure gradient turbulent boundary layers at moderate Reynolds numbers2013In: Experiments in Fluids, ISSN 0723-4864, E-ISSN 1432-1114, Vol. 54, no 6, p. 1547-Article in journal (Refereed)
    Abstract [en]

    A detailed comparison between recent direct numerical simulation (DNS) and experiments of a turbulent boundary layer under zero pressure gradient at Re-theta = 2,500 and 4,000 (based on the free-stream velocity and momentum-loss thickness) is presented. The well-resolved DNS is computed in a long spatial domain (Schlatter and Orlu in J Fluid Mech 659: 116, 2010a), including the disturbance strip, while the experiments consist of single hot-wire probe and oil-film interferometry measurements. Remarkably, good agreement is obtained for integral quantities such as skin friction and shape factor, as well as mean and fluctuating streamwise velocity profiles, higher-order moments and probability density distributions. The agreement also extends to spectral/structural quantities such as the amplitude modulation of the small scales by the large-scale motion and temporal spectral maps throughout the boundary layer. Differences within the inner layer observed for statistical and spectral quantities could entirely be removed by spatially averaging the DNS to match the viscous-scaled length of the hot-wire sensor, thereby explaining observed differences solely by insufficient spatial resolution of the hot-wire sensor. For the highest Reynolds number, Re-theta = 4,000, the experimental data exhibit a more pronounced secondary spectral peak in the outer region (y/delta(99) = 0.1) related to structures with length on the order of 5-7 boundary layer thicknesses, which is weaker and slightly moved towards lower temporal periods in the DNS. The cause is thought to be related to the limited spanwise box size which constrains the growth of the very large structures. In the light of the difficulty to obtain "canonical" flow conditions, both in DNS and the wind tunnel where effects such as boundary treatment, pressure gradient and turbulence tripping need to be considered, the present cross-validation of the data sets, at least for the present Re-theta-range, provides important reference data for future studies and highlights the importance of taking spatial resolution effects into account when comparing experiment and DNS. For the considered flow, the present data also provide quantitative guidelines on what level of accuracy can be expected for the agreement between DNS and experiments.

  • 126764.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Schlatter, Philipp
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Inflow length and tripping effects in turbulent boundary layers2011In: 13TH European Turbulence Conference (ETC13): Wall-Bounded Flows And Control Of Turbulence, Institute of Physics Publishing (IOPP), 2011, p. 022018-Conference paper (Refereed)
    Abstract [en]

    A recent assessment of available direct numerical simulation (DNS) data from turbulent boundary layer flows [Schlatter & Orlu, J. Fluid Mech. 659, 116 (2010)] showed surprisingly large differences not only in the skin friction coefficient or shape factor, but also in their predictions of mean and fluctuation profiles far into the sublayer. For the present paper the DNS of a zero pressure-gradient turbulent boundary layer flow by Schlatter et al. [Phys. Fluids 21, 051702 (2009)] serving as the baseline simulation, was re-simulated, however with physically different inflow conditions and tripping effects. The downstream evolution of integral and global quantities as well as mean and fluctuation profiles are presented and results indicate that different inflow conditions and tripping effects explain most of the differences observed when comparing available DNS. It is also found, that if transition is initiated at a low enough Reynolds number (based on the momentum-loss thickness) Re-theta < 300, all data agree well for both inner and outer layer for Re-theta > 2000; a result that gives a lower limit for meaningful comparisons between numerical and/or wind tunnel experiments.

  • 126765.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Schlatter, Philipp
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    On the fluctuating wall-shear stress in zero pressure-gradient turbulent boundary layer flows2011In: Physics of fluids, ISSN 1070-6631, E-ISSN 1089-7666, Vol. 23, no 2, p. 021704-Article in journal (Refereed)
    Abstract [en]

    Recent direct numerical simulation (DNS) results relating to the behavior of the fluctuating wall-shear stress tau(+)(w,rms) in turbulent boundary layer flows are discussed. This new compilation is motivated by a recent article [Wu and Moin, "Transitional and turbulent boundary layer with heat transfer," Phys. Fluids 22, 085105 (2010)], which indicates a need for clarification of the value of tau(+)(w,rms). It is, however, shown here, based on other recent DNS data, that most results, both in boundary layer and channel geometry, yield tau(+)(w,rms)approximate to 0.4 plus a small increase with Reynolds number coming from the growing influence of the outer spectral peak. The observed discrepancy in experimental data is mainly attributed to spatial resolution effects, as originally described by Alfredsson et al. [" The fluctuating wall-shear stress and the velocity field in the viscous sublayer, "Phys. Fluids 31, 1026 (1988)].

  • 126766.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. Royal Inst Technol, Linn FLOWCtr, KTHMech, SE-10044 Stockholm, Sweden..
    Schlatter, Philipp
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. Royal Inst Technol, Linn FLOWCtr, KTHMech, SE-10044 Stockholm, Sweden..
    Turbulent Boundary-Layer Flow: Comparing Experiments with DNS2012In: PROGRESS IN TURBULENCE AND WIND ENERGY IV / [ed] Oberlack, M Peinke, J Talamelli, A Castillo, L Holling, M, SPRINGER-VERLAG BERLIN , 2012, p. 213-216Conference paper (Refereed)
  • 126767.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Segalini, Antonio
    Alfredsson, Henrik
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Talamelli, Alessandro
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    On the passive control of the near-field of coaxial jets by means of vortex shedding2008In: Int. Conf. on Jets, Wakes and Separated Flows, ICJWSF-2, September 16-19, 2008, Technical University of Berlin, Germany, 2008, p. 1-16Conference paper (Refereed)
  • 126768.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Segalini, Antonio
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Alfredsson, P. Henrik
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Talamelli, Alessandro
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Passive control of mixing in a coaxial jet2008In: Proc. 7th Int. ERCOFTAC Symp. on Engineering Turbulence Modelling and Measurements (ETMM7), 2008, p. 450-455Conference paper (Refereed)
    Abstract [en]

    An experimental investigation regarding interacting shear layers in a coaxial jet geometry has been performed. The present paper confirms experimentally the theoretical result by Talamelli and Gavarini (2006), who proposed that the wake behind the separation wall between the two stream of a coaxial jet creates the condition for an absolute instability. This instability, by means of the induced vortex shedding, may provide a continuous forcing mechanism for the control of the flow field. The potential of this passive mechanism as an easy, effective and practical way to control the near-field of interacting shear layers has been demonstrated.

  • 126769.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Segalini, Antonio
    KTH, School of Engineering Sciences (SCI), Mechanics, Stability, Transition and Control. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Alfredsson, P. Henrik
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Talamelli, Alessandro
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Turbulence Enhancement in Coaxial Jet Flows by Means of Vortex Shedding2009In: PROGRESS IN TURBULENCE III / [ed] Peinke, J.; Oberlack, M.; Talamelli, A., 2009, Vol. 131, p. 235-238Conference paper (Refereed)
    Abstract [en]

    Over the past decades a variety of passive and active flow control mechanisms have been tested and applied in a variety of canonical as well as applied flow cases. An example for the latter is the coaxial jet flow, which has mainly been investigated regarding the receptivity to active flow control strategies (see e.g. [1]), probably due to the multitude of parameters characterising the complex flow field [2]. Physical and numerical experiments (see e.g. [3] and [5]) have established that the vortical motion in coaxial jet flows is dominated by the vortices emerging from the outer shear layer. The frequency of these vortices is related to the Kelvin- Helmholtz instability as predicted by linear stability analysis for single jets. The vortices in the inner shear layer, on the other hand, are trapped in the spaces left free between two consecutive outer shear layer vortices, and are therefore sharing the frequencies of the most amplified modes of the outer shear layer and do not relate to the values one would expect from linear stability analysis. This fact has become known as the “locking phenomenon”, which describes the mutual interaction of both shear layers. Nevertheless it is believed that only the outer shear layer is able to significantly control the evolution of the inner shear layer [7], which may explain the focus of control strategies on the outer shear layer.

  • 126770.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics.
    Segalini, Antonio
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Klewicki, J.
    Alfredsson, P. Henrik
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Generalization of the diagnostic plot to higher-order moments in turbulent boundary layers2016In: Springer Proceedings in Physics, Springer, 2016, p. 333-338Conference paper (Refereed)
    Abstract [en]

    The present work extends the diagnostic plot concept for the streamwise turbulence intensity in wall-bounded turbulent flows [Alfredsson and Örlü, Eur. J. Mech. B/Fluids 42, 403 (2010)], and generalizes it for higher-order (even and odd) moments, thereby providing a general description of the probability density distribution of streamwise velocity fluctuations. Turbulent boundary layer data up to a friction Reynolds number of 20000 are employed and demonstrate the feasibility of the diagnostic plot to scale data throughout the logarithmic and wake regions. © Springer International Publishing Switzerland 2016.

  • 126771.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Segalini, Antonio
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Klewicki, J.
    Alfredsson, P. Henrik
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    High-order generalisation of the diagnostic scaling for turbulent boundary layers2016In: Journal of turbulence, ISSN 1468-5248, E-ISSN 1468-5248, Vol. 17, no 7, p. 664-677Article in journal (Refereed)
    Abstract [en]

    The diagnostic scaling concept, introduced for the streamwise turbulence intensity in wall-bounded turbulent flows (Alfredsson, Segalini and Örlü, Phys. Fluids 2011;23:041702), is here extended and generalised not only for the higher even-order central statistical moments, but also for the odd moments and thereby the probability density distribution of the streamwise velocity fluctuations. Turbulent boundary layer data up to a friction Reynolds number of 60,000 are employed and demonstrate the feasibility of the diagnostic scaling for the data throughout the logarithmic and wake regions. A comparison with the generalised logarithmic law for even-order moments by Meneveau and Marusic (J. Fluid Mech. 2013;719:R1) based on the attached-eddy hypothesis, is reported. The diagnostic plot provides an apparent Reynolds-number-independent scaling of the data, and is exploited to reveal the functional dependencies of the constants needed in the attached-eddy-based model. In particular, the invariance of the lowest order diagnostic scaling poses an intriguing incompatibility with the asymptotic constancy of the Townsend–Perry constant.

  • 126772.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics.
    Segalini, Antonio
    Talamelli, Alessandro
    Alfredsson, P. Henrik
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics.
    Effect of oblique waves on jet turbulence2010In: SEVENTH IUTAM SYMPOSIUM ON LAMINAR-TURBULENT TRANSITION / [ed] Schlatter P; Henningson DS, 2010, Vol. 18, p. 541-544Conference paper (Refereed)
    Abstract [en]

    The paper describes experiments on acoustically excited axisymmetric turbulent jet flows The investigation is based on the hypothesis that so called oblique transition may play a role in the breakdown to turbulence for an axisymmetric jet. For wall bounded flows oblique transition gives rise to steady streamwise streaks that break down to turbulence, as for instance documented by Elofsson & Alfredsson (J Fluid Mech. 358). The scenario of oblique transition has so for not been considered for jet flows and the aim was to study the effect of two oblique modes on the transition scenario as well as on the flow dynamics. Even though it was not possible to detect the presence of streamwise streaks, for a certain range of the excitation frequencies. the turbulence intensity, at a fixed stream wise position, is found to be significantly reduced.

  • 126773.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Talamelli, A.
    Oberlack, M.
    Peinke, J.
    Preface2017In: Springer Proceedings in Physics, Springer Science+Business Media B.V., 2017, Vol. 196, p. v-viConference paper (Refereed)
  • 126774.
    Örlü, Ramis
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Vinuesa, Ricardo
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Vila, C. S.
    DIscetti, S.
    Ianiro, A.
    Schlatter, Philipp
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Towards canonical adverse-pressure-gradient turbulent boundary layers2017In: 10th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2017, International Symposium on Turbulence and Shear Flow Phenomena, TSFP10 , 2017, Vol. 3Conference paper (Refereed)
    Abstract [en]

    The present investigation focuses on the concerted investigation of pressure gradient and streamwise curvature effects on turbulent boundary layers. In particular, a number of direct and large-eddy simulations covering a wide range of pressure gradient parameters and streamwise histories on flat and curved surfaces is performed and will be compared with wind-tunnel experiments utilising hot-wire anemometry and particle image velocimetry that overlap and extend the Reynolds number range. Results are aimed at isolating the effects of pressure gradients, streamwise curvature and streamwise (pressure gradient) histories as well as Reynolds number, which have traditionally inhibited to draw firm conclusions from the available data.

  • 126775.
    Örn, Bisera
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    The aesthetics of clutter - A artistic examination in clay2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In “the aesthetics of clutter” clay has stretched out beyond conventional processes to take free form in an architectural context. What happens if clay in it´s rawest form dominates a process with the goal of becoming part of a construction: an ornamented building element? This project raises question about the importance of getting close to material as part of the process rather than only through computers and samples. Intimate knowledge of material unleashed in it´s fullest, explored by hand.

  • 126776.
    Örn, Bisera
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Vandrarhem i Mariefred2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The task was to draw a hotel in Mariefred and after analysis of the site and from the connections that were made by site visits developed the project to a hostel instead. With a main building and at least seven cabins for overnight scattered throughout town offer the new buildings not only accommodation but also new platforms to meet. In the main building, which is a kind of cultural center is the loan system for bicycles, listen to books, etc. and in addition to the coffee shop and restaurant area as the hostel caters is a open kitchen to the public and guests. All in the same plane on the ground floor. On the roof is a terrace for guests and the public that is  reached via a wide staircase and the entire surface to function as a park for the public. These planes are interspersed with a blackbox in the basement and a white room on the 1st floor. System similar tvättstugebokningssytem used as loan structure. The cottages are located around the city are positioned to create interesting meetings with the city such as Town Hall Square. Houses materials consist of stoneware reliefs with motifs taken from the people in the city and objects as

  • 126777.
    Örn, Hampus
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Banking and Finance.
    Zetterqvist, Carl
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Banking and Finance.
    Fastighetsderivat: Vilka förutsättningar måste uppfyllas för att möjliggöra handel med fastighetsderivat på den svenska marknaden?2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Handel med derivat har ökat explosionsartat på den svenska marknaden de senaste åren med möjligheter att handla i derivat med ett stort antal olika underliggande tillgångar. Denna utveckling har dock inte skapat möjligheten att handla derivat med utvecklingen på den svenska fastighetsmarknaden som underliggande tillgång.

    Möjligheterna att idag få fastighetsexponering utan att direkt äga fastigheter är begränsade och har låg korrelation med utvecklingen på den svenska fastighetsmarknaden. Ett ämne som har diskuterats flitigt innan fastighetskrisen 2007 är möjligheten att handla derivat med den svenska fastighetsmarknaden som underliggande tillgång. Problemet har varit att det inte funnits ett tillförlitligt index som man kan använda för att prissätta derivatet. Nya typer av index har utvecklats de senaste åren och därmed skapat en möjlighet att introducera fastighetsderivat som produkt på den svenska marknaden.

    För att kunna handla med fastighetsderivat krävs att en del förutsättningar uppnås däribland likviditet, ett fungerande underliggande index, en osymmetrisk marknad och en aktör som agerar som någon typ av återförsäljare av produkten det vill säga någon som erbjuder handel i fastighetsderivat. Än så länge finns idag ingen aktör som gör det även fast det finns underliggande index som skulle kunna användas som mätvariabel. Detta gör att det idag inte finns någon form av handel med produkten och därför ingen likviditet heller. Att marknaden är osymmetrisk och att olika aktörer söker olika typer av risk och diversifiering är tydligt. Därför måste någon aktör vara först med att erbjuda fastighetsderivat för att en handel ska kunna möjliggöras. Utöver det behövs också en aktör som vågar ta första traden och på så sätt öppnar möjligheter för likviditet.

  • 126778.
    Örn, Henrik
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Accuracy and precision of bedrock sur-face prediction using geophysics and geostatistics.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In underground construction and foundation engineering uncertainties associated with subsurface properties are inevitable to deal with. Site investigations are expensive to perform, but a limited understanding of the subsurface may result in major problems; which often lead to an unexpected increase in the overall cost of the construction project. This study aims to optimize the pre-investigation program to get as much correct information out from a limited input of resources, thus making it as cost effective as possible. To optimize site investigation using soil-rock sounding three different sampling techniques, a varying number of sample points and two different interpolation methods (Inverse distance weighting and point Kriging) were tested on four modeled reference surfaces. The accuracy of rock surface predictions was evaluated using a 3D gridding and modeling computer software (Surfer 8.02®). Samples with continuously distributed data, resembling profile lines from geophysical surveys were used to evaluate how this could improve the accuracy of the prediction compared to adding additional sampling points. The study explains the correlation between the number of sampling points and the accuracy of the prediction obtained using different interpolators. Most importantly it shows how continuous data significantly improves the accuracy of the rock surface predictions and therefore concludes that geophysical measurement should be used combined with traditional soil rock sounding to optimize the pre-investigation program.

  • 126779.
    Örn, Johan
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    I rummets kraftfält: om arkitektur och offentlig inredning i Sverige 1935-19752007Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    This thesis dealswith an essential direction inmodern Swedish architecture and interior design. Sven Ivar Lind (1902–80), the brothers Erik and Tore Ahlsén (1901–88, 1906–91) and Peter Celsing (1920–74) were architects that devoted intense concentration to artistic problems and sought close collaborationwith artists.They gave asmuch attention to furnishing, art and interior details as to plans, spatiality and lighting—in that respect they stood out among their colleagues. The purpose of the thesis is to describe and analyse the holistic approach of these architects to spatial design. One important hypothesis is that this approach is linked to the reappraisal of functionalism that took place in the late 1930s and the 1940s.

    The first chapter of the thesis is devoted entirely to the reappraisal of functionalism. In the following chapters three milieus are studied and interpreted: Stockholm’s City Archives (1939–59) by Sven Ivar Lind, the CivicHall in Örebro (1957–65) by Erik and Tore Ahlsén and the Bank of Sweden and the temporary Riksdag building at Sergels Torg (1965–1976) by Peter Celsing.

    What distinguishes Lind, the Ahlsén brothers and Celsing fromthemajority of their fellow architects is that they combined the ambition to design special furnishings—a heritage fromGunnar Asplund—with the use ofwhat could be described as commonplace stylistic features. Designing their own furniture was paradoxically the best way of attaining the unremarkable atmosphere they strove for.However, the conventional details and furnishings based on traditional patterns were sometimes highly expressive. The expressiveness is that which arises when commonplace objects are associated in new and unexpected combinations.

    Finally a common denominator was the belief that sense impressions alone do not create the beholder’s perception of spatiality, asmemories and previous spatial experienceswill also play their part.Widespread attentionwas paid to associations in the 1940s but theywere later considered to be illegitimate sources of architectonic effect. The main subjects of this study were to sustain awareness of the significance of associations for spatial experience well into the 1970s.

  • 126780.
    Örn, Rafaela
    KTH, School of Engineering Sciences (SCI), Physics.
    Measurement and modeling of the Multileaf collimator MLCi22019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 126781.
    Örnberg, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science.
    Study of Electrochemical Behaviour and Corrosion Resistance of Materials for Pacemaker Lead Applications2007Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    For patients suffering bradycardia, i.e., too slow heart rhythm, the common treatment is having a pacemaker implanted. The pacemaker system consists of the pacemaker and a pacing lead. The pacing lead is connected to the pacemaker and at the other end there is a stimulation electrode. The most common conductor material is a cobalt-based super alloy (MP35N® or 35N LT®), with the main constituents Ni, Co, Cr and Mo. The pacemaker electrode is often made of a substrate material with a rough surface coating. The substrate materials are predominantly platinum/iridium alloy and titanium. The material choice is of great importance for the performance and stability during long-term service. Excellent corrosion resistance is required to minimize elution of metal ions in the human body.

    In this thesis, the electrochemical behaviour and corrosion resistance of the Co-based alloys and Ta (as electrode substrate), in a phosphate buffer saline (PBS) solution with and without addition of H2O2, was investigated by means of potentiodynamic polarization, cyclic voltammetry, electrochemical impedance spectroscopy and simulated pacemaker pulsing. The metal release from the Co-based alloy during the passivation treatment and exposure in the synthetic biological media was measured by using inductive coupled plasma - atomic emission spectroscopy (ICP-AES). Moreover, surface composition was analyzed by using x-ray photoelectron spectroscopy.

    The results show that the chemical passivation of Co-based alloy 35N LT® increased the corrosion resistance and reduced Co release significantly, even in more hostile environment, i.e. PBS with addition of H2O2. The increased corrosion resistance is due to the Cr enrichment in the surface layer. The reduced Co release is due to a preferential dissolution of Co from the surface oxide layer during the chemical passivation. The electrochemical investigation of uncoated and rough TiN coated Ta show that uncoated Ta is not suitable electrode material due to formation of a highly resistive surface oxide film. Whereas the rough TiN coated Ta exhibits desirable electrochemical performance for pacemaker electrodes. The addition of H2O2 in the PBS has a large influence on the electrochemical behaviour of Ta, but the influence is small on the rough TiN coated Ta.

  • 126782.
    Örnberg, Andreas
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science.
    Herstedt, M.
    Leygraf, Christofer
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science.
    Corrosion resistance, chemical passivation and metal release of 35N LT and MP35N for biomedical material application2007In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 154, no 9, p. C546-C551Article in journal (Refereed)
    Abstract [en]

    The Co-based special wire alloys 35N LT and MP35N are used for biomedical applications. The corrosion resistance of the two alloys, chemical passivation, and metal release of 35N LT were studied by electrochemical measurements, surface analysis, and solution analysis. The results show no significant difference in the corrosion resistance between 35N LT and MP35N. Preferential dissolution of Co and Ni occurs during chemical passivation of 35N LT in an HNO3 solution, which results in enrichment of oxidized Cr and depletion of oxidized Co in the passive film. The passivation treatment leads to an increased corrosion resistance in a phosphate-buffered saline solution, even with addition of 100 mM H2O2 simulating an inflammatory response. A further effect of the passivation treatment is a significantly reduced metal release, especially Co, from 35N LT during exposure to the synthetic biological medium.

  • 126783.
    Örnberg, Andreas
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science.
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science.
    Leygraf, Christofer
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science.
    Electrochemical study of tantalum as substrate for pacemaker electrodesIn: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111Article in journal (Other academic)
  • 126784.
    Örnberg, Oscar
    et al.
    KTH, School of Engineering Sciences (SCI).
    Nylund, Jonas
    KTH, School of Engineering Sciences (SCI).
    Incrementally Expanding Environment in Deep Reinforcement Learning2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The very long times required to converge to optimal policies is a problem affecting machine learning and reinforcement learning in particular. Real-time solution on complex learning problems are necessary to expand the field into new domains where machine learning has previously been unfeasible. In this paper we introduce a novel method for training deep q-learning agents in an environment where the size can be dynamically scaled, in order to improve learning time. In this framework the agent starts in a very small environment where it can quickly experience different situations in a small scale and learn to handle them properly. As the agent learns the environment enough to reach certain predefined performance goals, the environment is expanded to increase complexity. The agent should then not have to relearn the environment completely, but simply adapt to the larger environment. This Incrementally Expanding Environment (IEE) method was compared to the conventional, deep q-learning method of training the agent on the full environment size from the beginning. Results showed that in some situations the methods performed identically, where in some situations the IEE method performed better. Particularly in scenarios with higher learning rates our framework improved its policy noticeably faster than the conventional method. The conventional method also notably never performed better than the IEE method. We thus conclude that the proposed framework is superior the the conventional one, being more robust to parameter choice and performing as well or better in all observed cases.

  • 126785.
    Örnebjär, Johanna
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Urban Building vid Hornsbruksgatan2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Mitt mål var att skapa västra söders identitet och samlingsplats, vilken helt saknas idag. Utmaningen var också att transformera Hornsbruksgatan från en baksida till en tillgänglig plats. Högalidsparken förlängs ner till gatunivå - Hornsbruksgatan blir en blandning av park/ torg genom ett specifikt grönt plattsystem. Nya stråk och ramper binder ihop nuvarande gatu- och parknivån. Bebyggelsen är småskalig och nätt, ändå är programmet större än förslagit proram. Siktlinjer från omkingliggande bebyggelse och ankomstpunkter till platsen mot Högalidskyrkan och parken bevaras. Kommersiell verksamhet, såsom flertalet gallerier och restauranger får klättra uppåt från gatunivå till parknivå och tvärtom. Det idag påbörjade projektet, stadsodling tas till vara på. Ett växthus bebyggs samt två odlingsplättar i parken förläggs. Den nya platsen är en grön kulturplats med många exponerade utställningar, utsällningar utomhus samt många uteserveringar.

  • 126786.
    Örnek, Cem
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Additive manufacturing–a general corrosion perspective2018In: Corrosion Engineering, Science and Technology, ISSN 1478-422X, E-ISSN 1743-2782, Vol. 53, no 7, p. 531-535Article in journal (Refereed)
    Abstract [en]

    Metallic additive manufacturing will replace some materials produced by conventional fabrication methods in the nearest future. However, corrosion will remain an important aspect needed to be prevented. The corrosion behaviour of additively manufactured alloys has been sparsely studied and very little work has been published so far. In this article, a general discussion about materials produced by additive manufacturing will be provided. 

  • 126787.
    Örnek, Cem
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. KTH Royal Inst Technol, Sch Engn Sci Chem Biotechnol & Hlth, Div Surface & Corros Sci, Drottning Kristinas Vag 51, S-10044 Stockholm, Sweden..
    Stress Corrosion Cracking and Hydrogen Embrittlement of Type 316L Austenitic Stainless Steel Beneath MgCl2 and MgCl2: FeCl3 Droplets2019In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 75, no 6, p. 657-667Article in journal (Refereed)
    Abstract [en]

    The atmospheric corrosion, as well as environmentally assisted cracking behavior of 316L austenitic stainless steel (UNS S31603) beneath MgCl2 and MgCl2: FeCl3 droplets under elastic and elastic-plastic strain exposed for 6 months at 50 degrees C and 30% relative humidity were investigated. Shallow and deep corrosion sites with filiform corrosion along with stress corrosion cracking (SCC) were formed beneath the salt-laden droplets, and the potential role of hydrogen embrittlement (HE) and crevice corrosion in damage evolution elucidated. Elastic strain (0.1%) was sufficient to cause SCC cracking as well as HE under droplets with 145 mu g/cmth> of chloride, with the severity of cracking increasing with increasing chloride deposition density (CDD). Elastic-plastic strain (0.2%) increased the propensity to both corrosion and SCC/HE, with cracks seen under droplets having CDD as low as 14.5 mu g/cm(2). Elastic-plastic strain was further seen to facilitate and accelerate pitting corrosion, leading to pits with more penetration depth. The extent of corrosion and cracking increases with increasing chloride deposition density, with ferric ions having more severe effect, in particular promoting localized corrosion with multiple nucleation sites. The work reported here was brought into a larger context of stainless steel corrosion and discussed in light of better understanding atmospheric corrosion of structural components such as nuclear waste storage containers.

  • 126788.
    Örnek, Cem
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. The University of Manchester, United Kingdom.
    Burke, M. G.
    Hashimoto, T.
    Engelberg, D. L.
    748 K (475 A degrees C) Embrittlement of Duplex Stainless Steel: Effect on Microstructure and Fracture Behavior2017In: Metallurgical and Materials Transactions. A, ISSN 1073-5623, E-ISSN 1543-1940, Vol. 48A, no 4, p. 1653-1665Article in journal (Refereed)
    Abstract [en]

    22Cr-5Ni duplex stainless steel (DSS) was aged at 748 K (475 A degrees C) and the microstructure development correlated to changes in mechanical properties and fracture behavior. Tensile testing of aged microstructures confirmed the occurrence of 748 K (475 A degrees C) embrittlement, which was accompanied by an increase of strength and hardness and loss of toughness. Aging caused spinodal decomposition of the ferrite phase, consisting of Cr-enriched alpha aEuro(3) and Fe-rich alpha' and the formation of a large number of R-phase precipitates, with sizes between 50 and 400 nm. Fracture surface analyses revealed a gradual change of the fracture mode from ductile to brittle delamination fracture, associated with slip incompatibility between ferrite and austenite. Ferrite became highly brittle after 255 hours of aging, mainly due to the presence of precipitates, while austenite was ductile and accommodated most plastic strain. The fracture mechanism as a function of 748 K (475 A degrees C) embrittlement is discussed in light of microstructure development.

  • 126789.
    Örnek, Cem
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. University of Manchester, UK.
    Burke, M. G.
    Hashimoto, T.
    Lim, J. J. H.
    Engelberg, D. L.
    475 degrees C Embrittlement of Duplex Stainless Steel-A Comprehensive Microstructure Characterization Study2017In: Materials Performance and Characterization, ISSN 2379-1365, Vol. 6, no 3, p. 409-436Article in journal (Refereed)
    Abstract [en]

    The effect of 475 degrees C embrittlement on microstructure development of grade 2205 duplex stainless steel was investigated. Spinodal decomposition products and associated precipitates in ferrite, austenite, and at interphase boundaries were characterized using analytical transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques. Microanalyses confirmed the presence of Cr-enriched alpha'' and Cr-depleted alpha' spinodal structures in the ferrite after 5 h of aging at 475 degrees C. Long-term aging for 255 h resulted in heavily-faulted R-phase precipitates with sizes of similar to 50-400 nm, chi-phase, and epsilon-Cu in the ferrite, TiN and Cr2N precipitates in the austenite, and a continuous network of M23C6-carbides at interphase boundaries. A significant hardness increase was observed after 255 h of aging, which was accompanied by a reduction of ferrite fraction. X-ray diffraction (XRD) stress measurements showed a general reduction of residual stresses in both ferrite and austenite with aging. Electron backscatter diffraction (EBSD) showed increased local misorientations, primarily close to precipitate interfaces within the ferrite, indicating the development of strain heterogeneities in the microstructure. The data presented provided a better understanding of 475 degrees C embrittlement in duplex stainless steel, suggesting that not only the ferrite alone is responsible for embrittlement. A comprehensive microstructure characterization study has been provided and the explanation for 475 degrees C embrittlement of duplex stainless steel has been discussed.

  • 126790.
    Örnek, Cem
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Engelberg, D. L.
    Univ Manchester, Corros & Protect Ctr, Sackville St, Manchester M13 9PL, Lancs, England.;Univ Manchester, Mat Performance Ctr, Sch Mat, Sackville St, Manchester M13 9PL, Lancs, England..
    Toward Understanding the Effects of Strain and Chloride Deposition Density on Atmospheric Chloride-Induced Stress Corrosion Cracking of Type 304 Austenitic Stainless Steel Under MgCl2 and FeCl3:MgCl2 Droplets2019In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 75, no 2, p. 167-182Article in journal (Refereed)
    Abstract [en]

    Type 304 (UNS S30400) austenitic stainless steel was exposed for 6 months under elastic (0.1%) and elastic/plastic (0.2%) strain to MgCl2 and mixed MgCl2:FeCl3 droplets with varying chloride deposition densities (1.5 mu g/cm(2)-1,500 mu g/cm(2)) at 30% relative humidity (RH) and 50 degrees C. The occurrence of pitting corrosion, crevice corrosion, atmospheric chloride-induced stress corrosion cracking (AISCC), and hydrogen embrittlement (HE) was observed, and the average crack growth rates estimated. Exposure to elastic/plastic strain resulted in longer and more severe cracks. AISCC was found at chloride deposition densities down to 14.5 mu g/cm(2), whereas no cracks were seen at lower deposition densities, with cracks developing at pit or crevice corrosion sites. More severe cracks were seen under MgCl2 droplets as contrasted to mixed MgCl2:FeCl3 salt droplets, which were seen to promote more localized corrosion sites with deeper penetration and in conjunction with shorter crack lengths. Differences in AISCC propagation rates and associated crack morphologies are discussed in relation to understanding long-term atmospheric corrosion exposures.

  • 126791.
    Örnek, Cem
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Leygraf, Christofer
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Pan, Jinshan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    On the Volta potential measured by SKPFM - fundamental and practical pects with relevance to corrosion science2019In: Corrosion Engineering, Science and Technology, ISSN 1478-422X, E-ISSN 1743-2782, Vol. 54, no 3, p. 185-198Article, review/survey (Refereed)
    Abstract [en]

    The Volta potential is an electron-sensitive parameter and describes the ermodynamic propensity of a metal to take part in electrochemical actions. It has found widespread acceptance among corrosion searchers due to its connection to the corrosion potential and its sy measurability in local scale, being often used to study localised rrosion phenomena and micro-galvanic activities. The principle object this paper is to provide a comprehensive, fundamental insight into e meaning of the Volta potential and to define a polarity convention measured potentials by the scanning Kelvin probe force microscopy KPFM) in order to assess local nobilities in microstructures. nditions to relate the Volta potential with the mixed-potential theory e discussed and a possible connection to corrosion phenomena plained. The limitations of the Volta potential as well as the SKPFM chnique are also aimed to be explained, with some practical formation to maximise the output of high quality data.

  • 126792.
    Örnek, Cem
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Leygraf, Christopher
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Pan, Jinshan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Passive film characterisation of duplex stainless steel using scanning Kelvin probe force microscopy in combination with electrochemical measurements2019In: npJ Materials Degradation, ISSN 2397-2106, Vol. 3, no 1, p. 1-8Article in journal (Refereed)
    Abstract [en]

    The characterisation of passive oxide films on heterogeneous microstructures is needed to assess local degradation (corrosion, cracking) in aggressive environments. The Volta potential is a surface-sensitive parameter which can be used to assess the surface nobility and hence passive films. In this work, it is shown that the Volta potential, measured on super duplex stainless steel by scanning Kelvin probe force microscopy, correlates with the electrochemical properties of the passive film, measured by electrochemical impedance spectroscopy and potentiodynamic polarisation. Natural oxidation by ageing in ambient air as well as artificial oxidation by immersion in concentrated nitric acid improved the nobility, both reflected by increased Volta potentials and electrochemical parameters. Passivation was associated with vanishing of the inherent Volta potential difference between the ferrite and austenite, thereby reducing the galvanic coupling and hence improving the corrosion resistance of the material. Hydrogen-passive film interactions, triggered by cathodic polarisation, however, largely increased the Volta potential difference between the phases, resulting in loss of electrochemical nobility, with the ferrite being more affected than the austenite. A correlative approach of using the Volta potential in conjunction with electrochemical data has been introduced to characterise the nobility of passive films in global and local scale.

  • 126793.
    Örnek, Cem
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. Swerea KIMAB AB, Isafjordsgatan 28A, Kista, 164 40, Sweden.
    Liu, Min
    Univ Sci & Technol Beijing, Natl Ctr Mat Serv Safety, Xueyuan Rd 30, Beijing 100083, Peoples R China..
    Pan, Ying
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Jin, Y.
    Univ Sci & Technol Beijing, Natl Ctr Mat Serv Safety, Xueyuan Rd 30, Beijing 100083, Peoples R China..
    Leygraf, Christopher
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Volta Potential Evolution of Intermetallics in Aluminum Alloy Microstructure Under Thin Aqueous Adlayers: A combined DFT and Experimental Study2018In: Topics in catalysis, ISSN 1022-5528, E-ISSN 1572-9028, Vol. 61, no 9-11, p. 1169-1182Article in journal (Refereed)
    Abstract [en]

    In this work, first-principle density functional theory (DFT) was used to calculate the work function and Volta potential differences between aluminum alloy matrix and two intermetallic phases (Mg2Si and Al2Cu) with varying surface terminations as a function of adhering monolayers (ML) of water. The calculated data were compared with experimental local Volta potential data obtained by the scanning Kelvin probe force microscopy (SKPFM) on a commercial aluminum alloy AA6063-T5 in atmospheric environments with varying relative humidity (RH). The calculations suggest that the surface termination has a major effect on the magnitude and polarity of the Volta potential of both intermetallic phases (IMP's). The Volta potential difference between the IMP's and the aluminum matrix decreases when the surface is gradually covered by water molecules, and may further change as a function of adhering ML's of water. This can lead to nobility inversions of the IMP's relative to the aluminum matrix. The measured Volta potential difference between both IMP's and their neighboring matrix is dependent on RH. Natural oxidation in ambient indoor air for 2 months led to a nobility inversion of the IMP's with respect to the aluminum matrix, with the intermetallics showing anodic nature already in dry condition. The anodic nature of Al2Cu remained with the introduction of RH, whereas Mg2Si became cathodic at high RH, presumably due to de-alloying of Mg and oxide dissolution. The DFT calculations predicted an anodic character of both IMP's in reference to the oxidized aluminum matrix, being in good agreement with the SKPFM data. The DFT and SKPFM data were discussed in light of understanding localized corrosion of aluminum alloys under conditions akin to atmospheric exposure.

  • 126794.
    Örnek, Cem
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Långberg, Marie
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Evertsson, Jonas
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Harlow, Gary
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Linpe, Weronica
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Rullik, Lisa
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Carla, Francesco
    European Synchrotron Radiat Facil, F-38000 Grenoble, France..
    Felici, Roberto
    Area Ric Roma 2 Tor Vergata, SPINCNR, I-00133 Rome, Italy..
    Bettini, Eleonora
    Sandvik Mat Technol, SE-81181 Sandviken, Sweden..
    Kivisakk, Ulf
    Sandvik Mat Technol, SE-81181 Sandviken, Sweden..
    Lundgren, Edvin
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Pan, Jinshan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    In-situ synchrotron GIXRD study of passive film evolution on duplex stainless steel in corrosive environment2018In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 141, p. 18-21Article in journal (Refereed)
    Abstract [en]

    This paper presents new findings about the passive film formed on super duplex stainless steel in ambient air and corrosive environments, studied by synchrotron grazing-incidence X-ray diffraction (GIXRD). The passive film, formed in air, was seen to be a nano-crystalline mixed-oxide. Electrochemical polarisation to the passive region in aqueous 1 M NaCl at room temperature resulted in an increase of the passive film thickness, preferential dissolution of Fe, and partial loss of crystallinity. After termination of polarization to the transpassive regime, reformation of the mixed-oxides was observed, showing a thicker, semi-crystalline, and more defective nature (more vacancies) with further new oxides/hydroxides.

  • 126795.
    Örnek, Cem
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Långberg, Marie
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. Swerim, SE-16407 Kista, Sweden..
    Evertsson, Jonas
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden.;Deutsch Elektronen Synchrotron DESY, D-22607 Hamburg, Germany.;Justus Liebig Univ Giessen, Phys Chem Dept, D-35392 Giessen, Germany..
    Harlow, Gary
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Linpe, Weronica
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Rullik, Lisa
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Carla, Francesco
    Diamond Light Source, Didcot OX11 0DE, Oxon, England..
    Felici, Roberto
    SPINCNR, Area Ric Roma 2 Tor Vergata, I-00133 Rome, Italy..
    Kivisakk, Ulf
    Sandvik Mat Technol, SE-81181 Sandviken, Sweden..
    Lundgren, Edvin
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Pan, Jinshan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Influence of Surface Strain on Passive Film Formation of Duplex Stainless Steel and Its Degradation in Corrosive Environment2019In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 166, no 11, p. C3071-C3080Article in journal (Refereed)
    Abstract [en]

    The effect of surface strain on the passive film evolution of SAF 2507 super duplex stainless steel exposed to ambient air and 0.1 M NaCl solution with varying anodic polarization at room temperature has been investigated using in-situ grazing incidence X-ray diffraction (GIXRD) in combination with electrochemical measurements. Surface strain affected the crystallinity of the passive film as such that the surface oxides/hydroxides were predominantly amorphous, with some minor crystalline CrOOH and FeOOH present in the film. Crystalline CrOOH was seen to diminish in volume upon immersion in the NaCl solution, well-possibly becoming amorphous during anodic polarization, whereas crystalline FeOOH was seen to increase in volume during polarization to the passive potential regime. Strain relaxation, associated with metal dissolution, occurred in both austenitic and ferritic grains during immersion in the electrolyte. Anodic polarization to the transpassive regime led to maximum strain relaxation, occurring more on the austenite than the ferrite. The selective transpassive dissolution nature of the ferrite was significantly reduced due to large strains in the austenite. Passive film breakdown was reflected by enhanced dissolution of Fe, Cr, Mo and Ni occurring simultaneously around 1300 mV vs. Ag/AgCl. 

  • 126796.
    Örnek, Cem
    et al.
    KTH.
    Reccagni, Pierfranco
    Kivisakk, Ulf
    Bettini, Eleonora
    Engelberg, Dirk L.
    Pan, Jinshan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Hydrogen embrittlement of super duplex stainless steel - Towards understanding the effects of microstructure and strain2018In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 43, no 27, p. 12543-12555Article in journal (Refereed)
    Abstract [en]

    The effects of austenite spacing, hydrogen charging, and applied tensile strain on the local Volta potential evolution and micro-deformation behaviour of grade 2507 (UNS 532750) super duplex stainless steel were studied. A novel in-situ methodological approach using Digital Image Correlation (DIC) and Scanning Kelvin Probe Force Microscopy (SKPFM) was employed. The microstructure with small austenite spacing showed load partitioning of tensile micro-strains to the austenite during elastic loading, with the ferrite then taking up most tensile strain at large plastic deformation. The opposite trend was seen when the microstructure was pre-charged with hydrogen, with more intense strain localisation formed due to local hydrogen hardening. The hydrogen-charged microstructure with large austenite spacing showed a contrasting micro-mechanical response, resulting in heterogeneous strain localisation with high strain intensities in both phases in the elastic regime. The austenite was hydrogen-hardened, whereas the ferrite became more strain-hardened. SKPFM measured Volta potentials revealed the development of local cathodic sites in the ferrite associated with hydrogen damage (blister), with anodic sites related to trapped hydrogen and/or micro voids in the microstructure with small austenite spacing. Discrete cathodic sites with large Volta potential variations across the ferrite were seen in the coarse-grained microstructure, indicating enhanced susceptibility to micro-galvanic activity. Microstructures with large austenite spacing were more susceptible to hydrogen embrittlement, related to the development of tensile strains in the ferrite.

  • 126797.
    Örnek, Cem
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. University of Manchester, UK.
    Walton, J.
    Hashimoto, T.
    Ladwein, T. L.
    Lyon, S. B.
    Engelberg, D. L.
    Characterization of 475 degrees C Embrittlement of Duplex Stainless Steel Microstructure via Scanning Kelvin Probe Force Microscopy and Magnetic Force Microscopy2017In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 6, p. C207-C217Article in journal (Refereed)
    Abstract [en]

    Scanning Kelvin probe force microscopy (SKPFM) measured local Volta potentials in microstructure of 22Cr-5Ni duplex stainless steel have been correlated to microstructure development with aging treatments at 475 degrees C. Magnetic force microscopy (MFM) was employed to differentiate crystallographic phases to provide complementary information. The absolute Volta potentials of both ferrite and austenite increased after 5 hours of aging, indicating electrochemical ennoblement of the entire microstructure. Longer aging resulted in a gradual decrease of measured Volta potentials in both phases. The microstructure showed after 255 hours aging up to 2.5-times larger potential differences than in the as-received condition, indicating impaired electrochemical nobility. In the as-received microstructure, the ferrite phase was less noble than the austenite, whereas after 5 hours aging both phases had similar, balanced Volta potentials which indicated a balanced nobility of ferrite and austenite. Longer aging treatment caused severe loss of nobility for the entiremicrostructure, with ferrite showing larger changes in Volta potential than the austenite. Spinodal microstructure decomposition and associated phase reactions of the ferrite, with elemental redistribution in the austenite, are the reason for the observed changes in microstructure nobility.

  • 126798.
    Örning, Camilla
    KTH, School of Industrial Engineering and Management (ITM).
     Konceptutveckling av en stereotaktisk huvudram för användning inom neurokirurgi2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

     

     

    This report presents the development of a concept for a new stereotactic head frame for use in neurosurgery. The work has been performed at Elekta Instrument AB, which is one of the world's leading companies for the development of equipment that is used to treat cancer and other diseases of the brain.

     

    Doublebend

     The conclusions of the work are that the developed concept has the potential to progress into a quality product, however much work remains. Further analysis, material testing and detailed design remain as future work.

  • 126799.
    Örnstedt, Karolina
    KTH, School of Engineering Sciences (SCI).
    En studie av kompetensutveckling och utbilding av erfarna projektledare på Vectura Consulting AB2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 126800.
    Örtegren, Jonas
    KTH, Superseded Departments, Polymer Technology.
    Liquid crystalline polymers for nonlinear optics: pyroelectric polymers and ferroelectric dendrimers2001Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    This thesis deals with liquid crystalline materialsincluding monomers, side-chain polymers, crosslinked polymers,and dendrimers. The materials are pyroelectric, meaning thatthere is a macroscopic electric polarization in the material,which is energetically stable in the absence of externalfields. The energetically stable, or spontaneous, polarizationmakes the material suitable for second-order nonlinear optics(NLO). Examples of second order NLO processes are secondharmonic generation (SHG), optical parametric amplification,and processes involving modulations of the refractive indices.In isotropic polymeric systems, the material is made secondorder NLO active by applying an electric field at hightemperatures, thereby inducing polar order, and by cooling toroom temperature with the field applied. The polarization isthereby "locked-in" into the polymer, and the material issecond-order NLO active. Such systems often loose polar order,and thereby second order NLO response, quite rapidly. The polarorder in pyroelectric materials is however energeticallystable, and one may therefore expect better time-dependentsecond order NLO properties in these materials. In this work,pyroelectric polymers were prepared by photopolymerization ofsurface stabilized ferroelectricliquid crystals. Thephotopolymerized material showed a clear second order NLOresponse, as measured by SHG, also in the absence of anexternal electric field. The d23-coefficient was 0.25 pm V-1. Furthermore, the pyroelectric polymers werestable at room temperature for approximately 50 days. In orderto improve the thermal stability of the polymers, a crosslinkedpolymer system was prepared, which exhibited improved thermalstability, compared to the uncrosslinked polymers. Thecrosslinked polymers were unaffected by aging at 130°C forseveral hours. The thermal stability of the polymers wasfurther analyzed by a pyroelectric technique. The largestestimated pyroelectric coefficient was 2 nC cm-2K-1. The crosslinked polymer showed a weak but clearpyroeletric response even after being heated to 260 °C.Novel liquid crystalline dendrimers of different generationwere also studied. The dendrimers were ferroelectric, meaningthat there are two stable polarization states in the material,and that the polarization may be reversed by application of anelectric field. The dendrimers showed a slightly lower value ofspontaneous polarization than their low molar mass analogue.The spontaneous polarization of the LC dendrimers wasapproximately 40 nC cm-2, and was basically independent of the generationnumber of the dendrimer. A clear, but rather small SHG responsewas recorded in these systems. By incorporating a nitro-groupin the mesogen of the LC dendrimer, the d23- coefficient of the second order NLO responsecould be improved by a factor 3, to 0.03 pm V-1. This thesis gives an introduction topyroelectricity, ferroelectricity, and linear and nonlinearoptical effects in materials. It further contains descriptionsof various techniques that were used to characterize the novelliquid crystalline materials. It discusses the results from themeasurements and the properties of the liquid crystallinematerials, with focus on second order NLO.

2533253425352536253725382539 126751 - 126800 of 127252
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf