Tracing an Uneven History: Notes on Sources and Trajectories of Thai State Violence

Haberkorn, Tyrell 서울대학교 통일평화연구원 2013 Asian Journal of Peacebuilding Vol.1 No.1

This research note outlines a series of questions about conducting research on state violence and human rights in Thailand. Taking as a central problem the recurrence of state violence across regimes both dictatorial and democratic in the 80 years since the end of the absolute monarchy, I argue that the failure to secure accountability for state violence can productively be placed at the center of researching and writing about modern Thai history. Unevenness is common both to the attempts to secure state accountability for state violence and to the available archival and other sources for writing histories of such violence. This research note examines the particular methodological and analytical difficulties and productive possibilities presented by the partial attempts and failures to secure state accountability and the equally partial available documentation of state violence.

Reactive nanorods based on activated ester polymers: a versatile template-assisted approach for the fabrication of functional nanorods

Haberkorn, Niko,Nilles, Katja,Schattling, Philipp,Theato, Patrick Royal Society of Chemistry 2011 Polymer chemistry Vol.2 No.3

<P>A new route for the fabrication of polymeric nanorods with functional moieties <I>via</I> post-modification of reactive nanorods is described. To this end reactive nanorods with a homogenous and narrow size distribution were fabricated by utilizing an anodic aluminium oxide (AAO) template-assisted approach. The nanorods are based on activated pentafluorophenyl esters, to enable quantitative post-modification with amines under very mild reaction conditions yielding the corresponding functionalized amide. Post-modification with fluorescent dyes as well as the conversion into well-dispersed rod-shaped poly(<I>N</I>-isopropylacrylamide) (PNIPAM) hydrogels that exhibit a thermal-responsive phase transition was demonstrated. The platform of reactive nanorods provides the fabrication of various functional nanoobjects and may find application in research fields like drug delivery.</P> <P>Graphic Abstract</P><P>A new route for the fabrication of polymeric nanorods with functional moieties <I>via</I> post-modification of reactive nanorods based on activated pentafluorophenyl esters is described. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0py00314j'> </P>

Template-Based Preparation of Free-Standing Semiconducting Polymeric Nanorod Arrays on Conductive Substrates

Haberkorn, Niko,Weber, Stefan A. L.,Berger, Rü,diger,Theato, Patrick American Chemical Society 2010 ACS APPLIED MATERIALS & INTERFACES Vol.2 No.6

<P>We describe the synthesis and characterization of a cross-linkable siloxane-derivatized tetraphenylbenzidine (DTMS-TPD), which was used for the fabrication of semiconducting highly ordered nanorod arrays on conductive indium tin oxide or Pt-coated substrates. The stepwise process allow fabricating of macroscopic areas of well-ordered free-standing nanorod arrays, which feature a high resistance against organic solvents, semiconducting properties and a good adhesion to the substrate. Thin films of the TPD derivate with good hole-conducting properties could be prepared by cross-linking and covalently attaching to hydroxylated substrates utilizing an initiator-free thermal curing at 160 °C. The nanorod arrays composed of cross-linked DTMS-TPD were fabricated by an anodic aluminum oxide (AAO) template approach. Furthermore, the nanorod arrays were investigated by a recently introduced method allowing to probe local conductivity on fragile structures. It revealed that more than 98% of the nanorods exhibit electrical conductance and consequently feature a good electrical contact to the substrate. The prepared nanorod arrays have the potential to find application in the fabrication of multilayered device architectures for building well-ordered bulk-heterojunction solar cells.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2010/aamick.2010.2.issue-6/am100085t/production/images/medium/am-2010-00085t_0002.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am100085t'>ACS Electronic Supporting Info</A></P>

Templated Organic and Hybrid Materials for Optoelectronic Applications

Haberkorn, Niko,Lechmann, Maria C.,Sohn, Byeong Hyeok,Char, Kookheon,Gutmann, Jochen S.,Theato, Patrick WILEY-VCH Verlag 2009 Macromolecular Rapid Communications Vol.30 No.14

<P>The review highlights different approaches to template organic materials as well as hybrid materials that find or are expected to find application in optoelectronic devices. The first templating approach focuses on the use of preformed nanoporous membranes as templates for organic materials and polymeric materials. Such nanoporous templates can be track-etched membranes, anodic aluminum oxide membranes and other variants thereof, or block copolymer templates. Further, opals have been described as templates. In the second part, we have summarized developments that take advantage of self-assembly processes to pattern hybrid materials. Examples are sol-gel templating techniques using amphiphiles, evaporation-induced self-assembly, lyotropic templating as well as templating from block copolymers. Both routes are very promising templating approaches for optoelectronic materials and represent complementary rather than competing techniques.</P><P> <img src='wiley_img/10221336-2009-30-14-MARC200900213-gra001.gif' alt='wiley_img/10221336-2009-30-14-MARC200900213-gra001'> </P> <B>Graphic Abstract</B> <P>This review compiles different approaches to template organic materials as well as hybrid materials that find application in optoelectronic devices. Two templating approaches are presented and discussed in detail, e.g. the use of preformed nanoporous membranes as templates for organic materials, and self-assembly processes of materials to pattern hybrid materials. Both routes are very promising templating approaches for optoelectronic materials and represent complementary rather than competing techniques. <img src='wiley_img/10221336-2009-30-14-MARC200900213-content.gif' alt='wiley_img/10221336-2009-30-14-MARC200900213-content'> </P>

Tracing an Uneven History: Notes on Sources and Trajectories of Thai State Violence

( Tyrell Haberkorn ) 서울대학교 통일평화연구원 2013 Asian Journal of Peacebuilding Vol.1 No.1

This research note outlines a series of questions about conducting research on state violence and human rights in Thailand. Taking as a central problem the recurrence of state violence across regimes both dictatorial and democratic in the 80 years since the end of the absolute monarchy, I argue that the failure to secure accountability for state violence can productively be placed at the center of researching and writing about modern Thai history. Unevenness is common both to the attempts to secure state accountability for state violence and to the available archival and other sources for writing histories of such violence. This research note examines the particular methodological and analytical difficulties and productive possibilities presented by the partial attempts and failures to secure state accountability and the equally partial available documentation of state violence.

Strong magnetic field dependence of critical current densities and vortex activation energies in an anisotropic clean MgB₂ thin film

Kim, Jeehoon,Haberkorn, N.,Nazaretski, E.,Paula, R. de,Tan, Teng,Xi, X.X.,Tajima, T.,Movshovich, R.,Civale, L. Elsevier 2015 Solid state communications Vol.204 No.-

<P><B>Abstract</B></P> <P>We report the influence of two-band superconductivity on the flux creep and the critical current densities of a MgB<SUB>2</SUB> thin film. The small magnetic penetration depth of <I>λ</I>=50±10nm at <I>T</I>=4K is related to a clean π-band. We find a high self-field critical current density <I>J</I> <SUB> <I>c</I> </SUB>, which is strongly reduced with applied magnetic field, and attribute this to suppression of the superconductivity in the π-band. The temperature dependence of the creep rate <I>S</I> (<I>T</I>) at low magnetic field can be explained by a simple Anderson–Kim mechanism. The system shows high pinning energies at low field that are strongly suppressed by high field.</P>

Mapping of Local Conductivity Variations on Fragile Nanopillar Arrays by Scanning Conductive Torsion Mode Microscopy

Weber, Stefan A. L.,Haberkorn, Niko,Theato, Patrick,Berger, Rü,diger American Chemical Society 2010 NANO LETTERS Vol.10 No.4

<P>A gentle method that combines torsion mode topography imaging with conductive scanning force microscopy is presented. By applying an electrical bias voltage between tip and sample surface, changes in the local sample conductivity can be mapped. The topography and local conductivity variations on fragile free-standing nanopillar arrays were investigated. These samples were fabricated by an anodized aluminum oxide template process using a thermally cross-linked triphenylamine-derivate semicondcutor. The nanoscale characterization method is shown to be nondestructive. Individual nanopillars were clearly resolved in topography and current images that were recorded simultaneously. Local current−voltage characteristics suggest a space-charge limited conduction in the semiconducting nanopillars.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2010/nalefd.2010.10.issue-4/nl9035274/production/images/medium/nl-2009-035274_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl9035274'>ACS Electronic Supporting Info</A></P>

Characterization of the insulator barrier and the superconducting transition temperature in GdBa₂Cu₃O_7−δ/BaTiO₃ bilayers for application in tunnel junctions

Navarro, H.,Yang, Ilkyu,Sirena, M.,Kim, Jeehoon,Haberkorn, N. American Institute of Physics 2015 Journal of Applied Physics Vol.118 No.4

<P>The optimization of the superconducting properties in a bottom electrode and the quality of an insulator barrier are the first steps in the development of superconductor/insulator/superconductor tunnel junctions. Here, we study the quality of a BaTiO3 tunnel barrier deposited on a 16 nm thick GdBa2Cu3O7-delta thin film by using conductive atomic force microscopy. We find that the tunnel current is systematically reduced (for equal applied voltage) by increasing the BaTiO3 barrier thickness between 1.6 and 4 nm. The BaTiO3 layers present an energy barrier of approximate to 1.2 eV and an attenuation length of 0.35-0.5 nm (depending on the applied voltage). The GdBa2Cu3O7-delta electrode is totally covered by a BaTiO3 thickness above 3 nm. The presence of ferroelectricity was verified by piezoresponse force microscopy for a 4 nm thick BaTiO3 top layer. The superconducting transition temperature of the bilayers is systematically suppressed by increasing the BaTiO3 thickness. This fact can be associated with stress at the interface and a reduction of the orthorhombicity of the GdBa2Cu3O7-delta. The reduction in the orthorhombicity is expected by considering the interface mismatch and it can also be affected by reduced oxygen stoichiometry (poor oxygen diffusion across the BaTiO3 barrier). (C) 2015 AIP Publishing LLC.</P>