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2019


The acoustic hologram and particle manipulation with structured acoustic fields
The acoustic hologram and particle manipulation with structured acoustic fields

Melde, K.

Karlsruher Institut für Technologie (KIT), May 2019 (phdthesis)

Abstract
This thesis presents holograms as a novel approach to create arbitrary ultrasound fields. It is shown how any wavefront can simply be encoded in the thickness profile of a phase plate. Contemporary 3D-printers enable fabrication of structured surfaces with feature sizes corresponding to wavelengths of ultrasound up to 7.5 MHz in water—covering the majority of medical and industrial applications. The whole workflow for designing and creating acoustic holograms has been developed and is presented in this thesis. To reconstruct the encoded fields a single transducer element is sufficient. Arbitrary fields are demonstrated in transmission and reflection configurations in water and air and validated by extensive hydrophone scans. To complement these time-consuming measurements a new approach, based on thermography, is presented, which enables volumetric sound field scans in just a few seconds. Several original experiments demonstrate the advantages of using acoustic holograms for particle manipulation. Most notably, directed parallel assembly of microparticles in the shape of a projected acoustic image has been shown and extended to a fabrication method by fusing the particles in a polymerization reaction. Further, seemingly dynamic propulsion from a static hologram is demonstrated by controlling the phase gradient along a projected track. The necessary complexity to create ultrasound fields with set amplitude and phase distributions is easily managed using acoustic holograms. The acoustic hologram is a simple and cost-effective tool for shaping ultrasound fields with high-fidelity. It is expected to have an impact in many applications where ultrasound is employed.

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link (url) DOI [BibTex]

2019



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X-ray microscopic characterization of high-Tc-supercoductors using image processing

Bihler, M.

Universität Stuttgart, Stuttgart, 2019 (mastersthesis)

mms

[BibTex]


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Novel X-ray lenses for direct and coherent imaging

Sanli, U. T.

Universität Stuttgart, Stuttgart, 2019 (phdthesis)

mms

link (url) DOI [BibTex]

link (url) DOI [BibTex]


Dynamics of self-propelled colloids and their application as active matter
Dynamics of self-propelled colloids and their application as active matter

Choudhury, U.

University of Groningen, Zernike Institute for Advanced Materials, 2019 (phdthesis)

Abstract
In this thesis, the behavior of active particles spanning from single particle dynamics to collective behavior of many particles is explored. Active colloids are out-of equilibrium systems that have been studied extensively over the past 15 years. This thesis addresses several phenomena that arise in the field of active colloids.

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link (url) [BibTex]

link (url) [BibTex]

2007


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On the theory of magnetization dynamics of non-collinear spin systems in the s-d model

De Angeli, L.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

2007


[BibTex]


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Zur ab-initio Elektronentheorie des Magnetismus bei endlichen Temperaturen

Dietermann, F.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Röntgenzirkulardichroische Untersuchungen an ferromagnetischen verdünnten Halbleitersystemen

Tietze, T.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Low-dimensional Fe on vicinal Ir(997): Growth and magnetic properties

Kawwam, M.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Macke, S.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Schmitz, B.

Universität Bonn, Bonn, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Towards spin injection into silicon

Dash, S. P.

Universität Stuttgart, Stuttgart, 2007 (phdthesis)

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link (url) [BibTex]

link (url) [BibTex]


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Soehnle, S.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Puzic, A.

Universität Stuttgart, Stuttgart, 2007 (phdthesis)

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link (url) [BibTex]

link (url) [BibTex]


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Chou, K. W.

Universität Stuttgart, Stuttgart, 2007 (phdthesis)

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link (url) [BibTex]

link (url) [BibTex]


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Resonante magnetische Reflektometrie an Ferromagnet/Paramagnet Heterostrukturen

Ferreras Paz, V.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Herstellung und Charakterisierung dünner Niob-Schichten auf verschiedenen Substraten

Mayer, M. W. R.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Formation of hard magnetic L10-FePt/FePd monolayers from elemental multilayers

Goo, N. H.

Universität Stuttgart, Stuttgart, 2007 (phdthesis)

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link (url) [BibTex]

link (url) [BibTex]


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Köberle, I.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Theorie der Kernspektroskopie mit zirkular polarisierter Gammastrahlung

Engelhart, W.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Untersuchung der Adsorption von Wasserstoff in porösen Materialien

Hönes, K.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Untersuchung der mechanischen Eigenschaften dünner Chromschichten

Jüllig, P.

Universität Stuttgart, Stuttgart, 2007 (mastersthesis)

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[BibTex]

[BibTex]


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Elektronentheorie der magnetischen EXAFS

Gü\ssmann, M.

Universität Stuttgart, Stuttgart, 2006 (mastersthesis)

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[BibTex]

[BibTex]


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Elektronenspektroskopie an Übergangsmetallclustern

He\ssler, M.

Bayerische Julius-Maximilians-Universität, Würzburg, 2006 (phdthesis)

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[BibTex]

[BibTex]


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Hydrogen storage by physisorption on porous materials

Panella, B.

Universität Stuttgart, Stuttgart, 2006 (phdthesis)

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link (url) [BibTex]

link (url) [BibTex]


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Theory of magnetic x-ray reflectometry on the Co2Pt7 multilayer system

Martosiswoyo, L.

Universität Stuttgart, Stuttgart, 2006 (mastersthesis)

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[BibTex]

[BibTex]


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Magnetischer zirkularer Röntgendichroismus an Übergangsmetalloxiden

Lafkioti, M.

Universität Stuttgart, Stuttgart, 2006 (mastersthesis)

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[BibTex]

[BibTex]


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Contributions to the theory of x-ray magnetic dichroism

Dörfler, F.

Universität Stuttgart, Stuttgart, 2006 (mastersthesis)

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[BibTex]

[BibTex]