@article{SokolowskiTintenHornvonHoegenvonderLindeetal., author = {Sokolowski-Tinten, Klaus and Horn-von Hoegen, Michael and von der Linde, D. and Cavalleri, Andrea and Siders, C. W. and Brown, F. L. H. and T{\´o}th, Csaba and Squier, Jeff A. and Barty, C. P. J. and Wilson, K. R. and Kammler, Martin}, title = {Time-resolved x-ray diffraction study of ultrafast acoustic phonon dynamics in Ge/Si-heterostructures}, series = {International Conference on Ultrafast Phenomena , 9 July 2000, Charleston}, journal = {International Conference on Ultrafast Phenomena , 9 July 2000, Charleston}, publisher = {Optica}, abstract = {Using time-resolved x-ray diffraction the ultafast strain dynamics in fs-laserexcited Ge/Si-heterostructures has been studied. A fluence dependent, anharmonic damping of the impulsively generated acoustic phonons and vibrational transport across the buried Ge/Si-interface are observed.}, language = {en} } @article{SidersCavalleriSokolowskiTintenetal., author = {Siders, C. W. and Cavalleri, Andrea and Sokolowski-Tinten, Klaus and T{\´o}th, Csaba and Guo, T. and Kammler, Martin and Horn-von Hoegen, Michael and Wilson, K. R. and von der Linde, D. and Barty, C. P. J.}, title = {Detection of nonthermal melting by ultrafast X-ray diffraction}, series = {Science}, volume = {286}, journal = {Science}, number = {5443}, doi = {10.1126/science.286.5443.1340}, pages = {1340 -- 1342}, abstract = {Using ultrafast, time-resolved, 1.54 angstrom x-ray diffraction, thermal and ultrafast nonthermal melting of germanium, involving passage through nonequilibrium extreme states of matter, was observed. Such ultrafast, optical-pump, x-ray diffraction probe measurements provide a way to study many other transient processes in physics, chemistry, and biology, including direct observation of the atomic motion by which many solid-state processes and chemical and biochemical reactions take place.}, language = {en} } @article{ReinkingKammlerHoffmannetal., author = {Reinking, D. and Kammler, Martin and Hoffmann, N. and Horn-von Hoegen, Michael and Hofmann, K. R.}, title = {Fabrication of high-mobility Ge p-channel MOSFETs on Si substrates}, series = {Electronics Letters}, volume = {35}, journal = {Electronics Letters}, number = {6}, publisher = {IET}, doi = {10.1049/el:19990349}, pages = {503 -- 504}, abstract = {The first fabrication of Ge p-channel MOSFETs (p-MOSFETs) on Si substrates is reported. A CMOS compatible process based on relaxed Ge layers grown on Si(111) substrates by surfactant mediated epitaxy (SME) was used. The non-optimised low temperature process yielded normally-off Ge p-MOSFETs with record channel drift mobilities of 430 cm2/Vs}, language = {en} } @article{SidersCavalleriSokolowskiTintenetal., author = {Siders, C. W. and Cavalleri, Andrea and Sokolowski-Tinten, Klaus and T{\´o}th, Csaba and Guo, T. and Kammler, Martin and Horn-von Hoegen, Michael and Wilson, K. R. and von der Linde, D. and Barty, C. P. J.}, title = {Direct Observation of Ultrafast Non-thermal Melting by Ultrafast X-ray Diffraction}, series = {Ultrafast Phenomena XII}, volume = {66}, journal = {Ultrafast Phenomena XII}, publisher = {Springer}, doi = {10.1007/978-3-642-56546-5_80}, pages = {276 -- 280}, abstract = {Ultrafast nonthermal melting of femtosecond laser-irradiated germanium was observed directly for the first time using sub-picosecond, 1.54-angstrom x-ray diffraction. Such measurements allow the study of transient atomic motion fundamental to many processes in physics, chemistry, and biology.}, language = {en} } @incollection{SokolowskiTintenvonderLindeSidersetal., author = {Sokolowski-Tinten, Klaus and von der Linde, D. and Siders, C. W. and Cavalleri, Andrea and T{\´o}th, Csaba and Guo, T. and Wilson, K. R. and Barty, C. P. J. and Kammler, Martin and Horn-von Hoegen, Michael}, title = {Lattice dynamics of femtosecond laser-excited semiconductors probed by ultrafast x-ray diffraction}, series = {Applications of High Field and Short Wavelength Sources VIII}, booktitle = {Applications of High Field and Short Wavelength Sources VIII}, publisher = {Optica}, doi = {10.1364/HFSW.1999.PD3}, abstract = {The present knowledge of the atomic structure of matter is to a large extent due to x-ray spectroscopies.}, language = {en} } @article{SteindlMittermayrSakoparnigetal., author = {Steindl, Florian R. and Mittermayr, Florian and Sakoparnig, Marlene and Juhart, Joachim and Briendl, Lukas G. and Lindlar, Benedikt and Ukrainczyk, Neven and Dietzel, Martin and Kusterle, Wolfgang and Galan, Isabel}, title = {On the porosity of low-clinker shotcrete and accelerated pastes}, series = {Construction and Building Materials}, volume = {368}, journal = {Construction and Building Materials}, publisher = {Elsevier}, address = {14}, issn = {0950-0618}, doi = {10.1016/j.conbuildmat.2023.130461}, abstract = {Although the number and size of interconnected pores have been identified as the most important aspects of concrete microstructure, comprehensive datasets on shotcrete porosity and pore size distributions are still scarce and their key controls are poorly investigated. In this study we investigate the effects of the spraying process, setting accelerator addition and mix design on the microstructure of real-scale dry- and wet-mix shotcrete and hand-mixed and sprayed accelerated pastes. A newly proposed deconvolution analysis of the pore size distributions, measured by mercury intrusion porosimetry, offers increased precision in determining the critical and median pore diameter parameters. In total >50 samples were analysed. Results show that the dry-mix shotcrete exhibits a shift towards coarser pore sizes (∼100-1 μm) than wet-mix shotcrete. Combinations of different supplementary cementitious materials are favourable for producing wet-mix shotcretes with refined pore structures. The addition of setting accelerators, up to 10 wt-\% of binder mass, and the spraying process cause systematic variations in the pore volume and pore structure of (sprayed) paste and shotcrete.}, language = {en} } @article{KrenzerHanischBlicharskiSchneideretal., author = {Krenzer, Boris and Hanisch-Blicharski, Anja and Schneider, Paul and Payer, Thomas and M{\"o}llenbeck, Simone and Osmani, O. and Kammler, Martin and Meyer, R. and Horn-von Hoegen, Michael}, title = {Phonon confinement effects in ultrathin epitaxial bismuth films on silicon studied by time-resolved electron diffraction}, series = {Physical Review B}, volume = {80}, journal = {Physical Review B}, number = {2}, publisher = {APS}, doi = {10.1103/PhysRevB.80.024307}, abstract = {The transient temperature evolution of ultrathin bismuth films, epitaxially grown on a silicon single crystal, upon femtosecond laser excitation is studied by time-resolved electron diffraction. The exponential decay of the film temperature is explained by phonon reflection at the interface, which results in a strongly reduced thermal conduction in the cross plane of the layered system. The thermal boundary conductance is found to be as low as 1273 W/(K cm2). Model calculations, including phonon confinement effects, explain the linear relationship between the observed film-temperature decay constant and the film thickness. Even for 2.5 nm thin films the phonon transmission probability across the interface is given by bulk properties. Our simulations show that phonon confinement effects are negligible for bismuth-film thicknesses larger than 1 nm.}, language = {en} } @article{IlgnerPalmSchuetzetal., author = {Ilgner, Justus F. R. and Palm, Christoph and Sch{\"u}tz, Andreas G. and Spitzer, Klaus and Westhofen, Martin and Lehmann, Thomas M.}, title = {Colour Texture Analysis for Quantitative Laryngoscopy}, series = {Acta Otolaryngologica}, volume = {123}, journal = {Acta Otolaryngologica}, doi = {10.1080/00016480310000412}, pages = {730 -- 734}, abstract = {Whilst considerable progress has been made in enhancing the quality of indirect laryngoscopy and image processing, the evaluation of clinical findings is still based on the clinician's judgement. The aim of this paper was to examine the feasibility of an objective computer-based method for evaluating laryngeal disease. Digitally recorded images obtained by 90 degree- and 70 degree-angled indirect rod laryngoscopy using standardized white balance values were made of 16 patients and 19 healthy subjects. The digital images were evaluated manually by the clinician based on a standardized questionnaire, and suspect lesions were marked and classified on the image. Following colour separation, normal vocal cord areas as well as suspect lesions were analyzed automatically using co-occurrence matrices, which compare colour differences between neighbouring pixels over a predefined distance. Whilst colour histograms did not provide sufficient information for distinguishing between healthy and diseased tissues, consideration of the blue content of neighbouring pixels enabled a correct classification in 81.4\% of cases. If all colour channels (red, green and blue) were regarded simultaneously, the best classification correctness obtained was 77.1\%. Although only a very basic classification differentiating between healthy and diseased tissue was attempted, the results showed progress compared to grey-scale histograms, which have been evaluated before. The results document a first step towards an objective, machine-based classification of laryngeal images, which could provide the basis for further development of an expert system for use in indirect laryngoscopy.}, language = {en} } @inproceedings{HassanIlgnerPalmetal., author = {Hassan, H. and Ilgner, Justus F. R. and Palm, Christoph and Lehmann, Thomas M. and Spitzer, Klaus and Westhofen, Martin}, title = {Objective Judgement of Endoscopic Laryngeal Images}, series = {Advances in Quantitative Laryngoscopy, Voice and Speech Research, Proceedings of the 3rd International Workshop, RWTH Aachen}, booktitle = {Advances in Quantitative Laryngoscopy, Voice and Speech Research, Proceedings of the 3rd International Workshop, RWTH Aachen}, editor = {Lehmann, Thomas M. and Spitzer, Klaus and Tolxdorff, Thomas}, pages = {135 -- 142}, abstract = {Video Documentation of endoscopic findings simplifies diagnostic counseling of the patient and aids pre-operative discussion among the medical team. Judgment of such images is still subjective and can not give a quantitative evaluation of the disease process regarding diagnosis or response to treatment. Modern treatment of early laryngeal cancer with laserablation requires intensive follow up and frequent direct laryngoscopy under general anesthesia with blind biopsies to detect any tumor residual or recurrence. Inflammatory conditions of the larynx are frequently confused with other causes of dysphonia. Mapping anddigital analysis of the documented image will suggest the tumor site and avoids undue blind biopsies under anesthesia. However, varying illumination results in different colors reflected from the same object. To achieve quantitative analysis, color constancy has to be assured. Inthis paper, the environment is presented which allow the objective judgment of larngoscopies.}, language = {en} }