High resolution 3-dimensional tomography with X-rays at Singapore synchrotron light source

10.1016/j.nimb.2007.01.276Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms260145-48NIMB

El desplazamiento forzado en Colombia : 10 años de la sentencia T-025 de 2004 : ponencias ganadoras del IV Concurso Nacional de Semilleros de Investigación

"Al igual que en los tres años anteriores, la Universidad del Rosario, por conducto del Observatorio Legislativo y el Grupo de Investigación en Derechos Humanos de la Facultad de Jurisprudencia, se ha asociado con la Fundación Hanns Seidel para organizar el Concurso Nacional de Semilleros de Investigación, el cual tiene por objeto promover e incentivar entre los estudiantes de diferentes áreas del conocimiento, la investigación enfocada hacia temáticas de especial relevancia para el país, lo cual representa un aporte que, desde la etapa de formación, los futuros profesionales de nuestra nación hacen para el análisis y la reflexión de esos temas. Entendiendo la importancia de que las nuevas generaciones de profesionales se comprometan y construyan una visión propia y estructurada de esos temas, la cuarta versión del concurso buscó hacer una reflexión, desde diversas perspectivas, alrededor del desplazamiento forzado en Colombia y las medidas que se han adoptado desde la declaratoria del estado de cosas inconstitucional de la Sentencia T-025 de 2004, proferida por la Corte Constitucional."--presentación

X-ray phase-contrast imaging with an inverse compton scattering source

Abstract Single-shot in-line phase-contrast imaging with the Inverse Compton Scattering X-ray source available at ATF (Accelerator Test Facility) at Brookhaven National Laboratory is experimentally demonstrated. Phase-contrast images of polymer wires are obtained with a single X-ray pulse whose time length is about 1 picosecond. The edge-enhancement effect is clearly visible in the images and simulations show a quantitative agreement with experimental data. A phase-retrieval step in the image processing leads to a accurate estimation of the projected thickness of our samples. Finally, a single-shot image of a wasp is presented as an example of a biological sample. © 2010 American Institute of Physics

Applications of phase-contrast X-ray microscopy in an SEM

We have developed a new approach to SEM-based X-ray projection microscopy which utilises phase contrast to enhance the quality and information content of images. The development of SEMs based on highbrightness field emission guns and highly sensitive CCD cameras enables us to produce an extremely fine microfocus source with sufficient flux for imaging. By combining this fine source with an appropriate imaging geometry, phase contrast arising from Fresnel diffraction at edges and boundaries within the sample leads to images with greatly enhanced edge detail. We have also developed phase-retrieval algorithms for quantitative determination of the projected phase shift in the object-plane from either a single image or multiple images acquired at different energies or magnifications. These developments have been realised in an instrument, dubbed the X-ray ultramicroscope (XuM), which has enabled us to acquired images down to ~200 nm resolution. Examples of applications of the XuM are described here including the use of phase-retrieval algorithms and microtomography

Quantitative investigation of phase retrieval from x-ray phase-contrast tomographic images

10.1117/12.794497Proceedings of SPIE - The International Society for Optical Engineering7078-PSIS