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123 results on '"Cusatis C"'

1. Autofinding egg parasitoids in moth eggs by using machine learning methods in synchrotron-coherent X-ray imaging

Author

Rodrigo Perez Vargas, J., Javier Talavera, R., Bostel, R., Rigon, L., Arfelli, F., Menk, Ralf Hendrik, Rocio Foerster, M., Amilton Foerster, L., Cusatis, C., Hönnicke, M. G., Rodrigo Perez Vargas, J., Javier Talavera, R., Bostel, R., Rigon, L., Arfelli, F., Menk, Ralf Hendrik, Rocio Foerster, M., Amilton Foerster, L., Cusatis, C., and Hönnicke, M. G.

Abstract

The use of a non-destructive technique, such as the propagation-based X-ray phase contrast radiography (PBR) can be an innovative method for automatic parasitism analysis, especially if it presents standard structures. Herein, an artificial intelligence (AI) model is applied in order to establish a computer vision of egg parasitoids in PBRs of parasitized moth eggs acquired at the Synchrotron Radiation for Medical Physics (SYRMEP) beamline at ELETTRA. PBRs of eggs parasitized in four different stages of parasitism (0 days, 3 days, 5 days and 7 days) have been tested. The AI model performance was evaluated by using different metrics. Average Precision (AP), which measures the accuracy of object detection, was found to be 0.866 and 0.741 for the moth eggs and for the parasites, respectively. Additionally, we found that as stage of parasitism becomes longer, the accuracy of parasitism detection also increases (76 % at 7 days).

Published
2024
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2. Propagation-based x-ray phase-contrast imaging with broad focus conventional x-ray sources

Author

Hönnicke, M. G., Kakuno, E. M., Manica, J., and Cusatis, C.

Subjects
Condensed Matter - Other Condensed Matter
Abstract

A propagation-based x-ray phase-contrast imaging (PBI) setup using a conventional x-ray source (LFF Cu target) is presented. A virtual x-ray source of 40 x 50 $\mu$$m^2$ was created by using, horizontally, a $6^o$ take-off angle (with the x-ray tube working in the line focus geometry) and, vertically, a 50 $\mu$m slit . The sample was set 12 $m$ from the source. Propagation-based x-ray phase-contrast (PB) image and conventional radiography (CR) of a polypropylene tube were acquired. Edge enhanced effects and a crack, not detected in CR, were clearly seen in the PB image. Contrast, visibility of the object edges and signal to noise ratio of the acquired images were exploited. The results show that PB images can be acquired by using normal focus (macro focus) conventional x-ray sources. This apparatus can be used as an standard phase-contrast imaging setup to analyze different kind of samples with large field of view (75 x 75 $mm^2$), discarding the use of translators for sample and detector., Comment: 8 pages, 3 figures

Published
2007

5. Explaining the Effect of a Grid by Using an Optical Analog to an X-ray Radiographic Imaging System

Author

Honnicke, M. G., Gavinho, L., and Cusatis, C.

Abstract

Compton scattering and diffuse scattering degenerate the contrast in radiographic images. To avoid such scattering effects, a grid, between the patient and the film is currently used to improve the image quality. Teaching this topic to medical physics students requires demonstration experiments. In this paper, an optical analog to an x-ray radiographic imaging system is described. The setup is inexpensive and is easy to be mounted. A He-Ne laser and a set of lenses (objective lens from a microscope + glass magnifier) were employed to direct a huge parallel beam at the sample. A washer glued onto pinhead-frosted glass was used as a sample. The ceramic part of a catalytic converter was used as a grid. The images, acquired by using a photographic digital camera, show the effect of a grid in cleaning the image (higher contrast): the washer, not seen in the image without the grid, is clearly seen in the image with the grid. (Contains 4 figures.)

Published
2008
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22. Plasmon excitation in beryllium: inelastic x-ray scattering experiments and first-principles calculations

Author

Secretaría de Ciencia y Técnica de la Nación (Argentina), Universidad Nacional de Córdoba (Argentina), Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), European Commission, Eusko Jaurlaritza, Tirao, G., Stutz, G., Silkin, Viatcheslav M., Chulkov, Eugene V., Cusatis, C., Secretaría de Ciencia y Técnica de la Nación (Argentina), Universidad Nacional de Córdoba (Argentina), Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), European Commission, Eusko Jaurlaritza, Tirao, G., Stutz, G., Silkin, Viatcheslav M., Chulkov, Eugene V., and Cusatis, C.

Abstract

An experimental and theoretical study of collective electronic excitations in Be is presented. The plasmon energy and linewidth were measured by means of inelastic x-ray scattering spectroscopy. Measurements were performed on a polycrystalline sample and in a broad range of momentum transfers within the plasmon excitation regime. Theoretical plasmon dispersion and its linewidth in the whole Brillouin zone were derived from ab initio evaluations of the electron density response function. The calculations were performed with full inclusion of the electron band structure within the random-phase approximation. Good agreement of experimental plasmon energy and linewidth dispersions with direction-averaged theoretical results in all investigated q-range is obtained. We conclude that, in Be, the band structure effects alone can account for the observed finite plasmon lifetime at q = 0, as well as for the linewidth dispersion in the long-wavelength domain.

Published
2007

48. Measurements of transmitted diffraction profiles on Bragg angles at pi/2.

Author

Giles, C. and Cusatis, C.

Subjects
*OPTICAL diffraction, *GERMANIUM crystals, *BACKSCATTERING
Abstract

Examines the measurement of transmitted diffraction profiles of a germanium crystal at Bragg angles around and including pi/2. Description of a grooved crystal monochromator operating at Bragg angles; Detection of an intensity enhancement at the normal incidence position; Verification of properties of the backscattered regime.

Published
1991
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