A computer program named ANKAphase is presented that processes X‐ray inline phase‐contrast radiographs by reconstructing the projected thickness of the object(s) imaged. The program uses a ...single‐distance non‐iterative phase‐retrieval algorithm described by David Paganin et al. (2002), J. Microsc.206, 33–40. Allowing for non‐negligible absorption in the sample, this method is strictly valid only for monochromatic illumination and single‐material objects but tolerates deviations from these conditions, especially polychromaticity. ANKAphase is designed to be applied to tomography data (although it does not perform tomographic reconstruction itself). It can process series of images and perform flat‐field and dark‐field correction. Written in Java, ANKAphase has an intuitive graphical user interface and can be run either as a stand‐alone application or as a plugin to ImageJ, a widely used scientific image‐processing program. A description of ANKAphase is given and example applications are shown.
Digital pulse processor for ion beam microprobe imaging Bogovac, M.; Jakšić, M.; Wegrzynek, D. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
06/2009, Letnik:
267, Številka:
12
Journal Article
Recenzirano
Capabilities of spectroscopic ion beam analysis (IBA) techniques that are available in ion microprobe facilities can be greatly improved by the use of digital pulse processing. We report here ...development of a digital multi parameter data acquisition system suitable for IBA imaging applications. Input signals from charge sensitive preamplifier are conditioned by using a simple circuit and digitized with fast ADCs. The digitally converted signals are processed in real time using FPGA. Implementation of several components of the system is presented.
A long-standing question in morphological evolution is why male genitalia tend to diverge more rapidly than other structures. One possible explanation is that male genitalia are under sexual ...selection to function as ‘internal courtship devices’. Males of closely related species may provide divergent stimulation using different genital morphologies and behaviors. Testing this hypothesis has been difficult, however, because the presumed genital courtship behavior is often hidden from view inside the female, and because studies of how the male’s genitalia interact with those of the female are nearly always limited to a single species in a given group, thus restricting opportunities for comparison of closely related species. We present new morphological and behavioral data for portions of the male genitalia that are hidden in the female during copulation in five species in the tsetse fly genus Glossina using data from dissections of pairs frozen in copula, artificially stimulated males, and from copulating pairs viewed with a new X-ray technique that allows events inside the female to be recorded in real time. These data almost certainly give only an incomplete view of this complex, previously hidden world. But even so they clearly reveal that, as predicted by sexual selection theory, the male genitalia of Glossina flies perform dramatic, stereotyped, rhythmic movements deep within the female’s reproductive tract and in inward folds of her external surface, and that many of these movements probably differ among closely related species. Most of the movements are not explicable as means by which the male anchors himself more securely to the female; all are likely to result in stimulation of the female. A female Glossina can be stimulated tactilely at a given moment during copulation at up to 8–10 or more different sites on her body.
A portable focused-beam XRF spectrometer was designed, constructed, and manufactured. The spectrometer allows to detect and perform analysis of chemical elements from Na upwards. The system is ...equipped with a compact vacuum chamber to reduce absorption of both the excitation and the fluorescence radiation in air. A low power Pd-anode tube operated up to 50 kV and 1 mA with a point focus of 400 μm is used as excitation source. A polycapillary lens with a spot size of about 160 μm, or a collimator with a 1 mm inner diameter can be used alternatively for either focusing or collimating the primary beam. The fluorescence radiation is collected by an Si drift detector with an active area of 10 mm
2 and equipped with an 8 μm Be entrance window.
A compact vacuum chamber was designed to house the X-ray beam optics and the detector snout. The chamber is attached to the X-ray tube and can be pumped down to 0.1 mbar. A Kapton™ window of 7.5 μm thickness allows to locate the investigated spot at about 1–2 mm distance outside of the chamber, thus minimizing absorption losses in the excitation and X-ray fluorescence radiation paths. Two lasers pointers are mounted inside the chamber. The laser beams cross at a point outside the chamber in front of the entrance window and coincide with the focal spot of the polycapillary.
This paper reports some preliminary results obtained from an in situ analysis of bronze samples as well as a comparison of these data with those given by other laboratory spectrometers and the reference values provided by the Italian bronze foundry Venturi Arte Bologna, Italy.
This paper shows how the Monte Carlo N-Particle eXtended (MCNPX) computer code can easily be applied to calculate the Kα/Kβ ratios of elements distributed heterogeneously in an analyzed specimen. ...Experiments were performed on specimens made of thick substrates covered by one or two mono-elemental layers (Ti, Ni, and Cu) of intermediate thickness. The Kα/Kβ ratios of the elements present in a substrate and in the layers were measured and then compared with the ratios obtained with the MCNPX computer code and with simple analytical calculations. Good correspondence was achieved between the experimental and calculated values. It was demonstrated that the MCNPX code makes it possible to predict the Kα/Kβ ratios for a specimen composed of layers and a substrate. This code can be applied for recognizing sample homogeneity or the depth heterogeneity of a specimen. In addition, the depth distribution of elements can be estimated and then the coating thicknesses in layered samples can also be determined.
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