A new methodology for very high-speed, energy-dispersive detection of X-ray fluorescence is being developed. The underlying reasoning behind it, as well as early results from the evaluation of the first prototype, is presented.

Visual features constitute compact yet effective representations of visual content, and are being exploited in a large number of heterogeneous applications, including augmented reality, image registration, content-based retrieval, and classification. Several visual content analysis applications are distributed over a network and require the transmission of visual data, either in the pixel or in the feature domain, to a central unit that performs the task at hand. Furthermore, large-scale applications need to store a database composed of up to billions of features and perform matching with low latency. In this context, several different implementations of feature extraction algorithms have been proposed over the last few years, with the aim of reducing computational complexity and memory footprint, while maintaining an adequate level of accuracy. Besides extraction, a large body of research addressed the problem of ad-hoc feature encoding methods, and a number of networking and transmission protocols enabling distributed visual content analysis have been proposed. In this survey, we present an overview of state-of-the-art methods for the extraction, encoding, and transmission of compact features for visual content analysis, thoroughly addressing each step of the pipeline and highlighting the peculiarities of the proposed methods.

Gamma-ray energy absorption buildup factors of gaseousmixtures; neon (95%) + argon (5%), argon (95%) + acetylene (5%),argon (95%) + methane (5%), argon (95%) + carbon dioxide (5%), methane(70%) + pentane (30%) and argon (90%) + methane (10%) were studiedby Geometrical Progression (G-P) fitting for the photon energy range0.015-15 MeV. It was found that the equivalent atomic number, Zeq ofthe gaseous mixtures sharply reduces after 1 MeV photon energy. TheZeq for the mixture of methane (70%) + pentane (30%)is the minimum, whereas the maximum is for argon (95%) + carbondioxide (5%) for the photon energies under investigation. The EnergyAbsorption Buildup Factor (EABF) for methane (70%) + pentane (30%)was found to be the highest among all the selected gaseous mixtures.The chemical composition of the gaseous mixtures has an impact onthe EABF values for photon energy and penetration depth. The investigationof the EABF is useful for selection of gaseous mixtures in designconsideration of gaseous radiation detectors for gamma radiation.

Silver halide based photographic imaging elements have been utilized as detectors for X-rays for over 100 years. These elements comprised of gelatin dispersed silver halide coated on one or both sides of a support, have been utilized in diffraction experiments since the discovery of X-ray diffraction by Laue and co-workers. X-ray film has high spatial resolution and can be adapted to flat or curved two-dimensional detection geometries. This paper describes the use of X-ray film as a two-dimensional detector for X-ray diffraction analysis, and discusses X-ray film composition, exposure, and processing, along with considerations for analyzing X-ray diffraction data collected using X-ray film.

Advances in X-ray texture solutions require new methods and descriptions for the texture analysis process, e.g., when using general area detector diffraction systems. A new method is presented that defines a general pole figure resolution and provides the possibility to optimize strategies for efficient pole figure data collection. Application of the new method improves resolution and (!) speed. New software enables simultaneous monitoring of pole and detector space. This allows a fundamentally better understanding of the collected information, e.g., in situations where peaks overlap or high backgrounds compromise data quality.

We present a brief description of the Berkeley Visible Imaging Tube (BVIT) detector system, which is a user instrument on the 10-m Southern African Large Telescope (SALT), and include some preliminary observational results gained in mid-2011. The data show that BVIT is capable of revealing emission features occurring on time-scales of < 0.1 sec, thus opening up for the general user a window of high time-resolution astronomy at visible wavelengths.

Background: Microswitches are the most commonly used input device for people with multiple disabilities to control environmental stimulation. However, little is known about adopting the commercial trackball with a revised trackball driver as a more feasible input device. Aims: To assess whether two children with profound multiple disabilities and minimal motor skills would be able to control environmental stimulation using thumb poke ability through cordless trackballs installed with a newly developed mouse driver (i.e. a new mouse driver replacing a standard mouse driver, turning a trackball mouse into a precise thumb poke detector). Method: An ABAB design and a 2-month post-intervention check were adopted to perform the study. Results: Data showed that the two children improved significantly in their target response (thumb poke) to activate the control system to produce environmental stimuli during the B (intervention) phases. This performance was maintained at the post-intervention check. Conclusions: The use of thumb poke in connection with a trackball allowed the children with multiple disabilities and minimal motor skills to increase their level of response and stimulation control.

Les performances remarquables des détecteurs fonctionnant à très basse température ont franchi les limites inhérentes aux détecteurs conventionnels à semi-conducteur ou à scintillateur. Ceci s’explique par les principes physiques de détection exploités par les différentes technologies développées aujourd’hui. L’élégance de ces technologies est de mettre en jeu la création de quanta d’énergie inférieure de trois à quatre ordres de grandeur par rapport à celle des détecteurs classiques. Les très faibles fluctuations statistiques du nombre de quanta créés pour une interaction donnent ainsi accès à des seuils de détection et des résolutions en énergie meilleurs de un à deux ordres de grandeur. De plus le rendement de détection n’est pas limité à basse énergie comme dans le cas des semi-conducteurs en germanium ou en silicium. Les détecteurs cryogéniques sont aujourd’hui développés et utilisés dans des applications multiples (caméras pour télescopes, spectromètres imageurs, analyse de matériaux par fluorescence X, mesure d’activité, ...), qui recouvrent la détection des rayonnements sub-millimétriques, infrarouges, UV, X, gamma, bêta et des particules alpha. L’apparition très récente sur le marché de réfrigérateurs sans liquide cryogénique et très simples d’utilisation ouvre de nouvelles perspectives d’applications industrielles de ces détecteurs.

La production de neutrons secondaires issus de l'interaction dun faisceau de particules avec une cible épaisse a été déterminée à plusieurs angles par la méthode des détecteurs à activation. Lescouples projectile-cible étudiés sont au nombre de trois : deutons (100 MeV/u) + 238U, deutons (100 MeV/u) + 9Be et 36Ar (95 MeV/u) + 12C. À 00 pour les cibles de Be et U, la mesure a aussiété faite avant et après des blocs de béton, ceci nous a permis d'évaluer les longueurs d'atténuation correspondantes en fonction de l'énergie. L'évolution du débit de dose de la cible d'uranium aété suivi durant plusieurs jours après la fin de l'irradiation.