1,721,125 research outputs found
Apparatus for the Production of Electron Beams and X-Ray Beams for Interstitial and Intra-Operatory Radiation Therapy
No full textThe present invention refers to an apparatus for the production of electron beams and X-ray beams for interstitial and intra-operatory radiation therapy, more commonly named IORT (Intra Operative Radio Therapy). More specifically, the invention refers to an apparatus IORT using a Plasma Focus type of machine, coupled to an electron guide which conveys the beam directly to the tissue to be treated with a low-energy, extremely high dose rate of electron or photonic X-ray irradiation
Radiation Physics for Preservation of the Cultural Heritage
No full textThis volume brings together examples of the application of the major radiation techniques existing today to a wide variety of cultural heritage specimens. It fulfils the needs of conservation institutions and museums, which frequently make recourse to these techniques to obtain thorough information on many types of materials. The book is arranged in four major topical sections grouping the rich assortment of non-destructive instrumental solutions. Within each section can be found a large diversity of solutions achieved by the specialists in cultural heritage conservation. Section I illustrates the impact of radiation techniques in the conservation of cultural heritage. It discusses the relationship between physics and the humanities, and introduces the large assortment of non-destructive techniques using radiation, which are applied today to cultural heritage artefacts. Section II presents some fundamental aspects of radiation physics, which can be used successfully for improving the quality of the measurement and for extracting more hidden information. Section III is devoted to the experimental application of X-ray fluorescence (XRF) under different setups (portable XRF, micro XRF, synchrotron radiation XRF) to archaeometallurgical investigations; pigments in wood carving; old master prints; glasswork; frescoes; and monuments. Section IV brings together applications of techniques which require excitation with highly energetic x- or gamma-rays (Compton scattering), charged particles (PIXE, EPMA), neutrons (PGAA), special setups (tomography), and lower energy regimes of the electromagnetic spectrum (spectral analysis). These articles describe applications to marble and stone tombstones and mural support of frescoes; the study of manufacturing techniques of artworks; vitrified terracotta; historical photographs; metals, stones and pottery; Egyptian corn-mummies; and XVIII century paintings
Scattering Computations with the Vector Code MCSHAPE for Applications in Cultural Heritage.
No full textThe vector equation is the best model known for describing the diffusion of incoherent photon beams. In this article, a brief overview of the Boltzmann transport equation (scalar and vector) will be given. Then, it will be described the state-of-the-art of the transport codes developed at Bologna based on this model. Finally, the application of the codes will be illustrated with some examples of interest in cultural heritage
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Monte Carlo simulation of the dose deposited into GAFCHROMIC® film by X-rays produced by the electron beam of PFMA-3
No full textThe electron beam emitted backward by Plasma Focus devices is being investigated as a radiation source for IORT (Intra-Operative Radiation Therapy) applications. A Plasma Focus device is being developed to this aim, to be utilized as an X-ray source. The electron beam is driven to impinge on a 50 μm brass foil, where conversion X-rays are generated. Monte Carlo simulations of the X-ray emission have been conducted with MCNPX, with the purpose of estimating penetration in and dose to human tissue. The electron spectrum had been determined experimentally and is used in the present work as input to the simulations. X-ray emission both from bremsstrahlung and from characteristic lines is predicted. The spectrum is found to be comprised of two components: one peaked at 10 keV and one centred around 50 keV. Doses to film determined from the present simulations are compared to experimental values obtained in a previous work by the authors: the results are found in very good agreement
Editorial
No full textEditorial for the Proceedings of the 5th Topical Meeting on Industrial Radiation and Radioisotope Measurement Applications, Bologna, Italy, 9 June - 14 June 2002
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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