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John J Munro - One of the best experts on this subject based on the ideXlab platform.
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the use of new gafchromic ebt Film for 125i seed dosimetry in solid water phantom
Medical Physics, 2008Co-Authors: Soutung Chiutsao, David C Medich, John J MunroAbstract:Radiochromic Film dosimetry has been extensively used for intravascular brachytherapy applications for near field within 1 cm from the sources. With the recent introduction of new model of radiochromic Films, GAFCHROMIC EBT, with higher sensitivity than earlier models, it is promising to extend the distances out to 5 cm for low dose rate (LDR) source dosimetry. In this study, the use of new model GAFCHROMIC EBT Film for {sup 125}I seed dosimetry in Solid Water was evaluated for radial distances from 0.06 cm out to 5 cm. A multiple Film technique was employed for four {sup 125}I seeds (Implant Sciences model 3500) with NIST traceable air kerma strengths. Each Experimental Film was positioned in contact with a {sup 125}I seed in a Solid Water phantom. The products of the air kerma strength and exposure time ranged from 8 to 3158 U-h, with the initial air kerma strength of 6 U in a series of 25 experiments. A set of 25 calibration Films each was sequentially exposed to one {sup 125}I seed at about 0.58 cm distance for doses from 0.1 to 33 Gy. A CCD camera based microdensitometer, with interchangeable green (520 nm) and red (665 nm) light boxes, wasmore » used to scan all the Films with 0.2 mm pixel resolution. The dose to each {sup 125}I calibration Film center was calculated using the air kerma strength of the seed (incorporating decay), exposure time, distance from seed center to Film center, and TG43U1S1 recommended dosimetric parameters. Based on the established calibration curve, dose conversion from net optical density was achieved for each light source. The dose rate constant was determined as 0.991 cGy U{sup -1} h{sup -1} ({+-}6.9%) and 1.014 cGy U{sup -1} h{sup -1} ({+-}6.8%) from Films scanned using green and red light sources, respectively. The difference between these two values was within the uncertainty of the measurement. Radial dose function and 2D anisotropy function were also determined. The results obtained using the two light sources corroborated each other. We found good agreement with the TG43U1S1 recommended values of radial dose function and 2D anisotropy function, to within the uncertainty of the measurement. We also verified the dosimetric parameters in the near field calculated by Rivard using Monte Carlo method. The radial dose function values in Solid Water were lower than those in water recommended by TG43U1S1, by about 2%, 3%, 7%, and 14% at 2, 3, 4, and 5 cm, respectively, partially due to the difference in the phantom material composition. Radiochromic Film dosimetry using GAFCHROMIC EBT model is feasible in determining 2D dose distributions around low dose rate {sup 125}I seed. It is a viable alternative to TLD dosimetry for {sup 125}I seed dose characterization.« less
A L Rees - One of the best experts on this subject based on the ideXlab platform.
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a history of Experimental Film and video from the canonical avant garde to contemporary british practice
2011Co-Authors: A L ReesAbstract:Acknowledgements Introduction to the 2nd Edition Preface Introduction Sitting the Avant-Garde Vision Machine Time Base Point of View Modernisms PART I: THE CANONICAL AVANT-GARDE Origins of the Moving Image (1780-1880) Photography Art and the Avant-Garde: Summary 1909-20 The Cubists Primitives and Pioneers (1880-1915) Futurists Abstract Film The Comic Burlesque The Art Cinema and its Circuit Cine-Poems and Lyric Abstraction Origins of Abstract Film The Absolute Film Cubism and Poular Film Dada and Surrealist Film The French Avant-Garde 1924-32 Voice and Vision in the Pre-War Avant-Garde Transition: into the 1930s and Documentary Reviewing the First Avant-Garde Underground Two Avant-Gardes (Mark 1)? Structural PART II: BRITAIN, 1966-98 English Structuralists Primitives and Post-Structralists Video Stirs Art and Politics A cinema of Small Gestures Rebel Waves Art Cinema's Odd Couple: Derek Jarman and Peter Greenaway New Pluralism Black British Electronic Arts yBa "Where are we now?" Points of Resistance Conclusion: In the Gallery and on the Air The Migrating Frame from Film to Video Topologies The Origins of the Avant-garde and Current Practice Notes Bibliography Index
Adam Jean-françois - One of the best experts on this subject based on the ideXlab platform.
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Hybrid dose calculation algorithm for high flux synchroton X-Rays Microbeam Radiation Therapy (MRT)
HAL CCSD, 2019Co-Authors: Keshmiri Sarvenaz, Ocadiz Alexandre, Serduc Raphaël, Adam Jean-françoisAbstract:International audienceSarvenaz KESHMIRI, Alexandre Ocadiz, Raphaël Serduc, Jean-François AdamInserm UA7, Université Grenoble Alpes, STROBE, Grenoble, FranceAbstractA curative radiation therapy treatment requires high absorbed dose in a malignant area and minimizing the damages to the neighbouring normal tissues. Increased normal tissue sparing effect to highly spatially fractionated radiation therapy (SFRT) has been extensively explored for the past 25 years. Microbeam radiation therapy (MRT) is an approach based on dose-volume effect which uses spatially fractionated high flux synchrotron X-ray beams as arrays of micrometric beamlets. The zone of interest is irradiated with high doses through beams path (>100 Gy) and doses below tolerance level between the beamlets. The precilinical experiences performed at the European Synchrotron Radiation Facility (ESRF) confirmed the MRT’s higher therapeutic index compared to non-fractionated beams with the same characteristics.The biological response and in consequence the effectiveness of MRT treatments depend on beamlet dose (peak) and central dose between beamlets (valley) as well as peak to valley dose ratio (PVDR). In order to have an optimal therapeutic gain, the PVDR should be maximised and accurately calculated. The commercially available treatment planning systems (TPS) are not suitable for MRT dose planning, due to its distinct features of irradiation geometry, beam source, low energy spectrum and beam polarization compared to conventionalradiotherapy. Therefore, in pursuing the realisation of this treatment modality, it is important to have a modern treatment planning paradigm. There are three categories of dose calculation methods for MRT: pure Monte Carlo, convolution based methods and hybrid methods. The aims of this study was to investigate the reliability, the pros and cons of hybrid dose calculation algorithm and to validate this algorithm using Experimental Film dosimetr
Sun Weiwei - One of the best experts on this subject based on the ideXlab platform.
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The expressions and parameters of moving image art, based on Experimental Film, video art and media art
2013Co-Authors: Sun WeiweiAbstract:This thesis is dedicated to the development of the aesthetic expressions of three main genres of “Moving Image Art” from the 20's until today, so as to refine their different forms and directions. Furthermore, it takes the moving image as one of the clues to track the evolution of media in contemporary art, which is a course from sole-media to inter-media. In this research, “Moving Image Art” refers to “Experimental” moving images created by contemporary artists, excluding commercial moving images such as industrial Films and TV programs. The history of “Moving Image Art”is divided into three periods according to my study, which are “The Film Times”, “The Cassette Times”, and “The Digital Times”. In correspondence, three genres of moving image art that were born in the three eras are “Experimental Film”,”Video Art” and “Media Art”. “The Film Times” is from the 20s to the 60s of the 20th century. A new division of “artistic”, “avant-garde” Films that compared to standardized fiction or documentary Films was called “Experimental Film”. Through studies of some leading Experimental Filmmakers like Viking Eggeling, Oskar Fischinger, Fernand Leger, Stan Brakhage, the first aesthetic expression of this genre is defined as “moving painting", due to the fact that their works are often animations composed of abstract paintings without coherent movement. From the works of Maya Deren and Andy Warhol, the second aesthetic expression is summarized as "extreme narrative", the extensions of which are “metaphoric narrative” and “minimalist narrative”. “The Cassette Times” is between the 60s and the 90s, therein the new category of moving image art is “Video Art”. From the representative works of Nam June Paik, Bruce Nauman, William Wegman and Bill Viola, three chief aesthetic expressions of Video Art are analyzed. First,"nonlinear time", which means that to be watched in a fixed sequence is often not vital for video art works, nevertheless Experimental Films basically follow linear timeline. The second is "conceptual", which indicates that many video art works focus more on concept than on Film language, while the latter is crucial in Experimental Films. The last,"space based", because a video art work is often shown as an installation interacting with the exhibiting space, yet a typical Experimental Film is just shown on a screen. “The Digital Times” started since the 90s, until today, in our time “Media Art” with moving images has become a tendency of “Moving image Art”. After some analysis on the works of Stelarc, Mariana Rondón and Cao Fei, as well as some multi-media performances, two dominant aesthetic expressions of media art are deduced. One is "Interaction", obviously manifested in Internet art works and interactive performances. The other one is"Intermedia", which encompasses media art works that are made of various medias overlapping each other. Among media art works, the role of the moving image is distinct in every work, increasingly it has become a component or a method, but not the main media of the creation, because today’s art has a hybrid face
Jaramillo Laura - One of the best experts on this subject based on the ideXlab platform.
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Devorational cinema: spectacle, ritual, and the senses in Cold War Latin American and Spanish Experimental Film
2019Co-Authors: Jaramillo LauraAbstract:This dissertation revisits a neglected archive of avant-garde Cold War-era Latin American and Spanish Films which use baroque, excessive aesthetic strategies inspired by popular religious ritual: the Experimental documentaries and expanded cinema inventions of Spanish Filmmaker-mystic José Val del Omar; the Mexican psychedelic exploitation epics of Chilean polymath Alejandro Jodorowsky; and the Cuban revolutionary Films of Manuel Octavio Gómez. This corpus of Filmmakers grappled with the problem of cinema’s role within the global system of capitalist media spectacle. Drawing on Guy Debord’s 1967 theorization of spectacle as the culmination of the West’s privileging of vision above all other senses, I contend that the ultimate end of capitalist spectacle’s offer of seemingly limitless pleasure is sensorial numbing. My project tracks a growing recognition during the 1960s that the ubiquity of imported Western media images within the global south doomed subjects to passive consumerism and worse, to the extinction of older epistemologies based in the nonvisual senses like touch, hearing, taste, and smell. The Films I examine counter ocular centric rationalism with the sensorial immersion of ecstatic experience. By contrast to the better-known militant anti-colonial Films of the period that depict armed struggle, these Films experiment with forms of ritual in order to reconstitute the body’s senses as a major ground for decolonial epistemic resistance where the rationality of political discourse fails. In doing so, these Filmmakers reconstitute the cinema as a key site for immersive, collective experience
