1,721,134 research outputs found
Principles of highly resolved detemination of texture and microstructure using high-energy synchrotron radiation
No full textDiffraction imaging with hard X-rays (high-energy synchrotron radiation) using the detector sweeping techniques allows measurement of the texture and microstructure of polycrystalline materials with high orientation- and location-resolution. These techniques provide continuous two-dimensional images of different sections and projections of the six-dimensional "orientation-location" space. For the high orientation resolution case, it is possible to measure the orientation and location coordinates of up to 105 individual grains simultaneously. From these parameters, the grain size and shape can also be obtained, yielding the complete orientation stereology of the polycrystalline aggregate, which is required for its complete characterization. For the high location resolution case, the intensity at any point of the diagrams; corresponds to a pole density as a function of the orientation-location space.German Research Foundation DFG; HASYLAB at DES
Grain Growth Analyses of AlMn Alloys Using Texture and Microstructure Imaging Techniques with High-Energy Synchrotron Radiation
No full textAnnealed AlMn alloys with different amounts of Manganese (0.4; 0.7 and 1 wt.-%) were analyzed with texture and microstructure imaging techniques using high-energy synchrotron radiation. These techniques allow getting reliable information about grain shape and grain size distribution the different crystallographic directions due high orientation and location resolution. The)served trends of the grain growth in dependence on the AlMn alloys composition and the crystallographic directions, are well correlated with the different texture components occurring with increasing annealing time. In comparison to the SEM/EBSD technique, these methods allow get orientation dependent information about the grain size and shape related with additionally good statistics.Deutsche Forchungsgemeinschaft (DFG
Grain Growth Analyses of AlMn Alloys Using Texture and Microstructure Imaging Techniques with High-Energy Synchrotron Radiation
No full textAnnealed AlMn alloys with different amounts of Manganese (0.4; 0.7 and 1 wt.-%) were analyzed with texture and microstructure imaging techniques using high-energy synchrotron radiation. These techniques allow getting reliable information about grain shape and grain size distribution the different crystallographic directions due high orientation and location resolution. The)served trends of the grain growth in dependence on the AlMn alloys composition and the crystallographic directions, are well correlated with the different texture components occurring with increasing annealing time. In comparison to the SEM/EBSD technique, these methods allow get orientation dependent information about the grain size and shape related with additionally good statistics.Deutsche Forchungsgemeinschaft (DFG
Oriented Grain Growth Analyses With In Situ Annealing Experiments Using High Energy Synchrotron Radiation
No full textThe development of the recrystallization and annealing textures of Al-Mn alloys with 0.4, 0.7 and 1 wt.-% manganese is analyzed using specific techniques that allow the detection of changes in grain orientation during in situ annealing. In order to investigate the evolution of texture components during annealing, highly rolled samples were annealed from room temperature to 500 C at a constant heating rate. The advantage of in situ annealing experiments using synchrotron radiation is the detection of grain orientations over time, which allows observation of the development of the recrystallization and annealing textures in a sample. In fact, the recrystallization and annealing textures in the Al-0.4Mn are characterized by an interruption in the detection of most of the grain orientations between 380 and 425 C and by competition between the cube {001}, {011}, {011} and rotated-cube {001} grain orientations, where the latter is detected until the end of the experiment. In the Al-0.7Mn sample a competition between the cube {001}, {011}, and rotated cube {001}, {011} grain orientations is observed. In the sample with the highest manganese concentration (1 wt.-%) an unhindered grain growth of all possible grain orientations with a high amount of the {011} grain orientation is observed. The evolution of the resulting local textures is discussed in terms of preferentially oriented grain growth depending on the temperature and manganese concentration.Deutsche Forschungsgemeinschaft [KL1402/2-1
Calculation of anisotropic properties of dental enamel from synchrotron data
No full textObtaining information about the intrinsic structure of polycrystalline materials is of prime importance owing to the anisotropic behaviour of individual crystallites. Grain orientation and its statistical distribution, i.e. the texture, have an important influence on the material properties. Crystallographic orientations play an important role in all kinds of polycrystalline materials such as metallic, geological and biological. Using synchrotron diffraction techniques the texture can be measured with high local and angular resolving power. Here methods are presented which allow the spatial orientation of the crystallites to be determined and information about the anisotropy of mechanical properties, such as elastic modulus or thermal expansion, to obtained. The methods are adapted to all crystal and several sample symmetries as well as to different phases, for example with overlapping diffraction peaks. To demonstrate the abilities of the methods, human dental enamel has been chosen, showing even overlapping diffraction peaks. Likewise it is of special interest to learn more about the orientation and anisotropic properties of dental enamel, since only basic information is available up to now. The texture of enamel has been found to be a tilted fibre texture of high strength (up to 12.5×). The calculated elastic modulus is up to 155 GPa and the thermal expansion up to 22.3 × 10(-6)°C(-1)
FXD-CSD-GUI : a graphical user interface for the X-ray-diffraction-based determination of crystallite size distributions
No full textA fast X-ray-diffraction-based method for the determination of crystal size distributions (FXD-CSD)
No full text
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
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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