173,298 research outputs found
Influence of confining pressure on the mechanical and structural evolution of laboratory deformation bands
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Continuous flow (micro-)reactors for heterogeneously catalyzed reactions : main design and modelling issues
Get PDFContinuous flow chemistry is a rapidly developing branch in organic and drugs synthesis, whereas it is common practice in heterogeneous catalysis for base chemicals production. Heterogeneously catalysed synthetic protocols are being developed and can take advantage of the reaction and reactor engineering experience at the macro-scale, provided that suitable models are applied to the micro- and meso-reactors in use. The main process parameters that define possible mass, heat and momentum transport limitations in heterogeneous catalytic reactors are reviewed. Specific models applying such concepts to microreactors are proposed. Finally, examples are reported of heterogeneously catalysed reactions carried out in microreactors for different applications
The ethical ambivalence of holism: An exploration through the thought of Carl Jung and Gilles Deleuze
Get PDFThis chapter examines the disputed ethical status of holism through comparing aspects of the work of Carl Jung and Gilles Deleuze as two twentieth-century thinkers who reflected deeply on the concept of wholeness. Using Jung’s psychology as a sophisticated and influential example of holistic thought, the chapter first highlights relevant holistic features of this model, especially the concepts of the self and unus mundus (one world), and traces the cultural and social benefits that are claimed to flow from such a version of holism. It then confronts Jung’s model with Deleuze’s more constructivist way of thinking about wholes and totality in terms of difference, multiplicity, and pure immanence, which aims to ensure that his concept of the whole remains open. The Deleuzian perspective arguably exposes a number of questionable philosophical assumptions and less salubrious ethical implications in Jung’s holism. In order to assess whether this Deleuzian critique is answerable, the chapter focuses attention on the understanding of transcendence and immanence within each thinker’s model. Distinguishing between theism, pantheism, and panentheism, the author proposes that the metaphysical logic of panentheism can provide a framework that is capable of reconciling the two thinkers’ concepts of the whole
Modelling of continuous reactors for flow chemistry
Get PDFFlow chemistry is gaining increasing attention as a mean to achieve process intensification in the fine chemicals synthesis field. Furthermore, it can overcome heat and mass transfer limitations thanks to more efficient mixing, allowing applications characterised by insufficient yield or safety issues, when carried out in the traditional batch mode. Despite their spreading use, micro- and meso-reactors are complex systems that require some detailed modelling in order to achieve the desired process intensification effect. In this review, some examples will be provided dealing with three main modelling items. On one hand, kinetic modelling is needed in order to correctly size the reactor and to estimate its productivity with time-on-stream under different conditions. Then, fluid dynamics issues have to be carefully modelled to predict heat and mass transport properties, which are ultimately related to fluid flow inside micromixers and microreactors. All these topics will be discussed, to review the current developments in continuous microreactors modelling and design, together some examples of process simulation
Numerical simulation of wave propagation in 2-D fractured media : scattering attenuation at different stages of the growth of a fracture population
Get PDFIn this paper, we systematically examine the multiple scattering process of seismic waves at consecutive stages of the evolution of 2-D fracture population. Synthetic seismograms are computed using the pseudo-spectral method for elastic wave propagation, where spatial derivations are computed using fast Fourier transforms and time derivatives are computed using second-order finite differences. The grid sizes are 2560 × 2560 with 1 m interval and a Ricker wavelet with a peak frequency of 30 Hz is used (or equivalently a wavelength of 10 m for the P-wave velocity of 3000 m s–1 used in our modelling). Fracture patterns are generated using a 2-D cellular automaton model of rupture with healing to account for clustering and anisotropy in the fracture growth process. The cellular automation model takes into account the discontinuous and segmented nature of a fracture population, and reproduces in the statistical sense the intermediate stages of fracture growths. To estimate the frequency-dependence of scattering attenuation (quantified by the inverse quality factor Q−1) at different stages of the fracture evolution, we use the spectral ratio method. Variations of Q−1 with frequency are then fitted to a polynomial of order up to 8 for each state of the fracture evolution as we do not want to make an assumption about how Q−1 should depend on frequency or scales. This allows us to determine the nature of the frequency-dependence of scattering attenuation as a function of fracture evolution. Our results confirm, as expected, the dependence of scattering attenuation on frequency, and the fifth-order polynomial seems to fit the measured attenuation from synthetic seismograms better. In addition, the inverse quality factor Q−1 is shown to be linearly dependent on fracture density, reaching a maximum when fracture density is the highest. In summary, our numerical results confirm that scattering attenuation has a complex dependence on frequency, and measurements of attenuations may be potentially used to characterize spatial distributions of fracture networks in particular, the scale distributions
I.G. Farben\u27s Petro-Chemical Plant and Concentration Camp at Auschwitz
Get PDFThis study examines the history of the petrochemical plant and concentration camp run by I.G. Farbenindustrie (the dominant German chemical company during World War II) at Auschwitz to decide upon the degree of Farben’s involvement with Hitler and the Holocaust. The study traces the construction of the plant to determine Farben\u27s participation at Auschwitz. The main sources consulted were the transcripts of the postwar Farben trial at Nuremberg along with eyewitness accounts of members of the prosecution staff. Based on the court\u27s verdict, one might conclude that I.G. Farben operated in a state of coercion during the war and could not be held accountable for most of its actions. The history of the Auschwitz plant indicates, however, that I.G. Farben had some involvement in the extermination process
Fachkatalog Neuguinea / Stadt- und Universitätsbibliothek Frankfurt am Main
No full textAus Anlaß des Kongresses der "Deutsch-Pazifischen Gesellschaft" im Juni 1981 in Düsseldorf legt die Stadt- und Universitätsbibliothek Frankfuxt am Main ein Verzeichnis ihrer Bestände zum Raum "Neuguinea" vor . Dabei umfaßt der Katalog sowohl die Literatur zu "Papua-Neuguinea" (Niugini)" als auch zur indonesischen Provinz "West-Irian (Irian Jaya)". Aus Gründen des geographischen Zusammenhangs werden in einem Anhang allgemeine Publikationen zum Raum Melanesien in den Katalog aufgenommen. Die gezielte Sammlung der Literatur zu diesem Raum ist ein Ergebnis der Zuweisung des Sondersarnmelgebietes "Ozeanian" durch die Deutsche Forschungagemeinschaft an die Frankfurter Stadt- und Univeraitätsbibliothek. Dabei liegt der Schwerpunkt auf der Sammlung historischer und ethnologischer Literatur. Grundlage des Katalogausdruckes ist der Länderteil des Sachkataloges der Bibliothek, der nach feststehenden Länderkennziffern, Fachgruppen und Schlüsselnummern gegliedert ist. Unter jeder Schlüsselnummer sind die Eintragungen chronologisch geordnet. Auf jeder Titelkarte befindet sich rechts oben die Signatur, unter der das Buch über Fernleihe bei der Stadt- und Universitätsbibliothek Frankfurt am Main bestellt werden kann
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