1,355,380 research outputs found
Computational Fluid Dynamics (CFD) modelling to estimate fluvial bank erosion—a case study
No full textRiver bank erosion models are an important prerequisite for understanding the development of river meanders and for estimating likely land-loss and potential danger to floodplain infrastructure. Although bank erosion models have been developed that consider large-scale mass failure, the contribution of fluvial erosion (the process of particle-by-particle erosion due to the shearing action of the river flow) to bank retreat has not received as much consideration. In principle, such fluvial bank erosion rates can be quantified using excess shear stress formulations, but in practice, it has proven difficult to estimate the parameters involved. In this study, a series of three-dimensional Computational Fluid Dynamics (CFD) simulations for a meander loop on the River Asker (200 m long) at Bridport in southern England were undertaken to elucidate the overall flow structures and in particular to provide estimates of the applied fluid shear stress exerted on the riverbanks. The CFD models, which simulated relatively low and relatively high flow conditions, were established using Fluent 6.2 software. The modelling outcomes show that the key qualitative features of the flow endure even as flow discharge varies. At bank full, the degrees of velocity and simulated shear stresses within the inner bank separation zones are shown to be higher than those observed under low flow conditions, and that these elevated shear stresses may be sufficient to result in the removal of accumulated sediments into the main downstream flow
Bet fat:Eat gel
No full textFotis Spyropoulos, a senior research fellow at the University of Birmingham's School of Chemical Engineering, UK, is conducting studies to develop a near zero-calorie gel that eliminates hunger problems in people by by lining the stomach. The lining the stomach results in making people satisfied by creating a food replacement. The food replacement is a pH sensitive hydrocolloid, a type of hydrophilic polymer that binds with water molecules to form a gel similar to the gelatine that is the main component of jelly. In vitro tests suggest the gel forms spheres in the stomach, but the ideal situation will be to gel the entire contents of the stomach. Spyropoulos expects the solution will involve finding a way to make the hydrocolloid gel more slowly so that it has time to disperse throughout the stomach.</p
Modelling near-bank flow hydraulics
No full textRiver bank erosion models are a fundamental requirement for understanding the migration and
evolution of river meanders, estimating the potential for land-loss and threat to floodplain
infrastructure, and predicting the delivery of contaminated floodplain sediments to aquatic
ecosystems. While progress has recently been made in understanding and modelling processes
controlling large-scale mass failure, less attention has been paid to the role that fluvial erosion
plays in bank retreat. This project aims to address this gap by developing a new fluvial erosion
model. Recent developments in bank erosion monitoring technology, and in the quantification of
the bank erodibility parameters using jet-testing devices, offer the means of determining fluvial
erosion rates and bank erodibility. However, the missing link remains the need to obtain highresolution,
spatially distributed, flow data to characterize the near-bank fluid shear stresses that
drive bank erosion. One possible solution is to use Computational Fluid Dynamics (CFD) models
as a substitute for empirical data.Herein I evaluate a series of three-dimensional CFD simulations for a meander loop on the River
Asker at Bridport in southern England. CFD models under specific steady peak flow conditions
were developed using Fluent 6.2, with peak flow discharge estimates obtained from an adjacent
gauging station. All the models obtained from the three examined flow events were successfully
verified and validated using clearly defined and structured procedures. The modelling results
indicated that the main qualitative features of the flow remain even as flow discharge varies.
However, notable differences were observed between the examined flow events, such as, a
general increasing of velocity and shear stress throughout the reach as flow stage is gradually
increased, a slight reduction in the size and extent of separation zones at bank full stage, a
movement of impingement points further downstream, and a continuation of the secondary flow
within the fast streamtube further towards the bends exits. Bed/bank shear stress is mostly seen to
decrease at shallow riffles as discharge approaches bankfull, while pools experience an increase
in bed/bank shear stress with increase in discharge. Zones of higher bed/bank shear stress extend
and combine, while marginal recirculation zones and areas of relatively low bed/bank shear stress
generally reduce in area to form discrete locations for erosion and deposition phenomena. At
bank full stage, the magnitudes of velocity and simulated shear stresses within the inner bank
separation zones are found to be higher than those observed under low flow conditions and they
may be sufficient to result in the removal of accumulated sediments into the main downstream
flow. The presence of regions of high velocity in the form of a streamtube, especially along the
outer banks, creates high shear stresses within these areas. As a result, outer bank migration rates
are likely to be relatively high in bends with inner bank separation zones
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Las prótesis culturales y sus consecuencias espaciales
No full textLa premisa del Advanced Architectural Design Studio, dirigido por el Prof. Dr. Theodore Spyropoulos en la Stadelschule Architecture Class es explotar la idea de "arquitectura corporal" y pensar en sus implicaciones para la producción de la arquitectura. El estudio entiende al espacio como una interfaz que tiene la capacidad de generar conexiones entre personas y ciudad, que explora al cuerpo como un sitio para examinar la comunicación, el comportamiento y la experiencia del mundo. El enfoque presentado se interesa en la relación entre la psique y el cuerpo: reconoce el potencial que tienen para convertirse en un sitio para explorar interfaces colectivas. El punto de partida es cuerpo que alberga traumas e inseguridades, que son mediadas por el concepto de "prótesis social". Dentro de este universo, el espacio psicológico tiene el potencial de empoderar al portador: la "arquitectura corporal" se convierte en la exploración de la identidad y los aspectos psicológicos que constituyen nuestro día a día. Las implicaciones finales incluyen la interacción y la comunicación entre el usuario, la audiencia y la experiencia de la ciudad. La prótesis social se utilizó en Frankfurt am Main (Alemania) y en Trujillo (Perú) como una interfaz para experimentar ambas ciudades. Ver video: https://bit.ly/3i7pEAPThe premise for the Advanced Architectural Design Studio, led by Prof.
Dr. Theodore Spyropoulos at the Städelschule Architecture Class is to explore
the idea of “body architecture”, that is to think of its implications and
entailments for the production of architecture. The studio understands space
as an interface that has the capacity to raise connections between people and
the city, and that explores the body as a site for examining communication,
behavior and the experience of the world1. This approach understands the
body not as a holistic, finite entity nor as a set of proportions that conform a
physical site but understands the relationship between the psyche and the
body and acknowledges the potential they have to become a site for collective
interfacing. The concept of social prosthesis is then examined, as a way to
engage with the psychological space, that has the potential to empower the
wearer: “body architecture” becomes the exploration of identity and the
psychological aspects that constitute our everyday. Watch video: https://bit.ly/3i7pEAPAlemania. Servicio Alemán de Intercambio Académico (Deutscher Akademischer Austauschdienst - DAAD)
Variations on the Author
No full text“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
THE PAINTINGS OF YANNIS SPYROPOULOS
No full textTHE SUBJECT OF THIS THESIS IS THE PAINTINGS OF YANNIS SPYROPOULOS (1912-1990) A PROMINENT REPRESENTATIVE OF ABSTRACT ART IN GREECE. A TOTAL OF 1270 WORKS IS PRESENTED AND ANALYSED. THROUGH COMPARISONS AND CORRELATIONS THERE ARISES A PROCESS FROM NATURALISM TO ABSTRACTIVENESS AND FURTHER INTO ABSTRACTION. A METHODOLOGY IS SET UP SUGGESTING THE KNOWLEDGE OF THE LAWS OF THE NATURAL WORLD AS A BASIC POINT OF REFERENCE. FINALLY, THE ARTISTIC CONTRIBUTION OF SPYROPOULOSIS EVALUATED WITHIN THE CONTEXT OF THE INVESTIGATIONS OF ABSTRACT ART BOTH INGREECE AND ABROAD.ΑΝΤΙΚΕΙΜΕΝΟ ΤΗΣ ΔΙΑΤΡΙΒΗΣ ΕΙΝΑΙ ΤΟ ΖΩΓΡΑΦΙΚΟ ΕΡΓΟ ΤΟΥ ΓΙΑΝΝΗ ΣΠΥΡΟΠΟΥΛΟΥ (1912-1990), ΣΗΜΑΝΤΙΚΟΥ ΕΚΠΡΟΣΩΠΟΥ ΤΗΣ ΑΦΗΡΗΜΕΝΗΣ ΤΕΧΝΗΣ ΣΤΗΝ ΕΛΛΑΔΑ. ΕΚΤΙΘΕΤΑΙ ΚΑΙΑΝΑΛΥΕΤΑΙ ΕΝΑ ΣΥΝΟΛΙΚΟ ΕΡΓΟ 1270 ΠΙΝΑΚΩΝ ΟΠΟΥ ΜΕΣΑ ΑΠΟ ΣΥΣΧΕΤΙΣΜΟΥΣ ΚΑΙ ΣΥΓΚΡΙΣΕΙΣ ΠΡΟΚΥΠΤΕΙ ΜΙΑ ΔΙΑΔΙΚΑΣΙΑ ΕΠΕΞΕΡΓΑΣΙΑΣ ΑΠΟ ΤΟΝ ΝΑΤΟΥΡΑΛΙΣΜΟ ΣΤΗΝ ΑΦΑΙΡΕΤΙΚΟΤΗΤΑ ΚΑΙ ΑΡΓΟΤΕΡΑ ΣΤΗΝ ΑΦΑΙΡΕΣΗ. ΣΤΟΙΧΕΙΟΘΕΤΕΙΤΑΙ ΜΙΑ ΜΕΘΟΔΟΛΟΓΙΑ ΠΟΥ ΠΡΟΤΕΙΝΕΙ ΣΑΝ ΒΑΣΙΚΟ ΣΗΜΕΙΟ ΑΝΑΦΟΡΑΣ ΤΗ ΓΝΩΣΗ ΤΩΝ ΝΟΜΩΝ ΤΟΥ ΦΥΣΙΚΟΥ ΚΟΣΜΟΥ. ΤΕΛΟΣ ΑΞΙΟΛΟΓΕΙΤΑΙ Η ΘΕΣΗ ΤΟΥ ΣΠΥΡΟΠΟΥΛΟΥ ΣΤΑ ΠΛΑΙΣΙΑ ΤΩΝ ΠΑΓΚΟΣΜΙΩΝ ΑΛΛΑ ΚΑΙ ΤΩΝ ΕΛΛΗΝΙΚΩΝ ΑΝΑΖΗΤΗΣΕΩΝ ΤΗΣ ΑΦΗΡΗΜΕΝΗΣ ΖΩΓΡΑΦΙΚΗΣ
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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