1,234 research outputs found
Net sediment transport under sheet flow conditions: Measurements in the Large Wave Flume, Hannover
No full textThis study focuses on time-averaged sediment transport in oscillatory flow in the sheet flow regime. The tests, used in this study, are part ofthe experiments, carried out under the name SISTEX99 (Small-scale International Sediment Transport Experiments 1999). SISTEX99 focuses on near-bed sediment transport processes under influence of regular and irregular non-breaking waves in different wave conditions. The main goal is to increase insight in these processes by obtaining quantitative data of bedform characteristics, near-bed flow velocities, near-bed sediment concentrations and net transport rates. This information can be used for the verification, improvement and development of mathematical models. The main objectives of this study were: 1) To obtain a detailed data set on time-averaged sediment transport rates, measured under progressive waves in sheet flow conditions. 2) To compare the measured time-averaged sediment transport rate with different sediment transport models and other experimental data sets in order to verify if there are differences between net transport rates, measured in a purely horizontal oscillatory water motion (water tunnel) or measured under progressive waves. Experimental research The experiments for this study were carried out in the Large Wave Flume (Grosser WellenKanal, GWK) of the ForschungsZentrum Kiiste (FZK) in Hannover, Germany. Four different test conditions in the sheet flow regime with monochromatic asymmetrical waves with varying wave heights and periods, above a horizontal sand bed, were carried out. The sand bed consisted of uniform sand with a median grain diameter of 0.24 mm. The net sediment transport rates were calculated from the measured bed profiles, using a mass conservation technique. Near-bed oscillatory flow velocities were measured, just outside the wave boundary layer. Also spatial measurements of the wave heights and periods were carried out during the tests. Sediment transport models The net transport rate data are used for the verification of four sediment transport models: three quasi-steady models (Bailard, 1981; Ribberink & AI-Salem, 1993; Ribberink, 1998) and one semi-unsteady model (Dibajnia & Watanabe, 1992). All transport models underpredict the measured net transport rates. The quasi-steady model of Bailard (1981) underpredicts the measured net transport rates with about a factor 2. The quasi-steady model of Al-Salem (1993) underpredicts the measured transport rates. When coefficient A=5 (1993) is applied, the measured transport rate is underpredicted with about a factor 3 and applying coefficient A=4 (1994) leads to an underprediction with about a factor 3-4. The quasi-steady model of Ribberink (1998) underpredicts the measured net transport rate with about a factor 4. The semi-unsteady model of Dibajnia & Watanabe performs best. The transport rates are underpredicted with about factor 1-2. Other experimental data-sets In addition, a comparison is made with three other experimental data sets, obtained from the Large Oscillating Water Tunnel (LOWT) of Delft Hydraulics: series B, conducted by AISalem (1993), series E, conducted by Katopodi et at. (1994) and series J, conducted by Janssen & V.d. Hout (1997). The experimental conditions of Al-Salern consisted of regular and irregular asymmetric oscillatory water motions. The conditions of Katopodi et at. (1994) and Janssen & V.d. Hout (1997) consisted of a symmetrical oscillatory water motion, superimposed on a net current. In series B, E and J sand with a median grain diameter of 0.21 mm was applied, opposed to 0.24 mm of the present experimental sand. A comparison with the experimental data-set of Al-Salem (1993) shows that the present results are about a factor 2-3 larger than results under comparable conditions. The present results are larger than series E, conducted by Katopodi (1994) and series J, conducted by Janssen & V.d. Hout (1997), larger than about a factor 7-8.Civil Engineering and Geoscience
Artysta nowoczesny jako T.W.
No full textThe author analyses archival materials from IPN (Instytut Pamięci Narodowej – The Institute of National Remembrance) concerning a painter nicknamed ‘Tadeusz’. In 1973–1979, ‘Tadeusz’ was active as secret collaborator (t.w. – ”tajny współpracownik”) of SB (Służba Bezpieczeństwa – Interior Ministry Security Service). IPN documents contribute to the mapping of Polish art of the 1970s only to a limited extent. Nevertheless, they can form a basis for posing questions on artists’ collaborations with SB. The author claims that the acceptance of collaboration with SB was grounded in Tadeusz’s understanding of art based on the Enlightenment concept of modern art. He argues with a commonly accepted view that experimental art was persecuted in the Polish People’s Republic in the 1960s and the 1970s, and that the communist government showed any particular interest in fine art. In the annex, the author provides a full list of names found in Tadeusz’s files
[T.W Brown read-in with children and other black women authors]
No full textVideo footage from The Black Academy of Arts and Letters recorded during a library event with author T.W. Brown in February of 1989. The footage shows children seated in a library listening as she reads from a book in her hands. The event includes two other black women authors
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[T.W Brown read-in with children and other black women authors]
No full textVideo footage from The Black Academy of Arts and Letters recorded during a library event with author T.W. Brown in February of 1989. The footage shows children seated in a library listening as she reads from a book in her hands. The event includes two other black women authors
Plantagenets tragicall story [electronic resource] : or, The death of King Edward the Fourth: with the unnaturall voyage of Richard the Third, through the Red Sea of his nephews innocent bloud, to his usurped crowne. Metaphrased by T.W. Gent.
No full textT.W. = Thomas Wincoll. Sometimes attributed to Thomas Weaver.In verse.With an errata slip.The portrait of the author is signed: W.M. fecit., i.e. William Marshall.Annotation on Thomason copy: "Nou: 17".Reproduction of the original in the British Library.Wing (2nd ed.)ThomasonElectronic reproduction
T.W. Adorno e a psicologia social T.W. Adorno and social psychology
No full textNeste ensaio, ressalta-se a importância da disciplina Psicologia Social na obra de T. W. Adorno e a concepção que formula acerca dessa disciplina. Esse autor defende que há uma nova forma de configuração dos indivíduos, expressada por atitudes e comportamentos individuais padronizados e por um ego frágil, facilmente cooptado por movimentos sociais totalitários. Tais indivíduos surgem em uma sociedade caracterizada por uma forma de dominação calcada na racionalidade administrativa e tecnológica. Para esse autor, a Psicologia Social deveria estudar esse objeto para que, com o esclarecimento produzido e difundido, os indivíduos possam resistir à adesão cega a movimentos sociais irracionais, tal como o fascismo, insistindo que a determinação desses movimentos não é individual, mas social.In this assay, the importance of Social Psychology discipline in the T.W. Adorno's work and the specific conception that he formulates about it are pointed out. He defends that there is a new way of individuals' configuration, expressed by standardized attitudes and their own behaviors, such as a fragile ego, which is easily co-opted by totalitarian social movements. Such individuals appear in a society characterized by a form of domination based on administrative and technological rationality. For that author, Social Psychology would have to study this issue so that, with the enlightenment achieved and diffused, the individuals are able to resist to the blind adhesion in irrational social movements, such as the fascism. Adorno empathized that the determination of these movements is not individual, but social
Before Responsible Innovation: Teaching Anticipation as a Competency for Engineers
No full textThis paper focuses on engineering ethics education utilizing Responsible Innovation (RI). As a forward-looking approach aiming to embed ethics within innovation practices, RI strives to align technology development with societal values. However, when teaching the concepts and methods of RI, we face two intertwined challenges. First, RI presupposes we can estimate the consequences of an innovation or design intervention, while evidence shows it is nearly impossible to fully predict the consequences of new technologies. RI acknowledges this by replacing an ambition to predict with a call to anticipate innovation-consequences. However, without a robust account of anticipation this merely kicks the can down the road. Second, RI seems to suggest that we know what is meant by a specific value (e.g., privacy, sustainability) and its relation to a specific technology. While such knowledge is key to an anticipatory perspective, values are often treated superficially and a historically in RI literature. To address these challenges, we argue that RI-focused education – and engineering ethics generally – should be fostering historically informed anticipation as a core competency. To do so, we will define and characterize a set of interrelated virtues essential for engaging in historically informed anticipation: moral sensitivity (an ability to identify values at stake), epistemic humility (an awareness of the limits of one’s understanding), and moral imagination (an ability to envision new perspectives and solutions). We suggest this can be cultivated via a novel teaching method that involves an in-depth historically informed normative analysis of a value technology dynamic (called a value-genealogy of technology).Ethics & Philosophy of Technolog
Suzuki-Miyaura diversification of amino acids and dipeptides in aqueous media
No full textThe authors gratefully acknowledge the IWT Flanders and Janssen Pharmaceutica for financial support of T.W. This work is supported by the Scientific Research Network (WOG) “Sustainable chemistry for the synthesis of fine chemicals” of the Research Foundation - Flanders (FWO).The Suzuki-Miyaura derivatisation of free amino acids, peptides and proteins is an attractive area with much potential utility for medicinal chemistry and chemical biology. Here we report the modification of unprotected and Boc-protected aromatic amino acids and dipeptides in aqueous media, enabling heteroarylation and vinylation. We systematically investigate the impact of the peptide backbone and adjacent amino acid residues upon the reaction. Our studies reveal that whilst asparagine and histidine hinder the reaction, by utilising dppf, a ferrocene-based bidentate phosphine ligand, cross-coupling of halophenylalanine or halotryptophan adjacent to such a residue could be enabled. Our studies reveal dppf to have good compatibility with all unprotected, proteinogenic amino acid side chains.Peer reviewe
Programmatuur electrolytmodellen: Supplement bij het afstudeerverslag van R.A.C. van Kwartel (Metingen aan het binaire systeem NH3-H2O, modellering van de systemen CO2-H2O en NH3-H2O met electrolytmodellen)
No full textIn dit supplement zijn drie programma's op genomen t.w. het programma PITCO2 , het programma CHEN en het programma CHENCO2…Applied SciencesAnorganische en Fysische Chemi
Oosterschelde: Getij berekening
No full textDe resultaten van dit onderzoek moeten gezien worden als een bijdrage tot de oplossing van de Oosterseheldeproblematiek in zijn geheel en meer in het bijzonder als een uitwerking van een vergelijking van twee mathematische modellen t.w. de Expliciete Differentie methode en de Impliciete Differentie methode.Hydraulic EngineeringCivil Engineering and Geoscience
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