Search results for "Hagen"
showing 10 items of 30 documents
Self-assembly of colloidal micelles in microfluidic channels.
2016
The self-assembly of amphiphilic Janus colloids in microfluidic channels is studied using hybrid molecular dynamics simulations with fully resolved hydrodynamic interactions incorporated through the multi-particle collision dynamics algorithm. The simulations are conducted at a density and temperature where the Janus particles spontaneously self-assemble into spherical micelles to minimize the interface between the solvophobic caps and the surrounding solvent. In confined systems, this contact area can also be reduced by aggregation at the channel walls. Indeed, a sizable fraction of free particles and small clusters with three and four members are found at the walls when the microfluidic c…
High Reynolds number Navier-Stokes solutions and boundary layer separation induced by a rectilinear vortex
2013
Abstract We compute the solutions of Prandtl’s and Navier–Stokes equations for the two dimensional flow induced by a rectilinear vortex interacting with a boundary in the half plane. For this initial datum Prandtl’s equation develops, in a finite time, a separation singularity. We investigate the different stages of unsteady separation for Navier–Stokes solution at different Reynolds numbers Re = 103–105, and we show the presence of a large-scale interaction between the viscous boundary layer and the inviscid outer flow. We also see a subsequent stage, characterized by the presence of a small-scale interaction, which is visible only for moderate-high Re numbers Re = 104–105. We also investi…
Challenges in EU External Climate Change Policy-Making in the Early Post-Lisbon Era: The UNFCCC Copenhagen Negotiations
2011
The 15th United Nations Framework Convention on Climate Change (UNFCCC) Conference of the Parties (COP) meeting held in Copenhagen from 7 to 18 December 2009, which took place one week after the entry into force of the Treaty of Lisbon on 1 December 2009, has brought about rather disappointing outcomes from the perspective of the European Union (EU), which had previously displayed substantial leadership within the UN climate regime. Contrary to the EU’s objectives for the COP15 meeting, no legally binding agreement was reached to succeed the Kyoto Protocol after 2012 and the final Copenhagen Accord contained disappointingly few ambitious targets. This chapter tries to explain how this resul…
Copenhagen consensus statement 2019: physical activity and ageing
2019
From 19th to 22nd November 2018, 26 researchers representing nine countries and a variety of academic disciplines met in Snekkersten, Denmark, to reach evidence-based consensus about physical activity and older adults. It was recognised that the term ‘older adults’ represents a highly heterogeneous population. It encompasses those that remain highly active and healthy throughout the life-course with a high intrinsic capacity to the very old and frail with low intrinsic capacity. The consensus is drawn from a wide range of research methodologies within epidemiology, medicine, physiology, neuroscience, psychology and sociology, recognising the strength and limitations of each of the methods. …
The Copenhagen Concensus Conference 2016: Children, youth, and physical activity in schools and during leisure time
2016
From 4 to 7 April 2016, 24 researchers from 8 countries and from a variety of academic disciplines gathered in Snekkersten, Denmark, to reach evidence-based consensus about physical activity in children and youth, that is, individuals between 6 and 18 years. Physical activity is an overarching term that consists of many structured and unstructured forms within school and out-of-school-time contexts, including organised sport, physical education, outdoor recreation, motor skill development programmes, recess, and active transportation such as biking and walking. This consensus statement presents the accord on the effects of physical activity on children's and youth's fitness, health, cogniti…
Między spotkaniem a mijaniem. Rahel Varnhagen, Hannah Arendt, Judith Butler
2020
The article is an attempt at capturing the relationship between the lives and creative attitudes of Rahel Varnhagen, Hannah Arendt and Judith Butler. Starting with Varnhagen’s biography written by Arendt, the essay’s author wonders about the philosopher’s writing strategy. Instead of a classic reconstruction of life, the biographer offers a collage of excerpts from Rahel’s letters with extensive commentary. This form encourages one to read Rahel Varnhagen as a narration about the author and her own struggle with Jewish and female identity. The second relationship analysed in the essay is the impact of Hannah Arendt’s texts on Judith Butler’s writings. Despite the criticism of the philosophe…
Contexto editorial, cultural y socio-político de la edición príncipe de la «Historia de la doncella Teodor» (Toledo: Pedro Hagenbach, 1500-1501)
2021
The material analysis of the only surviving copy of the editio princeps of the Historia de la doncella Teodor allows us to date it back to the incunabula era and to attribute its printing to Pedro Hagenbach’s workshop. The close relationship amongst Hagenbach’s workshop, the reformist project of Archbishop Cisneros, and the interests of the Catholic Monarchs sets an editorial and cultural context that supports the adaptation of Teodor to the printing press. This work perfectly agreed with the thematic and ideological guidelines for the renewal of Christian customs and values. The forceful religious and intellectual imposition of the young and learned slave, turned into a “fijadalgo” in the …
DIRECT NUMERICAL SIMULATION OF MOTION OF FERROMAGNETIC PARTICLES IN MAGNETORHEOLOGICAL SUSPENSION
2008
ABSTRACT Results simulation of magnetorheological suspension at particle level are reported. The present approach accounts for a better description of hydrodynamic interaction between close spheres. Development of lamellar structures similar to those obtained by other researchers in Poiseuille flow is observed in shear flow. Studies of single layer lamellar structures reveal presence of short chains and more complex aggregates.
Cross-stream migration of a Brownian droplet in a polymer solution under Poiseuille flow
2018
The migration of a Brownian fluid droplet in a parallel-plate microchannel was investigated using dissipative particle dynamics computer simulations. In a Newtonian solvent, the droplet migrated toward the channel walls due to inertial effects at the studied flow conditions, in agreement with theoretical predictions and recent simulations. However, the droplet focused onto the channel centerline when polymer chains were added to the solvent. Focusing was typically enhanced for longer polymers and higher polymer concentrations with a nontrivial flow-rate dependence due to droplet and polymer deformability. Brownian motion caused the droplet position to fluctuate with a distribution that prim…
Morphological determination of the phototrophic community composition of biological soil crusts in coastal sand dunes in northern Germany
2022
This dataset comprises the microbial community composition of biological soil crusts in north-German sand dunes. For this we obtained enrichment cultures of phototrophic microorganisms, by placing fragments of biocrusts of the same Petri dishes as used for sequencing, in Petri dishes with Bold Basal (1N BBM) agarized medium (Bischoff and Bold 1963). Cultures were grown under standard laboratory conditions: with a 12-hour alteration of light and dark phases and irradiation of 25 μmol photons m-2 s-1 at a temperature 20 ± 5 ºС. Microscopic study of these raw cultures began in the third week of cultivation. Morphological examinations were performed using Olympus BX53 light microscope with Noma…