590 research outputs found
On the Relation between Eulerian and Lagrangian Averages in the Statistical Theory of Turbulence
Racial depictions in visual culture during World War One: A transnational and comparative study
How can we understand British depictions of the German ‘race’, if they are understood as belonging to the same racial category? We argue that an analysis of racial depictions must be based on historical and cultural understandings. We present ‘race’ as an all-encompassing, flexible historical phenomenon, that includes cultural racism. We found that cultural and biological racism overlapped, working in tandem to create a single depiction within a spectrum of culturally or biologically based racial stereotypes. We argue that racialized stereotypes were deployed in both intra-white and non-white depictions depending on the desired function of the propaganda resulting in both positive or/and negative portrayals that worked mainly in consolidating the Self and Othering the enemy – with the exception of white depictions of non-white soldiers often showcasing Othering exotic elements
Assessment of risks related to agricultural use of sewage sludge, pig and cattle slurry
In April 2017, the Organic Business Development Team released a report with 25 recommendations for the Minister of Environment and Food (Det økologiske erhvervsteam 2017). Among these was a recommendation that organic farmers should have opportunities for utilizing nutrients from treated domestic wastewater for nutrient recycling.
A prerequisite for future use of nutrients from treated wastewater is, that quality requirements are met and that application can be explained to (and accepted by) consumers. In partial fulfilment of this, the business team identified a need for a scientific overview of the risks of using nutrients from treated municipal wastewater in relation to other authorized fertilizer sources – e.g. conventional animal manures. Thus, it was assumed that a comparative approach to assess potential risk of using sewage sludge and conventional manures, could usefully inform decision makers in the future regulation of organic farming systems.
Dependent on the result of the scientific investigation, the Organic Business Development Team foresaw that Denmark could chose to work to expand Annex 1 of the EU Ecology Regulation, to allow the organic farmers to use nutrients from municipal wastewater or other acceptable derived sludge products. Mobilization of support for this should be done by the Ministry of Environment and Food in collaboration with the Organic Farming Industry.
Thus, based on available literature, this report aims at creating an overview of the environmental and human risks associated with application of pig and cattle slurry as well as sewage sludge to agricultural soils. The risk evaluation was performed for the following compound groups: Metals, Chlorophenyls, Dioxins, Furans, Halogenated aliphatic and aromatic hydrocarbons (HAH), Linear alkylbenzenesulfonates (LAS), Polyaromatic hydrocarbons (PAH), Polybrominated diphenyl ethers (PBDE), Polychlorinated biphenyls (PCB), Poly- and perfluorinated alkylated substances (PFAS), Phenols, Phosphate-triesters
VII, Phthalates, Polychlorinated naphtalenes (PCN), Polychlorinated alkanes (PCA), Triclosan, Triclocarban, Medicines, Estrogens, Antibiotic resistance genes.
Additionally the fertilizer potential of the two nutrient sources was characterized and compared
Generation of micro-droplet arrays by dip-coating of biphilic surfaces; the dependence of entrained droplet volume on withdrawal velocity
Abstract Droplet array chips were realized using an alignment-free fabrication process in silicon. The chips were textured with a homogeneous nano-scale surface roughness but were partially covered with a self-assembled monolayer of perfluorodecyltrichlorosilane (FDTS), resulting in a super-biphilic surface. When submerged in water and withdrawn again, microliter sized droplets are formed due to pinning of water on the hydrophilic spots. The entrained droplet volumes were investigated under variation of spot size and withdrawal velocity. Two regimes of droplet formation were revealed: at low speeds, the droplet volume achieved finite values even for vanishing speeds, while at higher speeds the volume was governed by fluid inertia. A simple 2D boundary layer model describes the behavior at high speeds well. Entrained droplet volume could be altered, post-fabrication, by more than a factor of 15, which opens up for more applications of the dip-coating technique due to the significant increase in versatility of the micro-droplet array platform
On alfa-particle heating of a thermonuclear plasma
The theory of the slowing down and thermalization of alfa-partides created in and slowed down by a plasma considered as an undisturbed thermal bath is re-examined. The considerations are limited to a homogeneous, isotropic plasma. Also the alfaparticles are considered as a density-wise negligible component of the plasma. Under these circumstances, all essential parts of the theory can be studied analytically. Thus all standard approximations can be studied with precision. However, the conclusions do not differ from numerical results earlier obtained by numerous authors. In this sense the present paper must be considered as a review based on analytical methods. The standard approximations referred to are such as the neglect of the variation of the Coulomb logarithm with velocity, the influence of quantum-mechanical effects, the significance of the impact parameter cut-off (the Debye length), and the assumption of a Maxwellian plasma. Some of these effects have been examined analytically by other authors. However, the present work shows that the Fokker-Planck equation can be solved without the aid of computers for the simplest set of standard approximations. The result thereof is a determination of slowing down rates and rate of growth of energy spread and thereby thermalization of the alfa-particles
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