2,582 research outputs found
tritrophic-dispersal-model: Code used for creating figures for "Non-hierarchical dispersal promotes stability and resilience in a tri-trophic metacommunity"
No full text<p>This is the commented code used for creating figures for the paper. Any questions regarding the code should be directed to the corresponding author and repository owner (Eric Pedersen). </p>
Analytical microextraction with supported liquid membranes
No full textThis chapter focuses on microextraction using supported liquid membranes (SLMs) and discusses two- and three-phase hollow-fiber liquid-phase microextraction, solvent bar microextraction, 96-well liquid-phase microextraction (parallel artificial liquid membrane extraction), and electromembrane extraction. These techniques all rely on mass transfer across an SLM, which is a microliter volume of organic solvent held by capillary forces in the pores of porous polymeric membrane. The organic solvent is immiscible with water, such as 1-octanol. The polymeric membrane is either a hollow-fiber membrane or a flat membrane and is hydrophobic such as polypropylene or polyvinylidene fluoride. Extraction can be in two-phase systems, from aqueous sample, across organic SLM and into organic acceptor; or in three-phase systems from aqueous sample, across organic SLM and into aqueous acceptor. The volume of acceptor is typically 2-50µL and preconcentration is feasible. Extraction can be by passive diffusion or by migration in an electrical field sustained across the SLM. In the following, we discuss the different principles, along with practical examples and method development.</p
Odontites verna (Bell.) Dum. subsp. pumila (Nordst.) A. Pedersen in Nederland
No full textThe author gives a brief survey of ecology, distribution, and differences in flowering time of Odontites verna (Bell.) Dum. subsp. verna, subsp. litoralis (Fr.) A. Pedersen, subsp. fennica (Markl.), subsp. serotina (Wettst.) E. F. Warb., and subsp. pumila (Nordst.) A. Pedersen. In a description of the last named differential characters with subsp. serotina are stressed. Subsp. pumila is known from sandy pastures along the coasts of S. W. Sweden, Denmark, N. and N. W. Germany, and the Netherlands. Fig. 1 gives a map, showing the distribution in the Netherlands, based on the material of the Rijksherbarium, Leiden
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