Search results for "suspensio"
showing 10 items of 266 documents
Fecal pellets from a dense aggregation of suspension-feeders in a stream: An example of ecosystem engineering
1998
Blackfly larvae (Diptera: Simuliidae) are "allogenic ecosystem engineers" that capture fine particulate and dissolved matter from suspension and egest much larger fecal pellets. We investigated the effects of blackfly larvae on organic matter transport at 25 sites along a small stream that flowed 500 m from a lake to the sea. Blackfly density was high upstream (>6 x 10(5) ind. m(-2)) and the numbers of fecal pellets in suspension rose markedly downstream from the blackfly aggregation. A total of 1.6 x 10(9) fecal pellets (biomass 3.2 kg C d(-1)) were discharged to the sea each day and 8.0 x 10(8) pellets (biomass 1.6 kg C d(-1)) were lost from suspension. Sedimenting pellets were available …
Enzymatic Formation of Raucaffricine, the Major Indole Alkaloid ofRauwolfia serpentinaCell-Suspension Cultures
1991
The major alkaloid from Rauwolfia serpentina cell-suspension cultures, the glucoalkaloid raucaffricine (2), was enzymatically formed from vomilenine (1) and UDPG in presence of microsomal-bound enzyme. This glucosyltransferase exhibits a relatively high substrate specificity with strong preference for 1 and UDPG. The apparent Km values for 1 and UDPG were 40 μM and 0.8 mM, respectively, for raucaffricine formation. Optimum transferase activity was observed at 50° and pH 6.3. The taxonomic distribution of this enzyme seems to be very limited because transferase can he exclusively detected in raucaffricine-producing plant cells.
Iron oxide-based magnetic photocatalysts: Recent developments, challenges, and environmental applications
2021
Abstract Magnetic separation of the solid photocatalyst from the reacting suspension has received great interest in recent research because it offers a suitable way for removing and recycling the heterogeneous photocatalytic material particles preventing the agglomeration and sedimentation during and after their use. The use of iron oxides such as heterogeneous photocatalysts is an appropriate choice to obtain a suitable photocatalyst easily separable from the fluid. This chapter presents a detailed investigation of iron oxide-based magnetic photocatalysts (IOMPs). We will discuss the required conditions for the synthesis of these photocatalysts, followed by their applications for the remov…
Modification of Polymer-Magnetic Nanoparticles by Luminescent and Conducting Substances
2014
The polymer encapsulated magnetic nanoparticles were obtained by suspension polymerization of styrene in the aqueous dispersion of magnetite. Functionalization of capsules was carried out by adsorp...
Re-entrant glass transition in a colloid-polymer mixture with depletion attractions.
2002
Performing light scattering experiments we show that introducing short-ranged attraction to a colloidal suspension of nearly hard spheres by addition of free polymer produces new glass transition phenomena. We observe a dramatic acceleration of the density fluctuations amounting to the melting of a colloidal glass. Increasing the strength of the attractions the system freezes into another nonergodic state sharing some qualitative features with gel states occurring at lower colloid packing fractions. This reentrant glass transition is in qualitative agreement with recent theoretical predictions.
The structure of gas-filled n-butyl-2-cyanoacrylate (BCA) polymer particles
1995
Abstract The structure of gas-filled poly-[n-butyl-2-cyanoacrylate] (BCA) particles has been demonstrated by negative staining with uranyl acetate, platinum-carbon shadowing of air-dried material and thin sectioning of the aqueous suspension of BCA particles, embedded in water-soluble melamine resin. The polymer shell of the hollow particles possesses a globular outer surface and a smoother inner surface.
Synthesis of V-ZrSiO4 solid solutions
1990
This letter describes the results of the preparation of V-ZrSiO 4 solid solutions from a sol or alkoxide and solute salts. This technique allows a greater degree of product formation to be achieved at lower temperatures, as well as the possibility of studying the characteristics of possible solid solutions
Inverse correlated 1H-13C in vivo NMR as a probe to follow the metabolism of unlabeled vanillin by plant cell cultures
1997
Abstract Inverse correlated 2D 1H-13C NMR spectroscopy was used to follow the metabolism of vanillin (1) in vivo by plant cell suspension cultures of Nicotiana plumbaginifolia at the natural abundance of 13C. Under the non-invasive conditions four products could be detected: vanillylalcohol (2), vanillinglucoside (3) and the phenolic and benzylic glucosides of vanillylalcohol (4 and 5).
Chapter 2 Biosynthesis in Rauwolfia serpentina Modern Aspects of an Old Medicinal Plant
1995
Publisher Summary This chapter discusses a research on Rauwolfia , which was achieved after the generation of a cell suspension with extraordinary growth characteristics and physiological behavior. The investigations demonstrated that a range of techniques is now available for the clarification of complete metabolic pathways, provided that the appropriate efficient biological system is available. The isolation and identification of each single enzyme have almost become routine, even if an extremely sensitive protein analytic technique is necessary when several kilograms of fresh plant cells are reduced to a few micrograms of homogenous protein. The successful identification of a total of 20…
Umsetzungen von polyacroleinen mit formaldehyd. Polymere acroleine. 28. Mitt.1
1963
Polyacroleine wurden in wasriger Suspension und in einem Pyridin-Wasser-Gemisch in Anwesenheit von basischen Katalysatoren mit Formaldehyd umgesetzt. Die Reaktions-produkte enthalten, in Abhangigkeit von den Versuchsbedingungen, neben Carboxylgruppen hauptsachlich primare Alkoholgruppen. Die chemischen Eigenschaften und Vergleiche mit polymeren Modellsubstanzen lassen darauf schliesen, das die gewonnenen Polymeren im wesentlichen aus Methylen-propandiol-1,3-Grundbausteinen aufgebaut sind. Polyacroleins were reacted with formaldehyde in aqueous suspension and in a pyridin water mixture in the presence of basic catalysts. Depending on the experimental conditions the products of the reaction m…