Bridging mechanism

A fourth mechanism is called sweep flocculation. It is used primarily in very low soflds systems such as raw water clarification. Addition of an inorganic salt produces a metal hydroxide precipitate which entrains fine particles of other suspended soflds as it settles. A variation of this mechanism is sometimes employed for suspensions that do not respond to polymeric flocculants. A soHd material such as clay is deUberately added to the suspension and then flocculated with a high molecular weight polymer. The original suspended matter is entrained in the clay floes formed by the bridging mechanism and is removed with the clay. 

Short Random Fibers. The whiskers bridging mechanics given in equations 21 through 25 apply also to short random fiber bridging mechanisms. The bridging terms come from (44) ... 

The interparticle bridging mechanism was affected by the charge [7], adsorption sites [5] of particles extending in the flocculation system, the physical characteris-... 

Chitosan samples with degrees of deacetylation of 65,73,85, and 92% were almost completely adsorbed onto the surfaces of cellulosic fibers, especially onto the surfaces of fines in a variety of cellulosic systems used in industrial operations. Adsorption increased as the degree of deacetylation of chitosan increased. The aggregation of the fine cellulosic particles was maximum at a dosage of about 10 mg/kg. The interactions between chitosan and the cellulosic substrates were dominated by a bridging mechanism at about pH 7 [32]. 

Basolo et al., have found similar platinum(II)-catalysed chloride exchange reactions with other Pt(IV) complexes, including cis- and ran5-Pt(NH3)4Cl, Pt(NH3)5CP and rra J-Pt(NH3)3Cl3. These reactions proceed by the chloride bridge mechanism above and the apparent rate coefficients k P.mole . sec, 25 °C) for platinum exchange, which was concluded to occur via this pathway. 

In dimethylformamide solution, platinum exchange between Pt(en)Br2 and Pt(en)Br4 has been found to be light-sensitive and catalysed by bromide ions. In the absence of light, a value < 1.33 x 10" l.mole . sec was obtained for the observed rate coefficient (25 °C) from data obtained by the isotopic method (i95pt) separation using an ether precipitation of Pt(en)Br2. The bridge mechanism was thought to occur... 

Flocculation of microorganisms is thought to be affected by a bridging mechanism of polymers excreeted by the microorganisms or exposed to the microbial surface under suitable physiological conditions. More recently new work on adhesion of bacteria have been carried out (Van Loosdrecht et al., 1990) see Chapter 7.9. 

In Section 2222, we described a bridging mechanism in which polymer was laterally squeezed away from the near-contact region upon approach of the droplets. 

White, D. C. S., Wilson, M. G. A., Thorson, J. In Cross-bridge Mechanism in Muscle Contraction (eds. Sugi, H., Pollack, G. H.) University Park Press, Baltimore (1979)... 

Establishing a common baseline for medical data collection and research, and compatibility or bridging mechanisms for all technologies... 

Confining ourselves for the moment to reactions knowrn to go via inner sphere bridging mechanisms, namely those involving Cr+2 and Co(CN)6 3 as reductants, the trend in each case is for the rate to increase along the series F < Cl < Br < I, the largest increase occurring in each case in going from F to Cl. 

Interaction energies obtained from molecular dynamic simulations are statistically equivalent for both 2-sulfated a-L-galactan from . lucunter (Fig. 12.2A) and 2-sulfated ot-L-fucan from S. franciscanus (Fig. 12.1H). This would be expected based on the structural similarities of these two compounds, especially conformations in solution. Flowever, they revealed markedly different interactions for binding with the complex AT/IIa. The explanation for this result is the extreme difference in orientations on the AT-binding site ( 90°, Fig. 12.4C and D). Such difference in orientation upon binding to AT explains the lack of activity of SF under the same experimental conditions and fully supports the expected bridging mechanism in the activity of SG, as previously described (Melo et ah,... 

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