. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. K. A. BROWNE AND R. K. ZIMMER initiated with ammonium persulfate (APS; w/v, final) and catalyzed with tetramethylenediamine (TEMED; v/v, final). These methods resulted in polymerization within 30 min and pore diameters of about 39 A (20). c, 1 (2N + I)2 (I) Eq. 1 indicates that the fraction of solute remaining in a cylindrical gel (Cf/C0) with a single open end is a nonlinear function of time (/). the gel length (L), and the diffusion coefficient (Dp) for a particular acrylamide concentration summated in a Bessel
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. K. A. BROWNE AND R. K. ZIMMER initiated with ammonium persulfate (APS; w/v, final) and catalyzed with tetramethylenediamine (TEMED; v/v, final). These methods resulted in polymerization within 30 min and pore diameters of about 39 A (20). c, 1 (2N + I)2 (I) Eq. 1 indicates that the fraction of solute remaining in a cylindrical gel (Cf/C0) with a single open end is a nonlinear function of time (/). the gel length (L), and the diffusion coefficient (Dp) for a particular acrylamide concentration summated in a Bessel series of N terms. Dp was estimated from Eq. 2 and a rearranged version of the Wilke-Chang formula (Eq. 3): X (2) (3) where D() is the diffusion coefficient of a solute in H,O: M is molecular mass (g mol~') of the solute and H2O in Eq. 2 and Eq. 3. respectively; P is the percent (w/v) of polyacryl- amide; ju is the dynamic viscosity of ( = centi- pose); K is the temperature in Kelvin; is the "association" parameter of H,O (=); and V is the molal volume of the solute at its normal boiling point (370 cm3 g mol"1 for disodium fluorescein). Through computer simulations, the rates of solute release from acrylamide were determined by applying Eq. 1 to cylindrical gels with lengths ranging from to 10 cm for up to 5 days of field exposure. Fluorescein was chosen as a tracer because its molecular mass (and. hence, diffusion coefficient) is close to that of the small peptides used in the settlement assays (330 g moP' versus 269 and 288 g mol~' for GGH and GGR. respectively). The diffusion coefficients for fluorescein in acrylamide (Dr) and H2O (D0) were calculated from Eq. 2 and Eq. 3, respectively, to be X 10~6 and X 10~6 cm2 s~' at 27 °C. From these simu- lations, it was clear that at lengths greater than 4-5 cm, gels release very little (<50%) of their included organic com- pounds in 3-5 d (Figs. 1 and 2). If the gel is too thin (
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
