Membrane measurements

The response from sandwich membranes measurements of species interactions in situ. 

It should be emphasized here that the four major complexes of the electron transport chain operate quite independently in the inner mitochondrial membrane. Each is a multiprotein aggregate maintained by numerous strong associations between peptides of the complex, but there is no evidence that the complexes associate with one another in the membrane. Measurements of the lateral diffusion rates of the four complexes, of coenzyme Q, and of cytochrome c in the inner mitochondrial membrane show that the rates differ considerably, indicating that these complexes do not move together in the membrane. Kinetic studies with reconstituted systems show that electron transport does not operate by means of connected sets of the four complexes. 

Bowen et al. [94] made a B-MFI membrane on a monohthic support. The pervaporation fluxes and selectivities of several alcohol/water mixtures were comparable to similar tubular-based B-MFI membranes, demonstrating the scale-up, although, for pervaporation, the quality requirements are much more forgiving. Kuhn etal. tested a multicharuiel high-silica MFI membrane for ethanol/water separation. The membrane was supphed by NGK Insulators and, also, in this case, the multicharuiel membrane measures up to its tubular counterparts [95] (Figure 10.8). 

Omann G, Lakowicz JR. 1977. Pesticide uptake into membranes measured by fluorescence quenching. Science 197(4302) 465-467. 

C. L. Poglitsch and N. L. Thompson, Interaction of antibodies with Fc receptors in substrate-supported planar membranes measured by total internal reflection fluorescence microscopy, Biochemistry 29, 248-254 (1990). 

D. Axelrod, R. M. Fulbright, and E. H. Hellen, Adsorption kinetics on biological membranes Measurement by total internal reflection fluorescence, in Applications of Fluorescence in the Biomedical Sciences (D. L. Taylor, A. S. Waggoner, F. Lanni, R. F. Murphy, and R. Birge, eds.), pp. 461-467, Alan R. Liss, New York (1986). 

Figure 6.4 shows that long-range diff usivities of water in Nafion membranes measured by QENS, Di are equal to self-diff usivities determined by PFG-NMR, Dg, at A > 10. In well-hydrated membranes, the major geometric constraints for water mobility due to the phase-segregated, random network morphology of... 

Nghiem LD, Schafer AI, Elimelech M (2004) Removal of natural hormones by nanofiltration membranes measurement, modeling, and mechanisms. Environ Sci Technol 38 1888-1896... 

Diffusive salt permeability through u treated PVA membranes measured at atmospheric pressure ( car Is x 10 )... 

Membranes certainly introduce cooperative processes, so that a merely molecular approach will not be enough, particularly with reference to boundary conditions. Whether a cell is large enough, on the other hand, to justify statistical averaging as implied by such terms as phase and dielectric field may involve quite a profound distinction. As a speculation, a cell diameter might be conditioned by the natural mode interval in diffusive systems and phase is not a justifiable term. A related question is whether the thickness of a membrane measured in molecular dimensions can play an important role structurally or whether a membrane behaves merely as an indefinitely thin boundary. 

G.B. Sigal, D.G. Hafeman, J.W. Parce and H.M. Mcconnell, Electrical-properties of phospholipid-bilayer membranes measured with a light addressable potentiometric sensor, ACS Symp. Ser., 403 (1989) 46-64. J.D. Olson, P.R. Panfili, R. Armenta, M.B. Femmel, H. Merrick, J. Gumperz, M. Goltz and R.F. Zuk, A silicon sensor-based filtration immunoassay using biotin-mediated capture, J. Immunol. Methods, 134(1) (1990) 71-79. 

In this chapter, the term. / is the volume flux (cm3/cm2 s) through the membrane measured at the feed-side conditions of the process. 

Some confusion can occur over the rejection coefficients quoted by membrane module manufacturers. The intrinsic rejection of good quality membranes measured in a laboratory test system might be in the range 99.5 to 99.7 %, whereas... 

C. Lagerholm, T. E. Starr, Z. N. Volovyk, and N. L. Thompson, Rebinding of IgE Fabs at haptenated planar membranes Measurement by total internal reflection with fluorescence photobleaching recovery, Biochemistry 39, 2042-2051 (2000). 

By adding water sensitive dyes to the PVC based membranes we are able to determine the distribution of water as a function of position inside the membrane, measured from the water interface, as a function of time (7). We present here a... 

Potts, J.R., Hounslow, A.M., Kuchel, P.W. (1990). Exchange of fluorinated glucose across the red cell membrane measured by 19F n.m.r. magnetisation transfer. Biochem. J. 266,925-928. 

Li, Qilin, and Menachem Elimelech, "Organic Fouling and Chemical Cleaning of Nanofiltration Membranes Measurements and Mechanisms," volume 38, number 17,2004. 

Fig. 1 shows proton conductivity for the perfluorosulfonic acid membranes, measured at 300 K in air by the DC resistance measurement, after gamma-ray irradiation at the several doses up to 414 kGy. The conductivity was calculated from the applied voltage and the measured current and dimension of the polymers. It can be seen in Fig.l that the conductivity increases with increasing the dose. The conductivities at 300 K in air atmosphere rapidly increased until about 50 kGy, and achieved to be higher by about three orders of magnitude than that of the unirradiated one. 

Zhu, X. and M. Elimelech (1997). Colloidal fouling of reverse osmosis membranes Measurements and fouling mechanisms. Environ. Science Technol. 31, 12, 3654-3662. 

R.V. Bucur and V. Mecca, The duffusivity and solubility of hydrogen in metallized polymer membranes measured by the non-equilibrium stripping potentiostatic method. Surf, Coat, TechnoL 28 3S7 (1986). 

Ion selective membranes measure ion activity (o) which is related to concentration (c) by... 

P/l is also referred to as permeability flux and expressed as (m (STP)/(m bar h)). Ap, is the partial pressure difference of i across the membrane measured in pascals or bars. This equation shows that the flux through the membrane is proportional to the pressure difference across the membrane and inversely proportional to the membrane thickness. Por selectivity between gas components the Equations 4.3 and 4.4 are referred to. The ideal separation factor, a (Equation 4.3), may be expressed by the ratio of the pure gas permeabilities for the individual components i and j. 

The comparison of the pore size measured on non-supported membranes by N2 absorption-desorption with that on supported silica membranes measured with gas permeation and separation with molecules of greatly different sizes indicates that the average pore diameter of supported silica layers is slightly smaller (0.40-0.45 nm). See Chapter 9 on gas transport. 

Vroon et al. report values obtained by transient measurements on their silicalite membranes using Eq. (9.61b) and find a good agreement with values obtained from steady-state membrane measurements. Values obtained from transient measurements in sorption experiments on powdered material are two orders of magnitude smaller. 

Fig. 3.82 Pore creation through 13 tm thick PET membranes exposed to 254 and 312 nm wavelengths for 1 h. Ion beam of 58Ni with incident energy 10.7 MeV/u (1 h, 254 nm) 9.1 MeV/u (15 h, 254 nm). Etching occurs at the both faces, d is the pore diameter measured with AFM (surface image) and he is the depth of etching penetration through the membrane measured with SEM (cross-section image) and fe = etching time. Reproduced with permission from [173]. Copyright 2007. Elsevier...

Johnstone BM, Patuzzi R, Yates GK. 1986. Basilar membrane measurements and the travelling wave. Hear Res 22 147-153. 

Labbez. C. et al.. Evaluation of the DSPM model on a titania membrane Measurements of charged and uncharged solute retention, elecUokinetic charge, pore size, and water permeability,. 1. Colloid Interf. Sci., 262, 200, 2003. 

Huster D, Jin AJ, Arnold K, Gawrisch K. Water permeability of polyunsaturated lipid membranes measured by O NMR. Biophys J 1997 73 855-864. 

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