Effect of Organic Type

As indicated previously for the 5 kDa membrane, charge effects may cause an increased rejection. For the 10 kDa membrane, rejection is 5-20% lower (than found for the 5 kDa membrane), but the pattern is again the same. 

The size of the organics is important (see Chapter 4 for more detail on organic molecular weight and size). The mass average molecular weight of the organics follows the order IHSS HA NOM HA Aldrich HA 100 kDa permeate IHSS FA NOM NOM FA NOM hydrophilic fraction with sizes ranging feom 2747 to 970 Da (molecule radii of 1.35 to 0.79 nm). Membrane pore radii arc shown to vary from 0.94 to 9.1 nm in Table 6.1. 

The greatest difference in rejection occurs between the 10 kDa and the 30 kDa membrane. Rejection drops to about 10% for the 30 kDa membrane, followed by rejections near zero by the 100 kDa membrane (results not shown). These results indicate that a 5 kDa membrane is ideal if 80% of organics are to be removed. A tighter membrane shows no improvement and operates at a lower flux whilst a more open membrane has a very low rejection. The hydrophilic fraction is overall less retained and a tighter membrane (such as NF or RO) will be required to successfully remove this fraction. It has to be noted here, however, that the hydrophilic fraction has, due to the fractionation method used, an increased ionic strength (see Chapter 4 for fractionation method and salt content). The hydrophilic fraction is the fraction that is biologically most available, whereas chlorination by-product formation occurs preferentially for larger, more aromatic compounds. 

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Figure 7.20 Effect of organic type on flux decline of TFC-S membrane (0.5 mM CaCl, 1 mM NaHCOp noNaCl and 12.5 mgE DOC).

Table 7.30 Effect of organic type and concentration with TFC-S membrane (12.5 mgL DOC, 2.5 mM CaCl().

The crossed polarizer effects of both types are used in analysis work. The concentration of optically active organic materials is determined by the degree of rotation. In plastic processing the residual strains in molded materials as well as the degree of orientation of polymers is determined by the effect on polarized light. Crossed polarizers are used with special wave plates to control the amount of light that passes through an optical system. 

S. Y Wang, and J. P. Chen et al., Selective Debenzylation in the Presence of Aromatic Chlorine on Pd/C Catalysts Effects of Catalyst Types and Reaction Kinetics , paper presented at 20th Organic Reactions Catalysis Society Meeting, March 21-25, 2004, Hilton Head Island, SC, USA. 

Unwanted effects of sulfonamide-type diuretics (a) hypokalemia is a consequence of excessive 1C loss in the terminal segments of the distal tubules where increased amounts of Na are available for exchange with 1C (b) hyperglycemia and glycosuria (c) hyper-uricemia-increase in serum urate levels may precipitate gout in predisposed patients. Sulfonamide diuretics compete with urate for the tubular organic anion secretory system. 

Daisey, J. M., C. F. Allen, G. McGarrity, T. Atherholt, J. Louis, L. McGeorge, and P. J. Lioy, Effects of Filter Type on the Organic Composition and Mutagenicity of Inhalable Particulate Matter, Aerosol Sci. Technol., 5, 69-80 (1986a). 

When the entire body or parts of the body are irradiated externally, individual tissues and organs receive different absorbed doses. In order to relate the absorbed doses in tissue from non uniform irradiation to radiation detriment in humans, a quantity is required which reflects the relative effects of different types of radiation and the relative radiosensitivity of the irradiated organs and tissues. 

On the other hand, Bhattacharya et al. have reported the plasticization effect of organically modified layered silicates on dynamic mechanical properties [13]. In this work, nanocomposites of SBR have been prepared using various nanofillers like modified and unmodified montmorillonite, SP, hectorite etc. It has been observed that the Tg shifts to lower temperature in all the nanocomposites, except for systems from hectorite and NA. This is due to the fact that clay layers form capillaries parallel to each other as they become oriented in a particular direction. Due to wall slippage of the unattached polymer through these capillaries, the Tg is lowered, which could be even more in the absence of organo-modifiers [13]. A similar type of plasticization effect is also noted in the case of the low... 

Eriksen, J., Askegaard, M. and Kristensen, K. 2004. Nitrate leaching from an organic dairy crop rotation the effects of manure type, nitrogen input and improved crop rotation. Soil Use and Management 20 48-54. 

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