Emerson effect

Emerson, W. H. (1973) Conference on Advances in Thermal and Mechanical Design of Shell and Tube Exchangers, NEL Report No. 590. (National Engineering Laboratory, East Kilbride, Glasgow, UK). Effective tube-side temperature in multi-pass heat exchangers with non-uniform heat-transfer coefficients and specific heats. 

The following calculations show the range of effects from infinitely slow hydration-dehydration to infinitely fast. Emerson (1975) and Kirk and Rachhpal-Singh (1992) and have made calculations allowing for the kinetics of the uncatalysed hydration-dehydration reactions, giving intermediate results. 

McConnaughey T (1989b) C and 0 disequilibrium in biological carbonates. II. In vitro simulation of kinetic isotope effects. Geochim Cosmochim Acta 53 163-171 McCorkle DC, Emerson SR (1988) The relationship between pore water isotopic composition and bottom water oxygen concentration. Geochim Cosmochim Acta 52 1169-1178 McCorkle DC, Emerson SR, Quay P (1985) Carbon isotopes in marine porewaters. Earth Planet Sci Lett 74 13-26... 

Why is the Emerson enhancement effect (i.e., light at 650 nm plus 680 nm gives a higher rate of photosynthesis than either one alone) not observed with photosynthetic bacteria ... 

Pagliai, H., Guidi, G., and Petruzzelli, G. (1979). Effect of molecular weight on dextran-soil interactions. In Modifications of Soil Structure, Emerson, W. W., Bond, A. D., and Dexter, A. R., eds., John Wiley Sons, New York, pp. 175-180. 

Murray J.W., Emerson S. and Jahnke R. (1980) Carbonate saturation and the effect of pressure on the alkalinity of interstitial waters from the Guatemala Basin. Geochim. Cosmochim. Acta 44, 963-972. 

Emerson CH, Utiger RD (1975) Plasma thyrotropin-releasing hormone concentrations in the rat. Effect of thyroid excess and deficiency and cold exposure. J Clin Invest 56(6) 1564-70... 

Tebo, B.M. and Emerson, S., Effect of oxygen tension, manganese-II concentration and temperature on the microbially catalyzed manganese-II oxidation rate in a marine fjord, Appl. Environ. Microbiol., 50, 1268, 1985. 

This effect is pH dependent (Emerson, 1975) and is most important at low wind speeds and high water temperatures (e.g., equatorial regions). Modeling studies have indicated that chemical enhancement may increase fe o by up to 8% in these regions (Boutin andEtcheto, 1995). 

Nitrous oxide (N2O) is a long-lived (120 yr) trace component of the atmosphere (Prinn et al., 1990). It is a climate-active gas as it has a radiative forcing 300 times that of CO2, although N2O presently contributes only 5% to the total greenhouse effect (Schimel, 1996). N2O also acts as a source of nitric oxide in the stratosphere and therefore participates in the catalytic removal of ozone (Crutzen, 1970). It is produced as a reaction intermediate in both microbial denitrification and nitrification processes and at greater rates under conditions of low O2 (Law and Owens, 1990) (see Chapter 6.11 by Emerson and Hedges for more details). 

Organic matter degradation within the sediments creates a microenvironment that is corrosive to CaCOa even if the bottom waters are not, because addition of DIC and no At to the pore water causes it to have a lower pH and smaller [COa ]. Using a simple analytical model and first-order dissolution rate kinetics, Emerson and Bender (1981) predicted that this effect should result in up to 50% of the CaCOa that rains to the seafloor being dissolved even at the saturation horizon, where the bottom waters are saturated with respect to calcite. Because the percent CaCOa in sediments is so insensitive to dissolution and the saturation-horizon depth so uncertain, this suggestion was well within the constraints of environmental observations. 

The effect of organic matter driven dissolution is to raise the carbonate transition in sediments relative to the saturation horizon in the water column (Emerson and Archer, 1990 Figure 11), but there should be little change in the ACOa iys ccD necessary to create the transition in %CaCOa. Thus, the argument about the relationship between the dissolution rate constant and observed transition of %CaCOa in sediments (Appendix A) should not be affected. 

Emerson, M. R. Samson, F. E. Pazdemik, T. L. Effects of hypoxia preconditioning on expression of metallothionein-1,2 and heme oxygenase-1 before and after kainic acid-induced seizures. Cell Mol. Biol. (Noisy-le-grand). 46 619-626 2000. 

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