Comparison of two materials for storage of nitrogen standard solutions

Abstract

Electrometers for gas chromatographic detection are, at least in our hands, prone to malfunction; and they are expensive to repair or replace. Faced with such a dilemma, we recently assembled a simple amplifier from readily available components. It served as an inexpensive electrometer substitute for use with our Shimadzu flame photometric detector (FPD).Due to the relatively high current output of the photomultiplier tube, the FPD lends itself well to low-cost amplification. This is possible through the use of inexpensive monolithic field-effect transistor (FET) operational amplifiers that became readily available after the mid 1970s. Futhermore, we are making use of the fact that, nowadays, many recorders have multirange capability. Of course, there is nothing fundamentally new in our approach; however, it is certainly not common knowledge that one can significantly reduce the high cost of a flame photometric detection system in this manner. The price one pays for doing this-in terms of detector performance as well as in terms of electronic components-is minimal.

A model system for delocalized chemiosmotic coupling exhibited the features thought diagnostic of localized coupling

“…(Westerhoff et al, 1984;Ferguson, 1985) are not readily understandable in terms of the 'delocalized' chemiosmotic coupling model (Mitchell, 1981). Whereas it is appropriate to develop alternative views, the experimental observations should also be scrutinized both with respect to systematic experimental errors (e.g.…”

The use of valinomycin, nigericin and trichlorocarbanilide in control of the protonmotive force in Escherichia coli cells

“…Ap-consuming reactions include: osmotic work by transport proteins, chemical work by the ATP synthase and kinetic work by the flagellar motor (Hamilton, 1975;Harold, 1976;Mitchell, 1981). More recently, other cellular functions have also been associated with Ap, such as protein secretion (Date et al, 1980), nitrogen fixation (Veeger et al, 1980) and bacteriophage infection (Labedan & Goldberg, 1979).…”