Abstract: A device for determining electrical properties of a dielectric material on a metal substratum is provided. First and second electrodes are suspended in a spaced apart relationship above the dielectric material thereby forming first and second air gaps, respectively, between the electrodes and the dielectric material. A resulting circuit path is formed that includes the first and second electrodes, the first and second air gaps, the dielectric material and the metal substratum. Changes in the measured complex impedance of the circuit path are indicative of the electrical properties of the dielectric material.

Abstract: A process for conveniently producing microcapsules containing a gelatin wall crosslinked with quinone and a core of an active compound such as a fouling reducing agent, particularly a tributyl tin chloride, involves use of a simple or complex coacervation technique. The quinone crosslinking provides microcapsules of excellent strength, storage stability, and resistance to aqueous exposure, such that the rate of release of the fouling reducing agent can be controlled with precision.

Abstract: A membrane perfusion apparatus and method for determining the effective rase rates of soluble biologically active chemical agents from a surface. A test cell houses a porous membrane so as to expose one surface of the membrane to a fluid containing at least one organism potentially reactive with a chemical agent of interest being perfused through the membrane at predetermined rates. In the context of antifoulant chemical agents, the invention permits the determination of the minimum effective release rates for biocides.

Abstract: A stable, inexpensive and easily constructed photometer consisting of a cercial intergrated photodetection assembly, complementary solid-state operational amplifiers and a solid-state power supply for use in the detection and quantification of low level light emissions from bioluminescence organisms and for the detection of the absence of bioluminescence. Means are provided for controlling the sensitivity of the system as well as providing for direct readout or intergration of the detected signals where they are intermittent.