A method for determining the molecular weights of proteins by placing a dilute aqueous solution of the protein in contact with a porous 96 percent Silica glass membrane. At various time intervals, the percent loss of protein from solution to the membrane is calculated. A molecular weight of the protein is inversely proportional to the rate of molecular inclusion after a predetermined time.

A method enabling the frequency of the radiation emitted by a multi-frequency CO.sub.2 laser to be determined with precision by adjusting the optical length of the resonant cavity, so as to be a multiple of the wavelengths of the two beams emitted, and so as to obtain a central dip in the power curve for one of the beams.

A method and device for error prevention in incremental measuring systems which comprise a measuring scale and a sensing device producing, during relative movement, sensing signals, and an electronic circuit, and a counter circuit of a measuring system. A comparison is performed of the residue of the counter result after subtraction of a whole multiple of a full number n with signals and signal combinations, respectively, derived from the sensing signals which bypass the counter circuit.

Apparatus for the rapid and automatic determination of elements such as halogen and sulphur in organic compounds comprises a closed vessel; means for introducing into said vessel and for supporting in said vessel a sample of said compound to be analyzed; means for filling said vessel with oxygen; means for causing combustion of said sample; means for causing circulation of an absorption liquid in a closed circuit including said vessel; means for determining and detecting said element to be analy...

In a method for determining the particle size distribution in a fluid stream wherein the concentration of one size fraction is compared with that of another, the concentration of a given fraction is determined by determining the rate of accumulation of the material of that fraction over a series of successive short time intervals.

Test composition and method for assaying dehydrogenase enzymes in test fluids which comprises contacting the fluid with a test reagent comprising a coenzyme, a substrate for the dehydrogenase enzyme, a terminal acceptor dye and Meldola's Blue as an intermediary hydrogen carrier. A preferable embodiment of the present invention comprises incorporating the test composition with a solid carrier therefor and using the same as a dip and read test device.

A method for determining the percentage oil in an oil-water emulsion which is predominately water, such as in a fluid stream produced from an oil field during a thermal secondary recovery process. The produced fluid stream is sampled continuously, the collected sample is then homogenized and sampled, and oil is removed from the second sample with an oil solvent heavier than water. Percentage oil is determined from the volume of oil removed by the solvent.

Method and apparatus for making remote surface temperature surveys of the earth, as from aircraft, wherein the emissivity error is eliminated by use of a laser which is pulsed on and off to permit determination of earth reflectivity and hence a value for its emissivity. Apparent measured temperature is then corrected to true temperature using this value of emissivity.

A fluidic level sensor in which a stream of energy fluid is alternatively diverted between two discharge channels by a control channel. One of the discharge channels is connected to an indicator, and the control channel is connected to a hollow probe which is adapted to have its free end closed by the surface of the fluid material being sensed. A branch channel is provided between the supply line of the fluid of the device and the control channel to permit the use of the supplied energy fluid to...

In a character recognition system, a threshold voltage determination system for providing a decision making voltage level separating "black" data signals from "white" data signals. A plurality of scanning amplifiers are individually coupled in an electrical parallel circuit to a voltage divider which responds to variations in the "black" data signals. The threshold voltage determination system generates a voltage level which is intermediate the voltage magnitude of the "black" data signal and th...