Abstract: An anaerobic process for the digestion of organic wastes, and novel anaerobic digester. In digestion of the organic wastes in the presence of anaerobic microorganisms, at anaerobic conditions, the carbon:nitrogen and nitrogen:phosphorus ratios of the digestion are adjusted to optimize the rate of anaerobic digestion, generally only about 12 to 72 hours, or less, being required to produce a stabilized low solids sludge and clean liquid effluent. The anaerobic digester is designed to facilitate this process, and is transportable from site to site.

Abstract: An ultrasonic device in which a concave transducer, partially surrounded by and insulated from a pair of electrically-grounded shields, focuses a signal and directs it to a limited portion of a second lens which further focuses the signal and directs a highly concentrated signal into a fluid, whereby particles therein can be detected with increased sensitivity, and whereby the composition of a homogeneous fluid can be determined by measuring the amount of the attenuation or the sound velocity of ultrasonic pulses therethrough or by comparing the frequency spectrum of the pulse with known spectra.

Abstract: An apparatus for identifying and determining the size of particulates in a flowing fluid by detecting the portion of an ultrasonic pulse scattered from a particulate at a preselected angle, converting the results into density and elasticity-related values and comparing the values with measured or computed values for known particulates.

Abstract: An ultrasonic detection apparatus having a transducer, a lens, and a damping ring, the damping ring being made of a material which is impedance-matched to the lens but which has a lower speed of sound so that stray noise in the lens travels into the damping ring and dissipates rather than remaining in the lens and reflecting back to the transducer as noise.

Abstract: A method of and apparatus for determining the concentration of oil in a recirculating fluid flow for an oil recovery system by detecting the forward-scattering of ultrasonic energy from oil droplets in the flow and comparing the detected information with forward-scattering measurements for flows with known concentrations of oil.

Abstract: A method of identifying and determining the size of particulates in a flowing fluid comprising detecting the portion of an ultrasonic pulse scattered from a particulate at a preselected angle, converting the results into density and elasticity-related values and comparing the values with measured or computed values for known particulates.

Abstract: A probe for obtaining information about a fluid comprising an electrically-shielded transducer having a lens for focusing energy waves, the transducer being attached to a cable and mounted in a protective sheath supported by a rod, whereby the transducer can be immersed in the fluid and moved around therein to take readings at various locations.

Abstract: A pulse-echo device with an improved signal-to-noise ratio, in which sound-transmitting material adjacent to the device is coated with a sound-absorbing layer, the layer being sound-impedance matched to the material so that much of the spurious ultrasonic energy travelling in the material passes through the layer-material interface into the layer where it dissipates instead of remaining in the material and reflecting back to the device.

Abstract: A method of detecting and identifying particulates in the recirculating fluid flow for an oil recovery system by counting the number of ultrasonic pulses reflected from the particulates and comparing the number counted with the amount of attenuation of ultrasonic energy across the flow.

Abstract: A pulse-echo device for obtaining information about a flowing fluid in which a transducer unit comprises an electrically-shielded transducer with a lens for three-dimensionally focusing energy waves, which unit can be inserted into a hole extending through the sidewall of a pipe so that the energy waves focused by the lens are directed across the flow through the pipe. The transducer is surrounded by two electrically-grounded shields which are insulated from each other and separately grounded to isolated the transducer from stray electrical pulses.

Abstract: A method of identifying discontinuities in a flow by transforming an ultrasonic pulse reflected from an unknown discontinuity into a frequency spectrum and comparing that spectrum with the spectra of known discontinuities.

Abstract: A pulse echo device for obtaining information about matter discontinuities in flowing fluid with a sidewall spaced from and surrounding the walls of a transducer situated with respect thereto in such a way that over half the waves radiating from the transducer walls strike the surrounding sidewall at angles less than 90.degree. thereby improving sensitivity and increasing signal-to-noise ratio.