Abstract: This disclosure provides an optical interferometer including a multi-faceted optical element that is rotated to introduce an optical path length difference between two different optical paths in the interferometer. The multi-faceted optical element can be configured to be rotated about an axis such that the optical path length difference between the first and second optical paths varies between a first value and a second value several times during one complete rotation of the optical element. The multi-faceted optical element can be rotationally symmetric having n-fold rotational symmetry. The two different optical paths can be non-coplanar with respect to each other and the multi-faceted optical element can be disposed in one of the optical paths or both the optical paths.

Abstract: Method and apparatus for determining the concentration of optically attenuating materials in fluids, such as soot in diesel engine lubricating oils. An optical cell is employed in the form of a very thin tapered sample volume which is inserted into a light beam. The attenuation of the beam is measured at a plurality of locations along the varying thickness of the sample.

Abstract: The present invention relates to an improvement in a capillary tube viscometer which includes light sensitive triggering means for timing the flow of oil between two points therein. The improvement includes optic fibers that are positioned on the tube at selected places. In addition, the tube includes impulse receiving means wherein the voltage received from start and stop positions are passed to triggering means and measuring means to translate the same into figures for manual or automatic calculation of time for the flow of oil.

Abstract: A larval table for the collection of the early life stages of fish; i.e., eggs, larvae and juveniles as well as invertebrate macrozooplankton is disclosed. The larval table assembly includes a head or water delivery module, two or more screen separation modules, and a collection box module and concentration receptacle. The larval table is utilized in the collection of specimens where it is desired to recover the specimens alive. This is accomplished by reducing the flow velocity of the specimen carrying liquid which flows through the larval table. In addition, the collection box module and concentration receptacle eliminate the need for manual removal of the specimens from the larval table. The modular arrangement of the larval table allows modification of the table to accommodate varying flow rates of liquid to be sampled by adding additional screen separation modules, as needed.

Abstract: An automated entrainment abundance sampler for the collection of ichthyoplankton specimens and its operation is disclosed. An inverted conical screen or net is utilized to collect specimens from water supplied by a suitable pump. After a set time period, the collected specimens are further concentrated in a secondary concentrator and transferred to a sample container. The conical screen is rinsed to insure that all the specimens are transferred to the secondary collector which is, in turn, rinsed to further insure that all the specimens are carried to the sample container. A suitable control system is provided to allow the sampler system to operate automaticaly in the collection of specimens over a preselected period of time.

Abstract: A mobile marine drilling unit comprising: a floatable base; a floatable platform; and a vertical support leg attached to said base and extending upwardly through a well provided therefor in said platform. Said base and a major portion of said leg being submergible in a body of water for support on the floor thereof. The support leg and platform are provided with elevating mechanisms for elevating the platform above said body of water on said leg. In deploying the drilling unit, the unit is floated to a selected site with the base drawn up underneath the platform and the leg extending upwardly through the well. When the site is reached the base is submerged with ballast until it is supported on the water body floor. Then the platform is elevated above the water body by the elevating mechanisms. A derrick may be moved over the leg well and drilling in the water body floor conducted through the well and leg.

Abstract: Leg apparatus for an offshore drilling unit of the self-elevating type having a floatable hull and a plurality of legs movable from a raised position, in which the legs are supported by the hull in a body of water, to a lowered position, in which the hull is supported by the legs on the floor of the body of water. The legs may comprise a plurality of mutually parallel tubular chord members rigidly interconnected by structural bracing members. The tubular chord members may comprise an elongated tubular body and an elongated plate member, whose longitudinal axis coincides with the axis of the tubular body, rigidly connected to and spanning the interior of the tubular body.