Abstract: Agricultural mulch sheeting which provides soil moisture retention and weed control during the growing season, yet is readily degradable when harrowed into the soil after harvest, comprises a creped natural kraft paper coated on both sides with a polyvinylidene chloride latex dispersion. The coating on one side of the sheet includes carbon black which provides the opacity to prevent weed growth while also yielding a reversible sheet which may be installed to absorb or reflect the sun's rays. The mulch may also include a sleeve of the same material sealed to the upper surface of the main sheet to form a conduit for irrigating water which seeps into the underlying soil through a row of puctures in the sheet.

Abstract: Caprolactam, caprylolactam, and azacyclooctanone have been found to be equally effective as thiourea in stabilizing diazotype compositions and materials against pre-coupling, loss of shelf life, and dye image fading.

Abstract: A linear actuator mechanism which comprises skewed roller members arranged about a drive shaft and translates rotation of the drive shaft to linear displacement along the shaft includes a pair of body members having a ball joint between them which serves as a pivot about which adjustable spring compression constrains each of the three normal degrees of freedom in the body member pair to provide a kinematic union which eliminates indiscriminate displacement between the actuator mechanism and the drive shaft.

Abstract: An electrooptic light modulator is constructed from a pair of subassemblies each comprising a lithium tantalate crystal fixed between two rigid, conductive electrodes. Such subassemblies may be individually tested to ensure the selection of a pair of crystals which are matching in thermal and electrical responses. The modulator construction is completed by arranging the selected subassembly pair with crystal optic axes in orthogonal relationship in order to negate the effects of natural crystal birefringence, and fixing the subassemblies between a pair of rigid pole pieces which, together with the electrodes, serve as heat sinks to moderate the effect of thermal fluctuations, and further stabilize the assembly against mechanical and piezoelectric perturbations.

Abstract: The finished surface of a multicolor surprint proof is made to exhibit a matte appearance and closely simulate the surface texture of the printing stock to which it is applied. Individual colored image adhesive layers are laminated in register to a receptor sheet which comprises a coated layer of film-forming polymer composition on a polyester carrier sheet having a matte texture surface. Subsequent to final adhesive lamination of the assembled surprint to desired printing stock, the receptor carrier sheet is stripped from the polymer film layer to yield a tough protective film overlayer which complements the matte texture of the original receptor carrier sheet surface and provides the desired matte appearance of the multicolor proof.

Abstract: A method of forming a color-proofing surprint includes the image-wise light exposing of an imaging sheet having a photoresist top layer, removing by the application of developer fluid the more soluble areas remaining after light exposure, thereby revealing image-defining areas of an underlying layer of pressure-sensitive adhesive, and applying a powdered colorant to such image-defining areas of adhesive. The residual areas of the photoresist layer may then be removed to reveal the non-imaged areas of the adhesive layer and the image-bearing adhesive surface of the sheet pressed into adhesive contact with a receiving surface. Removal of the original carrier film of the imaging sheet from the adhesive layer renders this layer accessible to receive, in image registration, the image-bearing adhesive layer, in different color, of a separate imaging sheet.

Abstract: Apparatus for safely transporting a sheet of photographic material through a development or other processing station comprises means for concurrently circulating processing liquid in the form of a plurality of streams both downward onto the sheet and upward from an underlying plate, the latter streams supporting the sheet and providing for the formation of a liquid layer between the plate and the sheet which facilitates the unrestricted passage of the sheet along the processing path. The downwardly projected streams are angled in the direction of sheet travel to provide further impetus to the movement of the sheet.

Abstract: A press apparatus comprising a pair of parallel rollers sequentially joins a plurality of pre-imaged adhesive layers in precise registration to form a composite color proof. Detent and coupling means maintain the respective rollers and mounted image sheets in predetermined registration until the rollers are brought together and rotated by separate drive means to effect lamination of the complementary imaged layers.

Abstract: In an electro-optical measuring system which utilizes a sin/cos signal pair to determine the extent and direction of physical displacement, measurement errors often occurring as a result of extraneous DC level shifts in generated signals are corrected in a procedure which regularly samples the maxima and minima of the signals, derives from those values the median DC levels of the signals, compares the median levels to a reference DC level in the system to determine any differences, and applies any detected differences as corrective factors to position measurement signal values.

Abstract: An AC coupled amplifier system is protected from overloading input signals by means of a "bootstrap" circuit which provides a compensation signal substantially matching the overscale portion of such input signal and applies that compensation signal to the coupling capacitor as an offset in order to prevent excessive charge accumulation on that capacitor. A voltage controlled current source serves as a signal range limiter in the circuit and responds to overscale input signals by causing a circuit loop opening and forcing loop closure in a secondary feedback circuit from which the extent of input signal overscale is determined. The matching compensation signal is then derived from such determination. The protection circuit further provides a reset function to account for extended overscale input signal levels.