Abstract: Improvements in shallow-homojunction solar cells based upon a plurality of layers of a direct gap semiconductor material such as GaAs, as well as their fabrication, are disclosed. The shallow-homojunction solar cells have a n.sup.+ /p/p.sup.+ structure in which the n.sup.+ top layer is limited to a thickness which permits significant carrier generation to occur in a lower semiconductor layer. An anodic antireflection coating is applied over the n.sup.+ top layer, and a particularly preferred method for applying the antireflection coating is by anodization. These solar cells can be grown on relatively inexpensive substrates, if desired, such as silicon or germanium.

Abstract: A process is disclosed for applying an adherent, optically clear, abrasion resistant coating to polymeric substrates formed from unsaturated monomers. Typical substrates are lenses formed from either acrylic or allylic polymers, such as CR-39 lenses.This process includes (a) forming a solution of a partially hydrolyzed vinyltri (lower alkoxy) silane, such as vinyltriethoxysilane, in a water-miscible, volatile, organic solvent, the silane being present from 25-75% by weight; (b) applying this solution to a clean surface of the substrate; (c) dehydrating the coated substrate under low humidity conditions at an elevated temperature below the temperature at which the substrate degrades; and, (d) then submitting the dehydrated coated substrate to irradiation with ultraviolet light or other high energy radiation until an adherent, abrasion resistant coating is formed.

Abstract: Sustained flavor release compositions are disclosed which comprise polymer backbones having pendant flavor groups thereon. Such compositions can be used, for example, in chewing gums. Release of the flavor can be accomplished by hydrolysis upon mastication of the chewing gum.In one embodiment, aldehyde flavors are reacted with polymers having hydroxy groups thereon to produce a polymer backbone with pendant acetal or hemi-acetal flavor groups. An example is the reaction product of cinnamic aldehyde and partially hydrolyzed polyvinyl acetate. In a like manner, ketone flavors can be reacted with similar polymers to form pendant ketal flavor groups. Also, alcohol flavors can be reacted with polymers having aldehyde or ketone groups to provide polymer backbones with pendant acetal or ketal moieties thereon.

Abstract: A pheresis process and apparatus for carrying it out. Blood from a donor is transferred to a pheresis bowl formed to have a red cell reservoir and a plasma reservoir in fluid communication through plasma ducts. The pheresis bowl is adapted for centrifuging to separate the red cells and plasma. This separation is accomplished simultaneously with the withdrawal of blood from the donor. At the end of the withdrawal the red cells are returned to the donor. The connection with the donor is thus continuously maintained during the entire procedure. The process is safe, fast and economical.

Abstract: Sensitive testing transducers are mounted to an internally threaded cap. A split-ring sleeve having external threads is positioned around the cold tip of a cryogenic refrigerator. An internal flange on the sleeve abuts a shoulder on the cold tip to hold the sleeve on the cold tip while permitting rotation thereof. By positioning the cap over the cold tip and rotating the sleeve, the transducer supporting cap is moved into tight thermal contact with the end of the cold tip without disturbing the sensitive transducers.

Abstract: An improved bird feeder is disclosed herein of the type having a hollow housing for holding a main supply of bird feed with a plurality of feeding apertures located at different heights thereon. This improved bird feeder has means for retaining a supply of bird feed at the vertically staggered feeding apertures which are independent of the level of main supply in the housing. Because of this, bird feed is provided at a feeding aperture even after the main supply has dropped below that feeding aperture.

Abstract: A method of passivating imperfections, such as grain boundaries and/or dislocations, in semiconductor materials is disclosed which comprises selectively passing electrical current along the imperfections by employing the semiconductor material as an electrode in an electrolytic cell.

Abstract: A portable loam screening apparatus includes a nearly-square sloping shaker screen supported by a box-like frame. The frame has a tall end and a short end joined by two sides. Funneling surfaces directed toward the screen are provided along the upper edges of the tall end and the sides. The short end is closed to provide a wall between separated loam and coarse material. A mixture of loam and coarse material is dumped onto the shaker screen from the shovel of an excavating vehicle. The coarse material falls from the lower end of the shaker screen outside of the frame, and the loam passes through the shaker screen to within the box-like frame. The separated loam falls down a sloping table within the frame and can then be retrieved by an excavating vehicle through the open tall end of the frame. A set of wheels mounted to one side of the frame is moveable relative to the frame from an operative position for transporting the apparatus to an inoperative position for resting the frame flush on the ground.

Abstract: A cryogenic apparatus is disclosed herein with an improved flow path for removing impurities introduced by a make-up stream of cryogenic fluid by directing the make-up stream to means to adsorb impurities therein prior to combining the make-up stream with the main feed stream for the cryogenic apparatus.

Abstract: A kit for determining the level of LDL cholesterol in body fluids is disclosed which contains a plant lectin which is a specific agglutinating agent for LDL.

Abstract: Improved cell culture microcarriers, and methods for their production and use, are disclosed herein. These improved microcarriers have positive charge capacities adjusted and/or controlled within a range suitable for good cell growth. One method for producing such improved microcarriers is by treating beads formed from polymers containing pendant hydroxy groups, such as dextran beads, with an aqueous solution of an alkaline material and a chloro- or bromo-substituted tertiary amine under precisely controlled conditions to produce the desired exchange capacity. The resultant positively charged microcarriers have been used in microcarrier cultures to produce outstanding growth of anchorage-dependent cells. Such cells can be harvested, or used for the production of viruses, vaccines, hormones, interferon or other cellular growth by-products.

Abstract: In a cryogenic apparatus wherein the refrigerator has a reciprocable displacer which must be coordinated with fluid control means, such as a rotary valve, to control the inlet and exhausting of high and low pressure fluid, respectively, to produce cooling, an improvement is disclosed comprising including means for providing proper coordination between displacer movement and fluid control means regardless of the direction in which the motor drive shaft is rotated.

Abstract: Polymeric paraxylylene coatings and films possessing significantly improved oxidation resistance, particularly at elevated temperatures, are disclosed as well as a process for their preparation wherein certain antioxidants are vaporized and codeposited with vaporous poly(paraxylylene) precursors onto a substrate.

Abstract: A solar energy concentrator comprising a cylindrical Fresnel lens, a specially shaped and positioned reflecting mirror, and a shaped tubular receptor for conveying the collected energy to terminals is described. These concentrators are arrayed parallel and contiguous to each other and oriented generally along an East-West line to receive the sun's radiant energy, and the lenses together with the special reflectors and designed to accomodate large elevation angle variations of the sun. The large acceptance angles achieved with the image collapsing concentrator, while at the same time maintaining a high concentration ratio, improves the reception of diffused as well as direct sunlight and the small surface area of receiving tubes diminishes the thermal radiation losses. A method for determining the shape and location of the special image collapsing reflector is described and applied to solar concentrators employing both lenses and reflectors of cylindrical and three dimensional forms.

Abstract: An anti-theft device for positioning over the ignition housing of a vehicle's steering column to protect ignition and anti-theft components contained therein is disclosed. This device has armored guard means including a band which extends around the ignition housing, a cylindrical portion to protect the ignition key cylinder housing, and a cover with an ignition key slot therethrough. Means for fastening the armored guard onto the steering column in a permanent manner are also provided. This anti-theft device is passive, aesthetically pleasing, economical to manufacture, has an extremely low likelihood of mechanical failure and yet is capable of providing outstanding protection against forced entry into the ignition and anti-theft components of a vehicle.

Abstract: A system is disclosed which will sense the image-development state of toner in the development subsystem of an electrophotographic copier apparatus. This image-development state is related to both toner concentration and the charge-to-mass ratio (q/m) existing on toner particles. The sensing system employs an optical fiber bundle having both transmitting and receiving fibers. At one end, herein referred to as the common end, and transmitting and receiving fibers are interspersed. This common end is positioned flush with the inside chamber wall on a developer housing. At the other end, the transmitting and receiving fibers are bifurcated. The transmitting fibers of the optical bundle are used to guide light from a light source to the common end, and part of the transmitted light is backscattered and guided through the receiving fibers to an optical sensor. The signal received is inversely proportional to the amount of toner deposited on the end of the bundle and the toner on the surface of carrier particles.

Abstract: An improved method of fabricating thermoelectric power generator modules, which are particularly useful in converting solar energy into electrical power and heat, is disclosed. This method involves the formation of an array of longitudinally elongated n- and p-type semiconductor elements tightly contained in a supporting matrix; slicing the supporting matrix containing the semiconductor elements to provide a plurality of matrix plates; and the application of a pattern of electrically conductive pads on opposite surfaces of the matrix plates to connect n- and p-type semiconductor elements, in series, thereby forming a thermoelectric power generator module. This method is simpler, less expensive and more adaptable to large scale production than methods heretofore proposed.

Abstract: Liquid crystal mixtures are disclosed which contain 30-60% of a Schiff's base nematic liquid crystal compound, 25-65% of a second nematic liquid crystal compound selected from the classes of azoxy, ester and biphenyl, and 5-15% of a triphenyl compound to raise the isotropic transition temperature. This combination results in liquid crystal compositions having unexpectedly wide nematic temperature ranges.