Abstract: An improved method for stereolithographically making an object by alternating the order in which similar sets of vectors are exposed over two or more layers. In another method, a pattern of tightly packed hexagonal tiles are drawn. Each tile is isolated from its neighboring tiles by specifying breaks of unexposed material between the tiles. Using an interrupted scan method, vectors are drawn with periodic breaks along their lengths. In another method, modulator and scanning techniques are used to reduce exposure problems associated with the acceleration and deceleration of the scanning system when jumping between vectors or changing scanning directions.

Abstract: A system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.

Abstract: The invention involves an improved system for producing a three-dimensional object by forming successive cross-sections of the object from a material which is normally solid but which may be made flowable, including using data manipulation for converting a three-dimensional object representation into cross-sectional representations.

Abstract: This invention relates to the stepwise layer-by-layer formation of a three-dimensional object through application of the principles of stereolithography and to the automatic detection of surface features of each layer of a three-dimensional object to manufacture parts more reliably, more accurately and more quickly. Automatic detection of trapped volume regions and size of solidified cross-sectional regions are disclosed. Automatic selection of recoating styles is made based on(1) the detected regions, (2) empirically or otherwise determined optimum recoating styles for different types of regions, and (3) a look-up table, other correlation system, or processor for associating recoating style information with laminae containing particular identified regions.

Abstract: A heating element assembly for use in a rapid prototype modeling machine is described. The heating element of the hot melt assembly and an associated product container deliver hot melt product to the jets of the rapid prototype modeling machine.

Abstract: A bioassay method for supporting human tumor stem cell colony growth is disclosed. The method is suitable for culture of a variety of neoplasms of differing histopathology. Tumor stem cell colonies arising from different types of cancer have differing growth characteristics and colony morphology. The present bioassay may be employed in clinical studies of the effects of anticancer drugs or irradiation on human tumor stem cells.

Abstract: A standard Transmission Electron Microscope is modified to include electrostatic deflection plates for deflecting the image of the specimen across an aperture plate. The electrons passing through the aperture plate are detected and converted into image pixels for either instantaneous display or for further conversion into digital form for subsequent storage of the image.

Abstract: An improved solar cell structure is described wherein the cell's front region is provided with a plurality of raised structures, each structure comprising a multilayer of a highly doped region and a high-low junction. On these raised structures sit the solar cell's conductive grid. By emplacing the multilayer structure directly underneath the front region metallized conductive grid, the efficiency losses which would have been present had the highly doped region extended entirely or partially across the front layer, are avoided and the high surface recombination velocity associated with the grid is masked.

Abstract: The surface of an electrically conductive substrate is electrolytically modulated to a predetermined profile by subjecting the surface to electrodeposition or electrodissolution through ionically conductive body portions of an ionic conductance resist which masks the surface. The rate of passage of ionic species to or from any given point along the masked surface is controlled by the trans-resist ionic conductance or resistance at that point. The predetermined surface profile is generated by providing the resist with a trans-resist ionic conductance or resistance profile which patterns the predetermined surface profile.

Abstract: A specular cavity is provided in which an optical receiver is emplaced. The cavity is provided with a series of V groove-like indentations (or pyramidal-type indentations) which redirect energy entering between the receiver and cavity structure onto the receiver. The aperture opening of each V groove is less than half the cavity opening and in most preferred embodiments, much less than half. This enables the optical receiver to be emplaced a distance g from the cavity wherein 0.414r<g.ltoreq.r (r is the radius of the receiver) leading to an attendant increase in energy concentration capability.

Abstract: An alloy capable of reversible sorption of hydrogen having the formula Fe.sub.1-x Mn.sub.x Ti.sub.1-y V.sub.y, where x is within the range from 0 to 0.2 and y is within the range of from 0.005 to 0.08.

Abstract: The reticulocyte content present in a specimen of red blood cells is quantitatively measured based upon the selective immunoreactivity of the reticulocyte portion of the specimen with a reticulocyte-specific antibody which is immunoreactive with proteinaceous material associated with reticulocytes but not associated with mature red blood cells. Such immunoreactive proteinaceous material may be transferrin, transferrin receptor, transcobalamin II, or transcobalamin II receptor. Various procedures are described for quantitating such selective immunoreactivity, including fluorescent and radioactive detection techniques employing direct or indirect fluorescent or radioactive labeling of the reticulocyte-specific antibody.

Abstract: Conjugated polymers are doped with dopant ions to a preselected room temperature electrical conductivity ranging from that characteristic of semiconductor behavior to that characteristic of metallic behavior, by means of an electrochemical procedure wherein the polymer is employed as one or both of the electrodes of an electrolytic cell, including as the electrolyte a compound which is ionizable into the dopant ions. Upon electrolysis of the electrolyte, the polymer, if used as the anode, becomes doped with anionic dopant ions to a p-type material; or if used as the cathode, becomes doped with cationic dopant ions to an n-type material.The above-described electrochemical doping procedure finds particularly useful application in the charging of novel secondary batteries in which a doped conjugated polymer is employed as one or both of the electrodes. Such secondary batteries, in their charged state, comprise a metal whose Pauling electronegativity value is no greater than 1.

Abstract: In accordance with the finding of undesired, non-uniform, heterojunction layers in heterojunction light emitters, it has been determined that completely uniform layers can be grown by growing individual super thin layers (i.e., .ltoreq.200 A) of uniform composition and stacking as many of these layers as desired into a uniform "thick" (.about.0.1.mu.) layer. This growth is accomplished by employing an LPE system wherein the substrate and melt are brought into contact for only the period of time during which the constituents of the melt deposit on the substrate in proper ratios. Steady-state diffusion-limited growth is avoided. The substrate is then removed from the melt, the melt allowed to re-equilibrate, and the process repeated as many times as desired.

Abstract: Acrylate ester monomers are produced in high yield and without polymerization by reacting an .alpha.,.beta.-unsaturated organic acid halide and a hydroxyl containing organic compound in the presence of molecular sieves. In the absence of molecular sieves the same reactants produce the monomer ester products in low yield and/or form polymers.

Abstract: A process for separating molybdenum values from sea nodules which includes sulfation of the sea nodules, volatilization of the molybdenum values from the sea nodules and collection of the volatile molybdenum values.

Abstract: Live Bovine Herpesvirus A.T.C.C. VR-2003 is employed in vaccination of horses to confer immunity to infection by Equid Herpesvirus Type 1.

Abstract: Electrically conducting organic polymeric material having a preselected room temperature p-type electrical conductivity which may vary over the entire range characteristic of semiconductor behavior and into the range characteristic of metallic behavior, is prepared by controlled chemical doping of polyacetylene in the form of a polycrystalline film. Exceptionally high room temperature p-type electrical conductivity within the range of from about 0.1 to of the order of 10.sup.3 ohm.sup.-1 cm.sup.-1 is achieved with several electron acceptor dopants, including bromine, iodine, iodine chloride, iodine bromide and arsenic pentafluoride.

Abstract: Electrically conducting organic polymeric film material exhibiting a preselected room temperature n-type electrical conductivity ranging from that characteristic of semiconductor behavior to that characteristic of metallic behavior, is prepared by controlled electron donor doping of a polycrystalline film of polyacetylene with a metal dopant whose Pauling electronegativity value is no greater than 1.6. Preferred metal dopants are the alkali metals. The procedure may be employed in preparing polyacetylene film with a p-n junction formed by two adjacent portions of the film respectively provided wth p-type and n-type electrical conductivities.