Abstract: A periodic dielectric structure which is capable of producing a photonic band gap and which is capable of practical construction. The periodic structure is formed of a plurality of layers, each layer being formed of a plurality of rods separated by a given spacing. The material of the rods contrasts with the material between the rods to have a refractive index contrast of at least two. The rods in each layer are arranged with their axes parallel and at a given spacing. Adjacent layers are rotated by 90.degree., such that the axes of the rods in any given layer are perpendicular to the axes in its neighbor. Alternating layers (that is, successive layers of rods having their axes parallel such as the first and third layers) are offset such that the rods of one are about at the midpoint between the rods of the other. A four-layer periocity is thus produced, and successive layers are stacked to form a three-dimensional structure which exhibits a photonic band gap.

Abstract: A strain tolerant multifilamentary wire capable of carrying superconducting currents is provided comprising a plurality of discontinuous filaments formed from a high temperature superconducting material. The discontinuous filaments have a length at least several orders of magnitude greater than the filament diameter and are sufficiently strong while in an amorphous state to withstand compaction. A normal metal is interposed between and binds the discontinuous filaments to form a normal metal matrix capable of withstanding heat treatment for converting the filaments to a superconducting state. The geometry of the filaments within the normal metal matrix provides substantial filament-to-filament overlap, and the normal metal is sufficiently thin to allow supercurrent transfer between the overlapped discontinuous filaments but is also sufficiently thick to provide strain relief to the filaments.

Abstract: A communication device, an apparatus, and a method for acoustic echo cancellation which makes use of a pseudonoise signal. An audio mixer adds the pseudonoise signal to an input signal received from another communication device to produce a first composite signal. An audio system converts the first composite signal to sound in an at least partially enclosed space. The at least partially enclosed space produces an acoustical echo in response. The audio system then converts the acoustical echo and other sounds in the at least partially enclosed space to a second composite signal. A signal processor cross-correlates the second composite signal with the pseudonoise signal to produce an estimate of the overall impulse response of the combined system formed by the at least partially enclosed space and the audio system. The processor then convolves the first composite signal with the impulse response estimate to produce an echo estimation signal.

Abstract: A fluorescence detection system for capillary electrophoresis is provided wherein the detection system can simultaneously excite fluorescence and substantially simultaneously monitor separations in multiple capillaries. This multiplexing approach involves laser irradiation of a sample in a plurality of capillaries through optical fibers that are coupled individually with the capillaries. The array is imaged orthogonally through a microscope onto a charge-coupled device camera for signal analysis.

Abstract: An electronic livestock record system stores the individual animal's identification and performance data on a programmable electronic identification and data storage module carried with the animal so that the animal's identification, the animal's performance data and the animal itself become one. The system includes a programmable electronic identification and data storage module carried by the animal, and a reading and recording device which communicates with the electronic identification and data storage module.

Abstract: The present invention provides a biodegradable thermoplastic composition made of a cereal grain that is treated with an organic solvent, and optionally a cross-linking agent such as an aldehyde, an acid anhydride or an epoxide, to link together the starch and protein of the cereal grain. The compositions may be used to make extruded or molded articles that are biodegradable, water-resistant, and have a high level of physical strength.

Abstract: A system and a related method for non-destructive evaluation of the surface characteristics of a magnetic material. The sample is excited by an alternating magnetic field. The field frequency, amplitude and offset are controlled according to a predetermined protocol. The Barkhausen response of the sample is detected for the various fields and offsets and is analyzed. The system produces information relating to the frequency content, the amplitude content, the average or RMS energy content, as well as count rate information, for each of the Barkhausen responses at each of the excitation levels applied during the protocol. That information provides a contiguous body of data, heretofore unavailable, which can be analyzed to deduce information about the surface characteristics of the material at various depths below the surface.

Abstract: The present invention provides linear organosilicon polymers including acetylene and vinylene moieties, and a process for their preparation. These diorganosilacetylene-alt-diorganosilvinylene linear polymers can be represented by the formula: --[--(R.sup.1)(R.sup.2)Si--C.tbd.C--(R.sup.3)(R.sup.4)Si--CH=CH--].sub.n-- , wherein n.gtoreq.2; and each R.sup.1, R.sup.2, R.sup.3, and R.sup.4 is independently selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, aryl, and aralkyl radicals. The polymers are soluble in organic solvents, air stable, and can be pulled into fibers or cast into films. They can be thermally converted into silicon carbide ceramic materials.

Abstract: An ion processing apparatus for processing a target with ions includes a plasma ion source and a mass spectrometer for producing an ion beam for depositing ions onto the surface of the target to form a thin film or for implanting the ions into the target to modify the composition or properties of the target or for separation and collection of individual, separated isotopes. The plasma ion source is preferably an inductively coupled plasma ion source, and the mass spectrometer is preferably a quadrupole mass spectrometer. The stoichiometry of the deposited or implanted ions can be adjusted by controlling the mass spectrometer to produce an ion beam having a desired composition. Mixtures of different elements can be easily deposited or implanted in any desired stoichiometry by introducing a multielement sample into the plasma ion source and controlling the time the mass spectrometer transmits each element to be deposited or implanted.

Abstract: A flexible system for determining the quality of agricultural products based on characteristics such as, for example, mass, shape, hardness, size, color and surface texture is disclosed herein. The quality determination apparatus includes a feeder assembly for sequentially dropping individual product samples upon an impact transducer arrangement. The impact transducer generates transducer signals indicative of the physical characteristics of each product sample. In addition, an imaging device operates to synthesize a digital image representation of each product sample. The transducer signal and digital image representation corresponding to each product are analyzed so as to determine the appropriate degree of quality to be associated therewith.

Abstract: A dual wavelength optical sensor for measuring chemical properties of a particular quantity, the optical sensor including a sensor probe having a thin sensing film whose optical characteristics are responsive to the chemical properties of the measured quantityThe United States Government has certain rights in this invention pursuant to Contract No. ITA87-02 between the U.S. Department of Commerce and Iowa State University.

Abstract: A nonholonomic camera space manipulation system which allows a mobile manipulator which can have both holonomic and nonholonomic movement to autonomously use computer vision to move with respect to a goal position without any prior knowledge or calibration between the two or more video cameras used with the computer vision and the manipulator base or arm, the cameras and the goal, or the base and arm and the goal position. Cues are associated with the manipulator arm and the goal position(s) or target bodies; the cues being distinguishable in the two dimensional focal plane camera spaces of the cameras from the surrounding environment. A processing unit, identifying the position of the cues in each camera space, compares those positions and instructs movements of the manipulator base and/or manipulator arm to achieve movement of the visual cue on the arm with respect to the goal position or target body visual cue in camera space.

Abstract: A method of genetically evaluating animals by using mitochondrial DNA is disclosed. Polymorphisms in mitochondrial DNA are detected by isolating, fragmenting, and sequencing the DNA. The restriction patterns and nucleotide sequences of mitochondrial DNA of different animals are correlated to expressed traits in the animals. This may be confirmed by comparing results to expression of the trait in maternal lineages of animals. Further, effects of maternal lineages are determined by partitioning maternal genetic variation from nuclear variation.

Abstract: A composition useful as a selective preemergence herbicide is provided, comprising an effective amount of a dipeptide selected from the group consisting of Gln-Gln, Ala-Asn, Ala-Gln, Gly-Ala, Ala-Ala and mixtures thereof, in combination with a compatible carrier vehicle.

Abstract: A method of selectively inhibiting growth of unwanted plants in a plot of soil is provided comprising the application of a plant protein hydrolysate to the plot of soil, prior to emergence of the unwanted plants and at a concentration of application which inhibits the growth of the unwanted plants.

Abstract: Preparation of chicken embryo allantoic fluids for animal health requires opening the eggshell by cutting, drilling or punching methods. Laser cutting and drilling is used as an alternative to known processes. Both CO.sub.2 and Nd:YAG lasers are employed. A focused CO.sub.2 laser beam at a power of 200 watts in conjunction with an X-Y motion table produced 25 mm diameter "clean-cuts" in eggshells with a cutting time of 0.5 seconds per egg. The material removal mechanism was vaporization. When an axicon/lens combination is used with a CO.sub.2 laser, the cutting time was further reduced to 0.2 seconds per egg and the mechanism of material removal is changed from vaporization to decomposition of the eggshell into fine powders. Small holes, typical diameters of 0.5 mm to 1 mm are generated in the eggshell using the pulsed Nd:YAG laser.

Abstract: Energy recovery apparatus for recovering and using thermal energy comprises multiple series of shape memory elements having decreasing transformation temperatures from one element to the next in the direction of a heating fluid to extract heat over a range of fluid temperatures to effect a shape change of each element. Cooling fluid is flowed alternately through each series of elements to cool the elements and effect another shape change. The cooling fluid exiting a preceding series of elements is used as the heating fluid of the next series of elements to extract further heat indirectly from the original heating fluid. The shape changes of the elements are converted to mechanical work.

Abstract: The thermodynamics-based signal receiver transforms contiguous segments of a received signal into thermodynamics-related quantities using an analog of a statistical-mechanics-related quantities using an analog of a statistical-mechanics expression for a thermodynamic variable and uses these thermodynamics-related quantities as the means to measure changes in the signal as a function of time or origin. The changes that are of interest are those associated with either signal level or signal structure. Signal-processing analogs of statistical mechanics expressions for thermodynamic variables are measures that respond in some fashion to either type of change. By comparing thermodynamics-related transformations of received signals, one can obtain information about the emitters of the received signals and the nature of the medium through which the signals were propagated.

Abstract: Device for separating and collecting ultrafine atomized powder from the gas stream of a gas atomizing apparatus comprises a housing having an interior wall oriented at an angle relative to horizontal so as to form a downwardly converging, conical expansion chamber, an inlet conduit communicated to the expansion chamber proximate an upper region thereof for receiving the gas stream, and an outlet proximate a lower region of the expansion chamber. The inlet conduit is oriented at a compound inclined angle (with respect to horizontal) selected to promote separation and collection of powder from the gas stream in the expansion chamber. The compound angle comprises a first entrance angle that is greater than the angle of repose of the powder on the housing interior wall such that any powder accumulation in the inlet conduit tends to flow down the wall toward the outlet.

Abstract: Corn gluten meal is used as a natural preemergence herbicide.