Abstract: An ionic gel formed by polymerization of isopropylacrylamide in the presence of an ion-containing monomer, a crosslinking agent and a suitable liquid medium is provided. The gel is capable of drastic volume change in response to solvent composition, temperature, pH, or ion composition.

Abstract: Myocardial electrical stability is assessed by sampling an ECG waveform at corresponding fiducial locations for a plurality of beats and creating a scatter plot of the i.sup.th sample versus the (i- 1)th sample. A parameter .lambda. is determined which minimizes the sum of the total distances of the points of the scatter plot to an equation x(i)= 4.lambda.x(i- 1)[ 1-x(i- 1)]. The value of the parameter .lambda. is related to the electrical stability of the heart.

Abstract: A substantially fluid orientation insensitive, simple, relatively inexpensive gauge for measuring the quantity (mass/volume) of a liquid, such as fuel, stored in a tank subjected to low gravity conditions is disclosed. The gauge comprises, in general, a transmitter and a receiver coupled to a liquid storage tank in which a liquid of known dielectric behavior, such as fuel for a space vehicle, is stored. The transmitter comprises an R.F. oscillator for generating R.F. energy across a predetermined variable frequency range. The transmitted R.F. energy is coupled to an antenna inserted into the tank and is also coupled to an R.F. energy detector. The receiver measures the received power as a function of frequency above and below the dominant resonant frequency, or harmonics thereof. The measured power decreases substantially before and after resonance because, at resonance, most of the power is absorbed or stored in the cavity and less is transmitted to the receiver.

Abstract: A method of producing sheets of crystalline material is disclosed, as well as devices employing such sheets. In the method, a growth mask is formed upon a substrate and crystalline material is grown at areas of the substrate exposed through the mask and laterally over the surface of the mask to form a sheet of crystalline material. This sheet is separated, and the substrate can optionally be reused. The method has particular importance in forming sheets of crystalline semiconductor material for use in solid state devices.

Abstract: Compounds of the formula:M(NR.sup.1)(OR.sup.2).sub.2 (CHR.sup.3)whereinM is molybdenum or tungsten;R.sup.1 and R.sup.2 are alkyl, aryl, aralkyl or halogen-substituted derivatives or silicon-containing analogs thereof;R.sup.3 is an alkyl, aryl, aralkyl or any substituent that results from the initial reaction between the M.dbd.CHR.sup.3 complex and the olefin(s) that is(are) being metathesized;alkyl has 1-20 carbons, aryl has 6-20 carbons and aralkyl has 7-20 carbons.These compounds are catalysts for the metathesis of ordinary olefins (hydrocarbons) and especially functionalized olefins in the homogeneous phase.

Abstract: A new type of infrared reflectance device is disclosed to provide a quantitative evaluation of skin pallor. The instrument is designed to produce a measurement proportional to the percentage of infrared reflectance of the skin. In one embodiment, it consists of a miniature GaAs light emitting diode, which provides a pulsed infrared light source, a silicon photodiode detector, and processing circuitry. The device electronics are temperature compensated and are designed to respond only to the pulsed component of the detector output and to reject components due to stray light from external sources. The wavelength is chosen such that the measurement is relatively insensitive to the level of blood oxygenation and melanin pigment in the skin.

Abstract: Several types of new microelectronic devices including diodes, transistors, sensors, surface energy storage elements, and light-emitting devices are disclosed. The properties of these devices can be controlled by molecular-level changes in electroactive polymer components. These polymer components are formed from electrochemically polymerizable material whose physical properties change in response to chemical changes, and can be used to bring about an electrical connection between two or more closely spaced microelectrodes. Examples of such materials include polypyrrole, polyaniline, and polythiophene, which respond to changes in redox potential. Each electrode can be individually addressed and characterized electrochemically by controlling the amount and chemical composition of the functionalizing polymer. Sensitivity of the devices may be increased by decreasing separations between electrodes as well as altering the chemical environment of the electrode-confined polymer.

Abstract: Transparent heat-mirrors are disclosed which are comprised of composite films. These films include a discrete and continuous layer of metallic silver sandwiched between a transparent, outer, protective, anti-reflection layer and a transparent, phase-matching layer. This combination of layers is chosen to provide high solar transmission with minimum loss of thermal radiation. Transparent heat-mirrors are useful in the collection and trapping of solar energy, and in other applications where it is desired or necessary to have high infrared reflectivity with high solar transmission.

Abstract: A distributed feedback (DFB) type laser and a method and apparatus for forming same wherein a quaternary semiconductor active lasing strip of material is buried between a substrate of binary compound of one type conductivity material and a mesa binary compound body of opposite type conductivity and a periodic grating structure is etched into the plateau of the mesa. In one embodiment, ohmic contacts are provided on either side of the grating structure and the mesa is undercut adjacent the active strip to partly isolate the ohmic contacts from the homojunction formed when the active strip is buried, preferably using a mass-transport process. In another embodiment, the ohmic contacts are formed on the top of a deeply etched grating structure. A buried layer double heterostructure (DH) laser is also described with DFB grating formed on the side wallsGOVERNMENT SUPPORTThe Government has rights in this invention pursuant to Contract No. F19628-85C-0002, awarded by the Department of the Air Force.

Abstract: A method for preparing preceramic polymers is disclosed. This method includes the steps of(1) reacting in solution anhydrous ammonia with a mixture of R.sup.1 SiHX.sub.2 (where R.sup.1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower alkenyl group having from 2 to about 6 carbon atoms, or a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, and X is a halogen) and RSiX.sub.

Abstract: A method of forming preceramic polymers by mixing (A) an organic polysilane, preferably either a methylpolysilane of the formula [(RSiH).sub.x (RSi).sub.y ].sub.n, (where R is a lower alkyl group having from 1 to about 6 carbon atoms, a cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group x+y=1, (x and y are each >0 and also x=1, y=0), and n is an integer greater than 1) or a polycarbosilane having repeat units of the formula [R.sup.a Si(H)--(CH.sub.2).sub.q ], [R.sup.a Si(H)--CH.dbd.CH], and [R.sup.a Si(H)--C.tbd.C] (where R.sup.

Abstract: A method of diagnosis of the type of tissue in an artery, including distinguishing artery wall from atheromateous plaque is described, in which a catheter with one or more optical fibers is enclosed at a distal end by an optical shield transparent to light radiation and wherein the proximal end of the catheter and optical fibers are coupled to a source of optical radiation. The catheter is inserted into an artery until the optical shield is brought into contact with a suspected arterial lesion or other tissue to be diagnosed.An optical fiber is selected and light coupled from the source at a wavelength of about 480 nm enters the proximal end of the optical fiber and is transmitted by the selected optical fiber to the distal end out the optical shield and impineges on the suspected lesion.

Abstract: Methods for producing RNA viral cDNA, such as poliovirus ds cDNA, products thereof, and uses thereof, are described. Poliovirus cDNA is produced, for example, by reverse transcribing poliovirus RNA and subsequently inserting the poliovirus cDNA into bacterial plasmids by genetic-engineering techniques. Transformed bacteria are then cloned and cultured to produce replicated chimeric plasmids containing the cDNA poliovirus. Such poliovirus cDNA is useful in assaying for the presence of poliovirus and in the production of antibodies against poliovirus. It has also been found that full-length poliovirus cDNA is infectious, which means it can be employed in producing altered virus particles for vaccines.

Abstract: A method and apparatus for forming a monolithic surface emitting laser diode array by providing vertical partly light transmissive mirror surfaces opposite parabolic light reflective mirror surfaces formed adjacent the active buried layer of a heterostructure diode laser. The mirror surfaces are preferably formed using a mass-transport heating process. Other mirror shapes may be formed in accordance with the invention.

Abstract: Very stable, polymer-based electrochemical devices, formed by polymerization of thiophene or a derivative such as 3-methylthiophene which is durable in an aqueous electrolyte over a wide pH range, which respond rapidly to chemical or electrical signals, are disclosed. In one embodiment, the device functions as an extremely sensitive sensor which measures changes in chemical concentration or pH. For example, a poly-3-methylthiophene-based device is sensitive to as little as 8.times.10.sup.-16 moles of an oxidant which reversibly interacts with the polymer, including gas phase oxidants such as I.sub.2. In a variation of the polymer-based device, a catalyst such as a noble metal or an enzyme, is dispersed on or within the conducting polymer matrix so that the device is responsive to chemicals such as H.sub.2 and O.sub.2 which the polymer would otherwise respond very slowly to.

Abstract: Optical strain gauge employing evanescent field coupling between optical fibers. Optical fibers are spaced apart for evanescent field coupling on a structure whose strain is to be measured. Light is introduced into an input fiber which couples into an output fiber depending on the separation between the fibers. Light coupled into the output fiber is detected to generate an output signal indicative of the separation between fibers and hence strain in the supporting structure. In one embodiment, apparatus is provided to measure strain at a plurality of locations with but a single input and a single output fiber. In this embodiment, the input fiber and the output fiber are separated for evanescent coupling at a plurality of locations. The lengths of the input and output fibers between the locations where strain is measured are unequal to produce light propagation time delays.

Abstract: Disclosed is a method for the deletion of a gene from a bacteria using a single step procedure that is applicable to any essential or nonessential gene which has been cloned. The process requires the construction of chromosomal deletions by transformation of a cell strain with linear DNA fragments containing a locus for resistance to an antibiotic, or any other gene allowing for rapid phenotypic selection, flanked by sequences homologous to a closely spaced region on the cell chromosome. By selecting for a double-crossover event between the homologous sequences, shown by the antibiotic resistant or other detectable phenotype, a chromosome disruption can be selected for which has effectively deleted an entire gene.If the gene is essential to viability, the bacteria may be transformed with a plasmid which has a temperature-sensitive replicon and a wild-type allele of the essential gene. When E.

Abstract: A very small, very flexible, high-quality, linear predictive vocoder has been implemented with commercially available integrated circuits. This fully digital realization is based on a distributed signal processing architecture employing three commercial Signal Processing Interface (SPI) single chip microcomputers. One SPI implements a linear predictive speech analyzer, a second implements a pitch analyzer while the third implements the excitation generator and synthesizer.

Abstract: Closed-loop controller for altering the power level of nuclear reactors in a safe manner and without overshoot. Apparatus is provided for moving a control element such as a control rod or for adjusting the concentration of a soluble neutron absorber (chemical shim) for altering the nuclear reactor power level. A computer computes at short time intervals the two functions [.rho.(t)-.vertline..rho..sub.c .vertline./.lambda..sub.e '(t)]/.vertline..rho..sub.c .vertline. and .tau.(t)ln(P.sub.F /P(t)). The direction of motion of the control element is altered when these two functions become equal thereby resulting in the attainment of a new power level without overshoot. In a preferred embodiment, these two functions are computed at intervals of approximately one second.

Abstract: A method for preparing a coordination complex of an isonitrile ligand and radionuclide such as Tc, Ru, Co, Pt, Fe, Os, Ir, W, Re, Cr, Mo, Mn, Ni, Rh, Pd, Nb and Ta is disclosed. The method comprises preparing a soluble metal adduct of said isonitrile ligand by admixing said ligand with a salt of a displaceable metal having a complete d-electron shell selected from the group consisting of Zn, Ga, Cd, In, Sn, Hg, Tl, Pb and Bi to form a soluble metal-isonitrile salt, and admixing said metal isonitrile salt with a salt comprising said radioactive metal in a suitable solvent to displace said displaceable metal with the radioactive metal thereby forming said coordination. The complex is useful as a diagnostic agent for labelling liposomes or vesicles, and selected living cells containing lipid membranes, such as blood clots, myocardial tissue, gall bladder tissue, etc.