Abstract: In order to meet the demands of simplicity and reliability in active control systems for flexible structures, an inexpensive active truss element and control law has been developed. A decentralized switching control law is used along with a compressible fluid in the truss element in order to dissipate energy during the motion of the structure. However, the energy is not absorbed in the same manner as a conventional viscous damper. The truss element retains its maximum stiffness, but has a resettable nominal unstressed length. Energy is absorbed in the working fluid of the truss element through heat transfer to the environment when the nominal length is reset at the proper switching times. The control law is insensitive to changes in structural parameters such as mass, stiffness, and damping.

Abstract: A plasma chamber for use in isotope enrichment has a microwave feed to the ECRH microwave horns, which feed is led into the plasma chamber behind the sputter plate and perpendicular to the magnetic field for improved microwave waveguide routing and ease of microwave window handling and maintenance. Improved collector design includes a collector assembly placed behind the plasma source comprising a dump plate and flat and shield collector. A ring collector is provided outside the main plasma region in the case where two opposing magnetic mirrors are used and the resonant ions maintained between them. An improved collector assembly can also be provided by disposing the collector assembly in front of the plasma source region and having a double shield-and-slat collector for capturing high energy resonant ions or permitting passage of low energy ions therethrough. Sputter sources for nonconducting materials can be provided by using a thin surface coating applied to a metal backing.

Abstract: An improved ring display box is realized by providing a holding platform made from sheet material to which the ring is attached and which is unfolded as the ring box is opened. As the sheet is unfolded by the opening of the box, a folded surface to which the ring is attached is rotated upwardly out of the box and presented at an inclination to the viewer. The sheet is multiply folded by parallel sets of folds so that the surface to which the ring is attached extends outwardly and forwardly from the hinge of the box to make a visually forward projection to the viewer.

Abstract: Successful laser treatment of hemangiomas requires selective photocoagulation of subsurface targeted blood vessels without thermal damage to the overlying epidermis. An apparatus for in vivo exposure of laser radiation from a continuous Nd:YAG laser at 1064 nm delivers repetitive cryogen spurts, each having a duration of the order of milliseconds during continuous laser irradiation. Control of the cryogen spray cooling is achieved through monitoring of the radiometric surface temperature of the tissue site and either controlling the repetition rate of the cryogen spurts according to temperature or according to a threshold temperature of the irradiated surface and/or repetition rate of the cryogen spurts according to power density and the duration of continuous irradiation.

Abstract: Spray atomization of molten metal and/or intermetallic matrix composites reinforced with ceramic particles is practiced by atomizing the matrix into micron sized droplets and depositing the semisolid droplets in a bulk deposition upon a temperature controlled substrate. The semiliquid droplets are injected with refinement particles while in a range of 0 to 40% by volume solid phase and deposited on the substrate surface while in a 40 to 90% by volume solid phase. Refined grain morphology, increased solid solubility, nonequilibrium phases, absence of macro segregation, and elimination of the need to handle fine reactive particles are all achieved by performing the spray deposition process under a controlled atmosphere. Materials fabricated by the process exhibit unusual combinations of properties, such as spatially varying properties.

Abstract: The fabrication of an optical cavity for use in a laser, in a frequency doubling external cavity, or any other type of nonlinear optical device, can be simplified by providing the nonlinear crystal in combination with a surrounding glass having an index of refraction substantially equal to that of the nonlinear crystal. The closed optical path in this cavity is formed in the surrounding glass and through the nonlinear crystal which lies in one of the optical segments of the light path. The light is transmitted through interfaces between the surrounding glass in the nonlinear crystal through interfaces which are formed at the Brewster-angle to minimize or eliminate reflection.

Abstract: An apparatus is provided for electrocoagulating blood and tissue at an occlusion site by means of application of an alternating signal or current through a detachable partially insulated coil on the end of a microcatheter. A Guglielmi Detachable Coil (GDC) is preferably used in the combination with damped radio frequency energy to cause local heating at the location of the coil but without local ohmicly heated tissue damage or hot spots. Damping of the radio frequency energy facilitates the avoidance of hot spots. Once carbonization of blood at the detachment zone of the GDC coil occurs, the impedance of the entire system increases. The impedance increase is detected to automatically turn off the alternating current and then to apply a direct current to electrolytically detach the GDC coil from the microcatheter.

Abstract: An artery, vein, aneurysm, vascular malformation or arterial fistula is occluded through endovascular occlusion by the endovascular insertion of a platinum wire and/or tip into the vascular cavity. The vascular cavity is packed with the tip to obstruct blood flow or access of blood in the cavity such that the blood clots in the cavity and an occlusion if formed. The tip may be elongate and flexible so that it packs the cavity by being folded upon itself a multiple number of times, or may pack the cavity by virtue of a filamentary or fuzzy structure of the tip. The tip is then separated from the wire mechanically or by electrolytic separation of the tip from the wire. The wire and the microcatheter are thereafter removed leaving the tip embedded in the thrombus formed within the vascular cavity. Movement of wire in the microcatheter is more easily tracked by providing a radioopaque proximal marker on the microcatheter and a corresponding indicator marker on the wire.

Abstract: Displacement is measured using two overlaid parallel optic gratings as the sensing elements of a sensor head. Optic fibers are employed as the transmission media between the sensor head and a central signal processing unit. The light intensity signals of Moire fringes generated by the overlaid optic gratings are transmitted through optic fibers to the central signal processing unit. By digitally counting the number of Moire fringes, the changes in both direction and magnitude of the displacement are measured. A number of sensor heads employing the overlaid optic gratings as sensing elements are multiplexed through a common optic fiber link to comprise a multipoint sensor system. By similarly modifying the sensor head, this sensor system also measures other physical quantities such as strain, acceleration, and pressure.

Abstract: The antenna of an RFID tag or label is disconnected from the balance of the RFID chip by means of a series switch activated in response to a logic command, CLOAK, generated by the RFID chip. Activation of the switch disconnects the antenna of the RFID tag for the remainder of the RFID chip and effects a high impedance resistance across the antenna terminals. An RC circuit is charged by activation of the CLOAK signal and thereafter discharges during a predetermined RC time period as determined by a high impedance series antifuse leakage transistor. The antenna is thus disconnected for a time sufficient to allow the remaining RFID tags in an RF interrogation field to be identified. Meanwhile, during the disconnection of the antenna from the RFID chip and its loading causes its effective absorption and scattering aperture to be reduced near zero so as to electromagnetically remove the RFID tag from the zone of interrogation during the predetermined time period.

Abstract: A surgical implement, such as a surgical electrode, and an ultrasound transducer, both extend through a single elongated insertion member, typically, a catheter. The ultrasound transducer extends from the proximal region of the surgical instrument containing the instrument controls toward the distal end of the catheter from which at least the operative tip of the surgical implement and the ultrasound transducer extend. In one embodiment, the catheter also contains a fiber-optic endoscope, thus allowing visual as well as ultrasound monitoring of the surgical site, before, during and after conduct of the surgical procedures. Means are provided for rotation of the ultrasound transducer to enable generation of a circular tissue reflectivity image transverse to the axis of the ultrasound transducer. Means are also provided for selective longitudinal movement of all elements contained within the catheter.

Abstract: A low power, low noise driving circuit for a bank of LEDs utilized in the station units of the MAN system is provided by coupling each bank of LEDs in a series circuit between the voltage supply and a constant current source. Each LED has a controllable logic switch in parallel across it and the switches are further in series circuit with each other to form a ladder network. Any selected LED may be turned off by closing its corresponding logic switch. The current continues to flow then through the shunting switch into the remaining LEDs in the series circuit that are on. A plurality of such ladder networks may be coupled in parallel with each other and each ladder network controlled by a switching gate which selectively couples it to the constant current source so that the LED ladder networks are operated at a predetermined duty cycle.

Abstract: Sinusoidal voltammetry was employed to detect both purine and pyrimidine-based nucleic acids. Adenine and cytosine, representing these two classes of nucleic acids, could be detected with nanomolar detection limits at a copper electrode under these conditions, where the sensitivity for adenine was much higher than that for cytosine. Detection limits for purine-containing nucleotides (e.g., adenosine 5'-monophosphate (AMP), adenosine 5'-diphosphate (ADP), and adenosine 5'-triphosphate (ATP)) were on the order of 70-200 nM using this method. These detection limits are achieved for native nucleotides and are over two orders of magnitude lower than those found with UV absorbance detection. Pyrimidine-based nucleotides could also be detected with high sensitivity due to the presence of a sugar backbone which is electroactive at the copper surface.

Abstract: A fluid drip tape splicing coupling is provided with two sequential sections, the first of which possesses a plurality of circumferential frustoconical barbs of essentially equal diameter. In the second section, which likewise contains a plurality of frustoconical barbs, at least one of the frustoconical barbs, a step barb, possesses a dimension, transverse to the axis of the coupling, which is greater than the diameter of the frustoconical barbs in the first section of the coupling. The step barb may be circular or elliptic in cross section. The fluid drip tape may be joined over this coupling by sliding and stretching a first piece of drip tape over the first section, which has been azimuthally aligned to line up the seam of the drip tape with the radial high point of step barb, until the tape abuts the step barb. A second piece of tape is slid over the coupling from the opposite direction over the second section and over the step barb until it overlaps the first drip tape.

Abstract: An artery, vein, aneurysm, vascular malformation or arterial fistula is occluded through endovascular occlusion by the endovascular insertion of a platinum wire and/or tip into the vascular cavity. The vascular cavity is packed with the tip to obstruct blood flow or access of blood in the cavity such that the blood clots in the cavity and an occlusion if formed. The tip may be elongate and flexible so that it packs the cavity by being folded upon itself a multiple number of times, or may pack the cavity by virtue of a filamentary or fuzzy structure of the tip. The tip is then separated from the wire mechanically or by electrolytic separation of the tip from the wire. The wire and the microcatheter are thereafter removed leaving the tip embedded in the thrombus formed within the vascular cavity. Movement of wire in the microcatheter is more easily tracked by providing a radioopaque proximal marker on the microcatheter and a corresponding indicator marker on the wire.

Abstract: An artery, vein, aneurysm, vascular malformation or arterial fistula is occluded through endovascular occlusion by the endovascular insertion of a platinum wire and/or tip into the vascular cavity. The vascular cavity is packed with the tip to obstruct blood flow or access of blood in the cavity such that the blood clots in the cavity and an occlusion if formed. The tip may be elongate and flexible so that it packs the cavity by being folded upon itself a multiple number of times, or may pack the cavity by virtue of a filamentary or fuzzy structure of the tip. The tip is then separated from the wire mechanically or by electrolytic separation of the tip from the wire. The wire and the microcatheter are thereafter removed leaving the tip embedded in the thrombus formed within the vascular cavity. Movement of wire in the microcatheter is more easily tracked by providing a radioopaque proximal marker on the microcatheter and a corresponding indicator marker on the wire.

Abstract: An artery, vein, aneurysm, vascular malformation or arterial fistula is occluded through endovascular occlusion by the endovascular insertion of a platinum wire and/or tip into the vascular cavity. The vascular cavity is packed with the tip to obstruct blood flow or access of blood in the cavity such that the blood clots in the cavity and an occlusion if formed. The tip may be elongate and flexible so that it packs the cavity by being folded upon itself a multiple number of times, or may pack the cavity by virtue of a filamentary or fuzzy structure of the tip. The tip is then separated from the wire mechanically or by electrolytic separation of the tip from the wire. The wire and the microcatheter are thereafter removed leaving the tip embedded in the thrombus formed within the vascular cavity. Movement of wire in the microcatheter is more easily tracked by providing a radioopaque proximal marker on the microcatheter and a corresponding indicator marker on the wire.

Abstract: Nanocrystalline coating are prepared using a two step approach. First, the grain size of: micrometer sized powders is reduced to nanometer dimensions using high energy ball milling. This is undertaken using attritor mills. Second, the nanocrystalline powders are dried and introduced into the high velocity oxygen fuel (HVOF) process and produce a coating with refined microstructure. The finished coating can be several mm in thickness. In addition a three dimensional device can be spray formed.

Abstract: An artery, vein, aneurysm, vascular malformation or arterial fistula is occluded through endovascular occlusion by the endovascular insertion of a platinum wire and/or tip into the vascular cavity. The vascular cavity is packed with the tip to obstruct blood flow or access of blood in the cavity such that the blood clots in the cavity and an occlusion if formed. The tip may be elongate and flexible so that it packs the cavity by being folded upon itself a multiple number of times, or may pack the cavity by virtue of a filamentary or fuzzy structure of the tip. The tip is then separated from the wire mechanically or by electrolytic separation of the tip from the wire. The wire and the microcatheter are thereafter removed leaving the tip embedded in the thrombus formed within the vascular cavity. Movement of wire in the microcatheter is more easily tracked by providing a radioopaque proximal marker on the microcatheter and a corresponding indicator marker on the wire.

Abstract: An artery, vein, aneurysm, vascular malformation or arterial fistula is occluded through endovascular occlusion by the endovascular insertion of a platinum wire and/or tip into the vascular cavity. The vascular cavity is packed with the tip to obstruct blood flow or access of blood in the cavity such that the blood clots in the cavity and an occlusion if formed. The tip may be elongate and flexible so that it packs the cavity by being folded upon itself a multiple number of times, or may pack the cavity by virtue of a filamentary or fuzzy structure of the tip. The tip is then separated from the wire mechanically or by electrolytic separation of the tip from the wire. The wire and the microcatheter are thereafter removed leaving the tip embedded in the thrombus formed within the vascular cavity. Movement of wire in the microcatheter is more easily tracked by providing a radioopaque proximal marker on the microcatheter and a corresponding indicator marker on the wire.