An FTIR spectrometer for remote measurements of atmospheric composition

The JPL IV interferometer, and infrared Michelson interferometer, was built specifically for recording high resolution solar absorption spectra from remote ground-based sites, aircraft and from stratospheric balloons. The instrument is double-passed, with one fixed and one moving corner reflector, allowing up to 200-cm of optical path difference (corresponding to an unapodised spectral resolution of 0.003/cm). The carriage which holds the moving reflector is driven by a flexible nut riding on a lead screw. This arrangement, together with the double-passed optical scheme, makes the instrument resistant to the effects of mechanical distortion and shock. The spectral range of the instrument is covered by two liquid nitrogen-cooled detectors: an InSb photodiode is used for the shorter wavelengths (1.85 to 5.5 microns, 1,800 to 5,500/cm) and a HgCdTe photoconductor for the range (5.5 to 15 microns, 650 to 1,800/cm). For a single spectrum of 0.01/cm resolution, which requires a scan time of 105 seconds, the signal/noise ratio is typically 800:1 over the entire wavelength range

Infrared aircraft measurements of stratospheric composition over Antarctica during September 1987

The JPL Mark IV interferometer recorded high resolution, infared solar spectra from the NASA DC-8 aircraft during flights over Antarctica in September 1987. The atmospheric absorption features in these spectra were analyzed to determine the overburdens of O3, NO, NO2, HNO3, ClONO2, HCl, HF, CH4, N2O, CO, H2O and CFC-12. The spectra were obtained at latitudes which ranged between 64 degrees S and 86 degrees S, allowing the composition in the interior of the polar vortex to be compared with that at the edge. The latitude dependence observed for NO, HO2, HNO3, ClONO2, HCl and HF are summerized. The values at 30 deg S were observed on the ferry flight from New Zealand to Hawaii. The dashed lines connecting the two were interpolated across the region for which there are no measurements. The chemically perturbed region is seen to consist of a collar of high HNO3 and ClONO2 surrounding a core in which the overburdens of these and of HCl and NO2 are very low. Clear increases in the overburdens of HF and HNO3 were observed during the course of September in the vortex core. HCl and NO2 exhibited smaller, less significant increases. The overburdens of the tropospheric source gases, N2O, CH4, CF2Cl2, and H2O were observed to much smaller over Antarctica than at mid-latitudes. This, together with the fact that HF over Antarctica was more that double its mid-latitude value, suggests that downwelling has occurred

Method of planarizing polycrystalline diamonds, planarized polycrystalline diamonds and products made therefrom

A method of planarizing a diamond film which generally includes orifices in the surface is described. The method includes first polishing the diamond film surface to reduce the surface roughness. A filler material is applied to the surface of the film to fill the orifices in the film. The film is polished to remove excess filler material and expose the diamond film surface. Also disclosed are planarized diamond films diamond substrate having a polished surface of both diamond and filler material and a variation in thickness of less than 8 percent

RC terminator and production method therefor

A thin-film RC circuit element suitable for a transmission line termination circuit is prepared by a process where (1) a first metal layer of an anodizable metal is deposited on a substrate, (2) the exposed surface of the anodizable metal layer is anodized to produce an oxide layer, (3) a second metal layer of electrically conductive metal is provided on the oxide layer, and (4) the first metal layer is etched to form an electrically resistive conductive path electrically connected to the region of the first metal layer beneath the second metal layer. A thin-film RC circuit element is also provided having a first layer of an anodizable metal formed on an electrically insulating substrate so as to provide two capacitor plates connected by a resistive strip, an oxide layer formed on the capacitor plates, and upper capacitor plates positioned on the oxide layer in register with the lower capacitor plates

Surgery groups of the fundamental groups of hyperplane arrangement complements

Using a recent result of Bartels and Lueck (arXiv:0901.0442) we deduce that the Farrell-Jones Fibered Isomorphism conjecture in L-theory is true for any group which contains a finite index strongly poly-free normal subgroup, in particular, for the Artin full braid groups. As a consequence we explicitly compute the surgery groups of the Artin pure braid groups. This is obtained as a corollary to a computation of the surgery groups of a more general class of groups, namely for the fundamental group of the complement of any fiber-type hyperplane arrangement in the complex n-space.Comment: 11 pages, AMSLATEX file, revised following referee's comments and suggestions, to appear in Archiv der Mathemati

Method of electroplating a substrate, and products made thereby

Disclosed is an electroplating method and products made therefrom, which in one embodiment includes using a current density to form a conductive metal layer having a surface roughness no greater than the surface roughness of the underlying member. In another embodiment of electroplating a substrate surface having peaks and valleys, the method includes electroplating a conductive metal onto the peaks to cover the peaks with the conductive metal, and into the valleys to substantially fill the valleys with the conductive metal

Method of packaging RF MEMS

Describes a structure and process for packaging RF MEMS and other devices, employing a substrate of silicon and a cap of glass that have the cavities to receive the devices. MEMS or other devices are supported on an upper surface of the substrate, into which metal-filled blind vias are formed. The cap is attached to the substrate so as to enclose designated MEMS or other devices in the cavities. The substrate is then thinned so as to expose the metal of the vias at a lower surface of the substrate. Electrical connecting elements such as solder balls are then applied to the metal of the vias. The resultant composite substrate is then divided to provide individual packaged devices