A novel noncontacting waveguide backshort for millimeter and submillimeter wave frequencies

A new noncontacting waveguide backshort was developed for millimeter and submillimeter wave frequencies. It employs a metallic bar with rectangular or circular holes. The size and spacing of the holes are adjusted to provide a periodic variation of the guide impedance on the correct length scale to give a large reflection of RF frequency power. This design is mechanically rugged and can be easily fabricated for millimeter wave frequencies above 300 GHz where conventional backshorts are difficult to fabricate. Model experiments were performed at 4 to 6 GHz to optimize the design. Values of reflected power greater than 95 percent over a 30 percent bandwidth were achieved. The design was scaled to WR-10 band (75 to 110 GHz) with comparably good results

The M5 and M4 Edges of Gold in the Pure State and in a Gold Copper Alloy

For most of the M5 and M4 x-ray absorption edges already measured there is a discrepancy between observed and calculated values. The M1 edges occasionally have a small discrepancy while the M2 and M3 edges seldom show any. Siegbahn and Phelps have suggested that the final levels in the edge transitions are valence and low lattice levels and that the selection rule Δ1= ± 1 is usually giving the transition preference. A change in atomic spacing of a metal, such as often results from alloying it, should produce a change in the energies of its lattice levels. The gold M5 and M4 edges from gold and from a 50 atomic per cent copper gold alloy were photographed in a vacuum spectrometer. Significant shifts to higher energies in M5 of 2.5 electron volts and in M4 of 6.8 volts were found. These results show that the final levels in M absorption transitions are lattice levels, and they give credence to the assumption that there are preferred atomic to lattice level transitions

Alien Registration- Mcgrath, Louise W. (Houlton, Aroostook County)

https://digitalmaine.com/alien_docs/34791/thumbnail.jp

PILOT: design and capabilities

The proposed design for PILOT is a general-purpose, wide-field 1 degree 2.4m, f/10 Ritchey-Chretien telescope, with fast tip-tilt guiding, for use 0.5-25 microns. The design allows both wide-field and diffraction-limited use at these wavelengths. The expected overall image quality, including median seeing, is 0.28-0.3" FWHM from 0.8-2.4 microns. Point source sensitivities are estimated.Comment: 4 pages, Proceedings of 2nd ARENA conference 'The Astrophysical Science Cases at Dome C', Potsdam, 17-21 September 200

Providing Public Transport for Tourists in Rural Areas

Travel, both to the destination area and within the area, accounts for a high proportion of tourism’s emissions. Yet, relatively little attention has been directed at reducing emissions through encouraging visitors to use public rather private transport. This paper reports the findings of surveys of bus passengers within British rural tourist areas and demonstrates how they bring extra visitors and spending to attractions, while reducing car use. It discusses the potential of using public transport to enhance the tourism offer and the problems, and some solutions, of funding such services. Recent developments are introduced

Key to the Wood-Decaying Polyporaceae of the East Texas Region

The family includes those pore fungi whose fruiting bodies are tough, leathery or woody and whose pore layer usually cannot be separated easily from the context. The pores on the undersurface are only exterior openings of tubes bearing spores and in each species these tube mouths, or pores, are a definite shape and size. Occasionally pore walls will break up giving the appearance of teeth or gills. Fruiting bodies can be sessile, stemmed, effused-reflexed or resupinate (Fig . 2). Members of the family can be either perennial or annual, with the annual species growing during the summer and maturing that fall. All are typically wood-inhabiting, only rarely terrestrial. No other family of comparable size is more important economically than the Polyporaceae, causing 90 percent of the more important timber decays in the United States (Overholts 1967). Decay caused by the Polyporaceae can affect any part of the tree.https://scholarworks.sfasu.edu/ebooks/1007/thumbnail.jp

Jovian equatorial H2 emission from 1979-1987

Ninety two IUE observations of the Jovian equatorial region taken between 2 Dec. 1978 and 1 Feb. 1988 were averaged together by date of observation, resulting in 22 averaged spectra which were fit with a model to determine the amount of H2 Lyman band emission in the region 1552 to 1624A. The data suggest that the H2 emission may vary with time. Especially suggestive is the marked downward trend of the emission between 1983 and 1987, during which time the strength of the emission in the 1552 to 1624A region decreases by a factor of 10. Uncertainty in the existing data and a gap in the data in 1980 and 1981 preclude a positive identification of a correlation between the brightness of the H2 emission and the major solar cycle

Easily missed? Bladder cancer in women

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