The theory of scattering by a turbulent medium is applied to radio waves in the troposphere. In region below horizon transmitter, energy received (1) diffraction round curved surface earth (modified as appropriate atmospheric refraction), and (2) from turbulence high field strength above horizon. At distances beyond that are not too great, we may think giving mean signal received, fading. However, contribution usually decreases with distance more slowly than (1). Beyond certain distance,...

Free electrons in an ionized medium scatter radio waves weakly. Under certain conditions only incoherent scattering exists. A powerful radar can detect the backscatter from free and above earth's ionosphere. The received signal is spread frequency by Doppler shifts associated with thermal motion of electrons. On basis a radar, but one whose components are presently within state art, capable of: 1) measuring electron density temperature as function height time at all levels ionosphere to...

Observations are reported of enhancements the incoherent scatter spectrum excited by strong high frequency (HF) radio waves. A number enhancement characteristics, observed during an ionospheric heating experiment in January at Arecibo, described. The includes: a narrow line displaced below HF (5.62 MHz) ion acoustic waves fi plasma (about 4 kHz); broader 30-kc width) and other weak lines near HF; fi. Enhancements above thermal levels range factor 104 may be taken as verification excitation...

Enhancements of various features the incoherent scatter spectrum are observed when ionosphere is illuminated with powerful, high frequency radio waves. The waves excite plasma instabilities producing lines or more complex spectral near local frequency, at ion acoustic gyrofrequency, and twice gyrofrequency. enhancements occur in a thin slab as by radar both upshifted downshifted frequencies respect to probing frequency. vary time excitation held constant turned on off. power produced 160 kw...

The theory of radio scattering in the troposphere is modified light recent observations fluctuations refractive index. applied to communication problem and yields some characteristics which are peculiar mechanism. One characteristic imposes a limit on maximum size an antenna its full theoretical gain. This deduced from prediction diversity distance. Height gain also Other derived pertinent problem, including fading rates frequency bandwidth

By means of piezoelectric gauges, a study has been made the development detonation from shock wave propagated into mixture. With sufficiently strong shock, above stable velocity is immediately established which decays smoothly to steady state. When weaker than required for phenomena ensue depend upon strength and nature medium. A zone combustion, accompanied by build-up pressure, develops in wake front. This may lead smooth acceleration latter until established; waves be formed overtake...

The VHF radar at Jicamarca (12.0°S, 76.9°W) was used to probe the mesosphere for 24 hours on May 23–24, 1974. inferred zonal wind shows a strong eastward prevailing component below 75 km these winter conditions, as would be expected from annual and semiannual oscillations. winds are in good agreement their region of overlap with rocket observations made Ascension Island (8.0°S, 14.4°W) same period. This is first direct confirmation that measuring mesospheric winds. Substantial oscillations...

Journal Article Knowledge and Value: Their Distinction Relationship in Clarifying Social Work Practice Get access William E. Gordon, Ph.D. Professor of Research George Warren Brown School Work, Washington University, St. Louis, Missouri Search for other works by this author on: Oxford Academic PubMed Google Scholar Volume 10, Issue 3, July 1965, Pages 32–39, https://doi.org/10.1093/sw/10.3.32 Published: 01 1965

A Critique of the Working Definition Get access William E. Gordon, Ph.D. professor research, chairman second Subcommittee on Social Work Practice NASW Commission George Warren Brown School Work, Washington University, St. Louis, Missouri Search for other works by this author on: Oxford Academic PubMed Google Scholar Volume 7, Issue 4, October 1962, Pages 3–13, https://doi.org/10.1093/sw/7.4.3 Published: 01 1962

Staff members of the Cornell University Center for Radiophysics and Space Research have designed an ionospheric radar probe to be located near Arecibo, Puerto Rico. The will following general specifications: 1) Antenna reflector, 1000-foot-diameter spherical bowl, illuminated by a 430-Mc dual-polarized feed. 2) Transmitter 2.5 Mw peak, 150 kw average power, or 100 CW power. 3) Dual-channel receiver, capable measuring total polarization received spectrum. initially used measure variation...

This is a most welcome addition to the library of books on radio waves in ionosphere. The standard references western world are all quite old, although they still remarkably useful: S.K. Mitra's Upper Atmosphere (Asiatic Society, Calcutta, India, 1952), K.G. Budden's Radio Waves Ionosphere (Cambridge University Press, London, 1961), and K. Davies' Ionospheric (Blaisdell, Waltham, Mass., 1969). In eastern world, Y.L. Alpert V.L. Ginzburg authorities, both now have volumes English: Alpert's...

Which, if either, of these communities can logically be considered climax in the Park area has not been clearly determined. Lee (1924) noted that hard maple (Acer saccharum) is limited to heavier soils and hence, though able reproduce itself, could become climax. Of spruce-fir (Picea-Abies) type he wrote: . it seems both possible probable may develop into true region. Kell (1938) supported polyclimax view stating there are three communities: are: 1. ash-elm-fir on peat, 2. sugar...

Experiments were performed at Arecibo, Puerto Rico, to investigate the evolution times of 3‐m field‐aligned Striations produced in ionosphere by powerful high‐frequency (HF) radio waves. The results this investigation are now summarized. First, striations' rise dependent on HF electric field. E region data suggest that dependence is nonlinear. Second, threshold value field required produce detectable was experimentally determined. At component perpendicular geomagnetic calculated be 0.09 V/m...

In September 1983 a series of ionospheric modification experiments was performed in Scandinavia using the high‐frequency (HF) heating facility located near Tromsø, Norway. The were designed to study production geomagnetic field‐aligned irregularities auroral E region by powerful HF radio wave. this initial report, observations 3.2‐m made with mobile 46.9‐MHz field radar are presented. When conditions correct, having peak cross sections about 10 4 m² excited over Tromsø. present results...

All acute hospitalizations from a 229‐bed home for the aged four‐year period were analyzed. Of 373 residents eligible study, 239 individuals hospitalized total of 503 times. Five patients admitted seven Median length stay was 9.4 days. 235 primary diagnoses, only nine occurred at least 1% time. Sixty‐six different complications, representing 131 occurrences, noted during hospitalization. Hospital mortality 11.7%. first admissions 9.2% died and 19% survivors required higher level care. One...