scholarly journals I. Observations Of Small Diameter Sources

1966 ◽  
Vol 19 (3) ◽  
pp. 441 ◽  
Keyword(s):  
Wavelength Range ◽  
Small Diameter ◽  
Short Wave ◽  
Polarization Angle ◽  
Radio Sources ◽  
Slight Variation ◽  
Fine Scale ◽  
Antenna Gain ◽  
System Noise ◽  
Made In

This paper is concerned with the observations of the polarization of small diameter radio sources made in 1963 with the Parkes 210 ft telescope over the wavelength range 11-74 cm. The sources of error in making such measurements with a single dish are discussed. At the short-wave end, the main limitation is system noise, and there is some complication from a slight variation of antenna gain with polarization angle; at long wavelengths, the limitation is the fine-scale structure of the galactic polarization in the direction of the source. The latter varies greatly across the sky.

scholarly journals 20. Spectra of some radio sources

1957 ◽  
Vol 4 ◽  
pp. 142-144 ◽  
Author(s):  
J. P. Hagen
Keyword(s):  
Wave Length ◽  
Short Wave ◽  
Naval Research ◽  
Calibration Error ◽  
Radio Sources ◽  
Consistent Picture ◽  
Sufficient Magnitude ◽  
Discrete Radio Sources ◽  
Considerable Doubt ◽  
Made In

At the tenth General Assembly of U.R.S.I. held in The Hague, Netherlands, in August 1954, the author presented a set of curves showing spectra of five bright, non-thermal, discrete radio sources. The spectra were based on the recent measurements at centimetre wave-lengths made with the 50-ft. antenna at the Naval Research Laboratory and on earlier published values for the flux at longer wave-lengths. The spectra are shown in Fig. 1. It is seen that there is in each case a discontinuity in the region between 30 and 100 cm. wave-length. Unfortunately, there had been no measurements made in this middle region. The slope of the two ends of the curve is nearly the same. There was considerable doubt at the time as to whether the spectra were in fact S-shaped as they would be if the two ends were joined in the simplest fashion. One possibility was that, due to the different techniques used in the centimetre and metre regions both in antennas and receivers, there might exist a calibration error of sufficient magnitude to cause the offset. For many reasons, this was hard to believe. In particular, measurements of solar flux at long and short wave-lengths yield a consistent picture.

scholarly journals Albedo of Melting Sea Ice in the Southern Beaufort Sea

1971 ◽  
Vol 10 (58) ◽  
pp. 101-104 ◽  
Author(s):  
M.P. Langleben
Keyword(s):  
Sea Ice ◽  
Northwest Territories ◽  
Beaufort Sea ◽  
Ice Cover ◽  
Short Wave ◽  
Wave Radiation ◽  
Short Wave Radiation ◽  
Melting Period ◽  
Fast Ice ◽  
Made In

AbstractTwo Kipp hemispherical radiometers mounted back to back and suspended by an 18 m cable from a helicopter flying at an altitude of about 90 m were used to make measurements of incident and reflected short-wave radiation. The helicopter was brought to a hovering position at the instant of measurement to ensure that the radiometers were in the proper attitude and a photograph of the ice cover was taken at the same time. The observations were made in 1969 during 16 flights out of Tuktoyaktuk, Northwest Territories (lat. 69° 26’N., long. 133° 02’W.) over the fast ice extending 80 km north of Tuktoyaktuk. Values of albedo of the ice cover were found to decrease during the melting period according to the equation A = 0.59 —0.32P where P is the degree of puddling of the surface.

scholarly journals Oh Observations in the Directions of Galactic Thermal Sources

1967 ◽  
Vol 20 (4) ◽  
pp. 407 ◽  
Author(s):  
RX McGee ◽  
FF Gardner ◽  
BJ Robinson
Keyword(s):  
Linear Polarization ◽  
The Other ◽  
Radio Sources ◽  
Line Radiation ◽  
Thermal Sources ◽  
Made In

A survey for the hydroxyl line radiation has been made in the directions of 30 radio sources (most of them thermal) with the 210 ft telescope of beamwidth 12'� 2 and the multichannel line receiver of bandwidths 10 and 37 kHz. The line at frequency 1665�401 MHz was observed for all sources and the other three lines at 1612, 1667, and 1720 MHz were observed for 10 of the more important sources. The latter were investigated for circular and linear polarization.

Drill holes deflection determination for small diameter bits in wood-based materials

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3808-3814
Author(s):  
Patryk Maciej Król
Keyword(s):  
Computer Vision ◽  
Medium Density Fiberboard ◽  
Small Diameter ◽  
Automatic Measurement ◽  
Medium Density ◽  
Research Attention ◽  
High Class ◽  
Drill Holes ◽  
Made In

The growing interest in wood accessories has focused scientific research attention on wood cutting with small diameter tools. A problem that may arise when drilling wood is the phenomenon of wandering – when the hole is not made in the designed place. The difficulty in studying small diameter drill holes (0.5 mm to 0.9 mm) is due to the difficulty of automatic measurement. The development of an appropriate methodology may allow for the observation of this phenomenon without the need for high-class hardware and expensive software. This article presents the results of tests carried out on nearly 500 samples made of various wood-based materials (high-density fiberboard (HDF), medium-density fiberboard (MDF), chipboard, and plywood) in terms of the usefulness of the OpenCV computer vision library for the determination of wandering.

High-Resolution Observations of Small-Diameter Radio Sources at 18-CENTIMETER Wavelength

1968 ◽  
Vol 153 ◽  
pp. 705 ◽  
Author(s):  
B. G. Clark ◽  
K. I. Kellermann ◽  
C. C. Bare ◽  
M. H. Cohen ◽  
D. L. Jauncey
Keyword(s):  
High Resolution ◽  
Small Diameter ◽  
Radio Sources

A catalog of small-diameter radio sources in the Galactic plane

1990 ◽  
Vol 74 ◽  
pp. 181 ◽  
Author(s):  
S. Zoonematkermani ◽  
D. J. Helfand ◽  
R. H. Becker ◽  
R. L. White ◽  
R. A. Perley
Keyword(s):  
Galactic Plane ◽  
Small Diameter ◽  
Radio Sources

The Plane Parallel Flow of a Binary Mixture of Fluids

1981 ◽  
Vol 48 (4) ◽  
pp. 707-716
Author(s):  
L. M. Srivastava ◽  
V. P. Srivastava
Keyword(s):  
Binary Mixture ◽  
Particle Deposition ◽  
Numerical Study ◽  
Infinite Plate ◽  
Small Diameter ◽  
Hankel Transform ◽  
Physical Importance ◽  
Strong Motivation ◽  
Insight Into ◽  
Made In

The flow of a binary mixture of chemically inert incompressible, Newtonian fluids over an infinite plate, set into motion in its plane by impulse and by oscillation, is studied. The binary mixture consists of (i) two different viscous density nonstratified fluids, and (ii) two different viscous density stratified fluids. The exact solutions are obtained using two methods, (i) Laplace transform and (ii) Hankel transform. To further study the velocities and the wall shear stress, asymptotic expansion are found for small and large times. Some other results of physical importance such as results for noninteracting fluids, strongly interacting fluids, and extremely different fluids are also derived and compared analytically with other results. Finally, to gain an insight into the patterns of the flow, numerical study of the results has been made in detail using digital computer. A strong motivation of the present analysis has been the hope that such a theory of fluids is useful in providing some insight in rheological properties of complex fluids as polymers, liquid crystals and, in particular, blood in the vessels of small diameter. Also the theory of fluids might provide an improved understanding of such diverse subjects as diffusion of proteins, swimming of micro-organism and particle deposition in respiratory tract.

The investigation of the Universe by radio astronomy

1961 ◽  
Vol 16 (1) ◽  
pp. 65-68
Keyword(s):  
Wavelength Range ◽  
Radio Astronomy ◽  
Outer Space ◽  
Sunspot Cycle ◽  
Short Wave ◽  
Radio Waves ◽  
Residual Noise ◽  
The Earth ◽  
Long Wave ◽  
The Universe

Although nearly all the major advances in radio astronomy have taken place during the last fifteen years the basic discoveries were made 30 years ago. At that time Jansky realized that the residual noise in his receiving equipment had a daily sidereal variation and must be the result of radio waves reaching the earth from outer space, and Appleton in the U. K. with Breit and Tuve in America through their studies of the ionosphere laid the foundation of the radio echo techniques of radio astronomy. The radio emission from outer space can be received on earth in the wavelength range from a few millimetres to 10 or 20 metres. The short wave end is limited by absorption in the atmosphere and the long wave end by the ionosphere, and this upper limit tends to vary in sympathy with ionospheric conditions throughout the sunspot cycle. These hindrances will soon be overcome when suitable equipment can be carried in earth satellites; then it should be possible to determine the true wavelength range of these extraterrestrial emissions.

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