Author
B. Ramachandra Rao
Other affiliations: Australian National Drag Racing Association, Pennsylvania State University
Bio: B. Ramachandra Rao is an academic researcher from Andhra University. The author has contributed to research in topics: Diffraction & Ionosphere. The author has an hindex of 8, co-authored 94 publications receiving 310 citations. Previous affiliations of B. Ramachandra Rao include Australian National Drag Racing Association & Pennsylvania State University.
Topics: Diffraction, Ionosphere, Ultrasonic sensor, Fading, Latitude
Papers published on a yearly basis
Papers
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TL;DR: The diffraction effect at such high frequencies (λ* = 0·00148 cm.) appears to be very much like reflexion in the Bragg sense.
Abstract: RECENTLY diffraction patterns have been produced in this laboratory1 by using ultrasonic waves of frequencies higher than 100 Mc./sec. At such high frequencies, the patterns show some interesting features. Progressive waves of frequency 102.6 Mc./sec. and maintained in water have been employed. When the sound wave is exactly normal to the incident light, the diffraction pattern disappears altogether. On tilting the crystal holder to one side or the other, so that the light rays meet the sound wave-front at an angle of 52', the first-order diffraction line alone on the appropriate side is obtained. This angle agrees closely with the value derived from the equation ?/?8=2µ sin I¸ where I» and I»* are the wave-lengths employed and µ is the refractive index of water. In no position of the sound wave-front has it been possible to get the first-order line on both sides at the same time. The value of the above angle for which the first-order line attains the maximum intensity is quite critical. Even a slight variation of about 2' has been found to reduce its intensity to half. Thus the diffraction effect at such high frequencies (I»* = 0·00148 cm.) appears to be very much like reflexion in the Bragg sense.
18 citations
TL;DR: The analysis of drift measurements made at Waltair for the F1 and F2-regions over a period of 2 years is presented in this article.The main features of the diurnal and seasonal variation of drifts in F2 region are given in detail.
14 citations
TL;DR: The phase path technique is a very sensitive experimental method for detecting travelling ionospheric perturbations in the FZ-region and is capable of giving much information on the various characteristics of the perturbation.
12 citations
01 Sep 1945
11 citations
01 Aug 1948
10 citations
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TL;DR: In this paper, the elastic constants of the isotropic medium have been studied and a tabulation of elastic constants for such specimens is provided, not only for itself, but also because the data can be correlated with other physical measurements and thereby provide possible insight into the nature of the atomic forces in solid matter.
Abstract: Publisher Summary This chapter discusses the elastic constants of crystals. The elastic properties of solid matter hold interest for both technology and basic research. In the first field applied elasticity is an important discipline for those fundamental considerations of engineering design which are usually included under the designation “strength of materials.” The treatment of structural materials requires semiempirical methods, because their compositions are complex and prior treatment has a pronounced effect. On the other hand, basic research into elastic properties is usually concerned with work on specimens in the simplest state which can be obtained reproducibly—for example, annealed single crystals. The complete tabulation of elastic constants for such specimens is valuable, not only for itself, but also because the data can be correlated with other physical measurements and thereby provide possible insight into the nature of the atomic forces in solid matter. The research aspect of elastic studies is of primary interest for this chapter. The case of the isotropic medium is important both for the chronological development of the subject of elasticity and also for its applicability to polycrystals and glasses.
694 citations
TL;DR: In this article, it was shown that sporadic-E is most likely due to a vertical shear in the horizontal east-west wind and this theory accounts for the detailed observations of the wind and electron density profiles.
427 citations
TL;DR: The theoretical and observational evidence concerning the global propagation of atmospheric gravity waves is reviewed in this article, with special emphasis on the waves generated in the auroral zones, and it is concluded that the only natural sources of large-scale TIDs are in the ionospheric zones.
392 citations
TL;DR: The adiabatic elastic constants of two garnets (spessartite-almandite and almandite), spinel (synthetic), rutile and olivine are reported in this paper.
Abstract: The adiabatic elastic constants of two garnets (spessartite-almandite and almandite), spinel (synthetic), rutile (synthetic), and olivine are reported. The stiffness constants Cpq were determined from the velocities of acoustic wave propagation in crystals. The velocities of wave propagation were measured by McSkimin's method. A frequency range of 6 to 12 Mc/s was used.
341 citations
TL;DR: The elastic constants of anisotropic materials have been studied in this article, where the elastic constants are defined as the ratio of the elasticity of a given material to its elasticity.
Abstract: (1956). The elastic constants of anisotropic materials—II. Advances in Physics: Vol. 5, No. 19, pp. 323-382.
265 citations