522 research outputs found
Stress Waves in Nonhomogeneous Elastic Rods
No full textLongitudinal wave propagation in a nonhomogeneous semi infinite elastic rod is considered. The non homogeneity may be due to the axial variation of Young\u27s modulus or of density or of both. An arbitrary time dependent stress is applied at the end, x = 0, of the rod. The normal stress as a function of position and time is obtained using the theory of the propagating surfaces of discontinuity by expanding the stress as a Taylor series about the time of arrival of the wavefront. The coefficients of the Taylor expansion are obtained as solutions of linear ordinary differential equations with variable coefficients. For the case where the Young\u27s modulus E(x) varies as (1 + ax)2a, it is shown that the stress at the wavefront varies as (1 + ax)⋔±, where a and ⋔± are constants. © 1966, Acoustical Society of America. All rights reserved
Synthesis, Structural Elucidation and Bioassay of Morpholine/Thiomorpholine and Piperidine Containing Oxazoles
No full textThe series of novel oxazole derivatives (3-4) have been synthesized. All the entitles compounds were characterized by IR, 1H, 13C NMR, mass spectra. All the lead compounds were tested for antimicrobial activity. The compound 4f having chloro substituent on the aromatic ring displays greater antimicrobial activity particularly against P. aeruginosa and P. crysogenum. © 2020 Author(s).The authors G. Sravya and N. Bakkthavatchala Reddy are thankful to Ural Federal University, Yekaterinburg, Russia for giving postdoctoral fellowship
Synthesis of a New Class of Thiazolyl Morpholines / Thiomorpholines and Evaluation as Antimicrobials
No full textThe series of novel thiazole derivatives (4-5) have been synthesized. All the synthesized compounds were characterized by IR, 1H, 13C NMR, mass spectra. All the lead compounds were tested for antimicrobial activity. The compound 5f having chloro substituent on the aromatic ring displays greater antimicrobial activity particularly against P. aeruginosa and P. crysogenum. © 2020 Author(s).The authors G. Sravya and N. Bakkthavatchala Reddy are thankful to Ural Federal University, Yekaterinburg, Russia for giving postdoctoral fellowship
Propagation of Shear-Stress Waves in an Infinite Nonhomogeneous Elastic Medium with Cylindrical Cavity
No full textThe problem of the radial propagation of shear waves in a nonhomogeneous elastic medium with a cylindrical cavity is solved by the theory of propagating surfaces of discontinuity. Thus, numerical integration that is required in using method of characteristics is avoided. An analytical solution, in the form of a Taylor series expanded about the time of arrival of the wavefront, is obtained. Two numerical examples, which are shown to agree with previous results, are also presented. © 1969, Acoustical Society of America. All rights reserved
Simple waves and shock waves in a thin prestressed elastic rod
No full textEin halb-unendlicher dünner elastischer Stab wird einer monoton ansteigenden Störung am freien Ende unterworfen. Die unstetige Wellenbewegung für endliche Verzerrungen wird untersucht, und die Bedingungen zur Bildung von Stössen werden aufgestellt. Eine implizite Lösung für die Wellenbewegung im Gebiete einfacher Wellen wird mittels der Methode der Charakteristiken erhalten. Eine andere und explizite Lösung in diesem Gebiete wird gefunden durch Anwendung der Theorie sich fortpflanzender Diskontinuitätsflächen, als eine Taylor-Reihe um die Ankunftszeit der Wellenfront. Es wird gezeigt dass der Koeffizient des ersten Gliedes in der Entwicklung eine Lösung für eine homogene nichtlineare gewöhnliche Differentialgleichung ecster Ordnung darstellt. Die übrigen Koeffizienten befriedigen lineare, jedoch inhomogene gewöhnliche Differentialgleichungen mit veränderlichen Koeffizienten. Für den Fall einer rampenartigen Belastung und für Stossbildung an der Wellenfront wird für schwache Stösse durch Anwendung einer Methode von Friedrichs die Vereinigung von einfachen Wellen untersucht. Als Beispiel wird die Entlastung eines Stabes betrachtet, der einer anfänglichen Dehnung von 50% unterworfen ist
ROTATIONAL ANALYSTS OF THE b-X SYSTEM OF SELENIUM MONOXIDE
No full textAzam and S. P. Reddy, Can. J. Phys. 51, 2166 (1973). R. F. Barrow and E. W. Deutsch, Proc. Phys. Soc. 82, 548 (1963). K. K. Verma, M. Azam, and S. P. Reddy, J. Mol. Spectrosc. (in press).Author Institution: Department of Physics, Memorial University of NewfoundlandThe 00 bands at 10 296 and 10 491 {\AA} of the near-infrared band system X. of the SeO were photographed at high resolution and their rotational structure has been analyzed. The analysis shows that the bands represent the transition (X being the case-c ground state of the SeO molecule). The observed isotopic shifts of the rotational lines of from those of are in agreement with the calculated values. The derived constants in for are as follows:[FIGURE] For the ground state, the separation , Klein-Dunham potential curves were constructed for the and states as well as for the previously known and of the Seo molecule
REINVESTIGATION OF THE COMET-TAIL SYSTEM OF
No full textS. P. Reddy and C.V.V. Prasad, J. Phys. E. Sci. Instrum. 22, 1972 (1989). C. Haridass, C. V.V. Prasad and S.P. Reddy, Astrophys. J. 338, 669 (1992).Author Institution: Department of Physics and Physical Oceanography, Memorial University of NewfoundlandThe emission spectrum of the system of produced in the cathode glow of a hollow cathode discharge tube of special and photographed in the spectral region 3345-8500 {\AA} at high was reinvestigated. Detailed rotational analysis of ten bands involving five vibrational levels to 4 of each of the A and X states was carried out. Spin-splitting of the rotational levels was observed for the analyzed bands. The observed intensity distribution of the branches is found to be in good agreement with theoretical calculations. Rotational constants for both the A and X states were obtained from a global fit of the present data of the A-X system and the infrared and microwave data available from the literature. The Fortrat diagram for the 0-2 band confirms that the state changes from Hurd’s case (a) at lower J values to Hund’s case (b) at higher J values
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