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51.
The maximum number of non-vanishing and independent second order photoelastic coefficients required by the seven pentagonal
and the two icosahedral point groups 5(C5),
(S10),
(C5h
),
m2(D5h
), 52(D5), 5m(C5v
),
2m(D5d
); 235(I), 2/m
(I
h
)—that describe the quasicrystals symmetry groups in two and three dimensions—is obtained. The schemes of non-vanishing and
independent coefficients have been calculated and listed. Finally the results of this group-theoretical study are briefly
discussed. 相似文献
52.
The transmitted photon spectra of133Ba,22Na,137Cs,54Mn and60Co point sources are measured through different thicknesses of water, concrete and sand. The multiple-scatter peaks observed
in these materials at 60, 90 and 100 keV energies respectively are found to be independent of incident photon energy and thickness
of the medium. 相似文献
53.
The downward movement of water in the soil due to 1971 monsoon precipitation and supplemental surface irrigation has been traced at about forty-five sites in Western Uttar Pradesh, using a thin layer of moisture tagged with tritiated water. The tritiated layer was found to move down to different depths at different sites. The movement, averaged over the forty sites is found to be 96 cm, indicating that the average recharge for the year 1971 (a year of normal monsoon) was 21.5 cm of water. 相似文献
54.
Y. Rama Krishna Sarma 《Annals of the Institute of Statistical Mathematics》1987,39(1):497-512
Summary In this note some asymptotically optimum tests for testing hypotheses concerning parameters when the observations are dependent
are obtained. Test statistics based on the score functions, similar to the one proposed by Rao in the case when the observations
are i.i.d. are proposed. Asymptotically UMP tests for one sided hypotheses against one sided alternatives and asymptotically
UMP unbiased test for a simple hypothesis against two sided alternatives are derived. In the multiparameter case tests for
simple hypotheses that have asymptotically best constant power on some family of surfaces in the parameter space are derived. 相似文献
55.
Bhogi Jai Rama Satyanarayana Swamy Rangu Vijay Pamidi Ramesh Babu Bhaskar Sanyal Yerramreddy Gandhi Nalluri Veeraiah 《Ionics》2016,22(9):1625-1634
γ-Ray-induced dielectric dispersion in CaF2–B2O3–P2O5 glasses doped with different concentrations of CuO was investigated. The glass samples were exposed to γ-rays with dose varying within the range 0–10 kGy. The dielectric dispersion and spectroscopic properties were measured before and after γ-ray treatment. Additionally, thermoluminescence studies were performed on post-irradiated glass samples. The results of dielectric properties and dielectric breakdown strength indicated a substantial increase in the insulating strength of CuO containing glasses due to γ-ray irradiation. The analysis of these results together with UV-vis optical absorption, IR spectra, and thermoluminescence studies have indicated a gradual increase in the concentration of mono-valent copper ions due to γ-ray treatment of the glass network. The additional studies have confirmed that these Cu+ ions occupy network-forming positions, increase the polymerization of the borophosphate glass network, and facilitates for the increase of insulating strength of the titled glass. 相似文献
56.
57.
K.?Sanjeev RaoEmail author Rajeswari?Seshadri Rama?Govindarajan 《Theoretical and Computational Fluid Dynamics》2004,17(4):233-248
A new minimal composite theory that extends the approach of Govindarajan and Narasimha [1] is proposed here for 2D non-parallel compressible boundary-layer stability subject to 3D disturbances. The mean profiles are obtained from Hortons analysis, which provides a good approximation for a large range of Prandtl numbers at non-zero pressure gradients. In the lowest order, all effects of order lower than O(R-2/3) anywhere in the boundary-layer are included, R being the local boundary-layer Reynolds number; the resulting non-parallel formulation yields a set of four ordinary differential equations, as compared to the five coupled equations of classical parallel flow theory of Mack [2]. The largest effect on stability of flow non-parallelism is found to be due to the wall-normal advection of velocity and temperature disturbance quantities by the mean flow. The present theory shows that the bulk viscosity, invariably included in compressible stability theories, is irrelevant at the lowest order. In comparison with the full [O(R-1)] non-parallel theory, the present theory is marginally better than the parallel flow theory. PACS 03.50.De, 04.20-q, 42.65-k 相似文献
58.
Free convection flow from an isothermal horizontal circular cylinder immersed in a fluid with viscosity proportional to an inverse linear function of temperature is studied. The governing boundary layer equations are transformed into a non-dimensional form and the resulting nonlinear system of partial differential equations is reduced to local non-similarity equations which are solved numerically by a very efficient implicit finite difference method together with Keller box scheme. Numerical results are presented by velocity and viscosity profiles of the fluid as well as heat transfer characteristics, namely the local heat transfer rate and the local skin-friction coefficients for a wide range of viscosity parameter (= 0.0, 0.5, 1.0, 2.0, 3.0,4.0) and the Prandtl number Pr (= 1.0, 7.0, 10.0, 15.0, 20.0, 30.0). 相似文献
59.
In this study, the mixed convection of water at 4°C along a wedge in a porous medium is investigated numerically using finite
difference method. In order to explore the effect of mixed convection, both forced and free convection-dominated regimes are
considered. Non-similarity solutions are obtained for the variable wall flux boundary condition. Velocity and temperature
profiles as well as local dimensionless skin friction and Nusselt number are obtained and compared with the available numerical
results for various values of different parameters. The wedge angle geometry parameter m and mixed convection parameter ξ are ranged from 0 to 1 in both regimes whereas different values of λ are considered for the purpose of comparison of heat transfer results. 相似文献
60.
M.V. Madhubabu R. Shankar T. Krishna Y. Satish Kumar Y. Chiranjeevi Ch. Muralikrishna H. Rama Mohan Satish S. More M.V. Basaveswara Rao Raghunadh Akula 《Tetrahedron: Asymmetry》2017,28(12):1803-1807
A convergent approach towards the synthesis of the 2-alkyl-substituted tetrahydroquinoline alkaloid (?)-cuspareine via enantiospecific construction of the (R)-benzyl 2-formyl-3,4-dihydroquinoline-1(2H)-carboxylate. We have achieved an efficient enantiospecific synthesis of (?)-cuspareine starting from known key starting materials. The reactions employed for individual transformations are simple and high yielding, and the strategy could potentially be easily extended. 相似文献