Browsing by Issue Date, starting with "1947"
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PublicationNote PublicationArticle A new theorem on the transformability of a line-element into the spherically symmetric form(1947) K.R. KarmarkarThe differential equations for the geodesics of a general spherically symmetrical line-element of the form, ds2 = - A dr2 - B (dθ2 + sin2θdφ2)+ 2 C dr dt+ D dt2, are shown invariably to admit an integral of the form, a sin θ cos φ{symbol}+b sin θ sin φ{symbol}+c cos θ=0, where a, b, c are arbitrary constants. It is further shown that if the corresponding equations for a general lineelement of the form, ds2=-A(dx1)2-B(dx2)2-C(dx3)2+D dt2, admit an integral of the type ax1+bx2+cx3=0, the line-element is a transform of a spherically symmetrical line-element. Thus a necessary and sufficient condition for an orthogonal line-element in pseudo-cartesian co-ordinates x1, x2 x3, and t to be a transform of a sperically symmetrical line-element is that the geodesics satisfy the equation ax1+bx2+cx3=0. © 1947 Indian Academy of Sciences.PublicationLetter A spherically symmetrical non-static electromagnetic field [9](1947) V.V. Narlikar; P.C. Vaidya[No abstract available]PublicationArticle Interaction of nitrous oxide, nitrogen and phosphorus under silent electric discharge(1947) G.S. Deshmukh; Y.D. KaneInteraction with phosphorus films of nitrous oxide, nitrogen and oxygen in silent discharge under fields due to potentials (V) of 50, 500 cycles and the high frequencies has been studied at various pressures p. In agreement with a general finding due to Prof. Joshi,2, 3, 4 the change sets in above a minimum Vm and that both the current i and the reaction rate at a given V depend upon V-Vm. p decreases progressively to zero, when the reaction terminates; this is characterised by a remarkably sudden drop of the corresponding i. Free O2 is not observed; NO occurs only at early stages. Two simultaneous changes (ia) and (ib), the former being the more rapid, followed by (ii) represent the reaction mechanism viz., N2O→N2+O (ia) N2O→N+NO (ib) NO→N+O (ii). The atomic products react with phosphorus immediately. Removal of molecular N2, from (ia) and that formed by recombination of N from (ib) and (ii) by phosphorus, is the longest stage. Phosphorus nitride is the chief product with both N2O and N2. The time-variation of i is markedly synchronous with, but more pronounced than that of p; and more helpful in revealing the stages of the reaction, suggested as a general proposition by Joshi.3 Interaction with oxygen produces a rise of i in striking contrast with that with nitrogen. © 1947 Indian Academy of Sciences.PublicationArticle The use of indian zircon sand in ceramic opaque glazes(1947) H.N. Roy; D.K. Patwardhan[No abstract available]PublicationArticle PublicationArticle Emission bands of halogens - Part II. Iodine bands arising in 1g (3Π1 g) and Π2,1 g states(1947) Putcha VenkateswarluThe wavelengths of the maxima of all the diffuse bands from 4800 to 2680 A are given. The bands occur in different groups which involve frequency differences of the order of 165 cm.-1, 215 cm.-1 and 360 cm.-1 among the component bands. Five groups of bands with frequency difference of 165 cm.-1 are explained in Paper I. In this paper five groups with frequency differences of 215 cm.-1 and another five groups with frequency differences of 360 cm.-1 among the component bands are discussed. It is shown that they arise in a transition from two initial stable states with frequencies of 215 cm.-1 and 360 cm.-1 to a common set of five different final states which are all unstable. These final states are identified with just those states which are the only theoretically possible ones. The well-known continuum at 3416 A which occurs in emission and in absorption at high temperature is attributed to the transition 1g (3Π1 g → Ou- (1Σu-)) in the iodine molecule. The mechanism of the fluorescent bands corresponding to the emission bands is also discussed. © 1947 Indian Academy of Sciences.PublicationArticle Influence of the applied potential on the Joshi-effect(1947) B.N. Prasad; T.C. JainThe distribution of the total current i, as inerial which represents (owing to the low capacity of the aerial) the highest (mean) frequency; as iHF and iLF, the filtered high and low frequency parts of the tube current in the LT line has been studied in dark and in light at applied potentials varied in the range 5-9 kV, using a vacuo-junction and double diode as detectors. The relative Joshi-effect %Δi, i.e., the percentage photo-diminution of the current in dark in a given frequency region varies as iaeriai >iHF >iLT >iLF, which is also the order in respect of their mean frequencies. The 'threshold potential' Vm is found to be independent of the nature of both the detectors and also of the frequency regions; for each of these, % Δi is maximum near Vm. The decrease on increasing the applied potential, in % Δi is attributed to the corresponding preponderance of iLF which is comparatively insensitive to the production of this phenomenon. © 1947 Indian Academy of Sciences.PublicationArticle PublicationArticle Emission bands of halogens - Part V. Continuous bands of chlorine(1947) Putcha VenkateswarluWavelengths of the maxima of continuous bands of chlorine in the ultra-violet obtained with uncondensed transformer discharge, are given. These are practically the same as were previously recorded by other observers. The chlorine spectrum is shown to be apparently similar to that of iodine and bromine. The bands are conveniently arranged in three sets which are shown to be respectively arising in the three states σg, πu4, πu4, σu. 1u (3Σu+);σg, πu4, πg3, σu2. 1 (3Π1 g);σg, πu4, πg3, σu2. 1g (1Πg). The approximate positions are at about 58000, 67700 and 75000 cm-1 respectively whereas for bromine they are at 47000, 55534 and 61444 cm-1 and for iodine they are at 44900, 51528 and 58572 cm-1. The final states of all these bands will be repulsive, and will have steep potential energy curves. They have been attributed, in analogy with iodine and bromine, to those electronic states which are theoretically possible. The potential energy diagram for chloride molecule has been given. © 1947 Indian Academy of Sciences.PublicationArticle Emission bands of halogens - Part III. Iodine bands arising in 1u (3Πu+) and 1g (1Πg) states(1947) Putcha VenkateswarluThe three broad bands at 4747·2, 4662·1 and 4575·2 A are explained as due to transitions from a single stable state 1u (3Σu+) at 44900 cm.-1 to three unstable states Og+ (3Σg), 1g (3Σg-) and 1g (1Πg) which dissociate into2P3/2+2P1/2 iodine atoms at 20037 cm.-1 The bands in the region 2687 to 2400 A form three groups which are explained as arising in a level 1g (1Πg) at 58572 cm.-1 and having for their final level the three unstable states 1u (3Δ1 u), 2u (3Δ2 u) and 1u (1Πu) which dissociate into2P3/2+2P1/2 iodine atoms. The potential energy diagram for iodine molecule is given. © 1947 Indian Academy of Sciences.PublicationArticle Emission bands of halogens - Part IV. Diffuse bands of bromine(1947) Putcha VenkateswarluA large number of new diffuse bands in the emission spectrum of bromine are recorded. The wavelengths of all the diffuse bands of bromine in the region 4200-2000 A are given together with the experimental details. The bands occur in different sets of groups which involve frequency differences of the order of 330, 220 and 480 cm.-1 among the component bands. These are explained, as in the case of iodine, as arising in three initial states 1g (3Π1 g), 1g (1Πg) and Π2,1 g with frequencies of about 330, 220 and 480 cm.-1 The final states of all these bands will be repulsive, and they are attributed to just these states which are theoretically possible. Besides these bands, there are nine broad bands whose mutual vibrational frequencies are so irregular that they cannot be considered as belonging to a single group arising in a single transtion. These bands are explained as arising in a state 1u (3Σu+) and having for their final levels nine repulsive states which are identified with just the theoretically possible ones. The approximate position of these four states 1g (3Π1 g), 1g (1Πg), Π2,1 g and 1u (3Σu+) are at 55534, 61444, 66500 and 47000 cm.-1, whereas for iodine they are at 51583, 58572, 56000 and 44900 cm.-1 © 1947 Indian Academy of Sciences.PublicationArticle Fritschiella tuberosa iyeng(Oxford University Press, 1947) Rama Nagina Singh[No abstract available]PublicationArticle PublicationArticle