Browsing by Issue Date, starting with "1950"

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The 14th annual general meeting
(1950) H.N. Roy
[No abstract available]
Studies in crop physiology - On some physiological attributes of transpiring surface in relation to drought resistance in sugarcane
(1950) K.N. Lal; O.N. Mehrotra
[No abstract available]
The Isothermals of Rocksalt from Its Thermal Expansion
(1950) Bisheshwar Dayal
[No abstract available]
Studies in crop physiology - Interrelation between leaf area, leaf indices and drought resistance in sugarcane
(1950) K.N. Lal; O.N. Mehrotra
This paper elucidates the interrelation between leaf area and other leaf characteristics in six varieties of sugarcane grown under field conditions. Relation between these features and drought resistance in sugarcane is also analysed. Drought-resistant behaviour of Rheora is associated with poor leaf surface and small size of leaves. Co 205 approaches this variety most in the characteristics of its leafy growth. Leaf surface expansion is found to be determined by three conditions, namely, increase in (i) leaf length, (ii) leaf width and (iii) dry weight of leaves. High positive correlation between these factors and leaf area indicates that these characteristics are highly correlated. The possibilities of water content showing negative correlation with leaf area is also pointed out. Relation between leaf area and linear measurements of length and breadth is expressed by the following two equations: For a single leaf:- Log A = Log L + Log B + Log K (1) For a population of leaves:- Log Σ A = Log Σ L + Log ΣB + Log K - Log N, (2) where A is leaf area, L = leaf length, B is leaf breadth, K is leaf factor and N is number of leaves. The leaf factor K appears to be an important physiological constant representing the relation between linear growth (L x B) and leaf area. Its relatively low value in drought-resistant Rheora and also in Co 205, as against its relatively high value in other varieties with high leaf indices- Co 290, Co 453, Co 385 and Co 312-is characteristic. © 1950 Indian Academy of Sciences.
Periodic fading of short-wave radio signals
(1950) S.R. Khastgir; P.M. Das
Periodic fading patterns were recorded photographically with Calcutta signals of frequency 4,840 kc/s. received at Dacca (distance 240 km.) during the evening and early night hours of December 1948 and January 1949. The main features in the experimental conditions were: (i) the operating frequency was much less than the maximum usable frequency (M.U.F.) for the F layer transmission, (ii) the frequency was slightly greater than the M.U.F. for the ordinary wave transmission through the E layer and (iii) it was slightly less than the M.U.F. for the extraordinary wave transmission through the E layer between the transmitting and receiving stations. The following patterns of periodic or rhythmic fading were observed: Sinuous fading of comparatively quick period: this is considered to be of magnetoionic origin, due to the interference between the upper and lower trajectory extraordinary waves in the E layer, the ordinary waves having passed through the E layer. Periodic or rhythmic fading of comparatively slow period: the slow periodic fading is considered to be due to the beat-effect between the singly and doubly reflected waves from the F2 region or between the singly reflected waves from the E and F2 regions, the two interfering waves in different directions having suffered different amounts of Doppler change of frequency due to the vertical movement of the ionospheric layer or layers. The vertical velocity of the ionosphere as computed from this view agrees with the observed value. Slow periodic fading with superposed ripples: this was observed when the ionospheric conditions were favourable for the simultaneous occurrence of the magneto-ionic type of sinuous fading and the Doppler beat type of slow periodic fading. In a few patterns of periodic fading there was evidence of extremely high frequencies (4-12 cycles/second) the origin of which is unknown.
Interaction of carbon monoxide and hydrogen under silent electric discharge: Production of formaldehyde - Part II. Influence of temperature
(1950) R.H. Sahasrabudhey; S.M. Deshpande
The study of the interaction of CO and H2 under silent electric discharge yielding fairly good amounts of formaldehyde has been extended to the investigation of the influence of temperature. About 3 litres of gas mixture in the ratio CO:H2 as 1:1 were circulated at the rate of 5 and 8 litres per minute through a Siemens' all glass ozoniser subjected to an A.C. discharge of 7·2 and 9·6 kV respectively, and 500 cycles frequency. The ozoniser was maintained at a given temperature by heating a surrounding water jacket. After six hours' exposure to discharge the washings from the absorbers were estimated for formaldehyde and acidity and the residual gas analysed with an Orsat's apparatus. Experiments were conducted at 25, 45, 60 and 80° C. Although an overall increase in the total reaction is indicated with increasing temperature, the net yield of formaldehyde, but for a slight increase at 80° C. which is perhaps due to the depolymerising effect at high temperature, is almost a constant quantity. Since very small quantities of CO2 and unsaturated hydrocrbons are indicated in the residual gas and the proportion of CO:H2 in it remains almost the same as the original one, it is concluded that formaldehyde is formed according to the reaction CO+H2→HCHO. © 1950 Indian Academy of Sciences.
Reclamation of 'Usar' lands in India through blue-green algæ
(1950) Rama Nagina Singh
WHILE other plants, including crops, fail to grow on the alkaline 'Usar' lands of northern India, blue-green algæ form a thick stratum on the surface of the soil during the rainy season (from July to September) and during the retreating monsoon (December-January). The most important algæ are species of Nostoc (N. commune, N. muscorum, N. punctiforme), Scytonema (S. ocellatum, S. javanicum), Microcoleus (M. chthonoplastes, M. vaginatus), Porphyrosiphon (P. Notarisii), Camptylonema (C. lahorense), and Cylindrospermum (C. licheniforme, C. muscicola). In later stages, when the soil is waterlogged, forms like Aulosira fertilissima, various species of Anabœna, Cylindrospermum gorakhporense and Wollea Bharadwajœ make their appearance. Nostoc commune, which covers many miles, fulfils an especially striking role. The annual addition of organic matter to the soil is of the order of 36.5-59.7 per cent and that of nitrogen, 30-38.4 per cent. Although the nitrogen-fixing capacity of Nostoc commune and of other species is still being investigated in bacteria-free cultures, results so far obtained suggest such fixation, which has already been established in certain forms1-4. The numbers of Azotobacter appear to be considerably reduced in these soils. © 1950 Nature Publishing Group.
Studies on the dependence of optical activity on chemical constitution - Part XXXV. The rotatory dispersion of 5-quinolinoimino and amino-camphors (d and dl)
(1950) Bawa Kartar Singh; Narinder Singh Kapur
(1) The rotatory dispersion of 5-quinolinoimino-d-camphor and 5-quinolinoamino-d-camphor is found in different solvents to obey Drude's one term equation, {Mathematical expression}, it is, therefore, "simple". (2) The sequence of rotatory power of 5-quinolinoamino-d-camphor in different solvents runs in the reverse order of the dielectric constants of the solvents and that in the case of 5-quinolinoimino-d-camphor follows the same order of the dielectric constants except with minor discrepencies. (3) The influence of quinoline and naphthalene ring on the rotatory power has been considered. (4) The reduction of 5-quinolinoimino-d-camphor to 5-quinolinoamino d-camphor resulting in a great lowering of its rotatory power, has been discussed. (5) The nature of the racemic form has also been investigated. (6) The d-and dl-forms of 5-quinolinoaminocamphor are found to exhibit phototropy in chloroform solution. © 1950 Indian Academy of Sciences.
Production of an irreversible joshi effect in the hysteresis-range below the threshold potential
(1950) B.R. Marathe; S.S. Bommannavar
THE fundamental importance of the threshold potential Vm in the production of the Joshi effect Δi and the preferential incidence of the latter in the high-frequency components of the discharge current have been established1-6. Results were suggestive when Δi was studied in chlorine at and below Vm. Until this latter is reached, the current is small, say, i1; it increases suddenly by a large amount at V m, and rises rapidly thereafter. On decreasing the voltage below Vm, it decreased gradually to i1 at V1 (see graph). CA denotes iD, the current in the dark when the voltage is reduced below Vm, and DE the corresponding current iL under irradiation. The larger current (in the dark) while decreasing below the voltage Vm is due to hysteresis. © 1950 Nature Publishing Group.
Some studies on the influence of spacing, seed piece and manuring on the yield of potato crop
(1950) S.L. Kapoor
1. Yield increases with more manure, larger size of seed piece and closer spacing between hills. Maximum increase is noticed under manuring factor. 2. Size of seed piece affects the yield but the degree of effectiveness varies with the level of manuring. At high manuring size of seed piece proves less effective and the difference in yield from 5, 10 and 20 gm. seed piece is relatively small. 3. As regards planting distance, a spacing of 8 inches is more suitable at low and medium manuring and with high manuring, close planting gives more yield. 4. Size of potato improves by heavy application of manure, using small seed pieces in comparison to large sets and adopting wider spacing between hills. 5. It is concluded that potato growing is not profitable under conditions of poor manuring. When manuring is moderate, the use of 10 gm. set sown 8 inches apart is more desirable and with heavy manuring 5 gm. seed piece sown 4 inches apart proves more useful. © 1950 Indian Academy of Sciences.