B N Desai
Articles written in Proceedings – Section A
Volume 4 Issue 4 October 1936 pp 468-479
Changes in the conductivity and colour of silver chromate in gelatine solution have been studied. It is observed that by suitable adjustment of the (i) temperature of the experiments, (ii) pH of gelatine, (iii) concentration of the reactants (AgNO3 and K2CrO4) and (iv) amount of gelatine, the conductivity may (
In the end we would like to mention that our preliminary experiments on the precipitation of lead iodide in agar have shown that the (
Volume 4 Issue 5 November 1936 pp 503-513
Measurements of conductivity and cataphoretic speed of pure Benzopurpurin 4B, Congo Red and Sky Blue F.F. have been made and it is found that on increasing the concentration of the dye solutions although the equivalent conductivity continuously decreases the cataphoretic speed increases regularly. The cataphoretic speed of Benzopurpurin 4B first increases and then decreases with the progress of dialysis. On adding small increasing amounts of sodium chloride to Benzopurpurin 4B and Congo Red and barium chloride to Sky Blue F.F. the cataphoretic speed first increases and then decreases. The changes in conductivity and cataphoretic speed are explained on the basis of aggregation of the dye ions to form ionic micelles. It is shown that the process of dyeing of cotton fibre by substantive dyestuffs in the presence of salt can be easily understood on the basis of aggregation of dye ions.
Volume 4 Issue 5 November 1936 pp 590-602
Volume 10 Issue 5 November 1939 pp 344-358
Adsorption of some dyestuffs of the Naphthol AS series by cotton fibre has been studied in the presence of alcohol, sodium hydroxide, sodium chloride, sodium sulphate, sodium phosphate, soap, gum tragacanth and agar-agar and at different temperatures to understand the mechanism of the process of dyeing.
It is observed that adsorption of the dyestuffs decreases with increasing amount of alcohol, gum tragacanth and agar-agar, while it first increases, reaches a maximum and then decreases on adding increasing amounts of sodium hydroxide, sodium chloride, sodium sulphate, sodium phosphate and soap solutions. Regarding the effect of temperature on adsorption, it is found that (1) the rate of adsorption is greater at higher than at lower temperatures, (2) the equilibrium adsorption increases with the rise of temperature, and (3) the amount of increase of adsorption for a particular range of temperature is greater at lower than at higher temperatures.
The results obtained become easily intelligible if it is assumed that the dye particles exist in colloidal condition and the process of dyeing is interpreted from that point of view.
Volume 13 Issue 2 February 1941 pp 100-107
The changes in the cataphoretic speed, stability and conductivity of colloidal zinc ferrocyanide dialysed, diluted, allowed to age and exposed to sunlight for different periods have been studied.
With the progress of dialysis the cataphoretic speed first increases and then decreases, while the stability and conductivity continuously decrease.
In the case of sols dialysed for periods shorter than the maximum in the cataphoretic speed-dialysis curve, the cataphoretic speed first increases and then decreases on dilution, while for sols dialysed for longer periods the cataphoretic speed continuously decreases. The stability and conductivity, however, continuously decrease on dilution in all the cases.
It is found that for short period dialysed sols, the cataphoretic speed first increases and then decreases on adding small increasing amounts of KCl, K2SO4, K4Fe (CN)6, MgCl2 and MgSO4; for long period dialysed sols the cataphoretic speed continuously decreases with all the electrolytes except K4Fe (CN)6 where it first increases and then decreases. The idea of critical potential is not supported.
On allowing both the short period and long period dialysed sols to age or exposing them to sunlight, the cataphoretic speed, stability and conductivity continuously decrease.
The results are interpreted by means of assumptions similar to those employed in the case of the other colloidal solutions investigated in this laboratory.
Volume 66 Issue 6 December 1967 pp 306-318
A review has been made of the ideas about the south-west monsoon upto 1963 and the modifications necessary in the same in the light of the results of the International Indian Ocean Expedition (IIOE) during 1963–64. Important papers on the IIOE results published in India and elsewhere have been discussed in brief from the point of their usefulness in forecasting, indicating in what respects the interpretations are against weather, climatic and topographical features of the Indo-Pakistan subcontinent. Taking into account the presence of the Western Ghats, changes which occur within about 500 km. of the west coast of the Peninsula regarding clouds and weather and depth of the moist current brought to light by the IIOE results, become intelligible. There are no cyclonic circulations in the north-east Arabian Sea and Bombay area and in the South Bay of Bengal of the type of ‘subtropical cyclone’ in the eastern Pacific; existence of the same has been postulated due to inadequate appreciation of the Indian conditions by the workers concerned.
Volume 68 Issue 2 August 1968 pp 103-107
Views of Flohn (1965, 1966) and of Ramage (1966) regarding the causes of aridity and inversion over the desert areas of West Pakistan and neighbourhood have been examined. It is shown on the basis of climatic features of the area that the inversion is due to air masses and
Volume 69 Issue 1 January 1969 pp 1-6
Soundings over the Arabian Sea during the International Indian Ocean Expedition period and climatological data over the west coast of India have been discussed to determine the cause of the low-level inversion and the influence of the Western Ghats on the inversion and precipitation. There does not appear relation between maximum divergence and lowest height of base of inversion as presumed by Flohn
The air-mass considerations to explain the low-level inversion over the Arabian Sea, would appear substantially valid even now.
Volume 82 Issue 1 July 1975 pp 31-35
Meteorological conditions prevailing over and west of Bombay on the four days on which Bhat