Volume

Volume 12 - Year :1962

(50)

Issue 3-July 1962

(19)

	On noise figures in transistor audio amplifiers Author : Rao, E. Bhagiratha Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 1-10 Subject : 534.8 Acoustics Keywords : Frequency ;Collector voltage ;Collector current ;Emitter current ;Input impedance Abstract : The noise figures of two general purpose transistors of Philips and Hitachi (Japanese) make have been determined under identical experimental conditions with a view to see whether they differ in their noise properties. The variation of noise figure of Philips as well as Hitachi transistors with (i) frequency (ii) collector voltage (iii) collector current (iv) emitter current (v) input impedance have been investigated. It was concluded that Philips and Hitachi transistors do not differ much in their noise properties, when operated under identical conditions. For both the transistors the noise figure increase with collector voltage, collector current and emitter current. Increasing input impedance of either of the transistors increases the noise figure when the input impedance exceeds two thousand ohms. For both transistors the noise figure decrease with frequency, then remains constant over a small frequency band and finally increases slowly with frequency.
	Variation of burning surface area for multitubular charges Author : Jain, B.S Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 205-240 Subject : 623.4 Armaments and Ballistics;623 Military Science and Engineering Keywords : Multitubular charges Abstract : In continuation of the earlier work already published the variation of burning surface are for multi-tubular charges is discussed in this paper.
	Volatile corrosion inhibitors Part II: amine salts and amine adsorbed cation-exchangers Author : Rajagopalan, K.S. ;Gupta, S.K. ;Khanna, V.P. ;Sanyal, B. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 21-30 Subject : 621.78.019.84 Corrosion Keywords : Corrosion ;Amine salts ;Cation-exchangers ;Nitrites ;Carbonates ;Amine adsorbed Abstract : Amine salts and amine adsorbed cation-exchanger have been examined to ascertain their vapour phase inhibition property for protection of metals against corrosion.The investigation has shown that amine adsorbed cation-exchangers are efficient inhibitors. They can be conveniently handled unlike free amines, are less harmful to non-ferrous metals and possess a longer life. Amine nitrites and carbonates which are well known volatile corrosion inhibitors, have shown good results. Amine benzoate's and stearates have been found to provide good inhibition under milder test conditions but failed in severe exposure conditions.
	Statistics tolerances on built up guns. Author : Sirpal, J.P. ;Subramanian, A.M Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 241-244 Subject : 623.4 Armaments and Ballistics;623 Military Science and Engineering Keywords : Guns ;Production Abstract : The strength of built up guns depends on the shrinkages allowed between cylinders and therefore for a given strength, the assembly is either selective or the nominal sizes are so chosen as to give the required shrinkage for a worst combination, it can be seen from the analysis that with little disadvantage tolerances can be greatly increased assuming random assemblies of parts whose sizes follow a normal pattern. This can bring down production costs considerably.
	Some integrals involving three Bessel functions. Author : Bhatnagar, R.K. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 245-249 Subject : 51 Mathematics Keywords : Mathematics Abstract : Abstract not available.
	A method for testing rangefinder collimator in respect of parallelism of beams in the directions of coincidence and halving. Author : Datta , K.P. ;Sinha, R.C.P. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 251-252 Subject : 681.783.2 Laser Range Finder Keywords : Collimators ;Beams Abstract : A method has been described for testing simultaneously the two beams of a Rangefinder Collimator in the direction of coincidence and halving.
	A simple non destructive method for the determination of the refractive indices of finished lenses. Author : Rao, V. Ramakrishna ;Mehta, K.R. ;Joshi, B.C. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 253-255 Subject : 535 Optics;53 Applied Physics Keywords : Refractometry ;lenses Abstract : A simple and rapid method for the determination of the refractive indices of finished lenses has been described which depends upon immersion refractometry. Observations taken on some lenses of known material to establish the validity of the method have also been reported.
	Ultra high strength in steel. Author : Parameswaran, V.R. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 256-263 Subject : 669 Metallurgy Keywords : Ausforming ;Quenching ;Thermal-Mechanical Abstract : Very high strength levels in steel, not obtained by conventional methods of hardening by quenching and low temperature tempering, are obtained by mew hardening techniques involving the thermal-mechanical treatment of metastable austenite.The earlier attempts on such hardening techniques and the development of new processes such as 'Ausforming' investigated in the Ford Motor Company Research Laboratories and ''Maraging'' developed and patented by the International Nickel Company (Mond)Limited, are briefly reviewed here.
	Apparatus for testing deflection due to thin prisms Author : Dharmayya , S.S. ;Rao, K.Rama Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 264-269 Subject : 53 Applied Physics;535 Optics Keywords : Prisms ;Fabricated Abstract : An instrument for testing deflection due to thin prisms, which has been designed and fabricated at IRDE, Dehradun is described in this paper.
	The rat heart lipase. Author : Scaria, K.S. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 270-284 Subject : 61 Medical Sciences Keywords : Muscle lipase ;Lipoprotein lipase ;Pancreatic Abstract : The properties of rat heart lipase are compared with those of the pigeon pancreatic and breast muscle lipase, In almost all respects these enzymes very much resembles the pigeon breast muscle lipase. The activity of this enzyme is not dependent on any added cations or heparin. It is claimed that these enzyme and the ''lipoprotein lipase'' of literature are one and the same and is identical to the pigeon pancreatic and breast muscle lipase.
	Decomposition of cellulose by the fungus Urvularia Lunata Wakker. Author : Verma, G.M. ;Verma, R.K. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 285-297 Subject : 61 Medical Sciences Keywords : Metabolic liquor ;Curvularia lunata wakker ;Enzymes ;Fungus Abstract : Active celluloytic enzymes have been found in the metabolic liquor as well as en the mycelia mat of the fungus Curvularia lunata Wakker. The properties of the enzymes from the metabolic liquor have been investigated in detail and their purification has been attempted.
	Studies on contact toxicity-part v: residual activity of DDT applied in admixture with glue-dichromate on mud surface. Author : Paul, R.K. ;Perti, S.L. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 298-308 Subject : 632.9 Pest Control Keywords : Gluedichromate ;Musca nebulo ;Mosquitos;Insecticides Abstract : Residual activity of DDT applied in admixture with gluedichromate on mud surface has been investigated against the housefly, Musca nebulo Linn. and the mosquito, Culex fatigans Wied. It has been found that the addition of gluedichromate to DDT dispersion in water or DDT emulsion considerably enhances the residual activity of the insecticide against flies and mosquitoes. The practical value of the results has been discussed.
	Volatile Corrosion Inhibitors Part III: Ammonium stearate and m-Dinitrobenezene Author : Rajagopalan, K.S. ;Gupta, S.K.;Sanyal, B. ;Khanna, V.P. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 31-38 Subject : 621.78.019.84 Corrosion Keywords : Stearate ;Chemical compound ;Ammonium ;Corrosion ;m-dinitrobenzene Abstract : In earlier studies while screening various chemical compound for their vapour phase inhibiting properties. Some ammonium salts and nitro-compounds had shown promising results. Of these, ammonium stearate and m-dinitrobenzene gave the best results in accelerated short term tests. In the present paper a more detailed investigation on the corrosion protection given by them has been made.Ammonium stearate and m-dinitrobenzene, both, have been found to perform satisfactorily under all test conditions except SOsub2 test where m-dinitrobenzene failed. Their indigenous availability, low cost and good corrosion inhibiting properties demands favorable consideration for their adoption as VCIs for general use.
	A new pattern of the periodic table Author : Tripathi, B.N. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 39-44 Subject : 54 Chemistry;546 Inorganic Chemistry Keywords : Periodic table ;Atomic structure ;Neutron ;Helium Abstract : A new pattern of the Periodic Table is described which incorporates all the points for which various models of two or three dimensional tables have been proposed from time to time.
	A note on the estimation of chloracetophenone in mixture Author : Ganguly, S.C. ;Dutta Gupta, B.K. ;Sanyal, B. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 45-46 Subject : 54 Chemistry;547 Organic Chemistry Keywords : Chloracetophenone Abstract : Abstract not available.
	Electrical conductance and pH studies on the composition of copper arsenite (Scheeles Green) Author : Bhadraver, M.S. ;Gaur, J.N. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 47-50 Subject : 546 Inorganic Chemistry;54 Chemistry Keywords : Copper sulphate ;Meta sodium arsenite ;Titrations Abstract : The formation of a coloured complex between copper sulphate and meta sodium arsenite (pH=9.3) has been reported. The composition of scheeles green arrived at by Job's method of continuous variation and pH titrations, is CuOAssub2Osub3 or Cu(AsOsub2)sub2.
	Physico chemical studies on the composition of complex arsenites of metals Part IV: conductometric and potentiometric studies on the composition of cadmium arsenite Author : Bhadraver, M.S. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 51-54 Subject : 54 Chemistry;544 Physical Chemistry Keywords : Physico-chemical ;Complex arsenites ;Cadmium arsenite ;Sodium arsenite ;Cadmium ;Conductometric Abstract : The formation and precipitation of cadmium arsenite has been studied by conductometric and potentiometric titrations between cadmium nitrate and sodium arsenite (meta) at different concentrations with either of the substances used as the reagent in titration. In the case of direct titrations (cadmium nitrate added to sodium arsenite in the conductivity cell), one distinct break in the curves is observed corresponding to the formation of the Cd (AsO/sub 2/)/sub 2/ where the molecular ratio is 2:1. The direct and reverse potentiometric titrations curves give one maxima in dE/dV at point corresponding to the formation of the complex Cd (AsO/sub/2)/sub/2 where the molecular ratio of reactants Cd:AsO/sub/2 is 1:2. The composition has been arrived at by comparing the calculated values with observed values by conductometric and potentiometric titrations. The composition of cadmium arsenite arrived at both by conductometry and potentiometry is best representative as Cd(AsO/sub/2)/sub/2.
	Physico-chemical studies on the composition of thiosulphates of metals Part V: Thermometric studies of bismuth thiosulphate complexes Author : Bhadraver, M.S. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 55-58 Subject : 544 Physical Chemistry;54 Chemistry Keywords : Physico-chemical ;Thiosulphates Abstract : Abstract not available.
	Physico-chemical studies on the composition of complex thiosulphates of metals Part VI: Potentiometric studies on the reaction between cadmium nitrate and sodium thiosulphate Author : Bhadraver, M.S. ;Gaur, J.N. Source : Defence Science Journal ; Vol:12(3) ; 1962 ; pp 59-62 Subject : 54 Chemistry;544 Physical Chemistry Keywords : Physico-chemical ;Thiosulphates ;Cadmium nitrate ;Sodium thiosulphate Abstract : Abstract not available.