 | Inertia Effects of Squeeze Films between Two Parallel Plates Author : Kapur, V.K. Source : Defence Science Journal ; Vol:18(3) ; 1968 ; pp 111-124 Subject : 621 Mechanical Engineering Keywords : Elliptical Plates Abstract : In this paper, a theoretical study of effects in squeeze films between rectangular and elliptical plates in the presence of transverse magnetic field has been made. It is shown that lead capacity and time of approach, for sufficiently large M/Sub0, increase as the interia increases sufficiently. |
 | Siacci Approximation to the Mean Twisted Trajectory of a Projectile Author : Rath, P.C.;Vasudevan, R.;Kumar, V. Source : Defence Science Journal ; Vol:18(3) ; 1968 ; pp 125-134 Subject : 531.55 Projectiles Keywords : Dynamical Equations;Spinning Shell Abstract : In this paper, we have integrated the dynamical equations of the mean twisted trajectory of a spinning shell in terms of step functions similar to those of Siacci. The air resistance is assumed to be a known tabulated function of Mach number. Using our solutions we have calculated the drift of a 3 inch 16Ib. shell which agrees well with the observation. The corrections arising in the various elements of the trajectory are also calculated. |
 | Experimental Study on the Influence of the Spatial Distribution of Grains on the Graininess of Photographic Films Author : Som, S.C.;Basu, Uma;Ghosh, A.K. Source : Defence Science Journal ; Vol:18(3) ; 1968 ; pp 135-140 Subject : 77 Photography Keywords : Photographic Films;Psychometric Method Abstract : An experimental investigation has been conducted to determine the influence of the spatial distribution of grains on the graininess of photographic films. This has been done using model photographic films and a psychometric method of assessment of graininess. It has been shown, within the inherent limitations of the present experiment, that the spatial distribution of grains significantly influence the perception of graininess. |
 | Solidification of a Liquid Sphere with a given Heat Flux at the Surface Author : Lal, Jangi;Ahuja, K.L. Source : Defence Science Journal ; Vol:18(3) ; 1968 ; pp 141-146 Subject : 536 Thermodynamics Keywords : Inward Freezing;Parameter Temperature Profile Abstract : The method of the heat balance integral is used to investigate of a problem involving the inward freezing of a liquid sphere. The solidification is effected under the assumption of constant heat flux from the surface. Solutions are presented by considering a two parameter temperature profile and the position of the front is expressed in the form of a series in time parameter. Finally the results are graphically exhibited. |
 | Launch Angles with Optimum Trajectories for Rocket interception at Preassigned Destinations Author : Srivastava, T.N. Source : Defence Science Journal ; Vol:18(3) ; 1968 ; pp 147-160 Subject : 629.76 Rockets and Missiles Keywords : Optimal Path;Coaxial Orbits;Earth Mars Transfer Abstract : The problem of interception of a rocket vehicle by optimal path at a preassigned point on the destination orbit by a commuter rocket vehicle launched from the peri centre of the launch orbit is solved by evaluating launch angle and orbital parameters of the transfer trajectory. The analysis is general in so far as it can be applied to any system non coaxial coplanar elliptic orbits under all gravitational fields. The equations have been reduced for axially aligned launch and destination orbits; various particular cases of coaxial orbits are analysed. Interception through Hohmann transfer trajectories have also been considered. The theory illustrated by taking a practical case of Earth Mars transfer. |
 | Application of Discrete Maximum Principle to Optimization Problem of Multiple Stage Rockets Author : Tawakley, V.B.;Jain, S.C. Source : Defence Science Journal ; Vol:18(3) ; 1968 ; pp 161-172 Subject : 629.76 Rockets and Missiles Keywords : Gravity;Optimization Abstract : The Discrete Maximum Principle has been applied to solve a few optimization problems of multiple staged rockets by including the gravity into the performance equations. The problem of finding the minimum mass in order to obtain a specified velocity at the end of powered phase has been solved under various assumptions about the structure factors both when the stages are arranged in series as well as in parallel. The problem when the objective function to be minimised is the cost per pound of the payload has also been investigated. |
 | Shear Strength of Fresh Snow Author : Sharma, H.D.;Yadav, M.P.;Sharma, B.M. Source : Defence Science Journal ; Vol:18(3) ; 1968 ; pp 173-178 Subject : 551.32 Glaciology Keywords : Cohesion;Grouser Plates ;Snow Abstract : The paper reports a new apparatus for determining the cohesion , 'C' and friction phi for fresh snow. The values of 'C' and phi are measured under different of snow with different grouser plates, values of which are found to be 0.11Ib/sq in and 40 degree respectively. |
 | Sandwich Structure Author : Rao, K. Jayathirtha Source : Defence Science Journal ; Vol:18(3) ; 1968 ; pp 179-184 Subject : 621 Mechanical Engineering Keywords : Honey Comb Structure;Sandwich Structure Abstract : This paper deals with the theory, functions and certain design considerations of the sandwich. The various materials used in the construction of sandwiches are mentioned and the honey comb is explained. Their merits, drawbacks and applications in various fields are given. |
 | Yield of Fumaric Acid from Different Carbohydrates by Stationary Surface Culture Method Author : Saijwani, Maya;Aggarwal, P.N. Source : Defence Science Journal ; Vol:18(3) ; 1968 ; pp 185-192 Subject : 577 Biochemistry;57 Biological Sciences Keywords : Rhizopus Arrhizus;Bhizopus Nigricans;Deionized Bagasses Hydrolysate Abstract : Studies on the yield of fumaric acid by Rhizopus arrhizus and Bhizopus nigricans using glucose, sucrose, xylose,cane molassess and bagasse hydrolysate either alone or in combination with glucose were undertaken. Thirty three and 26 per cently yield of fumaric acid were obtained from 12 and 10 per cent glucose media respectively, in 15 days at 33 degree calcius by stationary surface culture method. Higher yields of fumaric acid were obtained from glucose using R. arrhizus. Ability of this organism to produce fumaric acid from media containing (i) 50:50 glucose and deionized bagasse,hydrolysate (ii) deionized bagasse hydrolysate, and (iii) clarified cane molasses was investigated. A 7 per cent yield of fumaric acid was obtained from 50:50 glucose and deionized bagasse hydrolysate medium. In the case of xylose good growth of the fungus was obtained but no fumaric acid was produced. These studies have indicated that R. arrhizus is not able to utilize pentose sugars. |
 | Synthesis of 2,4 Diamino 5 Phenylthiazole Hydrochloride Author : Singh, J.M.;Chaudhary, Govind Rai Source : Defence Science Journal ; Vol:18(3) ; 1968 ; pp 193-194 Subject : 547 Organic Chemistry Keywords : Daptazole;Acetonitrile;Benzenesulphonate Abstract : A process for the synthesis of 2,4-diamino-5-phenylthiazole hydrochloride starting from Alpha chloro Alpha phenyl acetonitrile has been developed. Alternative method for the synthesis of 2,4-diamino-5-phenylthiazole hydrochloride from Alpha cyanobezyl benzenesulphonate has also been developed. The drug is known in trade as "Daptazole". |