Showing papers by "Indian Institute of Technology Madras published in 1982"
TL;DR: In this article, the hydrogen reduction of pure α-Fe 2 O 3 doped with foreign metal oxides employing a sensitive micro-gravimetric technique was carried out by a consecutive two-step mechanism via Fe 3 O 4, the overall rate being controlled by the topochemical reduction of Fe 3 o 4 while that of doped oxides and hematite ore takes place by a different mechanism involving the mixed ferrite formed.
119 citations
TL;DR: In this paper, a scheme for stereoscopic 3D colour TV employing mostly the conventional 2D color TV trasmitter and receiver is described, where left and right eye view images of the object registered in two colour TV cameras are trasmitted, received and displayed in two miniature picture tubes fixed on the respective eyes of the viewer to visualize the depth effect.
Abstract: A Scheme for stereoscopic 3-D colour TV employing mostly the conventional 2-D colour TV trasmitter and receiver is described. The left and right eye view images of the object registered in two colour TV cameras are trasmitted, received and displayed in two miniature picture tubes fixed on the respective eyes of the viewer to visualize the depth effect. Four methods of realization of such a scheme compat ble to the conventional 2-D colour TV standards are illustrated and compared for their relative merits and demerits.
83 citations
TL;DR: An overview of the semiconductor based photoelectrochemical (pec) cells for solar energy conversion is presented in this article, where the principles involved, electrode and electrode/electrolyte interface characteristics, experimental methods of investigation and energy conversion efficiency are discussed in detail.
Abstract: An overview of the semiconductor based photoelectrochemical (pec) cells for solar energy conversion is presented.pec cells are of two types: photoelectrolysis cells and photovoltaic cells. The principles involved, electrode and electrode/electrolyte interface characteristics, experimental methods of investigation and energy conversion efficiency are discussed in detail. Up-to-date data on variouspec cells are also presented and discussed.
73 citations
TL;DR: In this paper, a conventional single cylinder, four-stroke diesel engine has been converted to work on the dual-fuel principle with hydrogen as the inducted fuel and the main objectives of the investigation were to determine the optimum proportions between hydrogen and diesel oil under various engine operating conditions and to study the combustion process in the engine under these conditions.
72 citations
TL;DR: In this article, the sound transmission through an infinite sandwich panel with a constrained viscoelastic damping layer was analyzed, and the results showed that the sandwich panel has better sound transmission characteristics than a homogeneous elastic panel of equivalent weight.
51 citations
TL;DR: In this paper, the dynamic axisymmetric behavior of clamped orthotropic shallow spherical shell subjected to instantaneously applied uniform step-pressure load of infinite duration, is investigated, and the resulting modal equations, two in number, are numerically integrated using Runge-Kutta method, and hence the load-deflection curves are plotted.
48 citations
47 citations
TL;DR: A hybrid circuit for producing a three-phase reference sine wave required with PWM inverters is described in this article, which can easily be extended to generate sine waves of any number of phases.
Abstract: A hybrid circuit for producing a three-phase reference sine wave required with PWM inverters is described in this paper. The principle of the circuit is simple and the implementation of the circuit is easy. The circuit has all the features discussed in the literature. The unit built has, apart from the three-phase sine waves, balanced three-phase square and triangular waves. A high-frequency triangular wave already available in the circuit can be used for the PWM control circuitry. The scheme can easily be extended to generate sine waves of any number of phases.
36 citations
01 Oct 1982
TL;DR: In this article, an algorithm for obtaining stable reduced-order models using the combined advantages of the stability-equation method and the modified Cauer continued fraction is proposed, and the reduction procedure is simple and computer oriented.
Abstract: An algorithm is proposed for obtaining stable reduced-order models using the combined advantages of the stability-equation method and the modified Cauer continued fraction. The reduction procedure is simple and computer oriented.
35 citations
TL;DR: The main methods of speckle shear interferometry include Michelson's interferometric arrangement, two or multiple apertures in conjunction with a lens and defocusing, and use of parallel plates and wedges in front of the lens with or without aperture.
Abstract: The main methods of speckle shear interferometry include Michelson's interferometric arrangement, two or multiple apertures in conjunction with a lens and defocusing, and use of parallel plates and wedges in front of the lens with or without apertures. It has been our experience that the partial slope fringes are not localized at the plane of the specklegram in the case when defocusing is used for shear.
31 citations
TL;DR: In this paper, the finite element formulation and equivalent linearization technique used in the study of nonlinear vibrations of beams have been reexamined based on the earlier comments and errors present in the equivalent linearisation procedure, in the substitution of inplane boundary conditions at the element level instead of at the system level, and in the use of different connotation for the frequency, are discussed.
TL;DR: A simple and convenient way to generate stiffness matrices in closed-form for all members of the family of plane triangular elements is presented in this article, where numerical integration is completely avoided.
TL;DR: In this article, the decomposition of isopropyl alcohol was carried out on the solid solution system MgAI2−xFexO4 (x = 0 to 2) and the system exhibited both dehydrogenation and dehydration activities.
TL;DR: In this paper, the initial force fields considered are based on the bending and interaction force constants obtained from the CNDO/Force calculations and the stretching force constants transferred from chemically related molecules.
Abstract: CNDO/Force calculations have been done for formaldehyde, acetaldehyde and acetone, and the theoretical force fields evaluated. Experimental force fields are obtained from vibrational frequencies using the least-squares refinement method. The initial force fields considered are based on the bending and interaction force constants obtained from the CNDO/Force calculations and the stretching force constants transferred from chemically related molecules. Vibrational frequencies of H 2 CO, D 2 CO, HDCO, H 2 13 CO and D 2 13 CO for formaldehyde, CH 3 CHO, CH 3 CDO, CD 3 CHO, CD 3 CDO and CH 2 DCHO for acetaldehyde, and CH 3 COCH 3 CD 3 COCH 3 and CD 3 COCD 3 for acetone are employed in the force field refinements. The final force fields obtained are found to be reasonable with respect to the diagonal and interaction force constants.
TL;DR: In this article, the role of surface irregularities in the production of noise in rolling and sliding contacts was investigated and the noise spectra of rolling contacts were recorded in a small free-field chamber which was specially designed.
TL;DR: In this article, the acid dissociation constants of the above mentioned secondary ligands were determined at 35, 45 and 55°C together with the thermodynamic parameters involved in their ionization reactions.
TL;DR: In this paper, a general construction procedure for geodetic blocks, starting from an arbitrary Geodetic block, is given, which unifies and generalizes many of the known general procedures.
TL;DR: In this paper, the volume changes due to membrane penetration are influenced by the following primary factors: (a) Grain size; (b) effective confining pressure; (c) density index; and (d) geometry of sample.
Abstract: Interpretation of data of the writers and other investigators relating to volume changes due to membrane penetration in sands of different grain sizes has led to the following conclusions: 1. Volume changes due to membrane penetration are influenced by the following primary factors: (a) Grain size; (b) effective confining pressure; (c) density index; and (d) geometry of sample. 2. These volume changes can be predicted with reasonable accuracy. 3. The effect of membrane penetration can be considerably minimized by adopting large diameter test samples, and with other parameters remaining constant. (Author)
TL;DR: In this paper, le diagramme concentration-enthalpie de la combinaison frigorifique a absorption de vapeur (VARS) fonctionnat au R 21-DMF is presented.
Abstract: Resume On presente le diagramme concentration-enthalpie pour la combinaison frigorigene-absorbant R 21-DMF dans un domaine de temperatures valables pour les applications frigorifiques solaires. On effectue une analyse thermodynamique du systeme frigorifique a absorption de vapeur (VARS) fonctionnat au R 21-DMF afin d'etudier les criteres theoriques de performance. A des temperatures d'evaporateur inferieures a 0°C environ, les systemes a R 21-DMF presentent un net avantage par rapport aux systemes a R 22-DMF en ce qu'ils peuvent fonctionner a des temperatures inferieures du bouilleur. On observe aussi que les systemes a R 21-DMF sont plus performants que les systemes a R 22-DMETEG (dimethylether du tetraethyleneglycol).
TL;DR: In this article, the authors presented correlations for the pressure drop, solids concentration and mean holding time of the solids in multistage fluidisation, based on experimental data of the present study and that available in literature covering a wide range in process variables.
Abstract: Correlations for the pressure drop, solids concentration and mean holding time of the solids in multistage fluidisation have been presented based on the experimental data of the present study and that available in literature covering a wide range in process variables.
On presente des correlations relatives a la perte de charge, a la concentration des matieres solides ainsi qu'au temps moyen de retention des solides en fluidisation a etages multiples; elles reposent sur les resultats obtenus dans la presente etude ainsi que sur les donnees disponibles dans la litterature, et portent donc sur une large plage des variables operatoires.
TL;DR: In this article, four sets of NMR signals, two each from 55Mn and 75As nuclei, have been observed, and the authors have shown that there is a phase transition at T 1 ≈ 220 K. This transition may be due to introduction of a local spontaneous distortion in the region of the domain walls in the lattice.
TL;DR: In this paper, experimental studies on the performance characteristics of a horizontal floating plate breakwater are presented, and the results of this two-dimensional model study are for regular waves of shallow and intermediate water depths.
TL;DR: In this article, the results of photoelectrochemical studies carried out with sintered discs of pure Fe 2 O 3 and of Fe 2 o 3 doped with TiO 2, SnO 2, ZrO 2 and Ta 2 o 5 are compared and discussed.
TL;DR: In this paper, the residence time distribution of the solids in multistage fluidisation, wherein downcomers for transferring solids from stage to stage are provided to the horizontal perforated plates, is experimentally investigated covering a wide range in process variables using flat, baffle and spiral plates developed in the study.
TL;DR: In this article, an assessment of the wave power potential along the Indian coastline has been made for different seasons, and the locations off Bombay on the west coast and off Visakhapatnam on the east coast have the greatest potentials.
TL;DR: Cyclohexanone has been used as an acceptor for the dehydrogenation of some natural products in the presence of RuCl2(PPh3)3 as mentioned in this paper.