Showing papers by "Indian Institute of Technology Kharagpur published in 1970"
TL;DR: In this article, a comparison of the Boundedary-shear-drone-based algorithm with other inDIRECT and indirect methods is made, based on KEULEGAN'S RESISTANCE LAWS.
Abstract: BOUNDARY SHEAR DISTRIBUTION IN BOTH ROUGH AND SMOOTH OPEN CHANNELS OF RECTANGULAR AND TRAPEZOIDAL SECTIONS IS OBTAINED BY DIRECT MEASUREMENT OF SHEAR DRAG ON AN ISOLATED LENGTH OF THE TEST CHANNEL UTILIZING THE TECHNIQUE OF THREE POINT SUSPENSION SYSTEM SUGGESTED BY BAGNOLD. EXISTING SHEAR MEASUREMENT TECHNIQUES HAVE BEEN REVIEWED CRITICALLY. COMPARISON OF THE MEASURED DISTRIBUTION HAS BEEN MADE WITH OTHER INDIRECT ESTIMATES, FROM ISOVELS, AND PRESTON TUBE MEASUREMENTS, BASED ON KEULEGAN'S RESISTANCE LAWS. THE DISCREPANCIES BETWEEN THE DIRECT AND INDIRECT ESTIMATES ARE EXPLAINED. OF THE TWO INDIRECT ESTIMATES THE SURFACE PITOT TUBE TECHNIQUE IS FOUND TO BE MORE RELIABLE. THE INFLUENCE OF SECONDARY FLOW ON THE BOUNDARY SHEAR DISTRIBUTION COULD NOT BE ACCURATELY DEFINED IN THE ABSENCE OF A DEPENDABLE THEORY ON SECONDARY FLOW. /ASCE/
97 citations
TL;DR: In this article, the preparation of salicylaldazinate (SAA) metal complexes of Cu(II, Ni(II), Co(II) and Fe(II).
54 citations
TL;DR: In this article, the authors show that the Dalma band does not occupy the core of a syncline but instead forms a sheet in the folded Archean sequence and the stratigraphic sequence is revised.
Abstract: In the Singhbhum district of Bihar (eastern India) there is a prominent band of metamorphosed basaltic rocks (known as Dalma volcanics) in a complex Archean terrain. Its outcrops were interpreted as the core of a regional syncline and, accordingly, a stratigraphic sequence was erected. We question this interpretation and show by both geological and geophysical investigation that this basaltic band does not occupy the core of a syncline but instead forms a sheet in the folded Archean sequence. On this basis, the stratigraphic sequence is revised.
28 citations
TL;DR: In this paper, the fundamental non-linear coupled equations of large amplitude free vibration of heated circular plates are derived from the energy equations, and the simplified quasilinear, decoupled differential equations for the same case are also obtained by Berger's analysis.
26 citations
TL;DR: In this paper, it is observed that CBS increases the rate of DCP decomposition and decreases the crosslinking maxima due to DCP, leading to zero cross links with high amounts of CBS.
Abstract: Sulfuration by CBS acceleration both in presence and absence of ZnO and stearic acid with or without DCP has been studied in detail. It is observed that CBS increases the rate of DCP decomposition and decreases the crosslinking maxima due to DCP—ultimately leading to zero cross links with high amounts of CBS. In accordance with the observed sulfur decrease, free MBT formation, combined sulfur as MS etc., a predominantly radical mechanism has been presented, presumably not proceeding through intermediate complex formation. In mixes containing DCP together with sulfur, CBS, ZnO, and stearic acid crosslinks are found to be formed nearly additively, further confirmed by methyl iodide treatment of vulcanizates. Attempts have been made to interpret the results in terms of radical and polar mechanisms.
23 citations
21 citations
TL;DR: In this article, the thermal bleaching characteristics of colour centres in CaF2:Mn samples have been investigated and an enhancement of colorability with increasing Mn content and formation of α- and β-bands were observed.
Abstract: Optical absorption in the region 220 to 800 nm and thermoluminescence of X-ray-irradiated CaF2 single crystals were measured. Similar measurements were also taken on manganese-doped CaF2 crystals (with 0.2, 1, and 5 mol% of manganese content). The thermal bleaching characteristics of colour centres in CaF2:Mn samples have been investigated. Two features are observed in manganese-doped CaF2 crystals after X-ray irradiation (in comparison to X-ray-irradiated CaF2): (i) an enhancement of colorability with increasing Mn content and (ii) formation of α- and β-bands in CaF2:Mn (1%) and also new absorption bands in CaF2:Mn (5%). A new absorption band at 300 nm obtained in the X-ray-irradiated CaF2:Mn (5%) may probably be connected with Mn° centres. The thermoluminescence of CaF2 is considerably affected with manganese doping. An attempt has been made to understand these results.
20 citations
TL;DR: In this article, an attempt has been made to fit the data in the inverse logarithmic equation, using the differential form itself, thereby eliminating all the boundary conditions and assumptions which are not always justified.
Abstract: A detailed fundamental investigation of the oxidation of copper in the very thin film range at temperatures below 60°C has been carried out. The results have been analyzed on the basis of Mott and Cabrera's theory of oxidation. Most of the earlier workers have tried to fit in the data in the integrated form of the equation which necessarily involves imposition of certain boundary conditions and assumptions which are not always justified. Hence in the present work, an attempt has been made to fit the data in the inverse logarithmic equation, using the differential form itself, thereby eliminating all the boundary conditions. The accuracy of the procedure used has been checked by back calculation and plotting the theoretical curve with the superimposed experimental points. The different parameters in the equation have been calculated and are found to be in excellent agreement with the theoretical values, thereby supporting Mott's equation quantitatively. The change in rate with temperature has been interpreted as due to the change in the energy of solution of the metal ion in the oxide.
17 citations
TL;DR: In this article, the salient features of both non-elemental sulfur vulcanization by TMTD and elemental sulphur vulcanisation promoted by tMTD both in presence and absence of ZnO and stearic acid have been investigated.
Abstract: The salient features of both non-elemental sulfur vulcanization by TMTD and elemental sulfur vulcanization promoted by TMTD both in presence and absence of ZnO and stearic acid have been s...
17 citations
TL;DR: In this paper, sets of theoretical two-layer master curves, suitable for interpretation of field data involving measurement of the vertical magnetic component of the field induced at the center of a loop placed on a 2-layer earth, have been presented.
Abstract: The paper deals with the early stages of development of a convenient form of electromagnetic induction method of sounding referred to as ‘Central Frequency Sounding’ and abbreviated as CFS. The method is introduced as a rapid and useful technique for investigation of shallow engineering and hydro-geological problems. Sets of theoretical two-layer master curves, suitable for interpretation of field data involving measurement of the vertical magnetic component of the field induced at the center of a loop placed on a two-layer earth, have been presented.
The approximate but reasonably accurate solutions for a two-layer earth of any arbitrary resistivity contrast have been considered for the purpose and expressed in a form suitable for computation. The computed results have been presented in sets of curves useful for interpretation of field data.
17 citations
TL;DR: The metamorphic rocks of the Jutogh Series around Simla, structurally overlying the less metamorphosed rock groups along a thrust contact, have been involved in three phases of deformation and two episodes of metamorphism as discussed by the authors.
Abstract: The metamorphic rocks of the Jutogh Series around Simla, structurally overlying the less metamorphosed rock groups along a thrust contact, have been involved in three phases of deformation and two episodes of metamorphism. The first metamorphism is in the albite-epidote-amphibolite facies in a major part of the area, reaching the amphibolite facies locally in the central part. This metamorphism is late-to post-kinematic with reference to the F
1 movement, the thermal peak having been reached in a post-F
1 pre-F
2 static phase. The second metamorphism, syn-to post-tectonic with respect to F
2 but preceding F
3, is generally in the greenschist facies, and only locally in the albite-epidote-amphibolite facies in the higher structural levels. Metamorphic overprinting has caused widespread retrogression and disequilibrium assemblages. As the large scale recumbent folding and thrusting of F
1 and F
2 phases belong to the Tertiary Himalayan orogeny, the metamorphism in the Jutogh Series could not have been Precambrian in age.
TL;DR: In this article, the actual chronological sequence of the three episodes (Viz. mineralization intrusion, and dregional metamorphism) can be deciphered only through analyses of changes in the fabric, mineralogy, and chemistry of the contact zone and through consideration of heat and mass transfer phenomena across the interface.
Abstract: Relation of orebodies to adjacent dykes, often obscured by their mutual interpenetration along the contact, may be further masked due to the effects of intervening or subsequent regional metamorphism. The actual chronological sequence of the three episodes (Viz. mineralization intrusion, and dregional metamorphism) — an information often crucial from stratigraphic an oregenetic viewpoints — can be deciphered only through analyses of changes in the fabric, mineralogy, and chemistry of the contact zone and through consideration of heat and mass transfer phenomena across the interface. An attempt is made to establish objective criteria for recognition of the actual sequence of events, after examining numerous cases representing almost all possible time-sequence combinations.
TL;DR: In this paper, large amplitude free vibrations of rectangular plates with different boundaries and temperature distributions are analyzed in the light of Berger's analysis using a successive approximate method of Poincare [10, 1] or a modified Galerkin technique.
Abstract: Large amplitude free vibrations of rectangular plates with different boundaries and temperature distributions are analyzed in the light of Berger's analysis. A successive approximate method of Poincare [10, 1] or a modified Galerkin technique is used to derive a Duffing type non-linear differential equation of which the solution is obtained by use of elliptic functions or by the use of method of successive approximation [7, 1]. The subject is treated in a simple and unified manner. Numerical results are obtained for different boundary conditions and are shown in graphical form.
TL;DR: In this article, the results for the accelerating field application are discussed with reference to Mott and Cabrera's parabolic equation for the thin film range, and the changes from logarithmic to parabolic law due to the application of current is probably due to a change in the mechanism of the process.
TL;DR: In this paper, the authors examined the properties of hornblende-orthopyroxene-calcic pyroxene triads, half of them from the type charnockite area near Madras.
Abstract: Hornblende-orthopyroxene-calcic pyroxene-plagioclase (andesine-labradorite) — magnetite-ilmenite±quartz assemblages are evidently the most common granulite facies representatives of basic rocks throughout the world, and they must represent a variance of more than one. Ramberg (1948) invoked an additional degree of freedom arising out of unequal fractionation of Mg and Fe in the ferromagnesian silicates in such rocks. This is examined in detail on the basis of chemical data on twentytwo hornblende-orthopyroxenecalcic pyroxene triads, half of them from the type charnockite area near Madras.
TL;DR: In this paper, the propriety of treating a channel as an equivalent pipe, the use of hydraulic mean radius and the application of pipe resistance laws to channels was investigated, and it was shown that smooth pipe laws cannot be applied to smooth channels without reservations.
Abstract: Experiments were conducted on smooth open channels of different shapes to study the propriety of treating a channel as an equivalent pipe, the use of hydraulic mean radius and the application of pipe resistance laws to channels. The findings indicate that smooth pipe laws cannot be applied to smooth channels without reservations. A new approach has been suggested. The method takes into account the force causing motion, the geometrical parameters of the channel, and fluid properties. It is shown that it is possible to obtain mean velocity values without any need to determine the Darcy-Weisbach friction factor, f , or the mean shear stress along the boundary.
TL;DR: In this article, a procedure to analyze statistically a mixture of two populations that cannot be Separated by usual methods is outlined, where the joint distribution of a suitable character is resolved by Pearson or Rao methods of moments; this gives estimates of the mean and standard deviation of that character for each of the two constituent populations.
Abstract: This paper outlines a procedure to analyze statistically a mixture of two populations that cannot be Separated by usual methods. In such instances, frequency histograms of taxonomically important characters that are normally distributed show the presence of two modes revealing the possible existence of two populations. As a first step in the analysis, the joint distribution of a suitable character is resolved by one of the two, Pearson or Rao, methods of moments; this gives estimates of the mean and standard deviation of that character for each of the two constituent populations. A numerical example explains the computational procedure. Rao's method is easier to use but is applicable only if the two standard deviations are assumed equal. If the distribution of the characters have less than 10-percent overlap, it is possible to make further statistical analysis on the basis of results obtained by either of the two methods. In paleobiometrical work the problem of having a mixed population is fairly common. The procedure outlined in this paper may be utilized in such situations for a better evaluation and interpretation of data.
TL;DR: In this article, an externally pressurized gas journal bearing with multiple supply holes is analyzed theoretically by numerical method of solution The load and flow are predicted by considering both axial and circumferential flow.
Abstract: An externally pressurized gas journal bearing with multiple supply holes is analysed theoretically by numerical method of solution The load and flow are predicted by considering both axial and circumferential flow These load and flow expressed in dimensionless factors are presented for different bearing design parameters The results are compared with the similar available approximate method
TL;DR: A combination of Schwarz-Christofel method and numerical methods of solving nonlinear differential equations has enabled as discussed by the authors to solve for the effect of an anticline on the telluric field and apparent resistivity.
Abstract: A combination of Schwarz-Christofel method and numerical methods of solving non-linear differential equations has enabled us to solve for the effect of an anticline on the telluric field and apparent resistivity. From the computed anomaly curves we conclude that complete information about an anticline can be obtained only if its height is at least thirty per cent of the total depth to the basement. However, partial information; e.g., depth to the top of an anticline, can be obtained even for smaller anticlines.
TL;DR: In this article, the authors have shown that the low temperature magnetic anisotropy data of concentrated salt is consistent with a structural model which assumes that there are two inequivalent sites of Co +2 ions in the unit cell.
TL;DR: In this paper, the expansion coefficients involve generalized hypergeometric series of the 4 F 3 (1) type, which are shown to be multiples of 6-j symbols, and subjecting the variables of a basic state to the appropriate transformation and expanding the function so obtained in a series of basic states.
TL;DR: In this paper, the problem of Cherenkov radiation in anisotropic media is studied in a Lorentz frame in which the charged particle is at rest and the medium is moving with a uniform velocity.
Abstract: The problem of Cherenkov radiation in anisotropic media is studied in a Lorentz frame in which the charged particle is at rest and the medium is moving with a uniform velocity Both electric and magnetic anisotropy are assumed to be present, but the axes of the permittivity and permeability ellipsoids are taken to be parallel to one another The electromagnetic field generated by the charge is described by two scalar potentials Each of these satisfies a partial differential equation of the fourth order when the velocity vector lies in a principal plane of the ellipsoids The two equations closely resemble one another, and passage from one to the other is possible by means of certain simple symmetry operations The equation for the scalar potential of the electric field is solved by the standard technique of Fourier transformation In evaluating the Fourier integrals, however, it is found necessary to assume that two of the ratios $\epsilon \_{i}$/$\mu \_{i}$ of the principal permittivities and permeabilities are equal With this additional restriction the integrals are evaluated easily by the residue theorem and expressions for the field and the radiated energy are obtained in closed forms
TL;DR: In this paper, a mathematical model has been developed to provide the manner in which the inflow stream size at the upstream end of a furrow must be reduced stepwise according to the infiltration characteristics of the soil so as to eliminate runoff losses from the downstream end and keep the deep percolation losses to the minimum.
Abstract: A mathematical model has been developed to provide the manner in which the inflow stream size at the upstream end of a furrow must be reduced stepwise according to the infiltration characteristics of the soil so as to eliminate runoff losses from the downstream end and keep the deep percolation losses to the minimum. Owing to the high infiltration rate in the beginning the initial stream size may be large and kept constant till water reaches the end of furrow length. The total period of irrigation is divided into equal intervals of advance time. Equation for calculating the factors by which the initial stream size should be multiplied to get inflow rates during subsequent time intervals has been developed. Graphs have been presented for simplifying the calculations. The method of practical application of the analysis is illustrated by an example.
TL;DR: In this paper, the authors developed analytically general equations for the velocity of solid particles and pressure drop due to them in 90° horizontal bends during pneumatic conveyance under pseudo-fluid conditions.
TL;DR: In this paper, the distribution coefficients for magnesium-iron point to equilibration under granulite facies metamorphism were found to be of a near invariant nature and the compositions of orthopyroxene and biotite in the nongarnetiferous tonalite are different.
Abstract: Chemical data on eight ferromagnesian silicates from a syenitic and two tonalitic charnockites from the type area near Madras show remarkably regular cation fractionation patterns. The distribution coefficients for magnesium-iron point to equilibration under granulite facies metamorphism. Orthopyroxene-garnet-biotite subsystem has been found to be of a near invariant nature, while the compositions of orthopyroxene and biotite in the nongarnetiferous tonalite are different. Analysis of phase equilibrium by Thompson type AFM projection strongly indicates that pressure, temperature and the chemical potential of water were constant for assemblages separated by large distances.
Journal Article•
TL;DR: In this paper, a map pattern characterized by four-fold hinges is brought out by the swerve of axial planes of these folds from NNE in south-west through E-W in the central part to N-S in southern part in a broad sweep.
Abstract: In the type area of the charnockites, south of the city of Madras, foliation attitudes of marker horizons of leptynites and of basic granulite bands trace a map pattern characterized by four-fold hinges. The overall structure of the area is brought out by the swerve of axial planes of these folds from NNE in south-west through E-W in the central part to N-S in southern part in a broad sweep. The folding is noncylindrical; and a probable structural interpretation, as advanced here, envisages a series of tight isoclinal folds on which a folding around a N-S axial plane has been superposed.
TL;DR: In this paper, the effects of radial clearance, viscosity of the lubricating oil, and inlet pressure, on the oil whip phenomena of flexible rotors were studied experimentally.
TL;DR: In this article, a laboratory study was conducted to find out the effect of temperatures on rice seedling emergence under different levels of bulk density, and aluminum cylinders with top open and bottom provided with a removable 20-mesh brass screen were used as soil containers.
Abstract: A laboratory study was conducted to find out the effect of temperatures on rice seedling emergence under different levels of bulk density. The temperatures ranging from 10 to 40°C in increments of 5°C were maintained constant with ±1°C accuracy. The bulk density levels were 1.3, 1.5, 1.7, and 1.9 g cm−3. Aluminum cylinders with top open and bottom provided with a removable 20-mesh brass screen, were used as soil containers. The moisture content in soil was always above field capacity which could be accomplished by placing the cylinders in a tray in which water level was maintained constant to 5 cm depth.
TL;DR: In this article, the authors investigated the noncyclic squeeze films in full and half journal bearings in the presence of an axial magnetic field and found that the squeezing in a short circuit case is slower than that in an open circuit case.
Abstract: Hydromagnetic noncyclic squeeze films in full and half journal bearings in the presence of an axial magnetic field have been investigated theoretically. Both for full and half journal bearing, it is found that the squeezing in a short circuit case is slower than that in an open circuit case. In both the cases the time of approach is increased by the application of magnetic field.
TL;DR: In this article, a semi-empirically calculated triplet-triplet absorption in benzene has been calculated by considering all single excitations and a limited number of double excitations.