The geology of the manganese ore deposits of talwara,district Banswara,Rajasthan

Talwara (23° 34′: 74° 22′) is a small Manganese-producing locality in the district of Banswara, Rajasthan. From the Banswara Town, Talwara can be reached by a motorable road. In the past, the Manganese ores of the locality have drawn very little attention of the geologists. The ores of Manganese, being associated exclusively with the Aravalli limestone of Rajasthan, occur in the form of scattered masses occupying solution cavities, fissures, etc., in limestone. Aravalli quartzites, conglomerates, phyllites and slates also occur in the vicinity of Talwara. The white limestone with a mosaic structure is of common occurrence and is composed of calcite and dolomite with some magnetite. The impurer varieties of limestone are characterised by the presence of tremolite, hornblende and quartz with a little of biotite. Schistosity is developed only in a calc-amphibole rock having alternating bands of hornblende and limestone. Crush-breccia is noticed occurring in association with manganiferous limestone at a distance of about 2 miles west of Talwara. This breccia might have originated due to severe local crushing of the country-rock. The limestones seemed to be a product of low-grade metamorphism of a calcareous sediment. Fresh ores are generally hard and cavernous but on weathering they become softer and soily. Fragments of unreplaced limestone are occasionally present in the ore-bodies. This limestone has also been replaced by the Manganese ores to a greater or lesser extent, depending on the structural characters of the host rock. The ores are composed largely of massive and colloform cryptomelane. Pyrolusite forms an insignificant part of the ores. There are two generations of cryptomelane, of which, the earlier colloform one is veined by the later generation of cryptomelane. There are also examples of pseudomorphous replacement of limestone by cryptomelane. Most of the pyrolusite was derived from the supergene alteration of cryptomelane. From their nature and mode of occurrence the Manganese ores are classified as outcrop secondary ores formed in cavities in crystalline limestones belonging to the less metamorphosed type of Dharwar.     

Studies of copper minerals in old workings for copper in Yenambail,Khamman District,Andhra Pradesh

The old workings for copper about 2 miles north of Yenambail (Long. 80° 41′, Lat. 17° 41′) in Khammam District were first reported by C. Mahadevan in 1943, while in Hyderabad Geological Survey and later were taken up for detailed prospecting in summer, 1957, by the staff and students of the Geology and Geophysics Departments of the Andhra University. The work was sponsored by the Government of Andhra Pradesh. The formations in this area consist of hornblende schists, phyllites, magnesian limestones and quartzites, striking N.E.-S.W. to N.N.E.-S.S.W., dipping towards west, with concordant intrusions of quartz veins. Some of the quartz veins carry the copper minerals—chalcopyrite, chalcocite and covellite along with other sulphide minerals like pyrite and arsenopyrite. Malachite, azurite and cuprite are conspicuous as thin films and coatings on the surfaces of quartzites and silicified limestones. The ore minerals have been studied both in the field and the laboratory and the results are briefly recorded. The textures are due to replacement and colloform zoning. The paragenetic sequence of the minerals is arsenopyrite, pyrite, chalcopyrite, covellite and chalcocite. Chalcopyrite, pyrite and arsenopyrite are considered to be hypogene and covellite and chalcocite are of supergene origin.     

Studies on lead-zinc mineralization in Karempudi area,Guntur District,Andhra Pradesh

The geological formations near Karempudi area in Guntur District of Andhra Pradesh (Lat. 16° 20′ and 16° 26′; Long. 79° 38′ 40″ and 79° 45′) consist of slaty shales of Cumbum, Irlakonda quartzites, Kolumnala slates and shales with intercalations of siliceous dolomitic limestones and Sreesailam quartzites of Krishna Series, forming a perfect conformable sequence, all the formations striking N.E.-S.W. and dipping on average 25° S.E. The Srisailam quartzites are overlaid unconformably by Palnad limestones (Narjis) of Jammalamadugu stage of Kurnool Series with a constant dip of 8–12° in the same direction. The Krishna Series were subjected to local but intense structural disturbances resulting in an overfold. Subsequent to the overfolding, lead mineralization has taken place in dolomitic limestones. The lead-zinc minerals of Karempudi consist of Galena, Sphalerite, Jamesonite, Tetrahedrite as primary minerals, and Anglesite as secondary mineral; there is association of chalcopyrite with Sphalerite. The textures are due to replacement and unmixing (?). The paragenetic sequence of the minerals is established to be sphalerite, chalcopyrite, galena, jamesonite, tetrahedrite and anglesite. Correlation of field to laboratory studies revealed that the minerals are of hydrothermal (hypogene) origin. The structural and lithological favourability and controlling of the mineralisation are also explained. Anglesite owes its origin to the oxidation of galena due to air-water processes. The mineralization is surmised to have taken place in Pre-Palnads and Post-Krishna times.     

Delayed effects of sudden ionospheric disturbances on 164 Kc/s transmission between Tashkent and Ahmedabad

Continuous recording of the field strength of 164 Kc/s CW transmission from Tashkent (42° N, 69° E) has been going on at Ahmedabad (23° 01′ N, 72° 36′ E) since March 1960. The present communication deals with a delayed effect of S.I.D.’s which has been observed on the 164 Kc/s transmissions.     

Spectrophotometric study of the uranyl-streptomycin complex

Spectrophotometric studies of the yellow coloured complex of uranyl ion with streptomycin have been carried out. The complex absorbs maximum at 420 mµ and at a pH value of 3·5. The composition of the complex has been ascertained employing Job’s method, mole ratio method and slope ratio method and found to be 1:1. The apparent stability constant (logK) and free energy of formation (ΔF) of the complex at 40° C have been found to be 3·37 and ?4·83K cal per mole respectively.     

Vector magnetic field in solar polar region

By means of ‘deep integration’ observations of a videomagnetograph the vector magnetic field was first systematically measured near the solar south polar region on April 12, 1997 when the Sun was in the minimal phase between the 22nd and 23rd solar cycle. It was found that the polar magnetic field deviated from the normal of solar surface by about 42.2° ± 3.2°, a stronger magnetic element may have smaller inclination, and that within the polar cap above heliolatitude of 50°, the unsigned and net flux densities were 7.8 × 10⁻⁴) T and −3.4×10⁻⁴T, respectively, and consequently, the unsigned and net fluxes were about 5.5 × 10²² and − 2.5 × 10²² Mx. The net magnetic flux, which belongs to the large-scale global magnetic field of the Sun, roughly appmaches the order of the interplanetary magnetic field (IMF) measured at distance of 1 AU. Project supported by the National Natural Science Foundation of China (Grant No. 19791090).     

Potential constants,mean amplitudes of vibration,and thermodynamic properties of ethylene oxide,ethylene oxide-d4 and ethylene sulphide

A normal co-ordinate analysis of ethylene oxide, ethylene oxide-d₄ and ethylene sulphide is carried out and the potential energy constants are determined using both the most general quadratic potential function and Urey-Bradley force field. Using the potential energy constants obtained by the former method the mean amplitudes of vibration of these molecules are calculated by the secular equation method. The thermodynamic properties of these molecules are reported for the ideal gaseous state at one atmosphere pressure for eleven temperatures from 100° K. to 1000° K.     

Directional variation of geomagnetic cut-off rigidity around Hyderabad,India

The geomagnetic cut-off rigidities for cosmic ray particles arriving at the top of the atmosphere over Hyderabad, India (geographic latitude 17.6°N. and longitude 78.5° E.), as a function of zenith and azimuthal angles and the vertical cut-off rigidities for a few neighbouring locations, have been made using the sixth degree simulation of the geomagnetic field by the C.D.C. 3600 Computer.     

Spectrophotometric investigation of beryllium-2-hydroxy chalcone complex

2′-Hydroxy chalcone gave an intense orange-yellow color with beryllium in the pH range 5·5–6·2. The limits of identification and dilution were 0·125γ and 1:4 × 10⁵ respectively. A detailed spectro-photometric investigation of the color reaction was carried out. The complex obeyed Beer’s Law in the concentration range of 0·5–6·0p.p.m. at 460 nm. In the complex the ratio of metal to ligand is 1:2. The instability constant of the complex was 2·176 × 10^?6 at 28°. Oxalate, tartrate, citrate and fluoride interfered. The tolerance limits of iron, aluminium, chromium, uranium, thorium and vanadium are reported.     

The equatorial anomaly in ionospheric total electron content and the equatorial electrojet current strength

Faraday Rotation of 40 and 41 MHz signals from the satellite BE-B (Explorer 22) recorded simultaneously at Ahmedabad (dip 34° N) and Kodaikanal (dip 3·4° N) during the years 1964–69 are used to derive the latitudinal profiles of Total Electron Content (TEC) over the Indian equatorial anomaly region. From these profiles the diurnal development of the equatorial anomaly and its correlation with equatorial electrojet strength are studied. The anomaly is found to maximise around 1400 LT,i.e., two-three hours after the electrojet attains its peak. The anomaly parameters such as the dip latitude of the anomaly peak,φ, the normalised depth,d, of the anomaly and the strength of the anomaly defined asS=? _xd are found to be well correlated with the electrojet strength.     

Some studies on wave refraction in relation to beach erosion along the kerala coast

Using the British Admiralty bathymetric charts off the West Coast of India and employing the graphical method of constructing wave refraction diagrams, an attempt is made to study the behaviour of the shortperiod waves (4, 5 and 6 seconds) which are found to affect the coast generally in the neighbourhood of Cochin Port entrance. Nineteen stations, at intervals of roughly one mile, are chosen around the three-fathom line in this area. Considering a probable field of approach of deep-water waves, limited to a cone of 90°, five directions of approach are chosen at intervals of 22 1/2;° in the range of 202 1/2° to 292 1/2°. Refraction diagrams are prepared for these directions and periods, and from these, the refraction functions and directional parameters are evaluated for each station. The possible directions of flow of long-shore current and the areas vulnerable to erosion and sedimentation are investigated.     

Bounds,monotonicity, uniqueness,and analytical calculation of a class of similarity solutions for the fluid flow over a nonlinearly stretching sheet

Invoking some estimates obtained in [F.T. Akyildiz et al., Mathematical Methods in the Applied Sciences 33 (2010) 601–606] (which presented an alternate method of proof for the present problem), we correct the parameter regime considered in [R.A. Van Gorder, K. Vajravelu, and F. T. Akyildiz, Existence and uniqueness results for a nonlinear differential equation arising in viscous flow over a nonlinearly stretching sheet, Applied Mathematics Letters 24 (2011) 238–242] and add some details, which were omitted in the original proof. After this is done, we formulate a more elegant method of proof, converting the nonlinear ODE into a first nonlinear order system. This gives us a more natural way to view the problem and lends insight into the behavior of the solutions. Finally, we give a new way to approximate the shooting parameter α = f ′ ′ (0) analytically, through minimization of the L²([0, ∞ )) norm of residual errors. This approximation demonstrates the behavior of the parameter α we expect from the proved theorems, as well as from numerical simulations. In this way, we obtain a concise analytical approximation to the similarity solution. In summary, from this analysis, we find that monotonicity of solutions and their derivatives is essential in determining uniqueness, and these monotone solutions can be approximated analytically in a fairly simple way. Copyright © 2014 John Wiley & Sons, Ltd.     

Mathematical model of the oxidation of a uranium carbide fuel pellet including an adherent product layer

Uranium carbide is a candidate fuel for Generation IV nuclear reactors. However, like any candidate fuel, a reprocessing route should be established before implementation. One proposed method involves a pre-oxidation step, where the carbide fuel is oxidized to an oxide and then reprocessed as normal. A mathematical model has been developed to simulate such an oxidation using finite difference approximations of the heat and mass transfer processes occurring. Available literature was consulted to provide coefficients for the reaction rates and importantly the diffusion of oxygen through the adherent oxide layer that forms on the carbide: the rate limiting step. The transient temperature, oxygen and carbon monoxide distributions through the system are modeled in order to predict oxidation completion times and the temperatures reached. It was found that for a spherical pellet of radius 0.935 cm, the oxidation can take from 1 to 19 h depending on the oxidation conditions and reach temperatures of up to 1556 °C. A robust model results that offers increased understanding of a process crucial to the sustainable use of carbide fuels in energy generation.     

Modelling a copper electrowinning cell based on reactive electrodialysis

This work reports the development of a mathematical model for the operation of a laboratory-scale copper electrowinning cell based on reactive electrodialysis (RED). Data were obtained from experiments and from the literature. The cathodic reaction was copper electrodeposition and the anodic reaction was ferrous to ferric ion oxidation. The catholyte was aqueous cupric sulphate in sulphuric acid and the anolyte was aqueous ferrous sulphate in sulphuric acid. An anion membrane separated anolyte from catholyte while keeping a conductive path between them. The model includes (a) the cathodic and anodic kinetics, (b) the speciation of catholyte and anolyte and (c) ion transport through the membrane. The computer code was implemented in MATLAB software. The model was calibrated and validated and its predictions are in good agreement with experimental results for: amount of deposited copper, amount of produced Fe(III) species, cell voltage and specific energy consumption.     

Principal ideal theorems in the genus field for absolutely abelian extensions

This paper has the following contents. 1°. In an abelian extension field K over the rational number field, any ambiguous ideal is a principal ideal in the genus field in the wide sense. 2°. A number theoretical proof of the following. In a cyclic extension field K over the rational number field, any ambiguous class ideal is a principal ideal in the genus field in the wide sense.     

Quaternionic Manin symbols, Brandt matrices, and Hilbert modular forms

In this paper, we propose a generalization of the algorithm we developed previously. Along the way, we also develop a theory of quaternionic -symbols whose definition bears some resemblance to the classical -symbols, except for their combinatorial nature. The theory gives a more efficient way to compute Hilbert modular forms over totally real number fields, especially quadratic fields, and we have illustrated it with several examples. Namely, we have computed all the newforms of prime levels of norm less than 100 over the quadratic fields and , and whose Fourier coefficients are rational or are defined over a quadratic field.

     

Orthogonality Matrices for Modules over Finite Frobenius Rings and MacWilliams' Equivalence Theorem

MacWilliams' equivalence theorem states that Hamming isometries between linear codes extend to monomial transformations of the ambient space. One of the most elegant proofs for this result is due to K. P. Bogart et al. (1978, Inform. and Control37, 19–22) where the invertibility of orthogonality matrices of finite vector spaces is the key step. The present paper revisits this technique in order to make it work in the context of linear codes over finite Frobenius rings.     

Emission spectrum of bromine excited in the presence of argon

The wavelengths and wavenumbers of the band heads of the system 3150–2970 Å as obtained from the plates taken on the first order 21′ grating spectrograph are given along with the vibrational analysis. This system is shown to be due to a transition from an upper electronic state at T_e = 48516 cm.^-1 with ω′ _e = 162·0 cm.^?1 and ω′ _e χ′ _e = 0·29 cm.^?1 to the well-known³ Π _u (O _u ⁺) state at T_e = 15918 cm.^-1 This lower state is common with that of the system 2950–2670 Å.     

A new symmetric design with parameters (176, 50, 14)

A new symmetric non‐self‐dual design with parameters (176, 50, 14) is constructed, where its full automorphism group of order 1000 is a faithful extension of the non‐abelian group of order 125 and exponent 5 by the cyclic group of order 8. © 2000 John Wiley & Sons, Inc. J Combin Designs 8: 387–390, 2000