Browsing by Issue Date, starting with "1972"

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Stacking‐faults in deformed molybdenum diselenide (MoSe2)
(1972) R. Pratap; D.L. Bhattacharya
Faulting studies in deformed molybdenum diselenide (MoSe2) have been made using anomalous X‐ray line broadening technique as applied to the simple hexagonal close‐packed (2 H) structure. The stacking fault probability has been accounted for the glide only on SeSe (Selenium–Selenium) slip planes and it is found to be considerably high (≈0.10). Domain size and lattice strain parameters have been estimated and the former has been used to calculate the dislocation density (≈2.17 × 1011 cm‐2) in the bulk sample. Copyright © 1972 WILEY‐VCH Verlag GmbH & Co. KGaA
CALCULATION OF THE VERTICAL GRADIENT OF THE GRAVITY FIELD USING THE FOURIER TRANSFORM
(1972) B.N.P. AGARWAL; T. LAL
Fourier transform techniques have been used to calculate the theoretical filter (amplitude) response function of Nth order vertical derivative continuation operation. The amplitude response functions of the vertical gradient and its continuation follow from the same. These response functions are subsequently used to calculate the weighting coefficients suitable for two dimensional equispaced data. A shortening operator has been incorporated to limit the extent of the operator. For comparative study, some of the developed coefficient sets and the one presented in this paper are analysed in the frequency domain and their merits and demerits are discussed. Copyright © 1972, Wiley Blackwell. All rights reserved
A new leaf spot of maize incited by Curvularia clavata
(Kluwer Academic Publishers, 1972) A.M. Mandokhot; K.C. Basu Chaudhary
In September 1969 a leaf spot of maize 'Composite Jawahar', incited by C. lavata Jain, was observed at the College Farm of the Banaras Hindu University, Varanasi. The fungus seriously damages maize leaves and considerably reduces its fodder value. The symptoms of the disease and taxonomic characters of the pathogen are being described in detail. © 1972 Koninklijke Nederlandse Planteziektenkundige Vereniging.
Effect of an intense magnetic field on the diffusion of minority carriers in semiconductors
(1972) R. Swami; B.A.P. Tantry
The transport equations for electron and hole currents in the base region of alloy junction PNP transistors have been solved by taking into consideration the mobilities and diffusion constants as tensors of second rank and the recombination-dependent Hall field. These transport equations have been used to predict the behaviour of the change in diffusion constant due to magnetic field at different injection levels, including the high injection level. The theoretical results are confirmed by our experimental results.
A technique for isolation of Penicillia from soil
(Martinus Nijhoff, The Hague/Kluwer Academic Publishers, 1972) Rajpati Dwivedi
The effect of Nystatin (Mycostatin) on colonization of microfungi from mixed soil inocula was studied on nutrient agar plates supplemented with its various concentration. It was discovered that at its highest concentration only Penicillia could colonise the agar discs. It is a new suggestive technique for isolation of Penicillia from soil. © 1972 Martinus Nijhoff.
On the deduction of polytypic structural series in cadmium iodide based on layer transposition mechanism
(1972) B. Prasad; O.N. Srivastava
Structural-geometrical schemes for the creation of structural series for cadmium iodide polytypes have been worked out based on layer-transposition mechanism. The existence of all the cadmium iodide polytypic series have been accounted for. The occurrence of polytypic structural series has remained inexplicable so far based on the layer transposition mechanism; the present study therefore lends direct support to Jagodzinski's layer-transposition mechanism. © 1972, Walter de Gruyter. All rights reserved.
Calorimetric investigations of low-melting alloy systems
(1972) H.P. Singh
The construction and design of a liquid Wood's alloy solution calorimeter and a thermal analysis calorimeter, and their applications for the determination of the thermodynamic properties of the systems PbBi, InBi, HgIn, HgCd and of Wood's alloy are described. © 1972.
Thyroxine and hypothalamic neurosecretory system in chick embryos
(1972) Kamalaveni Chandrasekhar
Thyroxinisation of chick embryos brings about the appearance of stainable neuro-secretory material a day earlier than what is found in the control embryos. The Gomori-positive granules are found to appear first in the lateral group of neurons of the supra-optic nucleus. This is so in the treated as well as in the control embryos. It is observed that in the thyroxinised as well as control embryos, the fuchsinophil granules appeared much later in the paraventricular nucleus but in the thyroxinised embryos, the granules appeared consistently a day earlier than in the controls. The interesting phenomenon observed is that when the supra-optic nucleus got depleted of the stainable granules, the pericapillary part of the median eminence got deposited with the Gomori-positive granules. Similarly when the paraventricular nucleus got depleted, the neural lobe was seen getting filled with the fuchsinophil granules. In all the cases, the depletion and deposition of the stainable granules took place a day in advance in the thyroxinised embryos than in the controls. The purpose of this precocious appearance of the stainable granules in the thyroxinised embryos is inexplicable without further experimentation. © 1972 Indian Academy of Sciences.
Vnyeshnyeye polye lokalizovannogo zaryada v yedinoi{cyrillic, short} tyeorii polya
(1972) D.N. Pant
Einstein's Unified Field Theory equations (1953) have been considered in order to find the external field of an isolated charged distribution for a special axially symmetric case. The field equations have been solved in two cases. In one case the space-time becomes flat and the electrostatic field is found to be constant in the direction of the axis of symmetry. The solution for the other case is non-existent. © 1972 with the authors.
Phonon dispersion relations for zinc
(1972) J.S. Rajput; S.S. Kushwaha
Phonon dispersion relations for zinc have been studied using Krebs' model, as extended to hexagonal close packed metals. The results are in reasonable good agreement with the neutron inelastic scattering data. © 1972.
Lattice Dynamical Calculation of Thermal Expansion Coefficient and Grüneisen Parameter for Lithium
(1972) K. Singh; R.S. Srivastava
Phonon frequencies, thermal expansion coefficient and Grüneisen parameters are calculated from the dispersion relation derived by Toya for bcc lithium. Improved correlation term derived by Sham on the basis of Thomas-Fermi approach has been incorporated. The phonon frequencies are in good qualitative agreement with the experiment. Lattice specific heats, thermal expansion coefficient and γM- the mean value of Grüneisen parameters at different temperatures have been calculated by this method and are presented in this paper. The results obtained show that the correlation term is an essential feature of realistic calculations. © 1972, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.
Multiple W chromosome in a sea snake, Enhydrina schistosa daudin
(Birkhäuser-Verlag, 1972) L. Singh
[No abstract available]
Histological studies of the neurosecretory and retrocerebral complex of the water beetle, Hydrophilus olivaceus Fabr. (Insecta, Coleoptera)
(Springer-Verlag, 1972) H.S. Gundevia; P.S. Ramamurty
The neurosecretory cells (NSC) in the breeding phases show gigantic sized droplets. NSC show two peaks of activity in females at midnight and at 9 A.M., while a single peak occurs in males between midnight and 3 A.M. Light has a triggering effect on the neurosecretory release. The corpus cardiacum is the main neurohaemal organ. It has a nerve core formed by the nervi corpus cardiacum I and II, which is surrounded by the glandular region. Intrinsic secretory chromophilic cells and chromophobic cells occur randomly. Aorta is probably not a storage-release centre. The corpora allata are lobulated structures, showing cyclical activity which is correlated with egg-maturation. No neurosecretory material occurs in allatum. © 1972 Springer-Verlag.
Quantitative separation of calcium, barium and phosphate
(Springer-Verlag, 1972) T.S.B. Narasaraju; V.L.N. Rao
[No abstract available]
Power spectrum analysis of atmospheric ozone during the summer
(Birkhäuser-Verlag, 1972) J. Chattopadhyay; H.S. Rathor
This paper describes a study of the fluctuations in total atmospheric ozone amount as measured with a Dobson Spectrophotometer during the summer season over three north Indian stations, using the technique of power spectrum analysis. In all 19 spectra have been constructed. The long term trend was removed by applying a high pass filter. The main conclusions are: (1) The nature of the spectrum at a station generally differs from year to year. (2) Spectra of different stations during the same year, are generally different. (3) From the significance study of the spectral peaks, most of the spectra revealed the presence of two types of periodicities. One of these is in the range of 10-17 days while the other is found to have a range of 4.5-8.3 days. (4) It has been suggested that the former periodicity may be closely linked to the index cycle, while the latter may be related to the long waves in the Westerlies. © 1972 Birkhäuser-Verlag.
An unusual 6r structure in gadolinium and samarium monoxides
(1972) B.M.S. Bist; Jitendra Kumar; O.N. Srivastava
An unusual six-layered structure in gadolinium and samarium monoxides has been identified employing electron-diffraction methods. This structure is derived from the zincblende-type gadolinium or samarium monoxide. The lattice parameters of the 6R structure are aR =bR = 2aO]2, CR 2ao]3 (referred to hexagonal axes), where oo is the lattice parameter of the fundamental zincblende-type gadolinium or samarium monoxide unit cell. A six-layered rhombohcdral structure consisting of close-packed structural layers is usually not possible since it is equivalent to face-centered cubic structure. The detailed atomic structure of the GR variant has been determined. It is further shown that the stabilization of this structure is duo to existence of nonstoichiometric oxygen layers in the sequence forming the 6R structure. © 1972, Walter de Gruyter. All rights reserved.
Analysis of some bands of the β system of PO
(1972) S.B. Rai; D.K. Rai; K.N. Upadhya
The rotational analysis of some bands of the beta band system of the PO molecule has been revised and some new bands, for example (1,2), (3,2), (3,4), (4,3), (4,5) and (7,8) of the subsystem B2 Sigma +-x 2 Pi 3/2 and (4,3), (5,4), (5,5) and (6,7) of the subsystem B2 Sigma +-x2 Pi 1/2 have been analysed. Perturbation in the 6th and 7th vibrational levels of the upper excited state have been investigated.
Three-phonon scattering strengths and ziman limit of resistivity due to three-phonon scattering processes in Ge
(1972) G.P. Srivastava; D.P. Singh; G.S. Verma
The contributions of different three-phonon scattering processes to the thermal resistivity of isotopically pure Ge are presented in the Ziman limit. The modified expressions of Hamilton and Parrott for three-phonon scattering strengths are considered. © 1972 The American Physical Society.
On the evaluation of planetary albedo of the earth from turbidity measurements in India
(Birkhäuser-Verlag, 1972) Murari Lal; H.S. Rathor
The planetary albedo of the earth has been evaluated from the turbidity measurements in India by using Ångström's empirical relation [1]2) and the same has been presented in this paper. The diurnal and seasonal variations of the planetary albedo have been discussed. It has been found that during the morning hours, albedo is usually more than that during afternoon hours. Further, it shows a minima during winter season and a maxima during hot summer months. © 1972 Birkhäuser Verlag.
Integral‐breadth analysis of X‐ray line broadening in cold‐worked natural molybdenite (MoS2) crystals
(1972) R. Pratap; R.K. Gupta
An anomalous X‐ray line broadening effect has been studied in cold‐worked natural molybdenite (MoS2)crystals using the integral‐breadth method. The stacking‐fault probability is calculated on the basis of simple h.c.p. structure and is found to be approximately 0.03 on taking account the glide on S–S (sulphur–sulphur) slip planes only. Also, lattice strain and domain‐size parameter have been estimated. The dislocation density calculated from the domain‐size is found to be ≈2.6 × 1010 cm/cm3. A justification for using the simple h.c.p. structure theory for molybdenite has also been given. Copyright © 1972 WILEY‐VCH Verlag GmbH & Co. KGaA