Refine your search
Co-Authors
Journals
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Chhabra, Jyotsna
- Anomalous Concentration of Silver in Uraniferous Siwalik Sandstones of Romehra, Hamirpur District, Himachal Pradesh
Abstract Views :167 |
PDF Views:127
Authors
Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Begumpet, Hyderabad- 500 016, IN
2 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, West Block, R.K. Puram, New Delhi - 110 066, IN
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Begumpet, Hyderabad- 500 016, IN
2 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, West Block, R.K. Puram, New Delhi - 110 066, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 62, No 4 (2003), Pagination: 495-497Abstract
No Abstract.- Mineralogical and Chemical Features of Radioactive Biotites from Chhotanagpur Gneiss, Kudri Hills, Sonbhadra District, Uttar Pradesh
Abstract Views :192 |
PDF Views:2
Authors
Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, New Delhi - 110066, IN
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, New Delhi - 110066, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 59, No 3 (2002), Pagination: 219-224Abstract
Textural, mineralogical and chemical features of radioactive biotites from the melanosomes and leucosomes of migmatites in Chhotanagpur Gneiss at Kudri Hills are described. Biotite from melanosome is usually large and contains profuse inclusions of zircon, allanite, uranothorite and uraninite, as compared to thc biotite from leucosome. The melanosome biotite also shows contrasting microtextures, viz., presence of Fe-Ti oxide granules along cleavages and as rims around the flakes, as well as sieve texture as compared to leucosome biotite. The FeO(t)/MgO value in melanosome biotite varies from 5.0 to 5.3, whereas it is 5.9 to 6.5 in leucosome biotite. Structural formulae of biotite, calculated on the basis of 24 (0, OH, CI, F), show that the 12-coordinated cations of X-group do not reach the ideal figure of 2 in either case. The octahedral sites occupied by Y-group cations have a wide range in leucosome biotite in contrast to the very narrow range in melanosome biotite.Anomalous concentration of rare and radioactive elements, viz., U (up to 1200 ppm), Th (up to 656 ppm), Zr (up to 31076 ppm), Ce (up to 1576 ppm), Nb (up to 193 ppm) and Y (up to 2053 ppm) in melanosome biotite seems to result from its favourable crystal structure, conducive physico-chemical attributes and stability at high temperature of amphibolite facies. The most important feature of melanosome biotite is the presence of inclusions of radioactive minerals like uraninite, uranothorite, allanite and zircon.
Keywords
Mineralogy, Radioactive biotite, Migmatite, Leucosome, Melanosome, Sonbhadra District, Uttar Pradesh.- First Report of Domeykite and Koutekite (Copper Arsenides) in Siwalik Sandstones of Romehra, Hamirpur District, Himachal Pradesh
Abstract Views :227 |
PDF Views:149
Authors
Affiliations
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Begumpet, Hyderabad - 500 016, IN
2 R.K. Puram, West Block VII, New Delhi - 110 066, IN
1 Atomic Minerals Directorate for Exploration and Research, Department of Atomic Energy, Begumpet, Hyderabad - 500 016, IN
2 R.K. Puram, West Block VII, New Delhi - 110 066, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 60, No 6 (2002), Pagination: 695-699Abstract
Koutekite and two polymorphs (i.e., alpha and beta) of domeykite (rare copper arsenide minerals) are reported for the first time from the uraniferous Lower Siwalik sandstones of the Romehra area, Hamirpur district, Himachal Pradesh. The calculated cell size of . alpha-domeykite (Cubic) is a0 = 9.646 Å and that of betadomeykite (Hexagonal) is a0 = 7.151 Å and c0 = 7.304 Å. Koutekite (Hexagonal) has measured cell parameters of a0 = 11.58 Å and c0 = 14.55 Å. However, in koutekite of Romehra area an important interplanar spacing (d) at 2.081Å is merging with 'd' of beta dorneykite at 2.061Å and another interplanar spacing at 2.47Å exhibits comparatively higher intensity than the one published in JCPDS Data Card No.13-581. Association of domeykite with uraniferous sandstones points out that uranium mineralisation in Lower Siwaliks of the Romehra took place possibly below 90°C temperature.- Theoretical Prediction of Ultrasonic Velocities and Interaction Studies for the Pb-Sn Alloy
Abstract Views :150 |
PDF Views:0
Authors
Affiliations
1 Department of Chemistry, University of Allahabad, Allahabad-211 002, IN
2 Department of Physics, Brahmanand College, Kanpur, IN
1 Department of Chemistry, University of Allahabad, Allahabad-211 002, IN
2 Department of Physics, Brahmanand College, Kanpur, IN
Source
Journal of Pure and Applied Ultrasonics, Vol 29, No 4 (2007), Pagination: 111-115Abstract
A comparative study of ultrasonic velocity evaluated from Schaaffs collision factor theory (CFT), Nomoto relation, ideal mixing relation and Junjie relation has been carried out for the Pb-Sn alloy at three different temperatures and at various compositions. The agreement between experimental and theoretical values is quite satisfactory. The computed values of sound velocities from ideal-mixing relation have been used to obtain the degree of molecular interaction. Interaction studies have also been made in terms of excess intermolecular free-length and excess acoustic impedance.- Ultrasonic and Volumetric Studies of Binary Liquid Mixture Acetonitrile+Nitromethane at 298.15 K
Abstract Views :175 |
PDF Views:0
Authors
Affiliations
1 Department of Chemistry, University of Allahabad, Allahabad-211002, IN
1 Department of Chemistry, University of Allahabad, Allahabad-211002, IN