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B. K. Nath ¹, P. K. Chakrabarti ², S. Das ³, U. Kumar ⁴, P. K. Mukhopadhyay ⁴, D. Das ¹

Affiliations
1 IUC-DAEF, Bidhannagar, Kolkata 700 098, IN
2 Department of Physics, Asutosh College, Kolkata 700 026, IN
3 Department of Physics, Jadavpur University, Kolkata 700 032, IN
4 S. N Bose National Centre for Basic Sciences, Bidhannagar, Kolkata 700 098, IN

Abstract

Nanoparticles of zinc substituted Mg-ferrite (Mg_(1-x)Zn_xFe₂O₄, x = 0.70 and 0.85) with well-developed spinel phases have been prepared by standard co-precipitation method. Single-phase ferrite with a spinel structure began to form at a relatively lower temperature (∼200 °C). X-ray diffratometry and ⁵⁷Fe Mossbauer effect measurements were carried out to characterize Mg-Zn-ferrite nanoparticles. The particle sizes obtained from Sherrer equation lie in the range, 6.4 nm to 25.6 nm. Mossbauer measurements at room temperature and down to 20 K clearly indicate the presence of superparamagnetic particles in all the samples. Superparamagnetic relaxation was observed at room temperature even for larger particle size of the samples and this may be due to the weakening of A-B exchange interaction in ferrite lattice due to replacement of Fe³⁺ ions in tetrahedral sites by Zn²⁺ ions.

Keywords

Spinel Ferrites, Superparamagnetism, Mosshauer Spectroscopy, Relaxation Pacs No. : 75.50 Tt, 76.80+y, 75.30 Cr.

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P. P. Satsangi ¹, P. K. Mukhopadhyay ¹

Affiliations
1 Geological Survey of India, IN

Abstract

No Abstract.

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P. K. Mukhopadhyay ¹

Affiliations
1 Department of Geological Sciences, Jadavpur University, Calcutta, IN

Abstract

The petrographic and provenance study of the sediments of Barakar Formation in North Karanpura Coalfield reveals the presence of cyclic sedimentation from coarse to fine clastics, coal and clay arkose. The evidences indicate that the sediments were deposited in a broad river channel with intermittent flooding.

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K. Muthuraman ¹, M. P. Tiwari ¹, P. K. Mukhopadhyay ¹

Affiliations
1 Geological Survey of India, New GSI Complex, Seminary Hills, Nagpur 440006, IN

Abstract

Major element chemistry of the saline and the non-saline waters occurring between Popat-Khed and north of Akola indicate that the saline/fresh water contact is quite sharp and the saline waters are significantly restricted to the sandy aquifers inter-layered by clay beds, creating quasi-confined condition.

The ratios of major anions and cations of the saline waters are not comparable to those of sea-water. The plots of the major cations versus chloride are quite scattered and do not indicate any trend similar to their evaporite curves.

In view of the high 'Na/(Ca+Mg)' ratio, negative indices of base exchange and high SiO₂-content of these waters, it is contended that these saline waters are nothing but diagenetically altered meteoric water having a long residence time.

Keywords

Groundwater, Salinity, Purna Basin, Hydrogeology, Maharashtra.

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P. K. Mukhopadhyay ¹

Affiliations
1 S.N. Bose National Centre for Basic Sciences (SNBNCBS), Kolkata, IN

Abstract

The Symposium and the General Body Meeting of the Ultrasonics Society of India, was held in S. N. Bose National Centre for Basic Sciences (SNBNCBS), Kolkata, from 08 to 10^th, November, 2016. Prof. P. K. Mukhopadhyay of this centre was Convenor and Prof. B. Pal, S,N. Bose Institute of Nuclear Physics (SINP) was the Co-Convenor of the Symposium Organizing Committee.

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P. K. Mukhopadhyay ¹

Affiliations
1 Deptt of Sociology, Presidency College, IN

Abstract

No Abstract.

Keywords

No Keywords.

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