Current Science

Achutananda Parhi ¹, V. Mahesh ¹, Khadarvoli Kalluru ¹, S. Reshmi ¹, R. Harikrishnan ¹, V. M. Lakshmi ¹, J. Paul Murugan ¹, Renjith Kumar Reddy ¹

Affiliations
1 Vikram Sarabhai Space Centre, Indian Space Research Organisation, Thiruvananthapuram 695 022, IN

Abstract

This article discusses the developmental challenges of the low-thrust, long-duration solid rocket motor for the launch of the experimental Reusable Launch Vehicle-Technological Demonstrator (RLV-TD). The main challenges were: (1) developing a motor case and subsystems with low inert mass; (2) design of an optimum nozzle such that the motor can have maximum specific impulse at atmospheric conditions, but with no flow separation at low operation pressures; (3) developing a slow-burning propellant (3 mm/s) to meet the mission requirements; (4) design of propellant grain for the motor so that it has long burning time, the vehicle experiences low dynamic pressure at the transonic regime, and the motor is without combustion instability; (5) developing necessary thermal protection system to take care of long-duration operations, and (6) developing the igniter to ensure the ignition of the motor, especially when easy ignition is difficult with slow-burning propellants and that there should be sufficient overlap of igniter functioning with motor initiation. Performance of the motor in flight indicated that the design met all the required criteria within the expected tolerance.

Keywords

Burning Rate, Igniter, Motor Case, Performance Prediction, Solid Rocket Booster.

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A. P. Dineshbabu ¹, Sujitha Thomas ¹, Josileen Jose ¹, P. T. Sarada ¹, Lakshmi Pillai ¹, Rekha Devi Chakraborty ¹, Gyanranjan Dash ¹, Anulekshmi Chellappan ¹, Shubhadeep Ghosh ¹, G. B. Purushottama ¹, Rajan Kumar ¹, M. Rajkumar ¹, Indira Divipala ¹, D. Nakhava Ajay ¹, R. Ratheeshkumar ¹, K. V. Akhilesh ¹, V. Mahesh ¹, Swathipriyanka Sen ¹, Rajesh Pradhan ¹, Shikha Rahangdale ¹, R. Vinothkumar ¹, Shoba Joe Kizhakudan ¹, K. M. Rajesh ¹, R. Narayanakumar ¹, P. S. Swathilekshmi ¹, S. S. Raju ¹, G. Maheswarudu ¹, M. Sivadas ¹

Affiliations
1 Central Marine Fisheries Research Institute, Kochi 682 018, India, IN

Abstract

Globally, trawl is the major fishing gear used in marine fisheries and in India, it contributes to more than one-third of the marine fish production. Trawl fishing has been critically evaluated from a sustainability perspective, especially analysing its bycatch composition. Most of the bycatch from trawlers contains valuable edible species with high market demand. However, a portion of the bycatch which does not have such demand in the edible fish market, known as low-value bycatch (LVB), continues to be a matter of concern from an ecological and economic perspective. During 2017–19, 30–60% of trawl landing in India was constituted by LVB, which was mainly used for fishmeal preparation. To enhance the value and utility of LVB, this study explores the possibility of converting waste from LVB into edible resources using pufferfish and triggerfish. It also highlights the positive impact of efforts by different Government agencies for bycatch mitigation like the implementation of minimum legal size in reducing the juvenile component in bycatch, with a social survey-based account of fisher’s perceptions and suggestions on successful bycatch mitigation

Keywords

Ecological impacts, fishery economics, low-value bycach, minimum legal size, trawl.

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K. V. Akhilesh ¹, Shoba Joe Kizhakudan ¹, M. Muktha ¹, T. M. Najmudeen ¹, Sujitha Thomas ¹, Divya Karnad ², Dipani Sutaria ³, Merwyn Fernandes ⁴, Trisha Gupta ⁵, Naveen Namboothri ⁵, Vardhan Patankar ⁶, Swatipriyanka Sen ¹, Sijo P. Varghese ⁷, A. Biju Kumar ⁸, Alissa Barnes ⁵, K. K. Bineesh ⁹, Sajan John ¹⁰, Mayuresh Gangal ¹¹, M. Hashim ¹², Vinod Malayilethu ¹³, Zoya Tyabji ⁶, Malaika Vaz ¹⁴, Sandhya Sukumaran ¹, G. B. Purushottama ¹, Livi Wilson ¹, V. Mahesh ¹, Rekha J. Nair ¹, L. Remya ¹, Shikha Rahangdale ¹, P. P. Manojkumar ¹, K. Sivakumar ¹⁵, E. Vivekanandan ¹, P. U. Zacharia ¹, A. Gopalakrishnan ¹

Affiliations
1 ICAR-Central Marine Fisheries Research Institute, Kochi 682 018, IN
2 Department of Environmental Studies, Ashoka University, Sonipat 131 029, IN
3 9 Aranya Farms, Shilaj, Ahmedabad 382 115, IN
4 TRAFFIC India Office, New Delhi 110 003, IN
5 Dakshin Foundation, #1818, 9th Cross, 5th Main Road, Sahakar Nagar, Bengaluru 560 092, IN
6 Wildlife Conservation Society-India, Rajiv Gandhi Nagar, 2nd Phase, Bengaluru 560 097, IN
7 Fishery Survey of India, Cochin Base, Kochi 682 005, IN
8 Department of Aquatic Biology & Fisheries, University of Kerala, Thiruvananthapuram 695 581, IN
9 Zoological Survey of India, Chennai 600 028, IN
10 Wildlife Trust of India, Delhi 201 301, IN
11 Nature Conservation Foundation, Mysuru 570 017, IN
12 Centre for Marine Living Resources and Ecology, Kochi 682 508, IN
13 WWF-India, ‘Prasanthi’, Kadavanthra, Kochi 682 020, IN
14 Untamed Planet Films, Bengaluru 560 001, IN
15 Wildlife Institute of India, Dehradun 248 001, IN

Abstract

Historically, India has been projected as one of the major elasmobranch fishing nations in the world. However, management and conservation efforts are not commensurate with this trend. Along with the Wildlife (Protection) Act, 1972, several generic conservation measures are in place at the regional/local level. But India is still a long way from meeting global conservation commitments. We present here the status of elasmobranch management and conservation in India, with the specific objective of identifying the gaps in the existing set-up. We also present recommendations based on a national consultative workshop held at the Central Marine Fisheries Research Institute, Kochi, in February 2020. We recommend the implementation of a National Plan of Action (NPOA-Sharks) and more inclusive governance and policymaking for elasmobranch conservation in India.

Keywords

Consultative Meeting, Elasmobranch, Fisheries, Management and Conservation, Regulations.

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