NOPR Community:http://nopr.niscpr.res.in/handle/123456789/32026-05-20T09:43:58Z2026-05-20T09:43:58ZNonlinear structural assessment of self-installing platforms in the Indian Ocean for offshore wind turbines using push-over analysisAndavar, PMeiaraj, CPremalatha, Jhttp://nopr.niscpr.res.in/handle/123456789/674982026-03-20T11:15:41Z2024-12-01T00:00:00ZTitle: Nonlinear structural assessment of self-installing platforms in the Indian Ocean for offshore wind turbines using push-over analysis
Authors: Andavar, P; Meiaraj, C; Premalatha, J
Abstract: The Indian offshore wind energy industry is gaining momentum, driven by strong coastal wind resources and national
efforts toward clean energy, economic development, and climate change mitigation. However, the installation of wind
turbines in deep-water regions poses significant technical and economic challenges. This study explores the development
and assessment of a novel Self-Installing Platform (SIP) tailored for a 10 MW offshore wind turbine at a depth of 75 meters.
The SIP aims to overcome current installation limitations by eliminating the need for heavy-lift vessels, thereby reducing
cost, increasing efficiency, and enhancing deployment flexibility. A coupled numerical modelling approach is employed,
integrating structural analysis using SACS software and geotechnical evaluation through PLAXIS 3D, including the
modelling of a suction bucket foundation. The platform’s performance is analysed under a range of environmental
conditions, including extreme wave and wind loads, over a design life of 100 years. Nonlinear static pushover analysis is
conducted to determine the maximum load capacity and assess system resilience. Results demonstrate that the SIP meets
structural safety requirements, with Reserve Strength Ratios (RSRs) exceeding 2.5 in all directions, and maintains
acceptable displacement levels under critical load cases. Additionally, the study identifies the most vulnerable structural
sections under extreme E180° loading, enabling targeted design improvements. Overall, the SIP exhibits robust structural
and geotechnical performance, proving to be a viable, cost-effective solution for deep-water offshore wind turbine
installations. This research contributes valuable insights into the behaviour of self-installing platforms in harsh marine
environments and supports the advancement of sustainable offshore wind energy infrastructure installation, especially in
challenging deep-water environments.
Page(s): 747-7632024-12-01T00:00:00ZCORAL–Classification of Reefs and Analysis using Learning algorithms of image processingBhagat, JTandel, MSaha, Ghttp://nopr.niscpr.res.in/handle/123456789/674972026-03-20T11:00:24Z2024-11-01T00:00:00ZTitle: CORAL–Classification of Reefs and Analysis using Learning algorithms of image processing
Authors: Bhagat, J; Tandel, M; Saha, G
Abstract: Coral bleaching, driven primarily by rising sea temperatures, poses a severe threat to coral reefs and the millions who
depend on these resources. This study investigates the potential of deep learning for automated bleaching detection, a crucial
step towards effective monitoring and conservation. Study evaluated five classification algorithms, each paired with three
feature extractors, using a publicly available dataset of 1150 coral images. The findings demonstrate the superior
performance of the DenseNet-Logistic Regression model, achieving the highest average accuracy (83 %), F1-score (0.84),
and precision (0.85), highlighting its effectiveness in capturing subtle bleaching indicators. While this research underscores
the promising outcomes of deep learning for this critical task, further investigation with larger, more diverse datasets is
warranted to develop highly accurate and generalisable models for safeguarding these vital ecosystems.
Page(s): 764-7752024-11-01T00:00:00ZA report of the Four-lined tonguesole, Cynoglossus quadrilineatus (Bleeker, 1851) and Lachner's tonguesole, Cynoglossus lachneri Menon, 1977 from the Andaman and Nicobar Islands, IndiaUmmath, AKalita, SS Fahmeeda Parveen, PKashyap, KV Mohammed Ramees, PVenu, Shttp://nopr.niscpr.res.in/handle/123456789/674962026-03-20T10:56:11Z2024-12-01T00:00:00ZTitle: A report of the Four-lined tonguesole, Cynoglossus quadrilineatus (Bleeker, 1851) and Lachner's tonguesole, Cynoglossus lachneri Menon, 1977 from the Andaman and Nicobar Islands, India
Authors: Ummath, A; Kalita, S; S Fahmeeda Parveen, P; Kashyap, K; V Mohammed Ramees, P; Venu, S
Abstract: This study reports the occurrence of Cynoglossus quadrilineatus (Four-lined tonguesole) and Cynoglossus lachneri
(Lachner's tonguesole) from the Andaman and Nicobar Islands, India, extending their known distribution range. Notably,
C. lachneri is recorded from the Andaman Sea for the first time. Three specimens of C. quadrilineatus and one specimen of
C. lachneri were collected from the vicinity of the South Andaman Islands. Cynoglossus quadrilineatus is characterised by
12 caudal fin rays and two lateral lines on each side of the body, while C. lachneri is identified by 10 caudal fin rays, two
lateral lines, and 15 interlinear scales. Species identification was further validated through partial cytochrome coxidase I
(COI) gene sequencing. The genetic distance analysis using the Kimura-2-parameter model revealed no overlap among
closely related species within the family Cynoglossidae. This study also provides the first COI gene sequence for
C. lachneri, contributing to the assessment of phylogenetic diversity in future research.
Page(s): . 776-7842024-12-01T00:00:00ZA mega-toothed shark, Otodus megalodon (Agassiz, 1835) from the Middle Miocene Bhuban Formation of Mizoram, IndiaFanai, LM Sharma, KP Tiwari, RPatnaik, RA Singh, NLalrammuana, ALalnuntluanga, PLalnunmawia, Jhttp://nopr.niscpr.res.in/handle/123456789/674952026-03-20T10:45:53Z2024-12-01T00:00:00ZTitle: A mega-toothed shark, Otodus megalodon (Agassiz, 1835) from the Middle Miocene Bhuban Formation of Mizoram, India
Authors: Fanai, L; M Sharma, K; P Tiwari, R; Patnaik, R; A Singh, N; Lalrammuana, A; Lalnuntluanga, P; Lalnunmawia, J
Abstract: The Bhuban Formation of Mizoram is known for its fossil assemblages of invertebrates, foraminiferans, sharks and
batoids. Recent fieldwork at Tuithum Quarry of the Bhuban Formation, Mizoram, yielded an isolated tooth of Otodus
megalodon (Agassiz, 1835), the largest fish that ever lived on earth. The present record of O. megalodon is not only the
first-time report from the Miocene of Mizoram but also from the entire Northeast India. The O. megalodon was a
cosmopolitan giant predator, known to inhabit tropical, subtropical, and temperate seas during the early Miocene to early
Pliocene epochs. Based on regression analyses, the tooth belonging to this individual specimen is estimated to indicate a
total body length of approximately 7.81 meters, suggesting that it was likely a juvenile. The present finding of O. megalodon
and the earlier record of the elasmobranch fauna and associated invertebrates indicate that a warm, shallow marine
(nearshore), high-energy environment prevailed during the deposition of the upper Bhuban Formation.
Page(s): 785-7952024-12-01T00:00:00Z