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Temporal variation of solar flare index during solar cycles 21–24

Research in Astronomy and Astrophysics 2021年第3期21卷 21-33页

作者： soumya roy Amrita Prasad Subhash Chandra Panja Sankar Narayan Patra Department of Applied Electronics and Instrumentation Engineering Haldia Institute of TechnologyHaldiaMidnapore(E)-721657West BengalIndia Department of Mechanical Engineering Jadavpur UniversityKolkata-700032West BengalIndia Department of Instrumentation and Electronics Engineering Jadavpur UniversityKolkata-700106West BengalIndia

The present investigation attempts to quantify the temporal variation of Solar Flare Index(SFI)with other activity indices during solar cycles 21-24 by using different techniques such as linear regression,correlation,cross-correlation with phase lag-lead,etc.Different Solar Activity Indices(SAI)considered in this present study are Sunspot Number(SSN),10.7 cm Solar Radio Flux(F10.7),Coronal Index(CI)and MgⅡCore-to-Wing Ratio(MgⅡ).The maximum cycle amplitude of SFI and considered SAI has a decreasing trend from solar cycle 22,and cycle 24 is the weakest solar cycle among all other cycles.The SFI with SSN,F10.7,CI and MgⅡshows hysteresis during all cycles except for solar cycle 22 where both paths for ascending and descending phases are intercepting each other,thereby representing a phase reversal.A positive hysteresis circulation exists between SFI and considered SAI during solar cycles 22 and 23,whereas a negative circulation exists in cycles 21 and 24.SFI has a high positive correlation with coefficient values of 0.92,0.94,0.84 and 0.81 for SSN,F10.7,CI and MgⅡrespectively.According to crosscorrelation analysis,SFI has a phase lag with considered SAI during an odd-number solar cycle(solar cycles21 and 23)but no phase lag/lead during an even-numbered solar cycle(solar cycles 22 and 24).However,the entire smoothed monthly average SFI data indicate an in-phase relationship with SSN,F10.7 and MgⅡ,and a one-month phase lag with CI.The presence of those above characteristics strongly confirms the outcomes of different research work with various solar indices and the highest correlation exists between SFI and SSN as well as F10.7 which establishes that SFI may be considered as one of the prime activity indices to interpret the characteristics of the Sun’s active region as well as for more accurate short-range or long-range forecasting of solar events.

关键词： Methods:data analysis Methods:statistical Sun:activity Sun:flares Sun:general

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Two-Stent Strategy for Bifurcation Lesions in Percutaneous Transluminal Coronary Angioplasty: Real-World Evidence

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World Journal of Cardiovascular Diseases 2024年第3期14卷 140-156页

作者： Dilip Kumar Amit Malviya Animesh Mishra Rabin Chakraborty Sanjeev S. Mukherjee soumya Patra Arindam Pande Rana Rathor roy Debopriyo Mondal Ashesh Halder Sumit Shanker Medica Superspecialty Hospital 127 Eastern Metropolitan Bypass Nitai Nagar Mukundapur Kolkata West Bengal India North Eastern Indira Gandhi Regional Institute of Health & Medical Sciences (NEIGRIHMS) Mawdiangdiang Shillong Meghalaya India

Background: Bifurcation lesions pose a high risk for adverse events after percutaneous coronary intervention (PCI). Evidence supporting the benefits of the two-stent strategy (2SS) for treating coronary bifurcation lesions in India is limited. This study aimed to evaluate the clinical outcomes of various 2SSs for percutaneous transluminal coronary angioplasty for bifurcation lesions in India. Materials and Methods: This retrospective, observational, multicentric, real-world study included 64 patients over 8 years. Data on demographics, medical history, PCI procedures, and outcomes were recorded. Descriptive statistics were computed using the SPSS software. Results: Patients (n = 64) had an average age of 65.3 ± 11.1 years, with 78.1% males. Acute coronary syndrome was reported in 18.8%, chronic stable angina in 40.6%, and unstable angina in 34.4% of participants. Two-vessel disease was observed in 98.4% of patients, and 99.4% had true bifurcation lesions. The commonly involved vessels were the left anterior descending artery (50%), left circumflex coronary artery (34.4%), and first diagonal artery (43.8%). Mean percent diameter stenosis was 87.2% ± 10.1%. The mean number of stents used was 2.00 ± 0.34. The 2SS techniques included the T and small protrusion (TAP) (39.1%), double kissing (DK) crush (18.8%), and the culotte techniques (14.1%). Procedural and angiographic success rate was 92.18%. Major adverse cardiovascular events at 1-year follow-up occurred in 7.8% of cases. Conclusion: The 2SS for bifurcation lesions showed favorable in-hospital and follow-up outcomes. Findings can serve as a resource for bifurcation angioplasty in India. Larger real-world studies with robust methodology are needed to validate these results.

关键词： Bifurcation Stenting Coronary Bifurcation Lesions Percutaneous

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Chaos and Periodicities in Solar Flare Index from Kandilli Observatory during 1976–2014

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Research in Astronomy and Astrophysics 2020年第7期20卷 177-186页

作者： soumya roy Amrita Prasad Koushik Ghosh Subhash Chandra Panja Sankar Narayan Patra Department of Applied Electronics and Instrumentation Engineering Haldia Institute of TechnologyHaldiaMidnapore(E)-721657West BengalIndia Department of Mechanical Engineering Jadavpur UniversityKolkata-700032West BengalIndia Department of Mathematics University Institute of TechnologyThe University of BurdwanBurdwan-713104West BengalIndia Department of Instrumentation and Electronics Engineering Jadavpur UniversityKolkata 700106West BengalIndia

The Solar Flare Index is regarded as one of the most important solar indices in the field of solarterrestrial research. It has the maximum effect on Earth of all other solar activity indices and is being considered for describing the short-lived dynamo action inside the Sun. This paper attempts to study the short as well as long-term temporal fluctuations in the chromosphere region of the Sun using the Solar Flare Index. The daily Solar Flare Index for Northern, Southern Hemisphere and Total Disk are considered for a period from January 1976 to December 2014(total 14 245 days) for chaotic as well as periodic analysis.The 0–1 test has been employed to investigate the chaotic behavior associated with the Solar Flare Index.This test revealed that the time series data is non-linear and multi-periodic in nature with deterministic chaotic features. For periodic analysis, the Raleigh Power Spectrum algorithm has been used for identifying the predominant periods within the data along with their confidence score. The well-known fundamental period of 27 days and 11 years along with their harmonics are well affirmed in our investigation with a period of 28 days and 10.77 years. The presence of 14 days and 7 days periods in this investigation states the short-lived action inside the Sun. Our investigation also demonstrates the presence of other mid-range periods including the famous Rieger type period which are very much confirming the results obtained by other authors using various solar activity indicators.

关键词： chaos method:data analysis Sun:activity Sun:flares Sun:fundamental parameters Sun:rotation

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Simulation Study of Active Noise Control in Wind Turbines Using FxLMS Adaptation Algorithm

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Journal of Power and Energy Engineering 2017年第8期5卷 72-83页

作者： soumya roy Pratik Naik School of Mechanical Engineering Purdue University West Lafayette USA

Utility scale wind turbines produce a significant amount of noise which has been identified as one of the most critical challenges to the widespread use of wind energy. Aerodynamic noise caused primarily by the interaction of the boundary layer and (or) the upstream atmospheric turbulence with the trailing edge of the blade has been identified as the most dominant source of noise in wind turbines. The authors here propose an active noise control system based on the FxLMS algorithm which can achieve suppression of noise from a modern wind turbine. Two types of noise sources have been simulated: monopole and dipole. The results of the active noise control algorithm are validated with simulations in MATLAB. The agreement between the results shows the far impact of active noise control techniques will have in future wind turbines.

关键词： Active Noise Control Monopole Dipole FxLMS Algorithm

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Oxidative stress and mitochondrial transfer:A new dimension towards ocular diseases

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Genes & Diseases 2022年第3期9卷 610-637页

作者： Mohana Devi Subramaniam Mahalaxmi Iyer Aswathy P.Nair Dhivya Venkatesan Sinnakaruppan Mathavan Nimmisha Eruppakotte soumya Kizhakkillach Manoj kumar Chandran Ayan roy Abilash Valsala Gopalakrishnan Balachandar Vellingiri SN ONGC Department of Genetics and Molecular Biology Vision Research FoundationChennai 600006Tamil NaduIndia Department of Zoology Avinashilingam Institute for Home Science and Higher Education for WomenCoimbatore 641043Tamil NaduIndia Human Molecular Cytogenetics and Stem Cell Laboratory Department of Human Genetics and Molecular BiologyBharathiar UniversityCoimbatore 641046Tamil NaduIndia Department of Biotechnology Lovely Professional UniversityPunjab 144411India Department of Biomedical Sciences School of Bio Sciences and Technology(SBST)Vellore Institute of Technology(VIT)Vellore 600127India

Ocular cells like,retinal pigment epithelium(RPE)is a highly specialized pigmented monolayer of post-mitotic cells,which is located in the posterior segment of the eye between neuro sensory retina and vascular choroid.It functions as a selective barrier and nourishes retinal visual cells.As a result of high-level oxygen consumption of retinal cells,RPE cells are vulnerable to chronic oxidative stress and an increased level of reactive oxygen species(ROS)generated from mitochondria.These oxidative stress and ROS generation in retinal cells lead to RPE degeneration.Various sources including mtDNA damage could be an important factor of oxidative stress in RPE.Gene therapy and mitochondrial transfer studies are emerging fields in ocular disease research.For retinal degenerative diseases stem cell-based transplantation methods are developed from basic research to preclinical and clinical trials.Translational research contributions of gene and cell therapy would be a new strategy to prevent,treat and cure various ocular diseases.This review focuses on the effect of oxidative stress in ocular cell degeneration and recent translational researches on retinal degenerative diseases to cure blindness.

关键词： Mitochondrial transfer Oxidative stress Retinal pigment epithelium(RPE) RPE Degeneration Stem cell treatment

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Phytochemicals Screening, Phenolic Estimation and Evaluation for Anti-Oxidant, Anti-Inflammatory and Anti-Microbial Activities of Sequentially Soxhlet Extracted Coconut Testa

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Food and Nutrition Sciences 2019年第8期10卷 900-922页

作者： Sashi Bhusan Ojha Shaktirekha roy soumya Das Gunanidhi Dhangadamajhi Department of Biotechnology North Orissa University Baripada Odisha India

Background: In many coconut industries, the outer layer of thin brown skin of coconut kernel known as testa is peeled out as a byproduct. Despite the testa is rich in fat and plenty of polyphenolic compounds, it has been underutilized either as animal feed, serving as raw materials for bio-diesel production or discarded directly. Anticipating coconut testa (CT) as a natural source of multiple phyto-chemicals, its exploitation for the pharmacological activity or utilization as value added product is required which may reduce the disposal costs as well. Methods: Secondary metabolites from CT were extracted sequentially with different organic solvents based on polarity in the soxhlet apparatus followed by extraction with sterilized water. The crude dried extracts thus prepared were evaluated for qualitative screening of phytochemicals and quantitative estimation of total phenols, flavonoids and tannin content. Moreover, the antioxidant, anti-inflammatory and anti-microbial activities were also investigated. Results: Phytochemicals screening revealed the presence of polyphenolic compounds in methanolic fraction including phenols (822.60 ± 16.36 mg/g), flavonoids (103.30 ± 9.78 mg/g) and tannin (663.50 ± 19.26 mg/g), whereas non-phenolic compounds were present in other fractions. While methanolic fraction showed invariably the highest anti-oxidant activity in multiple assay methods, non-phenolic compounds in aqueous and chloroform fractions exhibited high anti-inflammatory activity. Antimicrobial activity was observed by both phenolic and non-phenolic compounds. Conclusion: The findings of the study reveal that CT is a rich source of various polyphenolic and non-phenolic natural antioxidants, anti-inflammatory and antimicrobial compounds. These findings are promising and form the basis to identify the number of active components and their characterization.

关键词： Coconut Testa Phytochemicals Anti-Oxidant Anti-Inflammatory Anti-Microbial Soxhlet Extraction

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