Identification of flutter derivatives from full-scale ambient vibration measurements of the Clifton Suspension Bridge

Nikitas, Nikolaos,Macdonald, John H.G.,Jakobsen, Jasna B. Techno-Press 2011 Wind and Structures, An International Journal (WAS Vol.14 No.3

The estimated response of large-scale engineering structures to severe wind loads is prone to modelling uncertainties that can only ultimately be assessed by full-scale testing. To this end ambient vibration data from full-scale monitoring of the historic Clifton Suspension Bridge has been analysed using a combination of a frequency domain system identification method and a more elaborate stochastic identification technique. There is evidence of incipient coupling action between the first vertical and torsional modes in strong winds, providing unique full-scale data and making this an interesting case study. Flutter derivative estimation, which has rarely previously been attempted on full-scale data, was performed to provide deeper insight into the bridge aerodynamic behaviour, identifying trends towards flutter at higher wind speeds. It is shown that, as for other early suspension bridges with bluff cross-sections, single-degree-of-freedom flutter could potentially occur at wind speeds somewhat below requirements for modern designs. The analysis also demonstrates the viability of system identification techniques for extracting valuable results from full-scale data.

Identification of flutter derivatives from full-scale ambient vibration measurements of the Clifton Suspension Bridge

Nikolaos Nikitas,John H.G. Macdonald,Jasna B. Jakobsen 한국풍공학회 2011 Wind and Structures, An International Journal (WAS Vol.14 No.3

The estimated response of large-scale engineering structures to severe wind loads is prone to modelling uncertainties that can only ultimately be assessed by full-scale testing. To this end ambient vibration data from full-scale monitoring of the historic Clifton Suspension Bridge has been analysed using a combination of a frequency domain system identification method and a more elaborate stochastic identification technique. There is evidence of incipient coupling action between the first vertical and torsional modes in strong winds, providing unique full-scale data and making this an interesting case study. Flutter derivative estimation, which has rarely previously been attempted on full-scale data, was performed to provide deeper insight into the bridge aerodynamic behaviour, identifying trends towards flutter at higher wind speeds. It is shown that, as for other early suspension bridges with bluff crosssections, single-degree-of-freedom flutter could potentially occur at wind speeds somewhat below requirements for modern designs. The analysis also demonstrates the viability of system identification techniques for extracting valuable results from full-scale data.

Is Europe an Optimum Currency Area? Business Cycles in the EU

( Guglielmo Maria Caporale ),( Nikitas Pittis ),( Kyprianos Prodromidis ) 세종대학교 경제통합연구소(구 세종대학교 국제경제연구소) 1999 Journal of Economic Integration Vol.14 No.2

This paper aims to assess whether the EU is an optimum currency area (OCA) by examining synchronization of business cycles and long-run output linkages in the EU countries. We argue that a necessary condition for the desirability of EMU membership for national economies is that the degree of persistence of shocks affecting them should be similar Given the low power of unit root tests, we measure the relative importance of permanent versus transitory components in output. The existence of a "European business cycle" is confirmed by correlation and cointegration analysis respectively. Finally, it appears that monetary coordination, by reducing exchange rate volatility, results in more synchronised cycles. EMU is therefore likely to be a successful experience, since the benefits of monetary integration will outweigh the costs of surrendering the exchange rate instrument. (JEL Classification: E42, F36, F42)

Is Europe an Optimum Currency Area? Business Cycles In the EU

Caporale, Guglielmo Maria,Pittis, Nikitas,Peodromidis, Kyprianos 세종대학교 국제경제연구소 1999 Journal of Economic Integration Vol.14 No.2

This paper aims to assess whether the EU is an optimum currency area(OCA) by examining synchronization of business cycle and long-run output linkages in the EU countries. We argue that a necessary condition for the desirability of EMU membership for national economies is that the degree of persistence of shocks affecting them should be similar. Given the low power of unit root tests, we measure the relative importance of permanent versus transitory components in output. The existence of a "European business cycle" is confirmed by correlation and cointegration analysis respectively. Finally, it appears that monetary coordination, by reducing exchange rate volatility, results in more synchronised cycles. EMU is therefore likely to be a successful experience, since the benefits of monetary integration will outweigh the costs of surrendering the exchange rate instrument. (JEL Classification: E42, F36, F42)

A k-Tree-Based Resource(CU/PE) Allocation for Reconfigurable MSIMD/MIMD Multi-Dimensional Mesh-Connected Architectures

Jeeraporn Srisawat,Wanlop Surakampontom,Nikitas A. Alexandridis 대한전자공학회 2002 ITC-CSCC :International Technical Conference on Ci Vol.2002 No.7

Development of a High-Resolution Multi-Locus Microsatellite Typing Method for Colletotrichum gloeosporioides

( Nikita Mehta ),( Ferry Hagen ),( Sadaf Aamir ),( Sanjay K. Singh ),( Abhishek Baghela ) 한국균학회 2017 Mycobiology Vol.45 No.4

Colletotrichum gloeosporioides is an economically important fungal pathogen causing substantial yield losses indifferent host plants. To understand the genetic diversity and molecular epidemiology of this fungus, we have developed a novel, highresolution multi-locus microsatellite typing (MLMT) method. Bioinformatic analysis of C. gloeosporioides unannotated genome sequence yielded eight potential microsatellite loci, of which five, CG1 (GT)_n, CG2 (GT1)_n, CG3 (TC)_n, CG4 (CT)_n, and CG5 (CT1)_n were selected for further study based on their universal amplification potential, reproducibility, and repeat number polymorphism. The selected microsatellites were used to analyze 31 strains of C. gloeosporioides isolated from 20 different host plants from India. All microsatellite loci were found to be polymorphic, and the approximate fragment sizes of microsatellite loci CG1, CG2, CG3, CG4, and CG5 were in ranges of 213-241, 197-227, 231-265, 209-275, and 132-188, respectively. Among the 31 isolates, 55 different genotypes were identified. The Simpson’s index of diversity (D) values for the individual locus ranged from 0.79 to 0.92, with the D value of all combined five microsatellite loci being 0.99. Microsatellite data analysis revealed that isolates from Ocimum sanctum, Capsicum annuum (chili pepper), and Mangifera indica (mango) formed distinct clusters, therefore exhibited some level of correlation between certain genotypes and host. The developed MLMT method would be a powerful tool for studying the genetic diversity and any possible genotype-host correlation in C. gloeosporioides.

Diversity and distribution of gall-forming aphids of the genus Pemphigus (Sternorrhyncha: Aphididae, Pemphigini) in Eastern Siberia

Nikita Babichev,Natalia Kirichenko 국립중앙과학관 2020 Journal of Asia-Pacific Biodiversity Vol.13 No.3

We reviewed the diversity and distribution of the gall-forming aphids of the genus Pemphigus developingon poplars in Eastern Siberia. As a result, the checklist of this group was compiled comprising 13 speciesdistributed in this macroregion that accounts about 29% of the world’s known poplar-feeding Pemphigusspecies. Biogeographical and host plant data are provided for all listed species. Pemphigus birimatusIvanovskaja, Pem. laurifoliae Dolgova, and Pem. matsumurai Monzen were documented for the first timein the Republic of Tuva. In addition, the latter two species were also discovered in the Republic ofBuryatia and Zabaikalskii Krai, respectively. Two poplars Populus sibirica and Pop. laurifolia wererecorded as novel hosts for 3 Pemphigus species. The origin of Pem. passeki Börner, Pem. spyrothecaePasserini, and Pem. microsetosus Aoki in Eastern Siberia remains unclear. Four species Pem. populiCourchet, Pem. bursarius (Linnaeus), Pem. matsumurai, and Pem. spyrothecae Lichtenstein cause noticeabledamage to poplars in man-made plantations.

Beneficial effect of phospholipase A2 group IIA inhibitors from Acacia suma in obesity: an in silico and in vitro study

Nikita Kanbarkar,Sanjay Mishra,Pukar Khanal 경희대학교 융합한의과학연구소 2020 Oriental Pharmacy and Experimental Medicine Vol.20 No.4

Acacia suma Roxb. (Fabaceae) is Ayurvedic medicine distributed in Karnataka, Bengal and Bihar region. Phytoconstituents of A. suma were retrieved from ChEIB databases and queried for phospholipase A2 group IIA inhibitors. The present study is an effort to find out a novel therapeutic solution for the management of obesity disorders. Out of 29 reported compounds three were identified in modulating phospholipase A2 group IIA inhibitor their drug likeness score andprobable gene expression was identified. Docking study was performed using autodock4.0 to predict binding affinity of phytoconstituents with phospholipase A2 group IIA inhibitor and compared with clinically proven drug ‘Orlistat’ as lipase inhibitor. The respected pathway to show networking between phytochemicals and target were analyse by kyoto encyclopedia of genes and genomes pathway analysis for regulated genes. Further, in silico findings were validated for hydroalcoholic extract of A. suma by in vitro lipase inhibition assay. Molecular docking result revealed the presence of three flavonoid compounds for lipase inhibition activity namely: (1) (5S,7R,8R,9R,10S)-(−)-7,8–seco-7,8–oxacassa-13,15-diene-7,17-diol (2) Fisetinidol-(4α,6)-gallocatechin and (3) Quercetin4′-O-α-l-rhamnopyranosyl-3-O-β-d-allopyranoside. However, Quercetin4′-O-α-l-rhamnopyranosyl-3-O-β- d-allopyranoside was predicted to possess the highest docking score i.e. − 7.6 kcal/mol with phospholipase A2 group IIA. The in vitro findings revealed significant anti-lipase activity with IC50 value − 46.07 μg/ml. Hence, the in silico and in vitro approaches has presented strong binding affinity and significant lipase inhibition activity respectively which supports antiobesity potential of heart wood hydroalcoholic extract of A. suma.

Ultra-high Efficiency Ion Heating System Technology for Industrial and Building Heat Supply

Nikita Ha(하은정) 한국태양에너지학회 2023 한국태양에너지학회 학술대회논문집 Vol.2023 No.4

Carbon nanotubes: synthesis, properties and engineering applications

Nikita Gupta,Shipra Mital Gupta,S. K. Sharma 한국탄소학회 2019 Carbon Letters Vol.29 No.5

Carbon nanotubes (CNT) represent one of the most unique materials in the field of nanotechnology. CNT are the allotrope of carbon having sp2 hybridization. CNT are considered to be rolled-up graphene with a nanostructure that can have a length to diameter ratio greater than 1,000,000. CNT can be single-, double-, and multi-walled. CNT have unique mechanical, electrical, and optical properties, all of which have been extensively studied. The novel properties of CNT are their light weight, small size with a high aspect ratio, good tensile strength, and good conducting characteristics, which make them useful for various applications. The present review is focused on the structure, properties, toxicity, synthesis methods, growth mechanism and their applications. Techniques that have been developed to synthesize CNT in sizeable quantities, including arc discharge, laser ablation, chemical vapor deposition, etc., have been explained. The toxic effect of CNT is also presented in a summarized form. Recent CNT applications showing a very promising glimpse into the future of CNT in nanotechnology such as optics, electronics, sensing, mechanical, electrical, storage, and other fields of materials science are presented in the review.