Characterization of tri-o-methylcellulose by one- and two-dimensional NMR methods

1999 ◽  
Vol 37 (21) ◽  
pp. 4019-4032 ◽  
Author(s):  
Navzer D. Sachinvala ◽  
Othman A. Hamed ◽  
David L. Winsor ◽  
Walter P. Niemczura ◽  
Karol Maskos ◽  
...  
Keyword(s):  
Two Dimensional ◽  
Nmr Methods

Chemical constituents of two Ecuadorian medicinal plants, Tagetes terniflora Kunth and Croton rivinifolius Kunth

2021 ◽  
Author(s):  
Alírica I Suárez ◽  
Vladimir Morocho ◽  
Vladimir Luna ◽  
Katty Castillo ◽  
Chabaco Armijos
Keyword(s):  
Medicinal Plants ◽  
Spectroscopic Analysis ◽  
Chemical Constituents ◽  
Two Dimensional ◽  
Phytochemical Study ◽  
Isolation And Characterization ◽  
Organic Extracts ◽  
Medicinal Properties ◽  
Nmr Methods

Phytochemical study of two medicinal plants from Ecuador, Tagetes terniflora Kunth, and Croton rivinifolius Kunth, led to the isolation and characterization of the major constituents present in the organic extracts obtained from these plants: 5-(4-acetoxy-1-butynil)-2,2’-bi-thiophene (1), 5-methyl-2,2’:5’,2”- terthiophene (2), patuletin (3) from Tagetes terniflora, and isocorydine (4), sweroside (5), tiliroside (6) from Croton rivinifolius. The structures of these compounds were established by spectroscopic analysis including two-dimensional NMR methods, MS, and comparison with published spectral data. They are recognized as secondary metabolites that represent the chemotaxonomy of Tagetes and Croton genera and could be responsible for the recognized medicinal properties attributed to these species. This paper deals with the first report that shows the presence of these compounds in these plants.

Characterization of compounds in crude oils by gas purge micro-syringe extraction coupled to comprehensive two-dimensional gas chromatography

2014 ◽  
Vol 32 (10) ◽  
pp. 1144
Author(s):  
Ting TONG ◽  
Wanfeng ZHANG ◽  
Donghao LI ◽  
Jinhua ZHAO ◽  
Zhenyang CHANG ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Crude Oils ◽  
Two Dimensional ◽  
Gas Purge

scholarly journals Terahertz characterization of two-dimensional low-conductive layers enabled by metal gratings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Prashanth Gopalan ◽  
Yunshan Wang ◽  
Berardi Sensale-Rodriguez
Keyword(s):  
Optical Transmission ◽  
Terahertz Spectroscopy ◽  
Design Guidelines ◽  
Two Dimensional ◽  
Highly Sensitive ◽  
Transmission Measurements ◽  
Metal Gratings ◽  
Low Sensitivity ◽  
Non Destructive

AbstractWhile terahertz spectroscopy can provide valuable information regarding the charge transport properties in semiconductors, its application for the characterization of low-conductive two-dimensional layers, i.e., σs <  < 1 mS, remains elusive. This is primarily due to the low sensitivity of direct transmission measurements to such small sheet conductivity levels. In this work, we discuss harnessing the extraordinary optical transmission through gratings consisting of metallic stripes to characterize such low-conductive two-dimensional layers. We analyze the geometric tradeoffs in these structures and provide physical insights, ultimately leading to general design guidelines for experiments enabling non-contact, non-destructive, highly sensitive characterization of such layers.

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