scholarly journals Detection of Counterfeit Tequila by Fluorescence Spectroscopy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
José Manuel de la Rosa Vázquez ◽  
Diego Adrián Fabila-Bustos ◽  
Luis Felipe de Jesús Quintanar-Hernández ◽  
Alma Valor ◽  
Suren Stolik
Keyword(s):  
Fluorescence Spectroscopy ◽  
Fluorescence Intensity ◽  
Uv Light ◽  
Fluorescence Emission ◽  
Good Method ◽  
Fluorescence Signal ◽  
Fluorescence Measurement ◽  
Fluorescence Study ◽  
Light Emitting ◽  
High Fluorescence

An ultraviolet (UV) light induced fluorescence study to discriminate fake tequila from genuine ones is presented. A portable homemade system based on four light emitting diodes (LEDs) from 255 to 405 nm and a miniature spectrometer was used. It has been shown that unlike fake and silver tequila, which produce weak fluorescence signal, genuine mixed, rested, and aged tequilas show high fluorescence emission in the range from 400 to 750 nm. The fluorescence intensity grows with aging in 100% agave tequila. Such fluorescence differences can even be observed with naked eyes. The presented results demonstrate that the fluorescence measurement could be a good method to detect counterfeit tequila.

scholarly journals Enhancement of UV Excited Photoluminescence by Fabry-Perot Microcavity

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Chunxian Tao ◽  
Jun Ruan ◽  
Dong Liang ◽  
Zhaoxia Han ◽  
Liang He ◽  
...  
Keyword(s):  
Uv Light ◽  
Resonant Cavity ◽  
Fluorescence Emission ◽  
Light Emitting ◽  
Dielectric Mirror ◽  
Fabry Perot ◽  
Measurement Results ◽  
Phosphor Coating ◽  
Uv Visible ◽  
Higher Sensitivity

A light-emitting microcavity with the structure of dielectric mirror/phosphor coating/dielectric mirror for the enhancement of PL efficiency excited under UV light was designed and fabricated. The fluorescence emission of Lumogen S0795 coating within microcavity structure is significantly enhanced compared with the coating on bare substrate. The measurement results indicate the possibility of developing front illuminated CCD based on optical resonant cavity for UV-visible imaging with higher sensitivity.

scholarly journals Construction of Thermo-Responsive Elastin-Like Polypeptides (ELPs)-Aggregation-Induced-Emission (AIE) Conjugates for Temperature Sensing

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1725 ◽  
Author(s):  
Zhe Chen ◽  
Zhaoyang Ding ◽  
Guangya Zhang ◽  
Leilei Tian ◽  
Xuanjun Zhang
Keyword(s):  
Fluorescence Intensity ◽  
Gel Electrophoresis ◽  
Emission Spectroscopy ◽  
Water Solubility ◽  
Fluorescence Emission ◽  
Amide Bond ◽  
Aggregation Induced Emission ◽  
Bio Imaging ◽  
High Fluorescence Intensity ◽  
High Fluorescence

In this work, an aggregation-induced emission (AIE) molecule (tetraphenylethene derivative, TPE-COOH) was conjugated to elastin-like polypeptides (ELPs40) via an amide bond to form ELPs40-TPE. The successful synthesis of ELPs40-TPE was confirmed by Circular Dichroism spectroscopy, gel electrophoresis, UV-vis absorption, and fluorescence emission spectroscopy. ELPs40-TPE possessed both amphiphilicity and the features of an AIE, and the fluorescence intensity was dependent on the local temperature. The Hela cells imaging indicated that ELPs40-TPE has great potential for bio-imaging applications because of its advantages of high fluorescence intensity, good water-solubility, and remarkable biocompatibility.

An attempt to correlate the physical properties of fossil and subfossil resins with their age and geographic location

2019 ◽  
Vol 39 (8) ◽  
pp. 716-728 ◽  
Author(s):  
Paweł Stach ◽  
Gintarė Martinkutė ◽  
Petras Šinkūnas ◽  
Lucyna Natkaniec-Nowak ◽  
Przemysław Drzewicz ◽  
...  
Keyword(s):  
Physical Properties ◽  
Fluorescence Intensity ◽  
Chemical Structure ◽  
Fluorescence Emission ◽  
Geographic Location ◽  
Principal Component ◽  
Physical Parameters ◽  
Geological Conditions ◽  
Natural Resins ◽  
High Fluorescence

Abstract Testing of the correlation between physical properties of natural resins such as microhardness, density and UV-excited fluorescence emission with their age, geological conditions, botanical and geographical origin and chemical structure was performed. These physical parameters, especially microhardness, are the result of resins fossilization processes like cross-linking and polymerizations of compounds present in the fossils. In addition, hardening of the resins may be also an effect of miscellaneous chemical processes induced by various environmental, biological and geological conditions. The principal component analysis found that the correlation of microhardness, density and fluorescence intensity with the resin age is quite low. The results suggest that variability of physical properties is caused by geographic location and locally occurring geological conditions. The physical properties of natural resins are most strongly correlated with chemical structure and geographic location. The resins with higher microhardness values come from marine environment depositions. The same trend was observed for resins affected by volcanic activity. Moreover, high fluorescence intensity was also observed for resins affected by above mentioned geological conditions. However, the density values of tested resins revealed the lowest correlation with their age, botanical source and geological history.

Synthesis, aggregation-induced emission and electroluminescence properties of three new phenylethylene derivatives comprising carbazole and (dimesitylboranyl)phenyl groups

2017 ◽  
Vol 5 (45) ◽  
pp. 11741-11750 ◽  
Author(s):  
Heping Shi ◽  
Xinlei Zhang ◽  
Chen Gui ◽  
Shujuan Wang ◽  
Li Fang ◽  
...  
Keyword(s):  
Solid State ◽  
Fluorescence Intensity ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Aggregation Induced Emission ◽  
Organic Light ◽  
High Fluorescence Intensity ◽  
High Fluorescence

It is essential that light-emitting materials possess high fluorescence intensity in the solid-state and a stable charge-transporting ability for the construction of organic light-emitting diodes (OLEDs) with outstanding performance.

Quantitative Measurement of Fluorescent Layers with Respect to Spatial Thickness Variations and Substrate Properties

2020 ◽  
Vol 74 (4) ◽  
pp. 439-451
Author(s):  
Philipp Holz ◽  
Christoph Pönisch ◽  
Albrecht Brandenburg
Keyword(s):  
Manufacturing Industry ◽  
Quantitative Measurement ◽  
Fluorescence Emission ◽  
Fluorescence Analysis ◽  
Thin Layers ◽  
Fluorescence Signal ◽  
Functional Coatings ◽  
Custom Made ◽  
Substrate Properties ◽  
Thickness Variations

Imaging fluorescence spectroscopy proves to be a fast and sensitive method for measuring the thickness of thin coatings in the manufacturing industry. This encouraged us to systematically study, theoretically and experimentally, parameters that influence the fluorescence of thin layers. We analyzed the fluorescence signal as a function of the scattering and reflectance properties of the sample substrate. In addition, we investigated effects of the layer properties on fluorescence emission. A ray-tracing software is used to describe the influence of these parameters on the fluorescence emission of thin layers. Experiments using a custom-made system for imaging fluorescence analysis verify the simulations. This work shows a factor five variation of fluorescence intensity as a function of the reflectance of the sample substrate. Simulations show variations by a factor of up to eight for samples with different surface roughness. Results on tilted samples indicate a significant increase of the detected fluorescence signal, for fluorescent droplets on reflective substrates, if illuminated and coaxially observed at angles greater than 25°. These findings are of utmost relevance for all applications which utilize the fluorescence emission to quantify thin layers. These applications range from in-line lubricant monitoring in press plants to monitoring of functional coatings in medical technology and the detection of filmic contaminations.

Performance of vertical type deep UV light-emitting diodes depending on the Ga-face n-contact hole density

2021 ◽  
Vol 118 (23) ◽  
pp. 231102
Author(s):  
Youn Joon Sung ◽  
Dong-Woo Kim ◽  
Geun Young Yeom ◽  
Kyu Sang Kim
Keyword(s):  
Light Emitting Diodes ◽  
Uv Light ◽  
Hole Density ◽  
Light Emitting ◽  
Deep Uv

New Results on Electroluminescence from Porous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
Peter Steiner ◽  
Frank Kozlowski ◽  
Hermann Sandmaier ◽  
Walter Lang
Keyword(s):  
Porous Silicon ◽  
Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Uv Light ◽  
Green Light ◽  
Light Emitting ◽  
Porous Region ◽  
First Results

ABSTRACTFirst results on light emitting diodes in porous silicon were reported in 1991. They showed a quantum efficiency of 10-7 to 10-5 and an orange spectrum. Over the last year some progress was achieved:- By applying UV-light during the etching blue and green light emitting diodes in porous silicon are fabricated.- When a p/n junction is realized within the porous region, a quantum efficiency of 10-4 is obtained.

Robust 285 nm Deep UV Light Emitting Diodes over Metal Organic Hydride Vapor Phase Epitaxially Grown AlN/Sapphire Templates

2007 ◽  
Vol 46 (No. 23) ◽  
pp. L537-L539 ◽  
Author(s):  
Vinod Adivarahan ◽  
Qhalid Fareed ◽  
Surendra Srivastava ◽  
Thomas Katona ◽  
Mikhail Gaevski ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Light Emitting Diodes ◽  
Uv Light ◽  
Light Emitting ◽  
Organic Hydride ◽  
Metal Organic ◽  
Deep Uv

Synthesis of NIR-emitting O-chelated BODIPYs fused with benzene and acenaphthylene

2014 ◽  
Vol 18 (08n09) ◽  
pp. 752-761 ◽  
Author(s):  
Tetsuo Okujima ◽  
Yoichi Shida ◽  
Keishi Ohara ◽  
Yuya Tomimori ◽  
Motoyoshi Nishioka ◽  
...  
Keyword(s):  
Near Infrared ◽  
Photophysical Properties ◽  
Fluorescence Emission ◽  
Fluorescence Measurement ◽  
Aromatic Rings ◽  
Nir Absorption ◽  
Intense Absorption ◽  
Near Infrared Dye

A series of O-chelated BODIPYs fused with aromatic rings such as benzene and acenaphthylene at β,β-positions was synthesized as a near-infrared dye. The photophysical properties were examined by UV-vis-NIR absorption and fluorescence measurement. Acenaphthylene-fused O-BODIPYs showed a intense absorption at 750–840 nm with the ε of 105 M-1.cm-1. and a fluorescence emission at 770–850 nm with the high Φ value of 0.06–0.43.

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