OLEDs as prospective light sources for microstructured photoreactors

2014 ◽  
Vol 13 (7) ◽  
pp. 1005-1015 ◽  
Author(s):  
Dirk Ziegenbalg ◽  
Günter Kreisel ◽  
Dieter Weiß ◽  
Dana Kralisch
Keyword(s):  
Photochemical Reactions ◽  
Light Sources ◽  
First Time

The use of OLEDs to initiate photochemical reactions is demonstrated for the first time by conducting photooxygenations in a modular microstructured photoreactor.

Photochemical reactions of azo compounds. IX. Further studies related to the photochemical reactions of bisazo compounds

1967 ◽  
Vol 20 (2) ◽  
pp. 321 ◽  
Author(s):  
NC Jamieson ◽  
GE Lewis
Keyword(s):  
Sulphuric Acid ◽  
Photochemical Reaction ◽  
Photochemical Reactions ◽  
Azo Compounds ◽  
Bisazo Compounds ◽  
First Time

The photochemical reactions of 4,4?-bis(phenylazo)biphenyl and 4- phenyl-azoazobenzene in 98% sulphuric acid have been examined, for comparison with the corresponding reactions in 22N acid. Photochemical cyclodehydrogenation of 4-phenylazoazobenzene to two benzo[c]cinnoline derivatives has thereby been effected for the first time. The observed course of the latter reaction has led, in turn, to studies of the benzidine rearrangement of 2-(2-phenylhydrazino)benzo[c]- cinnoline, of the photochemical cyclodehydrogenation of 3-phenylazobenzene, and of the photochemical reaction of 2-phenylazobenzo[c]cinnoline. The results of these investigations are now recorded and discussed.

LED Light Sources in Organic Synthesis: An Entry to A Novel Approach

2021 ◽  
Vol 18 ◽  
Author(s):  
Aparna Das
Keyword(s):  
Organic Compounds ◽  
Organic Synthesis ◽  
Photochemical Reaction ◽  
Low Cost ◽  
Environmentally Friendly ◽  
Photochemical Reactions ◽  
Light Sources ◽  
Blue Led ◽  
Oxidation Reduction ◽  
Novel Approach

: In recent years, photocatalytic technology has shown great potential as a low-cost, environmentally friendly, and sustainable technology. Compared to other light sources in photochemical reaction, LEDs have advantages in terms of efficiency, power, compatibility, and environmentally-friendly nature. This review highlights the most recent advances in LED-induced photochemical reactions. The effect of white and blue LEDs in reactions such as oxidation, reduction, cycloaddition, isomerization, and sensitization is discussed in detail. No other reviews have been published on the importance of white and blue LED sources in the photocatalysis of organic compounds. Considering all the facts, this review is highly significant and timely.

scholarly journals Illuminating Insights into the Biodiversity of the Australian Psyllids (Hemiptera: Psylloidea) Collected Using Light Trapping

Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 354
Author(s):  
Francesco Martoni ◽  
Gary S. Taylor ◽  
Mark J. Blacket
Keyword(s):  
Host Plants ◽  
Light Trapping ◽  
Light Sources ◽  
Undescribed Species ◽  
Biological Control Agents ◽  
Numerous Species ◽  
Lack Of Information ◽  
Species Of Conservation Concern ◽  
Conservation Concern ◽  
First Time

The superfamily Psylloidea includes numerous species which play a key role in Australian ecology and biodiversity, as well as pests and biological control agents, and sometimes threatened species of conservation concern. Different psyllid sampling and collection techniques are usually performed depending on the nature and aim of the study: from the beating and sweeping of psyllid host plants for conservation and biodiversity assessment, to suction and sticky traps in agriculture. Due to a general lack of information on its efficacy for psyllids, however, light trapping has not usually been employed. Here we present the results obtained trapping psyllids using different light sources and we discuss the strengths and weaknesses of this technique to assess psyllid biodiversity. In particular, we highlight the strength of using this methodology paired with DNA barcoding, to cast some light on psyllid biodiversity. The results obtained here suggest that the psyllid fauna of Australia is heavily understudied and the number of undescribed species might be many times higher than previously expected. Additionally, we report, for the first time, the species Trioza adventicia Tuthill 1952, and Cryptoneossa triangula Taylor 1990 in the state of Queensland.

scholarly journals Spatial–Spectral Evidence of Glare Influence on Hyperspectral Acquisitions

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4374
Author(s):  
Alberto Signoroni ◽  
Mauro Conte ◽  
Alice Plutino ◽  
Alessandro Rizzi
Keyword(s):  
Hyperspectral Image ◽  
Imaging System ◽  
Reflectance Spectra ◽  
Hyperspectral Images ◽  
Imaging Systems ◽  
Light Sources ◽  
Optical Phenomenon ◽  
Lighting Conditions ◽  
First Time ◽  
Glare Effect

Glare is an unwanted optical phenomenon which affects imaging systems with optics. This paper presents for the first time a set of hyperspectral image (HSI) acquisitions and measurements to verify how glare affects acquired HSI data in standard conditions. We acquired two ColorCheckers (CCs) in three different lighting conditions, with different backgrounds, different exposure times, and different orientations. The reflectance spectra obtained from the imaging system have been compared to pointwise reference measures obtained with contact spectrophotometers. To assess and identify the influence of glare, we present the Glare Effect (GE) index, which compares the contrast of the grayscale patches of the CC in the hyperspectral images with the contrast of the reference spectra of the same patches. We evaluate, in both spatial and spectral domains, the amount of glare affecting every hyperspectral image in each acquisition scenario, clearly evidencing an unwanted light contribution to the reflectance spectra of each point, which increases especially for darker pixels and pixels close to light sources or bright patches.

scholarly journals SYNTHESIS OF ZINC SULFIDE RADIOLUMINESCENT PHOSPHORS WITH USE OF ELECTRONIC BEAM MODIFICATION AND INVESTIGATION OF THEIR PROPERTIES

2021 ◽  
Vol 58 ◽  
pp. 46-50
Author(s):  
Mikhail A. Shvindin ◽  
◽  
Vadim V. Bakhmetyev ◽  
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Electron Beam ◽  
Solid State ◽  
Zinc Sulfide ◽  
Spectral Characteristics ◽  
Light Sources ◽  
Synthesis Conditions ◽  
Radioluminescent Light Sources ◽  
First Time

Synthesized recombination-type zinc sulfide phosphors used in solid-state radioluminescent light sources (SSRLS) are the object of the research. In the course of the study, experimental data were obtained for the first time on the effect of the amount of the incorporated activator on the brightness-spectral characteristics of radioluminescence upon excitation by β-radiation of tritium. Data were obtained on the changes in the radioluminescence parameters under various synthesis conditions, phase composition and electron-beam modification of the crystal structure of the initial phosphors. The results of the work make it possible to find the best light compositions for the use in solid-state radioluminescent light sources

scholarly journals Far-UVC light: A new tool to control the spread of airborne-mediated microbial diseases

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
David Welch ◽  
Manuela Buonanno ◽  
Veljko Grilj ◽  
Igor Shuryak ◽  
Connor Crickmore ◽  
...  
Keyword(s):  
Public Health ◽  
Low Dose ◽  
H1n1 Influenza ◽  
Light Sources ◽  
H1n1 Influenza Virus ◽  
Microbial Diseases ◽  
Low Dose Rate ◽  
Mammalian Skin ◽  
Public Health Challenges ◽  
First Time

AbstractAirborne-mediated microbial diseases such as influenza and tuberculosis represent major public health challenges. A direct approach to prevent airborne transmission is inactivation of airborne pathogens, and the airborne antimicrobial potential of UVC ultraviolet light has long been established; however, its widespread use in public settings is limited because conventional UVC light sources are both carcinogenic and cataractogenic. By contrast, we have previously shown that far-UVC light (207–222 nm) efficiently inactivates bacteria without harm to exposed mammalian skin. This is because, due to its strong absorbance in biological materials, far-UVC light cannot penetrate even the outer (non living) layers of human skin or eye; however, because bacteria and viruses are of micrometer or smaller dimensions, far-UVC can penetrate and inactivate them. We show for the first time that far-UVC efficiently inactivates airborne aerosolized viruses, with a very low dose of 2 mJ/cm2 of 222-nm light inactivating >95% of aerosolized H1N1 influenza virus. Continuous very low dose-rate far-UVC light in indoor public locations is a promising, safe and inexpensive tool to reduce the spread of airborne-mediated microbial diseases.

scholarly journals Photodynamic Therapy: A Compendium of Latest Reviews

Cancers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 4447
Author(s):  
José Francisco Algorri ◽  
Mario Ochoa ◽  
Pablo Roldán-Varona ◽  
Luís Rodríguez-Cobo ◽  
José Miguel López-Higuera
Keyword(s):  
Photodynamic Therapy ◽  
Light Sources ◽  
Scientific Publications ◽  
Wide Audience ◽  
Broad Scope ◽  
Key Issues ◽  
Meta Analyses ◽  
First Time

Photodynamic therapy (PDT) is a promising therapy against cancer. Even though it has been investigated for more than 100 years, scientific publications have grown exponentially in the last two decades. For this reason, we present a brief compendium of reviews of the last two decades classified under different topics, namely, overviews, reviews about specific cancers, and meta-analyses of photosensitisers, PDT mechanisms, dosimetry, and light sources. The key issues and main conclusions are summarized, including ways and means to improve therapy and outcomes. Due to the broad scope of this work and it being the first time that a compendium of the latest reviews has been performed for PDT, it may be of interest to a wide audience.

scholarly journals On the Sustainability of Photochemical Reactions

2019 ◽  
Vol 73 (9) ◽  
pp. 720-723 ◽  
Author(s):  
Christian G. Bochet
Keyword(s):  
Uv Light ◽  
Environmentally Friendly ◽  
Photochemical Reactions ◽  
Light Sources ◽  
Photoredox Catalysis ◽  
Recent Introduction ◽  
Short Essay ◽  
A Current

Photochemical reactions are often presented as intrinsically environmentally friendly ('green'). This may be indeed the case, but only in particular circumstances. This short essay comments on various aspects of the greenness of photochemical reactions, both in a historical (when only mercury-based hard UV light sources were available) and a current (with the recent introduction of LED technology and photoredox catalysis) perspective.

Peripheral Detection of Reflectorized License Plates

1986 ◽  
Vol 30 (4) ◽  
pp. 408-412
Author(s):  
Helmut T. Zwahlen
Keyword(s):  
Visual Field ◽  
License Plate ◽  
Light Sources ◽  
Detection Distance ◽  
Horizontal Curves ◽  
Detection Angle ◽  
The Right ◽  
First Time ◽  
Order Of Presentation ◽  
Made In

This paper contains data on the peripheral detection distances of a reflectorized license plate (24 CIL) at night. Detection distances were obtained for two car heading angles (-3 degrees to the left and 10 degrees to the right), and seven detection angles (-30, −20, −10, 0, 10, 20, and 30 degrees) using two groups of 7 young and healthy drivers each. The order of presentation for the 7 detection angles was random and balanced. Each driver sat in a stationary car on a 2000 feet long runway and detected an approaching target under low beam conditions against a background containing a number of luminaires and other light sources. There were three parallel approach paths on the runway. A total of nine consecutive approaches were made for each detection angle. The approaches were divided into 3 blocks and within each block each approach path was randomly chosen once. Each subject detected a total of 63 approaching targets. The results of this study indicate that the average peripheral detection distance for a 30 degree peripheral detection angle can be as short as 25 percent of the average foveal detection distance, while a 20 degree peripheral detection angle resulted in an average peripheral detection distance 3 6 percent of the average foveal detection distance and a 10 degree peripheral detection angle resulted in an average peripheral detection distance of 54 percent of the average foveal detection distance. Based upon the peripheral detection distances obtained in this study we conclude that in roadway situations such as in horizontal curves where reflective targets could become visible for the first time in the periphery of a driver's visual field, appropriate increases in the reflecitvity of a target must be made in order to assure timely detection.

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