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.

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.

Immobilization of ZnO Suspension on Glass Substrate to Remove Filtration During the Removal of Remazol Red R from Aqueous Solution

2016 ◽  
Vol 12 (6) ◽  
pp. 4127-4133
Author(s):  
Nazmul Kayes ◽  
Jalil Miah ◽  
Md. Obaidullah ◽  
Akter Hossain ◽  
Mufazzal Hossain
Keyword(s):  
Aqueous Solution ◽  
Glass Substrate ◽  
Uv Light ◽  
Aqueous Suspension ◽  
Light Irradiation ◽  
Zno Films ◽  
Light Sources ◽  
Zno Film ◽  
Semiconductor Oxides ◽  
Remazol Red

Photodegradation of textile dyes in the presence of an aqueous suspension of semiconductor oxides has been of growing interest. Although this method of destruction of dyes is efficient, the main obstacle of applying this technique in the industry is the time and cost involving separation of oxides from an aqueous suspension. In this research, an attempted was made to develop ZnO films on a glass substrate by simple immobilization method for the adsorption and photodegradation of a typical dye, Remazol Red R (RRR) from aqueous solution. Adsorption and photodegradation of  RRR were performed in the presence of glass supported ZnO film. Photodegradation of the dye was carried out by varying different parameters such as the catalyst dosage, initial concentrations of RRR, and light sources. The percentage of adsorption as well as photodegradation increased with the amount of ZnO, reaches a maximum and then decreased. Maximum degradation has been found under solar light irradiation as compared to UV-light irradiation. Removal efficiency was also found to be influenced by the pre-sonication of ZnO suspension.

scholarly journals Beeporter: a high-throughput tool for non-invasive analysis of honey bee virus infection

2021 ◽  
Author(s):  
Jay D. Evans ◽  
Olubukola Banmeke ◽  
Evan C. Palmer-Young ◽  
Yanping Chen ◽  
Eugene V. Ryabov
Keyword(s):  
Virus Infection ◽  
Honey Bee ◽  
High Throughput ◽  
Honey Bees ◽  
High Throughput Screening ◽  
Fluorescent Protein ◽  
Imaging System ◽  
Uv Light ◽  
Light Sources ◽  
Deformed Wing Virus

ABSTRACTHoney bees face numerous pests and pathogens but arguably none are as devastating as Deformed wing virus (DWV). Development of antiviral therapeutics and virus-resistant honey bee lines to control DWV in honey bees is slowed by the lack of a cost-effective high-throughput screening of DWV infection. Currently, analysis of virus infection and screening for antiviral treatments in bees and their colonies is tedious, requiring a well-equipped molecular biology laboratory and the use of hazardous chemicals. Here we utilize a cDNA clone of DWV tagged with green fluorescent protein (GFP) to develop the Beeporter assay, a method for detection and quantification of DWV infection in live honey bees. The assay involves infection of honey bee pupae by injecting a standardized DWV-GFP inoculum, followed by incubation for up to 44 hours. GFP fluorescence is recorded at intervals via commonly available long-wave UV light sources and a smartphone camera or a standard ultraviolet transilluminator gel imaging system. Nonlethal DWV monitoring allows high-throughput screening of antiviral candidates and a direct breeding tool for identifying honey bee parents with increased antivirus resistance. For even more rapid drug screening, we also describe a method for screening bees using 96-well trays and a spectrophotometer.

scholarly journals Visible-Light Photoswitching of G-Quadruplex Ligand Binding Mode Allows Reversible Control of G-Tetrad Structure

2020 ◽  
Author(s):  
Michael O'Hagan ◽  
Javier Ramos Soriano ◽  
Susanta Haldar ◽  
Juan Carlos Morales ◽  
Adrian Mulholland ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Visible Light ◽  
Uv Light ◽  
Binding Mode ◽  
High Energy ◽  
Light Sources ◽  
Biologically Relevant ◽  
G Quadruplex ◽  
Potential Applications ◽  
Robust Regulation

<div><p>Photoresponsive ligands for G-quadruplex oligonucleotides (G4) offer exciting opportunities for the reversible regulation of these assemblies with potential applications in biological chemistry and responsive nanotechnology. However, achieving the robust regulation of G4 ligand activity with low-energy visible light sources that are easily accessible and compatible with biological systems remains a significant challenge to realizing these applications. Herein, we report the G4-binding properties of a photoresponsive dithienylethene (DTE). We demonstrate the first example of G4-specific acceleration of the photoswitching kinetics of a small molecule and the visible-light mediated switching of the G4 ligand binding mode in physiologically-relevant conditions, which in turn allows control over the G4 tetrad structure of telomeric G4 in potassium buffer. The process is fully reversible and avoids the need for high-energy UV light. This affords an efficient, practical and biologically-relevant means of control that may be applied in the generation of new responsive G4/ligand supramolecular systems.</p></div><br>

scholarly journals Researching CdZnS/ZnS (GT) Quantum Dots in Cathodoluminescent Mode

2019 ◽  
Vol 8 (9S2) ◽  
pp. 841-843
Keyword(s):  
Quantum Dots ◽  
Research And Development ◽  
Uv Light ◽  
Spectral Characteristics ◽  
Light Sources ◽  
Application Field ◽  
Medium Pressure

Application field of UV light sources is getting larger at the last decades. Among the most widespread are high and medium pressure vacuum lamps. But there currently is a trend of moving away from using mercury both in household applications and manufacturing. This creates a necessity to conduct research and development for UV sources made and operating without Hg. Cathodoluminescent UV sources are in this category. One of the possible ways to create a viable UV anode phosphor is using quantum dots with needed spectral characteristics.

scholarly journals Effect of light on aggregational behavior of planarian Dugesia tigrina

2017 ◽  
Author(s):  
Jaemin Lee
Keyword(s):  
Defense Mechanisms ◽  
Uv Light ◽  
Infrared Light ◽  
Light Sources ◽  
Initial Exposure ◽  
Dugesia Tigrina ◽  
Wide Range ◽  
Photophobic Response ◽  
Negative Effect ◽  
Effect Of Light

Introduction. Planarians are renowned for their regenerative ability due to pluripotent stem cells, as well as their peculiar photophobic response. However, few facts are known about their aggregational behavior. This study aims to reveal the effect of light on aggregational behavior. Reynierse (1966) suggested that light has a negative effect on the formation of aggregations. However, one of his objectives for aggregational behavior was inappropriate. This study reevaluated the effect of existence of light on aggregational behavior, as well as ascertained the effect of wavelength on the formation of aggregations. Methods. In this study, the ratio of individuals participating in aggregations was measured as a criterion to determine aggregational behavior. Aggregational behavior was measured after two hours from the initial exposure to different light sources. The behaviors under white LED light and under shade were compared, as well as the behaviors under five different light sources: infrared lamp, red, green, blue LED, and ultraviolet lamp. Results. The existence of light interfered the formation of aggregations (t-test, p < 0.0001), which supports the former study of Reynierse. Also, aggregational behavior differed under different wavelengths (ANOVA, p < 0.0001). Except for the infrared light which emitted a wide range of wavelengths, the behavior showed hierarchy: decreasing aggregational behavior in accordance with decreasing wavelength. UV light has the most significant negative effect on the formation of aggregations. Discussion. Exposure to light caused negative effects on performing aggregational behavior. Participation in aggregations appears to be influenced by photophobic response, especially under lights of short wavelength. Disintegrating aggregations under exposure to lights can potentially bring evolutionary benefit. This behavior possibly makes the aggregating planarians altogether exposed to a higher risk or predation, considering that they lack defense mechanisms. Planarians can lower the risk and continue the populations by disintegrating the aggregational behavior under the existence of UV and lights of higher wavelength, which are indicatives of daytime. Understanding aggregational behavior of animals of a lower order would give better insight on general herding behavior, and potentially help interpreting more complex behaviors of higher animals.

scholarly journals TIPS-Naphthalene for Efficient Visible-to-UV Photon Upconversion under Sunlight and Room Light

2020 ◽  
Author(s):  
Naoyuki Harada ◽  
Yoichi Sasaki ◽  
Masanori Hosoyamada ◽  
Nobuo Kimizuka ◽  
Nobuhiro Yanai
Keyword(s):  
High Performance ◽  
Uv Light ◽  
Light Sources ◽  
Solar Simulator ◽  
Visible Absorption ◽  
Excitation Light ◽  
Uv Emission ◽  
Threshold Excitation ◽  
Weak Light ◽  
Optimized Conditions

Until now, the efficiency of triplet-triplet annihilation-based photon upconversion (TTA-UC) from visible to ultraviolet (UV) light has been limited to ca. 10% due to the absence of high-performance acceptors (emitters). Here, we present the first example of visible-to-UV TTA-UC internal efficiency <i>η</i><sub>UC</sub> beyond 20% by developing a novel UV emitter, 1,4-bis((triisopropylsilyl)ethynyl)naphthalene (TIPS-Nph), and sensitizing its triplet by a donor Ir(C6)<sub>2</sub>(acac) with strong visible absorption and weak UV absorption. Under optimized conditions, 97% of the excitation light is absorbed, the threshold excitation intensity (<i>I</i><sub>th</sub> = 1.1 mW cm<sup>−2</sup>) is lower than the solar irradiance (1.4 mW cm<sup>−2</sup> for 445 ± 5 nm), and significantly, the highest external UC efficiency <i>η</i><sub>UC,ext</sub> of 17.4% for vis-to-UV TTA-UC is achieved. Upconverted UV emission can also be obtained with weak light sources such as an AM 1.5 solar simulator and room LEDs, paving the way for a variety of solar and indoor applications.

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.

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