A simple method for water discrimination based on an light emitting diode (LED) photometer

2007 ◽  
Vol 596 (1) ◽  
pp. 66-72 ◽  
Author(s):  
Alexandre Fonseca ◽  
Ivo M. Raimundo
Keyword(s):  
Light Emitting Diode ◽  
Simple Method ◽  
Light Emitting ◽  
Led Photometer

A Compact Microcontrolled Microfluidic System for Photometric Determination of Phosphate in Natural Water Samples

2015 ◽  
Vol 68 (7) ◽  
pp. 1108 ◽  
Author(s):  
Osmundo Dantas Pessoa-Neto ◽  
Tiago Almeida Silva ◽  
Vagner Bezerra dos Santos ◽  
Orlando Fatibello-Filho
Keyword(s):  
Light Emitting Diode ◽  
Flow Analysis ◽  
Photometric Determination ◽  
Microfluidic System ◽  
Experimental Conditions ◽  
Light Emitting ◽  
Experimental Parameters ◽  
Led Photometer

A compact environmentally friendly microcontrolled microfluidic device ideal for in situ phosphate determination was developed based on a microsystem based on low-temperature co-fired ceramics (LTCC) coupled to a light-emitting diode (LED)–photometer with a multicommutation flow analysis (MCFA) approach. The experimental parameters of the MCFA analyzer were optimized by chemometric studies. Under the best experimental conditions, limits of detection and quantification of 0.02 mg P L–1 and 0.07 mg P L–1, respectively, and a sampling frequency of 67 h–1 were estimated. Moreover, a low sample consumption of only 60 μL per determination was the other advantage that fully meets the requirements of sustainable research and green chemistry purposes.

scholarly journals Encapsulation method developed for OLED devices mounted at laboratory

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Emerson Roberto Santos ◽  
Erik Yassuo Yuki ◽  
Wang Shu Hui
Keyword(s):  
Thin Film ◽  
Indium Tin Oxide ◽  
Electrical Resistance ◽  
Light Emitting Diode ◽  
Low Cost ◽  
Simple Method ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Polymer Semiconductor ◽  
Encapsulation Process

A simple method with low cost of encapsulation for organic light emitting diode (OLED) devices mounted at laboratory was proposed to obtain considerable increase of the lifetime. In this study, it was used a capsule formed by: glass slide as substrate, a layer of polyvinyl acetate glue diluted in methyl alcohol, a layer of calcium oxide as secant and epoxy placed at the edges of capsule. The performance of this capsule was analyzed using a thin film of polymer semiconductor called as PEDOT:PSS, that is sensitive to moisture and oxygen from atmospheric air. The PEDOT:PSS thin layer was deposited between anode and cathode electrodes using commercial indium tin oxide (ITO) thin film deposited on glass substrate. The capsule was placed covering completely the PEDOT:PSS thin film, and the electrical resistance was measured by elapsed days. This result revealed lowest electrical resistance compared with other methods, showing also good performance as encapsulation process.

Polymer Electrodes for Flexible Organic Light-Emitting Devices

2004 ◽  
Vol 814 ◽  
Author(s):  
Woohong Kim ◽  
Leonidas C. Palilis ◽  
Antti J. Mäkinen ◽  
Heungsoo Kim ◽  
Manabu Uchida ◽  
...  
Keyword(s):  
Polymer Film ◽  
Buffer Layer ◽  
Conducting Polymer ◽  
Light Emitting Diode ◽  
Plastic Substrate ◽  
Dramatic Improvement ◽  
Operating Voltage ◽  
Simple Method ◽  
Light Emitting ◽  
Organic Light

AbstractWe report a high luminance and low operating voltage molecular organic light-emitting diode (MOLED) using a conducting polymer hole-injecting electrode (anode) on a plastic substrate. A dramatic improvement in the rectification ratio is observed upon the insertion of a buffer layer between the conducting polymer anode and the organic hole-transporting layer (HTL). Micro-shorts leading to a leakage current caused by the non-uniformity of the polymer film are greatly reduced. Atomic force microscope (AFM) images show a much smoother surface of the polymer anode/buffer layer relative to that of the bare polymer film. A slight increase (0.3eV ± 0.2eV) in the work function of the polymer anode upon the addition of the buffer layer is also measured. A simple method of patterning the conducting polymer electrode on various substrates including plastics is also reported. This approach conveniently provides finely patterned conducting polymer films with νm resolution while maintaining their intrinsic electrical and optical properties such as the surface sheet resistance and the optical transmittance.

Multicolor luminescence in oxygen-deficient Tb3+-doped calcium aluminogermanate glasses

2008 ◽  
Vol 23 (7) ◽  
pp. 1890-1894 ◽  
Author(s):  
Geng Lin ◽  
Bin Zhu ◽  
Shifeng Zhou ◽  
Hucheng Yang ◽  
Jianrong Qiu
Keyword(s):  
White Light ◽  
Light Emitting Diode ◽  
Simple Method ◽  
Light Emitting ◽  
Led Lighting ◽  
Red Luminescence

In this paper, we report on the multicolor luminescence in oxygen-deficient Tb3+-doped calcium aluminogermanate glasses. A simple method was proposed to control oxygen-deficient defects in glasses by adding metal Al instead of the corresponding oxide (Al2O3), resulting in efficient blue and red emissions from Tb3+-undoped glasses with 300 and 380 nm excitation wavelengths, respectively. Moreover, in Tb3+-doped oxygen-deficient glasses, bright three-color (sky-blue, green or yellow, and red) luminescence was observed with 300, 380, and 395 nm excitation wavelengths, respectively. These glasses are useful for the fabrication of white light-emitting diode (LED) lighting.

scholarly journals Method to improve the survival of night-swarming mayflies near bridges in areas of distracting light pollution

2017 ◽  
Vol 4 (11) ◽  
pp. 171166 ◽  
Author(s):  
Ádám Egri ◽  
Dénes Száz ◽  
Alexandra Farkas ◽  
Ádám Pereszlényi ◽  
Gábor Horváth ◽  
...  
Keyword(s):  
Detrimental Effect ◽  
Light Emitting Diode ◽  
Egg Laying ◽  
Small Rivers ◽  
Light Pollution ◽  
Simple Method ◽  
Light Emitting ◽  
Artificial Lighting ◽  
Quality Degradation ◽  
Oviposition Sites

Numerous negative ecological effects of urban lighting have been identified during the last decades. In spite of the development of lighting technologies, the detrimental effect of this form of light pollution has not declined. Several insect species are affected including the night-swarming mayfly Ephoron virgo : when encountering bridges during their mass swarming, these mayflies often fall victim to artificial lighting. We show a simple method for the conservation of these mayflies exploiting their positive phototaxis. With downstream-facing light-emitting diode beacon lights above two tributaries of the river Danube, we managed to guide egg-laying females to the water and prevent them from perishing outside the river near urban lights. By means of measuring the mayfly outflow from the river as a function of time and the on/off state of the beacons, we showed that the number of mayflies exiting the river's area was practically zero when our beacons were operating. Tributaries could be the sources of mayfly recolonization in case of water quality degradation of large rivers. The protection of mayfly populations in small rivers and safeguarding their aggregation and oviposition sites is therefore important.

Synchronization of Chaotic Quantum Dot Light Emitting Diodes under Optical Feedback Effect

2020 ◽  
pp. 144-148
Keyword(s):  
Quantum Dot ◽  
Delay Time ◽  
Chaos Synchronization ◽  
Optical Feedback ◽  
Light Emitting Diode ◽  
Feedback Effect ◽  
Complete Synchronization ◽  
Light Emitting ◽  
Coupling Methods ◽  
Coupling Parameters

Chaos synchronization of delayed quantum dot light emitting diode has been studied theortetically which are coupled via the unidirectional and bidirectional. at synchronization of chaotic, The dynamics is identical with delayed optical feedback for those coupling methods. Depending on the coupling parameters and delay time the system exhibits complete synchronization, . Under proper conditions, the receiver quantum dot light emitting diode can be satisfactorily synchronized with the transmitter quantum dot light emitting diode due to the optical feedback effect.

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