Research and Implementation on Methods of Evaluating Lifetime of LED Light Source for LED Lighting System

2014 ◽  
Vol 941-944 ◽  
pp. 635-639
Author(s):  
Rong Wang ◽  
Hai Bo Ma ◽  
Bin Qu

This research adopts comprehensive evaluation to evaluate lifetime of LED light source for lighting system. By the method, under the condition of LED light source working outside, the situations of LED light source lifetime are analyzed with attenuation rate of illumination got from illumination data of LED light source in practical work. The real lifetime characteristics and real life curve of the LED light source are obtained eventually.

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Snjezana Soltic ◽  
Andrew Chalmers

The advent of the LED light source has promoted the concept of human-centric lighting (HCL). The LED has also been responsible for increases in the electrical efficiency of lighting systems, coupled with recent improvements in their colour properties. We have found that it is also possible to create a lit environment with enhanced clinical attributes by providing a source spectrum that meets the requirements of the Cyanosis Observation Index (COI). This paper describes the use of a differential evolution (DE) algorithm for the spectral design of a mixed LED light source capable of meeting COI recommendations as well as HCL performance criteria.


2020 ◽  
Vol 10 (4) ◽  
pp. 1330
Author(s):  
Vincent K. S. Hsiao ◽  
Teng-Yun Cheng ◽  
Chih-Feng Chen ◽  
Hao Shiu ◽  
Yong-Jin Yu ◽  
...  

We investigated a light emitting diode (LED) lighting system applied to a water bamboo field during winter season at night, and the results indicated that this lighting system can prevent the stunting of water bamboo leaves and further assist its growth. Compared with previous LED systems, in which the LED bulbs were placed directly above water bamboo leaves, our LED lighting system presents the benefit of easy handling during harvest. To prevent the inhomogeneous coverage of LED light patterns, a new design of LED lenses was also incorporated.


2016 ◽  
Vol 10 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Ádám Bálint ◽  
József Sárosi

Technological advances allow us to control LED (Light Emitting Diode) lighting at home, in the office it can even allow us to change the intensity of the light and this is just the beginning of what the future holds for us. In this study an LED internal lighting fixture of our own design will be presented focusing on each step in its design. Firstly, the features, types and history of LEDs will be presented, next the products available in market that are required for the completion of the device. Finally, the design and implementation as well as the radio frequency controlled LED indoor lighting fixture will be shown.


Author(s):  
Nikolai N. Bespalov ◽  
Sergei S. Kapitonov ◽  
Mikhail V. Ilyin ◽  
Alexander V. Zorkin ◽  
Alexander G. Volkov

2019 ◽  
Vol 9 (5) ◽  
pp. 826 ◽  
Author(s):  
Seung-Taek Oh ◽  
Dae-Hwan Park ◽  
Jae-Hyun Lim

The ultraviolet (UV) rays emitted from sunlight greatly influence human health. Excessive exposure to UV rays can be harmful to eyes and skin; however, limited UVB exposure is essential for the synthesis of vitamin D. Nowadays, owing to insufficient exposure to natural light, there is increasing concerns about low vitamin D amongst individuals. To address this issue, many lighting devices that provide UVB doses have been released; however, such devices are only used for treatments or for special purposes. This study proposes a general indoor lighting system with a UVB LED light source to provide safe UVB doses to users who spend large amounts of time indoors. The optical characteristics of two UVB LEDs with output of 20 and 100 mW were analyzed based on their distances and applied currents. The light source combination of UVB LEDS that meets the UV hazard standard of IEC-62471 was derived; this is a photobiological safety evaluation standard of LED lighting devices. We then produced a lighting module in which the UVB LED light source was applied to general LED lighting and measured and analyzed the spectral irradiance of the proposed lighting according to the measurement standard for the general lighting of IEC 62471. The actinic UV hazard (AUV) and near-UV hazard (NUV) were calculated to be 0.001 and 10 W/m2, respectively. Thus, the provision of UVB dose did not pose any risks. In addition, the total EUV (Erythemal weighted UV) dose when the proposed lighting was implemented for 16 h was 187.66 J/m2, confirming that this dose did not cause erythema for the general skin types (Skin Types 1–6). Further, the design plan of general indoor lighting with a UVB LED light source is presented.


2021 ◽  
Vol 233 ◽  
pp. 01101
Author(s):  
Zhiqiang Liu ◽  
Peifeng Li ◽  
Haifeng Jiang ◽  
Dan Wang

In recent years, tunnel LED lighting has been widely used in tunnel lighting engineering because of its advantages such as fast start, low energy consumption and good light color controllability. However, at present, the tunnel LED lighting mostly adopts the single dimming control function of light brightness, which does not give full play to the technical advantages of the tunnel LED lighting with two indicators of light brightness and light color temperature control, and does not consider the influence of the color temperature and spectral distribution of the LED light source on the safety and comfort of the tunnel LED lighting environment. Therefore, this paper studies the relationship between the color temperature of tunnel LED lighting source and the visual comfort and visual recognition distance, analyzes the actual impact of the color temperature of LED light source on the tunnel lighting light environment, and puts forward the color temperature index applicable to the entrance and exit sections of tunnel LED lighting, which provides a theoretical basis for building a safe and comfortable "two types" tunnel LED lighting light environment.


EDIS ◽  
2019 ◽  
Vol 2019 (5) ◽  
pp. 14
Author(s):  
John Rutledge ◽  
Joy C. Jordan ◽  
Dale W. Pracht

 The 4-H Citizenship Project offers the opportunity to help 4-H members relate all of their 4-H projects and experiences to the world around them. The 4-H Citizenship manuals will serve as a guide for 4-H Citizenship experiences. To be truly meaningful to the real-life needs and interests of your group, the contribution of volunteer leaders is essential. Each person, neighborhood, and community has individual needs that you can help your group identify. This 14-page major revision of Unit IV covers the heritage project. Written by John Rutledge, Joy C. Jordan, and Dale Pracht and published by the UF/IFAS Extension 4-H Youth Development program. https://edis.ifas.ufl.edu/4h019


MISSION ◽  
2019 ◽  
pp. 54-57
Author(s):  
Marco Riglietta ◽  
Paolo Donadoni ◽  
Grazia Carbone ◽  
Caterina Pisoni ◽  
Franca Colombi ◽  
...  

In Italy, at the end of the 1970s, methadone hydrochloride was introduced for the treatment of opioid use disorder, in the form of a racemic mixture consisting of levomethadone and dextromethadone.In 2015 Levometadone was introduced, a new formulation marketed in Italy for the treatment of opioid use disorder in 2015.The article aims to bring the experience of an Italian Addiction Centre back to the use of this new formulation in the "real life" analyzing the efficacy, the trend of adverse events and pharmacological iterations in a context in which the treated population often uses besides the opiates, cocaine and alcohol, are burdened by a relevant physical and psychic comorbidity and frequently have a prescribed polypharmacy.


Sign in / Sign up

Export Citation Format

Share Document