scholarly journals The Study of Aviation Safe Incapacitating Device Based on LED Technology with a Smart-Illumination Sensor Unit

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 81
Author(s):  
Jan Leuchter ◽  
Lukas Hon ◽  
Radim Bloudicek ◽  
Teodor Balaz ◽  
Erik Blasch
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Constant Current ◽  
Flash Duration ◽  
Light Emitting ◽  
Flash Rate ◽  
Design And Implementation ◽  
Lighting Conditions ◽  
Basic Characteristics ◽  
High Level

This paper deals with a design and implementation of optical defensive device for protection of aviation personnel. The design is built on the basic characteristics of human eyesight, illumination sensing of the environment, and microcontroller implementation for adaptation over sensed power, flash duration, and person distance. The aviation safe LED-based optical dazzler equipment (ASLODE) utilizes light emitting diode (LED) technology implemented with constant current regulators to control several modes of effects based on situational sensing. The temporarily incapacitating device can be extended by means of real-time illumination sensing to improve power efficiency and reach the highest level of safety. The smart pulse sets the flashing frequency from 8Hz for high-level light intensities and up to 20 Hz in low-level lighting conditions. Experimental results demonstrate the effectiveness of the ASLODE device over numerous experiments with controlled onboard aircraft scenarios that adapt the energy, flash rate, and processing to the sensed environmental illumination to meet aviation hygienic standards for people without eyesight defects.

Optimization for white organic light-emitting diode based on DCJTB as color conversion layer

2018 ◽  
Vol 32 (27) ◽  
pp. 1850299
Author(s):  
Pei Wang ◽  
Zhen Wang ◽  
Ai Chen ◽  
Jia-Feng Xie ◽  
Xin Zheng
Keyword(s):  
Current Efficiency ◽  
Current Density ◽  
White Light ◽  
Power Efficiency ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
High Efficient ◽  
Color Conversion

In this paper, combining phosphorescence and fluorescence to form white light was realized based on DCJTB:PMMA/ITO/NPB/TCTA/FIrpic:TCTA/TPBi/Ir(ppy)3:TPBi/TPBi/Cs2CO3/Al. The effects of red fluorescence on this white light device was studied by adjusting the concentration of DCJTB. The study shows that the device with a DCJTB concentration of 0.7% in the color conversion layer (CCL) generates a peak current efficiency and power efficiency of 23.4 cd ⋅ A[Formula: see text] and 7.5 lm ⋅ W[Formula: see text], respectively. And it is closest to the equal-energy white point of (0.33, 0.33) which shows a CIE (Commission Internationale de L’Eclairage) coordinate of (0.35, 0.43) and a color rendering index (CRI) of 70 at current density of 10 mA ⋅ cm[Formula: see text]. In order to improve the efficiency, we design and fabricate both high efficient and pure white organic light-emitting diode (WOLED) by replacing the single blue emission layer (EML) with double EMLs of FIrpic:TCTA and FIrpic:TPBi. The further study shows that, when the layers of EML is three and the concentration of DCJTB at 0.7%, the device exhibits good performance specifically, at current density of 10 mA ⋅ cm[Formula: see text], the current efficiency of 28.2 cd ⋅ A[Formula: see text] (power efficiency of 10.3 lm ⋅ W[Formula: see text]), and the CIE coordinate of (0.33, 0.31) (CRI of 80.38).

scholarly journals A hybrid inorganic–organic light-emitting diode using Ti-doped ZrO2 as an electron-injection layer

RSC Advances ◽  
2018 ◽  
Vol 8 (15) ◽  
pp. 8402-8411 ◽  
Author(s):  
Jayaraman Jayabharathi ◽  
Sekar Panimozhi ◽  
Venugopal Thanikachalam ◽  
Annadurai Prabhakaran ◽  
Palanivel Jeeva
Keyword(s):  
Current Efficiency ◽  
Power Efficiency ◽  
Light Emitting Diode ◽  
Electron Injection ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Electron Injection Layer ◽  
Organic Light

Ti-doped ZrO2 facilitates electron injection effectively, leading to enhanced current efficiency of 2.84 cd A−1 and power efficiency of 1.32 lm W−1

The effectiveness of light-emitting diode lighting for providing circadian stimulus in office spaces while minimizing energy use

2019 ◽  
Vol 52 (2) ◽  
pp. 167-188 ◽  
Author(s):  
C Jarboe ◽  
J Snyder ◽  
MG Figueiro
Keyword(s):  
Energy Use ◽  
Spectral Power ◽  
Light Emitting Diode ◽  
Visual Performance ◽  
Luminous Intensity ◽  
Light Emitting ◽  
Lighting Conditions ◽  
Office Space ◽  
Discomfort Glare ◽  
Architectural Lighting

Architectural lighting has traditionally addressed visual performance and horizontal illuminance on the work plane, later focussing on energy efficiency, while only recently paying particular regard to human health outcomes. The present study evaluated the effectiveness of several light-emitting diode lighting strategies for delivering circadian stimulus to occupants of a typical office space while minimizing energy use. The study employed photometric simulations in a typical open-office space, delivering a criterion circadian stimulus of 0.3 to calculation points modelled at the simulated occupants’ eye level. Six luminaire types, two luminous intensity distributions, six spectral power distributions and two horizontal illuminances were evaluated, resulting in 144 unique lighting conditions. Additionally, the study calculated the discomfort glare for selected luminaires with the highest total lumen output, smallest aperture and direct-only luminous intensity distributions at the higher of the two horizontal illuminances (500 lx). The most impactful strategy involved supplementing common overhead lighting with a desktop luminaire delivering light directly to the simulated office occupants’ eyes, which provided greater circadian stimulus and used less energy than overhead luminaires that were capable of delivering the criterion circadian stimulus of 0.3.

Changes in Lighting Source Can Produce Inaccurate Assessment of Visual Poultry Doneness and Induce Consumers To Eat Undercooked Ground Turkey Patties

2019 ◽  
Vol 82 (3) ◽  
pp. 528-534 ◽  
Author(s):  
CURTIS MAUGHAN ◽  
EDGAR CHAMBERS IV ◽  
SANDRIA GODWIN ◽  
DELORES CHAMBERS
Keyword(s):  
Foodborne Pathogens ◽  
Light Emitting Diode ◽  
The United States ◽  
Extrinsic Factors ◽  
Visual Appearance ◽  
Light Emitting ◽  
End Point ◽  
Lighting Conditions ◽  
Compact Fluorescent Lamp ◽  
End Point Temperature

ABSTRACT Undercooked poultry is a potential source of foodborne pathogens, such as Salmonella and Campylobacter. The best way to avoid eating undercooked poultry is to use a food thermometer during cooking. However, consumers who cook poultry often use visual appearance for determining doneness, which relies on extrinsic factors, including lighting conditions. Because the United States recently mandated changes in lighting to promote energy conservation, this study evaluated the effect of lighting sources on consumer perceptions of doneness and willingness to eat cooked poultry patties. Consumers (n = 104) evaluated validated photographs of turkey patties cooked to different end point temperatures (57 to 79°C) and rated the level of perceived doneness and willingness to eat each sample. Evaluations were conducted under different lighting sources: incandescent (60 W, soft white), halogen (43 W, soft white), compact fluorescent lamp (13 W, soft white), light-emitting diode (LED; 10.5 W, soft white), and daylight LED (14 W). Lighting changed perception of doneness and willingness to eat the patties, with some of the energy-efficient options, such as LED and halogen making samples appear more done than they actually were, increasing the willingness to eat undercooked samples. This poses a risk of consuming meat that could contain bacteria not killed by heat treatment. Recent changes in lighting regulations can affect lighting in homes that affects perceptions of poultry doneness, requiring that educators place extra emphasis on the message that properly using a meat thermometer is the only way to ensure meat is cooked to a safe end point temperature.

High Brightness White Organic Light Emitting Devices Employing Phosphorescent Iridium Complex as RGB Dopants

2007 ◽  
Vol 364-366 ◽  
pp. 1072-1076
Author(s):  
Rui Li Song ◽  
Yu Duan
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Iridium Complex ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Color Mixing ◽  
Coordinate Changes ◽  
Cie Chromaticity

An efficient phosphorescent white organic light-emitting diode (WOLED) was realized by using a bright blue-emitting layer, iridium (III) bis [(4, 6-di-fluoropheny)-pyridinato-N, C2’] picolinate doped 4.4’-bis (9-carbazolyl)-2, 2’-dimethyl-biphenyl, together with tris (2- Phenylpyridine) iridium and bis (1-phenyl-isoquinoline) acetylacetonate iridium (III) were codoped into 4,4’-N,N’-dicarbazole-biphenyl layer to provide blue, green, and red emission for color mixing. The device emission color was controlled by varying dopant concentrations and the thickness of blue and green-red layers as well as tuning the thickness of exciton-blocking layer. The maximum luminance and power efficiency of the WOLED were 37100cd/m2 at 17 V and 7.37lm/W at 5V, respectively. The Commission Internationale de 1’Eclairage (CIE) chromaticity coordinate changes from (0.41, 0.42) to (0.37, 0.39) when the luminance rangeed from 1000cd/m2 to 30000cd/m2.

Modeling and Analysis of Organic Light Emitting Diode with Thin Film Anti-Reflective Coatings

2020 ◽  
Vol 15 (4) ◽  
pp. 425-431
Author(s):  
B. M. Chaya ◽  
Prasant Kumar Pattnaik ◽  
K. Narayan
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Fdtd Method ◽  
Light Output ◽  
Single Layer ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Reflective Coating ◽  
Organic Light ◽  
Reflective Coatings

The effects of anti-reflective coatings (ARC) on organic light emitting diode (OLED) optical characteristics are reported in this paper. The light output produced from the OLED is not 100%. But the emitted light is trapped due to various Modes. The losses at the glass air substrate interfaces of an OLED are addressed in this work. The Anti-Reflective coatings increase the light output by reducing OLED reflections at the interface between glass and air. The Finite Difference Time Domain (FDTD) method and the Fresnel theory have been used to design the device and study the effects on OLED of the Single Layer Anti-Reflective Coating (SLAR) and Double Layer Anti-Reflective Coating (DLAR). The thicknesses and refractive indices of the layers of the anti-reflective coatings were optimized. We also compared the light out coupling power efficiency of the SLAR coated OLED with that of an OLED with a DLAR coating and also with Conventional OLED. The results show that the enhancement in light output efficiency of the DLAR coated OLED was slightly higher than that of the SLAR coated OLED.

An optimisation toolbox for multi-colour LED lighting

2016 ◽  
Vol 50 (3) ◽  
pp. 467-481 ◽  
Author(s):  
S Afshari ◽  
L Moynihan ◽  
S Mishra
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Optimal Choice ◽  
Light Emitting ◽  
Conference Room ◽  
Channel Choice ◽  
White Light Generation ◽  
Manufacturing Applications ◽  
The Individual ◽  
Mixing Problem

This paper introduces a software toolbox designed for the optimisation of white light generation using multiple light-emitting diode (LED) channels. The toolbox solves two separate types of multi-colour optimisation problems. These are the multi-channel mixing and the channel choice problems. In the multi-channel mixing problem, it is assumed that the available LEDs are pre-determined and fixed. The toolbox obtains the individual channel intensities that solve a constrained optimisation problem based on the mixed output light. It provides the user with the flexibility to choose an arbitrary formulation for the optimisation problem as well as various mathematical metrics to represent the different properties of the output light including colour rendering, power efficiency and colour accuracy. For the channel choice problem, the toolbox solves for the number and type of used LED channels as well as the intensity of individual channels to assist in optimal choice of deployed channels for luminaire manufacturing applications. This paper describes the graphical user interface and the back-end formulation of the optimisation problem and presents experimental results obtained by utilising the toolbox in a full-size conference room with 5-channel LED luminaires.

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