Measurement of the Opacity of Smoke and Suspensions under Ambient Lighting Conditions

1977 ◽  
Vol 10 (1) ◽  
pp. 2-3 ◽  
Author(s):  
A. R. Churchley
Keyword(s):  
Solid State ◽  
Light Emitting Diode ◽  
Reference Beam ◽  
Ambient Light ◽  
Entry And Exit ◽  
Optical Cell ◽  
Light Emitting ◽  
Lighting Conditions ◽  
Ambient Lighting ◽  
Scattering Systems

An entirely solid state photoelectric meter for the measurement of optical density is described. No light sealing arrangements are required, greatly simplifying the cleaning of the optical cell and facilitating the entry and exit of material when measurements are taken on flowing systems. Ambient light reaching the detector does not interfere with the measurements since the reference beam is coded. This beam is generated by a light emitting diode, avoiding many of the problems of conventional sources. The system has a wide application and its robustness should assure it a position in the field as well as the laboratory. Any change in the intensity of the reference beam can be measured, so the properties of transmissive, reflective or scattering systems may be measured.

Broadband near-infrared BaMSi3O9:Cr3+ (M = Zr, Sn, Hf) phosphors for light-emitting diode applications

2021 ◽  
Author(s):  
Yan Zhang ◽  
Yanjie Liang ◽  
Shihai Miao ◽  
Dongxun Chen ◽  
Shao Yan ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Near Infrared ◽  
Light Emitting Diode ◽  
Solid State Reaction Method ◽  
Luminescence Properties ◽  
Light Emitting ◽  
Reaction Method ◽  
Simple Solid State Reaction

A series of Cr3+-doped BaMSi3O9 (M = Zr, Sn, Hf) near-infrared emitting phosphors with tunable luminescence properties have been successfully synthesized by using a simple solid-state reaction method. The developed...

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.

Simple, Accurate Solid-State Diode Photometer for Use in Measuring Oxygen Saturation of Whole Blood

1974 ◽  
Vol 20 (9) ◽  
pp. 1135-1137 ◽  
Author(s):  
R Fesler ◽  
Th Clerbaux
Keyword(s):  
Solid State ◽  
Oxygen Saturation ◽  
Light Source ◽  
Whole Blood ◽  
Continuous Measurement ◽  
Light Emitting Diode ◽  
Detector Response ◽  
Typical Application ◽  
Light Emitting ◽  
Absorption Characteristics

Abstract A small, easily-built photometer is described, in which a solid-state light-emitting diode is used as the light source and a phototransistor as the detector. The detector response is kept constant by modulating the diode intensity in proportion to the absorption characteristics of the sample being analyzed. Linearity and stability are good, even with turbid solutions (drift is <0.001 absorbance unit per hour). A typical application of this photometer is the continuous measurement of the percentage of oxyhemoglobin (0 to 100 %) in blood. For hemoglobin concentrations from 3 to 18 g/dl, the relation between oxyhemoglobin as estimated with this diode photometer and by a galvanic method (LEX-O2-CON) was: SO2LED = 0.993 SO2 % LEX + 0.69;r = 0.9975; n = 129; Syx = 1.59.

scholarly journals Passive Visible Light Detection of Humans

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1902 ◽  
Author(s):  
Kenneth Deprez ◽  
Sander Bastiaens ◽  
Luc Martens ◽  
Wout Joseph ◽  
David Plets
Keyword(s):  
Visible Light ◽  
Detection Rate ◽  
Detection System ◽  
Light Emitting Diode ◽  
Line Of Sight ◽  
Controlled Environment ◽  
Ambient Light ◽  
Light Emitting ◽  
Light Sensing ◽  
Reflected Light

This paper experimentally investigates passive human visible light sensing (VLS). A passive VLS system is tested consisting of one light emitting diode (LED) and one photodiode-based receiver, both ceiling-mounted. There is no line of sight between the LED and the receiver, so only reflected light can be considered. The influence of a human is investigated based on the received signal strength (RSS) values of the reflections of ambient light at the photodiode. Depending on the situation, this influence can reach up to ± 50 % . The experimental results show the influence of three various clothing colors, four different walking directions and four different layouts. Based on the obtained results, a human pass-by detection system is proposed and tested. The system achieves a detection rate of 100% in a controlled environment for 21 experiments. For a realistic corridor experiment, the system keeps its detection rate of 100% for 19 experiments.

Orange- to green-emitting Li(Sr,Ca)4(BO3)3:Eu2+ phosphor: emission-tunable properties and white light emitting diode application

RSC Advances ◽  
2016 ◽  
Vol 6 (86) ◽  
pp. 82824-82831 ◽  
Author(s):  
Hua Yu ◽  
Degang Deng ◽  
Youjie Hua ◽  
Chenxia Li ◽  
Shiqing Xu
Keyword(s):  
High Temperature ◽  
Solid State ◽  
White Light ◽  
Solid State Reaction ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Tunable Properties

An emission-tunable phosphor, Eu2+-activated LiSr(4−x−y)Cax(BO3)3:yEu2+ phosphor, was synthesized by high temperature solid state reaction.

scholarly journals Side-Chain Polyimides as Binder Polymers for Photolithographic Patterning of a Black Pixel Define Layer for Organic Light Emitting Diode

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Genggongwo Shi ◽  
Sung Hoon Park ◽  
Jeseob Kim ◽  
Minji Kim ◽  
Lee Soon Park
Keyword(s):  
Light Emitting Diode ◽  
Side Chain ◽  
Ambient Light ◽  
Light Emitting ◽  
Organic Layers ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Black Pixel ◽  
Chain Type

A pixel define layer (PDL) in an organic light emitting diode (OLED) is patterned using a photolithographic process before the deposition of organic layers on top of ITO anode. If the patterning of PDL on OLED panels can be achieved using a black photoresist, the patterning of black matrix (BM) on top of PDL patterns can be omitted by reducing the reflection of ambient light from OLED panels. In this study, we synthesized a series of side-chain-type polyimides as binder polymers of black photoresists and investigated the potential of using the black photoresist for the fine patterning of black PDL on OLED panels.

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.

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