Effect of color temperature on melatonin production for illumination of working environments.

Appl Ergon

Leibniz Research Centre for Working Environment and Human Factors, University of Dortmund, Dortmund, Germany.

Published: January 2017

Unlabelled: We studied the influence of correlated color temperature (CCT) of 7 polychromatic white light illuminations (1600 K-14,000 K, 200 lx) in two experiments. Visual performance was tested in 17 students (8 men) during daytime. Visual acuity, contrast sensitivity and sleepiness did not vary with illuminations but polychromatic white light of <2000 K impaired color discrimination. Melatonin synthesis was tested with weekly intervals in 8 trials from 10pm to 2am (7 polychromatic illuminations and a dim light reference (<0.1 lx)) in 16 students (9 men, semi-recumbent position). Melatonin suppression was almost negligible for CCT <2000 K but increased with increasing CCT.

Conclusions: CCTs <2000 K are not suitable for work places. Polychromatic white light with higher CCTs and significant melatonin suppression is expected to shift the circadian rhythm and to accelerate the adaptation to night work. This effect should be enhanced with elevation of luminance.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.apergo.2016.08.006DOI Listing

Publication Analysis

Top Keywords

color temperature
8
polychromatic white
8
white light
8
temperature melatonin
4
melatonin production
4
production illumination
4
illumination working
4
working environments
4
environments unlabelled
4
unlabelled studied
4

Similar Publications

Natural pigments, or natural colorants, are frequently utilized in the food industry due to their diverse functional and nutritional attributes. Beyond their color properties, these pigments possess several biological activities, including antioxidant, anti-inflammatory, anticancer, antibacterial, and neuroprotective effects, as well as benefits for eye health. This review aims to provide a timely overview of the potential of natural pigments in the pharmaceutical, medical, and food industries.

View Article and Find Full Text PDF

Influence of sintering temperature and aging on the color and translucency of zirconia.

J Prosthet Dent

January 2025

Full Professor, Department of Dentistry, Health Sciences Center, Federal University of Santa Catarina (UFSC), Florianópolis, Santa Catarina, Brazil. Electronic address:

Statement Of Problem: Translucent zirconias are promising materials for monolithic prostheses. However, information on their optical behavior after sintering and aging protocols is scarce.

Purpose: The purpose of this in vitro study was to evaluate the color and translucency of zirconia subjected to different sintering temperatures and aging.

View Article and Find Full Text PDF

Hazy transparent cellulose nanocrystal-based films with tunable structural colors.

Carbohydr Polym

March 2025

State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China. Electronic address:

Cellulose nanocrystals (CNCs) are powerful biosourced nanomaterials for the construction of chiral photonic films. While various techniques have been used to enrich the optical properties of such systems, surface roughness engineering has yet to be exploited to significantly modify their optical properties. In this work, by using vacuum filtration-assisted self-assembly, CNCs are densely packed into films with high optical transparency.

View Article and Find Full Text PDF

Alginate films were prepared from the brown seaweed Dictyota mertensii using glycerol as a plasticizer. The effects of extraction conditions-time, temperature, and NaCO concentration-on the optical, barrier, and mechanical properties of the films were investigated using a central composite design (CCD). ANOVA and F tests confirmed the models' statistical significance at p ≤ 0.

View Article and Find Full Text PDF

To strengthen starch gel quality and improve the deterioration from freeze-thaw cycles, corn starch/whey protein isolate (WPI)/caffeic acid (CA) composite gels were rationally constructed in this study. The results showed that the introduction of WPI and CA significantly optimized the microstructure of the gels, an observation verified by SEM and CLSM. In addition, FT-IR and XRD analyses further revealed that the interaction mechanism within the composite gel was mainly due to the reinforcement of hydrogen bonds.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!