The effects of different bedroom light environments in the evening on adolescents

Wen, Peijun; Tan, Fuyun; Wu, Meng; Cai, Qijun; Xu, Ruiping; Zhang, Xiaowen; Wang, Yongzhi; Khan, Muhammad Saddique Akbar; Hu, Xiaodong

doi:10.1016/j.buildenv.2021.108321

Cited by 19 publications

(11 citation statements)

References 49 publications

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“…These results are reasonable because the M/P ratios of daytime and nighttime HC-LEDs were designed differently compared with the c-LEDs. Therefore, it is anticipated that use of the developed HC-LED would help maintain a healthy circadian rhythm by further suppressing melatonin during the daytime and increasing melatonin secretion at nighttime. − However, in the 50 h protocol, the participants were not restricted in their behavior, and thus, the vertical illuminance and CS value could vary depending on their position, gaze, and posture. In addition, the vertical illuminance varies greatly depending on the characteristics of the room, such as the size of the room, the reflectance of the wall, and the location of the lighting.…”

Section: Resultsmentioning

confidence: 99%

Development and Verification of a 480 nm Blue Light Enhanced/Reduced Human-Centric LED for Light-Induced Melatonin Concentration Control

Eo,

Choi,

Kim

et al. 2023

ACS Omega

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Section: Resultsmentioning

confidence: 99%

Development and Verification of a 480 nm Blue Light Enhanced/Reduced Human-Centric LED for Light-Induced Melatonin Concentration Control

Eo,

Choi,

Kim

et al. 2023

ACS Omega

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“…Serious health problems or even compromising health and well-being were reported when large deviations from the recommended range of sleep continued for a longer period. [2] The IE can affect the sleeping quality through thermal conditions [3,4], external noise [5], lighting conditions [6], or indoor air quality [7].…”

Section: Introductionmentioning

confidence: 99%

Is there an optimum balance between indoor environment, energy consumption and health?

Larsen,

Rohde,

Jensen

et al. 2023

J. Phys.: Conf. Ser.

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This study investigates the pros and cons of passive strategies in the indoor environment (IE) in relation to energy consumption (EC). It is widely accepted that IE improvements often require energy, particularly for thermal and atmospheric IE. As a result, demands for energy savings might compromise the indoor environmental comfort and health. However, the energy consumption can be reduced by introducing passive measures both regarding temperature and ventilation rates. To investigate this, measurements of temperature and ventilation rates were carried out in eight newly built single-family homes and four renovated single-family homes in a Danish context for three years. The study analyzes the effect of passive cooling using different types of solar shading. The findings show that external solar shading can effectively reduce high temperatures without additional energy consumption for cooling in a Scandinavian context. Also, the difference between mechanical and natural ventilation on CO2 levels in bedrooms and children’s rooms in relation to sleep quality are analysed. Here the results show, that natural ventilation is insufficient to ensure healthy sleeping conditions when it comes to proper ventilation rates and air quality. Supplemental ventilation by either window airing or mechanical aid is necessary.

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“…Owing to its direct-bandgap nature, gallium nitride (GaN)based binary alloy is ideal for the gain medium of visible-light laser diode (LDs). Over the past three decades, tremendous progress has been made on high-efficiency and long-lifetime LDs, which are promising in color display, lighting, storage, and biological applications [1][2][3][4]. Benefitting from the carrier clamping effect of stimulated emission, LDs can work at high injection levels up to several kA cm -2 , and their power can exceed several watts, distinguished from light-emitting diodes (LEDs) mostly working at a few hundred A cm -2 [5].…”

Section: Introductionmentioning

confidence: 99%

Demonstrating the electron blocking effect of AlGaN/GaN superlattice cladding layers in GaN-based laser diodes

Lei

Lang

et al. 2023

Semicond. Sci. Technol.

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Electronleakage currents seriously limit the power conversion efficiencies (PCEs) of gallium nitride (GaN)-based laser diodes (LDs). To minimize the leakage currents, electron blocking layers (EBLs) are generally applied in the p-type region. However, few works have discussed the electron blocking effect of a p-cladding layer, which is found to be critical in suppressing the leakage currents of an LD. In this work, we compare the blocking performance of single AlGaN p-cladding layers and AlGaN/GaN superlattice (SL) p-cladding layers with the same average Al component respectively. Both light-emitting diodes (LEDs) and LDs with the same epitaxy structures are fabricated. Light-current (L-I) curves and current-voltage (I-V) curves are measured. The latest analytical model of leakage currents is applied to fit the L-I curves of LEDs. Smaller leakage coefficients are observed for the SL structures than the single-layer structures. 80 LDs with different ridge widths are characterized, whose threshold current density, slope efficiencies (SEs), and PCEs are compared. Statistically significant advantages of an SL-based p-cladding layer are demonstrated compared to a single AlGaN layer. The blocking effects of both scattering- and bound-state electrons by SL are investigated. Continuous reflection and thermal relaxation are responsible for the blocking effect of scattering-state electrons. By simulation, the tunneling effect of bound-state electrons through a miniband mechanism is found to be insignificant at a large injection level due to a negative differential conductivity by the Esaki-Tsu effect. We demonstrate a better electron blocking performance of p-cladding layers based on SLs than single AlGaN layers in GaN-based LDs.

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The effects of different bedroom light environments in the evening on adolescents

Cited by 19 publications

References 49 publications

Development and Verification of a 480 nm Blue Light Enhanced/Reduced Human-Centric LED for Light-Induced Melatonin Concentration Control

Development and Verification of a 480 nm Blue Light Enhanced/Reduced Human-Centric LED for Light-Induced Melatonin Concentration Control

Is there an optimum balance between indoor environment, energy consumption and health?

Demonstrating the electron blocking effect of AlGaN/GaN superlattice cladding layers in GaN-based laser diodes

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