Article
Nanoscience & Nanotechnology
Claire Arneson, Xinjing Huang, Stephen R. Forrest
Summary: This study demonstrates a method for achieving tunable white light through the side-by-side positioning of monochromatic blue and yellow phosphorescent OLED stripes using a high-resolution mechanical peel-off patterning method. The results show a peak luminous power efficiency of 17.1 lm W-1 and an external quantum efficiency of 11.8%, as well as the ability to adjust the color temperature and color rendering index of the light source. The peel-off technique used in this method ensures a comparable device lifetime to conventionally patterned devices.
Article
Engineering, Civil
Jennifer A. Brons, John D. Bullough, Daniel C. Frering
Summary: LED luminaires are increasingly replacing HPS street lighting systems in municipalities due to their ability to achieve the same light levels with lower wattage, direct more light onto roads, and create brighter illuminated street scenes with reduced overall lumens compared to HPS systems. LED technology continues to improve while HPS systems are unlikely to see significant advancements in the future.
TRANSPORTATION RESEARCH RECORD
(2021)
Article
Construction & Building Technology
Francesco Palma, Giulia Baldelli, Giulia Amagliani, Mattia Paolo Aliano, Mauro Magnani, Giorgio Brandi, Giuditta Fiorella Schiavano
Summary: The beneficial effects of physical activity may be compromised by reduced indoor air quality in confined sports environments. However, the use of UV-C LED technology can significantly reduce the airborne microbial load and provide hygienic and ecological advantages. A new eco-friendly technology called 'CSA System technology' was integrated into an innovative continuous sanitation air device and demonstrated high efficacy in eliminating airborne microorganisms, making it a promising solution for efficient and healthy sanitation in indoor sports environments.
INDOOR AND BUILT ENVIRONMENT
(2023)
Article
Plant Sciences
R. Schipper, M. van der Meer, P. H. B. de Visser, E. Heuvelink, L. F. M. Marcelis
Summary: In the past decade, the potential of using LED lamps for intra-canopy lighting in greenhouse cultivation has been explored. This study used a functional structural plant model to estimate light absorption and found that intra-canopy lighting resulted in a more uniform light distribution and higher total light absorption compared to top lighting alone.
FRONTIERS IN PLANT SCIENCE
(2023)
Article
Environmental Sciences
Bangwoo Han, Keejung Hong, Dongho Shin, Hak-Joon Kim, Yong-Jin Kim, Sang Bok Kim, Sangwoo Kim, Cheong-Ha Hwang, Kwang-Chul Noh
Summary: Control of fine particles is crucial in childcare centers, elementary schools, elderly care facilities, and other locations where vulnerable people spend most of their time. This study found that the use of air cleaners effectively reduced PM2.5 levels in classrooms, but had limited effects on PM10 reduction. Air cleaners were more effective in classrooms with better airtightness. Additionally, classrooms generally had elevated levels of CO2, regardless of the use of air cleaners.
AEROSOL AND AIR QUALITY RESEARCH
(2022)
Article
Physics, Applied
Ziqian Qi, Linning Wang, Yingze Liang, Pengzhan Liu, Hongbo Zhu, Yongjin Wang
Summary: This article introduces a solar-blind full-duplex light communication system using 275-nm DUV LEDs, which eliminates electromagnetic interference and solar noise. The system allows a maximum communication distance of 7 meters and supports real-time video and file sharing.
APPLIED PHYSICS LETTERS
(2023)
Article
Public, Environmental & Occupational Health
Chenxi Liu, Jia Peng, Yubo Liu, Yi Peng, Yuanyuan Kuang, Yinzhuang Zhang, Qilin Ma
Summary: Using Mendelian randomisation (MR) analysis, a potential causal association was found between PM2.5 absorbance and COVID-19 infection, hospitalisation, and severe respiratory symptoms. Prevention and control of air pollution could help delay and halt the negative progression of COVID-19.
JOURNAL OF GLOBAL HEALTH
(2023)
Article
Chemistry, Analytical
Hua Xiao, Guancheng Wang, Wenda Zhang, Sirong Lu, Bingxin Zhao, Zhanlang Wang, Yanglie Li, Jiada Liu
Summary: This study proposes a method for energy-saving illumination control systems by considering the influence of outdoor environment and neighboring lighting units. By optimizing the correlated color temperature and color rendering index of the lighting system, the visual comfort level of users can be improved.
Article
Engineering, Electrical & Electronic
G. Kalyon, S. Mutlu, F. Kuruoglu, I. Pertikel, I. Demir, A. Erol
Summary: We report an n-type In0.53Ga0.47As based Gunn light emitting diode operated at around 1.6 mu m. The device structure comprises of an n-type In0.53Ga0.47As epilayer with a thickness of 5 mu m grown by Metal Organic Vapour Phase Epitaxy (MOVPE) on a semi-insulating InP substrate and fabricated in a planar architecture with a stepped structure at anode side to suppress the destructive effect of high built-in electric field in propagating Gunn domain. Gunn diode is operated under pulsed voltage with a pulse width of 60 ns and pulse duration of 4.5 ns to keep the duty cycle as low as 0.0013%. The Gunn oscillations with an 1 ns period are observed at around 4.1 kV/ cm, which corresponds to the electric field threshold of Negative Differential Resistance (NDR). The light emission at around 1.6 mu m also starts at the threshold electric field of the NDR region (E = 4.2 kV/cm) of the current-voltage curve, and the emission intensity increases drastically with increasing applied electric field. The observed light emission at NDR threshold electric field where Gunn oscillations appear on the voltage pulse is attributed to the impact ionisation process occurring in the current domains along the sample, which generates excess carriers to initiate the band-to-band recombination in In0.53Ga0.47As.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Environmental Sciences
Savannah L. Lewis, Lynn M. Russell, John A. McKinsey, William J. Harris
Summary: The Oceano Dunes in California is a natural source of wind-driven dust emissions, primarily consisting of particulate matter (PM) with a particle size larger than 1 μm. To evaluate the impact of reducing PM emissions from the dune area on air quality, samples were collected during high-wind months from 2019 to 2021 to analyze the organic and elemental composition of PM10 and PM2.5. The results suggest that while the contribution of unidentified components from the dunes is relatively high, there is no evidence of toxic substances, indicating that current dust abatement strategies may not significantly improve downwind air quality.
ATMOSPHERIC ENVIRONMENT
(2023)
Article
Engineering, Environmental
Amirhosein Mousavi, Jun Wu
Summary: During the COVID-19 lockdown, indoor PM2.5 concentrations increased significantly, particularly with clear peaks in residential areas in the afternoon and evening, reflecting increased human activity and household chores during meal times. The contribution of indoor-generated PM2.5 to total indoor concentrations increased as high as 80% during and post-lockdown periods compared to before lockdown.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Yu-Jin Kim, Sung-Won Kim, Ju-Ro Lee, Soong Ho Um, Yoon Ki Joung, Suk Ho Bhang
Summary: This study investigated the cytotoxic effects of LED and OLED light sources on stem cells, finding that the LED group induced higher apoptotic activity due to significant heat generation compared to OLED. Additionally, the LED group showed significant expression of intracellular reactive oxygen species, while increased cell proliferation was confirmed in the OLED group.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2021)
Article
Computer Science, Information Systems
Uzair Aslam Bhatti, Yuhuan Yan, Mingquan Zhou, Sajid Ali, Aamir Hussain, Qingsong Huo, Zhaoyuan Yu, Linwang Yuan
Summary: As Pakistan's economy, transportation, and industry develop, environmental pollution has become a prominent issue, with air quality in Lahore exceeding national standards. There is a strong correlation between particulate matter and other pollutants, with future predictions showing an increase in PM2.5 concentration.
Article
Construction & Building Technology
Elizabeth Cooper, Yan Wang, Samuel Stamp, Esfandiar Burman, Dejan Mumovic
Summary: The quality of indoor air is crucial for people's well-being, and using air purifiers can effectively reduce PM2.5 concentrations indoors. However, the main motivation for most people to use air purifiers is thermal comfort rather than improving air quality.
BUILDING AND ENVIRONMENT
(2021)
Article
Environmental Sciences
Younghun Kim, Dongho Shin, Kee-Jung Hong, Gunhee Lee, Sang Bok Kim, Inyong Park, Bangwoo Han, Jungho Hwang
Summary: This study established a theoretical model to estimate the performance of various indoor air quality management methods for controlling indoor PM2.5 concentrations and energy consumption. The model was verified through comparative experiments. The study identified efficient energy-saving PM2.5 management scenarios using different IAQ management methods based on the annual life patterns of residents in South Korea. The results showed that energy consumption could be significantly reduced by applying natural ventilation in certain seasons and mechanical ventilation in others.