scholarly journals Enhancing the cooling potential of photoluminescent materials through evaluation of thermal and transmission loss mechanisms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samira Garshasbi ◽  
Shujuan Huang ◽  
Jan Valenta ◽  
Mat Santamouris
Keyword(s):  
Near Infrared ◽  
Transmission Loss ◽  
Energy State ◽  
Stokes Shift ◽  
Future Research ◽  
Thermal Loss ◽  
Urban Heat ◽  
Photoluminescent Materials ◽  
Ground Energy ◽  
Loss Mechanisms

AbstractPhotoluminescent materials are advanced cutting-edge heat-rejecting materials capable of reemitting a part of the absorbed light through radiative/non-thermal recombination of excited electrons to their ground energy state. Photoluminescent materials have recently been developed and tested as advanced non-white heat-rejecting materials for urban heat mitigation application. Photoluminescent materials has shown promising cooling potential for urban heat mitigation application, but further developments should be made to achieve optimal photoluminescence cooling potential. In this paper, an advanced mathematical model is developed to explore the most efficient methods to enhance the photoluminescence cooling potential through estimation of contribution of non-radiative mechanisms. The non-radiative recombination mechanisms include: (1) Transmission loss and (2) Thermal losses including thermalization, quenching, and Stokes shift. The results on transmission and thermal loss mechanisms could be used for systems solely relying on photoluminescence cooling, while the thermal loss estimations can be helpful to minimize the non-radiative losses of both integrated photoluminescent-near infrared (NIR) reflective and stand-alone photoluminescent systems. As per our results, the transmission loss is higher than thermal loss in photoluminescent materials with an absorption edge wavelength (λAE) shorter than 794 nm and quantum yield (QY) of 50%. Our predictions show that thermalization loss overtakes quenching in photoluminescent materials with λAE longer than 834 nm and QY of 50%. The results also show that thermalization, quenching, and Stokes shift constitute around 56.8%, 35%, and 8.2% of the overall thermal loss. Results of this research can be used as a guide for the future research to enhance the photoluminescence cooling potential for urban heat mitigation application.

A novel near-infrared fluorescent probe based on isophorone for the bioassay of endogenous cysteine

2021 ◽  
Author(s):  
Hong-Bo Liu ◽  
Hai Xu ◽  
Xin Guo ◽  
Jian Xiao ◽  
Zheng-Hong Cai ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Fluorescent Probe ◽  
Near Infrared ◽  
Stokes Shift ◽  
Rapid Identification ◽  
Large Stokes Shift

A near-infrared (NIR) fluorescent probe with a large Stokes shift (143 nm) for the rapid identification of Cys over Hcy and GSH in aqueous solution was developed.

scholarly journals A Methodological Review of fNIRS in Driving Research: Relevance to the Future of Autonomous Vehicles

2021 ◽  
Vol 15 ◽  
Author(s):  
Stephanie Balters ◽  
Joseph M. Baker ◽  
Joseph W. Geeseman ◽  
Allan L. Reiss
Keyword(s):  
Brain Imaging ◽  
Near Infrared ◽  
Functional Neuroimaging ◽  
Meta Analysis ◽  
Autonomous Driving ◽  
Functional Brain Imaging ◽  
Future Research ◽  
Functional Near Infrared Spectroscopy ◽  
Methodological Review ◽  
The Future

As automobile manufacturers have begun to design, engineer, and test autonomous driving systems of the future, brain imaging with functional near-infrared spectroscopy (fNIRS) can provide unique insights about cognitive processes associated with evolving levels of autonomy implemented in the automobile. Modern fNIRS devices provide a portable, relatively affordable, and robust form of functional neuroimaging that allows researchers to investigate brain function in real-world environments. The trend toward “naturalistic neuroscience” is evident in the growing number of studies that leverage the methodological flexibility of fNIRS, and in doing so, significantly expand the scope of cognitive function that is accessible to observation via functional brain imaging (i.e., from the simulator to on-road scenarios). While more than a decade’s worth of study in this field of fNIRS driving research has led to many interesting findings, the number of studies applying fNIRS during autonomous modes of operation is limited. To support future research that directly addresses this lack in autonomous driving research with fNIRS, we argue that a cogent distillation of the methods used to date will help facilitate and streamline this research of tomorrow. To that end, here we provide a methodological review of the existing fNIRS driving research, with the overarching goal of highlighting the current diversity in methodological approaches. We argue that standardization of these approaches will facilitate greater overlap of methods by researchers from all disciplines, which will, in-turn, allow for meta-analysis of future results. We conclude by providing recommendations for advancing the use of such fNIRS technology in furthering understanding the adoption of safe autonomous vehicle technology.

Optical properties of hemicyanines with terminal amino groups and their applications in near-infrared fluorescent imaging of nucleoli

2014 ◽  
Vol 2 (40) ◽  
pp. 7065-7072 ◽  
Author(s):  
Jia-Tao Miao ◽  
Chen Fan ◽  
Ru Sun ◽  
Yu-Jie Xu ◽  
Jian-Feng Ge
Keyword(s):  
Optical Properties ◽  
Near Infrared ◽  
Water Solubility ◽  
Stokes Shift ◽  
Fluorescent Imaging ◽  
Amino Groups ◽  
Long Wave ◽  
Terminal Amino ◽  
Wave Emission ◽  
Low Cytotoxicity

A cellular dye with properties of long-wave emission, large Stokes shift, water solubility, low cytotoxicity, and good photostability is reported.

Stable Twisted Conformation Aza-BODIPY NIR-II Fluorescent Nanoparticles with Ultra-large Stokes Shift for Imaging-Guided Phototherapy

2022 ◽  
Author(s):  
Youliang Tian ◽  
Huiting Zhou ◽  
Quan Cheng ◽  
Huiping Dang ◽  
Hongyun Qian ◽  
...  
Keyword(s):  
Fluorescence Imaging ◽  
In Vivo Imaging ◽  
Near Infrared ◽  
Stokes Shift ◽  
Great Promise ◽  
Deep Penetration ◽  
Fluorescent Nanoparticles ◽  
Spatiotemporal Resolution ◽  
Large Stokes Shift

Fluorescence imaging in the second near-infrared window (NIR-II, 1000–1700 nm) holds great promise for in vivo imaging and imaging-guided phototherapy with deep penetration and high spatiotemporal resolution. It is very...

scholarly journals The Influence of NIR Pigments on Coil Coatings’ Thermal Behaviors

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 514 ◽  
Author(s):  
Stefano Rossi ◽  
Massimo Calovi ◽  
Domenico Dalpiaz ◽  
Michele Fedel
Keyword(s):  
Thermal Behavior ◽  
Urban Areas ◽  
Near Infrared ◽  
Salt Spray ◽  
Chemical Degradation ◽  
Initial State ◽  
Island Effect ◽  
Urban Heat ◽  
Appearance Properties ◽  
Chamber Exposure

The effect of over-heating in urban areas, called the urban heat island effect (UHI effect), is responsible for greater energy consumption for cooling buildings. Several reflective near-infrared (NIR) coatings, called cool coatings have proved to be effective for contrasting the UHI effect. The thermal and appearance properties of cool coatings depend on the color and they often have been studied only at the initial state, without undergoing atmospheric degradation and soiling. In this work, the thermal, visual and durability behaviors of red and brown polyester-based organic coatings for roof applications were studied. All samples were subjected to accelerated degradation cycles composed of UV-B and salt spray chamber exposure. The sample degradation was assessed by infrared spectroscopy, gloss and colorimetric analyses. Moreover, the thermal behavior was studied by means of a simplified experimental setup. Finally, a soiling and weathering test was conducted to simulate the soiling of three years’ external exposure. Despite the phenomena of chemical degradation and a decrease in aesthetic properties, the samples maintain their thermal performance, which is not even influenced by dirt products. In addition, NIR pigments significantly improve the thermal behavior of brown coatings.

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