scholarly journals Scattering of Light from the Systemic Circulatory System

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1026
Author(s):  
Sidra Batool ◽  
Mehwish Nisar ◽  
Fabio Mangini ◽  
Fabrizio Frezza ◽  
Eugenio Fazio

There are many factors of methodological origin that influence the measurement of optical properties of the entire circulatory system which consists of blood as the basic component. The basic idea of this review article is to provide the optical properties of the circulatory system with all those factors of influence that have been employed in biomedical optics for different applications. We begin with the available optical properties, i.e., absorption, scattering and, reduced scattering coefficient, in general for any tissue inside the human body and prominent scattering theories (e.g., light, X-rays, neutrons) that are helpful in this regard. We have reviewed and compiled already available formulas and their respective available data for different human tissues for these optical properties. Then we have descended to the blood composition and to different scattering techniques available in the literature to study scattering and light propagation inside blood. We have reviewed both computational and theoretical scattering techniques.

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shaoni Kar ◽  
Nur Fadilah Jamaludin ◽  
Natalia Yantara ◽  
Subodh G. Mhaisalkar ◽  
Wei Lin Leong

Abstract Perovskite semiconductors have experienced meteoric rise in a variety of optoelectronic applications. With a strong foothold on photovoltaics, much focus now lies on their light emission applications. Rapid progress in materials engineering have led to the demonstration of external quantum efficiencies that surpass the previously established theoretical limits. However, there remains much scope to further optimize the light propagation inside the device stack through careful tailoring of the optical processes that take place at the bulk and interface levels. Photon recycling in the emitter material followed by efficient outcoupling can result in boosting external efficiencies up to 100%. In addition, the poor ambient and operational stability of these materials and devices restrict further commercialization efforts. With best operational lifetimes of only a few hours reported, there is a long way to go before perovskite LEDs can be perceived as reliable alternatives to more established technologies like organic or quantum dot-based LED devices. This review article starts with the discussions of the mechanism of luminescence in these perovskite materials and factors impacting it. It then looks at the possible routes to achieve efficient outcoupling through nanostructuring of the emitter and the substrate. Next, we analyse the instability issues of perovskite-based LEDs from a photophysical standpoint, taking into consideration the underlying phenomena pertaining to defects, and summarize recent advances in mitigating the same. Finally, we provide an outlook on the possible routes forward for the field and propose new avenues to maximally exploit the excellent light-emitting capabilities of this family of semiconductors.


2019 ◽  
Vol 486 (4) ◽  
pp. 4863-4879 ◽  
Author(s):  
Ali Takey ◽  
Florence Durret ◽  
Isabel Márquez ◽  
Amael Ellien ◽  
Mona Molham ◽  
...  

ABSTRACT We present X-ray and optical properties of the optically confirmed galaxy cluster sample from the 3XMM/SDSS Stripe 82 cluster survey. The sample includes 54 galaxy clusters in the redshift range of 0.05–1.2, with a median redshift of 0.36. We first present the X-ray temperature and luminosity measurements that are used to investigate the X-ray luminosity–temperature relation. The slope and intercept of the relation are consistent with those published in the literature. Then, we investigate the optical properties of the cluster galaxies including their morphological analysis and the galaxy luminosity functions (GLFs). The morphological content of cluster galaxies is investigated as a function of cluster mass and distance from the cluster centre. No strong variation of the fraction of early- and late-type galaxies with cluster mass is observed. The fraction of early-type galaxies as a function of cluster radius varies as expected. The individual GLFs of red sequence galaxies were studied in the five ugriz bands for 48 clusters. The GLFs were then stacked in three mass bins and two redshift bins. Twenty clusters of the present sample are studied for the first time in X-rays, and all are studied for the first time in the optical range. Altogether, our sample appears to have X-ray and optical properties typical of ‘average’ cluster properties.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
G. L. C. Spicer ◽  
A. Eid ◽  
D. Wangpraseurt ◽  
T. D. Swain ◽  
J. A. Winkelmann ◽  
...  

Abstract The success of reef-building corals for >200 million years has been dependent on the mutualistic interaction between the coral host and its photosynthetic endosymbiont dinoflagellates (family Symbiodiniaceae) that supply the coral host with nutrients and energy for growth and calcification. While multiple light scattering in coral tissue and skeleton significantly enhance the light microenvironment for Symbiodiniaceae, the mechanisms of light propagation in tissue and skeleton remain largely unknown due to a lack of technologies to measure the intrinsic optical properties of both compartments in live corals. Here we introduce ISOCT (inverse spectroscopic optical coherence tomography), a non-invasive approach to measure optical properties and three-dimensional morphology of living corals at micron- and nano-length scales, respectively, which are involved in the control of light propagation. ISOCT enables measurements of optical properties in the visible range and thus allows for characterization of the density of light harvesting pigments in coral. We used ISOCT to characterize the optical scattering coefficient (μs) of the coral skeleton and chlorophyll a concentration of live coral tissue. ISOCT further characterized the overall micro- and nano-morphology of live tissue by measuring differences in the sub-micron spatial mass density distribution (D) that vary throughout the tissue and skeleton and give rise to light scattering, and this enabled estimates of the spatial directionality of light scattering, i.e., the anisotropy coefficient, g. Thus, ISOCT enables imaging of coral nanoscale structures and allows for quantifying light scattering and pigment absorption in live corals. ISOCT could thus be developed into an important tool for rapid, non-invasive monitoring of coral health, growth and photophysiology with unprecedented spatial resolution.


2010 ◽  
Author(s):  
P. Sun ◽  
Run Q. Yang ◽  
Feng H. Xie ◽  
Jia Q. Ding ◽  
Fu Q. Zhang ◽  
...  

2007 ◽  
Vol 22 (6) ◽  
pp. 1609-1617 ◽  
Author(s):  
W.G. Chu ◽  
L.N. Zhang ◽  
H.F. Wang ◽  
Z.H. Han ◽  
D. Han ◽  
...  

Single-crystalline nanobelts of molybdenum trioxides were grown by direct thermal oxidization evaporation of metal molybdenum foils. Their structures, defects, and optical properties were investigated via x-ray diffraction, field-emission scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM), atomic force microscopy, micro-Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible spectroscopy (UV-VIS). Single-crystalline nanobelts were identified as an orthorhombic structure with an average stoichiometry of MoO3.02analyzed by energy dispersive spectroscopy of x-rays. The length, width, and thickness of a nanobelt were determined to be parallel to the b, c, and aaxis of the MoO3unit cell, respectively. The thickness of the nanobelt increased by integer multiples of 0.5ain a layer-by-layer fashion during growth. A density of dislocations as high as about 1.2 × 1013cm−2was formed, which may be attributed to relaxation of large strains during cooling. A special dislocation configuration was observed by HRTEM, which was well reproduced by image simulations based on the proposed model. The resulting morphology of nanobelts was proposed to be governed by growth kinetics. Micro-Raman and FTIR spectra were successfully analyzed on the basis of vibration of MoO6octahedra. It was found that micro-Raman spectra were quite dependent on the size of the nanobelts. A band gap energy of 3.04 eV derived from UV-VIS measurements was observed to be red shifted relative to the previously reported experimental values, which may be due to the presence of a high density of defects.


Author(s):  
Tomohiro Ota ◽  
Masatoshi Tarumi ◽  
Hidenobu Arimoto ◽  
Miho Shimada ◽  
Yukio Yamada

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