scholarly journals Generalization of Kirchhoff’s Law: The inherent relations between quantum efficiency and emissivity

2022 ◽  
Author(s):  
Matej Kurtulik ◽  
Michal Shimanovich ◽  
Rafi Weill ◽  
Assaf Manor ◽  
Michael Shustov ◽  
...  
Keyword(s):  
Thermal Radiation ◽  
Quantum Efficiency ◽  
Chemical Potential ◽  
Thermal Emission ◽  
Photon Emission ◽  
The Body ◽  
Energy Devices ◽  
Planck’S Law ◽  
Electron Photon ◽  
Kirchhoff's Law

Abstract Planck’s law of thermal radiation depends on the temperature, \(T\), and the emissivity, \(\epsilon\), which is the coupling of heat to radiation depending on both phonon-electron nonradiative-interactions and electron-photon radiative-interactions. In contrast, absorptivity, \(\alpha\), only depends on the electron-photon radiative-interactions. At thermodynamic equilibrium, nonradiative-interactions are balanced, resulting in Kirchhoff’s law of thermal radiation, \(\epsilon =\alpha\). For non-equilibrium, Quantum efficiency (QE) describes the statistics of photon emission, which like emissivity depends on both radiative and nonradiative interactions. Past generalized Planck’s equation extends Kirchhoff’s law out of equilibrium by scaling the emissivity with the pump-dependent chemical-potential \(\mu\), obscuring the relations between the body properties. Here we theoretically and experimentally demonstrate a prime equation relating these properties in the form of \(\epsilon =\alpha \left(1-QE\right)\). At equilibrium, these relations are reduced to Kirchhoff’s law. Our work lays out the evolution of non-thermal emission with temperature, which is critical for the development of lighting and energy devices.

scholarly journals Magnetic Resonace–Based Attenuation Correction for Micro–Single-Photon Emission Computed Tomography

2012 ◽  
Vol 11 (2) ◽  
pp. 7290.2011.00036 ◽  
Author(s):  
Vincent Keereman ◽  
Yves Fierens ◽  
Christian Vanhove ◽  
Tony Lahoutte ◽  
Stefaan Vandenberghe
Keyword(s):  
Attenuation Correction ◽  
Single Photon ◽  
Photon Emission ◽  
The Body ◽  
Emission Computed Tomography ◽  
Micro Ct ◽  
Mr Images ◽  
Brain Scans ◽  
The Brain ◽  
Photon Emission Computed Tomography

Attenuation correction is necessary for quantification in micro–single-photon emission computed tomography (micro-SPECT). In general, this is done based on micro–computed tomographic (micro-CT) images. Derivation of the attenuation map from magnetic resonance (MR) images is difficult because bone and lung are invisible in conventional MR images and hence indistinguishable from air. An ultrashort echo time (UTE) sequence yields signal in bone and lungs. Micro-SPECT, micro-CT, and MR images of 18 rats were acquired. Different tracers were used: hexamethylpropyleneamine oxime (brain), dimercaptosuccinic acid (kidney), colloids (liver and spleen), and macroaggregated albumin (lung). The micro-SPECT images were reconstructed without attenuation correction, with micro-CT-based attenuation maps, and with three MR-based attenuation maps: uniform, non-UTE-MR based (air, soft tissue), and UTE-MR based (air, lung, soft tissue, bone). The average difference with the micro-CT-based reconstruction was calculated. The UTE-MR-based attenuation correction performed best, with average errors ≤ 8% in the brain scans and ≤ 3% in the body scans. It yields nonsignificant differences for the body scans. The uniform map yields errors of ≤ 6% in the body scans. No attenuation correction yields errors ≥ 15% in the brain scans and ≥ 25% in the body scans. Attenuation correction should always be performed for quantification. The feasibility of MR-based attenuation correction was shown. When accurate quantification is necessary, a UTE-MR-based attenuation correction should be used.

Ultra high-efficiency multi-photon emission blue phosphorescent OLEDs with external quantum efficiency exceeding 40%

2012 ◽  
Vol 13 (11) ◽  
pp. 2615-2619 ◽  
Author(s):  
Hisahiro Sasabe ◽  
Kazuhiro Minamoto ◽  
Yong-Jin Pu ◽  
Masakatsu Hirasawa ◽  
Junji Kido
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Photon Emission ◽  
Blue Phosphorescent

scholarly journals Method for auxiliary use of thermography in diagnosing inflammation in the coxofemoral joint in dogs

2018 ◽  
Vol 39 (4) ◽  
pp. 1565
Author(s):  
Fernanda Lúcia Passos Fukahori ◽  
Daniela Maria Bastos de Souza ◽  
Eduardo Alberto Tudury ◽  
George Chaves Jimenez ◽  
José Ferreira da Silva Neto ◽  
...  
Keyword(s):  
Thermal Emission ◽  
Low Cost ◽  
Joint Inflammation ◽  
Domestic Animals ◽  
The Body ◽  
Joint Diseases ◽  
Infrared Images ◽  
Infrared Thermometry ◽  
Non Invasive ◽  
Sensitivity Specificity

Joint diseases are relatively common in domestic animals, such as dogs. The involved inflammation produces thermal emission, which can be imaged using specific sensors that allow capturing of infrared images. Given that there have been few reports on the use of thermography in the diagnosis of inflammation associated with diseases of the hip joint in dogs, we here propose a method for identification of inflammatory foci in dogs by using infrared thermometry. The present study aimed to find non-invasive and low-cost resources that couldfacilitate a clinical diagnosis in cases withinflammation in the coxofemoral joint of dogs.To this end, we developed a system in whichthe Flir Systems TG165 thermograph is coupled to a black PVC cannula with a 30-cm focus-to-animal distance.External effects of the environment on the temperature of the animalswere compared with the body temperature as measured by a conventional thermometer.Thirty-one dogs with and without inflammation in the coxofemoral joint underwent clinical evaluation.We verified that the temperature registered by the thermograph inthe animals with joint inflammation was significantlydifferentfrom that incontrol animals without inflammation, in the lateral projection.The method showed a sensitivity of 80%, specificity of 87.5%, and accuracy of 83.87%. This standardized method of diagnosis of inflammatory foci in the coxofemoral articulation of dogs by way of thermography showed sensitivity, specificity, and satisfactory accuracy.

Basic principles and technological state of the art: SPECT

ESC CardioMed ◽  
2018 ◽  
pp. 573-577
Author(s):  
Alessia Gimelli ◽  
Riccardo Liga
Keyword(s):  
Single Photon ◽  
Imaging Modality ◽  
Photon Emission ◽  
Nuclear Imaging ◽  
The Body ◽  
Emission Computed Tomography ◽  
Non Invasive ◽  
Photon Emission Computed Tomography ◽  
Invasive Evaluation

Single-photon emission computed tomography (SPECT) photons as a medical imaging technique detects the radiation emitted by radioisotopes injected into the body to provide in vivo measurements of regional tissue function. From its introduction in the cardiologic clinical field, nuclear imaging has classically represented the reference technique for the non-invasive evaluation of myocardial perfusion, becoming the most frequently performed imaging modality for the functional assessment of patients with ischaemic heart disease.

Non-thermal emission and spectral evolution properties of G54.1+0.3

2019 ◽  
Vol 487 (4) ◽  
pp. 5781-5787
Author(s):  
Ji-Yang Ren ◽  
Quan-Gui Gao ◽  
Huai-Zhen Li ◽  
Ju Ma ◽  
Shan-Shan Zhao ◽  
...  
Keyword(s):  
Thermal Emission ◽  
Spectral Energy Distribution ◽  
Photon Emission ◽  
Dynamical Evolution ◽  
Spectral Energy ◽  
Model Parameters ◽  
Spectral Evolution ◽  
Proton Proton ◽  
X Ray ◽  
Γ Ray

ABSTRACT The multiband photon emission and spectral evolution of G54.1+0.3 are investigated in the framework of leptonic and leptonic–hadronic models. We model the spectral energy distribution (SED) of the pulsar wind nebula (PWN) and find that both the leptonic and leptonic–hadronic models can well reproduce the multiband observations of the nebula with appropriate model parameters. Combining with dynamical evolution of the PWN, we investigate the time evolution of photon SED and radiative luminosity in the X-ray and TeV γ-ray bands of G54.1+0.3. The results indicate that the synchrotron spectrum and radiative luminosity in the X-ray band of the PWN calculated with these two models have obvious differences as the age increases to about 4 kyr, and the largest difference is present at about 40 kyr. The γ-ray luminosity calculated by the leptonic–hadronic model shows that the contribution of TeV photons arising from the decay of neutral pions produced in proton–proton interaction also changes with time and is always important for modifying the TeV γ-ray spectrum of G54.1+0.3 during the evolution of the PWN.

Synthesis and Photoluminescence Properties of Sc0.88-xLu0.05VO4:Eu3+0.07,Bi3+x Red Phosphor

2017 ◽  
Vol 727 ◽  
pp. 604-611
Author(s):  
Di Wu ◽  
Xin Yu Ye ◽  
Xin Hua Yang ◽  
Jian Zhou ◽  
Xiao Qiang Wen ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Emission Intensity ◽  
Doping Concentration ◽  
Internal Quantum Efficiency ◽  
The Body ◽  
Luminescence Spectra ◽  
Intensity Increase ◽  
X Ray Diffraction ◽  
Red Phosphor ◽  
Red Phosphors

Sc0.88-xLu0.05VO4:Eu3+0.07,Bi3+x(0≤x≤0.05) red phosphors were synthesized by solid state reaction at 1200°C for 3h. The structure, morphology and luminescence spectra of samples are investigated by X-ray diffraction (XRD), Scanning electron microscope (SEM) and fluorescence spectrophotometer, respectively. The samples doped with Eu3+, Lu3+ and Bi3+ maintain the body-centered tetragonal structure of ScVO4 and the morphology remains essentially unchanged with slight agglomeration. The excitation spectrum of Sc0.88-xLu0.05VO4:Eu3+0.07,Bi3+x emerged redshift and the excitation intensity increase within the near UV excitation (360-400nm). The optimum doping concentration of Bi3+ is 0.02(x value), and the maximum emission intensity of Sc0.86Lu0.05VO4:Eu3+0.07,Bi3+0.02 is higher than 88 % in comparison with Sc0.88Lu0.05VO4:Eu3+0.07 under 365 nm excitation. Decay curve of 5D0 state for as-prepared samples fits the single order exponential behavior, the lifetime of 5D0 increase first and then decrease with the increase of Bi3+ doping concentration. The internal quantum efficiency is up to 74.08% under 365nm excitation; When the temperature raises to 200°C, the emission intensity maintains 79% of that in the room temperature. Sc0.86Lu0.05VO4:Eu3+0.07,Bi3+0.02 phosphor show high internal quantum efficiency and thermal stability, which is suitable for the UV-pumped white LED as red phosphor.

scholarly journals Evaluation of strontium aluminate phosphorescent effect on blood as potential light source for phototherapy

2020 ◽  
Vol 9 (3) ◽  
pp. 21-29
Author(s):  
H. Choong ◽  
N. Suardi ◽  
N. Ahmed
Keyword(s):  
Blood Plasma ◽  
Light Source ◽  
Photon Emission ◽  
Visible Spectrum ◽  
The Body ◽  
Cubic Phase ◽  
Strontium Aluminate ◽  
Fixed Amount ◽  
Visible Absorption ◽  
Uv Visible

Phototherapy has shown its effect on cell stimulation and inhibition based on Arndt-Schulz model. Even though this therapeutic method has apparent effect, but it has limitations for epithelial application due to limitations on light penetration. Hence, with the ideology of fully overcoming this limitation, phosphorescent powder (strontium aluminate) is proposed as the potential light source that emitting photon from inside the body for phototherapy purposes. The strontium aluminate powder used in the experiment has the highest peak absorption at wavelength around 650 nm and lowest at around 350 nm. According to FESEM images, the powder has the particle size varies from 10 to 50 μm at cubic phase. The assessment is done by studying the effect on erythrocyte after blood plasma is irradiated by strontium aluminate powder’s photon. The powder luminesces with a maximum at 491.5 nm when pumped with 473 nm laser at 100 mW in fixed amount of 0.005±0.001 g. Later, it is mixed with  centrifuged blood plasma for a predetermined time period (5, 10, 15, and 20 minutes). From this study, it shows that 5 minutes irradiation is the optimum  period for erythrocyte in term of morphology enhancement and increase of UV-visible absorption spectrum with at least 21% in comparing  with control blood. While the significant increment located at wavelengths 340 nm and 414 nm with both increased by 54% and 41%, respectively. However, for 10 minutes and beyond, the irradiation leads to morphology deterioration while the UV-visible spectrum decrement starts at 15 minutes and beyond. In conjunction, a comparison between blood plasma that either interacted with powder emitting photon or powder with no emission shows that photon emission plays a role in the phototherapy effect.

scholarly journals Theoretical and Experimental Study for New Titanium Metal Complexes in Biophysical Applications

2019 ◽  
Vol 54 (6) ◽  
Author(s):  
Ali S. Hasan ◽  
Mohammed A. Akraa ◽  
Salim J. Abbas
Keyword(s):  
Metal Complexes ◽  
Chemical Potential ◽  
Chemical Vapor ◽  
The Body ◽  
Titanium Metal ◽  
Potential Surfaces ◽  
B3lyp Method ◽  
Biological Effectiveness ◽  
Orbital Analysis ◽  
Deposition Technology

In this research, new titanium metal complexes were designed and prepared for use in biophysical applications, because titanium is biocompatible (non-toxic and accepted by the body). New models of TiMC were designed and prepared by DFT/B3LYP method with SDD base sets and chemical vapor deposition technology, respectively. Structural, electronic transitions, and surface morphology properties were calculated by Gaussian 09 program package, XRD and SEM. The optimized structures for molecules under study have been found in great concurrence with empirical information. The results showed that these complexes have an electronic transition, UV-Vis spectrum, low band gaps, low chemical potential and are softer, can easily interact with enzymes because the enzymes are big soft molecules. The present study is aimed at investigating the effect of TiMC in Biophysics. Moreover, we used an orbital analysis, counting the 3-D electron density and electrostatic potential surfaces to find out the possible orbital hybridization for molecules, thus determining the biological effectiveness of the molecules under study.

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