scholarly journals Optical characteristics of finite temperature quantum electron gas

2017 ◽  
Vol 95 (12) ◽  
pp. 1225-1233
Author(s):  
M. Akbari-Moghanjoughi

In this paper we study the propagation of elliptically polarized transverse electromagnetic waves in a quasineutral plasma with arbitrary degenerate electron fluid ranging from classical dilute to fully degenerate density regimes by using the appropriate collisional magnetohydrodynamics model, which incorporates the adiabatic quantum equation of states for high-frequency electron fluid compression and the Bohm quantum potential responsible for the collective quantum diffraction effect. Three distinct propagation modes are categorized corresponding to electron density regimes of dilute, intermediate, and fully degenerate plasmas. One of these modes is found to be purely of quantum mechanical origin and disappears in the absence of the quantum diffraction effect. The present generalized magnetohydrodynamics theory qualitatively describes key features of optical parameters and experimental data of dilute classical, semiconducting, and in fully degenerate plasmas. Different optical parameters, such as the refractive and absorption index of the new mode are investigated. It is shown that the optical response of the magnetized plasma with arbitrary degeneracy is essentially governed by three characteristic frequencies, namely, collision, plasmon, and cyclotron frequencies. The profound experimental minimum in the refractive index of arbitrary degenerate quantum plasmas and its dependence on the characteristic frequencies is studied in detail. Current investigation is of fundamental importance in high energy density and fusion plasma diagnostics and may provide key knowledge on the characteristics of astrophysical dense matter.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
E. R. Tubman ◽  
A. S. Joglekar ◽  
A. F. A. Bott ◽  
M. Borghesi ◽  
B. Coleman ◽  
...  

AbstractMagnetized plasma interactions are ubiquitous in astrophysical and laboratory plasmas. Various physical effects have been shown to be important within colliding plasma flows influenced by opposing magnetic fields, however, experimental verification of the mechanisms within the interaction region has remained elusive. Here we discuss a laser-plasma experiment whereby experimental results verify that Biermann battery generated magnetic fields are advected by Nernst flows and anisotropic pressure effects dominate these flows in a reconnection region. These fields are mapped using time-resolved proton probing in multiple directions. Various experimental, modelling and analytical techniques demonstrate the importance of anisotropic pressure in semi-collisional, high-β plasmas, causing a reduction in the magnitude of the reconnecting fields when compared to resistive processes. Anisotropic pressure dynamics are crucial in collisionless plasmas, but are often neglected in collisional plasmas. We show pressure anisotropy to be essential in maintaining the interaction layer, redistributing magnetic fields even for semi-collisional, high energy density physics (HEDP) regimes.


TAPPI Journal ◽  
2010 ◽  
Vol 9 (6) ◽  
pp. 24-30 ◽  
Author(s):  
NIKLAS BERGLIN ◽  
PER TOMANI ◽  
HASSAN SALMAN ◽  
SOLVIE HERSTAD SVÄRD ◽  
LARS-ERIK ÅMAND

Processes have been developed to produce a solid biofuel with high energy density and low ash content from kraft lignin precipitated from black liquor. Pilot-scale tests of the lignin biofuel were carried out with a 150 kW powder burner and a 12 MW circulating fluidized bed (CFB) boiler. Lignin powder could be fired in a powder burner with good combustion performance after some trimming of the air flows to reduce swirl. Lignin dried to 10% moisture content was easy to feed smoothly and had less bridging tendencies in the feeding system than did wood/bark powder. In the CFB boiler, lignin was easily handled and cofired together with bark. Although the filter cake was broken into smaller pieces and fines, the combustion was not disturbed. When cofiring lignin with bark, the sulfur emission increased compared with bark firing only, but most of the sulfur was captured by calcium in the bark ash. Conventional sulfur capture also occurred with addition of limestone to the bed. The sulfur content in the lignin had a significantly positive effect on reducing the alkali chloride content in the deposits, thus reducing the high temperature corrosion risk.


1966 ◽  
Author(s):  
S. CHODOSH ◽  
E. KATSOULIS ◽  
M. ROSANSKY

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.


2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.


2019 ◽  
Author(s):  
Yamin Zhang ◽  
Lina Chen ◽  
Chongyang Hao ◽  
Xiaowen Zheng ◽  
Yixuan Guo ◽  
...  

For the applications of aqueous Li-ion hybrid capacitors and Na-ion hybrid capacitors, potassium ions are pre-inserted into MnO<sub>2</sub> tunnel structure, the as-prepared K<sub>1.04</sub>Mn<sub>8</sub>O<sub>16</sub> materials consist of <a>nanoparticles</a> and nanorods were prepared by facile high-temperature solid-state reaction. <a></a>The as-prepared materials were well studied andthey show outstanding electrochemical behavior. We assembled hybrid supercapacitors with commercial activated carbon (YEC-8A) as anode and K<sub>1.04</sub>Mn<sub>8</sub>O<sub>16 </sub>as cathode. It has high energy densities and power densities. Li-ion capacitors reach a high energy density of 127.61 Wh kg<sup>-1 </sup>at the power density of 99.86 W kg<sup>-1</sup> and Na-ion capacitor obtains 170.96 Wh kg<sup>-1 </sup>at 133.79 W kg<sup>-1</sup>. In addition, the <a>hybrid supercapacitor</a>s demonstrate excellent cycling performance which maintain 97 % capacitance retention for Li-ion capacitor and 85 % for Na-ion capacitor after 10,000 cycles.


2013 ◽  
Vol 28 (11) ◽  
pp. 1207-1212 ◽  
Author(s):  
Jian-Wen LI ◽  
Ai-Jun ZHOU ◽  
Xing-Quan LIU ◽  
Jing-Ze LI

2018 ◽  
Vol 28 (5) ◽  
pp. 273-278
Author(s):  
Beomhee Kang ◽  
Soonhyun Hong ◽  
Hongkwan Yoon ◽  
Dojin Kim ◽  
Chunjoong Kim

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