scholarly journals Linear-in-mass-ratio contribution to spin precession and tidal invariants in Schwarzschild spacetime at very high post-Newtonian order

2015 ◽  
Vol 91 (12) ◽  
Author(s):  
Abhay G. Shah ◽  
Adam Pound
Keyword(s):  
Spin Precession ◽  
Mass Ratio ◽  
Schwarzschild Spacetime ◽  
Very High

scholarly journals Potential microwave probes of the proton-to-electron mass ratio at very high redshifts

2014 ◽  
Vol 439 (1) ◽  
pp. 1136-1139 ◽  
Author(s):  
L. Augustovičová ◽  
P. Soldán ◽  
W. P. Kraemer ◽  
V. Špirko
Keyword(s):  
Electron Mass ◽  
Mass Ratio ◽  
Very High ◽  
Microwave Probes

scholarly journals Electrorefining of U-Pu-Zr-alloy fuel onto solid Aluminium cathodes in molten LiCl-KCl

2008 ◽  
Vol 96 (4-5) ◽  
Author(s):  
P. Souček ◽  
L. Cassayre ◽  
Rikard Malmbeck ◽  
E. Mendes ◽  
Régis Jardin ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
High Capacity ◽  
Mass Ratio ◽  
Molten Chloride ◽  
Edx Analysis ◽  
Potentiostatic Mode ◽  
Chloride Salts ◽  
Very High ◽  
Zr Alloy

An electrorefining process in molten chloride salts using solid aluminium cathodes is being developed at ITU to recover actinides (An) from the spent nuclear fuel. The maximum possible loading of aluminium electrodes with actinides was investigated during the electrorefining of U-Pu-Zr alloy in a LiCl-KCl eutectic at 450 °C. Two different electrolytic techniques were applied during the experiment and almost 6000 C has been passed, corresponding to 3.7 g of deposited actinides. A very high capacity of aluminium to retain actinides has been proven as the average Al: An mass ratio was 1:1.58 for galvanostatic and 1:2.25 for potentiostatic mode. The obtained deposits were characterized by XRD and SEM-EDX analysis and alloys composed of (U,Pu)Al

Conflicting Design Issues Hallmark the Compound Rocket Motors

2014 ◽  
Vol 555 ◽  
pp. 49-56
Author(s):  
Radu D. Rugescu
Keyword(s):  
Mass Ratio ◽  
Lower Mass ◽  
Propulsive Efficiency ◽  
Rocket Motors ◽  
Optimal Velocity ◽  
Space Rocket ◽  
Overall Efficiency ◽  
Lift Off ◽  
High Thrust ◽  
Very High

A series of conflicting requirements to which the design of the compound rocket motors are subjected are considerably diminishing the efficiency of that type of rocket motors. The necessity of delivering a high thrust level at lift-off and during the sustainer phase up to optimal velocity accommodation, coupled with the requirement for a slander body configuration for air drag mitigation during the atmospheric ascent are the dominant issues that end into a compromise that lower the overall efficiency to a great extent, in comparison the available theoretical performance of compound rocket motors. The optimal design is imposing a lower mass ratio that expected and is the main cause of efficiency reduction when very high velocity requirements are searched for, like in orbital launchers. However, the margins of propulsive efficiency build-up can be conveniently manipulated through geometrical optimization and attentive risk management of the propulsion system as shown by the experimental results protruded during the development of the NERVA-ORVEAL space rocket motor.

scholarly journals The quasar main sequence and its potential for cosmology

2019 ◽  
Vol 15 (S356) ◽  
pp. 66-71
Author(s):  
Paola Marziani ◽  
Deborah Dultzin ◽  
Ascensión del Olmo ◽  
Mauro D’Onofrio ◽  
José A. de Diego ◽  
...  
Keyword(s):  
Black Holes ◽  
Spectral Properties ◽  
Main Sequence ◽  
Accretion Rate ◽  
Mass Ratio ◽  
Redshift Range ◽  
Massive Black Holes ◽  
Line Widths ◽  
Very High

AbstractThe main sequence offers a method for the systematization of quasar spectral properties. Extreme FeII emitters (or extreme Population A, xA) are believed to be sources accreting matter at very high rates. They are easily identifiable along the quasar main sequence, in large spectroscopic surveys over a broad redshift range. The very high accretion rate makes it possible that massive black holes hosted in xA quasars radiate at a stable, extreme luminosity-to-mass ratio. After reviewing the basic interpretation of the main sequence, we report on the possibility of identifying virial broadening estimators from low-ionization line widths, and provide evidence of the conceptual validity of redshift-independent luminosities based on virial broadening for a known luminosity-to-mass ratio.

scholarly journals Spin precession in the Schwarzschild spacetime: circular orbits

2005 ◽  
Vol 22 (14) ◽  
pp. 2947-2970 ◽  
Author(s):  
Donato Bini ◽  
Fernando de Felice ◽  
Andrea Geralico ◽  
Robert T Jantzen
Keyword(s):  
Spin Precession ◽  
Schwarzschild Spacetime ◽  
Circular Orbits

scholarly journals Quasars: From the Physics of Line Formation to Cosmology

Atoms ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 18 ◽  
Author(s):  
Paola Marziani ◽  
Edi Bon ◽  
Natasa Bon ◽  
Ascension del Olmo ◽  
Mary Martínez-Aldama ◽  
...  
Keyword(s):  
Black Holes ◽  
Big Bang ◽  
Mass Ratio ◽  
Ionized Gas ◽  
Massive Black Holes ◽  
New Class ◽  
Physical Conditions ◽  
The Big Bang ◽  
Distance Indicators ◽  
Very High

Quasars accreting matter at very high rates (known as extreme Population A (xA) or super-Eddington accreting massive black holes) provide a new class of distance indicators covering cosmic epochs from the present-day Universe up to less than 1 Gyr from the Big Bang. The very high accretion rate makes it possible that massive black holes hosted in xA quasars can radiate at a stable, extreme luminosity-to-mass ratio. This in turn translates into stable physical and dynamical conditions of the mildly ionized gas in the quasar low-ionization line emitting region. In this contribution, we analyze the main optical and UV spectral properties of extreme Population A quasars that make them easily identifiable in large spectroscopic surveys at low- ( z ≲ 1 ) and intermediate-z (2 ≲ z ≲ 2.6), and the physical conditions that are derived for the formation of their emission lines. Ultimately, the analysis supports the possibility of identifying a virial broadening estimator from low-ionization line widths, and the conceptual validity of the redshift-independent luminosity estimates based on virial broadening for a known luminosity-to-mass ratio.

scholarly journals Research on materials of solar selective absorption coating based on the first principle

Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 477-485
Author(s):  
Xuelin Zhang ◽  
Junjie Zhou ◽  
Weidong Fu ◽  
Lei Chen
Keyword(s):  
Composite Material ◽  
Optical Properties ◽  
Composite Coatings ◽  
Selective Absorption ◽  
First Principle ◽  
Mass Ratio ◽  
Materials Studio ◽  
Very High ◽  
Emission Ratios ◽  
Good Agreement

Abstract Based on the first principle, this paper studies the optical properties of Ni, Mo, CoO, and Cr2O3 according to the Materials Studio software. It is found that the absorptivity of Ni is low, while Ni has low emissivity. Hence, it can be used to reduce emissivity. The absorption rate of CoO is very high. Therefore, Ni and CoO are very suitable to be composed to make a solar selective absorption coating with high absorptivity and low emissivity. The mass ratio of Ni and CoO has a greater impact on the optical properties of the composite material, so the absorption–emission ratios of the composite material Ni–CoO at different mass ratios are calculated. The absorption–emission ratio is the highest when the mass ratio is 1:1, and the performance is the best, which is in good agreement with the result of the experiment. And we hope that our method will provide some help for the study of solar selective absorption composite coatings.

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