scholarly journals Pumping wavelength related population inversion in Nd:doped laser

AIP Advances ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 105309
Author(s):  
Yingxin Bai
Keyword(s):  
Population Inversion ◽  
Related Population

scholarly journals Ten-year trends in epidemiology and outcomes of pediatric kidney replacement therapy in Europe: data from the ESPN/ERA-EDTA Registry

2021 ◽  
Author(s):  
Marjolein Bonthuis ◽  
Enrico Vidal ◽  
Anna Bjerre ◽  
Özlem Aydoğ ◽  
Sergey Baiko ◽  
...  
Keyword(s):  
Replacement Therapy ◽  
Cox Regression ◽  
Patient Survival ◽  
Healthcare Providers ◽  
Resource Planning ◽  
Policy Makers ◽  
Age Related ◽  
Kidney Replacement Therapy ◽  
Over Time ◽  
Related Population

Abstract Background For 10 consecutive years, the ESPN/ERA-EDTA Registry has included data on children with stage 5 chronic kidney disease (CKD 5) receiving kidney replacement therapy (KRT) in Europe. We examined trends in incidence and prevalence of KRT and patient survival. Methods We included all children aged <15 years starting KRT 2007–2016 in 22 European countries participating in the ESPN/ERA-EDTA Registry since 2007. General population statistics were derived from Eurostat. Incidence and prevalence were expressed per million age-related population (pmarp) and time trends studied with JoinPoint regression. We analyzed survival trends using Cox regression. Results Incidence of children commencing KRT <15 years remained stable over the study period, varying between 5.5 and 6.6 pmarp. Incidence by treatment modality was unchanged over time: 2.0 for hemodialysis (HD) and peritoneal dialysis (PD) and 1.0 for transplantation. Prevalence increased in all age categories and overall rose 2% annually from 26.4 pmarp in 2007 to 32.1 pmarp in 2016. Kidney transplantation prevalence increased 5.1% annually 2007–2009, followed by 1.5% increase/year until 2016. Prevalence of PD steadily increased 1.4% per year over the entire period, and HD prevalence started increasing 6.1% per year from 2011 onwards. Five-year unadjusted patient survival on KRT was around 94% and similar for those initiating KRT 2007–2009 or 2010–2012 (adjusted HR: 0.98, 95% CI:0.71–1.35). Conclusions We found a stable incidence and increasing prevalence of European children on KRT 2007–2016. Five-year patient survival was good and was unchanged over time. These data can inform patients and healthcare providers and aid health policy makers on future resource planning of pediatric KRT in Europe.

Supradegeneracy and the Second Law of Thermodynamics

2020 ◽  
Vol 45 (2) ◽  
pp. 121-132
Author(s):  
Daniel P. Sheehan
Keyword(s):  
Steady State ◽  
Statistical Mechanics ◽  
Population Inversion ◽  
Laboratory Experiments ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Boltzmann Factor ◽  
Energy Currents ◽  
Non Equilibrium

AbstractCanonical statistical mechanics hinges on two quantities, i. e., state degeneracy and the Boltzmann factor, the latter of which usually dominates thermodynamic behaviors. A recently identified phenomenon (supradegeneracy) reverses this order of dominance and predicts effects for equilibrium that are normally associated with non-equilibrium, including population inversion and steady-state particle and energy currents. This study examines two thermodynamic paradoxes that arise from supradegeneracy and proposes laboratory experiments by which they might be resolved.

scholarly journals Population inversion in hyperfine states of Rb with a single nanosecond chirped pulse in the framework of a four-level system

2014 ◽  
Vol 89 (4) ◽  
Author(s):  
G. Liu ◽  
V. Zakharov ◽  
T. Collins ◽  
P. Gould ◽  
S. A. Malinovskaya
Keyword(s):  
Population Inversion ◽  
Level System ◽  
Chirped Pulse

Feasibility Of Novel Si-Based Interminiband Lasers

1998 ◽  
Vol 533 ◽  
Author(s):  
Gregory Sun ◽  
Lionel Friedman ◽  
Richard A. Soref
Keyword(s):  
Quantum Wells ◽  
Current Density ◽  
Population Inversion ◽  
Heavy Hole ◽  
Optical Gain ◽  
Laser Structure ◽  
Strained Si ◽  
Superlattice Structures ◽  
A Current

AbstractWe have designed a parallel interminiband lasing in superlattice structures of coherently strained Si0.5Ge0.5/Si quantum wells (QWs). Population inversion is achieved between the non-parabolic heavy-hole valence minibands locally in-k-space. Lasing transition is at 5.4μm. Our analysis indicates that an optical gain of 134/cm can be obtained when the laser structure is pumped with a current density of 5kA/cm2.

Observation of population inversion in recombining Al plasma by time‐ and space‐resolved x‐ray spectroscopy

1996 ◽  
Vol 68 (11) ◽  
pp. 1479-1481 ◽  
Author(s):  
M. Katsuragawa ◽  
J. Itatani ◽  
S. Orimo ◽  
T. Ozaki ◽  
H. Kuroda ◽  
...  
Keyword(s):  
Population Inversion ◽  
Time And Space ◽  
X Ray

Research Progress and Prospect of Fiber Gas Laser Sources (II): Based on Population Inversion

2021 ◽  
Vol 48 (4) ◽  
pp. 0401009
Author(s):  
王泽锋 Wang Zefeng ◽  
周智越 Zhou Zhiyue ◽  
崔宇龙 Cui Yulong ◽  
黄威 Huang Wei ◽  
李智贤 Li Zhixian ◽  
...  
Keyword(s):  
Population Inversion ◽  
Research Progress ◽  
Gas Laser ◽  
Laser Sources

Dynamics of entanglement and population inversion of two qubits in a hybrid nonlinear system

2021 ◽  
pp. 2150037
Author(s):  
E. M. Khalil ◽  
A.-B. A. Mohamed
Keyword(s):  
Electromagnetic Field ◽  
Nonlinear System ◽  
Analytical Solution ◽  
Nonlinear Interaction ◽  
Population Inversion ◽  
Stark Shift ◽  
Parametric Amplifier ◽  
Kerr Medium ◽  
Interaction Terms

An analytical solution is obtained when the Kerr medium and Stark shift are considered as nonlinear interaction terms to the system containing two-qubit and two-mode electromagnetic field from the parametric amplifier. Dynamics of the population inversion, cavity–qubit and qubit–qubit entanglements are analyzed under the unitary cavity–qubit interaction, the Kerr medium and the Stark shift. The population inversion of a qubit presents periodic revivals and collapses. The results show that the entanglement and the population inversion as well as the inversion have the same stable intervals, that is, the collapse intervals. It is found that the Kerr medium and the Stark shift may lead to reduction of the periods and the amplitudes of the population inversion and the cavity–qubit/qubit–qubit entanglement. The deteriorated qubit–qubit/cavity–qubit entanglement and the population inversion, due to the Kerr medium, may be increased by increasing the Stark shift and vice versa.

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