Hydrogen Atmospheres in the Absence of Thermodynamic Equilibrium. IV. The Solar Chromosphere

1948 ◽  
Vol 1 (4) ◽  
pp. 360
Author(s):  
RG Giovanelli
Keyword(s):  
Observational Data ◽  
Density Gradient ◽  
Electron Concentration ◽  
Hydrostatic Equilibrium ◽  
Profile Measurement ◽  
Solar Chromosphere ◽  
Hydrogen Atoms ◽  
Lower Accuracy ◽  
Good Agreement ◽  
Lower Chromosphere

A discussion of the observational data shows that in the range 0<z<2.5 x 108 cm. the electron concentration in the lower chromosphere may be expressed as Ne=5x 1011 exp(-6 x 10-9z) per cc., where z cm. is the height measured from a level 500 km. above the base of the chromosphere. It is shown that above the 500-km. level hydrogen atoms are almost completely ionized, and that with hydrostatic equilibrium the observed density gradient corresponds to a temperature of 2.7 X 104 �K . This is in good agreement with the temperature derived by Redman from line profile measurement, so that the lower chromosphere appears to be effectively in thermal and hydrostatic equilibrium. Estimates of lower accuracy are given for the electron concentrations at some higher levels in the chromosphere. A discussion is given of the mechanism of absorption of Hα radiation by a chromosphere whose temperature is well above that of the photosphere.

A New Condition of Formation and Stablity of All Crystalline Systems in a Good Agreement with Experimental Data

2015 ◽  
Vol 11 (3) ◽  
pp. 3224-3228
Author(s):  
Tarek El-Ashram
Keyword(s):  
Experimental Data ◽  
Brillouin Zone ◽  
Electron Concentration ◽  
Free Electron ◽  
Lattice Point ◽  
Valence Electron ◽  
Fermi Gas ◽  
Valence Electron Concentration ◽  
Fermi Sphere ◽  
Good Agreement

In this paper we derived a new condition of formation and stability of all crystalline systems and we checked its validity andit is found to be in a good agreement with experimental data. This condition is derived directly from the quantum conditionson the free electron Fermi gas inside the crystal. The new condition relates both the volume of Fermi sphere VF andvolume of Brillouin zone VB by the valence electron concentration VEC as ;𝑽𝑭𝑽𝑩= 𝒏𝑽𝑬𝑪𝟐for all crystalline systems (wheren is the number of atoms per lattice point).

scholarly journals Atmospheric Optical Turbulence Profile Measurement and Model Improvement over Arid and Semi-arid regions

2021 ◽  
Author(s):  
Hao Yang ◽  
Zhiyuan Fang ◽  
Cheng Li ◽  
Xu Deng ◽  
Kunming Xing ◽  
...  
Keyword(s):  
Observational Data ◽  
Arid Regions ◽  
Northwestern China ◽  
Profile Measurement ◽  
Height Distribution ◽  
Optical Turbulence ◽  
Different Seasons ◽  
Combined Action ◽  
Model Improvement ◽  
Improved Model

Abstract. From August 4th to 30th, 2020 and from November 27th to December 25th, 2020, a self-developed radiosonde balloon system was used to observe high-altitude atmospheric optical turbulence at three sites in northwestern China, and an improved model based on the observational data was established. Through comparative analysis of the observational data and the improved model, the distribution characteristics of atmospheric optical turbulence under the combined action of different meteorological parameters and different landform features in different seasons were obtained. The improved model can show the variation of the detailed characteristics of turbulence with the height distribution, and the degree of correlation with the measured values is above 0.82. The improved model can provide a theoretical basis and supporting data for turbulence estimation and forecasting in northwestern China.

Determination of Electrically Active Defect Profiles in Semiconductors Using a Photoelectrochemical Technique

1986 ◽  
Vol 82 ◽  
Author(s):  
F.D. Gealy ◽  
H.L. Tuller
Keyword(s):  
Impedance Spectroscopy ◽  
Liquid Electrolyte ◽  
Profile Measurement ◽  
Acceptor Concentration ◽  
Defect Profile ◽  
Profile Depth ◽  
Charge Capacitance ◽  
Substitutional Impurities ◽  
Good Agreement

ABSTRACTElectrically active defects are common in semiconductors. Such defects include easily ionized substitutional impurities, vacancies, and interstitials which can act as shallow donors or acceptors. If one type of defect predominates, its concentration corresponds directly to the local donor or acceptor concentration. Consequently, measurement of a carrier profile in a nonhomogeneous semiconductor is effectively the same as measurement of the defect profile.The photoelectrochemical profiling technique allows for carrier profile measurement with submicrometer spatial resolution. The sample is profiled by photoetching, then carrier measurement, and iterating this procedure until the desired profile depth is obtained.Derivation of the space charge capacitance by impedance spectroscopy is discussed. An analysis of the P-doped Si-liquid electrolyte interface is presented. Phosphorous diffusivity coefficients in good agreement with literature values are derived from photoelectrochemical derived profiles.

scholarly journals <i>Letter to the Editor</i> Why do ultra-low-frequency MHD oscillations with a discrete spectrum exist in the magnetosphere?

2005 ◽  
Vol 23 (3) ◽  
pp. 1075-1079 ◽  
Author(s):  
A. S. Leonovich ◽  
V. A. Mazur
Keyword(s):  
Discrete Spectrum ◽  
Observational Data ◽  
High Latitude ◽  
Plasma Sheet ◽  
Low Frequency ◽  
Magnetosonic Wave ◽  
Letter To The Editor ◽  
Morning Sector ◽  
Good Agreement

Abstract. A new concept of the global magnetospheric resonator is suggested for fast magnetosonic waves in which the role of the resonator is played by the near-Earth part of the plasma sheet. It is shown that the magnetosonic wave is confined in this region of the magnetosphere within its boundaries. The representative value of the resonator's eigenfrequency estimated at f~1MHz is in good agreement with observational data of ultra-low-frequency MHD oscillations of the magnetosphere with a discrete spectrum (f~0.8, 1.3, 1.9, 2.6...MHz). The theory explains the ground-based localization of the oscillations observed in the midnight-morning sector of the high-latitude magnetosphere.

scholarly journals Diagnostics of Non-thermal Particles in Solar Chromospheric Flares

2004 ◽  
Vol 219 ◽  
pp. 171-175
Author(s):  
C. Fang ◽  
Z. Xu ◽  
M. D. Ding
Keyword(s):  
Total Energy ◽  
Energy Flux ◽  
Atmospheric Condition ◽  
Particle Beam ◽  
Profile Measurement ◽  
Solar Chromosphere ◽  
Line Profiles ◽  
Total Energy Flux ◽  
Hydrogen Lines ◽  
Semi Empirical

Particle beam bombardment on the solar chromosphere produces non-thermal ionization and excitation. The effect on hydrogen lines is investigated by using non-LTE theory and semi-empirical flare models. It has been found that in the case of electron bombardment, the Hα line is widely broadened and enhanced. Significant enhancements at the wings of Lyα and Lyβ lines are also predicted. In the case of proton bombardment, less strong broadening and less central reversal are expected. We found that the total energy flux of the particle beam and the atmospheric condition give much influence on the line profiles, which, however, are less sensitive to the power index. Based on the Hα line profile measurement, a method to deduce the total energy flux of the particle beam is proposed.

Importance of coupling for inelastic collisions between protons and hydrogen atoms

1965 ◽  
Vol 283 (1392) ◽  
pp. 100-114 ◽  
Keyword(s):  
Cross Sections ◽  
Intermediate State ◽  
Relative Velocity ◽  
Inelastic Collisions ◽  
Hydrogen Atoms ◽  
Resonance Reactions ◽  
The Cross ◽  
Good Agreement

The importance of coupling for fast collisions between protons and hydrogen atoms is examined with the two-centred expansion in atomic eigenfunctions proposed by Bates (1958 a ). Cross-sections are evaluated for reactions H + + H (I s ) → H(I s ) + H + , H + + H( I s ) → H(2 s ) + H + , and H + + H(l a ) → H + + H(2 s ). The effect of a single intermediate state, either I s or 2 s , is considered. For the non-resonance processes, it is found that the cross-sections may be substantially increased by passage through intermediate state for incident energies less than about 10 keV, tending towards equality with decrease in relative velocity. Results obtained for the symmetrical resonance reactions are in good agreement with the two-state solutions of McCarroll (1961).

scholarly journals On the Deterioration of a Grounded Iceberg

1986 ◽  
Vol 32 (111) ◽  
pp. 161-167
Author(s):  
S. Venkatesh
Keyword(s):  
Observational Data ◽  
Water Volume ◽  
Ocean Bottom ◽  
Model Simulations ◽  
Seaward Side ◽  
Mass Losses ◽  
Wave Erosion ◽  
S Model ◽  
Simulated Time ◽  
Good Agreement

AbstractThis paper examines the deterioration of an iceberg grounded outside St. John’s Harbour, Newfoundland, Canada, in terms of its initial velocity prior to grounding. Theoretical expressions for the lifting of the iceberg and hence its buoyancy loss during grounding are derived as a function of initial iceberg velocity and ocean-bottom slope. Wave erosion and calving are two of the most significant mechanisms for iceberg deterioration. With wave erosion occurring on the seaward side of the grounded iceberg, model simulations are compared with observational data from a field study conducted on the grounded iceberg between 10 and 17 June 1983. Model–simulated time of re-flotation of the iceberg agrees with observations, for initial iceberg velocity of 0.3–0.5 m/s. Model simulations of the deterioration of the iceberg beyond the point of re-flotation are also compared with observations. Allowing for a 10% error in the observed above-water volume of the iceberg on 10 June, the model-simulated mass losses are in good agreement with observations. Best results are obtained for the model initialized with data observed on 14 June 1983, the first day for which detailed observational data are available following re-flotation of the iceberg.

Anisotropically Nanostructured Silicon: A First-Principle Approach.

2004 ◽  
Vol 832 ◽  
Author(s):  
Yuri Bonder ◽  
Chumin Wang
Keyword(s):  
Experimental Data ◽  
Density Functional ◽  
First Principle ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Nanostructured Silicon ◽  
Plane Anisotropy ◽  
The Density Functional Theory ◽  
The Difference ◽  
Good Agreement

ABSTRACTOptical properties of birefringent porous-silicon layers are studied within the density functional theory. Starting from a (110)-oriented supercell of 32 silicon atoms, columns of atoms in directions [100] and [010] are removed and the dangling bonds are saturated with hydrogen atoms. The results show an in-plane anisotropy in the dielectric function and in the refractive index (n). The difference Δn defined as n[110] -n[001] is compared with experimental data and a good agreement is observed. Also, the possibility in determining the morphology of pores by using polarized lights is analyzed.

scholarly journals Induced energy polarization of the vacuum and the Coma cluster

2013 ◽  
Vol 91 (12) ◽  
pp. 1114-1120 ◽  
Author(s):  
A. Raymond Penner
Keyword(s):  
Mass Distribution ◽  
Velocity Dispersion ◽  
Hydrostatic Equilibrium ◽  
Coma Cluster ◽  
Measured Velocity ◽  
Virial Mass ◽  
Intracluster Gas ◽  
Good Agreement

The theory of an induced energy polarized vacuum is applied to the Coma cluster. The theoretical virial mass distribution of the cluster is determined and found to be in good agreement with previous virial mass estimates. A more concentrated intracluster gas profile than one based on the assumption that the gas is in hydrostatic equilibrium and isothermal does, however, lead to better agreement with measured shear values in the inner regions. The theory also leads to good agreement with measured velocity dispersion values in the case of the galaxies of the cluster being in radial orbits.

scholarly journals SPATIAL AND TEMPORAL VARIATIONS OF K Ca II LINE PROFILE SHAPES IN DIFFERENT STRUCTURES OF THE SOLAR CHROMOSPHERE. II. DETERMINATION TECHNIQUE AND CORRELATION RELATIONSHIPS BETWEEN THE K CA II LINE PARAMETERS FOR K1 AND K2 FEATURES

2020 ◽  
Vol 6 (4) ◽  
pp. 10-16
Author(s):  
Irina Turova ◽  
Sofiya Grigoryeva ◽  
Olga Ozhogina
Keyword(s):  
Magnetic Field ◽  
Line Profile ◽  
Direct Determination ◽  
Temporal Variations ◽  
Solar Chromosphere ◽  
Considerable Contribution ◽  
Opposite Behavior ◽  
Scatter Plots ◽  
Different Levels ◽  
Lower Chromosphere

We have studied two regions located at the base of a coronal hole. For the K₁ intensity minima and K₂ peaks, which form between the upper photosphere and the lower chromosphere and in the lower chromosphere respectively, a number of Ca II line parameters have been computed. We have improved the determination technique for ∆λᴋ₁ᵥ and ∆λᴋ₁ᵣ, ∆λᴋ₂ᵥ and ∆λᴋ₂ᵣ line profile shifts, including certain cases when their direct determination was complicated. We have determined Iᴋ₁ᵥ, Iᴋ₁ᵣ, Iᴋ₂ᵥ, Iᴋ₂ᵣ intensities, K₁ minima and K₂ peaks separations SEPᴋ₁ = ∆λᴋ₁ᵣ – ∆λᴋ₁ᵥ, SEPᴋ₂ = ∆λᴋ₂ᵣ – ∆λᴋ₂ᵥ, respectively. We have constructed scatter plots and have computed correlation relationships between parameters relating to different levels of atmosphere. We have obtained the following results. The intensities observed in the lower and middle chromosphere are connected closer than intensities related to the upper photosphere and middle chromosphere. The structures with a stronger magnetic field are brighter at the upper photosphere and lower chromosphere levels as compared to the structures with a weaker magnetic field. K₁ minima separations are of greater value for the structures with a stronger magnetic field relative to the structures with a weaker magnetic field, whereas K₂ peaks separations demonstrate the opposite behavior. They are lower for the structures with a stronger magnetic field. It is true not only for the chosen structures belonging to quiet regions but also for the plage, though we need additional statistics for plages. The relation between shifts of K₁ minima and K₂ peak intensities for violet and red wings appeared to be weak. This may be due to the considerable contribution of random movements to the velocity field at the upper photosphere and lower chromosphere levels or due to different forming levels for the profile violet and red wings.

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