scholarly journals The Diffusion of Electrons in Dry, Carbon Dioxide Free Air

1964 ◽  
Vol 17 (3) ◽  
pp. 307 ◽  
Author(s):  
JA Rees ◽  
RL Jory
Keyword(s):  
Carbon Dioxide ◽  
Cross Sections ◽  
Electron Attachment ◽  
Energy Factor ◽  
Free Air ◽  
Beam Type ◽  
The Cross

Values of Townsend's energy factor kl for electrons in dry, carbon dioxide free air have been determined as a function of the parameter E Ip for 0 . 2 < E Ip < 40 at a temperature of 293�K. The results are first compared with those of other workers and are then utilized in a recomparison of the cross sections for electron attachment deduced from swarm and beam-type experiments.

scholarly journals Measurements of Townsend's Energy Factor k1 for Electrons in Carbon Dioxide

1964 ◽  
Vol 17 (4) ◽  
pp. 462 ◽  
Author(s):  
JA Rees
Keyword(s):  
Carbon Dioxide ◽  
Cross Sections ◽  
Electron Attachment ◽  
Energy Factor ◽  
The Cross

Values of Townsend's energy factor kl for electrons in carbon dioxide have been determined as a function of the parameter E/p for 0�1 .;;; E/p .;;; 50 at a temperature of 293�K. The results are compared with those of other investigators and are used in a recomparison of the cross sections for electron attachment deduced from swarm and beam types of experiments for swarms of electrons having mean energies of up to 5 eV.

The determination of cross sections for quenching of resonance radiation of metal atoms III. Results for thallium

1968 ◽  
Vol 303 (1475) ◽  
pp. 467-475 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Cross Section ◽  
Cross Sections ◽  
Rate Constants ◽  
Resonance Radiation ◽  
Metal Atoms ◽  
The Cross

The intensity of fluorescence of thallium has been measured in hydrogen-oxygen flames diluted with each of the gases, argon, helium, nitrogen and carbon dioxide and the measurements used to obtain the following values for the quenching cross section (Å 2 ) for the 7 s 2 S ½ state of thallium σ 2 H 2 = 0.03, σ 2 O 2 = 13.2 ± 1.5, σ 2 N 2 = 6.4 ± 0.2, σ 2 H 2 O = 1.75 ± 0.2, σ 2 CO = 13.6 ± 0.8, σ 2 CO 2 = 32.5 ± 1.5, σ 2 Ar ≤ 0.1, σ 2 He ≤ 0.12. These values for the cross sections have been used to re-calculate the rate constants of the reactions, Tl + H + X → H X + Tl*, where X = H, OH, Cl or Br, from the data obtained by Phillips & Sugden (1961). The re-calculated values are lower than the original ones by a factor of 2.2.

The determination of cross-sections for the quenching of resonance radiation of metal atoms. V. Results for lead

1969 ◽  
Vol 313 (1515) ◽  
pp. 551-564 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Cross Sections ◽  
Intensity Distribution ◽  
Equilibrium Distribution ◽  
Metal Atoms ◽  
The Cross ◽  
Equilibrium Effect ◽  
Non Equilibrium

The flame fluorescence method has been used to determine the cross-sections for the collisional de-excitation of lead atoms from the first resonance level (6p7s 3 P 0 1 ) by hydrogen, oxygen, water, nitrogen, carbon dioxide, carbon monoxide, argon and helium. The values obtained for the cross-sections—the square of the collision diameter—are (in 10 -16 cm 2 units) σ 2 H 2 = 0.4 ± 0.1, σ 2 O 2 , = 15 ± 3, σ 2 N 2 = 5.7 ± 0.5, σ 2 H 2 O = 8 ± 2, σ 2 CO = 13 ± 3, σ 2 CO 2 = 29 ± 5, σ 2 Ar ≈ 0 ( < 1.6), σ 2 He ≈ 0 (< 0.6). The interpretation of these overall quenching cross-sections in terms of the various possible quenching processes is discussed. For some flames the fluorescence has been resolved into the component wavelengths— 405.8, 368.3, and 364.0 nm—and found to have a non-equilibrium distribution of intensities. An additional non-equilibrium effect on the intensity distribution which is attributable to chemi-excitation of lead atoms in the flames is described and discussed. The apparatus previously used is modified; the high intensity hollow cathode lead lamp used is described.

The cross sections for different channels in heavy ion nuclear reactions

1971 ◽  
Vol 32 (1) ◽  
pp. 7-9 ◽  
Author(s):  
J. Galin ◽  
D. Guerreau ◽  
M. Lefort ◽  
X. Tarrago
Keyword(s):  
Cross Sections ◽  
Nuclear Reactions ◽  
Heavy Ion ◽  
The Cross

Experimental Studies Of Multilayer Glass Structures On Compression, Compression With Bending And Simple Bending

2019 ◽  
pp. 22-30
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Applied Load ◽  
Experimental Studies ◽  
Strength Properties ◽  
Research Topic ◽  
Normative Values ◽  
Laminated Glass ◽  
The Cross ◽  
Experimental Values

The work of multilayer glass structures for central and eccentric compression and bending are considered. The substantiation of the chosen research topic is made. The description and features of laminated glass for the structures investigated, their characteristics are presented. The analysis of the results obtained when testing for compression, compression with bending, simple bending of models of columns, beams, samples of laminated glass was made. Overview of the types and nature of destruction of the models are presented, diagrams of material operation are constructed, average values of the resistance of the cross-sections of samples are obtained, the table of destructive loads is generated. The need for development of a set of rules and guidelines for the design of glass structures, including laminated glass, for bearing elements, as well as standards for testing, rules for assessing the strength, stiffness, crack resistance and methods for determining the strength of control samples is emphasized. It is established that the strength properties of glass depend on the type of applied load and vary widely, and significantly lower than the corresponding normative values of the strength of heat-strengthened glass. The effect of the connecting polymeric material and manufacturing technology of laminated glass on the strength of the structure is also shown. The experimental values of the elastic modulus are different in different directions of the cross section and in the direction perpendicular to the glass layers are two times less than along the glass layers.

scholarly journals Total cross sections of eγ → $$ eX\overline{X} $$ processes with X = μ, γ, e via multiloop methods

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Roman N. Lee ◽  
Alexey A. Lyubyakin ◽  
Vyacheslav A. Stotsky
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Elliptic Integral ◽  
High Energy ◽  
Calculation Methods ◽  
Complete Elliptic Integral ◽  
Total Cross Sections ◽  
Multiloop Calculation ◽  
The Cross ◽  
Analytical Expressions

Abstract Using modern multiloop calculation methods, we derive the analytical expressions for the total cross sections of the processes e−γ →$$ {e}^{-}X\overline{X} $$ e − X X ¯ with X = μ, γ or e at arbitrary energies. For the first two processes our results are expressed via classical polylogarithms. The cross section of e−γ → e−e−e+ is represented as a one-fold integral of complete elliptic integral K and logarithms. Using our results, we calculate the threshold and high-energy asymptotics and compare them with available results.

scholarly journals Asymptotic Behavior of Stable Structures Made of Beams

2021 ◽  
Author(s):  
Georges Griso ◽  
Larysa Khilkova ◽  
Julia Orlik ◽  
Olena Sivak
Keyword(s):  
Asymptotic Behavior ◽  
Cross Section ◽  
Cross Sections ◽  
Linear Elasticity ◽  
Circular Cross Section ◽  
Linear Elasticity Theory ◽  
Linear Elastic ◽  
The Cross ◽  
Small Rotation ◽  
Stable Structures

AbstractIn this paper, we study the asymptotic behavior of an $\varepsilon $ ε -periodic 3D stable structure made of beams of circular cross-section of radius $r$ r when the periodicity parameter $\varepsilon $ ε and the ratio ${r/\varepsilon }$ r / ε simultaneously tend to 0. The analysis is performed within the frame of linear elasticity theory and it is based on the known decomposition of the beam displacements into a beam centerline displacement, a small rotation of the cross-sections and a warping (the deformation of the cross-sections). This decomposition allows to obtain Korn type inequalities. We introduce two unfolding operators, one for the homogenization of the set of beam centerlines and another for the dimension reduction of the beams. The limit homogenized problem is still a linear elastic, second order PDE.

ISOSPIN DECOMPOSITION OF pp → NNππ CROSS SECTIONS — DO WE SEE A SIGN OF Δ(1600) EXCITATION IN THE nnπ+π+ CHANNEL?

2009 ◽  
Vol 24 (02n03) ◽  
pp. 450-453
Author(s):  
◽  
T. SKORODKO ◽  
M. BASHKANOV ◽  
D. BOGOSLOWSKY ◽  
H. CALÉN ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Pion Production ◽  
Significant Contribution ◽  
Differential Cross Sections ◽  
Pp Collisions ◽  
Theoretical Predictions ◽  
Order Of Magnitude ◽  
The Cross

The two-pion production in pp-collisions has been investigated in exclusive measurements from threshold up to Tp = 1.36 GeV . Total and differential cross sections have been obtained for the channels pnπ+π0, ppπ+π-, ppπ0π0 and also nnπ+π+. For intermediate incident energies Tp > 1 GeV , i.e. in the region, which is beyond the Roper excitation but at the onset of ΔΔ excitation the total ppπ0π0 cross section falls behind theoretical predictions by as much as an order of magnitude near 1.2 GeV, whereas the nnπ+π+ cross section is a factor of five larger than predicted. A model-unconstrained isospin decompostion of the cross section points to a significant contribution of an isospin 3/2 resonance other than the Δ(1232). As a possible candidate the Δ(1600) is discussed.

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