scholarly journals The Behaviour of a Chapman Layer in the Night F2 Region of the Ionosphere, Under the Influence of Gravity, Diffusion, and Attachment

1956 ◽  
Vol 9 (4) ◽  
pp. 436 ◽  
Author(s):  
RA Duncan
Keyword(s):  
Electron Density ◽  
Density Maximum ◽  
Attachment Coefficient ◽  
Equilibrium Height

It is shown that, in the presence of diffusion, gravity, and attachment, a Chapman layer, no matter what its height, maintains its shape, decaying uniformly with an effective attachment coefficient equal to the true attachment coefficient at the height of the electron density maximum; and that, at the same time, the layer drifts bodily towards an equilibrium height.

scholarly journals An investigation of the ionospheric F region near the EIA crest in India using OI 777.4 and 630.0 nm nightglow observations

2018 ◽  
Vol 36 (3) ◽  
pp. 809-823 ◽  
Author(s):  
Navin Parihar ◽  
Sandro Maria Radicella ◽  
Bruno Nava ◽  
Yenca Olivia Migoya-Orue ◽  
Prabhakar Tiwari ◽  
...  
Keyword(s):  
Electron Density ◽  
Gravity Waves ◽  
Satellite Mission ◽  
Low Latitude ◽  
Density Maximum ◽  
Density Profiles ◽  
F Region ◽  
Equatorial Ionization Anomaly ◽  
Low Latitude Ionosphere ◽  
Electron Density Profiles

Abstract. Simultaneous observations of OI 777.4 and OI 630.0 nm nightglow emissions were carried at a low-latitude station, Allahabad (25.5° N, 81.9° E; geomag. lat.  ∼  16.30° N), located near the crest of the Appleton anomaly in India during September–December 2009. This report attempts to study the F region of ionosphere using airglow-derived parameters. Using an empirical approach put forward by Makela et al. (2001), firstly, we propose a novel technique to calibrate OI 777.4 and 630.0 nm emission intensities using Constellation Observing System for Meteorology, Ionosphere, and Climate/Formosa Satellite Mission 3 (COSMIC/FORMOSAT-3) electron density profiles. Next, the electron density maximum (Nm) and its height (hmF2) of the F layer have been derived from the information of two calibrated intensities. Nocturnal variation of Nm showed the signatures of the retreat of the equatorial ionization anomaly (EIA) and the midnight temperature maximum (MTM) phenomenon that are usually observed in the equatorial and low-latitude ionosphere. Signatures of gravity waves with time periods in the range of 0.7–3.0 h were also seen in Nm and hmF2 variations. Sample Nm and hmF2 maps have also been generated to show the usefulness of this technique in studying ionospheric processes.

The effect of attachment on radio echo observations of meteors

1959 ◽  
Vol 253 (1272) ◽  
pp. 130-139 ◽  
Keyword(s):  
Light Intensity ◽  
Electron Density ◽  
Diffusion Processes ◽  
Diffusion Theory ◽  
Electron Attachment ◽  
Companion Paper ◽  
A Value ◽  
Meteor Trail ◽  
Meteor Trails ◽  
Attachment Coefficient

This paper is concerned with the effects of electron attachment to neutral air molecules on the characteristics of radio echoes from meteor trails. Previously it has been assumed that diffusion processes were primarily responsible for the reduction of volume electron density in a meteor trail, and also in limiting the echo duration. In a companion paper a value of the attachment coefficient β e = 5 x 10 -15 cm 3 s -1 has been determined from combined photo­graphic and radio echo observations of a meteor. An effect of an attachment coefficient of this magnitude is to reduce the expected echo duration by a factor of 1000 or more for a bright fireball. The observed relation between visual meteor magnitude and echo duration is explained by this mechanism, as are the departures from the wavelength squared variation of echo dura­tion predicted by diffusion theory. Attachment processes also account for the observation that the final heights of enduring meteor echoes all centre about 95 km, even though bright meteors may show a maximum in light intensity below 80 km.

ELECTRON DECAY FOLLOWING d-c. DISCHARGE IONIZATION IN NO AND NO–Ne MIXTURES

1967 ◽  
Vol 45 (4) ◽  
pp. 1565-1578 ◽  
Author(s):  
Michael H. Mentzoni ◽  
James Donohoe
Keyword(s):  
Time Dependence ◽  
Electron Density ◽  
Sampling Techniques ◽  
Penning Ionization ◽  
Collision Processes ◽  
Ion Recombination ◽  
Yield Formula ◽  
Three Body ◽  
Attachment Coefficient ◽  
Good Agreement

The time dependence of the electron density, Ne(t), and radiation temperature, Te(t), has been measured in d-c. discharge afterglows of NO and NO–Ne mixtures. Microwave wave-guide transmission and noise-sampling techniques were used. In pure NO the experimental results were compared with those computed for a recombination–attachment controlled plasma using Gunton and Shaw's values, and good agreement was found. In the NO–Ne mixtures p(Ne) was about 20 Torr, and p(NO) was varied from 0.5 × 10−3 to 0.10 Torr. It was found that 1/Ne(t) was linear over extensive ranges of Ne(t) indicating two-body electron–ion recombination. The results yield [Formula: see text] and the three-body attachment coefficient K = 2.2 × 10−31 cm6sec−1 for Te = Tgas = 300 °K. Te(t) decayed nonexponentially varying with p(NO) indicating that Penning ionization takes place together with other collision processes which are briefly discussed.

scholarly journals Plasma Spectroscopy Diagnostics of V2O5 at a Variable of Operating Power and Pressure With Radio Frequency Magnetron Sputtering.

2019 ◽  
Vol 16 (1) ◽  
pp. 0209
Author(s):  
Salman Et al.
Keyword(s):  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Electron Temperature ◽  
Electron Density ◽  
Gas Pressure ◽  
Rf Power ◽  
Plasma Parameters ◽  
Density Maximum ◽  
Density Decrease ◽  
Sputtering Power

   In this paper, we investigate the basic characteristics of "magnetron sputtering plasma" using the target V2O5. The "magnetron sputtering plasma" is produced using "radio frequency (RF)" power supply and Argon gas. The intensity of the light emission from atoms and radicals in the plasma measured by using "optical emission spectrophotometer", and the appeared peaks in all patterns match the standard lines from NIST database and employed are to estimate the plasma parameters, of computes electron temperature and the electrons density. The characteristics of V2O5 sputtering plasma at multiple discharge provisos are studied at the "radio frequency" (RF) power ranging from 75 - 150 Watt and gas pressure (0.03, 0.05 and  0.007) torr.  One can observe that the intensity of the emission lines increases with increasing the sputtering power. We find that the electron temperature excess drastically from 0.95 eV to 1.11eV when the emptying gas pressure excess from 0.03 to 0.05 Torr. On other hand excess electron temperature from 0.9 to 1.01 eV with increasing sputtering power from 100 to 125 Watt, while the electron density decrease from 5.9×1014 to 4.5×1014 cm-3 with increasing sputtering power. and electron density decrease with increasing of pressure from 4.25×1014 to 2.80×1014 cm-3, But the electron density maximum values  5.9×1014 at pressure  0.03 Torr.

scholarly journals An investigation of the ionospheric F-region near the EIA crest in India using OI 777.4 and 630.0 nm nightglow observations

2018 ◽  
Author(s):  
Navin Parihar ◽  
Sandro M. Radicella ◽  
Bruno Nava ◽  
Yenca Olivia Migoya Orue ◽  
Prabhakar Tiwari ◽  
...  
Keyword(s):  
Electron Density ◽  
Gravity Waves ◽  
Satellite Mission ◽  
Low Latitude ◽  
Density Maximum ◽  
Density Profiles ◽  
F Region ◽  
Equatorial Ionization Anomaly ◽  
Low Latitude Ionosphere ◽  
Electron Density Profiles

Abstract. Simultaneous observations of OI 777.4 nm and OI 630.0 nm nightglow emissions were carried at a low latitude station, Allahabad (25.5º N, 81.9º E, geomag. lat. ~16.30º N), located near the crest of Appleton anomaly in India during September–December 2009. This study attempts to examine the behaviour of the F region of ionosphere using airglow derived parameters. Using an empirical approach put forward by Makela et al. (2001), firstly, we propose a novel technique to calibrate OI 777.4 and 630.0 nm emission intensities using Constellation Observing System for Meteorology, Ionosphere, and Climate/Formosa Satellite Mission 3 (COSMIC/FORMOSAT-3) electron density profiles. Next, electron density maximum (Nm) and its height (hmF2) of the F-layer have been derived from the information of two calibrated intensities. Nightglow derived Nm and hmF2 were in reasonable agreement with few measurements reported earlier. Nm and hmF2 were used to study the behaviour of the F-region over Allahabad on the limited number of nights. Nocturnal variation of Nm showed the signatures of the retreat of equatorial ionization anomaly (EIA) and mid-night temperature maximum (MTM) phenomenon that are usually observed in the equatorial and low-latitude ionosphere. Signatures of gravity waves having period in the range of 0.7–3.0 h were also seen in Nm and hmF2 variations. Sample Nm and hmF2 maps have also been generated to show the usefulness of this technique in studying the ionospheric processes.

scholarly journals Plasma Spectroscopy Diagnostics of V2O5 at a Variable of Operating Power and Pressure With Radio Frequency Magnetron Sputtering.

2019 ◽  
Vol 16 (1(Suppl.)) ◽  
pp. 0209
Author(s):  
Salman Et al.
Keyword(s):  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Electron Temperature ◽  
Electron Density ◽  
Gas Pressure ◽  
Rf Power ◽  
Plasma Parameters ◽  
Density Maximum ◽  
Density Decrease ◽  
Sputtering Power

   In this paper, we investigate the basic characteristics of "magnetron sputtering plasma" using the target V2O5. The "magnetron sputtering plasma" is produced using "radio frequency (RF)" power supply and Argon gas. The intensity of the light emission from atoms and radicals in the plasma measured by using "optical emission spectrophotometer", and the appeared peaks in all patterns match the standard lines from NIST database and employed are to estimate the plasma parameters, of computes electron temperature and the electrons density. The characteristics of V2O5 sputtering plasma at multiple discharge provisos are studied at the "radio frequency" (RF) power ranging from 75 - 150 Watt and gas pressure (0.03, 0.05 and  0.007) torr.  One can observe that the intensity of the emission lines increases with increasing the sputtering power. We find that the electron temperature excess drastically from 0.95 eV to 1.11eV when the emptying gas pressure excess from 0.03 to 0.05 Torr. On other hand excess electron temperature from 0.9 to 1.01 eV with increasing sputtering power from 100 to 125 Watt, while the electron density decrease from 5.9×1014 to 4.5×1014 cm-3 with increasing sputtering power. and electron density decrease with increasing of pressure from 4.25×1014 to 2.80×1014 cm-3, But the electron density maximum values  5.9×1014 at pressure  0.03 Torr.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Glycogen in guinea pig neutrophils: Ultrastructural study of neutrophils at the intradermal site of BCG injection

1983 ◽  
Vol 41 ◽  
pp. 726-727
Author(s):  
Corazon D. Bucana
Keyword(s):  
Bone Marrow ◽  
Guinea Pig ◽  
Electron Density ◽  
Peritoneal Cavity ◽  
Ultrastructural Study ◽  
Guinea Pigs ◽  
Random Distribution ◽  
Glycogen Content ◽  
Polymorphonuclear Neutrophils ◽  
Ultrastructural Studies

In the circulating blood of man and guinea pigs, glycogen occurs primarily in polymorphonuclear neutrophils and platelets. The amount of glycogen in neutrophils increases with time after the cells leave the bone marrow, and the distribution of glycogen in neutrophils changes from an apparently random distribution to large clumps when these cells move out of the circulation to the site of inflammation in the peritoneal cavity. The objective of this study was to further investigate changes in glycogen content and distribution in neutrophils. I chose an intradermal site because it allows study of neutrophils at various stages of extravasation.Initially, osmium ferrocyanide and osmium ferricyanide were used to fix glycogen in the neutrophils for ultrastructural studies. My findings confirmed previous reports that showed that glycogen is well preserved by both these fixatives and that osmium ferricyanide protects glycogen from solubilization by uranyl acetate.I found that osmium ferrocyanide similarly protected glycogen. My studies showed, however, that the electron density of mitochondria and other cytoplasmic organelles was lower in samples fixed with osmium ferrocyanide than in samples fixed with osmium ferricyanide.

Application of ruthenium red/osmium tetroxide to bacteria, plant and animal tissue

1986 ◽  
Vol 44 ◽  
pp. 54-55
Author(s):  
R. L. Grayson ◽  
N. A. Rechcigl
Keyword(s):  
Electron Microscopy ◽  
Electron Density ◽  
Osmium Tetroxide ◽  
Biological Materials ◽  
Ruthenium Red ◽  
Animal Tissue

Ruthenium red (RR), an inorganic dye was found to be useful in electron microscopy where it can combine with osmium tetroxide (OsO4) to form a complex with attraction toward anionic substances. Although Martinez-Palomo et al. (1969) were one of the first investigators to use RR together with OsO4, our computor search has shown few applications of this combination in the intervening years. The purpose of this paper is to report the results of our investigations utilizing the RR/OsO4 combination to add electron density to various biological materials. The possible mechanisms by which this may come about has been well reviewed by previous investigators (1,3a,3b,4).

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