Comparison between Swarm measured and IRI-2016 ,IRI-Plas 2017 modeled electron density over low and mid latitude region

2021 ◽  
Vol 189 ◽  
pp. 476-482
Author(s):  
Arun Kumar Singh ◽  
Olga Maltseva ◽  
Sampad Kumar Panda
Keyword(s):  
Electron Density ◽  
Latitude Region

Interhemispheric comparison of the ionospheric electron density response during geomagnetic storm conditions

2020 ◽  
Author(s):  
John Bosco Habarulema ◽  
Nicolas Bergeot ◽  
Jean-Marie Chevalier ◽  
Elisa Pinat ◽  
Dalia Buresova ◽  
...  
Keyword(s):  
Electron Density ◽  
Geomagnetic Storms ◽  
Empirical Modeling ◽  
Ionospheric Electron Density ◽  
Satellite Systems ◽  
Physical Mechanisms ◽  
Density Response ◽  
Storm Duration ◽  
Latitude Region ◽  
Short And Long Term

<p>The ionospheric electron density response to the occurrence of geomagnetic storms remains one of the challenges that is less understood partially on both short and long-term scales. This is even more complicated given that different locations within the same latitude region (for example in mid-latitudes) at times show different electron density responses as a result of complex dynamic and electrodynamics processes that may be present during one storm duration.  Mid-latitude regions are influenced by storm induced processes originating from both low and high latitudes. Using a combination of ionosonde and Global Navigational Satellite Systems (GNSS) observations, we show differences and or similarities in the electron density response during selected storm periods in both northern and southern hemisphere over the Europe-African sector. Physical mechanisms at play within different storm phases are explored using both observations and empirical modeling efforts.  </p>

scholarly journals Ionospheric E–F valley observed by a sounding rocket at the low-latitude station Hainan

2013 ◽  
Vol 31 (8) ◽  
pp. 1459-1462 ◽  
Author(s):  
J. K. Shi ◽  
Z. Wang ◽  
K. Torkar ◽  
M. Friedrich ◽  
X. Wang ◽  
...  
Keyword(s):  
Electron Density ◽  
Density Profile ◽  
Physical Mechanism ◽  
East Asian ◽  
Electron Density Profile ◽  
Sounding Rocket ◽  
Low Latitude ◽  
Ionospheric Electron Density ◽  
Simultaneous Observation ◽  
Latitude Region

Abstract. According to the sounding rocket experiment conducted at Hainan ionospheric observatory (19.5° N, 109.1° E), a valley between the E layer and F layer in the ionospheric electron density profile is observed and presented. The sounding rocket was launched in the morning (06:15 LT) on 7 May 2011, and the observed electron density profile outside the valley agrees with the simultaneous observation by the DPS-4 digisonde at the same station. The width of the observed valley was about 42 km, the depth almost 50%, and the altitude of the electron density minimum 123.5 km. This is the first observation of the E–F valley in the low-latitude region in the East Asian sector. The results are also compared with models, and the physical mechanism of the observed valley is discussed in this paper.

scholarly journals Electron Densities and Scale Heights in the Mid-latitude Topside Ionosphere

1967 ◽  
Vol 20 (4) ◽  
pp. 401 ◽  
Author(s):  
PL Dyson
Keyword(s):  
Electron Density ◽  
Northern Hemisphere ◽  
Scale Height ◽  
Topside Ionosphere ◽  
Electron Densities ◽  
Night Time ◽  
Transition Level ◽  
Latitude Region ◽  
Latitudinal Variations

The diurnal and latitudinal variations of electron density and plasma scale height in the topside ionosphere during summer and winter have been calculated from Alouette I ionograms recorded at Woomera. The electron density behaviour is anomalous in that the winter night-time values are generally as large or larger than those occurring during the day. At heights near 1000 km the winter night-time values are greater than those for night-time summer. The behaviour of the scale height is very similar to that reported by others for the mid-latitude region of the northern hemisphere and implies that at night-time the transition level from 0+ to lighter ions occurs at heights of about 550 km in summer and 500 km in winter.

Measured and predicted electron density at 600 KM of altitude in the low latitude region

2001 ◽  
Vol 27 (1) ◽  
pp. 71-74 ◽  
Author(s):  
R.G. Ezquer ◽  
M.A. Cabrera ◽  
S.M. Radicella ◽  
J.R. Manzano
Keyword(s):  
Electron Density ◽  
Low Latitude ◽  
Latitude Region

scholarly journals Simulated east–west differences in F-region peak electron density at Far East mid-latitude region

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Zhipeng Ren ◽  
Biqiang Zhao ◽  
Weixing Wan ◽  
Libo Liu ◽  
Xing Li ◽  
...  
Keyword(s):  
Electron Density ◽  
Far East ◽  
F Region ◽  
Latitude Region ◽  
East West

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).

A study on α-RuCl3 crystal structure by scanning tunneling microscopy

1989 ◽  
Vol 47 ◽  
pp. 30-31
Author(s):  
H.-J. Cantow ◽  
H. Hillebrecht ◽  
S. Magonov ◽  
H. W. Rotter ◽  
G. Thiele
Keyword(s):  
Crystal Structure ◽  
Density Distribution ◽  
Scanning Tunneling Microscopy ◽  
Electron Density ◽  
Structure Determination ◽  
Electron Density Distribution ◽  
Scanning Tunneling ◽  
Monoclinic Space Group ◽  
Tunneling Microscopy ◽  
X Ray

From X-ray analysis, the conclusions are drawn from averaged molecular informations. Thus, limitations are caused when analyzing systems whose symmetry is reduced due to interatomic interactions. In contrast, scanning tunneling microscopy (STM) directly images atomic scale surface electron density distribution, with a resolution up to fractions of Angstrom units. The crucial point is the correlation between the electron density distribution and the localization of individual atoms, which is reasonable in many cases. Thus, the use of STM images for crystal structure determination may be permitted. We tried to apply RuCl3 - a layered material with semiconductive properties - for such STM studies. From the X-ray analysis it has been assumed that α-form of this compound crystallizes in the monoclinic space group C2/m (AICI3 type). The chlorine atoms form an almost undistorted cubic closed package while Ru occupies 2/3 of the octahedral holes in every second layer building up a plane hexagon net (graphite net). Idealizing the arrangement of the chlorines a hexagonal symmetry would be expected. X-ray structure determination of isotypic compounds e.g. IrBr3 leads only to averaged positions of the metal atoms as there exist extended stacking faults of the metal layers.

Improved immunolabelling of ultrathin cryosections using antibody conjugated with 1nm gold particles

1990 ◽  
Vol 48 (3) ◽  
pp. 928-929
Author(s):  
Morten H. Nielsen ◽  
Lone Bastholm
Keyword(s):  
Pituitary Gland ◽  
Liquid Nitrogen ◽  
Electron Density ◽  
Small Diameter ◽  
Cytochemical Staining ◽  
Gold Particles ◽  
Labelling Density ◽  
Ultrathin Cryosections ◽  
Mouse Pituitary ◽  
Electron Microscopical

During the last 5 years the diameter of the gold probes used for immuno-cytochemical staining at the electron microscopical (EM) level has been decreased. The advantage of small diameter gold probes is an overall increased labelling density. The disadvantage is a lower detectability due to the low electron density of smaller gold particles consequently an inconvenient high primary magnification needed for EM examination. Since 1 nm gold particles are barely visible by conventional EM examination the need for enlargement by silverenhancement of the gold particles has increased.In the present study of ultrathin cryosectioned material the results of immunostaining using 5 nm gold conjugated antibody and 1 nm gold conjugated antibodies are compared after silverenhancement of the 1 nm gold particles.Slices of freshly isolated mouse pituitary gland were immersion fixed for 20 min in 2 % glutaraldehyde /2 % paraformaldehyde. Blocks cryoprotected with 2.3 M sucrose were frozen in liquid nitrogen and ultra-cryosectioned on a RMC cryoultra-microtome.

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