Tilt angle and lifetime of sunspot groups

2020 ◽  
Author(s):  
Yury A Nagovitsyn ◽  
Aleksandra A Osipova ◽  
Alexei A Pevtsov
Keyword(s):  
Functional Dependence ◽  
Active Regions ◽  
Limited Range ◽  
Linear Section ◽  
First Approximation ◽  
Subsurface Zones ◽  
Latitudinal Variations ◽  
The Difference ◽  
Two Populations ◽  
Sunspot Groups

Abstract We use the Catalog of Solar Activity (CSA) to study the latitudinal variations of tilt of solar active regions. The tilt angles β are computed taking into account changes of the heliographic grid with latitude ϕ. We show that when sunspot groups of different sizes and lifetimes are included, a classical representation of the Joy’s law as a linear function of latitude (β∝ϕ) is only the first approximation valid within a limited range of latitudes (−25○ ≤ ϕ ≤ +25○). Outside this range, the functional dependence β = f(ϕ) becomes non-linear. Separating the dataset on large long-living groups (LLG) and small short-living groups (SSG) reveals two quite different dependencies in β = f(ϕ): non-linearity in tilt is only present in LLGs and the steepness of linear section of β = f(ϕ) fit is higher for LLGs. This suggests a difference in the physical properties of two populations of solar groups, which could be hypothesized as an indication of different localization of subsurface zones of their formation in the framework of a distributed dynamo. However, since CSA contains the coordinates of sunspots averaged over the lifetime (or disk passage) of each group, one cannot ruled out that the difference in tilts of SSG and LLG groups may be affected by the evolution of tilt angles during the lifetime/disk passage of the groups.

scholarly journals Difference of source regions between fast and slow coronal mass ejections

2019 ◽  
Vol 36 ◽  
Author(s):  
B. Filippov
Keyword(s):  
Magnetic Field ◽  
Coronal Mass Ejections ◽  
Solar Flares ◽  
Magnetic Energy ◽  
Active Regions ◽  
Coronal Magnetic Field ◽  
Source Regions ◽  
Free Magnetic Energy ◽  
The Difference ◽  
Sunspot Groups

Abstract Coronal mass ejections (CMEs) are tightly related to filament eruptions and usually are their continuation in the upper solar corona. It is common practice to divide all observed CMEs into fast and slow ones. Fast CMEs usually follow eruptive events in active regions near big sunspot groups and associated with major solar flares. Slow CMEs are more related to eruptions of quiescent prominences located far from active regions. We analyse 10 eruptive events with particular attention to the events on 2013 September 29 and on 2016 January 26, one of which was associated with a fast CME, while another was followed by a slow CME. We estimated the initial store of free magnetic energy in the two regions and show the resemblance of pre-eruptive situations. The difference of late behaviour of the two eruptive prominences is a consequence of the different structure of magnetic field above the filaments. We estimated this structure on the basis of potential magnetic field calculations. Analysis of other eight events confirmed that all fast CMEs originate in regions with rapidly changing with height value and direction of coronal magnetic field.

The Magnetic Anisotropy of Stretched Rubber as a Function of the Tension to Which It Is Subjected

1945 ◽  
Vol 18 (1) ◽  
pp. 8-9 ◽  
Author(s):  
Eugénie Cotton-Feytis
Keyword(s):  
Magnetic Field ◽  
Magnetic Anisotropy ◽  
Uniaxial Crystal ◽  
Horizontal Magnetic Field ◽  
First Approximation ◽  
The Difference ◽  
The Times ◽  
Angular Displacements ◽  
The Magnetic Field ◽  
Oscillation Method

Abstract From the standpoint of its magnetic anisotropy, stretched rubber is comparable in a first approximation to a uniaxial crystal, in which the direction of the axis is the same as the direction of elongation. It is possible to measure this anisotropy by means of the oscillation method used by Krishnan, Guha and Banerjee in studying crystals. The sample to be examined is suspended in a uniform horizontal magnetic field in such a manner that its axis is horizontal. It is then so arranged that the torsion of the suspension wire is zero when the rubber sample is in a position of equilibrium in the field. The times of oscillation T′ and T for very small angular displacements around this position, in the presence and then in the absence of the magnetic field, are then recorded. In this way the difference between the specific susceptibilities in the direction of the axis and in the horizontal direction perpendicular to the axis is calculated by application of the equation:

A Critique and Improvement of the CL Common Language Effect Size Statistics of McGraw and Wong

2000 ◽  
Vol 25 (2) ◽  
pp. 101-132 ◽  
Author(s):  
András Vargha ◽  
Harold D. Delaney
Keyword(s):  
Effect Size ◽  
Continuous Distribution ◽  
Interval Estimation ◽  
Continuous Variable ◽  
Common Language ◽  
Exact Methods ◽  
Normal Distributions ◽  
The Difference ◽  
Discrete Values ◽  
Two Populations

McGraw and Wong (1992) described an appealing index of effect size, called CL, which measures the difference between two populations in terms of the probability that a score sampled at random from the first population will be greater than a score sampled at random from the second. McGraw and Wong introduced this "common language effect size statistic" for normal distributions and then proposed an approximate estimation for any continuous distribution. In addition, they generalized CL to the n-group case, the correlated samples case, and the discrete values case. In the current paper a different generalization of CL, called the A measure of stochastic superiority, is proposed, which may be directly applied for any discrete or continuous variable that is at least ordinally scaled. Exact methods for point and interval estimation as well as the significance tests of the A = .5 hypothesis are provided. New generalizations ofCL are provided for the multi-group and correlated samples cases.

Optimization of Carrier Distributions in Periodic Gain Structures toward Blue VCSELs

2014 ◽  
Vol 1736 ◽  
Author(s):  
Kenjo Matsui ◽  
Kosuke Horikawa ◽  
Yugo Kozuka ◽  
Kazuki Ikeyama ◽  
Daisuke Komori ◽  
...  
Keyword(s):  
Emission Intensity ◽  
Intermediate Layer ◽  
Intensity Ratio ◽  
Active Regions ◽  
Cavity Surface ◽  
Carrier Injection ◽  
Vertical Cavity Surface ◽  
The Difference ◽  
Emitting Lasers ◽  
Emission Intensity Ratio

ABSTRACTWe have fabricated light emitting diodes (LEDs) in which two active regions separated with a Mg-doped GaN intermediate layer were placed in a single pn junction toward periodic gain structures (PGS) for blue vertical-cavity surface emitting lasers (VCSELs). By current density dependence on a emission intensity ratio from two different active regions, we obtained a very stable emission intensity ratio over 1 kA/cm2. This result is also confirmed with the simulation result. Furthermore, we found that the difference of emission wavelength affect the carrier injection and the emission intensity ratio. On the basis of this result, the optimized well-balanced Mg concentration in the intermediate layer for the two identical active regions were estimated approximately 5 x 1018 cm-3.

Testing for Asymmetrical Gene Flow in aDrosophila melanogasterBody-Size Cline

Genetics ◽  
2003 ◽  
Vol 165 (2) ◽  
pp. 667-673 ◽  
Author(s):  
W Jason Kennington ◽  
Julia Gockel ◽  
Linda Partridge
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Flow ◽  
Body Size ◽  
Genetic Parameter ◽  
Good Evidence ◽  
Microsatellite Data ◽  
Eastern Australia ◽  
The Difference ◽  
Two Populations ◽  
Private Alleles

AbstractAsymmetrical gene flow is an important, but rarely examined genetic parameter. Here, we develop a new method for detecting departures from symmetrical migration between two populations using microsatellite data that are based on the difference in the proportion of private alleles. Application of this approach to data collected from wild-caught Drosophila melanogaster along a latitudinal body-size cline in eastern Australia revealed that asymmetrical gene flow could be detected, but was uncommon, nonlocalized, and occurred in both directions. We also show that, in contrast to the findings of a previous study, there is good evidence to suggest that the cline experiences significant levels of gene flow between populations.

scholarly journals First results of Central Asiatic Euchalcia DNA-studies: comparison of nucleotide sequence differences in COI between Euchalcia herrichi and Euchalcia gyulai (Lepidoptera: Noctuidae)

2020 ◽  
Vol 6 ◽  
pp. 1-4
Author(s):  
Stanislav K Korb
Keyword(s):  
Nucleotide Sequence ◽  
Cytochrome C ◽  
Dna Barcoding ◽  
Cytochrome C Oxidase ◽  
Coi Gene ◽  
First Results ◽  
The Difference ◽  
Coi Sequences ◽  
Lepidoptera Noctuidae ◽  
Two Populations

We submitted first results of the DNA studies of the Central Asiatic owlet moths of the genus Euchalcia. Standard cytochrome C oxidase subunit I (COI) gene fragments were sequenced for DNA barcoding of six specimens belonging to Euchalcia herrichi and Euchalcia gyulai. We compared the received sequences between discussed species and with two European Euchalcia species (E. variabilis and E. consona). We found no variability within the COI sequences of the samples collected in the same locality (Alai Mts., Kyrgyzstan), whereas the difference in COI sequences between two populations (Ketmen Mts., Kazakhstan and Alai Mts., Kyrgyzstan) was 0.005.

Method of Generated Responses and Schizophrenic Deficit

1971 ◽  
Vol 29 (3) ◽  
pp. 975-982
Author(s):  
Anne Marie Bercik ◽  
John H. Mueller
Keyword(s):  
Paired Associates ◽  
High Dominance ◽  
The Difference ◽  
And Control ◽  
Two Populations ◽  
Do So

Schizophrenic and control Ss were compared on the method of generated responses (MGR) and conventional paired-associates (PA), using lists of stimuli which elicited either primarily one response or several responses. The low-dominance list was more difficult, and schizophrenics were generally slower in learning. The MGR, with Ss producing their own responses, was easier than conventional PA (yoked controls). While the MGR reduced the difference between the low- and high-dominance lists, it did not do so differentially for the two populations. The results were discussed in terms of Broen and Storms' theory of “collapsed” response hierarchies in schizophrenia.

scholarly journals Which Recurrent Selection Scheme To Improve Mixtures of Crop Species? Theoretical Expectations

2019 ◽  
Vol 10 (1) ◽  
pp. 89-107 ◽  
Author(s):  
Jean-Paul Sampoux ◽  
Héloïse Giraud ◽  
Isabelle Litrico
Keyword(s):  
Recurrent Selection ◽  
Genetic Correlations ◽  
Limited Range ◽  
Pure Stand ◽  
Crop Species ◽  
Selection Scheme ◽  
Selection Indices ◽  
Species Mixture ◽  
Set Up ◽  
Two Populations

In a context of increasing environmental challenges, there is an emerging demand for plant cultivars that are adapted to cultivation in species mixture. It is thus pressing to look for the optimization of selection schemes to grow species mixtures, and especially recurrent selection schemes which are at the core of the improvement of many plant species. We considered the case of two populations from different species to be improved by recurrent selection for their performances in mixture. We set up an analytical model of performances in mixture. We expressed the expected responses of the performances in mixture to one cycle of selection in the case of a Reciprocal Mixture Ability selection scheme and of two parallel selection schemes aiming to improve General Mixture Abilities or performances in pure stands. We numerically compared these selection schemes when half-sib or topcross progeny families of selection candidates are tested in mixture. Selection in pure stands appeared efficient within a limited range of genetic correlations between pure stand performance and mixture model effects. The Reciprocal Mixture Ability selection scheme was expected to be less efficient than parallel selections for General Mixture Ability in some situations. The last option enables to control the ratio of expected responses of species contributions to the mixture performance without bias when using selection indices. When more than two species are be improved for their performances in mixture, the advantage of parallel selections for General Mixture Ability is even more marked, providing that compensation trends between species are not too prevalent.

scholarly journals Degree of electric current neutralization and the activity in solar active regions

2019 ◽  
Vol 486 (4) ◽  
pp. 4936-4946 ◽  
Author(s):  
P Vemareddy
Keyword(s):  
Current Density ◽  
Active Regions ◽  
Magnetic Polarity ◽  
Vector Magnetic Field ◽  
Polarity Inversion ◽  
Source Regions ◽  
Solar Active Regions ◽  
The Difference ◽  
Emergence Phase ◽  
Local Nature

Abstract Using time-sequence vector magnetic field observation from Helioseismic and Magnetic Imager, we examined the connection of non-neutralized currents and the observed activity in 20 solar active regions (ARs). The net current in a given magnetic polarity is algebraic sum of direct current (DC) and return current (RC) and the ratio |DC/RC| is a measure of degree of net current neutralization (NCN). In the emerging ARs, the non-neutrality of these currents builds with the onset of flux emergence, following the relaxation to neutrality during the separation motion of bipolar regions. Accordingly, some emerging ARs are source regions of CMEs occurring at the time of higher level non-neutrality. ARs in the post-emergence phase can be CME productive provided they have interacting bipolar regions with converging and shearing motions. In these cases, the net current evolves with higher level (>1.3) of non-neutrality. Differently, the |DC/RC| in flaring and quiet ARs vary near unity. In all the AR samples, the |DC/RC| is higher for chiral current density than that for vertical current density. Owing to the fact that the non-neutralized currents arise in the vicinity of sheared polarity-inversion-lines (SPILs), the profiles of the total length of SPIL segments and the degree of NCN follow each other with a positive correlation. We find that the SPIL is localized as small segments in flaring-ARs, whereas it is long continuous in CME-producing ARs. These observations demonstrate the dividing line between the CMEs and flares with the difference being in global or local nature of magnetic shear in the AR that reflected in non-neutralized currents.

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