scholarly journals Estimating Precipitating Energy Flux, Average Energy, and Hall Auroral Conductance From THEMIS All-Sky-Imagers With Focus on Mesoscales

2021 ◽  
Vol 9 ◽  
Author(s):  
Christine Gabrielse ◽  
Toshi Nishimura ◽  
Margaret Chen ◽  
James H. Hecht ◽  
Stephen R. Kaeppler ◽  
...  
Keyword(s):  
Energy Flux ◽  
Average Energy ◽  
Time History ◽  
Global Response ◽  
Hall Conductance ◽  
Expansion Phase ◽  
Data Resolution ◽  
Total Energy Flux ◽  
History Of

Recent attention has been given to mesoscale phenomena across geospace (∼10 s km to 500 km in the ionosphere or ∼0.5 RE to several RE in the magnetosphere), as their contributions to the system global response are important yet remain uncharacterized mostly due to limitations in data resolution and coverage as well as in computational power. As data and models improve, it becomes increasingly valuable to advance understanding of the role of mesoscale phenomena contributions—specifically, in magnetosphere-ionosphere coupling. This paper describes a new method that utilizes the 2D array of Time History of Events and Macroscale Interactions during Substorms (THEMIS) white-light all-sky-imagers (ASI), in conjunction with meridian scanning photometers, to estimate the auroral scale sizes of intense precipitating energy fluxes and the associated Hall conductances. As an example of the technique, we investigated the role of precipitated energy flux and average energy on mesoscales as contrasted to large-scales for two back-to-back substorms, finding that mesoscale aurora contributes up to ∼80% (∼60%) of the total energy flux immediately after onset during the early expansion phase of the first (second) substorm, and continues to contribute ∼30–55% throughout the remainder of the substorm. The average energy estimated from the ASI mosaic field of view also peaked during the initial expansion phase. Using the measured energy flux and tables produced from the Boltzmann Three Constituent (B3C) auroral transport code (Strickland et al., 1976; 1993), we also estimated the 2D Hall conductance and compared it to Poker Flat Incoherent Scatter Radar conductance values, finding good agreement for both discrete and diffuse aurora.

scholarly journals The history effect in bubble growth and dissolution. Part 1. Theory

2016 ◽  
Vol 800 ◽  
pp. 180-212 ◽  
Author(s):  
Pablo Peñas-López ◽  
Miguel A. Parrales ◽  
Javier Rodríguez-Rodríguez ◽  
Devaraj van der Meer
Keyword(s):  
Bubble Dynamics ◽  
Ambient Pressure ◽  
Time History ◽  
Interfacial Concentration ◽  
Interface Concentration ◽  
Governing Differential Equation ◽  
History Of ◽  
History Effect ◽  
Isothermal Regime

The term ‘history effect’ refers to the contribution of any past mass transfer events between a gas bubble and its liquid surroundings towards the current diffusion-driven growth or dissolution dynamics of that same bubble. The history effect arises from the (non-instantaneous) development of the dissolved gas concentration boundary layer in the liquid in response to changes in the concentration at the bubble interface caused, for instance, by variations of the ambient pressure in time. Essentially, the history effect amounts to the acknowledgement that at any given time the mass flux across the bubble is conditioned by the preceding time history of the concentration at the bubble boundary. Considering the canonical problem of an isolated spherical bubble at rest, we show that the contribution of the history effect in the current interfacial concentration gradient is fully contained within a memory integral of the interface concentration. Retaining this integral term, we formulate a governing differential equation for the bubble dynamics, analogous to the well-known Epstein–Plesset solution. Our equation does not make use of the quasi-static radius approximation. An analytical solution is presented for the case of multiple step-like jumps in pressure. The nature and relevance of the history effect is then assessed through illustrative examples. Finally, we investigate the role of the history effect in rectified diffusion for a bubble that pulsates under harmonic pressure forcing in the non-inertial, isothermal regime.

Energies of precipitating electrons during pulsating aurora events derived from ionosonde observations

1981 ◽  
Vol 59 (8) ◽  
pp. 1070-1076 ◽  
Author(s):  
J. W. MacDougall ◽  
J. Hofstee ◽  
J. A. Koehler
Keyword(s):  
Energy Flux ◽  
Time History ◽  
Time Interval ◽  
Characteristic Energy ◽  
Morning Sector ◽  
History Of

The time-history of particle energies and fluxes associated with pulsating auroras in the morning sector is derived from ionosonde measurements. All the pulsating auroras studied showed a similar history with the pulsations occurring during a time interval of the order of an hour during which the average auroral Maxwellian characteristic energy stays relatively constant but the energy flux decreases progressively during the event. A possible explanation for this behaviour in terms of an injection of particles into a magnetospheric "bottle" near the midnight meridian and the progressive precipitation out of the bottle during the pulsating event is suggested.

On the mechanics of high speed liquid jets

1977 ◽  
Vol 357 (1689) ◽  
pp. 143-162 ◽  
Keyword(s):  
Sound Speed ◽  
High Speed ◽  
Supersonic Jet ◽  
Time History ◽  
Taylor Instability ◽  
Liquid Jets ◽  
Late Time ◽  
History Of ◽  
Theoretical Evidence

Both experimental and theoretical methods are used to investigate the mechanics of the emergence and flight of a liquid jet travelling at speeds supersonic relative to the sound speed of the liquid. The experimental work uses an Imacon image converter camera to follow the mechanical events at micro-second framing intervals. The theoretical investigation employs similarity arguments and the Tschaplygin transformation to investigate the role of liquid overcompression in the process of the jet emergence. In addition, simple theoretical arguments are used to examine the effects of Stokes drag on the small liquid particle shroud surrounding the jet and Taylor instability effects in the late time history of the jet’s flight. An evacuated chamber is used to verify the theoretical prediction that subsonic (relative to the liquid sound speed) jets will not undergo the violent decompression process predicted for supersonic jets. The experimental and theoretical evidence are synthesized into an overall picture of the jet’s history from initial decompression of an overdense supersonic jet to the breakup of the resulting liquid slugs by deceleration and Taylor instability.

scholarly journals Miejsce i rola kobiety w rodzinie na przestrzeni wieków. Od Antyku po I wojnę światową. Zarys problematyki

2018 ◽  
pp. 33-41
Author(s):  
Rafał Kamprowski
Keyword(s):  
Twentieth Century ◽  
Time History ◽  
Women's Issues ◽  
The Past ◽  
The Status ◽  
Long Time ◽  
History Of ◽  
Role Of Women ◽  
The One

For a long time, history of women was not in the mainstream of interest. The interest for this topic was not shown untill the twentieth century. The aim of this paper is to present a long and difficult struggle to gain the status similar to the one women have nowadays. It is difficult to understand the present reality without going back to the past. The role of women is undergoing a lot of changes all the time. This subject is a huge field for research. The article attempts to give a summary of publications which deal with women’s issues.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

The role of a family history of adenocarcinomas in patients with Barrett oesophagus

2001 ◽  
Vol 120 (5) ◽  
pp. A442-A442
Author(s):  
P TSIBOURIS ◽  
M HENDRICKSE ◽  
P ISAACS
Keyword(s):  
Family History ◽  
History Of ◽  
Barrett Oesophagus

Protective Factors and Suicidality in Members of Arab Kindred

Crisis ◽  
2012 ◽  
Vol 33 (2) ◽  
pp. 80-86 ◽  
Author(s):  
Sami Hamdan ◽  
Nadine Melhem ◽  
Israel Orbach ◽  
Ilana Farbstein ◽  
Mohammad El-Haib ◽  
...  
Keyword(s):  
Risk Factors ◽  
Protective Factors ◽  
Suicidal Behavior ◽  
Composite International Diagnostic Interview ◽  
Diagnostic Interview ◽  
Suicidal Risk ◽  
Arab Population ◽  
Psychiatric Interview ◽  
History Of

Background: Relatively little is known about the role of protective factors in an Arab population in the presence of suicidal risk factors. Aims: To examine the role of protective factors in a subsample of in large Arab Kindred participants in the presence of suicidal risk factors. Methods: We assessed protective and risk factors in a sample of 64 participants (16 suicidal and 48 nonsuicidal) between 15 and 55 years of age, using a comprehensive structured psychiatric interview, the Composite International Diagnostic Interview (CIDI), self-reported depression, anxiety, hopelessness, impulsivity, hostility, and suicidal behavior in first-degree and second-relatives. We also used the Religiosity Questionnaire and suicide attitude (SUIATT) and multidimensional perceived support scale. Results: Suicidal as opposed to nonsuicidal participants were more likely to have a lifetime history of major depressive disorder (MDD) (68.8% vs. 22.9% χ2 = 11.17, p = .001), an anxiety disorder (87.5% vs. 22.9, χ2 = 21.02, p < .001), or posttraumatic stress disorder (PTSD) (25% vs. 0.0%, Fisher’s, p = .003). Individuals who are otherwise at high risk for suicidality have a much lower risk when they experience higher perceived social support (3.31 ± 1.36 vs. 4.96 ± 1.40, t = 4.10, df = 62, p < .001), and they have the view that suicide is somehow unacceptable (1.83 ± .10 vs. 1.89 ± .07, t = 2.76, df = 60, p = .008). Conclusions: Taken together with other studies, these data suggest that the augmentation of protective factors could play a very important role in the prevention of incidental and recurrent suicidal behavior in Arab populations, where suicidal behavior in increasing rapidly.

THE ROLE OF RECTAL EUS-FNA/B IN PRE-SACRAL UNDEFINED LESIONS IN PATIENTS WITH HISTORY OF LOWER GI NEOPLASIA

2020 ◽  
Author(s):  
B Mangiavillano ◽  
S Carrara ◽  
E Dabizzi ◽  
F Auriemma ◽  
V Cennamo ◽  
...  
Keyword(s):  
History Of

The problem of periodization of the history of religion

1997 ◽  
pp. 3-8
Author(s):  
Borys Lobovyk
Keyword(s):  
Religious Studies ◽  
Human Being ◽  
Religious Development ◽  
History Of Religion ◽  
The Social ◽  
The World ◽  
History Of ◽  
Role Of Religion

An important problem of religious studies, the history of religion as a branch of knowledge is the periodization process of the development of religious phenomenon. It is precisely here, as in focus, that the question of the essence and meaning of the religious development of the human being of the world, the origin of beliefs and cult, the reasons for the changes in them, the place and role of religion in the social and spiritual process, etc., are converging.

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