scholarly journals Dust observations with antenna measurements and its prospects for observations with Parker Solar Probe and Solar Orbiter

2019 ◽  
Author(s):  
Ingrid Mann ◽  
Libor Nouzák ◽  
Jakub Vaverka ◽  
Tarjei Antonsen ◽  
Åshild Fredriksen ◽  
...  
Keyword(s):  
Interplanetary Medium ◽  
Subsequent Development ◽  
Plasma Waves ◽  
The Sun ◽  
Spacecraft Potential ◽  
The Impact ◽  
Empirical Approaches ◽  
Orbiter Mission ◽  
Qualitative Discussion ◽  
Inner Heliosphere

Abstract. The electric and magnetic field instrument suite FIELDS on board the NASA Parker Solar Probe and the radio and plasma waves instrument RPWS on the ESA Solar Orbiter mission that explore the inner heliosphere are sensitive to signals generated by dust impacts. Dust impacts were observed using electric field antennas on spacecraft since the 1980s and the method was recently used with a number of space missions to derive dust fluxes. Here, we consider the details of dust impacts, subsequent development of the impact generated plasma and how it produces the measured signals. We describe empirical approaches to characterise the signals and compare to a qualitative discussion of laboratory simulations to predict signal shapes for spacecraft measurements in the inner solar system. While the amount of charge production from a dust impact will be higher near the sun than observed in the interplanetary medium before, the amplitude of pulses will be lower because of the different recovery behaviour that varies with the plasma environment. The photocurrent, that is expected to be higher near the Sun, is found to have moderate influence on the spacecraft potential.

scholarly journals Dust observations with antenna measurements and its prospects for observations with Parker Solar Probe and Solar Orbiter

2019 ◽  
Vol 37 (6) ◽  
pp. 1121-1140 ◽  
Author(s):  
Ingrid Mann ◽  
Libor Nouzák ◽  
Jakub Vaverka ◽  
Tarjei Antonsen ◽  
Åshild Fredriksen ◽  
...  
Keyword(s):  
Interplanetary Medium ◽  
Subsequent Development ◽  
Plasma Waves ◽  
The Sun ◽  
Electric And Magnetic Field ◽  
The Impact ◽  
Empirical Approaches ◽  
Orbiter Mission ◽  
Qualitative Discussion ◽  
Inner Heliosphere

Abstract. The electric and magnetic field instrument suite FIELDS on board the NASA Parker Solar Probe and the radio and plasma waves instrument RPW on the ESA Solar Orbiter mission that explore the inner heliosphere are sensitive to signals generated by dust impacts. Dust impacts have been observed using electric field antennas on spacecraft since the 1980s and the method was recently used with a number of space missions to derive dust fluxes. Here, we consider the details of dust impacts, subsequent development of the impact generated plasma and how it produces the measured signals. We describe empirical approaches to characterise the signals and compare these in a qualitative discussion of laboratory simulations to predict signal shapes for spacecraft measurements in the inner solar system. While the amount of charge production from a dust impact will be higher near the Sun than observed in the interplanetary medium before, the amplitude of pulses is determined by the recovery behaviour that is different near the Sun since it varies with the plasma environment.

The Homeland, Imprisoned and Illegal: The Impact of Marginalisation on Views of the Homeland in Kanafānī's and Khalīfa's Work

2019 ◽  
Vol 13 (1) ◽  
pp. 1-18
Author(s):  
Jedidiah Anderson
Keyword(s):  
Affect Theory ◽  
The Sun ◽  
Minor Literature ◽  
War Machine ◽  
Ghassan Kanafani ◽  
The Impact

This paper deals with the concept of Al-Waṭan, or ‘the homeland’, in Arabic in The Shell (Al-Qawqʿa) by Muṣṭafā Khalifa and Men in the Sun (Rijāl fīsh-Shams) by Ghassān Kanafānī. Analysis of how alienation from this concept has affected both Khalifa's and Kanafānī's characters is carried out through the lenses of Deleuze and Guattari's theories of rhizomatic associations and minor literature, as well as through the lens of affect theory. The paper also examines parallels between definitions of Al-Waṭan/the homeland in Ibn Manẓūr's classical dictionary Lisān al-ʿArab and Deleuze and Guattari's concepts of the war machine and the apparatus of capture.

scholarly journals Absence of Association between Previous Mycoplasma pneumoniae Infection and Subsequent Myasthenia Gravis: A Nationwide Population-Based Matched Cohort Study

2021 ◽  
Vol 18 (14) ◽  
pp. 7677
Author(s):  
Kuan Chen ◽  
James Cheng-Chung Wei ◽  
Hei-Tung Yip ◽  
Mei-Chia Chou ◽  
Renin Chang
Keyword(s):  
Cohort Study ◽  
Myasthenia Gravis ◽  
Mycoplasma Pneumoniae ◽  
Pathogenic Bacteria ◽  
Case Reports ◽  
Statistical Significance ◽  
Subsequent Development ◽  
Population Based ◽  
Cox Proportional Hazards ◽  
The Impact

Mycoplasma pneumoniae (M. pneumoniae) is not only one of the most common pathogenic bacteria for respiratory infection but also a trigger for many autoimmune diseases. Its infection process shared many similarities with the pathogenesis of myasthenia gravis (MG) at cellular and cytokine levels. Recent case reports demonstrated patients present with MG after M. pneumoniae infection. However, no epidemiological studies ever looked into the association between the two. Our study aimed to investigate the relationship between M. pneumoniae infection and subsequent development of MG. In this population-based retrospective cohort study, the risk of MG was analyzed in patients who were newly diagnosed with M. pneumoniae infection between 2000 and 2013. A total of 2428 M. pneumoniae patients were included and matched with the non-M. pneumoniae control cohort at a 1:4 ratio by age, sex, and index date. Cox proportional hazards regression analysis was applied to analyze the risk of MG development after adjusting for sex, age, and comorbidities, with hazard ratios and 95% confidence intervals. The incidence rates of MG in the non-M. pneumoniae and M. pneumoniae cohorts were 0.96 and 1.97 per 10,000 person-years, respectively. Another case–control study of patients with MG (n = 515) was conducted to analyze the impact of M. pneumoniae on MG occurrence as a sensitivity analysis. The analysis yielded consistent absence of a link between M. pneumoniae and MG. Although previous studies have reported that M. pneumoniae infection and MG may share associated immunologic pathways, we found no statistical significance between M. pneumoniae infection and subsequent development of MG in this study.

scholarly journals Ulysses COSPIN observations of cosmic rays and solar energetic particles from the South Pole to the North Pole of the Sun during solar maximum

2003 ◽  
Vol 21 (6) ◽  
pp. 1217-1228 ◽  
Author(s):  
R. B. McKibben ◽  
J. J. Connell ◽  
C. Lopate ◽  
M. Zhang ◽  
J. D. Anglin ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Solar Maximum ◽  
Cosmic Ray ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Polar Regions ◽  
The Sun ◽  
The South ◽  
The North ◽  
Inner Heliosphere

Abstract. In 2000–2001 Ulysses passed from the south to the north polar regions of the Sun in the inner heliosphere, providing a snapshot of the latitudinal structure of cosmic ray modulation and solar energetic particle populations during a period near solar maximum.  Observations from the COSPIN suite of energetic charged particle telescopes show that latitude variations in the cosmic ray intensity in the inner heliosphere are nearly non-existent near solar maximum, whereas small but clear latitude gradients were observed during the similar phase of Ulysses’ orbit near the 1994–95 solar minimum. At proton energies above ~10 MeV and extending up to >70 MeV, the intensities are often dominated by Solar Energetic Particles (SEPs) accelerated near the Sun in association with intense solar flares and large Coronal Mass Ejections (CMEs). At lower energies the particle intensities are almost constantly enhanced above background, most likely as a result of a mix of SEPs and particles accelerated by interplanetary shocks. Simultaneous high-latitude Ulysses and near-Earth observations show that most events that produce large flux increases near Earth also produce flux increases at Ulysses, even at the highest latitudes attained. Particle anisotropies during particle onsets at Ulysses are typically directed outwards from the Sun, suggesting either acceleration extending to high latitudes or efficient cross-field propagation somewhere inside the orbit of Ulysses. Both cosmic ray and SEP observations are consistent with highly efficient transport of energetic charged particles between the equatorial and polar regions and across the mean interplanetary magnetic fields in the inner heliosphere.Key words. Interplanetary physics (cosmic rays) – Solar physics, astrophysics and astronomy (energetic particles; flares and mass ejections)

scholarly journals The influx rate of long-period comets in the Earth's neighborhood and their debris contribution to the interplanetary medium

2012 ◽  
Vol 10 (H16) ◽  
pp. 140-140
Author(s):  
Julio Angel Fernández
Keyword(s):  
Steady State ◽  
Interplanetary Medium ◽  
Interplanetary Dust ◽  
Large Contribution ◽  
Influx Rate ◽  
Long Period ◽  
Impact Rate ◽  
Total Magnitude ◽  
Dust Complex ◽  
The Impact

AbstractWe analyze the flux of new and evolved long-period comets (LPCs) reaching the Earth's neighborhood (perihelion distances q < 1.3 AU), their physical lifetimes, and their implications as regards to the amount of meteoritic matter that is being deposited in the near-Earth region. The flux of LPCs with q < 1.3 au is found to be of about 340 ± 40, brighter than absolute total magnitude 8.6 (radius R ~ 0.6 km) (Fernández and Sosa 2012). Bearing in mind that most of these comets disintegrate into meteoritic matter, this represents a large contribution to the interplanetary dust complex which requires an amount of matter of about 10 tons s−1 to keep it in steady state. These aspects, as well as the impact rate with Earth of meteoroids of LPC origin, will be discussed in this presentation.

scholarly journals Solar cycle changes of large-scale solar wind structure

2009 ◽  
Vol 5 (S264) ◽  
pp. 356-358 ◽  
Author(s):  
P. K. Manoharan
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
Large Scale ◽  
Interplanetary Space ◽  
The Sun ◽  
Wind Structure ◽  
Level Of Activity ◽  
Solar Wind Structure ◽  
Current Minimum ◽  
Inner Heliosphere

AbstractIn this paper, I present the results on large-scale evolution of density turbulence of solar wind in the inner heliosphere during 1985–2009. At a given distance from the Sun, the density turbulence is maximum around the maximum phase of the solar cycle and it reduces to ~70%, near the minimum phase. However, in the current minimum of solar activity, the level of turbulence has gradually decreased, starting from the year 2005, to the present level of ~30%. These results suggest that the source of solar wind changes globally, with the important implication that the supply of mass and energy from the Sun to the interplanetary space has significantly reduced in the present low level of activity.

scholarly journals Analytical and Experimental Analysis of a Free Link in Contact with a Granular Medium

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Dan B. Marghitu ◽  
Seung Lee
Keyword(s):  
Granular Medium ◽  
Stopping Time ◽  
The Body ◽  
Resistance Force ◽  
Time Interval ◽  
The Moment ◽  
Static Resistance ◽  
The Impact ◽  
Resistance Forces ◽  
Empirical Approaches

In this study, the experimental and the simulation results for a planar free link impacting a granular medium are analyzed. The resistance force of the granular medium on the body from the moment of the impact until the body stops is very important. Horizontal and vertical static resistance forces developed by theoretical and empirical approaches are considered. The penetrating depth of the impacting end of the free link increases with the increase of the initial impacting velocity. We define the stopping time as the time interval from the moment of impact until the vertical velocity of the link end is zero. The stopping time of the end decreases as the initial velocity increases. The faster the end of the link impacts the surface of the granular medium, the sooner it will come to a stop. This phenomenon involves how rapidly a free link strikes the granular medium and how it slows down upon contact.

scholarly journals Models and data analysis tools for the Solar Orbiter mission

2020 ◽  
Vol 642 ◽  
pp. A2 ◽  
Author(s):  
A. P. Rouillard ◽  
R. F. Pinto ◽  
A. Vourlidas ◽  
A. De Groof ◽  
W. T. Thompson ◽  
...  
Keyword(s):  
Data Analysis ◽  
Solar Disk ◽  
Source Region ◽  
Solar Interior ◽  
The Sun ◽  
Science Operations ◽  
Wide Range ◽  
Tools And Techniques ◽  
Orbiter Mission ◽  
Current Modelling

Context. The Solar Orbiter spacecraft will be equipped with a wide range of remote-sensing (RS) and in situ (IS) instruments to record novel and unprecedented measurements of the solar atmosphere and the inner heliosphere. To take full advantage of these new datasets, tools and techniques must be developed to ease multi-instrument and multi-spacecraft studies. In particular the currently inaccessible low solar corona below two solar radii can only be observed remotely. Furthermore techniques must be used to retrieve coronal plasma properties in time and in three dimensional (3D) space. Solar Orbiter will run complex observation campaigns that provide interesting opportunities to maximise the likelihood of linking IS data to their source region near the Sun. Several RS instruments can be directed to specific targets situated on the solar disk just days before data acquisition. To compare IS and RS, data we must improve our understanding of how heliospheric probes magnetically connect to the solar disk. Aims. The aim of the present paper is to briefly review how the current modelling of the Sun and its atmosphere can support Solar Orbiter science. We describe the results of a community-led effort by European Space Agency’s Modelling and Data Analysis Working Group (MADAWG) to develop different models, tools, and techniques deemed necessary to test different theories for the physical processes that may occur in the solar plasma. The focus here is on the large scales and little is described with regards to kinetic processes. To exploit future IS and RS data fully, many techniques have been adapted to model the evolving 3D solar magneto-plasma from the solar interior to the solar wind. A particular focus in the paper is placed on techniques that can estimate how Solar Orbiter will connect magnetically through the complex coronal magnetic fields to various photospheric and coronal features in support of spacecraft operations and future scientific studies. Methods. Recent missions such as STEREO, provided great opportunities for RS, IS, and multi-spacecraft studies. We summarise the achievements and highlight the challenges faced during these investigations, many of which motivated the Solar Orbiter mission. We present the new tools and techniques developed by the MADAWG to support the science operations and the analysis of the data from the many instruments on Solar Orbiter. Results. This article reviews current modelling and tool developments that ease the comparison of model results with RS and IS data made available by current and upcoming missions. It also describes the modelling strategy to support the science operations and subsequent exploitation of Solar Orbiter data in order to maximise the scientific output of the mission. Conclusions. The on-going community effort presented in this paper has provided new models and tools necessary to support mission operations as well as the science exploitation of the Solar Orbiter data. The tools and techniques will no doubt evolve significantly as we refine our procedure and methodology during the first year of operations of this highly promising mission.

scholarly journals HISTORIC MOLDOVA. HISTORICAL DISPARITIES, REGIONALISATION AND CROSS-BORDER INTEGRATION

2017 ◽  
Vol 5 ◽  
pp. 920-926
Author(s):  
Cristian Ploscaru ◽  
IonuČ› Nistor
Keyword(s):  
Development Strategy ◽  
Theoretical Approach ◽  
Subsequent Development ◽  
Religious Communities ◽  
Economic Role ◽  
E Learning ◽  
Chronological Sequence ◽  
Integration Strategies ◽  
Research And Education ◽  
The Impact

This study proposes a theoretical approach to the idea of a platform for research and education on the historical substance of regionalization in Romania, with reference to the case of the historical province of Moldova. Furthermore, to identify the consequences, reactions, weaknesses, opportunities afforded by administrative restructuring from a post-regionalization demographic and socioeconomic viewpoint. An inter-disciplinary analysis – historical, demographic, economic – the traits of a Romanian society stemming from Moldova, the historical dynamics that underpin the modern Romanian state, will provide a picture of the current situation, focused mainly on its causes while trying to find explanations rooted in economic and social behaviours and attitudes which came to define and inform the subsequent development strategy of regionalization, allowing Moldova to play a central economic role in relation to other territories, similar to the role it played in the past two centuries, in the context of European integration strategies, in neighbouring parts of the continent (Republic of Moldova, Ukraine). The theoretical approach involves three components, expanding concentrically: 1) component of knowledge / research; 2) digital platform; 3) e-learning component. The research component seeks dynamic historical development of Moldova, from the time after the Union of the Romanian Principalities until today, focusing on specific regional elements. We will try to identify and analyze the specific features of Moldova, links with other areas of historical Moldavia, as the interaction between them and the Romanian public policy. Within the demographic component, we look at the historical population dynamics of Moldova, including various ethnic and religious communities, rural-urban ratios, social and professional structures. Another issue concerns the economic and comparative analysis in space and time, with respect to Moldova historical economic dynamics parameters - resources, infrastructure, industry, agriculture, trade, transport, etc. Both aspects will be analyzed in correlation with the impact of a permanent political factor, pursuing public policies promoted by the political regimes in their chronological sequence.

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