scholarly journals Summary and Conclusions

2021 ◽  
pp. 221-225
Author(s):  
Donald V. Reames
Keyword(s):  
Magnetic Fields ◽  
Source Parameters ◽  
Physical Models ◽  
Current Understanding ◽  
Energy Spectra ◽  
Physical Processes ◽  
Indelible Mark ◽  
Time Profiles

AbstractIn this chapter we summarize our current understanding of SEPs, of properties of the sites of their origin and of the physical processes that accelerate or modify them. These processes can leave an indelible mark on the abundances of elements, isotopes, ionization states, anisotropies, energy spectra and time profiles of the SEPs. Transport of the ions to us along magnetic fields can impose new variations in large events or even enhance the visibility of the source parameters as the SEPs expand into the heliosphere. We lack physical models that can follow the complexity of SEP abundance variations.

Distributed Modeling Of Building Systems Through Cyber-Physical Integration

2019 ◽  
pp. 12-17
Keyword(s):  
Data Structure ◽  
Operating Conditions ◽  
Physical Models ◽  
Distributed Model ◽  
Physical Processes ◽  
Distributed Modeling ◽  
Distributed Models ◽  
Operating Modes ◽  
Building Systems ◽  
Important Practical Application

This article describes the proposed approaches to creating distributed models that can, with given accuracy under given restrictions, replace classical physical models for construction objects. The ability to implement the proposed approaches is a consequence of the cyber-physical integration of building systems. The principles of forming the data structure of designed objects and distributed models, which make it possible to uniquely identify the elements and increase the level of detail of such a model, are presented. The data structure diagram of distributed modeling includes, among other things, the level of formation and transmission of signals about physical processes inside cyber-physical building systems. An enlarged algorithm for creating the structure of the distributed model which describes the process of developing a data structure, formalizing requirements for the parameters of a design object and its operating modes (including normal operating conditions and extreme conditions, including natural disasters) and selecting objects for a complete group that provides distributed modeling is presented. The article formulates the main approaches to the implementation of an important practical application of the cyber-physical integration of building systems - the possibility of forming distributed physical models of designed construction objects and the directions of further research are outlined.

scholarly journals Planetary Magnetic Fields and Habitability in Super Earths

2018 ◽  
Vol 27 (1) ◽  
pp. 183-231 ◽  
Author(s):  
Pablo Cuartas-Restrepo
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Scaling Laws ◽  
Thermal Evolution ◽  
Solid Core ◽  
Direct Influence ◽  
Physical Processes ◽  
Planetary Magnetic Fields ◽  
Planetary Magnetic Field ◽  
Planetary Dynamos

Abstract This work seeks to summarize some special aspects of a type of exoplanets known as super-Earths (SE), and the direct influence of these aspects in their habitability. Physical processes like the internal thermal evolution and the generation of a protective Planetary Magnetic Field (PMF) are directly related with habitability. Other aspects such as rotation and the formation of a solid core are fundamental when analyzing the possibilities that a SE would have to be habitable. This work analyzes the fundamental theoretical aspects on which the models of thermal evolution and the scaling laws of the planetary dynamos are based. These theoretical aspects allow to develop models of the magnetic evolution of the planets and the role played by the PMF in the protection of the atmosphere and the habitability of the planet.

Science and Techniques Using Pulsed Magnetic Fields

MRS Bulletin ◽  
1993 ◽  
Vol 18 (8) ◽  
pp. 44-49 ◽  
Author(s):  
J.J.M. Franse ◽  
N. Miura
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
High Field ◽  
Materials Science ◽  
Copper Wire ◽  
Field Research ◽  
Outer Diameter ◽  
Electricity Grid ◽  
Pulsed Magnet ◽  
Time Profiles

In this article, we examine materials behavior in the magnetic field region from about 40 T to 500 T using pulsed magnet technology. Examples of materials science using two different pulsed magnet technologies are described in this article.Semicontinuous MagnetsSince the late 1960s, the University of Amsterdam has operated a semicontinuous magnetic field installation that produces magnetic fields up to 40 T with typical time constants of about one second. The magnet coil is constructed from hard-drawn copper wire with a reinforcement cylinder of maraging steel positioned at roughly one third of the outer diameter. Before operation, the coil is cooled to 30 K by cold neon gas. The power for this installation is taken directly from a 10 kV connection to the public electricity grid. By means of a thyristor-based power control system, highly flexible field-time profiles can be realized: step-wise pulses can be generated with field levels constant within 10−4 during 100 ms; linearly increasing and decreasing fields as well as exponentially ripple-free decreasing fields are other examples of standard field-time profiles. Among the measuring techniques frequently used are magnetization, magneto-transport, quantum oscillations, relaxation phenomena, etc. Temperatures at which experiments can be performed range from 400 mK to room temperature. In the Netherlands, the Amsterdam High Field Facility has recently been combined with the High Magnetic Field Laboratory in Nijmegen, where static magnetic fields up to 30 T are produced in hybrid magnet systems, to form the Amsterdam-Nijmegen Magnet Laboratory (ANML). The high field research of ANML comprises semiconductors, magnetism in transition-metal compounds, heavy-fermion physics, superconductors, organic conductors, and magnetic separation. We present here a few selected topics.

scholarly journals Formation of a strong southward IMF near the solar maximum of cycle 23

2004 ◽  
Vol 22 (2) ◽  
pp. 673-687 ◽  
Author(s):  
S. Watari ◽  
M. Vandas ◽  
T. Watanabe
Keyword(s):  
Solar Wind ◽  
Magnetic Fields ◽  
Geomagnetic Storms ◽  
Solar Maximum ◽  
Interplanetary Shocks ◽  
Physical Processes ◽  
Interplanetary Magnetic Fields ◽  
Interplanetary Physics ◽  
Solar Wind Parameters ◽  
Interplanetary Disturbance

Abstract. We analyzed observations of the solar activities and the solar wind parameters associated with large geomagnetic storms near the maximum of solar cycle 23. This analysis showed that strong southward interplanetary magnetic fields (IMFs), formed through interaction between an interplanetary disturbance, and background solar wind or between interplanetary disturbances are an important factor in the occurrence of intense geomagnetic storms. Based on our analysis, we seek to improve our understanding of the physical processes in which large negative Bz's are created which will lead to improving predictions of space weather. Key words. Interplanetary physics (Flare and stream dynamics; Interplanetary magnetic fields; Interplanetary shocks)

scholarly journals Processes in the magnetized chromosphere of the Sun

2008 ◽  
Vol 4 (S257) ◽  
pp. 121-131
Author(s):  
S. S. Hasan
Keyword(s):  
Magnetic Fields ◽  
Large Field ◽  
The Sun ◽  
Physical Processes ◽  
Flux Tubes ◽  
Weak Magnetic Fields ◽  
Space Experiments ◽  
New Space ◽  
Magnetic Network

AbstractWe review physical processes in magnetized chromospheres on the Sun. In the quiet chromosphere, it is useful to distinguish between the magnetic network on the boundaries of supergranules, where strong magnetic fields are organized in mainly vertical flux tubes and internetwork regions in the cell interiors, which have traditionally been associated with weak magnetic fields. Recent observations from Hinode, however, suggest that there is a significant amount of horizontal magnetic flux in the cell interior with large field strength. Furthermore, processes that heat the magnetic network have not been fully identified. Is the network heated by wave dissipation and if so, what is the nature of these waves? These and other aspects related to the role of spicules will also be highlighted. A critical assessment will be made on the challenges facing theory and observations, particularly in light of the new space experiments and the planned ground facilities.

FEW-ELECTRON DOUBLE-LAYER QUANTUM DOTS IN MAGNETIC FIELDS: ENERGY SPECTRUM OF AN ARTIFICIAL MOLECULE

1999 ◽  
Vol 13 (09n10) ◽  
pp. 291-302
Author(s):  
WENFANG XIE ◽  
CHUANYU CHEN ◽  
D. L. LIN
Keyword(s):  
Magnetic Field ◽  
Angular Momentum ◽  
Magnetic Fields ◽  
Double Layer ◽  
Ground State ◽  
Energy Spectra ◽  
Electron Interaction ◽  
Magic Numbers ◽  
Total Orbital Angular Momentum ◽  
Artificial Molecule

An exact method is proposed to diagonalize the Hamiltonian of a double-layer quantum dot containing N electrons in arbitrary magnetic fields. For N = 3 and 4, energy spectra of the dot are calculated as a function of the applied magnetic field. As a result of the electron–electron interaction, complete sets of "magic numbers" are found to characterize the total orbital angular momentum of the N-electron dot in the ground state for both the polarized and unpolarized spins. It is shown that discrete transitions of the ground state between magic numbers takes place when the external magnetic field changes. The origin of the magic numbers is completely explained in terms of the underlying symmetry.

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