Commission 49: The Interplanetary Plasma and the Heliosphere (Plasma Intsrplanetaire Et L’heliosphere)

1988 ◽  
Vol 20 (1) ◽  
pp. 677-681
Author(s):  
S. Grzedzielski ◽  
L.F. Burlaga
Keyword(s):  
Solar Wind ◽  
Three Dimensional ◽  
List Type ◽  
Type Number ◽  
Local Interstellar Medium ◽  
Solar Origin ◽  
Area Of Interest ◽  
Recent Developments ◽  
Interplanetary Plasma ◽  
Solar Wind Composition

The area of interest to the Commission includes: 1.Solar wind composition and dynamics;2.Solar Interaction of solar wind with extended interplanetary sources of plasma and gases of non-solar origin;3.SolarStructure and dynamics of the three-dimensional heliosphere;4.SolarInteraction of heliosphere with the local interstellar medium.The following reports summarize recent developments in the aforementioned fields.

scholarly journals Commission 49: Interplanetary Plasma and Heliosphere: (Plasma Interplanetaire et Heliosphere)

2000 ◽  
Vol 24 (1) ◽  
pp. 77-84
Author(s):  
F. Verheest ◽  
M. Vandas ◽  
B. Buti ◽  
N.F. Cramer ◽  
M. Dryer ◽  
...  
Keyword(s):  
Solar Wind ◽  
Gas Flow ◽  
Recent Literature ◽  
Interplanetary Space ◽  
Charged Dust ◽  
Interstellar Gas ◽  
Interplanetary Plasma ◽  
Flow Through ◽  
Transient Events ◽  
Solar Wind Composition

In the last decade the triennial reports from Commission 49 have covered various topics like (nonlinear) plasma processes, magnetohydrodynamic phenomena and flows in the heliosphere, solar wind composition, transient events in, and latitudinal dependencies of, the heliosphere, interstellar gas flow through the interface region, kinetic versus magnetohydrodynamic theory in heliospheric plasmas and charged dust in space plasmas. Continuing the tradition of summarizing specific aspects to give astronomers outside our own specialty a flavour of our field, we now address recent advances in understanding coronal mass ejections in interplanetary space and the inner heliospheric solar wind under quiet and perturbed conditions. We owe a great debt of gratitude to the eminent contributors for their valiant efforts in writing these succinct but clear reports and guiding us through the recent literature.

Tethering in pastures new

2018 ◽  
Vol 102 (554) ◽  
pp. 233-245
Author(s):  
John D. Mahony
Keyword(s):  
Numerical Methods ◽  
Three Dimensional ◽  
The Other ◽  
List Type ◽  
Type Number ◽  
The Third ◽  
Slip Rings

In a recent and illuminating article that provided much food for thought [1], the problem of tethering a goat at the edge of a circular pasture so as to restrict its attentions to only one half of the grazing supply was elegantly addressed and developed further to embrace the corresponding three-dimensional scenario involving a bird. The exercises resulted in mathematical formulations that required the use of numerical methods to extract practical results. Following the article, various questions and different scenarios sprang to my mind. The following poser perhaps best illustrates one of these, and it is the purpose of this Article to address this particular conundrum:A grazier has three troublesome beasts that are water averse, eat grass and who will, given half a chance, eat one another also in some fashion. The first will eat the other two and the second will eat only the third, which eats just grass. Having stabled and fed them in separate stalls during the winter months he plans to release them in the spring to an arbitrarily elliptic shaped pasture up to the water's edge in the middle of a lake. He has at his disposal: (1)A drum of tethering rope from which he can cut just once any required length, TBD (To Be Determined).(2)Slip rings and two tethering pegs that can be positioned only on the pasture boundary (i.e. at the water's edge).

Simultaneous Ultramicrotomy of Multiple Areas and Examination of Ribbons on One New Grid

1985 ◽  
Vol 43 ◽  
pp. 460-461
Author(s):  
K. Chien ◽  
R. Van de Velde ◽  
R. Heusser
Keyword(s):  
List Type ◽  
Type Number ◽  
Entire Surface ◽  
Small Areas ◽  
Ultrastructural Studies ◽  
Area Of Interest ◽  
Direct Technique ◽  
Trailing Edges ◽  
Block Face ◽  
Areas Of Interest

The localization of an area of interest for ultramicrotomy within a tissue block is usually determined by first surveying large thick sections under the light microscope. Yang has shown that multiple areas from a large block face can be vertically divided for sequential sectioning. By applying a simple and direct technique, two or more areas of interest from the same block can be sectioned simultaneously and examined on one grid for ultrastructural studies.Depending on the size and distance between the areas that are going to be sectioned, there are several possible approaches:1.Two Small Areas Widely Separated. Since the entire surface of the block is in one plane after thick sectioning, it is possible to rotate the block and trim selected areas into two trapezoids so that their leading and trailing edges are parallel to the knife edge. If their combined total areas do no exceed the average area routinely sectioned, the two trapezoids can be cut simultaneously and two ribbons formed (fig.1).

Practicable Mental Science. A scientific comparison of established views and recent developments in Psychology

1863 ◽  
Vol 8 (44) ◽  
pp. 513-535
Author(s):  
Kenneth McLeod
Keyword(s):  
List Type ◽  
Type Number ◽  
Practical Science ◽  
Recent Developments ◽  
Science Of Mind

Two recent numbers of the ‘Journal of Mental Science’ contain two communications, respectively entitled— 1.On the Principles and Method of a practical Science of Mind. By Dr. Thomas Laycock. (Journal, January, 1862.)2.On the practical use of Mental Science. By Dr. J. Stephenson Bushnan. (Journal, April, 1862.)

scholarly journals Recent Developments in Improving Daytime Angular Resolution from the Ground

1974 ◽  
Vol 56 ◽  
pp. 27-30 ◽  
Author(s):  
K. O. Kiepenheuer
Keyword(s):  
Angular Resolution ◽  
Solar Chromosphere ◽  
List Type ◽  
Type Number ◽  
Modulation Transfer ◽  
Recent Developments ◽  
The Subject ◽  
High Degree ◽  
Atmospheric Seeing

The subject of this symposium is the fine structure of the solar chromosphere. Progress in this field of reserach will depend to a high degree of the quality of seeing, resp. on the effective angular resolution available on the ground. Today's situation of solar ground seeing has changed distinctly in the last years. I would like to report here a few new aspects, which could be condensed into 3 questions: (1)Are there on the ground ‘good seeing windows’, comparable in quality with stratosphere results obtained from balloon borne equipment?(2)Is there a chance to resolve from the ground the solar scale height, corresponding to about 0.1″.(3)Is there a residual fundamental atmospheric seeing noise resp. a basic limit to the atmospheric Modulation Transfer Function (MTF)?

New Three-Dimensional Algebraic Reconstruction Techniques (Art)

1971 ◽  
Vol 29 ◽  
pp. 82-83 ◽  
Author(s):  
Richard Gordon ◽  
Robert Bender
Keyword(s):  
Three Dimensional ◽  
Fourier Method ◽  
List Type ◽  
Type Number ◽  
Data Set ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Algebraic Reconstruction Techniques ◽  
Electron Microscope Data ◽  
Algebraic Reconstruction

Algebraic reconstruction techniques (ART) for 3-dimensional reconstruction from electron microscope data have been developed and implemented in this laboratory. These methods are an alternitive to the Fourier method of de Rosier and Klug and have several advantages over it, such as:relatively few views are required (about 6-12)limited angular ranges give useful reconstructions (+/-30°)no presumption of symmetry is necessary for facile implementingcomputation is fasterthe computation is stable in the presence of noiseThe dimensionality of the problem may be reduced from three to two by tilts about a single axis, so that planes perpendicular to the axis of tilt are independent of each other. This is not absolutely necessary, but is by far the most tractable mode computationally. A typical input data set, then, consists of m≥6 photos of the same region of the specimen at several known angles of tilt about the same axis. In general the direction of the tilt axis is not known.

scholarly journals Modelling declassification policies using abstract domain completeness

2011 ◽  
Vol 21 (6) ◽  
pp. 1253-1299 ◽  
Author(s):  
ISABELLA MASTROENI ◽  
ANINDYA BANERJEE
Keyword(s):  
Three Dimensional ◽  
Public Information ◽  
Denotational Semantics ◽  
Program Execution ◽  
List Type ◽  
Type Number ◽  
The Third ◽  
Trace Semantics ◽  
Third Dimension ◽  
Partition Refinement

This paper explores a three dimensional characterisation of a declassification-based non-interference policy and its consequences. Two of the dimensions consist of specifying:(a)the power of the attacker, that is, what public information a program has that an attacker can observe; and(b)what secret information a program has that needs to be protected.Both these dimensions are regulated by the third dimension:(c)the choice of program semantics, for example, trace semantics or denotational semantics, or any semantics in Cousot's semantics hierarchy.To check whether a program satisfies a non-interference policy, one can compute an abstract domain that over-approximates the information released by the policy and then check whether program execution can release more information than permitted by the policy. Counterexamples to a policy can be generated by using a variant of the Paige–Tarjan algorithm for partition refinement. Given the counterexamples, the policy can be refined so that the least amount of confidential information required for making the program secure is declassified.

The Bonner Spectral Atlas and Three-Dimensional Classification at Low Dispersions

1976 ◽  
Vol 72 ◽  
pp. 129-133
Author(s):  
W. C. Seitter
Keyword(s):  
Three Dimensional ◽  
List Type ◽  
Type Number ◽  
Late Type ◽  
The Third ◽  
The Past ◽  
Dimensional Classification ◽  
Composite Spectra ◽  
Peculiar Stars ◽  
Ap Stars

Work on the third part of the Bonner Spectral Atlas: Peculiar Stars has well progressed during the past year. Observations of the more than 200 stars – photographed with a dispersion of 240 Å mm−1 at Hγ on I-N plates – is nearing completion.The arrangement of the spectra will be as follows: 1.WR-stars2.O-stars Of sequence3.Peculiar B-type stars emission-line objects4.Ap-stars with various sequences: Cr-Mn-Hg-rare earths5.Asi-stars6.Am-stars7.Late-type peculiar stars Ba II, CH8.C-stars9.Late M-type stars10.S-stars11.Composite spectra12.Spectra with large rotational broadeningThe 12 groups are displayed on 40 plates, each with 6–8 objects. Stars of groups 8 to 10 will be presented with different exposures in order to facilitate the discovery of faint objects.Sample plates will be shown and discussed.

Recent Developments in Political Geography, II

1935 ◽  
Vol 29 (6) ◽  
pp. 943-966 ◽  
Author(s):  
Richard Hartshorne
Keyword(s):  
Political Geography ◽  
Cultural Landscape ◽  
Descriptive Analysis ◽  
The State ◽  
List Type ◽  
Type Number ◽  
Natural Landscape ◽  
Recent Developments ◽  
The Comparative Study ◽  
State Area

With the field of political geography defined on the lines indicated in the preceding instalment of this article, its content may be outlined in terms of the study of a single state area. Naturally, such studies of different states may lead to the comparative study of state areas, just as regional studies may lead to a comparative science of regions. The outline which follows represents perhaps a minimum, including only those topics which I think are unquestionably to be included.I.Descriptive analysis of the stateA.Description or analysis of the state as a whole1.Size2.Form and shape3.Location in relation to other state areas4.BoundariesB.Analysis of the internal structure of the area1.Natural landscape areas, or provinces2.Cultural landscape areas, or provinces3.Areal distribution of significant population groups4.Location of the administrative center (capital)5.Geographic relations of the different areas thus analyzed, to each other and to the capital

Some Recent Developments in the Landing Gear Field

1948 ◽  
Vol 52 (445) ◽  
pp. 27-74 ◽  
Author(s):  
Rene Lucien
Keyword(s):  
Laminar Flow ◽  
Landing Gear ◽  
List Type ◽  
Type Number ◽  
Wing Loading ◽  
Special Effect ◽  
Recent Developments ◽  
Physical Dimensions

What are the particular factors of the aeroplane of 1947, which have a special effect on landing gear technique?(i)Increase in the speed of take-off and landing.1940: 65 to 90 m.p.h.1947: up to 130 m.p.h.(ii)Increase in wing loading and the use of thin or laminar flow wing sections.1940: 301b. sq.ft.1947: more than 50 lb. sq. ft.(iii)Increase in physical dimensions and all-up-weight of the aircraft.1940: 80,000 lb.1947: 300,000 1b.(iv)Increase in operational altitude.1940: 10,000 to 15,000 ft.1947: 15,000 to 30,000 ft.

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