Dynamo mechanism for turbulent wave in celestial bodies

1981 ◽  
Vol 76 (1) ◽  
pp. 13-21 ◽  
Author(s):  
Li Xiao-Qing ◽  
Song Guo-Xuan
Keyword(s):  
Dynamo Mechanism ◽  
Celestial Bodies ◽  
Turbulent Wave

Symmetric Multistep Methods Revisited: II. Numerical Experiments

1999 ◽  
Vol 173 ◽  
pp. 309-314 ◽  
Author(s):  
T. Fukushima
Keyword(s):  
Multistep Methods ◽  
Computational Time ◽  
Integration Time ◽  
Implicit Methods ◽  
Symmetric Methods ◽  
Celestial Bodies ◽  
The Stability ◽  
Predictor Corrector ◽  
Symmetric Multistep Methods ◽  
Integration Errors

AbstractBy using the stability condition and general formulas developed by Fukushima (1998 = Paper I) we discovered that, just as in the case of the explicit symmetric multistep methods (Quinlan and Tremaine, 1990), when integrating orbital motions of celestial bodies, the implicit symmetric multistep methods used in the predictor-corrector manner lead to integration errors in position which grow linearly with the integration time if the stepsizes adopted are sufficiently small and if the number of corrections is sufficiently large, say two or three. We confirmed also that the symmetric methods (explicit or implicit) would produce the stepsize-dependent instabilities/resonances, which was discovered by A. Toomre in 1991 and confirmed by G.D. Quinlan for some high order explicit methods. Although the implicit methods require twice or more computational time for the same stepsize than the explicit symmetric ones do, they seem to be preferable since they reduce these undesirable features significantly.

scholarly journals III. On the nature and construction of the sun and fixed stars

1795 ◽  
Vol 85 ◽  
pp. 46-72 ◽  
Keyword(s):  
Central Body ◽  
Planetary System ◽  
Considerable Progress ◽  
The Sun ◽  
Great Satisfaction ◽  
The Earth ◽  
The World ◽  
Celestial Bodies ◽  
The Universe ◽  
Made In

Among the celestial bodies the sun is certainly the first which should attract our notice. It is a fountain of light that illuminates the world! it is the cause of that heat which main­tains the productive power of nature, and makes the earth a fit habitation for man! it is the central body of the planetary system; and what renders a knowledge of its nature still more interesting to us is, that the numberless stars which compose the universe, appear, by the strictest analogy, to be similar bodies. Their innate light is so intense, that it reaches the eye of the observer from the remotest regions of space, and forcibly claims his notice. Now, if we are convinced that an inquiry into the nature and properties of the sun is highly worthy of our notice, we may also with great satisfaction reflect on the considerable progress that has already been made in our knowledge of this eminent body. It would require a long detail to enumerate all the various discoveries which have been made on this subject; I shall, therefore, content myself with giving only the most capital of them.

scholarly journals Cycles and circulation: a theme in the history of biology and medicine

2021 ◽  
Vol 43 (3) ◽  
Author(s):  
Nick Hopwood ◽  
Staffan Müller-Wille ◽  
Janet Browne ◽  
Christiane Groeben ◽  
Shigehisa Kuriyama ◽  
...  
Keyword(s):  
Natural Philosophy ◽  
Life Cycles ◽  
Modern Times ◽  
Systems Ecology ◽  
The Face ◽  
History Of ◽  
Celestial Bodies ◽  
Reproductive Cycles ◽  
Economics And Biology

AbstractWe invite systematic consideration of the metaphors of cycles and circulation as a long-term theme in the history of the life and environmental sciences and medicine. Ubiquitous in ancient religious and philosophical traditions, especially in representing the seasons and the motions of celestial bodies, circles once symbolized perfection. Over the centuries cyclic images in western medicine, natural philosophy, natural history and eventually biology gained independence from cosmology and theology and came to depend less on strictly circular forms. As potent ‘canonical icons’, cycles also interacted with representations of linear and irreversible change, including arrows, arcs, scales, series and trees, as in theories of the Earth and of evolution. In modern times life cycles and reproductive cycles have often been held to characterize life, in some cases especially female life, while human efforts selectively to foster and disrupt these cycles have harnessed their productivity in medicine and agriculture. But strong cyclic metaphors have continued to link physiology and climatology, medicine and economics, and biology and manufacturing, notably through the relations between land, food and population. From the grand nineteenth-century transformations of matter to systems ecology, the circulation of molecules through organic and inorganic compartments has posed the problem of maintaining identity in the face of flux and highlights the seductive ability of cyclic schemes to imply closure where no original state was in fact restored. More concerted attention to cycles and circulation will enrich analyses of the power of metaphors to naturalize understandings of life and their shaping by practical interests and political imaginations.

scholarly journals Note on the intensity decrement in the balmer series

1919 ◽  
Vol 96 (675) ◽  
pp. 112-119 ◽  
Keyword(s):  
Hydrogen Atom ◽  
Low Pressure ◽  
Quantitative Comparison ◽  
The Sun ◽  
Previous Knowledge ◽  
Balmer Series ◽  
Celestial Bodies ◽  
Theoretical Considerations

One of the most remarkable examples of spectrum lines which are common in celestial bodies, but which have hitherto resisted all attempts to reproduce them in the laboratory, is afforded by the higher members of the Balmer series of hydrogen. As many as 29 members of this series have been observed by Dyson and Evershed in the chromosphere of the sun, but the greatest number observed in the laboratory by Ames and by Cornu was only 13, and the last of these were of such a character that it would hardly have been possible to record them without a previous knowledge of their localisation. In many respects the failure to reproduce in the laboratory lines whose chemical origin is known, and which are so prominent in celestial spectra, is even more conspicuous than in the case of the nebular and coronal lines, which cannot yet be referred to any atom known in chemistry, and which may be due to substances which do not, or perhaps cannot, exist under terrestrial conditions. A further interest has been added to the problem by the important theoretical wrork of Bohr, whose theory of the production of the Balmer series requires that the space occupied by a hydrogen atom, in the process of emitting lines of the higher members of the Balmer series, is such that these radiations cannot be expected to be visible except under conditions of extremely low pressure. Bohr has pointed out that this view is consistent with the appearance of the lines in celestial spectra, and our inability to produce them under the conditions ordinarily obtaining in the laboratory. Liveing and Dewar have found that in a mixture of the more volatile gases of the atmosphere, consisting mainly of neon and helium and containing hydrogen, the Balmer series could be traced as far as the ninth member; and in a recent investigation we have made a quantitative comparison of the distribution of intensity in the earlier members of the series in hydrogen, and in neon containing hydrogen as an impurity. This observation of Liveing and Dewar is remarkable, but we have recently found that similar results can be obtained in helium containing hydrogen at pressures so great that, on the theoretical considerations above referred to, it would seem impossible that these radiations should be detected.

Rotational dynamics of celestial bodies

1985 ◽  
Vol 114 (1) ◽  
pp. 175-189
Author(s):  
V. S. Geroyannis
Keyword(s):  
Rotational Dynamics ◽  
Celestial Bodies

Magnetism of Celestial Bodies and Gravitation

Nature ◽  
1948 ◽  
Vol 162 (4120) ◽  
pp. 612-613 ◽  
Author(s):  
J. MARIANI
Keyword(s):  
Celestial Bodies

Understanding Humma-e-Wabai (epidemic fever) and Amraz-e-Wabai (epidemic disease) in the light of Unani medicine

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Md Anzar Alam ◽  
Mohd Aleemuddin Quamri ◽  
Umme Ayman ◽  
Ghulamuddin Sofi ◽  
Bangalore Nagaraj Renuka
Keyword(s):  
Clinical Characteristics ◽  
Santalum Album ◽  
Cinnamomum Camphora ◽  
Myrtus Communis ◽  
Epidemic Disease ◽  
Ibn Sina ◽  
Unani Medicine ◽  
Ibn Rushd ◽  
Celestial Bodies

Abstract The pathogenesis and clinical characteristics of Humma-e-Wabai were described several years ago in the Unani System of Medicine close to the clinical manifestation associated with epidemic or pandemic situations. In the Unani System of Medicine, Humma-e-Wabai described under the legend of epidemic disease (Amraz-e-Wabai). Amraz-e-Wabai is an umbrella term which is applied for all types of epidemic or pandemic situation. Renowned Unani Scientists like; Zakariya Rhazi (865–925 AD), Ali Ibn Abbas Majusi (930–994 AD), Ibn Sina (980–1037 AD), Ismail Jorjani (1,042–1,137 AD), Ibn Rushd etc., explained that Humma-e-Waba is an extremely rigorous, lethal fever, that is caused due to morbid air (fasid hawa) and it frequently spreads among the larger population in the society. There are four etiological factors responsible for Amraz-e-Wabai viz; change in the quality of air, water, earth, and celestial bodies, which was described by Ibn Sina in Canon of Medicine. He also advised that movements should be limited during epidemic situations. Shelters should be fumigated with loban (Styrax benzoin W. G. Craib ex Hartwich.), Kafoor (Cinnamomum camphora L.), Oodkham (Aquilaria agallocha Roxb.), Hing (Ferula foetida L.), myrtle (Myrtus communis L.), and sandalwood (Santalum album L.), etc. The use of vinegar (sirka) and rose water (arque gulab) has been advocated to prevent the infection by spray. Avoid consumption of flesh, oil, milk, sweets, alcohol. Food prepared with vinegar. Specific antidotes (e.g. Tiryaq-e-Wabai, Tiryaq-e-Farooque), should be used as prophylaxis. This review attempts to explain the concept, prevention, and management of epidemic or pandemic situations.

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