Commission 16: Physical Study of Planets and Satellites (Etude Physique Pes Planetes Et Satellites)

1988 ◽  
Vol 20 (1) ◽  
pp. 167-178
Author(s):  
G. Hunt ◽  
A. Brahic ◽  
D. Morrison ◽  
J. L. Bertaux ◽  
J. Burns ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Laboratory Experiments ◽  
Space Exploration ◽  
Theoretical Models ◽  
Physical Study ◽  
Perfect Complementarity ◽  
Planets And Satellites ◽  
Space Data

The physical study of planets and satellites is probably one of the more active fields of research of the second half of this century. This is due to space exploration by spacecraft, but also to the use of modern detectors, of large ground-based telescopes, and of powerful computers by active researchers. Planetary research (or planetology) is a pluridisciplinary domain, which requires not only the competence of astronomers, but also of geophysicists, of mineralogists, of climatologists, of biologists, of chemists, of physicists, of “pure„ mathematicians, and many other scientists. Many results are at the boundary of those of other commissions such as the 15, 20, 7, 19, 33, 40, 44, 49 and 51 ones. The study of the main results obtained during this last triennum shows a perfect complementarity between space and ground-based observations. It should be arbitrary to separate space and ground-based scientists. The have the same goal and they study the same objects. Quite often, the same individuals use both techniques, depending on the most efficient one for the problem under study. It is remarkable to see that space data collected more than ten years ago are still analysed in connection with ground-based observations. The same remarks can apply for ground-based data. In addition to that, new theoretical models, new numerical simulations and new laboratory experiments have ben recently developed. They all contribute to a better understanding of planets and satellites physics.

scholarly journals Commission 16: Physical Study of Planets and Satellites (Etude Physique pes Planetes et Satellites)

1991 ◽  
Vol 21 (1) ◽  
pp. 161-168
Author(s):  
Andre Brahic
Keyword(s):  
Working Group ◽  
Planetary System ◽  
Space Exploration ◽  
Active Participation ◽  
Planetary Surfaces ◽  
Planetary Geology ◽  
Physical Study ◽  
Planets And Satellites

It is with great sadness that we have to report the death of Harold Masursky on August 24, 1990 at the age of 66. Harold Masursky was the President of the Working Group for Planetary System Nomenclature. He was well known for his active participation to space exploration of the planets. He was one of the pioneers of planetary geology. He wrote many important contributions on planetary surfaces.

Mate availability facilitates cannibalistic behaviour in a nest brooding fish: effects of timing during the brood cycle

Behaviour ◽  
2011 ◽  
Vol 148 (2) ◽  
pp. 247-264 ◽  
Author(s):  
Masanori Kohda ◽  
Nobuhiro Ohnishi ◽  
Noboru Okuda ◽  
Tomohiro Takeyama ◽  
Omar Myint
Keyword(s):  
Laboratory Experiments ◽  
Gravid Female ◽  
Theoretical Models ◽  
Filial Cannibalism ◽  
Mate Availability ◽  
Stimulus Female ◽  
Trade Offs ◽  
Future Reproduction ◽  
Cannibalistic Behaviour ◽  
The Subject

AbstractFilial cannibalism, eating one's own viable offspring, is accepted as an adaptive response to trade-offs between current and future reproduction. Theoretical models predict that high mate availability may induce more filial cannibalism, but this prediction is rarely tested. To examine this prediction, we performed laboratory experiments using the nest breeding goby Rhinogobius flumineus. Subject males were allowed to mate with a gravid female and care for the broods. A separate gravid female housed in a small cage (stimulus-female) was shown to the subject males at one of three different points during the brood cycle: prior to spawning, within 1 day after spawning and 1 week after spawning. Empty cages were shown as a control. Males that were shown the stimulus-female before spawning cannibalised more eggs than control males. In contrast, males that were shown the stimulus-females after spawning cannibalised as few eggs as control males did. Additionally, males that were shown the stimulus-female prior to spawning did not court females more intensively than other males. Thus, we suggest that the presence of an additional mate, rather than energy expenditure associated with courtship directed toward an additional mate, can facilitate males to cannibalise their eggs.

scholarly journals A Review of the Geomechanics Aspects in Space Exploration

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7522
Author(s):  
Dariusz Knez ◽  
Mohammad Ahmad Mahmoudi Zamani
Keyword(s):  
Plate Tectonics ◽  
Laboratory Experiments ◽  
Research Study ◽  
Space Exploration ◽  
Physical And Mechanical Properties ◽  
Primary Objective ◽  
Water Extraction ◽  
Scientific Investigations ◽  
Operational Constraints ◽  
Comprehensive Reference

From the 2000s onwards, unprecedented space missions have brought about a wealth of novel investigations on the different aspects of space geomechanics. Such aspects are related to the exploratory activities such as drilling, sampling, coring, water extraction, anchoring, etc. So far, a whole range of constitutive research projects on the plate tectonics, morphology, volcanic activities and volatile content of planetary bodies have been implemented. Furthermore, various laboratory experiments on extraterrestrial samples and their artificial terrestrial simulants are continually conducted to obtain the physical and mechanical properties of the corresponding specimens. Today, with the space boom being steered by diverse space agencies, the incorporation of geomechanics into space exploration appreciably appears much needed. The primary objective of this article is to collate and integrate the up-to-date investigations related to the geomechanical applications in space technologies. Emphasis is given to the new and future applications such as planetary drilling and water extraction. The main impetus is to provide a comprehensive reference for geoscience scientists and astronauts to quickly become acquainted with the cutting-edge advancements in the area of space geomechanics. Moreover, this research study also elaborates on the operational constraints in space geomechanics which necessitate further scientific investigations.

PC-Based Computer Modeling of Combustion Processes

1999 ◽  
Author(s):  
Greg W. Gmurczyk ◽  
Ashwani K. Gupta
Keyword(s):  
Numerical Simulations ◽  
Computer Modeling ◽  
Numerical Experiments ◽  
Laboratory Experiments ◽  
Combustion Process ◽  
Numerical Algorithms ◽  
Computer Hardware ◽  
Simplifying Assumptions ◽  
High Level ◽  
Analytical Approaches

Abstract Constant and significant progress in both computer hardware and numerical algorithms, in recent years, have made it possible to investigate complex phenomena in engineering systems using computer modeling and simulations. Advanced numerical simulations can be treated as an extension of traditional analytical-theoretical analyses. In such cases, some of the simplifying assumptions can usually be dropped and the nonlinear interactions between various processes can be captured. One of the most complex engineering processes encountered in industry is a combustion process utilized either for power/thrust generation or incineration. However, even nowadays, because of the high level of complexity of the general problem of a combustion process in practical systems, it is not currently possible to simulate directly all the length and time scales of interest. Simplifying assumptions still need to be made, but they can be less drastic than in analytical approaches. Therefore, another view of numerical simulations is as a tool to simulate idealized systems and conduct numerical experiments. Such numerical experiments can be complementary to laboratory experiments and can also provide more detailed, nonintrusive diagnostics. Therefore, simulations, along with theory and laboratory experiments, can provide a more complete picture and better understanding of a combustion process. As an example of computer modeling of industrial combustion systems, an enclosed spray flame was considered. Such a flame can frequently be encountered in power generation units, turbine engines, and incinerators. Both the physical and mathematical models were formulated based on data from earlier laboratory studies and results obtained for open air spray flames. The purpose of this study was to use those data as model input to predict the characteristics of a confined flame and provide a means of optimizing the system design with a PC computer.

scholarly journals Numerical Simulations of Jets from Active Galactic Nuclei

Galaxies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 24 ◽  
Author(s):  
José-María Martí
Keyword(s):  
Numerical Simulations ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Theoretical Models ◽  
The Status ◽  
Hydrodynamical Description ◽  
Jet Plasma ◽  
The Impact ◽  
Continuous Injection ◽  
Double Radio Galaxies

Numerical simulations have been playing a crucial role in the understanding of jets from active galactic nuclei (AGN) since the advent of the first theoretical models for the inflation of giant double radio galaxies by continuous injection in the late 1970s. In the almost four decades of numerical jet research, the complexity and physical detail of simulations, based mainly on a hydrodynamical/magneto-hydrodynamical description of the jet plasma, have been increasing with the pace of the advance in theoretical models, computational tools and numerical methods. The present review summarizes the status of the numerical simulations of jets from AGNs, from the formation region in the neighborhood of the supermassive central black hole up to the impact point well beyond the galactic scales. Special attention is paid to discuss the achievements of present simulations in interpreting the phenomenology of jets as well as their current limitations and challenges.

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