Found 115 results
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2010
Authors: Mozer F. S., and Hull A.
Title: Scaling the energy conversion rate from magnetic field reconnection to different bodies
Abstract:

Magnetic field reconnection is often invoked to explain electromagnetic energy conversion in planetary magnetospheres, stellar coronae, and other astrophysical objects. Because of the huge dynamic range of magnetic fields in these bodies, it is important to understand energy conversion as a function of magnetic field strength and related parameters. It is conjectured theoretically and shown experimentally that the energy conversion rate per unit area in reconnection scales as the cube of an appropriately weighted magnetic field strength divided by the square root of an appropriately weighted density. With this functional dependence, the energy release in flares on the Sun, the large and rapid variation of the magnetic flux in the tail of Mercury, and the apparent absence of reconnection. . .
Date: 10/2010 Publisher: Physics of Plasmas Pages: 102906 DOI: 10.1063/1.3504224 Available at: http://aip.scitation.org/doi/10.1063/1.3504224http://aip.scitation.org/doi/pdf/10.1063/1.3504224
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Authors: Guo Yanping
Title: Solar Probe Plus: Mission design challenges and trades
Abstract:

NASA plans to launch the first mission to the Sun, named Solar Probe Plus, as early as 2015, after a comprehensive feasibility study that significantly changed the original Solar Probe mission concept. The original Solar Probe mission concept, based on a Jupiter gravity assist trajectory, was no longer feasible under the new guidelines given to the mission. A complete redesign of the mission was required, which called for developing alternative trajectories that excluded a flyby of Jupiter. Without the very powerful gravity assist from Jupiter it was extremely difficult to get to the Sun, so designing a trajectory to reach the Sun that is technically feasible under the new mission guidelines became a key enabler to this highly challenging mission. Mission design requirements and challen. . .
Date: 11/2010 Publisher: Acta Astronautica Pages: 1063 - 1072 DOI: 10.1016/j.actaastro.2010.06.007 Available at: https://linkinghub.elsevier.com/retrieve/pii/S0094576510001980https://api.elsevier.com/content/article/PII:S0094576510001980?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0094576510001980?httpAccept=text/plain
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Authors: Ergun R. E., Malaspina D. M., Bale S. D., McFadden J. P., Larson D. E., et al.
Title: Spacecraft charging and ion wake formation in the near-Sun environment
Abstract:

A three-dimensional, self-consistent code is employed to solve for the static potential structure surrounding a spacecraft in a high photoelectron environment. The numerical solutions show that, under certain conditions, a spacecraft can take on a negative potential in spite of strong photoelectron currents. The negative potential is due to an electrostatic barrier near the surface of the spacecraft that can reflect a large fraction of the photoelectron flux back to the spacecraft. This electrostatic barrier forms if (1) the photoelectron density at the surface of the spacecraft greatly exceeds the ambient plasma density, (2) the spacecraft size is significantly larger than local Debye length of the photoelectrons, and (3) the thermal electron energy is much larger than the characterist. . .
Date: 07/2010 Publisher: Physics of Plasmas Pages: 072903 DOI: 10.1063/1.3457484 Available at: http://aip.scitation.org/doi/10.1063/1.3457484http://aip.scitation.org/doi/pdf/10.1063/1.3457484
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2009
Authors: Plus M., Dumas F., ère J.-Y., and Maurer D.
Title: Hydrodynamic characterization of the Arcachon Bay, using model-derived descriptors
Abstract:

A numerical model (MARS-2D) was developed, with the aim of describing the hydrodynamics that prevail in Arcachon Bay. Direct model results as well as derived mixing and transport time-scales (tidal prism, local and integrated flushing times, age of water masses), were used to understand the behaviour of water masses and exchanges between the Bay and its frontiers. Particular attention was paid to the processes that drive the hydrodynamics (tides, wind and rivers), in order to understand their respective influence. The Arcachon Bay hydrodynamic system appears primarily to be highly influenced by tides; secondarily, by winds. About two third of the lagoon total volume is flushed in and out at each tidal cycle, which represent a mean tidal prism of 384 millions of cubic meters. The percent. . .
Date: 03-/2009 Publisher: Continental Shelf Research Pages: 1008 - 1013 DOI: 10.1016/j.csr.2008.12.016 Available at: https://linkinghub.elsevier.com/retrieve/pii/S0278434309000193https://api.elsevier.com/content/article/PII:S0278434309000193?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0278434309000193?httpAccept=text/plain
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2003
Authors: ZALDIVAR J
Title: Long-term simulation of main biogeochemical events in a coastal lagoon: Sacca Di Goro (Northern Adriatic Coast, Italy)
Abstract:

A biogeochemical model for the Sacca di Goro Lagoon has been developed and partially validated with field data from 1989 to 1998. The model considers the nutrient cycles in the water column as well as in the sediments. Furthermore, phytoplankton, zooplankton, and Ulva sp. dynamics, as well as shellfish farming, are taken into account. Due to the recent anoxic crises in the lagoon, the dynamic of oxygen has also been simulated. The actual version of the model is a 0D with input fluxes from the watershed and exchange with the Northern Adriatic Sea. Nutrients from the watershed, wet and dry deposition, temperature, light intensity, wind speed and shellfish production are considered as forcing functions. The results show that the model is able to capture the essential dynamics of the lagoon. . .
Date: 11/2003 Publisher: Continental Shelf Research Pages: 1847 - 1875 DOI: 10.1016/j.csr.2003.01.001 Available at: http://linkinghub.elsevier.com/retrieve/pii/S027843430300150Xhttp://api.elsevier.com/content/article/PII:S0278-4343(03)00150-X?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:S0278-4343(03)00150-X?httpAccept=text/plain
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Authors: Plus M
Title: Modelling of oxygen and nitrogen cycling as a function of macrophyte community in the Thau lagoon
Abstract:

A three-dimensional model coupling physical and biological processes for the whole Thau lagoon (Mediterranean coast of France) was developed in order to assess the relationships between macrophytes and the oxygen and nitrogen cycles. Ten species have been inserted as forcing variables in the model. Plankton dynamics, shellfish cultivation impact and mineralization of organic matter are also considered, as well as nutrient and oxygen exchanges between the sediment and the water column. Simulations with and without the macrophytes have shown that the system can be characterized as having a highly structured pattern involving lagoon nitrogen and oxygen cycles. This pattern is created by the combined influence of macrophytes, watershed and oyster farming. The model has been also used to ass. . .
Date: 11/2003 Publisher: Continental Shelf Research Pages: 1877 - 1898 DOI: 10.1016/j.csr.2003.03.001 Available at: https://linkinghub.elsevier.com/retrieve/pii/S0278434303001511https://api.elsevier.com/content/article/PII:S0278-4343(03)00151-1?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:S0278-4343(03)00151-1?httpAccept=text/plain
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1986
Authors: Brucker G. J., Herbert J., Stewart R., and Plus D.
Title: Sapphire Photocurrent Sources and Their Impact on RAM Upset
Abstract:

This paper reports on the transient photocurrent measurements made with test structures fabricated on sapphire substrates, and the computer simulation model which was developed to use the test results. Predictions of logic upset for a 4 K RAM CMOS/SOS compared with measured upset rates showed agreement within a factor of 2. The test structure results indicate that the sapphire photoconductance is 6.3 x 10 to the -19th mhos/(rads/s)-micron. The use of this value in the present simulation model will increase the predicted upset rate, and thus, increase the disagreement by more than a factor of two.


Date: 12/1986 Publisher: IEEE Transactions on Nuclear Science Pages: 1377 - 1380 DOI: 10.1109/TNS.1986.4334608 Available at: http://ieeexplore.ieee.org/document/4334608/http://xplorestaging.ieee.org/ielx5/23/4334557/04334608.pdf?arnumber=4334608
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1982
Authors: Stewart R.G., and Plus D.
Title: A 40 ns CMOS E/SUP 2/PROM
Abstract:

New high-performance CMOS circuit techniques have been developed and used to build an 8K E/SUP 2/PROM with an access time of 38 ns at 5 V. Using standard CMOS/SOS technology, the device dissipates only 0.8 mW quiescent power at 5 V and 60 mW at 1 MHz. A midpoint precharge and sense technique permits operation form a supply voltage of 4-12 V.


Date: 10/1982 Publisher: IEEE Journal of Solid-State Circuits Pages: 841 - 846 DOI: 10.1109/JSSC.1982.1051828 Available at: http://ieeexplore.ieee.org/document/1051828/http://xplorestaging.ieee.org/ielx5/4/22585/01051828.pdf?arnumber=1051828
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1976
Authors: Plus R.
Title: Utilisation des isotopes D, 15N, 26Mg pour l'étude vibrationnelle de Mg(NH3)6Cl2.
Abstract:

The following substituted magnesium chloride hexa-ammines: 24Mg( 14NH 3) 6Cl 2; 26Mg( 14NH 3) 6Cl 2; 24Mg( 15NH 3) 6Cl 2; 24Mg( 14ND 3) 6Cl 2; 24Mg( 14ND 3) 6Cl 2 have been studied by i.r. and Raman spectroscopy. The frequency shifts have been measured for all active vibrational bands predicted by group theory analysis. The results show that measurements made on isotopically substituted compounds can provide confirmation of assignments of vibrational bands previously proposed [2].


Date: 01/1976 Publisher: Spectrochimica Acta Part A: Molecular Spectroscopy Pages: 263 - 268 DOI: 10.1016/0584-8539(76)80076-1 Available at: http://linkinghub.elsevier.com/retrieve/pii/0584853976800761http://api.elsevier.com/content/article/PII:0584853976800761?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:0584853976800761?httpAccept=text/plain
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1975
Authors: Plus R., and Lutz M.
Title: Resonance Raman Scattering of Mesoporphyrin IX Dimethylester in Solution
Abstract:

Resonance Raman spectra of Mesoporphyrin IX dimethylester in solution were obtained using various wavelengths in the region of electronic band IV. Vibrational data, as well as variations in the depolarization ratios and the band intensities with excitation wavelengths were compared to those previously obtained for porphin. The new data provide confirmation of the existence of three, most probably purely electronic transitions in band IV of both Mesoporphyrin IX dimethylester and porphin.


Date: 01/1975 Publisher: Spectroscopy Letters Pages: 119 - 139 DOI: 10.1080/00387017508067314 Available at: https://www.tandfonline.com/doi/full/10.1080/00387017508067314https://www.tandfonline.com/doi/pdf/10.1080/00387017508067314
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1974
Authors: Plus R., and Lutz M.
Title: Resonance Raman Spectroscopy of Porphin
Abstract:

We report and discuss Raman spectra of porphin. These were obtained by resonance effect, irradiating in the electronic band IV. Unexpected variations of vibrational band intensities and depolarization ratios were recorded on changing the excitation wavelength. Some implications on the symmetry types of the vibrations are discussed. Results are compared with current data from quasi-linear electronic spectra.


Date: 01/1974 Publisher: Spectroscopy Letters Pages: 133 - 145 DOI: 10.1080/00387017408067229 Available at: https://www.tandfonline.com/doi/full/10.1080/00387017408067229https://www.tandfonline.com/doi/pdf/10.1080/00387017408067229
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Authors: Plus R., and Lutz M.
Title: Study of Band IV of Porphin by Resonance Raman Spectroscopy
Abstract:

Excitation spectra were obtained for 21 resonance Raman bands of porphin from 455 to 515 nm. Each of them exhibited one to three maxima which generally lay close to 453, 475 and 490 nm. These three resonance levels were tentatively attributed to the presence of pure electronic transitions in band IV. The few other maxima could be interpreted as resonance at vibrational sublevels of band III. The structure of band IV is thus shown to be of greater complexity than has been generally suspected up to now.


Date: 01/1974 Publisher: Spectroscopy Letters Pages: 73 - 84 DOI: 10.1080/00387017408067222 Available at: http://www.tandfonline.com/doi/abs/10.1080/00387017408067222http://www.tandfonline.com/doi/pdf/10.1080/00387017408067222
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1973
Authors: Plus émi
Title: Étude par spectroscopie infrarouge des composés Mg(NH 3 ) 6 Cl 2 et Mg(ND 3 ) 6 Cl 2
Abstract:

The infrared spectra of pure Mg(NH3)6Cl2 and Mg(ND3)6Cl2 were recorded from 4 000 to 50 cm-1 at 40 and — 180 °C. The observed bands are assigned. The hydrogenated compound was studied by differential thermal analysis.

The observed infrared spectral data are compared with the previously reported experimental values for other divalent metals (Co2+, Ni2+, Fe2+, Mn2+). This comparison proves that (he coordination bond is stronger for Mg than for the other metals.


Date: 01/1973 Publisher: Journal de Chimie Physique Pages: 900 - 904 DOI: 10.1051/jcp/1973700900 Available at: http://jcp.edpsciences.org/10.1051/jcp/1973700900http://jcp.edpsciences.org/10.1051/jcp/1973700900/pdf
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Authors: Plus émi
Title: Étude vibrationnelle de complexes du magnesium. Spectroscopie Raman de Mg(NH3)6Cl2et Mg(ND3)6Cl2
Abstract:

L'auteur a pu obtenir les fréquences des vibrations actives en diffusion Raman du chlorure de magnésium hexa‐amminé hydrogéné et deutérié à l'état cristallisé. Toutes les vibrations attendues ont pu être observées pour la première fois pour un composé de ce type (vibrations internes et vibrations externes). L'attribution de toutes les bandes du spectre est proposée. Ces résultats, rapprochés de ceux obtenus par spectroscopie infrarouge, permettent de connaître la structure vibrationnelle complète du complexe. L'éclatement de certaines vibrations montre que les coordinats ne sont pas en rotation libre et que leur orientation donne à l'ion complexe la symétrie du groupe ponctuel D3d.


Date: 12/1973 Publisher: Journal of Raman Spectroscopy Pages: 551 - 563 DOI: 10.1002/jrs.v1:610.1002/jrs.1250010605 Available at: https://onlinelibrary.wiley.com/doi/abs/10.1002/jrs.1250010605
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1969
Authors: Lewis John S.
Title: Observability of spectroscopically active compounds in the atmosphere of Jupiter
Abstract:

The abundances of several hundred volatile compounds have been calculated at several different levels in the atmosphere of Jupiter. Complete chemical equilibrium has been assumed, and a solar-composition, adiabatic-equilibrium model of the atmospheric composition and structure is used throughout. The results which relate to upper limits on the abundances of spectroscopically active compounds in the upper atmosphere are, however, directly applicable to subadiabatic models. The principal results are that only H2, CH4, and NH3 are predicted to be observable with present techniques. These three species are in fact the only compounds conclusively identified in Jupiter spectra to date. A number of plausible previously suggested constituents of the upper atmosp. . .
Date: 05/1969 Publisher: Icarus Pages: 393 - 409 DOI: 10.1016/0019-1035(69)90094-3 Available at: https://linkinghub.elsevier.com/retrieve/pii/0019103569900943https://api.elsevier.com/content/article/PII:0019103569900943?httpAccept=text/xmlhttps://api.elsevier.com/content/article/PII:0019103569900943?httpAccept=text/plain
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