NOVA system

Observations suggest that the average mass of white dwarfs in classical nova systems... 

Our main purpose is to compare absorption and luminescence spectra of R(IH) in glasses with the behavior in crystalline compounds and in aqueous solution. In one way, it is surprising how close many of the similarities are, and also how technologically attractive glasses can be as laser materials compared to crystals. It may be noted that the largest-scale terawatt lasers, such as the SHIVA and NOVA systems in Livermore, CA, are neodymium(III) glasses. We summarize most of the major results described in this chapter in seven conclusions ... 

In 1985, the first active magnetic bearing in a pipeline compressor for continuous use was installed on the Alberta Gas Transmission System of NOVA Corporation. Tlie bearings have been running smoothly, with a noted improvement in compressor operation and efficiency. 

Loeated at the eastern terminus of the NOVA and Foothills (Alberta) pipeline systems and about one mile west of the Alberta/Saskatehewan border, the BP-Amoeo Empress NGL proeessing plant extraets liquids equivalent to approximately 2% of the (maximum value of) 5.2 Bef of natural gas that passes through the faeility every day. Most of the... 

Nova, I., Castoldi, L., Lietti, L. et al. (2006) A Low Temperature Pathway Operating the Reduction of Stored Nitrates in Pt-Ba/Al203 Lean NOr Trap Systems, SAE Technical Paper, 2006-01-1368. 

GC-MS analysis used a Finnigan 4000 quadrupole EI/CI mass spectrometer. Electron Impact spectra were recorded continually using an Incos Nova 4 data system. Ion source temperature was 250°C and the ionisation energy 70 eV. 

Fig. 7.7. Stellar duo. The presence of a companion star can considerably perturb a star s evolution. Hence, mass transfer by accretion transforms a rather dull white dwarf into an erupting nova or a type la supernova. As an example, let us follow the life of a star with mass between 4 and 9 Mq and its little sister star with mass between 0.9 and 3 M , separated by a distance of between 1500 and 30000 Rq (where Rq is the solar radius). In childhood, the system is calm. The big star evolves more quickly than the small one, however, a universal feature of stellar evolution. It soon becomes an asymptotic giant, sweeping the companion star with its winds, and then a white dwarf. The oxygen- and carbon-built white dwarf shares an envelope with its partner and together they evolve beneath this cloak as one and the same star. The result is a pair comprising a white dwarf with mass between 0.9 and 1.2 M and a normal star with mass between 0.9 and 3 M , still evolving on the main sequence. The two components are separated by a distance of some 40-400 Rq, corresponding to a period of revolution of 30-800 days. The second star swells up and becomes a red giant. This is a boon for the dwarf. It captures the matter so generously donated. However, it cannot absorb it A tremendous wind is generated and, in the end, a cataclysmic explosion ensues. (After Nomoto et al. 2001.)...

Geldart DJW, Rasolt M (1992) In M.P. Das and D. Neilson (eds) Strongly Correlated Electron Systems. Nova Science, New York, p 123... 

Transient experiments also require that the analysis of the outlet gas mixture must be continuous this determines the choice of suitable gas analyzers with high time resolution, which should allow to monitor the temporal evolution of the largest possible number of species involved in the considered reactions. Measured composition dynamics typically need to be corrected for the transfer functions of the test rig and of the analyzers, as done, e.g. by Oh and Cavendish (1985), Siemund et al. (1996) and Nova et al. (2006a) on the basis of blank composition step change experiments. The important role of suitable gas analyzers in understanding the dynamic behavior of SCR systems is specifically discussed in (Ciardelli et al., 2007b). 

Classical nova (CN) and dwarf nova (DN) systems have the same binary components (a low-mass main sequence star and a white dwarf) and the same orbital periods. An important question that therefore arises is are these systems really different (and if so, what is the fundamental difference ) or, are these the same systems, metamorphosing from one class to the other ... 

The first thing to note in this respect is that the white dwarfs in DN systems are believed to accrete continuously (both at quiescence and during eruptions). At the same time, both analytic (e.g. Fujimoto 1982) and numerical calculations show, that when sufficient mass accumulates on the white dwarf, a thermonuclear runaway (TNR) is obtained and a nova outburst ensues (see e.g. reviews by Gallagher and Starrfield 1978, Truran 1982). It is thus only natural, to ask the question, is the fact that we have not seen a DN undergo a CN outburst (in about 50 years of almost complete coverage) consistent with observations of DN systems ... 

In an attempt to answer this question, we have calculated the probability for a nova outburst not to occur (in 50 years) in 86 DN systems (for which at least some of the orbital parameters are known). 

We used a mass-radius relation for white dwarfs. Based on (1) — (4) we found that the probability for a nova not to occur in 50 years in these systems is 0.78-0.84, with the range resulting from differences in mass radius relations. We therefore find, that the fact that a nova outburst has not been observed in these systems is not surprising and does not imply that DN and CN systems are different. Incidentally, the systems found most likely to undergo a CN outburst in the near future were ... 

The class of such systems includes V446 Her, Q Cyg, V3830 Sgr, Nova Vul (1979), WY Sge,.GK Per, BV Cen and V1017 Sgr (Livio 1987 and references therein). The problem with this observation lies in the fact that in the disk instability model for dn eruptions (Meyer and Meyer-Hofmeister 1983 Faulkner, Lin and Papaloizou 1983, Cannizzo and Wheeler 1984, Mineshige... 

THE CHEMICAL COMPOSITION OF THE WHITE DWARFS IN CATACLYSMIC VARIABLE SYSTEMS WHICH PRODUCE NOVAE... 

The Chemical Composition of the White Dwarfs in Cataclysmic Variable Systems Which Produce Novae... 

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