Process Elements

Artificial Neural Networks. An Artificial Neural Network (ANN) consists of a network of nodes (processing elements) connected via adjustable weights [Zurada, 1992]. The weights can be adjusted so that a network learns a mapping represented by a set of example input/output pairs. An ANN can in theory reproduce any continuous function 95 —>31 °, where n and m are numbers of input and output nodes. In NDT neural networks are usually used as classifiers... 

Manufacture of friction elements includes the impregnation of fabrics and subsequent lamination, the wet-dough process, and the dry-mix process. Elements from the last two are prepared by compression-molding the formulation for up to an hour at 150—175°C. Thick brake elements require a carefully controUed heating-and-cooHng cycle to minimize stresses created by expansion and contraction (see Brake linings and clutch facings Fillers). 

With few exceptions, treatment technologies are limited to some extent by the size of the material that they are able to process. These limitations can apply to the throat of the feed devices, the inner workings of the equipment, the treatment mechanisms, or the process elements. To make these remedial technologies efficient and cost effective, separation techniques are used to make the feed stream uniform... 

Due to the direct contact of water with various species, the aqueous streams are laden with various compounds including methanol, non-process elements NPEs, and organic and inorganic species. In this problem, we focus on methanol as the pimary species in water. Methanol is classified as a high priority pollutant for the pulping industry. In addition, it may provide a source of revenue if properly recovered. 

Nasae,/. wetness, moisture, humidity. Nass-echtheit, /. fastness to wetting or wet processing, -element, n. (Elec.) wet cell, wet battery. 

Only additional abundance studies, of both clusters and the field, and the inclusion of additional elements, such as the r- and s-process elements will tell. Fortunately, there are efforts underway, many of them described at this conference, that promise some answers to these questions. 

Linked to 1) is of course the enrichment of the interstellar medium, to which they are important contributors in nuclearly processed elements as He, C, N, s-elements (Ba etc). Goal 2) can be pursued with nuclearly unprocessed elements , the best accessible of them being O, Ne, Ar and S. 

Barium stars were recognized as a distinct group of peculiar stars by [1], The objects initially included in this group were red giants of spectral type G and K, which showed strong lines of s-process elements, particularly Ba II and Sr II, as well as enhanced CH, CN and C2 bands. The discovery that HR 107, a dwarf star, shows a composition similar to that of a mild Barium giant by [6] has pushed the search for new Barium dwarfs. 

The relation between s- and r-process for a sample of Barium stars are showed, using europium as representative of r-process, since it is a nearly pure r-process element, and La and Ba as representatives of s-process. 

Comparison of GCE model parameters with production ratio data from the literature Tq = 9.9 3.5 Gyr. The high uncertainty reflects the difficulties of estimating theoretically the production ratio of r-process elements, whose production sites are not well known. 

The discussion on abundances will focus on metallicities, a- and r-process elements, as probes of the nucleosynthesis history in the bulge, and timescale of bulge formation. 

Summarizing, we can consider various mass ranges of candidate polluters. Stars with 1.2 < M < 3-5 Mq are the classical donors of CH stars, but this is unlikely since they are very scarce in GCs and moreover they would produce also s—process elements, not observed to vary in unevolved GC stars ([13]). 

It is important to note that we have tried to avoid carbon-rich stars, because they have a rich molecular line spectrum, mostly CN, CH and C2, obliterating many interesting atomic lines of rare elements. This is why we had in our sample a star, CS 31082-001, in which we were able to measure the 385.97 nm line of U II, whereas in the similar r-process element enriched star CS 22892-052, but carbon rich, a CN line obliterates the U II line. 

Fig. la shows the abundance ratio [Ba/Fe] for this sample as a function of [C/Fe]. Thirty stars (77% of the sample) have [Ba/Fe] > +0.7, while the others have [Ba/Fe] < 0.0. There is a clear gap in the Ba abundances between the two groups, suggesting at least two different origins of the carbon excesses. Ba-enhanced stars The Ba-enhanced stars exhibit a correlation between the Ba and C abundance ratios (Fig. la). This fact suggests that carbon was enriched in the same site as Ba. The Ba excesses in these objects presumably originated from the s-process, rather than the r-process, because (1) nine stars in this group for which detailed abundance analysis is available clearly show abundance patterns associated with the s-process [2], and (2) there is no evidence of an r-process excess in the other 21 objects. Hence, the carbon enrichment in these objects most likely arises from Asymptotic Giant Branch (AGB) stars, which are also the source of the s-process elements. 

Since most (if not all) low-metallicity objects that are currently observed in the halo are not in the AGB phase, material enriched in carbon and the s-process elements is assumed to have accreted from the companion AGB stars, which have already evolved to faint white dwarfs, to the surface of the surviving companion. This scenario is the same as that applied to classical CH stars [4], Unfortunately, long-term radial velocity monitoring has been obtained for only a limited number of objects a clear binarity signature has been established for six objects in our sample to date. However, there exists additional support for the mass-accretion scenario for the Ba-rich CEMP stars. Fig. lb shows [C/H] as a function of luminosity roughly estimated from the effective temperature... 

Abstract. Observed large scatters in abundances of neutron-capture elements in metal-poor stars suggest that they are enriched a single or a few supernovae. Comparing predictions by an inhomogeneous chemical evolution model and new observational results with Subaru HDS, we attempt to constrain the origins of r-process elements. 

Massive stars (M > 10Mq) we have adopted Nomoto et al. (1997). They produce a-elements (O, Ne, Mg, Si, S, Ca), some Fe-peak elements, s-process elements (A < 90) and r-process elements. 

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