Heavy elements formation

Zagrebaev, V.I. New approach to description of fusion-fission dynamics in super-heavy element formation. J. Nucl. Radiochem. Sci. 3, 13-16 (2002)... 

Zagrebaev, V.I. Fusion-fission dynamics of super-heavy element formation and decay. Nucl. Phys. A734, 164-167 (2004)... 

The epoch and mode of galaxy formation are not well known, but both quasars and star-forming galaxies are known with redshifts up to about 7, corresponding to an era when the expanding Universe was only 1/8 of its present size, and the emission-line spectra of quasars indicate a large heavy-element abundance (solar or more Hamann Ferland 1999), suggesting prior stellar activity. The first stars, on the other hand, known as Population IIP, would have been devoid of metals whether they differed from normal stars in other basic characteristics, notably their mass distribution, is not known, since no completely metal-free stars have been... 

Figure 1 Schematic structures of micelle and liposome, their formation and loading with a contrast agent, (a) A micelle is formed spontaneously in aqueous media from an amphiphilic compound (1) that consists of distinct hydrophilic (2) and hydrophobic (3) moieties. Hydrophobic moieties form the micelle core (4). Contrast agent (asterisk gamma- or MR-active metal-loaded chelating group, or heavy element, such as iodine or bromine) can be directly coupled to the hydrophobic moiety within the micelle core (5), or incorporated into the micelle as an individual monomeric (6) or polymeric (7) amphiphilic unit, (b) A liposome can be prepared from individual phospholipid molecules (1) that consists of a bilayered membrane (2) and internal aqueous compartment (3). Contrast agent (asterisk) can be entrapped in the inner water space of the liposome as a soluble entity (4) or incorporated into the liposome membrane as a part of monomeric (5) or polymeric (6) amphiphilic unit (similar to that in case of micelle). Additionally, liposomes can be sterically protected by amphiphilic derivatization with PEG or PEG-like polymer (7) [1].

When were the atoms that became our solar system synthesized The star formation rate in the galaxy was highest early in galactic history and a lot of heavy elements were produced. However, most of this material was subsequently incorporated into stars, and much of that has been permanently sequestered. On the other hand, much of the recently synthesized material has not yet been incorporated into a new generation of stars. This balance between synthesis and sequestration means that the birth dates of the elements that became the solar system are roughly evenly distributed over the 7.5 Gyr of galactic history prior to the solar system s birth (Clayton, 1988). 

The examples in Table III, show that the hydrogen atoms occupy tetrahedral holes at the beginning of the transition series. As we move along the transition series, we observe the interstitial hydride shift toward octahedral holes and the hydrides of the heavier elements become progressively unstable. Palladium is exceptional since it is the only heavy element of group VIII that gives a simple hydride. Hydride formation is accompanied in most cases by a change in metallic lattice type and in all cases by a considerable increase in metal-metal distances. 

To give one a feel for the magnitude of the quantities involved, we outline below a very simple schematic method for estimating heavy-element production cross sections. It is intended to show the relevant factors and should not be taken too seriously, except to indicate the order of magnitude of a particular formation cross section. 

It was the formation of stars and then second-generation stars (such as our sun) with rocky planets that made life as we know it possible. Entropy still applied, yet the Universe became habitable in the period (which continues today) succeeding that first eon when it would have seemed entropic death was already gripping the Universe. Life was made possible by the nucleosynthesis of heavy elements and the condensation of solids and formation of planets where aqueous fluids could exist. 

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