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Energy dependence of 209-Bi fragmentation in relativistic nuclear collisions
The results of cross-section measurements for the reactions 209Bi(12C,X)Au, E=4.8 and 25.2 GeV and 209Bi(20Ne,X)Au, E=8.0 GeV are reported. The observed yields of the gold isotopes show a similar dependence on mass number for each reaction, differing slightly in the position of the centroid of the distribution. As the projectile energy increases, the inferred excitation energy of the primary residues remains the same or decreases slightly. This observation is in agreement with the predictions of the intranuclear cascade model of relativistic heavy ion collisions.
NUCLEAR REACTIONS 209Bi(12C,X)Au, E=4.8,25.2 GeV; 209Bi(20Ne,X)Au, E=8.0 GeV; measured Au isotopic distributions, relativistic heavy ions, target fragmentation, Ge(Li) spectroscopy.
Energy dependence of 209-Bi fragmentation in relativistic nuclear collisions, , Physical Review C, 3/1981, Volume 23, Issue 3, p.1044 - 1046, (1981)Element 122?
Hard to know what to make of this as it is not my field. But here is a claim for element 122, or maybe 124, detection in thorium by a mass spectrometric method. The authors have claimed previously the observation of very heavy isotopes, for instance Rg isotopes in the mass spectra of natural gold.
Abstract: "Evidence for the existence of a superheavy nucleus with atomic mass number A=292 and abundance (1-10) x 10-12 relative to 232Th has been found in a study of natural Th using inductively coupled plasma-sector field mass spectrometry. The measured mass matches the predictions for the mass of an isotope with atomic number Z=122 or a nearby element. Its estimated half-life of t1/2 <= 108 y suggests that a long-lived isomeric
state exists in this isotope. The possibility that it might belong to a new class of long-lived high spin super- and hyperdeformed isomeric states is discussed."
Full reference: A. Marinov, I. Rodushkin, D. Kolb, A. Pape, Y. Kashiv, R. Brandt, R.V. Gentry, and H.W. Miller, "Evidence for a long-lived superheavy nucleus with atomic mass number A=292 and atomic number Z=~122 in natural Th", http://arxiv.org/abs/0804.3869v1. Submitted 24 April 2008.
Chemical characterization of element 112
Partial Abstract. Here we report a more reliable chemical characterization of element 112, involving the production of two atoms of 283112 through the alpha decay of the short-lived 287114 (which itself forms in the nuclear fusion reaction12 of 48Ca with 242Pu) and the adsorption of the two atoms on a gold surface. By directly comparing the adsorption characteristics of 283112 to that of mercury and the noble gas radon, we find that element 112 is very volatile and, unlike radon, reveals a metallic interaction with the gold surface. These adsorption characteristics establish element 112 as a typical element of group 12, and its successful production unambiguously establishes the approach to the island of stability of superheavy elements through 48Ca-induced nuclear fusion reactions with actinides.
Chemical characterization of element 112, , Nature, 5/2007, Volume 447, Issue 7140, p.72 - 75, (2007)Self-cleaning titania nanotube hydrogen sensors
The Science Blog reports that researchers at Penn State in the USA are developing self-cleaning titania nanotube hydrogen sensors. The hydrogen sensors are titania nanotubes coated with a discontinuous layer of palladium. Hydrogen sensors are widely used in the chemical, petroleum and semiconductor industries. They are also used as diagnostic tools to monitor certain types of bacterial infections.
"The photocatalytic properties of titania nanotubes are so large - a factor of 100 times greater than any other form of titania - that sensor contaminants are efficiently removed with exposure to ultraviolet light, so that the sensors effectively recover or retain their original hydrogen sensitivity in real world application"
"By doping the titania nanotubes with trace amounts of different metals such as tin, gold, silver, copper, niobium and others, a wide variety of chemical sensors can be made. This doping does not alter the photocatalytic properties of the titania nanotubes" says Dr. Craig A. Grimes, associate professor of Electrical Engineering and Materials Science and Engineering.1
- 1. A room-temperature titania-nanotube hydrogen sensor able to self-clean photoactively from environmental contamination,
, Journal of Materials Research, 02/2004, Volume 19, Issue 2, p.628?634, (2004)
