89 research outputs found
Inelaticity in hadron-nucleus collisions from emulsion chamber studies
The inelasticity of hadron-carbon nucleus collisions in the energy region
exceeding 100 TeV is estimated from the carbon-emulsion chamber data at Pamirs
to be . When combined with the recently presented data on
hadron-lead nucleus collisions taken at the same energy range it results in the
mass number dependence of inelasticity. The evaluated partial
inelasticity for secondary () interactions, ,
suggests that the second and higher interactions of the excited hadron inside
the nucleus proceed with only slight energy losses.Comment: LaTeX file and 5 LaTeX files with figures, 11 pages altogether.
Thoroughly rewritten and modified, one figure addded one removed. To be
published in Phys. Rev.
Cross-shelf exchange in the northwestern Black Sea
The transports of water, heat, and salt between the northwestern shelf and deep interior of the Black Sea are investigated using a high-resolution three-dimensional primitive equation model. From April to August 2005, both onshore and offshore cross-shelf break transports in the top 20 m were 0.24 Sv on average, which is equivalent to the replacement of 60% of the volume of surface shelf waters (0–20 m) per month. Two main exchange mechanisms are studied: Ekman transport, and transport by mesoscale eddies and associated meanders of the Rim Current. The Ekman drift causes nearly uniform onshore or offshore flow over a large section of the shelf break, but it is confined to the upper layers. In contrast, eddies and meanders penetrate deep down to the bottom, but they are restricted laterally. During the strong wind events of 15–22 April and 1–4 July, some 0.66 × 1012 and 0.44 × 1012 m3 of water were removed from the northwestern shelf, respectively. In comparison, the single long-lived Sevastopol Eddy generated a much larger offshore transfer of 2.84 × 1012 m3 over the period 23 April to 30 June, which is equivalent to 102% of the volume of northwestern shelf waters. Over the study period, salt exchanges increased the average density of the shelf waters by 0.67 kg m−3 and reduced the density contrast between the shelf and deep sea, while lateral heat exchanges reduced the density of the shelf waters by 0.16 kg m−3 and sharpened the shelf break front
Models for Metal Hydride Particle Shape, Packing, and Heat Transfer
A multiphysics modeling approach for heat conduction in metal hydride powders
is presented, including particle shape distribution, size distribution,
granular packing structure, and effective thermal conductivity. A statistical
geometric model is presented that replicates features of particle size and
shape distributions observed experimentally that result from cyclic hydride
decreptitation. The quasi-static dense packing of a sample set of these
particles is simulated via energy-based structural optimization methods. These
particles jam (i.e., solidify) at a density (solid volume fraction) of
0.665+/-0.015 - higher than prior experimental estimates. Effective thermal
conductivity of the jammed system is simulated and found to follow the behavior
predicted by granular effective medium theory. Finally, a theory is presented
that links the properties of bi-porous cohesive powders to the present systems
based on recent experimental observations of jammed packings of fine powder.
This theory produces quantitative experimental agreement with metal hydride
powders of various compositions.Comment: 12 pages, 12 figures, 2 table
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