Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Fragment distributions resulting from $\mathrm{Au}+\mathrm{Au}$ collisions at an incident energy of $E/A\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}600\phantom{\rule{0ex}{0ex}}\mathrm{MeV}$ are studied. From the measured fragment and neutron distributions the mass and the excitation energy of the decaying prefragments were determined. A temperature scale was derived from observed yield ratios of He and Li isotopes. The relation between this isotope temperature and the excitation energy of the system exhibits a behavior which is expected for a phase transition. The nuclear vapor regime takes over at an excitation energy of 10 MeV per nucleon, a temperature of 5 MeV, and may be characterized by a density of 0.15--0.3 normal nuclear density.

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Probing the nuclear liquid-gas phase transition.

Recent experimental observations of the onset of calcium carbonate (CaCO3) mineralization suggest the emergence of a population of clusters that are stable rather than unstable as predicted by classical nucleation theory. This study uses molecular dynamics simulations to probe the structure, dynamics, and energetics of hydrated CaCO3 clusters and lattice gas simulations to explore the behavior of cluster populations before nucleation. Our results predict formation of a dense liquid phase through liquid-liquid separation within the concentration range in which clusters are observed. Coalescence and solidification of nanoscale droplets results in formation of a solid phase, the structure of which is consistent with amorphous CaCO3. The presence of a liquid-liquid binodal enables a diverse set of experimental observations to be reconciled within the context of established phase-separation mechanisms.

/pdf/microscopic-evidence-for-liquid-liquid-separation-in-54gka3oozk.pdf

Microscopic Evidence for Liquid-Liquid Separation in Supersaturated CaCO3 Solutions

Nuclear multifragmentation and phase transition for hot nuclei

When a shock wave interacts at a metal vacuum interface “ejected particulates” (ejecta) can be emitted from the surface. The mass, size, shape, and velocity of the ejecta varies depending on the initial shock conditions and the material properties of the metal sample. To understand this phenomena, experiments have been conducted at the Pegasus Pulsed Power Facility located at Los Alamos National Laboratory. For the experiments reported in this article, the facility is used to implode a cylinder to a velocity of 3.4 mm/μs. When this cylinder impacts a smaller diameter target cylinder, shock pressures of 30 and 40 GPa can be obtained in Al and Sn metals, respectively. Ejecta formation proceeds as the shock wave in the metal sample interacts at the metal vacuum interface. The size of the ejected particles is then measured using an in-line Fraunhofer holography technique. In this report, ejecta particle size distributions will be presented for shocked Al and Sn metals. The measured particle size distributions...

/pdf/ejecta-particle-size-distributions-for-shock-loaded-sn-and-5ap5hmkxq6.pdf

Ejecta particle size distributions for shock loaded Sn and Al metals

We predict that self-bound clusters of particles exist in the supercritical phase of simple fluids. These clusters define a percolation line that starts at the critical point. This line is energy invariant and should be physically observable.

Percolation line of self-bound clusters in supercritical fluids

We suggest a multifragmentation scenario in which fragments are pro- duced at an early, high temperature and high density, stage of the reaction. In this scenario, self-bound clusters of particles in the hot and dense uid are the precursors of the observed fragments. This solves a number of re- current problems concerning the kinetic energies and the temperature of the fragments, encountered with the standard low density fragmentation picture. The possibility to recover the initial thermodynamic parameters (T and ) from the inspection of the asymptotic fragment size and kinetic energy distributions is discussed.

“Little big bang” scenario of multifragmentation

The size and energy distributions of spectators in ALADIN fragmentation experiments with gold projectiles are inferred from experimental data. For the most violent collisions of Au on Cu, the mean projectile spectator has the size of an iron nucleus, with an excitation energy of about 23 MeV/nucleon. We claim that a correct interpretation of these data should take into account the large range covered by the extracted distributions, which are in good agreement with the prediction of the Boltzmann-Uheling-Uhlenbeck calculations and with those of a new diabatic abrasion model.

Size and excitation energy distributions of projectile spectators in multifragmentation data.

We propose a definition of droplets in the lattice-gas model that is based on a stability requirement. It leads to a percolation line in the supercritical region of the ρ – T diagram. According to numerical simulations, the excitation energy remains nearly constant along this line. These observations may be useful to understand the fragmentation of suddenly heated liquid drops, atomic clusters and nuclei.

On a definition of stable droplets in the lattice-gas model

We discuss the meaning of Zipf's law in nuclear multifragmentation. We remark that Zipf's law is a consequence of a power-law fragment size distribution with exponent {tau}{approx_equal}2. We also recall why the presence of such a distribution is not a reliable signal of a liquid-gas phase transition.

/pdf/zipf-s-law-in-multifragmentation-3ooi3qiejy.pdf

Hubert Krivine

Papers

Percolation line of self-bound clusters in supercritical fluids

“Little big bang” scenario of multifragmentation

Size and excitation energy distributions of projectile spectators in multifragmentation data.

On a definition of stable droplets in the lattice-gas model

Zipf's law in Multifragmentation