Modelled ocean changes at the Plio-Pleistocene transition driven by Antarctic ice advance

The Earth underwent a major transition from the warm climates of the Pliocene to the Pleistocene ice ages between 3.2 and 2.6 million years ago. The intensification of Northern Hemisphere Glaciation is the most obvious result of the Plio-Pleistocene transition. However, recent data show that the ocean also underwent a significant change, with the convergence of deep water mass properties in the North Pacific and North Atlantic Ocean. Here we show that the lack of coastal ice in the Pacific sector of Antarctica leads to major reductions in Pacific Ocean overturning and the loss of the modern North Pacific Deep Water (NPDW) mass in climate models of the warmest periods of the Pliocene. These results potentially explain the convergence of global deep water mass properties at the Plio-Pleistocene transition, as Circumpolar Deep Water (CDW) became the common source

Coupling of CFD and semiempirical methods for designing three-phase condensate separator: case study and experimental validation

This study presents an approach to determine the dimensions of three-phase separators. First, we designed different vessel configurations based on the fluid properties of an Iranian gas condensate field. We then used a comprehensive computational fluid dynamic (CFD) method for analyzing the three-phase separation phenomena. For simulation purposes, the combined volume of fluid–discrete particle method (DPM) approach was used. The discrete random walk (DRW) model was used to include the effect of arbitrary particle movement due to variations caused by turbulence. In addition, the comparison of experimental and simulated results was generated using different turbulence models, i.e., standard k–ε, standard k–ω, and Reynolds stress model. The results of numerical calculations in terms of fluid profiles, separation performance and DPM particle behavior were used to choose the optimum vessel configuration. No difference between the dimensions of the optimum vessel and the existing separator was found. Also, simulation data were compared with experimental data pertaining to a similar existing separator. A reasonable agreement between the results of numerical calculation and experimental data was observed. These results showed that the used CFD model is well capable of investigating the performance of a three-phase separator

Rarities in rare : illuminating the microvascular and dermal status in juvenile localised scleroderma : a case series

Objective. To assess the (structural and functional) characteristics of the microvascular and dermal status in juvenile localised scleroderma (jLoS), using novel non-invasive standardised research tools commonly used in adult systemic sclerosis (SSc). Methods. Ten consecutive patients with a confirmed jLoS diagnosis were studied cross-sectionally in this two-centre case series. For each patient, the most prominent lesion (i.e. "target lesion") was chosen for further examination of the centre, edge and contralateral unaffected site. High-frequency ultrasonography was used to determine dermal thickness, durometer for skin hardness, and laser speckle contrast analysis (LASCA) for a dynamical evaluation of the microcirculation. The structure of the microcirculation was evaluated at the nailfolds of the 2nd-5th finger bilaterally, using nailfold videocapillaroscopy (NVC). Results. 6 linear and 4 plaque subtype jLoS lesions were included. Dermal thickness was thinner at the centre of the "target lesions"vs. the edges (p<0.001) and control sites (p<0.001). Skin hardness was harder at the centre of the "target lesions"vs. the edges (p=0.012) and control sites (p=0.003). A higher perfusion was found in the centre of the "target lesion"(124.87±66.40 PU) vs. the edges (87.27±46.40 PU; p<0.001) and control sites (67.85±37.49; p<0.001). Of note, all patients had a "non-scleroderma"pattern on NVC. Conclusion. This case series suggests the supportive value of both microcirculatory and dermal assessments of skin lesions using novel non-invasive research tools, adopted from adult SSc, for (j)LoS