Industrial structural geology : principles, techniques and integration : an introduction

The authors wish to acknowledge the generous financial support provided in association with this volume to the Geological Society and the Petroleum Group by Badley Geoscience Ltd, BP, CGG Robertson, Dana Petroleum Ltd, Getech Group plc, Maersk Oil North Sea UK Ltd, Midland Valley Exploration Ltd, Rock Deformation Research (Schlumberger) and Borehole Image & Core Specialists (Wildcat Geoscience, Walker Geoscience and Prolog Geoscience). We would like to thank the fine team at the Geological Society’s Publishing House for the excellent support and encouragement that they have provided to the editors and authors of this Special Publication.Peer reviewedPublisher PD

Improving efficiency of coupled schemes for Navier--Stokes equations by a connection to grad-div stabilized projection methods

We prove that in finite element settings where the divergence-free subspace of the velocity space has optimal approximation properties, the solution of Chorin/Temam projection methods for Navier-Stokes equations equipped with grad-div stabilization with parameter γ, converge to the associated coupled method solution with rate γ-1 as γ → ∞. We prove this first for backward Euler schemes, and then extend the results to BDF2 schemes, and finally to schemes with outflow boundary conditions. Several numerical experiments are given which verify the convergence rate, and show how using projection methods in this setting with large grad-div stabilization parameters can dramatically improve accuracy

Stabilizing poor mass conservation in incompressible flow problems with large irrotational forcing and application to thermal convection

We consider the problem of poor mass conservation in mixed finite element algorithms for flow problems with large rotation-free forcing in the momentum equation. We provide analysis that suggests for such problems, obtaining accurate solutions necessitates either the use of pointwise divergence-free finite elements (such as Scott-Vogelius), or heavy grad-div stabilization of weakly divergence-free elements. The theory is demonstrated in numerical experiments for a benchmark natural convection problem, where large irrotational forcing occurs with high Rayleigh numbers

Stable computing with an enhanced physics based scheme for the 3D Navier--Stokes equations

We study extensions of an earlier developed energy and helicity preserving scheme for the 3D Navier-Stokes equations and apply them to a more general class of problems. The scheme is studied together with stabilizations of grad-div type in order to mitigate the effect of the Bernoulli pressure error on the velocity error. We prove stability, convergence, discuss conservation properties, and present numerical experiments that demonstrate the advantages of the scheme

The Mass Function of Super Giant Molecular Complexes and Implications for Forming Young Massive Star Clusters in the Antennae (NGC 4038/39)

We have used previously published observations of the CO emission from the Antennae (NGC 4038/39) to study the detailed properties of the super giant molecular complexes with the goal of understanding the formation of young massive star clusters. Over a mass range from 5E6 to 9E8 solar masses, the molecular complexes follow a power-law mass function with a slope of -1.4 +/- 0.1, which is very similar to the slope seen at lower masses in molecular clouds and cloud cores in the Galaxy. Compared to the spiral galaxy M51, which has a similar surface density and total mass of molecular gas, the Antennae contain clouds that are an order of magnitude more massive. Many of the youngest star clusters lie in the gas-rich overlap region, where extinctions as high as Av~100 imply that the clusters must lie in front of the gas. Combining data on the young clusters, thermal and nonthermal radio sources, and the molecular gas suggests that young massive clusters could have formed at a constant rate in the Antennae over the last 160 Myr and that sufficient gas exists to sustain this cluster formation rate well into the future. However, this conclusion requires that a very high fraction of the massive clusters that form initially in the Antennae do not survive as long as 100 Myr. Finally, we compare our data with two models for massive star cluster formation and conclude that the model where young massive star clusters form from dense cores within the observed super giant molecular complexes is most consistent with our current understanding of this merging system. (abbreviated)Comment: 40 pages, four figures; accepted for publication in Ap

High-Resolution Imaging of Molecular Gas and Dust in the Antennae (NGC 4038/39): Super Giant Molecular Complexes

We present new aperture synthesis CO maps of the Antennae (NGC 4038/39) obtained with the Caltech Millimeter Array. These sensitive images show molecular emission associated with the two nuclei and a partial ring of star formation to the west of NGC 4038, as well as revealing the large extent of the extra-nuclear region of star formation (the ``overlap region''), which dominates the CO emission from this system. The largest molecular complexes have masses of 3-6x10^8 M_sun, typically an order of magnitude larger than the largest structures seen to date in more quiescent galaxy disks. The extremely red luminous star clusters identified previously with HST are well-correlated with the CO emission, which supports the conclusion that they are highly embedded young objects rather than old globular clusters. There is an excellent correlation between the CO emission and the 15 micron emission seen with ISO, particularly for the brightest regions. The most massive complexes in the overlap region have similar [NeIII]/[NeII] ratios, which implies that all these regions are forming many massive stars. However, only the brightest mid-infrared peak shows strong, rising continuum emission longward of 10 microns, indicative of very small dust grains heated to high temperatures by their proximity to nearby luminous stars. Since these grains are expected to be removed rapidly from the immediate environment of the massive stars, it is possible that this region contains very young (< 1 Myr) sites of star formation. Alternatively, fresh dust grains could be driven into the sphere of influence of the massive stars, perhaps by the bulk motions of two giant molecular complexes. The kinematics and morphology of the CO emission in this region provide some support for this second scenario.Comment: Accepted for publication in The Astrophysical Journal, 13 pages, 5 figures, higher quality color images available at http://www.astro.cornell.edu/staff/vassilis/papers/ngc4038_co.ps.g

Multivariate models from RNA-Seq SNVs yield candidate molecular targets for biomarker discovery: SNV-DA

Breast: up and downstream SNVs model. (CSV 22.1 kb

'Magic coins' and 'magic squares': the discovery of astrological sigils in the Oldenburg Letters

Enclosed in a 1673 letter to Henry Oldenburg were two drawings of a series of astrological sigils, coins and amulets from the collection of Strasbourg mathematician Julius Reichelt (1637–1719). As portrayals of particular medieval and early modern sigils are relatively rare, this paper will analyse the role of these medals in medieval and early modern medicine, the logic behind their perceived efficacy, and their significance in early modern astrological and cabalistic practice. I shall also demonstrate their change in status in the late seventeenth century from potent magical healing amulets tied to the mysteries of the heavens to objects kept in a cabinet for curiosos. The evolving perception of the purpose of sigils mirrored changing early modern beliefs in the occult influences of the heavens upon the body and the natural world, as well as the growing interests among virtuosi in collecting, numismatics and antiquities