Petroleum generation and migration in the Cambro-Ordovician Laurentian margin succession of NW Scotland

NERC are thanked for continued funding of the Argon Isotope Facility, which is housed at SUERC. We are grateful to B. Fulton, J. Johnston and C. Taylor for skilled technical help. DM was in receipt of a NERC PhD studentship. A.G. Leslie and H. Volk provided critical comments that helped to improve the manuscript.Peer reviewedPublisher PD

Internal ballistics model update for ASRM dome

A previous report (no. 5-32279, contract NAS8-36955, DO 51) describes the measures taken to adapt the NASA Complex Burning Region Model and code so that is was applicable to the Advanced Solid Rocket Motor as envisioned at that time. The code so modified was called the CBRM-A. CBRM-A could calculate the port volume and burning area for the star, transition, and cylindrically perforated regions of the motor. Described here is a subsequent effort to add computation of port volume and burning area for the Advanced Solid Rocket Motor head dome. Sample output, input, and overview of the models are included. The software was configured in two forms - a stand alone head dome code and a code integrating the head dome solution with the CBRM-A

Waveguide mode imaging and dispersion analysis with terahertz near-field microscopy

Propagation of terahertz waves in hollow metallic waveguides depends on the waveguide mode. Near-field scanning probe terahertz microscopy is applied to identify the mode structure and composition in dielectric-lined hollow metallic waveguides. Spatial profiles, relative amplitudes, and group velocities of three main waveguide modes are experimentally measured and matched to the HE11, HE12, and TE11 modes. The combination of near-field microscopy with terahertz time-resolved spectroscopy opens the possibility of waveguide mode characterization in the terahertz band

Aesthetic Perception, Attention and Aesthetic Psychology

What are the psychological foundations of aesthetic experience? Disagreements about how to answer this question underlie tensions between the experiences described by those in the developing field of everyday aesthetics and many art-centred accounts of aesthetic experience. I argue that neither has provided the psychological framework to support their arguments in favour of or against the extension of aesthetic experience into everyday life. Such a framework is required in order to reconcile the two fields. This thesis aims to develop an empirically informed aesthetic psychology which accommodates both everyday and paradigmatic aesthetic experience without compromising what is distinctive about each. In order to understand the oft-unacknowledged assumptions in everyday and mainstream accounts of aesthetic experience I distinguish between “broad” and “narrow” aesthetic psychology. I argue that each approach differs with respect to the necessity of attention for aesthetic experience. The narrow approach to aesthetic psychology underlies many contemporary accounts and places an “attention condition” on aesthetic experience; the broad approach underlies many accounts of everyday aesthetic experience and involves no such condition. I develop a broad psychological account of aesthetic perception as the perceptual representation of bound qualities and suggest that its minimal or “bare” form goes on in the absence of attention, whilst its “rich” form requires attention and supports characteristically appreciative activities of mind. Using contemporary empirical and philosophical work on attention and its relation to consciousness and cognition I argue that there is an attention condition on rich aesthetic perception (and aesthetic appreciation), but not on bare aesthetic perception: this establishes a broad aesthetic psychology. In this way I reconcile everyday and mainstream aesthetic experience by creating a continuum of aesthetic engagement which runs from the fleeting and unattended experiences of broad aesthetic psychology to the complex and appreciative experiences of narrow aesthetic psychology

Stiffness of Contacts Between Rough Surfaces

The effect of self-affine roughness on solid contact is examined with molecular dynamics and continuum calculations. The contact area and normal and lateral stiffnesses rise linearly with the applied load, and the load rises exponentially with decreasing separation between surfaces. Results for a wide range of roughnesses, system sizes and Poisson ratios can be collapsed using Persson's contact theory for continuous elastic media. The atomic scale response at the interface between solids has little affect on the area or normal stiffness, but can greatly reduce the lateral stiffness. The scaling of this effect with system size and roughness is discussed.Comment: 4 pages, 3 figure

Survival of Organic Materials in Hypervelocity Impacts of Ice on Sand, Ice, and Water in the Laboratory

The survival of organic molecules in shock impact events has been investigated in the laboratory. A frozen mixture of anthracene and stearic acid, solvated in dimethylsulfoxide (DMSO), was fired in a two-stage light gas gun at speeds of ?2 and ?4?km s?1 at targets that included water ice, water, and sand. This involved shock pressures in the range of 2–12 GPa. It was found that the projectile materials were present in elevated quantities in the targets after impact and in some cases in the crater ejecta as well. For DMSO impacting water at 1.9?km s?1 and 45° incidence, we quantify the surviving fraction after impact as 0.44±0.05. This demonstrates successful transfer of organic compounds from projectile to target in high-speed impacts. The range of impact speeds used covers that involved in impacts of terrestrial meteorites on the Moon, as well as impacts in the outer Solar System on icy bodies such as Pluto. The results provide laboratory evidence that suggests that exogenous delivery of complex organic molecules from icy impactors is a viable source of such material on target bodies

Propyl­amine–borane

The title compound, C3H12BN, was solved using data collected from a multiple crystal (note incomplete data shell). The cell packing is dominated by bifurcated attractive N—Hδ+⋯δ−H—B inter­actions

Contact area of rough spheres: Large scale simulations and simple scaling laws

We use molecular simulations to study the nonadhesive and adhesive atomic-scale contact of rough spheres with radii ranging from nanometers to micrometers over more than ten orders of magnitude in applied normal load. At the lowest loads, the interfacial mechanics is governed by the contact mechanics of the first asperity that touches. The dependence of contact area on normal force becomes linear at intermediate loads and crosses over to Hertzian at the largest loads. By combining theories for the limiting cases of nominally flat rough surfaces and smooth spheres, we provide parameter-free analytical expressions for contact area over the whole range of loads. Our results establish a range of validity for common approximations that neglect curvature or roughness in modeling objects on scales from atomic force microscope tips to ball bearings.Comment: 2 figures + Supporting Materia

There and Back Again: Self-supervised Multispectral Correspondence Estimation

Across a wide range of applications, from autonomous vehicles to medical imaging, multi-spectral images provide an opportunity to extract additional information not present in color images. One of the most important steps in making this information readily available is the accurate estimation of dense correspondences between different spectra. Due to the nature of cross-spectral images, most correspondence solving techniques for the visual domain are simply not applicable. Furthermore, most cross-spectral techniques utilize spectra-specific characteristics to perform the alignment. In this work, we aim to address the dense correspondence estimation problem in a way that generalizes to more than one spectrum. We do this by introducing a novel cycle-consistency metric that allows us to self-supervise. This, combined with our spectra-agnostic loss functions, allows us to train the same network across multiple spectra. We demonstrate our approach on the challenging task of dense RGB-FIR correspondence estimation. We also show the performance of our unmodified network on the cases of RGB-NIR and RGB-RGB, where we achieve higher accuracy than similar self-supervised approaches. Our work shows that cross-spectral correspondence estimation can be solved in a common framework that learns to generalize alignment across spectra