Trees suck. Notes on the physics of transpiration in trees.

The Cohesion Theory of the ascent of water in trees is a quiet triumph of modern science. Besides hydrodynamics, the physics of transpiration involves capillarity, evaporation and osmosis - phenomena which all have a history of considerable theoretical confusion. The aim of this paper is to supplement existing accounts of this physics in the plant science literature.

The role of molybdenum in suppressing cold dwell fatigue in titanium alloys.

We test a hypothesis to explain why Ti-6242 is susceptible to cold dwell fatigue (CDF), whereas Ti-6246 is not. The hypothesis is that, in Ti-6246, substitutional Mo-atoms in α-Ti grains trap vacancies, thereby limiting creep relaxation. In Ti-6242, this creep relaxation enhances the loading of grains unfavourably oriented for slip and they subsequently fracture.

Nanocrystalline copper films are never flat.

We used scanning tunneling microscopy to study low-angle grain boundaries at the surface of nearly planar copper nanocrystalline (111) films. The presence of grain boundaries and their emergence at the film surface create valleys composed of dissociated edge dislocations and ridges where partial dislocations have recombined. Geometric analysis and simulations indicated that valleys and ridges were created by an out-of-plane grain rotation driven by reduction of grain boundary energy.

Elastodynamic image forces on dislocations.

The elastodynamic image forces on edge and screw dislocations in the presence of a planar-free surface are derived. The explicit form of the elastodynamic fields of an injected, quiescent screw dislocation are also derived. The resulting image forces are affected by retardation effects: the dislocations experience no image force for a period of time defined by the arrival and reflection at the free surface of the dislocation fields.

Attenuation of the dynamic yield point of shocked aluminum using elastodynamic simulations of dislocation dynamics.

When a metal is subjected to extremely rapid compression, a shock wave is launched that generates dislocations as it propagates. The shock wave evolves into a characteristic two-wave structure, with an elastic wave preceding a plastic front. It has been known for more than six decades that the amplitude of the elastic wave decays the farther it travels into the metal: this is known as "the decay of the elastic precursor.

General practitioners' conflicts of interest, the paramountcy principle and safeguarding children: a psychodynamic contribution.

Wainwright and Gallagher propose that when child protection concerns emerge significant difficulties arise for General Practitioners because of conflicts between the individual interests of children and parents who are their patients and the Paramountcy Principle. From a psychodynamic perspective their analysis does not give sufficient weight to the nature of personal as opposed to interpersonal conflict of a conscious or unconscious nature. When issues of major import arise, ordinary parenting inevitably involves parents in putting their children's needs first if competing possibilities occur.

A genetic algorithm for predicting the structures of interfaces in multicomponent systems.

Recent years have seen great advances in our ability to predict crystal structures from first principles. However, previous algorithms have focused on the prediction of bulk crystal structures, where the global minimum is the target. Here, we present a general atomistic approach to simulate in multicomponent systems the structures and free energies of grain boundaries and heterophase interfaces with fixed stoichiometric and non-stoichiometric compositions.

Promoting interdisciplinarity through educational initiative: a qualitative evaluation.

This paper describes a multi-professional teaching innovation that took place at The University of Manchester during October 2001. Ideas for the project were first established in December 2000 when a multi-professional team of educationalists began exploring ways in which three disparate student groups could be brought together as part of an integrated learning activity (). For this reason, a problem-based learning scenario was developed to encourage nursing, midwifery, and medical students to share their previous knowledge and principles of care.

Computational steering in Monte Carlo simulations of thin film polystyrene.

High molecular weight polymer systems show very long relaxation times, of the order of milliseconds or more. This time-scale proves practically inaccessible for atomic-scale dynamical simulation such as molecular dynamics. Even with a Monte Carlo (MC) simulation, the generation of statistically independent configurations is non-trivial.

Interprofessional education in a midwifery curriculum: the learning through the exploration of the professional task project (LEAPT).

Objective: to develop interprofessional education for students of midwifery, nursing and medicine. To foster collaborative working and learning between students of midwifery, nursing and medicine.

Design: a quasi-experimental method to evaluate the outcomes of an intervention (a problem-based learning (PBL) scenario) with interprofessional students and facilitators.