Phase-field approach to heterogeneous nucleation

We consider the problem of heterogeneous nucleation and growth. The system is described by a phase field model in which the temperature is included through thermal noise. We show that this phase field approach is suitable to describe homogeneous as well as heterogeneous nucleation starting from several general hypotheses. Thus we can investigate the influence of grain boundaries, localized impurities, or any general kind of imperfections in a systematic way. We also put forward the applicability of our model to study other physical situations such as island formation, amorphous crystallization, or recrystallization.Comment: 8 pages including 7 figures. Accepted for publication in Physical Review

Human factors aspects of control room design: Guidelines and annotated bibliography

A human factors analysis of the workstation design for the Earth Radiation Budget Satellite mission operation room is discussed. The relevance of anthropometry, design rules, environmental design goals, and the social-psychological environment are discussed

The Commodification of Public Land Records

The United States deed recording system alters the “first in time, first in right” doctrine to enable good faith purchasers to record their deeds to protect themselves against prior unrecorded conveyances and to provide constructive notice of their interests to potential subsequent purchasers. Constructive notice, however, works only when land records are available for public inspection, a practice that had long proved uncontroversial. For centuries, deed archives were almost exclusively patronized by land-transacting parties because the difficulty and cost of title examination deterred nearly everyone else. The modern information economy, however, propelled this staid corner of property law into a computer age in which land records are electronically maintained and instantaneously accessible over the internet. That development transformed public land records into a marketable commodity independent of the deed recording system’s notice-giving function. In response to booming demand for big data, content extracted from public land records (name, home address, marital status, among other personal information) is now actively traded on the internet and routinely purchased by commercial firms for targeted marketing and customer prospecting. Data from public land records are now more accessible than ever before, representing a win for transparency, but, as tragically illustrated by the recent high-profile attack against a federal judge, an erosion of privacy that can dangerously equip wrongdoers with on-demand entrée to personal information. This Article provides the first scholarly account of the deed recording system’s transformation from a notice-giving mechanism of property law to a primary supplier of commodified data for sale in the modern information economy. The Article surveys the traditional functions of deed recording, describes the recent migration of deeds from paper to electronic form as the predicate for commodification, and considers the implications of electronic disclosure for privacy, transparency, and the regulation of anonymous entity ownership. The Article concludes by appraising the efficacy of recent privacy reforms under consideration by Congress and state legislatures, and by outlining voluntary precautions that homeowners can implement under existing law

Neutron-diffraction study of field-induced transitions in the heavy-fermion compound Ce2RhIn8

We present neutron diffraction measurements in high magnetic fields (0 to 14.5 T) and at low temperatures (2.5, 2.3, 0.77 and 0.068 K) on single crystals of the tetragonal heavy fermion antiferromagnet Ce2RhIn8. For B//[110] the field dependence of selected magnetic and nuclear reflections reveals that the material undergoes several transitions, the temperature dependence of which suggests a complex B-T phase diagram. We present the detailed evolution of the integrated intensities of selected reflections and discuss the associated field-induced transitions.Comment: 12 pages, 3 figures Proceeding Euro-conference "Properties of Condensed Matter probed by x-ray and neutron scattering"; to appear in Physica

Removal of terrestrial DOC in aquatic ecosystems of a temperate river network

Surface waters play a potentially important role in the global carbon balance. Dissolved organic carbon (DOC) fluxes are a major transfer of terrestrial carbon to river systems, and the fate of DOC in aquatic systems is poorly constrained. We used a unique combination of spatially distributed sampling of three DOC fractions throughout a river network and modeling to quantify the net removal of terrestrial DOC during a summer base flow period. We found that aquatic reactivity of terrestrial DOC leading to net loss is low, closer to conservative chloride than to reactive nitrogen. Net removal occurred mainly from the hydrophobic organic acid fraction, while hydrophilic and transphilic acids showed no net change, indicating that partitioning of bulk DOC into different fractions is critical for understanding terrestrial DOC removal. These findings suggest that river systems may have only a modest ability to alter the amounts of terrestrial DOC delivered to coastal zones

The asymptotic quasi-stationary states of the two-dimensional magnetically confined plasma and of the planetary atmosphere

We derive the differential equation governing the asymptotic quasi-stationary states of the two dimensional plasma immersed in a strong confining magnetic field and of the planetary atmosphere. These two systems are related by the property that there is an intrinsic constant length: the Larmor radius and respectively the Rossby radius and a condensate of the vorticity field in the unperturbed state related to the cyclotronic gyration and respectively to the Coriolis frequency. Although the closest physical model is the Charney-Hasegawa-Mima (CHM) equation, our model is more general and is related to the system consisting of a discrete set of point-like vortices interacting in plane by a short range potential. A field-theoretical formalism is developed for describing the continuous version of this system. The action functional can be written in the Bogomolnyi form (emphasizing the role of Self-Duality of the asymptotic states) but the minimum energy is no more topological and the asymptotic structures appear to be non-stationary, which is a major difference with respect to traditional topological vortex solutions. Versions of this field theory are discussed and we find arguments in favor of a particular form of the equation. We comment upon the significant difference between the CHM fluid/plasma and the Euler fluid and respectively the Abelian-Higgs vortex models.Comment: Latex 126 pages, 7 eps figures included. Discussion on various forms of the equatio

Reducing weight and increasing physical activity in people at high risk of cardiovascular disease: a randomised controlled trial comparing the effectiveness of enhanced motivational interviewing intervention with usual care.

OBJECTIVE: The epidemic of obesity is contributing to the increasing prevalence of people at high risk of cardiovascular disease (CVD), negating the medical advances in reducing CVD mortality. We compared the clinical and cost-effectiveness of an intensive lifestyle intervention consisting of enhanced motivational interviewing in reducing weight and increasing physical activity for patients at high risk of CVD. METHODS: A three-arm, single-blind, parallel-group randomised controlled trial was conducted in consenting primary care centres in south London. We recruited patients aged 40-74 years with a QRisk2 score ≥20.0%, which indicates the probability of having a CVD event in the next 10 years. The intervention was enhanced motivational interviewing which included additional behaviour change techniques and was delivered by health trainers in 10 sessions over 1 year, in either group (n=697) or individual (n=523) format. The third arm received usual care (UC; n=522). The primary outcomes were physical activity (mean steps/day) and weight (kg). Secondary outcomes were changes in low-density lipoprotein cholesterol and CVD risk score. We estimated the relative cost-effectiveness of each intervention. RESULTS: At 24 months, the group and individual interventions were not more effective than UC in increasing physical activity (mean difference=70.05 steps, 95% CI -288.00 to 147.90 and mean difference=7.24 steps, 95% CI -224.01 to 238.50, respectively), reducing weight (mean difference=-0.03 kg, 95% CI -0.49 to 0.44 and mean difference=-0.42 kg, 95% CI -0.93 to 0.09, respectively) or improving any secondary outcomes. The group and individual interventions were not cost-effective at conventional thresholds. CONCLUSIONS: Enhancing motivational interviewing with additional behaviour change techniques was not effective in reducing weight or increasing physical activity in those at high CVD risk

Supporting Innovative Co-operative Development: The Case of the Nova Scotia Co-operative Development System

In recent years, social science research has increasingly acknowledged the role of the social economy in building sustainable communities, and, around the world, co-operatives are recognized as major actors in the social economy. In Canada, the Nova Scotia Cooperative Council has forged several innovations in the past decade resulting in the development of a co-operative development system unparalleled in Anglophone Canada

Supporting Innovative Co-operative Development: The Case of the Nova Scotia Co-operative Development System

Description The research was initiated in order to contribute to one of the central research goals of BALTA – namely, to highlight “the scope and characteristics of social economy innovations that are achieving demonstrable social and economic results in other regions” in order to provide lessons and insights for strengthening the social economy in BC and Alberta. This research was subsequently used to inform further action research on how to strengthen the co-operative development systems in the provinces of Alberta and British Columbia. The NS-CDS case study looks at 6 main areas of the co-operative development system including: 1. Development Finance 2. Human Resource Development 3. Planning, Advocacy and Research 4. Policy and Governance 5. Community Economic Development 6. Accountability and EvaluationThis research paper was presented to the 2007 Canadian Congress of the Humanities and Social Sciences. It discusses a case study of the recent history of successful innovation and development in the co-operative sector in the province of Nova Scotia, Canada, that has been unparalleled in other parts of Anglophone Canada. The case study looks at the Nova Scotia Co-operative Development System from a systems perspective in order to encompass a wide range of interacting processes that are involved in the Nova Scotia experience. The research identifies success factors in the Nova Scotia experience that might be relevant to co-operative development in other regions.BC-Alberta Social Economy Research Alliance (BALTA) ; Social Sciences and Humanities Research Council of Canada (SSHRC) ; Canadian Centre for Community Renewal (CCCR

Reduction of critical temperatures in pure and thoriated UBe13 by columnar defects

We investigate the influence of columnar defects on the superconducting transition temperatures of pure and thoriated UBe13. The defects cause all the transitions to widen and to drop slightly in temperature. Quantitatively, the single UBe13 transition resembles the lower transition in a sample with 3% thorium more closely than the upper thoriated transition.Comment: 3 pages, 1 figure. To be presented at M2S-HTSC-V