Anomalous vortex ring velocities induced by thermally-excited Kelvin waves and counterflow effects in superfluids

Dynamical counterflow effects on vortex evolution under the truncated Gross-Pitaevskii equation are investigated. Standard longitudinal mutual friction effects are produced and a dilatation of vortex rings is obtained at large counterflow. A strong temperature-dependent anomalous slowdown of vortex rings is observed and attributed to the presence of thermally exited Kelvin waves. This generic effect of finite-temperature superfluids is estimated using energy equipartition and orders of magnitude are given for weakly interacting Bose-Einstein condensates and superfluid $^4{\rm He}$

A feasibility study of a home-based exercise intervention for prostate cancer patients on androgen deprivation therapy

Purpose: Androgen deprivation therapy (ADT) is an effective treatment for advanced-stage prostate cancer. Unfortunately, ADT has several adverse effects that significantly impair health-related quality of life (HRQOL). In patients receiving ADT, resistance training has been shown to improve important physical and psychosocial outcomes. However, little is known about the effects of aerobic exercise in this population. This feasibility study compares the effects of aerobic and resistance exercise interventions on a panel of psychological, physical fitness, and biological outcomes related to prostate cancer and ADT. Methods: 66 men receiving ADT for prostate cancer were recruited for this prospective, randomized trial. Participants are assigned to either a resistance or aerobic, moderate-intensity exercise 3-5 times per week for 30-60 minutes/session. Participants were provided with equipment so that they could exercise at home. The primary outcomes were related to feasibility for future, large-scale trials. Secondary outcomes included: fatigue, HRQOL, physical fitness, adipokines, insulin-like growth factor axis proteins, and exercise adherence. Outcomes were assessed at baseline and at 3, 6, and 12 months. Results: Preliminary findings are presented. 205 patients were approached for participation, 66 of which agreed to participate (n=34 in the resistance training group and 32 in the aerobic training group). Over the intervention period we experienced an attrition rate of 33%. There were no adverse events and biweekly booster sessions were poorly attended (n=27 aerobic training participants and n=22 resistance training participants did not attend any booster sessions). Intention-to-treat analyses showed that fatigue and HRQOL were not significantly different between groups; however, in a per-protocol analysis the resistance-training group demonstrated clinically significant improvements in HRQOL. Differential within-groups effects on physical fitness and biomarkers were also observed at various time-points. At all time-points, the aerobic training group engaged in significantly more physical activity than the resistance training group. Conclusion: Our findings suggest that both resistance and aerobic training can have positive effects on body composition with differential effects on psychosocial and biological outcomes. It appears that the aerobic exercise intervention was more effective at producing long-term, clinically significant increases in physical activity volume than resistance training. Our study has set the framework to conduct future clinical trials investigating the effects of exercise in men treated for prostate cancer

The restoration of Loch Leven, Scotland, UK

This paper reviews the progress made towards the restoration of Loch Leven, the largest lake in lowland Scotland, over the last 20 years. In particular, the importance of direct regulation and of setting water quality objectives and targets is examined. Various means of engaging with stakeholders and the general public are also considered. Success criteria and catchment management initiatives are described and briefly reviewed

Three regularization models of the Navier-Stokes equations

We determine how the differences in the treatment of the subfilter-scale physics affect the properties of the flow for three closely related regularizations of Navier-Stokes. The consequences on the applicability of the regularizations as SGS models are also shown by examining their effects on superfilter-scale properties. Numerical solutions of the Clark-alpha model are compared to two previously employed regularizations, LANS-alpha and Leray-alpha (at Re ~ 3300, Taylor Re ~ 790) and to a DNS. We derive the Karman-Howarth equation for both the Clark-alpha and Leray-alpha models. We confirm one of two possible scalings resulting from this equation for Clark as well as its associated k^(-1) energy spectrum. At sub-filter scales, Clark-alpha possesses similar total dissipation and characteristic time to reach a statistical turbulent steady-state as Navier-Stokes, but exhibits greater intermittency. As a SGS model, Clark reproduces the energy spectrum and intermittency properties of the DNS. For the Leray model, increasing the filter width decreases the nonlinearity and the effective Re is substantially decreased. Even for the smallest value of alpha studied, Leray-alpha was inadequate as a SGS model. The LANS energy spectrum k^1, consistent with its so-called "rigid bodies," precludes a reproduction of the large-scale energy spectrum of the DNS at high Re while achieving a large reduction in resolution. However, that this same feature reduces its intermittency compared to Clark-alpha (which shares a similar Karman-Howarth equation). Clark is found to be the best approximation for reproducing the total dissipation rate and the energy spectrum at scales larger than alpha, whereas high-order intermittency properties for larger values of alpha are best reproduced by LANS-alpha.Comment: 21 pages, 8 figure

Fast Numerical simulations of 2D turbulence using a dynamic model for Subgrid Motions

We present numerical simulation of 2D turbulent flow using a new model for the subgrid scales which are computed using a dynamic equation linking the subgrid scales with the resolved velocity. This equation is not postulated, but derived from the constitutive equations under the assumption that the non-linear interactions of subgrid scales between themselves are equivalent to a turbulent viscosity.The performances of our model are compared with Direct Numerical Simulations of decaying and forced turbulence. For a same resolution, numerical simulations using our model allow for a significant reduction of the computational time (of the order of 100 in the case we consider), and allow the achievement of significantly larger Reynolds number than the direct method.Comment: 35 pages, 9 figure

Transformation kinetics of alloys under non-isothermal conditions

The overall solid-to-solid phase transformation kinetics under non-isothermal conditions has been modeled by means of a differential equation method. The method requires provisions for expressions of the fraction of the transformed phase in equilibrium condition and the relaxation time for transition as functions of temperature. The thermal history is an input to the model. We have used the method to calculate the time/temperature variation of the volume fraction of the favored phase in the alpha-to-beta transition in a zirconium alloy under heating and cooling, in agreement with experimental results. We also present a formulation that accounts for both additive and non-additive phase transformation processes. Moreover, a method based on the concept of path integral, which considers all the possible paths in thermal histories to reach the final state, is suggested.Comment: 16 pages, 7 figures. To appear in Modelling Simul. Mater. Sci. En

Building Information Modelling (BIM) value realisation framework for asset owners

The paper is presenting a value realisation framework for asset owners based on an exploratory study. The study is descriptive in nature and adopting a qualitative approach towards data collection. The paper adopts the viewpoint of BIM business value measurement considering that; (i) if the process is better as a result of BIM-based processes, then it is different in some relevant way; (ii) if it is different in some relevant way as a result of certain BIM properties or characteristics, then the change is observable; (iii) if the change is observ-able because of certain direct BIM benefits, then it is countable; (iv) if it is countable using defined measurement metrics, then it is measurable; (v) if it is measurable using established measurement techniques, an organisation can value each unit and therefore, realise the benefits of BIM. The specific contribution of paper is to improve asset owners’ understanding of BIM-business value measurement techniques and approaches