Probing liquid surface waves, liquid properties and liquid films with light diffraction

Surface waves on liquids act as a dynamical phase grating for incident light. In this article, we revisit the classical method of probing such waves (wavelengths of the order of mm) as well as inherent properties of liquids and liquid films on liquids, using optical diffraction. A combination of simulation and experiment is proposed to trace out the surface wave profiles in various situations (\emph{eg.} for one or more vertical, slightly immersed, electrically driven exciters). Subsequently, the surface tension and the spatial damping coefficient (related to viscosity) of a variety of liquids are measured carefully in order to gauge the efficiency of measuring liquid properties using this optical probe. The final set of results deal with liquid films where dispersion relations, surface and interface modes, interfacial tension and related issues are investigated in some detail, both theoretically and experimentally. On the whole, our observations and analyses seem to support the claim that this simple, low--cost apparatus is capable of providing a wealth of information on liquids and liquid surface waves in a non--destructive way.Comment: 25 pages, 12 figures, to appear in Measurement Science and Technology (IOP

Instrumentation issues in implementation science

Background Like many new fields, implementation science has become vulnerable to instrumentation issues that potentially threaten the strength of the developing knowledge base. For instance, many implementation studies report findings based on instruments that do not have established psychometric properties. This article aims to review six pressing instrumentation issues, discuss the impact of these issues on the field, and provide practical recommendations. Discussion This debate centers on the impact of the following instrumentation issues: use of frameworks, theories, and models; role of psychometric properties; use of ‘home-grown’ and adapted instruments; choosing the most appropriate evaluation method and approach; practicality; and need for decision-making tools. Practical recommendations include: use of consensus definitions for key implementation constructs; reporting standards (e.g., regarding psychometrics, instrument adaptation); when to use multiple forms of observation and mixed methods; and accessing instrument repositories and decision aid tools. Summary This debate provides an overview of six key instrumentation issues and offers several courses of action to limit the impact of these issues on the field. With careful attention to these issues, the field of implementation science can potentially move forward at the rapid pace that is respectfully demanded by community stakeholders

Factors that influence career decision-making among elite athletes

A common belief about elite athletes is that they invest so much effort into the pursuit of their athletic careers that they fail to develop good career decision-making skills. Recent findings challenge that belief. The present study investigated career decision-making difficulties among 117 elite Australian athletes. Participants completed adapted versions of the Career Decision-Making Difficulties Questionnaire, the Athlete Identity Measurement Scale, the Career Decision-making Self-efficacy Short Form, and the Work Locus of Control Scale. These elite athletes showed no evidence of career decision-making difficulties. Combinations of this set of variables accounted for 35% of the variance in decision status and 20% of the variance in career decision-making difficulties. Career decision-making self-efficacy was a major contributor in both instances. Internal locus of control was also identified as a desirable characteristic in the context of career decision-making. The implications of these findings are discussed