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

Measuring specialty indecision among career-decided students

Increasing numbers of career-decided students in professional and graduate schools have difficulty choosing a specialty. To begin to examine this problem, a measure of specialty indecision was devised by changing the Career Decision Scale items to deal with specialty indecision rather than career indecision. The scale was then administered to 567 medical students along with measures of vocational development and exploratory behavior. Initial evaluation of the psychometric properties of the Specialty Indecision Scale indicate that it is internally consistent, relates more to specialty choice than to career choice, and inversely relates to both vocational development and exploratory behavior. A factor analysis of the scale items extracted four factors that reflect cognitive, conative, criterion, and implementation restraints on the decision-making process. The Specialty Indecision Scale seems to be useful for diagnostic and research purposes in the study and treatment of specialty indecision.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25480/1/0000020.pd

Validation of the short form of the career development inventory with an Iranian high school sample

A short 33-item form of the Career Development Inventory was validated on a sample of 310 Iranian high school students. Factor analysis indicated that attitude and cognitive subscale items loaded on their respective factors, and that internal reliability coefficients at all levels were satisfactory to good. Support for validity was demonstrated by associations in the expected direction for career decidedness and career decision-making self-efficacy. This short form of the inventory shows promise as a measure of career maturity with students from a non-Western country.Full Tex