The structure of trailing vortices generated by model rotor blades

Hot-wire anemometry to analyze the structure and geometry of rotary wing trailing vortices is studied. Tests cover a range of aspect ratios and blade twist. For all configurations, measured vortex strength correlates well with maximum blade-bound circulation. Measurements of wake geometry are in agreement with classical data for high-aspect ratios. The detailed vortex structure is similar to that found for fixed wings and consists of four well defined regions--a viscous core, a turbulent mixing region, a merging region, and an inviscid outer region. A single set of empirical formulas for the entire set of test data is described

Effects of Cytochalasin B and Colchicine on the Morphology of SW-13 Human Adrenal Cortical Tumor Cells in Culture

Human adrenal cortical tumor cells (SW-13) grow into a typical epithelial cell monolayer when seeded onto culture dishes. The cells of the SW-13 population monolayer appear flattened with few conspicuous surface features. The cells are attached to one another at their lateral borders and are arranged in a cobblestone-like manner. Following Triton X-100 extraction, the distribution of the cytoskeletal elements was observed with scanning electron microscopic techniques to correspond to the shape of the non-extracted cell. Changes in the distribution and morphology of projections on the cell surface as well as changes in cell shape were revealed after treatment of the cultures with compounds which bring about microtubular and microfilament disruption. Following 60 minute treatment of the cell population with cytochalasin B (10μg/ml), 90% of the cells became round while remaining attached to neighboring cells and to the substrate by slender cell processes and filopodia. Some blebbing could be seen on the cell surfaces of cytochalasin B treated cultures and an increase in the number of microvilli was evident. When the cytoskeletal elements were observed with scanning electron microscopic techniques after Triton X-100 extraction, the amount of peripheral cytoskeletal elements was decreased and only slender projections of the microfilaments and microtubules were evident. Colchicine (0.06μg/ml) treatment of the SW-13 adrenal cell population resulted in the appearance of surface blebs within 10 minutes of the initiation of treatment. The changes in surface projections are discussed in relationship to the loss of microtubules and microfilaments from the cytoplasm of the cell

Competitiveness and workforce performance: Asia vis-à-vis the “West”

© 2016, © Emerald Group Publishing Limited. Purpose: The purpose of this eight-country study is to examine what drives performance at the individual worker’s level and compare the explanatory power of such drivers between emerging, newly developed and developed markets around the globe. Design/methodology/approach: The study combines established behavioural theory developed in a Western context with three factors anticipated to be most relevant in Asia (competitive attitude, willingness to serve and speed) as drivers of workforce performance. Four thousand working and middle-class respondents from eight countries were sampled. The associations were tested using structural equation modelling, and workforce performance was measured using univariate analysis. Findings: Three country clusters emerged from the research: emerging economies in Asia (Indonesia, India), where the three factors powerfully explain performance; “Confucian orbit countries” (China, Japan, Korea), where the factors explain 81-93 per cent; and highly developed Western countries (the USA, the UK, Germany), where the factors account for only 20-29 per cent. Practical implications: As well as providing a framework for modelling workforce performance, particularly in Asian countries, the findings indicate that workforce performance should be incorporated in performance indexes. The findings as to which drivers best explain workforce performance in each county can inform workforce recruitment and management, as well as the location of businesses and outsourcing. Originality/value: For the first time, the study addresses the anomaly between economic growth and development experienced by Asian countries and their relatively low rankings in global competitiveness indexes by making the link between workforce performance and country performance

Customers’ savings rate and share of wallet: the moderating role of religion and ethnicity/immigrant generation vis-à-vis attitude as mediator

© 2016, © 2016 Informa UK Limited, trading as Taylor & Francis Group. This study explores the role of attitude toward money, religion and ethnicity in the relationship between income and consumer behavior. The three-country (Australia, Canada and China) study sampled 755 consumers and uses structural equation modeling and multivariate analysis to test for mediating effects of attitude toward money and moderating effects of religion and ethnicity/immigrant generation. Religion is found to be a moderating variable for savings rate and share of wallet, while ethnicity/immigrant generation only moderates the association between income and savings rate. We also demonstrate the interaction effects of religion and ethnicity/immigrant generation with income as determinants of savings rate and share of wallet. This research provides the foundation for modeling savings rate and share of wallet, incorporating attitude, religion, and ethnicity/immigrant generation, as well as income, demonstrating the need to include other factors (i.e. demographic factors in addition to attitudinal/satisfaction measures) to better identify, understand and strategically target consumer segments with potential for profitability and growth

Neutrino Dimuon Production and the Strangeness Asymmetry of the Nucleon

We have performed the first global QCD analysis to include the CCFR and NuTeV dimuon data, which provide direct constraints on the strange and anti-strange parton distributions, $s(x)$ and $\bar{s}(x)$. To explore the strangeness sector, we adopt a general parametrization of the non-perturbative $s(x), \bar{s}(x)$ functions satisfying basic QCD requirements. We find that the strangeness asymmetry, as represented by the momentum integral $[S^{-}]\equiv \int_0^1 x [s(x)-\bar{s}(x)] dx$, is sensitive to the dimuon data provided the theoretical QCD constraints are enforced. We use the Lagrange Multiplier method to probe the quality of the global fit as a function of $[S^-]$ and find $-0.001 < [S^-] < 0.004$. Representative parton distribution sets spanning this range are given. Comparisons with previous work are made.Comment: 23 pages, 4 figures; expanded version for publicatio

On Parametrically Excited Flexural Motion of an Extensible and Shearable Rod with a Heavy Attachment

A simple Cosserat model is used to explore the coupled planar flemural and arial vibrations of a slender rod clamped at one end with a heauy attached mass free to move at the other. By assuming that the inertia of the rod is small compared to that of the attached mass it is shown how the equations of motionreduce to a dynamical system. The effects of grauity on the rod can be incorporated within this frame-work and the linearised stability of the system discussed in terms of solutions to the Mathieu-Hill equation

Thermoelastic Noise and Homogeneous Thermal Noise in Finite Sized Gravitational-Wave Test Masses

An analysis is given of thermoelastic noise (thermal noise due to thermoelastic dissipation) in finite sized test masses of laser interferometer gravitational-wave detectors. Finite-size effects increase the thermoelastic noise by a modest amount; for example, for the sapphire test masses tentatively planned for LIGO-II and plausible beam-spot radii, the increase is less than or of order 10 per cent. As a side issue, errors are pointed out in the currently used formulas for conventional, homogeneous thermal noise (noise associated with dissipation which is homogeneous and described by an imaginary part of the Young's modulus) in finite sized test masses. Correction of these errors increases the homogeneous thermal noise by less than or of order 5 per cent for LIGO-II-type configurations.Comment: 10 pages and 3 figures; RevTeX; submitted to Physical Review

The microcanonical ensemble of the ideal relativistic quantum gas with angular momentum conservation

We derive the microcanonical partition function of the ideal relativistic quantum gas with fixed intrinsic angular momentum as an expansion over fixed multiplicities. We developed a group theoretical approach by generalizing known projection techniques to the Poincare' group. Our calculation is carried out in a quantum field framework and applies to particles with any spin. It extends known results in literature in that it does not introduce any large volume approximation and it takes particle spin fully into account. We provide expressions of the microcanonical partition function at fixed multiplicities in the limiting classical case of large volumes and large angular momenta and in the grand-canonical ensemble. We also derive the microcanonical partition function of the ideal relativistic quantum gas with fixed parity.Comment: 38 pages; minor corrections to the formulae for the published versio