Optimum performance and potential flow field of hovering rotors

Rotor and propeller performance and induced potential flowfields were studied on the basis of a rotating actuator disk concept, with special emphasis on rotors hovering out of ground effect. A new theory for the optimum performance of rotors hovering OGE is developed and presented. An extended theory for the optimum performance of rotors and propellers in axial motion is also presented. Numerical results are presented for the optimum distributions of blade-bound circulation together with axial inflow and ultimate wake velocities for the hovering rotor over the range of thrust coefficient of interest in rotorcraft applications. Shapes of the stream tubes and of the velocities in the slipstream are obtained, using available methods, for optimum and off-optimum circulation distributions for rotors hovering in and out of ground effect. A number of explicit formulae useful in computing rotor and propeller induced flows are presented for stream functions and velocities due to distributions of circular vortices over axi-symmetric surfaces

Challenges and choices : fit for life (2009)

Reviewed June 2009

Fit for life (1996)

"3/96/3M.""Nutrition.""Information from Human Environmental Sciences Extension.""Here are some fun, simple ways to eat fruits and vegetables with your meals and snacks."--Page 1

Corporations

The major 1969 corporate law developments of particular interest to the California practitioner were: (1) California appellate decisions which, at least by implication, greatly broaden the scope of a controlling shareholder\u27s duty to minority shareholders; (2) amendments to the California Corporations Code; and (3) amendments to the Delaware General Corporation Law

One-year follow-up of family versus child CBT for anxiety disorders: Exploring the roles of child age and parental intrusiveness.

ObjectiveTo compare the relative long-term benefit of family-focused cognitive behavioral therapy (FCBT) and child-focused cognitive behavioral therapy (CCBT) for child anxiety disorders at a 1-year follow-up.MethodThirty-five children (6-13 years old) randomly assigned to 12-16 sessions of family-focused CBT (FCBT) or child-focused CBT (CCBT) participated in a 1-year follow-up assessment. Independent evaluators, parents, and children rated anxiety and parental intrusiveness. All were blind to treatment condition and study hypotheses.ResultsChildren assigned to FCBT had lower anxiety scores than children assigned to CCBT on follow-up diagnostician- and parent-report scores, but not child-report scores. Exploratory analyses suggested the advantage of FCBT over CCBT may have been evident more for early adolescents than for younger children and that reductions in parental intrusiveness may have mediated the treatment effect.ConclusionFCBT may yield a stronger treatment effect than CCBT that lasts for at least 1 year, although the lack of consistency across informants necessitates a circumspect view of the findings. The potential moderating and mediating effects considered in this study offer interesting avenues for further study

The Incidence of Pollution Control Policies

This paper reviews theoretical and empirical literature on the household distribution of the costs and benefits of pollution control policies, and ways of integrating distributional issues into environmental cost/benefit analysis. Most studies find that policy costs fall disproportionately on poorer groups, though this is less pronounced when lifetime income is used, and policies affect prices of inputs used pervasively across the economy. The policy instrument itself is also critical; freely allocated emission permits may hurt the poor the most, as they transfer income to shareholders via scarcity rents created by higher prices, while emissions taxes offer opportunities for progressive revenue recycling. And although low-income households appear to bear a disproportionate share of environmental risks, policies that reduce risks are not always progressive, for example, they may alter property values in ways that benefit the wealthy. The review concludes by noting a number of areas where future research is badly needed.

A Systematic Search for Structure-Activity Relationships of Skin Contact Sensitizers: Methodology

A computerized resource for the systematic evaluation of the structure-activity relationships and other aspects of contact allergens is described. This resource consists of a data base of results of contact dermatitis tests and a structural classification scheme for contact allergens that is called a Structure-Activity (S/A) Tree. The data base now contains approximately 2200 test results extracted from the journal Contact Dermatitis (1975–1982) and is continually being expanded. The S/A Tree is being developed to provide an index to structure-activity relationships of contact allergens; 63 structural groups are currently indexed. Analyses of benzoquinones and gallic acid esters are presented as examples of the potential application of this resource to such problems as the identification of potential cross-reactants, appropriate test concentrations and vehicles, and the reliability of available test results