Aerospace

The two-phase flowfield environment around a hovering micro-rotor is simulated using a fluid dynamics solver coupled with a Lagrangian sediment tracking algorithm. The present work attempts to examine the capabilities of a high fidelity CFD analysis together with a sediment tracking algorithm to analyze the evolution of brownout clouds. The effect of particle size on the evolution of the cloud and the predominant transport mechanisms are analyzed and compared with experimental data. The resolution of vortices for longer wake ages by the CFD solver along with better estimation of velocity profiles further outboard of the rotor were shown to be vital for the coupled simulation to achieve qualitative agreement with experiment. This better resolution is achieved through the use of additional overset meshes placed near the ground. Three size ranges of spherical particles are used to represent the sediment bed. The variation of the phenomenological attributes of the cloud evolution as a function of particle size was analyzed and found to agree with experimental evidence.

As Internet usage becomes more commonplace, researchers are beginning to explore the use of email interviews. Email interviews have a unique set of tools, advantages, and limitations, and are not meant to be blind reproductions of traditional face-to-face interview techniques. Email interviews should be implemented when: 1) researchers can justify email interviews are useful to a research project; 2) there is evidence that the target population will be open to email interviewing as a form of data collection; and 3) the justification of the email interview supports the researchers’ theoretical perspective. The objective of this study was to develop an email interviewing methodology. As with other forms of qualitative interviewing, it is important that the researcher: 1) identifies constraints; 2) adequately prepares for the interview; 3) establishes rapport; 4) asks appropriate questions; 5) actively listens; and 6) ends the email interview appropriately.

Field research was conducted to assess the effects of organic and inorganic soil amendments on soil humified carbon content and plant physiological properties. Long term applications of various types and rates of compost, poultry litter and inorganic fertilizer were assessed for their effects on corn [Zea mays (L.) Pioneer 31G20] and soybean [Glycine max (l.) Delta Pine 4933RR] grown in a Virginia (United States) Piedmont soil in 2004 and 2005. Treatment differences in leaf antioxidant activity were only observed in the corn plots. Corn fertilized with amendments supplying the crop's nitrogen needs, regardless of the source, had greater leaf nitrogen (+29%), chlorophyll (+33%), and protein contents (+37%), lower superoxide dismutase (-29%) and ascorbate peroxidase (-17%) activities, and lower malondialdehyde (-33%) contents than the control and low nitrogen treatments. Yield was strongly related to midseason leaf nitrogen contents (R 2 =0.87, p<0.0001) and not with soil humified carbon (R 2 =0.02, p=0.0543). Soybean grown in the organically amended soil had higher yields (9-21% increase), protein contents (4-9% increase) and seed weights (5-14% increase) than the inorganically fertilized and unfertilized treatments. Improvements in soybean yield and seed quality were due to organic amendment benefits other than plant available water or nutrient supply.

This 4-page fact sheet provides a brief description of the Endangered Species Act and updated action pertaining to the endangered species issue. The goal of this publication is to provide brief but clear information about the legislation and current agreements around this issue that Extension agents can use to increase educated conversations. Written by Chandra Bowden, Alexa Lamm, Tracy Irani, and Sebastian Galindo, and published by the UF Department of Agricultural Education and Communication, May 2013. http://edis.ifas.ufl.edu/wc141

Immigration in Florida is a contested issue and having an understanding of this issue can help facilitate communication. This 6-page fact sheet provide brief but clear information about the trends in policies that can be used by Extension agents to increase educated conversations around immigration issues. Written by Chandra Bowden, Alexa Lamm, Hannah Carter, Tracy Irani, and Sebastian Galindo, and published by the UF Department of Agricultural Education and Communication, December 2012. http://edis.ifas.ufl.edu/wc132

In this paper we look for a rotating beam, with pinned-free boundary conditions, whose eigenpair (frequency and mode-shape) is same as that of a uniform non-rotating beam for a particular mode. It is seen that for any given mode, there exists a flexural stiffness function (FSF) for which the i th mode eigenpair of a rotating beam with uniform mass distribution, is identical to that of a corresponding non-rotating beam with same length and mass distribution. Inserting these derived FSF's in a finite element code for a rotating pinned-free beam, the 2 Korak Sarkar, Ranjan Ganguli frequencies and mode shapes of a non-rotating pinned-free beam are obtained. For the first mode, a physically realistic equivalent rotating beam is possible, but for higher modes, the FSF has internal singularities. Strategies for addressing these singularities in the FSF for finite element analysis are provided. The proposed functions can be used as test functions for rotating beam codes and also for targeted destiffening of rotating beams.

It is shown that centrifugal stiffening effects in rotating beams can be countered by spanwise stiffness variation for a given mode. Smart materials such as magnetorheological elastomer can be used to vary the stiffness in a manner such that a given mode is destiffened. The flexural stiffness functions are demonstrated using a p-version finite element rotating beam code and represent a multifunctional rotating structure concept which can be used for active stiffness control.