Real-time flutter identification

The techniques and a FORTRAN 77 MOdal Parameter IDentification (MOPID) computer program developed for identification of the frequencies and damping ratios of multiple flutter modes in real time are documented. Physically meaningful model parameterization was combined with state of the art recursive identification techniques and applied to the problem of real time flutter mode monitoring. The performance of the algorithm in terms of convergence speed and parameter estimation error is demonstrated for several simulated data cases, and the results of actual flight data analysis from two different vehicles are presented. It is indicated that the algorithm is capable of real time monitoring of aircraft flutter characteristics with a high degree of reliability

The future of bioethanol

Yeasts have been domesticated by mankind before horses. After the mastering of alcoholic fermentation for centuries, yeasts have become the protagonist of one of the most important biotechnological industries worldwide: the production of bioethanol. This chapter will initially present some important challenges to be overcome in this industry, both in first and second generation biofuel production. Then, it will briefly revisit some advances obtained in recent years. Finally, it will present and discuss some opportunities, in the scope of metabolic engineering and synthetic biology, that will likely be present in the future of bioethanol

Postcard: Two Horses Pulling a Decorated Wagon for the Morris County Fair

This black and white photographic postcard depicts men standing on a wagon decorated for a parade. Two men are at the front of the wagon. Both are wearing hats. One man is wearing a shirt and trousers and is looking at the camera. The other man is wearing overalls and is holding the reins to two horses in front of the wagon. There is a large banner with words on it attached to the wagon and American flags surrounding the framed in part of the float. Calves and cows are behind the men on the framed part of the float. There are trees and a car in the background.https://scholars.fhsu.edu/tj_postcards/1091/thumbnail.jp

Fixed gain and adaptive techniques for rotorcraft vibration control

The results of an analysis effort performed to demonstrate the feasibility of employing approximate dynamical models and frequency shaped cost functional control law desgin techniques for helicopter vibration suppression are presented. Both fixed gain and adaptive control designs based on linear second order dynamical models were implemented in a detailed Rotor Systems Research Aircraft (RSRA) simulation to validate these active vibration suppression control laws. Approximate models of fuselage flexibility were included in the RSRA simulation in order to more accurately characterize the structural dynamics. The results for both the fixed gain and adaptive approaches are promising and provide a foundation for pursuing further validation in more extensive simulation studies and in wind tunnel and/or flight tests

Altering HIF-1α through 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure affects coronary vessel development.

Differential tissue hypoxia drives normal cardiogenic events including coronary vessel development. This requirement renders cardiogenic processes potentially susceptible to teratogens that activate a transcriptional pathway that intersects with the hypoxia-inducible factor (HIF-1) pathway. The potent toxin 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is known to cause cardiovascular defects by way of reduced myocardial hypoxia, inhibition of angiogenic stimuli, and alterations in responsiveness of endothelial cells to those stimuli. Our working hypothesis is that HIF-1 levels and thus HIF-1 signaling in the developing myocardium will be reduced by TCDD treatment in vivo during a critical stage and in particularly sensitive sites during heart morphogenesis. This inadequate HIF-1 signaling will subsequently result in outflow tract (OFT) and coronary vasculature defects. Our current data using the chicken embryo model showed a marked decrease in the intensity of immunostaining for HIF-1α nuclear expression in the OFT myocardium of TCDD-treated embryos. This area at the base of the OFT is particularly hypoxic during normal development; where endothelial cells initially form a concentrated anastomosing network known as the peritruncal ring; and where the left and right coronary arteries eventually connect to the aortic lumen. Consistent with this finding, anomalies of the proximal coronaries were detected after TCDD treatment and HIF-1α protein levels decreased in a TCDD dose-dependent manner

Higher Resolution VLBI Imaging with Fast Frequency Switching

Millimetre-VLBI is an important tool in AGN astrophysics, but it is limited by short atmospheric coherence times and poor receiver and antenna performance. We demonstrate a new kind of phase referencing for the VLBA, enabling us to increase the sensitivity in mm-VLBI by an order of magnitude. If a source is observed in short cycles between the target frequency, nu_t, and a reference frequency, nu_ref, the nu_t data can be calibrated using scaled-up phase solutions from self-calibration at nu_ref. We have demonstrated the phase transfer on 3C 279, where we were able to make an 86 GHz image with 90 % coherence compared to self-calibration at nu_t. We have detected M81, our science target in this project, at 86 GHz using the same technique. We describe scheduling strategy and data reduction. The main impacts of fast frequency switching are the ability to image some of the nearest, but relatively weak AGN cores with unprecedented high angular resolution and to phase-reference the nu_t data to the nu_ref core position, enabling the detection of possible core shifts in jets due to optical depth effects. This ability will yield important constraints on jet properties and might be able to discriminate between the two competing emission models of Blandford-Konigl jets and spherical advection-dominated accretion flows (ADAFs) in low-luminosity AGNs.Comment: 4 pages, 6 figures, appears in: Proceedings of the 6th European VLBI Network Symposium held on June 25th-28th in Bonn, Germany. Edited by: E. Ros, R.W. Porcas, A.P. Lobanov, and J.A. Zensu

Discriminatory Taxation of Carbonated Beverages: The Case of Ireland

A study of Ireland\u27s decision to eliminate its discriminatory excise tax shows that the revenue loss associated with this action was far less than might otherwise have been expected