Rotor burst protection criteria and implications

Current aircraft design practices to minimize the hazard from rotor bursts are described. The consequences of non-contained engine failures and the impact of rotor burst protection systems on aircraft design are discussed

Propeller dynamic and aeroelastic effects

Various aspects of propeller blade dynamics are considered including those factors which are exciting the blades and the dynamic response of the blades to the excitations. Methods for treating this dynamic system are described and problems are discussed which may arise with advanced turboprop designs employing thin, swept blades

On the status of V/STOL flight

Basic principles relating to the accomplishment of V/STOL flight are reviewed as they pertain to current prototype developments. Particular consideration is given to the jet flap, flow augmentation and circulation control separately and in combination. Configurations as the augmentor wing, upper-surface blown flaps, externally blown flaps and the circulation-controlled rotor are also examined

Rotor blade-vortex interaction

The vortex lattice method has been extended to a single bladed rotor operating at high advance ratios and encountering a free vortex from a fixed wing upstream of the rotor. The predicted unsteady load distributions on the model rotor blade are generally in agreement with the experimental results. This method has also been extended to full scale rotor flight cases in which vortex induced loads near the tip of a rotor blade were indicated. Using conformal transformation methods an exact analysis of the effects of thickness on the lift due to a two dimensional wing vortex interaction is presented

Satellite stratospheric aerosol measurement validation

The validity of the stratospheric aerosol measurements made by the satellite sensors SAM II and SAGE was tested by comparing their results with each other and with results obtained by other techniques (lider, dustsonde, filter, and impactor). The latter type of comparison required the development of special techniques that convert the quantity measured by the correlative sensor (e.g. particle backscatter, number, or mass) to that measured by the satellite sensor (extinction) and quantitatively estimate the uncertainty in the conversion process. The results of both types of comparisons show agreement within the measurement and conversion uncertainties. Moreover, the satellite uncertainty is small compared to aerosol natural variability (caused by seasonal changes, volcanoes, sudden warmings, and vortex structure). It was concluded that the satellite measurements are valid

Enterohemorrhagic Escherichia coli colonization of human colonic epithelium in vitro and ex vivo

Enterohemorrhagic E. coli (EHEC) are important foodborne pathogens causing gastroenteritis and more severe complications such as hemorrhagic colitis and hemolytic uremic syndrome. Pathology is most pronounced in the colon, but to date there is no direct clinical evidence showing EHEC binding to colonic epithelium in patients. In this study, we investigated EHEC adherence to the human colon by using in vitro organ culture (IVOC) of colonic biopsies and polarized T84 colon carcinoma cells. We showed for the first time that EHEC colonized human colonic biopsies by forming typical attaching/effacing (A/E) lesions which were dependent on EHEC type III secretion (T3S) and binding of the outer membrane protein intimin to the Translocated intimin receptor (Tir). A/E lesion formation was dependent on oxygen levels and suppressed under oxygen-rich culture conditions routinely used for IVOC. In contrast, EHEC adherence to polarized T84 cells occurred independently of T3S and intimin and did not involve Tir translocation into the host cell membrane. Neither colonization of biopsies nor T84 cells was significantly affected by expression of Shiga toxins. Our study suggests that EHEC colonize and form stable A/E lesions on the human colon which is likely to contribute to intestinal pathology during infection. Furthermore, care needs to be taken when using cell culture models as they might not reflect the in vivo situation

A survey of the health facilities in a Massachusetts community.

Thesis (Ed.M.)--Boston Universit

Alien Registration- Mccormick, Mary B. (Presque Isle, Aroostook County)

https://digitalmaine.com/alien_docs/33419/thumbnail.jp