Method of making a composite sandwich lattice structure

A lattice type structural panel is described, which utilizes the unidirectional character of filamentary epoxy impregnated composites to produce stiff lightweight structural panels for use in constructing large area panels for space satellites and the like

Composite sandwich lattice structure

A lattice type structural panel is described. The panel utilizes the unidirectional character of filamentary epoxy impregnated composites. The panels are stiff lightweight structures for use in constructing space satellites and the like

Deployable M-braced truss structure

A deployable M-braced truss structure, efficiently packaged into a compact stowed position and expandable to an operative position at the use site is described. The M-braced configuration effectively separates tension compression and shear in the structure and permits efficient structural design. Both diagonals and longerons telescope from an M-braced base unit and deploy either pneumatically, mechanically by springs or cables, or by powered reciprocating mechanisms. Upon full deployment, the diagonals and longerons lock into place with a simple latch mechanism

High temperature compounds for turbine vanes

Fabrication and microstructure control studies were conducted on SiC, Si3N and composites based on Si3N. Charpy mode impact testing to 2400 F established that Si3N4/Mo composites have excellent potential. Attempts to fabricate composites of Si3N4 with superalloys, both by hot pressing and infiltration were largely unsuccessful in comparison to using Mo, Re, and Ta which are less reactive. Modest improvements in impact strength were realized for monolithic Si3N4; however, SiC strengths increased by a factor of six and now equal values achieved for Si3N4. Correlations of impact strength with material properties are discussed. Reduced MgO densification aid additions to Si3N4 were found to decrease densification kinetics, increase final porosity, decrease room temperature bend strength, increase high temperature bend strength, and decrease bend stress rupture properties. The decrease in bend strength at high temperature for fine grain size SiC suggested that a slightly larger grain size material with a nearly constant strength-temperature relation may prove desirable in the creep and stress rupture mode

Applications of the magneto-optical filter to stellar pulsation measurements

A proposed method of employing the Cacciani magneto-optical filter (MOF) for stellar seismology studies is described. The method relies on the fact that the separation of the filter bandpasses in the MOF can be changed by varying the level of input power to the filter cells. With the use of a simple servosystem the bandpass of a MOF can be tuned to compensate for the changes in the radial velocity of a star introduced by the orbital motion of the Earth. Such a tuned filter can then be used to record intensity fluctuations through the MOF bandpass over an extended period of time for each given star. Also, the use of a two cell version of the MOF makes it possible to alternately chop between the bandpass located in the stellar line wing and a second bandpass located in the stellar continuum. Rapid interchange between the two channels makes it possible for atmospheric-introduced noise to be removed from the time series

Carotid intima-media thickness and physical and cognitive function in elderly men and women: role of physical activity

The incidence of cognitive impairment in the aging population remains one of the most common morbidities in the elderly, often associated with a decrease in physical function, institutionalization, and death. Several different mechanisms have been proposed, including age-related changes to the vasculature. The purpose of this study was to examine the relationship between physical activity, carotid intima-media thickness and other vascular measures, and measures of cognitive and physical function in older adults. Measures of daily physical activity, vascular structure and function, and cognitive and physical function were examined in 109 participants [age=81±11 yrs]. Daily physical activity was assessed using the Yale Activity Index (YAI) and by calculating total daily energy (TDEE) using the doubly labeled water technique. Vascular structure was assessed using carotid-intima media thickness (CIMT), while cognitive function and physical function were assessed using the Mini-Mental State Examination (MMSE) and the CSPFP-10, respectively. The average YAI score was 37.75±22.78, TDEE was 2133.02±585.68 kcal/d, CIMT was 0.91±0.06 mm, MMSE score 28.17 , and total CSPFP-10 score 42±20. A unique finding was the relationship between daily physical activity levels, vascular measures, and measures of cognitive and physical function, suggesting that those with higher levels of daily physical activity exhibit more favorable vascular, cognitive, and physical measures. In addition, more favorable measures of cognitive and physical function may be due in part to preserved vascular health. In conclusion, the findings of this study strongly suggest that maintaining a more physically active lifestyle may result in physiological changes, and yield vascular, cognitive, and physical functional benefits