Effects of forward velocity and acoustic treatment on inlet fan noise

Flyover and static noise data from several engines are presented that show inlet fan noise measured in flight can be lower than that projected from static tests for some engines. The differences between flight and static measurements appear greatest when the fan fundamental tone due to rotor-stator interaction or to the rotor alone field is below cutoff. Data from engine and fan tests involving inlet treatment on the walls only are presented that show the attenuation from this treatment is substantially larger than expected from previous theories or flow duct experience. Data showing noise shielding effects due to the location of the engine on the airplane are also presented. These observations suggest that multiringed inlets may not be necessary to achieve the desired noise reduction in many applications

Program for computing partial pressures from residual gas analyzer data

A computer program for determining the partial pressures of various gases from residual-gas-analyzer data is given. The analysis of the ion currents of 18 m/e spectrometer peaks allows the determination of 12 gases simultaneously. Comparison is made to ion-gage readings along with certain other control information. The output data are presented in both tabular and graphical form

Effect of forward motion on engine noise

Methods used to determine a procedure for correcting static engine data for the effects of forward motion are described. Data were analyzed from airplane flyover and static-engine tests with a JT8D-109 low-bypass-ratio turbofan engine installed on a DC-9-30, with a CF6-6D high-bypass-ratio turbofan engine installed on a DC-10-10, and with a JT9D-59A high-bypass-ratio turbofan engine installed on a DC-10-40. The observed differences between the static and the flyover data bases are discussed in terms of noise generation, convective amplification, atmospheric propagation, and engine installation. The results indicate that each noise source must be adjusted separately for forward-motion and installation effects and then projected to flight conditions as a function of source-path angle, directivity angle, and acoustic range relative to the microphones on the ground

Back-reacted saponite in Jurassic mudstones and limestones intruded by a Tertiary sill, Isle of Skye

The Lón Ostatoin stream section, Trotternish Peninsula, Isle of Skye, exposes a sequence of Middle Jurassic mudstones and limestones which have been locally metasomatized by a transgressive sill of Tertiary age. Limestones in the sequence, including some previously reported as bentonite, have been altered to an unusual assemblage of grossular garnet and saponite clay. The mudstones also contain large proportions of saponite together with pyroxene and zeolites. Saponite also occurs within the basalt intrusion. Grossular and pyroxene represent artifacts of relatively high-temperature assemblages that formed during an early phase of alteration. As the intrusion and adjacent altered country rocks cooled, lower-temperature fluids flowed through a late set of contraction (micro)fractures. Back-reacted saponite, analcime and clinoptilolite were formed, possibly as alteration products of the unstable higher-temperature minerals. The lower-temperature mineral assemblage eventually sealed the late fracture system. This paper highlights an important concept for the study of analogue sites used to investigate thermal effects on engineered liners or barrier host rocks for the landfill and radioactive-waste industries. This is that the original thermally altered mineral assemblage may be overprinted by later, lower-temperature back-reactions. A detailed understanding of both processes is necessary in order to construct a sensible model for the thermal and mineralogical evolution of the site

Product stewardship in the composites industry

The definition and purpose of Product Stewardship is discussed. Its' impact in the composites industry is stated. The report also outlines 12 ways that Product Stewardship can be utilized by consumers

Systematically Controlling for the Influence of Age, Sex, Hertz and Time Post-Whole-Body Vibration Exposure on Four Measures of Physical Performance in Community-Dwelling Older Adults: A Randomized Cross-Over Study

Though popular, there is little agreement on what whole-body vibration (WBV) parameters will optimize performance. This study aimed to clarify the effects of age, sex, hertz and time on four physical function indicators in community-dwelling older adults (N = 32). Participants were exposed to 2 min WBV per session at either 2 Hz or 26 Hz and outcome measures were recorded at 2, 20 and 40 min post-WBV. Timed get up-and-go and chair sit-and-reach performances improved post-WBV for both sexes, were significantly different between 2 Hz and 26 Hz treatments (P ≤ 0.05) and showed statistically significant interactions between age and gender (P ≤ 0.01). Counter movement jump and timed one-legged stance performances showed a similar but non-significant response to 2 Hz and 26 Hz treatments, though male subjects showed a distinct trended response. Age and gender should be statistically controlled and both 2 Hz and 26 Hz exert a treatment effect

Whole-Body Vibration Improves Functional Mobility, Flexibility, and Relative Risk for Falling in the Assisted Living Elderly: A Case Series

Study design: A randomized double blind repeated measures, case series study of whole body vibration (WBV) in the assisted living elderly. Background: A single exposure to WBV has been shown to have benefit with respect to muscle activity, strength, balance, and power in some studies while other studies have found no benefit. Its overall effectiveness is unknown due to the conflicting findings reported in the literature. Case description: Six subjects (5 female, 1 male; mean age = 85.4) in an assisted living community volunteered to participate. Subjects were exposed to a single bout of WBV at 0, 2, 20, and 26 Hz. Dependent variables including timed get up and go, chair sit and reach, one-legged stance time, and counter-movement jump were collected ten minutes prior, and two, twenty, forty, and sixty minutes after exposure. Published times for predicting falls using the timed up and go test and one-legged stance time were used to determine the number of outcome measures predicting falls prior to WBV. This was then compared to the number of outcome measures that predicted falls after exposure to determine any change. Outcomes: WBV had no statistically significant effect on mobility in the elderly. However, trends suggest mean timed get up and go may improve after 20 Hz and 26Hz. Mean chair sit and reach showed minimal improvement with time bilaterally following all frequencies of WBV. No trends were found for one-legged stance time and counter-movement jump. The fall risk assessment suggested improvements following 2 Hz of WBV, but findings were not significant. Conclusion: WBV had no significant effect on mobility in the assisted living elderly. Further research with larger sample size would be beneficial