Review of measured vibration and noise environments experienced by passengers in aircraft and in ground transportation systems

Measured vibration and interior noise data are presented for a number of air and surface vehicles. Consideration is given to the importance of direction effects; of vehicle operations such as take-off, cruise, and landing; and of measurement location on the level and frequency of the measurements. Various physical measurement units or descriptors are used to quantify and compare the data. Results suggest the range of vibration and noise associated with a particular mode of transportation and illustrate the comparative levels in terms of each of the descriptors. Collectively, the results form a data base which may be useful in assessing the ride of existing or future systems relative to vehicles in current operation

Flexible ring slosh damping baffle Patent

Flexible ring slosh damping baffle for spacecraft fuel tan

Cost/benefit analysis of advanced materials technologies for future aircraft turbine engines

The materials technologies studied included thermal barrier coatings for turbine airfoils, turbine disks, cases, turbine vanes and engine and nacelle composite materials. The cost/benefit of each technology was determined in terms of Relative Value defined as change in return on investment times probability of success divided by development cost. A recommended final ranking of technologies was based primarily on consideration of Relative Values with secondary consideration given to changes in other economic parameters. Technologies showing the most promising cost/benefits were thermal barrier coated temperature nacelle/engine system composites

Fourth Aircraft Interior Noise Workshop

The fourth in a series of NASA/SAE Interior Noise Workshops was held on May 19 and 20, 1992. The theme of the workshop was new technology and applications for aircraft noise with emphasis on source noise prediction; cabin noise prediction; cabin noise control, including active and passive methods; and cabin interior noise procedures. This report is a compilation of the presentations made at the meeting which addressed the above issues

A two-degree Kelvin refrigerator

Open-cycle cryogenic refrigerator maintains temperature as low as 2K for periods up to six months. Designed to cool an infrared detector, refrigerator can be used in cooling Josephson-junction devices, magnetic bubble domains, and superconducting devices

Rocket plume properties measured in space simulators

Molecular sink facility and 25-foot space simulator have been used to distinguish nature of exhaust plumes from nozzles with relatively large internal boundary layer flow. Plume density has been measured by electron beam/photomultiplier system

Secondary reflectors for economical sun-tracking energy collection system: A concept

Mechanism is simpler and lower in cost because it moves heat-collector pipe to stay in focus with sun, instead of moving heavy reflectors

Dialogue, argumentation, and belief revision: a study of apologetic conversations in West Cameroon

This work studies dialogue, argumentation, and their relationship to belief revision in person-to-person apologetics in five West Cameroonian dialogues. The seeming irrelevance of Western Apologetics to West Cameroonian thought is the problem that stimulated the study. The primary methodological steps of the study include obtaining meticulously transcribed scripts of unrehearsed conversations, and subjecting those transcripts to an inquiry about the presence and nature of dialogue, argument patterns, commitment, questions, rhetoric, and belief revision in the conversations. These primary tools are drawn from Commitment in Dialogue (1995), Argumentation Schemes (2008), ‘A Truth Maintenance System’ (1979), ‘Reason Maintenance and Belief Revision’ (1992), and related sources. The initial premise, to be tested by the research, is that these conversational elements are present, and that the theories are useful in understanding the dialogues’ rationality. The second, but no less important, premise of the study is that this research contributes to an understanding of the nature and role of the cumulative case in the practice of person-to-person apologetics in West Cameroon and cultural situations dominated by relativism. Chapter 1 introduces the background of the research and the questions of the inquiry, which I call ‘tools’. Chapter 2 questions the significance of the tools and the analysis of the data for person-to-person apologetics in pluralistic contexts. Chapters 3-7 document the analysis of the dialogues. And chapter 8 ends with a summary of the evidence for the thesis of the work: ‘A belief’s entrenchment, the result of argument patterns converging into a cumulative case for the belief, is primarily sensitive to understanding and revision in the context of dialogue.’ This work contributes to the understanding of modern African rationality, and the relationships of dialogue, argument, belief revision, and the cumulative case in relativistic contexts

Solar energy collection system

A fixed, linear, ground-based primary reflector having an extended curved sawtooth-contoured surface covered with a metalized polymeric reflecting material, reflects solar energy to a movably supported collector that is kept at the concentrated line focus reflector primary. The primary reflector may be constructed by a process utilizing well known freeway paving machinery. The solar energy absorber is preferably a fluid transporting pipe. Efficient utilization leading to high temperatures from the reflected solar energy is obtained by cylindrical shaped secondary reflectors that direct off-angle energy to the absorber pipe. A seriatim arrangement of cylindrical secondary reflector stages and spot-forming reflector stages produces a high temperature solar energy collection system of greater efficiency

Solar pond

Shallow pools of liquid to collect low-temperature solar generated thermal energy are described. Narrow elongated trenches, grouped together over a wide area, are lined with a heat-absorbing black liner. The heat-absorbing liquid is kept separate from the thermal energy removing fluid by means such as clear polyethylene material. The covering for the pond may be a fluid or solid. If the covering is a fluid, fire fighting foam, continuously generated, or siloons are used to keep the surface covering clean and insulated. If the thermal energy removing fluid is a gas, a fluid insulation layer contained in a flat polyethlene tubing is used to cover the pond. The side of the tube directed towards the sun is treated to block out ultraviolet radiation and trap in infrared radiation