A proposed system for aviation noise measurement and control

January 1973Includes bibliographical references (p. 61-64)This report reviews previous work on various measures for aviation noise, and proposes a completely new system for aviation noise measurement and control compatible with real time, operational noise monitoring hardware. This new system allows new methods of control and regulation to be introduced and is designed to cover problems arising from future CTOL, RTOL, STOL, and VTOL aviation systems operating from current airports as well as new urban sites. New measures are proposed for aircraft flyover noise, airport noise exposure, and community noise impact

The implications of lung-regulated buoyancy control for dive depth and duration

Among air-breathing divers, control of buoyancy through lung volume regulation may be most highly developed in marine turtles. In short, the turtle lung may serve a dual role as both an oxygen store and in buoyancy control. A simple model is developed to show that, for turtles diving up to the maximum depth at which they can still use their lungs to attain neutral buoyancy, the total oxygen store will increase greatly with dive depth, and hence a corresponding increase in dive duration is predicted. Time–depth recorders attached to free-living green turtles (Chelonia mydas) at Ascension Island confirmed a marked increase in dive duration with depth, with the gradient of this relationship being >10 times that seen in diving birds and mammals. Consistent with the prediction that the lungs serve a dual role, we found that, when lead weights were added to some turtles to increase their specific gravity, the mean depth of dives decreased, but for dives to the same depth, weighted animals dived for longer. The depth distribution of green turtles seems to be generally constrained by the maximum depth at which they can still attain close to neutral buoyancy

The future of very large subsonic transports

The Very Large Subsonic Transport (VLST) is a multi-use commercial passenger, commercial cargo, and military airlifter roughly 50% larger than the current Lockheed C-5 and Boeing 747. Due to the large size and cost of the VLST, it is unlikely that the commercial market can support more than one aircraft production line, while declining defense budgets will not support a dedicated military VLST. A successful VLST must therefore meet airline requirements for more passenger and cargo capacity on congested routes into slot-limited airports and also provide a cost effective heavy airlift capacity to support the overseas deployment of US military forces. A successful VLST must satisfy three key missions: commercial passenger service with nominal seating capacity at a minimum of 650 passengers with a range capability of 7,000 to 10,000 miles; commercial air cargo service for containerized cargo to support global manufacturing of high value added products, 'just-in-time' parts delivery, and the general globalization of trade; and military airlift with adequate capacity to load current weapon systems, with minimal break-down, over global ranges (7,000 to 10,000 miles) required to reach the operational theater without need of overseas bases and midair refueling. The development of the VLST poses some technical issues specific to large aircraft, but also key technologies applicable to a wide range of subsonic transport aircraft. Key issues and technologies unique to the VLST include: large composite structures; dynamic control of a large, flexible structure; aircraft noise requirements for aircraft over 850,000 pounds; and increased aircraft separation due to increased wake vortex generation. Other issues, while not unique to the VLST, will critically impact the ability to build an efficient and affordable aircraft include: active control systems: Fly-By-Light/Power-By-Wire (FBL/PBW); high lift systems; flight deck associate systems; laminar flow; emergency egress; and modular design. The VLST will encounter severe restrictions on weight, ground flotation, span, length, and door height to operate at current airports/bases, gates, and cargo loading systems. One option under consideration is for a sea-based VLST, either a conventional seaplane or Wing-In-Ground effect (WIG) vehicle, which would allow greater operational flexibility, while introducing other design challenges such as water impact loads and salt-water corrosion. Lockheed Martin is currently developing a floatplane version of the C-130 Hercules which will provide experience with a modern sea-based aircraft. In addition to its own ongoing research activities, Lockheed Martin is also participating in the NASA Advanced Subsonic Technology, High Speed Research (HSR), and other programs which address some of the technologies needed for the VLST. The VLST will require NASA and US aerospace companies to work together to develop new capabilities and technologies for make the VLST a viable part of transportation beyond 2000

Electrical and Magnetic Properties of High Temperature Superconductors Using Varying forms of Data Acquisition

High temperature superconductors (HTS) are materials that display superconducting properties at temperatures above that of liquid nitrogen. Possible applications and ease of use in a typical physics laboratory make them interesting systems to study. In this experiment we measured the critical temperatures of two samples made of different HTS materials. We also devised a method that makes taking data automated

LASER SAFETY FOR THE EXPERIMENTAL HALLS AT SLAC’S LINAC COHERENT LIGHT SOURCE (LCLS) *

The LCLS at the SLAC National Accelerator Laboratory will be the world’s first source of an intense hard x-ray laser beam, generating x-rays with wavelengths of 1nm and pulse durations less than 100fs. The ultrafast x-ray pulses will be used in pump-probe experiments to take stop-motion pictures of atoms and molecules in motion, with pulses powerful enough to take diffraction images of single molecules, enabling scientists to elucidate fundamental processes of chemistry and biology. Ultrafast conventional lasers will be used as the pump. In 2009, LCLS will deliver beam to the Atomic Molecular and Optical (AMO) Experiment, located in one of 3 x-ray Hutches in the Near Experimental Hall (NEH). The NEH includes a centralized Laser Hall, containing up to three Class 4 laser systems, three x-ray Hutches for experiments and vacuum transport tubes for delivering laser beams to the Hutches. The main components of the NEH laser systems are a Ti:sapphire oscillator, a regen amplifier, green pump lasers for the oscillator and regen, a pulse compressor and a harmonics conversion unit. Laser safety considerations and controls for the ultrafast laser beams, multiple laser controlled areas, and user facility issues are discussed

Autonomous satellite docking system

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76348/1/AIAA-2001-4527-378.pd

Outcome Predictors in Treatment of Yaws

To estimate failure rates after treatment with benzathine penicillin and to identify determinants of failure that affected outcomes for yaws, we conducted a cohort study of 138 patients; treatment failed in 24 (17.4%). Having low initial titers on Venereal Disease Research Laboratory test and living in a village where yaws baseline incidence was high were associated with increased likelihood of treatment failure

A Comparison of Mechanical and Electrical Wind-Powered Water Pumps

Worldwide, 783 million people do not have access to clean water; 319 million of them reside in Sub-Saharan Africa. In this region, the transportation of water from its source to its point-of-use can be arduous to complete using current methods. The men and women in developing communities must exert considerable effort to retrieve the few gallons of water they need to survive. Due to the lack of infrastructure and no external source of energy, new methods to transport the water must be capable of generating their own energy. The Archimedes Initiative has set out to identify a mechanically powered pump that performs as effectively as an electrical pump based on the following criteria: a 5-10L/min flow rate, 1-mile flow distance, and 150 ft. vertical head distance. The team will conduct research into the efficiency and performance of both hybrid and mechanical systems. At the project’s conclusion, The Archimedes Initiative plans to have a fully functioning wind-powered water pump capable of meeting the design criteria. The project is currently ongoing and much progress has been made towards developing preliminary designs and a viable prototype. After several iterations of design review and redesign, the team plans to begin construction of a prototype in January and testing is scheduled for February 2017. A fully functioning and usable prototype will be complete by the conclusion of the 2016-2017 school year

Powering Ocean Giants: The Energetics of Shark and Ray Megafauna

Shark and ray megafauna have crucial roles as top predators in many marine ecosystems, but are currently among the most threatened vertebrates and, based on historical extinctions, may be highly susceptible to future environmental perturbations. However, our understanding of their energetics lags behind that of other taxa. Such knowledge is required to answer important ecological questions and predict their responses to ocean warming, which may be limited by expanding ocean deoxygenation and declining prey availability. To develop bioenergetics models for shark and ray megafauna, incremental improvements in respirometry systems are useful but unlikely to accommodate the largest species. Advances in biologging tools and modelling could help answer the most pressing ecological questions about these iconic species

Valuation of scleroderma and psoriatic arthritis health states by the general public

<p>Abstract</p> <p>Objective</p> <p>Psoriatic arthritis (PsA) and scleroderma (SSc) are chronic rheumatic disorders with detrimental effects on health-related quality of life. Our objective was to assess health values (utilities) from the general public for health states common to people with PsA and SSc for economic evaluations.</p> <p>Methods</p> <p>Adult subjects from the general population in a Midwestern city (N = 218) completed the SF-12 Health Survey and computer-assisted 0-100 rating scale (RS), time trade-off (TTO, range: 0.0-1.0) and standard gamble (SG, range: 0.0-1.0) utility assessments for several hypothetical PsA and SSc health states.</p> <p>Results</p> <p>Subjects included 135 (62%) females, 143 (66%) Caucasians, and 62 (28%) African-Americans. The mean (SD) scores for the SF-12 Physical Component Summary scale were 52.9 (8.3) and for the SF-12 Mental Component Summary scale were 49.0 (9.1), close to population norms. The mean RS, TTO, and SG scores for PsA health states varied with severity, ranging from 20.2 to 63.7 (14.4-20.3) for the RS 0.29 to 0.78 (0.24-0.31) for the TTO, and 0.48 to 0.82 (0.24-0.34) for the SG. The mean RS, TTO, and SG scores for SSc health states were 25.3-69.7 (15.2-16.3) for the RS, 0.36-0.80 (0.25-0.31) for the TTO, and 0.50-0.81 (0.26-0.32) for the SG, depending on disease severity.</p> <p>Conclusion</p> <p>Health utilities for PsA and SSc health states as assessed from the general public reflect the severity of the diseases. These descriptive findings could have implications regarding comparative effectiveness research for tests and treatments for PsA and SSc.</p