22,201 research outputs found
Absorption spectrum of iron in the vacuum ultraviolet 2950 - 1588 angstrom
Absorption spectrum of iron in vacuum ultraviole
Comparison of speech intelligibility in cockpit noise using SPH-4 flight helmet with and without active noise reduction
Active Noise Reduction (ANR) is a new technology which can reduce the level of aircraft cockpit noise that reaches the pilot's ear while simultaneously improving the signal to noise ratio for voice communications and other information bearing sound signals in the cockpit. A miniature, ear-cup mounted ANR system was tested to determine whether speech intelligibility is better for helicopter pilots using ANR compared to a control condition of ANR turned off. Two signal to noise ratios (S/N), representative of actual cockpit conditions, were used for the ratio of the speech to cockpit noise sound pressure levels. Speech intelligibility was significantly better with ANR compared to no ANR for both S/N conditions. Variability of speech intelligibility among pilots was also significantly less with ANR. When the stock helmet was used with ANR turned off, the average PB Word speech intelligibility score was below the Normally Acceptable level. In comparison, it was above that level with ANR on in both S/N levels
Impacts of technology on the capacity needs of the US national airspace system
A review of the U.S. air transportation system is undertaken, focusing on airspace and airport capacity. Causes of delay and congestion are investigated. Aircraft noise is identified as the fundamental hindrance to capacity improvement. Research areas for NASA are suggested to improve capacity through technology
The cutoff-dependence of the Casimir force within an inhomogeneous medium
We consider the ground state energy of the electromagnetic field in a piston
geometry. In the idealised case, where the piston and the walls of the chamber
are taken as perfect mirrors, the Casimir pressure on the piston is finite and
independent of the small scale physics of the media that compose the mirrors;
the Casimir-energy of the system can be regularised and is cutoff-independent.
Yet we find that, when the body of the piston is filled with an inhomogeneous
dielectric medium, the Casimir energy is cutoff-dependent, and the value of the
pressure is thus inextricably dependent on the detailed behaviour of the mirror
and the medium at large wave-vectors. This result is inconsistent with recent
proposals for regularising Casimir forces in inhomogeneous media.Comment: 6 pages, 2 figure
Potential impacts of advanced technologies on the ATC capacity of high-density terminal areas
Advanced technologies for airborne systems (automatic flight control, flight displays, navigation) and for ground ATC systems (digital communications, improved surveillance and tracking, automated decision-making) create the possibility of advanced ATC operations and procedures which can bring increased capacity for runway systems. A systematic analysis is carried out to identify certain such advanced ATC operations, and then to evaluate the potential benefits occurring over time at typical US high-density airports (Denver and Boston). The study is divided into three parts: (1) A Critical Examination of Factors Which Determine Operational Capacity of Runway Systems at Major Airports, is an intensive review of current US separation criteria and terminal area ATC operations. It identifies 11 new methods to increase the capacity of landings and takeoffs for runway systems; (2) Development of Risk Based Separation Criteria is the development of a rational structure for establishing reduced ATC separation criteria which meet a consistent Target Level of Safety using advanced technology and operational procedures; and (3) Estimation of Capacity Benefits from Advanced Terminal Area Operations - Denver and Boston, provides an estimate of the overall annual improvement in runway capacity which might be expected at Denver and Boston from using some of the advanced ATC procedures developed in Part 1. Whereas Boston achieved a substantial 37% increase, Denver only achieved a 4.7% increase in its overall annual capacity
Cherenkov-dE/dx-range measurements on cosmic ray iron group nuclei
A balloon experiment which combined a large area plastic detector unit with electronic dE/dx-C data is presented. The correlation of the electronic data with the range data of the plastic detector stack was achieved by rotating plastic detector disks which provided in this way the passive plastic detector with an incorporated time determination. The constant flux of cosmic ray particles with charge Z greater than two was used to gauge the time resolving system. Stopping cosmic ray iron group nuclei in the energy range 400 to 700 MeV/nuc are identified using their electronic scintillator and Cherenkov signals and their etch conelengths and range data. The precise knowledge of the particle's trajectory proposes refined pathlength corrections to the electronic data
Detention without Trial in the Second World War: Comparing the British and American Experiences
My interest in the detention of citizens, without trial, in Britain during the war of 1939-1945 arose as a byproduct of a more general interest. The study of cases has long been central to the common law tradition. But the legal dramas we examine so minutely are too often both contextless and dehumanized. Real people assume the masks of the law, becoming plaintiffs and defendants, offerors and offerees, grantors and contingent remainderpersons, concealed from us by the forms into which their problems have been packaged for legal analysis. Two English leading cases, decided by the House of Lords on November 3, 1941, strikingly illustrate this point. Their names are Liversidge v. Anderson and Greene v. Secretary of State for Home Affairs. In both cases individuals, Robert William Liversidge, alias Jack Perlsweig, and Ben Greene respectively, attempted to challenge the legality of their detention without trial under Regulation 18B of the wartime Defense Regulations. The defendants in the cases were Sir John Anderson, Home Secretary in 1939-1940, and his successor, Herbert Morrison, who took office in October 1940.
These cases are regarded as major decisions in English and Commonwealth constitutional law. Their counterparts in the United States are the Supreme Court decisions concerning the treatment, including detention, of Japanese American citizens after the attack on Pearl Harbor on December 7, 1941, particularly the decisions in Korematsu v. United States and Ex Parte Endo, both decided on December 18, 1944. These American cases at least reveal the official reason why the individuals were detained; their English counterparts give virtually no indication as to who Liversidge and Greene were, why the authorities had locked them up, and why the government lawyers had been prepared to resist their attempts to secure liberty. There is a real sense in which the reported decisions give no indication as to what the litigation was really about.
I have attempted to recreate the historical context of these cases and to locate them in the general history of civil liberty during the Second World War. This is in part a comparative study. Both in Britain, the original home of the common law, and in the United States of America, its present day principal place of residence, individuals were detained without trial in the name of military necessity or national security. Some few turned to the courts to vindicate that most basic of all civil rights, the right to personal freedom. They had little success. In Britain, one individual, a Captain Budd, secured his liberty through habeas corpus proceedings in May 1941. Curiously enough, the score in the United States seems to have been the same, Mitsuye Endo having secured her complete liberty through legal action in 1944
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