Evaluation of Microwave Landing System (MLS) effect on the delivery performance of a fixed-path metering and spacing system

Metering and spacing (M & S) system's algorithms described assume an aircraft two dimensional are navigation capability. The three navigation systems compared were: very high frequency omnidirectional range/distance measuring equipment (VOR/DME) and ILS, VOR/DME and + or - 40 MLS, and VOR/DME and + or - 60 MLS. Other factors studied were M & S tentative schedule point location, route geometry effects, and approach gate location effects. Summarized results are: the MLS offers some improvement over VOR/DME and ILS if all approach routes contain computer assisted turns; pilot reaction to moving the gate closer to the runway threshold may adversely affect M & S performance; and coupling en route metering to terminal scheduling transfers most of the terminal holding to more full efficient, higher altitude en route delay

Experimentation with Human Beings: Light or Only Shadows?

We have failed Jay Katz. Like the man looking under the lamp-post for his keys-not because that was where he was standing when he dropped them but because the light is better there-we have labored too long in the light and poked too infrequently into the shadows where the often painful truth is to be found. We have treated as exact the imprecise process of balancing research risks and benefits. We have exalted autonomy and made a sacrament of consent forms, even those that run to hellish lengths, littered with jargon - and forgotten the myriad constraints on subjects\u27 choices. We have realized that, however well-intentioned researchers may be, their individual judgment of when and how to conduct research is usually very partial, in both senses of that word. Yet, from that realization we have moved to the contradictory conclusion that by instituting prior review by Institutional Review Boards (IRBs), we have solved the ethical problems involved in deciding when and how to conduct research. Above all, we have developed elaborate rules and processes to normalize human experimentation, to treat it as an ordinary activity. We have thus avoided looking clearly at the moral dilemma that lies at the heart of every research encounter: We are asking you to do this not for yourself but for others, even though we know that the role of human subject entails real and sometimes unforeseen risks including death. Such a statement is significant not becauseor not solely because-it clearly describes the potential harm. I agree with Jay that this is not the critical issue, though it is hardly one that we can ignore, in light both of the historical abuses of research subjects and also of what has occurred much more recently at such renowned medical institutions as the University of Pennsylvania and Johns Hopkins. Rather, its central significance lies in its frank description of the aims of research and, hence, of the potential divergence of interest between the prospective subject and the person offering to enroll him or her in the research project

The impact of analysis on bargaining in government

"1691"--handwritten on coverIncludes bibliographical references (p. 32

The C(3P) + NH3 reaction in interstellar chemistry: II. Low temperature rate constants and modeling of NH, NH2 and NH3 abundances in dense interstellar clouds

A continuous supersonic flow reactor has been used to measure rate constants for the C + NH3 reaction over the temperature range 50 to 296 K. C atoms were created by the pulsed laser photolysis of CBr4. The kinetics of the title reaction were followed directly by vacuum ultra-violet laser induced fluorescence (VUV LIF) of C loss and through H formation. The experiments show unambiguously that the reaction is rapid at 296 K, becoming faster at lower temperatures, reaching a value of 1.8 10-10 cm3 molecule-1 s-1 at 50 K. As this reaction is not currently included in astrochemical networks, its influence on interstellar nitrogen hydride abundances is tested through a dense cloud model including gas-grain interactions. In particular, the effect of the ortho-to-para ratio of H2 which plays a crucial role in interstellar NH3 synthesis is examined