Space Shuttle External Tank Gaseous Oxygen Vent System

Two problems had to be solved to assure successful elimination of ice on the External Tank (ET). First, an access/support structure was provided from the Launch Complex 39A Fixed Service Structure to the vicinity of the nose cone on the ET approximately 82.3 meters (270 feet) above the surface of the pad and 22.9 meters (75 feet) from the face of the FSS. Second, an umbilical was designed and tested that would seal around the ET gaseous oxygen (GOX) vent louvers and not allow ice to form on the tank or the umbilical. A modified Apollo service arm was chosen. An inflatable vent seal subsystem was chosen, providing a cloth seal around each vent louver with an internal annulus to provide a path for the gaseous oxygen from the ET to a hard duct on the swing arm

Coercion, vertical trust and entrepreneurism in bureaucracies: evidence from the Nazi Holocaust

Breton and Wintrobe (1982) develop a non-traditional (modern) model of bureaucratic management that is based on the notion of “vertical trust†– the notion that subordinates “trade services†that advance the goals of the bureau''s leadership in return for various “informal payments,†none of which are codified in formal contracts between the two sets of parties. Applying the model to the Nazi bureaucracy explains how Nazi functionaries, such as Adolf Eichmann, acted as bureaucratic entrepreneurs in accomplishing goals relating to “the Jewish question,†and ultimately “the Final Solution,†for their superiors, such as Adolf Hitler and Heinrich Himmler (Breton and Wintrobe, 1986). As an extension of prior research, the current study examines the hypothesis that the use these vertical trust relationships within the borders of their minor Axis partners (e.g., Hungary) worked more effectively for the Germans than coercion, which would have been required to a greater degree within the borders of occupied European countries (e.g., Holland). Specifically, our estimates suggest that, ceteris paribus, owing to their use of vertical trust networks the minor Axis countries each contributed about 152,000 more European Jews to the Nazi Holocaust apparatus than their German-occupied European country counterparts, wherein the Nazis relied more heavily on coercion.bureaucratic entrepreneurship, vertical trust networks, coercion, statistical decomposition tests

Effects of low level military training flights on wading bird colonies in Florida

During 1983 and 1984 the effect of low level military training flights on the establishment. size and reproductive success of wading bird colonies was studied in Florida. Based on the indirect evidence of colony distributions and turnover rates in relation to military areas (training routes designated to 500 feet or less above ground level and military operations areas). there was no demonstrated effect of military activity on wading bird colony establishment or size on a statewide basis. Colony distributions were random with respect to military areas and turnover rates were within 2% when military and non-military areas were compared. Colony distributions and turnover rates, however. were related to the amount and type.Les tuer-tne or freshwater) of wetland. respectively. During two breeding seasons the behavioral responses and reproductive success of selected species were monitored in a non-habituated treatment colony (military overflights) and a control colony (no overflights). Breeding wading birds responded to F-16 overflights at 420 knots indicated airspeed. 82-84% maximum rpm. 500 feet above ground level and sound levels ranging from 55-100 dBA by exhibiting no response. looking up or changing position (usually to an alert posture): no productivity limiting responses were observed. High-nesting Great Egrets responded more than other species, nestling Great Egrets and Cattle Egrets responded significantly (r <.05) more intensely than adults of their respective species, and adults responded less during incubation and late chick-rearing than at other times. In addition, no differences in adult attendance, aggressive interactions or chick feeding rates were observed to result from F-16 overflights. No evidence of habituation to overflights was noted. Humans entering the colony or airboats approaching the colony vicinity elicited the most severe responses (flushing and panic flights) observed at both sites. Since relatively little coastal military activity occurs at low levels ( ~500 ft) and only one Brown Pelican colony (5-6% of the breeding population) was located in such an area, the reproductive success of five, more lIexposedll study species (Great Egrets, Snowy Egrets, Tricolored Herons, Little Blue Herons, Cattle Egrets) nesting in interior freshwater colonies was studied. Reproductive activity including such factors as nest success, nestling survival, nestling mortality, and nesting chronology was independent of F-16 overflights but related to ecological factors including colony location, colony characteristics and climatology. The responses to and effects of F-16 overflights, as reported here, should not be considered representative of military aircraft at lower altitudes or greater noise levels. (194 pages

Switchable Genetic Oscillator Operating in Quasi-Stable Mode

Ring topologies of repressing genes have qualitatively different long-term dynamics if the number of genes is odd (they oscillate) or even (they exhibit bistability). However, these attractors may not fully explain the observed behavior in transient and stochastic environments such as the cell. We show here that even repressilators possess quasi-stable, travelling-wave periodic solutions that are reachable, long-lived and robust to parameter changes. These solutions underlie the sustained oscillations observed in even rings in the stochastic regime, even if these circuits are expected to behave as switches. The existence of such solutions can also be exploited for control purposes: operation of the system around the quasi-stable orbit allows us to turn on and off the oscillations reliably and on demand. We illustrate these ideas with a simple protocol based on optical interference that can induce oscillations robustly both in the stochastic and deterministic regimes.Comment: 24 pages, 5 main figure

Mesoscopic one-way channels for quantum state transfer via the Quantum Hall Effect

We show that the one-way channel formalism of quantum optics has a physical realisation in electronic systems. In particular, we show that magnetic edge states form unidirectional quantum channels capable of coherently transporting electronic quantum information. Using the equivalence between one-way photonic channels and magnetic edge states, we adapt a proposal for quantum state transfer to mesoscopic systems using edge states as a quantum channel, and show that it is feasible with reasonable experimental parameters. We discuss how this protocol may be used to transfer information encoded in number, charge or spin states of quantum dots, so it may prove useful for transferring quantum information between parts of a solid-state quantum computer.Comment: 4 pages, 3 figure

Coherent Quantum-Noise Cancellation for Optomechanical Sensors

Using a flowchart representation of quantum optomechanical dynamics, we design coherent quantum-noise-cancellation schemes that can eliminate the back-action noise induced by radiation pressure at all frequencies and thus overcome the standard quantum limit of force sensing. The proposed schemes can be regarded as novel examples of coherent feedforward quantum control.Comment: 4 pages, 5 figures, v2: accepted by Physical Review Letter

Racial Differences in the Relationship Between Infant Mortality and Socioeconomic Status

This study presents an ecological analysis of the relationship between infant mortality and economic status by race in metropolitan Ohio, using census data on mother\u27s residence and economic status determined by the percentage of low-income families living in each area. The analysis updates previous studies as white-non-white comparisons for total infant mortality are examined for the US censuses of 1960, 1970, 1980, 1990 and 2000; and more detailed period- and broad cause-specific rates are presented for 2000. A pronounced inverse association is consistently found between income status and infant mortality for whites, while for non-whites this pattern first emerges in 1979-81, disappears during the 1980s and then returns more strongly during the 1990s. Similarly, the 2000 data reveal a consistent inverse pattern between income status and infant mortality for white and non-white neonatal and postneonatal death rates, as well as exogenous cause-specific death rates. It is concluded that low-income whites and non-whites have infant mortality rates substantially higher than the overall rate for the population. Policy implications are discussed

Machine learning differentiates enzymatic and non-enzymatic metals in proteins

Metalloenzymes are 40% of all enzymes and can perform all seven classes of enzyme reactions. Because of the physicochemical similarities between the active sites of metalloenzymes and inactive metal binding sites, it is challenging to differentiate between them. Yet distinguishing these two classes is critical for the identification of both native and designed enzymes. Because of similarities between catalytic and non-catalytic metal binding sites, finding physicochemical features that distinguish these two types of metal sites can indicate aspects that are critical to enzyme function. In this work, we develop the largest structural dataset of enzymatic and non-enzymatic metalloprotein sites to date. We then use a decision-tree ensemble machine learning model to classify metals bound to proteins as enzymatic or non-enzymatic with 92.2% precision and 90.1% recall. Our model scores electrostatic and pocket lining features as more important than pocket volume, despite the fact that volume is the most quantitatively different feature between enzyme and non-enzymatic sites. Finally, we find our model has overall better performance in a side-to-side comparison against other methods that differentiate enzymatic from non-enzymatic sequences. We anticipate that our model’s ability to correctly identify which metal sites are responsible for enzymatic activity could enable identification of new enzymatic mechanisms and de novo enzyme design

Dynamics and energetics of the South Pacific Convergence Zone during FGGE SOP-1 and South Pacific Convergence Zone and global-scale

Significant accomplishments (papers published, conference presentations, and education degrees) are presented. The focus of the current research is outlined. Plans for the coming year are discussed briefly

Flight evaluation of advanced flight control systems and cockpit displays for powered-lift STOL Aircraft

A flight research program was conducted to assess the improvements, in longitudinal path control during a STOL approach and landing, that can be achieved with manual and automatic control system concepts and cockpit displays with various degrees of complexity. NASA-Ames powered-lift Augmentor Wing Research Aircraft was used in the research program. Satisfactory flying qualities were demonstrated for selected stabilization and command augmentation systems and flight director combinations. The ability of the pilot to perform precise landings at low touchdown sink rates with a gentle flare maneuver was also achieved. The path-control improvement is considered to be applicable to other powered-lift aircraft configurations