Vehicle Design for Mars Landing and Return to Mars Orbit

This paper briefly describes three modes for accomplishing the Mars landing mission and compares them on a gross basis to indicate their probable order of merit and to identify design requirements placed on the Mars-excursion module (MEM) by the choice of mode. The paper shows that a flyby-rendezvous mode requiring low weight in earth orbit requires the MEM to enter the Mars atmosphere at velocities ranging from 20,000 to 30,000 ft/sec. The MEM for the flyby-rendezvous mode is not covered in this paper but merits further study. The MEM for the other modes of mission accomplishment begins its active operational sequence in Mars orbit and need not be greatly influenced by the method of delivery to Mars orbit. Parametric studies of the entry problem for two vehicles typifying a ballistic-type and a lifting-body-type were conducted to identify the problems associated with design of a MEM to accommodate the extremes of Mars atmospheric density presently predicted. This brief study indicates that: (a) the presently predicted density extremes of the Mars atmosphere present no serious design problems for a MEM which can operate across the entire band of predicted densities; (b) details of operational requirements and mission objectives will control the choice of configuration rather than entry requirements; and (c) the ballistic-type MEM is lighter and simpler but has less operational flexibility than a high L/D MEM

Integrated Geophysical Investigations of a Methane Releasing Pingo in a Changing Permafrost Environment, Svalbard

Open-system pingos form a fluid-flow conduit through continuous permafrost that enables the release of methane; a potent greenhouse gas. However, the factors that impact the formation and structure of open-system pingos remains poorly understood, and the parallels that these terrestrial landforms have with methane emitting submarine forms is uncertain. In this thesis, a series of geophysical investigations are conducted on Lagoon Pingo, Svalbard: a coastal open-system pingo that emits locally significant quantities of methane. In investigations into pingo structure through electrical resistivity tomography, resistivities imply that Lagoon Pingo is dominated by segregation ice, thereby highlight the impact of frost-susceptible, fine-grained sediments on pingo formation. Seismic investigations outline the depth of these sediments locally (~68 m), and indicate an uncertainty surrounding the flow path of local groundwaters. Constraining the groundwater dynamics through self-potential investigations, elevated magnitudes in potential measurements on the northern side of the pingo are interpreted as groundwaters flowing beneath the pingo complex from an alluvial fan on the northern side of Lagoon Pingo. Transient electromagnetics, when combined with seismic velocities within a four-phase model, identify a heterogeneous layer containing alluvial fan deposits beneath the open-system pingo. The integrated geophysical observations highlight the role that alluvial fans can have in pingo growth, by providing a hydraulically conductive medium through poorly permeable sediments characteristic of Holocene marine environments. This can act as a confined aquifer, explaining the artesian conditions at Lagoon Pingo. This also provides sedimentological circumstances that were favourable for previous pockmark formation, and may explain how a spring has persisted through Holocene sedimentation. These integrated geophysical investigations therefore highlight the role that alluvial fans have in pingo formation, and indicate how open-system pingos may evolve from submarine seeps and pockmarks

Structure, function and context : the impact of morphometry and ecology on olfactory sensitivity

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February, 2005In this thesis, the relationships of olfactory sensitivity to three biological variables were tested. The sensitivity of a marine mammal, the sea otter (Enhydra lutris) was measured in order to determine whether a marine lifestyle results in impaired olfaction. The effect of dietary relevance on sensitivity to specific odorants was evaluated. Finally, a new morphometric model of olfactory uptake efficiency was developed and tested against behavioral measurements of olfactory sensitivity in twelve mammalian species from five orders. Olfactory thresholds were obtained for the first time from two sea otters for seven odorant compounds from various natural sources. Otters were trained using operant conditioning to participate in direct behavioral testing. Sea otter olfactory sensitivity was comparable to that of previously studied terrestrial mammals. The incidence of an odorant in the diet of the olfactor was found to influence specific sensitivity to that compound but to varying degrees among different mammalian orders. Nasal cavity specimens were measured using radiologic (CT scan) and histologic (light microscopy) techniques. Surface areas and volumes of the nasal cavity were used to calculate the Olfactory Uptake Efficiency (OUE). OUE is significantly related to olfactory bulb volume. A possible relationship was found between OUE and general olfactory sensitivity.I am grateful to the Oregon Zoo and the Oregon Coast Aquarium, whose exhibit animals provided the olfactory threshold data, as well as the Monterey Bay Aquarium, the Point Defiance Zoo and the New England Aquarium, which also participated. Nasal cavity specimens were generously donated by the American Museum of Natural History, the Whitehead Institute at the Massachusetts Institute of Technology, the Biology Department of MIT, the California Oiled Wildlife Network, the Harvard Museum of Comparative Zoology, the Institute for Hydrology and Ecology at Monk's Hood, Tufts Veterinary School, the New England Regional Primate Research Center, Lion Country Safari Zoo, and the Cameron Park Zoo. Funding was provided by the Woods Hole Oceanographic Institution's Education Department, Biology Department and Ocean Ventures Fund, the National Science and Engineering Research Council of Canada, the Gen Foundation, the Massachusetts Institute of Technology's Student Assistance Fund, the European Chemoreception Research Organization, the Society for Experimental Biology, the Company of Biologists, and the Office of Naval Research

Examination of IV antibiotic use and length of stay in community-acquired pneumonia patients

The purpose of this study was to examine the relationship between IV antibiotic administration and the length of stay for patients with community-acquired pneumonia. Research demonstrates that pneumonia is a large economic burden to acute care facilities across the United States. An ex post facto design was used to examine the difference in lengths of stay (LOS) for two groups of patients diagnosed with community-acquired pneumonia in the Appalachian region. The first group received IV antibiotic therapy at or within 8 hours of arrival to the hospital. The second group received IV antibiotic therapy after 8 hours of arrival to the hospital. All subjects in this study were at least 18 years old and admitted to the hospital for one or more days during the fiscal year 2000. Patients who were discharged within 14 days prior to admission were excluded from the study. Data were collected from 60 medical records randomly selected from 349 patients admitted for one or more days with pneumonia during the same year. An adapted version of the Medicare Quality Indicator System: Pneumonia Module was used to audit the medical records. All subjects in this study received appropriate IV antibiotics according to the Infectious Disease Society of America’s guidelines. The mean LOS for each group was examined using an independent t-test. The retrospective ex post facto analysis revealed that the administration of IV antibiotics within 8 hours of arrival to the hospital does not significantly reduce LOS for this CAP sample (p = .25). Further investigation revealed that the nurses at this facility understand the importance of administering timely IV antibiotic therapy. This evidence is supported in that 77% of the study sample received appropriate IV antibiotic therapy within 8 hours of arrival to the hospital

Constructing History: Richard III and the Wars of the Roses: A Teaching Unit

The entirety of modern academia is founded on some form of historical authentication and interpretation. Historical exploration, in fact, represents the necessary element for the cognitive linking of interdisciplinary learning. At essence academic historiography is first - the product of intrigue - and then its contemporary expression. But though the field of academic history poses the perfect union of science and literary arts, modern instruction has sometimes grappled with finding and striking the optimal balance for effectively teaching historical authentication and its interpretation. Recognition and application of both aspects are essential to the effective demonstration of history as a viable, if not primary choice of high school-aged students for academic career path. The focus of this project relies on the premise that young people find fascination in history as readily as they might music, mathematics, medicine, or any other form of science and art. Using the dramatic Wars of the Roses as a backdrop, Constructing History: Richard III and the Wars of the Roses: A Teaching Unit aims to whet the historical appetite of students, and to instill in them a sense of historical awareness as individuals. Our curriculum provides high school educators with lessons that clearly demonstrate to students the difference between academic historiography and historical narrative while highlighting the imperative for interdisciplinarity. The unit introduces and profiles figures - both likely and unlikely historians - of various academic and public professions from the past and the present. Students will begin to understand the importance of discovering for themselves whether the histories they themselves have either accepted (or rejected) are true. Armed with this knowledge they can then determine how best to reasonably express their conclusions, leading directly to the main focal point of the project wherein students will learn that history is a cultural construct, and that especially now, all of us participate in its construction as both actors and narrators

Music with a Racial Nexus: Culture Clash in Los Angeles Punk Rock Communities, 1976-1981

The chief argument of this work rests on the idea that culture-blindness—especially White ethnic-cultural blindness—contributed as much as issues of race to the heavily documented social rift between predominantly Chicanx, Eastside punk and the mostly-White, Westside punk rock communities of Los Angeles, 1976-1981. To date, historical blame for the divide has centered on racism, including racist intent. The second area of analysis directly relates to the first in that it demonstrates the inextricable link between cultural and spatial identity formation and assignment among the various scenes. This aspect of the study evaluates the complaints of some Eastside acts who have contended that based on racist attitude(s), they were prohibited from playing in Westside venues, thereby limiting their opportunities for gaining notoriety in the industry overall. This evaluation attempts to weigh the validity of that complaint against other determinative, influential aspects of the entire punk phenomenon. Lastly, through historically tracking the remnants of cultural Chicanismo clear into L.A.’s first and succeeding punk waves, this work analyzes the art of protest, and the protest in art as applied to that city’s diverse punk aesthetics

F-15 inlet/engine test techniques and distortion methodologies studies. Volume 3: Power spectral density plots

Power spectral density plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle

F-15 inlet engine test techniques and distortion methodologies studies. Volume 9: Stability audits

Stability audit plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle