Velocity Requirements for Abort From the Boost Trajectory of a Manned Lunar Mission

An investigation is made of the abort velocity requirements associated with failure of a propulsion system for a manned lunar mission. Two cases are considered: abort at less than satellite speed, which results in maximum decelerations in the following entry, and abort at greater than satellite speed with immediate return to earth. The velocity requirements associated with the latter problem are found to be substantial (several thousand feet per second) and are found to be even more severe if boost trajectories which lead to burnout at high altitudes or large flight-path angles are used. The velocity requirements associated with abort at less than satellite speed are found to be less severe than those for abort at greater than satellite speed except for nonlifting vehicles. It is found that abort rockets sufficient for abort at greater than satellite speed can be used to reduce maximum decelerations in entries following an abort at lower speeds. This reduction is accomplished by use of the abort rockets to decrease entry angle immediately prior to entry into the atmosphere

Computer-aided boundary delineation of agricultural lands

The National Agricultural Statistics Service of the United States Department of Agriculture (USDA) presently uses labor-intensive aerial photographic interpretation techniques to divide large geographical areas into manageable-sized units for estimating domestic crop and livestock production. Prototype software, the computer-aided stratification (CAS) system, was developed to automate the procedure, and currently runs on a Sun-based image processing system. With a background display of LANDSAT Thematic Mapper and United States Geological Survey Digital Line Graph data, the operator uses a cursor to delineate agricultural areas, called sampling units, which are assigned to strata of land-use and land-cover types. The resultant stratified sampling units are used as input into subsequent USDA sampling procedures. As a test, three counties in Missouri were chosen for application of the CAS procedures. Subsequent analysis indicates that CAS was five times faster in creating sampling units than the manual techniques were

Motion and Heating During Atmosphere Reentry of Space Vehicles

The results of an analysis of the motion and heating during atmospheric reentry of manned space vehicles has shown the following: 1. Flight-corridor depths which allow reentry in a single pass decrease rapidly as the reentry speed increases if the maximum deceleration is limited to 10 g. 2. Use of aerodynamic lift can result in a three-to five fold increase in corridor depth over that available to a ballistic vehicle for the same deceleration limits. 3. Use of aerodynamic lift to widen these reentry corridors causes a heating penalty which becomes severe for values of the lift-drag ratio greater than unity for constant lift-drag entry. 4. In the region of most intense convective heating the inviscid flow is generally in chemical equilibrium but the boundary-layer flows are out of equilibrium. Heating rates for the nonequilibrium boundary layer are generally lower than for the corresponding equilibrium case. 5. Radiative heating from the hot gas trapped between the shock wave and the body stagnation region may be as severe as the convective heating and unfortunately occurs at approximately the same time in the flight

Mental Illness and the Law of Contracts

The traditional and most important problem relative to mental illness and the contract is the situation created when mental illness exists at the time of agreement (the problem of contractual capacity). One principal result of mental illness at this time may be the avoidance of the contract by the mentally ill person. Since case law in this area is extensive, the major portion of the study is concerned with this problem (parts II, III and IV) and the effects of such incapacity throughout the remaining course of the contract. Mental illness occurring after agreement and at the time of performance of a party to a contract can also have important effects on the remainder of the contract, and these effects are discussed in part V. Finally, there can be a number of other effects caused by mental illness which occur after agreement but do not directly affect performance. These are discussed in part VI

Employment as HIV Prevention: An Employment Support Intervention for Adolescent Men Who Have Sex With Men and Adolescent Transgender Women of Color

BACKGROUND: The purpose of this study was to adapt and pilot-test an employment support, primary HIV intervention tailored to the needs of adolescent men who have sex with men and adolescent transgender women of color. SETTING: The intervention was implemented in 2 settings: controlled environment (Phase 1) and real-world community-based (Phase 2) setting in Chicago, IL. METHODS: Eighty-seven adolescent men who have sex with men and adolescent transgender women of color ages 16-24 participated in Work2Prevent , a 4-session employment and HIV prevention intervention, designed to increase job-readiness and reduce HIV risk. Intervention sessions consisted of group activities: educational games, roleplaying/modeling behavior, and self-regulation exercises. Participants were assessed at baseline, postintervention, and 8-month (Phase 1) or 3-month follow-up (Phase 2). RESULTS: Participants evaluated Work2Prevent as feasible and acceptable, rating intervention quality, usefulness, and satisfaction highly. Overall, 59.6% (Phase 1) and 85.0% (Phase 2) participants attended 2 or more sessions. At 8 months, Phase 1 participants reported a mean increase of 11.4 hours worked per week. Phase 2 participants reported a mean increase of 5.2 hours worked per week and an increase in job-seeking self-efficacy. Phase 2 participants also reported a decrease in transactional sex work. CONCLUSION: Work2Prevent is one of the first structural primary HIV interventions to specifically focus on adolescent employment readiness. Findings suggest Work2Prevent is feasible and acceptable, improved adolescent employment outcomes, and reduced HIV risk associated with transactional sex work. Our study underscores the need for alternative pathways, such as addressing socioeconomic determinants, to prevent adolescent HIV infection

Solar-Powered Airplane with Cameras and WLAN

An experimental airborne remote sensing system includes a remotely controlled, lightweight, solar-powered airplane (see figure) that carries two digital-output electronic cameras and communicates with a nearby ground control and monitoring station via a wireless local-area network (WLAN). The speed of the airplane -- typically <50 km/h -- is low enough to enable loitering over farm fields, disaster scenes, or other areas of interest to collect high-resolution digital imagery that could be delivered to end users (e.g., farm managers or disaster-relief coordinators) in nearly real time

Optimizing training event schedules at Naval Air Station Fallon

Naval Air Station (NAS) Fallon, located in Northwestern Nevada, is best known for one of its resident training schools, the United States Navy Fighter Weapons School, popularly known as Topgun. Fallon training range airspace overlays 10,200 square miles and contains ground ranges for bombing and electronic warfare. In addition to servicing the flight training requirements of its resident programs, NAS Fallon provides airspace, land, and logistical support for dozens of outside commands, ranging from carrier airwing detachments to special operations forces. It follows that scheduling training events at NAS Fallon is heavily constrained due to large demands on limited training airspace and aircraft availability. This thesis constructs, implements, and produces sample results using the Scheduling Assistance Tool (SAT), a mixed integer program designed as an aid to the operations department at NAS Fallon. SAT optimizes allocation of range space, subject to limited resources such as operational field hours, equipment, and event turnaround times. The primary output is a deconflicted daily flight schedule that includes unit, event, day, start time, and range assignment. We test SAT with 323 real-world event requests over a one-month period. SAT’s baseline test results in 86% of events being scheduled. By giving optional ranges and start times to the unscheduled events, SAT is able to schedule 99% of the same events. Several additional excursions from the baseline scenario demonstrate how SAT can improve event schedules.http://archive.org/details/optimizingtraini1094558370Outstanding ThesisLieutenant Junior Grade, United States NavyApproved for public release; distribution is unlimited

Long-term survivorship and crown area dynamics of tropical rainforest canopy trees

Lateral shading of direct-beam irradiation among neighboring canopy tree crowns in a nonequatorial tropical rain forest canopy was modeled as a function of solar position using a photogrammetric database derived from large-scale color aerial stereopairs (1:1500–1:3000 scale) acquired in 1976. The interception of direct-beam irradiation by the orthogonally projected crown area of each tree was computed at hourly intervals over a full calendar year using a Parameterization model of cloud-attenuated direct-beam availability. The annual totals of intercepted direct-beam irradiation (Ib) ranged from 1.81 to 4.13 GJ·m−2·yr−1. Expressed as a percentage of the available incident direct-beam irradiation, these values ranged from 44% to 100%. Approximately 20% of the sample population intercepted <70% of the available annual direct-beam irradiation. The long-term effects of lateral shading and the intertree differences in Ib were assessed using repeat aerial stereophotography of the same section of forest 18 yr later in 1994 for the determination of the mortality, survivorship, and crown growth of the canopy trees delimited in the 1976 stereopairs. Mortality over the 18-yr period amounted to 27.2%. Based on the lateral shading simulations, the mean annual Ib totals of the survivors and those that died were significantly different (P < 0.001). Approximately 40% of the survivors experienced crown area reductions. Although there was no significant difference in the Ib of survivors with crown growth and those with crown reductions, a relationship was established between Ib and the extent of crown area change. Canopy trees that intercept the most direct-beam irradiation and experience the least lateral shading have higher probabilities of survivorship and significant crown area changes that may be in the form of crown growth or crown reduction. Their laterally shaded neighbors have a lower survivorship probability, and those that survive persist in an inhibited state with limited crown area change. We conclude that the effects of lateral shading are not limited to the margins of treefall gaps and that lateral shading determined by crown position in the uneven upper canopies of nonequatorial tropical rain forests has a detectable effect on the long-term fates of neighboring canopy trees.\u