Training vehicle for controlling attitude Patent

Attitude control training device for astronauts permitting friction-free movement with five degrees of freedo

Model for Estimating the Probability of Crop Production for Ginkgo biloba L.

Mature female Maidenhair trees (Ginkgo biloba L.)have been observed to produce seed dispersal units in some years and none in other years. A temperature and/or photoperiod flowering threshold is suggested. Daily temperatures and daylengths at five Ginkgo sites in continental U.S. for January-April 1964-1974 were evaluated. A computer program was designed to estimate daily photothermal equivalent (PTE = temperature and photoperiod), and the magnitude and duration of the PTE in relation to a series of photothermal constants. Use of the data from production and nonproduction years provided a mathematical model for prediction of dispersal unit production. The model was tested with environmental data for additional sites recorded in the botanical literature

Gravity stabilized flying vehicle Patent

Hovering type flying vehicle design and principle mechanisms for manned or unmanned us

Oxygen and Sodium Abundances in M13 (NGC 6205) Giants: Linking Globular Cluster Formation Scenarios, Deep Mixing, and Post-RGB Evolution

We present O, Na, and Fe abundances, as well as radial velocities, for 113 red giant branch (RGB) and asymptotic giant branch (AGB) stars in the globular cluster M13. The abundances and velocities are based on spectra obtained with the WIYN-Hydra spectrograph, and the observations range in luminosity from the horizontal branch (HB) to RGB-tip. The results are examined in the context of recent globular cluster formation scenarios. We find that M13 exhibits many key characteristics that suggest its formation and chemical enrichment are well-described by current models. Some of these observations include: the central concentration of O-poor stars, the notable decrease in [O/Fe] (but small increase in [Na/Fe]) with increasing luminosity that affects primarily the "extreme" population, the small fraction of stars with halo-like composition, and the paucity of O-poor AGB stars. In agreement with recent work, we conclude that the most O-poor M13 giants are likely He-enriched and that most (all?) O-poor RGB stars evolve to become extreme HB and AGB-manqu\'e stars. In contrast, the "primordial" and "intermediate" population stars appear to experience standard HB and AGB evolution.Comment: Accepted for publication in The Astrophysical Journal Letters. 18 pages; 3 figures; 1 tabl

Calculated Hovering Helicopter Flight Dynamics with a Circulation Controlled Rotor

The influence of the rotor blowing coefficient on the calculated roots of the longitudinal and lateral motion was examined for a range of values of the rotor lift and the blade flap frequency. The control characteristics of a helicopter with a circulation controlled rotor are discussed. The principal effect of the blowing is a reduction in the rotor speed stability derivative. Above a critical level of blowing coefficient, which depends on the flap frequency and rotor lift, negative speed stability is produced and the dynamic characteristics of the helicopter are radically altered

Three isoparametric solid elements for NASTRAN

Linear, quadratic, and cubic isoparametric hexahedral solid elements have been added to the element library of NASTRAN. These elements are available for static, dynamic, buckling, and heat-transfer analyses. Because the isoparametric element matrices are generated by direct numerical integration over the volume of the element, variations in material properties, temperatures, and stresses within the elements are represented in the computations. In order to compare the accuracy of the new elements, three similar models of a slender cantilever were developed, one for each element. All elements performed well. As expected, however, the linear element model yielded excellent results only when shear behavior predominated. In contrast, the results obtained from the quadratic and cubic element models were excellent in both shear and bending

Long Distance Business Travel and Mode Choice: The Results of Two Surveys of Business Travellers.

This report contains a descriptive analysis of two UK samples of lomg distance business travellers. Each sample answered the same mailback quesitonnaire which asked for detailed information about a recent long distance business trip and a limited amount of socio-economic data from each respondent. In particular; questions were asked about reasons for choice of the main travel mode and the alternative modes available to the respondent. In both samples it was found that the main factors influencing mode choices were journeytime and a convenient start time; with the ability to work en route being a significant factor for rail travellers. Company travel policies did not appear to have a significant influence on mode choice; although the set of permitted alternative modes was dependent on the respondents' income and occupation

Balancing Leisure and Work: Evidence from the Seasonal Home

Seasonal homes are used during leisure time for many recreational activities, yet recent technological innovations have diminished the separation between the work place and the seasonal home. In a survey of Walworth County seasonal home owners, most who work full time report they seldom work during vacations and weekends from their seasonal home. Yet there is a distinct subgroup who do mix work into weekends and vacations for a variety of reasons. The most frequent reasons given by these people for working from the seasonal home were related to the expectations of coworkers and clients. Understanding more about the habits and motivations of those who frequently work during weekends and on vacations could provide a new perspective on the obstacles everyone faces in balancing work and leisure

Demographic Trends in National Forest, Recreational, Retirement, and Amenity Areas

Those who live near national forests are both potential forest visitors and neighbors who feel the impact of many forest management decisions. This paper provides some insights about those proximate populations. It does so by measuring the proportion of national forest land within each county and then combining that with an analysis of the patterns of demographic change over the past several decades. Because there is considerable overlap between counties that contain national forests and those designated as recreational, high amenity, and retirement destination counties, demographic trends in such counties are compared. A total of 757 of the 3,141 U.S. counties contain national forest land. More than 66.1 million people resided in these counties in 2000, some 24% of the U.S. total. The population in national forest counties grew by 19% between 1990 and 2000 compared to 13% for the nation as a whole. Most of the population gain in national forest areas resulted from net in-migration. Population gains in national forest counties were slightly smaller than those in recreational and natural amenity counties and significantly less than those in retirement destination counties; however, the gains were considerably larger than those in other counties. National forest counties that are metropolitan have significantly more Hispanics than other metropolitan counties but fewer Blacks and Whites. Nonmetropolitan national forest counties contain a much larger proportion of non-Hispanic Whites than their metropolitan counterparts, a finding consistent with that for nonmetropolitan counties in general. Knowledge about the changing size and demographic structure of the population in national forest counties has particular relevance to Forest Service planners and policymakers