5,849 research outputs found
F-15 composite engine access door
This paper presents a summary of the successfully concluded phase 1 of the two-phase Design and Manufacture of Advanced Thermoplastic Structures (DMATS) program. It addresses the design, manufacture, and validation testing of a thermoplastic F-15E forward engine access door and includes lessons learned during the concurrent product and process design development phases of the program
The renegotiation of Chinese cultural identity in the post -mao era a public lecture delivered at the University of Hong Kong on 19 March 1991 /
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Evaluating the effectiveness of group leader trade shows
The purpose of this study was to develop a system for evaluating the costs and benefits of exhibiting in a group leader trade show, while additionally determining the return on investment for the host destination. The population was defined as the 39 tour operators from North America, and the 13 6 exhibitors from New York State, who were in attendance at Travel Expo \u2790 held in Sullivan County, New York. An initial survey was distributed to all the attending tour operators and exhibitors from New York State. A follow-up evaluation was distributed to all tour operators and exhibitors who returned the initial survey, and agreed to participate in the study. An evaluation system was thoroughly developed as a measurement tool. Due to extremely low survey return rates, it was not possible to completely test the evaluation system for validity and effectiveness. The lack of cooperation among tour operators and exhibitors posed as a significant research obstacle. It was recommended that incentives and industry education be an option to increase participatory levels
Surface wind convergence as a short-term predictor of cloud-to-ground lightning at Kennedy Space Center: A four-year summary and evaluation
Since 1986, USAF forecasters at NASA-Kennedy have had available a surface wind convergence technique for use during periods of convective development. In Florida during the summer, most of the thunderstorm development is forced by boundary layer processes. The basic premise is that the life cycle of convection is reflected in the surface wind field beneath these storms. Therefore the monitoring of the local surface divergence and/or convergence fields can be used to determine timing, location, longevity, and the lightning hazards which accompany these thunderstorms. This study evaluates four years of monitoring thunderstorm development using surface wind convergence, particularly the average over the area. Cloud-to-ground (CG) lightning is related in time and space with surface convergence for 346 days during the summers of 1987 through 1990 over the expanded wind network at KSC. The relationships are subdivided according to low level wind flow and midlevel moisture patterns. Results show a one in three chance of CG lightning when a convergence event is identified. However, when there is no convergence, the chance of CG lightning is negligible
Hawaiian Plumerias
Reprint June 1972The plumeria is an important ornamental tree in Hawaii as well as in Florida, the West Indies, Central America, India, China, Indonesia, Australia, islands of the Pacific basin, and some other tropical regions. This booklet covers all aspects of plumeria cultivation in Hawaii
Economics of Field Pea Supplementation for Cattle Grazing Crested Wheatgrass
Heifers grazing crested wheat grass were supplemented either field peas or dried distillers grains plus solubles (DDGS) at 0.4% or 0.8% of body weight. Heifers supplemented with field peas had 10% lower daily gain compared to their DDGS supplemented counterparts. The decision to supplement field peas for producers depends on the price at which field peas can be acquired, as well as the distance that DDGS has to be hauled in order to be utilized. Field peas are a viable option in western Nebraska as a supplement for grazing cattle when DDGS is unavailable or field peas are in excess and can be obtained below the human consumption and pet food market price
Tests of an alternate mobile transporter and extravehicular activity assembly procedure for the Space Station Freedom truss
Results are presented from a ground test program of an alternate mobile transporter (MT) concept and extravehicular activity (EVA) assembly procedure for the Space Station Freedom (SSF) truss keel. A three-bay orthogonal tetrahedral truss beam consisting of 44 2-in-diameter struts and 16 nodes was assembled repeatedly in neutral buoyancy by pairs of pressure-suited test subjects working from astronaut positioning devices (APD's) on the MT. The truss bays were cubic with edges 15 ft long. All the truss joint hardware was found to be EVA compatible. The average unit assembly time for a single pair of experienced test subjects was 27.6 sec/strut, which is about half the time derived from other SSF truss assembly tests. A concept for integration of utility trays during truss assembly is introduced and demonstrated in the assembly tests. The concept, which requires minimal EVA handling of the trays, is shown to have little impact on overall assembly time. The results of these tests indicate that by using an MT equipped with APD's, rapid EVA assembly of a space station-size truss structure can be expected
Degradation and forgone removals increase the carbon impact of intact forest loss by 626%
Intact tropical forests, free from substantial anthropogenic influence, store and sequester large amounts of atmospheric carbon but are currently neglected in international climate policy. We show that between 2000 and 2013, direct clearance of intact tropical forest areas accounted for 3.2% of gross carbon emissions from all deforestation across the pantropics. However, full carbon accounting requires the consideration of forgone carbon sequestration, selective logging, edge effects, and defaunation. When these factors were considered, the net carbon impact resulting from intact tropical forest loss between 2000 and 2013 increased by a factor of 6 (626%), from 0.34 (0.37 to 0.21) to 2.12 (2.85 to 1.00) petagrams of carbon (equivalent to approximately 2 years of global land use change emissions). The climate mitigation value of conserving the 549 million ha of tropical forest that remains intact is therefore significant but will soon dwindle if their rate of loss continues to accelerate
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