Study on utilization of advanced composites in fuselage structures of large transports

The potential for utilizing advanced composites in fuselage structures of large transports was assessed. Six fuselage design concepts were selected and evaluated in terms of structural performance, weight, and manufacturing development and costs. Two concepts were selected that merit further consideration for composite fuselage application. These concepts are: (1) a full depth honeycomb design with no stringers, and (2) an I section stringer stiffened laminate skin design. Weight reductions due to applying composites to the fuselages of commercial and military transports were calculated. The benefits of applying composites to a fleet of military transports were determined. Significant technology issues pertinent to composite fuselage structures were identified and evaluated. Program plans for resolving the technology issues were developed

Conceptual approach study of a 200 watt per kilogram solar array

Solar array candidate configurations (flexible rollup, flexible flat-pact, semi-rigid panel, semi-rigid flat-pack) were analyzed with particular attention to the specific power (W/kg) requirement. Two of these configurations (flexible rollup and flexible flat-pack) are capable of delivering specific powers equal to or exceeding the baseline requirement of 200 W/kg. Only the flexible rollup is capable of in-flight retraction and subsequent redeployment. The wrap-around contact photovoltaic cell configuration has been chosen over the conventional cell. The demand for ultra high specific power forces the selection of ultra-thin cells and cover material. Based on density and mass range considerations, it was concluded that 13 micrometers of FEP Teflon is sufficient to protect the cell from a total proton fluency of 2(10 to the 12th power) particles/sq cm over a three-year interplanetary mission. The V-stiffened, lattice boom deployed, flexible substrate rollup array holds the greatest promise of meeting the baseline requirements set for this study

FORWARD SHIPPING OPTIONS FOR GRAIN BY RAIL: A STRATEGIC RISK ANALYSIS

Grain hauling railroads began offering shipping alternatives in the late 1980s that have made transportation decisions more strategic. Shippers now confront alternatives ranging from nearby and unguaranteed ordering to various durations of forward and guaranteed shipment. A dynamic stochastic simulation model was developed to analyze grain shipping and merchandising strategies that integrate these alternatives.railroads, grain merchandising, logistics, simulation, risk analysis, Crop Production/Industries, Marketing,

PRICE ADJUSTMENTS IN CHERRY MARKETS

Buyers of cherries trade initially without inspection. Upon receipt, buyers sometimes seek to renegotiate the earlier agreements. Empirical results suggest that changing market conditions, fruit quality, and characteristics of the trading partners significantly affect the probability that a trade is renegotiated.Demand and Price Analysis,

Vacuum thermal conductivity measurements of NASA E4A1 elastomeric heat shield material

Line source vacuum thermal conductivity measures for elastomeric heat shield materia

Behavior of composite bolted joints at elevated temperature

Experimental results from an investigation which examines the combined effects of temperature, joint geometry and out-of-plane constraint upon the response of mechanically fastened composite joints are presented. Data are presented for simulated mechanically fastened joint conditions in two laminate configurations fabricated from Hercules AS/3501-6 graphite-epoxy. Strength and failure mode results are presented for the test temperatures of 21 C, 121 C and 177 C and for a range of the geometric parameters W/D and e/D from 3.71 to 7.43 and 1.85 to 3.69, respectively. A hole diameter, D of 5.16 mm was utilized for all tests. Pin bearing tests with out-of-plane constraint were conducted at room temperature only. All elevated temperature data were generated for pin bearing conditions. Ultrasonic C scan inspection of the failed specimens was employed to assess the damage region and to determine failure mode. Comparative data are presented for pin bearing and out-of-plane constraint conditions for the above mentioned joint configurations. The joint under pin loading was modeled by two dimensional finite element methods. Predicted net section strain concentrations were compared with experimental results

IMPACTS OF GENETICALLY MODIFIED (GM) TRAITS ON CONVENTIONAL TECHNOLOGIES

In hard red spring (HRS) wheat, the two GM traits nearest to commercialization are fusarium resistant wheat (FRW) from Syngenta and Roundup Ready® wheat (RRW). Monsanto announced that it has deferred the commercialization of RRW until issues of market acceptance are alleviated. Monsanto acknowledged that it might reconsider its position if another agbiotechnology firm enters the GM wheat market. A Cournot quantity competition model was developed to determine the equilibrium quantities of conventional pesticide and agbiotechnology firms. The Cournot model was used because firms that must make production decisions ahead of the selling period, and firms with extensive research and development costs are not able to aggressively set prices. Rather, the conventional and agbiotechnology firms determine Nash equilibrium quantities and then determine a market clearing price for their respective products. The agbiotechnology firm determined a profit maximizing technology fee ($/acre) for its GM trait. The market with conventional wheat only was compared to the market with conventional and GM wheat varieties to determine the price decreases of the conventional pesticide as a result of the GM trait introduction. Changes in farmer surplus, tech firm payoffs, and sector welfare were also analyzed. Using the actual number of firms with conventional herbicides labeled for use on HRS wheat in North Dakota and marginal production costs ranging from one to three dollars, introduction of RRW would cause a 20-25% price decrease for conventional herbicides. Similarly, four firms produce conventional fungicides labeled for the suppression of FHB in HRS wheat. This value, combined with per acre marginal production costs ranging from one to three dollars, would likely cause a 19-22% price decrease for conventional fungicides, post introduction of GM FRW. Several implications arise from these results. First, adoption of a new GM wheat variety may not be as high as expected due to likely concurrent price decreases of conventional pesticides. The price decrease leads to a lower production cost of conventional varieties, and some farmers who would likely adopt the GM variety, if there were no price decrease, do not adopt because of the lower cost of conventional production. This price decrease must be included in the determination of potential adoption rates by agbiotechnology firms in their pricing decisions. Second, the release of a GM wheat variety results in an increase in surplus for all types of wheat farmers (GM adopters, conventional pesticide adopters, and no technology adopters). GM adopters benefit because of the release of the GM variety. Conventional pesticide adopters benefit due to the price decreases of the conventional pesticides. Farmers who did not adopt any technology prior to the release of GM wheat may adopt the conventional pesticide because of the lower cost. Third, the release of a GM wheat variety would result in slightly lower payoffs for conventional pesticide producing firms but higher payoffs for agbiotechnology firms. Overall, surplus to farmers and conventional and agbiotechnology firms increases due to the release of a GM wheat variety.genetic modification, fusarium resistance, Roundup Ready®, technology, Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

STRATEGIC ANALYSIS OF TRAIT COMMERCIALIZATION IN GENETICALLY MODIFIED (GM) GRAINS: THE CASE OF GM WHEAT

The prospective commercialization of GM traits leads to several strategic questions for agbiotechnology and seed firms. Important issues addressed in this study include the method of trait commercialization by agbiotechnology firms and variety production decisions by seed firms. Specifically, agbiotechnology firms must decide whether to license their traits to seed firms, to purchase a seed firm, or to not license or release their traits. These issues are highly strategic. The purpose of this study was to determine equilibrium strategies of agbiotechnology and seed firms regarding the prospective commercialization of two GM traits. Two game theory models were developed to examine equilibrium strategies in two different scenarios. In the first model, both agbiotechnology firms had commercialization strategies of licensing and not licensing. In the second model, the first moving agbiotechnology firm was allowed to have a strategic option to purchase a seed firm as a commercialization strategy. The second agbiotechnology firm remained with two strategies, licensing and not licensing. These models were applied to the case of Roundup Ready® (RR) and fusarium resistant (FR) HRS wheat, although the general structure of the models could be used to analyze other crops and traits. Studies on trait commercialization and stacking are lacking the public literature. This study uses game theory models to develop likely situations that may occur regarding the prospective commercialization of GM traits.genetically modified grains, wheat, Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

Analytical investigation of side jet supersonic stream interaction including vortex flow in rocket nozzles for thrust vector control

Analytical investigation of side jet supersonic stream interaction including vortex flow in rocket nozzles for thrust vector contro

Influence of constituent properties and geometric form on behavior of woven fabric reinforced composites

Th potential for woven fabric composite forms to increase the interlaminar strength and toughness properties of laminated composite septems is studied. Experimental and analytical studies were performed on a z-axis fabric