Filament wound data base development, revision 1

The objective was to update the present Space Shuttle Solid Rocket Booster (SRB) baseline reentry aerodynamic data base and to develop a new reentry data base for the filament wound case SRB along with individual protuberance increments. Lockheed's procedures for performing these tasks are discussed. Free fall of the SRBs after separation from the Space Shuttle Launch Vehicle is completely uncontrolled. However, the SRBs must decelerate to a velocity and attitude that is suitable for parachute deployment. To determine the SRB reentry trajectory parameters, including the rate of deceleration and attitude history during free-fall, engineers at Marshall Space Flight Center are using a six-degree-of-freedom computer program to predict dynamic behavior. Static stability aerodynamic coefficients are part of the information required for input into this computer program. Lockheed analyzed the existing reentry aerodynamic data tape (Data Tape 5) for the current steel case SRB. This analysis resulted in the development of Data Tape 7

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,

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,

Archaeological Data and Small Projects: A Case Study from the Pyla-Koustopetria Archaeological Project on Cyprus

A case study in how small projects use digital tools

Survey of Inter-satellite Communication for Small Satellite Systems: Physical Layer to Network Layer View

Small satellite systems enable whole new class of missions for navigation, communications, remote sensing and scientific research for both civilian and military purposes. As individual spacecraft are limited by the size, mass and power constraints, mass-produced small satellites in large constellations or clusters could be useful in many science missions such as gravity mapping, tracking of forest fires, finding water resources, etc. Constellation of satellites provide improved spatial and temporal resolution of the target. Small satellite constellations contribute innovative applications by replacing a single asset with several very capable spacecraft which opens the door to new applications. With increasing levels of autonomy, there will be a need for remote communication networks to enable communication between spacecraft. These space based networks will need to configure and maintain dynamic routes, manage intermediate nodes, and reconfigure themselves to achieve mission objectives. Hence, inter-satellite communication is a key aspect when satellites fly in formation. In this paper, we present the various researches being conducted in the small satellite community for implementing inter-satellite communications based on the Open System Interconnection (OSI) model. This paper also reviews the various design parameters applicable to the first three layers of the OSI model, i.e., physical, data link and network layer. Based on the survey, we also present a comprehensive list of design parameters useful for achieving inter-satellite communications for multiple small satellite missions. Specific topics include proposed solutions for some of the challenges faced by small satellite systems, enabling operations using a network of small satellites, and some examples of small satellite missions involving formation flying aspects.Comment: 51 pages, 21 Figures, 11 Tables, accepted in IEEE Communications Surveys and Tutorial

Jet Effects on the Base Drag of a Cylindrical Afterbody with Extended Nozzles

A wind-tunnel investigation to determine the effects of both single and twin jets on base drag of a cylindrical body has been conducted at Mach numbers from 0.6 to 1.4. The plane of the jet exit was varied with respect to that of the afterbody. Jet total-pressure ratio ranged up to 20. Significant improvements in base drag were obtained by extending the plane of the jet exits beyond the afterbody base and by venting the base cavity to the external stream

Estimation and Analysis of Expenses of In-Lieu-Fee Projects that Mitigate Damage to Streams from Land Disturbance in North Carolina

As North Carolina’s economy has grown, the need to mitigate adverse impacts of land disturbance on aquatic ecosystems has also grown. When land disturbance adversely affects streams, a developer or the state’s Department of Transportation can satisfy mitigation requirements through payment of fees to the state’s Ecosystem Enhancement Program (EEP). EEP then manages a stream mitigation project on behalf of the responsible party. EEP has had regulatory authority to require stream mitigation for 10 years. The needs of EEP to reassess its mitigation fee and identify ways to reduce costs of the program have grown over the decade. The first objective of this study was to account for all EEP expenses of design-bid and design-bid-build projects. The second objective was to analyze the determinants of contractual expenses with a cost function. EEP has spent or committed to spend $46.34 million for 45 design-build or designbid-build projects to restore or enhance 191,374 ft. of streams. Expenses per foot have been$242.12. Given its mandate to cover expenses for stream mitigation, EEP must raise mitigation fees, especially those for urban projects, make changes to reduce project expenses, or do both. As the length of a restored or enhanced stream increases, the expenses per foot decrease. The decrease is more pronounced in undeveloped, rural areas. Thus, EEP could produce mitigation for less expense by financing fewer projects with longer reaches or by financing more projects in undeveloped, rural areas. Other states with in-lieu-fee programs for compensatory mitigation might also use these results to reduce contractual expenses.Environmental Economics and Policy,