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A novel gelatin system for use in oil spills at sea provides rapid immobilization of liquids upon demand. 相似文献
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Jon T. Biermacher B. Wade Brorsen Francis M. Epplin John B. Solie William R. Raun 《Agricultural Economics》2009,40(4):397-407
Plant-based precision nitrogen fertilizer application technologies have been developed as a way to predict and precisely meet nitrogen needs. Equipment necessary for precision application of nitrogen, based on sensing of growing wheat plants in late winter, is available commercially, but adoption has been slow. This article determines the expected profit from using a plant-sensing system to determine winter wheat nitrogen requirements. We find that plant-sensing systems have the potential to be more profitable than traditional nonprecise systems, but the existing system simulated was roughly breakeven with a traditional system. 相似文献
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The objective of this paper is to evaluate the effect of Plant Variety Protection (PVP) on the productive merit/yield increases of US seed varieties. As an example, we use wheat varieties, which are and have been available as both protected and unprotected under PVP from both the public and private sectors. We find evidence that PVP has contributed to the genetic improvement of wheat, using varietal trial data from Washington State. As the private open‐pollinated varieties exist only because of PVP and are higher yielding, these results indicate a clear public benefit from PVP. 相似文献
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Electricity Market Restructuring: Reforms of Reforms 总被引:5,自引:1,他引:5
Electricity systems present complicated challenges for public policy. In many respects these challenges are similar to those in other network industries in providing a balance between regulation and markets, public investment and private risk taking, coordination and competition. As with other such industries, naturally monopoly elements interact with potentially competitive services, but electricity has some unusual features that defy simple analogy to other network industries. Following a reversal of a long-term decline in real electricity prices, the last two decades of the twentieth century were for the United States a time of reform, reaction, and reforms of reforms in electricity systems, moving slowly towards greater reliance on competition and markets. Changing technology, new entrants in the generation market, and a legislative mandate to provide access to the essential transmission facility accelerated a process that required major innovations in institutions and operations. Complete laissez faire competition is not possible, and the details of an efficient competitive electricity market are neither obvious nor easy to put in place. The benefits of reform may be substantial, but they require careful attention to market design. A review of the past identifies some choices on the road ahead. 相似文献
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The comprehensive business exam: Usefulness for assessing instructional and student performance outcomes 总被引:1,自引:1,他引:0
The authors explore the results of the Comprehensive Business Exam (CBE) administered to business majors during their senior-year business capstone course. The study results identified students' SAT and grade point average as a predictor of CBE performance, and variables that explain the correlation between CBE performance, SAT score, and grade point average are discussed. This study expands the research stream by demonstrating how faculty can use CBE information to more deeply assess student learning at both the course and instructor level than is possible with the Major Field Test for Bachelor's Degree in Business. 相似文献