The Effect of Green Payments on the Diffusion of Conservation Technologies

The benefits from green payments for the adoption of a conservation technology or practice are reduced if the technology would have eventually been adopted regardless of the green payment. This source of additionality is likely a significant concern for some technologies subsidized by EQIP.Environmental Economics and Policy, Research and Development/Tech Change/Emerging Technologies,

Spatially Explicit Estimates of Crop Rotation Responses

Crop Production/Industries, Environmental Economics and Policy, Land Economics/Use,

Critical mass flux through short Borda type inlets of various cross sections

Mass flux measurements associated with chocked flows through four Borda type inlet geometries: circular, square, triangular and rectangular (two-dimensional) and two sharp edged geometries taken over a very wide range of inlet stagnation conditions. The measurements indicate that: (1) the mass flux is independent of the inlet cross-section geometry and (2) the mass flux is dependent only on the inlet stagnation conditions. Also by using choked flow results found in the literature, the reduced mass flux is independent of working fluid. Two implications are drawn which remain to be verified: (1) since seal leak rates are weakly dependent on geometry but pressure distribution is strongly dependent on geometry, seal design efforts should be directed more toward controlling the dynamics, and (2) high-L/D ducts of arbitrary cross section and Borda type inlets can possess free jets

Prolonging thermal barrier coated specimen life by thermal cycle management

Measurements were made of the rate of increase in temperature of a ZrO2-8Y2O3 thermal barrier coated (TBC) specimen for various values of fuel/air (F/A) ratios when the specimen is exposed to a 0.3 Mach burner flame. For rod specimens in a carousel, the heating rates increased with (F/A) ratio and were higher at the inward facing surface for a given (F/A). Plate specimens were more sensitive to burner variations. Calculated results are given for the radial stress in the coated rod specimens for variations in (F/A) ratios from 0.04 to 0.065. Over this range, the radial stress varies from 4.3 to 5.3 MPa. The results indicate that controlling the heating rate of a TBC by controlling the (F/A) ratio offers a potential method to prolong TBC cyclic life; uncontrolled (F/A) ratios will produce scatter in experimental results. Geometric arrangement can have an equivalent effect, but is usually fixed by design

Das Just Community Konzept nach Lawrence Kohlberg – von der Theorie in die Praxis :die heutige Umsetzung an deutschsprachigen Schulen

Die vorliegende Arbeit beabsichtigt, sowohl die theoretische Grundlage des Moraltheorie Kohlbergs in einer kompakten Form darzulegen, als auch zwei exemplarische Schulkonzepte vorzustellen und zu untersuchen, wie Elemente des Just Community Konzepts darin umgesetzt werden. Nach der Online-Recherche erschien es mir als besonders ergiebig, eine Primarschule in der Schweiz und eine Gemeinschaftsschule in Berlin für dieses Anliegen auszuwählen, um das Konzept Kohlbergs in seinem vollen Potenzial abbilden zu können. Trotz der theoretischen Fundierung erachte ich es zudem als relevant, das Just Community Konzept und dessen konkrete Realisierungsformen auch unter kritischen Gesichtspunkten zu betrachten, um schließlich resümieren zu können, inwieweit das in den 1960er Jahren entwickelte Konzept Kohlbergs gegenwärtig gesellschaftliche Relevanz und Umsetzungsfähigkeit besitzt

Twitter Strategies for Web-Based Surveying : Descriptive Analysis From the International Concussion Study

BACKGROUND: Social media provides researchers with an efficient means to reach and engage with a large and diverse audience. Twitter allows for the virtual social interaction among a network of users that enables researchers to recruit and administer surveys using snowball sampling. Although using Twitter to administer surveys for research is not new, strategies to improve response rates are yet to be reported. OBJECTIVE: To compare the potential and actual reach of 2 Twitter accounts that administered a Web-based concussion survey to rugby players and trainers using 2 distinct Twitter-targeting strategies. Furthermore, the study sought to determine the likelihood of receiving a retweet based on the time of the day and day of the week of posting. METHODS: A survey based on previous concussion research was exported to a Web-based survey website Survey Monkey. The survey comprised 2 questionnaires, one for players, and one for those involved in the game (eg, coaches and athletic trainers). The Web-based survey was administered using 2 existing Twitter accounts, with each account executing a distinct targeting strategy. A list of potential Twitter accounts to target was drawn up, together with a list of predesigned tweets. The list of accounts to target was divided into 'High-Profile' and 'Low-Profile', based on each accounts' position to attract publicity with a high social interaction potential. The potential reach (number of followers of the targeted account), and actual reach (number of retweets received by each post) between the 2 strategies were compared. The number of retweets received by each account was further analyzed to understand when the most likely time of day, and day of the week, a retweet would be received. RESULTS: The number of retweets received by a Twitter account decreased by 72% when using the 'high-profile strategy' compared with the 'low-profile strategy' (incidence rate ratio (IRR); 0.28, 95% confidence interval (CI) 0.21-0.37, P.001) and 6 PM to 11:59 PM (IRR 1.48, 95% CI 1.05-2.09, P>.05) were significantly increased relative to 6 AM to 11:59 AM. However, posting tweets during the hours of 12 PM to 5:59 PM, decreased the IRR for retweets by 40% (IRR 0.60, 95% CI 0.46-0.79, P<.001) compared with 6 AM to 11:59 AM. Posting on a Monday (IRR 3.57, 95% CI 2.50-5.09, P<.001) or Wednesday (IRR 1.50, 95% CI 1.11-1.11, P<.01) significantly increased the IRR compared with posting on a Thursday. CONCLUSIONS: Surveys are a useful tool to measure the knowledge, attitudes, and behaviors of a given population. Strategies to improve Twitter engagement include targeting low-profile accounts, posting tweets in the morning (12 AM-11:59 AM) or late evenings (6 PM-11:59 PM), and posting on Mondays and Wednesdays

A high quality, efficiently coupled microwave cavity for trapping cold molecules

We characterize a Fabry-Perot microwave cavity designed for trapping atoms and molecules at the antinode of a microwave field. The cavity is fed from a waveguide through a small coupling hole. Focussing on the compact resonant modes of the cavity, we measure how the electric field profile, the cavity quality factor, and the coupling efficiency, depend on the radius of the coupling hole. We measure how the quality factor depends on the temperature of the mirrors in the range from 77 to 293K. The presence of the coupling hole slightly changes the profile of the mode, leading to increased diffraction losses around the edges of the mirrors and a small reduction in quality factor. We find the hole size that maximizes the intra-cavity electric field. We develop an analytical theory of the aperture-coupled cavity that agrees well with our measurements, with small deviations due to enhanced diffraction losses. We find excellent agreement between our measurements and finite-difference time-domain simulations of the cavity.Comment: 16 pages, 8 figure

The dryout region in frictionally heated sliding contacts

Some conditions under which boiling and two-phase flow can occur in or near a wet sliding contact are determined and illustrated. The experimental apparatus consisted of a tool pressed against an instrumented slider plate and motion picture sequences at 4000 frames/sec. The temperature and photographic data demonstrated surface conditions of boiling, drying, trapped gas evolution (solutions), and volatility of fluid mixture components. The theoretical modeling and analysis are in reasonable agreement with experimental data

Fixed effects estimation of the intensive and extensive margins of irrigation water demand

Irrigation water demand is estimated using field-level panel data from Kansas over 16 years. The cost of pumping varies over time due to changes in energy prices and across space due to differences in the depth to water. Exploiting this variation allows us to estimate the demand elasticity while controlling for field-farmer and year fixed effects. Fixed effects also allow us to control for land use without an instrument or assumptions about the distribution of errors. Our estimates of water demand are used to calculate the cost of reducing irrigation water use through water pricing, irrigation cessation, and intensity-reduction programs