Low leak rate poppet-and-seat check valve

Valve leakage due to contaminant entrapment and chattering is effectively minimized by a metallic poppet-and-seat check valve designed for use in extreme environmental and fluid temperature conditions

Managing Saline Groundwater Impacts from Irrigation - Designing and Testing Emissions Trading in Coleambally Irrigation Area

Irrigated agriculture often leads to recharge to local and regional groundwater systems greater than what the systems can absorb, resulting in the development of shallow watertables causing salinity and waterlogging. Policy based on emissions trading offers one option for effective management of existing recharge externalities if effective property rights to diffuse emissions can be defined. In this paper we combine the conclusions drawn from biophysical research with economic principles underpinning emissions trading to present such a system. Allocation of net recharge contracts to irrigation farms will internalize the costs associated with saline aquifer impacts. Irrigators may reduce their compliance costs by creating or purchasing credits that reduce recharge through perennial vegetation, engineering solutions or crop rotation options. We discuss the economic impacts of adopting such a policy in the Coleambally Irrigation Area in southwestern New South Wales, Australia. We also demonstrate some of the conclusions drawn from our research using experimental economics.salinity, irrigation, recharge, tradeable emissions, cap and trade, hydrologic-economic modelling, experimental economics

Implications of Teacher Motivation and Renewal Indicators in Arkansas Toward Professional Growth and Achievement

This qualitative study was designed to determine if the teaching population in the state of Arkansas had a more favorable attitude toward specific motivational theories and practices; and to determine if that attitude significantly affected the teacher retention rate and the quality of work produced. The literature reviewed included the role of the school leader, motivational theory, and other relevant studies on teacher motivation. Eight National Board Certified teachers in Arkansas were interviewed about motivation as it related to professional improvement and development. The interviews focused on characteristics that serve as intrinsic motivators toward professional improvement and development and their impact on the teachers\u27 attitudes. The interviews also attempted to identify differences between experienced and non-experienced teachers in relation to intrinsic motivational factors. The data revealed achievement and acceptance as the intrinsic motivational factors with the most significant impact on the teachers\u27 attitudes toward professional improvement and development. The data did not reveal a difference between experienced and non-experienced teachers in relation to motivation and professional growth. This study contributed to the field of education by providing an extension of the established research on intrinsic motivation. Intrinsic motivators vary in the effect they have on teachers and their desire to improve professionally. This study outlines the significance of these intrinsic motivators and the impact they have on accomplished teachers

Wind-tunnel investigation of the powered low-speed longitudinal aerodynamics of the Vectored-Engine-Over (VEO) wing fighter configuration

A wind-tunnel investigation incorporating both static and wind-on testing was conducted in the Langley 4- by 7-Meter Tunnel to determine the effects of vectored thrust along with spanwise blowing on the low-speed aerodynamics of an advanced fighter configuration. Data were obtained over a large range of thrust coefficients corresponding to takeoff and landing thrust settings for many nozzle configurations. The complete set of static thrust data and the complete set of longitudinal aerodynamic data obtained in the investigation are presented. These data are intended for reference purposes and, therefore, are presented without analysis or comment. The analysis of the thrust-induced effects found in the investigation are not discussed

Groups versus individuals in the determination of caribou distribution

Studies of caribou (Rangifer tarandus) habitat selection based on group analyses have led to erroneous conclusions. Convenient designations such as «male-» or «female-dominated» group encompass a wide array of possible sizes and compositions which change continuously and erratically. Whenever individuals of at particular sex/age class can occur in more than one group type, and/or whenever groups within a type vary in size, an analysis based on groups alone is fallacious. Data must be based on individual caribou for most, if not all, determinations of distribution

The large gender gap in Trump’s support threatens his reelection. Here’s what’s driving it.

While women have tended to be more supportive of Democrats than Republicans in recent years, the gender gap in support for Donald Trump between men and women is exceptionally large, write Harold Clarke, Marianne Stewart, Paul Whiteley and Guy D. Whitten

Experiments with regulations & markets linking upstream tree plantations with downstream water users

Land-use change in upper catchments impact downstream water flows. As trees use large amounts of water the expansion of upstream plantations can substantially reduce water availability to downstream users. There can also be impacts on downstream salinity due to reduced dilution flows. In some jurisdictions afforestation requires the purchase of water rights from downstream holders, while in others it does not, effectively handing the water rights to the upstream landholders. We consider the economic efficiency and equity (profitability and distributional) consequences of upstream land use change in the presence of a water market under alternate property rights regimes and different salinity scenarios.experimental-economics, tree-plantations, environmental-services, urban, irrigation, stock & domestic, water use, land use,