THE EFFECT OF STOCHASTIC IRRIGATION DEMANDS AND SURFACE WATER SUPPLIES ON ON-FARM WATER MANAGEMENT

This study presents a procedure for simultaneously addressing stochastic input demands and resource supplies for irrigated agriculture within a linear modeling framework. Specifically, the effect of stochastic crop net irrigation requirements and streamflow supplies on irrigation water management is examined. Irrigators pay a self-protection cost, in terms of water management decisions, to increase the probability that stochastic crop water demand is satisfied and anticipated water supply is available. Self-protection cost is lower when increasing the probability that anticipated water supplies are delivered, ceteris paribus, than when increasing the probability that the crop receives full net irrigation requirement in the study region.Resource /Energy Economics and Policy,

WATER MANAGEMENT POLICIES FOR STREAMFLOW AUGMENTATION IN AN IRRIGATED RIVER BASIN

The value of maintaining a minimum streamflow objective on average is lessened when there is considerable dispersion around the average. An integrated economic and hydrology model is presented which provides water policy planners with a way to accurately measure both the economic cost and hydrologic consequences of maintaining a minimum streamflow level in an irrigated river basin at alternative probabilities of maintaining the target flow level. Water markets for streamflow augmentation are shown to be the most cost-effective policy in the study area.Resource /Energy Economics and Policy,

Geometric efficiency of an electroformed nickel solar concentrator

Geometric efficiency of electroformed paraboloidal nickel solar energy concentrator calculated from optical ray trace dat

Optimization of the magnetic dynamo

In stars and planets, magnetic fields are believed to originate from the motion of electrically conducting fluids in their interior, through a process known as the dynamo mechanism. In this Letter, an optimization procedure is used to simultaneously address two fundamental questions of dynamo theory: "Which velocity field leads to the most magnetic energy growth?" and "How large does the velocity need to be relative to magnetic diffusion?" In general, this requires optimization over the full space of continuous solenoidal velocity fields possible within the geometry. Here the case of a periodic box is considered. Measuring the strength of the flow with the root-mean-square amplitude, an optimal velocity field is shown to exist, but without limitation on the strain rate, optimization is prone to divergence. Measuring the flow in terms of its associated dissipation leads to the identification of a single optimal at the critical magnetic Reynolds number necessary for a dynamo. This magnetic Reynolds number is found to be only 15% higher than that necessary for transient growth of the magnetic field.Comment: Optimal velocity field given approximate analytic form. 4 pages, 4 figure

Local Environment Control and Institutional Crowding-out

Regulations that are designed to improve social welfare typically begin with the premise that individuals are purely self-interested. Experimental evidence shows, however, that individuals do not typically behave this way; instead, they tend to strike a balance between self and group interests. From experiments performed in rural Colombia, we found that a regulatory solution for an environmental dilemma that standard theory predicts would improve social welfare clearly did not. This occurred because individuals confronted with the regulation began to exhibit less other-regarding behavior and made choices that were more self-interested; that is, the regulation appeared to crowd out other-regarding behavior.institutional crowding-out, external regulation, local environment quality, experiments, South America, Colombia

Economic inequality and burden-sharing in the provision of local environmental quality

A large, but inconclusive, literature addresses how economic heterogeneity affects the use of local resources and local environmental quality. One line of thought, which derives from Nash equilibrium provision of public goods, suggests that in contexts in which individual actions degrade local environmental quality, wealthier people in a community will tend to do more to protect environmental quality. In this paper we report on experiments performed in rural Colombia that were designed to explore the role that economic inequality plays in the å¢rovision-of local environmental quality. Subjects were asked to decide how much time to devote to collecting firewood from a local forest, which degrades local water quality, and how much to unrelated pursuits. Economic heterogeneity was introduced by varying the private returns to these alternative pursuits. Consistent with the Nash equilibrium prediction, we found that the players with more valuable alternative options put less pressure on local water quality. However, the subjects with less valuable alternative options showed significantly more restraint relative to their pure Nash strategies. Furthermore, they were willing to bear significantly greater opportunity costs to move their groups to outcomes that yielded higher average payoffs and better water quality than the Nash equilibrium outcome.Local environment quality, burden sharing, economic inequality, experiments

Closed loop fiber optic rotation sensor

An improved optical gyroscope is provided, of the type that passes two light components in opposite directions through an optic fiber coil, and which adds a small variable frequency to one of the light components to cancel the phase shift due to rotation of the coil. The amount of coil rotation from an initial orientation, is accurately determined by combining the two light components, one of which has a slightly increased frequency, to develop beats that each represent a predetermined angle of rotation. The direction of rotation is obtained by combining the two light components on a photodetector, intermittently phase shifting a single light component by 90 deg and comparing the direction of change of photodetector output (+ or -) caused by the 90 deg shift, with the slope (+ or -) of the photodetector output at about the same time, when there is a 90 deg shift

The Effects of Motivation and Goal Setting on Response Latency and Mental Effort

Researchers have found that performance is enhanced when participants set goals that are specific, difficult, and perceived as attainable. Also, motivation contributes to performance; specifically, intrinsic motivation, approach motivation, and avoidance motivation. Ninety participants were assigned randomly to one of two motivation groups; a goal setting or a control and assessed over a series of memory problems; solvable and unsolvable. Participant’s response latencies (RL) following an unsolvable problem was examined as a function of motivation type. Based upon the results from a 2 (Group; goal setting vs control) X 2 (test order) X 2 (memory problem difference scores) mixed ANOVA, a significant Group difference was found. The goal setting group had significantly faster RL’s compared to the control group. Secondary analyses of motivation type by goal setting group revealed no significant differences between the goal group and control group on the BAS, BIS, and Intrinsic Scales. It was hypothesized that the magnitude and type of motivation would be predictive of memory problem performance. However, no consistent relationships between motivation and RL were evident, an unexpected result