Magnetohydrodynamic Shallow Water Waves: Linear Analysis

We present a linear analysis of inviscid, incompressible, magnetohydrodynamic (MHD) shallow water systems. In spherical geometry, a generic property of such systems is the existence of five wave modes. Three of them (two magneto-Poincare modes and one magneto-Rossby mode) are previously known. The other two wave modes are strongly influenced by the magnetic field and rotation, and have substantially lower angular frequencies; as such, we term them "magnetostrophic modes". We obtain analytical functions for the velocity, height and magnetic field perturbations in the limit that the magnitude of the MHD analogue of Lamb's parameter is large. On a sphere, the magnetostrophic modes reside near the poles, while the other modes are equatorially confined. Magnetostrophic modes may be an ingredient in explaining the frequency drifts observed in Type I X-ray bursts from neutron stars.Comment: 15 pages (emulateapj), 4 figures. Accepted by ApJ (no changes in text from previous versions, but ApJ wants no acronyms in title). To appear in Oct 2009, Vol 703/704 of the Astrophysical Journa

Instantaneous Normal Mode Analysis of Supercooled Water

We use the instantaneous normal mode approach to provide a description of the local curvature of the potential energy surface of a model for water. We focus on the region of the phase diagram in which the dynamics may be described by the mode-coupling theory. We find, surprisingly, that the diffusion constant depends mainly on the fraction of directions in configuration space connecting different local minima, supporting the conjecture that the dynamics are controlled by the geometric properties of configuration space. Furthermore, we find an unexpected relation between the number of basins accessed in equilibrium and the connectivity between them.Comment: 5 pages, 4 figure

Diagnostic analysis of RO desalting treated waste water

Diagnostic analysis of reverse osmosis membranes that were fed with Western treatment plant (WTP) recycled water was investigated by both thermodynamic calculations and laboratory experiments in order to predict the feasibility of RO desalting for WTP. The thermodynamic calculations suggested that RO recoveries of 80–85% were feasible with careful control of feed water pH and the use of chemical additives such as antiscalants and chelating agents, it also predicted the major minerals of concern to be silica, calcium fluoride, calcium carbonate, and calcium phosphate. Following the thermodynamic simulations, diagnostic laboratory experiments were undertaken. The experiments showed that the major contributor to scale formation was indeed calcium phosphate and possibly another calcium based compound, which was strongly suspected to be calcium carbonate. Based on previously published literature that indicated anti-scalants did not substantially decrease the scaling effect of calcium phosphate and laboratory tests that indicated controlling the pH to 6.4 in the feed water dramatically reduced scaling formation, it was suggested that the feed water could be controlled by pH adjustments only. Inter-stage pH correction was suggested as an optional technique to enhance the overall water recovery to above 95%

A Meta-Analysis of Alternative Water Sources

Roughly one half of the Earth’s population suffers from shortage or lack of clean water. While many innovations and products have been created to address this Global Water Crisis, no comparisons have been done as to which innovations and products are the best overall choice for philanthropic investment. The crisis can be broken down into three specific crises including the transportation crisis, the access crisis, and the sanitation crisis. The study examined fifteen innovations and products, targeted to address the three crises to determine which innovation in each group is the overall smart investment. Pulse tool was used to create reports of data comparing the innovations and products to one another. Findings concluded that the Hippo Roller is the smart investment for transportation of water, the Treadle Pump is the smart investment for gaining access to water, and the Filtron and the Mobile MaxPure are the equally smart investments for sanitizing water. Therefore, for future development of social innovation comparison, it is recommended that an investor look at the overall benefits of an innovation before donating money to that cause

Water jet/spray measurement analysis

The objective of this study was to provide analysis of data obtained under a previous contract entitled Characterization of Drop Spectra from High Volume Flow Water Jets. Measurements of drop spectra were obtained in the spray resulting from the breakup of high volume flow water jets from a variety of nozzle types. The drop spectra measurements were obtained from two drop spectrometers covering a range from 10 microns to 12 millimeters diameter. The task addressed was to select representative spectra from the individual tests and provide analyses in both numerical and graphical formats as outlined in the proposal. The intended application of these results is an evaluation of the feasibility of fog clearing by high volume water sprays. During the tests, a fog event occurred making it possible to test the concept of fog clearing. Visual range data and fog drop spectra were analyzed, with particular emphasis placed on the modification of these parameters due to the water spray

Arkansas Water Resources Research Center Pamphlet

Arkansas Water Resources Center (AWRC) works closely with state and federal agencies and academic institutions. Priority research categories are: surface water analysis, ground water pollution, surface and ground water quality/quanity, and water resource management

Managing water loss for sustainability of rural water supply

Water supply for rural areas flows through pipelines from many sources such as underground water and reservoirs. Due to factors such as human activities, geographic changes and natural hazards, pipelines are exposed to the ground, crack, leak and burst. Water flows out from the pipelines before reaching to the consumers is considered as water loss and this is a major component in non-revenue water. This paper highlights a framework and a work procedure for non-revenue water analysis. Based on this analysis, a comprehensive and flexible web based prototype has been developed to manage the water loss. Functions that have been developed are data recording,non-revenue water estimation and report generation. This prototype can be used by the water authority for assisting decision making and planning

Dependability and Survivability Evaluation of a Water Distribution Process with Arcade

Among others, drinking water belongs to the socalled critical infrastructures. To ensure that the water production meets current and future societal needs, a systematic and rigorous analysis is needed. In this paper, we report our first experience with dependability analysis of the last phase of a water treatment facility, namely the water distribution. We use the architectural language Arcade to model this facility and use the Arcade toolset to compute three relevant dependability measures: the availability of the water distribution, the reliability, i.e., the probability that the water distribution fails, and the survivability, that is, the ability to recover from disasters. Since survivability is not directly expressible in the Arcade formalism, we show how one can modify the toolchain for the analysis of survivability.\u

An Analysis of Watermove Water Markets

This paper conducts an analysis of the water markets in Victoria covered by Watermove. The analysis in this paper examines the weekly trading activity across trading zones. For the majority of trading zones there is little trading activity that occurs. There are three trading zones in which the markets for temporary water rights are reasonably active and liquid on a weekly basis, and for these zones an analysis is conducted of their demand and supply elasticities and consumer and producer surplus. The results of this analysis suggest a stronger relationship on the supply side between prices, volumes, elasticity and producer surplus.Water, Water markets, Elasticities, Consumer and Producer Surplus