Taylor Slough Hydrology

Taylor Slough, in Everglades National Park, has experienced an evolution of water management infrastructure since drainage activities arrived in South Florida. This has included the excavation of canals, installation of large capacity pump stations, and a variety of operational strategies focused on resolving the conflict between managing the water level for developed areas while providing water supply for Everglades National Park. This study provides a review of water management practices and the concurrent hydrologic conditions in the Taylor Slough basin and adjacent canal system from 1961 through 2010. Analyses of flow, water level and rainfall data were divided into time periods that correspond to significant changes in structural features and operational plans. In the early 1960s, Taylor Slough was disconnected from the greater Everglades system by the construction of levees upstream. As water supply for Taylor Slough became more urgent, the Slough was connected to the regional water supply system via a network of canals and pump stations to relieve over-drained conditions. The increased water supply and pump capacity succeeded in raising water level and increasing flow and hydroperiod in the marsh.

Mathematical model for manoeuvrability of a riverine support patrol vessel with a pump-jet propulsion system

A study on the manoeuvrability of a riverine support patrol vessel is made to derive a mathematical model and simulate maneuvers with this ship. The vessel is mainly characterized by both its wide-beam and the unconventional propulsion system, that is, a pump-jet type azimuthal propulsion. By processing experimental data and the ship characteristics with diverse formulae to find the proper hydrodynamic coefficients and propulsion forces, a system of three differential equations is completed and tuned to carry out simulations of the turning test. The simulation is able to accept variable speed, jet angle and water depth as input parameters and its output consists of time series of the state variables and a plot of the simulated path and heading of the ship during the maneuver. Thanks to the data of full-scale trials previously performed with the studied vessel, a process of validation was made, which shows a good fit between simulated and full-scale experimental results, especially on the turning diameter

Combined Monte Carlo and quantum mechanics study of the solvatochromism of phenol in water. The origin of the blue shift of the lowest pi-pi* transition

A combined and sequential use of Monte Carlo simulations and quantum mechanical calculations is made to analyze the spectral shift of the lowest pi-pi* transition of phenol in water. The solute polarization is included using electrostatic embedded calculations at the MP2/aug-cc-pVDZ level giving a dipole moment of 2.25 D, corresponding to an increase of 76% compared to the calculated gas-phase value. Using statistically uncorrelated configurations sampled from the MC simulation,first-principle size-extensive calculations are performed to obtain the solvatochromic shift. Analysis is then made of the origin of the blue shift. Results both at the optimized geometry and in room-temperature liquid water show that hydrogen bonds of water with phenol promote a red shift when phenol is the proton-donor and a blue shift when phenol is the proton-acceptor. In the case of the optimized clusters the calculated shifts are in very good agreement with results obtained from mass-selected free jet expansion experiments. In the liquid case the contribution of the solute-solvent hydrogen bonds partially cancels and the total shift obtained is dominated by the contribution of the outer solvent water molecules. Our best result, including both inner and outer water molecules, is 570 +/- 35 cm(-1), in very good agreement with the small experimental shift of 460 cm(-1) for the absorption maximum.