Debris- and Ice-Skimming Booms at Riverside Diversions

Hydraulic-design guidelines are presented for deploying debris- and ice-skimming booms at riverside diversions such as water intakes for thermal power stations, municipal water-supply facilities, and irrigation canals. Based on laboratory-flume tests and boom literature, the guidelines aim to reduce debris passage into and accumulations at diversions. Important design variables include boom distance out from the diversion entrance, boom orientation to the diversion, and boom draft. Optimal deployment of skimming booms is related to the flow field at riverside diversions. The flume tests established how these variables influence the physical processes governing skimming-boom performance, and they led to recommendations on effective deployment of straight and bent booms for debris flushing. Bent booms, which comprise two segments (one angled from upstream and one parallel to the diversion), are the more effective boom type for wider ranges of river and diversion flows.     

Development of a Hydro-Salinity Simulation Model for Colorado’s Arkansas Valley

A model to calculate the quantity and quality of river flows by simulating hydro-chemical processes in soil and the spatial/temporal distribution of irrigation return flows is introduced. By simulating the hydro-chemical processes, the quantity and quality of the deep percolating water can be predicted. The spatial and temporal distribution of the deep percolating water is simulated by constructing a groundwater flow path and calculating the groundwater travel time using response functions. A probabilistic approach was developed to calculate the groundwater travel time taking into account the fact that some irrigated fields have subsurface drainage which shortens travel times. All related hydrological components are integrated into the computation of river flow quantity and quality including groundwater return flow, irrigation tail water, tributary inflow, river diversion, phreatophyte consumption, river channel losses, and river depletion due to pumping. An illustrative example is included to demonstrate the capabilities of the model. The results of this example show that river salinity is lower during the irrigation season and higher during the off season. Due to salts carried by return flows, downstream reaches have higher salinity levels than upstream reaches.     

Method for Quantifying Freshwater Input and Flushing Time in Estuaries

A method is developed to quantify total freshwater input and flushing time in estuaries using measured flow and salinity data at the estuary-ocean boundary. A formula is derived to calculate the volume of mixed estuarine water that leaves the estuary on the ebb tide. The calculated volume of mixed estuarine water, along with the volume of new ocean water that enters the estuary on the flood tide, is used to quantify the total volume of freshwater input. The calculated volume of mixed estuarine water is also used to quantify the flushing time. The developed method is applied to Barnegat Bay, N.J. The volume of freshwater input calculated from the new method compares well with that estimated using watershed, aquifer, and meteorological data. The flushing time calculated from the new method is between that calculated from the classical tidal prism method and that from the fraction of freshwater method. An assessment is made on the sensitivity of calculated values to the quality of measured data at the estuary-ocean boundary. The volume of freshwater input and the flushing time calculated from the developed method are highly reliable when there is a significant salinity difference between flood and ebb tides.     

Development of Management Models for Sustainable Use of Coastal Aquifers

A number of nonlinear optimization-based multiple-objective management models for sustainable utilization of coastal aquifers are formulated and solved. The management objectives represent plausible scenarios for planned withdrawal and salinity control in coastal aquifers. The first multiple-objective management model is developed for spatial and temporal control of aquifer salinity through planned pumping (withdrawal) from locations closest to the ocean boundary. The second multiple-objective management model is useful for maximizing sustainable water withdrawal from the aquifer for beneficial uses, while limiting the maximum salinity in the aquifer. The third multiple-objective management model is developed for maximizing sustainable water withdrawal from the aquifer for beneficial uses and minimizing the total pumping at locations adjacent to the ocean boundary to control the salinity in the aquifer. The nonlinear finite-difference form of the steady-state density-dependent miscible flow and salt transport model for seawater intrusion in coastal aquifers is embedded within the constraints of the management model. The constraint method of generating noninferior solutions is used to solve the multiple-objective management problems. The management models are solved for a hypothetical unconfined coastal aquifer system. The projected augmented Lagrangian method of nonlinear programming is used to solve the resulting large-scale optimization problem. The solution results demonstrate the feasibility of the developed optimization models and also the conflicting nature of the various objectives of coastal aquifer management.     

Case Study: Analysis and Forecasting of Salinity in Apalachicola Bay, Florida, Using Box-Jenkins ARIMA Models

The Apalachicola Bay is one of the most productive estuaries in Florida. Variations of salinity directly influence the productivity of the aquatic habitats. Physical conditions that affect the salinity include tidal elevations, wind and current velocities, precipitation, and the discharge of the Apalachicola River. In the present paper, cross-correlation techniques, autoregressive integrated moving average (ARIMA), and dynamic regression transfer models using the Box-Jenkins methodology are employed to analyze the time series data. The rational distributed lag transfer functions between hourly variations of tidal water levels and salinity allow forecasting of short-term fluctuations in the salinity, whereas multivariate correlation analyses of daily salinity with river discharge, wind stresses, water levels and currents, and precipitation shed light on the important control variables. Several conclusions with regard to the hydrodynamics and water quality of the bay can be drawn from identification of auto- and cross correlations and the appropriate ARIMA models. Fluctuations of tidal water levels result only in short-term periodic variations in salinity, with a linear transfer function that has a lag-two as the highest coefficient. The cross-correlation analysis shows that the Apalachicola River, being the major fresh-water source of the bay, strongly affects the currents and salinity in the bay area over the long term. Though regional precipitation controls the amount of fresh-water inflow, either through river discharge or groundwater seepage, its effect on the daily variations in salinity is statistically insignificant. In contrast, the effect of daily wind stress is significant. Salinity is positively correlated with western currents in the bay because most of the oceanic flow enters the bay from the east. A lag between the daily discharge and salinity indicates that up to a week is required for the peak of the inflow fresh water to flush through the exit of the bay.     

Self-Adaptive Fitness Formulation for Evolutionary Constrained Optimization of Water Systems

In design of water distribution networks, there are several constraints that need to be satisfied; supplying water at an adequate pressure being the main one. In this paper, a self-adaptive fitness formulation is presented for solving constrained optimization of water distribution networks. The method has been formulated to ensure that slightly infeasible solutions with a low objective function value remain fit. This is seen as a benefit in solving highly constrained problems that have solutions on one or more of the constraint bounds. In contrast, solutions well outside the constraint bounds are seen as containing little genetic information that is of use and are therefore penalized. In this method, the dimensionality of the problem is reduced by representing the constraint violations by a single infeasibility measure. The infeasibility measure is used to form a two-stage penalty that is applied to infeasible solutions. The performance of the method has been examined by its application to two water distribution networks from literature. The results have been compared with previously published results. It is shown that the method is able to find optimum solutions with less computational effort. The proposed method is easy to implement, requires no parameter tuning, and can be used as a fitness evaluator with any evolutionary algorithm. The approach is also robust in its handling of both linear and nonlinear equality and inequality constraint functions. Furthermore, the method does not require an initial feasible solution, this being an advantage in real-world applications having many optimization variables.     

Methotrexate tolerance in patients with ileal conduits and continent diversions

BACKGROUND: Methotrexate is readily absorbed from the intestinal tract. When given to patients with urinary diversion to the intestinal tract, methotrexate may be reabsorbed into the circulation, thus increasing its serum concentration and potentially increasing its toxicity. METHODS: Forty-eight patients with transitional cell carcinoma of the urinary tract who had undergone cystectomy and either an ileal conduit or a continent diversion were evaluated for their tolerance of chemotherapy. Of the 42 evaluable patients, 23 had a continent diversion and 19 had an ileal conduit. None of the patients with the continent diversion had an indwelling Foley catheter during the course of chemotherapy. RESULTS: There were no statistically significant differences in incidence of fever or neutropenia, mucositis, dose modification, or delay in chemotherapy between the two groups. When compared with a group of patients with native bladders who received the same chemotherapy, patients with continent diversions did not have increased incidence or severe toxicity from chemotherapy. CONCLUSIONS: Patients with continent diversions tolerated chemotherapy as well as patients with ileal conduits.     

Structure of Flow Upstream of Vertical Angled Screens in Open Channels

This paper presents the results of a laboratory study of the structure of flow in a diversion structure with a vertical angled wedge-wire fish screen. This screen had a 10×25?mm mesh and was tested at three angles of 10.4, 17.5, and 26.8°, to the direction of the approaching flow, for two mean velocities of 0.5 and 0.8?m/s, with a depth of flow of about 0.75?m. In this water and fish diversion (channel or) structure, it was found that the depth of flow at any section is approximately constant with a drop at the screen on the side of the canal and decreased towards the bypass located at the downstream end. The distribution of the velocity component u in the direction of the approaching flow as well as the perpendicular component w and the resultant velocity V was uniform in the vertical direction. The depth averaged mean velocity for different verticals at any section in the diversion structure increased with the longitudinal distance x and was correlated with the relative width, bs/b (in the diversion structure) for all five experiments. Correlations have been found for the depth averaged transport velocity and the impinging velocity on the screen in terms of the approach velocity U. A general relation has also been developed for the attack angle of the flow on the screen. The downstream part of the screen carried more flow into the canal compared to the upstream part as a result of the uniform mesh size used in this study. The results of this hydraulic study should be useful, particularly for freshwater adult fish, in designing screens in irrigation canals and for micro-hydro sites that use diversion canals.     

Adjoint Sensitivity Analysis of Contaminant Concentrations in Water Distribution Systems

Sensitivity analysis is used to determine how a system state or a model output changes due to a change in the value of a system parameter or a model input. We present the adjoint approach for determining the sensitivity of the concentration of a contaminant in a water distribution system to a change in a system parameter such as the location of the source of contamination, the reaction rate of the contaminant, and others. With the adjoint method, the sensitivity of the model output to any number of parameters can be obtained with one simulation of the adjoint model. If the number of parameters of interest exceeds the number of model outputs for which the sensitivity is desired, the adjoint method is more efficient than traditional direct methods of calculating sensitivities. We develop the adjoint equations for water quality in a water distribution system, verify the adjoint-based sensitivity equation using an analytical example, and demonstrate the numerical calculation of adjoint sensitivities using EPANET.     

Impact of Salinity on MS-2 Sorption in Saturated Sand Columns—Fate and Transport Modeling

This research investigated the sorption and transport of MS-2 in saturated sand under a wide range of salinities using one-dimensional column experiments. The salinity varied from 0 ppt (fresh water) to 30 ppt. The MS-2 in the fresh water showed very weak adsorption due to having the same negative charge as the sand. Increasing the salinity concentrations dramatically enhanced MS-2 adsorption. The MS-2 breakthrough revealed the existence of reversible and irreversible sorption sites in the sand. Salinity increased MS-2 attachment by compressing the double layers of MS-2 and reversible sorption sites. The salinity also changed some reversible sorption sites into irreversible sorption sites by reversing to positive surface charges of silica powder. An advection-dispersion-sorption model with a two-site reversible-irreversible kinetic sorption was developed to describe MS-2 breakthrough under different salinity conditions. The sorption parameters were estimated and their independence was evaluated by minimizing the total squared error of the MS-2 data. The proposed model showed good agreement with the experimental data for a wide range of salinity levels from fresh water to near seawater. The strong sorption shown in the MS-2 breakthrough at high salinity levels above 8 ppt was able to distinguish the proposed model from other sorption models. This study promotes the understanding of the viral sorption with salinity and provides a useful model for coastal management of viral migration in saline coastal groundwater.     

Sediment Control at Lateral Diversions: Limits and Enhancements to Vane Use

This paper presents the findings of laboratory flume experiments conducted to determine the limits to which submerged vanes can be used in preventing excessive bed-sediment ingestion into lateral diversions of flow from alluvial channels. The experiments show that a scheme of submerged vanes placed at the diversion entrance admits only a negligible rate of bed-sediment entry into the diversion when the ratio of unit discharge in the diversion to unit discharge in the main channel, qr, is less than about 0.2. Beyond this value, the effectiveness of the vanes diminishes. The sediment-control performance of the vanes can be enhanced in several ways. One enhancement is the use of a skimming wall in conjunction with the vanes. The wall and the vanes are effective for values of qr up to about 0.3. Another enhancement is to widen the diversion entrance such that, at the entrance, qr does not exceed about 0.3. Further potential enhancements (modified vane shape, uniformity of flow distribution into the diversion, and increased flow velocity into the diversion) were found not to be effective. The findings are supported by observations of flow and bed-sediment behavior at a flume-scale diversion.     

Numerical Simulation of Bromate Formation during Ozonation of Bromide

The purpose of this study is to develop a kinetic model that links O3 decomposition reactions from the TFG ozone decay model with recognized Br? oxidation reactions, secondary ?OH reactions, and H2O2 reactions in order to improve O3 decay and bromate formation prediction capabilities under multiple water quality conditions. The model was compared with experimentally measured ozone decomposition and final bromate concentration data sets provided by two researchers. The data sets included varying pH (6.5–8.5), initial hydrogen peroxide (0–1 mM), and initial bromide concentration (0.1–1 mM). Model verification was carried out by sensitivity analysis of the rate constants and then optimization of the most sensitive rate constants using the method of least squares. Model predicted ozone decay data was analyzed and compared with measured ozone decay data using R-squared statistic for linear regression model. The model predicted final bromate concentration is analyzed by comparing it with the residual Δ(%) between experimental and model results. The TFG model was effectively tested for multiple data sets and it was found that model prediction was a success both for ozone decay (regression coefficients >0.95 for all experimental conditions but one) and bromate prediction with residual of less than 100% for all experimental conditions except low peroxide dose (<20 μm).     

Field Experiment Study of Transient Stratified Flow in an Estuary

An experimental study of stratified flow was conducted in this study. An electromagnetic measurement instrument, the S4 current meter, was used in field data collections of salinity and currents in the lower Apalachicola River estuary, Florida. The S4 current meter has an advantage in field deployments for long periods of time due to its preprogrammable capability for automatic data sampling and recording of fluid flow. Time series of surface and bottom salinity and currents obtained from field experiments were used to characterize the stratified flow at the measurement location in the Apalachicola River. Analysis of field data indicated that the river was strongly stratified. The stratification was affected by the upstream river flow and the downstream tidal variations. Stratification was stronger at high tide than at low tide. By removing the tidal signal using low-passing filtering, subtidal salinity, and currents were obtained to investigate the salinity stratification and currents responses to the changes of fresh water input. Subtidal vertical salinity and velocity profiles were presented at different flow conditions. At high flow conditions, both surface and bottom subtidal currents were in the seaward direction. At low flow conditions, the bottom subtidal currents were in the upstream direction due to the strong effects of density gradients. Empirical regression equations were obtained to quantify the effects of river flow on the subtidal salinity and the bottom currents. Regression analysis indicated good linear relationship between subtidal salinity stratification and the bottom currents.     

信丰县第二水厂取水工程设计

信丰县第二水厂水库引水工程设计通过方案比选确定的钢竖管配长杆蝶阀重力流分层取水形式,为一种全新概念取水形式,该取水形式与传统形式相比具有结构简单、造价低、后期生产运行管理方便、维护量小等优点。     

Effects of Soil Water Salinity on Field Soil Hydraulic Functions

Unsaturated soil hydraulic parameters and functions used in numerical models to simulate water flow and solute transport in the unsaturated zone are generally considered invariant of soil water salinity levels. This study uses 5 years of field soil water salinity levels at three observation sites from the Land Retirement Demonstration Project (LRDP) (20069) located in western Fresno County, California, to test the hypothesis that field unsaturated soil hydraulic properties are also a function of soil water salinity level. The HYDRUS-1D software package for simulating one-dimensional (1D) movement of water, heat, and multiple solutes in variably saturated media, and Parameter Estimation (PEST), a model-independent parameter optimizer, is used to optimize the soil hydraulic parameters and downward bottom flux corresponding to three different average soil salinity levels at each site. The results show that at the same pressure head, soil water content is less with higher soil water salinity as compared with lower soil water salinity. It is thus concluded that the use of soil water salinity invariant soil water hydraulic parameters in numerical modeling can seriously compromise predictions, especially for a variable soil water salinity environment.     

Reduced-Runoff Irrigation of Sudan Grass Hay, Imperial Valley, California

Sudan grass is a moderately salt-tolerant annual that is capable of substantial osmotic adjustment under high soil salinity conditions, but little is documented about its actual water use and yield under saline conditions. We estimate water use and evaluate the effects of “reduced-runoff” irrigation on soil salinity associated with Sudan grass hay production during a three-year field study (1996–98) in the Imperial Valley, California. The reduced-runoff irrigation method relies on the application of a simplified volume-balance surface irrigation model, and can result in negligible surface runoff; however, its use may have adverse impacts on soil salinity. Despite an anticipated salinity-induced yield reduction of about 15% associated with an average soil salinity of 6 dS∕m (0–0.6 m depth), use of the reduced-runoff method resulted in satisfactory crop yields, practically no tailwater runoff, and a slight decrease from the initial average profile soil salinity. The average applied water depth and estimated consumptive use (ETc) during the project were 1,019 and 935 mm, respectively, resulting in an average hay yield of 14.4 Mg∕ha versus the 1996–98 county average of 12.6 Mg∕ha. The project average ETc/ET0 and yield∕ETc ratios of 0.73 and 15.5 kg∕ha?mm, respectively, were approximately 15% less than those estimated from water-use-efficiency studies, probably as a result of salinity-induced hay yield reduction.     

Sensitivity Statistics of 3D Structures under Parametric Uncertainty

Determination of sensitivity gradient is a major prerequisite for structural optimization, reliability assessment, and parameter identification. As the conventional deterministic sensitivity analysis cannot provide complete information, stochastic analysis is needed to tackle the uncertainties in structural parameters. This study focuses on the utility of the stochastic finite-element method for random response sensitivity analysis. The stochastic modeling of a random parameter is based on a commonly used 2D local averaging method generalized for a 3D case. The Choleski decomposition technique is then employed for digital simulation. The Neumann expansion based finite-element simulation method is extended for stochastic sensitivity analysis. This technique leads to a considerable saving of computational time. Example problems are used to compare the accuracy of this method to the direct Monte Carlo simulation and perturbation method in terms of varying stochasticity and efficiency in CPU time.     

Optimal City-Center Takeoff Operation of Tiltrotor Aircraft in One Engine Failure

This paper investigates optimal tiltrotor flight trajectories and performance in vertical takeoff operations from a city-center heliport considering the possibility of one engine failure. A two-dimensional longitudinal rigid body model of a tiltrotor aircraft is used. Tiltrotor flights after engine failure in both continued takeoff and rejected takeoff are formulated as nonlinear optimal control problems that minimize the heliport size, subject to various constraints from safety considerations and tiltrotor performance limitations. These problems are parametrized via collocation into parameter optimization for numerical solutions. Extensive numerical solutions are obtained, and sensitivity analyses are conducted to examine effects of model parameter uncertainties. Optimization results indicate that the maximum gross weight capability of a tiltrotor in a vertical operation is determined by the need for safe landing in the event of a single engine failure. The height at which the decision for either continuing or rejecting the takeoff is made depends on the need to maintain sufficient height during the continued takeoff flight after an engine failure.     

Pilot study of 5-azacytidine (5-AZA) and carboplatin (CBDCA) in patients with relapsed/refractory leukemia

The principle of bowel detubularization to decrease peristaltic pressure and increase reservoir capacity is applied in contemporary continent urinary diversions. The process of detubularization and refashioning of the spatulated bowel segment approximates 1 of operating time and is the most time-consuming aspect of pouch construction. The employment of devices applying absorbable staples ("absorbable staplers") has substantially reduced the time required to fashion bowel reservoirs. This article reviews the adaptation of the absorbable stapler to continent urinary diversion using small- and large-bowel segments.     

Soil Salinity Modeling over Shallow Water Tables. I:?Validation of LEACHC

Soil salinity is a very common problem in today's irrigated agriculture. High salinity levels adversely impact crop yields and reduce overall soil quality. The presence of a saline shallow water table can be a major contributor to this problem. The LEACHC version of LEACHM is one of the few numerical models that considers independent movement of individual ions along with their detailed chemistry. This model has apparently not previously been tested under saline shallow water table conditions. LEACHC was evaluated using both lysimeter and field data from the literature. The model performed reasonably well in simulating solute transport above a saline shallow water table. For both data sets used in model validation, less reactive ions (sodium and chloride) were predicted well while calcium concentrations were underpredicted. For the field data, the model predicted soil electrical conductivity (EC) profiles better than most of the individual ions. The water content profiles associated with the field data were also predicted quite well. Based on these results, LEACHC was selected as a simulation tool for evaluating the effects of management practices on salinity transport in crop root zones above a saline shallow water table.