A global mathematical model for simultaneously obtaining the optimal layout and design of urban drainage systems for foul sewage and stormwater is presented. The model can handle every kind of network, including parallel storm and foul sewers. It selects the optimal location for pumping systems and outfalls or wastewater treatment plants (defining the natural and artificial drainage basins), and it allows the presence of special structures and existing subsystems for optimal remodeling or expansion. It is possible to identify two basic optimization levels: in the first level, the generation and transformation of general layouts (consisting of forests of trees) until a convergence criterion is reached, and in the second level, the design and evaluation of each forest. The global

The presence of hydrogen sulphide gas in sewerage collection systems is a common source of odour nuisance, corrosion of sewers and toxic atmospheres. The hydrogen sulphide build-up in the sewer air may be related to sulphide concentrations in the flowing sewage and with other factors, such as turbulence, aerodynamic conditions of the ventilating air now and roughness of the unsubmerged surfaces. In the present work, a mathematical model is presented for forecasting hydrogen sulphide gas build-up along gravity sewers, which is based on the analysis of a differential mass balance equation applied to a sewer reach. Good correlation was obtained, comparing the results of the model with experimental information collected in the Funchal main trunk sewer. Funchal city is the capital of Madeira, a Portuguese island in the middle of the Atlantic Ocean, and its main trunk sewer was put into operation at the beginning of 1980.

The oxygen balance in wastewater collection systems is important in respect to the degree of biological oxidation that occurs within the stream and in respect to the control of septicity and its effects. In this paper, a simple mathematical model is presented, in order to predict dissolved oxygen concentration profiles along sanitary sewers. The mathematical model was developed based on an analytical solution of the simple differential equation of dissolved oxygen balance in sewers, and includes an empirical expression for prediction of dissolved oxygen transfer to the slime layer on the pipe walls. Because the factors controlling dissolved oxygen balance in sewers are so complex, it would be unrealistic to expect, that with this rather simple model, dissolved oxygen concentrations can be accurately predicted. Nevertheless, it is reasonable to suppose that the predictions may be adequate for some design and operation purposes.

Introduction: Neurofeedback training has been an increasingly used technique in sport; however, most of the protocols used in athletes are based in the results obtained in nonathletic population. Purpose: Understand if a specific neurofeedback training protocol implemented in a nonathletic population can improve short-term memory and reaction time in athletes. Methods: A total of 45 subjects participated in the experiment (mean ± SD for age: 23.31 ± 4.20 years). For athletes, 12 neurofeedback training sessions were performed; for the nonathletes, 15 neurofeedback training were performed. Each session had 25 min of effective neurofeedback training. Results: Despite the nonathletes group's increased standard alpha band (SAB) relative amplitude and individual alpha band (IAB) relative amplitude after 12 sessions of neurofeedback training (p < .005), only the athletes intervention group had positive results in reaction time (p < .001 in oddball test). Not only was the null hypothesis rejected by the differences of IAB and SAB relative amplitudes between and within protocols but also by the performance tests. Conclusion: Neurofeedback training increases the relative amplitude of the bands in the nonathletes group; however, only the athletes have shown to improve performances tests after 12 neurofeedback training sessions.

This paper concerns the dissolved oxygen (DO) balance in sewers and describes the experimental work and results obtained under a research project undertaken on a small wastewater collection system. For prediction of oxygen balance in sewers, reaeration and DO consumption, both within the stream and within the biological slime layer on the pipe wall, must be computed. In this study special emphasis is given to DO uptake by the slime layer. Comparison of experimental results concerning the activity of the slime layer with the results calculated by the Pomeroy and Parkhurst equation, the only one available in the literature applicable to sewers, did not lead to a good agreement. Under low flow conditions and high DO concentrations, a significative correlation was found between velocity and DO consumption by the slime layer. No correlation was found between DO concentration within the stream and DO utilization by the slime layer.