Energy Cost Optimization in a Water Supply System Case Study

The majority of the life cycle costs (LCC) of a pump are related to the energy spent in pumping, with the rest being related to the purchase and maintenance of the equipment. Any optimizations in the energy efficiency of the pumps result in a considerable reduction of the total operational cost. The Fátima water supply system in Portugal was analyzed in order to minimize its operational energy costs. Different pump characteristic curves were analyzed and modeled in order to achieve the most efficient operation point. To determine the best daily pumping operational scheduling pattern, genetic algorithm (GA) optimization embedded in the modeling software was considered in contrast with a manual override (MO) approach. The main goal was to determine which pumps and what daily scheduling allowed the best economical solution. At the end of the analysis it was possible to reduce the original daily energy costs by 43.7%. This was achieved by introducing more appropriate pumps and by intelligent programming of their operation. Given the heuristic nature of GAs, different approaches were employed and the most common errors were pinpointed, whereby this investigation can be used as a reference for similar future developments

Growth influences biomechanical profile of talented swimmers during the summer break

This study aimed to analyse the effect of growth during a summer break on biomechanical profile of talented swimmers. Twenty-five young swimmers (12 boys and 13 girls) undertook several anthropometric and biomechanical tests at the end of the 2011-2012 season (pre-test) and 10 weeks later at the beginning of the 2012-2013 season (post-test). Height, arm span, hand surface area, and foot surface area were collected as anthropometric parameters, while stroke frequency, stroke length, stroke index, propelling efficiency, active drag, and active drag coefficient were considered as biomechanical variables. The mean swimming velocity during an all-out 25 m front crawl effort was used as the performance outcome. After the 10-week break, the swimmers were taller with an increased arm span, hand, and foot areas. Increases in stroke length, stroke index, propelling efficiency, and performance were also observed. Conversely, the stroke frequency, active drag, and drag coefficient remained unchanged. When controlling the effect of growth, no significant variation was determined on the biomechanical variables. The performance presented high associations with biomechanical and anthropometric parameters at pre-test and post-test, respectively. The results show that young talented swimmers still present biomechanical improvements after a 10-week break, which are mainly explained by their normal growth.info:eu-repo/semantics/publishedVersio

Brewer’s spent grains protects against oxidative DNA damage in Saccharomyces cerevisiae

Brewer’s spent grain (BSG), obtained from barley malt during brewing, contains high amounts of phenolic acids, predominantly ferulic and p-coumaric acids. The protective effects of BSG extracts against oxidative DNA damage induced by H2O2 in Saccharomyces cerevisiae cells were investigated using an optimized yeast comet assay and flow cytometry. The results indicated that BSG extracts from black malt exhibited a 5-fold reduction in the genotoxic effects of H2O2, compared to the 2-fold decrease by the BSG extracts from pilsen malts. Flow cytometry analysis with dichlorofluorescein diacetate demonstrated that the intracellular oxidation of S. cerevisiae is also reduced to approximately 50% in the presence of 20-fold diluted BSG extracts. BSG extracts obtained from pilsen and black malt types exert dose-dependent protective properties against the genotoxic effects induced by ROS and decrease intracellular oxidation of yeast cells.This work received financial support from the European Union (FEDER Funds through COMPETE) and National Funds (FCT, Fundação para a Ciência e a Tecnologia) through project Pest-C/EQB/LA0006/2013 and PEst-C/BIA/UI4050/2011. The work also received financial support from the European Union (FEDER funds) under the framework of QREN through Project NORTE-07-0124-FEDER-000069. DOC receives a postdoc grant through the project Operação Norte-01-0145-FEDER-000011. MMM wishes to acknowledge to FCT for her postdoctoral grant (SFRH/BPD/97049/2013). The authors also thank Unicer – Bebidas de Portugal, S. A. for the supply of BSG samples.info:eu-repo/semantics/publishedVersio

Kinematic and kinetic study of sit-to-stand and stand-to-sit movements towards a human-like skeletal model

The movements of sit-to-stand and stand-to-sit are frequently executed on daily life. To develop robotic assistive devices for people with mobility problems, it is important to study how a healthy human performs these tasks. The goal of this study is to present a mathematical model based on acquired kinematic and kinetic data that represents a healthy human body performing these movements. The results revealed that the movements of sit-to-stand and stand-to-sit have symmetric ground reaction force, joint angles and torques. The joint angles and the torques are very similar between each leg. The knee and the hip show more variation of the angle and achieve higher values of torque in comparison to the ankle. Although, ankle has higher torque during standing position. The ground reaction force shows that it is necessary to create an additional force to the weight force to achieve the final position of the movement. The acquired data describe as expected the sit-to-stand and stand-to-sit movements and can be used, in the future, to validate the presented model.This work has been supported in part by the Fundacao para a Ciencia e Tecnologia (FCT) with the Reference Scholarship under Grant SFRH/BD/108309/2015, and part by the FEDER Funds through the Programa Operacional Regional do Norte and national funds from FCT with the project SmartOs -Controlo Inteligente de um Sistema Ortotico Ativo e Autonomo-under Grant NORTE-01-0145-FEDER-030386, and by the FEDER Funds through the COMPETE 2020-Programa Operacional Competitividade e Internacionalizacao (POCI)-with the Reference Project under Grant POCI-01-0145-FEDER-006941

Feedback-error learning for gait rehabilitation using a powered knee orthosis: first advances

Powered assistive devices have been playing a major role in gait rehabilitation. Hereby, the development of time-effective control strategies to manage such devices is a key concern to rehabilitation engineering. This paper presents a real-time Feedback-Error Learning control strategy, by means of an Artificial Neural Network as a feedforward controller to acquire the inverse model of the plant, and a Proportional-Integral-Derivative feedback controller to guarantee stability and handle with disturbances. A Powered Knee Orthosis was used as the assistive device and a trajectory generator assistive strategy, previously acquired through an inertial system, was applied. A validation with one subject walking in a treadmill at 1 km/h with the Powered Knee Orthosis controlled by the Feedback-Error Learning control was performed. Evidences on the control behavior presented good performances, with the Artificial Neural Network taking 90 seconds to learn the inverse model, which enabled a decrease in the angular position error by 75% and eliminated the phase delay, when compared to solo Proportional-Integral-Derivative feedback controller. Robust reactions to external disturbances were also achieved. The implemented Feedback-Error Learning strategy proves to be a time-effective asset to control assistive powered devices.This work has been supported in part by the Fundacao para a Ciencia e Tecnologia (FCT) with the Reference Scholarship under Grant SFRH/BD/108309/2015, and part by the FEDER Funds through the Programa Operacional Regional do Norte and national funds from FCT with the project SmartOs -Controlo Inteligente de um Sistema Ortotico Ativo e Autonomo-under Grant NORTE-01-0145-FEDER-030386, and by the FEDER Funds through the COMPETE 2020-Programa Operacional Competitividade e Internacionalizacao (POCI)-with the Reference Project under Grant POCI-01-0145-FEDER-006941 and supported by grant RYC-2014-16613 by Spanish Ministry of Economy and Competitiveness

The Role Of Videolaparoscopy In The Diagnostic And Therapeutic Approach Of Nonpalpable Testis.

Evaluate the results from the first 5 years of experience with laparoscopy for diagnosis and treatment of nonpalpable testes. Medical records of 51 patients submitted to laparoscopic testicular exploration, during a 5-year period, were retrospectively analyzed. Patients' mean age was 65.7 months (median = 48) on the first procedure. The youngest patient was 10 months and the oldest was 14 years old on the first surgery. Twenty-four (47%) patients presented nonpalpable testes bilaterally, 7 (14%) only at the right side and 20 (39%) at the left, totaling 75 testicular units assessed. Patients who had their testes palpated after anesthetic induction were excluded from the study, and in all other cases, surgical management was based on the testicular position and viability. During the post-operative follow-up, surgical success was classified as palpable testis in scrotal sac, with adequate consistency and volume. Nine (12%) testes were not localized, but their vessels and deferent duct were atrophic. Two (3%) testes were intra-abdominal and atrophic, and 2 (3%) gonads, in the same patient, had a dysmorphic aspect. Nineteen (25%) testicular units were located close to the internal inguinal ring (peeping testes) and, in 22 (29%) units, the spermatic vessels and deferent duct penetrated the internal inguinal ring. Eight (10%) testes were located at a distance of less than 2 cm from the internal inguinal ring and 13 (17%) at a distance greater than 2 cm. The 2 intra-abdominal atrophic testes were removed. Inguinotomy was performed in a total of 41 (54%) cases, reaching a surgical success of 89%. Laparoscopic orchiopexy in one stage, without vascular ligation, was performed in 9 (12%) testes, which presented a distance of less than 2 cm from the internal inguinal ring, also with a surgical success index of 89%. Orchiopexy in 2 stages, with ligation of the spermatic vessels, was performed in 13 (17%) testicular units located at a distance greater than 2 cm from the internal inguinal ring, reaching 77% of good results. Videolaparoscopy is a safe and effective method for diagnosis and treatment of nonpalpable testis.29345-51; discussion 351-

Combustion of Sugarcane Bagasse Pellets Produced with/without Glycerol: Chemical, Thermal and Emission Analyses

Purpose: Use of agricultural biomass in the form of pellets has gained worldwide prominence in recent decades, as part of the search for cleaner and renewable energy sources. Brazil is the largest sugarcane producer in the world, a fact that also places it as a major producer of residues from processing this crop. Methods: In this study, sugarcane bagasse pellets (SBP100) were handcrafted using glycerol as binder (30% - SBP30G) and, subsequently, analyses of their chemical and thermal properties, as well as those of the thermal decomposition exhaust gases, were conducted. Results: Average temperatures in the combustion range were 213.62±137.07° C (SBP100) and 211.97±86.85 °C (SBP30G). Combustion exhaust gas values were 20.04±0.15% (SBP100) and 19.95±0.19% (SBP30G) for O2; 1739.58±156.17 ppm (SBP100) and 1575±466.85 ppm (SBP30G) for CO; 19.92 ± 2.47 ppm (SBP100) and 17.33±4.69 ppm (SBP30G) for NOx; 341.67±134.37 ppm (SBP100) and 491.67±341.42 ppm (SBP30G) for CH4. SBP30G combustion proved to be less polluting with respect to CO and NOx generation than SBP100, but not for CH4. However, average thermal performance was similar for both. Conclusion: Use of glycerol contributed considerably to the changes in the pellets’ physical parameters. Exhaust gas analyses of the combustion of these substrates can serve as a basis for creating safety parameters and public policies to regulate the use of biomass for energy purposes

A Solution to the Challenge of Optimization on ''Golf-Course''-Like Fitness Landscapes

Genetic algorithms (GAs) have been used to find efficient solutions to numerous fundamental and applied problems. While GAs are a robust and flexible approach to solve complex problems, there are some situations under which they perform poorly. Here, we introduce a genetic algorithm approach that is able to solve complex tasks plagued by so-called ''golf-course''-like fitness landscapes. Our approach, which we denote variable environment genetic algorithms (VEGAs), is able to find highly efficient solutions by inducing environmental changes that require more complex solutions and thus creating an evolutionary drive. Using the density classification task, a paradigmatic computer science problem, as a case study, we show that more complex rules that preserve information about the solution to simpler tasks can adapt to more challenging environments. Interestingly, we find that conservative strategies, which have a bias toward the current state, evolve naturally as a highly efficient solution to the density classification task under noisy conditions