Simulação do sistema de esgotamento sanitário de Ponta Negra- Natal: mitigação dos riscos ambientais e estratégia de manutenção preditiva

The simulation of SES-Natal Ponta Negra: mitigation of environmental risks and predictive maintenance strategy was developed in the context of several operational irregularities in the pumping stations and sewage systems in the system Ponta Negra. Thus, the environmental risks and complaints against the company due to overflows of sewage into the public thoroughfare became common. This neighborhood has shown in recent years an increase of resident higher than the initial expectation of growth. In this sense presumed the large population growth and generation of sewers higher than expected, associated to the use of corrective maintenance and misuse of the system may be the main causes of operational failures occurring in the SES. This study aimed at analyzing the hydraulic behavior of SES Ponta Negrathrough numerical simulation of its operation associated to future scenarios of occupation. The SES Ponta Negra has a long lengthof collection networks and 6 pumping stations interconnected, being EE 1, 2, 4 coastal way, and beach Shopping interconnected EE3 to receives all sewers pumped from the rest pumping station and pumped to the sewage treatment station of neighborhood which consists of a facultative pond followed by three maturation ponds with disposal of treated effluent into infiltration ditches. Oncethey are connected with each other, the study was conducted considering the days and times of higher inflow for all lifts. Furthermore, with the aim of measuring the gatherer network failures were conducted data survey of on the networks. Thephysical and operational survey data was conducted between January/2011 and janeiro/2012. The simulation of the SES was developed with the aim ofdemonstrating its functioning, eithercurrently and in the coming years, based in population estimates and sewage flow. The collected data represents the current framework of the pumping stations of the SES Ponta Negra and served as input to the model developed in MS Excel ® spreadsheet which allowed simulating the behavior of SES in future scenarios. The results of this study show thatBeach Shopping Pumping Station is actually undersized and presents serious functioning problemsthatmay compromise the environmental quality of surrounding area. The other pumping stations of the system will reach itsmaximum capacity between 2013 and 2015, although the EE1 and EE3 demonstrateoperation capacity, even precariously, until 2017. Moreover, it was observed that the misuse of the network system, due to the input of both garbage and stormwater, are major factors of failures that occur in the SES. Finally, it was found that the corrective maintenance appliance, rather than predictive,has proven to beinefficient because of the serious failuresin the system, causing damage to the environment and health risks to users

Influência da fadiga no comportamento neuromuscular do quadríceps femoral, após reconstrução do ligamento cruzado anterior

Muscle fatigue is a phenomenon that promotes physiological and biomechanical disorders and their changes in healthy subjects have been widely studied and have significant importance for care in preventing injuries, but we do not have many information about its effects in patients after ACL reconstruction. Thus, this study is to analyze the effects of fatigue on neuromuscular behavior of quadriceps after ACL reconstruction. To reach this objective, participants were forty men, twenty healthy (26,90 ± 6,29 years) and twenty after ACL reconstruction (29,75 ± 7,01 years) with a graft of semitendinosus and gracilis tendons, between four to six months after surgery. At first, there was an assessment of joint position sense (JPS) at the isokinetic dynamometer at a speed of 5°/s and target angle of 45° to analyze the absolute error of JPS. Next, we applied the a muscle fatigue protocol, running 100 repetitions of isokinetic knee flexion-extension at 90°/s. Concurrently with this protocol, there was the assessment of muscle performance, as the peak torque (PT) and fatigue index, and electromyographic activity (RMS and median frequency). Finally, we repeated the assessment of JPS. The statistical analysis showed that patients after ACL reconstruction have, even under normal conditions, the amended JPS compared with healthy subjects and that after fatigue, both have disturbances in the JPS, but this alteration is significantly exacerbated in patients after ACL reconstruction. About muscle performance, we could notice that these patients have a lower PT, although there are no differences between the dynamometric and EMG fatigue index. These findings show the necessity about the cares of pacients with ACL reconstruction in respect of the risks of articulate instability and overload in ligamentar graft

Percepção de riscos ambientais de populações vulneráveis a inundações e deslizamentos de dunas em Natal-RN

In urban, flooding and landslides are among the troubles that most bring human and material loss. Therefore, this study objected to perform an analysis on the risk perception on the population living in social environmental vulnerable places in order to understand what is the way this population realize the risks they are exposed to and what are the outbrave strategies the develop. The first analyzed area was Complexo Passo da Pátria for the flooding risk problematic and then the Cidade Nova neighborhood threatened by the dunes slides. The areas locate, respectively, in the West and East zones of Natal-RN. Using an interview screenplay adapted from risk perception researches from different brazilian cities, it was collected primarily data on the variables: perception, evaluation and choice, safety threshold, adjustment, decision and participation. Due to the studied areas characteristics the qualitative approach adjusted itself to the difficulties for accessing the areas. The studied places characterize for its insecure situation like selling/using drugs, robbery and murder among others. Due to this situation the interviewed individuals were the ones that could be found more accessibly and available in the moment and the interviews were made in the community leader presence of each area. Through the discourse of the respondents analysis it was able to conclude that the interviewed population is exposed to a high vulnerability grade and risks. However it was identified substantial differences between the perception and risks of Complexo Passo da Pátria and bairro Cidade Nova, because in the first area the intervied ones can recognize the high risk they are exposed to in a more emphatic way to the interviewed ones for the Cidade Nova neighborhood. Furthermore, there is a heavy dissatisfaction for the population of the two places about the city hall positions relating to the present problems in the studied areas. It was also identified the strategy development of acquaintanceship with the risk in the research places beyond a feeling of belonging and affection between the dwellers and the places, yet it was more evident for Complexo Passo da Pátria. Though this analysis it was possible to understand and perceptions and the behavior of the individuals or social groups facing the risks as acceptance and rejection of determined risks beyond adaptation measures of living together with the persistence presence of risks. Therefore, qualitative nature researches emphasizing the perception approach are in the fundamental importance in the studies about risks making it possible to offer aids to the urban planning and management in the implement of effective preventive measures and compatible with the population aims

Estudo do comportamento da sinterização de compactos de cavacos de um aço SAE 1050 obtidos sob alta pressão

From an economic standpoint, the powder metallurgy (P/M) is a technique widely used for the production of small parts. It is possible, through the P/M and prior comminution of solid waste such as ferrous chips, produce highly dense sintered parts and of interest to the automotive, electronics and aerospace industries. However, without prior comminution the chip, the production of bodies with a density equal to theoretical density by conventional sintering techniques require the use of additives or significantly higher temperatures than 1250ºC. An alternative route to the production of sintered bodies with high density compaction from ferrous chips (≤ 850 microns) and solid phase sintering is a compression technique under high pressure (HP). In this work, different compaction pressures to produce a sintered chip of SAE 1050 carbon steel were used. Specifically, the objective was to investigate them, the effect of high pressure compression in the behavior of densification of the sintered samples. Therefore, samples of the chips from the SAE 1050 carbon steel were uniaxially cold compacted at 500 and 2000 MPa, respectively. The green compacts obtained were sintered under carbon atmosphere at 1100 and 1200°C for 90 minutes. The heating rate used was 20°C/min. The starting materials and the sintered bodies were characterized by optical microscopy, SEM, XRD, density measurements (geometric: mass/volume, and pycnometry) and microhardness measurements Vickers and Rockwell hardness. The results showed that the compact produced under 2000 MPa presented relative density values between 93% and 100% of theoretical density and microhardness between 150 HV and 180 HV, respectively. In contrast, compressed under 500 MPa showed a very heterogeneous microstructure, density value below 80% of theoretical density and structural conditions of inadequate specimens for carrying out the hardness and microhardness measurements. The results indicate that use of the high pressure of ferrous chips compression is a promising route to improve the sinterability conditions of this type of material, because in addition to promoting greater compression of the starting material, the external tension acts together with surface tension, functioning as the motive power for sintering process. Additionally, extremely high pressures allow plastic deformation of the material, providing an intimate and extended contact of the particles and eliminating cracks and pores. This tends to reduce the time and / or temperature required for good sintering, avoiding excessive grain growth without the use of additives. Moreover, higher pressures lead to fracture the grains in fragile or ductile materials highly hardened, which provides a starting powder for sintering, thinner, without the risk of contamination present when previous methods are used comminution of the powder.