Influência da pressão e da vazão de concentrado sobre o desempenho de ultrafiltração no pós-tratamento de esgotos

Despite the numerous advantages resulting from the use of membrane filters technology, intrinsic limitations fouling process become relevant to its applicability. The control of operating conditions is an important tool to mitigate fouling and achieve good levels of efficiency. In this sense, the objective of this study was to investigate the effect of transmembrane pressure and concentrate flow in the performance of ultrafiltration, applied to the post-treatment of domestic sewage. The process was evaluated and optimized by varying the pressure (0.5 and 1.5 bar) and the concentrate flow (300 and 600 L/h), using a 22 factorial design, in order to investigate the effects on the permeate flow and quality of effluents generated at each operating condition. We evaluated the following quality indicators for permeate: pH, electrical conductivity, total suspended solids, turbidity, calcium and Chemical Oxygen Demand (COD). In all tests, we observed marked reduction in the permeate flux at the early stages, followed by a slow decline that lasted until it reaches a relatively constant level, around 120 minutes of filtration. The increased pressure resulted in a higher initial permeate flux, but the decrease of the flow with time is greater for tests at higher pressure, indicating a more pronounced fouling process. On the other hand, increasing the concentrate flow resulted in a slower decline in permeate flux with the filtration time. Regarding the quality of permeate, the transmembrane pressure of 0,5 bar was the one that allowed better results, and was statistically confirmed through the two-way ANOVA test with repeated measures, significant effect of pressure on the turbidity of the permeate. The concentrate flow, in turn, showed no significant influence on any of the quality parameters. Thus, we conclude that, from an economic and environmental point of view, it is more interesting to operate ultrafiltration membrane system with a lower concentrate flow associated with a low transmembrane pressure, since under these conditions will produce less waste, and the permeate will present lower concentrations of the analyzed constituent, especially lower turbidity.

Adição de policloreto de alumínio e remoção de peixes bentívoros como técnicas de restauração de lagos rasos do semiárido brasileiro

Eutrophication is the most common cause of water quality degradation in the world. This process occurs by excessive nutrients inputs, nitrogen and phosphorus, to the aquatic systems resulting in algal and cyanobacterial blooms. In shallow lakes these effects are pronounced due to the higher interaction of the lake with watershed, air and sediment. There are innumerous restoration techniques of eutrophied lakes with a range of successful results but there is only one case of successful lake restoration in Brazil: Paranoá Lake in Brasília city. The Brazilian semiarid region has many artificial lakes, named açudes, which are mostly eutrophic and shallow lakes. The eutrophication in these lakes is reported and the phytoplankton community is dominated by potentially toxic cyanobacteria species, mainly Cylindrospermopsis raciborskii. The aim of this thesis is to test techniques for water quality management which can be easily applied in Brazilian semiarid lakes. Results from a laboratory experiment suggest that the addition of a phosphorus sorbent clay associated with an aluminium based coagulant is an effective technique in removing soluble reactive phosphorus and reducing C. raciborskii growth rate – cyanobacteria potentially toxic dominant in reservoirs of Brazilian semiarid – but this effect is dependent on the biomass in the application moment. Results from a field experiment in mesocosm in a eutrophied lake showed that the addition of aluminium based coagulant and removal of benthivorous fish is more efficient in removing total phosphorus and chlorophyll-a from water column than the isolated application of one of the techniques. Lastly, laboratory tests showed that aluminium based coagulant exhibited good performance in removing turbidity and total phosphorus from water of six reservoirs but the efficiency was reduced by algal biomass and pH. The results of this study showed that the improvement in water quality of eutrophied reservoirs in semiarid region is possible through internal loading control by phosphorus precipitation and inactivation in sediments or inhibition of phosphorus release by benthivorous fishes, and also that these results show are additives in water quality improvement.

Adição de policloreto de alumínio e remoção de peixes bentívoros como técnicas de restauração de lagos rasos do semiárido brasileiro

Eutrophication is the most common cause of water quality degradation in the world. This process occurs by excessive nutrients inputs, nitrogen and phosphorus, to the aquatic systems resulting in algal and cyanobacterial blooms. In shallow lakes these effects are pronounced due to the higher interaction of the lake with watershed, air and sediment. There are innumerous restoration techniques of eutrophied lakes with a range of successful results but there is only one case of successful lake restoration in Brazil: Paranoá Lake in Brasília city. The Brazilian semiarid region has many artificial lakes, named açudes, which are mostly eutrophic and shallow lakes. The eutrophication in these lakes is reported and the phytoplankton community is dominated by potentially toxic cyanobacteria species, mainly Cylindrospermopsis raciborskii. The aim of this thesis is to test techniques for water quality management which can be easily applied in Brazilian semiarid lakes. Results from a laboratory experiment suggest that the addition of a phosphorus sorbent clay associated with an aluminium based coagulant is an effective technique in removing soluble reactive phosphorus and reducing C. raciborskii growth rate – cyanobacteria potentially toxic dominant in reservoirs of Brazilian semiarid – but this effect is dependent on the biomass in the application moment. Results from a field experiment in mesocosm in a eutrophied lake showed that the addition of aluminium based coagulant and removal of benthivorous fish is more efficient in removing total phosphorus and chlorophyll-a from water column than the isolated application of one of the techniques. Lastly, laboratory tests showed that aluminium based coagulant exhibited good performance in removing turbidity and total phosphorus from water of six reservoirs but the efficiency was reduced by algal biomass and pH. The results of this study showed that the improvement in water quality of eutrophied reservoirs in semiarid region is possible through internal loading control by phosphorus precipitation and inactivation in sediments or inhibition of phosphorus release by benthivorous fishes, and also that these results show are additives in water quality improvement.

Avaliação do desempenho da paligorsquita modificada e do carvão da pirólise do lodo de esgoto no processo de degradação fotocatalítica do fenol

The uncontrolled disposal of wastewaters containing phenolic compounds by the industry has caused irreversible damage to the environment. Because of this, it is now mandatory to develop new methods to treat these effluents before they are disposed of. One of the most promising and low cost approaches is the degradation of phenolic compounds via photocatalysis. This work, in particular, has as the main goal, the customization of a bench scale photoreactor and the preparation of catalysts via utilization of char originated from the fast pyrolysis of sewage sludge. The experiments were carried out at constant temperature (50°C) under oxygen (410, 515, 650 and 750 ml min-1). The reaction took place in the liquid phase (3.4 liters), where the catalyst concentration was 1g L-1 and the initial concentration of phenol was 500 mg L-1 and the reaction time was set to 3 hours. A 400 W lamp was adapted to the reactor. The flow of oxygen was optimized to 650 ml min-1. The pH of the liquid and the nature of the catalyst (acidified and calcined palygorskite, palygorskite impregnated with 3.8% Fe and the pyrolysis char) were investigated. The catalytic materials were characterized by XRD, XRF, and BET. In the process of photocatalytic degradation of phenol, the results showed that the pH has a significant influence on the phenol conversion, with best results for pH equal to 5.5. The phenol conversion ranged from 51.78% for the char sewage sludge to 58.02% (for palygorskite acidified calcined). Liquid samples analyzed by liquid chromatography and the following compounds were identified: hydroquinone, catechol and maleic acid. A mechanism of the reaction was proposed, whereas the phenol is transformed into the homogeneous phase and the others react on the catalyst surface. For the latter, the Langmuir-Hinshelwood model was applied, whose mass balances led to a system of differential equations and these were solved using numerical methods in order to get estimates for the kinetic and adsorption parameters. The model was adjusted satisfactorily to the experimental results. From the proposed mechanism and the operating conditions used in this study, the most favored step, regardless of the catalyst, was the acid group (originated from quinone compounds), being transformed into CO2 and water, whose rate constant k4 presented value of 0.578 mol L-1 min-1 for acidified calcined palygorskite, 0.472 mol L-1 min-1 for Fe2O3/palygorskite and 1.276 mol L-1 min-1 for the sludge to char, the latter being the best catalyst for mineralization of acid to CO2 and water. The quinones were adsorbed to the acidic sites of the calcined palygorskite and Fe2O3/palygorskite whose adsorption constants were similar (~ 4.45 L mol-1) and higher than that of the sewage sludge char (3.77 L mol-1).

Avaliação do desempenho da paligorsquita modificada e do carvão da pirólise do lodo de esgoto no processo de degradação fotocatalítica do fenol

The uncontrolled disposal of wastewaters containing phenolic compounds by the industry has caused irreversible damage to the environment. Because of this, it is now mandatory to develop new methods to treat these effluents before they are disposed of. One of the most promising and low cost approaches is the degradation of phenolic compounds via photocatalysis. This work, in particular, has as the main goal, the customization of a bench scale photoreactor and the preparation of catalysts via utilization of char originated from the fast pyrolysis of sewage sludge. The experiments were carried out at constant temperature (50°C) under oxygen (410, 515, 650 and 750 ml min-1). The reaction took place in the liquid phase (3.4 liters), where the catalyst concentration was 1g L-1 and the initial concentration of phenol was 500 mg L-1 and the reaction time was set to 3 hours. A 400 W lamp was adapted to the reactor. The flow of oxygen was optimized to 650 ml min-1. The pH of the liquid and the nature of the catalyst (acidified and calcined palygorskite, palygorskite impregnated with 3.8% Fe and the pyrolysis char) were investigated. The catalytic materials were characterized by XRD, XRF, and BET. In the process of photocatalytic degradation of phenol, the results showed that the pH has a significant influence on the phenol conversion, with best results for pH equal to 5.5. The phenol conversion ranged from 51.78% for the char sewage sludge to 58.02% (for palygorskite acidified calcined). Liquid samples analyzed by liquid chromatography and the following compounds were identified: hydroquinone, catechol and maleic acid. A mechanism of the reaction was proposed, whereas the phenol is transformed into the homogeneous phase and the others react on the catalyst surface. For the latter, the Langmuir-Hinshelwood model was applied, whose mass balances led to a system of differential equations and these were solved using numerical methods in order to get estimates for the kinetic and adsorption parameters. The model was adjusted satisfactorily to the experimental results. From the proposed mechanism and the operating conditions used in this study, the most favored step, regardless of the catalyst, was the acid group (originated from quinone compounds), being transformed into CO2 and water, whose rate constant k4 presented value of 0.578 mol L-1 min-1 for acidified calcined palygorskite, 0.472 mol L-1 min-1 for Fe2O3/palygorskite and 1.276 mol L-1 min-1 for the sludge to char, the latter being the best catalyst for mineralization of acid to CO2 and water. The quinones were adsorbed to the acidic sites of the calcined palygorskite and Fe2O3/palygorskite whose adsorption constants were similar (~ 4.45 L mol-1) and higher than that of the sewage sludge char (3.77 L mol-1).

Controle de mobilidade infraestruturado e orientado à qualidade para maximização de admissões em sistemas WiNeMO: uma abordagem definida por software

The spread of wireless networks and growing proliferation of mobile devices require the development of mobility control mechanisms to support the different demands of traffic in different network conditions. A major obstacle to developing this kind of technology is the complexity involved in handling all the information about the large number of Moving Objects (MO), as well as the entire signaling overhead required to manage these procedures in the network. Despite several initiatives have been proposed by the scientific community to address this issue they have not proved to be effective since they depend on the particular request of the MO that is responsible for triggering the mobility process. Moreover, they are often only guided by wireless medium statistics, such as Received Signal Strength Indicator (RSSI) of the candidate Point of Attachment (PoA). Thus, this work seeks to develop, evaluate and validate a sophisticated communication infrastructure for Wireless Networking for Moving Objects (WiNeMO) systems by making use of the flexibility provided by the Software-Defined Networking (SDN) paradigm, where network functions are easily and efficiently deployed by integrating OpenFlow and IEEE 802.21 standards. For purposes of benchmarking, the analysis was conducted in the control and data planes aspects, which demonstrate that the proposal significantly outperforms typical IPbased SDN and QoS-enabled capabilities, by allowing the network to handle the multimedia traffic with optimal Quality of Service (QoS) transport and acceptable Quality of Experience (QoE) over time.

Remoção de carbonatos para otimizar a biolixiviação de rejeito calcopirítico empregando consórcio de microrganismos

The bioleaching of chalcopyrite has not been applied on a commercial scale due to the low process efficiency, so this process has been extensively studied in recent years. The bioleaching of chalcopyrite tailings becomes even more difficult by the presence of higher amounts of impurities, among them are the carbonates. The presence of carbonates in the ore promotes the increase in pH of the solution and may inhibit the development of bioleaching. Therefore, this research aims to apply the acid treatment for optimization of bioleaching process, in order to recover the lost copper throughout the process besides reducing the content of this toxic metal in the tailings pond. The removal and recovery of toxic metals is very important in protecting the environment and human health. The bioleaching experiments were performed in two stages, the first made up using the pre-treated tailing with sulfuric acid in bioleaching, and the second was made using the tailing without treatment with sulfuric acid addition at the beginning of bioleaching. The acid treatment was carried out in bioreactors with three different volumes of H2SO4 96% and a control experiment. All bioleaching experiments were performed in triplicate over a control, without addition of inoculum. The results showed that acid treatment was effective in removal of carbonates and managed to promote a good performance in the bioleaching of chalcopyrite in both steps studied, it is demonstrated that circa 47% copper recovery can be achieved.

Remoção de carbonatos para otimizar a biolixiviação de rejeito calcopirítico empregando consórcio de microrganismos

The bioleaching of chalcopyrite has not been applied on a commercial scale due to the low process efficiency, so this process has been extensively studied in recent years. The bioleaching of chalcopyrite tailings becomes even more difficult by the presence of higher amounts of impurities, among them are the carbonates. The presence of carbonates in the ore promotes the increase in pH of the solution and may inhibit the development of bioleaching. Therefore, this research aims to apply the acid treatment for optimization of bioleaching process, in order to recover the lost copper throughout the process besides reducing the content of this toxic metal in the tailings pond. The removal and recovery of toxic metals is very important in protecting the environment and human health. The bioleaching experiments were performed in two stages, the first made up using the pre-treated tailing with sulfuric acid in bioleaching, and the second was made using the tailing without treatment with sulfuric acid addition at the beginning of bioleaching. The acid treatment was carried out in bioreactors with three different volumes of H2SO4 96% and a control experiment. All bioleaching experiments were performed in triplicate over a control, without addition of inoculum. The results showed that acid treatment was effective in removal of carbonates and managed to promote a good performance in the bioleaching of chalcopyrite in both steps studied, it is demonstrated that circa 47% copper recovery can be achieved.

A interação ensino-serviço no processo de formação dos graduandos em fisioterapia da UFPB: a percepção dos docentes

The health paradigm, consolidated in the last century, directed the training of health professionals, educated under the aegis of the Flexnerian training, fragmentary and hospital-centered model. However, it proved to be insufficient to meet the demands of the Unified Health System and the population. In this sense, the National Curriculum Guidelines for Undergraduate health courses emerge as a normative framework in proposing a new professional profile, as well as the recommendation of strategies for the restructuring of curricula and teaching practices, and one of them is the teaching-service integration. Therefore, the aim of this study was to investigate the process of training of Physiotherapy course students of the Federal University of Paraíba with the guiding principle of teaching-service integration, considering DCN. In this sense, the chosen method was a case study with qualitative approach. The sample was intentional, including all faculty members of the permanent staff of the Department of Physiotherapy at UFPB, linked to curriculum components whose practice scenarios occur in the SUS network and time longer than one year in that component. The data collection technique was the semi-structured interview. Data analysis was performed using the content analysis technique. The following categories were considered: professional training for SUS, integration of students to the SUS network services, the relationship between theory and practice in the training of physiotherapists, teaching and health professional partnership in the teaching-learning process and programs of training reorientation and their integration with the course. The results allowed identifying positive points in the teaching-service integration: recognition of the importance of integration activities between university and health services based on the insertion of students in the network, the combined actuation with health service professionals and the opportunity to work in a multidisciplinary team; the existence of structured and organized School Network; participation of students and teachers in government programs that offer the experience of insertion in the labor market. The following weaknesses stood out: difficulties in agreement, planning and evaluation of activities by the service; gap between theoretical and practical activities; lack of definition of roles of teacher and health service professionals in the training process and the fragile relationship of reorientation of vocational training programs with the curricular activities of the course. The teaching-service integration as a guiding principle in the analysis of the formation of physiotherapists reveals limits and possibilities for training that meets the health needs of the population. Thus, the choices of educational institutions regarding the care model have an influence on health practices, as well as the commitment by management and services and the permeability to social control instances decisively contribute to the improvement in the training of future professionals. Thus, the commitment of all involved for the effective change in the training process of health paradigm is indispensable.

A interação ensino-serviço no processo de formação dos graduandos em fisioterapia da UFPB: a percepção dos docentes

The health paradigm, consolidated in the last century, directed the training of health professionals, educated under the aegis of the Flexnerian training, fragmentary and hospital-centered model. However, it proved to be insufficient to meet the demands of the Unified Health System and the population. In this sense, the National Curriculum Guidelines for Undergraduate health courses emerge as a normative framework in proposing a new professional profile, as well as the recommendation of strategies for the restructuring of curricula and teaching practices, and one of them is the teaching-service integration. Therefore, the aim of this study was to investigate the process of training of Physiotherapy course students of the Federal University of Paraíba with the guiding principle of teaching-service integration, considering DCN. In this sense, the chosen method was a case study with qualitative approach. The sample was intentional, including all faculty members of the permanent staff of the Department of Physiotherapy at UFPB, linked to curriculum components whose practice scenarios occur in the SUS network and time longer than one year in that component. The data collection technique was the semi-structured interview. Data analysis was performed using the content analysis technique. The following categories were considered: professional training for SUS, integration of students to the SUS network services, the relationship between theory and practice in the training of physiotherapists, teaching and health professional partnership in the teaching-learning process and programs of training reorientation and their integration with the course. The results allowed identifying positive points in the teaching-service integration: recognition of the importance of integration activities between university and health services based on the insertion of students in the network, the combined actuation with health service professionals and the opportunity to work in a multidisciplinary team; the existence of structured and organized School Network; participation of students and teachers in government programs that offer the experience of insertion in the labor market. The following weaknesses stood out: difficulties in agreement, planning and evaluation of activities by the service; gap between theoretical and practical activities; lack of definition of roles of teacher and health service professionals in the training process and the fragile relationship of reorientation of vocational training programs with the curricular activities of the course. The teaching-service integration as a guiding principle in the analysis of the formation of physiotherapists reveals limits and possibilities for training that meets the health needs of the population. Thus, the choices of educational institutions regarding the care model have an influence on health practices, as well as the commitment by management and services and the permeability to social control instances decisively contribute to the improvement in the training of future professionals. Thus, the commitment of all involved for the effective change in the training process of health paradigm is indispensable.

O controle da tuberculose no contexto da atenção primária à saúde no Brasil

O Brasil é um dos países que concentram 80% da carga de tuberculose no mundo. No contexto da atenção primária brasileira, fatores interferem para que as equipes de saúde da família possam incorporar as atividades de controle da doença no processo de trabalho. O controle da doença depende da forma como os serviços de saúde estão organizados para garantir o acesso ao diagnóstico precoce e ao tratamento. Esse estudo tem como objetivo geral analisar o controle da tuberculose no contexto da atenção primária à saúde no Brasil. Os objetivos específicos são comparar o tratamento diretamente observado com o regime autoadministrado em pessoas com tuberculose; Verificar se o Programa Nacional de Controle da Tuberculose é avaliável e elaborar um modelo teórico e lógico para avaliação deste programa; avaliar a relação entre porte populacional dos municípios e as características de estrutura e processo de cuidado a pacientes de tuberculose na atenção primária no Brasil. Realizou-se uma revisão sistemática, seguida de um estudo de avaliabilidade e de um estudo transversal. Os achados da revisão sistemática revelam que não houve diferença significativa entre os grupos de tratamento (observado e não observado) para cura (OR 1,06. IC95% 0,75 - 1,50) e para conclusão do tratamento (OR 1,64, IC 95% 0,79 - 3,42). Menor abandono no grupo com tratamento supervisionado e não houve diferença estatisticamente significativa entre os grupos (OR 0,73, CI 95% 0,58-0,92). O risco de morte foi maior no regime de tratamento autoadministrado (OR 1,49 IC 95% 1,03 - 2,45). A hetorogeinadade entre os estudos analisados não permite afirmar que nao há diferença estatisticamente significativa para cura e tratamento concluído. A pré-avaliação do Programa de Controle de Tuberculose possibilitou a descrição do Programa, elaboração e pactuação do modelo lógico e a matriz de relevância dos indicadores. Caracterizou-se os seus elementos estruturantes, definição de indicadores de estrutura e processo, além das perguntas avaliativas. Uma avaliação somativa com enfoque na análise dos efeitos da intervenção de controle da tuberculose é recomendada. A avaliação das características de estrutura e processo de cuidado à pessoa com tuberculose revelou melhor desempenho para as equipes de atenção básica de municípios classificados como metrópole no acesso, coordenação do cuidado e qualidade técnica da atenção. Em relação ao acesso: 98,5% acolhimento a demanda espontânea; 95,8% programação de consultas. Na coordenação do cuidado, 93,2% existência de protocolo para tuberculose. Quanto a qualidade técnica da atenção à tuberculose verifica-se que 93,4% acompanhamento de tratamento diretamente observado, 95,8% com busca ativa de faltosos ao tratamento, 64,0% oferta de ações educativas, 91,3% busca ativa de sintomáticos respiratórios. Cabe destacar que metrópoles apresentaram maior tempo médio de espera para escuta/acolhimento (24,41 minutos); para consulta previamente agendada (23,52 dias); para consulta em pneumologia (87,12 dias). Percebem-se fragilidades na estrutura e processo da atenção à tuberculose, principalmente no controle especializado da doença e na qualidade técnica entre os municípios. Recomenda-se reforço, particularmente na qualidade técnica para aumentar a cobertura de acompanhamento do tratamento, busca de sintomáticos respiratórios e das ações educativas.

Influência da utilização do fluido de corte com adição de grafeno na temperatura de usinagem e formação de rebarba no processo de micro fresamento

As time passed, humanity needed the development of new materials used in various activities. High strength materials such as titanium and Inconel for example, had been studied because they are widely used for implants in biomedicine, as well as their use in aerospace and automotive industries. Because of its thermal and mechanical properties, these materials are considered difficult to machine, promoting a rapid wear of cutting tools, primarily caused by the high temperatures in machining. With the development of new materials has emerged the need of developing new manufacturing processes. One of today’s innovative processes is the micro-manufacturing. Being a process with a defined cutting tool geometry, burr formation is a constant and undesirable phenomenon formed during the machininig process. Being detrimental to the manufacturing process, overspending deburring operations are constantly employed leading to increase the aggregate cost to the manufactured material. Assembly components are also impaired if there is no control of the burr, with consequences including the disposal of components due to the occurence of this phenomenon. This paper presents the study of micro-milling Inconel 718, investigating influential parameters in the formation of burrs in order to minimize the occurrence of this phenome non. Different feed rates per tooth and cutting speed are evaluated, and different cutting fluids with different methods of applying the fluid. Adding graphene to cutting fluids was considered as a variable to be investigated, which is considered an excellent solid lubricant, in addition to increasing the thermal conductivity of the cooling solution (AZIMI; MOZAF FARI, 2015). The micro-milling temperature was evaluated in the present work. It was observed a new phenomenon that causes the machined surface temperature decreases below room temperature when using the solution water + oil. This phenomenon is explained in further chapters. In order to unravel this phenomenon, a new test was proposed and, from this test, it can be concluded, comparatively, which cutting fluid has a better cooling property.Using cutting fluid with different thermal properties has shown influence when analy zing burr formation and reducing machining temperature.

Avaliação da soldagem GMAW mecanizada e automatizada para união de dutos utilizando fontes convencional e com controle de curto- circuito

Welding is one of the most employed process for joining steel pipes. Although, manual welding is still the most used one, mechanized version and even automatized one have increased its demand. Thus, this work deals with girth welding of API 5L X65 pipes with 8” of nominal diameter and 8.0 mm thickness, beveled with V-30º narrow gap. Torch is moved by a bug carrier (mechanized welding) and further the parameters are controlled as a function of angular position (automatized welding). Welding parameters are presented for filling the joint with two-passes (root and filling/capping passes). Parameters for the root pass were extracted from previous author´s work with weldments carried out in plates, but validated in this work for pipe welding. GMAW processes were assessed with short-circuit metal transfer in both conventional and derivative modes using different technologies (RMD, STT and CMT). After the parameter determination, mechanical testing was performed for welding qualification (uniaxial tension, face and root bending, nick break, Charpy V-notch impact, microhardness and macrograph). The initially obtained results for RMD and CMT were acceptable for all testing and, in a second moment, also for the STT. However, weld beads carried out by using the conventional process failed and revealed the existence of lack of fusion, which required further parametrization. Thus, a Parameter-Variation System for Girth Welding (SVP) was designed and built to allow varying the welding parameters as a function of angular position by using an inclinometer. The parameters were set for each of the three angular positions (flat, vertical downhill and overhead). By using such equipment and approach, the conventional process with parameter variation allowed reducing the welding time for joint accomplishment of the order of 38% for the root pass and 30% for the filling/capping pass.

Do trabalho de Deus... Adeus ao trabalho? Ontologia, precarização, controle do trabalho e fetichismo em A caverna de José Saramago

The aim of this study is to undertake a theoretical analysis of the literary and sociological Cave, Jose Saramago, having as main theme the precariousness of work and control, followed by some key developments. Anchored in the sociology of work and endorsed by the sociology of literature methodologically by Antonio Candido, and guided by the narrative Saramago in the cave, seeking to understand the work activity as central and essential to the production and reproduction of material life. It discusses the precariousness of work, as well as the historical forms of ownership and control of labor activity. Scales the impact of large corporations that control and the conflict between mechanized and manual labor in the process, questioning the nefarious effects of the restructuring of the productive working class, especially on small businesses and craft work. It also addresses the rise of a category gestorial in the process of labor control throughout history Finally, invoking the metaphor of Plato\'s cave in this work Saramago, explores how labor control by large corporations causes the estrangement in all dimensions of life, establishing relationships between fetishism, consumer relations and sociability.

Estudo comparativo do processo de tratamento por lamas ativadas em regime de arejamento prolongado

Atualmente a despoluição das águas, antes da sua descarga em meio hídrico, é considerada uma necessidade de elevada importância, sendo realizada em Estações de Tratamento de Águas Residuais (ETAR). Dependendo da origem e das características de cada afluente, as ETAR adotam diversos tipos de tratamento, adequando-os caso a caso, com o objetivo de conseguir uma elevada qualidade para o efluente final. O tipo de tratamento mais utilizado, e também o mais versátil, é o tratamento biológico por lamas ativadas. Neste contexto, o presente trabalho apresenta um estudo comparativo do processo de tratamento biológico por lamas ativadas, em operação em regime de arejamento prolongado, aplicado a três estações de tratamento de águas residuais, com características distintas no que se refere ao tipo de reator biológico utilizado, assim como, ao volume e à sazonalidade do caudal a tratar. As ETAR contempladas no estudo, nomeadamente, a ETAR do Juncal, a ETAR de Pedreiras e a ETAR de Fátima, localizam-se no distrito de Leiria e fazem parte do Saneamento Integrado dos Municípios do Lis (SIMLIS). A comparação do processo de tratamento das ETAR decorreu entre Outubro de 2013 e Junho de 2014, tendo-se baseado na monitorização dos reatores biológicos, no que se refere ao pH, potencial redox, OD, temperatura, concentração de SST e SSV, teste de sedimentabilidade, IVL, razão A/M e A/V, TRH, TRS, cor das lamas e microbiologia. Os valores obtidos permitiram concluir que, num contexto geral, as três ETAR apenas demonstraram um comportamento ideal relativamente aos valores de pH e potencial redox. Os valores de OD e temperatura mantiveram-se abaixo dos valores ideais para este tipo de tratamento; e a elevada concentração de SSV, nas ETAR de Fátima e de Pedreiras, e a baixa concentração de SSV, na ETAR de Juncal, impediram que a razão A/M, o teste de sedimentabilidade o IVL e o TRS cumprissem os valores ideais esperados. O incumprimento dos valores recomendados deve-se, muito provavelmente, ao facto das ETAR se encontrarem a operar abaixo da sua capacidade de utilização, no que respeita à população-equivalente a servir e ao volume de caudal afluente. Aparentemente as condições operacionais observadas durante o estudo não condicionaram o processo de tratamento biológico, uma vez que a qualidade do efluente tratado manteve sempre padrões elevados