Fábrica de ácido nítrico: operação e simulação do processo

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Química e Biológica: Processos QuímicosEste trabalho surge de um interesse e curiosidade em aprofundar os conhecimentos em simulação numérica de processos, nomeadamente com a utilização do simulador Aspen HYSYS. O objectivo desta dissertação é contribuir para a caracterização e análise ao funcionamento da unidade industrial de produção de ácido nítrico da empresa ADP - Fertilizantes (Lavradio). Para isso, foi efectuado um acompanhamento local da laboração da fábrica durante um período aproximado de seis meses, de modo a ganhar a compreensão e o know-how suficiente para proceder à modelização e simulação numérica de um processo industrial, no simulador Aspen HYSYS. Neste trabalho entende-se que a informação recolhida, em ambiente fabril, é essencial para a montagem do flowsheet de simulação. Por sua vez, o modelo numérico foi calibrado e validado com dados reais de funcionamento da unidade produtiva e, posteriormente, foram testadas numericamente condições alternativas para o funcionamento dos sectores da fábrica. O modelo numérico utilizado no simulador foi montado em estado estacionário, envolvendo dez espécies químicas e com o pacote de propriedades termodinâmico: UNIQUAC−SRK. Através deste trabalho foi possível compreender que, apesar do Aspen HYSYS ser um simulador potente e completo, existem importantes limitações na modelação de sistemas exigentes como o estudado neste trabalho. A complexidade do ambiente de fábrica apresenta nuances e particularidades, distintas do âmbito académico. A realização do estágio em ambiente fabril foi muito importante como componente formativa de engenharia.This dissertation arises from an interest and curiosity in deepening the knowledge in numerical simulation of processes, namely with the use of the Aspen HYSYS simulator. The aim of this dissertation is to contribute to the characterization and analysis of the functioning of the industrial unit for the production of nitric acid of the company ADP - Fertilizantes (Lavradio). For this purpose, local monitoring of the factory's operations was carried out for an approximate period of six months, in order to gain understanding and enough knowhow to carry out the modeling and numerical simulation in the Aspen HYSYS simulator. In this dissertation, it is understood that the information collected in a factory environment is essential for the assembly of the simulation owsheet and for obtaining accurate and reliable results in the simulator. The numerical model in the simulator was assembled in steady state, with the UNIQUAC - SRK properties package. Through this dissertation, it was possible to understand that, despite Aspen HYSYS being a powerful and complete simulator, it still has limitations. The complexity of the factory environment presents nuances and particularities, distinct from the academic sphere.info:eu-repo/semantics/publishedVersio

Predictors of cardiac involvement in idiopathic inflammatory myopathies

Copyright © 2023 Bandeira, Dourado, Melo, Martins, Fraga, Ferraro, Saraiva, Sousa, Parente, Soares, Correia, Almeida, Dinis, Pinto, Oliveira Pinheiro, Rato, Beirão, Samões, Santos, Mazeda, Chícharo, Faria, Neto, Lourenço, Brites, Rodrigues, Silva-Dinis, Dias, Araújo, Martins, Couto, Valido, Santos, Barreira, Fonseca and Campanilho-Marques. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Objectives: Idiopathic inflammatory myopathies (IIM) are a group of rare disorders that can affect the heart. This work aimed to find predictors of cardiac involvement in IIM. Methods: Multicenter, open cohort study, including patients registered in the IIM module of the Rheumatic Diseases Portuguese Register (Reuma.pt/Myositis) until January 2022. Patients without cardiac involvement information were excluded. Myo(peri)carditis, dilated cardiomyopathy, conduction abnormalities, and/or premature coronary artery disease were considered. Results: 230 patients were included, 163 (70.9%) of whom were females. Thirteen patients (5.7%) had cardiac involvement. Compared with IIM patients without cardiac involvement, these patients had a lower bilateral manual muscle testing score (MMT) at the peak of muscle weakness [108.0 ± 55.0 vs 147.5 ± 22.0, p=0.008] and more frequently had oesophageal [6/12 (50.0%) vs 33/207 (15.9%), p=0.009] and lung [10/13 (76.9%) vs 68/216 (31.5%), p=0.001] involvements. Anti-SRP antibodies were more commonly identified in patients with cardiac involvement [3/11 (27.3%) vs 9/174 (5.2%), p=0.026]. In the multivariate analysis, positivity for anti-SRP antibodies (OR 104.3, 95% CI: 2.5-4277.8, p=0.014) was a predictor of cardiac involvement, regardless of sex, ethnicity, age at diagnosis, and lung involvement. Sensitivity analysis confirmed these results. Conclusion: Anti-SRP antibodies were predictors of cardiac involvement in our cohort of IIM patients, irrespective of demographical characteristics and lung involvement. We suggest considering frequent screening for heart involvement in anti-SRP-positive IIM patients.info:eu-repo/semantics/publishedVersio

Cooperation between Apoptotic and Viable Metacyclics Enhances the Pathogenesis of Leishmaniasis

Mimicking mammalian apoptotic cells by exposing phosphatidylserine (PS) is a strategy used by virus and parasitic protozoa to escape host protective inflammatory responses. With Leishmania amazonensis (La), apoptotic mimicry is a prerogative of the intramacrophagic amastigote form of the parasite and is modulated by the host. Now we show that differently from what happens with amastigotes, promastigotes exposing PS are non-viable, non-infective cells, undergoing apoptotic death. As part of the normal metacyclogenic process occurring in axenic cultures and in the gut of sand fly vectors, a sub-population of metacyclic promastigotes exposes PS. Apoptotic death of the purified PS-positive (PSPOS) sub-population was confirmed by TUNEL staining and DNA laddering. Transmission electron microscopy revealed morphological alterations in PSPOS metacyclics such as DNA condensation, cytoplasm degradation and mitochondrion and kinetoplast destruction, both in in vitro cultures and in sand fly guts. TUNELPOS promastigotes were detected only in the anterior midgut to foregut boundary of infected sand flies. Interestingly, caspase inhibitors modulated parasite death and PS exposure, when added to parasite cultures in a specific time window. Efficient in vitro macrophage infections and in vivo lesions only occur when PSPOS and PS-negative (PSNEG) parasites were simultaneously added to the cell culture or inoculated in the mammalian host. The viable PSNEG promastigote was the infective form, as shown by following the fate of fluorescently labeled parasites, while the PSPOS apoptotic sub-population inhibited host macrophage inflammatory response. PS exposure and macrophage inhibition by a subpopulation of promastigotes is a different mechanism than the one previously described with amastigotes, where the entire population exposes PS. Both mechanisms co-exist and play a role in the transmission and development of the disease in case of infection by La. Since both processes confer selective advantages to the infective microorganism they justify the occurrence of apoptotic features in a unicellular pathogen

Multiple model SPGPC for blood pressure control

Multiple model adaptive control procedures have been considered for a computer-based feedback system, which regulates the infusion rate of a drug (nitroprusside) in order to maintain the desired blood pressure. Transfer function parameters can differ significantly between patients, and also time-dependent, the development of a suitable algorithm becomes desirable not only for maintaining steady-state but also the transient specifications. In this paper, based on computer simulations, a multiple model adaptive control procedures show to be successfully applied to control the blood pressure, despite the uncertainty related with delays, time constant, and gains associated.info:eu-repo/semantics/publishedVersio

Automated classification of tribological faults of alternative systems with the use of unsupervised artificial neural networks

Preventing, anticipating, avoiding failures in electromechanical systems are demands that have challenged researchers and engineering professionals for decades. Electromechanical systems present tribological processes that result in fatigue of materials and consequent loss of efficiency or even usefulness of machines and equipment. Several techniques are used in an attempt to minimize the inherent losses of these systems through the analysis of signals from the equipment studied and the consequences of these wastes at unexpected moments, such as an aircraft in flight or a drilling rig in an oil well. Among them we can mention vibration analysis, acoustic pressure measurement, temperature monitoring, particle analysis of lubricating oil etc. However, electromechanical systems are complex and may exhibit unexpected behavior. Reliability-centric maintenance requires ever faster, more efficient and robust technological resources to ensure its efficiency and effectiveness. Artificial neural networks (ANN) are computational tools that find applicability in several segments of the research and signal analysis, where it is necessary to handle large amounts of data, associating statistics and computation in the optimization of dynamic processes and a high degree of reliability. They are artificial intelligence systems that have the ability to learn, are robust to failures, and can deliver real-time results. This work aims at the use of artificial neural networks to treat signals from the monitoring of tribological parameters using a test bench to simulate contact failures in an air compressor in order to create an automated fault detection and classification system, unsupervised, with the use of self-organized maps, or SOM, applied to the preventive and predictive maintenance of electromechanical processes.This research was supported by UFRN – Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil, which is highly appreciated by the authors

Characteristics of expert judges in the nominal group meeting.

Characteristics of expert judges in the nominal group meeting.</p

Types of health units according to capacity for snakebite management.

Types of health units according to capacity for snakebite management.</p

Version of the minimal requirements checklist created by the steering committee for experts’ validation.

Version of the minimal requirements checklist created by the steering committee for experts’ validation.</p

Snakebite envenoming care continuum in the Brazilian Amazon.

A) Care pathways for snakebite patients under the current antivenom distribution structure. B) Care pathways under the proposed antivenom decentralization to community health centers (CHCs). Figure built using https://openclipart.org/ as source of the images or icons.</p