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Application of simulation tools to HAZOP analysis of exothermic reaction processes
No full textIntroduction: The article addressed the integration between process simulation and HAZOP studies as a tool for risk analysis in the chemical industry. It was identified that, despite the effectiveness of traditional HAZOP, its qualitative nature and dependence on expert judgment limited its scope in complex systems. In response, it was proposed to review the use of simulation - in steady state and dynamic - as a support to improve the identification and evaluation of deviations in industrial processes, especially in CSTR type reactors.Development: The principles of chemical process simulation and its application using tools such as Aspen HYSYS were described. The advantages of mathematical modeling for predicting the behavior of a system in the face of disturbances were analyzed. In particular, a case of propylene glycol production in a CSTR reactor was studied, highlighting the influence of parameters such as temperature, reactant flow and unstable operating zones. Key concepts of the HAZOP study, the LOPA methodology and the design of protection layers were reviewed and linked to data obtained from detailed simulations. Visual tools such as bifurcation diagrams and operational windows were exemplified.Conclusions: The review evidenced that the use of simulation strengthens risk analyses by complementing the HAZOP approach with quantitative data. This combination improved the accuracy of the analysis, reduced the study execution time and increased the reliability of the results. It was concluded that the integration of advanced simulators represents a key trend in the evolution towards more digitized and efficient risk management
Occupational exposure to hydrogen sulphide in the oil industry
No full textIntroduction: The study analysed hydrogen sulphide (H₂S) exposure in the hydrocarbon industry of the San Jorge Gulf Basin, one of the most relevant regions for oil and gas production in Argentina. This area, located between Chubut and Santa Cruz, presented demanding working conditions and high risks, especially due to the presence of toxic gases. The research sought to assess the level of exposure to H₂S and propose actions to protect the health of operational personnel.Development: Different work activities were identified, such as welding, maintenance, civil works and field operations, where personnel were in direct contact with possible H₂S emissions. Companies such as YPF, PAE and CAPSA implemented safety measures such as the use of gas detectors, personal protective equipment (PPE) and work permits. However, a lack of documented and specific procedures was detected, which increased operational risk. Through field measurements, regulatory analysis and recognition of critical tasks, it was observed that workers operated in hostile environments and with constant exposure to gas, especially in confined spaces, hot work and supervisory tasks.Conclusions: The research made it possible to determine the degree of occupational exposure to H₂S, highlighting the need to strengthen documentation, improve environmental controls and implement more rigorous prevention policies. It also proposed concrete actions to mitigate risks, contributing to a safer, more responsible industry aligned with current health and safety regulations
Phytoremediation efficiency of Pistia stratiotes and Eichhornia crassipes in leachates generated at the Cuñumbuqui landfill
No full textThe present investigation entitled "Eficiencia de fitorremediación de Pistia stratiotes y Eichornia crassipes en lixiviados generados en el botadero de Cuñumbuqui, San Martín 2020." It has as a general objective is to evaluate the efficiency of the phytoremediation of the selected species that are the Pistia stratiotes and Eichornia crassipes, this research is of an applied type since in the treatment, phytoremediation techniques were applied using macrophyte species under ex situ conditions; with a quasi - experimental design; The population corresponded to the leachate generated in the Cuñumbuqui dump, from which a sample of 130L was obtained, where 20L was distributed for each of the 6 ponds that were used in the treatment, which was carried out in a period After 15 days, the field parameters (pH, temperature, EC and DO) were monitored every 3 days during that time; Likewise, techniques and instruments were used to collect data, respectively, such as: the field record sheet, daily record, and chains of custody; The procedure was developed in stages both in the office for the systematization of information and data, and in the field to carry out the project. In conclusion, the application of macrophyte species in leachates formed in landfills is a treatment alternative, it was found that Eichhornia crassipes is more efficient than Pistia stratiotes, since it has a greater removal of pollutants to improve the quality of these waters, which that would allow giving it a different final disposition
Impacts of Particulate Matter (PM 2.5) on the atmospheric quality of the District of Morales - Province of San Martin – 2022
No full textThe particles (PM 2.5) contain a series of contaminants present on their surface, including minerals released into the environment and microplastics, among others, which affect air quality and people\u27s health. The objective of the study was to evaluate the impact of particulate matter (PM2.5) on atmospheric quality in the Morales district of the city of Tarapoto. The design was non-experimental, applied and cross-sectional. For this purpose, 10 sampling stations were considered where air samples were collected for the measurement of PM2.5 by gravimetry and the characterization of PM2.5 by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy analysis. (FTIR); Climatological measurements were also made, such as temperature, relative humidity, wind direction and speed, during a period of 10 days in the month of March 2022. The results indicated a range of PM2.5 between 71 µg/m3 (point: CA- 07) and 123 µg/m3 (point CA-10) and perfluorododecyl iodide type microplastic was identified, which suggests continuing with a monitoring program as an instrument to help control sources of pollution in the city
The bronchial asthma and its association with the changes in the weather
No full textIntroduction: Climate and weather influence human health. Asthma is a psychosomatic illness that constitutes a global health problem, and the influence of environmental factors on the onset of bronchial asthma attacks is well known.Objectives: To determine the peak occurrence of bronchial asthma attacks in the municipality of Pinar del Río, relating them to meteorological changes.Methods: The total number of people who attended the emergency services of the four clinics in the municipality of Pinar del Río for bronchial asthma attacks daily was collected, according to charge sheets and reports from the municipal health analysis and trends unit, between the 1st and 2nd of May. January 2023 and December 31, 2024. The data collected regarding the attendance of these patients was compared with the information provided by the biometeorological model maps provided by the Provincial CITMA. Case frequency graphs were created, by day and by month. Intervals were established for the histogram, and the different clinics were located according to the frequency intervals with which patients came to receive health services.Results: Under atmospheric hyperoxia conditions, the daily incidence of the disease was equal to or greater than 160% of the respective monthly average, demonstrating a massive meteorological-pathological response in the study population.Conclusions: Meteorotropic effects associated with sudden changes in weather can have deleterious impacts on human health
H2S Hydrogrn Sulfide risk factors, conditions and work environment in processes in the oil industry in Argentina
No full textThe purpose of this Final Graduation Project is to investigate exploring the different work processes, to visualize the occupational exposure to H2S hydrogen sulfide of a worker in the oil field, their atmospheric environment, working conditions, work environments, dangers and risks, in order to guarantee compliance with the permissible limits in current occupational health and safety regulations.In the oil industry, H2S is present in the atmosphere of all processes, various plants, batteries and locations because it is part of oil and gas, high concentrations can cause damage to health, or even death by suffocation and high contamination to the environment.For this, surveys were carried out obtaining data and analyzing the information of the workers of the different sectors, the majority have little knowledge of the exposure to H2S, the potentiality and severity of this gas, the work they do is dangerous
Evaluation of adhesive strength in bracket cementation
No full textThe cementation of metal brackets was an essential aspect of successful orthodontic treatment, as the adhesive strength against shear forces determined their stability during treatment. Various national and international studies analysed the effectiveness of different cements, such as orthodontic resins and glass ionomers, showing variations in the adhesive strength achieved. Research such as that conducted by Chumacero, Huaita and Aguilar showed that, although some cements offered higher resistance values, the differences were not always statistically significant. Furthermore, multiple factors were identified that influenced adhesion, such as the type of bracket base, enamel preparation, the pressure exerted during cementation, and the patient\u27s clinical condition. Likewise, the need to achieve adhesion that is strong enough to maintain the brackets during treatment, but also safe enough to allow removal without damaging the enamel, was highlighted. Studies such as those by García and Herrera emphasised the importance of the bracket base and the type of resin used, while Fraga and Spaccesi evaluated the effects of pre-conditioning and concluded that there were no significant differences between techniques or concentrations applied. Overall, the evidence supported the importance of selecting an adhesive system that is balanced in strength, safety and practicality, highlighting the need for further standardised research to improve clinical efficacy
Studies and technological advances in the treatment of contaminated wáter
No full textThe research addressed the environmental problems arising from the generation of leachates in landfills and municipal solid waste dumps, recognising them as highly polluting effluents due to their content of organic and inorganic compounds and heavy metals. National and international background information was reviewed, highlighting studies that applied advanced oxidation processes, such as the Fenton method, and phytoremediation techniques with plant species adapted to different environments. Research by Pellón, López and Espinoza characterised leachates based on climatic factors and waste composition, while Medina et al. optimised the Fenton process, finding differences between rainy and dry seasons. Alcalde et al. evaluated bioremediation as a viable alternative, and Jerez verified the ability of plants to accumulate heavy metals in roots and leaves. Sari et al. and Fasani et al. measured the effectiveness of species such as Echinodorus palaefolius and Chrysopogon zizanioides in reducing pollutants and evapotranspiration. Key parameters such as pH, total suspended solids, chemical and biochemical oxygen demand, and total petroleum hydrocarbons, as defined by the APHA and EPA, were highlighted. Phytoremediation, using species such as Eichhornia crassipes and Pistia stratiotes, proved to be a low-cost, highly efficient alternative capable of removing organic compounds, metals and microorganisms through processes such as phytoextraction, phytodegradation and rhizofiltration. It was concluded that the combination of these techniques with continuous monitoring and proper biomass management constituted a sustainable, technically and economically viable strategy for leachate management, contributing to the protection of water resources and the achievement of environmental objectives.
Fluoride Mouthwashes and Their Effect on Oral Health
No full textOral health was recognised as an essential component of general well-being, and fluoridated mouthwashes represented an effective alternative in the prevention of diseases such as caries and gingivitis. Throughout the study, it was observed that their effectiveness depended not only on the presence of fluoride, but also on physicochemical variables such as pH, viscosity and titratable acidity. Research conducted by Marinho et al. and Van der Kaaij et al. demonstrated the preventive capacity of fluoride against carious lesions, especially in children and adolescents. However, studies such as those by Hanan et al. and Lima et al. revealed that many commercial brands had pH values below 5.5, considered potentially erosive to tooth enamel. Alcohol content was also a controversial factor. While Fernández identified that its presence tended to reduce pH, Marchetti et al. showed that alcohol-free formulations maintained similar efficacy and were safer for certain groups. The importance of transparency in labelling was also highlighted, especially in products aimed at children, as indicated by Alves et al. Finally, it was concluded that, although fluoridated mouthwashes provided proven benefits, their use should be carefully evaluated, considering both their formulation and their potential impact on public health
Lon adsorption behavior (in aqueous solutions) of lanthanum, cerium, and europium in organic adsorbents: review of kinetic, isothermal, and thermodynamic studies
No full textRare earth elements are present in a large number of raw materials for different applications in high technology, including lasers, magnets, fiber optics, X-ray machines, and lamps. Therefore, efforts have been made to find new alternatives that improve the recovery and recycling of these important elements, given that rare earth reserves worldwide are scarce and highly polluting. The aim is to counteract demand and help the environment by using alternative methods and making use of waste at the end of its useful life. Some of this waste is found in water sources from treatment plants and mining, which is significantly dangerous for nature and humans. As a viable alternative, the adsorption method has been chosen as it is an effective and low-cost process. This document aims to analyze different literature on the adsorption of lanthanum, cerium, and europium ions (in aqueous solutions) on organic adsorbents such as biomass and activated carbons, in order to verify whether the adsorption technique proves to be effective for the recovery of these elements, analyzing the kinetic, isothermal, and thermodynamic models. The results obtained confirm that the parameters that depend on adsorption are contact time, pH, and temperature, with a high capacity for removing metal ions. The isotherms most used by the different authors were Langmuir and Freundlich. For the kinetic study, a correlation was found with the activation energy taking place in chemisorption. Most of the literature studied showed that these were spontaneous and endothermic processes