Understanding the active role of water in laboratory chamber studies of reactions of the OH radical with alcohols of atmospheric relevance

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In no event shall the Royal Society of Chemistry be held responsible for any errors or omissions in this Accepted Manuscript or any consequences arising from the use of any information it contains. Enlace autora: https://www.researchgate.net/profile/Maria-De-Los-Angeles-Garavagno/publication/379517439_Understanding_the_active_role_of_water_on_laboratory_chamber_studies_of_reactions_of_the_OH_radical_with_alcohols_of_atmospheric_relevance/links/6613e2603d96c22bc77ae8a0/Understanding-the-active-role-of-water-on-laboratory-chamber-studies-of-reactions-of-the-OH-radical-with-alcohols-of-atmospheric-relevance.pdfFil: Garavagno, María de los A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica, Córdoba, Argentina.Fil: Garavagno, María de los A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica. Centro Láser de Ciencias Moleculares, Argentina.Fil: Garavagno, María de los A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Físico-Química de Córdoba, Argentina.Fil: Garavagno, María de los A. University of Bristol. School of Chemistry, Bristol, United Kingdom.Fil: Hernández, Federico J. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica, Córdoba, Argentina.Fil: Hernández, Federico J. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica. Centro Láser de Ciencias Moleculares, Argentina.Fil: Hernández, Federico J. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Físico-Química de Córdoba, Argentina.Fil: Hernández, Federico J. University College London. Department of Chemistry, London, United Kingdom.Fil: Jara-Toro, Rafael A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica, Córdoba, Argentina.Fil: Jara-Toro, Rafael A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica. Centro Láser de Ciencias Moleculares, Argentina.Fil: Jara-Toro, Rafael A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Físico-Química de Córdoba, Argentina.Fil: Pino, Gustavo A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica, Córdoba, Argentina.Fil: Pino, Gustavo A. Université de Rennes. Institut de Physique de Rennes, France.Fil: Pino, Gustavo A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica. Centro Láser de Ciencias Moleculares, Argentina.Fil: Pino, Gustavo A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Físico-Química de Córdoba, Argentina.In this work, we studied the reactions of three cyclic aliphatic alcohols with OH at room temperature, atmospheric pressure and different humidities in a Teflon reaction chamber. It was determined that the lower the solubility of the alcohol in water, the larger the effect of the humidity on the acceleration of the reaction. This experimental evidence allows suggesting that the acceleration is due to the reaction of the co-adsorbed reactants at the air–water interface of a thin water film deposited on the Teflon walls of the reaction chamber, instead of between co-reactants dissolved in the water film or due to gas phase catalysis as previously suggested. Therefore, formation of thin water films on different surfaces could have some implications on the tropospheric chemistry of these alcohols in the tropical regions of the planet with high humidity.info:eu-repo/semantics/publishedVersionFil: Garavagno, María de los A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica, Córdoba, Argentina.Fil: Garavagno, María de los A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica. Centro Láser de Ciencias Moleculares, Argentina.Fil: Garavagno, María de los A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Físico-Química de Córdoba, Argentina.Fil: Garavagno, María de los A. University of Bristol. School of Chemistry, Bristol, United Kingdom.Fil: Hernández, Federico J. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica, Córdoba, Argentina.Fil: Hernández, Federico J. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica. Centro Láser de Ciencias Moleculares, Argentina.Fil: Hernández, Federico J. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Físico-Química de Córdoba, Argentina.Fil: Hernández, Federico J. University College London. Department of Chemistry, London, United Kingdom.Fil: Jara-Toro, Rafael A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica, Córdoba, Argentina.Fil: Jara-Toro, Rafael A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica. Centro Láser de Ciencias Moleculares, Argentina.Fil: Jara-Toro, Rafael A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Físico-Química de Córdoba, Argentina.Fil: Pino, Gustavo A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica, Córdoba, Argentina.Fil: Pino, Gustavo A. Université de Rennes. Institut de Physique de Rennes, France.Fil: Pino, Gustavo A. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Fisicoquímica. Centro Láser de Ciencias Moleculares, Argentina.Fil: Pino, Gustavo A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Físico-Química de Córdoba, Argentina

Trifluoroacetic Acid::Toxicity, Sources, Sinks and Future Prospects

Trifluoroacetic acid (TFA) is a known persistent pollutant in the environment. Although several direct anthropogenic sources exist, production from the atmospheric degradation of fluorocarbons such as some hydrofluorocarbons (HFCs) has been a known source for some time. The current transition from HFCs to HFOs (hydrofluoroolefins) is beneficial from a global warming viewpoint, because HFOs are much shorter-lived and pose a much smaller threat to warming, but the fraction of HFO conversion to TFA is higher than for the corresponding HFCs and the region over which the TFA is produced is close to the source. Therefore, it is timely to review the role of TFA in the Earth’s environment. This review considers its toxicity, sources and removal processes, measurements in a variety of environments and future prospects. New global model integrations quantify the impacts on TFA levels of uncertainties in the Henry’s Law constant for TFA and the range of gas-phase kinetic parameters determined for the reaction of OH radicals with a representative HFO (HFO-1234yf). Model runs suggest that TFA surface concentrations vary by up to 10% based on Henry’s Law data, but could be up to 25% smaller than previously modelled values depending on the kinetic analysis adopted. Therefore, future estimates of TFA surface concentrations based on HFO removal re-quire updating and the kinetic analysis of TFA production warrants further investigation. The toxicity of TFA appears to be low but further studies of a much wider range of animal and plant types are required

Long-term outcomes of the global tuberculosis and COVID-19 co-infection cohort

Background: Longitudinal cohort data of patients with tuberculosis (TB) and coronavirus disease 2019 (COVID-19) are lacking. In our global study, we describe long-term outcomes of patients affected by TB and COVID-19. Methods: We collected data from 174 centres in 31 countries on all patients affected by COVID-19 and TB between 1 March 2020 and 30 September 2022. Patients were followed-up until cure, death or end of cohort time. All patients had TB and COVID-19; for analysis purposes, deaths were attributed to TB, COVID-19 or both. Survival analysis was performed using Cox proportional risk-regression models, and the log-rank test was used to compare survival and mortality attributed to TB, COVID-19 or both. Results: Overall, 788 patients with COVID-19 and TB (active or sequelae) were recruited from 31 countries, and 10.8% (n=85) died during the observation period. Survival was significantly lower among patients whose death was attributed to TB and COVID-19 versus those dying because of either TB or COVID-19 alone (p<0.001). Significant adjusted risk factors for TB mortality were higher age (hazard ratio (HR) 1.05, 95% CI 1.03-1.07), HIV infection (HR 2.29, 95% CI 1.02-5.16) and invasive ventilation (HR 4.28, 95% CI 2.34-7.83). For COVID-19 mortality, the adjusted risks were higher age (HR 1.03, 95% CI 1.02-1.04), male sex (HR 2.21, 95% CI 1.24-3.91), oxygen requirement (HR 7.93, 95% CI 3.44-18.26) and invasive ventilation (HR 2.19, 95% CI 1.36-3.53). Conclusions: In our global cohort, death was the outcome in >10% of patients with TB and COVID-19. A range of demographic and clinical predictors are associated with adverse outcomes

Human Recognition for~Resource-Constrained Mobile Robot Applied to~Covid-19 Disinfection

The global COVID-19 pandemic has stimulated the use of disinfection robots: in September 2021, following a European Commission's action, 200 disinfection robots were delivered to European Hospitals. UV-C light is a common disinfection method, however, direct exposure to UV-C radiation is harmful and disinfection can be operated only in areas strictly forbidden to human personnel. We believe more advanced safety mechanisms are needed to increase the operational flexibility and safety level. We propose a safety mechanism based on vision and artificial intelligence, optimised for execution on mobile robot platforms. It analyses in real-time four video streaming and disables UV-C lamps when needed. Concerning other detection methods, it has a relatively wider and deeper range, and the capability to operate in a dynamic environment. We present the development of the method with a performance comparison of different implementation solutions, and an on-field evaluation through integration on a mobile disinfection robot

A hardware-aware neural architecture search algorithm targeting low-end microcontrollers

Hardware-aware neural architecture search (HW NAS), the process of automating the design of neural architectures taking into consideration hardware constraints, has already outperformed the best human designs on many tasks. However, it is known to be highly demanding in terms of hardware, thus limiting access to non-habitual neural network users. Fostering its adoption for the next-generation IoT and wearable devices design, we propose an HW NAS that can be run on laptops, even if not mounting a GPU. The proposed technique, designed to have both a low search cost and resource usage, produces tiny convolutional neural networks (CNNs) targeting low-end microcontrollers. It achieves state-of-the-art results in the human-recognition tasks, on the Visual Wake Word dataset a standard TinyML benchmark, in just 3:37:0 hours on a laptop mounting an 11th Gen Intel(R) Core(TM) i7-11370H CPU @ 3.30GHz equipped with 16 GB of RAM and 512 GB of SSD, without using a GPU

Understanding the active role of water in laboratory chamber studies of reactions of the OH radical with alcohols of atmospheric relevance

International audienceA photoinduced reaction takes place between reactants co-adsorbed at the interface of a thin film of water formed on the Teflon walls of the reaction chamber at high humidity

Atmospheric chemistry of 3-methoxy-1-propanol and 3-methoxy-1-butanol: Kinetics with OH radicals and Cl atoms, identification of the end-products in the presence of NO, mechanisms and atmospheric implications

The rate coefficients for the reactions of OH radicals and Cl atoms with 3-methoxy-1-propanol (3-M-1-POL) and 3-methoxy-1-butanol (3-M-1-BOL) in the gas-phase have been measured at (298 ± 2) K and atmospheric pressure. A conventional relative-rate technique was used to determine the rate coefficients: k1 (OH + 3-M-1-POL)= (2.15 ± 0.28) x 10−11, k2 (OH + 3-M-1-BOL)= (2.38 ± 0.31) x 10−11, k3 (Cl + 3-M-1-POL)= (2.66 ± 0.23) x 10−10 and k4 (Cl + 3-M-1-BOL)= (2.95 ± 0.27) x 10−10, all in units of cm3 molecule−1s−1. The present work provides the first kinetic study of the reactions of Cl atoms with 3-M-1-POL and 3-M-1-BOL, and of the reaction of OH radicals with 3-M-1-POL. The kinetic results are presented and compared with those calculated (kSAR) using the structure-reactivity relationship (SAR) method, and reactivity trends are discussed. Additionally, products identification under atmospheric conditions was performed for the first time for the reactions cited above in the presence of NO, using two sampling methods and GC-MS-FID. 3-methoxypropanal, methyl formate and glycolaldehyde were identified from the 3-M-1-POL + OH/Cl reactions, while 3-methoxybutyraldehyde, methyl acetate and glycolaldehyde, were identified from the 3-M-1-BOL + OH/Cl reactions. From these identified products, a general scheme of the reaction mechanisms is proposed. Finally, based on the kinetic results and radiative efficiencies (REs) of the titled compounds, a discussion on the atmospheric implications due to its emissions into the troposphere is also presented.Fil: Barrera, Javier Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Garavagno, María de los A.. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Dalmasso, Pablo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Taccone, Raul Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina. Universidad Nacional de Córdoba; Argentin

Rate coefficient and mechanism of the OH-initiated degradation of cyclobutanol: A combined experimental and theoretical study

International audienc