Reactive Collisional Spectroscopy: Scalar and Vector InformationFrom Numerically Intensive Computing

Advances in computer technologies have made it possible to extend the numerical investigation of the detailed structure of reactive properties to several atom–diatom systems. This has allowed a better understanding of the energy structure of the reaction intermediate and of the role it plays when reaction occurs

Self-Diffusion in Nanofluids of Nonelongated Particles in the Dilute Limit

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] The dynamic features of a dilute suspension of nanoparticles (nanofuid) are fully modifed depending on the dominant particles slip mechanism acting in the suspension. Self-difusion efects in highly sheared diluted suspensions (entrance conditions and microapplications) can lead to a particles distribution fully diferent from the bulk one. The reported investigation proposes a model to determine the self-difusion of three-planes symmetric nonelongated particles inmersed in a sheared Stokes fow. The model is based on the real displacements between any pair of particles and an statistical approach to determine contact kinematic irreversibilities. According to the proposed model, the source of hydrodynamic irreversibility is closely related to the particles shape. This is clearly demonstrated through the application of the model to cubic particles. The main conclusion is that the particles shape plays a signifcant role in the dynamic behavior of the suspension and, as a result, in the self-difusion coefcient. The reported results arising from the cubic particles trajectories in a Stokes fow are reasonably close to the ones reported by Brady and Morris (J Fluid Mech, 348:103–139, 1997) for suspensions under high Pe number, and Zarraga and Leighton (Phys Fluids 13(3):565-577, 2001)The authors gratefully acknowledge the support given to the investigation reported herein by the Galician High Performance Computing Center (CESGA) and the Ministry of Economy and Competitiveness, Spain, through the Grant No. ENE2012-38326-C02-01. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Natur

Thermal performance of one-pass shell-and-tube heat exchangers in counter-flow

[Abstract] A computational methodology is proposed and applied to calculate the temperature effectiveness, P, and the logarithmic mean temperature difference (LMTD) correction factor, F, of TEMA E shell-and-tube heat exchangers with one-pass and fluids flowing in counter-flow. An arbitrary number of baffles is considered along with three different mixture conditions of the shell-side fluid. The methodology is based on various modeling considerations adopted in several publications addressing crossflow and shell-and-tube heat exchangers. Each section between two baffles is idealized as a crossflow heat exchanger with different shell-side mixing conditions. The obtained results are compared to available solutions from the literature, showing a very good agreement. New closed-form mathematical P relations and approximate F correlations depending on the number of baffles, very appropriate for preliminary computerized analysis and design procedures, are provided. A theoretical study about the influence of the number of baffles and two shell-side fluid mixing hypotheses over P and F values is presented. The proposed methodology could be used to obtain P and F values for a particular arrangement of 1-1 shell-and-tube heat exchanger.The authors fully acknowledge the support provided by the Conselho Nacional de Desenvolvimento e Tecnológico (CNPq - Processes 306675/2014-5 and 304972/2017-7) and also from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP - Process 2016/09509-1).Brasil. Conselho Nacional de Desenvolvimento e Tecnológico; 306675/2014-5Brasil. Conselho Nacional de Desenvolvimento e Tecnológico; 304972/2017-7Brasil. Fundação de Amparo à Pesquisa do Estado de São Paulo; 2016/09509-

Dispersal history of SARS-CoV-2 in Galicia, Spain

The dynamics of SARS-CoV-2 transmission are influenced by a variety of factors, including social restrictions and the emergence of distinct variants. In this study, we delve into the origins and dissemination of the Alpha, Delta, and Omicron variants of concern in Galicia, northwest Spain. For this, we leveraged genomic data collected by the EPICOVIGAL Consortium and from the GISAID database, along with mobility information from other Spanish regions and foreign countries. Our analysis indicates that initial introductions during the Alpha phase were predominantly from other Spanish regions and France. However, as the pandemic progressed, introductions from Portugal and the USA became increasingly significant. Notably, Galicia’s major coastal cities emerged as critical hubs for viral transmission, highlighting their role in sustaining and spreading the virus. This research emphasizes the critical role of regional connectivity in the spread of SARS-CoV-2 and offers essential insights for enhancing public health strategies and surveillance measures.This work was funded by grant EPICOVIGAL FONDO SUPERA-COVID19 from Banco Santander-CSIC-CRUE and grant CT850A-2 from ACIS SERGAS from the Consellería de Sanidade Xunta de Galicia. PGG was supported by grant ED481A-2021/345 from the Consellería de Cultura, Educación e Universidade Xunta de Galicia. SD acknowledges support from the Fonds National de la Recherche (F.R.S.-FNRS, Belgium; grant no. F.4515.22). SD and GB acknowledge support from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, FWO, Belgium; grant no. G098321N) and from the European Union Horizon RIA 2023 project LEAPS (grant no. 101094685). GB acknowledges support from the Internal Funds KU Leuven (Grant No. C14/18/094), from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, FWO, Belgium; grant no. G0E1420N) and from the DURABLE EU4Health project 02/2023-01/2027, which is co-funded by the European Union (call EU4H-2021-PJ4; grant no. 101102733). SD and PL acknowledge support from the European Union Horizon 2020 project MOOD (grant agreement no. 874850). PL and MAS acknowledge support from the European Union's Horizon 2020 research and innovation programme (grant agreement no. 725422 - ReservoirDOCS), from the Wellcome Trust through project 206298/Z/17/Z and from the National Institutes of Health grants R01 AI153044, R01 AI162611 and U19 AI135995. PL also acknowledges support from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, G0D5117N, and G051322N); MIV, JCS and NSO acknowledge support from the Foundation for Science and Technology (FCT) (project UIDB/50026/2020, UIDP/50026/2020).N

Dispersal history of SARS-CoV-2 in Galicia, Spain

13 páginas, 4 figurasThe dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission are influenced by a variety of factors, including social restrictions and the emergence of distinct variants. In this study, we delve into the origins and dissemination of the Alpha, Delta, and Omicron-BA.1 variants of concern in Galicia, northwest Spain. For this, we leveraged genomic data collected by the EPICOVIGAL Consortium and from the GISAID database, along with mobility information from other Spanish regions and foreign countries. Our analysis indicates that initial introductions during the Alpha phase were predominantly from other Spanish regions and France. However, as the pandemic progressed, introductions from Portugal and the United States became increasingly significant. The number of detected introductions varied from 96 and 101 for Alpha and Delta to 39 for Omicron-BA.1. Most of these introductions left a low number of descendants (<10), suggesting a limited impact on the evolution of the pandemic in Galicia. Notably, Galicia's major coastal cities emerged as critical hubs for viral transmission, highlighting their role in sustaining and spreading the virus. This research emphasizes the critical role of regional connectivity in the spread of SARS-CoV-2 and offers essential insights for enhancing public health strategies and surveillance measures.This work was funded by grant EPICOVIGAL FONDO SUPERA-COVID19 from Banco Santander-CSIC-CRUE and grant CT850A-2 from ACIS SERGAS from the Consellería de Sanidade Xunta de Galicia. PGG was supported by grant ED481A-2021/345 from the Consellería de Cultura, Educación e Universidade Xunta de Galicia. SD acknowledges support from the Fonds National de la Recherche (F.R.S.-FNRS, Belgium; grant no. F.4515.22). SD and GB acknowledge support from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, FWO, Belgium; grant no. G098321N) and from the European Union Horizon RIA 2023 project LEAPS (grant no. 101094685). GB acknowledges support from the Internal Funds KU Leuven (Grant No. C14/18/094), from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, FWO, Belgium; grant no. G0E1420N) and from the DURABLE EU4Health project 02/2023-01/2027, which is co-funded by the European Union (call EU4H-2021-PJ4; grant no. 101102733). SD and PL acknowledge support from the European Union Horizon 2020 project MOOD (grant agreement no. 874850). PL and MAS acknowledge support from the European Union's Horizon 2020 research and innovation programme (grant agreement no. 725422 - ReservoirDOCS), from the Wellcome Trust through project 206298/Z/17/Z and from the National Institutes of Health grants R01 AI153044, R01 AI162611 and U19 AI135995. PL also acknowledges support from the Research Foundation - Flanders (Fonds voor Wetenschappelijk Onderzoek - Vlaanderen, G0D5117N, and G051322N); MIV, JCS and NSO acknowledge support from the Foundation for Science and Technology (FCT) (project UIDB/50026/2020, UIDP/50026/2020).Peer reviewe

Reaction dynamics of the D+ + H2 system. A comparison of theoretical approaches

The dynamics of the deuteron-proton exchange D+ + H2 → HD + H+ reaction on its ground 11A′ potential energy surface has been the subject of a theoretical study for collision energies below 1.5 eV. The results obtained with three theoretical approaches: quasi-classical trajectory (QCT), statistical quasi-classical trajectory (SQCT), and accurate time-independent quantum mechanical (QM) calculations are compared in the range of collision energies from 5 meV to 0.2 eV. The QM calculations included all total angular momentum quantum numbers, J, up to Jmax ≈ 40 and all the Coriolis couplings. For higher collision energies, the comparison was restricted to the QCT and SQCT results given the enormous computational cost implied in the QM calculations. Reaction cross sections as a function of collision energy (excitation functions) for various initial rovibrational states have been determined and compared with the corresponding results for the endothermic H+ + D2 → HD + D + isotopic variant. The excitation function for the title reaction decays monotonically with collision energy as expected for an exothermic reaction without a barrier, in contrast to the behaviour observed in the mentioned H+ + D2 (v = 0, j ≤ 3). Reaction probabilities as a function of J (opacity functions) at several collision energies calculated with the different approaches were also examined and important differences between them were found. The effect of using the Gaussian binning procedure that preserves, to a large extent, the zero point energy, as compared to the standard histogram binning in the QCT calculations, is also examined. At low collision energy, the best agreement with the accurate QM results is given by the SQCT data, although they tend to overestimate the reactivity. The deviations from the statistical behaviour of the QCT data at higher energies are remarkable. Nevertheless, on the whole, the title reaction can be deemed more statistical than the H+ + D2 reaction. © Royal Society of Chemistry 2010.Peer Reviewe

Photodetachment spectrum of OHF-: Three-dimensional study of the heavy–light–heavy resonances

12 pages, 14 figures, 1 table.-- PACS nrs.: 82.30.Cf; 82.20.Kh; 31.15.Ar; 33.15.Mt; 33.80.Gj; 31.25.Eb; 31.50.Bc.In this work a simulation of the OHF- photodetachment spectrum is performed in a three-dimensional potential energy surface recently developed for OHF(3A''). The ground 2A' state potential of the anion is calculated in three dimensions based on accurate ab initio calculations and the reaction dynamics is studied using a wave packet method. The calculated spectrum shows a sequence of bands associated to vibrational HF(ν) up to ν = 3. Each band is formed by a continuous spectrum and resonant structures. These resonances are associated to the OH–F channel well of the 3A'' PES, in which fragmentation occurs through vibrational predissociation. Above the OH(ν = 0) threshold a new resonant pattern appears corresponding to heavy–light–heavy resonances. Special attention is paid to the assignment of these resonances because they mediate the reaction dynamics in the OH + F collision at low kinetic energies. The sequence of bands is in rather good agreement with that appearing in the experimental spectrum, especially at higher electron kinetic energies. At low kinetic energies, however, some other electronic states may contribute. The resonance structures might be washed out by the rotational average and the relatively low energy resolution of the experiment.This work has been supported by MCYT (Spain), under Grant Nos. BFM2001-2179, BQU2001-0152, and BQU2002-04462-C02-01.Peer reviewe

Determination of plasma melatonin levels by enzyme-linked inmunoabsobent assay (EIA) in turbot (Scophthalmus maximus L.) and tench (Tinca tinca L.)

Publicado

Dynamics and kinetics of the F + OH reaction on the ground triplet potential energy surface

MRCI electronic energy calculations have been carried out for the ground triplet state of the OHF reactive system. 8069 ab initio points have been fitted with a two- and three-body polynomial expansion in modified Rydberg coordinates and a high quality global potential energy surface (PES) was thus generated. On the PES, quasiclassical trajectory calculations were run to simulate existing kinetic and dynamic experimental data for the title reaction. The calculated and measured trends with temperature of the thermal rate coefficient and rovibrational energy distribution of the HF molecule satisfactorily compare and discrepancies are explained. © 2003 Elsevier B.V. All rights reserved.This work has been supported by DGICYT (Ministerio de Ciencia y Tecnolog ıa, Spain) under grants BQU2002-04462-C02-01,BQU2001-0152andBFM2001- 2179.Peer Reviewe