Person: Martín Conde, María
Loading...
First Name
María
Last Name
Martín Conde
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Física
Area
Química Física
Identifiers
7 results
Search Results
Now showing 1 - 7 of 7
Item The Madrid-2019 force field for electrolytes in water using TIP4P/2005 and scaled charges: Extension to the ions F−, Br−, I−, Rb+, and Cs+(Journal of Chemical Physics, 2022) Blázquez Fernández, Samuel; Martín Conde, María; Fernández Abascal, José Luis; Vega De Las Heras, CarlosIn this work, an extension of the Madrid-2019 force field is presented. We have added the cations Rb+ and Cs+ and the anions F−, Br−, and I−. These ions were the remaining alkaline and halogen ions, not previously considered in the Madrid-2019 force field. The force field, denoted as Madrid-2019-Extended, does not include polarizability and uses the TIP4P/2005 model of water and scaled charges for the ions. A charge of ±0.85e is assigned to monovalent ions. The force field developed provides an accurate description of aqueous solution densities over a wide range of concentrations up to the solubility limit of each salt studied. Good predictions of viscosity and diffusion coefficients are obtained for concentrations below 2 m. Structural properties obtained with this force field are also in reasonable agreement with the experiment. The number of contact ion pairs has been controlled to be low so as to avoid precipitation of the system at concentrations close to the experimental solubility limit. A comprehensive comparison of the performance for aqueous solutions of alkaline halides of force fields of electrolytes using scaled and integer charges is now possible. This comparison will help in the future to learn about the benefits and limitations of the use of scaled charges to describe electrolyte solutions.- Project number: 52
Item I.amAble: El aprendizaje en ciencias al servicio de la inclusión educativa(2019) Herrero Domínguez, Santiago; Corrales Castellanos, María Eugenia; Sobrino Díaz, María Lourdes; Cilleros Prados, Olga; Barba Fernández, Carmen; Azor Lafarga, Alberto Eduardo; Hernández Díaz, María Yolanda; Martínez Del Pozo, Álvaro; Ranchal Sánchez, Rocío; Maestre Varea, David; Méndez Pozo, Gonzalo Rubén; Gervás Gómez-Navarro, Pablo; Pastor Gil, Lorena; Taravillo Corralo, Mercedes; Guerrero Martínez, Andrés; Sánchez Benítez, Francisco Javier; Martín Conde, María; Priego Bermejo, José Luis; González Prieto, Rodrigo; Jiménez Aparicio, Reyes; Álvarez Serrano, Inmaculada; Cortés Gil, Raquel; Osío Barcina, José De Jesús; Mancheño Real, María José; Arribas Fernández, Paula; Lobato Fernández, Álvaro; Sánchez Arroyo, Antonio José; Torrecilla Manresa, Sofía; Cárdenas Bonett, Marlón Félix; Desvoyes, Benedicte; Bárcena Espelleta, Araceli; Nacenta Torres, Pablo; Rubio Lago, Luis; Bautista Blasco, Susana; Julián Cortés, Alvaro; Arancibia Llaneza, Julieta Noelia; Lombraña Pascual, Rodrigo; Catalán Torrecilla, Cristina; Gutiérrez Franco, Yanna María; Martínez Ruiz, María PalomaI.amAble es un proyecto que nació con una filosofía centrada en la utilización de acciones de solidaridad como método de aprendizaje. Se diseñan y organizan talleres científicos inclusivos para realizarlos en parejas formadas por personas con discapacidad cognitiva y de educación secundaria ordinaria. Se pretende aprender a la vez que se da un servicio a la universidad y a la sociedad, y ese es el espíritu que se ha seguido manteniendo durante esta tercera edición del curso 2018-2019. Item Influence of contaminant-spiked polyethylene-type microplastics on the growth and primary production of the freshwater phytoplankton species Scenedesmus armatus and Microcystis aeruginosa(Environmental and Experimental Botany, 2022) Sánchez Fortún, A.; D’ors, A.; Fajardo Martínez, Carmen María; Martín Conde, María; Nande, Mar; Mengs, G.; Costa Buitrago, Gonzalo Antonio; Martín, M.; Sánchez-Fortún Rodríguez, SebastiánMicroplastic pollution and its ecological impact on the aquatic environment are a current focus of research in the scientific community. These microplastics may adsorb contaminants discharged into the aquatic environment, thereby serving as a sink and source for the dissemination of these associated chemical contaminants. However, knowledge about the potential risks of microplastics and associated chemical contaminants on aquatic biota, especially on primary freshwater producers, remains to be explored. In this study, the impact of a polyethylene microplastic type (MP) associated with amoxicillin, ibuprofen, sertraline and simazine (OCs) on the cell growth and photosynthetic activity of the green algae Scenedesmus armatus and the cyanobacteria Microcystis aeruginosa was evaluated after 28 days of exposure. The results show that all the organic contaminants and their respective MP-OC complexes induced stress on cell growth after 28 days of exposure, except when the cyanobacterial strain was exposed to amoxicillin and ibuprofen. Similarly, photosynthetic activity was affected by exposure to MP-OC complexes, with the most evident effect on cellular respiration in the cyanobacterial strain and on net photosynthesis in the green algae strain. Additionally, the ability of the M. aeruginosa strain to synthesize microcystin was significantly reduced. These results show that the formation of MP-OC complexes could reduce their adverse effects, although there is wide variability depending on both the type of organic contaminant and the photosynthetic organisms involved, so further studies are needed to better understand the interactions between these aquatic contaminants.Item Using single-species and algal communities to determine long-term adverse effects of silver nanoparticles on freshwater phytoplankton(Science of The Total Environment, 2024) Cortés Téllez, Alondra A.; D'Ors De Blas, Ana; Sánchez Fortún, A.; Fajardo, C.; Mengs, G.; Nande Barbeitos, María Del Mar; Martín Conde, María; Costa Buitrago, Gonzalo Antonio; Martín, M.; Bartolomé Camacho, María del Carmen; Sánchez-Fortún Rodríguez, Sebastián; Barceló, DamiàThe physical and chemical properties of silver nanoparticles (AgNPs) have led to their increasing use in various fields such as medicine, food, and industry. Evidence has proven that AgNPs cause adverse effects in aquatic ecosystems, especially when the release of Ag is prolonged in time. Several studies have shown short-term adverse effects of AgNPs on freshwater phytoplankton, but few studies have analysed the impact of long-term exposures on these populations. Our studies were carried out to assess the effects of AgNPs on growth rate, photosynthesis activity, and reactive oxygen species (ROS) generation on the freshwater green algae Scenedesmus armatus and the cyanobacteria Microcystis aeruginosa, and additionally on microcystin (MC-LR) generation from these cyanobacteria. The tests were conducted both in single-species cultures and in phytoplanktonic communities exposed to 1 ngL-1 AgNPs for 28 days. The results showed that cell growth rate of both single-species cultures decreased significantly at the beginning and progressively reached control-like values at 28 days post-exposure. This effect was similar for the community-cultured cyanobacteria, but not for the green algae, which maintained a sustained decrease in growth rate. While gross photosynthesis (Pg) increased in both strains exposed in single cultures, dark respiration (R) and net photosynthesis (Pn) decreased in S. armatus and M. aeruginosa, respectively. These effects were mitigated when both strains were exposed under community culture conditions. Similarly, the ROS generation shown by both strains exposed in single-species cultures was mitigated when exposure occurred in community cultures. MC-LR production and release were significantly decreased in both single-species and community exposures. These results can supply helpful information to further investigate the potential risks of AgNPs and ultimately help policymakers make better-informed decisions about their utilization for environmental restoration.Item Adverse effects of iron-based nanoparticles on freshwater phytoplankton Scenedesmus armatus and Microcystis aeruginosa strains(Chemosphere, 2023) D'Ors De Blas, Ana; Sánchez Fortún, A.; Cortés Téllez, A. A.; Fajardo, C.; Mengs, G.; Nande Barbeitos, María Del Mar; Martín Conde, María; Costa Buitrago, Gonzalo Antonio; Martín, M.; Bartolomé, M. C.; Sánchez-Fortún Rodríguez, SebastiánZero-valent nano-iron particles (nZVI) are increasingly present in freshwater aquatic environments due to their numerous applications in environmental remediation. However, despite the broad benefits associated with the use and development of nZVI nanoparticles, the potential risks of introducing them into the aquatic environment need to be considered. Special attention should be focused on primary producer organisms, the basal trophic level, whose impact affects the rest of the food web. Although there are numerous acute studies on the acute effects of these nanoparticles on photosynthetic primary producers, few studies focus on long-term exposures. The present study aimed at assessing the effects of nZVI on growth rate, photosynthesis activity, and reactive oxygen activity (ROS) on the freshwater green algae Scenedesmus armatus and the cyanobacteria Microcystis aeruginosa. Moreover, microcystin production was also evaluated. These parameters were assessed on both organisms singly exposed to 72 h-effective nZVI concentration for 10% maximal response for 28 days. The results showed that the cell growth rate of S. armatus was initially significantly altered and progressively reached control-like values at 28 days post-exposure, while M. aeruginosa did not show any significant difference concerning control values at any time. In both strains dark respiration (R) increased, unlike net photosynthesis (Pn), while gross photosynthesis (Pg) only slightly increased at 7 days of exposure and then became equal to control values at 28 days of exposure. The nZVI nanoparticles generated ROS progressively during the 28 days of exposure in both strains, although their formation was significantly higher on green algae than on cyanobacteria. These data can provide additional information to further investigate the potential risks of nZVI and ultimately help decision-makers make better informed decisions regarding the use of nZVI for environmental remediation.Item Lineability, spaceability, and algebrability of certain subsets of function spaces.(Taiwanese Journal of Mathematics, 2009) García-Pacheco, F.J.; Martín Conde, María; Seoane-Sepúlveda, Juan B.We construct infinite-dimensional Banach spaces and infinitely generated Banach algebras of functions that, except for 0, satisfy some kind of special or pathological property. Three of these structures are: a Banach algebra of everywhere continuous bounded functions which are not Riemann-integrable; a Banach space of Lebesgue-integrable functions that are not Riemann-integrable; an algebra of continuous unbounded functions defined on an arbitrary non-compact metric space.Item On the M/G/1 retrial queueing system with linear control policy(Top, 1995) Gómez Corral, Antonio; Martín Conde, MaríaThis paper is concerned with the study of a new M/G/1 retrial queueing system in which the delays between retrials are exponentially distributed random variables with linear intensityg(n)=α+nμ, when there aren≥1 customers in the retrial group. This new retrial discipline will be calledlinear control policy. We carry out an extensive analysis of the model, including existence of stationary regime, stationary distribution of the embedded Markov chain at epochs of service completions, joint distribution of the orbit size and the server state in steady state and busy period. The results agree with known results for special cases.