Fluid dynamics of mixing in the tanks of small vanadium redox flow batteries: Insights from order-of-magnitude estimates and transient two-dimensional simulations

This paper investigates the fluid dynamics of mixing in the tanks of small-scale vanadium redox flow batteries. These systems use two redox pairs dissolved in separate electrolytes to convert electrical energy into chemical energy, a process that can be reversed in an efficient way to restore the initial electrical energy with negligible chemical losses. After flowing through the electrochemical cell, the electrolytes are stored in separate tanks, where they discharge as submerged jets with small temperature and composition changes compared to the electrolyte already present in the tanks. The subsequent mixing process is critical for battery performance, as imperfect mixing tends to reduce the energy capacity and may lead to asymmetric battery operation. The analysis starts using order-of-magnitude estimates to determine the conditions under which the mixing process is dominated by momentum or buoyancy. Transient two-dimensional simulations illustrate the different flow regimes that emerge in the tanks under laminar flow conditions. The results show that, contrary to the common assumption, the electrolytes do not mix well in the tanks. In the presence of high-momentum -- and, specially, positively buoyant -- jets, a significant fraction of the electrolyte remains unmixed and unreacted for long periods, thus reducing the energy capacity. The results also show that the availability of reliable electrolyte properties is crucial for the accuracy of the numerical simulations, as, under the mixed convection conditions that typically prevail in vanadium redox flow batteries, small density variations can significantly impact the long-term mixing of the electrolytes. In particular, in momentum-dominated flows the cumulative effect of density changes over time eventually leads to flow instabilities that significantly promote mixing; therefore, they should be taken into account in future studies

Reuse Detector: improving the management of STT-RAM SLLCs

Various constraints of Static Random Access Memory (SRAM) are leading to consider new memory technologies as candidates for building on-chip shared last-level caches (SLLCs). Spin-Transfer Torque RAM (STT-RAM) is currently postulated as the prime contender due to its better energy efficiency, smaller die footprint and higher scalability. However, STT-RAM also exhibits some drawbacks, like slow and energy-hungry write operations that need to be mitigated before it can be used in SLLCs for the next generation of computers. In this work, we address these shortcomings by leveraging a new management mechanism for STT-RAM SLLCs. This approach is based on the previous observation that although the stream of references arriving at the SLLC of a Chip MultiProcessor (CMP) exhibits limited temporal locality, it does exhibit reuse locality, i.e. those blocks referenced several times manifest high probability of forthcoming reuse. As such, conventional STT-RAM SLLC management mechanisms, mainly focused on exploiting temporal locality, result in low efficient behavior. In this paper, we employ a cache management mechanism that selects the contents of the SLLC aimed to exploit reuse locality instead of temporal locality. Specifically, our proposal consists in the inclusion of a Reuse Detector (RD) between private cache levels and the STT-RAM SLLC. Its mission is to detect blocks that do not exhibit reuse, in order to avoid their insertion in the SLLC, hence reducing the number of write operations and the energy consumption in the STT-RAM. Our evaluation, using multiprogrammed workloads in quad-core, eight-core and 16-core systems, reveals that our scheme reports on average, energy reductions in the SLLC in the range of 37–30%, additional energy savings in the main memory in the range of 6–8% and performance improvements of 3% (quad-core), 7% (eight-core) and 14% (16-core) compared with an STT-RAM SLLC baseline where no RD is employed. More importantly, our approach outperforms DASCA, the state-of-the-art STT-RAM SLLC management, reporting—depending on the specific scenario and the kind of applications used—SLLC energy savings in the range of 4–11% higher than those of DASCA, delivering higher performance in the range of 1.5–14% and additional improvements in DRAM energy consumption in the range of 2–9% higher than DASCA.Peer ReviewedPostprint (author's final draft

Goat production systems of the central highlands of Veracruz, Mexico

ABSTRACT The objective of this study was to characterize the goat production units of the central mountainous area of the state of Veracruz. A multiple case study was carried out considering socioeconomic aspects, type of forage, goat feeding, reproduction, improvement, and health. The results showed that goat farming and cheese production represent between 50 and 100% of the producers' income. The cultivated forages and the type of goat feed of the production units in the mountainous area are King grass CT-115, Maralfalfa, African Star, Alfalfa and Corn. Animal reproduction is carried out by controlled mating and births occur at the beginning and end of each year. The goat herds do not exceed 150 heads with a predominance of Saanen and Alpine breeds. The average daily production of milk ranges between 16-90 L and with a production of 2-3 L milk for animal/day. The activity is family-type and involves cultivation, animal management, milk production and the manufacturing of artisanal cheeses. Studies are required to confirm individual milk production.Objective: This study was to characterize the goat production units of the central mountain area of the state of Veracruz, Mexico. Disign/methodology/approach: A multiple case study was carried out taking into consideration socioeconomic aspects, type of forage, goat feeding, reproduction, improvement, and health. Results: The results showed that goat and cheese production account for 50-100% of the producers' income. The forages grown and the type of goat feed used in the production units of the mountain area are: King grass, CT-115, maralfalfa, giant star grass, alfalfa, and corn. Animal reproduction is carried out by controlled mating and births take place at the beginning and end of each year. Flocks do not exceed 150 heads; the predominant breeds are Saanen and Alpine. The average daily production of milk ranges from 16 to 90 L, with a production of 0.75-3 L milk animal-1 day-1. Study limitations/implications: None Findings/conclusions: The activity is family-based and involves cultivation, animal management, and milk and artisanal cheese production. Further studies are required to confirm individual milk production

Research priorities for maintaining biodiversity’s contributions to people in Latin America

Maintaining biodiversity is crucial for ensuring human well-being. The authors participated in a workshop held in Palenque, Mexico, in August 2018, that brought together 30 mostly early-career scientists working in different disciplines (natural, social and economic sciences) with the aim of identifying research priorities for studying the contributions of biodiversity to people and how these contributions might be impacted by environmental change. Five main groups of questions emerged: (1) Enhancing the quantity, quality, and availability of biodiversity data; (2) Integrating different knowledge systems; (3) Improved methods for integrating diverse data; (4) Fundamental questions in ecology and evolution; and (5) Multi-level governance across boundaries. We discuss the need for increased capacity building and investment in research programmes to address these challenges

An Objective Scatter Index Based on Double-Pass Retinal Images of a Point Source to Classify Cataracts

PURPOSE: To propose a new objective scatter index (OSI) based in the analysis of double-pass images of a point source to rank and classify cataract patients. This classification scheme is compared with a current subjective system. METHODS: We selected a population including a group of normal young eyes as control and patients diagnosed with cataract (grades NO2, NO3 and NO4) according to the Lens Opacities Classification System (LOCS III). For each eye, we recorded double-pass retinal images of a point source. In each patient, we determined an objective scatter index (OSI) as the ratio of the intensity at an eccentric location in the image and the central part. This index provides information on the relevant forward scatter affecting vision. Since the double-pass retinal images are affected by both ocular aberrations and intraocular scattering, an analysis was performed to show the ranges of contributions of aberrations to the OSI. RESULTS: We used the OSI values to classify each eye according to the degree of scatter. The young normal eyes of the control group had OSI values below 1, while the OSI for subjects in LOCS grade II were around 1 to 2. The use of the objective index showed some of the weakness of subjective classification schemes. In particular, several subjects initially classified independently as grade NO2 or NO3 had similar OSI values, and in some cases even higher than subjects classified as grade NO4. A new classification scheme based in OSI is proposed. CONCLUSIONS: We introduced an objective index based in the analysis of double-pass retinal images to classify cataract patients. The method is robust and fully based in objective measurements; i.e., not depending on subjective decisions. This procedure could be used in combination with standard current methods to improve cataract patient surgery scheduling

Economic evaluation of three populational screening strategies for cervical cancer in the county of Valles Occidental: CRICERVA clinical trial

Copyright @ 2011 Acera et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.A high percentage of cervical cancer cases have not undergone cytological tests within 10 years prior to diagnosis. Different population interventions could improve coverage in the public system, although costs will also increase. The aim of this study was to compare the effectiveness and the costs of three types of population interventions to increase the number of female participants in the screening programmes for cancer of the cervix carried out by Primary Care in four basic health care areas.Fondo de Investigación Sanitaria del Instituto Carlos III de Madri

Rendimiento de cultivares de arveja (Pisum sativum, L) en diferentes ambientes de la República Argentina. Campaña 2021/2022

El mercado internacional de arveja transitó uno de los años de mayor volatilidad, comenzando por los efectos de la sequía en Canadá que recortó la oferta en más de un 50 % (AAFC, 2022), a la invasión de Ucrania por parte de Rusia. La oferta de arveja por parte de ambos países fue marcada en los últimos años, pero en el contexto actual es incierta la posibilidad de su participación en el mercado mundial. En ese contexto, traccionado por la suba del precio en Canadá, el mercado local se vio estimulado a incrementar el área de siembra, y así lo hizo, superando oficialmente las 100 mil hectáreas (Informe del INASE, 2022). Del citado informe surge, además que sólo 8 variedades dan cuenta del 85 % del total del área sembrada, y que una de ellas se siembra en más del 40 % de la superficie total. Por otro lado, es interesante destacar que la participación de las variedades amarillas sigue incrementándose anualmente y en la última campaña su proporción fue del 20 %, teniendo en cuenta que el mercado mundial es básicamente de este tipo de arvejas. Dado que en Argentina se vienen inscribiendo año tras año más variedades de arveja, es que se presentan en este trabajo el comportamiento agronómico de 13 variedades primaverales y 3 variedades invernales en 16 y 4 ambientes respectivamente, de la República Argentina.EEA OliverosFil: Prieto, Gabriel María. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Oliveros. Agencia de Extensión Rural Arroyo Seco; ArgentinaFil: Alamo, Juan Facundo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá. Agencia de Extensión Rural Trancas; ArgentinaFil: Appella, Cristian Manuel. Instituto Nacional de Tecnología Agropecuaria (INTA). Chacra Experimental Integrada Barrow; ArgentinaFil: Avila, F. Consorcio Regional de Experimentación Agrícola (CREA); ArgentinaFil: Bobadilla, Segundo Evaristo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Esquel; ArgentinaFil: Casciani, Andres. Actividad Independiente; ArgentinaFil: Díaz Zorita, Martín. Universidad de La Pampa. Facultad de Agronomía; Argentina.Fil: Dillchneider, Alexandra. Universidad Nacional de La Pampa. Facultad de Agronomía; Argentina.Fil: Espósito, María Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Oliveros; ArgentinaFil: Fariña, Leandro. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Agencia Regional de Desarrollo Productivo; ArgentinaFil: Gallego, Juan José. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Valle Inferior de Río Negro; ArgentinaFil: Introna, Jimena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Sección Agronomía; ArgentinaFil: Lázaro, Laura. Universidad Nacional del Noroeste de la Provincia de Buenos Aires (UNNOBA). Facultad de Agronomía; ArgentinaFil: Lexow, Guillermo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Esquel; ArgentinaFil: Loto, Ariel Roberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Oliveros. Agencia de Extensión Rural Arroyo Seco; ArgentinaFil: Maggio, J.C. Agrar del Sur; ArgentinaFil: Melin, Ariel Alejandro. Ministerio de Desarrollo Agrario Provincia de Buenos Aires. Chacra Experimental Coronel Suárez; ArgentinaFil: Mora, Julio Cesar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz. Agencia de Extensión Rural Los Antiguos; ArgentinaFil: Neira Zilli, Fernanda. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Valle Inferior de Río Negro; ArgentinaFil: Nemoz, Juan Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Cuenca del Salado. Agencia de Extensión Rural Azul; ArgentinaFil: Prece, Natalia María. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Sección Agronomía; ArgentinaFil: Vita Larrieu, Eduardo Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Oliveros. Agencia de Extensión Rural Máximo Paz; ArgentinaFil: Zubillaga, María Fany. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Valle Inferior de Río Negro; Argentin

Mitigación con Sistemas Silvopastoriles en Latinoamérica: Aportes para la incorporación en los sistemas de Medición Reporte y Verificación bajo la CMNUCC

En Latinoamérica el 46% de las emisiones de GEI proviene del cambio de usos de la tierra y el 20% de la agricultura, en donde el 58% y el 70% de las emisiones son debidas a la ganadería. El continuo crecimiento de este sector (+32% previsto al 2050) ha impulsado la expansión de la frontera agropecuaria en los bosques, generando múltiples impactos ambientales entre los cuales se encuentra la emisión de Gases Efecto Invernadero (GEI). Sin embargo, el sector tiene un alto potencial de mitigación reconocido por políticas, estrategias y programas de mitigación nacionales como las Contribuciones Nacionalmente Determinadas (NDC) y de desarrollo sectorial como las Acciones de Mitigación nacionalmente Apropiadas (NAMA). Entre estas acciones se incluye la implementación de sistemas silvopastoriles, cuya medición monitoreo y reporte a escala nacional presenta un estado de avance muy limitado, dejando su aporte a la mitigación invisible. A través de un Grupo Técnico de Trabajo ad hoc se han analizado el avance de los países de la región en la incorporación de los sistemas silvopastoriles en los sistemas nacionales de Medición/Monitoreo, Reporte y Verificación (MRV) de los Inventarios Nacionales de Gases Efecto Invernadero, y los requerimientos a cumplir para esto, generando una hoja de ruta a corto-medio plazo así como unas orientaciones técnicas para reducir la brecha existente

Mitigación con Sistemas Silvopastoriles en Latinoamérica: Aportes para la incorporación en los sistemas de Medición Reporte y Verificación bajo la CMNUCC

En Latinoamérica el 46% de las emisiones de GEI proviene del cambio de usos de la tierra y el 20% de la agricultura, en donde el 58% y el 70% de las emisiones son debidas a la ganadería. El continuo crecimiento de este sector (+32% previsto al 2050) ha impulsado la expansión de la frontera agropecuaria en los bosques, generando múltiples impactos ambientales entre los cuales se encuentra la emisión de Gases Efecto Invernadero (GEI). Sin embargo, el sector tiene un alto potencial de mitigación reconocido por políticas, estrategias y programas de mitigación nacionales como las Contribuciones Nacionalmente Determinadas (NDC) y de desarrollo sectorial como las Acciones de Mitigación nacionalmente Apropiadas (NAMA). Entre estas acciones se incluye la implementación de sistemas silvopastoriles, cuya medición monitoreo y reporte a escala nacional presenta un estado de avance muy limitado, dejando su aporte a la mitigación invisible. A través de un Grupo Técnico de Trabajo ad hoc se han analizado el avance de los países de la región en la incorporación de los sistemas silvopastoriles en los sistemas nacionales de Medición/Monitoreo, Reporte y Verificación (MRV) de los Inventarios Nacionales de Gases Efecto Invernadero, y los requerimientos a cumplir para esto, generando una hoja de ruta a corto-medio plazo así como unas orientaciones técnicas para reducir la brecha existente

Clustering COVID-19 ARDS patients through the first days of ICU admission. An analysis of the CIBERESUCICOVID Cohort

Background Acute respiratory distress syndrome (ARDS) can be classified into sub-phenotypes according to different inflammatory/clinical status. Prognostic enrichment was achieved by grouping patients into hypoinflammatory or hyperinflammatory sub-phenotypes, even though the time of analysis may change the classification according to treatment response or disease evolution. We aimed to evaluate when patients can be clustered in more than 1 group, and how they may change the clustering of patients using data of baseline or day 3, and the prognosis of patients according to their evolution by changing or not the cluster.Methods Multicenter, observational prospective, and retrospective study of patients admitted due to ARDS related to COVID-19 infection in Spain. Patients were grouped according to a clustering mixed-type data algorithm (k-prototypes) using continuous and categorical readily available variables at baseline and day 3.Results Of 6205 patients, 3743 (60%) were included in the study. According to silhouette analysis, patients were grouped in two clusters. At baseline, 1402 (37%) patients were included in cluster 1 and 2341(63%) in cluster 2. On day 3, 1557(42%) patients were included in cluster 1 and 2086 (57%) in cluster 2. The patients included in cluster 2 were older and more frequently hypertensive and had a higher prevalence of shock, organ dysfunction, inflammatory biomarkers, and worst respiratory indexes at both time points. The 90-day mortality was higher in cluster 2 at both clustering processes (43.8% [n = 1025] versus 27.3% [n = 383] at baseline, and 49% [n = 1023] versus 20.6% [n = 321] on day 3). Four hundred and fifty-eight (33%) patients clustered in the first group were clustered in the second group on day 3. In contrast, 638 (27%) patients clustered in the second group were clustered in the first group on day 3.Conclusions During the first days, patients can be clustered into two groups and the process of clustering patients may change as they continue to evolve. This means that despite a vast majority of patients remaining in the same cluster, a minority reaching 33% of patients analyzed may be re-categorized into different clusters based on their progress. Such changes can significantly impact their prognosis