On the nonlinear hunting stability of a high-speed train bogie

The hunting phenomenon is an intrinsic swaying motion appearing in railway vehicles due to the vehicle's forward speed and the wheel-rail contact forces. Hunting motion consists of wheelset and other vehicle's components oscillations that arise above a certain vehicle's speed known as critical or hunting speed. These oscillations are of unstable nature and represent a safety hazard as they could lead to the vehicle's derailment. This article analyses the stability of a bogie nonlinear model for a Spanish high-speed train when this is travelling at speeds near the hunting speed. The vehicle's stability is studied by means of root loci methods, and the value of the critical speed is found. In addition to this, the behaviour of the vehicle is studied in both stable and unstable regions and the existence of limit cycles is discussed in this work. Finally, a sensitivity analysis of the axle load and suspension parameters is performed. The results show that the axle load, the vertical stiffness of the primary suspension and the lateral damping of the secondary suspension have a significant influence on the value of the critical speed.The research work described in this paper is part of the R&D and Innovation projects MC4.0 PID2020-116984RB-C21 and MC4.0 PID2020-116984RB-C22 supported by the MCIN/AEI/10.13039/501100011033 and by the Universidad Carlos III de Madrid through the "Ayudas para la movilidad de investigadores de la UC3M en centros de investigación nacionales y extranjeros en sus dos modalidades 2019" project

Mesoporous niobium oxide for dehydration of D-xylose into furfural

Se ha demostrado que el óxido de niobio mesoporoso es un catalizador eficaz para la deshidratación de D-xilosa a furfural, alcanzando una conversión del 92% y un rendimiento de furfural 49,3% a 170º C y 90 minutos. La lixiviación de Nb, determinada por ICP-MS, era inferior al 0,5% en peso de la concentración de Nb inicial, confirmando de este modo la estabilidad del catalizador ácido sólido.El furfural posee un gran potencial como molécula plataforma de origen renovable para la síntesis de una alta variedad de compuestos químicos. Se obtiene mediante la deshidratación de pentosas, principalmente a partir de D-xilosa, proceso catalizado por ácidos minerales en fase homogénea. Por tanto, dentro de la química verde y la búsqueda de sostenibilidad de los procesos catalíticos, es necesaria su sustitución por catalizadores sólidos ácidos que sean tolerantes al agua, ya que es el disolvente más utilizado para esta reacción. El óxido de niobio posee propiedades ácidas y es insoluble en agua, pero su superficie específica es muy baja. Por lo tanto, resulta muy interesante la síntesis de un óxido de niobio mesoporoso para emplearlo como catalizador en esta reacción. En este trabajo, se ha sintetizado un Nb2O5 mesoporoso y se ha evaluado su comportamiento catalítico en la obtención de furfural a partir de D-xilosa.Spanish Ministry of Science and Innovation (ENE2009-12743-C04-03 project)Junta de Andalucía (P09-FQM-5070).Ministry of Science and Innovation for the financial support under the Program Ramón y Cajal (RYC-2008-03387)

Disconnecting the Golgi ribbon from the centrosome prevents directional cell migration and ciliogenesis

AKAP450 is a critical determinant of Golgi ribbon integrity, positioning, and function

Livestock activity biomarkers: Estimating domestication and diet of livestock in ancient samples

[EN]Faecal matter is commonly recovered from archaeological sites related to human/animal activity. The identification of its source is essential to understand the domestication process and the relationship between humans and domestic animals in ancient times. Additionally, faecal matter is useful for determining the diet of animals. Therefore, the use of an appropriate biomarker is essential. The ratios of 5 beta-Stanols and bile acid biomarkers are most commonly used to identify the biogenic origin of faecal matter. However, other biomarkers such as archaeol can be a good proxy for ruminants. Conversely, plant-based diet of the animals can be discerned by analysis of faecal matter. n-Alkanes are the most common proxies of the animal diet, followed by long-chain fatty acids and long-chain alcohols, and the interest in the analysis of carbon isotopes has recently increased owing to the possibility of distinguishing animal diets. In this review, we describe the identification of faecal and diet biomarkers in animals. Ratios and proxies used in archaeological fields are also described and discussed to determine the best approach for accurate identification.This work was funded by the Basque Government, Research Groups of the Basque University System (Project No. IT1186-19)

Perfil de los diagnósticos de enfermería en pacientes cardiópatas estables

Objective. To identify the nursing diagnoses through reports in the medical records of patients monitored in a specialized ischemic heart disease outpatient clinic. Methods. Cross-sectional study with retrospective data collection in the medical records. From the data collected, the nursing diagnoses were proposed by the researchers and submitted for validation by specialist cardiology nurses. Results. A total of 13 nursing diagnoses were evaluated from the medical records of 50 outpatients with the following validation agreements among the specialists: Ineffective health management (100%), Noncompliance (100%), Sedentary lifestyle (100%), Activity intolerance (100%), Decreased cardiac output (88%), Risk of decreased cardiac tissue perfusion (65%), Risk of intolerance to activity (65%), Acute pain (76%), Ineffective health maintenance (65%), Risk-prone health behavior (65%), Risk for decreased cardiac output (65%), Risk for intolerance to activity (65%), Ineffective respiratory pattern (53%), Impaired memory (29%). Conclusion. In this study, the nursing diagnoses validated for stable heart disease patients were linked to adherence to treatment and to the cardiovascular responses of the patients, reinforcing the importance of early intervention. These results allow the multidisciplinary team to individualize the goals and interventions proposed for ischemic heart disease patients.Objetivo. Identificar os diagnósticos de enfermagem através dos registros no seguimento dos pacientes que vão a um centro ambulatório especializado em cardiopatia isquêmica na cidade de Porto Alegre, Brasil. Métodos. Estudo transversal com toma de informação retrospectiva da história clínica. A partir dos dados recolhido, os diagnósticos de enfermagem identificados pelos investigadores foram submetidos a valoração de enfermeiros especialistas em cardiologia. Resultados. Foram identificados 13 diagnósticos de enfermagem nas histórias clínicas de 50 pacientes ambulatórios, com a seguinte concordância de validação entre os especialistas: controle ineficaz da saúde (100%), falta de aderência (100%), estilo de vida sedentário (100%), Intolerância à atividade (100%), Débito cardíaco diminuído (88%), irrigação de perfusão tissular cardíaca diminuída (76%), Dor agudo (76%), Manutenção ineficaz da saúde (65%), Comportamento de saúde propenso a risco (65%), Risco de débito cardíaco diminuído (65%), Risco de intolerância à atividade (65%), Padrão respiratório ineficaz (53%), Memória prejudicada (29%). Conclusão. Neste estudo os diagnósticos de enfermagem validados para os pacientes cardiopatas estáveis estão relacionados com a aderência ao tratamento e à resposta cardiovascular às intervenções dos pacientes, reforçando a importância de intervenção precoce. Esses resultados permitem em equipes multiprofissionais individualizar as metas e intervenções para os pacientes com cardiopatia isquêmica.Objetivo. Identificar los diagnósticos de enfermería a partir de los registros en el seguimiento de los pacientes que acuden a un centro ambulatorio especializado en cardiopatía isquémica en la ciudad de Porto Alegre, Brasil. Métodos. Estudio transversal con toma de información retrospectiva de la historia clínica. A partir de los datos recolectados, los diagnósticos de enfermería identificados por los investigadores se sometieron a valoración de enfermeros especialistas en cardiología. Resultados. Se identificaron 13 diagnósticos de enfermería en las historias clínicas de 50 pacientes ambulatorios, con la siguiente concordancia de validación entre los especialistas: control ineficaz de la salud (100%), falta de adherencia (100%), estilo de vida sedentario (100%), Intolerancia a la actividad (100%), Débito cardíaco disminuido (88%), Riego de perfusión tisular cardíaca disminuida (76%), Dolor agudo (76%), Mantenimiento ineficaz de la salud (65%), Comportamiento de salud propenso a riesgo (65%), Riesgo de débito cardíaco disminuido (65%), Riesgo de intolerancia a la actividad (65%), Patrón respiratorio ineficaz (53%), Memoria perjudicada (29%). Conclusión. En este estudio los diagnósticos de enfermería validados para los pacientes cardiópatas estables están relacionados con la adherencia al tratamiento y a la respuesta cardiovascular a las intervenciones, reforzando la importancia de intervención precoz. Esos resultados permiten, en equipos multiprofesionales, individualizar las metas e intervenciones para los pacientes con cardiopatía isquémica

Femto-to nanosecond photodynamics of Nile Red in metal-ion exchanged faujasites

[EN] We report on the photodynamics of Nile Red (NR) interacting with faujasite (NaY)-type zeolites having different Na/Al ratios and charge balancing metals (Li+, Mg2+, and Cs+) in dichloromethane (DCM) suspensions. The encapsulation of NR in these materials leads to the formation of different populations, reflected in H- and J-aggregates, monomers, and surface adsorbed species. Due to the interaction of the dye with both the Bronsted and Lewis sites of the zeolite, a bathochromic shift is observed in the steady-state diffuse transmittance and emission spectra. The relative contribution of each population is affected by the Na/Al ratio and the nature of the doping metal ion. These findings are further explored by femtoto nanosecond time-resolved emission experiments, where a multi-exponential behaviour is observed for the excited samples. The fluorescence lifetimes range from similar to 100 ps to similar to 2 ns. They are assigned to the emission from H- and J-aggregates and monomers. At low Na/Al ratios, we observed an increase in the fluorescence time constants which is explained in terms of H-bonds formation between NR and the zeolite framework, while the change in the emission lifetimes for the metal ion exchanged zeolites is due to the variation of the properties (size and polarization ability) of the exchanged cation. An ultrafast formation (similar to 200 fs) of a charge-separated state (CS) followed by a vibrational cooling (similar to 1-2 ps) are observed in the fluorescence up-conversion transients. These results indicate a strong interaction between NR and the studied zeolites and may help for the design of metal ion sensors and for a better understanding of nanocatalysis. (C) 2017 Elsevier Inc. All rights reserved.This work was supported by the JCCM and MINECO through projects: PEII-2014-003-P, Consolider Ingenio 2010 (CSD2009-0050, MULTICAT), and MAT2014-57646-P. A. Corma and M.T. Navarro thank the MINECO (Severo Ochoa program SEV-2012-0267 and MAT2015-71842-P) for financial support.Di Nunzio, MR.; Caballero-Mancebo, E.; Martin, C.; Cohen, B.; Navarro Villalba, MT.; Corma Canós, A.; Douhal, A. (2018). Femto-to nanosecond photodynamics of Nile Red in metal-ion exchanged faujasites. Microporous and Mesoporous Materials. 256:214-226. https://doi.org/10.1016/j.micromeso.2017.08.011S21422625

Processo De Tratamento De Efluente Papeleiro Kraft E1 Pelo Sistema De Enzima-mediador: Lacase-hidroxamatos

Este processo refere-se a uma metodologia no tratamento de efluente E1 pelo sistema lacase-mediador. O valor máximo atingido de diminuição de fenóis na ausência de mediadores foi de 23%. O 1-hidroxibenzotriazol (HBT) não apresentou efeito significativo em efluentes kraft. Dos mediadores estudados os hidroxamatos foram os mais eficientes no tratamento do efluente kraft E1 . Entre os hidroxamatos o ácido acetohidroxâmico (AHA-), foi o mais eficiente na degradação de fenóis (70%) e no carbono orgânico total (73%) e não apresentou degradação significativa pela lacase.BR0002329 (B1); BR0002329 (A)C02F3/00C02F3/00BR20000002329C02F3/00C02F3/0

Analysis of biophysical variables in an onion crop (Allium cepa L.) with nitrogen fertilization by sentinel-2 observations

The production of onions bulbs (Allium cepa L.) requires a high amount of nitrogen. Ac cording to the demand of sustainable agriculture, the information-development and communication technologies allow for improving the efficiency of nitrogen fertilization. In the south of the province of Buenos Aires, Argentina, between 8000 and 10,000 hectares per year−1 are cultivated in the districts of Villarino and Patagones. This work aimed to analyze the relationship of biophysical variables: leaf area index (LAI), canopy chlorophyll content (CCC), and canopy cover factor (fCOVER), with the nitrogen fertilization of an intermediate cycle onion crop and its effects on yield. A field trial study with different doses of granulated urea and granulated urea was carried out, where biophysical char acteristics were evaluated in the field and in Sentinel-2 satellite observations. Field data correlated well with satellite data, with an R2 of 0.91, 0.96, and 0.85 for LAI, fCOVER, and CCC, respectively. The application of nitrogen in all its doses produced significantly higher yields than the control. The LAI and CCC variables had a positive correlation with yield in the months of November and December. A significant difference was observed between U250 (62 Mg ha−1) and the other treatments. The U500 dose led to a yield increase of 27% compared to U250, while the difference between U750 and U500 was 6%.Fil: Casella, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; ArgentinaFil: Orden, Luciano. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; Argentina. Universidad Miguel Hernández. Centro de Investigación e Innovación Agroalimentaria y Agroambiental. GIAAMA Reseach Group; EspañaFil: Pezzola, Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Bellaccomo, Maria Carolina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Winschel, Cristina Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Caballero, Gabriel. Technological University of Uruguay. Departamento de Montevideo, UruguayFil: Delegido, Jesús. Universidad de Valencia. Image Processing Laboratory (IPL); EspañaFil: Navas Gracia, Luis Manuel. Universidad de Valladolid. Departamento de Ingenieria Agrícola y Forestal; EspañaFil: Verrelst, Jochem. Universidad de Valencia. Image Processing Laboratory (IPL); Españ