102 research outputs found
Mutarrotación e isomerización de iminas
Tesis - Universidad Complutense de Madrid, 1973.Fac. de Ciencias QuímicasTRUEProQuestpu
A straightforward alkynylation of Li and Mg metalated heterocycles with sulfonylacetylenes
Coupling of alkynyl moieties to heterocyclic rings, without using ransition metals, can be easily performed by the reaction of aryl or heteroaryl sulfonylacetylenes with heteroaryl-Li compounds or their corresponding less reactive magnesium derivativesFinancial support from the Spanish Government (CTQ2012-35957
Insight into the copper-catalyzed borylation of strained alkenes
This document is the accepted manuscript version of a published work that appeared in final form in Synlett 2015; 26(04): 494-500, copyright © Georg Thieme Verlag Stuttgart · New York after peer review and technical editing by the publisher. To access the final online work see DOI: 10.1055/s-0034-1379882The copper-catalyzed hydro- and carboboration of strain alkenes is presented. The reaction is highly diastereoselective and affords boronic ester derivatives many of which are difficult to synthesize by known methods. Competition experiments with different alkenes show that high
levels of chemoselectivity can be achieved. DFT calculations are in agreement with the observed chemoselectivityWe thank the European Research Council (ERC-337776) and MINECO (CTQ2012-35957 and CTQ2013-43698-P) for financial support. M. T. and S. D.-T thank MINECO for RyC contracts. A. P. thanks MINECO for JyC contrac
A straightforward alkynylation of Li and Mg metalated heterocycles with sulfonylacetylenes
Comparison between computed tomography and silicone-casting methods to determine gunshot cavities in ballistic soap
Current methods used in terminal ballistics to determine the volume of temporary cavities created by projectiles in soft tissue simulants (such as ballistic soap) usually involve silicone-casting to obtain the cavity moulds. However, these methods have important drawbacks including their little sensitivity and precision, besides the fact that they are destructive. Imaging techniques such as computed tomography (CT) might not only overcome those limitations but also offer useful tools for digitally reporting the scientific results. This work accomplished the 3D digital reconstruction of the cavities created by different projectiles in ballistic soap blocks. This way, the total volume of the cavities, the projectile penetration depths, and other measurements were determined, rendering better capabilities when compared to the current silicone method. All these features were achieved through the CT analysis and 3D Slicer imaging software. In addition, it is worth mentioning that the method can preserve the evidence by digitally obtaining, signing, and storing the infographic videos displaying the 3D-reconstructed cavities
The Acidity of a Carbon Nucleophile Dictates Enantioselectivity and Reactivity in Michael Additions to Aromatic and Aliphatic Enals via Iminium Activation
The Michael addition of activated methylenes to β-substituted α,β-unsaturated aldehydes (enals) via iminium catalysis takes place following reactivity and enantioselectivity patterns which depend on the electronic nature of the substituent in the β position (β-aryl or β-alkyl). Application of the same reaction conditions to both families of enals may result in erratic levels of asymmetric induction in the reactions of β-aryl enals or low reactivity with β-alkyl enals. A systematic analysis of this behavior using phenylacetic acid derivatives as case studies has led us to find a general trend: the different problems found for β-aryl and β-alkyl enals depend on the acidity of the nucleophile, and the outcome of the reaction for both types of enals can be improved substantially by careful choice of catalyst, solvent, and additive. Furthermore, this study has allowed us to understand subtle aspects of this transformation and has enabled the formulation of a general and reliable protocol to obtain high yields and enantioselectivities consistently, regardless of the acidity of the nucleophile and the nature of the substituent (aromatic or aliphatic) at the β positionWe thank CTQ-2009-12168, CAM (AVANCAT CS2009/PPQ-1634), UAM-CAM (CCG10-UAM/PPQ-5769), CTQ-2012-35957, CTQ2015-63997-C2-1-P, CTQ2016-78779-R and FOTOCARBON-CAM S2013/MIT-2841 for financial support. S.D. thanks the Comunidad Autónoma de Madrid (CAM), and E.R. and S.M. thank MICINN, for predoctoral fellowships. P.M. thanks MICINN for a Ramón y Cajal contract and the EU for a Marie Curie grant (CIG: HYPERCAT-30422
LQG control for dynamic positioning of floating caissons based on the Kalman filter
This paper presents the application of an linear quadratic gaussian (LQG) control strategy for concrete caisson deployment for marine structures. Currently these maneuvers are carried out manually with the risk that this entails. Control systems for these operations with classical regulators have begun to be implemented. They try to reduce risks, but they still need to be optimized due to the complexity of the dynamics involved during the sinking process and the contact with the sea bed. A linear approximation of the dynamic model of the caisson is obtained and an LQG control strategy is implemented based on the Kalman filter (KF). The results of the proposed LQG control strategy are compared to the ones given by a classic controller. It is noted that the proposed system is positioned with greater precision and accuracy, as shown in the different simulations and in the Monte Carlo study. Furthermore, the control efforts are less than with classical regulators. For all the reasons cited above, it is concluded that there is a clear improvement in performance with the control system proposed.The Spanish FEDER/Ministry of Science, Innovation and Universities—State Research Agency is greatly acknowledged for partially funding our research through the SAFE Project (Desarrollo de un Sistema Autónomo para el Fondeo de Estructuras para Obras Marítimas), GrantAgreement: RTC-2017-6603-4. The Regional Ministry of Universities, Equality, Culture and Sports of the Gov-ernment of Cantabria has supported this work through the ControlFond project (Control De Ve-hículos Subacuáticos No Tripulados Para Supervisión De Estructuras Para Obras Marítimas Fondeadas). The authors would like to thank FCC Construcción CO as a collaborator in the de-velopment of the SAFE Project, specially Victor Florez Casillas and Nuria Cotallo Aguado (Tech-nical Direction/Hydraulic and Maritime Works) and Alvaro de Toro Mingo (Machinery Direction). R. Guanche also acknowledges financial support from the Ramon y Cajal Program (RYC-2017-23260) of the Spanish Ministry of Science, Innovation and Universities
Dynamic positioning of floating caissons based on the UKF filter under external perturbances induced by waves
This paper presents a dynamic positioning control scheme for concrete caissons in an attempt to automate part of the manoeuvres which usually require a complex deploy of personnel and equipment for port infrastructures development. The aim of this paper is to propose a control scheme, which is able to provide a reduction in costs and an improvement in security for the dynamic positioning manoeuvres . To do so, a dual loop controller is developed and the unscented Kalman filter is applied for states and perturbances estimation. Furthermore, a control allocation algorithm is proposed based on anchoring lines and winches. Finally, some simulations are performed to verify the effectiveness of the proposed approach.The Spanish FEDER/Ministry of Science, Innovation and Universities — State Research Agency (Fig. 14) is greatly acknowledged for funding our research through SAFE Project (Desarrollo de un Sistema Autónomo para el Fondeo de Estructuras para Obras Marítimas), Grant Agreement: RTC-2017-6603-4.
The authors would like to thank FCC CO as a collaborator in the development of the SAFE Project.
R. Guanche also acknowledges financial support from the Ramon y Cajal Program (RYC-2017-23260) of the Spanish Ministry of Science, Innovation and Universities
Factores psicosociales de riesgo y burnout en policías: un análisis de redes
Work stress has been identified as a critical factor affecting mental health in police officers. Psychosocial factors increase the impact of work stress on police officers and,in the long run,contribute to the onset of burnout symptoms. In this research asample of 323 was studied to study the relationship between psychosocial risk factors and the probability of suffering burnout symptoms. The participant’s answers to the MBI-GSandF-PSICO(version4.0) were analysed by using network analysis.There sults show that psychosocial risk factors are strongly associated in network models when higher level of cynicism and emotional exhaustion are observed. Additionally, higher levels of burnout in police officers were observed when lower autonomy,higher psychological demands, role ambiguities and alower perceived social support were present. Results are discussed considering its theoretical and applied relevance to design healthier work environments an defficient psychologicalinterventionsEl estrés laboral crónico ha sido identificado como uno de los riesgos laborales más importantes que afecta a la salud mental de los agentes de policía. Existen ciertos factores psicosociales que incrementan el estrés laboral en la policía y que, a largo plazo, desencadenan síntomas compatibles con el burnout. En este trabajo se ha utilizado una muestra integrada por 323 policías para valorar la relación que se establece entre los factores psicosociales de riesgo y la probabilidad de experimentar síntomas compatibles con el burnout. Las respuestas de los participantes al MBI-GS y al F-PSICO (versión 4.0) fueron examinadas utilizando análisis de redes. Los resultados muestran que existen redes de factores psicosociales de riesgo más cohesionadas cuando los niveles de cinismo y agotamiento emocional son más elevados. Además, se observa mayor nivel de burnout asociados con una baja autonomía, altas demandas psicológicas, conflictos en el desempeño de rol y un bajo apoyo social percibido. Los resultados son discutidos en términos de su implicación teórica y de su utilidad práctica frente al diseño de entornos de trabajo más saludables, así como frente a la intervención psicológica
New frontiers from removal to recycling of nitrogen and phosphorus from wastewater in the Circular Economy
[EN] Nutrient recovery technologies are rapidly expanding due to the need for the appropriate recycling of key elements from waste resources in order to move towards a truly sustainable modern society based on the Circular Economy. Nutrient recycling is a promising strategy for reducing the depletion of non-renewable resources and the environmental impact linked to their extraction and manufacture. However, nutrient recovery technologies are not yet fully mature, as further research is needed to optimize process efficiency and enhance their commercial applicability. This paper reviews state-of-the-art of nutrient recovery, focusing on frontier technological advances and economic and environmental innovation perspectives. The potentials and limitations of different technologies are discussed, covering systems based on membranes, photosynthesis, crystallization and other physical and biological nutrient recovery systems (e.g. incineration, composting, stripping and absorption and enhanced biological phosphorus recovery).Robles Martínez, Á.; Aguado García, D.; Barat, R.; Borrás Falomir, L.; Bouzas Blanco, A.; Bautista-Giménez, J.; Martí Ortega, N.... (2020). New frontiers from removal to recycling of nitrogen and phosphorus from wastewater in the Circular Economy. Bioresource Technology. 300:1-18. https://doi.org/10.1016/j.biortech.2019.122673S11830
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