6,200 research outputs found
Revealing unbound β-diketiminate anions: structural dynamics from caesium complexes
This study reports the first structural elucidation of β-diketiminate anions (BDI−), known for strong coordination, in their unbound form within caesium complexes. β-Diketiminate caesium salts (BDICs) were synthesised, and upon the addition of Lewis donor ligands, free BDI− anions and donor-solvated Cs+ cations were observed. Notably, the liberated BDI− anions exhibited an unprecedented dynamic cisoid–transoid exchange in solution.The authors acknowledge financial support from the Spanish Ministry of Science and Innovation (PID2019-108292RA-I00,
EUR2020-112189), FEDER, the Andalusian Government (P20-00373), the University of Huelva (UHU-202043), and the
Spanish Research State Agency AEI for a Ramón y Cajal Research Contract (RYC-2017-21783). We thank Prof. F. J. Blas for his valuable assistance with the computational studies. Funding for open access charge: Universidad de Huelva/CBUA
Prediction of wake effects on wind farm power production using a RANS approach. Part II. Offshore: Case studies from the UPWIND project
The estimation of power losses due to wind turbine wakes is crucial to understanding overall wind farm economics. This is especially true for large offshore wind farms, as it represents the primary source of losses in available power, given the regular arrangement of rotors, their generally largerdiameter and the lower ambient turbulence level, all of which conspire to dramatically affect wake expansion and, consequently, the power deficit. Simulation of wake effects in offshore wind farms (in reasonable computational time) is currently feasible using CFD tools. An elliptic CFD model basedon the actuator disk method and various RANS turbulence closure schemes is tested and validated using power ratios extracted from Horns Rev and Nysted wind farms, collected as part of the EU-funded UPWIND project. The primary focus of the present work is on turbulence modeling, as turbulent
mixing is the main mechanism for flow recovery inside wind farms. A higher-order approach, based on the anisotropic RSM model, is tested to better take into account the imbalance in the length scales inside and outside of the wake, not well reproduced by current two-equation closure schemes
El problema del coste en la industria hotelera: el servicio de alojamiento
La innegable importancia del sector turÃstico en nuestro paÃs reclama, en nuestra opinión, un riguroso
estudio de los diversos componentes que configuran su oferta final, dentro de la que, sin ningún género de duda,
ocupa una importancia destacada la industria hotelera. Ello otorga especial relevancia a todo intento de
definición y cálculo de los costes que inciden en la misma, y en particular los servicios de restauración y
alojamiento, del último de los cuales nos ocupamos en el presente trabajo.We think that the great importance of tourism bussiness in our country makes necessary the elaboration of
a deep study about the different factors that shape the completed offer in the sector. The products dealing with
accommodations are undoubtedly an important part within this offer. It involves a special meaning for any
attempt to define this sort of products and to calculate the costs that affect them. These last aspects we treat in
the present piece of work
Reversible Encapsulation of Xenon and CH2Cl2 in a Solid-State Molecular Organometallic Framework (Guest@SMOM)
Reversible encapsulation of CH2Cl2 or Xe in a non-porous solid-state molecular organometallic framework of [Rh(Cy2PCH2PCy2)(NBD)][BArF4] occurs in single-crystal to single-crystal transformations. These processes are probed by solid-state NMR spectroscopy, including 129Xe SSNMR. Non-covalent interactions with the -CF3 groups, and hydrophobic channels formed, of [BArF4]− anions are shown to be important, and thus have similarity to the transport of substrates and products to and from the active site in metalloenzymes
Is Gastronomy A Relevant Factor for Sustainable Tourism? An Empirical Analysis of Spain Country Brand
Tourism has become a fundamental industry for the economic growth of many countries. Due to this, there is growing competitiveness among the different destinations to attract as many tourists as possible. As a result, disciplines such as marketing have developed tools to differentiate some destinations from others and concepts such as place branding and country brand have emerged. One of the key factors forming the country brand is gastronomy, as food tourism is one way to reduce
the growing problem of sustainability in tourism, as it impacts different aspects of the country’s environment. However, there is a great lack of scientific works that relate both variables. In this paper, we propose to establish that, in the case of Spain, tourists’ perception of Spanish gastronomy is a key element of its country brand. To do that, this study relies on the use of Partial Least Squares Structural Equations Modeling (PLS-SEM) using a 496 cases data set
El concepto de energÃa en los libros de textos : de las concepciones previas a la propuesta de un nuevo sublenguaje
In this work are studied the already existing interpretations and conceptions on the concept of energy and other allied concepts in Basic Physics textbooks commonly used in the initial courses at university and in courses prior to university level (Basic School) being given in Venezuela. In this study we have used techniques of analysis of content and have made a historic analysis to round up the conclusions of the work. It becomes necessary to build a new language, simple but internally coherent, and within the current scientific paradigms. In this work we start the discussion of this new language within the area of energy and related concepts
Intracrine prostaglandin E2pro-tumoral actions in prostateepithelial cells originate from non-canonical pathways
Prostaglandin E2(PGE2) increases cell proliferation and stimulates migratory andangiogenic abilities in prostate cancer cells. However, the effects of PGE2on non-transformed prostate epithelial cells are unknown, despite the fact that PGE2overproduction has been found in benign hyperplastic prostates. In the present workwe studied the effects of PGE2in immortalized, non-malignant prostate epithelialRWPE-1 cells and found that PGE2increased cell proliferation, cell migration, andproductionofvascularendothelialgrowthfactor-A,andactivatedinvitroangiogenesis.These actions involved a non-canonic intracrine mechanism in which the actualeffector was intracellular PGE2(iPGE2) instead of extracellular PGE2: inhibition of theprostaglandin uptake transporter (PGT) or antagonism of EP receptors prevented theeffects of PGE2, which indicated that PGE2activity depended on its carrier-mediatedtranslocation from the outside to the inside of cells and that EP receptors locatedintracellularly (iEP) mediated the effects of PGE2. iPGE2acted through transactivationof epidermal growth factor-receptor (EGFR) by iEP, leading to increased expressionand activityofhypoxia-induciblefactor-1α(HIF-1α).Interestingly,iPGE2alsomediatesthe effects of PGE2on prostate cancer PC3 cells through the axis iPGE2-iEP receptors-EGFR-HIF-1α. Thus, this axis might be responsible for the growth-stimulating effectsof PGE2on prostate epithelial cells, thereby contributing to prostate proliferativediseasesassociatedwithchronicinflammation.SincethisPGT-dependentnon-canonicintracrine mechanism of PGE2action operates in both benign and malignant prostateepithelial cells, PGT inhibitors should be tested as a novel therapeutic modality to treatprostate proliferative diseaseThis work was supported by grants SAF2011-26838 from the SpanishMinisterio de Ciencia e Innovació
Highly luminescent perovskite–aluminum oxide composites
In this communication we report on the preparation of CH3NH3PbBr3 perovskite/Al2O3 nanoparticle composites in a thin film configuration and demonstrate their high photoluminescence quantum yield. The composite material is solution-processed at low temperature, using stable alumina nanoparticle dispersions. There is a large influence of the alumina nanoparticle concentration on the perovskite morphology and on its photoluminescence
Minimization of measuring points for the electric field exposure map generation in indoor environments by means of Kriging interpolation and selective sampling
In a world with increasing systems accessing to radio spectrum, the concern for exposure to electromagnetic fields is growing and therefore it is necessary to check limits in those areas where electromagnetic sources are working. Therefore, radio and exposure maps are continuously being generated, mainly in outdoor areas, by using many interpolation techniques. In this work, Surfer software and Kriging interpolation have been used for the first time to generate an indoor exposure map. A regular measuring mesh has been generated. Elimination of Less Significant Points (ELSP) and Geometrical Elimination of Neighbors (GEN) strategies to reduce the measuring points have been presented and evaluated. Both strategies have been compared to the map generated with all the measurements by calculating the root mean square and mean absolute errors. Results indicate that ELSP method can reduce up to 70% of the mesh measuring points while producing similar exposure maps to the one generated with all the measuring points. GEN, however, produces distorted maps and much higher error indicators even for 50% of eliminated measuring points. As a conclusion, a procedure for reducing the measuring points to generate radio and exposure maps is proposed based on the ELSP method and the Kriging interpolation.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors
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