Biomimetic Design of Turbine Blades for Ocean Current Power Generation

The enhancement of energy technology and innovation play a crucial role in order to meet the challenges related to global warming in the coming decades. Inspired by bird wings, the performance of a bio-inspired blade assembled to a marine turbine model, is examined. Following a biomimetic pathway, the aerodynamic performance of the bird wings of the species Common Guillemot (Uria aalge) was tested in a wind tunnel laboratory. Based on our results, we derived a bio-inspired blade model by following a laser scanning method. Lastly, the bio-inspired blades were assembled to a marine turbine model and tested in a large flow tank facility. We found efficiencies (Cp) up to 0.3 which is around 53% of the maximum power that can be expected from the turbine model according to the Betz approach. Our findings are analyzed in the discussion section as well as considerations for future research

Determinación del Desbalance en Sistemas Rotor-cojinete a velocidad constante: Método de Identificación Algebraica

The development of a mathematical model for an on-line algebraic identifier is presented in this work. This model is used for determining the unbalance and its related angular position on vibrating rotor-dynamic systems of multiple degrees of freedom. The proposed identifier was obtained from the basis of a finite element mathematical model for rotating systems of multiple degrees of freedom. The model was developed under the consideration of four degrees of freedom beam-type element, where rotational inertia, gyroscopic moments, shearing strains and inner and outer damping effects were included. The on time behavior of proposed identifier was assessed for unbalance identification and its related angular position; the constant-speed unbalanced vibration response obtained from numerical simulation was used as input data

Experimental Study of the Dynamic Interaction Between the Foundation of the NEES/UCSD Shake Table and the Surrounding Soil

The results of an extensive experimental study of the dynamic interaction between the foundation block for the NEES/UCSD Large High Performance Outdoor Shake Table and the surrounding soil are presented. The vibrations induced by the two large NEES/UCLA eccentric mass shakers were recorded at multiple stations within the reinforced concrete foundation block and on the soil up to distances of 270 m from the block. The results obtained for the deformation pattern of the reaction block, the frequency response at selected stations on the block, and the average rigid-body motion of the foundation and its dependence on frequency for longitudinal (EW) excitation are presented in detail. Comparison of the response during shaker-induced vibrations with that resulting from the much stronger actuator forces shows that linearity holds for the range of forces involved. The attenuation of the ground motion away from the reaction block is also described

Active Temporal Multiplexing of Photons

Photonic qubits constitute a leading platform to disruptive quantum technologies due to their unique low-noise properties. The cost of the photonic approach is the non-deterministic nature of many of the processes, including single-photon generation, which arises from parametric sources and negligible interaction between photons. Active temporal multiplexing - repeating a generation process in time and rerouting to single modes using an optical switching network - is a promising approach to overcome this challenge and will likely be essential for large-scale applications with greatly reduced resource complexity and system sizes. Requirements include the precise synchronization of a system of low-loss switches, delay lines, fast photon detectors, and feed-forward. Here we demonstrate temporal multiplexing of 8 'bins' from a double-passed heralded photon source and observe an increase in the heralding and heralded photon rates. This system points the way to harnessing temporal multiplexing in quantum technologies, from single-photon sources to large-scale computation.Comment: Minor revision

Species‐specific effects of biocrust‐forming lichens on soil properties under simulated climate change are driven by functional traits

(1) Biocrusts are key drivers of ecosystem functioning in drylands, yet our understanding of how climate change will affect the chemistry of biocrust‐forming species and their impacts on carbon (C) and nitrogen (N) cycling is still very limited. (2) Using a manipulative experiment conducted with common biocrust‐forming lichens with distinct morphology and chemistry (Buellia zoharyi, Diploschistes diacapsis, Psora decipiens and Squamarina lentigera), we evaluated changes in lichen total and isotopic C and N and several soil C and N variables after 50 months of simulated warming and rainfall reduction. (3) Climate change treatments reduced δs13C and C:N ratio in B. zoharyi, and increased δ15N in S. lentigera. Lichens had species‐specific effects on soil dissolved organic N (DON), NH4+, β‐glucosidase and acid phosphatase activity regardless of climate change treatments, while these treatments changed how lichens affected several soil properties regardless of biocrust species. Changes in thallus δ13C, N and C:N drove species‐specific effects on DON, NH4+, β‐glucosidase and acid phosphatase activity. (4) Our findings indicate that warmer and drier conditions will alter the chemistry of biocrust‐forming lichens, affecting soil nutrient cycling, and emphasize their key role as modulators of climate change impacts in dryland soils.This research was funded by the European Research Council (ERC Grant Agreements 242658 [BIOCOM] and 647038 [BIODESERT] awarded to F.T.M), and by the Marie Skłodowska-Curie Actions (MSCA Grant Agreement 795380 [INDECRUST] awarded to L.C-Z.). E.V. was supported by the 2017 program for attracting and retaining talent of Comunidad de Madrid (no. 2017‐T2/ AMB‐5406). F.T.M. also acknowledges support from Generalitat Valenciana (CIDEGENT/2018/041)

El monte mediterráneo como paisaje cultural desde una perspectiva interdisciplinar

El paisaje actual de dehesas y encinares es valorado como una manifestación del patrimonio cultural a partir de las relaciones socieconómicas que se han establecido entre las comunidades humanas y estas formaciones vegetales en la Península Ibérica. Esta interacción es analizada en un marco cronológico de larga duración a partir de las aportaciones metodológicas de distintas disciplina

Diabetes in Panama: Epidemiology, Risk Factors, and Clinical Management

ObjectivesTo draw evidence-based conclusions about the epidemiology, drivers, and management of diabetes in Panama based on a literature review and original analyses of large databases.MethodsA search about diabetes in Panama was conducted through PubMed. We used the final reports of 2 studies: the first Survey of Health and Life Quality, 2007, and the first Survey of Risk Factors Associated to Cardiovasular Diseases, 2010-2011, conducted in Panama and analyzed the databases. We reviewed the approach adopted by the Panamanian Social Security institution and the diabetes national guidelines published by the Panamanian Ministry of Health.FindingsThe prevalence of diabetes, as estimated in 1 database (ENSCAVI), was 5.4% (4.3% men; 6.0% women; OR = 1.41 [confidence interval 1.26-1.59]; 'P' ConclusionsDiabetes is a serious national public health threat in Panama. To address this problem in a public health modality, information from large databases was analyzed and presented to the Panamanian Ministry of Health to prompt constructive policy change to enhance diabetes prevention

Visibility Assessment of New Photovoltaic Power Plants in Areas with Special Landscape Value

Power plants based on renewable sources offer environmental, technical and economic advantages. Of particular importance is the reduction in greenhouse gas emissions compared to conventional power plants. Despite the advantages, people are often opposed to the construction of these facilities due to their high visual impact, particularly if they are close to places with a great cultural and/or landscape value. This paper proposes a new methodology for identifying the most suitable geographical areas for the construction of new photovoltaic (PV) power plants in zones of special scenic or cultural interest, helping to keep the environment free from the visual intrusions caused by these facilities. From several repeated analyses, the degree of visibility of the new PV plant, the potential observation time of passing visitors, considering the route they follow and their speed, and the increase in visibility of the plants when seen totally or partially with the sky as background, are determined. The result obtained is a map showing the ranking of the geographical areas based on a variable calculated in such analyses: the Global Accumulated Perception Time (GAPT). The application of this methodology can help the different agents involved in the decision-making process for the installation of new PV plant by providing them with an objective visibility criterion