Biomimetic flow fields for proton exchange membrane fuel cells: A review of design trends

Bipolar Plate design is one of the most active research fields in Polymer Electrolyte Membrane Fuel Cells (PEMFCs) development. Bipolar Plates are key components for ensuring an appropriate water management within the cell, preventing flooding and enhancing the cell operation at high current densities. This work presents a literature review covering bipolar plate designs based on nature or biological structures such as fractals, leaves or lungs. Biological inspiration comes from the fact that fluid distribution systems found in plants and animals such as leaves, blood vessels, or lungs perform their functions (mostly the same functions that are required for bipolar plates) with a remarkable efficiency, after millions of years of natural evolution. Such biomimetic designs have been explored to date with success, but it is generally acknowledged that biomimetic designs have not yet achieved their full potential. Many biomimetic designs have been derived using computer simulation tools, in particular Computational Fluid Dynamics (CFD) so that the use of CFD is included in the review. A detailed review including performance benchmarking, time line evolution, challenges and proposals, as well as manufacturing issues is discussed.Ministerio de Ciencia, Innovación y Universidades ENE2017-91159-EXPMinisterio de Economía y Competitividad UNSE15-CE296

The energy-constrained quickest path problem

This paper addresses a variant of the quickest path problem in which each arc has an additional parameter associated to it representing the energy consumed during the transmission along the arc while each node is endowed with a limited power to transmit messages. The aim of the energy-constrained quickest path problem is to obtain a quickest path whose nodes are able to support the transmission of a message of a known size. After introducing the problem and proving the main theoretical results, a polynomial algorithm is proposed to solve the problem based on computing shortest paths in a sequence of subnetworks of the original network. In the second part of the paper, the bi-objective variant of this problem is considered in which the objectives are the transmission time and the total energy used. An exact algorithm is proposed to find a complete set of efficient paths. The computational experiments carried out show the performance of both algorithms

An exactly solvable model in P.R.M.: quantization. II

The quantization of a priori hamiltonian predictive systems is studied. It is applied to quantize the family of N-particle relativistic models presented in ref. 1. The relativistic two-particle oscillator is studied in detail and finally our results are compared with others that already appeared in the literature.On étudié la quantification de systèmes hamiltoniens pre-prédictifs a priori. Comme application, on quantifie la famille de modèles relativistes à N particules présentes dans la référence 1. On étudié en detail l’oscillateur relativiste a deux particules. Finalement on compare les résultats obtenus avec d’autres parus précédemment.Peer ReviewedPostprint (published version

On the incorporation of interval-valued fuzzy sets into the Bousi-Prolog system: declarative semantics, implementation and applications

In this paper we analyse the benefits of incorporating interval-valued fuzzy sets into the Bousi-Prolog system. A syntax, declarative semantics and im- plementation for this extension is presented and formalised. We show, by using potential applications, that fuzzy logic programming frameworks enhanced with them can correctly work together with lexical resources and ontologies in order to improve their capabilities for knowledge representation and reasoning

Effects of cooking over the stability of fatty acids as bioactive compounds in enriched pasta with a fish by-product

Background and objectives: Fusilli pasta enriched with sea bass concentrate (Dicentrarchus labrax) was developed with the aim of increasing its content in proteins and especially in polyunsaturated fatty acids (PUFA) like Omega-3. Pasta made from two types of cereals (wheat and spelt) and fish by-product with or without a natural antioxidant were cooking prior to consumption, and nutritional and physicochemical characteristics were evaluated. Findings: Enriched developed pasta showed high levels of protein, fat, and fiber, and the fatty acid profiles confirmed a substantial enrichment in bioactive compounds (omega-3 fatty acids). The cooking of pasta before consumption was able to reduce bacterial loads guaranteeing food safety and improving nutritional availability. Furthermore, an increase in the MUFA and PUFA content was revealed, which could represent an advantage to offer a better source of functional ingredients (EPA & DHA). Conclusions: The combination of heat from cooking with formulations containing antioxidants seems to offer a remarkable synergistic effect to preserve unsaturated fatty acids with desirable nutritional properties. Significance and novelty: Pasta enriched with bioactive compounds from fish by-product after cooking treatment before consumption appears to be an effectiveness option to improve healthy human nutrition

Estudio comparativo de las epidermis foliares de las licopodiaceas ibericas I. Estomas

Se realiza un estudio comparativo de los estomas, tanto de los esporofilos como de los trofofilos, de Huperzia selago (L.) Bernh ex Schrank & Mart., Lycopodium annotinum L.,Lycopodium clavatum L., Diphasiastrum alpinum (L.) Holub y Lycopodiella inundata (L.) Holub aportando datos sobre la localización de los estomas en la lámina foliar, su distribución y número.A comparative study of stomates was made, both in sporophylles and trophophylles of Huperzia selago (L.) Bernh ex Schrank & Mart.,Lycopodium annotinum L. ,Lycopodium clavatum L.,Diphasiastrum alpinum (L.) Holub and Lycopodiella inundata (L.) Holub, giving new data about the localization of stomates on the foliar lamina, their distribution and number

Prevalencia de insuficiencia renal «oculta» en población diabética tipo 2

ObjetivoDeterminar la prevalencia de insuficiencia renal en diabéticos tipo 2 y comparar dos criterios de definición: el basado en la estimación del filtrado glomerular por la fórmula de Cockcroft-Gault corregida para la superficie corporal y el basado en la creatinina sérica.DiseñoEstudio descriptivo y transversal.EmplazamientoZona básica del Centro de Salud de El Cristo, Oviedo.ParticipantesLa totalidad de pacientes diabéticos tipo 2 diagnosticados de la zona básica.Mediciones principalesSe recogieron datos demográficos, clínicos, factores de riesgo y enfermedad cardiovascular. Se diagnosticó insuficiencia renal (IR) según unas cifras de creatinina plasmática ≥ 1,3 mg/dl en mujeres y ≥ 1,4 mg/dl en varones y según el filtrado glomerular (FG) estimado mediante la fórmula de Cockcroft-Gault: moderada para FG, 60-30 ml/min/1,73 m2; grave para FG, 29-15 ml/min/1,73 m2, y terminal para FG, < 15 ml/min/1,73 m2.ResultadosSe incluyó a 499 pacientes. El 52,3% era mujer con una edad de 69,7 ± 0,4 años. La prevalencia de IR según la creatinina sérica fue del 12%, y según la fórmula de Cockcroft-Gault del 40,5%. Los pacientes con FG reducido y creatinina normal tenían mayor edad (75,5 ± 7,9 frente a 65,4 ± 9,8 años; p < 0,001), predominaban las mujeres (76,3 frente a 41,7%; p < 0,001), tenían un menor índice de masa corporal (27,3 ± 3,7 frente a 30,9 ± 4,4), presentaban un peor control glucémico (HbA1c 7,1 ± 1,8 frente a 6,9 ± 1,9%; p = 0,007) y la prevalencia de insuficiencia cardíaca era superior (6,4 frente a 2,1%; IC del 95%, 1,1-8,8; p = 0,02) en comparación con los pacientes con FG y creatinina normales.ConclusiónLa estimación del FG por la fórmula de Cockcroft-Gault corregida para la superficie corporal muestra una insuficiencia renal no conocida en uno de cada 3 pacientes diabéticos tipo 2.ObjectiveTo determine the prevalence of renal failure (RF) in type-2 diabetics and to compare two criteria of definition: that based on the calculation of glomerular filtration by the Cockcroft-Gault formula corrected for body surface area and that based on serous creatinine.DesignCross-sectional, descriptive study.SettingEl Cristo Health Centre,Oviedo, north of Spain.ParticipantsAll patients in the catchment area diagnosed with type-2 diabetes.MethodDemographic, clinical, risk factor, and cardiovascular pathology details were gathered. Renal failure was diagnosed on figures of plasma creatinine ≥1.3 mg/dL in women and ≥1.4 mg/dL in men, and glomerular filtration (GF) calculated by means of the Cockcroft-Gault formula: moderate GF, 60-30 mL/min/1.73 m2; severe GF, 29-15 mL/min/1.73 m2, and terminal GF: <15 mL/min/1.73 m2.Results499 patients were included. 52.3% were women, aged 69.7±10.4 years old. Prevalence of RF by serous creatinine was 12%; and by the Cockcroft-Gault formula, 40.5%. Patients with lower glomerular filtration and normal creatinine were older (75.5±7.9 vs 65.4±9.8; P<.001), mainly female (76.3% vs 41.7%; P<.001), had lower BMI (27.3±3.7 vs 30.9±4.4) and had worse glucaemia control (HbA1c 7.1±1.8% vs 6.9±1.9%; P=.007) and higher indices of cardiac failure (6.4% vs 2.1%; 95% CI, 1.1- 8.8; P=.02) than patients with normal glomerular filtration and creatinine.ConclusionCalculation of glomerular filtration by the Cockcroft-Gault formula corrected for body surface area revealed unknown renal failure in 1 in 3 type-2 diabetes patients