Wind-driven SWRO desalination prototype with and without batteries: A performance simulation using machine learning models

In this paper, two studies are carried out related to the performance simulation and analysis of a wind-powered seawater reverse osmosis (SWRO) desalination plant prototype installed on the island of Gran Canaria (Spain). Three machine learning techniques (artificial neural networks, support vector machines and random forests) were implemented to predict the performance (pressure, feed flow rate and permeate flow rate, and permeate conductivity) of the SWRO desalination plant. Subsequently, plant operation was analysed in two different operating modes: a) constant pressure and flow rate through connection with a wind-battery microgrid, b) variable pressure and flow rate as a function of the power supplied by a stand-alone wind microgrid without energy storage. The paper supports two main outcomes. First, support vector machines and random forests are significantly (5% significance level) better predictors of the plant's performances than neural networks. Second, over one year, the operating mode that considers variable pressure and flow rate operates more continuously (higher operating frequencies and lower stop/start frequencies) than the constant pressure and flow rate alternative; however 1.2 times less permeate with 1.08 higher conductivity is produced on an annual basis

Influence of pile radius on the pile head kinematic bending strains of end-bearing pile groups

An analytical solution is developed for the kinematic response of a group of end-bearing fixed-head cylindrical vertical piles embedded in a homogeneous elastic stratum subjected to vertically-propagating harmonic shear waves. Pile-soil interaction, incorporating group effects in a pile group, is represented through a simplified beam-on-dynamic-Winkler-foundation (BDWF) model with realistic frequency-dependent springs and dashpots. Expressions for interaction factors and curvature ratios atop the foundation are presented considering different boundary conditions at the tip of the piles. To investigate the fundamental characteristics of kinematic bending in end-bearing pile groups when kinematic interaction dominates, kinematic bending strains at the head of each pile are expressed in terms of the slenderness ratio. The methodology is verified by comparison against results of a coupled finite element-boundary element (FE-BE) model. Obtained results indicate that kinematic bending strains of end-bearing single piles and piles in a group follow the same trend, with values being almost coincident in the case of slender piles. In addition, boundary conditions at the pile tip markedly affect the kinematic bending at the pile head

Supplementation of arachidonic acid rich oil in European sea bass juveniles (Dicentrarchus labrax) diets: effects on growth performance, tissue fatty acid profile and lipid metabolism

The aim of this study was to evaluate the effects of increasing dietary arachidonic acid (ARA) levels (from 1 to 6% of total fatty acids) on European sea bass (Dicentrarchus labrax) juveniles’ growth performance, tissue fatty acid profile, liver morphology as well as long-chain polyunsaturated fatty acids (LC-PUFA) biosynthesis, triglyceride and cholesterol synthesis and lipid transport. A diet with total fish oil (FO) replacement and defatted fish meal (FM) containing a 0.1-g ARA g −1 diet was added to the experimental design as a negative control diet. Dietary ARA inclusion levels below 0.2 g ARA g −1 diet significantly worsened growth even only 30 days after the start of the feeding trial, whereas dietary ARA had no effect on fish survival. Liver, muscle and whole body fatty acid profile mainly reflected dietary contents and ARA content increased accordingly with ARA dietary levels. Tissue eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) levels were positively correlated among them. Hepatic lipid vacuolization increased with reduced dietary ARA levels. Expressions of fatty acyl desaturase 2 and 3-hydroxy-3-methylglutaryl-coenzyme genes were upregulated in fish fed the negative control diet compared to the rest of the dietary treatments denoting the influence of ARA on lipid metabolism. Results obtained highlight the need to include adequate n-6 levels and not only n-3 LC-PUFA levels in European sea bass diets

Earnings informativeness and institutional investors on boards

We study the role of directors appointed by banks and those appointed by investment funds in the informativeness of accounting earnings in a low investor protection environment with a high presence of institutional directors. Results suggest that the monitoring role of directors appointed by banks and funds improves investor protection and increases market confidence in accounting information. The paper has interesting academic and policy implications for the debate on the proper degree of institutional involvement in corporate governance, noting that when analyzing the role of institutional investors, researchers must take into account investors' participation in other mechanisms of corporate control such as the board of directors. We contribute to the literature by showing that, in a weak regulatory and low investor protection environment, one of the ways in which institutional investors play a monitoring role is through influencing earnings quality when they are both shareholders and board members.Estudiamos el papel de los consejeros que representan a las entidades bancarias y los fondos de inversión en la capacidad informativa de los resultados contables en un entorno con una baja protección de los inversores y con una alta presencia de consejeros institucionales. Los resultados sugieren que el control ejercido por los consejeros que representan los intereses de las entidades bancarias y de los fondos de inversión mejora la protección de los inversores e incrementa la credibilidad de la información contable divulgada. El artículo posee interesantes implicaciones políticas y académicas en el contexto del debate relativo al nivel de implicación de los inversores institucionales en el gobierno corporativo, apuntando la necesidad de que los investigadores tomen en consideración el papel de los inversores institucionales en otros mecanismos de control corporativo, como es el consejo de administración. Contribuimos a la bibliografía mostrando que, en un entorno de débil protección de los accionistas, una de las formas a través de las cuales los inversores institucionales desempeñan un papel de control es mediante su influencia en la calidad de la información contable cuando son, al mismo tiempo, consejeros y accionistas de la empresa

Textural and isotopic evidence for Ca-Mg carbonate pedogenesis

Models for evaluating the terrestrial carbon cycle must take into account not only soil organic carbon, represented by a mixture of plant and animal remains, but also soil inorganic carbon, contained in minerals, mainly in calcite and dolomite. Thick soil caliches derived from weathering of mafic and ultramafic rocks must be considered as sinks for carbon storage in soils. The formation of calcite and dolomite from pedogenic alteration of volcanic tephras under an aridic moisture regime is studied in an unusually thick 3-m soil profile on Gran Canaria island (Canary Islands, Spain). The biological activity of the pedogenic environment (soil respiration) releases CO 2 incorporated as dissolved inorganic carbon (DIC) in waters. It drives the formation of low-magnesian calcite and calcian dolomite over basaltic substrates, with a δ 13 C negative signature (−8 to −6‰ vs. V-PDB). Precipitation of authigenic carbonates in the soil is accompanied by the formation of Mg-rich clay minerals and quartz after the weathering of basalts. Mineralogical, textural, compositional, and isotopic variations throughout the soil profile studied indicate that dolomite formed at greater depths and earlier than the calcite. The isotopic signatures of the surficial calcite and deeper dolomite crusts are primary and resulted from the dissolution-precipitation cycles that led to the formation of both types of caliches under different physicochemical conditions. Dolomite formed within a clay-rich matrix through diffusive transport of reactants. It is precipitated from water with more negative δ 18 O values (−1.5 to −3.5‰ vs. V-SMOW) in the subsoil compared to those of water in equilibrium with surficial calcite. Thus, calcite precipitated after dolomite, and directly from percolating solutions in equilibrium with vadose water enriched in δ 18 O (−0.5 to +1.5‰) due to the evaporation processes. The accumulation of inorganic carbon reaches 586.1 kg m −2 in the soil studied, which means that the carbon sequestration capacity of mafic rocks must be taken into account for certain terrestrial settings. Dolomite together with calcite should be assessed when quantifying carbon stored in arid-semiarid soils as a result of the natural weathering processes

Effect of increasing docosahexaenoic acid content in weaning diets on survival, growth and skeletal anomalies of longfin yellowtail (Seriola rivoliana, Valenciennes 1833)

Five isoproteic (54.8%) and isolipidic (24.1%) microdiets, which varied in their docosahexaenoic acid (DHA) content (0.25%, 0.75%, 1.64%, 1.99% and 3.17%; dw), were manufactured to determine its effects on longfin yellowtail Seriola rivoliana larvae in terms of fish biological performance, whole body fatty acid profile and incidence of skeletal anomalies from 30 dah (11.31 ± 1.79 Total Length, TL) to 50 dah (19.80 ± 0.58 mm TL). The inclusion of dietary DHA up to 3.17% (dw) improved larval resistance to air exposure, although DHA did not significantly affect fish final growth or final survival. Indeed, high levels of dietary DHA (1.99% and 3.17%, dw) tended to increase the incidence of skeletal anomalies in S. rivoliana larvae, albeit no significant differences were observed. Furthermore, the occurrence of severe anomalies such as kyphosis and lordosis, was mainly associated to the larvae fed the highest levels of dietary DHA. In terms of survival, increasing dietary DHA levels did not significantly affect longfin yellowtail survival rate, despite a tendency for enhanced survival. The results of the present study proved that the inclusion of dietary DHA in inert diets up to a 3.17% (dw) and a DHA/EPA ratio above 3.1 increased the final survival and stress resistance in S. rivoliana larvae

Autosomal recessive hypercholesterolemia in Spain

Background and aims Autosomal recessive hypercholesterolemia (ARH) is a very rare disease, caused by mutations in LDL protein receptor adaptor 1 (LDLRAP1). It is characterized by high levels of low-density lipoprotein cholesterol (LDL-C) and increased risk of premature cardiovascular disease. We aimed to characterize ARH in Spain. Methods Data were collected from the Dyslipidemia Registry of the Spanish Atherosclerosis Society. A literature search was performed up to June 2017, and all diagnostic genetic studies for familial hypercholesterolemia of Spain were reviewed. Results Seven patients with ARH were identified, 6 true homozygous and one compound heterozygous with a novel mutation: c.[863C > T];p.[Ser288Leu] . High genetic heterogeneity was found in this cohort. True homozygous subjects for LDLRAP1 have more severe phenotypes than the compound heterozygous patient, but similar to patients with homozygous familial hypercholesterolemia (HoFH). Cardiovascular disease was present in 14% of the ARH patients. LDL-C under treatment was above 185 mg/dl and the response to PCSK9 inhibitors was heterogeneous. Finally, the estimated prevalence in Spain is very low, with just 1 case per 6.5 million people. Conclusions ARH is a very rare disease in Spain, showing high genetic heterogeneity, similarly high LDL-C concentrations, but lower incidence of ASCVD than HoFH

Factorial experimental design of imazalil-containing wastewater to be treated by Fenton-based processes

Fenton-based processes have been studied for the mineralization and detoxification of wastewaters from the postharvest of fruit, which were contaminated with the fungicide imazalil (IMZ). For this purpose, studies were carried out in a simulated agro-industrial wastewater. Statistical design of experiments was used to assess the influence of IMZ, Fe(II) and H 2 O 2 concentration in the efficiency of the process. The most significant factor affecting the process was Fe(II). Higher mineralization was obtained with the photo-Fenton process when compared with the Fenton reaction. The optimized Fe(II) and H 2 O 2 for the mineralization of 50 mg L −1 IMZ were 21.5 and 127.5 mg L −1 , respectively. LC/MS/MS was used to identify the main products formed during the reaction and a degradation pathway was proposed. An operational cost of 2.06 €/m 3 was estimated for the treatment of 10 m 3 wastewater contaminated with IMZ

Successional convergence in experimentally disturbed intertidal communities

Determining the causes of variation in community assembly is a central question in ecology. Analysis of β-diversity can provide insight by relating the extent of regional to local variation in diversity, allowing inference of the relative importance of deterministic versus stochastic processes. We investigated the effects of disturbance timing on community assembly at three distinct regions with varying environmental conditions: Northern Portugal, Azores and Canaries. On the lower rocky intertidal, quadrats were experimentally cleared of biota at three distinct times of the year and community assembly followed for 1 year. Similar levels of α- and γ-diversity were found in all regions, which remained constant throughout succession. When Jaccard (incidence-based) and Bray–Curtis (abundance-based) metrics were used, β-diversity (the mean dissimilarity among plots cleared at the different times) was larger during early stages of community assembly but decreased over time. The adaptation of the Raup–Crick’s metric, which accounts for changes in species richness, showed that the structure of assemblages disturbed at different times of the year was similar to the null model of random community assembly during early stages of succession but became more similar than expected by chance. This pattern was observed in all regions despite differences in the regional species pool, suggesting that priority effects are likely weak and deterministic processes determine community structure despite stochasticity during early stages of community assembly

Global change impacts on large-scale biogeographic patterns of marine organisms on Atlantic oceanic islands

Past climate changes provide important clues for advancement of studies on current global change biology. We have tested large-scale biogeographic patterns through four marine groups from twelve Atlantic Ocean archipelagos and searched for patterns between species richness/endemism and littoral area, age, isolation, latitude and mean annual sea-surface temperatures. Species richness is strongly correlated with littoral area. Two reinforcing effects take place during glacial episodes: i) species richness is expected to decrease (in comparison with interglacial periods) due to the local disappearance of sandy/muddy-associated species; ii) because littoral area is minimal during glacial episodes, area per se induces a decrease on species richness (by extirpation/extinction of marine species) as well as affecting speciation rates. Maximum speciation rates are expected to occur during the interglacial periods, whereas immigration rates are expected to be higher at the LGM. Finally, sea-level changes are a paramount factor influencing marine biodiversity of animals and plants living on oceanic islands