Development of Head Space Sorptive Extraction Method for the Determination of Volatile Compounds in Beer and Comparison with Stir Bar Sorptive Extraction

A headspace sorptive extraction method coupled with gas chromatography-mass spectrometry (HSSE-GC-MS) was developed for the determination of 37 volatile compounds in beer. After optimization of the extraction conditions, the best conditions for the analysis were stirring at 1000 rpm for 180 min, using an 8-mL sample with 25% NaCl. The analytical method provided excellent linearity values (R-2 > 0.99) for the calibration of all the compounds studied, with the detection and quantification limits obtained being low enough for the determination of the compounds in the beers studied. When studying the repeatability of the method, it proved to be quite accurate, since RSD% values lower than 20% were obtained for all the compounds. On the other hand, the recovery study was successfully concluded, resulting in acceptable values for most of the compounds (80-120%). The optimised method was successfully applied to real beer samples of different types (ale, lager, stout and wheat). Finally, an analytical comparison of the optimised HSSE method, with a previously developed and validated stir bar sorptive extraction (SBSE) method was performed, obtaining similar concentration values by both methods for most compounds

Comparativa del rendimiento teórico máximo y estimado de una planta solar de generación directa de vapor

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: En el presente trabajo, se discute el límite teórico máximo de una planta solar de generación directa de vapor bajo la teoría de la termodinámica endorreversible y la termodinámica clásica, comparándolo con el rendimiento estimado en condiciones de operación. La planta solar emplea reflectores Fresnel para la generación directa de vapor con la finalidad de alimentar dos configuraciones de ciclo Rankine, con dos y tres extracciones de vapor respectivamente. Las presiones de las extracciones de vapor se determinaron estipulando una mínima generación de entropía en el ciclo con la finalidad de maximizar el rendimiento térmico. Como resultado de haber optimizado la generación de entropía, la planta analizada presenta un rendimiento térmico muy próximo al de la termodinámica endorreversible, por lo que puede establecerse que los ciclos Rankine discutidos estarán operando prácticamente a la máxima producción de potencia bajo los límites físicos del propio sistema.ABSTRACT: In the present work, the maximum theoretical limit of a direct steam generation solar plant is discussed under the theory of endoreversible thermodynamics and classical thermodynamics, comparing it with the estimated efficiency in operating conditions. The solar plant uses Fresnel reflectors for direct steam generation in order to feed two Rankine cycle configurations, with two and three steam extractions respectively. The pressures of the steam extractions were determined by stipulating a minimum generation of entropy in the cycle in order to maximize the thermal performance. As a result of optimizing the generation of entropy, the analyzed plant has a thermal efficiency very close to that of endoreversible thermodynamics, so it can be established that the Rankine cycles discussed will be operating at practically the maximum power output under the physical limits of the plant itself system.info:eu-repo/semantics/publishedVersio

Exploring wind direction and SO2 concentration by circular-linear density estimation

The study of environmental problems usually requires the description of variables with different nature and the assessment of relations between them. In this work, an algorithm for flexible estimation of the joint density for a circular-linear variable is proposed. The method is applied for exploring the relation between wind direction and SO2 concentration in a monitoring station close to a power plant located in Galicia (NW-Spain), in order to compare the effectiveness of precautionary measures for pollutants reduction in two different years.Comment: 17 pages, 7 figures, 2 table

Culture: Not just Burns – what about the poet Robert Fergusson?

No abstract available

Cold-water corals and deep-sea sponges by-catch mitigation: Dealing with groundfish survey data in the management of the northwest Atlantic Ocean high seas fisheries

The integration of survey data in the processes of the Regional Fisheries Management Organisations is a key step for conservation of deep-sea ecosystems and sustainable exploitation of deep-sea fisheries resources, including the mitigation of by-catch and discards of cold-water corals and deep-sea sponges, both considered by FAO as vulnerable marine ecosystems (VMEs) indicator species. Information on corals and sponges from annual bottom trawl groundfish surveys in areas beyond national jurisdictions has been integrated into the “ecosystem management cycle” of the Northwest Atlantic Fisheries Organization (NAFO). Survey data have improved our knowledge on VMEs identification, distribution and extent, and has led to the proposal and implementation of conservation and management measures. These data have particular relevance to delineate and refine the boundaries of areas closed to commercial bottom fishing (14 closures), in order to prevent significant adverse impacts on VMEs, according to the mandate of United Nations General Assembly Resolution 61/105. Considering the European groundfish surveys in the NAFO Regulatory Area (high seas) as a case study, the paper presents an overview of how invertebrate catch data have been integrated into the fisheries management process as a basis to the implementation of VMEs closed areas. Fishing closures are considered effective spatial management measures to avoid by-catch and discards of cold-water corals and deep-sea sponges in commercial bottom fishing, mitigating the adverse impacts on deep-sea ecosystemsVersión del editor1,86

A theoretical exercise of Marine Spatial Planning in the Flemish Cap and Flemish Pass (NAFO Divs. 3LM): implications for fisheries management in the high seas

A theoretical exercise of Maritime Spatial Planning (MSP) is currently being conducted within the Regulatory Area of the Northwest Atlantic Fisheries Organization (NAFO), using the MESMA framework to assess whether the existing science base is sufficient to support a potential spatially managed area. The case study is located in the high seas within the Flemish Cap – Flemish Pass area. It includes cold-water coral and deep-sea sponge vulnerable marine ecosystems (VMEs), bottom fishing closed areas, and different blue economy activities, such as high seas fisheries and offshore oil and gas. The paper summarizes the context setting for MSP, in a theoretical scenario to accommodate an emergent offshore hydrocarbon exploration and exploitation, minimizing impacts on VMEs and existing high seas fisheries. Biophysical and socio-economic components of the ecosystem are mapped, including the spatial overlapping between new and traditional uses of the marine space, focused on potential conflicts user-user (e.g. hydrocarbon industry and deep-sea fisheries) or userenvironment (e.g. hydrocarbon industry and VMEs) and considering transboundary conflicts (e.g. recent oil spills). Current and potential management measures are described. This is followed by a discussion on the role and challenges of MSP in Areas Beyond National Jurisdiction, as lessons learned from the present exercise. Finally, the future work is briefly outlined

Parámetros, correlaciones y tendencias genéticas de caracteres reproductivos en ganado Holstein de México

The objective was to calculate the parameters, correlations and describe the genetic trends of reproductive traits in Holstein cattle from Mexico in three different periods of time, in females born between 2006 and 2019, using records of the Mexican Holstein association. The reproductive parameters calculated were: calving to first insemination interval (CFI), number of services per conception (NSC), days open (DO), interval between calving (IBC), and age at first calving (AFC). The components of variance were estimated using restricted maximum likelihood in an animal model, to calculate genetic parameters (narrow-sense heritability (h2), repeatability (r) and genetic correlations) and phenotypic correlations. Additive genetic variances and genetic values were also estimated in three periods of time (P1: 2006-2009, P2: 2010-2013 and P3: 2014-2017). The calculated heritabilities were from 4 to 9 % and the repeatabilities from 8 to 9 %, values close to previous reports for fertility traits. Phenotypic correlations were positive for almost all reproductive parameters and genetic correlations were positive over a wide range (0.13-0.99). Analyses by period showed changes, possibly derived from the influence of the import and use of germplasm from foreign bulls (mainly from the United States of America and Canada) which implement genomic selection and include fertility traits. The present research has made it possible to update the information on reproductive and genetic parameters in fertility traits that can be incorporated into national genetic evaluations.El objetivo fue calcular los parámetros, correlaciones y describir las tendencias genéticas de caracteres reproductivos en ganado Holstein de México en tres periodos diferentes de tiempo, en hembras nacidas entre 2006 y 2019, usando registros de la asociación Holstein de México. Los parámetros reproductivos calculados fueron: intervalo parto a primer servicio (IPPS), el número de servicios por concepción (NSC), los días abiertos (DAB), el intervalo entre partos (IEP) y la edad al primer parto (EPP). Los componentes de la varianza fueron estimados utilizando máxima verosimilitud restringida en un modelo animal, para calcular parámetros genéticos (heredabilidad en sentido estricto (h2), repetibilidad (r) y correlaciones genéticas) y correlaciones fenotípicas. También se estimaron varianzas genéticas aditivas y valores genéticos en tres periodos de tiempo (P1: 2006-2009, P2: 2010-2013 y P3: 2014-2017). Las heredabilidades calculadas fueron de 4 a 9 % y las repetibilidades del 8 al 9 %, valores cercanos a reportes previos para características de fertilidad. Las correlaciones fenotípicas fueron positivas para casi todos los parámetros reproductivos y las genéticas fueron positivas en un rango amplio (0.13-0.99). Los análisis por periodos mostraron cambios, posiblemente derivados de la influencia de la importación y uso de germoplasma de toros extranjeros (principalmente de los Estados Unido de América y Canadá) que implementan selección genómica e incluyen características fertilidad. La presente investigación ha permitido actualizar la información de parámetros reproductivos y genéticos en caracteres de fertilidad que podrán ser incorporados a las evaluaciones genéticas nacionales

Antifungal ativity against Botryosphaeriaceae fungi of the hydro-methanolic extract of Silybum marianum capitula conjugated with stevioside

Silybum marianum (L.) Gaertn, viz. milk thistle, has been the focus of research efforts in the past few years, albeit almost exclusively restricted to the medicinal properties of its fruits (achenes). Given that other milk thistle plant organs and tissues have been scarcely investigated for the presence of bioactive compounds, in this study, we present a phytochemical analysis of the extracts of S. marianum capitula during the flowering phenological stage (stage 67). Gas chromatography–mass spectroscopy results evidenced the presence of high contents of coniferyl alcohol (47.4%), and secondarily of ferulic acid ester, opening a new valorization strategy of this plant based on the former high-added-value component. Moreover, the application of the hydro-methanolic extracts as an antifungal agent has been also explored. Specifically, their activity against three fungal species responsible for the so-called Botryosphaeria dieback of grapevine (Neofusicoccum parvum, Dothiorella viticola and Diplodia seriata) has been assayed both in vitro and in vivo. From the mycelial growth inhibition assays, the best results (EC90 values of 303, 366, and 355 μg·mL−1 for N. parvum, D. viticola, and D. seriata, respectively) were not obtained for the hydroalcoholic extract alone, but after its conjugation with stevioside, which resulted in a strong synergistic behavior. Greenhouse experiments confirmed the efficacy of the conjugated complexes, pointing to the potential of the combination of milk thistle extracts with stevioside as a promising plant protection product in organic Viticulture

Seabed litter distribution in the high seas of the Flemish Pass area (NW Atlantic)

Seabed litter of the Flemish Pass area (NW Atlantic Ocean) was analysed and described using data from the EU-Spain groundfish survey (2006-2017 period). This study presents baseline information on seabed litter in this area. The Flemish Pass is located in areas beyond national jurisdiction within the Northwest Atlantic Fisheries Organization Regulatory Area Division 3L. A total of 1169 valid bottom trawl hauls were analysed (104-1478 m depth). Litter was found in 8.3% of the hauls, with mean densities of 1.4±0.2 items km–2 and 10.6±5.2 kg km–2. An increasing pattern with depth was found, the highest densities of seabed litter being identified in the deepest areas located in the Flemish Pass channel and down the northeastern flank of the Grand Bank. Fishing was found to be the main source of marine litter, and 61.9% of the hauls with litter presence showed litter included in the fisheries-related litter category. Whereas in most cases the litter was composed of small fragments of rope, in other cases it was composed of entire fishing gears such as traps. Plastics, metal and other anthropogenic litter were the next most abundant categories, accounting for 18.6%, 16.5% and 12.4% of the total, respectively.Versión del editor1,00