Summer 2018 GCSE, AS and A level exams : a summary of our monitoring

Uruguay has a forest resource of 1 million ha plantation of fast-growing eucalyptus and pine. Short-fiber pulp is the country second export product in value, but there is also a significant production of plywood and graded kiln-dried timber from both species, used mainly for appearance applications. However, the value chain of the wood industry is not yet fully developed, particularly for pine. This study classified different existing and potential wood products using added value as criteria, calculated at the industry level by adopting a system of inputs and outputs. Hypothetical plants to manufacture these products were technical and economically analyzed: thermally modified timber, cross laminated timber, laminated veneer lumber, pine timber, bleached Eucalyptus kraft pulp, pine bleached chemical thermo-mechanical, medium density fiberboards, oriented strand board and a power plant fueled with forest biomass. The data used for this study was obtained from the final project of undergraduate engineer students of the Faculty of Engineering, Universidad de la República, Uruguay, except for the eucalyptus pulp mill, which was proposed by the authors. The results showed that wood products obtained from logs that are the main objective of the plantation presented a higher added value than those manufactured from forest residues, thinnings or chips from the sawmilling industry. Solid wood products for appearance or structural applications are at the top of added value list, considering value added per product, unit of biomass or unit of forest land per year. The integration of the value chain of the products analyzed, linking solid wood products with panels or pulp, has the potential to boost the addition of value of the forest biomass in Uruguay

Eucalyptus Kraft Lignin as an Additive Strongly Enhances the Mechanical Resistance of Tree-Leaf Pellets

Pelleted biomass has a low, uniform moisture content and can be handled and stored cheaply and safely. Pellets can be made of industrial waste, food waste, agricultural residues, energy crops, and virgin lumber. Despite their many desirable attributes, they cannot compete with fossil fuel sources because the process of densifying the biomass and the price of the raw materials make pellet production costly. Leaves collected from street sweeping are generally discarded in landfills, but they can potentially be valorized as a biofuel if they are pelleted. However, the lignin content in leaves is not high enough to ensure the physical stability of the pellets, so they break easily during storage and transportation. In this study, the use of eucalyptus kraft lignin as an additive in tree-leaf pellet production was studied. Results showed that when 2% lignin is added the abrasion resistance can be increased to an acceptable value. Pellets with added lignin fulfilled all requirements of European standards for certification except for ash content. However, as the raw material has no cost, this method can add value or contribute to financing continued sweeping and is an example of a circular economy scenario

Evaluation of the influence of visual parameters on wave transmission velocity in sawn chestnut timber

Non-destructive, visual evaluation and mechanical testing techniques were used to assess the structural properties of 374 samples of chestnut (Castanea sativa). The principal components method was applied to establish and interpret correlations between variables obtained of modulus of elasticity, bending strength and density. The static modulus of elasticity presented higher correlation values than those obtained using non-destructive methods. Bending strength presented low correlations with the non-destructive parameters, but there was some relation to the different knot ratios defined. The relationship was stronger with the most widely used ratio, CKDR. No significant correlations were observed between any of the variables and density

Evaluation of the vertical sky component without obstructions for daylighting in Burgos, Spain

Daylight availability knowledge is the first step for an energetic and visually e cient building and city design. It can be estimated with the Vertical Sky Component (VSC), which is defined as the ratio of the vertical di use illuminance over the unobstructed horizontal di use illuminance, simultaneously measured at the same point. These illuminance magnitudes are obtained from luxmeter measurements but these data are scarce. Alternatively, VSC can be obtained from prior knowledge of the sky illuminance distribution, which can be measured with a sky scanner device or by reference to the CIE (Commission Internationale de L’Éclairage) Standard classification for homogeneous skies. Both approaches are compared in this study. The coherence of the results obtained for the four cardinal orientations are analyzed by applying classical statistical parameters and luxmeter measurements as references for the results. The measurement campaign was completed between September 2016 and January 2019 in Burgos (Spain), as representative case study and specific contribution of this work. It was observed that the VSC values were higher than 100 in many cases: 21.94% for the south- and 33.6% for the east-facing vertical surfaces. The study highlights the good daylighting conditions in Burgos, mainly due to the predominance of clear skies over much of the year. This fact implies high daylight availability that, with e cient city planning and building design, could potentially lead reduction energy consumption of buildings, improvements in visual comfort, and the well-being of occupants.Regional Government of Castilla y León under the “Support Program for Recognized Research Groups of Public Universities of Castilla y León” (ORDEN EDU/667/2019) and the Spanish Ministry of Science, Innovation & Universities under the I+D+i state program “Challenges Research Projects” (Ref. RTI2018-098900-B-I00). Diego Granados López also thankfully acknowledges the economic support from the Junta de Castilla-León (ORDEN EDU/556/2019

The effect of wood species on the anti-skid resistance of coatings

The anti-skid resistance of six coatings (Alfa, Beta, Gamma, Lambda, Mu and Theta) designed for outdoor wood flooring were tested in chestnut (Castanea sativa Mill.) and pine (Pinus pinaster Ait.) using a Portable Skid Resistance Tester according to standard ENV 12633. Film thickness, coating retention level, and presence of mineral particles were determined for each coating. Furthermore, the liquid water absorption coefficient of chestnut was determined in accordance with standard UNE-EN 1609, to relate all parameters.The highest value of skid resistance in both chestnut and pine was obtained with coating Mu (49.75) and coating Gamma (53.16), respectively. Film thickness and coating retention level were consistently higher for pine than for chestnut. Gamma presented the highest presence of minerals. For chestnut the absorption coefficient of liquid water in the tangential direction was 0.0056 ± 0.0010 kg·m-2·s-0.5, considerably lower than the value found for pine: 0.011 kg·m-2·s-0.5. The different performance of the system wood-coating, and consequently the anti-skid resistance, was attributed to the absorption properties of the different species

Matching microscopic and macroscopic responses in glasses

Primero reproducimos en las computadoras Janus y Janus II un experimento importante que mide la longitud de la coherencia de los hilados de vidrio a través de la reducción de las barreras de energía libre inducidas por el efecto Zeeman. En segundo lugar, determinamos el comportamiento de escala que permite un análisis cuantitativo de un nuevo experimento informado en la Carta complementaria [S. Guchhait y R. Orbach, Phys. Rev. Lett. 118, 157203 (2017)]. El valor de la longitud de coherencia estimada a través del análisis de las funciones de correlación microscópicas resulta ser cuantitativamente consistente con su medición a través de las funciones de respuesta macroscópica. Además, las susceptibilidades no lineales, recientemente medidas en líquidos formadores de vidrio, se escalan como potencias de la misma longitud microscópica.We first reproduce on the Janus and Janus II computers a milestone experiment that measures the spin glass coherence length through the lowering of free-energy barriers induced by the Zeeman effect. Secondly, we determine the scaling behavior that allows a quantitative analysis of a new experiment reported in the companion Letter [S. Guchhait and R. Orbach, Phys. Rev. Lett. 118, 157203 (2017)]. The value of the coherence length estimated through the analysis of microscopic correlation functions turns out to be quantitatively consistent with its measurement through macroscopic response functions. Further, nonlinear susceptibilities, recently measured in glass-forming liquids, scale as powers of the same microscopic length.• European Research Council. Beca No. NPRGGLASS. Ayuda para Marco Baity Jesi • Unión Europea. Marie Skłodowska- Curie. Beca No. 654971 • Consejo Europeo de Investigación (ERC). Subvención 694925 • University of Syracuse. Beca No. NSF-DMR-305184, para David Yllanes Mosquera • Ministerio de Economía y Competitividad. No. FIS2012-35719-C02, No. FIS2013-42840-P (I+D+i), No. FIS2015-65078-C2, No. FIS2016-76359-P (I+D+i), y No. TEC2016-78358-R • Junta de Extremadura y Fondos FEDER. Contrato parcial GRU10158 • Dipùtación General de Aragón y Fondos Social Europeo. AyudapeerReviewe

Infequus: plataforma de enfermedades infecciosas equinas

Desarrollo de la herramienta de formación online Infequus, que ofrecerá a los alumnos y profesionales información actualizada sobre el diagnóstico y control de las enfermedades infecciosas en la especie equina

Colour development in Pinus radiata D. Don. under kiln-drying conditions.

This study quantifies discolouration on the surface of Pinus radiata boards during kiln drying, particularly kiln brown stain (KBS), and models it as a function of chemical compounds present in the wood closest to the surface. The discolouration was investigated with two experimental factors: drying time, which consisted in drying at 70/120 ℃ for 0, 8, 16 and 24 hours; and leaching, done at three levels, noleaching, mild and severe, to reduce the soluble compounds present in wood suspected of developing coloured compounds. The colour change was quantified using a reflectance photometer (colour system CIE Yxy, brightness) and by the analysis of digital photographs (colour system CIE Lab). The chemical analysis of the wood closest to the surface of the boards determined fructose, glucose, sucrose (HPLC), total sugar (sum of fructose, glucose and sucrose), total nitrogen (combustion gas analysis), and phenols discriminated by molecular weight (Folin-Ciocalteu method). In the cause-effect analysis, colour was the dependent variable, and drying time and the determinations of chemical compounds were independent variables. After statistical analysis (ANOVA and MANOVA) the dependent variables to be included in the models were luminance factor (Y), brightness (R457 and the blue-to-yellow scale of CIE Lab (b); and the independent variables were drying time, nitrogen, total sugar, and high-molecular-weight phenols. Linear (multivariate regression) and non-linear models (Neural Networks) showed that discolouration during kiln drying was best predicted when the luminance factor (Y) was used to quantify colour change as a function of the content of nitrogen-containing compounds and drying time. Furthermore, the data were fitted into an empirical model based on simple reaction kinetics that considered the rate of discolouration as a function of nitrogen concentration. The results suggest that nitrogen could act as a limiting reactant in Maillard-type reactions that produce colour during kiln drying

Evaluation of the vertical sky component without obstructions for daylighting in Burgos, Spain

Daylight availability knowledge is the first step for an energetic and visually efficient building and city design. It can be estimated with the Vertical Sky Component (VSC), which is defined as the ratio of the vertical diffuse illuminance over the unobstructed horizontal diffuse illuminance, simultaneously measured at the same point. These illuminance magnitudes are obtained from luxmeter measurements but these data are scarce. Alternatively, VSC can be obtained from prior knowledge of the sky illuminance distribution, which can be measured with a sky scanner device or by reference to the CIE (Commission Internationale de L’Éclairage) Standard classification for homogeneous skies. Both approaches are compared in this study. The coherence of the results obtained for the four cardinal orientations are analyzed by applying classical statistical parameters and luxmeter measurements as references for the results. The measurement campaign was completed between September 2016 and January 2019 in Burgos (Spain), as representative case study and specific contribution of this work. It was observed that the VSC values were higher than 100 in many cases: 21.94% for the south- and 33.6% for the east-facing vertical surfaces. The study highlights the good daylighting conditions in Burgos, mainly due to the predominance of clear skies over much of the year. This fact implies high daylight availability that, with efficient city planning and building design, could potentially lead reduction energy consumption of buildings, improvements in visual comfort, and the well-being of occupants.Junta de Castilla y León | Ref. EDU / 667/2019Ministerio de Ciencia, Innovación y Universidades | Ref. RTI2018-098900-B-I00Junta de Castilla y León | Ref. EDU / 556/201

The effect of wood species on the anti-skid resistance of coatings

The anti-skid resistance of six coatings (Alfa, Beta, Gamma, Lambda, Mu and Theta) designed for outdoor wood flooring were tested in chestnut (Castanea sativa Mill.) and pine (Pinus pinasterAit.) using a Portable Skid Resistance Tester according to standard ENV 12633. Film thickness, coating retention level, and presence of mineral particles were determined for each coating. Furthermore, the liquid water absorption coefficient of chestnut was determined in accordance with standard UNE-EN 1609, to relate all parameters. The highest value of skid resistance in both chestnut and pine was obtained with coating Mu (49.75) and coating Gamma (53.16), respectively. Film thickness and coating retention level were consistently higher for pine than for chestnut. Gamma presented the highest presence of minerals. For chestnut the absorption coefficient of liquid water in the tangential direction was 0.0056 ± 0.0010 kg·m-2·s-0.5, considerably lower than the value found for pine: 0.011 kg·m-2·s-0.5. The different performance of the system wood-coating, and consequently the anti-skid resistance, was attributed to the absorption properties of the different species