285 research outputs found

    Mechanism of tribo-chemical reactions of ionic liquids on titanium alloys

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    In this paper, the tribological, the tribo-chemical reaction mechanisms and desorption properties of three ionic liquids (ILs), [Bu3MeP][ Tf2N], [Bu3MeN][ Tf2N] and [Bu3MeP][ (MeO)2PO2], in contact with titanium and under vacuum conditions are studied with the CATRI © UHV Tribometer developed by IK4-TEKNIKER [1]. The two ILs containing the bis(trifluoromethanesulfonyl)amide anion presented lower coefficient of friction compared to that having the dimethyl phosphate anion. The tribodesorption study revealed that it is required an induction period to decrease the friction coefficient. The end of this period is accelerated in the case of trifluoromethane ionic liquids by the CF3+ release. Hence, the CF3+ reacts with the titanium surface generating a titanium fluoride tribolayer that could act like a catalyst to generate the tribodesorption of ionic liquid cation fragments (CH3+, C2H5+, C3H7+, C4H9+). The XPS analysis confirmed the generation of a boundary film, comprising of sulfide and inorganic fluoride, and being possibly the responsible of decreasing the friction coefficient. The [Bu3MeP][MeO)2PO2] ionic liquid required a long induction period, it did not form any tribolayer and no reduction of friction coefficient, yielding instead a high abrasion and adhesion mechanism. Thus, it can be concluded that bis(trifluoromethanesulfonyl)amide anion is more effective than dimethylphosphate in generating a surface protective film on the titanium surface under the selected test conditions and the testing methodology seems to be useful to understand the tribodesorption mechanism.The partners would like to acknowledge the financing to the Austrian Government financing of COMET K2 Excellence Centre of Tribology called X-Tribology to carry out this research collaborative activity. The authors also would like to acknowledge the financing of the EMAITEK Programme by the Basque Country

    Evaluation HPDC Lubricant Spraying for Improved Cooling and Die Protection

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    This study tries to find out a better cooling and temperature homogenization as well as better die protection on high-pressure die-casting (HPDC) spray lubrication. Test procedures have been set up to study the Leidenfrost point (LFP), contact angle (CA), film thickness and protection from die soldering of lubricants typically applied into the die surfaces during HPDC process. Five different lubricants have been studied as well as the influence in different controllable process parameters (type of die material, oxidation of the surface, temperature, roughness, droplet diameter, water hardness and lubricant concentration). The increase of the LFP, avoiding film boiling regime, and a reduced CA, improve the cooling and film ability of die surface during spraying. The best chemistry exhibits high LFP, shows an increased thickness of the formed film and is more effective preventing the sticking of the aluminum part to the die surface. Thermogravimetric analysis shows better thermal properties for lubricants with anti-sticking performance. The study performed and the test protocols set up result in a better insight of the involved phenomena and allow selecting the most favorable operating window for HPDC lubrication

    NPG–TRIS Thermal Storage System. Quantification of the Limiting Processes: Sublimation and Water’s Adsorption

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    The NPG–TRIS binary system (NPG = (CH3)2C(CH2OH)2 = 2,2-dimetyl-1,3-propanodiol; TRIS = NH2C(CH2OH)3 = 2-Amino-2-(hydroxymethyl)-1,3-propanediol) was intensively investigated as a thermal energy storage system, due to the reversibility of its phase transitions and their associated energy. An adapted methodology was applied to precisely quantify its sublimation tendency. Relevant thermochemical data were revisited and evaluated using some specific experimental procedures. We also determined that the widely accepted requirement of working in an inert atmosphere to avoid deviations due to hygroscopicity is not necessary. Nevertheless, to take advantage of the energetic properties of the NPG–TRIS system, closed containers will be required to avoid NPG losses, due to its quantitatively determined high sublimation tendency.This study was financially supported by the Basque Government (IT1301-19, IT1364-19) and through the Elkartek18 R&D program, by the University of the Basque Country UPV/EHU (GIU19/019), and by the Ministry of Science and Innovation of Spain (PID2019-106644GB-I00

    Genomic prediction of grain yield in a barley MAGIC population modelling genotype per environment interaction

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    Multi-parent Advanced Generation Inter-crosses (MAGIC) lines have mosaic genomes that are generated shuffling the genetic material of the founder parents following predefined crossing schemes. In cereal crops, these experimental populations have been extensively used to investigate the genetic bases of several traits and dissect the genetic bases of epistasis. In plants, genomic prediction models are usually fitted using either diverse panels of mostly unrelated accessions or individuals of biparental families and several empirical analyses have been conducted to evaluate the predictive ability of models fitted to these populations using different traits. In this paper, we constructed, genotyped and evaluated a barley MAGIC population of 352 individuals developed with a diverse set of eight founder parents showing contrasting phenotypes for grain yield. We combined phenotypic and genotypic information of this MAGIC population to fit several genomic prediction models which were cross-validated to conduct empirical analyses aimed at examining the predictive ability of these models varying the sizes of training populations. Moreover, several methods to optimize the composition of the training population were also applied to this MAGIC population and cross-validated to estimate the resulting predictive ability. Finally, extensive phenotypic data generated in field trials organized across an ample range of water regimes and climatic conditions in the Mediterranean were used to fit and cross-validate multi-environment genomic prediction models including GE interaction, using both genomic best linear unbiased prediction and reproducing kernel Hilbert space along with a non-linear Gaussian Kernel. Overall, our empirical analyses showed that genomic prediction models trained with a limited number of MAGIC lines can be used to predict grain yield with values of predictive ability that vary from 0.25 to 0.60 and that beyond QTL mapping and analysis of epistatic effects, MAGIC population might be used to successfully fit genomic prediction models. We concluded that for grain yield, the single-environment genomic prediction models examined in this study are equivalent in terms of predictive ability while, in general, multi-environment models that explicitly split marker effects in main and environmentalspecific effects outperform simpler multi-environment models

    ClimBar : An Integrated Approach to Evaluate and Utilize Genetic Diversity

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    European agriculture anticipates an unprecedented combination of stress factors, production threats and quality needs due to climate change. Various regions of Europe will be affected differently. Barley & wheat domestication, and landrace formation in Europe, were under very different climates than those emerging now. Alleles needed for sustainable, resilient, quality yields in a changed climate are likely not combined in current haplotypes of elite barley cultivars. These alleles are likely found in diverse landraces and wild relatives in the Mediterranean basin and Fertile Crescent -- areas that prefigure expected climate change. New precision, high-throughput phenotyping tools are essential to find trait-allele associations needed for future-climate breeding. Combining genetics, genomics, modelling, molecular biology, morphology, and physiology, ClimBar takes an interdisciplinary approach to develop a strategy for breeding an increased resilience to climate change in barley. ClimBar, a new project under the framework of FACCE ERA-NET Plus Joint Programming Initiative on Climate Smart Agriculture, will identify genome regions, genes, and alleles conferring the traits needed to breed resilient barley varieties adapted to the climatic conditions predicted for 2070 in different European environments. Adapted, resilient germplasm created using ClimBar data, tools and models will provide food-chain security, economic stability and environmental sustainability. Website: http://plen.ku.dk/english/research/plant_soil/breeding/quality/climbar

    Aceites vegetales como fluidos hidráulicos en maquinaria agrícola

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    The formulation of environmentally friendly lubricants following the criterion of the European EcoLabel is expensive owing to the lack of technological development in this area. The present work deals with the development of lubricant formulations from vegetable oils, in particular using high oleic sunflower oil as base fluid. These new biolubricants have to perform as good as the reference lubricants used in the real application (an agricultural tractor) but with the additional condition and value of their biodegradability without toxicity. Formulation development has been performed by Verkol Lubricantes, involving the selection of the base oil and the design of the additive package. The investigation performed by Tekniker in the laboratory has covered different aspects, characterizing the most important physicochemical properties of the lubricants, including their behavior at low temperatures and their resistance to oxidation. The tribological properties of the new biolubricants have also been studied, analyzing their ability to protect the interacting surface from wear, as well as the level of friction generated during sliding. Moreover, the compatibility of the new formulated oil with all the seals present in the real application has been taken into consideration. The selected lubricant is now being tested in agricultural machinery from AGRIA.La formulación de lubricantes amigables con el medioambiente siguiendo los criterios Europeos de la EcoLabel resulta cara debido a la falta de desarrollo tecnológico en esta área. En el presente trabajo se han desarrollado formulaciones de lubricantes a partir de aceites de origen vegetal, en particular empleando como aceite base el GAO (Girasol de Alto Oleico). Estos nuevos lubricantes deben presentar un comportamiento tan bueno como el de los lubricantes de referencia empleados en la aplicación real (un tractor agrícola), pero con la condición y valor añadido de ser biodegradables y no tóxicos. Las formulaciones han sido desarrolladas por Verkol lubricantes, comenzando por la selección del aceite base hasta el diseño del paquete de aditivos. La investigación llevada a cabo por Tekniker en el laboratorio ha cubierto diferentes aspectos. Se han caracterizado las propiedades físico-químicas más importantes, incluyendo su comportamiento a bajas temperaturas y su resistencia a la oxidación. También se han estudiado las propiedades tribológicas de los nuevos biolubricantes, analizando su habilidad para proteger frente al desgaste las superficies interactuantes, así como el nivel de fricción generado durante el deslizamiento. Paralelamente, se ha considerado la compatibilidad de las nuevas formulaciones de aceite con todas las juntas presentes en la aplicación real. El lubricante seleccionado está siendo ensayado en un tractor agrícola de AGRIA

    Making sense of entertainment

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    This contribution explores the relationship of emotion and cognition in entertainment experience. Drawing on the reflective model of aesthetic experience (Cupchik, 1995) and the concept of appreciation (Oliver & Bartsch, 2010), we propose a multi-level view of affective processing that includes simple affect schemata as well as more elaborate forms of sociomoral reasoning that build on this basic layer of emotional meaning. To better understand how affective factors can stimulate or impede cognitive elaboration processes, we review research on motivated cognition that has dealt with the influence of arousal, valence, and personal relevance on cognitive depth. The role of affect in defensive information processing (i.e., the motivated neglect or denial of information) is also considered. Specifically, we discuss how research on motivated cognition can help explain thought-provoking entertainment experiences, and the potential of such experiences to stimulate self-reflection and personal growth

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