2,673 research outputs found

    Overview of ASDEX Upgrade results

    Get PDF
    The ASDEX Upgrade (AUG) programme is directed towards physics input to critical elements of the ITER design and the preparation of ITER operation, as well as addressing physics issues for a future DEMO design. Since 2015, AUG is equipped with a new pair of 3-strap ICRF antennas, which were designed for a reduction of tungsten release during ICRF operation. As predicted, a factor two reduction on the ICRF-induced W plasma content could be achieved by the reduction of the sheath voltage at the antenna limiters via the compensation of the image currents of the central and side straps in the antenna frame. There are two main operational scenario lines in AUG. Experiments with low collisionality, which comprise current drive, ELM mitigation/suppression and fast ion physics, are mainly done with freshly boronized walls to reduce the tungsten influx at these high edge temperature conditions. Full ELM suppression and non-inductive operation up to a plasma current of Ip = 0.8 MA could be obtained at low plasma density. Plasma exhaust is studied under conditions of high neutral divertor pressure and separatrix electron density, where a fresh boronization is not required. Substantial progress could be achieved for the understanding of the confinement degradation by strong D puffing and the improvement with nitrogen or carbon seeding. Inward/outward shifts of the electron density profile relative to the temperature profile effect the edge stability via the pressure profile changes and lead to improved/decreased pedestal performance. Seeding and D gas puffing are found to effect the core fueling via changes in a region of high density on the high field side (HFSHD). The integration of all above mentioned operational scenarios will be feasible and naturally obtained in a large device where the edge is more opaque for neutrals and higher plasma temperatures provide a lower collisionality. The combination of exhaust control with pellet fueling has been successfully demonstrated. High divertor enrichment values of nitrogen EN 10 have been obtained during pellet injection, which is a prerequisite for the simultaneous achievement of good core plasma purity and high divertor radiation levels. Impurity accumulation observed in the all-metal AUG device caused by the strong neoclassical inward transport of tungsten in the pedestal is expected to be relieved by the higher neoclassical temperature screening in larger devices.European Commission (EUROfusion 633053

    Experiences in teaching Hydrogen Technologies in the framework of the International Campus of Excellence Andalucia TECH

    Get PDF
    The increasing importance of hydrogen technologies is demanding prepared professionals in the numerous topics related to this energy vector. Apart from some basic and advanced courses given by actual experts in these topics, universities must play an important role in the general formation of future professionals. In this way, the International Campus of Excellence (ICE) Andalucía TECH has created several degrees taught jointly by its participating universities of Seville (US) and Málaga (UMA). Among those degrees, Energy Engineering is the best suited to the field of this conference because this degree provide future engineers with specialized training in energy generation, transformation and management. In relation to hydrogen technologies this degree includes a cross sectional optional unit named Hydrogen Based Systems (4.5 ECTS/112.5 h), which is placed in the last term of the fourth year and sharing space with work placement and mobility courses. This paper will present some author’s experiences as teachers of that unit during its short history of only three years. In spite of being a joint degree, which is coordinated between both universities (US and UMA) trying to give similar contents, it is interesting to highlight the differential experiences coming from the teachers of both universities in relation to the teaching methodologies and academic results.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Reversion of late progeny in mutants with reduced fertility in Caenorhabditis elegans.

    Get PDF
    The detailed study of fertility is an eminent objective due to its involvement in the human population. Interestingly, research in relation to dietary restriction in different species have related this circumstance to an increase in longevity and delay in fertility. The evolutionarily conserved insulin / insulin-like growth factor-1 pathway is directly related to this phenomenon. Caenorhabditis elegans is an animal model widely used for the study of, for which, and in relation to this pathway, the transcription factor DAF-16 (homologous to human FOXO) plays an especially important role. Mutants for the insulin pathway, which in some extent mimic a dietary restriction situation, have also shown to have reduced fertility. Based on this, previous studies corroborated that suppression by interfering RNA (iRNA) of DAF-16 in mutants with impaired fertility reverses this phenotype.The phenomenon of late progeny is that individuals appear to have offspring later in life than wild-type ones, not being described solidly in the literature; that is why the purposes of this project consist of its evaluation and the verification of a possible reversion. Two thermosensitive mutants of C. elegans have been selected for study, for which a reduction in fertility was observed: mutant daf-2 (e1370), receptor tyrosine kinase, and mutant age-1 (mg305), subunit of the PI3 Kinase. There is not much data regarding this second mutant.First, it has been necessary to establish a parameter to discern between what will be considered late progeny or not. To carry it out, its laying behavior has been observed after being incubated at different temperatures in its fertile period. The obtained results corroborate that the late progeny is a real and measurable phenomenon, reflecting a significant difference of the mutants with respect to the wild ones at a temperature of 22.5ºC; having established the fifth day of the fertile period as a margin to differentiate its existence. Subsequently, experiments are planned to observe a possible reversal of the condition through the administration of 4-5 iRNA for specific genes that have been previously identified through genetic screening, and that seem to intervene in some way in this route by suppressing the reduced fertility phenotype. If this is the case, these genes would be described as being involved in the phenomenon of late progeny, establishing a mechanical correlation between reduction of fertility and the phenomenon of late progeny

    Ultrastable CoxSiyOz Nanowires by Glancing Angle Deposition with Magnetron Sputtering as Novel Electrocatalyst for Water Oxidation

    Get PDF
    Cobalt is one of the most promising non‐noble metal as electrocatalyst for water oxidation. Herein, a highly stable silicon‐cobalt mixed oxide thin film with a porous columnar nanostructure is proposed as electrocatalyst for oxygen evolution reaction (OER). CoOx and CoxSiyOz layers with similar thickness were fabricated at room temperature by magnetron sputtering in a glancing angle configuration (MS‐GLAD) on tin‐doped indium oxide (ITO) substrates. After characterization, a comparative study of the electrocatalytic performance for OER of both layers was carried out. The excellent long‐term stability as electrocatalyst for OER of the porous CoxSiyOz thin film demonstrates that the presence of silicon on the mixed oxide network increases the mechanical stability of the Si/Co layer, whilst maintaining a considerable electrocatalytic response

    Effect of fermented, hardened, and dehulled of chickpea (Cicer arietinum) meals in digestibility and antinutrients in diets for tilapia (Oreochromis niloticus)

    Get PDF
    Among the most typical feed sources for tilapia, plants represent a low-cost source in substituting for traditional high-cost feed ingredients. Fermentation, hardening and dehulling are common grains processing techniques to make plant nutrients available and more digestible to fish. Apparent digestibility coefficients (ADC) of dry matter and protein, and antinutrients (phytic acid and tannins) in fermented, hardened and dehulled chickpea (Cicer arietinum) meals were determined for juvenile Nile tilapia (Oreochromis niloticus). The highest ADC was obtained with processed (fermented, hardened and dehulled) chickpea meals compared with non-processed. Results indicated that fermentation increased the protein content by 13.1%, decreased the content of ash and phytic acid (47.5 and 45%, respectively), and increased the ingredient apparent digestibility of dry matter (ADM) by 23.2%, and the ingredient apparent digestibility of protein (ADP) by 41.9%. Dehulling meal increased the protein (5.7%) and lipid (6.4%) content of chickpea grains; decreased fiber, ash and tannin content (75.3%, 19.1%, and 84.5%, respectively); and increased ADM by 12.8%, and ADP by 10.4%. We conclude that fermented, hardened and dehulled chickpea meals represent a potential alternative in diets for juvenile O. niloticus

    Selective synthesis of phenanthrenes and dihydrophenanthrenes via gold-catalyzed cycloisomerization of biphenyl embedded trienynes

    Get PDF
    Readily available o′-alkenyl-o-alkynylbiaryls, a particular type of 1,7-enynes, undergo a selective cycloisomerization reaction in the presence of a gold(I) catalyst to give interesting phenanthrene and dihydrophenanthrene derivatives in high yields. The solvent used provokes a switch in the evolution of the gold intermediate and plays a key role in the reaction outcome.Ministerio de Economıá y Competitividad (MINECO), AEI and FEDER (projects CTQ2017- 85263-R and CTQ2016-75023-C2-1-P), Instituto de Salud Carlos III (FEDER funds, ISCIII RETIC REDINREN RD16/ 0009/0015), Junta de Castilla y León and FEDER (BU291P18), and University of Alcalá (projects CCGP2017- EXP/016 and CCG2018/EXP-00

    Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution

    Get PDF
    Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n = 2 RMP maintaining good confinement HH(98,y2) 0.95. Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.European Commission (EUROfusion 633053

    Mean Sombor index

    Get PDF
    A Special Volume on Chemical Graph Theory in Memory of Nenad TrinajsticWe introduce a degree–based variable topological index inspired on the power (or generalized) mean. We name this new index as the mean Sombor index: SOα(G) = P uv∈E(G) [(d α u + d α v ) /2]1/α. Here, uv denotes the edge of the graph G connecting the vertices u and v, du is the degree of the vertex u, and α ∈ R\{0}. We also consider the limit cases mSOα→0(G) and SOα→±∞(G). Indeed, for given values of α, the mean Sombor index is related to well-known opological indices such as the inverse sum indeg index, the reciprocal Randic index, the first Zagreb index, the Stolarsky–Puebla index and several ´Sombor indices. Moreover, through a quantitative structure property relationship (QSPR) analysis we show that mSOα(G) correlates well with several physicochemical properties of octane isomers. Some mathematical properties of the mean Sombor index as well as bounds and new relationships with known topological indices are also discussed.J.A.M.-B. acknowledges financial support from CONACyT (Grant No. A1-S-22706) and BUAP (Grant No. 100405811VIEP2021) .E.D.M. and J.M.R. were supported by a grant from Agencia Estatal de Investigación (PID 2019-106433GBI00 / AEI / 10.13039 / 501100011033), Spain. J.M.R. was supported by the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual Agreement with UC3M in the line of Excellence of University Professors (EPUC3M23), and in the context of the VPRICIT (Regional Programme of Research and Technological Innovation)

    Rotura bilateral y simultánea del tendón de Aquiles

    Get PDF
    La rotura bilateral y simultánea del tendón de Aquiles es un hecho excepcional. La producción de esta lesión en una persona joven, sin antecedentes patológicos ni de administración de ciertos medicamentos es aún más excepcional. El tratamiento quirúrgico y un adecuado proceso de seguimiento y rehabilitación contribuyen a una buena recuperación y pronóstico en los individuos jóvenes y activos con roturas del tendón de Aquiles. Se presenta un caso clínico de una mujer de 21 años tratada quirúrgicamente con buen resultado.The bilateral and simultaneous rupture of Achilles tendon is an excepcional situation. The production of this injury in a young person, without history pathological or administration of certain drugs is even more exceptional. The surgical treatment and a proper process of following-up and rehabilitation help to a good recovery and prognosis in young and active people with Achilles tendon ruptures
    corecore