468 research outputs found
Exoesqueleto bípedo: revisión del estado del arte
El presente documento muestra las diferentes etapas que implica la marcha como tal, un análisis sobre las distintas etapas que se tiene al realizar la caminata, sus diferentes reacciones sobre las articulaciones de las extremidades inferiores tales como cadera,rodilla y tobillo
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Failure of Conventional Density Functionals for the Prediction of Molecular Crystal Polymorphism: A Quantum Monte Carlo Study
We have applied the diffusion Monte Carlo method, for the first time, to an organic molecular crystal (para-diiodobenzene) in order to determine the relative stability of its two well-known polymorphs. The DMC result predicts that the α phase is more stable than the β phase at zero temperature, in agreement with experiment. In comparison, we evaluated four commonly used local, semilocal, and hybrid density functionals, including an empirical correction to include the effects of dispersion. We conclude that while density functional theory may provide the most practical method for estimating the effects of electron correlation, conventional functionals which do not accurately describe noncovalent interactions may not be considered reliable for determining highly accurate energies in such systems.Chemistry and Chemical Biolog
Methods, data and tools for facilitating a 3D cultural heritage space
In recent years, the cultural heritage (CH) sector has experienced a rapid evolution due to the introduction of increasingly powerful digital technologies and ICT (Information and Communication Technologies) solutions. As for many other domains, digital data, Artificial Intelligence (AI), and Extended Reality (XR) are opening up extraordinary opportunities for expanding heritage knowledge capabilities while boosting the research on innovative solutions for its valorisation and preservation. Being aware of the fundamental and strategic role of CH in the history and identity of the European countries, the European Commission has assumed a central role in fuelling the policy debate and putting together stakeholders to take a step forward in CH digitization and use, primarily through initiatives, programs, and recommendations. Within this framework, the ongoing European 5DCulture project (https://www.5dculture.eu/) has been funded to enrich the offer of 3D CH digital assets in the common European Data Space for Cultural Heritage by creating high-quality 3D contents and to foster their re-use in several sectors, from tourism to education. Through 8 re-use scenarios around historic buildings and cityscapes, archaeology, and fashion, the project aims to deliver a set of digital tools and increase the capacity of CH institutions to more effectively re-use their 3D digital assets
The search for DM in nearby dSph galaxies with MAGIC: candidates, results and prospects
At present, dwarf spheroidal galaxies satellites of the Milky Way may
represent the best astrophysical objects for dark matter (DM) searches with
gamma-ray telescopes. They present the highest mass-to-light ratios known in
the Universe. Furthermore, many of them are near enough from the Earth to be
able to yield high predicted DM annihilation fluxes that might be observed by
current gamma-ray instruments like MAGIC. The picture has become even better
with the recent discovery of new dwarfs. These new objects are expected to
yield even higher DM annihilation fluxes, since most of them are nearer than
the previously known dwarfs and are even more DM dominated systems. Here a
tentative list of the best candidates is given. The observational results
obtained with MAGIC from the Draco dwarf as well as the observation of other
dwarfs carried out by other Cherenkov telescopes are presented as well.
Finally, we discuss the detection prospects of such kind of objects in the
context of DM searches.Comment: To appear in the proceedings of the 8th UCLA Dark Matter Symposium,
Marina del Rey, USA, 20-22 February 200
Herbicidal Potential of the Natural Compounds Carvacrol, Thymol, Eugenol, p-Cymene, Citral and Pelargonic Acid in Field Conditions: Indications for Better Performance
In recent years, interest in natural products with herbicidal activity as new tools for integrated weed management has increased. The European Union is demanding a reduction in the number of herbicides used, forbidding use of the most toxic ones, despite the problem of weed resistance increasing. Pelargonic acid (PA) is the only natural herbicide available in Spain. In this work, two field assays were performed with the natural compounds carvacrol (CAR), citral (CIT), eugenol (EUG), thymol (THY), p-cymene (P-CYM), (PA), and the combination of PA with CIT-all except P-CYM formulated by Seipasa-to test their herbicidal efficacy in real conditions. They were compared with commercial PA, glyphosate (GLY) and oxyfluorfen (OXY). In both experiments, GLY achieved the best weed control. Considering the natural herbicides, PA formulated by Seipasa and PA plus CIT were the most effective. From both experiments, some conclusions can be extracted for better herbicidal performance of natural products: (1) use products on sensitive weed species, (2) treat weeds at earlier phenological stages, (3) find the active doses in field conditions, (4) cover weeds well when treating, (5) ensure adequate formulation of products, and (6) develop a strategy for correct application
Technological study of kaolinitic clays from Fms. Escucha and Utrillas to be used in dermo-pharmaceutical products
The present study aims to evaluate five clay samples from different pits in the Teruel province, Spain. While these
clays are primarily utilized as raw materials in ceramics, their potential applications in pharmaceutical and
cosmetic domains, notably in sun protection and thermal mud products, are under investigation. Characterization
of these clays entailed X-ray diffraction, X-ray fluorescence, scanning electron microscopy, pH measurement,
analysis of technological properties, rheological assessment, and thermal property evaluation. Furthermore,
given the predominant composition of kaolin in most of the samples, their Sun Protection Factor (SPF) in suspensions
and physical stability were assessed. The studied samples exhibited varied mineralogical compositions,
primarily consisting of kaolinite (70% to 15%), quartz (75% to 5%), and illite (26% to 7%). The pH values of
these dispersions closely matched the skin's pH, exhibiting anti-thixotropic behavior at 50% w/w and demonstrating
suitable viscosity for skin application. Based on their composition and rheological properties, the
samples exhibited potential for use as therapeutic thermal muds. Analyses of cooling kinetics were performed to
validate this potential. Results showed that the dispersions systems attained temperatures between 33.89 ◦C and
34.62 ◦C within 20 min (the common application time for thermal muds) and reached 32 ◦C (skin temperature)
in 24.3 to 26.22 min, confirming their appropriateness as therapeutic muds. The SPF values of the dispersions
varied from 7.46 to 16.65, with the majority of samples showing significant stability during 45 h. Consequently,
it can be inferred that most of the studied samples show advantageous characteristics for inclusion in topical
formulations, especially in sun protection and thermal mud products
The effect of changing the pre-slaughter handling on bovine cattle DFD meat
ABSTRACT
Objective. To evaluate the effect that a series of changes in the handling techniques used throughout the pre and post slaughter periods and during the handling of cooled carcass have on the presence of DFD (Dark, firm and dry) meat. Materials and methods. Odds ratios (OR) and confidence intervals were estimated applying logistic regression models. Data from 18 visits to the slaughterhouse regarding: animal handling on arrival, slaughter period, and carcass storage was obtained through the use of a questionnaire. A total of 572 carcasses were analyzed to determine DFD meat using pH and color (L*, a*, b* and C*) measurements done on the Longissimus dorsi muscle. Results. Even after of the changes were made, the lairage period to slaughter continued to be a factor (p<0.05) associated to the presence of DFD meat (OR=1.13). Of the complementary variables, the amount of time that cattle spent on the resting pens was associated (p<0.05) to the presence of DFD meat (OR=1.003). Conclusions. Regardless of the changes made in the ante mortem handling, a high frequency of DFD was found (39%), suggesting a permanent audit program to detect other critical points in the supply chain.
RESUMEN
Objetivo. Para evaluar el efecto de una serie de modificaciones en las técnicas de manejo usadas en el periodo pre y post-sacrificio y manejo de las canales en refrigeración en relación con la presencia de carne DFD (dura, firme y seca). Materiales y métodos. Se obtuvieron razones de desigualdad e intervalos de confianza empleando modelos de regresión logística. En 18 visitas a la planta de sacrificio, se aplicó un cuestionario obteniendo información sobre manejo de los animales desde su llegada a la planta, etapa de sacrificio y almacenamiento de las canales. Se estimó la frecuencia de carne DFD de analizar un total de 572 canales, registrando en el Longissimus dorsi pH y color (L*, a* b*, C*). Results. De las modificaciones realizadas, el tiempo de permanencia al sacrificio sigue siendo fue un factor asociado (p<0.05) a la presencia de carne DFD (OR=1.13). De las variables complementarias, el tiempo de espera en los corrales de descanso resultó correlacionado (p<0.05) a la presencia de carne DFD (OR=1.003). Conclusiones. Independientemente de los cambios realizados en el manejo ante mortem, se encontró una alta frecuencia de carne DFD (39%), sugiriendo un programa de auditoría permanente para detectar otros puntos críticos de la cadena logística
Triplet Exciton Generation in Bulk-Heterojunction Solar Cells based on Endohedral Fullerenes
Organic bulk-heterojunctions (BHJ) and solar cells containing the trimetallic
nitride endohedral fullerene 1-[3-(2-ethyl)hexoxy
carbonyl]propyl-1-phenyl-Lu3N@C80 (Lu3N@C80-PCBEH) show an open circuit voltage
(VOC) 0.3 V higher than similar devices with [6,6]-phenyl-C[61]-butyric acid
methyl ester (PC61BM). To fully exploit the potential of this acceptor molecule
with respect to the power conversion efficiency (PCE) of solar cells, the short
circuit current (JSC) should be improved to become competitive with the state
of the art solar cells. Here, we address factors influencing the JSC in blends
containing the high voltage absorber Lu3N@C80-PCBEH in view of both
photogeneration but also transport and extraction of charge carriers. We apply
optical, charge carrier extraction, morphology, and spin-sensitive techniques.
In blends containing Lu3N@C80-PCBEH, we found 2 times weaker photoluminescence
quenching, remainders of interchain excitons, and, most remarkably, triplet
excitons formed on the polymer chain, which were absent in the reference
P3HT:PC61BM blends. We show that electron back transfer to the triplet state
along with the lower exciton dissociation yield due to intramolecular charge
transfer in Lu3N@C80-PCBEH are responsible for the reduced photocurrent
Born to be wild: captive-born and wild Iberian lynx (Lynx pardinus) reveal space-use similarities when reintroduced for species conservation concerns
An ambitious conservation programme to save the Iberian lynx from extinction conducted several reintroductions aiming to restore its historical range. The urgency due to the delicate conservation status prompted translocating captive-born and wild individuals, while preventing an early assessment of how both groups combined their space-use and differed in post-release movements. To address this issue, we conducted a comprehensive movement ecology analysis using GPS data of 161 Iberian lynxes from 9 populations. First, we classified five movement phases within individuals' trajectories: residence areas (stable and transient), excursions, post-release dispersals, and transitions between residences. Second, we used continuous-time movement models to estimate range size and daily speeds and measured the distance travelled during extra-territorial movements. Finally, we conducted comparative analyses to evaluate differences between captive-born, wild translocated, and wild non-translocated individuals across phases, sex, age-class and populations. Most individuals in all groups established home ranges, supporting the reintroduction main goal. Yet, contrary to the species' natural pattern, captive-born subadults did not show intersexual home range size differences, which emerged after experiencing free-ranging, when becoming adults. More differences emerged for non-residential behaviours. Captive-born lynxes were more prone to post-release dispersal, to slower post-release movements and to having smaller transient residences, indicating cautious behaviour. Our study supports using captive-born individuals for reintroductions, while prioritizing wild individuals for reinforcements in highly competitive populations. Further, we suggest relevant metrics for planning translocations and connectivity management, and we demonstrate how an integrated ex-situ and reintroduction initiative can substantially contribute to restoring an endangered species' distribution rang
Measurement of the production cross section for W-bosons in association with jets in pp collisions at s=7 TeV with the ATLAS detector
This Letter reports on a first measurement of the inclusive W + jets cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC, with the ATLAS detector. Cross sections, in both the electron and muon decay modes of the W-boson, are presented as a function of jet multiplicity and of the transverse momentum of the leading and next-to-leading jets in the event. Measurements are also presented of the ratio of cross sections sigma (W + >= n)/sigma(W + >= n - 1) for inclusive jet multiplicities n = 1-4. The results, based on an integrated luminosity of 1.3 pb(-1), have been corrected for all known detector effects and are quoted in a limited and well-defined range of jet and lepton kinematics. The measured cross sections are compared to particle-level predictions based on perturbative QCD. Next-to-leading order calculations, studied here for n <= 2, are found in good agreement with the data. Leading-order multiparton event generators, normalized to the NNLO total cross section, describe the data well for all measured jet multiplicitie
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