Excitation of wakefields in carbon nanotubes: a hydrodynamic model approach

The interactions of charged particles with carbon nanotubes may excite electromagnetic modes in the electron gas produced in the cylindrical graphene shell constituting the nanotube wall. This wake effect has recently been proposed as a potential novel method of short-wavelength high-gradient particle acceleration. In this work, the excitation of these wakefields is studied by means of the linearized hydrodynamic model. In this model, the electronic excitations on the nanotube surface are described treating the electron gas as a 2D plasma with additional contributions to the fluid momentum equation from specific solid-state properties of the gas. General expressions are derived for the excited longitudinal and transverse wakefields. Numerical results are obtained for a charged particle moving within a carbon nanotube, paraxially to its axis, showing how the wakefield is affected by parameters such as the particle velocity and its radial position, the nanotube radius, and a friction factor, which can be used as a phenomenological parameter to describe effects from the ionic lattice. Assuming a particle driver propagating on axis at a given velocity, optimal parameters were obtained to maximize the longitudinal wakefield amplitude

A chronological proposal for El Castillo Cave (Puente Viesgo, Cantabria) based on its iconographic stratigraphy

Some years ago, we began a review of the work done by E. Ripoll in 1953. During this time, we have examined not only each and every one of the figures discovered by him, but have also expanded the list, reaching nearly all the 450 new figures in the entire cave. This significant increase is thanks to the use of new technologies, such as a 3D scanner, digital filters, multispectral algorithms, giga images, or the newest innovation, the use, for the first time in our studies on cave art, of hyperspectral methodology. The latter gives us access to a much wider light spectrum than the one created by multispectral analysis.Hace unos años empezamos la revisión de los trabajos llevados a cabo por E. Ripoll en el año 1953, durante este tiempo no sólo hemos revisado todas y cada una de las representaciones descubiertas por E. Ripoll sino que hemos ampliado ese elenco hasta llegar casi a las 450 figuras nuevas. Este significativo aumento se debe a la aplicación de las Nuevas Tecnologías como son el Escáner 3D, los filtros digitales, algoritmos multiespectrales, gigaimágenes o la última innovación que es la aplicación por primera vez en nuestros estudios de arte rupestre de la metodología hiperespectral que nos permite acceder a un espectro lumínico mucho más amplio que el que produce el análisis multiespectral

Short-term effect of heat waves on hospital admissions in Madrid: Analysis by gender and comparision with previous findings

Global warming affects health through multiple exposures and pathways, in and is turn deeply influenced by climate change. Every year, several million deaths are caused by environmental factors, many of which are aggravated by climate change or its drivers (WHO, 2016). The adverse effects of climate change on health are varied, complex and far-reaching. Essentially, climate change acts as a multiplier for global health threats, compounding many of the health issues communities already face. Disproportionately affect the health of vulnerable groups and people in lower income countries, thus exacerbating inequalities and gender differences (Watts et al., 2018)

Tratamiento odontológico integral en un paciente afecto de Corea de Huntington

Se presenta un caso de rehabilitación oral con prótesis fija en un paciente afecto de corea de Huntington, con retraso psíquico moderado y una importante descoordinación motriz. El tratamiento consistió en una primera fase bajo anestesia general (tratamiento odontología conservadora, tratamiento periodontal y exodoncias). En una segunda sesión, después de mantener unos niveles de placa dental correctos, se procedió al tallado de los dientes pilares y toma de registros oclusales, todo ello bajo sedación profunda. El resto de las pruebas ajuste de oclusión y cementado con premedicación psico-sedante

Photoelectric Properties of MOS-like Structures with Twofold SRO Films

AbstractThe optical properties of silicon rich oxide (SRO) have been deeply studied because, between other reasons, they emit an intense photoluminescence (PL) from visible to the near infrared range when excited with UV light. MOS-like structures with SRO film as the active layer have shown an enhanced conductivity under different illumination conditions. In this paper, MOS-like structures with double SRO layer were fabricated in order to have a barrier to isolate the silicon substrate from the active SRO layer. Results show that all structures have a higher current when light shines on them than that obtained under dark conditions. A possible application of this photo-effect can be used to increase the response of photodetectors and silicon solar cells

Population vulnerability to extreme cold days in rural and urban municipalities in ten provinces in Spain

Background: The objective was to analyze whether there are differences in vulnerability to Extreme Cold Days (ECD) between rural and urban populations in Spain. Methodology: Time series analysis carried out from January 1, 2000, through December 31, 2013. Municipalities with over 10,000 inhabitants were included from 10 Spanish provinces, classified into 42 groups by isoclimate and urban/rural character as defined by Eurostat criteria. The statistical strategy was carried out in two phases. First: It was analyzed the relationship between minimum daily temperature (Tmin) (source: AEMET) and the rate of daily winter mortality due to natural causes —CIE-10: A00 – R99— (source: National Statistics Institute). Then, It was determinated the threshold of Tmin that defines the ECD and its percentile in the series of winter Tmin (Pthreshold), which is a measure of vulnerability to ECD so that the higher the percentile, the higher the vulnerability. Second: possible explanatory variables of vulnerability were explored using Mixed Generalized Models, using 13 independent variables related to meteorology, environment, socioeconomics, demographics and housing quality. Results: The average Pthreshold was 18 %. The final model indicated that for each percentage point increase in unemployment, the vulnerability to ECD increased by 0.4 (0.2, 0.6) points. Also, with each point increase in rurality index, this vulnerability decreased by −6.1 (−2.1, −10.0) points. Although less determinant, other factors that could contribute to explaining vulnerability at the province level included minimum winter daily temperatures and the percentage of housing with poor insulation. Conclusions: The vulnerability to ECD was greater in urban zones than in rural zones. Socioeconomic status is a key to understanding how this vulnerability is distributed. These results suggest the need to implement public health prevention plans to address ECD at the state level. These plans should be based on threshold temperatures determined at the smallest scale possibleThe authors wish to thank the funding provided by the ENPY107/18, ENPY 376/18, ENPY 304/20 projects of the Carlos III Health Institute III (ISCIII

Efecto de la adición de proteínas solubles recuperadas del agua de lavado de surimi de Pacific Whiting sobre las propiedades funcionales y mecánicas de surimi de Alaska pollock grado FA

Soluble proteins from surimi wash water (SWW) can be insolubilized by complexing with chitosan-alginate allowing its recovery and the reduction of the organic matter in the processing water discharged from surimi processing plants. The objective of this work was to evaluate the effect of adding soluble proteins recovered from Pacific whiting SWW on the mechanical and functional properties of commercial Alaska Pollock surimi grade FA. Levels evaluated were 0 (control), 10, 30 and 50 g insolubilized SWW solids/kg Alaska Pollock grade FA surimi. The mechanical and functional properties of Alaska Pollock surimi pastes and gels were characterized by texture profile analysis (TPA), puncture test, expressible water (EW) and color attributes. TPA and puncture test parameters increased significantly (P≤0.05) when 10–30 g/kg of soluble proteins from Pacific whiting SWW were added. EW values increased also, indicating a decrease of the water holding capacity. Color parameters showed that all surimi gels increased in redness, an undesirable effect in the production of Alaska Pollock grade FA surimiLas proteínas solubles del agua de lavado del surimi (ALS) pueden ser insolubilizadas por medio de la formación de complejos con quitosano y alginato. Su recuperación por este método permite reducir la materia orgánica en el agua de proceso. El objetivo de este trabajo fue evaluar el efecto de la adición de proteína soluble recuperada del ALS de Pacific whiting sobre las propiedades mecánicas y funcionales de surimi comercial de Alaska Pollock de grado FA. Los niveles de adición evaluados fueron 0 (control), 10, 30 y 50 g sólidos insolubilizados de ALS/kg de surimi de Alaska Pollock de grade FA. Las propiedades mecánicas y funcionales se caracterizaron por medio del análisis de perfil de textura (TPA), prueba de punción, agua extraíble y atributos de color. Los valores de los parámetros de TPA y prueba de punción incrementaron significativamente (P≤0.05) cuando se adicionaron de 10 a 30 g/kg de proteínas solubles de ALS de Pacific whiting. El agua extraíble también se incrementó, indicando un descenso de la capacidad de retención de agua. Los atributos de color indicaron que todos los geles de surimi incrementaron su color rojo, lo cual podría ser desfavorable para la producción de surimi de Alaska Pollock grado FAThis work was partially supported by Grant no. NA 16RG 1039 (Project no. R/SF-29) from the National Oceanic and Atmospheric Administration to the Sea Grant College Program at Oregon State University, and appropriations made by the Oregon State Legislature. Part of this study was supported by Grant no. TAMPS-2003-C02-14, FOMIXCONACYT, MéxicoS

Highly Stable and Reactive Platinum Single Atoms on Oxygen Plasma-Functionalized CeO₂ Surfaces: Nanostructuring and Peroxo Effects

Atomically dispersed precious metals on oxide supports have recently become increasingly interesting catalytic materials. Nonetheless, their non-trivial preparation and limited thermal and environmental stability constitutes an issue for their potential applications. Here we demonstrate that an oxygen plasma pre-treatment of the ceria (CeO2 ) surface serves to anchor Pt single atoms, making them active and resistant towards sintering in the CO oxidation reaction. Through a combination of experimental results obtained on well-defined CeO2 films and theory, we show that the O2 plasma causes surface nanostructuring and the formation of surface peroxo (O22-) species, favoring the uniform and dense distribution of isolated strongly bonded Pt2+ atoms. The promotional effect of the plasma treatment was further demonstrated on the powder Pt/CeO2 catalysts. We believe that plasma functionalization can be applied to other metal/oxide systems to achieve tunable and stable catalysts with a high density of active sites