Tres tipos monetarios inéditos en el Tesoro de Llíria

En el Tesoro de Llíria (compuesto por 5.990 denarios de época alto imperial) han aparecido tres tipos monetarios no identificados hasta ahora en los trabajos de referencia numismática, tratándose por tanto de monedas inéditas las cuales queremos dar a conocer en este trabajo

Carbon nanotube net as a conductive and transparent film for solar energy conversion

Vertically aligned silicon nanowires arrays have been grown through a metal-assisted chemical etching method, giving a heavily absorbing surface. Over this surface, a transparent and conductive net of carbon nanotubes has been formed by chemical vapour deposition. The optical characterisation of the net has been performed by the study of its hemispherical reflectance, and the electrical properties have been obtained by four-point probe method. A high transmittance of the net (over 99%) in the 300-900 nm range is reported. Also, a good sheet resistance value has been obtained (around 3 kΩ/□) for such a thin carbon nanotube netThis work was supported by MINECO research Project ENE2014-57977-C2-1-

Aprovisionamiento, circulación y uso de la moneda de plata en Hispania (siglos I-III d.C.): El Tesoro de Llíria

El objetivo del presente trabajo de investigación es el estudio de la circulación, el aprovisionamiento y la función de la moneda de plata durante el Alto Imperio (siglos I-III d.C.), desde el punto de vista político, social y económico, a partir del análisis minucioso del Tesoro de Llíria, compuesto por 5.990 denarios que comprenden el período cronológico indicado y que fue descubierto en el transcurso de las excavaciones realizadas en la ciudad. Este hallazgo monetario es, sin ninguna duda, excepcional por su volumen -se trata de uno de los tesoros imperiales más importantes de Europa- y resulta casi exclusivamente representativo de la moneda de plata en circulación durante el siglo II d.C. Asimismo, podemos constatar la gran relevancia que tiene, no sólo a nivel peninsular sino también a nivel europeo por haber aparecido en un territorio civil y no militar o de conflicto como la resta de tesoros de composición y cronología similar, y que por tanto nos reafirma en la hipótesis de que el Tesoro de Llíria es el resultado de los ahorros de un edetano con un rango social de especial relevancia.The aim of this research is the study of circulation, provisioning and role of silver coins during the High Roman Empire (1st to 3rd AD Centuries) from a political, social and economic point of view. The reasons are based on the analyse of Lliria’s Hoard, composed of 5.990 denarii, from the mentioned chronology discovered during an excavation in this town. Undoubtedly, this monetary discovery is exceptional for its volume: it is one of the most important imperial treasures in Europe. Furthermore, it is almost entirely representative of silver coin in circulation during the 2nd century AD. Also, it is possible to note the great importance which has not only in Hispania, also in Europe for appearing in a civil territory, without war as other of hoards, with similar composition and chronology. Therefore, the hypothesis about Lliria’s Hoard as a result of saving money from an Edetan person, with a high standard of living, is reaffirmed

Los hallazgos monetales y la plata en bruto de La Carència

El yacimiento de La Carència ha proporcionado una impor-tante muestra de material numismático, que en su mayor parte procede de hallazgos superciales. La ausencia de contexto arqueológico para casi todas las monedas limita nuestras va-loraciones, sin embargo la cantidad y la comparación con otros yacimientos permite una buena aproximación al panorama monetario que vivió la ciudad y al conocimiento del uso del metal y de las monedas como dinero. Para ello contamos con un numeroso lote de monedas, más de 800 piezas, y de más de un centenar de recortes de plata

Graphene Synthesis by Plasma-Enhanced CVD Growth with Ethanol

A modified route to synthesize graphene flakes is proposed using the Chemical Vapor Deposition (CVD) technique, by using copper substrates as supports. The carbon source used was ethanol, the synthesis temperature was 950°C and the pressure was controlled along the whole process. In this CVD synthesis process the incorporation of the carbon source was produced at low pressure and 950°C inducing the appearance of a plasma blue flash inside the quartz tube. Apparently, the presence of this plasma blue flash is required for obtaining graphene flakes. The synthesized graphene was characterized by different techniques, showing the presence of non-oxidized graphene with high purityThis work was supported by the Spanish Education and Research Ministry (MEC) under Grant MAT2010- 19804 and from Ministerio de Economía y Competitividad (MINECO) of Spain, through the grant ENE2014-57977-C2-1-R. Financial support from the U.S. Department of Energy, through the Massie Chair Project at Turabo University and from the U.S. Department of Defense under Grant W911NF-14-1- 0046, are also acknowledge

Análisis mediante Fluorescencia de Rayos-X Dispersiva en Energía (EDXRF) de denarios de Adriano y el problema del enriquecimiento superficial en la moneda de plata

En este trabajo presentamos los resultados obtenidos en el análisis EDXRF de 50 denarios emitidos durante el reinado de Adriano (117-138 d.C.), a nombre del propio emperador, de la emperatriz Sabina, de Elio César y de Antonino César todos ellos pertenecen al tesoro de Llíria, compuesto por 5.990 mone- das de plata. Los valores obtenidos son elevados para el periodo cronológico acotado, los cuales están asocia- dos a un enriquecimiento en la superficie de la moneda. Las monedas pudieron haber estado sometidas a un enriquecimiento superficial, por lo que los usuarios percibirían básicamente su apariencia externa y sería muy difícil distinguir pequeñas alteraciones de la calidad de la aleació

Microspheres for the growth of silicon nanowires via vapor-liquid-solid mechanism

Silicon nanowires have been synthesized by a simple process using a suitable support containing silica and carbon microspheres. Nanowires were grown by thermal chemical vapor deposition via a vapor-liquid-solid mechanism with only the substrate as silicon source. The curved surface of the microsized spheres allows arranging the gold catalyst as nanoparticles with appropriate dimensions to catalyze the growth of nanowires. The resulting material is composed of the microspheres with the silicon nanowires attached on their surfaceThis work was supported by MICINN research Project MAT2010-19804. Financial support fromthe US Department of Energy through the Massie Chair project at University of Turabo is also acknowledged.The work of Arancha Gómez-Martínez was supported by the FPI fellowship from the Universidad Autónoma de Madrid.The authors thank I. Poveda for his technical assistance. The “Servicio Interdepartamental de Investigación (SIdI)” a tUniversidad Autónoma de Madrid and “Centro Nacional de Microscopía Español” (CNME) at Universidad Complutense deMadrid are also acknowledge

La Moneda en el Área Rural de Ebusus (siglos IV-I a.C.)

El estudio y catalogación de la colección de monedas donadas por A. Martín al MAEF en 1991, procedente de hallazgos esporádicos en un medio rural ibicenco, ha permitido conocer mejor cómo estaba formada la masa monetaria en Ebusus entre los siglos V-IV y el I a.C. Durante este período la producción monetaria de Ebusus cubrió, casi en su totalidad, las necesidades monetarias de bronce de la isla. La nueva muestra también ratifica los niveles de producción en cada uno de los diversos períodos en los que se agrupa, así como la inexistencia de diferencias entre la moneda de bronce utilizada en un entorno urbano y de necrópolis y la que se empleó en ámbitos rurales y periurbanos. Por su tamaño y peso fue una moneda inapropiada para cubrir pagos de considerable cuantía, dado su reducido valor, pero pone de manifiesto la intensa y temprana monetización de Ebusus ya desde el pleno siglo III a.C. The study of the collection of coins presented by A. Martin to the MAEF, in 1991, coming from sporadic findings in rural areas of ibiza, has allowed us to improve our knowledge about the coinages circulating in Ebusus, between the 5th/4th centuries BC and the 1st BC. During this period the monetary output of Ebusus covered, almost in its totality the bronze monetary needs of the island. The new collection also ratifies the levels of production in every period in which coins are grouped. The sample also attested the nonexistence of differences between the bronze coins used in an urban media and in necropolis and those that were used in rural and periurban context. By its size and weight it was an unsuitable coinage to cover payments with considerable quantity, due to his reduced value, but they show the intense and early monetization of Ebusus, already from early 3rd century BC

Hydrogenated amorphous silicon-based nanomaterials as alternative electrodes to graphite for lithium-ion batteries

Graphite is the material most used as an electrode in commercial lithium-ion batteries. On the other hand, it is a material with low energy capacity, and it is considered a raw critical material given its large volume of use. In the current energy context, we must promote the search for alternative materials based on elements that are abundant, sustainable and that have better performance for energy storage. We propose thin materials based on silicon, which has a storage capacity eleven times higher than graphite. Nevertheless, due to the high-volume expansion during lithiation, it tends to crack, limiting the life of the batteries. To solve this problem, hydrogenated amorphous silicon has been researched, in the form of thin film and nanostructures, since, due to its amorphous structure, porosity and high specific surface, it could better absorb changes in volume. These thin films were grown by plasma-enhanced chemical vapor deposition, and then the nanowires were obtained by chemical etching. The compositional variations of films deposited at different temperatures and the incorporation of dopants markedly influence the stability and longevity of batteries. With these optimized electrodes, we achieved batteries with an initial capacity of 3800 mAhg−1 and 82% capacity retention after 50 cyclesThis research has been funded by the Spanish of Ministry of Economy and Competitiveness under projects SCALED (PID2019-109215RB-C42/ https://scaled-project.com/, accessed on June 2020), NanoCat-Com (PID2021-124667OB-I00, accessed on September 2022) and by the European Project STORIES (LC-GD-9-1-2020-European Research Infrastructures capacities and services to address European Green Deal challenges /https://www.eera-energystorage.eu/stories.html, accessed on November 202

0D-1D hybrid silicon nanocomposite as lithium-ion batteries anodes

Lithium ion batteries (LIBs) are the enabling technology for many of the societal changes that are expected to happen in the following years. Among all the challenges for which LIBs are the key, vehicle electrification is one of the most crucial. Current battery materials cannot provide the required power densities for such applications and therefore, it makes necessary to develop new materials. Silicon is one of the proposed as next generation battery materials, but still there are challenges to overcome. Poor capacity retention is one of those drawbacks, and because it is tightly related with its high capacity, it is a problem rather difficult to address with common and scalable fabrication processes. Here we show that combining 0D and 1D silicon nanostructures, high capacity and stability can be achieved even using standard electrode fabrication processes. Capacities as high as 1200 mAh/g for more than 500 cycles at high current densities (2 A/g) were achieved with the produced hybrid 0D/1D electrodes. In this research, it was shown that while 0D nanostructures provide good strain relaxation capabilities, 1D nanomaterials contribute with enhanced cohesion and conductive matrix integrityThis research was funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 713567 and Science Foundation Irelands Research Centre award 12/RC/2278_P2. This work was supported by the Ministerio de Economía y Competitividad (MINECO) of Spain, under Grant ENE2014-57977-C2-1-R and “Estancias de Movilidad Salvador Madariaga”. Financial support from the U.S. Department of Defense (grant W911NF-14-1-0046), and from the U.S. Department of Energy, through the Consortium for Integrating Energy Systems in Engineering and Science Education, CIESESE (DE-NA0003330) is also acknowledge