Vindicaciones

Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200

Estudios sobre el cosmopolitismo humano : apuntes para un libro

Copia digital : Biblioteca Virtual de Patrimonio Bibliográfico (Ministerio de Educación, Cultura y Deporte)Copia digital : Biblioteca Virtual de Patrimonio Bibliográfico (Ministerio de Educación, Cultura y Deporte)El subtit. precede al ti

Estudios físicos

Referències bibliogràfiquesConté: 2. Tratado de acústic

Neutral perfect fluids of Majumdar-type in general relativity

We consider the extension of the Majumdar-type class of static solutions for the Einstein-Maxwell equations, proposed by Ida to include charged perfect fluid sources. We impose the equation of state $\rho+3p=0$ and discuss spherically symmetric solutions for the linear potential equation satisfied by the metric. In this particular case the fluid charge density vanishes and we locate the arising neutral perfect fluid in the intermediate region defined by two thin shells with respective charges $Q$ and $-Q$. With its innermost flat and external (Schwarzschild) asymptotically flat spacetime regions, the resultant condenser-like geometries resemble solutions discussed by Cohen and Cohen in a different context. We explore this relationship and point out an exotic gravitational property of our neutral perfect fluid. We mention possible continuations of this study to embrace non-spherically symmetric situations and higher dimensional spacetimes.Comment: 9 page

Estudio del orígen, vida y obras de don Juan de Arfe y Villafañe [Manuscrito]

Copia digital : Junta de Castilla y León. Consejería de Cultura y Turismo, 201

Contrast Enhancement of Optical Coherence Tomography Images Using Branched Gold Nanoparticles

We propose the use of branched gold nanoparticles (B-GNPs) as a contrast agent for optical coherence tomography (OCT) imaging. Our results show that even when the central source of our OCT (1325 nm) is too far from the maximum peak of the plasmon resonance, branched nanoparticles scatter light very efficiently at this wavelength. B-GNPs were tested as a contrast agent in water and agarose-TiO2 tissue phantoms; the estimated increments in contrast were 9.19 dB and 15.07 dB for branched nanoparticles in water with concentrations of 2.2×109 NPs/mL and 6.6×109 NPs/mL, respectively, while for agarose-TiO2 tissue phantoms the estimated value was 3.17 dB. These results show the promising application of B-GNPs as a contrast agent for tissue imaging using OCT, not only for sources at 1325 nm but also at other central wavelengths located between 800 and 1000 nm

Carta del Excelentísimo Señor Don Antonio Ponce de León y Dávila, Duque de Montemar, á su primo el Marqués de Villafranca

A Fol. 296/01

Elementos de química

Copia digital. Madrid : Instituto San Isidro de Madrid, 2008Anteportad

Compendio de higiene ó arte de conservar la salud

Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200