Colección de fueros municipales y cartas pueblas de los reinos de Castilla, León, Corona de Aragón y Navarra /

Contiene: Tomo I.

Censo de poblacion de las provincias y partidos de la corona de Castilla en el siglio XVI con varios apendices para completar la del resto de la peninsula en el mismo siglo, y formar juicio comparativo con la del anterior y siguiente, segun resulta de los libros y registros que se custodian el el real archivo de Simancas.

Mode of access: Internet.

Colección de fueros municipales y cartas pueblas de los reinos de Castilla, León, Corona de Aragón y Navarra /

Contiene: Vol.1.

Registro y relación general de las minas de la Corona de Castilla /

Contiene: t.1. Primera Parte. Comprende los registros, relaciones y despachos tocantes a minas, en que se expresan los pueblos y sitios en que se hallaron -- t.II. Segunda y Tercera Parte. Comprende los registros, relaciones y despachos sobre el hallazgo, administración, labor y beneficio de minas en que no se expresan los pueblos ni sitios en que se hallaban, y varios privilegios concedidos a inventores de máquinas e ingenios para las artes mecánicas. Item : una relación y varios despachos tocantes al descubrimiento y provecho de varios tesoros. Y tres tratados científicos, relativos a la explotación y beneficio de los metales en las minas.

Colección de fueros municipales y cartas pueblas de los reinos de Castilla, León, Corona de Aragón y Navarra /

Contiene: Tomo I.

Tratado de paz, ajustado entre la corona de Castilla y de Portugal, año 1668.

Mode of access: Internet.

Béjar en el reinado de Isabel I de Castilla : estructuras de poder, cultura y patrimonio.

Este proyecto de innovación educativa se presentó en el Congreso Internacional de Innovación en la Educación celebrado en Valladolid los dias 26, 27 y 28 de abril de 2005

Isabel I, reina de Castilla.

Número monográfico sobre Isabel la Católica y su tiempo

El archivo de la Corona de Aragón.

Título anterior de la publicación : Boletín de la Comisión Española de la UNESCO

Corona Gótica castellana y austriaca : dividida en quatro partes : parte tercera /

Es continuación de "Corona Gothica... de Saavedra Fajardo"

Corona Gótica castellana y austriaca : dividida en quatro partes : parte tercera /

Es continuación de "Corona Gothica... de Saavedra Fajardo"

Corona discharges on the surfaces of high voltage composite insulators

The degradation of high voltage electrical insulation is a prime factor that can significantly influence the reliability performance and the costs of maintaining high voltage electricity networks. Little information is known about the system of localized degradation from corona discharges on the relatively new silicone rubber sheathed composite insulators that are now being widely used in high voltage applications. This current work focuses on the fundamental principles of electrical corona discharge phenomena to provide further insights to where damaging surface discharges may localize and examines how these discharges may degrade the silicone rubber material. Although water drop corona has been identified by many authors as a major cause of deterioration of silicone rubber high voltage insulation until now no thorough studies have been made of this phenomenon. Results from systematic measurements taken using modern digital instrumentation to simultaneously record the discharge current pulses and visible images associated with corona discharges from between metal electrodes, metal electrodes and water drops, and between waters drops on the surface of silicone rubber insulation, using a range of 50 Hz voltages are inter compared. Visual images of wet electrodes show how water drops can play a part in encouraging flashover, and the first reproducible visual images of water drop corona at the triple junction of water air and silicone rubber insulation are presented. A study of the atomic emission spectra of the corona produced by the discharge from its onset up to and including spark-over, using a high resolution digital spectrometer with a fiber optic probe, provides further understanding of the roles of the active species of atoms and molecules produced by the discharge that may be responsible for not only for chemical changes of insulator surfaces, but may also contribute to the degradation of the metal fittings that support the high voltage insulators. Examples of real insulators and further work specific to the electrical power industry are discussed. A new design concept to prevent/reduce the damaging effects of water drop corona is also presented.

Corona ions from overhead transmission voltage powerlines : effect on DC e-field and ambient particle concentration levels

Along with their essential role in electricity transmission and distribution, some powerlines also generate large concentrations of corona ions. This study aimed at comprehensive investigation of corona ions, vertical dc e-field, ambient aerosol particle charge and particle number concentration levels in the proximity of some high/sub-transmission voltage powerlines. The influence of meteorology on the instantaneous value of these parameters, and the possible existence of links or associations between the parameters measured were also statistically investigated. The presence of positive and negative polarities of corona ions was associated with variation in the mean vertical dc e-field, ambient ion and particle charge concentration level. Though these variations increased with wind speed, their values also decreased with distance from the powerlines. Predominately positive polarities of ions were recorded up to a distance of 150 m (with the maximum values recorded 50 m downwind of the powerlines). At 200 m from the source, negative ions predominated. Particle number concentration levels however remained relatively constant (103 particle cm-3) irrespective of the sampling site and distance from the powerlines. Meteorological factors of temperature, humidity and wind direction showed no influence on the electrical parameters measured. The study also discovered that e-field measurements were not necessarily a true representation of the ground-level ambient ion/particle charge concentrations.

Corona ions from high-voltage power lines : nature of emission and dispersion

Positive and negative small ions, aerosol ion and number concentration and dc electric fields were monitored at an overhead high-voltage power line site. We show that the emission of corona ions was not spatially uniform along the lines and occurred from discrete components such as a particular set of spacers. Maximum ion concentrations and atmospheric dc electric fields were observed at a point 20 m downwind of the lines. It was estimated that less than 7% of the total number of aerosol particles was charged. The electrical parameters decreased steadily with further downwind distance but remained significantly higher than background.

Fine tuning of elasticity via crosslinking collagen-based materials to mediate mechanotransduction and stability using corona treatment

The common goal of tissue engineering is to develop substitutes that can closely mimic the structure of extracellular matrix (ECM). However, similarly important is the intensive material properties which have often been overlooked, in particular, for soft tissues that are not to bear load assumingly. The mechanostructural properties determine not only the structural stability of biomaterials but also their physiological functionality by directing cellular activity and regulating cell fate decision. The aim here is to emphasize that cells could sense intensive material properties like elasticity and reside, proliferate, migrate and differentiate accordinglyno matter if the construct is from a natural source like cartilage, skin etc. or of synthetic one. Meanwhile, the very objective of this work is to provide a tunable scheme for manipulating the elasticity of collagen-based constructs to be used to demonstrate how to engineer cell behavior and regulate mechanotransduction. Articular cartilage was chosen as it represents one of the most complex hierarchical arrangements of collagen meshwork in both connective tissues and ECM-like biomaterials. Corona discharge treatment was used to produce constructs with varying density of crosslinked collagen and stiffness accordingly. The results demonstrated that elastic modulus increased up to 33% for samples treated up to one minute as crosslink density was found to increase with exposure time. According to the thermal analysis, longer exposure to corona increased crosslink density as the denaturation enthalpy increased. However the spectroscopy results suggested that despite the stabilization of the collagen structure the integrity of the triple helical structure remained intact. The in vitro superficial culture of heterologous chondrocytes also determined that the corona treatment can modulate migration with increased focal adhesion of cells due to enhanced stiffness, without cytotoxicity effects, and providing the basis for reinforcing three-dimensional collagen-based biomaterials in order to direct cell function and mediate mechanotransduction.