A free real-time hourly tilted solar irradiation data Website for Europe

The engineering of solar power applications, such as photovoltaic energy (PV) or thermal solar energy requires the knowledge of the solar resource available for the solar energy system. This solar resource is generally obtained from datasets, and is either measured by ground-stations, through the use of pyranometers, or by satellites. The solar irradiation data are generally not free, and their cost can be high, in particular if high temporal resolution is required, such as hourly data. In this work, we present an alternative method to provide free hourly global solar tilted irradiation data for the whole European territory through a web platform. The method that we have developed generates solar irradiation data from a combination of clear-sky simulations and weather conditions data. The results are publicly available for free through Soweda, a Web interface. To our knowledge, this is the first time that hourly solar irradiation data are made available online, in real-time, and for free, to the public. The accuracy of these data is not suitable for applications that require high data accuracy, but can be very useful for other applications that only require a rough estimate of solar irradiation.

Orientation in operator algebras

A concept of orientation is relevant for the passage from Jordan structure to associative structure in operator algebras. The research reported in this paper bridges the approach of Connes for von Neumann algebras and ourselves for C*-algebras in a general theory of orientation that is of geometric nature and is related to dynamics.

Tilted excitation implies odd periodic resonances

This work was supported by the Brazilian agencies FAPESP and CNPq. MSB also acknowledges the Engineering and Physical Sciences Research Council grant Ref. EP/I032606/1. GID thanks Felipe A. C. Pereira for fruitful discussions.

Weighted composition operators on the predual and dual Banach spaces of Beurling algebras on Z

Let vv be a weight sequence on ZZ and let ψ,φψ,φ be complex-valued functions on ZZ such that φ(Z)⊂Zφ(Z)⊂Z. In this paper we study the boundedness, compactness and weak compactness of weighted composition operators Cψ,φCψ,φ on predual Banach spaces c0(Z,1/v)c0(Z,1/v) and dual Banach spaces ℓ∞(Z,1/v)ℓ∞(Z,1/v) of Beurling algebras ℓ1(Z,v)ℓ1(Z,v).

Drusen do disco óptico e tilted disc

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Algebras and their arithmetics,

Reprint of the 1923 edition.

Linear algebras

Mode of access: Internet.

Arithmetica especulativa, y practica, y arte de algebra : en la qual se contiene todo lo que pertenece al arte menor, ò mercantil, y à las dos algebras, racional, è irracional, con la explicación de todas las proposiciones, y problemas de los libros quinto, septimo, octavo, nono y dezimo del principe de la matematica Euclides /

Mode of access: Internet.

Arithmetica especulativa y practiva [sic] y arte de algebra : en la qual se contiene todo lo qe pertenece al arte menor o mercantil, y a las dos algebras, racional e irracional : con la explicacion de todas las proposiciones y problemas de los libros quinto, septimo, octavo, nono y dezimo del principe de la mathematica Euclides /

Mode of access: Internet.

Arithmetica especulativa, y practica, y arte de algebra : en la qual se contiene todo lo que pertenece al arte menor, ò mercantivol, y à las dos algebras, racional, è irracional, con la explicación de todas las proposiciones, y problemas de los libros quinto, septimo, octavo, nono y decimo del principe de la matematica Euclides /

Mode of access: Internet.

Arithmetica especulativa, y practica, y arte de algebra : en la qual se contiene todo lo que pertenece al arte menor, ò mercantil, y à las dos algebras, racional, è irracional, con la explicación de todas las proposiciones, y problemas de los libros quinto, septimo, octavo, nono y dezimo del principe de la matematica Euclides /

Mode of access: Internet.

Arithmetica especulativa, y practica, y arte de algebra : en la qual se contiene todo lo que pertenece al arte menor, ò mercantil, y à las dos algebras, racional, è irracional, con la explicación de todas las proposiciones, y problemas de los libros quinto, septimo, octavo, nono y decimo del principe de la matematica Euclides /

Mode of access: Internet.

On the structure of Hopf algebras

Caption title.

Lie algebras /

"Winter 1956."

Quantum doubles from a class of noncocommutative weak Hopf algebras

The concept of biperfect (noncocommutative) weak Hopf algebras is introduced and their properties are discussed. A new type of quasi-bicrossed products is constructed by means of weak Hopf skew-pairs of the weak Hopf algebras which are generalizations of the Hopf pairs introduced by Takeuchi. As a special case, the quantum double of a finite dimensional biperfect (noncocommutative) weak Hopf algebra is built. Examples of quantum doubles from a Clifford monoid as well as a noncommutative and noncocommutative weak Hopf algebra are given, generalizing quantum doubles from a group and a noncommutative and noncocommutative Hopf algebra, respectively. Moreover, some characterizations of quantum doubles of finite dimensional biperfect weak Hopf algebras are obtained. (C) 2004 American Institute of Physics.