Singular Langmuir-Hinshelwood reaction-diffusion problems. strong absorption under quasi-isothermal conditions

The steady state reaction-diffusion problem is considered for a permeable catalytic particle with Langmuir-Hinshelwood kinetics under isothermal and quasi-isothermal conditions. It is known that there may be multiple solutions due to either strong adsorption or external thermal effects; in the first case, an arbitrarily large number of solutions may appear for symmetric pellets in two and three dimensions. An asymptotic analysis provides analytical expressions for the response curve of the particle and for the multiplicity bounds. The approximate results compare quite well with those computed numerically, even in cases in which the gauge functions of the approximation scheme are of the logarithmic type

Large activation energy analysis of the ignition of self-heating porous bodies

A large activation energy analysis of the problem of thermal ignition of self-heating porous bodies is carried out by means of a regular perturbation method. A correction to the well-known Frank-Kamenetskii estimate of the ignition limit is calculated, for symmetric bodies, by using similarity properties of the equations giving higher order terms in an expansion in powers of \/E (E = activation energy). Our estimate compares well with numerical results, and differs from others in the literature, which are not better than Frank-Kamenetskii's one from an asymptotic point of view. Dirichlet and Robin type of boundary conditions are considered. A brief analysis of the extinction problem for no reactant consumption is also presented

Madrid y América en la Edad Moderna: una revisión historiográfica,II.

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Formas de vida del clero regular en la época de la Contrarreforma: los franciscanos descalzos a la luz de la legislación provincial.

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Los mercaderes novohispanos: control virreinal y fraude fiscal en el primer tercio del siglo XVII.

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Los conventos franciscanos observantes en el Archivo Iberoamericano.

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Groupoïde fondamental et d'holonomie de certains feuilletages réguliers

Let M be a manifold with a regular foliation F. We recall the construction of the fundamental groupoid and the homotopy groupoid associated to. F. We describe some interesting particular cases and give some gluing techniques. We characterize the cases where these groupoids are Hausdorff spaces. We study in particular both groupoids associated to foliations with Reeb componente

Solenes [sic] i grandiosas fiestas, q[ue] la noble i leal ciudad de Valencia a echo por la Beatificacion desu Santo Pastor i Padre D. Tomas de Villanueva...

Sign. : []\p8\s, A-Z-\p8\s, Aa-Nn\p8\s, Oo\p4\sPort. orladaEsc. xil. de la Compañía de IHS en la p. /4/ del fina