Cost-Saving production technologies and strategic delegation

This work analyzes a managerial delegation model in which firms that produce a differentiated good can choose between two production technologies: a low marginal cost technology and a high marginal cost technology. For the former to be adopted more investment is needed than for the latter. By giving managers of firms an incentive scheme based on a linear combination of profit and sales revenue, we find that Bertrand competition provides a stronger incentive to adopt the cost-saving technology than the strict profit maximization case. However, the results may be reversed under Cournot competition. We show that if the degree of product substitutability is sufficiently low (high), the incentive to adopt the cost-saving technology is larger under strict profit maximization (strategic delegation).

Museos y turismo: expectativas y realidades

Cap. 1. La interrelación entre los sistemas turístico y patrimonial: más allá de los discursos apologéticos y las prácticas reduccionistas. Iñaki Arrieta Urtizberea Cap. 2. Turistas y museos. Apocalípticos e integrados. José Antonio Donaire. Cap. 3. Turismo cultural. Ficciones sobre realidades, realidades sobre invenciones. Agustín Santana Talavera, Pablo Díaz Rodríguez y Alberto Jonay Rodríguez Darias. Cap. 4. ¿Museos a la deriva o continentes a la deriva?: consecuencias de la crisis financiera para los museos de América del Norte, Yves Bergeron. Cap. 5. Patrimonio histórico, turismo, economía: ¿un desafío o una alianza? El caso de Populonia (Toscana, Italia). Daniele Manacorda. Cap. 6. Diagnóstico posrevolucionario en Túnez: delirio turístico, fiebre museística y la locura del jazmín. Habib Saidi. Cap. 7. Patrimonio etnológico: ¿recurso socioeconómico o instrumento sociopolítico? El caso de los Astilleros Nereo de Málaga. Esther Fernández de Paz. Cap. 8. De Rampas y Pasarelas: los museos Guggenheim como espacios artísticos genéricos. Sophia Carmen Vackimes. Cap. 9. El patrimonio como fuente de desarrollo sostenible en las regiones del interior norte de Portugal: el caso del municipio de Vieira do Minho. Eduardo Jorge Duque. Cap. 10. Museos, turismo y desarrollo local: el caso de Belmonte, Portugal. Luís Silva. Cap. 11. ¿Existen razones de eficiencia económica en las decisiones de cierre parcial de algunos museos locales? Análisis del caso del Museo Darder (Banyoles) en el contexto de los museos de Cataluña. Gabriel Alcalde, Josep Burch, Modest Fluvià, Ricard Rigall i Torrent y Albert Saló.

The "old" Celtic goddess Sena: a new testimony from Aquitania

Homenaje a Ignacio Barandiarán Maestu / coord. por Javier Fernández Eraso, Juan Santos Yanguas.

Studying the influence of substitutional elements on mechanical behavior of Alloy 718

In nickel-based superalloys, substitutional solute species have a strong impact on in service mechanical properties as well as on oxidation and corrosion resistances. In alloy 718, recent studies carried out by tensile tests highlighted the fact that refractory solute species are able to interact strongly with mobile dislocations during plastic deformation, generating dynamic strain ageing, and, in wide ranges of tests temperatures and strain rates, Portevin-Le Chatelier effect. The precise nature of the substitutional element responsible for such a dynamic interaction is still subject to debate. We addressed this question by means of mechanical spectroscopy studies of alloy 718 and various related alloys corresponding to monitored changes in the chemical composition. Only a single internal friction relaxation peak has been observed for all the studied alloys. By analyzing the damping behavior of these alloys at different imposed solicitation frequencies by sweeping a large temperatures range, the activation energies of the relaxation process and the type of mechanism involved have been determined. The process is a "Zener relaxation" in the alloys, i.e. a substitutional atoms dipole reorientation under applied stress. The results tend to prove that Niobium is not involved in the relaxation process whereas Molybdenum content seems to play an important role in the relaxation intensity.