La duración de las huelgas: evidencia empírica para España

El objetivo de este artículo es analizar empíricamente los determinantes de la duración de las huelgas en España utilizando datos de registro de la Estadística de Huelgas y Cierres Patronales (Ministerio de Trabajo y Asuntos Sociales). Para ello, se estiman modelos de duración. Los resultados muestran que las huelgas duran menos cuanto mayor es el número de trabajadores participantes, si hay varios convenios aplicables a las unidades en huelga, si son huelgas de Comunidad Autónoma, si se trata de huelgas cuyo motivo es la solidaridad, en actividades financieras e inmobiliarias, electricidad, agua y gas, vehículos y material de transporte, industria química y refinerías, hostelería, industria del papel y artes gráficas, educación e investigación, e industria transformadora de metales, si implican a Ceuta, Castilla-León, Castilla-La Mancha, La Rioja, Asturias, Cataluña, Madrid y Andalucía, en general si son posteriores a 1986-1987, y si se producen en el segundo y cuarto trimestre del año. Duran más cuando existen servicios mínimos, se convocan por el sindicato ELA-STV, por otros sindicatos distintos a UGT, CCOO, ELA-STV, INTG, USO y CNT, y por asambleas vecinales y formaciones políticas, cuando obtienen mayor ratio de seguimiento, afectan a una empresa o al sector, el motivo es la negociación colectiva, cuestiones salariales, de organización y sistemas de trabajo y de incumplimiento de acuerdos o normas legales, se producen en el sector privado, en el sector pesquero, y afectan a Extremadura y Cantabria.The aim of this paper is to empirically analyse the determinants of strike duration in Spain using registry data from the Estadística de Huelgas y Cierres Patronales (Spanish Ministry of Labour and Social Affairs). The empirical methodology includes estimation of duration models. The results show that strikes are shorter the higher the number of strikers, in the presence of several applicable agreements to strike units, in Autonomous Community strikes, when the strike motive is solidarity, in financial services and property developer, electricity, water and gas, cars and transport material, chemical and refineries, hotel trade, paper and printing, education and research, and metals transformation, when Ceuta, Castilla-León, Castilla-La Mancha, La Rioja, Asturias, Cataluña, Madrid and Andalucía are involved, in general after 1986-1987, and in the second and fourth quarters of the year. They last longer in the presence of minimum services, when the strike call comes from the ELA-STV union, from unions different to UGT, CCOO, ELA-STV, INTG, USO and CNT, and from neighbourhood assemblies and politic formations, when the support to the strike call is high, if they affect to a firm or a sector, when the strike motive is collective bargaining, related to wages, organization and working conditions, and violations of agreements or legal rules, in the private sector, in the fishing sector, and involving Extremadura and [email protected]; [email protected]

Semiconductor Porous Hydrogen-Bonded Organic Frameworks Based on Tetrathiafulvalene Derivatives

Herein, we report on the use of tetrathiavulvalene-tetrabenzoic acid, H4TTFTB, to engender semiconductivity in porous hydrogen-bonded organic frameworks (HOFs). By tuning the synthetic conditions, three different polymorphs have been obtained, denoted MUV-20a, MUV-20b, and MUV-21, all of them presenting open structures (22, 15, and 27%, respectively) and suitable TTF stacking for efficient orbital overlap. Whereas MUV-21 collapses during the activation process, MUV-20a and MUV-20b offer high stability evacuation, with a CO2 sorption capacity of 1.91 and 1.71 mmol g-1, respectively, at 10 °C and 6 bar. Interestingly, both MUV-20a and MUV-20b present a zwitterionic character with a positively charged TTF core and a negatively charged carboxylate group. First-principles calculations predict the emergence of remarkable charge transport by means of a through-space hopping mechanism fostered by an efficient TTF π-π stacking and the spontaneous formation of persistent charge carriers in the form of radical TTF¿+ units. Transport measurements confirm the efficient charge transport in zwitterionic MUV-20a and MUV-20b with no need for postsynthetic treatment (e.g., electrochemical oxidation or doping), demonstrating the semiconductor nature of these HOFs with record experimental conductivities of 6.07 × 10-7 (MUV-20a) and 1.35 × 10-6 S cm-1 (MUV-20b)

Through-space hopping transport in an iodine-doped perylene-based metal–organic framework

Electrically conductive metal-organic frameworks (MOFs) have emerged in the past few years as promising materials towards applications in (opto)electronics, electrocatalysis and energy storage, among others. One of the most common strategies for the design of conductive MOFs is based on the use of electroactive organic ligands and their partial oxidation/reduction to increase the number of charge carriers. Although perylene salts were reported as the first molecular conductors, they have been scarcely explored as building blocks for the construction of conductive MOFs. Herein we report the electrical conductivity enhancement of a microporous perylene-based MOF upon partial ligand oxidation by using two-probe single-crystal devices. The origin of the conductivity enhancement is rationalised by means of spectroscopic studies and quantum-chemical calculations, supporting a through-space hopping transport along the herringbone perylene packing. This study opens the way for the design of conductive MOFs based on perylene building blocks.publishe

A Competing Risks Analysis of Strike Duration in Spain: Agreement and Non-Agreement Outcomes'

En este artículo se analizan los determinantes de la duración de las huelgas en España teniendo en cuenta sus diferentes resultados (acuerdo y desacuerdo). Encontramos que la duración disminuye con el número de huelguistas o con varios acuerdos aplicables a las plantas en huelga. La duración aumenta con los servicios mínimos, el grado de apoyo a la huelga y en las empresas privadas. Con respecto a la tasa de crecimiento del PNB, la duración es pro-cíclica en las huelgas que terminan en acuerdo y contra-cíclica en las que terminan sin acuerdo. La inflación no compensada y no esperada disminuye la duración para las huelgas que terminan en acuerdo y aumenta en las que acaban en desacuerdo. La reforma de 1997, con un amplio consenso social, aumenta las oportunidades de resultados de acuerdo

Implementing Mesoporosity in Zeolitic Imidazolate Frameworks through Clip-Off Chemistry in Heterometallic Iron-Zinc ZIF-8

Bond breaking has emerged as a new tool to postsynthetically modify the pore structure in metal-organic frameworks since it allows us to obtain pore environments in structures that are inaccessible by other techniques. Here, we extend the concept of clip-off chemistry to archetypical ZIF-8, taking advantage of the different stabilities of the bonds between imidazolate and Zn and Fe metal atoms in heterometallic Fe-Zn-ZIF-8. We demonstrate that Fe centers can be removed selectively without affecting the backbone of the structure that is supported by the Zn atoms. This allows us to create mesopores within the highly stable ZIF-8 structure. The strategy presented, combined with control of the amount of iron centers incorporated into the structure, permits porosity engineering of ZIF materials and opens a new avenue for designing novel hierarchical porous frameworks

Multivariate sodalite zeolitic imidazolate frameworks: a direct solvent-free synthesis

Different mixed-ligand Zeolitic Imidazolate Frameworks (ZIFs) with sodalite topology, i.e. isoreticular to ZIF-8, unachievable by conventional synthetic routes, have been prepared using a solvent-free methodology. In particular, the versatility of this method is demonstrated with three different metal centres (Zn, Co and Fe) and binary combinations of three different ligands (2-methylimidazole, 2-ethylimidazole and 2-methylbenzimidazole). One combination of ligands, 2-ethylimidazole and 2-methylbenzimidazole, results in the formation of SOD frameworks for the three metal centres despite this topology not being obtained for the individual ligands. Theoretical calculations confirm that this topology is the lowest in energy upon ligand mixing