Non-Symmetric Hall-Littlewood Polynomials

Using the action of the Yang-Baxter elements of the Hecke algebra on polynomials, we define two bases of polynomials in n variables. The Hall-Littlewood polynomials are a subfamily of one of them. For q=0, these bases specialize into the two families of classical Key polynomials (i.e. Demazure characters for type A). We give a scalar product for which the two bases are adjoint of each other.Comment: Dedicated to Adriano Garsi

In situ thermochemical sulfate reduction during ore formation at the Itxaspe Zn-(Pb) MVT occurrence (Basque-Cantabrian basin, Northern Spain)

Organic matter is thought to play a role in the genesis of many Mississippi Valley-type (MVT) deposits, acting as a reducing agent during thermochemical sulfate reduction (TSR). Although TSR is an extremely slow reaction t low temperatures (<100ºC), under favorable conditions it may supply the necessary reduced sulfur during ore formation. To test this hypothesis, the Itxaspe Zn-(Pb) MVT occurrence in the Basque-Cantabrian basin (Northern Spain) was studied. Sphalerite, the main ore phase, is generally found disseminated in Urgonian (Lower Cretaceous) carbonates, and in close relationship with solid bitumen. The bitumen source rock was very likely deposited in a marine marginal setting. Differences in composition of the bitumen samples are attributed to a fractionation during hydrocarbon expulsion and/or migration. The fluids involved in ore deposition were low temperature (Th ~130ºC), Na-Ca-Cl-(K-Mg)-type brines (salinities ~12.5 equiv. mass % NaCl). The origin of brine solutes (including sulfate) is related to the dissolution of Mesozoic evaporite units, although the contribution of evaporated seawater brines cannot be ruled out. The temperatures of ore deposition, the close relationship between the bitumen and ore phases, the presence of aromatic sulfur-bearing compounds and the d34S of sulfides and sulfates are consistent with an in situ TSR during ore formation in the Itxaspe Zn-(Pb) occurrence. Therefore, at least for small mineralizations like Itxaspe, our conclusion is that the necessary reduced sulfur can be supplied by TSR during ore genesis at the site of metal deposition

Description of the first fossil species of Bathynectes (Brachyura, Polybiidae) in the Badenian (middle Miocene) of the Medobory Hills (Ukraine, Central Parathetys), with remarks on its habitat ecology

El descobriment d’una nova espècie del gènere Bathynectes Stimpson, 1871 (B. muelleri n. sp.) en els complexes d’esculls del Badenià (Miocè mig) de la pedrera de Maksymivka (Conca d’avantpaís dels Càrpats septentrionals), en els denominats Turons Medobory, prop de Ternopil (Ucraïna), representa el primer registre fòssil d’aquest gènere. La majoria de les espècies actuals d’aquest gènere, són d’aigües profundes. Es descriu Bathynectes muelleri n. sp. i s’argumenta el possible origen del gènere i els seus canvis d’hàbitat al llarg del temps. També s’analitza l’abundor de restes de decàpodes al complex d’esculls de Maksymivka i es presenta una hipòtesi per explicar la seva presència.El descobriment d’una nova espècie del gènere Bathynectes Stimpson, 1871 (B. muelleri n. sp.) en els complexes d’esculls del Badenià (Miocè mig) de la pedrera de Maksymivka (Conca d’avantpaís dels Càrpats septentrionals), en els denominats Turons Medobory, prop de Ternopil (Ucraïna), representa el primer registre fòssil d’aquest gènere. La majoria de les espècies actuals d’aquest gènere, són d’aigües profundes. Es descriu Bathynectes muelleri n. sp. i s’argumenta el possible origen del gènere i els seus canvis d’hàbitat al llarg del temps. També s’analitza l’abundor de restes de decàpodes al complex d’esculls de Maksymivka i es presenta una hipòtesi per explicar la seva presència.The discovery of a new species of the genus Bathynectes Stimpson, 1871 (B. muelleri n. sp.) in the Badenian (middle Miocene) coralgal frameworks of the Maksymivka quarry (northern Carpathian Foredeep Basin), in the so-called Medobory Hills, near Ternopil (Ukraine), represents the first recognition as fossil of this genus. All extant species of this genus are mainly living in deep water habitats. Bathynectes muelleri n. sp. is described herein with comments on both the possible origin of the genus and the habitat changes through time. The abundance of decapod remains in this coralline environment is also analysed and a hypothesis for their presence presented

Breu recorregut històric per Can Fàbregas - Sedunion. Mollet del Vallès, 1900-2001

L’any 2003, el CEM va dedicar les Jornades de Tardor a les empreses em· blemàtiques de la industrialització de Mollet del Vallès. Llavors vaig escriure un article sobre la indústria sedera de Can Fàbregas-Sedunion, que es va publicar al volum 19 de Notes, l’any 2004. Quan l’any 2014 el CEM es planteja dedicar les Jornades a les indústries tèxtils de la nostra ciutat, es va veure clar que s’havia de tornar a parlar de Can Fàbregas-Sedunion. Reprenem la història d’aquesta important empresa sedera que durant un segle va deixar sentir el soroll dels seus telers a Mollet i fem un breu recorregut per la seva trajectòria històrica, tot comentant aspectes que a l’anterior article no vam destacar

Mission design for LISA Pathfinder

Here we describe the mission design for SMART-2/LISA Pathfinder. The best trade-off between the requirements of a low-disturbance environment and communications distance is found to be a free-insertion Lissajous orbit around the first co-linear Lagrange point of the Sun-Earth system L1, 1.5x 10^6 km from Earth. In order to transfer SMART-2/LISA Pathfinder from a low Earth orbit, where it will be placed by a small launcher, the spacecraft carries out a number of apogee-raise manoeuvres, which ultimatively place it to a parabolic escape trajectory towards L1. The challenges of the design of a small mission are met, fulfilling the very demanding technology demonstration requirements without creating excessive requirements on the launch system or the ground segment.Comment: 7 pages, 6 figures, 5th International LISA Symposium, see http://www.landisoft.de/Markus-Landgra