Cordage, basketry and containers at the Pleistocene-Holocene boundary in southwest Europe. Evidence from Coves de Santa Maira (Valencian region, Spain)

In this study we present evidence of braided plant fibres and basketry imprints on clay recovered from Coves de Santa Maira, a Palaeolithic-Mesolithic cave site located in the Mediterranean region of Spain. The anatomical features of these organic fibre remains were identified in the archaeological material and compared with modern Stipa tenacissima (esparto grass). Based on direct dating, the fragments of esparto cord from our site are the oldest worked plant fibres in Europe. Sixty fragments of fired clay are described. The clay impressions have allowed us to discuss the making of baskets and containers. According to their attributes and their functional interpretation, we have grouped them into five types within two broad categories, hearth plates and baskets or containers. The clay pieces identified as fragments of containers with basketry impressions are less common than those of hearth plate remains and they are concentrated in the Epipalaeolithic occupation material (13.2-10.2 ka cal bp). The clay impressions from Santa Maira indicate that some fibres were treated or flattened, a preparation process that is known from historical and ethnological sources

Car d’hom cert era: Pràctiques de canibalisme en el Mesolític de les Coves de Santa Maira (Castell de Castells, la Marina Alta, Alacant)

Es presenten evidències de pràctiques antropofàgiques en un grup del Mesolític mediterrani. S’han documentat trenta restes humanes en el nivell mesolític de les coves de Santa Maira. A més de la descripció de les marques antropogèniques identificades, també se situa la troballa en el seu context regional dins les pautes de subsistència dels grups mesolítics de la zona, i es plantegen hipòtesis sobre la seua intencionalitat

Innovación en las enseñanzas universitarias: experiencias presentadas en las III Jornadas de Innovación Educativa de la ULL

En este libro se recoge un conjunto de experiencias de innovación educativa desarrolladas en la ULL en el curso 2011-12. Se abordan distintos ámbitos y ramas del conocimiento, y ocupan temáticas variadas que han sido desarrolladas con rigor, y con un claro potencial para su extrapolación a efectos de la mejora educativa en el ámbito universitario. Esta publicación constituye una primera edición de una serie que irá recogiendo las experiencias de innovación educativa de la ULL. Este es un paso relevante para su impulso en nuestra institución, como lo es el de su vinculación con la investigación educativa, para potenciar su publicación en las revistas científicas en este ámbito cada vez más pujante y relevante para las universidades. Sobre todo representan el deseo y el compromiso del profesorado de la ULL para la mejora del proceso educativo mediante la investigación, la evaluación y la reflexión compartida de nuestras prácticas y planteamientos docentes

Reaction cross-sections for the H+HCl(DCl) reaction: A quasiclassical trajectory study

The H+HCl and H+DCl reactions have been investigated with quasiclassical trajectory calculations performed on the ab initio G3 potential energy surface of Allison et al. [J. Phys. Chem. 100 (1996) 13575]. The cross-sections for the abstraction and exchange channels have been calculated for collision energies from threshold to 2.4 eV. The role of initial rotation and vibration on reactivity is addressed and the results are compared to experimental measurements and to previous theoretical calculations.Supported by the DGICYT of Spain under Grant PB95-0918-C03.Peer Reviewe

Influence of vibration in the reactive scattering of D + MuH: The effect of dynamical bonding

8 pags., 6 figs.The dynamics of the D + MuH(v = 1) reaction has been investigated using time-independent quantum mechanical calculations. The total reaction cross sections and rate coefficients have been calculated for the two exit channels of the reaction leading, respectively, to DMu + H and DH + Mu. Over the 100-1000 K temperature range investigated the rate coefficients for the DMu + H channel are of the order of 10 cm s and those for the DH + Mu channel vary between 1 × 10 and 8 × 10 cm s. These results point to a virtually barrierless reaction for the DMu + H channel and to the presence of a comparatively small barrier for the DH + Mu channel and are consistent with the profiles of their respective collinear vibrationally adiabatic potentials (VAPs). The effective barrier in the VAP of the DH + Mu channel is located in the reactant valley and, consequently, translation is found to be more efficient than vibration for the promotion of the reaction over a large energy interval in the post threshold region. Below this barrier, the DH + Mu channel can be accessible through an indirect mechanism implying crossing from the DMu + H pathway. The most salient feature found in the present study is revealed in the total reaction cross section for the DMu + H channel, which shows a sharp resonance caused by the presence of a deep well in the vibrationally adiabatic potential. This well has a dynamical origin, reminiscent of that found recently in the vibrationally bonded BrMuBr complex [Fleming, et al., Angew. Chem., Int. Ed., 2014, 53, 1], and is due to the stabilizing effect of the light Mu atom oscillating between the heavier H and D isotopes and to the bond softening associated with vibrational excitation of MuH.This work has been funded by the Spanish Ministry of Science and Innovation under grants CSD2009-00038 and by the MINECO of Spain under grant FIS2013-48087-C2-1P, CTQ2012-37404, CTQ-2015-65033-P. VJH acknowledges also funding from the EU project ERC-2013-Syg 610256. The research was conducted within the Unidad Asociada Química Física Molecular between the UCM and the CSIC of Spain.Peer Reviewe

INFRARED SPECTROSCOPY OF THE WEAKLY BONDED CO-Cl2Cl_{2} COMPLEX

Author Institution: U.S. Army Ballistic Research Laboratory, SLCRR-IB-I; Department of Chemical Engineering, University of Florida; Department of Chemistry, Denison University; Department de Quimica-Fisica, Facultad de Quimica; Department of Chemistry, University of Southern CaliforniaHigh-resolution rovibrational absorption spectra of the weakly bonded CO-$Cl_{2}$ complex have been recorded in the $2143 cm^{-1}$ region by existing the CO chromophore with a tunable diode laser. The spectra indicate that CO-$Cl_{2}$ is linear and semi-rigid. By fitting the data to a linear-molecule Hamiltonian, the following constants (in $cm^{-1}$) were obtained; $v_{0}= 2149.5424(4), B^{\prime} =0.031582339), B^{\prime} = 0.0314867(52), D_{J}^{\prime} = 4.37(25) \times 10^{-8}$, and $D_{J}^{\prime} = 4.58(35)\times 10^{-8}$. The distance between the CO and $Cl_{2}$ centers of mass is approximately 4.78 \AA. The orientation of CO is not determined experimentally. However, $Cl_{2}$ appears to act as a classical $\sigma$-electron acceptor, while CO behaves like a weak Lewis base, donating charge from the carbon side via the weakly antibonding 5$\sigma$ orbital, thereby raising the CO vibrational frequency."

Quantum study of reaction O (3P) + H2(v,j) → OH + H: OH formation in strongly UV-irradiated gas

13 pags., 3 figs., 1 tab.The reaction between atomic oxygen and molecular hydrogen is an important one in astrochemistry as it regulates the abundance of the hydroxyl radical and serves to open the chemistry of oxygen in diverse astronomical environments. However, the existence of a high activation barrier in the reaction with ground-state oxygen atoms limits its efficiency in cold gas. In this study we calculated the dependence of the reaction rate coefficient on the rotational and vibrational state of H2, and evaluated the impact on the abundance of OH in interstellar regions strongly irradiated by far-UV photons where H2 can be efficiently pumped to excited vibrational states. We used a recently calculated potential energy surface and carried out time-independent quantum mechanical scattering calculations to compute rate coefficients for the reaction O (3P) + H2 (v, j) → OH + H, with H2 in vibrational states v = 0-7 and rotational states j = 0-10. We find that the reaction becomes significantly faster with increasing vibrational quantum number of H2. However, even for high vibrational states of H2 (v = 4-5), for which the reaction is barrierless, the rate coefficient does not strictly attain the collision limit and still maintains a positive dependence with temperature. We implemented the calculated state-specific rate coefficients in the Meudon PDR code to model the Orion Bar PDR and to evaluate the impact on the abundance of the OH radical. We find the fractional abundance of OH is enhanced by up to one order of magnitude in regions of the cloud corresponding to AV = 1.3-2.3 mag, compared to the use of a thermal rate coefficient for O + H2, although the impact on the column density of OH is modest, about 60%. The calculated rate coefficients will be useful to model and interpret JWST observations of OH in strongly UV-illuminated environments.We acknowledge the Spanish Ministerio de Ciencia e Innovación for funding support through the projects AYA2016-75066-C2-1-P, FIS2017-83473-C2, PGC2018-096444-B-I00, PID2019-106110GB-I00, and PID2019-107115GB-C21. A.V. and P.G.J. acknowledge funding by Fundación Salamanca City of Culture and Knowledge (programme for attracting scientific talent to Salamanca). M.A. also acknowledges funding support from the Ramón y Cajal programme of Spanish Ministerio de Ciencia e Innovación (grant RyC-2014-16277)