Geoenvironmental Site Characterization to Treatment: Lead Contaminated Firing Range Case Study

The methodologies employed and the results obtained during the performance of a comprehensive geoenvironmental site characterization case study are presented. The study demonstrates the need to integrate research tools from various disciplines including geotechnical, analytical and mineralogical specialties in order to develop a thorough understanding of both the nature and extent of the environmental issues associated with the site and the most viable alternatives for its remediation. Particle size distribution coupled with contaminant fractionation studies and mineralogical and micromorphological analyses were performed on the soil samples collected onsite to identify the metals present, their concentrations and the mechanisms of transformation. Lead fragments found in the soil samples were analyzed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Quantitative phase analysis studies showed that the fine soil fractions contained considerable amounts of lead carbonates, which owing to their colloidal nature could not be readily removed using gravitational methods. To mitigate this deficiency, a bench-scale chemical treatment experiment based on dissolution of the Pb was performed. Although the study is still in progress, the benefits derived from using the multi-disciplinary approach for site characterization described herein warrant consideration by others who may face similar challenges in the future

Diethyl­enetriaminium hexa­fluorido­titanate(IV) fluoride

The title compound, (C6H21N4)[TiF6]F, was synthesized by the reaction of TiO2, tris­(2-amino­ethyl)amine, HF and ethanol at 463 K in a microwave oven. The crystal structure consists of two crystallographically independent [TiF6]2− anions, two fluoride anions and two triply-protonated tris­(2-amino­ethyl)­amine cations. The Ti atoms are coordinated by six F atoms within slightly distorted octa­hedra. The anions and cations are connected by inter­molecular N—H⋯F hydrogen bonds

Tris(ethyl­enediamine-κ2 N,N′)cadmium hexa­fluoridogermanate

In the title compound, [Cd(C2H8N2)3](GeF6), the CdII atom, lying on a 32 symmetry site, is coordinated by six N atoms from three ethyl­enediamine (en) ligands in a distorted octa­hedral geometry. The Ge atom also lies on a 32 symmetry site and is coordinated by six F atoms. The en ligand has a twofold rotation axis passing through the mid-point of the C—C bond. The F atom is disordered over two sites with equal occupancy factors. In the crystal, the [Cd(en)3]2+ cations and [GeF6]2− anions are connected through N—H⋯F hydrogen bonds, forming a three-dimensional supra­molecular network

Conversion of glucose to lactic acid derivatives with mesoporous Sn-MCM-41 and microporous titanosilicates

BACKGROUND: The production of value-added products from biomass has acquired increasing importance due to the high worldwide demand for chemicals and energy, uncertain petroleum availability and the necessity of finding environmentally friendly processes. This paper reports work on the synthesis of several catalysts for the conversion of glucose to methyl lactate. RESULTS: A MCM-41 type mesoporous material containing tin (Si/Sn = 55) was developed with a uniform ordered mesoporous structure, high specific surface area and high pore volume. Sn-MCM-41 was tested in three consecutive catalytic cycles to evaluate its reusability giving methyl lactate yields of 43%, 41% and 39%, in each cycle. The slightly reduction in activity could be explained by the reduction in the accessibility of active centers due to the adsorption of reaction products and structural changes. Microporous titanosilicates and MFI-type zeolite ZSM-5 showed a lower catalytic performance, but exfoliated materials gave higher yields of methyl lactate and pyruvaldehyde dimethyl acetal than their respective layered precursors. CONCLUSIONS: Sn-MCM-41 material showed good results in the conversion of glucose to methyl lactate over three catalytic cycles and exfoliated materials facilitated the access of glucose to the catalytic sites and fast desorption of products.The authors gratefully thank the Spanish Ministry of Economy and Competitiveness (MINECO) for financial support through project MAT2010-15870, as well as the Regional Government of Aragón (DGA), the Obra Social La Caixa (GA-LC-019/2011) and the European Social Fund (ESF). C. Casado also thanks MINECO for the ‘Ramón y Cajal’ program (RYC-2011-08550)

Tendances de la néologie dans la radio (analyse à travers la Radio France International)

La diffusion de RFI dans le monde entier (y compris en Azerbaïjan) nous a incité à étudier dans cette thèse les mots nouveaux produits par les acteurs de la radio, et à analyser à travers le corpus fourni par RFI les aspects suivants : - le sentiment néologique des mots. Les mots du corpus sont-ils perçus comme nouveaux par les natifs ? -les moyens de formation. Quels sont les procédés privilégiés pour la création des mots ? - les lieux d apparition des mots nouveaux. Dans quels domaines surgissent-ils le plus ? - la lexicalisation des mots. Quel est le taux de la lexicalisation des mots nouveaux produits par les acteurs de RFI ? - les tendances de la néologie actuelle du français dans la radio.STRASBOURG-B.N.U.S. (674821001) / SudocSudocFranceF