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Schlieren, Switzerland

Henkensmeier D.,Paul Scherrer Institute | Henkensmeier D.,Korea Institute of Science and Technology | Ben youcef H.,Paul Scherrer Institute | Ben youcef H.,Chemspeed Technologies AG | And 3 more authors.
Journal of Membrane Science | Year: 2013

A new membrane material for polymer electrolyte fuel cells (PEFC), ETFE-. graft-poly(. α-methylstyrenesulfonic acid-. co-methacrylonitrile), is presented. Its preparation by radiation-induced grafting and the dependence of the reaction kinetics on the irradiation dose (3 and 15. kGy) and crosslinker concentration are reported. A series of divinylbenzene crosslinked and uncrosslinked membranes is characterised with respect to ion exchange capacity (IEC) (up to 2.1. mmol/g), proton conductivity (up to 92. mS/cm at room temperature), and water uptake (10-67%). Furthermore, the correlation between the dimensional stability of the membrane and the graft level is presented. The ex situ hydrolytic stability of the membranes was tested and analysed by infrared (IR) spectroscopy. In a hydrogen/oxygen PEFC at 80. °C, Nafion 212 and a 35. μm thick grafted membrane showed the same performance, whereas the hydrogen permeability of the grafted membrane is only one third compared to that of Nafion 212. © 2013 Elsevier B.V. Source

Mottay P.,Brechbuehler Inc. | Stoop R.,Brechbuhler AG | Picher P.,Brechbuhler AG | Hofstetter U.,Brechbuhler AG
American Laboratory | Year: 2010

Brechbuehler, Inc., Houston, TX, has designed an Odor Search tool aimed to match GC-MS library search results and identify odor-active compounds without having to perform GC-O. Odor Search takes the results from a library search performed from a GC-MS run and compares each GC-MS library match to the internal odor database. Odor Search reads the results file, compares each library match based on the CAS number, and displays the chromatogram and raw spectrum and the library spectrum. The software requires the compound name, CAS number, and associated odor, while additionally, specific information includes the structure file and retention indexes. Odor Search also allows comparisons of chromatograms and a chromatogram database can be created from the results file. The tool can also compare sample to the chromatogram database to gain a knowledge of essential oils contained in it. Source

Spangenberg J.E.,University of Lausanne | Ferrer M.,University of Lausanne | Ferrer M.,Brechbuhler AG | Jacomet S.,University of Basel | And 2 more authors.
Organic Geochemistry | Year: 2014

Excellently preserved animal bone and antler artifacts are numerous among the archaeological finds in Neolithic Alpine lakeshore settlements. Use-wear and production traces on the surface of these artifacts include cuttings and hammer or grinding traces; there are also large bright and shiny areas. We have explored the origin of such shiny surfaces using molecular and isotopic analysis of the lipids staining freshly unearthed and non-conserved bone and antler artifacts from a recent excavation at the underground parking garage of Zurich Opera House (Switzerland), dating to ca. 3230-2729 BC. A set of 10 artifacts, covering distinct osteological and typological features, was selected for study. The lipids were extracted separately from the surfaces of the tapered thinner working part and the wider handling area of each tool. The lipid distribution was characterized by a significant amount of animal sterols (cholesterol, cholestanol, coprostanol and epicholestanol), wax n-alkanes, n-alkan-1-ols and phytosterols (β-sitosterol, sitostanol) and abundant saturated, mono- and polyunsaturated fatty acids (FAs) in the C14-C26 range. The δ13C values of the main FAs, and the relatively high C18:2 content (up to 31% of total FAs) and significant content of C18:3 (up to 6%) indicated that the lipids on the surface of the artifacts were a mixture of C3 plant oils rich in linoleic acid and (indigenous) animal lipids. The results provide evidence for the archaeological hypothesis that the bone and antler artifacts were specific tools which were deliberately fashioned, and pretreated and maintained with a preservative material based on plant oil likely from seeds of Linum usitatissimum (flax) and Papaver somniferum (poppy), with probably some contribution from Corylus avellana (hazelnut) and Brassica rapa (turnip). © 2014 Elsevier Ltd. Source

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