The fabrication and sensor properties of polyaniline-platinum oxide chemoresistors in the presence of combustible gases such as hydrogen, methane, ethylene, acetylene and carbon monoxide is reported. Prior conditioning of the sensors in a hydrogen atmosphere resulted in increased selectivity and sensitivity for hydrogen in air at concentrations between 1000 and 5400 ppm. The conditioned sensors showed negligible response to hydrocarbons and carbon monoxide.

A c c e p t e d m a n u s c r i p t A c c e p t e d m a n u s c r i p t A c c e p t e d m a n u s c r i p t Abstract 33 34We present a method for producing metal-coated low-density (<~1600 kg m -3 ) aggregate 35 silicate dust particles for use in hypervelocity impact (HVI) experiments. Particles fabricated 36 using the method are shown to have charged and electrostatically accelerated in the Max 37Planck Institut für Kernphysik (MPI-K) 2 MV Van de Graaff accelerator, allowing the 38 production of impact ionization mass spectra of silicate particles (impacting at velocities 39 ranging from <4 km s -1 to >30 km s -1 , corresponding to sizes of >1 µm to <0.1 µm) using the 40 Large Area Mass Analyser (LAMA) instrument, designed for cosmic dust detection in space. 41Potential uses for the coated grains, such as in the calibration of aerogel targets similar to 42 those used on the Stardust spacecraft, are also discussed. 43 44 45

Anorthite, the Ca‐rich end‐member of plagioclase feldspar, is a dominant mineral component of the Lunar highlands. Plagioclase feldspar is also found in comets, meteorites and stony asteroids. It is therefore expected to contribute to the population of interplanetary (and circumplanetary) dust grains within the solar system. After coating micron‐ and submicron‐sized grains of Anorthite with a conductive layer of Platinum, the mineral was successfully accelerated to hypervelocity speeds in the Max Planck Institut für Kernphysik's Van de Graaff accelerator. We present impact ionization mass spectra generated following the impacts of anorthite grains with a prototype mass spectrometer (the Large Area Mass Analyser, LAMA) designed for use in space, and discuss the behavior of the spectra with increasing impact energy. Correlation analysis is used to identify the compositions and sources of cations present in the spectra, enabling the identification of several molecular cations (e.g., CaAlO2, CaSiO2, Ca2AlO3/CaAlSi2O2) which identify anorthite as the progenitor bulk grain material.

Microbial communities in subsurface coal seams are responsible for the conversion of coal organic matter to methane. This process has important implications for both energy production and our understanding of global carbon cycling. Despite the environmental and economic importance of this process, little is known about which components of the heterogeneous coal organic matter are biodegradable under methanogenic conditions. Similarly, little is known about which taxa in coal seams carry out the initial stages of coal organics degradation. To identify the biodegradable components of coal and the microorganisms responsible for their breakdown, a subbituminous coal was fractionated into a number of chemical compound classes which were used as the sole carbon source for growth by a coal seam microbial community. This study identifies 65 microbial taxa able to proliferate on specific coal fractions and demonstrates a surprising level of substrate specificity among members of this coal-degrading microbial consortia. Additionally, coal kerogen, the solvent-insoluble organic component of coal often considered recalcitrant to microbial degradation, appeared to be readily converted to methane by microbial degradation. These findings challenge our understanding of coal organic matter catabolism and provide insights into the catabolic roles of individual coal seam bacteria.