High-accuracy multiphase humidity measurements using TDLAS: application to the investigation of ice growth in simulated cirrus clouds

Water vapor is a crucial quantity in cloud studies at the aerosol and cloud chamber AIDA (Aerosol Interactions and Dynamics in the Atmosphere). The chamber is equipped with three tunable diode laser (TDL) hygrometers for the accurate and precise measurement of water vapor and total water concentration as well as liquid/ice water content down to the low ppb range. This thesis presents instrumental improvements, new developments, and assessment of the performance of these instruments – with special emphasis on measurement accuracy. For online evaluation of the AIDA TDL hygrometers’ measurement data, there is demand for a fast, accurate, and robust method which has been developed with the advanced integrative fitting algorithm. Besides utilization at AIDA, this algorithm could find further application in atmospheric trace gas measurements, combustion process analysis, or could be integrated into embedded systems with limited computing power. The capabilities of the AIDA TDL hygrometers have been applied to AIDA experiments investigating ice particle growth within cirrus clouds in the temperature range between 190 K and 235 K. These experiments could constrain the accommodation coefficient of water molecules on growing cirrus ice particles, alpha_ice, which is relevant for the initial stage of ice growth in cirrus clouds. The temperature averaged result alpha_ice=0.8_(-0.5)^(+0.2) suggests that cirrus ice particle growth is not significantly suppressed as it would be for a low alpha_ice<0.1. Therefore, implications of alpha_ice for cirrus clouds and their characteristics should be minor and future cirrus cloud model studies can rely on a well constrained alpha_ice

Haiti - die Wahl der "Internationalen Gemeinschaft" und die Zukunft der Minustah

We investigate the effects of non-standard interactions on the determination of the neutrino oscillation parameters Delta m(31)(2), theta(23), and theta(13) in the MINOS experiment. We show that adding non-standard interactions to the analysis lead to an extension of the allowed parameter space to larger values of Delta m(31)(2) and smaller theta(23), and basically removes all predictability for theta(13). In addition, we discuss the sensitivities to the non-standard interaction parameters of the MINOS experiment alone. In particular, we examine the degeneracy between theta(13) and the non-standard interaction parameter epsilon(e tau). We find that this degeneracy is responsible for the removal of the theta(13) predictability and that the possible bound on vertical bar epsilon(e tau)vertical bar is competitive with direct bounds only if a more stringent external bound on theta(13) is applied.QC 2010063

An Artificial SEI Layer Based on an Inorganic Coordination Polymer with Self‐Healing Ability for Long‐Lived Rechargeable Lithium‐Metal Batteries

Upon immersion of a lithium (Li) anode into a diluted 0.05 to 0.20 M dimethoxyethanesolutionof the phosphoric acid derivative (CF 3 CH 2 O) 2 P(O)OH (HBFEP), anartificial solid electrolyte interphase (SEI) is generated on the Li-metal surface. Hence,HBFEP reacts on the surface to the corresponding Li salt (LiBFEP), which is a Li-ionconducting inorganic coordination polymer. This film exhibits -due to the reversiblybreaking ionic bonds- self-healing ability upon cycling-induced volume expansion of Li.The presence of LiBFEP as the major component in the artificial SEI is proven by ATRIRand XPS measurements. SEM characterization of HBFEP-treated Li samplesreveals porous layers on top of the Li surface with at least 3 μm thickness. Li-Lisymmetrical cells with HBFEP-modified Li electrodes show a three- to almost fourfoldcycle-lifetime increase at 0.1 mA·cm –2 in a demanding model electrolyte thatfacilitates fast battery failure (1 m LiOTf in TEGDME). Hence, the LiBFEP-enrichedlayer apparently acts as a Li-ion conducting protection barrier between Li and theelectrolyte, enhancing the rechargeability of Li electrodes