Tags: Physical Seminar

New particle formation (NPF) is the process by which trace atmospheric gases cluster and grow into small particles.  These particles make up a substantial fraction of climatically-relevant aerosols, but they are difficult to study due to their small size and ephemeral nature.  We are particularly interested in the role of intermolecular interactions such as proton transfer and hydrogen bonding in governing particle formation and growth…

A laser vaporization flow reactor (LVFR) apparatus has been developed for the synthesis of ligand-coated metal oxide nanomaterials. This method produces gas phase clusters followed by ligand coating and collection in a cold trap. Upon warming of the material, a solution is obtained for characterization by a variety of techniques including: mass spectrometry, electronic spectroscopy, infrared and Raman spectroscopy, and electron microscopy.…

In the Anthropocene humans have a global impact on the atmosphere and ecosystems. This became first visible with the discovery that man-made chlorine emissions modify stratospheric ozone (O3) over South Pole. More recent evidence suggests that atmospheric chemistry of bromine and iodine radicals dominates the relevance of halogens in the troposphere, and may be more active today than 100 years ago. Also, today’s wildfire season is starting…

With frequency combs having become available for the infrared regime, a new generation of precision spectrometers has been made possible. Combining the high power, wide range tunability, and narrow line width of OPO systems with the possibility to accurately determine their frequency via a frequency comb, spectrometers with a sub MHz accuracy are built.1 By locking the OPOs to the frequency comb their frequencies can be stabilized to an even…

DNA Intercalators have been clinically used as anti-tumor, anti-parasitic, and anti-bacterial agents. One method used to discover novel intercalators involves screening large virtual libraries of drug-like molecules with docking programs. In general, these programs dock flexible ligands into a rigid receptor and then rank binding poses based on a qualitative scoring function. However, the binding of DNA intercalators is not described well by…