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SURF: Announcements of Opportunity

Below are Announcements of Opportunity posted by Caltech faculty and JPL technical staff for the SURF program. Additional AOs for the Amgen Scholars program can be found here.

Specific GROWTH projects being offerred for summer 2018 can be found here.

Each AO indicates whether or not it is open to non-Caltech students. If an AO is NOT open to non-Caltech students, please DO NOT contact the mentor.

Announcements of Opportunity are posted as they are received. Please check back regularly for new AO submissions! Remember: This is just one way that you can go about identifying a suitable project and/or mentor.

Announcements for external summer programs are listed here.

Students pursuing opportunities at JPL must be
U.S. citizens or U.S. permanent residents.

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Project:  Novel means to obtain quantitative surface chemical information from synchrotron-based XPS on aqueous solutions
Disciplines:  Physics, Applied Physics, Chemical Engineering, Mechanical Engineering
Mentor:  Nonne Prisle, Associate Professor, (PMA), nonne.prisle@oulu.fi, Phone: +358 50 439 7018
Mentor URL:  http://www.oulu.fi/university/researcher/nonne-prisle  (opens in new window)
AO Contact:  Jack Lin, jacklin@alumni.caltech.edu
Background:  NOTE: This project is being offered by a Caltech alum (Jack Lin, the AO contact listed above) and will be conducted at University of Oulu in Oulu, Finland.

Atmospheric aerosols and their interaction with water are critical elements in regulating the Earth’s radiation balance and climate. Recent work strongly suggest that the surfaces of aqueous particles and cloud droplets may impact the atmospheric chemistry and aerosol-cloud interactions in a number of different ways. None of these processes are, however, well-quantified, as the surfaces of aqueous solutions and in particular sub-micron droplets are notoriously difficult to characterize. Previous work by Prisle and co-workers (e.g. Prisle et al., 2012, Werner et al., 2014, Walz et al., 2015, 2016) have demonstrated the potential for synchrotron radiation (SR) excited X-ray photoelectron spectroscopy (XPS) on liquid micro-jet and unsupported nanoparticles for highly sensitive and chemically specific characterization of their surface structure. New work, targeting the ability to obtain closure between surface concentrations of aqueous surface active organics derived from XPS and those predicted using a detailed statistical mechanics multilayer sorption model (Toribio, submitted 2018) however highlights immediate challenges to overcome for this to be realized. Directly determined surface composition data for aqueous surfactant systems of atmospheric relevance is urgently needed as part in resolving the recurring debate on significance of surface tension, surface adsorption in e.g. atmospheric chemistry and cloud microphysics (Ruehl 2016, Ovadnevaite 2017). SR excited XPS has a clear potential for delivering such direct, quantitative experimental information. The establishment of a framework and methodology for obtaining this quantitative surface concentrations from liquid jet and nano-particle measurements will pose a great leap forward towards closing the existing gap between models and measurements.
Description:  The SURF student will work with the ATMOS (host) team in implementing SR-XPS experiments on a liquid micro-jet setup and free-flying aqueous nano-particles, with the aim of obtaining closure with model predicted surface composition and experimentally quantified concentrations. The project can involve either experimental or computational objectives, or a combination. Synchrotron experiments will take place as part of the commissioning experiments at the Finnish-Estonian Beamline for Atmospheric and Materials Science (FinEstBEAMS) at new MAX IV synchrotron facility in Lund, Sweden. If the timing of the project coincides with our commissioning beamtimes, as according to the current schedule, the SURF student will have the possibility to take part in these experiments together with our experimental team. The experiment design phase will however also involve additional development of experimental setups in the University of Oulu home-lab. In parallel, a model framework for analyzing the obtained XPS spectra will be developed (using Matlab or Igor), based on the multilayer sorption model of Wexler, Clegg, and Dutcher, as well as a novel surface adsorption model by Prisle and Malila (in preparation). The SURF student will have the possibility to work on implementing additional processes related to the commissioning experiments in this framework.
References:  1. http://www.oulu.fi/nanomo/atmos

2. Ovadnevaite, J., et al. (2017), Nature, 546(7660), 637-641.

3. Prisle, N. L., et al. (2012), Atmos. Chem. Phys., 12(24), 12,227-12,242.

4. Ruehl, C. R., et al., (2016), Science, 351(6280), 1447-1450.

5. Walz, M.-M., et al., (2015), Phys. Chem. Chem. Phys., 17, 14,036-14,044.

6. Walz, M.-M., et al., (2016), Phys. Chem. Chem. Phys., 18, 6648-6656.

7. Werner, J., et al., (2014), Phys. Chem. Chem. Phys., 16, 21,486-21,495.
Student Requirements:  A background in Physics, Chemistry, Physical Chemistry, or Chemical Engineering is recommended. Knowledge of electron spectroscopy, atmospheric aerosols, surface science, aqueous phase thermodynamics, surface activity, and programming in Matlab will each be an advantage.
Programs:  This AO can be done under the following programs:

  Program    Available To
       SURF    Caltech students only 

Click on a program name for program info and application requirements.


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