Browsing by Author "Liu, Yuan"

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    High-temperature electrothermal remediation of multi-pollutants in soil
    (Springer Nature, 2023) Deng, Bing; Carter, Robert A.; Cheng, Yi; Liu, Yuan; Eddy, Lucas; Wyss, Kevin M.; Ucak-Astarlioglu, Mine G.; Luong, Duy Xuan; Gao, Xiaodong; JeBailey, Khalil; Kittrell, Carter; Xu, Shichen; Jana, Debadrita; Torres, Mark Albert; Braam, Janet; Tour, James M.; NanoCarbon Center and the Rice Advanced Materials Institute; Smalley-Curl Institute
    Soil contamination is an environmental issue due to increasing anthropogenic activities. Existing processes for soil remediation suffer from long treatment time and lack generality because of different sources, occurrences, and properties of pollutants. Here, we report a high-temperature electrothermal process for rapid, water-free remediation of multiple pollutants in soil. The temperature of contaminated soil with carbon additives ramps up to 1000 to 3000 °C as needed within seconds via pulsed direct current input, enabling the vaporization of heavy metals like Cd, Hg, Pb, Co, Ni, and Cu, and graphitization of persistent organic pollutants like polycyclic aromatic hydrocarbons. The rapid treatment retains soil mineral constituents while increases infiltration rate and exchangeable nutrient supply, leading to soil fertilization and improved germination rates. We propose strategies for upscaling and field applications. Techno-economic analysis indicates the process holds the potential for being more energy-efficient and cost-effective compared to soil washing or thermal desorption.
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    Laser ionization studies of supersonic semiconductor clusters
    (1985) Liu, Yuan; Tittel, Frank K.; Curl, Robert F.; Wilson, William L.
    Cold silicon and germanium clusters have been produced in a supersonic molecular beam by laser vaporization of a silicon or germanium rod. The cluster beam is characterized by laser ionization studies and time of flight mass analysis. Both large Si and Ge clusters are found to have similar fragmentation patterns. They fisson into stable subunits rather than lose atoms sequentially. Two-color stepwise ionization experiments reveal that large Si and Ge clusters have an intermediate state with a lifetime of approximately 1 ns, thereby establishing the feasibility of resonant two photon ionization (R2PI) spectroscopy on these clusters.