Engineering topics

Liu, Yun

Publications and source records attributed to Liu, Yun.

4 records

DOE OSTI2024

Recent progress in laser wire-based H- beam diagnostics at the SNS linac

Laser wire has been used for nonintrusive profile and emittance measurements of operational hydrogen ion (H-) beam at the SNS linac. In this talk, we will describe the following recent developments in the laser wire system. 1) An upgraded light source and laser transport line which enables novel measurement capabilities including longitudinal profile measurement and high-energy proton beam extraction over potentially an entire macropulse. 2) A dual-detector emittance measurement scheme that boosted the dynamic range by an order of magnitude. 3) Design and implementation laser-wire-based nonintrusive longitudinal phase space measurement system.

Liu, Yun↗

DOE OSTI2024

Aryl triazole cages

The present disclosure concerns synthesis, anion binding features, liquid-liquid extraction of salts, and anti-corrosion character of aryl-triazole bicyclic macrocycles of Formula (I) and related compounds:

Flood, Amar H.↗

DOE OSTI2024

Developing Coupled Data Assimilation Strategy for Understanding Model Bias and Extreme Climate Events in E3SM

We have successfully developed the first working version of online ensemble coupled data assimilation (ECDA) on E3SM for both version 1 and version 2. Our schemes have also been tested successfully for assimilating SST data in both synthetic observations and real world observations, laying a foundation for future development.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRS2013

An Update on the Non-Mass-Dependent Isotope Fractionation under Thermal Gradient

Mass flow and compositional gradient (elemental and isotope separation) occurs when flu-id(s) or gas(es) in an enclosure is subjected to a thermal gradient, and the phenomenon is named thermal diffusion. Gas phase thermal diffusion has been theoretically and experimentally studied for more than a century, although there has not been a satisfactory theory to date. Nevertheless, for isotopic system, the Chapman-Enskog theory predicts that the mass difference is the only term in the thermal diffusion separation factors that differs one isotope pair to another,with the assumptions that the molecules are spherical and systematic (monoatomic-like structure) and the particle collision is elastic. Our previous report indicates factors may be playing a role because the Non-Mass Dependent (NMD) effect is found for both symmetric and asymmetric, linear and spherical polyatomic molecules over a wide range of temperature (-196C to +237C). The observed NMD phenomenon in the simple thermal-diffusion experiments demands quantitative validation and theoretical explanation. Besides the pressure and temperature dependency illustrated in our previous reports, efforts are made in this study to address issues such as the role of convection or molecular structure and whether it is a transient, non-equilibrium effect only.

Sun, Tao↗