Engineering topics

Sun, T. C.

Publications and source records attributed to Sun, T. C..

4 records

DOE OSTI2020

Proper use of HHDRIFT in surveillance and production conditions

With higher quality optics, newer benchtop DRIFT (diffuse reflectance infrared Fourier transform) spectroscopy systems with modern electronic circuitries should be the preferred choice if detection sensitivity, intensity, and reliability are top priorities. However, when space consideration or other restrictions require the use of a HHDRIFT (handheld DRIFT), it is possible to convert the measurements of the HHDRIFT to those obtained from any benchtop DRIFT and vice versa. In this report, the conversion of the measurements between a HHDRIFT and a benchtop DRIFT at LLNL (Lawrence Livermore National Laboratory) are shown to be linear in both production and surveillance conditions. A similar methodology can be used to obtain the measurement correlations between any HHDRIFT and any benchtop DRIFT at other sites.

36 MATERIALS SCIENCE↗

DOE OSTI2019

Using Regression Analysis Method to Develop a Material Outgassing Model

Regression analysis is a powerful statistical method that allows us to examine the relationship among multiple variables of interest. There are many types of regression analysis, practically speaking, they all identify the influence of one or more independent variables on a dependent variable. Dependent variable is a main factor of interest that we are trying to assess, and independent variables are input factors which we believe to have an impact on dependable variable.

36 MATERIALS SCIENCE↗

DOE OSTI2018

An Improved Method of Background Extrapolation for Radiation Outgassing Study

This report describes an improved background extrapolation method used in our multi-year material-2 radiation outgassing experiments. Figure 1 shows a typical raw test data and the data analysis to acquire the net radiation effect on material outgassing. It includes three major parts.1) Acquire the thermal outgassing background of test sample for 200 days, 2) Start radiation exposure and acquire the radiation outgassing along with the thermal background, 3) Conduct a thermal background extrapolation assessment and remove the thermal background for the net radiation effect.

36 MATERIALS SCIENCE↗

DOE OSTI2016

Temperature-Dependent Kinetic Prediction for Reactions Described by Isothermal Mathematics

Most kinetic models are expressed in isothermal mathematics. In addition, this may lead unaware scientists either to the misconception that classical isothermal kinetic models cannot be used for any chemical process in an environment with a time-dependent temperature profile or, even worse, to a misuse of them. In reality, classical isothermal models can be employed to make kinetic predictions for reactions in environments with time-dependent temperature profiles, provided that there is a continuity/conservation in the reaction extent at every temperature–time step. In this article, fundamental analyses, illustrations, guiding tables, and examples are given to help the interested readers using either conventional isothermal reacted fraction curves or rate equations to make proper kinetic predictions for chemical reactions in environments with temperature profiles that vary, even arbitrarily, with time simply by the requirement of continuity/conservation of reaction extent whenever there is an external temperature change.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗