N-Heterocyclic Carbene to Actinide d-Based π-bonding Correlates with Observed Metal–Carbene Bond Length Shortening Versus Lanthanide Congeners
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Engineering topics
Miller, Jeffrey L.
Publications and source records attributed to Miller, Jeffrey L..
Trace Actinide Signatures of a Bulk Neptunium Sample
In nuclear forensic analyses, measurements of actinide elements in a sample can assist with identifying interdicted or unknown materials. While these radiochemical signatures have been extensively investigated in uranium materials, less is known about bulk neptunium samples. This paper describes the measurement of trace actinide concentrations and isotopic profiles in a 237 Np oxide sample. Uranium, plutonium, americium, and curium concentrations and isotopic profiles in the sample were determined and deemed potentially useful for distinguishing different sources of 237 Np. Furthermore, several different potential radiochronometry systems were also investigated; discordant results indicate that the Np sample was never completely purified of other actinide elements, or that subsequent contamination of the sample occurred. Few prior studies of neptunium materials have been reported, and these data suggest that trace actinide constituents could provide unique signatures to identify material out of regulatory control.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Photochemical separation of plutonium from uranium
Photochemical reduction and separation of plutonium from uranium in acidic solutions is described as a potential alternative to conventional separations that employ harsh chemical redox agents.
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
Analysis of a Bulk 237 Np Oxide Sample for Trace Actinides
A neptunium oxide sample was dissolved and trace actinide constituents were measured by isotope dilution ICP-MS (for 239–244 Pu, 233–238 U, 237 Np, 241–243 Am) and alpha spectrometry ( 238 Pu, 242 Cm, 244 Cm). This material contained significant quantities of transuranic elements, notably americium and curium. The isotopic composition of the material will continue to evolve over time due to radioactive decay; the measurements reported here include all isotopes decay corrected to a reference date of 1/1/2022. These factors may be considerations in criticality studies of the related 237 Np sphere.
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
A New Yield Assessment for the Trinity Nuclear Test, 75 Years Later
Not Available
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
June 2019 Depleted Uranium Irradiation
Three different irradiations were performed at the Annular Core Research Reactor (ACRR) at Sandia National laboratory on June 4-6, 2019. Each target assembly included two or three depleted uranium targets, as well as a bismuth target and dosimetry packets. In July 2019, the target assemblies were received at TA-48 RC-1, unpackaged, and radiochemical analyses were performed. The analyses included autoradiography and gamma counting of the whole depleted uranium targets, gamma counting of the activation foils, and dissolution of six of the depleted uranium targets, followed by separated radiochemical analysis for a suite of fission products. This report describes the details of the radiochemical analysis and provides final results for the fission and activation product concentrations.
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
Short-Lived Actinide QA Exercise Results and Summary (After Action Report) Exercise: QA-MVSLA-2017-04
In April 2017 an inter-laboratory exercise entitled Method Validation for Short-lived Actinide Production and Analysis (QA- MVSLA-2017-04) was supported by the LANL Radiochemistry and Mass Spectrometry Teams.
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
Table-driven software architecture for a stitching system
Native code for a CNC stitching machine is generated by generating a geometry model of a preform; generating tool paths from the geometry model, the tool paths including stitching instructions for making stitches; and generating additional instructions indicating thickness values. The thickness values are obtained from a lookup table. When the stitching machine runs the native code, it accesses a lookup table to determine a thread tension value corresponding to the thickness value. The stitching machine accesses another lookup table to determine a thread path geometry value corresponding to the thickness value.
Thrash, Patrick J.↗
Automated apparatus and method of generating native code for a stitching machine
A computer system automatically generates CNC code for a stitching machine. The computer determines the locations of a present stitching point and a next stitching point. If a constraint is not found between the present stitching point and the next stitching point, the computer generates code for making a stitch at the next stitching point. If a constraint is found, the computer generates code for changing a condition (e.g., direction) of the stitching machine's stitching head.
Miller, Jeffrey L.↗
Automated quality control for stitching of textile articles
Quality control for stitching of a textile article is performed by measuring thread tension in the stitches as the stitches are being made, determining locations of the stitches, and generating a map including the locations and stitching data derived from the measured thread tensions. The stitching data can be analyzed, off-line or in real time, to identify defective stitches. Defective stitches can then be repaired. Real time analysis of the thread tensions allows problems such as broken needle threads to be corrected immediately.
Miller, Jeffrey L.↗
Advanced stitching head for making stitches in a textile article having variable thickness
A stitching head for a computer numerically controlled stitching machine includes a thread tensioning mechanism for automatically adjusting thread tension according to the thickness of the material being stitched. The stitching head also includes a mechanism for automatically adjusting thread path geometry according to the thickness of the material being stitched.
Thrash, Patrick J.↗
Automated gantry-type stitching system
A stitching system includes a gantry that is movable along a material support table. Mounted to the gantry are a plurality of stitching heads and bobbins. The stitching heads are individually controllable in a z-direction, and the bobbins are individually controllable in the z-direction. Each stitching head is paired with a bobbin. Each pair of stitching heads and the bobbins is controlled synchronously in the z-direction. The stitching system is well-suited for stitching preforms of aircraft wing covers and other preforms having variable thickness and compound, contoured three-dimensional surfaces.
Thrash, Patrick J.↗