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Campbell, Christopher G.

Publications and source records attributed to Campbell, Christopher G..

Self Assembly-Assisted Additive Manufacturing: Direct Ink Write 3D Printing of Epoxy-Amine Thermosets

The use of self–assembling, pre–polymer materials in 3D printing is rare, due to difficulties of facilitating printing with low molecular weight species and preserving their reactivity and/or functions on the macroscale. Akin to 3D printing of small molecules, examples of extrusion–based printing of pre–polymer thermosets are uncommon, arising from their limited rheological tuneability and slow reactions kinetics. The direct ink write (DIW) 3D printing of a two–part resin, Epon 828 and Jeffamine D230, using a self–assembly approach is reported. Through the addition of self–assembling, ureidopyrimidinone–modified Jeffamine D230 and nanoclay filler, suitable viscoelastic properties are obtained, enabling 3D printing of the epoxy–amine pre–polymer resin. A significant increase in viscosity is observed, with an infinite shear rate viscosity of approximately two orders of magnitude higher than control resins, in addition to, an increase in yield strength and thixotropic behavior. As a result, printing of simple geometries is demonstrated with parts showing excellent interlayer adhesion, unachievable using control resins.

3D printing↗

Environmental Monitoring Plan (Revision 6)

The purpose of environmental monitoring is to promote the early identification of, and response to, potential adverse environmental impacts associated with Lawrence Livermore National Laboratory (LLNL) operations. Environmental monitoring supports the Integrated Safety Management System (ISMS), International Organization for Standardization (ISO) 14001 Environmental Management Systems standard, and U. S. Department of Energy (DOE) Order 458.1, Radiation Protection of the Public and the Environment. Specifically, environmental monitoring enables LLNL to detect, characterize, and respond to releases from LLNL activities; assess impacts; estimate dispersal patterns in the environment; characterize the pathways of exposure to members of the public; characterize the exposures and doses to individuals and to the population; and to evaluate the potential impacts to the biota in the vicinity of LLNL. Environmental monitoring is also a major component of compliance demonstration for permits and other regulatory requirements. The Environmental Monitoring Plan (EMP) addresses the sample collection and analytical work supporting environmental monitoring to ensure the following: (1) A consistent system for collecting, assessing, and documenting environmental data of known and documented quality; (2) A validated and consistent approach for sampling and analysis of samples to ensure laboratory data meets program-specific needs and requirements within the framework of a performance-based approach for analytical laboratory work; and (3) An integrated sampling approach to avoid duplicative data collection. LLNL prepares the EMP because it provides an organizational framework for ensuring that environmental monitoring work, which is integral to the implementation of LLNL's Environmental Management System, is conducted appropriately. Furthermore, the Environmental Monitoring Plan helps LLNL ensure compliance with DOE Order 231.1 Change 2, Environment, Safety and Health Reporting, which require the publication of an annual report that characterizes the site's environmental management performance. To summarize, the general regulatory drivers for this environmental monitoring plan are ISO 14001, DOE Order 458.1, and DOE Order 231.1. The environmental monitoring addressed by this plan includes preoperational characterization and assessment, effluent and surveillance monitoring, and permit and regulatory compliance monitoring. Additional environmental monitoring is conducted at LLNL as part of compliance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, also known as Superfund). LLNL coordinates its ground water surveillance monitoring program with the CERCLA monitoring program to gain sampling efficiencies.

54 ENVIRONMENTAL SCIENCES↗

Environmental Report 2009

The purposes of the Lawrence Livermore National Laboratory Environmental Report 2009 are to record Lawrence Livermore National Laboratory’s (LLNL’s) compliance with environmental standards and requirements, describe LLNL’s environmental protection and remediation programs, and present the results of environmental monitoring at the two LLNL sites—the Livermore site and Site 300. The report is prepared for the U.S. Department of Energy (DOE) by LLNL’s Environmental Protection Department. Submittal of the report satisfies requirements under DOE Order 231.1A, Environmental Safety and Health Reporting, and DOE Order 5400.5, Radiation Protection of the Public and Environment. The report is distributed electronically and is available at https://saer.lln.gov/, the website for the LLNL annual environmental report. Previous LLNL annual environmental reports beginning in 1994 are also on the website. Some references in the electronic report text are underlined, which indicates that they are clickable links. Clicking on one of these links will open the related document, data workbook, or website that it refers to. The report begins with an executive summary, which provides the purpose of the report and an overview of LLNL’s compliance and monitoring results. The first three chapters provide background information: Chapter 1 is an overview of the location, meteorology, and hydrogeology of the two LLNL sites; Chapter 2 is a summary of LLNL’s compliance with environmental regulations; and Chapter 3 is a description of LLNL’s environmental programs with an emphasis on the Environmental Management System including pollution prevention. The majority of the report covers LLNL’s environmental monitoring programs and monitoring data for 2009: effluent and ambient air (Chapter 4); waters, including wastewater, storm water runoff, surface water, rain, and groundwater (Chapter 5); and terrestrial, including soil, sediment, vegetation, foodstuff, ambient radiation, and special status wildlife and plants (Chapter 6). Complete monitoring data, which are summarized in the body of the report, are provided in Appendix A. The remaining three chapters discuss the radiological impact on the public from LLNL operations (Chapter 7), LLNL’s groundwater remediation program (Chapter 8), and quality assurance for the environmental monitoring programs (Chapter 9).

61 RADIATION PROTECTION AND DOSIMETRY↗