Influence of Nanocrystalline Grain Size on the Breakdown Strength of Ceramic Dielectrics

In an effort to develop transmission lines with higher energy storage capabilities for compact pulsed power applications, the University of Missouri-Rolla (UMR) and the University of New Mexico (UNM) have undertaken a collaborative approach to developing and studying ceramic dielectrics. At UMR, the electrical breakdown strength (BDS) of TiO2-based materials is investigated for high energy density applications. The results of research to-date show that dense titania ceramics with nanocrystalline grain size (~200 nm) exhibit significantly higher BDS as compared to ceramics made using coarse grain materials. Processing-microstructure-property relationships in TiO2 systems are found to play a role with respect to increasing the BDS. At UNM, a pulsed power system is being assembled to perform BDS studies of the ceramic materials produced at UMR. Electromagnetic simulations in support of this work will also presented. The long-term aim of this research is to enable the fabrication of large sizes of high energy density ceramics for use in pulsed power systems

Implementing an integrated standards-based management system to ensure compliance at Los Alamos National Laboratory

Los Alamos National Laboratory (LANL or the Laboratory) is developing and implementing a comprehensive, Integrated Standards-Based Management System (ISBMS) to enhance environmental, safety, and health (ESH) compliance efforts and streamline management of ESH throughout the Laboratory. The Laboratory recognizes that to be competitive in today`s business environment and attractive to potential Partnerships, Laboratory operations must be efficient and cost-effective. The Laboratory also realizes potential growth opportunities for developing ESH as a strength in providing new or improved services to its customers. Overall, the Laboratory desires to establish and build upon an ESH management system which ensures continuous improvement in protecting public health and safety and the environment and which fosters a working relationship with stakeholders. A team of process experts from the LANL Environmental Management (EM) Program Office, worked with management system consultants, and the Department of Energy (DOE) to develop an ESH management systems process to compare current LANL ESH management Systems and programs against leading industry standards. The process enabled the Laboratory to gauge its performance in each of the following areas: Planning and Policy Setting; Systems and Procedures; Implementation and Education; and Monitoring and Reporting. The information gathered on ESH management systems enabled LANL to pinpoint and prioritize opportunities for improvement in the provision of ESH services throughout the Laboratory and ultimately overall ESH compliance

The mechanical design and fabrication of a ridge-loaded waveguide for an RFQ

A Radio Frequency Quadrupole (RFQ) accelerator with an RF power input of 2 MW and an H{sup +} beam output current of 100 mAmps at 6.7 MeV, continuous duty factor utilizes twelve nearly identical ridge-loaded waveguides. The ridge-loaded, vacuum waveguides couple the RF power to the RFQ accelerating cavity. The mechanical design and fabrication of the ridge-loaded waveguides are the topics of this paper

Advanced Assay Systems for Radionuclide Contamination in Soils

Through the support of the Department of Energy (DOE) Office of Environmental Management (EM) Technical Assistance Program, the Idaho National Laboratory (INL) has developed and deployed a suite of systems that rapidly scan, characterize, and analyze surface soil contamination. The INL systems integrate detector systems with data acquisition and synthesis software and with global positioning technology to provide a real-time, user-friendly field deployable turn-key system. INL real-time systems are designed to characterize surface soil contamination using methodologies set forth in the Multi-Agency Radiation Surveys and Site Investigation Manual (MARSSIM). MARSSIM provides guidance for planning, implementing, and evaluating environmental and facility radiological surveys conducted to demonstrate compliance with a dose or risk-based regulation and provides real-time information that is immediately available to field technicians and project management personnel. This paper discusses the history of the development of these systems and describes some of the more recent examples and their applications

Systems Imaging of the Immune Synapse

Three-dimensional live cell imaging of the interaction of T cells with antigen presenting cells (APC) visualizes the subcellular distributions of signaling intermediates during T cell activation at thousands of resolved positions within a cell. These information-rich maps of local protein concentrations are a valuable resource in understanding T cell signaling. Here, we describe a protocol for the efficient acquisition of such imaging data and their computational processing to create four-dimensional maps of local concentrations. This protocol allows quantitative analysis of T cell signaling as it occurs inside live cells with resolution in time and space across thousands of cells

Real-Time Remediation Utilizing The Backpack Sodium Iodide System And The U.S. EPA Triad Approach

Real-time characterization during remediation activities is being accomplished at the Idaho National Laboratory (INL) with the use of the backpack sodium iodide system (BaSIS). The BaSIS is comprised of a 3-in. by 5-in. sodium iodide (NaI) detector, differential corrected global positioning system (GPS), and portable computer, integrated into a lightweight backpack deployment platform. The system is operated with specialized software that allows the operator and/or remediation field manager to view data as they are collected. Upon completion of planned excavation stages, the area is surveyed for residual radiological contamination. After data collection is complete, data is available to the remediation field manager as a contour map showing the area(s) that require further excavation. The use of real-time measurement systems, rapid turn-around time of data, and dynamic work strategy support the U.S. Environmental Protection Agency’s (EPA) Triad approach. Decisions are made in real-time as to the need for further remediation. This paper describes the BaSIS system calibration, testing and use, and outlines negotiations with the appropriate CERCLA regulatory agencies (U.S. Environmental Protection Agency, Idaho Department of Environmental Quality, and U.S. Department of Energy Idaho Operations Office) to allow the use of real-time instrumentation during the remediation process, and for confirmation surveys. By using the BaSIS in such a manner, the INL seeks to demonstrate compliance with remediation objectives

Cancer-Associated Fibroblasts Induce a Collagen Cross-link Switch in Tumor Stroma

Intratumoral collagen cross-links heighten stromal stiffness and stimulate tumor cell invasion, but it is unclear how collagen cross-linking is regulated in epithelial tumors. To address this question, we used KrasLA1 mice, which develop lung adenocarcinomas from somatic activation of a KrasG12D allele. The lung tumors in KrasLA1 mice were highly fibrotic and contained cancer-associated fibroblasts (CAFs) that produced collagen and generated stiffness in collagen gels. In xenograft tumors generated by injection of wild-type mice with lung adenocarcinoma cells alone or in combination with CAFs, the total concentration of collagen cross-links was the same in tumors generated with or without CAFs, but co-injected tumors had higher hydroxylysine aldehyde-derived collagen cross-links (HLCCs) and lower lysine-aldehyde-derived collagen cross-links (LCCs). Therefore, we postulated that an LCC-to-HLCC switch induced by CAFs promotes the migratory and invasive properties of lung adenocarcinoma cells. To test this hypothesis, we created co-culture models in which CAFs are positioned interstitially or peripherally in tumor cell aggregates, mimicking distinct spatial orientations of CAFs in human lung cancer. In both contexts, CAFs enhanced the invasive properties of tumor cells in 3-dimensional (3D) collagen gels. Tumor cell aggregates that attached to CAF networks on a Matrigel surface dissociated and migrated on the networks. Lysyl hydroxylase 2 (PLOD2/LH2), which drives HLCC formation, was expressed in CAFs, and LH2 depletion abrogated the ability of CAFs to promote tumor cell invasion and migration

The SNS linac high power RF system design, status, and results

The Spallation Neutron Source being built at the Oak Ridge National Lab in Tennessee requires a 1 GeV proton linac. Los Alamos has responsibility for the RF systems for the entire linac. The linac requires 3 distinct types of RF systems: 2.5-MW peak, 402.5 MHz, RF systems for the RFQ and DTL (7 systems total); 5-MW peak, 805 MHz systems for the CCL and the two energy corrector cavities (6 systems total); and 550-kW peak, 805 MHz systems for the superconducting sections (8 1 systems total). The design of the SNS Linac RF system was presented at the 2001 Particle Accelerator Conference in Chicago. Vendors have been selected for the klystrons (3 different vendors), circulators ( I vendor), transmitter (1 vendor), and high power RF loads (3 different vendors). This paper presents the results and status of vendor procurements, test results of the major components of the Linac RF system and our installation progress