Thin-film mechanical properties can be measured using nanoindentation combined with detailed finite element modeling. This technique was used for a study of very fine grained Ni films, formed using pulsed-laser deposition on fused silica, sapphire, and Ni substrates. The grain sizes in the films were characterized by electron microscopy, and the mechanical properties were determined by ultra-low load indentation, analyzed using finite element modeling to separate the mechanical properties of the thin layers from those of the substrates. Some Ni films were deposited at high temperature or annealed after deposition to enlarge the grain sizes. The observed hardnesses and grain sizes in these thin Ni films are consistent with the empirical Hall-Petch relationship for grain sizes ranging from a few micrometers to as small as 10 nm, suggesting that deformation occurs preferentially by dislocation movement even in such nanometer-size grains.
Enormous interest exists to develop the next generation of an integrated microsystem for chemical and biological analysis ({mu}ChemLab{trademark}) and to further reduce the volume of the system. One approach is to scale down the size of critical components and to explore any pumping mechanism that can minimize the power requirement. Since the majority of the pumping requirement is to overcome the wall resistance in the gas chromatography (GC) column, our attention is to study the gas flow in this GC column. As the column dimension decreases, the gaseous flow will go from a continuum regime into a non-continuum regime; i.e., slip, transition, and free molecular regimes. Thus it is very important to well characterize the gaseous flow in submicron columns and to understand its flow behavior. Specifically, in this study, our focus is to investigate the effects of viscosity, rarefaction, and compressibility as the column dimension decreases. Both theoretical predictions and experimental results will be presented.
Sandia National Laboratories was tasked by the Japan Nuclear Cycle Development Institute (JNC) to provide assistance in developing an emergency response plan for radioactive material transportation activities. Those tasks included compiling radioactive materials (RAM) transportation accident data from the open literature and databases, investigating emergency response plans for radioactive materials transport in the United States, and developing specific recommendations for the JNC' nuclear material transport emergency response plan, based on information gathered during the first two tasks. These recommendations include developing a RAM database, a public transparency Internet website, an emergency response infrastructure designed specifically for transportation needs, and a clear set of directives to provide authority in the case of transportation accidents or incidents involving RAM.
This report presents background information and methodology for a risk assessment of mixed oxide (MOX) reactor fuel transport in the nation of Japan to support their nuclear energy program. This work includes an extensive literature review, a review of other MOX activities worldwide, a survey of the statutory requirements for transporting nuclear materials, a discussion of risk assessment methodology, and calculation results for specific examples. Typical risk evaluations are given to provide guidance for later risk analyses specific to MOX fuel transport in Japan. This report also includes specific information that will be required for routes, cask types, accident-rate statistics, and population densities along specified routes, along with other detailed information needed for risk analysis studies pertinent to MOX transport in Japan. This information will be used in future specific risk studies.
The Cooperative Monitoring Center (CMC) promotes collaborations among scientists and researchers in several regions as a means of achieving common regional security objectives. To promote cooperation in South Asia on environmental research, an international working group made up of participants from Bangladesh, India, Nepal, Pakistan, and the United States convened in Kathmandu, Nepal, from February 17-23,2002. The workshop was held to further develop the South Asia Transboundary Water Quality Monitoring (SATWQM) project. The project is sponsored in part by the CMC located at Sandia National Laboratories in Albuquerque, New Mexico through funding provided by the US. Department of State, Regional Environmental Affairs Office, American Embassy, Kathmandu, Nepal, and the National Nuclear Security Administration's (NNSA) Office of Nonproliferation and National Security. This report summarizes the SATWQM project, the workshop objectives, process and results. The long-term interests of the participants are to develop systems for sharing regional environmental information as a means of building confidence and improving relations among South Asian countries. The more immediate interests of the group are focused on activities that foster regional sharing of water quality data in the Ganges and Indus River basins. Issues of concern to the SATWQM network participants include studying the impacts from untreated sewage and industrial effluents, agricultural run-off, salinity increases in fresh waters, the siltation and shifting of river channels, and the environmental degradation of critical habitats such as wetlands, protected forests, and endangered aquatic species conservation areas. The workshop focused on five objectives: (1) a deepened understanding of the partner organizations involved; (2) garnering the support of additional regional and national government and non-government organizations in South Asia involved in river water quality monitoring; (3) identification of sites within the region at which water quality data are to be collected; (4) instituting a data and information collection and sharing process; and, (5) training of partners in the use of water quality monitoring equipment.
This document provides a guide to the deployment of the software verification activities, software engineering practices, and project management principles that guide the development of Accelerated Strategic Computing Initiative (ASCI) applications software at Sandia National Laboratories (Sandia). The goal of this document is to identify practices and activities that will foster the development of reliable and trusted products produced by the ASCI Applications program. Document contents include an explanation of the structure and purpose of the ASCI Quality Management Council, an overview of the software development lifecycle, an outline of the practices and activities that should be followed, and an assessment tool.
Ultra fast, sub-nanosecond (picosecond to femtosecond) duration, laser pulses present unique challenges when performing laser safety analysis involving mode-locked lasers, which operate at pulse repetition frequencies above the critical frequency in the near infrared wavelength bands. Two specific cases are presented, one such case that agrees and one that disagrees with the general rule on critical frequency. The results show that in all cases the appropriate maximum permissible exposure is always the smallest of the values calculated from ANSI rule 1, 2 and 3.
Cavity expansion is a method for modeling the penetration of an axisymmetric or wedge-shaped solid body--a penetrator--into a target by using analytic expressions to capture the effects of the target on the body. Cavity expansion has been implemented as a third-party library (CavityExpansion) that can be used with explicit, transient dynamics codes. This document describes the mechanics of the cavity expansion model implemented as a third-party library. This document also describes the applications interface to CavityExpansion. A set of regression tests has been developed that can be used to test the implementation of CavityExpansion in a transient dynamics code. The mechanics of these tests and the expected results from the tests are described in detail.
Presto is a Lagrangian, three-dimensional explicit, transient dynamics code for the analysis of solids subjected to large, suddenly applied loads. Presto is designed for problems with large deformations, nonlinear material behavior, and contact. There is a versatile element library incorporating both continuum and structural elements. The code is designed for a parallel computing environment. This document describes the input for the code that gives users access to all of the current functionality in the code. Presto is built in an environment that allows it to be coupled with other engineering analysis codes. The input structure for the code, which uses a concept called scope, reflects the fact that Presto can be used in a coupled environment. This guide describes the scope concept and the input from the outermost to the innermost input scopes. Within a given scope, the descriptions of input commands are grouped based on code functionality. For example, all material input command lines are described in a section of the user's guide for all of the material models in the code.