Sandia National Laboratories Albuquerque Research Articles

Sensors for Environmental Monitoring

first_page settings Order Article Reprints Font Type: Arial Georgia Verdana Font Size: Aa Aa Aa Line Spacing:    Column Width:    Background: Open AccessEditorial Sensors for Environmental Monitoring by Clifford K. Ho 1,* and M. J. Schöning 2 1 Sandia National Laboratories Albuquerque, New Mexico, U.S.A. 2 University of Applied Sciences Aachen, Jülich Campus, Germany * Author to whom correspondence should be addressed. Sensors 2005, 5(1), 1-3; https://doi.org/10.3390/s5010001 Published: 28 January 2005 (This article belongs to the Special Issue Sensors for Environmental Monitoring) Download Download PDF Download PDF with Cover Download XML Download Epub Versions Notes Editor-in-Chief IntroductionDear readers, it is a pleasure for me, to introduce Clifford K. Ho as the guest editor for this special issue. Clifford K. Ho finished his PhD at the University of California at Berkeley in 1993. His research topics cover: -Development of microchemical sensor systems and novel characterization methods for real-time, continuous, in-situ sensing of volatile organic compounds.-Performance of numerical simulations and analytical analyses of problems related to environmental restoration and nuclear waste management.-Predicting of flow and transport of groundwater and contaminants in heterogeneous and fractured porous media in thermally perturbed systems.-Validating mathematical models of heat and mass transfer processes in porous media through combined experimental and numerical studies.At the moment, he is working at Sandia National Laboratories in Albuquerque, New Mexico, where he is a distinguished member of the technical staff. He also serves as an adjunct professor at the University of New Mexico in Albuquerque.I am very pleased to win Clifford K. Ho over as an expert and guest editor for this special issue. Furthermore, I would like to thank him for his work and his contribution to Sensors.Michael J. Schöning, Editor-in-ChiefUniversity of Applied Sciences Aachen, Jülich Campus, GermanyDepartment of Applied Sciences and Technology,Biomedical Engineering DivisionandResearch Centre Juelich GmbHInstitute of Thin Films and Interfaces (ISG-2)January 28, 2005 PrefaceMonitoring air, soil, and water for hazardous contaminants has traditionally been motivated by the need to protect our environment from industrial pollutants such as volatile organic compounds, pesticides, heavy metals, and radionuclides. Typical environmental sampling methods for these contaminants employ manual grab samples that are collected on site and then transported to a laboratory for analysis. These sampling methods can be very costly and time consuming, and ongoing research has focused on the development of sensors that can replace traditional sampling methods to monitor contaminants in the environment. More recently, the threat of chemical, biological, and radiological agents introduced into our air or water supplies has also stimulated the demand for continuous, real-time, in-situ sensors.The scope of this special issue focuses on sensors that are designed to detect hazardous substances that could potentially pollute the air, water, or subsurface. Laboratory and field investigations of new and emerging sensors are presented, and data analysis methods are also described. Eight papers from five different countries are included in this special issue that represent global research in the area of sensing for the environment. My hope is that this special issue will provide the reader with a broad overview and sampling of the innovative research that is occurring to improve our capabilities for realtime, continuous sensors for the environment.Clifford K. Ho, Guest EditorSandia National Laboratories Albuquerque, New Mexico, U.S.A.January 20, 2005 © 2005 by MDPI ( http://www.mdpi.org). Reproduction is permitted for non-commercial purposes. Share and Cite MDPI and ACS Style Ho, C.K.; Schöning, M.J. Sensors for Environmental Monitoring. Sensors 2005, 5, 1-3. https://doi.org/10.3390/s5010001 AMA Style Ho CK, Schöning MJ. Sensors for Environmental Monitoring. Sensors. 2005; 5(1):1-3. https://doi.org/10.3390/s5010001 Chicago/Turabian Style Ho, Clifford K., and M. J. Schöning. 2005. "Sensors for Environmental Monitoring" Sensors 5, no. 1: 1-3. https://doi.org/10.3390/s5010001 Find Other Styles Article Metrics No No Article Access Statistics For more information on the journal statistics, click here. Multiple requests from the same IP address are counted as one view.

A Benchmark Comparison of Predicted X-Ray and Neutron Doses for a Nuclear Effects Test in the Laboratory Microfusion Facility

An intermediate step in the development of inertial confinement fusion (ICF) for power production will be the development and testing of a high-gain facility. One concept being considered for this facility is the Laboratory Microfusion Facility (LMF). Other projected applications of the LMF include high-energy-density physics experiments and nuclear effects testing. At the Air Force Institute of Technology (AFIT), Lawrence Livermore National Laboratory (LLNL), and Sandia National Laboratories Albuquerque (SNLA), we have been studying the use of the LMF for nuclear effects experiments. Because of the amount of energy that will be released in a high-gain ICF test and the size of the LMF, test objects could be any size from very small electronic components to large systems; and nuclear effects in the LMF may include thermal radiation, x-rays, electromagnetic pulse, gamma rays, neutrons, or others. At AFIT, LLNL, and SNLA we have been investigating a test to expose systems to high-energy x-ray pulses, and have completed predictions of x-ray fluence, dose, etc. in various conceptual LMF reactors. However, comparison of our results is more meaningful if our prediction methods produce the same results for the same design. To establish a basis for comparison, we set up a simple benchmarkmore » problem and we each computed x-ray and neutron transport. The model and codes are described and the results are compared and discussed.« less

Materials analysis of TEXTOR limiter tiles

Graphite tiles from both the ALT-II and inner-bumper limiters were removed from TEXTOR and subjected to materials analysis. Scanning-electron microscopy and energy dispersive X-ray analysis were performed at the Institut für Reaktorwerkstoffe, Forschungszentrum Julich. Deuterium profiles and metallic contamination were examined using external ion beam analysis at Sandia National Laboratory-Albuquerque. The erosion and hydrogen recycling of the tiles, while subjected to plasma bombardment, were studied at University of California, Los Angeles. In-situ analysis of the inner-bumper limiter tiles was performed by Sandia National Laboratory-Livermore using beta backscattering. Results indicate low metallic impurity concentration on the surfaces of both types of tiles. Increased metallic concentration coincides with regions of increased plasma flux to the surface. The ALT-II tiles exhibit a uniformly eroded surface. The inner-bumper limiter tiles show both eroded and redeposited regions, in agreement with power deposition measurements to the tiles in TEXTOR. The redeposited regions show enhanced erosion and recycling when exposed to controlled plasma bombardment.

CTH: A three-dimensional shock wave physics code

CTH is a software system under development at Sandia National Laboratories Albuquerque to model multidimensional, multi-material, large deformation, strong shock wave physics. One-dimensional recti-linear, cylindrical, and spherical meshes; two-dimensional rectangular, and cylindrical meshes; and three-dimensional rectangular meshes are currently available. A two-step Eulerian solution scheme is used with these meshes. The first step is a Lagrangian step in which the cells distort to follow the material motion. The second step is a remesh step where the distorted cells are mapped back to the Eulerian mesh. CTH has several models that are useful for simulating strong shock, large deformation events. Both tabular and analytic equations of state are available. CTH can model elastic-plastic behavior, high explosive detonation, fracture, and motion of fragments smaller than a computational cell. The elastic-plastic model is elastic-perfectly plastic with thermal softening. A programmed burn model is available for modelling high explosive detonation. The Jones-Wilkins-Lee equation of state is available for modelling high explosive reaction products. Fracture can be initiated based on pressure or principle stress. A special model is available for moving fragments smaller than a computational cell with statistically the correct velocity. This model is very useful for analyzing fragmentation experiments and experiments with witness plates. CTH has been carefully designed to minimize the dispersion present in Eulerian codes. It has a high-resolution interface tracker that prevents breakup and distortion of material interfaces. It uses second order convection schemes to flux all quantities between cells. This paper describes the models, and novel features of CTH. Special emphasis will be placed on the features that are novel to CTH or are not direct generalizations of two-dimensional models. Another paper by Trucano and McGlaun (1989) describes several hypervelocity impact calculations using CTH.

Hypervelocity projectile acceleration with a railgun using a two-stage gas gun injector

Unique potential applications of electromagnetic railguns [R.S. Hawke, IEEE Trans. Nucl. NS-28 (2) (1981) 1542] have motivated a decade of continuous development throughout the world. This effort has led to routine acceleration of projectiles of from 1 g to about 1 kg, to velocities of nearly 4 km/s. Attempts to reach higher velocities have met with problems in the 6- to 8-km/s range [J.V. Parker, Proc. 4th Symp. on Electromagnetic Launch Tech., Austin, TX, 1988, to be published in IEEE Trans. Mag.]. The principal problem is “restrike”, which causes shunting of the propulsive plasma armature by the formation of a second plasma short circuit in the breech region of the railgun. One means of impeding restrike is the use of a two-stage light-gas gun (2SLGG) as a projectile injector. A joint development project was initiated in early 1986 between the Sandia National Laboratories Albuquerque (SNLA) and the Lawrence Livermore National Laboratory (LLNL). The project is based on the use of a 2SLGG to inject projectiles at about 7 km/s. The injection gas is hydrogen, which serves to inhibit formation of the secondary arc and to minimize barrel ablation and armature contamination. Results and status of this work are discussed.

Leakage potential of LWR containment penetrations under severe accident conditions

This paper is an overview of a Sandia National Laboratories, Albuquerque (SNLA) study of the performance of mechanical penetrations in light-water reactor (LWR) containment buildings that are subjected to severe accident environments. The study is concerned with modes of failure as well as the magnitude of leakage. The following tests have been completed, are under way, or are planned: (a) seals and gaskets have been tested to register the effects of radiation aging, thermal aging, seal geometry, and squeeze on seal and gasket materials in severe accident environments; (b) the performance of a full-scale airlock will be evaluated at severe accident temperature and pressure levels; (c) personnel airlock and equipment hatch tests were made on a 1 8 - scale model of a steel containment building; and (d) tests of mechanical penetrations are planned as part of a test on a 1 6 - scale model of a reinforced concrete building. This program is part of an overall US Nuclear Regulatory Commission (USNRC) effort to evaluate the integrity of LWR containment buildings.