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ATLAS: A Small, Light Weight, Time-Synchronized Wind-Turbine Data Acquistion System
No full textWind energy researchers at Sandia National Laboratories have developed a small, lightweight, time- synchronized, robust data acquisition system to acquire long-term time-series data on a wind turbine rotor. A commercial data acquisition module is utilized to acquire data simultaneously from multip!e strain-gauge, analog, and digital channels. Acquisition of rotor data at precisely the same times as acquisition of ground data is ensured by slaving the acquisition clocks on the rotor- based data unit and ground-based units to the Global Positioning Satellite (GPS) system with commercial GPS receiver units and custom-built and programmed programmable logic devices. The acquisition clocks will remain synchronized within two microseconds indefinitely. Field tests have confirmed that synchronization can be maintained at rotation rates in excess of 350 rpm, Commercial spread-spectrum radio modems are used to transfer the rotor data to a ground- based computer concurrently with data acquisition, permitting continuous acquisition of data over a period of several hours, days or even weeks
Photovoltaic module performance and durability following long-term field exposure
No full textOur investigations of both new and field-aged photovoltaic modules have indicated that, in general, today's commercially available modules area highly reliable product. However, by using new test procedures, subtle failure mechanisms have also been identified that must be addressed in order to achieve 30-year module lifetimes. This paper summarizes diagnostic test procedures, results, and implications of in-depth investigations of the performance and durability characteristics of commercial modules after long-term field exposure. A collaborative effort with U.S. module manufacturers aimed at achieving 30-year module lifetimes is also described
Task 6.7.3 - Interfacial Mass Transport Effects in Composite Materials
No full textA series of TiNX and Ti(N,O)X films formed from a TiC, N2, H2, and (N2 + 02 ) gas mixture was deposited on aluminum ceramics at 1073 K for 5 hr at atmospheric pressure, according to the procedure described in Dekker et al. These conditions were selected because they offer a reasonable deposition rate and low chlorine content in films. The TiNX films, with two different nonstoichiometries controlled by the ratio of to H2 and two Ti(N,O)X films with different nitrogen and oxygen content were prepared. The N2 and H2 gases were first purified in alkaline pyrogallol and dried over silica gel and further over a copper and palladium catalyst. TiCld concentration in flowing N2 and H2 (70/30) corresponded to its vapor pressure over liquid at 300 K. Film thickness was determined using a multiple interferometer. All of the films obtained were thicker than 1000 nm. Phase analysis and interatomic distances were determined by x-ray diffraction analysis (XRD) at room temperature
Surface-Roughness Induced Residual Stresses in Thermal Barrier Coatings: Computer Simulations
No full textAdherence of plasma-sprayed thermal barrier coatings (TBC'S} is strongly dependent on mechanical interlocking at the interface between the ceramic coating and the underlying metallic bond coat. Typically, a rough bond-coat surface topology is required to achieve adequate mechanical bonding. However, the resultant interfacial asperities modify the residual stresses that develop in the coating system due to thermal expansion differences, and other misfit strains, and generate stresses that can induce progressive fracture and eventual spallation of the ceramic coating. For a flat interface the principal residual stress is parallel to the interface as the stress normal to the interface is zero. However, the residual stress normal to the interface becomes non-zero, when the interface has the required interlocking morphology. In the present study, an actual microstructure of a plasma-sprayed TBC system was numerically simulated and analyzed with a recently developed, object-oriented finite element analysis program, OOF, to give an estimate of the localized residual stresses in a TBC system. Additionally, model TBC rnicrostructures were examined to evaluate the manner in which the topology of interfacial asperities influences residual stresses. Results are present for several scenarios of modifying interfacial roughness
Inspection of Nuclear Power Plant Containment Structures
No full textSafety-related nuclear power plant (NPP) structures are designed to withstand loadings from a number of low-probability external and interval events, such as earthquakes, tornadoes, and loss-of-coolant accidents. Loadings incurred during normal plant operation therefore generally are not significant enough to cause appreciable degradation. However, these structures are susceptible to aging by various processes depending on the operating environment and service conditions. The effects of these processes may accumulate within these structures over time to cause failure under design conditions, or lead to costly repair. In the late 1980s and early 1990s several occurrences of degradation of NPP structures were discovered at various facilities (e.g., corrosion of pressure boundary components, freeze- thaw damage of concrete, and larger than anticipated loss of prestressing force). Despite these degradation occurrences and a trend for an increasing rate of occurrence, in-service inspection of the safety-related structures continued to be performed in a somewhat cursory manner. Starting in 1991, the U.S. Nuclear Regulatory Commission (USNRC) published the first of several new requirements to help ensure that adequate in-service inspection of these structures is performed. Current regulatory in-service inspection requirements are reviewed and a summary of degradation experience presented. Nondestructive examination techniques commonly used to inspect the NPP steel and concrete structures to identify and quantify the amount of damage present are reviewed. Finally, areas where nondestructive evaluation techniques require development (i.e., inaccessible portions of the containment pressure boundary, and thick heavily reinforced concrete sections are discussed
Toxics Release Inventory Expansion Rule Phase 3 (TRI-P3)
No full textThe ORR [East Tennessee Technology Park (ETTP), Y-12 Plant, and Oak Ridge National Laboratory (ORNL)] is considered a single facility for reporting by the DOE prime contractors. The processing, manufacturing, or "otherwise use" Section313 chemicals are combined to determine TRI reportability. Such is the case with lead metal, which is one of two chemicals for which reportin~ forms were prepared in this pilot study (Task 2;1. The lead shop at ORNL exceeded the reporting threshold, causing a lead activity at a Y-1 2 machine shop and lead in waste at ETTP to be reportable. TRI-P3 report preparation time for lead totaled 36.5 hours. The second chemical investigated and reported (chromium) also required nearly a man-week for report preparation and documentation by experienced TRI personnel. The ORR TRI report typically includes about six chemicals, so an estimate of the TRI-P3 incremental reporting burden for ORR would be six weeks for experienced personnel axI d two/three man-months for first-time ORR preparers
Slag Characterization and Removal Using Pulse Detonation Technology During Coal Gasification. Quarterly Report. October 1 - December 31, 1997
No full textThe research activities performed in this quarter (reporting period: 10/01/97- 12/31/97) are summarized as follows: The activities concentrated on: . Partial analysis of the multi pulse test results . Data analysis and comparison with that of the single pulse test dat
Using DFX for Algorithm Evaluation
No full textEvaluating whether or not a new seismic processing algorithm can improve the performance of the operational system can be problematic: it maybe difficult to isolate the comparable piece of the operational system it maybe necessary to duplicate ancillary timctions; and comparing results to the tuned, full-featured operational system maybe an unsat- isfactory basis on which to draw conclusions. Algorithm development and evaluation in an environment that more closely resembles the operational system can be achieved by integrating the algorithm with the custom user library of the Detection and Feature Extraction (DFX) code, developed by Science Applications kternational Corporation. This integration gives the seismic researcher access to all of the functionality of DFX, such as database access, waveform quality control, and station-specific tuning, and provides a more meaningfid basis for evaluation. The goal of this effort is to make the DFX environment more accessible to seismic researchers for algorithm evalua- tion. Typically, anew algorithm will be developed as a C-language progmm with an ASCII test parameter file. The integration process should allow the researcher to focus on the new algorithm developmen~ with minimum attention to integration issues. Customizing DFX, however, requires soflsvare engineering expertise, knowledge of the Scheme and C programming languages, and familiarity with the DFX source code. We use a C-language spatial coherence processing algorithm with a parameter and recipe file to develop a general process for integrating and evaluating a new algorithm in the DFX environment. To aid in configuring and managing the DFX environment, we develop a simple parameter management tool. We also identifi and examine capabilities that could simplify the process further, thus reducing the barriers facing researchers in using DFX..These capabilities include additional parameter manage- ment features, a Scheme-language template for algorithm testing, a generic algorithm interface encompassing expected DFX functionality and algorithm input and output, and the aggregation of some DFX I?imctionality to sim- plify the interface
The SMAC Modal Parameter Extraction Package
No full textAfter the basic theory for SMAC is presented below, two applications of the algorithm with real hardware will be presented. The first moderate-damping application is a system with approximately 50 modes in the bandwidth with up to 5 percent damping. The second application has at least 70 modes in the bandwidth, but damping is always below 3 percent. In addition to the improved implementation of the SMAC root finder, coding has been written to extract the mode shapes based on quadrature fit, and this is described herein
Use of Dissolved and Colloidal Actinide Parameters within the 1996 Waste Isolation Pilot Plant Compliance Certification Application
No full textMany of the papers in this volume present detailed descriptions of the chemical analyses and methodologies that have been used to evaluate the maximum dissolved and colloid concentrations of actinides within the WIPP repository as part of the performance assessment. This paper describes the program fcm collecting experimental data and provides an overview of how the PA modeled the release of radionuclides to the accessible environment, and how volubility and colloid parameters were used by the PA models