This paper summarizes the U.S. Department of Energy R&D program in crystalline-silicon photovoltaic technology, which is jointly managed by Sandia National Laboratories and National Renewable Energy Laboratory. This program features a balance of basic an d applied R&D, and of university, industry, and national laboratory R&D. The goal of the crystalline-silicon R&D program is to accelerate the commercial growth of crystalline-silicon photovoltaic technology, and four strategic objectives were identified to address this program goal. Technical progress towards meeting these objectives is reviewed.
The automatic evaluation of graphical user interfaces can help reduce development costs in the creation of new designs or modification of existing designs. Several standards for the X Window System have been proposed or implemented that could greatly reduce the time spent evaluating GUIs. We implemented a User Interface Testbed (UseIT) based on the proposed Remote Access Protocol (RAP) standard. UseIT was created to automatically record an end user`s interaction with a Motif GUI application without modification or re-linking of existing code. The recorded interaction could then be replayed or displayed visually for interpretation by a human factors specialist. The end goal was to recreate the GUI and automatically recommend design changes based upon the interactions.
This paper provides new test methods and analytical procedures for characterizing the electrical performance of photovoltaic modules and arrays. The methods use outdoor measurements to provide performance parameters both at standard reporting conditions and for all operating conditions encountered by typical photovoltaic systems. Improvements over previously used test methods are identified, and examples of the successful application of the methodology are provided for crystalline- and amorphous-silicon modules and arrays. This work provides an improved understanding of module and array performance characteristics, and perhaps most importantly, a straight- forward yet rigorous model for predicting array performance at all operating conditions. For the first time, the influences of solar irradiance, operating temperature, solar spectrum, solar angle-of- incidence, and temperature coefficients are all addressed in a practical way that will benefit both designers and users of photovoltaics.
There has been little systematic study of the cause of dead (inactive) layers in II-VI phosphors used in thin film electroluminescent devices. This paper discusses preparation and characterization of rf sputter deposited Eu-doped Sr sulfide (SrS:Eu) thin films for use in a study to determine the cause of the dead layer. (The dead layer`s behavior is likely influenced by thin film composition, crystallinity, and microstructure.) We have deposited SrS:Eu thin films in a repeatable, consistent manner and have characterized properties such as composition, crystallinity, and microstructure as well as photoluminescent (PL) and electroluminescent behavior. The composition was determined using Rutherford backscattering spectrometry and electron microprobe analysis. XRD was used to assess crystalline orientation and grain size, SEM to image thin film microstructure. Measuring the PL decay after subnanosecond laser excitation in the lowest absorption band of the dopant allowed direct measurement of the dopant luminescence efficiency.
To ensure high levels of deterrent capability in the 21st century, new stockpile stewardship principles are being embraced at Sandia National Laboratories. The Department of Energy Accelerated Strategic Computing Initiative (ASCI) program is providing the computational capacity and capability as well as funding the system and simulation software infrastructure necessary to provide accurate, precise and predictive modeling of important components and devices. An important class of components require modeling of piezoelectric and ferroceramic materials. The capability to run highly resolved simulations of these types of components on the ASCI parallel computers is being developed at Sandia in the ElectroMechanical Modeling in Alegra (EMMA) code. This a simulation capability being developed at Sandia National Laboratories for high-fidelity modeling of electromechanical devices. these devices can produce electrical current arising from material changes due to shock impact or explosive detonation.
This paper discusses Sandia National Laboratories` development of new technologies for use in the Vietnam War - specifically the seismic sensors deployed to detect troop and vehicle movement - first along the Ho Chi Minh Trail and later in perimeter defense for American military encampments in South Vietnam. Although the sensor story is a small one, it is interesting because it dovetails nicely with our understanding of the war in Vietnam and its frustrations; of the creation of new technologies for war and American enthusiasm for that technology; and of a technological military and the organizational research and a m am development structure created to support it. Within the defense establishment, the sensors were proposed within the context of a larger concept - that of a barrier to prevent the infiltration of troops and supplies from North Vietnam to the South. All of the discussion of the best way to fight in Vietnam is couched in the perception that this was a different kind of war than America was used to fighting. The emphasis was on countering the problems posed by guerrilla/revolutionary warfare and eventually by the apparent constraints of being involved in a military action, not an outright war. The American response was to find the right technology to do the job - to control the war by applying a technological tincture to its wounds and to make the war familiar and fightable on American terms. And, when doubts were raised about the effectiveness of applying existing technologies (namely, the bombing of North Vietnam and Laos), the doubters turned to new technologies. The sensors that were developed for use in Vietnam were a direct product of this sort of thinking - on the part of the engineers at Sandia who created the sensors, the civilian scientific advisors who recommended them, and, ultimately, the soldiers in the field who had to use them.
For the past few years, the Minnesota Department of Corrections, assisted by Sandia National Laboratories, has developed a set of standards for perimeter security at medium, close, and maximum custody correctional facilities in the state. During this process, the threat to perimeter security was examined and concepts about correctional perimeter security were developed. This presentation and paper will review the outcomes of this effort, some of the lessons learned, and the concepts developed during this process and in the course of working with architects, engineers and construction firms as the state upgraded perimeter security at some facilities and planned new construction at other facilities.
Though the theme of System Engineering is integration, and it is normal to attempt in integration to ignore the lines between disciplines, there are distinct characteristics of the mechanical design portion of any major system design project that make this difficult. How these characteristics compound the difficulty of integration is discussed and means to minimize the associated obstacles are suggested.
One major thrust in FAA`s National Aging Aircraft Research Program is to foster new technologies in civil aircraft maintenance. Recent DOD and other government developments in using bonded composite doublers on metal structures support the need for validation of such doubler applications on US certificated airplanes. In this study, a specific composite application was chosen on an L-1011 aircraft. Primary inspection requirements for these doublers include identifying disbonds between composite laminate and aluminum parent material, and delaminations in the composite laminate. Surveillance of cracks or corrosion in the parent aluminum material beneath the double is also a concern. No single NDI method can inspect for every flaw type, therefore we need to know NDI capabilities and limitations. This paper reports on a series of NDI tests conducted on laboratory test structures and on a fuselage section from a retired L-1011. Application of ultrasonics, x-ray, and eddy current to composite doublers and results from test specimens loaded to provide a changing flaw profile, are presented in this paper. Development of appropriate inspection calibration standards are also discussed.
This paper documents the history of photovoltaic use within the Department of Defense leading up to the installation of 2.1 MW of photovoltaics underway today. This history describes the evolution of the Department of Defense`s Tri-Service Photovoltaic Review Committee and the committee`s strategic plan to realize photovoltaic`s fall potential through outreach, conditioning of the federal procurement system, and specific project development. The Photovoltaic Review Committee estimates photovoltaic`s potential at nearly 4,000 MW, of which about 700 MW are considered to be cost-effective at today`s prices. The paper describes photovoltaic`s potential within the Department of Defense, the status and features of the 2.1 MW worth of photovoltaic systems under installation, and how these systems are selected and implemented. The paper also documents support provided to the Department of Defense by the Department of Energy dating back to the late 70s.
High heat flux testing for the United States fusion power program is the primary mission of the Plasma Materials Test Facility (PMTF) located at Sandia National Laboratories in Albuquerque, New Mexico. This facility, an official Department of Energy User Facility, has been in operation for over 15 years and has provided much of the high heat flux data used in the design and evaluation of plasma facing components for many of the world`s magnetic fusion tokamak experiments. In addition to domestic tokamaks such as Tokamak Fusion Test Reactor (TFTR) at Princeton, the DIII-D tokamak pt General Atomics, and Alcator C-Mod at MIT, components for international experiments like TEXTOR, Tore-Supra, and JET also have been tested at the PMTF. High heat flux testing spans a wide spectrum including thermal shock tests on passively cooled materials, thermal response and thermal fatigue tests on actively cooled components, critical heat flux burnout tests, braze reliability tests, and safety related tests. The program`s main focus now is on testing of beryllium and tungsten armor tiles bonded to divertor, limiter, and first wall components for the International Thermonuclear Experimental Reactor (ITER). The ITER project is a collaboration among the US, EU, RF, and Japanese fusion programs. This article provides a brief overview of the high heat flux testing capabilities at the PMTF, and describes some recent test results.
Sandia National Labs (SNL) in 1994 completed a project funded by the National Institute of Justice (NIJ) to determine the applicability of sticky foam for correctional applications. Sticky foam is an extremely tacky, tenacious material used to block, entangle, and impair individuals. The NIJ project developed a gun capable of firing multiple shots of sticky foam, tested the gun and sticky foam effectiveness on SNL volunteers acting out prison and law enforcement scenarios, and had the gun and sticky foam evaluated by correctional representatives. Based on the NIJ project work, SNL supported the Marine Corps Mission, Operation United Shield, with sticky foam guns and supporting equipment to assist in the withdrawal of UN Peacekeepers from Somalia. Prior to the loan of the equipment, the Marines were given training in sticky foam characterization, toxicology, safety issues, cleanup and waste disposal, use limitations, use protocol and precautions, emergency facial clean-up, skin cleanup, gun filling, targeting and firing, and gun cleaning. The Marine Corps successfully used the sticky foam guns as part of that operation. This paper describes these recent developments of sticky foam for non-lethal uses and some of the lessons learned from scenario and application testing.
This paper provides perspectives gained from reviewing 75 Individual Plant Examination (IPE) submittals covering 108 nuclear power plant units. Variability both within and among reactor types is examined to provide perspectives regarding plant-specific design and operational features, and C, modeling assumptions that play a significant role in the estimates of core damage frequencies in the IPEs. Human actions found to be important in boiling water reactors (BWRs) and in pressurized water reactors (PWRs) are presented and the events most frequently found important are discussed.
As part of an ongoing investigation to characterize the properties and structure of Zn halide-Te oxide glasses, we report preliminary measurements of the optical properties of several Nd- and Er-doped tellurites. Measurements include fluorescence lifetimes and estimates of the theoretical radiative lifetimes (from traditional Judd-Ofelt analysis of optical absorption spectra) as well as phonon sideband studies sensitive to vibrational characteristics near the rare earth ion. Response of these optical features to the substitution of alternative halides is examined.
Algorithms for computing forces and associated surface deformations (graphical and physical) are given, which, together with a force feedback device can be used to haptically display virtual objects. The Bendable Polygon algorithm, created at Sandia National Labs and the University of New Mexico, for visual rendering of computer generated surfaces is also presented. An implementation using the EIGEN virtual reality environment, and the PHANToM (Trademark) haptic interface, is reported together with suggestions for future research.
We are developing a prototype zooming World-Wide Web browser within Pad++, a multiscale graphical environment. Instead of having a single page visible at a time, multiple pages and the links between them are depicted on a large zoomable information surface. Pages are scaled so that the page in focus is clearly readable with connected pages shown at smaller scales to provide context. We quantitatively compared performance with the Pad++ Web browser and Netscape in several different scenarios. We examined how quickly users could answer questions about a specific Web site designed for this test. Initially we found that subjects answered questions slightly slower with Pad++ than with Netscape. After analyzing the results of this study, we implemented several changes to the Pad++ Web browser, and repeated one Pad++ condition. After improvements were made to the Pad++ browser, subjects using Pad++ answered questions 23% faster than those using Netscape.
The popularization of the Internet has brought fundamental changes to the world, because it allows a universal method of communication between computers. This carries enormous benefits with it, but also raises many security considerations. Cryptography is a fundamental technology used to provide security of computer networks, and there is currently a widespread engineering effort to incorporate cryptography into various aspects of the Internet. The system-level engineering required to provide security services for the Internet carries some important lessons for researchers whose study is focused on narrowly defined problems. It also offers challenges to the cryptographic research community by raising new questions not adequately addressed by the existing body of knowledge. This paper attempts to summarize some of these lessons and challenges for the cryptographic research community.
Vertical-cavity surface-emitting lasers (VCSELs) are presently the subject of intense research due to their potential as compact, efficient, astigmatic laser sources for a number of important applications. Of special interest are the selectively-oxidized VCSELs that have recently set records for threshold current and wall-plug efficiency. The onset of higher-order modes at powers of a few milliWatts, however, presently limits the wide utilization of these devices and indicates the need for improvements in design. Unfortunately, their complexity precludes optimization based solely upon empirical methods, and points instead to the need for better numerical models. Modeling the optical field in a vertical-cavity laser, however, is especially difficult due to both the high Q of the optical cavity and the distributed reflectivity of the mirrors. Our approach to this dilemma has been the development of modeling techniques on two complexity scales. We first derived an effective- index model that is numerically efficient and thus can be included together with carrier transport and thermal models to make up a self-consistent modeling package. In addition to its use in the overall VCSEL model, this simplified optical model has been extremely valuable in elucidating the basic principles of waveguiding in VCSELs that in turn have led to new ideas in device design. More specifically, the derived expression for the effective index shows clearly that index guiding in a VCSEL depends only on variations in optical cavity length, and thus can be engineered without the need to alter the material index of refraction. Also, we have designed index- guided and antiguided devices whose cavity lengths are modified in certain regions by etching of the cavity material prior to growth of the second mirror. Fabrication of these new device designs is presently in progress.
A series of ``MiniLab`` end effectors are currently being designed for robotic deployment in hazardous areas such as waste storage tanks at Idaho National Engineering Laboratories (INEL) and Oak Ridge National Laboratory (ORNL). These MiniLabs will be the first ever multichannel hazardous waste characterization end effectors deployed in underground high level waste storage tanks. They consist of a suite of chemical, radiological, and physical properties sensors integrated into a compact package mounted on the end of a robotic arm and/or vehicle. Most of the sensors are commercially available thus reducing the overall cost of design and maintenance. Sensor configurations can be customized depending on site/customer needs. This paper will address issues regarding the cost of field sampling verses MiniLab in-situ measurements and a brief background of the Light Duty utility Arm (LDUA) program. Topics receiving in depth attention will include package size parameters/constraints, design specifications, and investigations of currently available sensor technology. Sensors include radiological, gas, chemical, electrolytic, visual, temperature, and ranging. The effects of radiation on the life of the systems/sensors will also be discussed. Signal processing, control, display, and data acquisition methods will be described. The paper will conclude with an examination of possible applications for MiniLabs.
For the past seven years, Sandia National Laboratories has been active in the development of robotic systems to help remediate DOE`s waste sites and decommissioned facilities. Some of these facilities have high levels of radioactivity which prevent manual clean-up. Tele-operated and autonomous robotic systems have been envisioned as the only suitable means of removing the radioactive elements. World modeling is defined as the process of creating a numerical geometric model of a real world environment or workspace. This model is often used in robotics to plan robot motions which perform a task while avoiding obstacles. In many applications where the world model does not exist ahead of time, structured lighting, laser range finders, and even acoustical sensors have been used to create three dimensional maps of the environment. These maps consist of thousands of range points which are difficult to handle and interpret. This paper presents a least squares technique for fitting range data to planar and quadric surfaces, including cylinders and ellipsoids. Once fit to these primitive surfaces, the amount of data associated with a surface is greatly reduced up to three orders of magnitude, thus allowing for more rapid handling and analysis of world data.
Sandia National Laboratories (SNL) has recently developed a 16 cm{sup 3} (1 in{sup 3}) autonomous robotic vehicle which is capable of tracking a single conducting wire carrying a 96 kHz signal. This vehicle was developed to assess the limiting factors in using commercial technology to build miniature autonomous vehicles. Particular attention was paid to the design of the control system to search out the wire, track it, and recover if the wire was lost. This paper describes the test vehicle and the control analysis. Presented in the paper are the vehicle model, control laws, a stability analysis, simulation studies and experimental results.
With the goal of improving the ability of people around the world to share the development and use of intelligent systems, Sandia National Laboratories` Intelligent Systems and Robotics Center is developing new Virtual Collaborative Engineering (VCE) and Virtual Collaborative Control (VCC) technologies. A key area of VCE and VCC research is in shared visualization of virtual environments. This paper describes a Virtual Collaborative Visualizer (VCV), named Rocinante, that Sandia developed for VCE and VCC applications. Rocinante allows multiple participants to simultaneously view dynamic geometrically-defined environments. Each viewer can exclude extraneous detail or include additional information in the scene as desired. Shared information can be saved and later replayed in a stand-alone mode. Rocinante automatically scales visualization requirements with computer system capabilities. Models with 30,000 polygons and 4 Megabytes of texture display at 12 to 15 frames per second (fps) on an SGI Onyx and at 3 to 8 fps (without texture) on Indigo 2 Extreme computers. In its networked mode, Rocinante synchronizes its local geometric model with remote simulators and sensory systems by monitoring data transmitted through UDP packets. Rocinante`s scalability and performance make it an ideal VCC tool. Users throughout the country can monitor robot motions and the thinking behind their motion planners and simulators.
A capacitive sensing technology has been applied to develop a Standoff Sensor System for control of robotically deployed tools utilized in Decontamination and Dismantlement (D and D) activities. The system combines four individual sensor elements to provide non-contact, multiple degree-of-freedom control of tools at distances up to five inches from a surface. The Standoff Sensor has been successfully integrated to a metal cutting router and a pyrometer, and utilized for real-time control of each of these tools. Experiments demonstrate that the system can locate stationary surfaces with a repeatability of 0.034 millimeters.
Colloid-facilitated transport of Pu, Am, U, Th, and Np has been recognized as a potentially important phenomenon affecting the performance of the Waste Isolation Pilot Plant (WIPP) facility being developed for safe disposal of transuranic radioactive waste. In a human intrusion scenario, actinide-bearing colloidal particles may be released from the repository and be transported by brines (approximately 0.8 to 3 molal ionic strength) through the Culebra, a thin fractured microcrystalline (mean grain size 2 micrometers) dolomite aquifer overlying the repository. Transport experiments were conducted using sieved, uniformly packed crushed Culebra rock or nonporous dolomite cleavage rhombohedra. Experiments with mineral fragments and fixed and live WIPP-relevant bacteria cultures showed significant levels of retardation due to physical filtration effects. Humic substances were not attenuated by the Culebra dolomite. Comparison of elution curves of latex microspheres in columns prepared with microcrystalline rock and nonporous rock showed minimal effect of Culebra micropores on colloid transport. These data form part of the basis to parameterize numerical codes being used to evaluate the performance of the WIPP.
The People`s Republic of China has undergone major economic reform in the past decade producing a new free-market system that is distinctly Chinese. The Chinese realize that to be successful in world trade, quality management and export trading must be given the highest priority in China`s strategic economic plans. Many manufacturing companies are now implementing Total Quality Management (TQM) and the ISO 9000 i quality management standards. A first hand survey of the quality movement in China today is the objective of this paper.
