The Simpson-Wilberg Technique for Expert Decision Tree Modeling (patent case number S-83,506) establishes and identifies the proper requirements governing effective business and operating practices through the use of knowledge-based engineering (KBE). The new application, Project Control Expert System (ProCon X) was created by the Simpson-Wilberg technique as a tool for project definition planning and control. ProCon X guides the project manager through an interview session asking project characteristic questions and establishes the proper project criteria. The criteria produced define the rigor applied to the project activities, i.e., level of work breakdown structure (WBS), type of scheduling, amount of cost estimating, etc. In this paper the use of the Simpson-Wilberg technique will be illustrated for solving the problems of identifying proper project criteria for project management. This technique has been used for other applications outside the project management field and can be used in any field with a need for consistent application of rules and procedures routinely used for business and operating practices.

Work is ongoing to characterize the dimensional variability of steel casting features. Data are being collected from castings produced at representative Steel Founders` Society of America foundries. Initial results based on more than 12,500 production casting feature measurements are presented for carbon and low alloy steel castings produced in green sand, no-bake, and shell molds. A comprehensive database of casting, pattern, and feature variables has been developed so that the influence of the variables on dimensional variability can be determined. Measurement system analysis is conducted to insure that large measurement error is not reported as dimensional variability. Results indicate that the dimensional variability of production casting features is less than indicated in current US (SFSA) and international (ISO) standards. Feature length, casting weight, parting line and molding process all strongly influence dimensional variability. Corresponding pattern measurements indicate that the actual shrinkage amount for casting features varies considerably. This variation in shrinkage will strongly influence the ability of the foundry to satisfy customer dimensional requirements.

A dimensionless parameter model previously developed for C0{sub 2} laser beam welding has been shown to be applicable to GTAW and PAW autogenous arc welding processes. The model facilitates estimates of weld size, power, and speed based on knowledge of the material`s thermal properties. The dimensionless parameters can also be used to estimate the melting efficiency, which eases development of weld schedules with lower heat input to the weldment. The mathematical relationship between the dimensionless parameters in the model has been shown to be dependent on the heat flow geometry in the weldment.

Semiempirical and ab initio Hartree Fock computational results indicate that the highly reactive dienophile tetramethyldisilene, Me{sub 2}Si=SiMe{sub 2}, is an excellent candidate for a novel functionalization of the equator of C{sub 70} via a [2+4] cycloaddition to the 21, 22, 23, 42 carbons. Thermal or photochemical generation of tetramethyldisilene in the presence of C{sub 70} results in similar complex mixtures in which the major product appears to be that of [2+2] cycloaddition to the 7,8 carbons of C{sub 70}. A minor product clearly results from [2+2] cycloaddition to the 1,9 carbons. Both of these products are hydrolytically unstable and are converted nonspecifically to mixtures of 1,9- and 7,8-C{sub 70}H{sub 2} which are also present in HPLC traces of the reaction mixtures.

In the US the general population is exposed to methylmercury (MeHg) principally through the consumption of fish. There is continuing discussion about the sources of this form of mercury (Hg), the magnitudes and trends in exposures to consumers, and the significance of the sources and their contributions to human health. In response to these discussions, the US Department of Energy, the US Food and Drug Administration, and the US Environmental Protection Agency cosponsored a two-day workshop to discuss data and methods available for characterizing the risk to human health presented by MeHg. This workshop was attended by 45 individuals representing various Federal and state organizations and interested stakeholders. The agenda covered: Agency interests; probabilistic approach to risk assessment; emission sources; atmospheric transport; biogeochemical cycling; exposure assessment; health effects of MeHg; and research needs.

The field of nuclear criticality safety is confronted with growing technical challenges and the need for forward-thinking initiatives to address and resolve issues surrounding economic, safe and secure packaging, transport, interim storage, and long-term disposal of spent nuclear fuel. These challenges are reflected in multiparameter problems involving optimization of packaging designs for maximizing the density of material per package while ensuring subcriticality and safety under variable normal and hypothetical transport and storage conditions and for minimizing costs. Historic and recently revealed uncertainties in basic data used for performing nuclear subcriticality evaluations and safety analyses highlight the need to be vigilant in assessing the validity and range of applicability of calculational evaluations that represent extrapolations from ``benchmark`` data. Examples of these uncertainties are provided. Additionally, uncertainties resulting from the safeguarding of various forms of fissionable materials in transit and storage are discussed.

Establishment of guidance for the protection of workers and members of the public from radiation exposures necessitates estimation of the radiation dose to tissues of the body at risk. The dosimetric methodology formulated by the International Commission on Radiological Protection (ICRP) is intended to be responsive to this need. While developed for radiation protection, elements of the methodology are often applied in addressing other radiation issues; e.g., risk assessment. This chapter provides an overview of the methodology, discusses its recent extension to age-dependent considerations, and illustrates specific aspects of the methodology through a number of numerical examples.

Double and single ionization of He and H{sub 2} by proton (p) and antiproton ({bar p})impact in the energy region below 50 keV was studied theoretically by using the semiclassical molecular picture. As the energy decreased, the ratio of the double- to the single-ionization cross section increased for impact and decreased for p impact for both He and H{sub 2}. These trends are consistent with recent measurements for He. Ionization mechanisms differ distinctly for p impact and {bar p} impact. For p impact, the dominant mechanism for double ionization at the lower energies is sequential ladder climbing by the two electrons through various excited channels and finally into the continuum. For {bar p} impact, in contrast, the approaching negative charge distorts both the He and H{sub 2} electron clouds toward the other side of the nucleus and decreases the electron binding energies. These effects enhance electron-electron interactions, increasing double ionization. For the H{sub 2}, an effect of molecular orientation is an additional complication in determining the dynamics.

A portable ergonomics data acquisition system consisting of state-of-the-art hardware being designed is described here. It will be employed to record driver, vehicle, and environment parameter data from a wide range of vehicles and trucks. The system will be unobtrusive to the driver and inconspicuous to the outside world. It will have three modes of data gathering and provide for extended periods of data collection. Modularity, flexibility, and cost will be key drivers in the development effort. The ergonomics data acquisition system project is being conducted in two phases--a feasibility study and a development, construction, and validation phase.

The degree and biochemical basis of drought tolerance and osmotic adjustment of dogwood (Cornus florida L.), white oak (Quercus alba L.), chestnut oak (Quercus prinus L.), and red maple (Acer rubrum L.) is being assessed in a mature hardwood forest using three hydrologic regimes: ambient, wet (+33% throughfall), and dry ({minus}33% throughfall). Currently, leaf water potential, osmotic potential at saturation, and metabolite concentrations are determined monthly for trees under the three treatments. First year results show that within the dry treatment, dogwood demonstrated the highest osmotic potential at saturation ({minus}1.2 MPa), indicating the greatest sensitivity to water stress. Increasing tolerance was evident in red maple ({minus}1.4 MPa), white oak ({minus}1.6 MPa), and chestnut oak ({minus}1.9 MPa). In June, dogwood displayed a 0.12 MPa adjustment to drought, relative to the ambient control. In July, chestnut oak displayed a 0.18 MPa adjustment. This osmotic adjustment resulted primarily from fructose and glucose accumulation in dogwood, and shikimic acid and sucrose accumulation in chestnut oak.

The response of brittle materials to dynamic loads was studied in this investigation based on a continuum damage model. Damage mechanism was selected to be interaction and growth of subscale cracks. Briefly, the cracks are activated by bulk tension and the density of activated cracks are described by a Weibull statistical distribution. The moduli of a cracked solid derived by Budiansky and O`Connell are then used to represent the global material degradation due to subscale cracking. This continuum damage model was originally developed to study rock fragmentation and was modified in the present study to improve on the post-limit structural response. The model was implemented into a transient dynamic explicit finite element code PRONTO 2D and then used for a numerical study involving the sudden stretching of a plate with a centrally located hole. Numerical results characterizing the dynamic responses of the material were presented. The effect of damage on dynamic material behavior was discussed.

Reconsolidated crushed salt is proposed as the sole long-term shaft seal between the Waste Isolation Pilot Plant (WIPP) and the biosphere. The concept for a long-term shaft seal for the WIPP repository is to place crushed salt in the four shafts and to develop an effective seal as the surrounding salt creeps into the shafts, reconsolidating the salt. Permeability of the salt components is calculated to achieve performance objectives at some acceptable time in the future, an expectation which is a key to performance assessment calculations for the WIPP. Such a seal has never been constructed, and until now no performance measurements have been made on an appropriately large scale. A full understanding of construction methods, achievable initial density and permeability and time-wise performance of reconsolidating salt is required. This paper discusses nearly full-scale dynamic compaction of mine-run WIPP salt, preliminary measurements of density and permeability, and their variability within a relatively large volume of compacted material

The dynamic response of a weapon`s internal components to an accident is critical in determining the safety of a weapon. The primary objective of this study was to determine the safety of the weapon based on the acceleration histories of its safety components. The accident scenario was a 80 feet/second impact of the weapon onto a railroad rail. Large deformations and many contacts were expected due to the severity of the impact condition. The complexity of this analysis required a nonlinear finite element code which could track many contact surfaces simultaneously and simulate material failure using element death. The damage to the structure and its contents was simulated using PRONTO3D (an explicit finite element code developed at Sandia National Laboratories). Some of PRONTO3D`s advanced features used in the calculations included the self-contacting algorithms, material death, and rigid body mechanics. Throughout the analysis, a large number of mechanical contacts, both normal and sliding with friction, were detected and tracked by PRONT03D. The analysis predicted large deformations and material failure that took the form of tears in the aluminum shroud and in the housing of the components. The predicted acceleration histories were then used to determine if the components remained functional.

The ecological risk assessment process in its ideal form is an unbiased approach for assessing the probability of harm to the environment as a consequence of a given action. This information can then be combined with other societal values and biases in the management of such risks. However, as the process currently is understood, decision makers often are accused of manipulating information in order to generate decisions or achieve buy in from the public in support of a particular political agenda. A clear understanding of the nature of the risk management process can help define areas where information should be free from social or personal bias, and areas where values and judgments are critical. The authors do not propose to discuss the individual`s decision-making process, but rather to address the social process of risk communication and environmentally-related decision-making, identifying which parts of that process require bias-free, scientifically generated information about the consequences of various actions and which parts need an understanding of the social values which underlie the informed choices among those possible actions.

The Advanced Liquid Metal Reactor (ALMR) has the potential to extend the economic life of the nuclear option and of reducing the number of high level waste repositories which will eventually be needed in an expanding nuclear economy. This paper reports on an analysis which models and evaluates the economics of the use of ALMRs as a component of this country`s future electricity generation mix. The ALMR concept has the ability to utilize as fuel the fissile material contained in previously irradiated nuclear fuel (i.e., spent fuel) or from surplus weapons grade material. While not a requirement for the successful deployment of ALMR power plant technology, the reprocessing of spent fuel from light water reactors (LWR) is necessary for any rapid introduction of ALMR power plants. In addition, the reprocessing of LWR spent fuel may reduce the number of high level waste repositories needed in the future by burning the long-lived actinides produced in the fission process. With this study, the relative economics of a number of potential scenarios related to these issues are evaluated. While not encompassing the full range of all possibilities, the cases reported here provide an indication of the potential costs, timings, and relative economic attractiveness …

Substitution of the B component in the prototype AB{sub 5} type (LaNi{sub 5}) metal hydride alloys have resulted in their increased acceptance as anodes for rechargeable alkaline batteries. Recently substitution of the A component (La) for imparting properties such as increased corrosion resistance has received attention. This investigation deals with the role of Ce as a substituent for the La and its effect in terms of corrosion resistance. The alloys chosen have the general composition of La{sub x}Ce{sub 1-x}B{sub 5} (x = 1, 0.8, 0.5 and 0.25) where B is Ni{sub 3.55}CO{sub 0.75}Mn{sub 0.4}Al{sub 0.3} together with alloys containing the mischmetal (Mm) as the A component (both synthetic and commercial). Electrochemical cycling results show that Ce lowers the capacity loss in the alloys and that this effect is not a simple function of the extent of lattice expansion during hydriding as was previously suggested. Correlation of the electrochemical and XAS results show that capacity loss is directly related to the extent of Ni corrosion. Effect of Ce substitution seems to result in a stable Ce oxide hydroxide coating which imparts the corrosion resistance.

Effect of I{sup -} concentration on mobility of Hg(II) in clay suspensions was studied over an environmentally significant pH range. The addition of I{sup -} decreased the adsorption of Hg(II), except at very low (50 {mu}g/L) I{sup -} concentrations. In suspensions of greater I{sup -} concentration (1.5 and 50 mg/L). Hg(II) adsorption increased with pH, presumably due to formation of Hg-OH complexes; at low concentrations, Hg(II) adsorption decreased with pH, presumably due to competition from hydrocomplexes for surface adsorption sites. I{sup -} was an effective extractant for Hg(II), outperforming all other halides in extraction efficiency.

This Paper continues earlier work on the reduction of the quench pressure in a doubler cable-in-conduit conductor achieved by perforating the inner jacket. The present study examines the effect of the perforations on the stability margin and on the onset of thermal hydraulic quenchback.

The purpose of hazardous and radioactive materials packaging is to, enable these materials to be transported without posing a threat to the health or property of the general public. To achieve this aim, regulations have been written establishing general design requirements for such packagings. While no regulations have been written specifically for mixed waste packaging, regulations for the constituents of mixed wastes, i.e., hazardous and radioactive substances, have been codified. The design requirements for both hazardous and radioactive materials packaging specify packaging compatibility, i.e., that the materials of the packaging and any contents be chemically compatible with each other. Furthermore, Type A and Type B packaging design requirements stipulate that there be no significant chemical, galvanic, or other reaction between the materials and contents of the package. Based on these requirements, a Chemical Compatibility Testing Program was developed in the Transportation Systems Department at Sandia National Laboratories (SNL). The program, supported by the US Department of Energy`s (DOE) Transportation Management Division, EM-261 provides the means to assure any regulatory body that the issue of packaging material compatibility towards hazardous and radioactive materials has been addressed. In this paper, we describe the general elements of the testing program and the experimental …

A variety of test methods are available to evaluate the solderability of printed wiring board [PWB] surface finishes. A new test has been developed which better simulates the capillary flow physics of typical solder assembly processing, especially surface mount soldering. The work was conducted under a cooperative research and development agreement between Sandia National Laboratories, the National Center for Manufacturing Sciences, and several PWB fabricators (AT&T, IBM, Texas Instruments, and United Technologies Corporation/Hamilton Standard) to advance PWB interconnect systems technology. Particular attention has been given at Sandia to characterizing the effects of accelerated aging in a simulated indoor industrial environment on subsequent PWB solderability. The program`s baseline surface finish was copper. Solderability testing on ``as-fabricated`` and ``pre-stressed copper`` pad-strip geometries was performed with Sn-Pb eutectic solder and three different fluxes at four different reflow temperatures.

In this paper, the effects of interface states in the Z-nO/CdS/CuinSe{sub 2}, and CdS/CdTe solar cells are presented. The effects are investigated through numerical modeling using ADEPT (A Device Emulation Program and Tool). The results show that donor-like interface states have very little effect but acceptor-like interface states at the resistive ZnO/CdS can cause pinning of the bands at the interface, thus leading to non-exponential illuminated I-V curves when the interface state densities are high enough. High density of acceptor-like states between the CdS and In-rich CIS does not result in the two-diode like IV curves. Instead they can significantly lower the fill factor. In the CdS/CdTe solar cells. either donor- or acceptor-like interface states have little effect since almost all the depletion region lies in the CdTe. Thus, the metallurgical junction where the interface states are located is away from the electrical junction where the conductivity type changes.

The majority of electric-motor applications are pumps, fans, blowers, and certain compressors that follow the load torque pattern described in this paper. It has been known for many years that simply replacing the old motor with a high-efficiency motor might not produce the expected efficiency gain. This paper suggests the calculations for the effective efficiency and temperature rise of the high-efficiency motor. The reliability in terms of temperature rise, downsizing, power factor, harmonics, mechanical structure, etc., are discussed.

This paper critically evaluates efficiency of soft switching inverters including an actively clamped resonant dc link inverter and a clamped-mode resonant pole inverter. An analytical approach to evaluating efficiency of the clamped-mode soft switching inverter has been developed. The evaluation results are compared with that of the standard pulse-width-modulation (PWM) inverter. A 50-kW induction motor is used as the variable load, and the inverter efficiency is evaluated under different speed and torque conditions. The clamped-mode soft-switching inverter, although eliminating the switching loss, shows poor efficiency over the entire load range. Under low load conditions, the efficiency profile is even worse. The actively clamped resonant dc link inverter shows highest efficiency over the entire speed and torque range. However, its energy saving over the standard PWM inverter is marginal under full load or high speed conditions.

Recent studies identified approximately 4000 check valve failures that occurred from 1984-1991. Of these, approximately 1600 were determined to be significant enough to require further analysis. This is to be compared with the existing check valve population of nearly 21,000 valves. The strategy proposed in this paper is to establish a refined, centralized check valve failure/reliability database based in part on existing Institute of Nuclear Power Operations (INPO) Nuclear Plant Reliability Data System (NPRDS) data. Ideally the database would be maintained in a central location, augmented with specific component information, overall reliability information, and updated at least biannually. The data would be available to sort and search as desired. The conceptual plan is provided and possible uses of the database are given.