Search NASA⌕ Search

SEARCH · Search NASA

Results for “Exploratory analysis”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9

Nevada National Security Site Site-Directed Research and Development Report (FY 2018 Annual Report)

This report compiles multiple articles describing activities developed and performed under the Site-Directed Research and Development Program for the benefit the Nation during Fiscal Year 2018. Sustained investment and ongoing core innovation are the keys to successful research and development programs. These elements drive the Site-Directed Research and Development (SDRD) Program and provide solutions to some of the most challenging problems our nation and our allies face. Our Nevada enterprise, consisting of both our management and operating entity and our NNSA field office, is aggressively investing in SDRD and injecting innovation through strategic partnerships. Our partnerships with universities, industry, and our sister institutions within the National Nuclear Security Administration (NNSA) build upon our core capabilities and allow us to create innovative solutions to support our mission requirements. In 2018, we raised the investment level of SDRD for only the second time in the history of the program. Nearly at our congressionally authorized limit, SDRD has substantial resources to successfully address numerous issues. Investment is only one part of the equation; innovation is generated through collaborations that bring discovery and provide the “technical differentiation” and the return on investment we seek. This report demonstrates an enduring theme of how partnerships help us drive the best outcomes and provide the maximum impact possible, while using our resources efficiently.

36 MATERIALS SCIENCE↗

The Joint Institute for Strategic Energy Analysis

This fact sheet provides an overview of the Joint Institute for Strategic Energy Analysis, including its approach, exploratory areas, notable successes, and ways to partner.

agricultural decarbonization↗

Measurement of the Neutron Electromagnetic Form Factor Ratio at High Momentum Transfer

The inner structure of the nucleon (proton and neutron) remains a topic of great interest in nuclear and particle physics, after many decades of study. For example, understanding the quark-gluon dynamics inside the nucleon would shed light on how 99% of the nucleon mass is created. The neutron electromagnetic form factors, Gn E and Gn M , give important insights into the neutron structure. The Super BigBite Spectrometer (SBS) program at Jefferson Lab (JLab) seeks to extend the form factor measurements for both the proton and the neutron. The neutron electric form actor, Gn E , has been historically difficult to measure due to the short lifetime of the free neutron and the small value of Gn E . The GEn-II experiment is part of the SBS program and seeks to measure Gn E , significantly increasing the high momentum transfer coverage. A newly designed polarized 3He target increased the figure of merit by three times compared to previous measurements. The analysis of this data is especially challenging due to the unprecedented high-rate environment caused by the open nature of the spectrometer with a direct line of sight to the target. This required developing new Gas Electron Multiplier (GEM) particle trackers which can cover large areas demanded by this setup and handle particle rates up to 500 kHz/cm2. Rates this high over a large area is unprecedented in particle tracking systems and came with a number of challenges. Data taken in the SBS program was critical to understanding hardware and software solutions that improved the track reconstruction efficiency to be >97% with a position resolution of 70 ?m. In previous experiments the proton electromagnetic form factors, Gp E and Gp M were measured up to Q2 = 8.5 GeV2 and Q2 = 30 GeV2, respectively, while Gn E has only been measured up to Q2 = 3.4 GeV2. The GEn-II experiment has measured the neutron form factor ratio, Gn E/Gn M, at Q2 values of 2.90, 6.50, and 9.47 GeV2 by scattering a polarized electron beam with a polarized 3He target, used here as an effective polarized neutron target, and measuring the double spin asymmetry of the cross section. Previous Gn E measurements do not extend above Q2 = 3.4 GeV2, and therefore this analysis has extended the world data by almost three times. The background correction is especially difficult at the higher Q2 settings leading to large systematic errors. As very exploratory results from this early analysis of the data, we find for Q2 = 2.90 GeV2, Gn E = 0.0157 ±stat 0.0016 ±sys 0.0011, for Q2 = 6.50 GeV2, Gn E = 0.0067 ±stat 0.0019 ±sys 0.0005, and for Q2 = 9.46 GeV2, Gn E = 0.0046 ±stat 0.0023 ±sys 0.0005. These results are compared to predictions from the Dyson-Schwinger Equations (DSE) model and a Relativistic Constituent Quark Model (RCQM).

Jeffas, Sean↗

SU-F-P-64: The Impact of Plan Complexity Parameters On the Plan Quality and Deliverability of Volumetric Modulated Arc Therapy with Canonical Correlation Analysis

Purpose: To evaluate the impact of complexity indices on the plan quality and deliverability of volumetric modulated arc therapy (VMAT), and to determine the most significant parameters in the generation of an ideal VMAT plan. Methods: A multi-dimensional exploratory statistical method, canonical correlation analysis (CCA) was adopted to study the correlations between VMAT parameters of complexity, quality and deliverability, as well as their contribution weights with 32 two-arc VMAT nasopharyngeal cancer (NPC) patients and 31 one-arc VMAT prostate cancer patients. Results: The MU per arc (MU/Arc) and MU per control point (MU/CP) of NPC were 337.8±25.2 and 3.7±0.3, respectively, which were significantly lower than those of prostate cancer patients (MU/Arc : 506.9±95.4, MU/CP : 5.6±1.1). The plan complexity indices indicated that two-arc VMAT plans were more complex than one-arc VMAT plans. Plan quality comparison confirmed that one-arc VMAT plans had a high quality than two-arc VMAT plans. CCA results implied that plan complexity parameters were highly correlated with plan quality with the first two canonical correlations of 0.96, 0.88 (both p<0.001) and significantly correlated with deliverability with the first canonical correlation of 0.79 (p<0.001), plan quality and deliverability was also correlated with the first canonical correlation of 0.71 (p=0.02). Complexity parameters of MU/CP, segment area (SA) per CP, percent of MU/CP less 3 and planning target volume (PTV) were weighted heavily in correlation with plan quality and deliveability . Similar results obtained from individual NPC and prostate CCA analysis. Conclusion: Relationship between complexity, quality, and deliverability parameters were investigated with CCA. MU, SA related parameters and PTV volume were found to have strong effect on the plan quality and deliverability. The presented correlation among different quantified parameters could be used to improve the plan quality and the efficiency of the radiotherapy process when creating a complex VMAT plan.

60 APPLIED LIFE SCIENCES↗

Exploratory Project: Rigid nanostructured organic polymer monolith for in situ collection and analysis of plant metabolites from soil matrices

Plant metabolites released from litter leachates and root exudates enable plants to adapt and survive in a wide range of habitats by facilitating resource foraging and plant-organismal interactions, and could influence soil carbon storage. The biological functions of these plant inputs and the organismal interactions they facilitate in soil are strictly governed by their composition and molecular identity. Our current understanding about the molecular identity of exudates is based on physiological studies that are done in soil-less axenic cultures. On the other hand, ecological studies that rely on isotope labeling to track the fluxes of carbon from plants to soil have found the complexities of soil-microbe matrices as an insurmountable barrier to undertake any meaningful molecular level characterization of plant inputs. Although it is constantly advocated to undertake a molecular level identification of the dynamicity of plant metabolites in soils, the complexity of soil system has thus far prevented any such endeavors. We developed polymeric probes through in-situ polymerization of poly(styrene-co-vinylbenzyl chloride-co-divinylbenzene) to elucidate the chemical environment of the soil to which the plant roots are exposed. Hypercrosslinking of the polymeric probes through an in-situ Friedel-Crafts alkylation significantly increased the surface area and the sorption capacity of the probes. Surface functionalization of the probes using a hybrid approach was also attempted. The efficacy of these probes was tested using batch equilibration. Scanning electron microscopy revealed extensive modification of the surface of the probes through hypercrosslinking. The probes exhibited a lower site specific sorption (slope of Freundlich adsorption isotherm close to unity) and percent recovery of the sorbed compounds from the probes were >70, indicating a predominance of reversible sorption. Further we imparted specificity to this copolymer matrix by using molecular-template imprinting approach for the selective capture of less abundant plant metabolites from a crowded soil/litter leachate. Our results suggests that i) the root exudate pattern of plants is highly dependent on the nutrient status of the plant, with greater specificity of root exudation occurring in growing medium with low available form of nutrients, ii) the chemical composition of root exudation is a function of the distance of sampling from the source-roots, with the composition of root exudation being more enriched in polar metabolites farther from the source-roots, iii) Further we demonstrated that the compounds present in real root exudates diffuse farther from the source roots than those in artificial root exudates that are traditionally used. Thus, our project highlights how the soil matrix is instrumental in modifying the chemical composition of root exudates, and highlights that, apart from the plant physiology, the specificity and function of root exudates is also modified by environmental factors.

54 ENVIRONMENTAL SCIENCES↗

Assessment of small mechanical wastewater treatment plants: Relative life cycle environmental impacts of construction and operations

Many slow growing and shrinking rural communities struggle with aging or inadequate wastewater treatment plants (WWTPs), and face challenges in constructing and operating such facilities. Although existing literature has provided insight into the environmental sustainability of large facilities, including both the construction and operational phases, these studies have not examined small, rural facilities treating less than 7,000 m 3 /d (1.8 MGD) of wastewater in adequate depth and breadth. In this study, a detailed inventory of the construction and operational data for 16 case studies of small WWTPs was developed to elucidate their environmental life cycle impacts. Conventional LCA framework was followed. The results show that the environmental impacts of both the construction and operational phases are considerable. Operational impacts are highly related to energy usage. Improving energy efficiency of a plant may reduce the environmental impacts related to operations. Construction impacts can vary considerably between facilities. Process-related factors (e.g., concrete and reinforcing steel used in basins) are typically sized using the design flow; thus much of the variability in construction impacts among plants stems from the non-process related infrastructure. Multiple regression analysis was used as an exploratory tool to identify which non-process related plant aspects contribute to the variable environmental impact of small WWTPs. These factors include aluminum, cast iron, and the capacity utilization ratio (defined as the ratio of average flow to design flow). Furthermore, industry practitioners should consider these factors when aiming to reduce the environmental impacts of a small WWTP related to construction. Scenario sensitivity analyses found that the environmental impact of construction became smaller with longer design life, and the end-of-life consideration does not heavily influence the environmental sustainability of a WWTP.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Advancing Diagnostic Model Evaluation to Better Understand Water Shortage Mechanisms in Institutionally Complex River Basins

Abstract Water resources systems models enable valuable inferences on consequential system stressors by representing both the geophysical processes determining the movement of water and the human elements distributing it to its various competing uses. This study contributes a diagnostic evaluation framework that pairs exploratory modeling with global sensitivity analysis to enhance our ability to make inferences on water scarcity vulnerabilities in institutionally complex river basins. Diagnostic evaluation of models representing institutionally complex river basins with many stakeholders poses significant challenges. First, it needs to exploit a large and diverse suite of simulations to capture important human‐natural system interactions as well as institutionally aware behavioral mechanisms. Second, it needs to have performance metrics that are consequential and draw on decision‐relevant model outputs that adequately capture the multisector concerns that emerge from diverse basin stakeholders. We demonstrate the proposed model diagnostic framework by evaluating how potential interactions between changing hydrologic conditions and human demands influence the frequencies and durations of water shortages of varying magnitudes experienced by hundreds of users in a subbasin of the Colorado River. We show that the dominant factors shaping these effects vary both across users and, for an individual user, across percentiles of shortage magnitude. These differences hold even for users sharing diversion locations, demand levels or water right seniority. Our findings underline the importance of detailed institutional representation for such basins, as institutions strongly shape how dominant factors of stakeholder vulnerabilities propagate through the complex network of users.

Hadjimichael, Antonia↗

Theory and applications of parton pseudodistributions

We review the basic theory of the parton pseudodistributions approach and its applications to lattice extractions of parton distribution functions. The crucial idea of the approach is the realization that the correlator $M(z,p)$ of the parton fields is a function $M(ν,-z^2)$ of Lorentz invariants $ν=-(zp)$, the Ioffe time, and the invariant interval $z^2$. This observation allows to extract the Ioffe-time distribution $M(ν,-z^2)$ from Euclidean separations z accessible on the lattice. Another basic feature is the use of the ratio $M(ν,-z^2)≡M(ν,-z^2)/M(0,-z^2)$, that allows to eliminate artificial ultraviolet divergence generated by the gauge link for spacelike intervals. The remaining $z^2$-dependence of the reduced Ioffe-time distribution $M(ν,-z^2)$ corresponds to perturbative evolution, and can be converted into the scale-dependence of parton distributions $f(x,μ^2)$ using matching relations. The ν-dependence of $M(ν,-z^2)$ governs the x-dependence of parton densities $f(x,μ^2)$. The perturbative evolution was successfully observed in exploratory quenched lattice calculation. The analysis of its precise data provides a framework for extraction of parton densities using the pseudodistributions approach. It was used in the recently performed calculations of the nucleon and pion valence quark distributions. We also discuss matching conditions for the pion distribution amplitude and generalized parton distributions, the lattice studies of which are now in progress.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Understanding Dynamical Systems in High-Dimensional Parameter Spaces (Final Report)

In the last few decades, computational models, especially of the complex dynamical systems of greatest interest, i.e., climate, high energy density science, combustion, etc. have become increasingly accurate and sophisticated. Consequently, they are now routinely used to predict outcomes of experiments or to inform design decisions. However, many such simulations depend on a (large) number of parameters in order to, for example, approximate physical phenom whose exact solution is unknown or describe material properties in situations with little or no experimental data. Choosing these parameters and understanding how the outcomes of such a simulation changes with respect to the inputs are rapidly becoming some of the primary challenges in many application areas. Simulations have long been too complex for humans to fully comprehend and thus are often treated as black-box systems. The inputs to the systems are typically a collection of parameters with expert-selected ranges, and the outputs are various quantities of interest (QoIs) describing the performance of the system. Therefore, the fundamental challenge can be described as one of understanding a high-dimensional (many input parameters), multi-variate (many QoIs) function. Unfortunately, existing analysis tools are only of limited use for this task as most techniques can neither deal with many input dimensions nor offer opportunities to jointly study several QoIs. Furthermore, data analysis has long relied on an exploratory process in which scientist first visualize the available data, for example, using scatter plots or 3D renderings, form new hypotheses on some phenomena of interest, and subsequently test these hypotheses using dedicated analysis or statistics approaches. However, for high-dimensional functions this exploration is difficult if not impossible using existing tools as there are too many QoIs to simultaneously observe, and visualizations of high-dimensional spaces are abstract and difficult to understand if they exist at all. The goal of this project is to build new analysis techniques and tool that offer high level insights for exploring high-dimensional scientific data. And to extend existing approach beyond single scalar functions and instead consider multiple QoIs simultaneously.

97 MATHEMATICS AND COMPUTING↗

Data and scripts associated with a manuscript on a meta-analysis synthesizing stream biogeochemical response to wildfires across space and time (v2)

This data package is associated with the publication “Catchment characteristics modulate the influence of wildfires on nitrate and dissolved organic carbon in lotic systems across space and time: A meta-analysis” submitted to Global Biogeochemical Cycles (Cavaiani et al. 2025). This study uses meta-analytical techniques to evaluate the effect of wildfire on in-stream responses in burned and unburned watersheds. The study aims to provide additional insight into the range of responses and net influences that wildfires have on hydro-biogeochemistry across broad spatial scales, burn extents, and the persistence of water-quality change. This study compiles data and metadata from 18 total publications that includes 1) surface water geochemistry data (dissolved organic carbon; nitrate), 2) climate classifications, 3) year of the wildfire, 4) the time lag between when the fire occurred and when the sampling occurred, and 5) study design of the publication. In total, this meta-analysis draws data that spans 8 climate guilds, 3 biomes, 62 watersheds, and 20 unique wildfires. See Sites_meta_data.csv for citations of the papers used in this meta-analysis. All R scripts and the associated data can also be found on GitHub at This data package was originally published in March 2024. It was updated in April 2025 (v2; new and modified files). See the change history section in the readme for more details. This data package contains five primary folders that include the following: (1) inputs; (2) output for analysis; (3) initial plots; (4) R scripts; and (5) GIS data. The data package also contains a data dictionary (dd) that provides column header definitions and a file-level metadata (flmd) file that describes every file. The “inputs” folder contains a list of all publications identified during the formal web search and an indication of whether each publication was included in the final analysis. Additionally, it includes site-level metadata, catchment characteristics, and GIS data for all publications included in the final analysis. The “Output_for_analysis” folder contains all data frames and figures generated from each R script used for additional data analysis. The “initial_plots” folder includes all exploratory figures that will be included in a supplemental and figures that will be submitted with the manuscript for publication. The “R_scripts” folder contains the scripts that perform all the data manipulations, statistical analyses, and plots. The “gis_data” folder includes shape files for each fire included in this meta-analysis. This data package contains the following file types: csv, pdf, jpeg, cpg, dbf, prj, shp, shp.ea.iso.xml, shp.iso.xml, shx.

54 ENVIRONMENTAL SCIENCES↗

Pharmacological inhibition of Polo Like Kinase 2 (PLK2) does not cause chromosomal damage or result in the formation of micronuclei

Polo Like Kinase 2 (PLK2) phosphorylates α-synuclein and is considered a putative therapeutic target for Parkinson's disease. Several lines of evidence indicate that PLK2 is involved with proper centriole duplication and cell cycle regulation, inhibition of which could impact chromosomal integrity during mitosis. The objectives of the series of experiments presented herein were to assess whether specific inhibition of PLK2 is genotoxic and determine if PLK2 could be considered a tractable pharmacological target for Parkinson's disease. Several selective PLK2 inhibitors, ELN 582175 and ELN 582646, and their inactive enantiomers, ELN 582176 and ELN 582647, did not significantly increase the number of micronuclei in the in vitro micronucleus assay. ELN 582646 was administered to male Sprague Dawley rats in an exploratory 14-day study where flow cytometric analysis of peripheral blood identified a dose-dependent increase in the number of micronucleated reticulocytes. A follow-up investigative study demonstrated that ELN 582646 administered to PLK2 deficient and wildtype mice significantly increased the number of peripheral micronucleated reticulocytes in both genotypes, suggesting that ELN 582646-induced genotoxicity is not through the inhibition of PLK2. Furthermore, significant reduction of retinal phosphorylated α-synuclein levels was observed at three non-genotoxic doses, additional data to suggest that pharmacological inhibition of PLK2 is not the cause of the observed genotoxicity. These data, in aggregate, indicate that PLK2 inhibition is a tractable CNS pharmacological target that does not cause genotoxicity at doses and exposures that engage the target in the sensory retina. - Highlights: • Active and inactive enantiomers test negative in the in vitro micronucleus test. • ELN 582646 significantly increased micronuclei at 100 and 300 mg/kg/day doses. • ELN 582646 significantly increased micronuclei in PLK2 knockout mice. • ELN 582646 decreased phosphorylation of alpha-synuclein at non-genotoxic doses.

60 APPLIED LIFE SCIENCES↗

Big Data Analytics for Scanning Transmission Electron Microscopy Ptychography

Electron microscopy is undergoing a transition; from the model of producing only a few micrographs, through the current state where many images and spectra can be digitally recorded, to a new mode where very large volumes of data (movies, ptychographic and multi-dimensional series) can be rapidly obtained. In this paper, we discuss the application of so-called “big-data” methods to high dimensional microscopy data, using unsupervised multivariate statistical techniques, in order to explore salient image features in a specific example of BiFeO 3 domains. Remarkably, k-means clustering reveals domain differentiation despite the fact that the algorithm is purely statistical in nature and does not require any prior information regarding the material, any coexisting phases, or any differentiating structures. While this is a somewhat trivial case, this example signifies the extraction of useful physical and structural information without any prior bias regarding the sample or the instrumental modality. Further interpretation of these types of results may still require human intervention. Finally, however, the open nature of this algorithm and its wide availability, enable broad collaborations and exploratory work necessary to enable efficient data analysis in electron microscopy.

36 MATERIALS SCIENCE↗

A Flow-Channel Analysis for the Mars Hopper

The Mars Hopper is an exploratory vehicle designed to fly on Mars using carbon dioxide from the Martian atmosphere as a rocket propellant. The propellent gasses are thermally heated while traversing a radioisotope ther- mal rocket (RTR) engine’s core. This core is comprised of a radioisotope surrounded by a heat capacitive material interspersed with tubes for the propellant to travel through. These tubes, or flow channels, can be manu- factured in various cross-sectional shapes such as a special four-point star or the traditional circle. Analytical heat transfer and computational fluid dynamics (CFD) anal- yses were performed using flow channels with either a circle or a star cross- sectional shape. The nominal total inlet pressure was specified at 2,805,000 Pa; and the outlet pressure was set to 2,785,000 Pa. The CO2 inlet tem- perature was 300 K; and the channel wall was 1200 K. The steady-state CFD simulations computed the smooth-walled star shape’s outlet temper- ature to be 959 K on the finest mesh. The smooth-walled circle’s outlet temperature was 902 K. A circle with a surface roughness specification at 0.01 mm gave 946 K and at 0.1 mm yielded 989 K. The The effects of a slightly varied inlet pressure were also examined. The analytical calculations were based on the mass flow rates computed in the CFD simulations and provided significantly higher outlet temperature results while displaying the same comparison trends. Research relating to the flow channel heat transfer studies was also done. Mathematical methods to geometrically match the cross-sectional areas of the circle and star, along with a square and equilateral triangle, were derived. A Wolfram Mathematica 8 module was programmed to analyze CFD results using Richardson Extrapolation and calculate the grid convergence index (GCI). A Mathematica notebook, also composed, computes and graphs the bulk mean temperature along a flow channel’s length while the user dynam- ically provides the input variables, allowing their effects on the temperature to be more easily observed.

33 ADVANCED PROPULSION SYSTEMS↗

Effect of Additional Incentives for Aviation Biofuels: Results from the Biomass Scenario Model

The National Renewable Energy Laboratory supported the Department of Energy, Bioenergy Technologies Office, with analysis of alternative jet fuels in collaboration with the U.S. Department of Transportation, Federal Aviation Administration. Airlines for America requested additional exploratory scenarios within FAA analytic framework. Airlines for America requested additional analysis using the same analytic framework, the Biomass Scenario Model. The results were presented at a public working meeting of the California Air Resources Board on including alternative jet fuel in the Low Carbon Fuel Standard on March 17, 2017 (https://www.arb.ca.gov/fuels/lcfs/lcfs_meetings/lcfs_meetings.htm). This presentation clarifies and annotates the slides from the public working meeting, and provides a link to the full data set. NREL does not advocate for or against the policies analyzed in this study.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Effect of Additional Incentives for Aviation Biofuels: Results from the Biomass Scenario Model

The National Renewable Energy Laboratory supported the Department of Energy, Bioenergy Technologies Office, with analysis of alternative jet fuels in collaboration with the U.S. Department of Transportation, Federal Aviation Administration. Airlines for America requested additional exploratory scenarios within FAA analytic framework. Airlines for America requested additional analysis using the same analytic framework, the Biomass Scenario Model. The results were presented at a public working meeting of the California Air Resources Board on including alternative jet fuel in the Low Carbon Fuel Standard on March 17, 2017 (https://www.arb.ca.gov/fuels/lcfs/lcfs_meetings/lcfs_meetings.htm). This presentation clarifies and annotates the slides from the public working meeting, and provides a link to the full data set. NREL does not advocate for or against the policies analyzed in this study.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Nonnegative tensor factorization for contaminant source identification

Unsupervised Machine Learning (ML) is becoming increasingly popular for solving various types of data analytics problems including feature extraction, blind source separation, exploratory analyses, model diagnostics, etc. In this work, we have developed a new unsupervised ML method based on Nonnegative Tensor Factorization (NTF) for identification of the original groundwater types (including contaminant sources) present in geochemical mixtures observed in an aquifer. Frequently, groundwater types with different geochemical signatures are related to different background and/or contamination sources. The characterization of groundwater mixing processes is a challenging but very important task critical for any environmental management project aiming to characterize the fate and transport of contaminants in the subsurface and perform contaminant remediation. This task typically requires solving complex inverse models representing groundwater flow and geochemical transport in the aquifer, where the inverse analysis accounts for available site data. Usually, the model is calibrated against the available data characterizing the spatial and temporal distribution of the observed geochemical types. Numerous different geochemical constituents and processes may need to be simulated in these models which further complicates the analyses. Additionally, the application of inverse methods may introduce biases in the analyses through the assumptions made in the model development process. Here, we substitute the model inversion with unsupervised ML analysis. The ML analysis does not make any assumptions about underlying physical and geochemical processes occurring in the aquifer. Our ML methodology, called NTFk, is capable of identifying (1) the unknown number of groundwater types (contaminant sources) present in the aquifer, (2) the original geochemical concentrations (signatures) of these groundwater types and (3) spatial and temporal dynamics in the mixing of these groundwater types. These results are obtained only from the measured geochemical data without any additional site information. In general, the NTFk methodology allows for interpretation of large high-dimensional datasets representing diverse spatial and temporal components such as state variables and velocities. NTFk has been tested on synthetic and real-world site three-dimensional datasets. Finally, the NTFk algorithm is designed to work with geochemical data represented in the form of concentrations, ratios (of two constituents; for example, isotope ratios), and delta notations (standard normalized stable isotope ratios).

58 GEOSCIENCES↗

Large High Resolution Displays for Co-Located Collaborative Sensemaking: Display Usage and Territoriality

Large, high-resolution vertical displays carry the potential to increase the accuracy of collaborative sensemaking, given correctly designed visual analytics tools. From an exploratory user study using a fictional textual intelligence analysis task, we investigated how users interact with the display to construct spatial schemas and externalize information, as well as how they establish shared and private territories. We investigated the space management strategies of users partitioned by type of tool philosophy followed (visualization- or text-centric). We classified the types of territorial behavior exhibited in terms of how the users interacted with information on the display (integrated or independent workspaces). Next, we examined how territorial behavior impacted the common ground between the pairs of users. Finally, we offer design suggestions for building future co-located collaborative visual analytics tools specifically for use on large, high-resolution vertical displays.

co-located collaborative sensemaking↗

There is Nothing Here for You: Passive Institutional Controls and Preemptive Resource Exploitation - 16197

The Department of Energy (DOE) Carlsbad Field Office (CBFO) is required by Title 40 CFR Part 191.14(c) and Title 40 CFR Part 194.43 to develop a Passive Institutional Controls (PICs) program to prevent the likelihood for future human intrusion into the Waste Isolation Pilot Plant (WIPP). The purpose of this paper is to explore how the exploitation of resources under nuclear waste repositories as a part of PICs could reduce the risk of future human intrusion. The WIPP, located in the northern Permian Basin near Carlsbad, New Mexico, is a geologic repository for the permanent isolation of defense-related transuranic waste. In 1995, a series of geophysical surveys by the New Mexico Bureau of Mines and Mineral Resources estimated the total hydrocarbon reserves underneath the WIPP, which included a 16-section area plus a one mile buffer. Since that time the Delaware Basin well database has been maintained to closely monitor hydrocarbon extraction activities. The database was used in compiling relevant oil and gas extraction data retrieved from The New Mexico Oil Conservation Division. The volume of hydrocarbons extracted from 1995 to the present suggests that if current extraction growth trends continue (as historic market and production data indicate they will), all known crude oil reserves under the WIPP, obtainable through current extraction technology, will be depleted within approximately 10 years, i.e., by 2026. This is well before the anticipated WIPP closure and start of the Active Institutional Controls (AICs) program called for in 40 CFR Part 194.41(b). In addition, gas resources, although more difficult to forecast, are not expected to last beyond 2137. Title 40 CFR 194.33 states, 'Inadvertent and intermittent intrusion by drilling for resources... is the most severe human intrusion scenario'. This human intrusion scenario is the feature, event, and process (FEP) that performance assessment (PA) has identified as having the most significant impact on radionuclide releases during the 10,000 year regulatory period for the WIPP. Title 40 CFR 194.43 requires a PICs program which contains '... [records] in the international archives that would likely be consulted by individuals in search of unexploited resources'. Due to political, social, and economic motivators for resource exploration and exploitation, the potential future absence of hydrocarbon resources under the WIPP is important in deterring possible human intrusion. To minimize the risk of future human intrusion, it may be necessary to consider actively removing as many of the exploitable hydrocarbon resources under and around a nuclear waste repository as is practicable before the end of the period of AICs (i.e., 100 years after closure of the repository). Additionally, communicating the absence of hydrocarbon resources under a nuclear repository should take a prominent role in any PICs program. Due to its high-cost nature, exploratory drilling of any kind currently involves cost/benefit analysis. If in the future the economic realities of resource exploration remain similar to today, and future oil companies know the resources for a particular area have already been heavily exploited, hypothetically, they would become less motivated to drill in that area. They would instead opt to explore an area with better prospects. It is important then that the remaining hydrocarbon reserves be clearly stated and prominently displayed. In essence we should communicate the message, loud and clear, 'There is nothing here for you'. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗