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DOE OSTI2023

Quantifying the Impact of Excluding the Submersion Exposure Route for Existing Superfund Radionuclide Screening Level Calculator Soil and Tap Water Models

The U.S. Environmental Protection Agency (EPA) provides initial data screening guidelines for radionuclide-contaminated Superfund sites using preliminary remediation goals (PRGs) and dose compliance concentrations (DCCs). PRGs and DCCs are target concentration values based on acceptable excess lifetime cancer risk and annual dose limits, respectively. They are calculated for various environmental media that may be encountered by residential and worker land uses. PRGs and DCCs typically consist of multiple exposure routes. One of these routes is submersion, which is exposure to a gaseous or particulate radionuclide that is suspended in air. Currently, submersion is only included in air calculations. This study focused on determining whether factoring submersion into total PRG/DCC calculations for soil and tap water created a significant difference in the target concentrations. New equations for individual submersion PRGs/DCCs for each land use of interest for soil and tap water were developed. A wind-driven particulate emission factor and Andelman’s constant were used to model the amount of soil and vapor in the air from soil and household use of tap water, respectively. The submersion PRG/DCC was then included in the total PRG/DCC for each radionuclide, followed by a percent difference comparison of the old and new totals to quantify the impact of the change. For total soil PRGs/DCCs, with and without submersion, the difference was less than 1 percent; however, many of the tap water radionuclides analyzed – including multiple radon and polonium isotopes – showed as high as a 200 percent difference.This technical memorandum (TM) presents recommendations for updates to current EPA guidelines for initial data screens of radionuclide contaminated tap water.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2023

Assessing the Optimality of LinDist3Flow for Optimal Tap Selection of Step Voltage Regulators in Unbalanced Distribution Networks

The adoption of distributed energy resources such as photovoltaics (PVs) has increased dramatically during the previous decade. The increased penetration of PVs into distribution networks (DNs) can cause voltage fluctuations that have to be mitigated. One of the key utility assets employed to this end are step-voltage regulators (SVRs). It is desirable to include tap selection of SVRs in optimal power flow (OPF) routines, a task that turns out to be challenging because the resultant OPF problem is nonconvex with added complexities stemming from accurate SVR modeling. While several convex relaxations based on semi-definite programming (SDP) have been presented in the literature for optimal tap selection, SDP based schemes do not scale well and are challenging to implement in large-scale planning or operational frameworks. This paper deals with the optimal tap selection (OPTS) problem for wye-connected SVRs using linear approximations of power flow equations. Specifically, the LinDist3Flow model is adopted and the effective SVR ratio is assumed to be continuous- enabling the formulation of a problem called LinDist3Flow-OPTS, which amounts to a linear program. The scalability and optimality gap of LinDist3Flow-OPTS are evaluated with respect to existing SDP-based and nonlinear programming techniques for optimal tap selection in three standard feeders, namely, the IEEE 13-bus, 123-bus, and 8500-node DNs. For all DNs considered, LinDist3Flow-OPTS achieves an optimality gap of approximately 1% or less while significantly lowering the computational burden.

linear approximations↗

DOE OSTI2023

TAP Absorption Coefficients

The data set of aerosol light absorption coefficients were collected by two tricolor absorption photometers (TAP; Brechtel Model 2901) in July and August, 2022 during the TRACER field campaign at the AMF1 site in La Porte, Texas. One of the TAPs at the La Porte site was an RGB model measuring aerosol light absorption at 652, 528, 467 nm, and the other was an UV model measuring absorption at the same red and green wavelengths but at an additional UV wavelength at 365 nm. Since TAP is a filter-based optical instrument using 47-mm glass fiber filters, the output absorption coefficients are corrected for filter loading and scattering effects based on a correction scheme developed in "Comment on ‘Calibration and Intercomparison of Filter-Based Measurements of Visible Light Absorption by Aerosols’" by John A. Ogren 2010. This uploaded dataset contains both the Ogren corrected absorption coefficients (column header with “ Ogren”) and the raw absorption coefficients without the correction scheme (column header with “_ Raw”). During the field campaign, the two TAPs operated side by side with a shared inlet at a flow rate of 2 lpm. In July, no inlet impactors/cyclones were installed; however, beginning in August, a PM2.5 cyclone inlet was installed.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2021

Transmitter with fully re-assignable segments for reconfigurable FFE taps

Methods and systems of performing feed forward equalization (FFE) on data streams are described. A circuitry may generate staggered data streams from data streams of an input signal. The staggered data streams may include data in staggered unit intervals. The circuitry may include a plurality of segments. A segment may define a specific unit interval to carve the staggered data streams into one unit interval pulses positioned at the specific unit interval. The specific unit interval to carve the staggered data streams may indicate an assignment of the segment as one of a FFE pre tap, a FFE main tap, and a FFE post tap. The plurality of segments may be assigned to different FFE taps based on different clock signal selection defining different unit intervals to perform the carving. The plurality of segments may output respective one unit interval pulses to reproduce the input signal.

Toprak-Deniz, Zeynep↗

DOE OSTI2022

Assessing the Optimality of LinDist3Flow for Optimal Tap Selection of Step Voltage Regulators in Unbalanced Distribution Networks: Preprint

The adoption of distributed energy resources such as photovoltaics (PVs) has increased dramatically during the previous decade. The increased penetration of PVs into distribution networks (DNs) can cause voltage fluctuations that have to be mitigated. One of the key utility assets employed to this end are step-voltage regulators (SVRs). It is desirable to include tap selection of SVRs in optimal power flow (OPF) routines, a task that turns out to be challenging because the resultant OPF problem is nonconvex with added complexities stemming from accurate SVR modeling. While several convex relaxations based on semi-definite programming (SDP) have been presented in the literature for optimal tap selection, SDP based schemes do not scale well and are challenging to implement in large-scale planning or operational frameworks. This paper deals with the optimal tap selection (OPTS) problem for wye-connected SVRs using linear approximations of power flow equations. Specifically, the LinDist3Flow model is adopted and the effective SVR ratio is assumed to be continuous–enabling the formulation of a problem called LinDist3Flow-OPTS, which amounts to a linear program. The scalability and optimality gap of LinDist3Flow-OPTS are evaluated with respect to existing SDP-based and nonlinear programming techniques for optimal tap selection in three standard feeders, namely, the IEEE 13-bus, 123-bus, and 8500-node DNs. For all DNs considered, LinDist3Flow-OPTS achieves an optimality gap of approximately 1% or less while significantly lowering the computational burden.

linear approximations↗

DOE OSTI2025

Emerging Per- and Polyfluoroalkyl Substances in Tap Water from the American Healthy Homes Survey II

Humans experience widespread exposure to anthropogenic per- and polyfluoroalkyl substances (PFAS) through various media, which can lead to a wide range of negative health impacts. Tap water is an important source of exposure in communities with any degree of contamination but routine or large-scale PFAS monitoring often depends on targeted analytical methods limited to measuring specific PFAS. We analyzed 680 tap water samples from the American Healthy Homes Survey II for PFAS using non-targeted analysis (NTA) to expand the range of detectable PFAS. Based on detection frequency and relative abundance, about half of the identified PFAS were found only by NTA. We identified (with varying degrees of confidence) 75 distinct PFAS, including 57 exclusively detected by NTA. The identified PFAS are members of seven structural subclasses differentiated by their head groups and degree of fluorination. Clustering analysis categorized the PFAS into four coabundance groups dominated by specific PFAS subclasses. One group uniquely identified by NTA contains zwitterionic PFAS and other PFAS transformation products which are likely associated with aqueous firefighting foam contaminants in a small number of spatially correlated samples. These results help further characterize the scope of exposure to emerging PFAS experienced by the U.S. population via tap water and augment nationwide targeted-PFAS monitoring programs.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗

DOE OSTI2022

Impact of Load Tap Changer Control Operation Under Microgrid Conditions

Every microgrid is unique in its diversity of assets, operation, and network structure. This uniqueness presents challenges for each microgrid implementation that need to be understood and addressed to prevent power quality concerns, stability issues, and blackouts. In this research work, we present one challenge faced during microgrid operation that could potentially cause a blackout in some microgrid configurations. Through the incorrect operation of the load tap changer controller during an islanding event for a microgrid with generation present on both primary and secondary busses, the primary voltage will increase or decrease beyond allowable bounds, causing a cascading failure. This work presents the issue first with simulation results to demonstrate the phenomenon and then presents results of load tap changer controller operation using a controller-hardware-in-the-loop experiment. Finally, details of the complete sequence of operation and the blackout scenarios are presented and summarized.

blackout↗

DOE OSTI2020

Materials Data on TaP by Materials Project

TaP is alpha Niobium phosphide structured and crystallizes in the tetragonal I4_1/amd space group. The structure is two-dimensional and consists of four TaP sheets oriented in the (0, 0, 1) direction. Ta3+ is bonded in a square co-planar geometry to four equivalent P3- atoms. All Ta–P bond lengths are 2.48 Å. P3- is bonded in a square co-planar geometry to four equivalent Ta3+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2025

Reversible parts-per-trillion-level detection of perfluorooctane sulfonic acid in tap water using field-effect transistor sensors

Widespread, persistent and toxic per- and polyfluoroalkyl substances (PFAS) pose a major threat to water systems and human health. Current detection methods are relatively expensive, slow and complex, underscoring the need for more accessible alternatives to meet increasingly stringent PFAS regulations. Here, in this study, we present an ultrasensitive sensing platform for perfluorooctane sulfonic acid detection in tap water with a reporting limit ( ~ 250 parts per quadrillion) lower than the US Environmental Protection Agency’s regulatory standard (4 parts per trillion), using a remote gate field-effect transistor featuring β-cyclodextrin (β-CD)-modified reduced graphene oxide as the sensing membrane. The sensor exhibits excellent selectivity against common inorganic ions, natural organic matter and select organic pollutants in tap water. The reversible and rapid response ( < 2 min) indicates the potential of remote gate field-effect transistor for continuous in-line monitoring. Mechanistic studies using quartz crystal microbalance and molecular dynamics simulations reveal key roles of analyte adsorption and charge properties in sensing performance and offer insights for designing more selective PFAS capture probes.

Wang, Yuqin [University of Chicago, IL (United Sta↗

DOE OSTI2020

Soft sample deformation, damage and induced electromechanical property changes in contact- and tapping-mode atomic force microscopy

Probe-induced soft sample damage in atomic force microscopy (AFM), as well as the resulting alteration of local mechanical and electrical properties of the material are explored, specifically comparing contact-mode and intermittent-contact-mode imaging methods. In our experiments, performed on conductive polymer films, induced changes are present in contact-mode imaging while they are negligible or absent in tapping-mode imaging. Here, to understand this result, a viscoelastic parameter extraction is performed, which suggests that permanent sample deformation can readily occur for tip-sample interactions with a duration on the timescale of contact-mode interactions. Using the extracted viscoelastic parameters, a dynamic AFM simulation is conducted, which suggests that the material responds more elastically with reduced or absent sample damage in tapping-mode AFM, due to the higher rate of mechanical deformation and shorter timescales.

42 ENGINEERING↗

DOE OSTI2023

Tools for Assessing Performance (TAP) Project: FY2023 Quarter 2 Report

LANL personnel presented TAP-sponsored work at the 103 rd Annual Meeting of the American Meteorological Society, which was held in Denver, CO in January 2023. There were four different presentations related to TAP-sponsored work that were given by LANL staff and studentsat this meeting: (1) Gloeckler, T., M. Nelson, H. Shah, M. Deshler, L. Wedell, R. Linn, N. Duboc, S. Pol, P. Bieringer, A. Annunzio, B. Martin, and H. Tinnesand, 2023. Testing Validity and Limitations of a Low-Order Diffusive Wake Model. 15 th Symposium on the Urban Environment, January 8-12, 2023, Denver, CO, U.S.A. (2) Nelson, M., H. Shah, T. Gloeckler, M. Deshler, L. Wedell, A. Ortega, R. Linn, N. Duboc, P. Conry, S. Pol, and H. Tinnesand, 2023. The Isolated Building Wake Experiment. Paper 1A.1. 24 th Symposium on Boundary Layers and Turbulence, January 8-12, 2023. Denver, CO, U.S.A. (3) Shah, H., M. Nelson, S. Pol, R. Linn, N. Duboc, and H. Tinnesand, 2023. Detailed Measurement of a Building Wake Under Real-World Atmospheric Conditions. Poster 102. 24 th Symposium on Boundary Layers and Turbulence, January 8-12, 2023, Denver, CO, U.S.A. (4) Wedell, L., M. Nelson, H. Shah, T. Gloeckler, M. Deshler, R. Linn, S. Pol, H. Tinnesand, 2023. The Isolated Building Wake Experiment: Using a Rotating Building to Mulitply the Number of Wake Measurement Locations without Moving the Instruments. Paper 1A.4A. 24 th Symposium on Boundary Layers and Turbulence, January 8-12, 2023, Denver, CO, U.S.A.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2024

U.S. DOE Midwest Combined Heat and Power Technical Assistance Partnership (Midwest CHP TAP) (Final Technical Report)

The University of Illinois Chicago (UIC) was awarded the U.S. DOE Midwest Combined Heat and Power Technical Assistance Partnership (Midwest CHP TAP) program to provided technical and policy expertise to support local opportunities to promote CHP, waste heat to power, district energy, and microgrids in the Midwest and Central regions of the U.S. that included the states of Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, Ohio, and Wisconsin. During this contract period, UIC, through the Midwest CHP TAP activities, provided significant regional support to the U.S. strategic goals of: 1) Stimulating America’s Energy Revolution and Promoting Energy Independence; 2) Promoting Jobs and Manufacturing Competitiveness; 3) Supporting a Positive Trade Balance; 4) Enhancing Energy System Resiliency and Energy Security; and 5) Improving the Nation’s Infrastructure. UIC met the annual go/no-go metrics each year and either met and/or exceeded the milestones each year.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2021

Serial communication tapping and transmission to routable networks

Apparatuses and methods for tapping serial communications and transforming the serial data into a format appropriate for routable networks are significant for purposes of security and troubleshooting, especially in critical infrastructure networks. Communication taps should be completely passive such that any failure would not interrupt the serial communications. Furthermore, automatic determination of unspecified serial protocol frames allow general implementation across various networks, or across devices within a single network, without the need to customize for each implementation.

Edgar, Thomas W.↗

DOE OSTI2024

Serial communication tapping and transmission to routable networks

Edgar, Thomas W.↗

DOE OSTI2020

Materials Data on TaPS by Materials Project

TaPS crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Ta5+ is bonded in a 8-coordinate geometry to four equivalent P3- and four equivalent S2- atoms. All Ta–P bond lengths are 2.58 Å. There are two shorter (2.61 Å) and two longer (2.62 Å) Ta–S bond lengths. P3- is bonded in a 6-coordinate geometry to four equivalent Ta5+ and two equivalent P3- atoms. There are one shorter (2.24 Å) and one longer (2.50 Å) P–P bond lengths. S2- is bonded to four equivalent Ta5+ atoms to form a mixture of distorted edge and corner-sharing STa4 tetrahedra.

36 MATERIALS SCIENCE↗

DOE OSTI2022

Efficient Region of Attraction Characterization for Control and Stabilization of Load Tap Changer Dynamics

In this article, we study the monitoring and control of long-term voltage stability considering load tap changer (LTC) dynamics. We show that under generic conditions, the LTC dynamics admit a unique stable equilibrium. For the stable equilibrium, we characterize an explicit inner approximation of its largest region of attraction (ROA). Compared to existing results, the computational complexity of the ROA characterization is drastically reduced. We propose a quadratically constrained linear program formulation for the ROA characterization problem. In addition, we formulate a second-order cone program for online voltage stability monitoring and control exploiting the proposed ROA characterization. Finally, we demonstrate the efficacy of the proposed formulations on the ROA characterization and stability monitoring and control using a standard IEEE test system.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2020

Tapsolver: A Python Package For The Simulation And Analysis Of Tap Reactor Experiments

TAPsolver is a python package, which automates TAP simulation and analysis routines. TAPsolver is built around the python packages FEniCS and Dolfin-Adjoint, which help take advantage of model adjoints to provide automatic derivatives. TAPsolver is flexible, with reaction mechanisms and rate constants that can be set through input files that allow users to take advantage of the different functionalities, which include sensitivity analyses, parameter optimization and uncertainty quantification.

Yonge, Adam↗

DOE OSTI2026

Stations Tool for Automated Permitting (S-TAP) User Manual

The Stations Tool for Automated Permitting (S-TAP) is a spreadsheet-based plan review questionnaire designed to help automate and expedite the electric vehicle supply equipment (EVSE) permitting process. This manual goes into detail on the development of the tool and guidance for use cases of the tool.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗