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At least 325 records · Page 18

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DOE OSTI2018

Microgrids for Service Restoration to Critical Load in a Resilient Distribution System

icrogrids can act as emergency sources to serve critical loads when utility power is unavailable. This paper proposes a resiliency-based methodology that uses microgrids to restore critical loads on distribution feeders after a major disaster. Due to limited capacity of distributed generators (DGs) within microgrids, dynamic performance of the DGs during the restoration process becomes essential. In this paper, the stability of microgrids, limits on frequency deviation, and limits on transient voltage and current of DGs are incorporated as constraints of the critical load restoration problem. The limits on the amount of generation resources within microgrids are also considered. By introducing the concepts of restoration tree and load group, restoration of critical loads is transformed into a maximum coverage problem, which is a linear integer program (LIP). The restoration paths and actions are determined for critical loads by solving the LIP. A 4-feeder, 1069-bus unbalanced test system with four microgrids is utilized to demonstrate the effectiveness of the proposed method. The method is applied to the distribution system in Pullman, WA, resulting in a strategy that uses generators on the Washington State University campus to restore service to the Hospital and City Hall in Pullman.

Xu, Yin (ORCID:0000000209459024)↗

DOE OSTI2013

ADEPT Final Report: Dynamic Control of Grid Assets Using Direct AC Converter Cells

Seedling funding was secured through the ARPA-E program to develop a robust, utility-scale Power Converter Augmented Transformer (PCAT). The project designed, fabricated, and tested two 13 kV, 1 MW PCATs operating at an effective switching frequency of up to 50 kHz and at an efficiency of greater than 99%. Two versions of the PCAT were fabricated – one using an imputed DC link (IDCL) topology and the other using a back-to-back (BTB) topology. The IDCL avoids the use of electrolytic capacitors for bulk energy storage, thus improving the lifetime and decreasing the size of the converter, while the BTB topology uses an industry-proven topology that is more commercially viable in the short term. To give the PCAT a lifetime and maintenance profile compatible with typical existing utility assets, a novel Passive Thermal Management System (PTMS) was designed and integrated into both PCATs. The PTMS uses a thermosiphon to remove heat from the power electronic devices without forced cooling and reject it to the ambient environment. In addition, a fail-normal feature was implemented to ensure that in the event of PCAT failure the functionality of the underlying transformer is retained. Attainment of project objectives was verified through testing at the Georgia Tech National Electrical Energy Testing Research and Applications Center (NEETRAC). The IDCL-based PCAT had an efficiency of more than 99.10% and the BTB-based PCAT had an efficiency of more than 99.75%. During testing, the PTMS exceeded project requirements by rejecting the 5 kW output of the converters to a 40 °C environment while keeping devices junction temperatures within their tolerances.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2012

Covered Product Categories (Fact Sheet)

List of Federal Energy Management Program (FEMP)-designated product categories for energy-efficient procurement requirements.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2016

Cell-based composite materials with programmed structures and functions

The present invention is directed to the use of silicic acid to transform biological materials, including cellular architecture into inorganic materials to provide biocomposites (nanomaterials) with stabilized structure and function. In the present invention, there has been discovered a means to stabilize the structure and function of biological materials, including cells, biomolecules, peptides, proteins (especially including enzymes), lipids, lipid vesicles, polysaccharides, cytoskeletal filaments, tissue and organs with silicic acid such that these materials may be used as biocomposites. In many instances, these materials retain their original biological activity and may be used in harsh conditions which would otherwise destroy the integrity of the biological material. In certain instances, these biomaterials may be storage stable for long periods of time and reconstituted after storage to return the biological material back to its original form. In addition, by exposing an entire cell to form CSCs, the CSCs may function to provide a unique system to study enzymes or a cascade of enzymes which are otherwise unavailable.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2018

Cell-based composite materials with programmed structures and functions

36 MATERIALS SCIENCE↗

DOE OSTI2020

Cell-based composite materials with programmed structures and functions

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2013

Planning Brings Vision Into Focus (Brochure)

This case study/fact sheet highlights the strategic energy planning process for Tribes that was developed by the DOE Office of Indian Energy. This nine-step process, which is outlined in one of the foundational education courses offered by the Office, enables Tribes to pursue energy projects in a well-planned and strategic manner.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2014

From Nanowires to Biofilms: An Exploration of Novel Mechanisms of Uranium Transformation Mediated by Geobacter Bacteria

One promising strategy for the in situ bioremediation of radioactive groundwater contaminants that has been identified by the SBR Program is to stimulate the activity of dissimilatory metal-reducing microorganisms to reductively precipitate uranium and other soluble toxic metals. The reduction of U(VI) and other soluble contaminants by Geobacteraceae is directly dependent on the reduction of Fe(III) oxides, their natural electron acceptor, a process that requires the expression of Geobacter’s conductive pili (pilus nanowires). Expression of conductive pili by Geobacter cells leads to biofilm development on surfaces and to the formation of suspended biogranules, which may be physiological closer to biofilms than to planktonic cells. Biofilm development is often assumed in the subsurface, particularly at the matrix-well screen interface, but evidence of biofilms in the bulk aquifer matrix is scarce. Our preliminary results suggest, however, that biofilms develop in the subsurface and contribute to uranium transformations via sorption and reductive mechanisms. In this project we elucidated the mechanism(s) for uranium immobilization mediated by Geobacter biofilms and identified molecular markers to investigate if biofilm development is happening in the contaminated subsurface. The results provided novel insights needed in order to understand the metabolic potential and physiology of microorganisms with a known role in contaminant transformation in situ, thus having a significant positive impact in the SBR Program and providing novel concept to monitor, model, and predict biological behavior during in situ treatments.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2014

DNAJC6 promotes hepatocellular carcinoma progression through induction of epithelial–mesenchymal transition

Highlights: • DNAJC6 is up-regulated in hepatocellular carcinoma tissues. • DNAJC6 promotes hepatocellular carcinoma cell proliferation and invasion. • DNAJC6 induces epithelial–mesenchymal transition by activating transforming growth factor β signaling. - Abstract: Epithelial–mesenchymal transition (EMT) is a developmental program, which is associated with hepatocellular carcinoma (HCC) development and progression. DNAJC6 (DNA/HSP40 homolog subfamily C member 6) encodes auxilin, which is responsible for juvenile Parkinsonism with phenotypic variability. However, the role of DNAJC6 in HCC development and progression is limited. Here, we report that DNAJC6 is up-regulated in HCC tissues and up-regulation of DNAJC6 expression predicts poor outcome in patients with HCC. Furthermore, overexpression of DNAJC6 enhances the ability for acquisition of mesenchymal traits, enhanced cell proliferation and invasion. DNAJC6 positively regulated expression of EMT-related transcription factor, also activating transforming growth factor β (TGF-β) pathway to contribute to EMT. Our findings demonstrated an important function of DNAJC6 in the progression of HCC by induction of EMT, and they implicate DNAJC6 as a marker of poor outcome in HCC.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2012

Compiled MPI: Cost-Effective Exascale Applications Development

The complexity of petascale and exascale machines makes it increasingly difficult to develop applications that can take advantage of them. Future systems are expected to feature billion-way parallelism, complex heterogeneous compute nodes and poor availability of memory (Peter Kogge, 2008). This new challenge for application development is motivating a significant amount of research and development on new programming models and runtime systems designed to simplify large-scale application development. Unfortunately, DoE has significant multi-decadal investment in a large family of mission-critical scientific applications. Scaling these applications to exascale machines will require a significant investment that will dwarf the costs of hardware procurement. A key reason for the difficulty in transitioning today's applications to exascale hardware is their reliance on explicit programming techniques, such as the Message Passing Interface (MPI) programming model to enable parallelism. MPI provides a portable and high performance message-passing system that enables scalable performance on a wide variety of platforms. However, it also forces developers to lock the details of parallelization together with application logic, making it very difficult to adapt the application to significant changes in the underlying system. Further, MPI's explicit interface makes it difficult to separate the application's synchronization and communication structure, reducing the amount of support that can be provided by compiler and run-time tools. This is in contrast to the recent research on more implicit parallel programming models such as Chapel, OpenMP and OpenCL, which promise to provide significantly more flexibility at the cost of reimplementing significant portions of the application. We are developing CoMPI, a novel compiler-driven approach to enable existing MPI applications to scale to exascale systems with minimal modifications that can be made incrementally over the application's lifetime. It includes: (1) New set of source code annotations, inserted either manually or automatically, that will clarify the application's use of MPI to the compiler infrastructure, enabling greater accuracy where needed; (2) A compiler transformation framework that leverages these annotations to transform the original MPI source code to improve its performance and scalability; (3) Novel MPI runtime implementation techniques that will provide a rich set of functionality extensions to be used by applications that have been transformed by our compiler; and (4) A novel compiler analysis that leverages simple user annotations to automatically extract the application's communication structure and synthesize most complex code annotations.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2014

ACDT: Architected Composite Data Types Trading-in Unfettered Data Access for Improved Execution

With Exascale performance and its challenges in mind, one ubiquitous concern among architects is energy efficiency. Petascale systems projected to Exascale systems are unsustainable at current power consumption rates. One major contributor to system-wide power consumption is the number of memory operations leading to data movement and management techniques applied by the runtime system. To address this problem, we present the concept of the Architected Composite Data Types (ACDT) framework. The framework is made aware of data composites, assigning them a specific layout, transformations and operators. Data manipulation overhead is amortized over a larger number of elements and program performance and power efficiency can be significantly improved. We developed the fundamentals of an ACDT framework on a massively multithreaded adaptive runtime system geared towards Exascale clusters. Showcasing the capability of ACDT, we exercised the framework with two representative processing kernels - Matrix Vector Multiply and the Cholesky Decomposition – applied to sparse matrices. As transformation modules, we applied optimized compress/decompress engines and configured invariant operators for maximum energy/performance efficiency. Additionally, we explored two different approaches based on transformation opaqueness in relation to the application. Under the first approach, the application is agnostic to compression and decompression activity. Such approach entails minimal changes to the original application code, but leaves out potential applicationspecific optimizations. The second approach exposes the decompression process to the application, hereby exposing optimization opportunities that can only be exploited with application knowledge. The experimental results show that the two approaches have their strengths in HW and SW respectively, where the SW approach can yield performance and power improvements that are an order of magnitude better than ACDT-oblivious, hand-optimized implementations.We consider the ACDT runtime framework an important component of compute nodes that will lead towards power efficient Exascale clusters.

exascale↗

DOE OSTI2017

ARPA-E: Redefining the Problem to Fine New Solutions

ARPA-E brings together experts from diverse disciplines and industries to frame new ways of looking at the energy challenge. By viewing the problem through a different lens, ARPA-E brings together new capabilities to develop new technology solutions. The DELTA and MONITOR programs illustrate this novel approach well. In this video, Associate Director of Technology Dr. Patrick McGrath discusses how ARPA-E has reframed the challenge of building efficiency with the DELTA program and methane leaks with the MONITOR program differently in order to yield “out of left field” technologies that can lead to transformational gains. The video features two projects – University of California San Diego’s DELTA project and Rebellion Photonics’ MONITOR project.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2016

Dual Active Bridge based DC Transformer LabVIEW FPGA Control Code [SWR-16-25]

In the area of power electronics control, Field Programmable Gate Arrays (FPGAs) have the capability to outperform their Digital Signal Processor (DSP) counterparts due to the FPGA’s ability to implement true parallel processing and therefore facilitate higher switching frequencies, higher control bandwidth, and/or enhanced functionality. National Instruments (NI) has developed two platforms, Compact RIO (cRIO) and Single Board RIO (sbRIO), which combine a real-time processor with an FPGA. The FPGA can be programmed with a subset of the well-known LabVIEW graphical programming language. The candidate software implements complete control algorithms in LabVIEW FPGA for a DC Transformer (DCX) based on a dual active bridge (DAB). A DCX is an isolated bi-directional DC-DC converter designed to operate at unity conversion ratio, M, defined by where Vin is the primary-side DC bus voltage, Vout is the secondary-side DC bus voltage, and n is the turns ratio of the embedded high frequency transformer (HFX). The DCX based on a DAB incorporates two H-bridges, a resonant inductor, and an HFX to provide this functionality. The candidate software employs phase-shift modulation of the two H-bridges and a feedback loop to regulate the conversion ratio at unity. The software also includes alarm-handling capabilities as well as debugging and tuning tools. The software fits on the Xilinx Virtex V LX110 FPGA embedded in the NI cRIO-9118 FPGA chassis, and with a 40 MHz base clock, supports a modulation update rate of 40 MHz, and user-settable switching frequencies and synchronized control loop update rates of tens of kHz.

Source record↗

DOE OSTI2018

Molecular water adsorption and reactions on (alpha)-Al2O3(0001) and (alpha)-Alumina Particles

The adsorption and reaction of water on single crystal, -Al2O3(0001) in ultrahigh vacuum, and -alumina particles in ambient conditions, was investigated using temperature programmed desorption (TPD), infrared reflection absorption spectroscopy (IRAS), diffuse reflectance infrared Fourier transform spectra (DRIFTS) and other surface science techniques. For a water coverage of 1 H2O/(surface Al3+) on -Al¬2O3(0001), no evidence for the surface hydroxyls expected from dissociative adsorption was observed in the infrared spectra, while the 2 vibration of molecular water was observed. Electron-stimulated desorption of molecular water at low coverages also indicated molecular or mixed (molecular plus dissociative) adsorption. Analysis of Kr TPD spectra showed that the water films wet the alumina substrate and suggested that the films were initially growing layer-by-layer. In contrast with the single crystal results, DRIFTS of water adsorption on alumina particles indicated the presence of surface hydroxyls that persist even after annealing to high temperatures in oxygen. For water on -Al2O3(0001) at coverages less than 0.3 H2O/(surface Al3+), water desorbed over a broad temperature range extending from ~250 K to 700 K. For larger coverages, water desorption occurred at temperatures between ~160 K and 250 K, consistent with desorption of molecular water. The results, which are consistent with at most a small amount of water dissociation on the Al-terminated (0001) surface, are difficult to reconcile with calculations suggesting that the barrier to dissociation is small. However, the results are consistent with recent vibrational sum frequency experiments showing that the hydroxylation of the Al-terminated (0001) surface takes many days even at ambient pressures and temperatures.

Petrik, Nikolay G.↗

DOE OSTI2013

Effect of Sodium on the Catalytic Properties of VOx/CeO2 Catalysts for Oxidative Dehydrogenation of Methanol

A series of VOx/CeO2 catalysts with various sodium loadings (Na/V ratio from 0 to 1) has been studied for oxidative dehydrogenation (ODH) of methanol. The effect of sodium on the surface structure, redox properties, and surface acidity/basicity of VOx/CeO2 was investigated using hydrogen temperature-programmed reduction (H2-TPR), Raman spectroscopy, and Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFT). The experimental results indicate that the effect of sodium on VOx/CeO2 is highly dependent on the Na/V ratio. At a low Na/V ratio (Na/V<0.25), sodium addition only slightly decreases the redox properties of VOx/CeO2 and has little effect on its activity and selectivity to formaldehyde, even though the Brönsted acidity is almost completely eliminated at a Na/V ratio of 0.25. At a high Na/V ratio (Na/V>0.25), sodium addition greatly alters the nature of the active sites by V-O-Ce bond cleavage and V-O-Na bond formation, leading to significantly reduced activity of the VOx/CeO2 catalysts. At Na/V>0.25, the selectivity to formaldehyde also decreases with increasing Na/V ratio due to: (1) the suppressed reducibility of VOx, and (2) increased basicity leading to increased CO2.

Environmental Molecular Sciences Laboratory↗

DOE OSTI2015

Analytico-numerical tool for studying the influence of the inhomogeneity on the behavior of cracked magneto-electro-elastic materials

Functionally graded materials (FGM) are extensively used in modern industry. They are composite materials with continuously varying properties in one or more special dimensions, according to the specific purpose. In view of the wide range of applications of FGM, stress analysis is important for their structural integrity and reliable service life. In this study we will consider functionally graded magneto-electro-elastic materials with one or more cracks subjected to SH waves. We assume that the material properties vary in one and the same way, described by an inhomogeneity function. The boundary value problem is reduced to a system of integro-differential equations based on the existence of fundamental solutions. Different inhomogeneity classes are used to obtain a wave equation with constant coefficients. Radon transform is applied to derive the fundamental solution in a closed form. Program code in FORTRAN 77 is developed and validated using available examples from literature. Simulations show the dependence of stress field concentration near the crack tips on the frequency of the applied time-harmonic load for different types of material inhomogeneity.

42 ENGINEERING↗

DOE OSTI2025

Accessible, uniform protein property prediction with a scikit-learn based toolset AIDE

Summary Protein property prediction via machine learning with and without labeled data is becoming increasingly powerful, yet methods are disparate and capabilities vary widely over applications. The software presented here, “Artificial Intelligence Driven protein Estimation (AIDE)”, enables instantiating, optimizing, and testing many zero-shot and supervised property prediction methods for variants and variable length homologs in a single, reproducible notebook or script by defining a modular, standardized application programming interface (API), i.e. drop-in compatible with scikit-learn transformers and pipelines. Availability and implementation AIDE is an installable, importable python package inheriting from scikit-learn classes and API and is installable on Windows, Mac, and Linux. Many of the wrapped models internal to AIDE will be effectively inaccessible without a GPU, and some assume CUDA. The newest stable, tested version can be found at https://github.com/beckham-lab/aide_predict and a full user guide and API reference can be found at https://beckham-lab.github.io/aide_predict/. Static versions of both at the time of writing can be found on Zenodo.

36 MATERIALS SCIENCE↗

DOE OSTI2022

Hierarchical Distributed Optimal Power Flow of HV and MV Distribution Networks With Continuous and Discrete Devices

With large-scale distributed photovoltaics (PVs) being integrated into distribution networks (DNs), coordinated optimal power flow (OPF) of high voltage (HV) and medium voltage (MV) DNs should be investigated to optimally dispatch the distributed PVs and other network devices. Here, this paper presents a hierarchical distributed OPF method for HV and MV DNs with on-load tap changers, reactive power compensators, feeder switches and distributed PVs. A hierarchical master-slave control architecture is applied to implement coordinated OPF of two-layer DNs. The HV master problem and MV subproblems are transformed into mixed-integer convex problems respectively with second order cone programming and LinDistFlow approximation. Since there is no efficient distributed algorithm to solve such OPF models with integer subproblems, a novel distributed algorithm is proposed in this paper to efficiently solve the hierarchical coordinated OPF model with integer subproblems in a distributed manner. In the proposed algorithm, the coordinated OPF model is solved in a branch-and-bound framework, where in each branch node generalized Benders decomposition (GBD) algorithm is applied to decompose the coordinated OPF model into a master problem and relaxed subproblems and solves them iteratively to get optimal solution. The GBD optimal and feasible cutting planes generated in a branch node are proved to be valid for its descendants. Moreover, three acceleration techniques are introduced into the proposed algorithm to improve computational efficiency. Finally, the effectiveness and accuracy of the proposed method are verified via simulation tests in Jinzhai DNs of China.

42 ENGINEERING↗