Combinatorial Evaluation of Systems Including Decomposition of a System Representation Into Fundamental Cycles
We construct an algebraic-combination model of networks-of-networks. A Petri net is used to construct an initial representation of the decision-making network, which in turn defines a hyperdigraph. We observe that the linear algebraic structure of each hyperdigraph admits a canonical set of algebraic-combinatorial invariants that correspond to the information flow conservation laws governing a kinetic network. The linear algebraic structure of the hyperdigraph and its sets of invariants can be generalized to define a discrete algebraic-geometric structure, which is referred to as an oriented Matroid. Oriented matroids define a polyhedral optimization geometry that is used to determine optimal subpaths that span the nullspace of a set of kinetic equations. Sets of constrained submodular path optimizations on the hyperdigraph are objectively obtained as a spanning tree of minimum cycle paths. This complete set of subcircuits is used to identify the network pinch points and invariant flow subpaths. We demonstrate that this family of minimal circuits also characteristically identifies additional significant pattern features. We used several applications (including the biochemistry of the Krebs Cycle, the SOS Compartment A of the EGFR biochemical pathway, and economics-driven electric power grids) to develop and demonstrate the application of our algebraic-combinatorial mathematical modeling methodology.
HIGHLY STABLE PHENAZINE DERIVATIVES FOR AQUEOUS REDOX FLOW BATTERIES
In this report, rationally functionalized, highly water-soluble phenazine derivatives are disclosed as a new class of redox-active anolyte material for aqueous redox flow batteries. These compounds are compatible with basic electrolytes leading to relatively high rate performance. They have sufficiently low redox potential (-1V vs Ag/AgCl) in basic electrolytes, which can enable high voltage flow batteries systems. In addition, they have two electron transfers and this is very helpful to improve their energy density by double. When coupled with potassium ferrocyanide, the flow cell exhibited a relatively stable cycling for ~300 cycles at 20 mA/cm2. The great cyclability indicate that these compounds and their charged species are chemically very stable, promising for highly durable flow battery systems. Moreover, these compounds can be synthesized from very inexpensive precursors through simple one-step synthesis. This feature allows easy molecular engineering to enable high solubilities and can lead to high cost-effectiveness redox materials. Therefore, the organic phenazine derivative compounds are expected to be promising material candidates to achieve competitive aqueous redox flow batteries that have high voltage, high energy density, good power density, long durability, and low cost.
Capacity Expansion Regional Feasibility Model (CERF) - Open Source
The Capacity Expansion Regional Feasibility (CERF) model is a geospatial model for scenario analysis of electricity system expansions, CERF is unique in that it determines suitable siting locations using a combination of traditional, static siting constraints (e.g., federally and state-protected lands) with dynamic constraints (e.g., cooling water availability and population growth) and then simulates an economic competition between technologies using an algorithm that minimizes 'net locational costs" to choose specific siting locations within suitable areas. The net locational costs are calculated for each technology type and depend on the distance to the existing transmission system and other infrastructure, technology-specific marginal operating costs, and technology- and location-specific marginal energy values. In effect, the algorithm posits the existence of a regional planner who determines the costs and benefits of having new generation in different locations and sites power plants in order from lowest to highest net locational cost. Technologies that share the same suitable areas compete for siting locations based on the locational economics. CERF can be parameterized either manually for customized scenarios, arbitrarily for use in uncertainty characterization, or from ancillary inputs provided by contributing socioeconomic/policy, hydrologic, and production cost models for the purpose of integrated assessment.
UnityMol-APBS (NIH iEdison No. 0685901-19-0009, Grant No. GM069702)
Virtual reality is a powerful tool with the ability to immerse a user within a completely external environment. This immersion is particularly useful when visualizing and analyzing interactions between small organic molecules, molecular inorganic complexes, and biomolecular systems such as redox proteins and enzymes. A common tool used in the biomedical community to analyze such interactions is the Adaptive Poisson-Boltzmann Solver (APBS) software, which was developed to solve the equations of continuum electrostatics for large biomolecular assemblages. Numerous applications exist for using APBS in the biomedical community including analysis of protein ligand interactions and APBS has enjoyed widespread adoption throughout this biomedical community. Currently, typical use of the full APBS toolset is completed via the command line followed by visualization using a variety of twodimensional external molecular visualization software. This process has inherent limitations: visualization of three-dimensional objects using a twodimensional interface masks important information within the depth component. Herein, we have developed a single application, UnityMol-APBS, that provides a dual experience where users can utilize the full range of the APBS toolset, without the use of a command line interface, by use of a simple graphical user interface (GUI) for either a standard desktop or immersive virtual reality experience.
CONTROL FOR ENERGY RESOURCES IN A MICROGRID
This concept uses a slider setting for microgrid operations that allows a user to select between "more efficient" and "more resilient". This is similar to the slider setting concept for transactive control, except that they are influencing different technical values. As the slider is set to more efficient, the dispatch and droop values of the generators are adjusted to increase the operating efficiency of the system. This is achieved by moving the operating points of the generators to their most efficient points while still meeting the current load. As the slider is set to more resilient, the dispatch and droop values of the generators are adjusted to minimize the frequency deviation from an expected increase in load or loss of generation. The value of the slider setting could be set by a human operator, or determined as part of a more complex control system. For example, the slider value could be determined as the output of a neural network that is optimization the operation of multiple networked microgrids. In its current state the work is using a modified version of the IEEE-123 node test system with 2 diesel generators and 1 PV inverter. As the slider setting is varied the control system determines the set points for both diesel generators and the PV inverter. The values for each generator include their power outputs and their current droop values for controls. The result is that the single slider setting determines multiple set points on multiple generators. The method is scalable, but the optimization becomes computationally burdensome with large number of generators. This should not be an issue with most operational microgrids.
PNNL to Host Women in Engineering Global Summit
The U.S. Department of Energy’s Pacific Northwest National Laboratory is one of 10 sites worldwide to host an IEEE Women in Engineering International Leadership Summit in 2019. The event will take place July 30 at Discovery Hall.
Establishing Ethical Nanobiotechnology
PNNL’s wide-ranging report maps the current nanobiotechnology landscape, flags potential concerns, and details the need for an organizing body to coordinate currently disparate disciplines.
2019 INCITE award fosters search for new elements, quantum interactions
PNNL researcher Kenneth Roche part of multi-institutional team awarded 2019 INCITE award