Xcel Energy (United States)

Our work seeks to introduce a computational tool tailored to the physics of inertial fusion energy chambers, in particular, those concepts based on thick liquid walls. In this approach, the structural materials are protected by several neutron mean-free-paths of renewable liquid and thus will be able to survive much longer than un-shielded walls, with virtually all structures lasting for the life of the plant and enabling the use of commercially available and qualified materials. The OpenFOAM-based solver named rhoCentralFoam has been used as a starting point. rhoCentralFoam belongs to the standard OpenFOAM solver toolset. It is a high-speed, explicit compressible flow solver with shock-capturing capability. While the main features have been retained, the solver had to be restructured to make use of tabular data for equations of states, a necessary addition to model the complex thermo-physical properties of ionized gasses. This entailed the need to change the independent state variables used by the solver, resulting in a new thermodynamic library and slightly different solution algorithm. Moreover, a radiation heat transfer model based on the P-1 approximation was added to the solver. The solver is verified against an analytical solution from the Sedov-Taylor-Neumann test problem to showcase the ability of the hydrodynamic solvers to handle strong shocks, whereas the P-1 model was verified using a simple one-dimensional problem with an analytical solution. Additionally, a validation case involving shock-wave propagation through jet array is presented, and the results are compared with experimental data from the open literature. Finally, in order to showcase the utility of the solver for practical cases, we applied the refined solver to two representative scenarios: gas venting within the HYLIFE-II chamber and the compression of the gas following the partial ablation of the liquid wall.

Mushrooms are widely available around the world and have various nutritional as well as therapeutic values. Many Asian cultures believe that medicinal mushrooms can prolong life and improve vitality. This study aims to characterize the phytochemical and polysaccharide content, mainly β-glucan content, of mycelial biomass and fruiting bodies collected from the Himalayan region, particularly Uttarakhand. Through molecular analysis of the LSU F/R-rDNA fragment sequence and phylogenetic analysis, the strain was identified as Trametes sp. We performed screening of phytochemicals and polysaccharides in mushroom and biomass extracts using high-performance liquid chromatography (HPLC) and a PC-based UV-Vis spectrophotometer. The macrofungal biomass was found to be high in saponin, anthraquinone, total phenolic, flavonoid, and β-glucan content. In biomass extract, we observed a high level of saponin (70.6µg/mL), anthraquinone (14.5µg/mL), total phenolic (12.45 µg/mL), and flavonoid (9.500 µg/mL) content. Furthermore, we examined the contents of alkaloids, tannins, terpenoids, and sterols in the biomass and mushroom extracts; the concentration of these compounds in the ethanol extract tested was minimal. We also looked for antioxidant activity, which is determined in terms of the IC50 value. Trametes sp. mushroom extract exhibits higher DPPH radical scavenging activity (62.9% at 0.5 mg/mL) than biomass extract (59.19% at 0.5 mg/mL). We also analyzed β-glucan in Trametes sp. from both mushroom and biomass extracts. The biomass extract showed a higher β-glucan content of 1.713 mg/mL than the mushroom extract, which is 1.671 mg/mL. Furthermore, β-glucan analysis was confirmed by the Megazyme β-glucan assay kit from both biomass and mushroom extract of Trametes sp. β-glucans have a promising future in cancer treatment as adjuncts to conventional medicines. Producing pure β-glucans for the market is challenging because 90-95% of β glucan sold nowadays is thought to be manipulated or counterfeit. The present study supports the recommendation of Trametes sp. as rich in β-glucan, protein, phytochemicals, and antioxidant activities that help individuals with cancer, diabetes, obesity, etc.

The integration of renewable energy resources into the power grid has introduced challenging problems that need to be overcome to ensure system stability and reliability. This paper applied an Integrated Protection-Planning Simulation (IPPS) technology to evaluate an innovative Underfrequency Load Shedding (UFLS) scheme with the objective of complying with NERC Standard PRC-006-5 considering penetration of Inverter-Based Resources (IBR). IPPS technology creates a simulation platform that allows the modeling of highly detailed protection models in transient stability analysis. This paper took advantage of the new features enabled by IPPS and modeled a novel UFLS relay logic with Rate-of-Change-of-Frequency (RoCoF) supervision. The RoCoF-supervised UFLS has the advantage of avoiding misoperation at industrial motor loads and allowing for reduced UFLS time delay. A sudden loss of generation condition was simulated in IPPS according to the PRC-006-5 standard requirements. The protection logic of both the conventional UFLS program and the RoCoF-supervised UFLS scheme have been examined by incrementally increasing the IBR penetration level. The IPPS tool provided accurate simulation results including frequency profile and Volts per Hertz values at all generation buses. The performance of the novel UFLS scheme has been compared with the conventional scheme to validate its effectiveness. An automatic load restoration scheme to prevent frequency overshoot after UFLS occurs has also been implemented along with the addition of a Battery Energy Storage Systems (BESS) to provide fast frequency response and further alleviate system-wide frequency decay.

Abstract Linear anomalies were discovered during construction activities near to the DC-ERW long seam weld of a 20-inch natural gas pipeline. Magnetic particle testing and phased array ultrasonic testing were applied to characterize the anomalies. Pipe samples were removed from the pipe for additional destructive laboratory analysis. Laboratory analysis included visual assessment, X-ray computed tomography, cryo-fracture, cross-sectioning, metallographic analysis, and scanning electron microscopy. Inspection and testing results indicated that the anomalies were consistent with roller contact marks introduced during pipe manufacturing and did not show evidence of time-dependent growth. Representative anomalies were evaluated using a Failure Assessment Diagram to provide an additional level of assurance. All flaws were found to be acceptable in accordance with general application of API 579 Part 9, Level 2.

The bare-hand technique is a common work method applied in high voltage power grids. Rules, guidelines, and recommendations must guarantee an appropriate level of protection against electric shock, electric field stress, open flames, and arc flash incident energy. Traditionally, conductive clothing has been used by line workers for protection against electric fields of extra-low frequency. Most conductive clothing designs offer high efficiency as Faraday-cages. Although screening efficiency of a well-designed clothing is high enough to significantly decrease electric fields for prevention against electric shock, other hazards should be addressed. Transmission line geometries may guarantee required clearances between conductive parts at different potentials. However, additional protection measures may be required. Several accidents occurred to line workers using hot sticks, insulating boom trucks, insulating scaffolds, and helicopters. During flashover, the incident energy of the arc may be high and exceed the threshold of a second-degree burn. This requires risk assessment and mitigation of arc flash and other thermal hazards. The most effective way of protecting against electric arcs is the integration of arc protective protection into conductive clothing. The improved design doesn’t compromise worker’s comfort. This paper presents an example on how to estimate arc incident energy for the transmission network of an electric utility, where protection from electric arcs and flames is mandatory. A procedure for selecting arc-rated conductive clothing is presented. The applications cover bare-hand work, and hot sticking.

Conductive suits are widely used in the industry for live work on transmission lines. This paper covers the use of special conductive suits for AC induction protection on de-energized lines. During de-energized work in the vicinity of live conductors, inductive and capacitive coupling may result in dangerous voltages and currents. Several accidents show that de-energized work has a high-risk level. The main reason is that de-energized parts are supposed to be grounded but line workers often do not have the proper knowledge and safety gear to assess and to protect against sources of induced voltages and currents. A US electric utility in co-operation with the High Voltage Laboratory of the Budapest University of Technology and Economics developed an AC induction suit; a special conductive suit designed to protect line workers against induced voltage and current while working on de-energized systems in the vicinity of energized lines. The range of induced voltage and current was analyzed based on preliminary calculations, and field measurements. The design of the special protective suit was based on these physical values. Several laboratory tests were performed to validate the results and to inspect prototypes at extreme voltages and currents. The aim of the developers is to increase the overall level of safety during vicinity work in transmission corridors with high AC induction and to greatly reduce accidents. Requirements for induction suits and test methods to prove protective capabilities will be standardized in the future. Based on the positive results of the prototype tests, a new product was introduced in the US market. The suits are currently being tested by the electric utility to gather experience, develop field procedures, and to effectively reduce the risk level, treating safety always as priority.

HER2+ breast leptomeningeal carcinomatosis (HER2+ LC) occurs when tumor cells spread to cerebrospinal fluid-containing leptomeninges surrounding the brain and spinal cord, a complication with a dire prognosis. HER2+ LC remains incurable, with few treatment options. Currently, much effort is devoted toward development of therapies that target mutations. However, targeting epigenetic or transcriptional states of HER2+ LC tumors might efficiently target HER2+ LC growth via inhibition of oncogenic signaling; this approach remains promising but is less explored. To test this possibility, we established primary HER2+ LC (Lepto) cell lines from nodular HER2+ LC tissues. These lines are phenotypically CD326+CD49f-, confirming that they are derived from HER2+ LC tumors, and express surface CD44+CD24-, a cancer stem cell (CSC) phenotype. Like CSCs, Lepto lines showed greater drug resistance and more aggressive behavior compared with other HER2+ breast cancer lines in vitro and in vivo. Interestingly, the three Lepto lines overexpressed Jumonji domain-containing histone lysine demethylases KDM4A/4C. Treatment with JIB04, a selective inhibitor of Jumonji demethylases, or genetic loss of function of KDM4A/4C induced apoptosis and cell-cycle arrest and reduced Lepto cell viability, tumorsphere formation, regrowth, and invasion in vitro. JIB04 treatment of patient-derived xenograft mouse models in vivo reduced HER2+ LC tumor growth and prolonged animal survival. Mechanistically, KDM4A/4C inhibition downregulated GMCSF expression and prevented GMCSF-dependent Lepto cell proliferation. Collectively, these results establish KDM4A/4C as a viable therapeutic target in HER2+ LC and spotlight the benefits of targeting the tumorigenic transcriptional network. SIGNIFICANCE: HER2+ LC tumors overexpress KDM4A/4C and are sensitive to the Jumonji demethylase inhibitor JIB04, which reduces the viability of primary HER2+ LC cells and increases survival in mouse models.

Interconnection reliability operating limits are system operating limits that, if exceeded, could result in instability, uncontrolled separation, or cascading if the critical contingency were to occur, and are operated within to ensure reliable operation of the bulk power system in North America. This paper presents an analytical framework for establishing IROLs, and recommended modeling and simulation techniques for instability assessment and cascading analysis. The recommended practices are being adopted and used in North America for consistency in study approaches for establishing IROLs.

When applied to a snow-covered surface, aerodynamic roughness length, z0, is typically considered as a static parameter within energy balance equations. However, field observations show that z0 changes spatially and temporally, and thus z0 incorporated as a dynamic parameter may greatly improve models. To evaluate methods for characterizing snow surface roughness, we compared concurrent estimates of z0 based on (1) terrestrial light detection and ranging derived surface geometry of the snowpack surface (geometric, z0G) and (2) vertical wind profile measurements (anemometric, z0A). The value of z0G was computed from Lettau’s equation and underestimated z0A but compared well when scaled by a factor of 2.34. The Counihan method for computing z0G was found to be unsuitable for estimating z0 on a snow surface. During snowpack accumulation in early winter, z0 varied as a function of the snow-covered area (SCA). Our results show that as the SCA increases, z0 decreases, indicating there is a topographic influence on this relation.