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A Model Predictive Control to Improve Grid Resilience
Get PDFThe following article details a model predictive control (MPC) to improve grid resilience when faced with variable generation resources. This topic is of significant interest to utility power systems where distributed intermittent energy sources will increase significantly and be relied on for electric grid ancillary services. Previous work on MPCs has focused on narrowly targeted control applications such as improving electric vehicle (EV) charging infrastructure or reducing the cost of integrating Energy Storage Systems (ESSs) into the grid. In contrast, this article develops a comprehensive treatment of the construction of an MPC tailored to electric grids and then applies it integration of intermittent energy resources. To accomplish this, the following article includes a description of a reduced order model (ROM) of an electric power grid based on a circuit model, an optimization formulation that describes the MPC, a collocation method for solving linear time-dependent differential algebraic equations (DAEs) that result from the ROM, and an overall strategy for iteratively refining the behavior of the MPC. Next, the algorithm is validated using two separate numerical experiments. First, the algorithm is compared to an existing MPC code and the results are verified by a numerically precise simulation. It is shown that this algorithm produces a control comparable to existing algorithms and the behavior of the control carefully respects the bounds specified. Second, the MPC is applied to a small nine bus system that contains a mix of turbine-spinning-machine-based and intermittent generation in order to demonstrate the algorithm’s utility for resource planning and control of intermittent resources. This study demonstrates how the MPC can be tuned to change the behavior of the control, which can then assist with the integration of intermittent resources into the grid. The emphasis throughout the paper is to provide systematic treatment of the topic and produce a novel nonlinear control compatible design framework applicable to electric grids and the control of variable resources. This differs from the more targeted application-based focus in most presentations
2024, A Landmark Year for Climate Change and Global Carbon Capture, Utilization, and Storage: Annual Progress Review
Get PDFThis annual review outlines the progress of carbon capture, utilization, and storage (CCUS) technologies in 2024. As human-induced CO2 emissions continued to rise, the year presented critical challenges. Notably, 2024 was the hottest year on record and the first in which global temperatures exceeded preindustrial levels by more than 1.5°C, driving intensified efforts to advance CCUS. Scientific interest in CCUS grew significantly, with the annual number of related publications increasing by 11.4% compared to 2023, reaching 53,970. The total number of operational commercial CCUS facilities also expanded, rising by 16.3% to a total of 50. In the political area, governments introduced targeted policies to accelerate CCUS adoption, focusing on economic investment and specific implementation requirements
Imine Crosslinked, Injectable, and Self-Healing Fucoidan Hydrogel with Immunomodulatory Properties
Get PDFBiomaterials with inherent anti-inflammatory properties and the ability to foster a pro-regenerative environment hold significant promise for enhancing cell transplantation and tissue regeneration. Fucoidan, a sulfated polysaccharide with well-documented immune-regulatory and antioxidant capabilities, offers strong potential for creating such biomaterials. Yet, there is a lack of engineered fucoidan hydrogels that are injectable and provide tunable physicochemical properties. In this study, the ability of fucoidan to undergo periodate-mediated oxidation is leveraged to introduce aldehydes into backbone (oxidized fucoidan, OFu), enabling the formation of reversible, imine-crosslinks with amine-containing molecules such as gelatin. The imine-crosslinked OFu-gelatin hydrogel provided excellent control over gelation rate and mechanical properties. Counter-intuitively, OFu-gelatin hydrogel exhibited excellent long-term stability (≥28 days), even though imine crosslinks are known to be relatively less stable. Moreover, the OFu-gelatin hydrogels are self-healing, injectable, and biocompatible, supporting cell culture and encapsulation. Furthermore, fucoidan hydrogels displayed immune-modulatory properties both in vitro and in vivo. This innovative injectable fucoidan hydrogel presents a versatile platform for applications in tissue engineering and regenerative medicine
Hemodynamic analysis of thrombosed intracranial aneurysms: a comparative correlation study
No full textA small fraction of intracranial aneurysms (IA) contains intrasaccular thrombosis (IST). This study explores the hemodynamic causes of IST formation in IAs. We performed computational hemodynamic analysis in 26 IAs: 13 thrombosed and 13 non-thrombosed. The IAs in the two cohorts were matching in size and anatomical location. The computational hemodynamic analysis used “patient-specific” IA geometries derived from 3D magnetic resonance imaging. A comprehensive hemodynamic analysis was conducted using commonly used hemodynamic metrics (e.g., wall shear stress [WSS] and its derivative), flow vortex analysis, and velocity informatics. We observed that more flow eddies and endothelial cell activation potential (ECAP) are present in thrombosed IAs. The flow eddies in thrombosed IAs change size and location over a cardiac cycle more significantly than those in non-thrombosed IAs. These two factors, coupled with more flow stagnation and positive WSS divergence in the thrombosed IAs, promoted thrombus formation in the thrombosed IA cohort
Sustainable management of copper-contaminated soils using vetiver root biochar
Get PDFThroughout the 19th and early 20th centuries, copper mining was a predominant industry in Michigan\u27s Upper Peninsula, resulting in substantial environmental issues due to the generation of mining waste. This waste, referred to as stamp sands, was disposed of in Lake Superior, causing severe harm to aquatic ecosystems. Later, the stamp sands were dredged and deposited along the lake shores, causing large-scale contamination with copper. This rendered the land incapable of supporting vegetation. This study investigates the efficacy of vetiver (Chrysopogon zizanioides) root biochar as a soil amendment to enhance the quality of copper-contaminated stamp sands. The biochar was produced from spent vetiver roots following essential oil extraction, using a circular economy approach. Biochar was incorporated with the stamp sand at various concentrations (0%, 2.5%, 5%, 10%, 20% w/w) and incubated over a 60-day period. Comprehensive soil analysis was conducted to assess carbon, nitrogen, phosphorus, organic matter, and copper speciation due to the amendments. The results indicated significant improvements in water-holding capacity, alkalinity, electrical conductivity, nutrient content, and organic matter levels. The 20% biochar amendment had a significantly higher impact on all parameters as compared to the other amendment rates. Geochemical fractionation of amended soil showed that Cu was predominantly in bound forms, thereby reducing its bioavailability. These findings indicate that vetiver root biochar can improve soil quality and potentially facilitate vegetation growth in contaminated Superfund sites integrating principles of circular economy for sustainable management of resources
Engineering electropolymerized molecularly imprinted polymer films for redox-integrated, reagent-free cortisol detection: The critical role of scan rate
No full textElectropolymerized molecularly imprinted polymers (eMIPs) represent a versatile platform for electrochemical biosensing, offering tailored specificity, high stability, and cost-effectiveness through direct synthesis on electrodes. This study investigates the fabrication-property-performance relationship of eMIPs for enhanced cortisol biosensing, with a focus on the interplay between scan rate and the number of polymerization cycles during cyclic voltammetry-based electropolymerization. The thickness, density, and morphology of the eMIP films were systematically characterized using electrochemical quartz crystal microbalance (EC-QCM), field-emission scanning electron microscopy (FE-SEM), and profilometry. Lower scan rates (25 mV s) produced denser and smoother polymer film compared to higher scan rates (50 mV s), highlighting the critical influence of scan rate on polymer properties. The eMIP films fabricated with different parameters were integrated with a Prussian Blue nanoparticles layer on screen-printed carbon electrodes for reagent-free cortisol detection. Square wave voltammetry (SWV) was used to evaluate sensor performance, which demonstrates that lower scan rates (25 mV s) combined with increased polymerization cycle counts yielded a denser and thicker film, resulting in enhanced sensitivity and selectivity. The sensor achieved a limit of detection (LOD) of 26 pM for cortisol. These findings provide valuable insights into the critical role of electropolymerization parameters in tailoring film properties (i.e., thickness and density), enhancing eMIP sensor design, and advancing biosensor technology through precise control of electropolymerization parameters
Denitrification processes, inhibitors, and their implications in ground improvement
Get PDFUreolysis and denitrification are the two major microbial metabolic pathways commonly used in Microbially induced calcite precipitation (MICP) for geoengineering applications. Although ureolysis is generally the more efficient pathway, the denitrification pathway has gained more attention recently because a diverse group of bacteria can precipitate calcite via denitrification, and no harmful byproduct is generated provided that the reduction of nitrate to nitrogen gas is complete. There are, however, many environmental factors that could inhibit or reduce the efficiency of the denitrification process in soil. Some examples of these factors include salinity, pH, temperature, biodiversity (abundance and species of denitrifiers and competitors), water stress (extreme wet-dry conditions), degree of saturation (anaerobic vs. aerobic conditions), high heavy metal content (e.g., mine tailings), and shortage of dissolved carbon sources. In this paper, the denitrification process, the denitrification inhibitors, and the mechanisms involved in their inhibition of the denitrification process are discussed in detail. This investigation indicates that although general optimum conditions can be formulated for MICP through denitrification, significant adjustments may be necessary if inhibitory conditions are anticipated. It was also shown that when inhibitors are expected, it is crucial to investigate not only the amount of precipitated calcium carbonate but also the 2/2 gase ratio to ensure the complete reduction of nitrate to nitrogen gas and prevent the release of byproducts (especially 2) into the environment. Finally, the implications of the inhibitory factors on the field application of denitrification MICP treatment for different geotechnical projects are discussed
PHYSICOCHEMICAL PROPERTIES OF JATROPHA SEED OIL: DISCLOSES POTENTIAL SOURCE OF BIODIESEL PRODUCTION
No full textJatropha is an alternative source of fossil fuel grown in the tropics and subtropics. This research focuses on measuring of physical, chemical and (lubricating) characteristics of Jatropha seed oil extracted from 45 genotypes to explore its potential as biodiesel feedstock. Significant genetical variation was observed from the ANOVA for the genotypes. High coefficient of variation for genotype and phenotype were found for all seed oil properties with moderate differences. The traits reported the highest values of broad sense heritability and genetic advance were oil moisture content (85.77%), free fatty acids (52.99%) and peroxide value (148.84%). Significant correlation coefficient was found at 10 physiochemical characteristics Jatropha seed oil samples. The oil content of seed (%) revealed significant positive correlation coefficient with oil density (0.40**), oil moisture content (0.21*), saponification value (0.26**). Cluster analysis based on seed oil properties; 45 Jatropha genotypes were clustered in six groups. The maximum number of the genotypes (11) were grouped into cluster V. The cluster V integrated the highest number of genotypes while the second and third top-performing genotypes were found in cluster IV (9) and II (8), respectively