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            Abstract Synthetic ensemble forecasts are an important tool for testing the robustness of forecast‐informed reservoir operations (FIRO). These forecasts are statistically generated to mimic the skill of hindcasts derived from operational ensemble forecasting systems, but they can be created for time periods when hindcast data are unavailable, allowing for a more comprehensive evaluation of FIRO policies. Nevertheless, it remains unclear how to determine whether a candidate synthetic ensemble forecasting approach is sufficiently representative of its real‐world counterpart to support FIRO policy evaluation. This highlights a need for formalfit‐for‐purposevalidation frameworks to advance synthetic forecasting as a generalizable risk analysis strategy. We address this research gap by first introducing a novel operations‐based validation framework, where reservoir storage and release simulations under a FIRO policy are compared when forced with a single ensemble hindcast and many different synthetic ensembles. We evaluate the suitability of synthetic forecasts based on formal probabilistic verification of the operational outcomes. Second, we develop a new synthetic ensemble forecasting algorithm and compare it to a previous algorithm using this validation framework across a set of stylized, hydrologically diverse reservoir systems in California. Results reveal clear differences in operational suitability, with the new method consistently outperforming the previous one. These findings demonstrate the promise of the newer synthetic forecasting approach as a generalizable tool for FIRO policy evaluation and robustness testing. They also underscore the value of the proposed validation framework in benchmarking and guiding future improvements in synthetic forecast development.more » « less
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            Previous studies have provided evidence that reinforcement of epoxy adhesives with nanostructures such as carbon nanofibers (CNFs) produces higher strength bonded joints between carbon fiber reinforced polymer (CFRP) laminates and shifts bond-line failure modes from the adhesive into the laminate. Despite this, there has been no research dedicated to applying reinforced adhesives to the bonding of nano-reinforced CFRP such as CNF z-threaded carbon fiber reinforced polymer (ZT-CFRP) laminates, which have been proven to exhibit increased interlaminar shear strength, mode-I delamination toughness, and compressive strength over traditional CFRP. This study examined the effectiveness of using CNF reinforced epoxy adhesives for unidirectional ZT-CFRP laminate bonding through single-lap shear tests using the ASTM D5868-01 standard. Unidirectional CFRP laminate samples bonded with both epoxy adhesive and CNF reinforced epoxy adhesive were also tested for comparison. It was found that the average shear strength observed for ZT-CFRP samples bonded with CNF reinforced epoxy adhesive was approximately 44% and 26 % higher than that of CFRP samples bonded with epoxy adhesive and CNF reinforced epoxy adhesive, respectively. Microscopic image analysis was performed to examine the mode of bond failure. The roles of nanomaterials in the fracture mechanism of the adhesives and the composite laminates are also discussed.more » « less
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            A film adhesive is commonly used to form the bond line between composite or metal parts. The bond line's quality and performance can be affected by defects such as voids, impurities, agglomerations, and other structural issues found within it; in addition, defects can form due to damage or delamination. Identifying these defects is possible with non-destructive evaluation (NDE). In this paper, the joule-heating effect through carbon nanofibers (CNF) and carbon nanotubes (CNT) modified film adhesive will be used along with infrared thermography for bond line defect inspection. Due to the difference in the electrical conductivity between the modified epoxy and the defect, joule heating can cause a different temperature at the defect; thus, in theory, the defect can be viewed by infrared thermography. The percentage of carbon nanofiller in a film adhesive changes the measurement quality due to its relationship to electrical conductivity. An Acrylonitrile Butadiene Styrene (ABS) equilateral triangle defect with 30 mm sides was used inside bond line samples. These bond lines were composed of epoxy and nanofillers of CNF and CNT at various concentrations. Each concentration was evaluated individually and bonded onto two single-ply CFRP coupons. In this study, the feasibility of using carbon nanofillers of different concentrations as a medium for identifying and characterizing defects through NDE infrared thermography was investigated and validated the effectiveness of this new NDE approach. In the future, aligning nanofiller for bond lines could be a potential research direction to improve upon what this study strives to achieve.more » « less
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            Carbon fiber reinforced polymer (CFRP) composites have been increasingly used in many vehicles such as airplanes, automobiles, and ships due to the advantages of high-strength, high-modulus, lightweight, and corrosion resistance. CFRP structures enhance the vehicle's performance, energy-efficiency, comfort, and safety. However, a common safety concern is how the CFRP materials perform when the vehicle is in fire and if there are enough time to safely evacuate the passengers. The elevated temperature can soften and decompose the polymer matrix, delaminate the CFRP laminate, and burn the CFRP through the contact with oxygen. As a result, the thermal and flammability response of CFRP is important for considering CFRP for vehicle applications; and some specialty high-temperature or flame/smoke/toxicity-proven resins have been investigated for CFRP parts manufacturing due to the needs. In this paper, a novel flame resistant hypothesis of utilizing the unique nano/micro- interlocked fiber reinforcing structure of the long-range carbon nanofiber z-threaded CFRP (ZT-CFRP) composite laminates for improving the flammability performance will be investigated. The carbon nanofibers (CNT) and carbon nanotubes (CNT), which have excellent thermal and mechanical properties, will be dispersed in an epoxy resin and will zig-zag thread through a carbon fiber fabric using an electrical/flow assisted impregnation process to create the unidirectional ZT-CFRP prepregs, respectively, which will be further processed into ZT-CFRP composite laminates. The UL-94 flammability test will be employed to characterize the ZT-CFRP laminates' flammability performance against the control baseline data of the regular CFRP, all without using any flame retardant chemicals. An impressive self-extinguishing flammability characteristic of the CNF based ZT-CFRP samples has been distinctly identified from all the samples. The UL-94 testing results and the effectiveness of using the long-range nanofiber z-threading strategy for enabling the novel nano/microstructure-induced flame resistant and self-extinguishing characteristics will be discussed.more » « less
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            L-type voltage-gated calcium (Ca2+) channels (L-VGCC) dysfunction is implicated in several neurological and psychiatric diseases. While a popular therapeutic target, it is unknown whether molecular mechanisms leading to disrupted L-VGCC across neurodegenerative disorders are conserved. Importantly, L-VGCC integrate synaptic signals to facilitate a plethora of cellular mechanisms; however, mechanisms that regulate L-VGCC channel density and subcellular compartmentalization are understudied. Herein, we report that in disease models with overactive mammalian target of rapamycin complex 1 (mTORC1) signaling (or mTORopathies), deficits in dendritic L-VGCC activity are associated with increased expression of the RNA-binding protein (RBP) Parkinsonism-associated deglycase (DJ-1). DJ-1 binds the mRNA coding for the alpha and auxiliary Ca2+channel subunits CaV1.2 and α2δ2, and represses their mRNA translation, only in the disease states, specifically preclinical models of tuberous sclerosis complex (TSC) and Alzheimer’s disease (AD). In agreement, DJ-1-mediated repression of CaV1.2/α2δ2 protein synthesis in dendrites is exaggerated in mouse models of AD and TSC, resulting in deficits in dendritic L-VGCC calcium activity. Finding of DJ-1-regulated L-VGCC activity in dendrites in TSC and AD provides a unique signaling pathway that can be targeted in clinical mTORopathies.more » « less
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            Moisture is a known issue for carbon fiber reinforced polymer (CFRP) manufacturing. During the process, in which a CFRP prepreg is carefully thawed, cut, stacked, and cured into a laminate, any bad moisture control can cause voids, affect the curing, and degrade the laminate. Recent studies of carbon nanofiber z-threaded CFRP (i.e., ZT-CFRP) prepreg and its laminates showed significant multifunctional improvements in the mechanical strengths, toughness, thermal conductivity, and electrical conductivity. The carbon nanofibers zig-zag thread among the carbon fibers in the through-thickness direction (i.e., z-direction) and mechanically interlock the fiber system together to form an effective 3D-fiber-network reinforced laminate. This paper presents a preliminary experimental study on the ZT-CFRP prepreg when facing the moisture exposure during the prepreg handling and lamination process. Both the ZT-CFRP and traditional CFRP prepregs, subjected to different humidity conditions, will be cut, and cured into laminate samples. The samples will be tested for their interlaminar shear strengths (ILSS) and hardness. Microscope pictures of the samples' fracture patterns will be compared for explaining the combined impact of the moistures and the carbon nanofiber z-threading strategy on the laminates' interlaminar shear strength and curing state.more » « less
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            Well-dispersed and unaligned multi-walled carbon nanotubes (MCNTs) infused liquid epoxy adhesive have been reported for significantly improving the adhesive-joint of carbon fiber reinforced polymer (CFRP) composite laminates. However, it has not been determined in the literature if the alignment of MCNTs would provide an additional improvement than the randomly aligned case. In this study, various epoxy film adhesives embedded with 1wt% through-thickness aligned MCNTs, unaligned MCNTs, aligned carbon nanofibers (CNFs), and unaligned CNFs were used for bonding CFRP laminates. These variants have been used to bond two CFRP laminates for the ASTM D5868-01 single lap test as well as a steel variant for the same bonding process. The average shear strengths of the samples bonded by the various film adhesives were compared with the samples bonded by the pure epoxy-films. Microscopic analysis has been used to examine the fracture surface after testing. It was also used to visualize how the film adhesives fail while experiencing shear. This study has investigated the effectiveness of infusing through-thickness directionally aligned vs. unaligned nanoparticles in an epoxy film adhesive for bonding CFRP laminates and steel plate. It also indicates the potential future research direction of using nanoparticles in advanced adhesive technologies.more » « less
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