Technology Center Research Articles

(General Student Poster Award Winner, 3rd Place) Designing and Evaluating Microelectrodes for Molten Salt Corrosion Electrochemistry

Due to the coupling of high temperature operation (>500°C) and propensity to contain oxidizing impurities (e.g., moisture, metallic cations), corrosion of structural alloys in molten chloride and fluoride salts is a major concern among developers of Generation IV nuclear reactors. To mitigate corrosion, it is essential to understand the corrosion mechanism and accurately determine its rate. Prior studies employ a forensic approach for corrosion testing, which does not provide insights on instantaneous rate of corrosion [1]. The use of electrochemical impedance spectroscopy (EIS) can provide in-operando method to interrogate dissolution processes. However, due to the high electrical conductivity and double-layer capacitance of metal salt interface [2], low frequency regimes normally dominated by polarization resistance (Rp) in aqueous systems require data acquisition at low frequencies. (<10-3 Hz). This renders access to charge-transfer resistance (Rct) and diffusional impedance effects difficult. This difficulty is compounded by issues such as signal noise associated with the use of long cables in conventional molten salt corrosion cells [2].To overcome this challenge, a working electrode may be designed as a 2D microdisk electrode to was used to interrogate the low-frequency impedance regimes. This disk has a non-uniform current distribution at such low Wagner number but it is easier to access the charge transfer and/or diffusional impedance regime, otherwise unattainable with the conventionally used partially immersed 3D macro-electrodes utilized in most studies [3]. In this work, a flush mounted microdisk electrode, compatible for use in molten LiF-NaF-KF (i.e., FLiNaK) salts at 600°C was designed and evaluated for its effectiveness towards accurately determining Rp through the EIS method. Pure Cr was selected as the model working electrode since its corrosion behavior in FLiNaK at 600°C has been thoroughly investigated [4,5,6],. Cr microdisks, with areas ranging from 100 to 10-2 cm2, were fabricated and subsequently exposed in FLiNaK containing 1 wt.% of EuF3 at 600°C for 24 hrs. EIS measurements were carried out over the commonly utilized frequency range from 105 to 10-2 Hz. Moreover, the error introduced by implementing various low “cut off” frequencies was examined. Acknowledgment Research is primarily supported as part of the fundamental understanding of transport under reactor extremes (FUTURE), an Energy Frontier Research Center (EFRC) funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES). This work was performed in the Department of Materials Science and Engineering (DMSE) in the Center for Electrochemical Science and Engineering (CESE) at the University of Virginia. Utilization of the Malvern-Panalytical Empyrean diffractometer was supported by Nanoscale Materials Characterization Facility (NMCF) with National Science Foundation (NSF) under award CHE-2102156. H.C. acknowledges the National Science Foundation Graduate Research Fellowship (GRFP), GRANT#: 1842490.

The Effect of Cold Work and Irradiation on the Dealloying Behavior of Ni-Cr Alloys in Molten Fluoride Salts

Molten salt nuclear reactor (MSR) environments present several challenges to structural materials, such as corrosion coupled with radiation damage occurring at high homologous temperatures. When a corrosion driving force exists, such as the presence of an oxidizing impurity with a half-cell redox potential higher than those of the alloying elements, selective dealloying of the less noble element (LN) in a multi-component structural alloy can occur [1]. This process can result in interesting corrosion morphologies such as the formation of a relatively uniform penetrating bicontinuous porous structures in grain interiors and penetrating dealloying along grain boundaries. Irradiation can induce solute segregation and/or saturation of non-equilibrium defects that interact with the corrosion front [2]. Currently, it remains uncertain how irradiation damage within an alloy impacts the process of molten salt dealloying, rendering the morphological instability.In this work, the corrosion dealloying behavior of Ni20Cr alloy (wt.%) was studied in molten LiF-NaF-KF (or FLiNaK) salts at 600°C. Ni20Cr alloys were subjected to two different conditions of Ni ion radiation, one carried out at 25°C and the other at 600°C, creating a peak damage depth nearing ~3µm at approximately 60 dpa. As a surrogate for microstructural damage by radiation, a separate set of Ni20Cr alloys were cold-worked to achieve reductions of thickness of 10%, 30%, and 50% which induce lattice defects in the form of dislocations. Additional samples were subjected to the identical potentiostatic holds attempted previously in molten FLiNaK in carefully selected electrochemical potential regimes where only Cr dealloying occurs in FLiNaK [2]. A porous Ni-rich ligament was formed that undergoes coarsening and densification. Electrochemical impedance spectroscopy (EIS) was used to quantify the porous structures. The pre-irradiated then post-corrosion samples were examined by scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) techniques to characterize micro and nanoscale changes in structure and composition. Irradiation produced deeper dealloying depths than observed on annealed samples. Furthermore, the roles of dislocation array and grain boundaries dislocation pile ups, which serve as short-circuit paths for outward Cr transport, during the dealloying process, were closely examined. Acknowledgment Research is primarily supported as part of the fundamental understanding of transport under reactor extremes (FUTURE), an Energy Frontier Research Center (EFRC) funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES). This work was performed in the Department of Materials Science and Engineering (DMSE) in the Center for Electrochemical Science and Engineering (CESE) at the University of Virginia. Utilization of the Malvern-Panalytical Empyrean diffractometer was supported by Nanoscale Materials Characterization Facility (NMCF) with National Science Foundation (NSF) under award CHE-2102156. H.C. acknowledges the National Science Foundation Graduate Research Fellowship (GRFP), GRANT#: 1842490.

Constraining Quasar Feedback from Analysis of the Hydrostatic Equilibrium of the Molecular Gas in Their Host Galaxies

We investigate the kinematics and dynamics of the molecular and ionized gas in the host galaxies of three Palomar-Green quasars at low redshifts, benefiting from the archival millimeter-wave interferometric and optical integral field unit data. We study the kinematics of both cold molecular and hot ionized gas by analyzing the CO and Hα data cubes, and construct the mass distributions of our sample through gas dynamics, utilizing a priori knowledge regarding the galaxy light distribution. We find no systematic offset between the stellar mass derived from our dynamical method and that from the broadband photometry and mass-to-light ratio, suggesting the consistency of both methods. We then study the kinetic pressure and the weight of the interstellar medium (ISM) using our dynamical mass model. By studying the relationship between kinetic pressure and gravitational pressure of the quasar host galaxies, we find an equivalence in the hydrostatic equilibrium states of ISM in the quasar host galaxies, similar to the result of gas equilibrium in normal star-forming galaxies, suggesting minimal quasar feedback. Regarding noncircular motion as indicative of quasar-driven outflows, we observe an exceptionally low coupling efficiency between molecular gas outflow and active galactic nucleus bolometric luminosities. These results demonstrate the marginal influence of the central engine on the properties of cold molecular gas in quasar host galaxies.

Optimizing Battery Development: Integrating Air-Controlled and Cryogenic Electron Microscopy Workflows

The global energy landscape is undergoing a profound transformation, shifting from traditional fossil fuel-based systems to sustainable, renewable energy sources like wind, solar, bioenergy, hydroelectric, and tidal energy. This transition signifies a significant evolution in global energy generation and consumption patterns, necessitating advanced energy storage solutions to manage the intermittent nature of renewables and ensure a stable and reliable energy supply. Advanced energy storage technologies, including batteries, supercapacitors, and other innovative systems, play a pivotal role in this transition by enabling effective load balancing, supporting the electrification of transportation through electric vehicles and charging infrastructure, managing peak demand, and facilitating the seamless integration of renewable energy into the grid. This evolution not only advances sustainability goals but also enhances energy security and independence. [1]Advanced analytical techniques are essential for developing energy storage systems, especially batteries, by providing critical insights into their complex chemical and physical processes. Battery materials' microstructure, composition, and operational dynamics can be explored using analytical techniques like scanning electron microscopy (SEM), focused ion beam (FIB), transmission electron microscopy (TEM), X-ray diffraction (XRD), and spectroscopy. The detailed analysis through these techniques is crucial for optimizing material properties, enhancing energy density, improving safety, and extending battery lifespan. By identifying degradation mechanisms and optimizing electrode and electrolyte materials, these techniques contribute to precise battery engineering. As demand grows for more efficient and higher-capacity batteries, these sophisticated tools are indispensable for advancing energy storage technology. [2]At Shell Technology Center Houston, we have developed air-controlled and cryogenic electron microscopy (EM) workflows for studying advanced energy storage systems in preparation for the energy transition. The air-controlled EM workflow, employing SEM, FIB, TEM, and XRD, plays a pivotal role in battery research by providing a controlled environment that prevents exposure to atmospheric elements that could alter material properties. These techniques are essential for examining the fine structural details and chemical compositions of battery components under near-native conditions. The cryo-EM workflow using SEM, FIB, and TEM is vital in battery research for studying materials and interfaces sensitive to environmental conditions or rapid degradation upon exposure. These cryogenic techniques involve rapid freezing of battery components to preserve their structure in a close-to-native state and prevent deleterious effects of air exposure such as oxidation or moisture interaction. [3]In our study, we present comprehensive results obtained using both air-controlled EM and cryogenic EM workflows to investigate advanced energy storage systems, including lithium-ion batteries (LIBs) and beyond-LIBs such as multivalent rechargeable batteries. The utilization of air-controlled EM techniques such as SEM, FIB, TEM, and XRD allows us to examine battery components under controlled environmental conditions, ensuring accurate analysis of structural details and chemical compositions without the risk of atmospheric contamination. Additionally, the use of cryo-EM techniques, including cryo-SEM, cryo-FIB, and cryo-TEM, enables the study of sensitive battery materials and interfaces in a preserved, near-native state. These cryogenic methods prevent degradation effects such as oxidation and moisture interaction, providing unprecedented insights into the ultrastructural properties and operational dynamics of battery materials at atomic or molecular levels. By leveraging both air-controlled and cryogenic EM workflows, we have achieved a comprehensive understanding of battery mechanics and chemistry, paving the way for improved battery design and enhanced performance in energy storage applications.Reference[1] International Renewable Energy Agent (IRENA) 2021 https://www.irena.org/publications/2021/Aug/Renewable-energy-statistics-2021[2] Tarascon, J.-M., Armand, M., Nature 414, 359–367 (2001). https://doi.org/10.1038/35104644[3] Cheng, D., Lu, B., Raghavendran, G., Zhang, M., and Meng, Y. S., Matter, Volume 5, Issue 1, p26-42, 2022 https://doi.org/10.1016/j.matt.2021.11.019

(Invited) Marine Plastic Waste-Based Supercapacitors for Saving Remote Island

Marine plastic waste is a global environmental issue that needs urgent attention as it adversely affects the environment and living organisms, including human beings. More than 32–280 million metric tons of plastic are produced every year; however plastic production decreased in 2020 owing to a drop in demand caused by COVID-19[1-4]. Plastic production is expected to reach 53 million metric tons by 2030[5] and 155–265 million metric tons by 2060[3]. As the amount of plastic waste from sources other than packaging is decreasing, most of the waste is not treated as waste and is discharged into the ocean. Approximately 4.7–12.7 million metric tons of plastic waste is dumped into the sea annually[4,6], covering an area of 1.6 million km2[2]. About 150 million tons of plastic waste is reportedly present in the sea, which will likely remain in the sea until at least 2050. Properties of plastic further exacerbate this problem. Plastic shopping bags take more than a thousand years to completely decompose naturally, and plastics that have once entered the sea continue to harm the environment for an extremely long time[7]. Approximately 700 species, including endangered marine species, have been injured and killed[8]. Such deaths were attributed to glass and trees in the past; however, in recent years, 92% of these deaths have occurred owing to marine plastic waste/microplastic particles[8-10]. The effects of plastic waste and microplastic particles also affect coral reefs[11] and the Arctic[12]. This research will increase the applicability of activated carbon (AC) in marine plastic recycling. However, marine plastics are a mixture of various plastics, and it is difficult to recycle all of them from deposits, additives, and paints. Therefore, a recycling destination with high added value is required. In contrast, applications of AC have evolved from those in improving water quality to those in electrode materials, and especially as a storage battery. Its application prospects differ from other storage batteries in terms of charge and discharge characteristics; therefore, it is regarded as a power storage device whose demand will continue to rise in the future. Moreover, impurities in the electrode materials of ordinary secondary batteries can have a large adverse effect on battery capacity, internal resistance, and cycle life. Supercapacitors with carbon electrodes can be charged and discharged even if some impurities are present. Therefore, this study presented the production of AC as one of the treatment methods for marine plastic waste and evaluated the performance of AC and its performance as a supercapacitor electrode. The aim of this study was to develop methods to manage marine plastic waste (Fig.1(A)) through the production of activated carbon (AC). The specific surface area, micropore volume, and mesopore volume of marine plastic AC prepared under arbitrary temperature and activator weight ratio were measured (Fig1(B),(C)), and the specific capacitance and supercapacitor electrode performance were evaluated. At an activation temperature of 800 °C and a weight ratio of 1:7 between the raw material and 8 M KOH solution, a specific capacitance of 201 F/g and a high surface area of 2389 m2/g were obtained. Accordingly, marine plastic waste-based AC can be used as the electrode material in supercapacitors.[1] C. M. Rochman, et al., Policy: Classify plastic waste as hazardous, Nature 494 (2013), 169–171.[2] L. Lebreton, et al., Evidence that the Great Pacific Garbage Patch is rapidly accumulating plastic, Sci. Rep. 8 (2018), 4666.[3] L. Lebreton, A. Andrady, Future scenarios of global plastic waste generation and disposal, Palgrave Commun. 5 (2019), 6.[4] J. R. Jambeck, et al., Marine pollution. Plastic waste inputs from land into the ocean, Science 347 (2015), 768–771.[5] T. M. Adyel, Accumulation of plastic waste during COVID-19, Science 369 (2020), 1314–1315.[6] E. MacArthur, Beyond plastic waste, Science 358 (2017), 843.[7] C. Giacovelli, Single-use plastics: A roadmap for sustainability. International Environmental Technology Centre (2018).[8] S. C. Gall, R. C. Thompson. The impact of debris on marine life. Mar. Pollut. Bull. 92 (2015), 170–179.[9] O. M. Lonnstedt, P. Eklov, Environmentally relevant concentrations of microplastic particles influence larval fish ecology, Science 352 (2016), 1213–1216.[10] Animal behaviour: Plastic smells good to marine birds, Nature 539 (2016), 332.[11] J. B. Lamb, et al., Plastic waste associated with disease on coral reefs, Science 359 (2018), 460–462.[12] M. Bergmann, et al., Plastic pollution in the Arctic, Nat. Rev. Earth Environ. 3 (2022), 323–337. Figure 1

(Invited) Low-Temperature Processing of Mixed Conducting Oxides: Control of Defects, Transport, and Reactions Away from Equilibrium

Low-to-intermediate temperature processing and use of mixed conducting oxides targets the following potential benefits: ultra-fine nanostructuring with avoidance of coarsening, control of surface chemistry, lower energy consumption, integration with thermally sensitive components, and slower degradation vs. conventional high temperature synthesis and use. In this lower temperature regime, we have pursued two routes for non-equilibrium control of defect chemistry and therefore properties of mixed ionic/electronic conductors (MIECs) in the ferrite perovskite family: crystallization and illumination.Room-temperature growth followed by mild anneals to induce crystallization has proven to yield superior oxygen surface exchange kinetics, attributed to development of facile charge transfer and pristine surface chemistry in our prior work. The close link between crystallinity and oxygen stoichiometry appears to play an important role in the structural evolution and electrical response. However the effect of evolving crystallinity on the ionic conductivity has not been studied in-depth. Therefore we recently pursued an approach combining in-situ synchrotron grazing-incidence X-ray diffraction with ac and dc electrical methods on thin-film blocking electrode cells to evaluate evolution of transference numbers during crystallization. In certain ferrite films we observe a ~2 orders-of-magnitude increase in ionic conductivity during crystallization, while the electronic conductivity increases much more. Through the process, we demonstrate that it is possible to turn a predominantly ionic conductor into a predominantly electronic conductor - and to access almost any ionic transference number in between - simply by controlling the degree of crystallinity. [1]Oxygen stoichiometry can alternatively be controlled at low-to-intermediate temperatures through application of low fluence above-gap illumination. We have shown in certain non-dilute ferrite films that UV light causes oxygen to enter the films from the gas phase with kinetics limited by the oxygen surface-exchange reaction, which is largely unchanged by the presence of excited carriers. We explain the response through simulations of excited state defect equilibria and transient absorption spectroscopy measurements. [2]Together these processing strategies indicate that low-temperature control of oxygen stoichiometry is feasible in mixed conductors, enabling wide tailoring of properties and potential for use in low-to-intermediate temperature solid-state ionic devices.[1] H.B. Buckner, J. Simpson-Gomez, A. Bonkowski, K. Rubartsch, H. Zhou, R.A. De Souza, N.H. Perry (in review)[2] E. Skiba, H.B. Buckner, G. McKnight, C. Lee, R. Wallick, R. van der Veen, E. Ertekin, N.H. Perry (in review)We gratefully acknowledge funding from the US Department of Energy, Basic Energy Sciences, under DOE Early Career grant DE-SC-0018963 and from the US National Science Foundation, through the University of Illinois at Urbana-Champaign Materials Research Science and Engineering Center DMR-2309037.

A CIGALE module tailored (not only) for low-luminosity active galactic nuclei

The spectral energy distribution (SED) of low-luminosity active galactic nuclei (LLAGN) presents unique challenges as the emission from these objects is comparable to the radiation from their host galaxy and the accretion physics involved is particularly complex. This study introduces a novel CIGALE module specifically designed to address these challenges. The module combines the empirical $L_ X $--$L_ m $ relationship with physically motivated accretion models, such as advection-dominated accretion flows (ADAFs) and truncated accretion disks, providing a more accurate depiction of LLAGN central engine emission. A mock analysis of the module revealed good recovery of true parameters, with only a slight bias toward higher input values, further validating its reliability. We tested the module on a sample of 50 X-ray-detected local galaxies, including low-ionization nuclear emission-line regions (LINERs) and Seyferts, and demonstrated its capacity to accurately estimate bolometric luminosities, even in the presence of significant galaxy contamination. Notably, the previous X-ray module failed to provide AGN solutions for this sample, stressing the need for a novel approach. Comparisons with mid-luminosity AGN datasets confirm the module’s robustness and applicability up to $L_ X $ erg/s. We also expanded the X-ray-to-bolometric correction formula, making it applicable to AGN spanning ten orders of magnitude in luminosity, and revealing lower $k_ X $ values for LLAGN than typically assumed. Additionally, our analysis of the $ ox $ index, which represents the slope between UV and X-ray emissions, uncovered trends that differ from those observed in high-luminosity AGN. Unlike quasars, where $ ox $ correlates with $ Edd $, LLAGN exhibit nearly constant or weakly correlated $ ox $ values, suggesting a shift in accretion physics and photon production mechanisms in low-luminosity regimes. These results underscore the importance of a multiwavelength approach in AGN studies and reveal distinct behaviors in LLAGN compared to quasars. Our findings significantly advance our understanding of LLAGN and offer a comprehensive framework for future research to complete the AGN population census.

Impact of different range bias corrections on orbit and Earth rotation parameters determination using BDS-3 satellite laser ranging observations

Abstract Satellite laser ranging (SLR) is an important technique that determines geodetic parameters, and its observation processing often calibrates range bias corrections to offset systematic errors. However, the impact of different range bias calibration methods on estimating the BDS-3 satellite orbit and Earth Rotation Parameters (ERP) has not been fully studied. The aim of this study is to explore the impact of employing different SLR range bias corrections on the accuracy of SLR-based BDS-3 satellite orbit and ERP. Eight months of experimental analysis revealed that the station–satellite-pair-dependent range bias correction resulted in the optimal orbit accuracy. Regarding orbit differences relative to precise ephemerides and overlap differences, the 3D root-mean-square (RMS) of satellites manufactured by the China Academy of Space Technology (CAST) are 1.00 and 0.94 m, respectively. The corresponding values of satellites manufactured by the Shanghai Engineering Center for Microsatellites (SECM) are 0.98 and 0.90 m, respectively. The station–satellite-pair-dependent range bias correction performed the best in terms of pole coordinate accuracy. The RMS of the X P and Y P differences relative to the International Earth Rotation and Reference Systems Service (IERS) 20 C04 product are 1.32 and 1.41 mas, respectively. The solution using satellite-dependent range bias corrections has the optimal length of day (LOD) accuracy, with a 44.92 μs rms of the LOD difference. However, due to the apparent satellite-related error characteristic reflected in the SLR residual, the station-dependent range bias correction is unsuitable for simultaneously processing the SLR observations of all BDS-3 satellites.

The Composite Spectral Energy Distribution of Quasars Is Surprisingly Universal Since Cosmic Noon

Leveraging the photometric data of the Sloan Digital Sky Survey and the Galaxy Evolution Explorer (GALEX), we construct mean/median spectral energy distributions (SEDs) for unique bright quasars in redshift bins of 0.2 and up to z≃3, after taking the GALEX non-detection into account. Further correcting for the absorption of the intergalactic medium, these mean/median quasar SEDs constitute a surprisingly redshift-independent mean/median composite SED from the rest-frame optical down to ≃500 A˚ for quasars with bolometric luminosity brighter than 1045.5ergs−1. Moreover, the mean/median composite quasar SED is plausibly also independent of black hole mass and Eddington ratio, and suggests similar properties of dust and gas in the quasar host galaxies since cosmic noon. Both the mean and median composite SEDs are nicely consistent with previous mean composite quasar spectra at wavelengths beyond ≃1000 A˚, but at shorter wavelengths, are redder, indicating, on average, less ionizing radiation than previously expected. Through comparing the model-predicted to the observed composite quasar SEDs, we favor a simply truncated disk model, rather than a standard thin disk model, for the quasar central engine, though we request more sophisticated disk models. Future deep ultraviolet facilities, such as the China Space Station Telescope and the Ultraviolet Explorer, would prompt revolutions in many aspects, including the quasar central engine, production of the broad emission lines in quasars, and cosmic reionization.

PKS 1424-418: A persistent candidate source of the mm--gamma -ray connection?

We present a long-term strong correlation between millimeter (mm) radio and gamma -ray emission in the flat-spectrum radio quasar (FSRQ) PKS\,1424$-$418. The mm --gamma -ray connection in blazars is generally thought to originate from the relativistic jet close to the central engine. We confirm a unique long-lasting mm --gamma -ray correlation of PKS\,1424$-$418 by using detailed correlation analyses and statistical tests, and we find its physical meaning in the source. We employed sim 8.5\,yr of (sub) mm and gamma -ray light curves observed by ALMA and Fermi -LAT, respectively. From linear and cross-correlation analyses between the light curves, we found a significant, strong mm --gamma -ray correlation over the whole period. We did not find any notable time delay within the uncertainties for the mm --gamma -ray correlation, which means zero lag. The mm wave spectral index values (S$_ nu alpha between the band 3 and 7 flux densities indicate a time-variable opacity of the source at (sub)mm wavelengths. Interestingly, the mm wave spectral index becomes temporarily flatter (i.e., alpha \,$&gt;$\,$-$0.5) when the source flares in the gamma -rays. We relate our results with the jet of PKS\,1424$-$418 and we discuss the origin of the gamma -rays and opacity of the inner (sub)parsec-scale jet regions.

A comprehensive approach to building a continuous hydrologic model with Soil Moisture Accounting using Earth Observation data

ABSTRACT In recent years, both availability and interest in Earth Observations (EO) have increased due to their ability to provide information with extensive spatial coverage, which is valuable for data-scarce regions. This study provides a roadmap to exploit EO/satellite data (EO-based model) for continuous hydrological simulation using the Hydrologic Engineering Center–Hydrologic Modelling System model with a soil moisture accounting (SMA) component. As a case study, we consider the Boeotikos Kephisos River basin, in Greece. The SMA component is calibrated using the HiHydroSoils dataset, to map its parameters to the regionally varying soil hydraulic properties and a comparison is made to an alternative parameterization, following the standard literature approach (literature-based model). The effectiveness of satellite data in enhancing model performance is further assessed, by comparing three different satellite precipitation datasets, as model drivers, and by using satellite-based soil moisture for model initialization. The discussion extends to the potential for integration of EO/satellite data at the operational level, by simulating a significant precipitation event. Yet, the most promising result pertains to the opportunity to exploit satellite-derived estimates of soil hydraulic properties to base the calibration of the data-intensive SMA scheme, with the EO-based model significantly outperforming the literature-based model parameterization.

Silver-Platinum Hollow Nanoparticles as Labels for Colorimetric Lateral Flow Assay

Article Silver-Platinum Hollow Nanoparticles as Labels for Colorimetric Lateral Flow Assay Jinfeng Zhou 1, Shikuan Shao 1, Zhiyuan Wei 1 and Xiaohu Xia 1,2,* 1 Department of Chemistry, University of Central Florida, Orlando, FL 32816, USA 2 NanoScience Technology Center, University of Central Florida, Orlando, FL 32816, USA * Correspondence: xiaohu.xia@ucf.edu Received: 23 September 2024; Revised: 7 November 2024; Accepted: 12 November 2024; Published: 18 November 2024 Abstract: Colorimetric lateral flow assay (CLFA) has been a widely recognized point-of-care testing technology over the past few decades. Driven by the increasing demand in various biomedical applications, it is urgently needed to develop CLFAs with high sensitivities and low costs. In this work, we report a type of CLFA that relies on unique colorimetric labels—silver-platinum hollow nanoparticles (Ag-Pt HNPs). The Ag-Pt HNPs possess intrinsic enzyme-like catalytic activities, providing the Ag-Pt HNP-based CLFA with strong color signal and thus a high sensitivity. Meanwhile, the Ag-Pt HNPs have hollow interiors and are mainly composed of less expensive silver, making the Ag-Pt HNP-based CLFA cost-effective. Using prostate-specific antigen (PSA) as a model disease biomarker, the Ag-Pt HNP-based CLFA achieved a high sensitivity with a detection limit at the low picogram-per-milliliter level. Potential application of the CLFA in clinical diagnosis was demonstrated by detecting PSA from human serum samples.

Glacial lake outburst flood (GLOF) modeling of Tsho Rolpa glacial lake, Nepal

Abstract. In recent decades, the Tsho Rolpa glacial lake has witnessed a significant increase in its surface area. Situated in the Eastern Himalayas at an elevation of 4552 m a.s.l. (meters above sea level), this lake has drawn attention due to the potential risks of glacial lake outburst floods (GLOFs). To comprehensively study and prepare for future GLOF events from Tsho Rolpa, advanced modeling techniques were employed, utilizing the National Weather Service BREACH (NWS-BREACH) and Hydrologic Engineering Center's River Analysis System (HEC-RAS) models. The assessment included the evaluation of dam breach scenarios, especially 20 and 40 m breaches, using the NWS-BREACH model to estimate breach hydrographs. This analysis revealed peak flow rates ranging from 8198 to 26 662 m3 s−1 for the respective breaching scenarios. Additionally, considering a change in the lake area over 20 to 40 years, the peak flow ranged from 8226 to 10 662 m3 s−1 for the 20 m breach scenario. The peak flow estimates obtained from NWS-BREACH were subsequently integrated into the HEC-RAS model to simulate peak discharge and flood heights at varying distances downstream of the lake outlet. To understand the consequences of a GLOF, the impact on downstream areas was assessed through flood inundation maps, and precautionary measures are recommended.

SN 1054 as a pulsar-driven supernova: implications for the crab pulsar and remnant evolution

ABSTRACT One of the most studied objects in astronomy, the Crab Nebula, is the remnant of the historical supernova SN 1054. Historical observations of the supernova imply a typical supernova luminosity, but contemporary observations of the remnant imply a low explosion energy and low ejecta kinetic energy. These observations are incompatible with a standard $^{56}$Ni-powered supernova, hinting at an an alternate power source such as circumstellar interaction or a central engine. We examine SN 1054 using a pulsar-driven supernova model, similar to those used for superluminous supernovae. The model can reproduce the luminosity and velocity of SN 1054 for an initial spin period of $\sim$14 ms and an initial dipole magnetic field of 10$^{14-15}$ G. We discuss the implications of these results, including the evolution of the Crab pulsar, the evolution of the remnant structure, formation of filaments, and limits on freely expanding ejecta. We discuss how our model could be tested further through potential light echo photometry and spectroscopy, as well as the modern analogues of SN 1054.

Update from the Entertainment Technology Center

As the work of the Entertainment Technology Center (ETC) at the University of Southern California (USC) moves into its fourth decade, the Center continues its role as a critical industry contributor to the Media and Entertainment (M&amp;E) industry's understanding and adoption of new technologies, creating programs, industry working groups, proof of concepts and full implementations to analyze and test their potential impact in the broader industry. Operating as a unique industry think tank, with funding and strategic participation by major studios and leading technology companies, including both traditional legacy and new industry entrants, the ETC drives collaborative projects among its member companies and engages with next-generation consumers to understand the impact of emerging technology on all aspects of the M&amp;E industry, especially technology development and implementation, creative process, business and workflow models, and future trends.

Refined subsidence monitoring and dynamic prediction in narrow and long mining areas based on InSAR and probabilistic integral method

Continuous exploitation in mining areas damages the surrounding environment and has various severe geological impacts. Hence, long-term monitoring of mining areas is crucial to reducing these impacts. Differential interferometric synthetic aperture radar (D-InSAR) is widely applied to monitor the subsidence in mining areas, but it cannot obtain accurate large-gradient subsidence result in the centre of the subsidence basin in mining areas due to the de-coherence phenomenon. The probability integral method (PIM) is a prediction method that can cooperate with D-InSAR (D-InSAR PIM, DPIM) to solve the problem. However, with this method, there is early convergence of the edge subsidence in narrow and long mining areas. Moreover, the PIM can only predict the spatial domain; it cannot achieve dynamic prediction. To address the above problems in the traditional DPIM data processing process, in this study, firstly, the traditional PIM was improved by adjusting the radius of the parameter and constructed an improved DPIM (IDPIM) method. The hybrid algorithm was applied to solve the parameters of the IDPIM method and then acquire subsidence results, thus solving the early convergence of edge subsidence problem characteristic of traditional PIM prediction in mining. Additionally, an area-weighting based fusion method was proposed to integrate the IDPIM results and the D-InSAR results (Area-weighting based fusion of the IDPIM and D-InSAR results, AFID) achieving whole-basin refined subsidence in mining areas. Secondly, based on a summary of subsidence laws in mining areas, the Hossfeld model was introduced and combined with the IDPIM method (IDPIM Hossfeld, IDPIM-H) to construct a subsidence dynamic prediction method. This achieved dynamic prediction of the subsidence in mining areas. A coal mine in Ordos was used as the study area, and the feasibility of the IDPIM method, the AFID method and the DPIM-H method was verified through a comparative analysis of leveling data. The results demonstrated that: (1) The results of the IDPIM method showed 8% and 66% improvement in RMSE along the striking and dip lines, respectively, over the D-InSAR results, improving the early convergence of the DPIM along the dip direction of the mine. (2) The results of the AFID method provide a 69% improvement in whole-basin RMSE over the D-InSAR results, which improves the lack of monitoring capacity in the D-InSAR technology center. (3) The results of the DPIM-H method provide a 35% improvement in basin-wide RMSE over the D-InSAR results, solving the problem of low temporal resolution of the D-InSAR technology and realizing the dynamic prediction with high temporal resolution. These findings provide a theoretical basis for future refined exploration of dynamic subsidence in mining areas

Possibility of enteral tube feeding in severe surgical pathology

Objective. To study the possibility of using new GASTROAXILIUM mixtures in complex therapy of patients with severe surgical abdominal pathology. Materials and methods. The study of characteristics of the developed mixtures was carried out by standard and non-standard methods in an accredited laboratory. Clinical studies were conducted in accordance with the Procedure for conducting studies of the effectiveness of specialized dietary therapeutic and dietary preventive food products. Statistical processing was carried out using analysis of variance. Results. GASTROAXILIUM, specialized food product for tube feeding developed by the specialists of the Research and Production Center for Healthy Nutrition Technologies of Saratov State Medical University named after V.I. Razumovsky, differs from foreign ones in its technological solutions. In the main group a statistically significant reduction in the duration of postoperative intestinal paresis was noted, both in planned and emergency surgeries, in contrast to the comparison group. Conclusions. We consider that the results of the use of daily nutritional complex of oligomeric dry mixtures for enteral nutrition GASTROAXILIUM are in agreement with the literature data, they will successfully complement the scientific data on the necessity for nutritional support and will play an important role in improving the quality of treatment of patients with severe postoperative abdominal pathologies.

A pragmatic approach to building a field and doing STS

The last scholar featured in our anniversary issue is professor emeritus Knut H. Sørensen. Sørensen has a decades long history working in science and technology-studies and played a key role in establishing the Centre for Technology and Society at the Department of interdisciplinary studies of culture (KULT) at NTNU. Sørensen is one of several key contributors to STS and in this interview, we will draw insights from his long career and explore STS as a changing field. Sørensen has witnessed the starting point, the development, as well as many changes in this field throughout his career. In this interview he reflects on how the field has developed and how it is a story about building STS institutions, and the many strategic choices it involves. We are reminded of how the making of science involves specific people, doing specific things at specific times and places. It is a chance to see behind a name put in as “standard citation” and see a person who combined ambition and pragmatism with hard work to make something happen. Revisiting the history of our field is also a chance to remind ourselves of how different things could have turned out; if they hadn’t come across that specific paper or hadn’t received funding at that time. In this interview we will touch on important contributions, about being pragmatic with external funding and research topics, how STS has changed as a field, the importance of advising and investing in students and what life is like now as an emeritus.

Increasing the effectiveness of total-skin electron beam therapy by reducing the manifestations of radiation dermatitis in patients with primary lymphomas. A comparative randomized prospective study

Background. One of the main adverse events that significantly reduce the quality of life of patients and limit the total focal dose is radiation-induced skin reactions (RISR). Their timely diagnosis, prevention, and treatment remain urgent tasks of modern radiotherapy. Aim. To improve the effectiveness of total skin irradiation (TSI) in patients with primary skin lymphomas by reducing the clinical manifestations of RISR by using additional therapy with a hydrogel containing active components with vasoprotective and anti-inflammatory action. Materials and methods. A comparative randomized prospective study was conducted, including data from 52 patients who received electron TSI by conventional fractionation at a total focal dose of 14 to 30 Gy for primary cutaneous lymphomas at the Granov Russian Research Center of Radiology and Surgical Technologies from September 2021 to January 2024. Before the first TSI session, during treatment and 2 weeks after the end of radiation therapy, all patients underwent assessment for RISR, quantitative assessment of various degrees of severity of radiodermatitis using instrumental methods and assessment scales; for the observation group, a therapeutic regimen for the prevention and treatment of RISR was used, including a hydrogel with troxerutin (2%) and trolamine (0.07%), and in the control group, basic skin care using moisturizers. Results. Analysis of the physiological parameters of the skin showed statistically significant differences between the study groups: patients of the study group (group I; 30 subjects receiving the above-mentioned therapeutic regimen) compared with the control group (group II; 28 subjects who did not receive specific treatment for radiodermatitis) reported significantly lower rates of erythema (386±12.3 and 572±14.4; p=0.005), transepidermal water loss (25±0.3 and 38±0.4 g/m2/h; p0.001) and a decrease in peak endothelial-dependent vasodilation of microvasculature and blood flow in the skin. A lower proportion of severe radiodermatitis (86.3 and 73.3%; p0.05) and a statistically significant difference in the subjective quality of life scores by the 29-point Skindex-29 scale by an average of 22.2% were also found. Conclusion. A comparative analysis of the quantitative indicators of radiodermatitis in the study group and the control group showed that the topical application of the hydrocolloid gel containing troxerutin and trolamine reduces the clinical manifestations of RISR concerning objectively measured physiological parameters of the skin and blood flow parameters of the microvasculature measured by high-frequency ultrasound, thus improving the quality of life of patients during and after the course of radiation therapy.

TMIC-82. CHARACTERIZATION OF GENETIC MARKERS AND BIOLOGICAL PROCESSES UNDERLYING THE TRANSITION OF GLIOBLASTOMA CELLS FROM A DIFFERENTIATED TO A STEM-CELL-LIKE STATE

Abstract BACKGROUND The main drivers of Glioblastoma (GBM) tumor growth are elevated angiogenesis and heightened characteristics of stemness. These driving factors make GBM an extremely invasive and aggressive tumor. While the GBM tumor microenvironment can be classified into several molecular subtypes, one common characteristic is the atypical induction of various signal transduction pathways including the receptor tyrosine kinases (RTKs), pro-angiogenic, and stem-cell-determining transcription factors, which all play important roles in GBM tumor formation, growth, and progression. OBJECTIVE To investigate the regulations of RTKs, pro-angiogenic, and stem-cell–determining transcription factors in two different tumor environments - monolayer cultures that induce a more differentiated state and neurosphere cultures that select for stem-like cells. METHODS Neurosphere- and monolayer-forming cell samples were cultured from four primary GBM cell lines including HK-336, HK-374, U87, and GS-154. RNA sequencing was performed at the Technology Center for Genomics and Bioinformatics at the University of California, Los Angeles. The transcriptomic data findings were validated by qPCR and western blot assays. RESULTS Our transcriptomic data revealed the significant upregulation of EGFR, PDGFR-α, VEGFA, and SOX2 in the neurosphere-forming HK-336, HK-374, U87, and GS-154 primary GBM cells. Consistent with the transcriptomic data, western blot, and qPCR assays demonstrated significantly higher expressions of these genes in the neurosphere-forming compared to the monolayer-forming GBM cells. Neurosphere-forming GBM cells possess stem-cell-like characteristics with the ability to self-renew and differentiate via the induction of various genes and disease progression pathways. CONCLUSIONS Neurosphere-forming GBM cells demonstrate upregulation of SOX2, EGFR, PDGFR-α, and VEGFA in RNA sequencing, western blot, and qPCR assays. Multipotent drug therapies designed to target multiple gene regulation pathways involving RTKs, pro-angiogenic, and stem-cell-determining transcription factors may be necessary to effectively treat GBM. Understanding the underlying mechanisms driving these aberrant cellular pathways could provide valuable insights for developing targeted therapies against this aggressive brain cancer.