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Measurement of the depth of maximum of air-shower profiles with energies between 1018.5 and 1020 eV using the surface detector of the Pierre Auger Observatory and deep learning
No full textWe report an investigation of the mass composition of cosmic rays with energies from 3 to 100 EeV (1 EeV=1018 eV) using the distributions of the depth of shower maximum Xmax. The analysis relies on ∼50,000 events recorded by the surface detector of the Pierre Auger Observatory and a deep-learning-based reconstruction algorithm. Above energies of 5 EeV, the dataset offers a 10-fold increase in statistics with respect to fluorescence measurements at the Observatory. After cross-calibration using the fluorescence detector, this enables the first measurement of the evolution of the mean and the standard deviation of the Xmax distributions up to 100 EeV. Our findings are threefold: (i) The evolution of the mean logarithmic mass toward a heavier composition with increasing energy can be confirmed and is extended to 100 EeV. (ii) The evolution of the fluctuations of Xmax toward a heavier and purer composition with increasing energy can be confirmed with high statistics. We report a rather heavy composition and small fluctuations in Xmax at the highest energies. (iii) We find indications for a characteristic structure beyond a constant change in the mean logarithmic mass, featuring three breaks that are observed in proximity to the ankle, instep, and suppression features in the energy spectrum
Advances in Conductive Polymer-Based Flexible Electronics for Multifunctional Applications
Full text linkThe rapid developments in conductive polymers with flexible electronics over the past years have generated noteworthy attention among researchers and entrepreneurs. Conductive polymers have the distinctive capacity to conduct electricity while still maintaining the lightweight, flexible, and versatile characteristics of polymers. They are crucial for the creation of flexible electronics or gadgets that can stretch, bend, and adapt to different surfaces have sparked momentous interest in electronics, energy storage, sensors, smart textiles, and biomedical applications. This review article offers a comprehensive overview of recent advancements in conductive polymers over the last 15 years, including a bibliometric analysis. The properties of conductive polymers are summarized. Additionally, the fabrication processes of conductive polymer-based materials are discussed, including vacuum filtering, hydrothermal synthesis, spray coating, electrospinning, in situ polymerization, and electrochemical polymerization. The techniques have been presented along with their advantages and limitations. The multifunctional applications of conductive polymers are also discussed, including their roles in energy storage and conversion (e.g., supercapacitors, lithium-ion batteries (LIBs), and sodium-ion batteries (SIBs)), as well as in organic light-emitting diodes (OLEDs), organic solar cells (OSCs), conductive textiles, healthcare monitoring, and sensors. Future scope and associated challenges have also been mentioned for further development in this field
Attitudes Toward the Continued Protection of Grizzly Bears Under the Endangered Species Act
Full text linkIn January 2025, the U.S. Fish & Wildlife Service published a proposed rule to continue protecting grizzly bears in the contiguous United States under the Endangered Species Act (ESA). The proposed rule and guidance for how the public can comment on the proposed rule can be found at this link: https://www.fws.gov/press-release/2025-01/usfws-proposes-update-grizzly-bear-esa-listing-management
In January 2025, we implemented a web-based survey designed to assess the attitudes of residents of the contiguous United States, as they pertain to the appropriateness of continuing protection of grizzly bears under the ESA. A large body of prior research indicates that individuals’ attitudes toward species protections can be affected by a variety of factors. As such, a key feature of this survey was understanding how attitudes about continued protections are affected by different kinds of information about grizzly bears and their protection
Multi-instrument sounding of a Jovian thunderstorm from Juno
No full textThunderstorms play a significant role in transporting heat from the deep interior to space on giant planets. We present observations of a 3,400-km wide thunderstorm complex in Jupiter\u27s North Equatorial Belt (NEB) during the 38th periapse of the Juno spacecraft on 29 Nov. 2021. Data were acquired by the Microwave Radiometer (MWR), the visible light JunoCam instrument, the Jovian InfraRed Auroral Mapper (JIRAM), and from supporting Earth-based imaging. This was the first time Juno was able to observe a thunderstorm at suitably low emission angles with multiple instruments at close range (∼5,690 km), making it the most comprehensive close-up assessment of a Jovian thunderstorm to date. Lightning detection confirmed the Storm\u27s vigorous convective nature. MWR brightness temperatures indicate this Storm appears to be wholly contained within the weather layer, i.e., no deeper than the expected base of the H2O cloud, and not as a result of any detected deep-seated upwelling beneath the H2O cloud base. Earth-based observations tracked it over its ∼ 2-week lifespan, providing evidence that mesoscale-to-synoptic-scale forcing mechanisms were involved in sustaining it, including the intriguing possibility of a humidity front (‘dryline’), a sharp gradient in the vapor abundance, promoting lift along a concentrated region
Highly efficient MnNi@NC catalyst for PMS Activation: A Dual-Radical system for sulfamethoxazole degradation in Chloride-Rich wastewater
No full textIn this study, carbon nanotubes (CNTs) doped manganese (Mn) and nickel (Ni) hypervalent metals (MnNi@NC) were synthesized using a two-step pyrolysis strategy. The resulting catalyst was employed to activate peroxymonosulfate (PMS) for the degradation of sulfamethoxazole (SMX). Degradation experiments revealed that 900MnNi@NC exhibited exceptional catalytic activity, achieving a 97.8 % degradation rate of SMX. Mechanistic investigations demonstrated that the degradation process was primarily driven singlet oxygen (1O2) and superoxide radical (O2·-), as confirmed through electron paramagnetic resonance (EPR) spectroscopy and quenching tests. X-ray photoelectron spectroscopy analysis attributed the excellent catalytic performance of 900MnNi@NC to the presence of hypervalent Mn and Ni species, along with abundant nitrogen functionalities. Further stability tests, including variations in pH, the presence of anions, diverse pollutants, and repeated cycles, demonstrated the robust environmental tolerance of the 900MnNi@NC/PMS system. Remarkably, chloride ions (Cl−) were found to significantly enhance SMX degradation. EPR data indicated that the addition of Cl− boosted the generation of O2·-, highlighting the system\u27s potential for treating industrial wastewater containing Cl−. Density functional theory calculations further revealed that the incorporation of bimetallic catalysts increased PMS adsorption energy, extended the O-O bond length, facilitated charge transfer, and ultimately improved degradation performance
Land use change and forest management affect soil carbon stocks in the central hardwoods, U.S.
No full textMost research addressing land use change and forest management effects on soil carbon (C) is conducted at large or localized scales, rather than intermediate scales where management is planned and implemented. We assessed effects of land use and forest management on soil C stocks, for the Central Hardwoods ecoregion of the U.S., using meta-analysis, soil survey and national forest inventory databases to examine baseline controls on soil C stocks and their responses to land use and forest management. Biotic and geologic factors drive baseline variation in soil C stocks across the ecoregion, with forest type and productivity being most important in surface horizons and parent material dominating at the whole profile level. Among forest management treatments, prescribed fire is most noteworthy, decreasing O horizons to an extent determined by place and practice (mean: −53 %). Coal mine reclamation is extensive in the region, and while there is no effect of forest vs. herbaceous reclamation, distinct overburden types have different effects on soil C stocks (mean: +183 %). Land use change effects on soil C are difficult to determine due to the preferential use of the most favorable soils for agriculture, the relegation of forests to the least productive soils, and the tendency for reforestation to occur on marginal soils. Overall, our results can help forest managers anticipate the C outcomes of typical burn prescriptions in this region of extensive prescribed fire, and help landowners and planners understand how parent material and soil properties influence soil C stocks under agriculture and mine reclamation
Absence of TeV halos around millisecond pulsars
No full textTeV halos are extended very-high-energy (VHE; 0.1-100 TeV) gamma-ray emission around middle-aged pulsars. So far they have only been found around isolated pulsars, but it has been suggested that they may also be powered by millisecond pulsars (MSPs). We searched for VHE gamma-ray emission from MSPs reported by radio and GeV gamma-ray observatories in 2565 days of data from the High Altitude Water Cherenkov (HAWC) Observatory. We found no significant emission from individual pulsars. By combining the likelihood profiles of all MSPs accessible to HAWC, our analysis suggests that the excess emission around the MSP population is consistent with a background. Our result suggests that MSPs are not as efficient as isolated pulsars in producing TeV halos. This finding has strong implications on the physics interpretation of the Galactic Center GeV excess and high-latitude Galactic diffuse emission
Study of Long-term Spectral Evolution and X-Ray and γ-Ray Correlation of Blazars Seen by HAWC
No full textThe HAWC Observatory collected 6 yr of extensive data, providing an ideal platform for long-term monitoring of blazars in the very high energy (VHE) band, without bias toward specific flux states. HAWC continuously monitors blazar activity at TeV energies, focusing on sources with a redshift of z ≤ 0.3, based on the Third Fermi-LAT Catalog of High-Energy sources. We specifically focused our analysis on Mrk 421 and Mrk 501, as they are the brightest blazars observed by the HAWC Observatory. With a data set of 2143 days, this work significantly extends the monitoring previously published, which was based on 511 days of observation. By utilizing HAWC data for the VHE γ-ray emission in the 300 GeV-100 TeV energy range, in conjunction with Swift-XRT data for the 0.3-10 keV X-ray emission, we aim to explore potential correlations between these two bands. For Mrk 501, we found evidence of a long-term correlation. Additionally, we identified a period in the light curve where the flux was very low for more than 2 yr. On the other hand, our analysis of Mrk 421 measured a strong linear correlation for quasi-simultaneous observations collected by HAWC and Swift-XRT. This result is consistent with a linear dependence and a multiple-zone synchrotron self-Compton model to explain the X-ray and γ-ray emission. Finally, as suggested by previous findings, we confirm a harder-when-brighter behavior in the spectral evolution of the flux properties for Mrk 421. These findings contribute to the understanding of blazar emissions and their underlying mechanisms
Bystanders to Bias: Witnessing Gendered Microaggressions Affects Men\u27s and Women\u27s Outcomes in STEM Small Group Contexts
Full text linkWe tested whether merely witnessing gendered microaggressions affects group work experiences among male and female undergraduate computer science and engineering students. Across three experiments (N = 753), we randomly assigned computer science and engineering students to witness microaggressions targeting female students, or control interactions, using a video manipulation. Witnessing microaggressions-compared to the control-resulted in heightened gender-specific stereotyping concerns, with women being concerned about appearing incompetent and men being concerned with appearing sexist. For both women and men, witnessing microaggressions resulted in decreased enthusiasm for participating in group work. Moreover, for women, the relationship between decreased enthusiasm and witnessing microaggressions was partially mediated by increased concerns about being stereotyped as incompetent. Across the experiments, mixed results emerged regarding the effect of witnessing microaggressions on the recall of engineering content in the video. This research extends previous work focused on personally experiencing microaggressions to merely witnessing them, showing that positivity toward anticipated group work is diminished for both women and men when they see peers engaging in microaggressions
Quality Evaluation for Colored Point Clouds Produced by Autonomous Vehicle Sensor Fusion Systems
Full text linkPerception systems for autonomous vehicles (AVs) require various types of sensors, including light detection and ranging (LiDAR) and cameras, to ensure their robustness in driving scenarios and weather conditions. The data from these sensors are fused together to generate maps of the surrounding environment and provide information for the detection and tracking of objects. Hence, evaluation methods are necessary to compare existing and future sensor systems through quantifiable measurements given the wide range of sensor models and design choices. This paper presents an evaluation method to compare colored point clouds, a common fused data type, among two LiDAR-camera fusion systems and a stereo camera setup. The evaluation approach uses a test artifact measured by the fusion system\u27s colored point cloud through the spread, area coverage, and color difference of the colored points within the computed space. The test results showed the evaluation approach was able to rank the sensor fusion systems based on its metrics and complement the experimental observations. The proposed evaluation methodology is, therefore, suitable towards the comparison of generated colored point clouds by sensor fusion systems