Search Results (168)

Per the United Nations, enhancing climate literacy can play an essential role in advancing climate mitigation, adaptation, and promoting sustainable human behaviors. Yet, there is a lack of empirical research explicitly studying the effects of climate solutions focused education. Here, we studied the effects of a climate solutions focused course—the University of California Bending the Curve (BtC) course on: (1) climate change beliefs, (2) personal pro-environmental actions, and (3) psychological health, using baseline and post-course surveys. A total of 374 youth (median age 21 ± 1.7 years, 63% female) participated in the study, and data analysis focused on statistically comparing pre- versus post-course survey-based data. We observed that the BtC course enhanced climate change beliefs. Specifically, at post-relative to pre-course, we observed significantly increased belief that global warming will impact individuals personally as well as impact our future generations; it tripled the number of students who believe that humans can and will act to reduce global warming; it significantly increased the number of individuals who believe in a scientific basis for climate change. Notably, climate solutions education also enhanced belief in the efficacy of personal climate action and increased agreement amongst youth that many of their friends also share the same views on global warming. With regard to personal pro-environmental actions, the course significantly improved self-reported actions, including waste reduction, making food choices with reduced emissions, and purchase of carbon offsets. These actions reduced the carbon footprint per student at post- vs. pre-course by a significant 0.3 ± 0.1 CO₂ tons/year, which is equivalent to the CO₂ absorbed by about 15 trees per year. While psychological health outcomes did not show any significant post- vs. pre-course change, we found that enhanced personal pro-environmental actions as well as enhanced psychological health were predicted by course-related strengthening of climate change beliefs. Overall, our findings provide evidence that solutions-based climate education can be an important strategy to enhance individual climate change awareness as well as personal pro-environmental actions that lead to significant individual carbon footprint reduction, with potential for widespread scale-up. Full article

Soil erosion in granite-derived weathering mantles poses serious threats to slope stability and ecological sustainability in subtropical regions. While polyacrylamide (PAM) is widely used to improve soil structure, its concentration-dependent effects on multiple soil functions remain unclear. This study developed a multifunctional Soil Function Index (SFI) framework integrating erosion resistance (SFI₁), water regulation (SFI₂), and ecological function (SFI₃) to evaluate the effects of PAM application (0‰, 1‰, 3‰, 5‰, 7‰) on gully-prone sandy material. Herein, SFI₁ was quantified through shear strength (τ) and soil erodibility (K_r); SFI₂ was assessed using soil hydraulic parameters (saturated hydraulic conductivity and water retention curves) and SFI₃ was derived from the grass root system analysis. The results showed that SFI₁ and SFI₂ increased nonlinearly with PAM concentration, reaching maximum values of 0.983 and 0.980 at 7‰, with K_r reduced by 77.3% and non-capillary porosity (NAP) increased by 8.1%. In contrast, SFI₃ peaked at 0.858 under 3‰ and declined sharply to 0.000 at 7‰, due to micropore over-compaction, reduced aeration, and limited plant-available water. The total SFI exhibited a unimodal trend, with a maximum of 0.755 at 3‰, beyond which ecological suppression offset physical improvements. These findings demonstrate that PAM modifies soil multifunctionality through pore-scale restructuring, inducing function-specific thresholds and trade-offs. A PAM concentration of 3‰ is identified as optimal, achieving a balance between erosion control, hydrological performance, and ecological viability in the management of subtropical granite-derived sandy slopes. Full article

Field surveys focused on detailed mapping and measurements of coseismic surface ruptures along the causative fault of the 6 February 2023, Mw 7.8 Kahramanmaraş earthquake. The aim was filling gaps in the previously available surface-faulting trace, validating the accuracy of data obtained from remote sensing, refining fault offset estimates, and gaining a deeper understanding of both the local and overall patterns of the main rupture strands. Measurements and observations confirm dominating sinistral strike-slip movement. An integrated and comprehensive slip distribution curve shows peaks reaching over 700 cm, highlighting the near-fault expressing up to 70% of the deep net offset. In general, the slip distribution curve shows a strong correlation with the larger north-eastern deformation of the geodetic far field dislocation field and major deep slip patches. The overall rupture trace is generally straight and narrow with significant geometric complexities at a local scale. This results in transtensional and transpressional secondary structures, as multi-strand positive and negative tectonic flowers, hosting different patterns of the mole-tracks at the outcrop scale. The comprehensive and detailed field survey allowed characterizing the structural framework and geometric complexity of the surface faulting, ensuring accurate offset measurements and the reliable interpretation of both morphological and geometric features. Full article

Glaciers worldwide are in retreat, and their meltwater can modulate mountain aquifers. We examined whether mass loss of the Juncal Norte Glacier (central Chile) has affected groundwater storage in the Juncal River basin between 1990 and 2022. Recession-curve modeling of daily streamflow shows no statistically significant trend in basin-scale groundwater reserves (τ = 0.06, p > 0.05). In contrast, glacier volume declined significantly (−3.8 hm³/yr, p < 0.05), and precipitation at the nearby Riecillos station fell sharply during the 2008–2017 megadrought (p < 0.05) but exhibited no significant change beforehand. Given the simultaneous decreases in meteoric inputs (rain + snow) and glacier mass, one would expect groundwater storage to decline; its observed stability therefore suggests that enhanced glacier-melt recharge may be temporarily offsetting drier conditions. Isotopic evidence from comparable Andean catchments supports such glacio-groundwater coupling, although time lags of months to years complicate detection with recession models alone. Hence, while our results do not yet demonstrate a direct glacier–groundwater link, they are consistent with the hypothesis that ongoing ice loss is buffering aquifer storage. Longer records and tracer studies are required to verify this mechanism and to inform sustainable water resources planning. Full article

The geometric structure design of three-layer hollow fan blades is extremely complex, which is not only directly related to the blade quality and manufacturing cost but also has a significant impact on engine performance. Based on geometric algorithms and combined with design rules and process constraints, an intelligent design method for the geometric structure of three-layer hollow blades is proposed: A new cross-section curve design method based on a non-equidistant offset is presented to enable the rapid design of wall plate structure. An innovative parametric design method for the corrugation structure in cross-sections driven by process constraints such as diffusion bonding angle thresholds is put forward. The spanwise rib smoothing optimization is realized based on the minimum energy method with the corrugation angle change term. The cross-section densification design is carried out to improve the accuracy of wireframe structure and achieve the rapid solid modeling of hollow blades. Finally, the proposed methods are seamlessly integrated into the NX software (version 12), and a three-layer hollow fan blade intelligent design system is developed, which enables the automated design and modeling of the complex geometric structure of the hollow blade under an aerodynamic shape and a large number of design and process constraints. Full article

Background/Objectives: The external hinged elbow fixator is a surgical choice both in the case of simple dislocations and elbow dislocation fractures. The correct positioning with respect to the elbow’s center of rotation is demanding. Authors developed a self-centering external fixator that does not require a pin in the elbow’s center of rotation. The aim of this study was to analyze the margin of error in its positioning. Methods: We subjected 16 patients to a CT-3D study reconstruction using 3D motion software to analyze the divergence angle and offset between the elbow’s center of rotation and that of the external fixator. The results were compared to those published on traditional implants. Results: All elbows were correctly reduced without re-dislocation. The average distance was 2° in relation to the center of rotation in the antero-posterior view, 3° in the cranio-caudal, and 2° in the medio-lateral. The divergence angle was 3.5° (min 0.4°; max 9.3°) and the offset 6.8 mm (min 0.06; max 17.5). The average range of motion was 10–145 (range 0–155). Discussion: The traditional hinged elbow external fixator creates severe complexity for surgeons in the necessary positioning of the elbow axial rod to correctly align the implant. The self-centering device avoids this step, making the procedure faster and easier. Although the alignment is still not perfect, the results are still comparable with traditional devices. Conclusions: The self-centering external fixator allows for correct alignment with the elbow’s center of rotation. It is less invasive and simpler, with a shorter learning curve, faster operating time, and less radiographic exposure. Full article

Devices employing cryptographic approaches have to be resistant to physical attacks. Side-Channel Analysis (SCA) and Fault Injection (FI) attacks are frequently used to reveal cryptographic keys. In this paper, we present a combined SCA and laser illumination attack against an Elliptic Curve Scalar Multiplication accelerator, while using different equipment for the measurement of its power traces, i.e., we performed the measurements using a current probe from Riscure and a differential probe from Teledyne LeCroy, with an attack success of 70% and 90%, respectively. Our experiments showed that laser illumination increased the power consumption of the chip, especially its static power consumption, but the success of the horizontal power analysis attacks changed insignificantly. After applying 100% of the laser beam output power and illuminating the smallest area of 143 µm², we observed an offset of 17 mV in the measured trace. We assume that using a laser with a high laser beam power, as well as concentrating on measuring and analysing only static current, can significantly improve the attack’s success. The attacks exploiting the Static Current under Laser Illumination (SCuLI attacks) are novel, and their potential has not yet been fully investigated. These attacks can be especially dangerous against cryptographic chips manufactured in downscaling technologies. If such attacks are feasible, appropriate countermeasures have to be proposed in the future. Full article

History-dependent hysteresis models can potentially describe magnetization curves of all orders accurately. This property is essential for modeling magnetization and power loss in magnetic components subjected to distorted excitation waveforms, which result in complex magnetization patterns such as offset minor loops. The basic Zirka–Moroz history-dependent hysteresis model offers a good balance between the model’s complexity and accuracy. However, estimating the model’s parameters can be challenging. This research provides insight into the parameter estimation procedure for the discussed hysteresis model. Based on the measured first-order reversal curves, the fundamental two-step parameter estimation procedure was employed and analyzed for two non-oriented and one grain-oriented electrical steel types used widely in contemporary electric drives and electromagnetic devices. For each sample evaluated, two sets of parameters were estimated and compared to the reference parameters recommended for non-oriented electrical steels. The performed analysis is essential for gaining a comprehensive understanding of the capabilities, challenges, requirements, and limitations associated with estimating the parameters and performance of the analyzed model for specific electrical steel types. Full article

The semi-airborne transient electromagnetic (SATEM) method has garnered increasing attention and research interest due to its superior detection depth and high efficiency. Theoretically, the SATEM method employs a long straight grounded wire as its transmitter source; however, in practical applications, various source shapes emerge due to terrain constraints. This paper investigates the influence of source shape on SATEM data. A three-dimensional (3D) block model is established, and a model order reduction algorithm is applied to calculate the 3D spatial distribution of electromagnetic fields generated by both an ideal linear source and a curved source. Numerical simulation results reveal that: (1) in the early stage, maximum values of electric and magnetic fields near the source are distributed along the source shape; this influence diminishes with time, and at the late stage, the spatial electromagnetic field distributions generated by linear and curved sources converge, exhibiting similar patterns regardless of the source geometry; (2) the source shape primarily affects early responses in small-offset areas while having minimal influence on late responses in large-offset regions; (3) for deep detection applications conducted in large-offset areas, the influence of the source shape can be disregarded; however, for shallow detection with receivers positioned in small-offset regions, the source shape effects should be taken into consideration. Full article

The construction of urban subway tunnels typically induces soil settlement within a specific radius of the surrounding area. However, the accuracy of current methods for predicting ground deformation curves corresponding to the excavation of double-track tunnels with small spacing remains insufficient. Most studies simplify this problem by modeling it as a two-dimensional plane problem; however, the actual ground deformation exhibits pronounced three-dimensional characteristics. Consequently, studying the ground settlement patterns caused by the construction of small-spacing double-track tunnels is crucial. This study is based on the Peck formula, used to calculate surface settlement caused by the excavation of single-track tunnels. By incorporating the maximum settlement offset e and the soil loss rate η(y), the soil displacement calculation formula is derived for small-spacing double-track tunnel excavation. The accuracy of the derived formula is then validated through a case study. The findings provide a theoretical reference for predicting surface settlement induced by the excavation of small-spacing double-track tunnels. Furthermore, the influence of different parameters on ground settlement patterns is explored. The results indicate that appropriately increasing the tunnel spacing, increasing burial depth, and adopting a sequential excavation method for the two tunnels help reduce ground settlement. Full article

LED solar simulators currently face limitations in their spectral simulation capabilities, especially in terms of accurately incorporating AM0G and AM1.5G solar spectra. To this end, this study introduced a framework for an LED solar spectrum simulation algorithm that considers both AM0G and AM1.5G. This study examined the principle of solar spectrum discretization and reconstruction, established a foundation for analyzing the quality of solar spectrum reconstruction, and developed a non-dominated sorting genetic algorithm II (NSGA-II)-assisted long short-term memory (LSTM)-based solar spectrum simulation strategy. This strategy integrates a multi-objective genetic algorithm to generate training datasets and a neural network for solar spectrum simulation. A dataset generation method using the NSGA-II algorithm was implemented, which leveraged the 6500 K standard blackbody spectral curve, the spectral curve offset coefficients, and the spectral distributions of various narrowband LEDs. An LSTM-based neural network for solar spectrum simulation was developed, with the RMSE serving as the evaluation function. The analysis and selection of 29 narrowband LEDs produced 5000 solar spectrum simulation training datasets. The trained LSTM model achieved spectral matching accuracies within ±10.5% and ±9.3% for AM0G and AM1.5G, respectively, meeting the A+ level simulation standard for solar spectrum reconstruction considering AM0G and AM1.5G. These findings provide a theoretical foundation and technical advancements for high-precision solar spectrum reconstruction, which has practical implications for improving the efficiency and accuracy of solar energy systems, as well as supporting further research on solar spectrum utilization, and is expected to influence the development of more efficient solar simulators. Full article

When printing overhanging parts with traditional additive manufacturing (AM) equipment, it is necessary to add support structures under the overhanging structure. The process of printing support structures not only wastes materials, but also increases the manufacturing time. Therefore, in order to reduce or eliminate the need for support structures when printing parts with overhanging structures, such as propellers, a five-axis support-free printing method for overhanging parts is proposed for one of the most commonly used processes involving AM technology: fused deposition modeling (FDM). By offsetting the surface of the basic part, the offset surface is intersected with the model to be printed to obtain the spatial surface-layered curve. The contour offset method for the spatial curve is used to obtain the printing path, and continuous path planning is performed on it. While the presented method is targeted specifically at this ideal overhanging part, physical experiments on five-axis FDM equipment are performed. Compared with the traditional three-axis AM method, the time taken to print parts using this support-free five-axis AM method is shortened by 13.76–26.93%, and the printing material required is reduced by 17.24–29.29%. The experimental results show that this method realizes support-free printing of overhanging parts with the five-axis AM equipment, which not only saves materials and time consumed during part of the printing, but also improves the surface quality of the parts. Full article

Antimonide laser diodes, with their high performance above room temperature, exhibit significant potential for widespread applications in the mid-infrared spectral region. However, the laser’s performance significantly degrades as the emission wavelength increases, primarily due to severe quantum-well hole leakage and significant non-radiative recombination. In this paper, we put up an active region with a high valence band offset and excellent crystalline quality with high luminescence to improve the laser’s performance. The miscibility gap of the InGaAsSb alloy was systematically investigated by calculating the critical temperatures based on the delta lattice parameter model. As the calculation results show, In_0.54Ga_0.46As_0.23Sb_0.77, with a compressive strain of 1.74%, used as the quantum well, is out of the miscibility gap with no spinodal decomposition. The quantum wells exhibit high crystalline quality, as evidenced by distinct satellite peaks in XRD curves with a full width at half maximum (FWHM) of 56 arcseconds for the zeroth-order peak, a smooth surface with a root mean square (RMS) roughness of 0.19 nm, room-temperature photoluminescence with high luminous efficiency and narrow FHWM of 35 meV, and well-defined interfaces. These attributes effectively suppress non-radiative recombination, thereby enhancing internal quantum efficiency in the antimonide laser. Furthermore, a novel epitaxial laser structure was designed to acquire low optical absorption loss by decreasing the optical confinement factor in the cladding layer and implementing gradient doping in the p-type cladding layer. The continuous-wave output power of 310 mW was obtained at an injection current of 4.6 A and a heatsink temperature of 15 °C from a 1500 × 100 μm² single emitter. The external quantum efficiency of 53% was calculated with a slope efficiency of 0.226 W/A considering both of the uncoated facets. More importantly, the lasing wavelength of our laser exhibited a significant blue shift from 3.4 μm to 2.9 μm, which agrees with our calculated results when modeling the interdiffusion process in a quantum well. Therefore, the interdiffusion process must be considered for proper design and epitaxy to achieve mid-infrared high-power and high-efficiency antimonide laser diodes. Full article

This paper presents a novel Q-value-based formability assessment for optimizing deep drawing processes. The Q-value, derived from thinning limit diagrams (TLDs), uses offset thinning and wrinkling limit curves to define severity levels. It is calculated by summing the product of Pascal’s triangle weighting factors and normalized element counts within each severity level. The effectiveness of this Q-value assessment was demonstrated using experimentally validated finite element analysis (FEA) to optimize blank size, tool geometry, and drawbead design (male bead height and contra-bead radius) for a deep-drawn AA5754-O automotive fuel tank. Validation of FEA results with experimental thickness measurements showed that the Barlat and Lian 1989 yield criterion provided higher accuracy than Hill’s 1948 model. An optimal condition, determined using the Q-value, consists of a 430 mm × 525 mm blank formed by a redesigned tool cooperated with optimized semi-circular drawbead geometries, achieving experimental significant formability improvements by minimizing wrinkling and thinning. During optimization, this study revealed a significant interaction between blank width and length, which influenced formability. Side-wall wrinkles were attributed to insufficient tool support for the blank during forming and were relieved through tool redesign. Furthermore, increasing the male drawbead height effectively reduced wrinkling but led to increased thinning, whereas increasing the contra-bead radius had the opposite effect. Full article

Background and Objectives: Two major classification systems exist for rib fracture (RFX) displacement. One system uses a 50% displacement threshold: Grade I (<50%), Grade II (≥50% to <100%), and Grade III (completely dislocated). Another proposes a 10% threshold: Undisplaced (<10%), Offset (≥10% to <100%), and Displaced (completely dislocated). We analyzed risk factors for adverse outcomes for pulmonary complications and mortality according to both classification criteria. Materials and Methods: We retrospectively reviewed trauma registry and medical records from January 2019 to December 2023. All radiographic parameters were recorded based on initial computed tomography. Primary outcomes were pneumonia and other pulmonary complications requiring surgery. Least absolute shrinkage and selection operator (LASSO) regression was conducted to select risk factors and minimize overfitting. Multivariable logistic regression (MLR) was performed after LASSO. Results: Among the 621 patients, 61 (9.8%) had one or more adverse outcomes. In MLR, regardless of both classifications, the age (p < 0.001), ISS (p < 0.001), and number of completely displaced RFX (p = 0.001) were statistically significant. After excluding 280 patients with completely displaced RFX, we conducted a subgroup analysis with the remaining 341 patients. In this analysis, 22 (6.5%) patients experienced one or more adverse outcomes. Regardless of both classifications, the AIS head (p = 0.006), AIS extremities (p = 0.012), and number of segmental RFX (p < 0.001) were statistically significant in MLR. The area under the receiver operating curve for both MLR models was 0.757 in the total patient group and 0.823 in the subgroup that excluded patients with completely displaced RFX. Conclusions: Completely displaced RFX is the most crucial factor, regardless of the classification criteria. Unless ribs are completely displaced, the degree of displacement may not be crucial, and the number of segmental RFX was a significant risk factor. Full article