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Factored-NeuS: Reconstructing Surfaces, Illumination, and Materials of Possibly Glossy Objects
No full textWe develop a method that recovers the surface, materials, and illumination of a scene from its posed multi-view images. In contrast to prior work, it does not require any additional data and can handle glossy objects or bright lighting. It is a progressive inverse rendering approach, which consists of three stages. In the first stage, we reconstruct the scene radiance and signed distance function (SDF) with a novel regularization strategy for specular reflections. We propose to explain a pixel color using both surface and volume rendering jointly, which allows for handling complex view-dependent lighting effects for surface reconstruction. In the second stage, we distill light visibility and indirect illumination from the learned SDF and radiance field using learnable mapping functions. Finally, we design a method for estimating the ratio of incoming direct light reflected in a specular manner and use it to reconstruct the materials and direct illumination. Experimental results demonstrate that the proposed method outperforms the current state-of-the-art in recovering surfaces, materials, and lighting without relying on any additional data
Reflect-and-Amplify: a Novel SWIPT Technique through Hybrid Active/Passive RIS
No full textThis paper presents a novel technique for the simultaneous wireless information and power transfer (SWIPT) toward low-power devices, by means of Reconfigurable Intelligent Surfaces (RISs). Our approach is based on a Reflect-and-Amplify protocol meaning that, based on the RIS beam-steering functionality and assuming different reflection coefficients for the RIS elements, it allows to reflect and amplify the impinging wireless signal from the transmitter toward the receiver, which will be able to both collect energy and download data. Specifically, by considering a hybrid RIS comprised of both passive and active elements, the proposed SWIPT approach is defined Active/Passive Switching (APS). The reflection of the wireless beam toward the receiver is accomplished by means of passive RIS elements, while an amplification of the wireless signal is provided through active RIS elements. Such amplification allows the receiver to convert the incoming wave power into a DC voltage, but also causes an increase of power consumption due to active elements. To assess the performance of the proposed SWIPT approach, we derive the closed-form expression of the joint data transmission and energy harvesting outage probability (OP) in case of both a single and multiple users. We compare the proposed technique to other SWIPT approaches from the literature, such as the power splitting and the time switching, under power fairness conditions. Our results validate the benefits of using hybrid RISs for SWIPT systems, as compared to other existing approaches showing reduced performance, also in case of asymptotic analysis for high power and high number of RIS elements
Effects of Microalgae Biomass (Nannochloropsis gaditana and Thalassiosira sp.) on Wheat Seed Germination at High Temperature
No full textAgricultural inputs based on microalgae have been successfully tested at different stages of the crop cycle, from sowing to harvest, to enhance crop performance. In this study, biomass from Nannochloropsis gaditana and Thalassiosira sp. was obtained to evaluate its effect on wheat seed germination under two temperature conditions. Microalgal biomass was produced under controlled conditions (neutral pH, air flow of 1 L·min−1, and a dilution rate of 0.2 day−1). The biomass was characterized for its lipid, carbohydrate, protein, and ash content. Subsequently, its effect on germination, as well as on glucose and amylose content in wheat seedlings, was assessed. Four biomass concentrations were tested (0.0 [distilled water], 0.5, 1.0, and 1.5 g·L−1) at two incubation temperatures (25 and 35 °C). Results showed that Thalassiosira sp. lightly promoted the germination rate more than N. gaditana. Germination parameters were negatively affected by high temperature, but treatments with Thalassiosira sp. alleviated this effect, showing values comparable to those obtained at the optimal temperature. Vigor parameters were improved compared with the control in both temperatures. Glucose and amylose contents exhibited irregular but consistent patterns. However, at a temperature of 35 °C, a slight conversion of starch to glucose could be observed. Overall, microalgal biomass did not significantly improve germination or its time variables, but it could exert a protective effect against high-temperature stress, particularly in the case of Thalassiosira sp.This study received financial support from Programa de Fomento y Apoyo a Proyectos de Investigación (PROFAPI) through project PROFAPI 2025-069. Dr. Gabriel Ivan Romero Villegas and M.C. Brisia Lizbeth’s contributions were financially supported by the Consejo Nacional de Humanidades, Ciencia y Tecnología (CONAHCyT, México). Maria Isabel Estrada Alvarado and Luis Alberto Cira Chavez received support from the SEP-SES, which was provided for conducting a research stay corresponding to the call “Short Stays for Research of Members of Consolidated Academic Bodies 2019”
Proton Exchange Membrane Water Splitting: Advances in Electrode Structure and Mass-Charge Transport Optimization.
No full textProton exchange membrane water electrolysis (PEMWE) represents a promising technology for renewable hydrogen production. However, the large-scale commercialization of PEMWE faces challenges due to the need for acid oxygen evolution reaction (OER) catalysts with long-term stability and corrosion-resistant membrane electrode assemblies (MEA). This review thoroughly examines the deactivation mechanisms of acidic OER and crucial factors affecting assembly instability in complex reaction environments, including catalyst degradation, dynamic behavior at the MEA triple-phase boundary, and equipment failures. Targeted solutions are proposed, including catalyst improvements, optimized MEA designs, and operational strategies. Finally, the review highlights perspectives on strict activity/stability evaluation standards, in situ/operando characteristics, and practical electrolyzer optimization. These insights emphasize the interrelationship between catalysts, MEAs, activity, and stability, offering new guidance for accelerating the commercialization of PEMWE catalysts and systems
Breaching a seismic gap: the 2025 magnitude 7.7 Myanmar earthquake
No full textSeismic gaps are fault sections that have not experienced large earthquakes for a long time compared to neighboring segments, making them likely sites for future large events. Historical information, earthquake catalogs, and field geology help define their dimensions, which inform estimates of potential earthquake size. The 2025 Mw 7.7 Myanmar earthquake ruptured a known seismic gap and extended far beyond it, producing an unusually ~460 km long fault rupture. Integrating SAR-image observations, back-projection analysis, kinematic Bayesian finite-fault estimation, and dynamic rupture simulations, we investigated the earthquake’s rupture process and factors that enabled the rupture to breach the seismic gap. Our results reveal a two-stage earthquake rupture: initial subshear bilateral propagation (~20 s), followed by unilateral supershear rupture (~70 s). Simulation-based sensitivity tests show the seismic gap boundary is not a strong mechanical barrier. Instead, rupture nucleation far away from the gap's boundary played a key role, rather than supershear rupture speed, in allowing the rupture to outgrow the gap and propagate ~160 km beyond it. This indicates that the dimensions of seismic gaps may not reflect the size of future earthquakes. Instead, ruptures may cascade through additional fault sections to generate larger and potentially more damaging earthquakes.This work was supported by King Abdullah University of Science and Technology (KAUST, Grant BAS/1/1339-01-01). We gratefully acknowledge the KAUST Supercomputing Laboratory (https://www.hpc.kaust.edu.sa/) for providing computing resources on the Shaheen III in project K10043. DL acknowledges funding from the New Zealand Ministry of Business, Innovation, and Employment to GNS Science via the National Seismic Hazard Model 2022 Revision Project (Contract Number 2020-BD101). YK acknowledges funding from ERC project BEFACT(project101142339)
OFDM Four-Color Micro-LED Point-to-Point Data Link Beyond 17 Gbit/s
No full textThis study develops high-performance red (R), yellow (Y), green (G), and blue (B) micro light-emitting diodes (μ-LEDs), achieving a total data transmission rate exceeding 17.73 Gbit/s using quadrature-amplitude-modulation (QAM) orthogonal frequency-division multiplexing (OFDM) and bit-loading discrete multitone (BL-DMT) modulation formats. With the greedy bandwidth management program specifically designed for broadband digital encoding of all four-colored μ-LEDs with quite limited bandwidth, the R/Y/G/B μ-LEDs respectively achieve the BL-DMT at their maximal allowable bit-rate of 2.25/3.00/5.36/7.12 Gbit/s, demonstrating their exceptional potential for high-speed digital optical communication with configurable format allocation and optimized spectral usage efficiency. By optimizing semipolar structures, strain-relief designs, and advanced packaging technologies, these μ-LEDs achieve enhanced data efficiency, concurrently paving the way for next-generation smart displays and optical communication applications
Investigating NO emissions, stability, and flame structure in co-fired premixed NH3/CH4/air swirling flames
No full textAmmonia combustion poses challenges due to low reactivity and high NOx emissions, requiring optimization of combustor designs and fueling strategies. This study examines NO emissions, flame stability, and structure in co-fired premixed NH3/CH4/air flames using a double-swirl burner. The inner swirl stream consists of NH3/CH4/air mixtures with varying ammonia mole fractions (xNH3: 0 to 1) and equivalence ratios (Φin: 0.4 to 1.4), while the outer stream contains CH4/air mixtures with Φout ranging from 0.5 to 0.8 and Reynolds numbers (Reout) of 4350, 5250, and 6000. NO emissions varied significantly with Reout, Φin, and Φout, prompting further investigation of flame structure using OH-NO PLIF and PIV diagnostics for three flame sets: FA (Φin=0.4), FB (Φin=0.8), and FC (Φin =1.4). Far-rich (FC) and far-lean (FA) flames exhibited an early conical OH layer followed by a V-shaped OH layer, while NO dispersed across the flame, forming a thin layer at the OH boundary with a V-shaped distribution downstream. Higher Reout facilitated V-OH/NO formation through enhanced mixing, increased recirculation, and more effective ammonia cracking in rich mixtures. At Reout=4350, the absence of a V-OH layer in FA resulted in reduced NO emissions. Flame FB showed a broader, positively correlated NO and OH structure along the central region of the flame, indicating enhanced NHi oxidation to NO. Overall, co-firing ammonia with methane in the outer stream was crucial for improving flame stability. To minimize NO emissions, it is important to lower Reout, increase Φout, and avoid premixing NH3/CH4 in the inner stream. At high Reout, limiting rich Φin to 1.2 or leaning it out, combined with increasing Φout, was the most effective strategy for reducing NO emissions.This research is dedicated to the memory of my beloved wife, Ghada Ahmed. May God have mercy on her soul and grant her eternal paradise and peace (A. M. Elbaz). This work was supported by Saudi Aramco (Project ID: RGC/3/5182) and King Abdullah University of Science and Technology (KAUST) (BAS/1/1370-01-01)
CCDC 2412317: Experimental Crystal Structure Determination : (pentamethylcyclopentadienyl)-(2-azaniumyl-N-[4-(dimethylamino)pyridine-2-carbonyl]ethan-1-aminide)-chloro-iridium(iii) hexafluorophosphate dichloromethane solvate
No full textAn entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures
Weak convergence analysis in the particle limit of the McKean–Vlasov equations using stochastic flows of particle systems
No full textWe present a proof showing that the weak error of a system of interacting stochastic particles approximating the solution of the McKean–Vlasov equation is . Our proof is based on the Kolmogorov backward equation for the particle system and bounds on the derivatives of its solution which we derive more generally using the variations of the stochastic particle system. The convergence rate is verified by numerical experiments which also indicate that the assumptions made here and in the literature can be relaxed.R. Tempone was partially supported by the KAUST Office of Sponsored Research (OSR), under Award numbers URF/1/2281-01-
01, URF/1/2584-01-01 in the KAUST Competitive Research Grants Program Round 8, and the Alexander von Humboldt Foundation, through the Alexander
von Humboldt Professorship award
Highly Selective IL-6 Detection through a Microwave Sensor for Sepsis Severity Evaluation
No full textInterleukin-6 (IL-6) is a protein biomarker that rises in concentration due to infections, tissue damage, and indicates the severity of sepsis, which is a leading cause of death globally. Majority IL-6 sensors are either electrochemical or optical based, which means that they require an active component as well as a power source. Microwave sensors can be completely passive, and thus are a good choice for sensing remotely and wearable applications. This paper presents the first microwave biosensor capable of detecting different concentrations of the IL-6 biomarker in a label-free manner. The sensor is highly selective, which is atypical for microwave sensors, because the sensor is passivated with a parylene-C layer before depositing a gold disc at the maximum electric field confinement area to immobilize IL-6 capture antibody specific to the IL-6 antigen. The frequency of the split ring resonator-based microwave sensor shifts when the IL-6 antigen (biomarker) binds with the IL-6 antibody. The design ensures maximum electric field confinement across the gap in the split ring resonator to achieve better sensitivity. Experimental results show a sensitivity of 0.44 MHz/(ng/ml) with a detection limit of 1 ng/ml. In conclusion, this study underscores the potential for developing completely passive and low-cost microwave sensors with high selectivity and sensitivity to detect various disease biomarkers in the future