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At least 973 records · Page 54

Enhanced neutrino polarizability

We point out that neutrinos can have enhanced couplings to photons, if light (pseudo)scalar mediators are present, resulting in a potentially measurable neutrino polarizability. We show that the expected suppression from small neutrino masses can be compensated by the light mediator mass, generating dimension 7 Rayleigh operators at low scales. We explore the rich phenomenology of such models, computing in detail the constraints on the viable parameter space, spanned by the couplings of the mediator to neutrinos and photons. Finally, we build several explicit models that lead to an enhanced neutrino polarizability by modifying the inverse see-saw majoron, i.e., the pseudo-Nambu-Goldstone boson of the U(1) L global lepton number responsible for generating small neutrino masses.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Automatic enhancement in 6D supergravity and F-theory models

We observe that in many F-theory models, tuning a specific gauge group G and matter content M under certain circumstances leads to an automatic enhancement to a larger gauge group G ' ⊂ G and matter content M ' ⊂ M . We propose that this is true for any theory G, M whenever there exists a containing theory G ' , M ' that cannot be Higgsed down to G, M . We give a number of examples including non-Higgsable gauge factors, nonabelian gauge factors, abelian gauge factors, and exotic matter. In each of these cases, tuning an F-theory model with the desired features produces either an enhancement or an inconsistency, often when the associated anomaly coefficient becomes too large. This principle applies to a variety of models in the apparent 6D supergravity swampland, including some of the simplest cases with U(1) and SU( N ) gauge groups and generic matter, as well as infinite families of U(1) models with higher charges presented in the prior literature, potentially ruling out all these apparent swampland theories.

79 ASTRONOMY AND ASTROPHYSICS↗

Investigating strangeness enhancement with multiplicity in pp collisions using angular correlations

A study of strange hadron production associated with hard scattering processes and with the underlying event is conducted to investigate the origin of the enhanced production of strange hadrons in small collision systems characterised by large charged-particle multiplicities. For this purpose, the production of the single-strange meson ${\textrm{K}}_{\textrm{S}}^0$ and the double-strange baryon Ξ ± is measured, in each event, in the azimuthal direction of the highest-p T particle (“trigger” particle), related to hard scattering processes, and in the direction transverse to it in azimuth, associated with the underlying event, in pp collisions at $\sqrt{s}$ = 5.02 TeV and $\sqrt{s}$ = 13 TeV using the ALICE detector at the LHC. The per-trigger yields of ${\textrm{K}}_{\textrm{S}}^0$ and Ξ ± are dominated by the transverse-to-leading production (i.e., in the direction transverse to the trigger particle), whose contribution relative to the toward-leading production is observed to increase with the event charged-particle multiplicity. The transverse-to-leading and the toward-leading Ξ ± /${\textrm{K}}_{\textrm{S}}^0$ yield ratios increase with the multiplicity of charged particles, suggesting that strangeness enhancement with multiplicity is associated with both hard scattering processes and the underlying event. The relative production of Ξ ± with respect to ${\textrm{K}}_{\textrm{S}}^0$ is higher in transverse-to-leading processes over the whole multiplicity interval covered by the measurement. The ${\textrm{K}}_{\textrm{S}}^0$ and Ξ ± per-trigger yields and yield ratios are compared with predictions of three different phenomenological models, namely Pythia8.2 with the Monash tune, Pythia8.2 with ropes and EPOS LHC. The comparison shows that none of them can quantitatively describe either the transverse-to-leading or the toward-leading yields of ${\textrm{K}}_{\textrm{S}}^0$ and Ξ ± .

hadron-hadron scattering↗

A data-driven framework for predicting machining stability: employing simulated data, operational modal analysis, and enhanced transfer learning

Chatter, a self-excited vibration phenomenon, presents a significant challenge in machining operations, particularly in high-speed milling, where it can degrade tool life, reduce material removal efficiency, and compromise workpiece quality. Addressing this challenge requires a reliable predictive model that can accommodate the complex dynamics of various machining scenarios. This study introduces a novel, data-driven approach to predicting machining stability, leveraging over 140,000 simulated datasets and employing advanced techniques such as operational modal analysis (OMA), enhanced transfer learning (TL), and receptance coupling substructure analysis (RCSA). By integrating these methodologies, the framework effectively classifies and predicts chatter across diverse operational modes, achieving robust and accurate outcomes. Our model utilizes a Random Forest (RF) classifier trained with the comprehensive dataset, which demonstrates substantial improvements in both predictive accuracy and robustness. Specifically, the RF model achieved an accuracy rate of 85%, an area under the curve (AUC) of 0.90, and an F1 score of 0.88, underscoring its capability to adapt to varying machining configurations. These results highlight the framework’s potential to enhance operational efficiency and machining quality by providing reliable chatter predictions across a broad range of machining parameters. In conclusion, this research thus offers a significant advancement in predictive maintenance for machining processes, enabling more stable and efficient manufacturing operations.

42 ENGINEERING↗

Invasive intraductal papillary mucinous neoplasms of the pancreas: relationships between mural nodules detected on thin-section contrast-enhanced MDCT and invasive components

Purpose: To elucidate the relationships between mural nodules (MNs) and invasive components in patients with invasive intraductal papillary mucinous neoplasm (IPMN) on the basis of thin-section contrast-enhanced multidetector CT (CE-MDCT) and pathologic findings. Methods: This retrospective study included 28 patients with surgically confirmed invasive IPMN. Two radiologists independently evaluated the thin-section (1-mm section thickness, no overlap) triple-phase CE-MDCT images for MNs, invasive components, and the continuity between them using a five-point scale (confidence scores of 1–3 as negative, 4 and 5 as positive). Kappa statistic was used to evaluate interobserver agreement. The CE-MDCT findings were correlated with pathologic findings. Results: Interobserver agreement was good or excellent. MNs consisting of tumor cells were recognized in 12 (42.9%) of 28 patients with no discrepancy between the two radiologists. Invasive components were detected in 85.7% and 82.1% in the pancreatic parenchymal phase for radiologist 1 and 2, respectively, and recognized as hypoattenuating areas. Pathologic continuities between MNs and invasive components were confirmed in five (41.7%) of 12 patients with MNs and these were detected on CE-MDCT. When combined seven patients without continuities between MNs and invasive components and 16 patients without MNs, the invasive components pathologically derived from non-nodular low-height papillary epithelium in 23 (82.1%) of 28 patients. Conclusions: The invasive components derived more often from low-height papillary epithelium without MN appearance on CE-MDCT than from MN. Careful attention should be paid to the existence of an invasive component even in the absence of an enhancing MN.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Reducing radiation dose for multi-phase contrast-enhanced dual energy renal CT: pilot study evaluating prior iterative reconstruction

Purpose: Prior iterative reconstruction (PIR) uses spatial information from one phase of enhancement to reduce image noise in other phases. We sought to determine if PIR could reduce radiation dose while preserving observer performance and CT number at multi-phase dual energy (DE) renal CT. Methods: CT projection data from multi-phase DE renal CT examinations were collected. Images corresponding to 40% radiation dose were reconstructed using validated noise insertion and PIR. Three genitourinary radiologists examined routine and 40% dose PIR images. Probability of malignancy was assessed [from 0 to 100] with malignancy assumed at probability ≥ 75. Observer performance was compared on a per patient and per lesion level. CT number accuracy was measured. Results: Twenty-three patients had 49 renal lesions (11 solid renal neoplasms). CT number was nearly identical between techniques (mean CT number difference: unenhanced 2 ± 2 HU; enhanced 4 ± 4 HU). AUC for malignancy was similar between multi-phase routine dose DE and lower dose PIR images [per patient: 0.950 vs. 0.916 (p = 0.356); per lesion: 0.931 vs. 0.884 (p = 0.304)]. Per patient sensitivity was also similar (78% routine dose vs. 82% lower dose [p ≥ 0.99]), as was specificity (91% routine dose vs. 93% lower dose PIR [p > 0.99]), with similar findings on a per lesion level. Subjective image quality was also similar (p = 0.34). Conclusions: Prior iterative reconstruction is a new reconstruction method for multi-phase CT examinations that promises to facilitate radiation dose reduction by over 50% for multi-phase DE renal CT exams without compromising CT number or observer performance.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Does Drug-Eluting Bead TACE Enhance the Local Effect of IRE? Imaging and Histopathological Evaluation in a Porcine Model

Objectives: We conducted an in vivo trial on swine to compare the ablation volumes of irreversible electroporation (IRE) followed by drug-eluting beads transarterial chemoembolization (DEB-TACE) versus IRE only. Materials and Methods: Nine swine underwent CT-guided IRE in one liver lobe and IRE immediately followed by DEB-TACE in a different liver lobe. For DEB-TACE, 100–300 µm beads (DC-Beads{sup ®}) were loaded with 50 mg doxorubicin. For IRE, the NanoKnife{sup ®} was used employing two electrodes according to the vendor’s protocol. Imaging follow-up was performed including CT-based lesion volume assessment using contrast-enhanced CT (venous phase) on days 1, 3, and 7 after the procedure. Three animals were killed for histopathological analysis after each follow-up. Results: Ablation volumes in CT in the IRE + DEB-TACE group were 15.4 ± 10.5 ml on day 1, 8.7 ± 5.6 ml on day 3, and 1.6 ± 0.7 ml on day 7. In the IRE group, the corresponding values were 5.2 ± 5.2 ml on day 1, 1.0 ± 1.2 ml on day 3, and 0.1 ± 0.1 ml on day 7. On day 1 and day 3, ablation volumes of IRE + TACE group were significantly larger than in the IRE group (p < 0.05). 96% of beads were depicted in or around ablative lesions. 69% of these beads were found in the surrounding hemorrhagic infiltration and 31% within the ablative lesion itself. Conclusions: Combination of IRE immediately followed by DEB-TACE resulted in larger ablation volumes compared to IRE alone, suggesting that local efficacy of IRE can be enhanced by post-IRE DEB-TACE.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Microwave resonance enhanced CO 2 reduction using biochar

The conventional process for CO 2 conversion requires high energy and expensive catalysts, and shows poor product selectivity. Here, in this study, we address these challenges by investigating an environmentally friendly method for CO production through the variable frequency microwave-driven CO 2 Boudouard reaction over biochar. We hypothesized that tuning the microwave frequency to align with the dielectric properties of biochar, and thereby induce a resonance effect, could significantly enhance reaction efficiency. Experiments were conducted to explore the effect of microwave frequency on CO 2 conversion efficiency in the variable frequency microwave reactor operating within a frequency range of 2430–6000 MHz. Results reveal a significant resonance effect at 4225 MHz resulting in an outstanding CO 2 conversion of 96.3%, in sharp contrast to the complete absence of conversion observed at the conventional 2450 MHz. The resonance frequency not only facilitated exceptional conversion but also remarkably improved energy efficiency, yielding a productivity of 1427.5 µmol/kJ of CO. This represents a remarkable 474-fold increase compared to electrical heating. Furthermore, continuous microwave irradiation at this optimized frequency demonstrated remarkable stability and induced substantial enhancements in the pore structure and surface area of biochar. This innovative approach provides promising insights into sustainable and efficient CO production processes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Quantum Fluctuations and Multifractally enhanced Superconductivity in Disordered Thin Films

The interplay between electron–electron interactions and weak localization (or anti-localization) phenomena in two-dimensional systems can significantly enhance the superconducting transition temperature. For this work, we develop the theory of quantum fluctuations within such multifractally enhanced superconducting states in thin films. In conditions of weak disorder, we employ the Finkel’stein nonlinear sigma model to derive an effective action for the superconducting order parameter and the quasiclassical Green’s function, meticulously accounting for the influence of quantum fluctuations. This effective action, applicable for interactions of any strength, reveals the critical role of well-known collective modes in a dirty superconductor, and its saddle-point analysis leads to modified Usadel and gap equations. These equations comprehensively incorporate the renormalizations stemming from the interplay between interactions and disorder, resulting in the non-trivial energy dependence of the gap function. Notably, our analysis establishes a direct relation between the self-consistent gap equation at the superconducting transition temperature and the known renormalization group equations for interaction parameters in the normal state.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Enhanced Magneto-optical and Antibacterial Studies of Bi{sub 1−x}Mg{sub x}FeO{sub 3} (0.0 ≤ x ≤ 0.15)) Nanoparticles

Mg-doped BiFeO{sub 3} (Bi{sub 1−x}Mg{sub x}FeO{sub 3} (0.00 ≤ x ≤ 0.15)) nanoparticles (NPs) have been successfully prepared by simple solution combustion method using urea as fuel. The obtained product was sintered at 550 °C for 2 h to get pure-phase formation. The as-prepared samples were characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), ultraviolet–visible (UV-Vis) absorption, photoluminescence (PL) spectra, and vibrating sample magnetometer (VSM) analysis. Powder XRD study revealed that all products exhibit rhombohedral structure with pure-phase formation. The average crystallite size of the samples decreased from 56.25 to 46.15 nm with increasing the concentration of Mg (x = 0.00, 0.05, 0.10, and 0.15). Surface morphology of the samples were analyzed by FE-SEM and TEM micrograph techniques, and the grain distribution was not quite homogeneous and observed agglomeration of the particles, which is mainly due to the magnetic interaction among them. EDX analysis confirmed the presence of Bi, Fe, O, and Mg elements without any form of impurity peak in all products. PL spectra shows a high intense peak at 464 nm, which is attributed to blue emission. The saturation magnetization is enhanced with increasing Mg doping level at RT. Antibacterial activity of Bi{sub 1−x}Mg{sub x}FeO{sub 3} NPs was found to be enhanced with increase in Mg doping concentration as it causes a reduction in the grain size of the samples.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

An innovative approach for performance enhancement of 320 Gbps free space optical communication system over turbulent channel

Free space optical (FSO) communication systems have recently gained huge attention as possible last mile solution in delivering high speed data services for terrestrial applications. However the FSO link performance, particularly the link range is significantly limited by the severity of atmospheric adversities affecting the channel. In this paper we advocate the use of multi-hop relay techniques to transmit wavelength division multiplexed (WDM) signal over the FSO channel. Since weather induced impairments in FSO links are distance dependent phenomena, hence relay transmission allows substantial performance enhancement by alleviating channel losses while, WDM provides cost effective solution in improving the transmission capacity. With aggregate link losses as high as 40 dB/km, the proposed 32 channel—10 Gbps (320 Gbps) FSO link has been evaluated by comparing bit error rate (BER) performances and eye patterns over different turbulent regimes. Gain optimized EDFA amplification and conventional electrical amplification have been employed to realize amplify-and-forward (A–F) multi-hop transmission in the proposed link with the former delivering more inspiring BER performance of over the latter. Our simulation results indicate that for receiver SNR of 35 dB, BER improvement up to five orders of magnitude can achieved using triple relay FSO link in contrast to direct link operating under similar conditions. Additionally, it is also observed during the analysis that for target BER of 10{sup −5}, incorporation of triple relay enhances the link range by approximately 1200 m over direct link. However on the flip side, our investigations also revealed that as the number of relay nodes is increased, the SNR gain for specified BER does increase but the magnitude of gain declines. The proposed link was designed and investigated using OptiSystem™ 14.2.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Efficiency enhancement in Si solar cell using 1D quasi-periodic antireflection coating

In order to enhance the efficiency of thin-film Si solar cell, two well-known Fibonacci and Thue–Morse sequences of 1D quasi-periodic structures have been considered to achieve a broadband (300–1100 nm) planar antireflection coating, in this article. As almost non-absorbing materials in the solar spectrum, TiO{sub 2} and SiO{sub 2} with optimized thicknesses are considered to eliminate the reflections in the front side of the solar cell. An optimized bilayer antireflection coating with thicknesses of 54.4 nm and 85.6 nm respectively for the TiO{sub 2} and SiO{sub 2} layers has been obtained. Considering material dispersion and solar power spectrum (AM1.5), maximum efficiency enhancements of 42.78%, 46.15%, and 50% have been achieved for the 3 µm thin-film Si solar cell using the FC(3,1) structure which correspond to the cells without any recombination, with bulk recombination, and with bulk and surface recombinations, respectively. The proposed quasi-periodic multilayer antireflection structures have been investigated and optimized using the TMM and FDTD methods. The electrical characteristic of the design is studied by the drift–diffusion method after extracting the electron–hole pair generation. Also, the stability of the performance of the proposed ARC against induced roughness in practice has been investigated and discussed.

14 SOLAR ENERGY↗

Microwave Plasma-Enhanced and Microwave Heated Chemical Reactions

Microwave plasma technology is revolutionizing reaction engineering fields such as methane dry reforming, chemical synthesis, biomass conversion, and waste treatment. Microwave generated plasma offers sustainable, cleaner and efficient operations compared to conventional methods. Microwave plasma reactions are more efficient when integrated with catalysts. In this article, a thorough categorization and comparison of microwave plasma-assisted catalytic reactions are presented, while highlighting their contribution to an energy efficient and sustainable future in chemical processing. An introduction on commercial applications of microwave plasma technology is also presented to emphasize its advantages in modern industries. Microwave irradiation can be used as a source of heat or plasma. The addition of heterogeneous catalyst to either microwave heated or microwave enhanced plasma systems can lead to complex pathways in reaction systems. Here, a final section in this article is dedicated to comprehend this complexity in chemical reactions occurring in microwave heated and microwave plasma-enhanced catalytic systems.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Enhancing climate-smart crop performance in arid agrivoltaics systems: effects of photovoltaic shading and soil amendments on tepary bean growth, yield, and associated soil microbiome

As climate change expands the world’s arid and semiarid regions, sustainable systems that integrate food and energy production are becoming increasingly critical. Agrivoltaics—co-locating crops with photovoltaic (PV) panels—offers a dual land-use strategy that mitigates environmental stress by shading crops, conserving soil moisture, and enhancing PV efficiency. While climate-smart crops like the tepary bean ( Phaseolus acutifolius ) are well adapted to heat and drought, little is known about how these crops and their associated soil microbiomes respond to the unique microclimates created by PV shading. This study evaluated tepary bean performance and plant–microbial interactions under PV-shade vs. no shade across three soil amendment treatments at two experimental sites. We assessed plant traits including germination, phenology, biomass, height, as well as yield and bean morphology, alongside shifts in soil microbial composition and functional potential. Plants grown under PV-shade were generally taller, with extended reproductive periods and higher yields: 42% of shaded plants produced beans compared to only 8% under full sun. Shaded plants also produced rounder, higher-quality beans, whereas non-shaded plants yielded flatter, less developed beans. Microbial community composition was more strongly influenced by amendment and site conditions than by shading alone. Key microbial taxa (e.g., Glomeromycetes, Desulfobacterota ) and predicted functions (e.g., denitrification, nitrogen-respiration, sulfate reduction) were associated with differences in plant performance. Finally, combining agrivoltaic systems with targeted soil amendments can enhance crop yield and soil microbial functionality—offering a promising strategy for sustainable agriculture in arid landscapes.

14 SOLAR ENERGY↗

Triaxial Constraint and Tensile Strength Enhancement in Brazed Joints

A brazed joint consists of a low-melting point and thin interlayer sandwiched between the high-melting-point base materials, in which the interlayer strength is typically lower than that of the base material. When this butt-joined composite is loaded uniaxially in the direction perpendicular to the plane of the brazing layer, the tensile strength is found to be much higher than that of the braze. This seems to violate the iso-stress condition in such a butt-joint serial configuration. Furthermore, the stress triaxiality has been usually ascribed, but without a quantitative rationalization, as being responsible for this tensile strength enhancement. Here a complete finite element simulation has been conducted to study the dependence of triaxiality and strength enhancement on geometric and material parameters. Two asymptotic limit solutions (based on Bridgman and Xia–Shih solutions, respectively) have been identified to understand the simulation results. The critical role of void evolution has been revealed when making a quantitative comparison to available experiments. In addition, ductility of the brazed joint, which has not been fully addressed in literature, is investigated by the Gurson–Tvergaard–Needleman model.

36 MATERIALS SCIENCE↗

Thermoelectric Properties of Nanocrystalline Silicon Films Prepared by Hot-Wire and Plasma-Enhanced Chemical-Vapor Depositions

We report thermoelectric measurements over a temperature range of 80 K to 300 K of heavily boron-doped nanocrystalline silicon films prepared by hot-wire and plasma-enhanced chemical-vapor depositions. The nanocrystalline silicon films were doped by either gaseous deposition precursors or post-deposition ion implantation, resulting in boron concentrations ranging from 1 -2 x 10 20 cm -3 to 3 x 10 21 cm -3 . Reasonable values of the Seebeck coefficient and electrical conductivity were obtained at 300 K, comparable to many other research work. We also report thermal conductivity measurements on these films before doping, which we use to estimate their prospective thermoelectric efficiency. These measurements show values as low as 0.76 W/mK at 300 K which depend highly upon the grain sizes of the nc-Si films. We find that post-deposition doping by ion-implantation is more effective at enhancing the power factor than gaseous doping, and the power factor is only weakly dependent upon doping concentration for the films doped by ion implantation. We conclude that improvements of the thermoelectric efficiency of nc -Si films may depend more on a reduction of their thermal conductivity than doping optimization. The small grain sizes and the low thermal conductivity of the undoped nc -Si films accomplished in this work are therefore encouraging developments.

14 SOLAR ENERGY↗

Enhancement of Thermal Conductivity and Mechanical Properties of Cu-Reduced Graphene Oxide Composites by Interface Modification

Copper matrix composites reinforced with reduced graphene oxide (rGO) were fabricated via charge adsorption process, thermal reduction, and hot-press sintering process. We investigated the effect of rGO on the thermal conductivity, electrical conductivity, mechanical properties, and microstructure of the composites. By controlling the reaction process, copper on the rGO surface was oxidized to form Cu{sub 2}O. The presence of Cu{sub 2}O at the interface enhanced interfacial bonding strength and reduced the interfacial thermal resistance, thus improving the thermal conductivity and mechanical properties. This enhancement occurred at low rGO contents. By contrast, excessive amounts led to rGO agglomeration and a degradation of the performance. At the optimum rGO content of 0.6 wt.%, the composites had a 10% increase in thermal conductivity and a 46% increase in yield strength (σ{sub 0.2}), while maintaining high electrical conductivity.

36 MATERIALS SCIENCE↗

A novel alkylating deacetylase inhibitor molecule EDO-S101 in combination with cytarabine synergistically enhances apoptosis of acute myeloid leukemia cells

Acute myeloid leukemia (AML) is a devastating disease. Hybrid agents with dual activity, which have been shown to possess anti-cancer effect, are expected to potentially improve the prognosis of AML patients. EDO-S101 is a novel alkylating deacetylase inhibitor molecule synthesized by the addition of the hydroxamic acid of histone deacetylases inhibitor vorinostat into bendamustine, a DNA-damaging agent. However, the effect of EDO-S101 in combination with traditional chemotherapy drugs has not been studied in AML. In this study, we investigated the effect of EDO-S101 in combination with cytarabine in treating AML cells. The synergic activity against AML was identified by remarkable reduction of cell viability, significant apoptosis enhancement and the upregulation of the cleaved PARP, Casepase-3 and -7 proteins compared with monotherapy. To explain the drivers, we detected the DNA damage pathway including DNA double-strand breaks marker γ-H2AX and DNA damage checkpoint proteins, which was supposed to be responsible for the enhanced apoptosis activity. In summary, our data demonstrated that EDO-S101 in combination with cytarabine could synergistically induce the apoptosis of AML cells and it might be a potential regimen for treating leukemia.

62 RADIOLOGY AND NUCLEAR MEDICINE↗