Peak Intensity Research Articles

Impact of Sensitizer Yb3+ on Structural and Optical Properties of AE2SiO4 (AE = Ba, Ca, Sr) Orthosilicates.

In the present work, BaSrSiO4: Yb and CaSrSiO4: Yb (Yb = 0mol %, 1mol %, 2mol % and 3mol %) nanophosphors were synthesized using the co-precipitation method, and their comparative structural and optical properties were studied to demonstrate the effect of Yb ion on the characteristic properties of the prepared nanophosphors. The powder X-ray diffraction (PXRD) patterns of BaSrSiO4:Yb and CaSrSiO4:Yb suggest the formation of a single-phase orthorhombic structure with space groups Pbnm and Pna21, respectively. The Raman shifts in BaSrSiO4 (BSS) and CaSrSiO4 (CSS) indicate out-of-phase bending of Sr-O and symmetric stretching of Si-O. The FTIR spectra show bands in the spectra between 1033 and 1063cm-1, which can be attributed to the vibration of the Si-O-Si bond in both samples. The result also supported the formation of orthosilicate. SEM revealed agglomerated chunks in the BSS samples and rod-like structures in the CSS samples. The PL spectra show a significant change in the intensity of the emission peak at 975nm following the transition 2F7/2 → 2F5/2 for different alkali earth metals (Ca, Ba), which is related to the energy level and formation of Yb2+ ion in the respective hosts. In CaSrSiO4 doped Yb a red emitting band at 700nm is observed which is not present in BaSrSiO4 host.

Finite-Difference Time-Domain Simulation of Double-Ridge Superimposed Structures for Optimizing Light-Trapping Characteristics in Ternary Organic Solar Cells

The double-ridge superimposed structures (DRSSs), formed by the superposition of a nano-ridged textured ZnO layer and a ternary organic active layer (PTB7:PC70BM:PC60BM) with self-assembled nano-ridged (SANR) structures, have been preliminarily examined experimentally for its positive effects in light-trapping for organic solar cells (OSCs). To obtain DRSSs with higher-performance light-trapping effects and enhance the light absorption of OSCs, the present work carried out prior theoretical simulations of the light-trapping characteristics of the DRSS using the finite-difference time-domain (FDTD) algorithm. The results show that the DRSS exhibits a significant light-trapping effect, with an active layer absorption peak around 530 nm due to the light-trapping effect. This helps the active layer capture more high-energy photons, significantly enhancing the photon utilization of the DRSS. Interestingly, the intensity of the light-trapping absorption peak is solely dependent on the height or width of the active layer ridges in the DRSS, while the position of the peak is jointly determined by both the ZnO and active layer ridges. By controlling the aspect ratio (W/H) of the dual ridges, the light-trapping absorption peak position can be fine-tuned, enabling precise light-trapping management for specific wavelength bands. It is certain that the outcomes of this work will provide theoretical foundations and practical guidance for the fabrication of light-trapping OSCs.

Energy Transfer Studies on Red Emitting CaGdSbWO8: Sm3+/Eu3+ Phosphor for w-LEDs and Indoor Plant Growth Lighting System.

In the present research work, a solid-state reaction method was employed to synthesize a series of CaGd(0.95-x)SbWO8:Sm0.05Eux (x = 1, 1.5, 2, 3 and 4mol%) phosphors. The phase purity, crystallinity, morphological and compositional studies were analysed via X-ray diffraction (XRD), scanning electron microscopy (SEM) imaging, and energy dispersive spectroscopy (EDS) analysis. The Fourier transform infrared (FT-IR) spectroscopy was utilized to measure OH content in the prepared phosphor material. The diffused reflectance spectroscopy (DRS) analysis was applied to measure the optical energy band gap. The photoluminescence (PL) spectroscopy at excitation wavelengths 275 and 405nm was carried out to analyze the luminescence properties of the prepared phosphors. The intensity of emission peaks of Sm3+ ions decreased as the concentration of Eu3+ ions increased showing the energy transfer mechanism from Sm3+ to Eu3+ ions. The dipole-dipole interaction mechanism is responsible for the energy transfer between Sm3+ to Eu3+ ions as assessed using the Reisfeld approximation. The CIE coordinates of the prepared samples lie in the warm red region represented by the relatively low (3200K) value of correlated color temperature. These results show the suitability of the prepared phosphor for white light emitting diode (w-LEDs) and also in indoor plant growth lighting systems.

Photo-physical mechanism of near-IR femtosecond laser-induced refractive-index change in PMMA

Micromodification in bulk undoped polymethylmethacrylate (PMMA) by single focused (numerical aperture (NA) = 0.25), 1030-nm 250-fs laser pump pulses was explored by pump self-transmittance; optical, 3D-scanning confocal photoluminescence (PL); Raman micro-spectroscopy; and optical polarimetric and interferometric microscopy. Starting from the threshold pulse energy Eth = 0.4 ± 0.1 μJ (peak laser intensity Ith ≈ 8 TW/cm2), visible bright micro-voxels emerged inside PMMA at the 100 ÷ 300-μm depth, with their PL-acquired dimensions increasing versus pulse energy. Optical phase change was interferometrically measured in the voxels at the 532-nm wavelength, exhibiting versus the pulse energy the isotropic refractive index increase Δn = +(4 ÷ 10) × 10−4, and a new 1640-cm−1 peak of C=C vibrations emerged in the Raman spectra. Pump self-transmittance measurements demonstrated the predominating eight-photon absorption (excited energy level ≈ 9.7 eV, coefficient β8 ≈ 3 × 10−5 cm13/TW7) at the sub-threshold I < Ith, implying photoionization of the PMMA chains (the ionization potential of MMA molecule ≈ 9.7 eV). At higher peak intensities I > Ith, inverse brems-strahlung absorption (coefficient ∼103cm−1) of near-critical micro-plasma (density >5 × 1020 cm−3) predominates over the multi-photon PMMA absorption, providing the bulk energy density >6 × 102 J/cm3 and the temperature rise ΔT > 2.2 × 102 K, which are sufficient for PMMA (de)polymerization near the equilibrium bulk temperature TP ≈ 220°C. These results uncover the quantitative mechanism of fs-laser modification of PMMA, justifying the previous qualitative findings and enabling controllable energy deposition during fs-laser PMMA micromachining of diverse functional applications.

Regulating Crystalline Phase/Plane of Polymer Electrolyte for Rapid Lithium Ion Transfer

Electronic‐rich functional groups and flexible segments have long been perceived to be the decisive factors influencing lithium‐ion transfer in polymer electrolytes, while crystallinity is regarded as the great scourge. Actually, the research on the influence of crystalline phase and crystalline plane is still in scarcity. Herein, taking poly(vinylidene fluoride)‐hexafluoropropylene (PVDF‐HFP) as an example, new (111/201) crystal planes (belonged to β‐phase) are regulated by dissolving process and clarified by Synchrotron radiation X‐ray diffraction and X‐ray diffraction. Density functional theory calculation indicates that the newly exposed (111/201) crystal planes provide higher binding energy with lithium ions and are conducive to provide more ion transport channels.7Li nuclear magnetic resonance of new crystalline planes contained PVDF‐HFP based electrolyte shows lower field and sharper peak intensity, further proves the rapid lithium ion transfer. Therefore, a high ionic conductivity of 6.42×10−4 S cm−1 and a large lithium‐ion transfer number of 0.7 are achieved. This study offers a new insight into the influence of crystalline phase and crystalline plane on the transfer of lithium ion for polymer electrolytes.

Direct laser micro-drilling of high-quality photonic nanojet achieved by optical fiber probe with microcone-shaped tip

Photonic nanojet can serve as a powerful tool for direct laser micro-machining based on a non-resonance focusing phenomenon. In this study, we propose a photonic nanojet-based direct micro-drilling technique for polymer material with low-cost and low-power continuous-wave laser. The high-quality photonic nanojet is produced using the microcone-shaped probe tip, which is fabricated by the dynamic chemical etching method. By utilizing laser photonic nanojet triggered thermoplasmonics, the high-aspect-ratio microcavity is fabricated with the low threshold value of laser power. The influences of the photonic nanojet peak intensities and distributions on the drilled microcavities are systematically investigated by the experiments and the finite-difference time-domain simulations. With the continuous-wave solid-state laser at a wavelength of 671 nm, the simulations show that the photonic nanojet with a quality factor of 103 is generated at a distance of ~ 20 μm from the surface of the microcone-shaped tip with a beam waist of 252 nm in the x direction, which could overcome the diffraction limit. The experimental results show that the length and peak intensity of the photonic nanojet have increased considerably in the propagation direction by the microcone-shaped probe tip, which leads to form a deep microcavity in the polymer substrate with an aspect ratio of 5.73. The presented microcone-shaped probe tip has potential applications in processing sub-diffraction features with a high aspect ratio.

Observation of Boson Peak of Fragile Baltic Amber Glass by Terahertz Time-Domain Spectroscopy.

Amber is a fragile (in Angell's classification) natural glass that has performed maturation processes over geological time. The terahertz dynamics of Baltic amber that was about 40 million years old were studied by terahertz time-domain spectroscopy (THz-TDS) in the frequency range of 0.2 and 6.0 THz. In general, the intensity of a boson peak is weak for fragile glass. In the terahertz transmission spectra of Baltic amber in the previous study, no boson peak was observed upon slow cooling. However, in the present study, upon rapid cooling down to 15 K, the boson peak was observed clearly at 0.36 THz by the suppression of ice nucleation of confined water. The dynamic correlation length determined by the boson peak frequency was compared with the static structure correlation length and the scale of the medium-range order as determined by the first sharp diffraction peak of X-ray diffraction (XRD) in the recent literature. It was found that the dynamic correlation length determined by THz-TDS was closely related to the static correlation length determined by the XRD analysis.

GFP Farnesylation as a Suitable Strategy for Selectively Tagging Exosomes.

Exosomes are small extracellular vesicles (EVs) constituting fully biological, cell-derived nanovesicles with great potential in cell-to-cell communication and drug delivery applications. The current gold standard for EV labeling and tracking is represented by fluorescent lipophilic dyes which, however, importantly lack selectivity, due to their unconditional affinity for lipids. Herein, an alternative EV fluorescent labeling approach is in-depth evaluated, by taking advantage of green fluorescent protein (GFP) farnesylation (GFP-f), a post-translational modification to directly anchor GFP to the EV membrane. The performance of GFP-f is analyzed, in terms of selectivity and efficiency, in several typical EV experimental setups such as delivery in recipient cells, surface engineering, and cargo loading. First, the capability of GFP and GFP-f to label exosomes was compared, showing significantly higher GFP protein levels and fluorescence intensity in GFP-f- than in GFP-labeled exosomes, highlighting the advantage of directly anchoring the GFP to the EV cell membrane. Then, the GFP-f tag was further compared to Vybrant DiD lipophilic dye labeling in exosome uptake studies, by capturing EV intracellular fluorescence in a time- and concentration-dependent manner. The internalization assay revealed a particular ability of GFP-f to monitor the uptake of tagged exosomes into recipient cells, with a significant peak of intensity reached 12 h after administration by GFP-f but not Vybrant-labeled EVs. Finally, the GFP-f labeling capability was challenged in the presence of a surface modification of exosomes and after transfection for siRNA loading. Results showed that both procedures can influence GFP-f performance compared to naïve GFP-f exosomes, although fluorescence is importantly maintained in both cases. Overall, these data provide direct insight into the advantages and limitations of GFP-f as a tagging protein for selectively and accurately tracking the exosome route from isolation to uptake in recipient cells, also in the context of EV bioengineering applications.

Optimizing electrical properties and efficiency of copper-doped CdS and CdTe solar cells through advanced ETL and HTL integration: a comprehensive experimental and numerical study

Abstract Copper is a commonly preferred dopant for cadmium telluride based solar cells. Even though it is widely used as it enhances the electrical properties, it has the tendency to diffuse into the CdTe layer as well as the CdS/CdTe junction interface which adversely affects the performance of CdTe solar cells. In this experimental study copper doping of buffer cadmium sulfide layer has been performed to analyse its effect on structural, electrical, and optical properties of CdS and CdTe layers. While from the X-ray diffraction analysis it was observed that there was reduction in peak intensities and crystallite sizes of both the CdS and CdTe layers with the increase in amount of copper dopant, from the electrical properties it was found that there were improvements in carrier concentration, mobility, and conductivity of both the layers. To mitigate the losses due to Cu doping, enhance the efficiency and stability of CdTe solar cells an extensive numerical modelling approach was undertaken to employ electron transport layers (ETL) and hole transport layers (HTL) to the copper-doped CdS/CdTe solar cells. We obtained optimum results with titanium dioxide and copper barium thiostannate as ETL and HTL respectively. Finally, CdTe-based solar cells were modelled integrating copper-doped CdS as the buffer layers, TiO2 as ETL and CBTS as HTL respectively. The obtained experimental values of Cu-doped CdS and CdTe layers were implemented into this model. This superstrate configuration yielded impressive output parameters: open circuit voltage of 1.07 V, short-circuit current density of 29.32 mA cm−2, fill factor of 85.08 %, and efficiency of 26.67 %.

Temperature and Ge fraction dependence of broad peaks observed in Ge-rich SiGe Raman spectra by oil-immersion Raman spectroscopy

Abstract We present the temperature and Ge fraction dependence of the broad peaks at the lower wavenumber side of the Ge-Ge vibration mode in Raman spectra from Ge-rich Si1−xGex thin films (x = 0.750, 0.852, and 0.918) investigated by oil-immersion Raman spectroscopy. The sample temperature was elevated by increasing laser power and estimated using the relation between Raman shift ω and temperature T (dω/dT) of Ge-Ge vibration mode. The broad peaks observed from all the Ge-rich SiGe thin films shifted toward the lower wavenumber side with increasing laser power. We confirmed that dω/dT of the broad peak differs from the Ge-Ge vibration mode and changes with increasing Ge fraction. In addition, we found that the correlation between Ge fraction and the peak intensity ratio of the broad peak and the Ge-Ge vibration mode is almost the same at various laser power conditions.

Object Recognition in Foggy and Hazy Conditions Using Dark Channel Prior-Based Fringe-Adjusted Joint Transform Correlator

Extreme weather conditions like fog and haze present substantial challenges to object recognition systems. Reduced visibility and contrast degradation significantly affect the auto-correlation process, often leading to failure in object recognition. To address this critical issue and to make object recognition accurate and invincible, we propose a hybrid digital–optical correlator specifically designed to perform under adverse weather conditions. This approach integrates the dark channel prior (DCP) with the fringe-adjusted joint transform correlator (FJTC), promising significant potential to enhance the robustness of the object recognition process under challenging environmental conditions. The proposed scheme presents a unique and alternative approach for object recognition under bad weather conditions. The incoming input scenes are processed with the DCP, enabling the FJTC to perform optical correlation on the refined images. The effectiveness of the proposed method is evaluated using several performance metrics like the structural similarity index measure (SSIM), peak signal-to-noise ratio (PSNR), correlation peak intensity (CPI), processing time, and recognition accuracy. To validate the performance of the proposed study, numerical simulation along with hybrid digital–optical demonstrations have been conducted.

Enhanced Peak and Extended Cooling of the Extreme-ultraviolet Late Phase in a Confined Solar Flare

We present observations and analysis of an X1.8 noneruptive solar flare on 2012 October 23, which is characterized by an extremely large late-phase peak seen in the warm coronal extreme-ultraviolet (EUV) emissions (∼3 MK), with the peak intensity over 1.4 times that of the main flare peak. The flare is driven by a failed eruption of a magnetic flux rope, whose strong squeeze force acting on the overlying magnetic structures gives rise to an intense early heating of the late-phase loops. Based on differential emission measure analysis, it is found that the late-phase loops experience a “longer-than-expected” cooling, without the presence of any obvious additional heating, while their volume emission measure maintains a plateau for a long time before turning into an evident decay. Without the need for an additional heating, we propose that the special thermodynamic evolution of the late-phase loops revealed in this flare might arise from loop cross-sectional expansions with height, which are evidenced by both direct measurements from EUV images and by magnetic field extrapolation. By blocking the losses of both heat flux and mass from the corona, such an upward cross-sectional expansion not only elongates the loop-cooling time, but also more effectively sustains the loop density, therefore leading to a later-than-expected occurrence of the warm coronal late phase in combination with a sufficiently high late-phase peak. We further verify such a scenario by analytically solving the cooling process of a late-phase loop characterized by a variable cross section.

A Physics-Informed Auto-Learning Framework for Developing Stochastic Conceptual Models for ENSO Diversity

Abstract Understanding El Niño–Southern Oscillation (ENSO) dynamics has tremendously improved over the past few decades. The ENSO diversity in spatial pattern, peak intensity, and temporal evolution is, however, still poorly represented in conceptual ENSO models. In this paper, a physics-informed auto-learning framework is applied to derive ENSO stochastic conceptual models with varying degrees of freedom. The framework is computationally efficient and easy to apply. Once the state vector of the target model is set, causal inference is exploited to build the right-hand side of the equations based on a mathematical function library. Fundamentally different from standard nonlinear regression, the auto-learning framework provides a parsimonious model by retaining only terms that improve the dynamical consistency with observations. It can also identify crucial latent variables and provide physical explanations. This methodology successfully reconstructs the equations of a realistic six-dimensional reference ENSO model based on the recharge oscillator theory from its data. A hierarchy of lower-dimensional models is derived, and their representation of ENSO (including its diversity) is systematically assessed. The minimum model that represents ENSO diversity is four-dimensional, with three interannual variables describing the western Pacific thermocline depth, the eastern and central Pacific sea surface temperatures (SSTs), and one intraseasonal variable for westerly wind events. Without the intraseasonal variable, the resulting three-dimensional model underestimates extreme events and is too regular. A limited number of weak nonlinearities in the model are essential in reproducing the observed extreme El Niño events and the observed nonlinear relationship between eastern and western Pacific SSTs. Significance Statement This study develops a physics-informed auto-learning approach to improve the modeling and understanding of El Niño–Southern Oscillation (ENSO), a major climate phenomenon influencing global weather and climate. The auto-learning framework explores the causality between key processes to systematically produce stochastic conceptual models with different climate factors that simulate the diversity of observed ENSO events. The key finding is that the minimal model for characterizing the ENSO diversity (with the least number of climate factors) is a four-variable model capturing thermocline depth, sea surface temperatures, and wind bursts that can reproduce intensity and spatial pattern variation. This advancement provides an interpretable tool to identify the minimum sufficient processes governing ENSO behavior for improved predictability.

Electron probe microanalysis of trace sulfur in experimental basaltic glasses and silicate minerals

Abstract Sulfur (S) in the mantle is conventionally assumed to be exclusively stored in accessory sulfide phases, but recent work shows that the major silicate minerals that comprise >99% of the mantle could be capable of hosting trace amounts of S. Assessing the incorporation of trace S in nominally S-free mantle minerals and determining equilibrium S partitioning between these minerals and basaltic melt requires analyzing small experimental phases with low S contents. Here, we develop a protocol for EPMA analysis of the trace levels of S in silicate phases. We use a suite of natural and experimental basaltic glass primary and secondary standards with S contents ranging from 44 ppm to 1.5 wt%. The effects of beam current and counting time are assessed by applying currents ranging from 50 to 200 nA and total counting times between 200 and 300 s at 15 kV accelerating voltage. We find that the combination of 200 nA beam current with a 200 s counting time (80 s peak, 60 s each for upper and lower background, respectively) achieves precise yet cost-effective measurements of S down to a calculated detection limit of ~5 ppm and a blank-derived, effective detection limit of ~17 ppm. Close monitoring of the S peak intensity and position throughout the duration of each spot also shows that high currents and extended dwell times do not compromise the accuracy of measurements, and even low S contents of 44 ppm can be reproduced to within one standard deviation. Using our developed recipe, we analyzed a small suite of experimental clinopyroxenes (Cpx) and garnets (Gt) from assemblages of silicate partial melt + Cpx ± Gt ± sulfide, generated at 1.5 to 3.0 GPa and 1200 to 1300 °C. We find S contents of up to 71 ± 35 ppm in Cpx and 63 ± 28 ppm in Gt and calculate mineral-melt partition coefficients (Dsmin/melt) of up to 0.095 ± 0.064 and 0.110 ± 0.064 for DsCpx/melt and DsGt/melt, respectively. The sulfur capacity and mineral-partitioning for Cpx are in good agreement with SXRF measurements in a prior study by Callegaro et al. (2020), serving as an independent validation of our EPMA analytical protocol.

A novel combining Raman-photoluminescence method to characterize the brittle and plastic states of fused silica based on nanoscale ring structures and atomic point defects

Fused silica has been widely used in many key technical domains. However, the inevitably induced micron-sized brittle fractures during manufacturing processes seriously affect its service performance. Scanning electron and atomic force microscopes are mainly employed to estimate the brittle and plastic states (BPS) of the precise fused silica components, which would put strict demands on the dimensions of detected components and damage the detected surfaces. Herein, the evolution rules of the D2 characteristic peak intensities in Raman spectra corresponding to three-fold rings with the BPS were explored. Interestingly, it is found that the D2 peak intensity first greatly increases in brittle-plastic mixing zones and then sharply decreases in brittle zones. The evolution mechanisms of the nanoscale rings with respect to the BPS were further revealed using the molecular dynamics modeling. The enveloping-space compression of rings and the ring conversion from large- to small rings are found to be the leading factors of the significant increase of the three-fold rings in brittle-plastic mixing zones. And the abrupt destruction of ring structures due to amounts of damaged Si-O bonds in brittle zones contributes to the sharp decrease of the three-fold rings. Based on the evolution rules of the nanoscale rings with the BPS, the brittle-plastic mixing zones could be distinguished from the brittle and plastic zones. It also implies that the rings, especially three-fold rings may dominate the BPS. Moreover, the change laws of the photoluminescence properties with BPS were also studied. It has been found that the photoluminescence envelope area sharply increases with the BPS. It indicates that the concentrations of the atomic point defects would sharply increase with the BPS. Based on the evolution rules of the atomic point defects with the BPS, the brittle and plastic zones could be distinguished. Therefore, a novel Raman-photoluminescence combined method was proposed to characterize the BPS. Finally, its wide applicability was also verified in various specific cases. To sum up, the investigation develops a novel spectral method to effectively characterize the BPS. It is significant for the early warning of the material brittle fractures and the nondestructive characterization of fused silica during the manufacturing processes, which could vigorously promote the further application of fused silica components in various fields.

Tracheal Anastomosis Leaks Across Suture Techniques and Tensions: A Biomechanical Ex Vivo Study.

Anastomotic leak after tracheal resection may occur while coughing in the early postoperative period. We investigated the varying effects of suturing technique, stretch, and tension on anastomotic leaks during simulated coughs. End-to-end anastomoses were performed using continuous or interrupted sutures on excised porcine larynges. Tracheas were secured to a pressurized system simulating cough forces, submerged in a water bath, and stretched to 1, 2, and 3 cm above baseline. Peak pressure, incomplete cough generation, and observed leakages were recorded. Parameters were analyzed using Analysis of Variance (ANOVA), multiple linear regression, and logistic regression modeling. Peak tension (B = -0.660, p < 0.001) and stretch lengths (B = -0.329, p = 0.006) were associated with variance in peak pressure (R2 = 0.77, F(3,294) = 8.182, p < 0.001). Incomplete coughs increased with higher peak tension (odds ratio [OR] = 15.627, p < 0.001) and stretching to 3 cm above baseline (OR = 4.335, p < 0.007). Similarly, leak occurrences, primarily from the posterior tracheal wall, increased with higher peak tension (OR = 1.787, p < 0.001) and stretching to 3 cm (OR = 2.613, p = 0.017). No significance was identified with suturing technique. Interrupted and continuous suture techniques do not differ in anastomotic strength during simulated coughs. Increased peak tracheal tension is associated with a weaker anastomosis, and tracheal stretch to 3 cm was associated with a weaker anastomosis. Our study supports the commonly held clinical belief that, to create a stronger anastomosis, tension should be minimized, and particular attention should be placed at the posterior tracheal wall during closure. NA, Benchtop study Laryngoscope, 134:4998-5005, 2024.

Effects of Peanut Shell Flavonoids on Composite Film Properties and Cherry Tomato Preservation

ABSTRACTThis study investigated the effects of varying concentrations of peanut shell flavonoids (PSFs) on the properties of peanut meal extract‐tilapia skin protein composite films and their impact on cherry tomatoes preservation. Peanut meal alcohol extract (Pe) and tilapia skin protein (Co) were used as base materials, combined with PSFs to prepare composite films with excellent antioxidant properties. The results demonstrated that the optimized composite films exhibited superior mechanical properties, with a tensile strength of 9.83 MPa and an elongation at break of 204.04%. Increased flavonoid content enhanced the films' antioxidant capacity, achieving superoxide anion and DPPH radical scavenging rates of 15.08% and 21.37%, respectively. The microstructure, IR spectra, and circular dichroism spectra of the composite films are also significantly different with the change of flavonoid content. In the cherry tomato preservation experiment, the PeCo‐0.5 composite film treatment group maintained a low weight loss rate (11.18%) and malondialdehyde content (13.33 μmol/g) after 15 days, delayed the peak respiration rate, and significantly reduced the peak respiration intensity (3.43 mgCO2∙ mg−1∙gh−1). At the same time, the activity of polyphenol oxidase in the tissue of Cherry Tomatoes was significantly inhibited, and the decrease rate of Vc content was also significantly decreased, which effectively preserving the bright color, smooth appearance, and good aroma of the cherry tomatoes. This study not only provides new insights into the comprehensive utilization of tilapia skin and peanut by‐products but also opens new avenues for the development and application of fruit and vegetable preservation films.

Ozone-microbubble-enhanced oxidation of pharmaceuticals and personal care products in municipal secondary effluents

Microbubble aeration can greatly improve ozonation by enhancing ozone transfer and subsequent hydroxyl radical formation. Here, we applied microbubble ozonation to treat pharmaceuticals and personal care products (PPCPs) in several municipal secondary effluents. Compared with conventional ozonation, microbubble ozonation efficiently eliminated both ozone-reactive and ozone-resistant PPCPs and greatly reduced the ozone doses in the complex water matrixes of the secondary effluents. In addition, compared with millibubble ozonation, the removal of chemical oxygen demand (COD) increased by 32.0%–67.2% at 60mg/L ozone dose during microbubble ozonation. The carbon emission of microbubble ozonation varied in different water matrix, and was 47–76% less than that of millibubble ozonation. The oxidizing capacity ratio of microbubble to millibubble for PPCPs was between 1.26 to 3.50 times, and ozone-resistant PPCPs removal was enhanced more than ozone-reactive PPCPs by microbubble ozonation. Specifically, the oxidizing capacity ratio of microbubble to millibubble for carbamazepine (ozone-reactive) was 1.30 to 2.43 times, whereas that for N,N-diethyl-3-tolumide (ozone-resistant) was 1.88 to 3.50 times. Microbubble ozonation also greatly decreased the UV absorbance and fluorescence for all of the water samples. The UV absorbance at 254, 280, and 320nm decreased by 64.0%–83.8%, and the fluorescence peak intensity decreased by more than 94%. Surrogates for the removal of PPCPs and COD were evaluated and compared. This study provides new insights into the application of microbubble ozonation to control PPCPs in secondary effluents.

Characterization of natural soda ash for dosimetry using thermoluminescence technique

Soda ash, due to its various use for industrial applications, is a phosphor likely to be found in the vicinities of radiation facilities where retrospective dosimetry may be required in the unlikely events of radiation accidents/incidents. The ash is therefore a potential material for retrospective dosimetry using luminescence techniques. In this report, the thermoluminescence characteristics of soda ash from Suan pan, Botswana are presented. The thermoluminescence glow curve of the soda ash consists three peaks near 79, 175 and 329 oC with a shoulder around 221oC. The peak intensities of the peaks and the whole glow curve integrated intensity are linear with dose. Tm-Tstop analysis reveals soda ash contains four peaks near 82, 211, 235 and 335 oC. The four peaks are affected by thermal quenching with activation energy of thermal quenching 0.64 eV, 0.29 eV, 0.66 eV and 0.29 eV respectively. The intensities of the peaks decrease with optical stimulation. The minimum dose the phosphor can measure is evaluated to be 0.34 Gy. The thermoluminescence from soda ash is suitable for dosimetry, especially for high dose measurement. The peak near 335oC with mean lifetime greater than 250 years is the most suitable for dosimetry. The phosphor may be able to produce phototransfer thermoluminescence.

Ruthenium Nanoparticles Supported on Bentonite: Enhanced Crystallinity, Conductivity, and Dielectric Performance for Advanced Applications

We used the wet impregnation method to synthesize Ru nanoparticles supported on bentonite (Ru/Bento). The X-ray diffraction and Energy-Dispersive (EDX) Spectrometer characterisations of the synthesized structures revealed that the montmorillonite is the predominant phase. The reduced crystallite size and lower diffraction peak intensities for Ru/Bento indicate improvement in crystallinity. EDX confirmed the successful incorporation of Ru, suggesting fewer reactive hydroxyl groups on the bentonite surface. Dielectric studies show a decrease in permittivity with increasing frequency, consistent with the Maxwell-Wagner polarization mechanism. Ru/Bento exhibits higher permittivity at elevated temperatures due to enhanced interfacial polarization, and higher low-frequency dielectric loss attributed to resistive interfacial regions. Electric modulus analysis indicates significant relaxation processes in Ru/Bento at higher temperatures. Conductivity studies demonstrate increased charge carrier mobility with frequency and temperature, following a correlated barrier hopping mechanism, with Ru nanoparticles enhancing conductivity by reducing barrier height. HOMO and LUMO analysis suggest improved conductivity and reactivity for Ru/Bento due to lower energy gaps and chemical hardness. Molecular dynamics calculations confirm the geometric stability of Ru nanoparticles on bentonite, making Ru/Bento bentonite a promising material for high conductivity applications.