High Peak Research Articles

Low-cost fabrication methods of ZnO nanorods and their physical and photoelectrochemical properties for optoelectronic applications

Zinc Oxide (ZnO) nanorods have great potential in several applications including gas sensors, light-emitting diodes, and solar cells because of their unique properties. Here, three low cost and ecofriendly techniques were used to produce ZnO nanorods on FTO substrates: hydrothermal, chemical bath deposition (CBD), and electrochemical deposition (ECD). This study explores the impact of such methods on the optical, structural, electrical, morphological, and photoelectrochemical properties of nanorods using various measurements. XRD analysis confirmed the hexagonal wurtzite structure of ZnO nanorods in all three methods, with hydrothermal showing a preferred orientation (002) and CBD and ECD samples showing multiple growth directions, with average particle sizes of 31 nm, 34 nm, and 33 nm, respectively. Raman spectra revealed hexagonal Wurtzite structure of ZnO, with hydrothermal method exhibiting higher E2 (high) peak at 438 cm−1 than CBD and ECD methods. SEM results revealed hexagonal ZnO nanorods became more regular and thicker for the hydrothermal method, while CBD and ECD led to less uniform with voids. UV-vis spectra showed absorption lines between 390 nm and 360 nm. Optical bandgap energies were calculated as 3.32 eV, 3.22 eV, and 3.23 eV for hydrothermal, CBD, and ECD samples, respectively. PL spectra revealed UV emission band with a small intensity peak around 389 nm and visible emission peaks at 580 nm. Temperature dependent PL measurements for ZnO nanorods indicated that the intensities ratio between bound exciton and free exciton decreases with temperature increases for the three methods. Photocurrent measurements revealed ZnO nanorod films as n-type semiconductors, with photocurrent values of 2.25 µA, 0.28 µA, and 0.3 µA for hydrothermal, CBD, and ECD samples, and photosensitivity values of 8.01, 2.79, and 3.56 respectively. Our results suggest that the hydrothermal method is the most effective approach for fabricating high-quality ZnO nanorods for optoelectronic applications.

Fluid-filled lattices for responsive orthotic insoles

Abstract Orthotic insoles are essential for alleviating discomfort and preventing injuries in the foot caused by high peak pressures in the plantar tissue. Traditional orthotic insoles, often prescribed to address these issues, are designed based on the static foot shape and pressure measurements, lacking responsiveness to dynamic movements. This study explores the behaviour of fluid-filled lattices for improving the functionality of orthotic insoles, focusing on energy dissipation and pressure redistribution capabilities. Using numerical homogenisation, the research integrates hyperelastic and permeability models to simulate the behaviour of Solid-Liquid Composites (SLCs). Experimental tests validated these models, examining the influence of fluid viscosity and structural variations on energy dissipation and pressure distribution. Results show that fluid-filled lattices provide enhanced energy dissipation and reduce peak pressures by evening out the pressure distribution compared to non-fluid-filled samples. These findings highlight the potential of fluid-filled lattices to improve the performance and comfort of orthotic insoles.

Dendrochronology Applied to Three Forest Species in the Brazilian Amazon

Sustainable forest management is a legal alternative to combat deforestation and preserve natural resources in the long term. However, the lack of information on the growth and productivity of forests and individual species compromises its effectiveness. To obtain this information, dendrochronological techniques can be used. The aim of the study was to evaluate the dendrochronological potential of three tree species found in terra firme tropical rainforests: Astronium graveolens Jacquin, Hevea brasiliensis (Willd. ex A.Juss.) Müll.Arg., and Inga cylindrica (Vell.) Mart. The method involved collecting disks from the base of the trees (cross-dating), preparing the disks through polishing and scanning, and analyzing the growth rings based on anatomical characteristics. This technique is essential for understanding forest growth patterns, assessing tree responses to environmental changes, and supporting sustainable forest management practices. The three species showed distinct and visible growth rings to the naked eye. H. brasiliensis was classified as distinct, while A. graveolens and I. cylindrica were classified as less distinct. The dendrochronological analysis indicated that the three species presented a correlation between the growth ring series, with A. graveolens and H. brasiliensis showing an average correlation of 0.568 and 0.575, respectively, and I. cylindrica 0.3281. By analyzing the Master series, high growth peaks were identified for H. brasiliensis in 2012, 2013, 2016, 2017, and 2021, for A. graveolens in 1996, 1982, 2011, 2020, and 2005, and for I. cylindrica in 1989, 2001, 2008, 2010, 2014, 2016, and 2017. The species have dendrochronological potential and can contribute to the study of the cycle and minimum cutting diameter in forest management.

Synthesis of Amorphous Nickel-Cobalt Hydroxides for Ni-Zn Batteries.

In this work we developed a hydrothermal method for synthesizing amorphous Ni-Co hydroxide (NC(OH)) and in the subsequent step crystalline NiCo2O4 (NCO) has been produced using water as the solvent. For nickel-zinc batteries, NC(OH) was found to have superior performance to its NCO prepared by two-step process. The thermal stability analysis exhibited the optimum temperature to obtain the NC(OH), and NCO electrode materials. The XRD pattern showed mixed phases containing both Ni and Co hydroxides (during the initial step) and in the subsequent step (calcined) the formation of cubic spinel structure was noticed. For NC(OH), aggregated particles with irregular morphology were observed while clustered nanorod-like shapes were noticed for NCO samples. To be noted, that the nanorod morphology was obtained through a facile approach without employing any structure-directing agent. Both NC(OH) and NCO were employed as cathodes for Ni-Zn battery studies against Zn foil anode with a polyamide-based separator soaked in 6 M KOH saturated with ZnO additive was used as electrolyte. The Ni-Zn cell was fabricated in CR2032 coin cell configuration. The electrochemical studies such as cyclic voltammetry (CV) showed the characteristic redox peaks for NC(OH) sample exhibiting high peak current compared to its NCO counterpart. The NC(OH) had a capacity of 268 mAh g-1 against 120 mAh g-1 for NCO at a current density of 1 Ag-1. The cell was able to retain 85 % of the capacity at the end of 500 cycles and showed remarkable rate capability. The Ni-Zn battery presents energy and power densities of 428.8 Wh Kg-1 and 2.68 kW Kg-1, respectively surpassing the normal values reported for aqueous rechargeable batteries. Owing to the presence of Ni and Co in hydroxide form (reduced crystallinity) the NC(OH) sample showed improved electrochemical activity. This work provides a facile approach and effective strategy for developing bimetallic hydroxides for optimal energy storage performance.

Meso/Microporous Single‐Atom Catalysts with Curved Fe‐N4 sites Boost the Oxygen Reduction Reaction Activity

Zeolitic‐imidazolate frameworks (ZIFs) are among the most efficient precursors for the synthesis of atomically dispersed Fe‐N/C materials, which are promising catalysts for enhancing the performance of Zn‐air batteries (ZABs) and proton exchange fuel cells (PEMFCs). However, existing ZIF‐derived Fe‐N/C electrocatalysts mostly consist of microporous materials, leading to insufficient mass transport and inadequate battery/cell performance. In this study, we synthesize an atomically dispersed meso/microporous Fe‐N/C material with curved Fe‐N4 active sites, denoted as FeSA‐N/TC, through the pyrolysis of hemin‐modified ZIF films on ZnO nanorods, obtained from the self‐assembly reaction between Zn2+ from ZnO hydrolysis and 2‐methylimidazole. Density functional theory calculations demonstrate that the curved Fe‐N4 active sites can weaken the intermediate adsorptions, resulting in lower free energy barriers and enhanced performance during oxygen reduction reaction (ORR). Specifically, FeSA‐N/TC exhibits exceptional ORR performance with half‐wave potentials of 0.925 V in alkaline media and 0.825 V in acidic media. When used as the cathodic catalyst in PEMFCs and ZABs, FeSA‐N/TC achieves high peak power densities (H2‐O2 PEMFC: 1100 mW cm–2; H2‐Air PEMFC: 715 mW cm–2; liquid‐state ZAB: 228 mW cm–2; solid‐state ZAB: 112 mW cm–2), demonstrating its feasibility and efficiency in practical applications.

A Study on the interaction of shock tube-generated blast waves with a circular object at different pressure ratios

The interaction of high peak overpressure blast waves with a circular object placed at two different axial locations from the shock tube exit is studied through numerical simulation using an in-house developed multi-component Navier–Stokes solver. The driver and driven sections of the shock tube were 0.8 m and 6 m, respectively. Helium is used in the driver section, while atmospheric air is used in the driven section and outside the shock tube. The evolution of blast waves inside an open-ended shock tube and its interaction with a rectangular object is reported in Murugan et al.. (2022). Here, the blast wave interacting with a circular object is examined for diaphragm pressure ratios of 13 and 57 by placing the objects at 250 mm and 500 mm from the shock tube exit. The flow field is evaluated through numerical Schlieren, vorticity, density, pressure plots, and the enstrophy plot, which shows the vortical structures that originated in the flow field. The blast load acting on the circular object is calculated for two diaphragm pressure ratios and axial locations. This study helps understand the reflection and diffraction of blast waves and associated flow fields around circular objects used in blast wave attenuation.

Meso/Microporous Single-Atom Catalysts with Curved Fe-N4 sites Boost the Oxygen Reduction Reaction Activity.

Zeolitic-imidazolate frameworks (ZIFs) are among the most efficient precursors for the synthesis of atomically dispersed Fe-N/C materials, which are promising catalysts for enhancing the performance of Zn-air batteries (ZABs) and proton exchange fuel cells (PEMFCs). However, existing ZIF-derived Fe-N/C electrocatalysts mostly consist of microporous materials, leading to insufficient mass transport and inadequate battery/cell performance. In this study, we synthesize an atomically dispersed meso/microporous Fe-N/C material with curved Fe-N4 active sites, denoted as FeSA-N/TC, through the pyrolysis of hemin-modified ZIF films on ZnO nanorods, obtained from the self-assembly reaction between Zn2+ from ZnO hydrolysis and 2-methylimidazole. Density functional theory calculations demonstrate that the curved Fe-N4 active sites can weaken the intermediate adsorptions, resulting in lower free energy barriers and enhanced performance during oxygen reduction reaction (ORR). Specifically, FeSA-N/TC exhibits exceptional ORR performance with half-wave potentials of 0.925 V in alkaline media and 0.825 V in acidic media. When used as the cathodic catalyst in PEMFCs and ZABs, FeSA-N/TC achieves high peak power densities (H2-O2 PEMFC: 1100 mW cm-2; H2-Air PEMFC: 715 mW cm-2; liquid-state ZAB: 228 mW cm-2; solid-state ZAB: 112 mW cm-2), demonstrating its feasibility and efficiency in practical applications.

8614 Low Dose Sublingual Estradiol Decreases Protein S, Generating a Potentially Pro-thrombotic Profile: Interim Results of a Controlled Prospective Pilot Study of Treatment-Naïve Trans Women

Abstract Disclosure: S. Bar On: None. I. Yaish: None. M. Barzilai: None. Y. Greenman: None. G. Gindis: None. Y. Moshe: None. K.M. Tordjman: None. Background: Sublingual estradiol (SLE) for gender-affirming hormone therapy (GAHT) of transgender women (TW) might obviate the need for an anti-androgen, and mitigate pro-coagulant changes. We recently showed that 2 mg E, divided into 4 daily sublingual doses, offers no clinical advantage over the same dose given orally in combination with cyproterone acetate (CPA)1. Furthermore, we showed that after each sublingual administration, serum estradiol (sE2) peaked to levels, the likes of which are achieved only during induction of ovulation with gonadotrophins. Hypothesis and Aim: Given the exceedingly high peak sE2 measured under SLE-GAHT, we hypothesized it could lead to partial acquired Protein S deficiency, a recognized pro-thrombotic state and risk factor for venous thromboembolic events (VTE). Our aim was to assess the hemostatic system under SLE in comparison with the standard combined oral (CO) approach. Design and Methods: In this ongoing open label study, treatment-naïve TW are assigned in a 1:1 ratio (15 in each arm) to either standard CO (2 mg E2 with 10 mg CPA once daily), or to SLE with 2 mg sublingual estradiol divided into 4 daily dose for 6 months (6M). An extensive battery of hemostatic biomarkers, including free Protein S antigen (fPS), are assessed at baseline (BL) and at 6M. Results: We herein report on 27 subjects (15 CO/12 SLE) who initiated treatment, 17 of whom have already completed it. The median age of the cohort is 20 y (IQR 19-27; range 18-42]. There were no BL differences between the groups. At 6M, none of the hemostatic markers differed between the groups except for fPS, which was significantly lower in the SLE group 79.7%±11.6% vs. 104.6%±5.6%, P=0.039. By paired comparisons for the entire group, fPS decreased from 104%.2±5.2% at BL to 95.8%±5.9% at 6M, P=0.003. This was entirely accounted for by the change in the SLE group, in which fPS went down from 95.7%±10.3% to 79.7%±11.6%, P<0.001; with some values reaching the fPS deficiency range. In contrast, fPS, remained unchanged under CO 108.9%±5.7% and 104.5%±5.2%, at BL and 6M respectively, P=0.153. Conclusions: The most notable interim finding was a clinically significant decrease in fPS under low dose SLE. Given the extreme peaks of sE2 we previously reported with this protocol, an acquired deficiency of this natural anti-coagulant was expected. These preliminary findings support our hypothesis, and raise the concern that GAHT of TW with chronic SLE might carry an increased long-term risk for VTE. 1 Yaish I, Gindis G, Greenman Y, et al. Sublingual Estradiol Offers no Apparent Advantage Over Combined Oral Estradiol and Cyproterone Acetate for Gender-Affirming Hormone Therapy of Treatment-Naive Trans Women: Results of a Prospective Pilot Study. Transgend Health. 2023;8(6):485-493. Published 2023 Dec 13. doi:10.1089/trgh.2023.0022 Presentation: 6/2/2024

8614 Low Dose Sublingual Estradiol Decreases Protein S, Generating a Potentially Pro-thrombotic Profile: Interim Results of a Controlled Prospective Pilot Study of Treatment-Naïve Trans Women

Abstract Disclosure: S. Bar On: None. I. Yaish: None. M. Barzilai: None. Y. Greenman: None. G. Gindis: None. Y. Moshe: None. K.M. Tordjman: None. Background: Sublingual estradiol (SLE) for gender-affirming hormone therapy (GAHT) of transgender women (TW) might obviate the need for an anti-androgen, and mitigate pro-coagulant changes. We recently showed that 2 mg E, divided into 4 daily sublingual doses, offers no clinical advantage over the same dose given orally in combination with cyproterone acetate (CPA)[1]. Furthermore, we showed that after each sublingual administration, serum estradiol (sE2) peaked to levels, the likes of which are achieved only during induction of ovulation with gonadotrophins. Hypothesis and Aim: Given the exceedingly high peak sE2 measured under SLE-GAHT, we hypothesized it could lead to partial acquired Protein S deficiency, a recognized pro-thrombotic state and risk factor for venous thromboembolic events (VTE). Our aim was to assess the hemostatic system under SLE in comparison with the standard combined oral (CO) approach. Design and Methods: In this ongoing open label study, treatment-naïve TW are assigned in a 1:1 ratio (15 in each arm) to either standard CO (2 mg E2 with 10 mg CPA once daily), or to SLE with 2 mg sublingual estradiol divided into 4 daily dose for 6 months (6M). An extensive battery of hemostatic biomarkers, including free Protein S antigen (fPS), are assessed at baseline (BL) and at 6M. Results: We herein report on 27 subjects (15 CO/12 SLE) who initiated treatment, 17 of whom have already completed it. The median age of the cohort is 20 y (IQR 19-27; range 18-42]. There were no BL differences between the groups. At 6M, none of the hemostatic markers differed between the groups except for fPS, which was significantly lower in the SLE group 79.7%±11.6% vs. 104.6%±5.6%, P=0.039. By paired comparisons for the entire group, fPS decreased from 104%.2±5.2% at BL to 95.8%±5.9% at 6M, P=0.003. This was entirely accounted for by the change in the SLE group, in which fPS went down from 95.7%±10.3% to 79.7%±11.6%, P<0.001; with some values reaching the fPS deficiency range. In contrast, fPS, remained unchanged under CO 108.9%±5.7% and 104.5%±5.2%, at BL and 6M respectively, P=0.153. Conclusions: The most notable interim finding was a clinically significant decrease in fPS under low dose SLE. Given the extreme peaks of sE2 we previously reported with this protocol, an acquired deficiency of this natural anti-coagulant was expected. These preliminary findings support our hypothesis, and raise the concern that GAHT of TW with chronic SLE might carry an increased long-term risk for VTE. [1] Yaish I, Gindis G, Greenman Y, et al. Sublingual Estradiol Offers no Apparent Advantage Over Combined Oral Estradiol and Cyproterone Acetate for Gender-Affirming Hormone Therapy of Treatment-Naive Trans Women: Results of a Prospective Pilot Study. Transgend Health. 2023;8(6): 485-493. Published 2023 Dec 13. doi:10.1089/trgh.2023.0022 Presentation: 6/2/2024

Predicting plateau atmospheric ozone concentrations by a machine learning approach: A case study of a typical city on the southwestern plateau of China

Atmospheric ozone (O3) has been placed on the priority control pollutant list in China's 14th Five-Year Plan. Due to their unique meteorological conditions, plateau regions contain high concentrations of atmospheric O3. However, traditional experimental methods for determining O3 concentrations using automatic monitoring stations cannot predict O3 trends. In this study, two machine learning models (a nonlinear auto-regressive model with external inputs (NARX) and a temporal convolution network (TCN)) were developed to predict O3 concentrations in a plateau area in the Kunming region by considering the effects of meteorological parameters, air quality parameters, and volatile organic compounds (VOCs). The plateau O3 prediction accuracy of the machine learning models was found to be much higher than those of numerical models that served as a comparison. The O3 values predicted by the machine learning models closely matched the actual monitoring data. The temporal distribution of plateau O3 displayed a high all-day peak from February to May. A correlation analysis between O3 concentrations and feature parameters demonstrated that humidity is the feature with the highest absolute correlation (−0.72), and was negatively correlated with O3 concentrations during all test periods. VOCs and temperatures were also found to have high positive correlation coefficients with O3 during periods of significant O3 pollution. After negating the effects of meteorological parameters, the predicted O3 concentrations decreased significantly, whereas they increased in the absence of NOx. Although individual VOCs were found to greatly affect the O3 concentration, the total VOC (TVOC) concentration had a relatively small effect. The proposed machine learning model was demonstrated to predict plateau O3 concentrations and distinguish how different features affect O3 variations.

Pulsed uplift of the South Tianshan since the Late Miocene indicated by the linear inversion on river longitudinal profiles

The early Cenozoic collision and subsequent continuous convergence between the Indian and Eurasian plates reactivated the Tianshan orogen in the Central Asia and caused multistage uplift of the mountain range. The modern Tianshan, with high mountain peaks of >7000 m, forms very prominent topography that profoundly affects the regional tectonics and climate. However, the late Cenozoic uplift process and topography growth of the South Tianshan remain controversial. River longitudinal profile inversion provides a distinctive way to reveal rock uplift history since the late Cenozoic. In this study, we presented linear inversion on river longitudinal profiles of four drainage basins originating from high mountains in the South Tianshan. The inversion results from two basins in the northern flank show fast and continuous increases in the uplift rates from about 0.1–0.2 mm/a to 0.6–1.0 mm/a since 4 Ma. While in the southern flank, the uplift rates of the two basins increased gradually from about 0.1 mm/a to 0.2 mm/a before 10 Ma and from 0.2 mm/a to 0.4 mm/a around 10 Ma and 6 Ma, respectively. Our results combined with recently published chronological data in this region indicate that the South Tianshan experienced a pulsed tectonic uplift process since the Late Miocene. Moreover, the pulsed tectonic uplift should lead to an elevated South Tianshan during 6–4 Ma, coinciding well with the ∼5.3 Ma extreme aridification in the Tarim Basin, thus supporting that the rain shadow effect caused by high topography of South Tianshan is a critical reason for aridification.

Chemical Pressure-Driven Band Convergence and Discordant Atoms Intensify Phonon Scattering Leading to High Thermoelectric Performance in SnTe.

SnTe is an intriguing alternative to PbTe for midtemperature thermoelectric applications. Despite steady progress, its performance is lagging, in part because of the large energy difference(ΔEL-Σ) between the light (L-band) and heavy (Σ-band) valence bands and higher lattice thermal conductivity (κL). Previous studies have shown that applying pressure can enhance the Seebeck coefficient (S) and power factor (PF) of SnTe. Inspired by this study, we showcase how the high-pressure effect can be emulated under ambient pressure by substituting Sn with atoms possessing smaller atomic radii. Specifically, Sb- and Ge-doping combined with CdTe- or CdS-alloying induce lattice shrinkage, also referred to as "chemical pressure", raising the energy of the Σ-band. Additionally, these substituted atoms lower the contribution of Sn 5s-Te 5p antibonding states to the L-band, thereby reducing its energy and dispersion. These combined effects decrease ΔEL-Σ from 0.36 to 0.09 eV, leading to the enhanced S and average PFavg. Notably, the PFavg, ranging from 323 to 873 K, increases from 8.1 μW cm-1 K-2 for pristine SnTe to 21.6 μW cm-1 K-2 for Sn0.79Ge0.15Sb0.06Te-5% CdTe. Furthermore, the intensified phonon scattering resulting from discordant nature of Ge and Cd atoms, creating point defects soften phonon modes, and the presence of Ge-rich nanoprecipitates lead to a substantial 62% reduction in κL at 873 K. This strong valence band convergence and enhanced phonon scattering collectively contribute to a high peak ZT of 1.5 (873 K) and high average ZTavg = 0.81 over the temperature range of 323-873 K.

Computer simulation of the electrical properties of carbon nanotubes encapsulated with alkali metal iodide crystals

The progress of modern electronics largely depends on the discovery and use of new materials with unique properties. One of such promising materials is carbon nanotubes. Their outstanding mechanical, thermal, and electrical properties open up new possibilities for creating small-sized electronic devices and improving the characteristics of existing materials by improving their manufacturing and processing technologies. One of the unique features of carbon nanotubes is their ability to encapsulate other atoms or molecules within their structure. This property can be used to create nanocontainers capable of protecting and transporting active substances or to change the electronic properties of nanotubes depending on the encapsulated substance. In this work, crystals of alkali metal iodides MI were encapsulated in carbon nanotubes with different structures and characteristics. The results obtained in terms of energy and density spectra of the state indicate the characteristics of conductivity due to an increase in energy and high peaks in the Fermi level. Thus, carbon nanotubes represent an important material for future developments in the field of nanoelectronics and nanotechnology.

Energy absorption of the kirigami-inspired pyramid foldcore sandwich structures under low-velocity impact

Foldcore sandwich structures offer a promising alternative to conventional honeycomb sandwiches in the field of lightweight structures, demonstrating significant potential as efficient energy absorption devices. The dynamic behavior of foldcore sandwich structures is crucial in response to low-velocity impacts in various engineering scenarios such as bird strikes, airdrops, and vehicle collisions. This study investigates the dynamic responses of a kirigami-inspired pyramid foldcore sandwich subjected to low-velocity impacts, which has previously exhibited remarkable energy absorption efficiency under quasi-static compression. Through a combination of experimental investigations and numerical simulations under impact conditions, it is observed that the pyramid foldcore initially undergoes pronounced localized deformation which results in a sensitivity to the loading rate and causes the high initial peak stress. Different from the mechanism observed under quasi-static compression, additional stationary plastic hinges on the facets are triggered during the post-buckling stage, thereby slightly enhancing the overall energy absorption. Moreover, the multi-layer pyramid foldcores with graded geometries are proposed, characterized by varying height and wall thickness for each layer. The graded pyramid foldcores significantly reduce the initial peak stress while maintaining energy absorption efficiency. In comparison with the conventional square honeycomb and Miura-ori foldcore under the impact velocity of 10 m/s, the uniformity ratio of the graded pyramid foldcore decreases by 70.9% and 80.5%, while the specific energy absorption improves by 0.97% and 138.37%, respectively. To summarize, the graded pyramid foldcore shows outstanding energy absorption efficiency, indicating its potential as a high-performance sandwich structure for impact applications.

Intelligent controllable ultrafast fiber laser via deep learning and adaptive optimization algorithm

Ultrafast fiber lasers based on nonlinear polarization rotation can generate femtosecond pulses with different pulse durations and high peak powers, which are powerful tools for engineering applications and scientific research. However, achieving a precise and repeatable polarization state for generating the ultrashort pulses with the shortest pulse duration remains a significant challenge. In this paper, we extend the use of recurrent neural networks and adaptive optimization algorithms, specifically designed to optimize repetitive processes in optical systems, to facilitate intelligent search and control aimed at achieving the minimum pulse duration within a mode-locked fiber laser cavity. Our multi-algorithm-based intelligent system can fully simulate and optimize the processes involved in hands-on experiments. Our intelligent system identified a mode-locked fiber laser with the shortest pulse duration of 465 fs, which was experimentally verified. The proposed intelligent algorithm not only identifies the shortest pulse but also holds significant potential for selecting related laser characteristic parameters. We believe this work opens up a novel avenue for exploration and optimization in mode-locked lasers and the intelligent laser can find practical applications in engineering and scientific research.

Maleic anhydride esterified potato starch as the binder in silicon nanoparticles anode for lithium-ion batteries

Potato starch is a natural carbohydrate binder. Starch has hydroxyl groups that can promote interaction with silicon particles using multifaceted hydrogen bonds. Maleic anhydride esterified potato starch can produce a binder that maintains the cycle stability of lithium-ion batteries. Fourier-transform infrared spectroscopy spectra show wavelengths of 1776 cm−1 and 1855 cm−1. Thermal gravimetric analysis curves decreased in weight percent by 80 % at 286 °C. Carbon-13 nuclear magnetic resonance spectra show high peaks at 3.37 ppm, 3.65 ppm, 4.56 ppm, 5.09 ppm, and 6.22 ppm. Scanning electron microscope images show that the morphological change in esterified starch was due to the increased length of starch and the maleic anhydride grafted onto the starch granules. The cyclic voltammetry curve shows that the reduction peak is around 0.16 V, and the oxidation peak is around 0.38 V and 0.56 V. Nyquist plots show a small half circle, indicating that the electrode's solid-electrolyte interphase layer is low. The cycling performance shows a capacity of 1950 mAh/g.

Development of Automotive and Marine Appliable Aluminium Composite by Utilizing Agro-Waste Material as Performance Enhancement Particles

Aluminium-based materials are lightweight materials used for producing automotive and aircraft components. However, aluminium materials diminish in performance on exposure to degrading environments, which limits their areas of usage and applications. The degrading effect results in poor resistance to wear and corrosion, reduced properties and defective microstructure. In this work, 6063 aluminium alloy was reinforced with particles of agricultural waste (walnut shell) to produce six samples with five samples of reinforced and a control (unreinforced) sample. Each of the samples of the reinforced alloy was moulded into a 25 mm diameter by 130 mm height using the stir casting method using an industrial pit furnace. The samples were thereafter machined to a diameter of 20 mm and cut into a thickness of 10 mm for characterizations. The potentiodynamic polarization method was used to test for the samples’ corrosion resistance properties following the ASTM G102 standard in 3.65% NaCl test medium. The hardness property was investigated using the Brinell hardness machine following the ASTM A-370 standard, while the microstructure and crystallographic phase studies were carried out using SEM/EDS and XRD profiles, respectively. The unreinforced 6063 Al alloy sample exhibited the highest corrosion rate (Cr) of 0.7321 mm/year and the lowest hardness of 104.94 kgf/mm2. The 10% wt. walnut shell particles (WSP) reinforced 6063 Al alloy sample exhibited the lowest corrosion rate (Cr) of 0.1336 mm/year and the highest hardness of 109.24 kgf/mm2. This indicated that the walnut shell particles enhanced the corrosion and indentation resistance of the alloy. In addition, the SEM images indicated that the agricultural waste (walnut shell particles) reinforced samples exhibited more refined microstructure, lower porosity and smoother morphology compared to the unreinforced (control) sample. Also, the XRD profile of samples revealed some high peak intensity crystallites such as Al(ZnS), Al2O3 and (FeMn)SiO2. These high peak intensity crystallites indicated that these reinforced samples possessed chemical and microstructural homogeneity, high stability and good surface texture.

Study on mechanical response control of metal-ceramic dual phase hybrid lattice structure

Different from the previous trial-and-error and empirical development process of new materials, the failure and deformation of meso-structure of lattice structures are considered as a means to customize the mechanical response in this paper. Based on this, a novel metal-ceramic dual phase hybrid lattice structure (DPHLS) with both high peak stress and long plateau stage mechanical response is designed here, which can satisfy the complex mechanical response requirements of impact target materials in hard target penetration research. DPHLS is composed of ceramic-based SC plate lattice structure and metal-based FCC plate lattice structure, which has a large range of mechanical properties control. Besides, combining the advantages of ceramic and metal, DPHLS also has seemingly conflicting properties of load-withstanding and energy absorption. In the present work, the contribution of failure and deformation behavior to the mechanical response of the structure is deeply analyzed at the mesoscopic level using theoretical analysis and numerical simulation. And the quantitative relationship between the geometrical parameters of the structure and the mechanical response is established actively. The results show that the three dimensionless geometric parameters, which characterize the geometry of DPHLS, can effectively regulate its mechanical response. This study not only provides a reliable theoretical basis for the meso-structure design of DPHLS, but also proposes a new strategy for the customization of mechanical response.

Relationship Between Fatigue and Quantitative Electromyography Findings in Patients with Myasthenia Gravis

BackgroundFatigue is a common complaint among patients with myasthenia gravis (MG). In this study, we investigated the alterations in muscle morphology in patients with MG experiencing fatigue using quantitative electromyography (QEMG), and explored the relationship between electrophysiological findings and the severity of both fatigue and disease. MethodsWe performed QEMG of the biceps brachii muscle using the peak ratio method and multi-motor unit potential (MUP) analysis across three groups: 18 MG patients with fatigue, 34 MG patients without fatigue, and 33 healthy subjects. Stimulated single-fiber EMG was performed on the frontalis muscle. The severity of perceived fatigue and disease was subsequently assessed using the quantitative myasthenia gravis (QMG) score, the MG-activities of daily living (MG-ADL) profile, self-reported fatigue questionnaires, and handgrip strength measurements. ResultsThe QEMG study revealed a reduced mean MUP duration and size index (SI), in addition to an increased peak ratio in patients with MG (p<0.05), which tended to be more pronounced in those experiencing fatigue. Compared to healthy subjects, MG patients with fatigue displayed a myopathic pattern characterised by a high peak ratio, short duration, and small-amplitude MUPs, without any increase in the number of phases or small time intervals. The mean peak ratio was positively correlated with the QMG, MG-ADL, and Fatigue Impact Scale total and physical subscores (p<0.05). Further, MG patients with fatigue exhibited reduced maximum grip strength, which was positively correlated with the mean MUP duration, amplitude, SI, and thickness, and negatively correlated with the mean peak ratio (p<0.05). No significant differences were observed in the jitter or block measurements (p>0.05). ConclusionsThe present study investigated electrophysiological findings that were not considered or theorised in prior studies on patients with MG experiencing fatigue. The results of this study suggest that myopathic changes may be a critical pathophysiological component underlying the fatigue associated with MG.

Calculation of in-situ steady-state heat flux on EAST lower divertor

Heat flux is a key issue in tokamak devices. The non-uniform high heat flux on Plasma-Facing Components (PFCs) has led to local severe damage, including cracks and melting, in current tokamaks such as EAST and WEST. To characterize the non-uniform heat flux loading on the divertor surfaces, the parallel incident heat flux q‖, the decay length λq along the radial direction and the Gaussian spreading width S are used. The q‖ can lead to a very high peak heat flux loading on the divertor surfaces, which may cause critical heat flux problems. Additionally, the decay length is a key consideration for future tokamak designs like ITER. Every effort on the present tokamak devices contributes to updating the scaling of the heat flux. In EAST, a calculation method based on a high spatial resolution IR camera is employed to obtain the heat flux and decay length. The main process involves comparing the surface temperature distribution calculated by Fluent simulation with that measured by an infrared camera. Taking a high heating source discharge (#123059 ∼ 10 MW heating source) as an example, the heat flux is as follows: q‖=216-14+19 MW/m2, with λq=6.2-1.1+1 mm, and S=1.2±0.4 mm; it is in line with Langmuir probe data. The infrared-based heat flux calculation method can calculate the peak incident heat flux and the decay length simultaneously, its result can help to update the scaling model of heat flux, thus not only helping to improve the present device but also offering important reference for future tokamaks