Long-term Tests Research Articles

Persistent resampling of external information despite 25 repetitions of the same visual search templates

We commonly load visual working memory minimally when to-be-remembered information remains available in the external world. In visual search, this is characterised by participants frequently resampling previously encoded templates, which helps minimize cognitive effort and improves task performance. If all search templates have been rehearsed many times, they should become strongly represented in memory, possibly eliminating the benefit of reinspections. To test whether repetition indeed leads to less resampling, participants searched for sets of 1, 2, and 4 continuously available search templates. Critically, each unique set of templates was repeated 25 trials consecutively. Although the number of inspections and inspection durations initially decreased strongly when a template set was repeated, behaviour largely stabilised between the tenth and last repetition: Participants kept resampling templates frequently. In Experiment 2, participants performed the same task, but templates became unavailable after 15 repetitions. Strikingly, accuracy remained high even when templates could not be inspected, suggesting that resampling was not strictly necessary in later repetitions. We further show that seemingly ’excessive’ resampling behaviour had no direct within-trial benefit to speed nor accuracy, and did not improve performance on long-term memory tests. Rather, we argue that resampling was partially used to boost metacognitive confidence regarding memory representations. As such, eliminating the benefit of minimizing working memory load does not eliminate the persistence with which we sample information from the external world – although the underlying reason for resampling behaviour may be different.

Efficient anti-frosting enabled by femtosecond laser-induced salt-philic and superhydrophobic surface

Frost formation is a normal phase transition phenomenon in cold climates, while it usually brings certain troubles to human lives and production. Therefore, it is of great significance to develop frost resistant materials and key technologies. Here, a salt-philic and superhydrophobic surface is designed on a PDMS substrate by femtosecond laser direct writing technology in combination with salt–ethanol–water mixtures droplet treatment. The laser-treated PDMS embedded salt (LTP-S) surface exhibits superhydrophobicity, which alone is a property that can resist the formation of frost and enables a self-cleaning effect. Meanwhile, the salt coating further enhances the frost resistance of the surface by reducing the freezing point temperature. The LTP-S surface is revealed to perform well in frosting-defrosting cycles, washing resistance, chemical corrosion resistance, heating resistance, and long-term air exposure tests as a highly efficient and stable anti-frosting surface. This work demonstrates a facile strategy to fabricate a salt-philic and superhydrophobic surface for efficient anti-frosting.

Time dependent anti-corrosion and anti-scaling efficiency of polyepoxysuccinic acid inhibitor in simulated hard water

In this study, the time-dependent performance of a phosphorus-free corrosion and scale inhibitor primarily composed of polyoxyuccinic acid (PESA) and zinc salts was investigated in a laboratory-simulated hard water environment. Long-term static scale inhibition tests and corrosion rotation coupon tests were conducted under two temperature conditions, 45 °C and 80 °C, following established literature standards. Changes in water quality, scale morphology, metal corrosion status, and electrochemical impedance were monitored using calcium ion concentration analysis, optical microscopy imaging, X-ray diffraction (XRD), and electrochemical testing. The study revealed a progressive decline in the corrosion and scale inhibition efficiency of the phosphorus-free inhibitor in simulated hard water with calcium carbonate hardness levels of 300, 400, and 500 mg/L over time. Moreover, higher water hardness accelerated corrosion onset, suggesting that calcium carbonate deposition promotes metal corrosion under the experimental conditions. Density functional theory (DFT) calculations indicated that PESA chemically adsorbs onto both metal and calcite surfaces, underscoring its dual role in corrosion and scale inhibition. These findings underscore the intrinsic corrosion and scale inhibition capabilities of PESA, complementing its synergistic film-forming properties with Zn2+.

Effects of Pr substitution in Y1-xPrxBaCo3ZnO7+δ (0 ≤ x ≤ 0.5) cathodes for intermediate temperature solid oxide fuel cells

In this investigation, we successfully synthesized a series of Swedenborgite-type Y1-xPrxBaCo3ZnO7+δ (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5, abbreviated as YPxBCZ) oxides by a solid-state reaction method. The results show that YPxBCZ (x = 0.0, 0.1, 0.2, and 0.3) are single-phase structures, but YP0.4BCZ and YP0.5BCZ show interesting self-assembled composite phases. After long-term phase stability testing, YP0.3BCZ showed the best thermal stability. All samples show good chemical and thermal compatibility with La0.9Sr0.1Ga0.8Mg0.2O3-δ electrolyte. The thermal expansion coefficients in the temperature range from 30 °C to 1000 °C are equal to 9.8-13.1 × 10−6 K−1, close to that of the LSGM electrolyte. It is also found that Pr doping improves high temperature conductivity of YPxBCZ. The conductivity of YP0.3BCZ, YP0.4BCZ, and YP0.5BCZ reach 15.1, 18.5, and 22.5 S cm−1 at 800 °C. In addition, the area specific resistance (ASR) value decreases as the Pr content increases (0.038, 0.033, and 0.027 Ω cm2 at 800 °C for YP0.3BCZ, YP0.4BCZ, and YP0.5BCZ), improving the catalytic activity of the material. Another interesting finding was that the ASR of samples subjected to high temperature thermal decomposition was not adversely affected by the presence of decomposition products. The maximum power densities of YP0.3BCZ, YP0.4BCZ, and YP0.5BCZ in the single cells at 800 °C were 845, 930, and 1044 mW cm2, respectively. These results indicate that YP0.3BCZ, YP0.4BCZ, and YP0.5BCZ are promising cathode materials for intermediate-temperature solid oxide fuel cell.

Asymmetric lithium supercapacitors with solid-state hybrid electrolytes containing zeolite particle and water-soluble polymer

Here we demonstrate that high-performance solid-state hybrid electrolytes are prepared via environment-friendly water-based processes of zeolite Y (Zy) particle, branched-poly(ethylene imine) (bPEI), and lithium hydroxide (LiOH). The hybrid Zy:bPEI:LiOH electrolytes (ZyPL) were successfully applied to fabricate asymmetric-type lithium supercapacitors consisting of graphite-based active electrodes and indium-tin-oxide (ITO) counter electrodes. Results showed that the ion conductivity of electrolytes was greatly dependent on the Zy content and reached the highest value (ca. 0.28 mS/cm) at Zy = 30 wt% due to the formation of interfacial ion transport channels between Zy particles and bPEI chains. The galvanostatic charging/discharging (GCD) test revealed that the ZyPL supercapacitors could deliver the highest potential of 2.28 V at Zy = 30 wt% compared to 1.86 V at Zy = 0 wt%. In particular, the ZyPL supercapacitors, after charging at 0.1 mA/g, exhibited a long-lasting high-potential level of > 1.0 V at Zy = 30 wt% compared to 0.5 V at Zy = 0 wt%. The long-term GCD cycle test disclosed that the ZyPL supercapacitors could work stably with a capacitance retention of 91.7 % even after 3000 cycles. The series connection of six ZyPL supercapacitors delivered ca. 10.94 V with consistent charging/discharging characteristics.

Cross-linked copolyimide-P84/CAU-10-H/branched polyethyleneimine membranes for organic solvent nanofiltration

The advancement of organic solvent nanofiltration (OSN) is often hindered by the inherent trade-off between permeance and rejection. In this study, we present a novel nanocomposite mixed matrix membrane (MMM) fabricated by integrating a compatible metal–organic framework (CAU-10-H) into a co-polyimide (P84) matrix. The resulting P84/CAU-10-H membrane was cross-linked using branched polyethyleneimine (PEI) to produce a P84/CAU-10-H/PEI MMM with robust resistance to harsh organic solvents, making it suitable for OSN applications. The integration of CAU-10-H, PEI, and P84 significantly enhanced the OSN performance, improving sieving efficiency and reducing fouling tendencies. The fabricated membrane exhibited outstanding permeance across various solvents, with values of 42.4, 45.4, 24.5, and 27.1 LMH/bar for methanol, acetone, N-methyl-2-pyrrolidone (NMP), and dimethyl sulfoxide (DMSO), respectively. Besides, the P84/CAU-10-H/PEI MMM demonstrated excellent rejection (Brilliant yellow (BY) > 90 %, Congo red (CR), Methyl blue (MB), Evans blue (EB), and Alcian blue (AB) > 99 %, respectively). In a 96-hour long-term test, the membrane demonstrated excellent stability and anti-fouling properties. This study presents a facile and viable approach for designing and constructing novel OSN MMMs.

Highly efficient removal of ozone on amorphous manganese oxides modified by alkali metals

Low stability deriving from the accumulation of moisture and intermediates represents the major challenge for practical applications of manganese oxides (MnOx) for ozone elimination. Here, Li+, Na+ and K+ were successfully introduced into the channel framework of amorphous MnOx to improve its stability through a simple post-treatment method. Alkali metal modification can promote the removal of ozone by amorphous MnOx, and Na-MnOx exhibited superior catalytic activity and remarkable stability in water-resistance, cycling and long-term tests. The Na introduction facilitated the formation of oxygen vacancies, and improved low-temperature reducibility and lattice oxygen mobility. The mechanism of ozone decomposition on amorphous MnOx and Na-MnOx catalysts was deeply investigated by in situ diffuse reflectance infrared Fourier transform spectra (in-situ DRIFTS). The Na addition strengthened the hydrophobicity of oxygen vacancies, but also greatly boosted the desorption of intermediate oxygen species and the ozone decomposition cycle.

Physical Properties of an Efficient MAPbBr3/GaAs Hybrid Heterostructure for Visible/Near-Infrared Detectors.

Semiconductor photodetectors can work only in specific material-dependent light wavelength ranges, connected with the bandgaps and absorption capabilities of the utilized semiconductors. This limitation has driven the development of hybrid devices that exceed the capabilities of individual materials. In this study, for the first time, a hybrid heterojunction photodetector based on methylammonium lead bromide (MAPbBr3) polycrystalline film deposited on gallium arsenide (GaAs) was presented, along with comprehensive morphological, structural, optical, and photoelectrical investigations. The MAPbBr3/GaAs heterojunction photodetector exhibited wide spectral responsivity, from 540 to 900 nm. The fabrication steps of the prototype device, including a new preparation recipe for the MAPbBr3 solution and spinning, will be disclosed and discussed. It will be shown that extending the soaking time and refining the precursor solution's stoichiometry may enhance surface coverage, adhesion to the GaAs, and film uniformity, as well as provide a new way to integrate MAPbBr3 on GaAs. Compared to the pristine MAPbBr3, the enhanced structural purity of the perovskite on GaAs was confirmed by X-ray Diffraction (XRD) upon optimization compared to the conventional glass substrate. Scanning Electron Microscopy (SEM) revealed the formation of microcube-like structures on the top of an otherwise continuous MAPbBr3 polycrystalline film, with increased grain size and reduced grain boundary effects pointed by Energy-Dispersive Spectroscopy (EDS) and cathodoluminescence (CL). Enhanced absorption was demonstrated in the visible range and broadened photoluminescence (PL) emission at room temperature, with traces of reduction in the orthorhombic tilting revealed by temperature-dependent PL. A reduced average carrier lifetime was reduced to 13.8 ns, revealed by time-resolved PL (TRPL). The dark current was typically around 8.8 × 10-8 A. Broad photoresponsivity between 540 and 875 nm reached a maximum of 3 mA/W and 16 mA/W, corresponding to a detectivity of 6 × 1010 and 1 × 1011 Jones at -1 V and 50 V, respectively. In case of on/off measurements, the rise and fall times were 0.40 s and 0.61 s or 0.62 s and 0.89 s for illumination, with 500 nm or 875 nm photons, respectively. A long-term stability test at room temperature in air confirmed the optical and structural stability of the proposed hybrid structure. This work provides insights into the physical mechanisms of new hybrid junctions for high-performance photodetectors.

Influence of Stress Factors on the Development of Post-Traumatic Stress Disorder in Children: Risk Factors

In the current conditions of the ongoing war in Ukraine, which began in February 2022, Ukrainian children might develop post-traumatic stress disorder (PTSD) due to stress factors caused by the conflict between Ukraine and Russian-backed separatist forces, along with the Russian military. In particular, the relationship between reduced emotional intelligence and the development of post-traumatic stress disorder in children has become more relevant. This study aimed to assess structural and cognitive changes in children with PTSD and their relationship to depression, anxiety, and event segmentation. The study methods included clinical interviews (CAPS-CA-5 scale), neuropsychological tests (short-term and long-term memory tests), self-assessment questionnaires (standardised CDI, RCADS and SCAS-Child scales), and a single-shotMRI. The results showed that patients with post-traumatic stress disorder had reduced hippocampal volume (p=0.018) and the volume of cingulate cortex isthmus (p=0.026). Diffusion in the cerebellum-hippocampal tract was reduced (p=0.014). The level of depression was positively correlated with hippocampal volume (r=0.32, p=0.021) and anxiety with the volume of cingulate cortex isthmus (r=0.26, p=0.048). These results emphasise the importance of the relationship between structural changes and levels of depression and anxiety in patients with PTSD. Prospects for further research are based on the study of the long-term effects of psychotherapeutic interventions aimed at improving cognitive function in patients with posttraumatic stress disorder.

Step-by-step strategy to improve the performance of the (La,Sr)(Ga,Mg)O3-δ electrolyte for symmetrical solid oxide fuel cells

Research on the highly conductive solid electrolyte with the overall composition of (La,Sr) (Ga,Mg)O3-δ (LSGM) has reached a new stage of development in recent years due to the successes in the field of symmetrical electrochemical devices in which LSGM utilizing as a supporting layer. This study shows a “step-by-step” approach to modify the LSGM electrolyte using both individual techniques and their combinations to improve the functional properties of the LSGM. As a result of a multi-step modification, the new electrolyte of composition (La0.8Sr0.2)0.98Ga0.7Fe0.1Mg0.2O3-δ + 0.5 wt% Fe2O3 was obtained. It is shown that the conductivity of new electrolyte is about five times higher than that of the basic La0.8Sr0.2Ga0.8Mg0.2O3-δ oxide at 600 °C. Furthermore, the better thermo-mechanical and chemical compatibility with the iron-based electrode was found. It also shows insignificant resistance degradation in long-term tests in air and satisfactory stability in wet hydrogen. Based on the results of the research it can be concluded that the new electrolyte obtained by step-by-step modification has great prospects for utilization in symmetrical fuel cells.

Novel fillers for wearable technology: Impact of titanium carbide and thinners on room temperature vulcanized silicone rubber composites

Wearable technology has emerged as a robust pathway to achieve smart functionalities in healthcare, sports, fitness, and beyond. This study investigates the mechanical and electromechanical properties of silicone rubber (SR) composites. The SR was reinforced with titanium carbide (TiC) and modified with varying (room-temperature vulcanized) RTV-thinner (silicone oil) concentrations. RTV-SR was utilized, which cures at room temperature to form a flexible, durable, and moldable rubber widely used for sealing, bonding, and making molds. The addition of TiC enhanced tensile strength from 0.5 MPa (control) to 0.59 MPa (5 phr of TiC), and tensile modulus from 0.41 MPa to 0.51 MPa. However, the thinner inclusion reduced tensile properties. For instance, the T10 sample (10 phr thinner) showed a tensile strength of 0.51 MPa and a tensile modulus of 0.29 MPa making the composites soft. Thinner addition also increased ductility, with fracture strains rising from 151 % (control) to 217 % (T10). Compressive strength followed a similar trend, with the control and 5 phr TiC samples exhibiting compressive strengths of 0.18 MPa and 0.17 MPa, respectively, which decreased to 0.12 MPa for the T20 sample. Under cyclic loading, TiC-filled samples showed consistent load patterns, while thinner addition resulted in increased energy dissipation and reduced stiffness. Electromechanical analysis revealed that TiC 5 phr samples exhibited stable piezoelectric responses, with voltage outputs increasing from ±0.1 mV at 15 % strain to ±1.0 mV at 40 % strain. The T5 samples demonstrated significant voltage improvements, generating ±2.5 mV at 15 % strain and ±5 mV at 40 % strain. Long-term cyclic tests confirmed the stability of T5 samples, maintaining voltage outputs of −1.5 mV to 1.5 mV over 50 minutes. Response time analysis indicated faster response times for TiC 5 phr samples, decreasing from 145 ms at 15 % strain to 102 ms at 40 % strain, while thinner addition led to longer response times. Real-time electromechanical tests under mechanical study showed that T5 samples achieved optimal performance with voltage peaks up to ±2.4 mV under thumb pressing. These findings highlight the trade-off between mechanical strength and flexibility, suggesting that an optimal balance of TiC and thinner enhances the properties of silicone rubber composites for applications in wearable technology and sensors.

Investigation of biodegradable surfactant as a corrosion inhibitor to the cold rolled steel in the membrane separation device process

The membrane process is an effective way to realize resource reutilization. Most membrane devices are made of cold-roll steel (CRS), which is easy to corrode when operating in acid conditions. Herein, the biodegradable surfactant dodecyl dimethyl betaine (BS-12) was used as the inhibitor to protect the CRS in the trichloroacetic acid (TCA) solution. The long-term stability membrane tests showed that adding BS-12 will not harm the membrane performance. The weight loss experiments proved that adding BS-12 with trace amount (10 mg·L−1) endowed the CRS with good inhibition efficiency (95.3 %). The electrochemical tests indicated that the mixed inhibitor- BS-12 works by inhibiting the anode and cathode simultaneously, and the polarization resistance increased to 21 times. The SEM, AFM, and CLSM tests proved that adding BS-12 enabled the CRS surface to remain stable. The FTIR and XPS tests proved that BS-12 adsorbed on the CRS surface via physical and chemical adsorption. The theoretical calculations proved the horizontal adsorption of BS-12 on the CRS surface and the existence of the electron transfer within the BS-12 and CRS. The BS-12 showed great potential in the CRS inhibition of the membrane separation and purification processing.

Interfacial modification by 2-fluoroisonicotinic acid enabling high-efficiency and stable n-i-p perovskite solar cells

The power conversion efficiency (PCE) of organic-inorganic halide perovskite solar cells (PSCs) developed rapidly in recent years. However, the defects at the bulk grain boundaries and heterojunction interfaces acting as non-radiative recombination centres and the ion-migration channels severely hinder the charge transport and stability of the PVKs, resulting in low PCE and poor stability. One of the principal impediments to the commercialization of PSCs resides in the challenge posed by this particular aspect. In this work, we employed 2-fluoroisonicotinic acid (2-FINA) as a passivation agent to improve the PCE and stability of n-i-p PSCs by interfacial modification strategy. Owing to the presence of carboxyl (COOH) functional groups and pyridine groups, 2-FINA can strongly interact with uncoordinated Pb2+ and regulate the growth of perovskite crystals, which in turn reduces ion migration and suppress non-radiative recombination along with improves optical properties. Thanks to these improvements, the champion n-i-p PSC solar cell, treated with 2-FINA, showed a PCE of 20.92 %, whereas the untreated one in the same batch exhibited a PCE of 17.13 %. In long-term stability tests, we demonstrated that 2-FINA treatment significantly increases the moisture resistance of non-encapsulated devices.

In Situ Measurement of Deep-Sea Salinity Using Optical Salinometer Based on Michelson Interferometer

Ocean salinity plays an important role in oceanographic research as one of the fundamental parameters. An optical salinometer based on the Michelson interferometer (MI) suitable for in situ measurement in deep-sea environments is proposed in this work, and it features real-time calibration and multichannel multiplexing using the frequency modulated continuous wave (FMCW) technique. The symmetrical sapphire structure used to withstand deep-sea pressure can not only achieve automatic temperature compensation, but also counteract the changes in optical path length under deep-sea pressure. A model formula suitable for optical salinity demodulation is proposed through the nonlinear least squares fitting method. In vertical profile testing, the optical salinometer demonstrated remarkable tracking performance, achieving an error of less than 0.001 psu. The sensor displays a stable salinity demodulation error within ±0.002 psu during a three-month long-term test at a depth of 4000 m. High stability and resolution make this optical salinometer have broad development prospects in ocean observation.

A time-series deep learning model for predicting concrete shrinkage and creep verified with in-situ and laboratory test data

This paper proposed a time series prediction method for concrete shrinkage and creep based on deep learning and the accuracy of the method was verified by field tests. Based on the experiment data in the Northwestern University (NU database), a deep learning model considering the material, environment, and history was constructed by integrating Gated Recurrent Units and Self-Attention mechanism (GSA model). To validated the model, short-term indoor and outdoor field tests of concrete shrinkage and creep were conducted. The proposed GSA model outperformed the LSTM model for both creep and shrinkage predictions. Moreover, the comparison between the GSA model prediction and the outdoor test data indicated that the model can accurately capture the real-time outdoor temperature and humidity variation through historical data. To predict the ten-year shrinkage and creep of concrete, a recursive multi-step method was proposed to extrapolate the short-term predictions of the GSA model. The effectiveness of the recursive multi-step method was validated against the long-term test data in the NU database. Overall, the proposed GSA model demonstrated high accuracy in both short-term and long-term predictions.

Quantitative study of early-stage transient bacterial adhesion to bioactive glass and glass ceramics: atomic force microscopic observations

Antimicrobial potential of bioactive glass (BAG) makes it promising for implant applications, specifically overcoming the toxicity concerns associated with traditional antibacterial nanoparticles. The 58S composition of BAG (with high Ca and absence of Na) has been known to exhibit excellent bioactivity and antibacterial behaviour, but the mechanisms behind have not been investigated in detail. In this pioneering study, we are using Atomic Force Microscopy (AFM) to gain insights into 58S BAG’s adhesive interactions with planktonic cells of both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria; along with the impact of crystallinity on antibacterial properties. We have recorded greater bacterial inhibition by amorphous BAG compared to semi-crystalline glass–ceramics and stronger effect against gram-negative bacteria via conventional long-term antibacterial tests. AFM force distance curves has illustrated substantial bonding between bacteria and BAG within the initial one second (observed at a gap of 250 ms) of contact, with multiple binding events. Further, stronger adhesion of BAG with E.coli (~ 6 nN) compared to S. aureus (~ 3 nN) has been found which can be attributed to more adhesive nano-domains (size effect) distributed uniformly on E.coli surface. This study has revealed direct evidence of impact of contact time and 58S BAG’s crystalline phase on bacterial adhesion and antimicrobial behaviour. Current study has successfully demonstrated the mode and mechanisms of initial bacterial adhesion with 58S BAG. The outcome can pave the way towards improving the designing of implant surfaces for a range of biomedical applications.

Hybrid Overlayer of Defective Ni-MOF and NiO Nanoparticles toward Efficient TiO2/CdS Type-II Heterojunction.

The severe photocorrosion of cadmium sulfide (CdS) restricts its practical application for solar hydrogen production. Although remarkable progress has been achieved with an overlayer strategy for isolating the CdS surface, the lifetime of CdS-based photoanodes is still far from the actual requirements. Herein, a hybrid overlayer of defective Ni-MOF and NiO nanoparticles has been developed through the chemical bath deposition method with postannealing. This hybrid overlayer of Ni-MOF-d is coated on the surface of the TiO2/CdS type-II heterojunction. The composite photoanode exhibits a photocurrent density of 4.41 mA cm-2 at 1.23 VRHE, which is 3.47- and 1.32-fold that of CdS and TiO2/CdS, respectively. The Ni-MOF-d overlayer gives rise to a negative shift of the onset potential by 59.51 mV. After a long-term stability test of 11 h, a photocurrent retention of 70% is observed, which is among the most robust CdS-based photoanodes. The kinetics studies reveal that the performance improvements can be attributed to the multiple functions of the Ni-MOF-d hybrid overlayer, including isolating the CdS surface from the electrolyte, cocatalyzing the electrode oxidation processes, passivating the surface defect states of CdS, and facilitating the charge injection from the photoanode to the electrolyte.

Synergistically enhanced ORR and HER performance on Co-N-C coupled in-situ generated PtCo intermetallic

Integrating multi-scale sites in a composite catalyst is vital to realize efficient electrocatalysis. Herein, a synergistic composite catalyst consisting of Co atomic sites and in-situ generated PtCo intermetallic compounds (IMCs) (o-PtCo@CoNC) is proposed through Co pre-anchoring and subsequent impregnation-reduction method. High loading of Co atoms provides a chance for in-situ generating PtCo ordered intermetallic compounds. The remaining Co single atoms and PtCo IMCs construct synergistic electrocatalytic micro-regions. Benefiting from the ordered structure, synergistic effect of PtCo IMCs and Co single atoms, o-PtCo@CoNC exhibits excellent electrocatalytic performance for oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) with mass activity of 1.21 A mgPt−1 (at 0.9 V) and 5.70 A mgPt−1 (at an overpotential of 100 mV), respectively. Besides, o-PtCo@CoNC delivers negligible loss of half-wave potential and overpotential during long-term stability test in acid solutions, with 13 mV decay after 50,000 potential cycles for ORR and a 2.7 mV decay after 20,000 potential cycles for HER. The integration strategy of single-atomic sites coupled IMCs paves the way for enhancing the activity and durability of Pt-based electrocatalysts.

Rapid assessment of the creep rupture life of metals: A model enabling experimental design

Prediction of the creep rupture life of engineering metals is critical for qualification and design of new materials. The use of long-term creep tests and the need to quantify the performance variability in a priori similar systems hinder the rapid creep assessment of a given material. Therefore, it is essential to develop methods that can extrapolate the long-term performance of alloys and the associated variability from short-term experiments. To this end, this study introduces a new model which enables the estimation of the rupture life of a material for a given stress and temperature. This model relies on two components. First, a new relation for the minimum creep rate (MCR) of materials is introduced. It includes a stress dependent stress exponent allowing the model to capture the variation of MCR across a wide range of temperatures and stresses. Second, employing the Monkman-Grant (MG) law, we establish a relation between stress, temperature and creep rupture life. Together, these two elements yield a new closed-form mathematical expression for the Larson Miller parameter as a function of stress and temperature. This expression captures the creep rupture time for many metals (Gr91, Copper, Gr122 and 347H) and compares favorably with alternate empirical approaches. The model is then used to assess the minimum duration of creep rates necessary to qualify the material up to 100000h. It is found that depending on the material system, creep tests as few as five limited to 5000 h for steels (Gr91, Gr122, 347H) and 100 h for copper are sufficient to model creep lifetimes. Finally, using a Bayesian inference-based approach to calibrate the model, we demonstrate that variability in rupture life can be captured via the quantification of the uncertainty in the model parameters and extrapolated from a limited number of short to moderately short creep tests; thereby paving the way for accelerated creep testing.

Innovative In/H-SSZ-39 Catalysts: An Exploration in NOx Reduction via CH4-SCR

Nitrogen oxides (NOx), pivotal atmospheric pollutants, significantly threaten the environment and human health. The CH4-SCR process, leveraging the abundance and accessibility have methane, emerges as a promising avenue for NOx abatement. Previous studies have demonstrated that zeolite support with twelve-membered ring (12-MR) and five-membered ring (5-MR) structures are susceptible to framework collapse in the presence of H2O, leading to catalyst deactivation. Consequently, there is a necessity to explore novel zeolites with enhanced hydrothermal stability for application in CH4-SCR processes. This research introduced for the first time an investigation into a novel In/H-SSZ-39 catalyst, which was synthesized via ion exchange and meticulously optimized for preparation conditions, including calcination temperature and In ions concentration, and reaction conditions, including CH4/NO ratio, O2 concentration, H2O content, and Gas Hourly Space Velocity (GHSV). Furthermore, long-term operation tests and stability tests were conducted on the In/H-SSZ-39 catalyst. In addition, a series of characterizations were conducted to delve into the reasons behind how preparation conditions influence catalytic activity, as well as to investigate the changes in physicochemical properties during the reaction process.