Prolonged Operation Research Articles

Possibilities for Improving Algorithms for Combat Use of Aircraft Using Unguided Weapons

Combat actions in recent local conflicts make us consider and re-evaluate some of the concepts concerning the development of combat aviation. As it turns out, conducting combat operations at high intensity for a long period of time using all components of the armed forces shows that the use of high-tech aircraft is extremely expensive and requires a large period of time to bring them back to full operational readiness when damage has been inflicted on them during hostilities. This is evidenced by the limited use of 5th generation aircraft in local conflicts. They are mainly used at long distances and with a tangible technological superiority over the enemy. Also, the sustained use of high precision guided weapons proves to be extremely expensive. All this makes us think and apply a creative approach to finding a solution to these problems. One of these approaches is through the improvement or rather the modernization of existing combat platforms through the implementation of advanced mathematical models and algorithms for combat use, which will increase the accuracy and efficiency of the use of unguided weapons, which are significantly cheaper compared to using guided ones. As the accuracy of using unguided weapons increases, it approaches that of guided ones. This is very important in the conduct of prolonged intensive combat operations in the conditions of limited resources. On the other hand, the use of advanced algorithms for combat use will simplify and facilitate the pilot's work with the controls of the aviation armament during the execution of combat tasks.A general mathematical model and a general algorithm for the combat use of aircraft weapons are proposed. A general mathematical model was developed for solving the ballistic task for large groups of guided and unguided weapons, which is a component of the general algorithm for combat use.

Enhancing collaboration of anammox with heterotrophic microbes mediated selectively by iron of different valences: Activities balance, metabolic mechanism, and functional genes regulation

The partial denitrification/anammox (PD/A) process is receiving increasing attention due to its cost-effectiveness advantages. However, effective strategies to alleviate organic matter inhibition and promote anammox activity have been proven to be a big challenge. This study investigated the effects of three types of iron (nano zero-valent iron (nZVI), Fe(II), and Fe(III)) on the PD/A process. It is worth noting that nZVI of 5–50 mg/L and Fe(III) of 5–120 mg/L promoted both PD and anammox activity. Long-term intermittent addition of nZVI (50 mg/L) resulted in a nitrogen removal efficiency of 98.2% in the mixotrophic PD/A system driven by iron and organic matter. The contribution of anammox for nitrogen removal reached as high as 93.8%. The organic carbon demand decreased due to the external electron donor provided by nZVI for PD. Multiple Fe–N metabolic pathways, primarily involving ammonia oxidation by Fe(III) and nitrate reduction by nZVI, play a crucial role in facilitating nitrogen transformation. Conversely, the direct addition of 30–120 mg/L Fe (II) resulted in a significant decrease in pH to below 5.0 and severe inhibition of PD and anammox activity. Following prolonged operation in the presence of nZVI, it was demonstrated that there is an enhancing effect on robust nitrite production for anammox. This was accompanied by a remarkable up-regulation of genes encoding nitrate reductase and iron-transporting proteins dominated by Thauera. Overall, this study has provided an efficient approach for advanced nitrogen removal through organic- and iron-driven anammox processes.

Optimal operation of solid-oxide electrolysis cells considering long-term chemical degradation

Optimizing the performance of solid oxide electrolysis cells (SOECs) for long-term hydrogen (H2) production at high temperatures is crucial, as prolonged operation leads to efficiency losses and shorter cell lifespans due to chemical degradation. In this work, we adopt a quasi-steady state approach for dynamic optimization over extended operational periods to address the disparity in timescales between cell operation and degradation. Integrating a 2-D non-isothermal SOEC model with balance-of-plant (BOP) equipment, we explore three optimization objectives: minimizing terminal degradation, maximizing integral efficiency, and minimizing the levelized cost of H2 (LCOH). Our dynamic optimization algorithm reduces LCOH by 9.5% and 16% compared to strategies focusing solely on terminal degradation and integral efficiency, respectively. For electricity prices of 0.03 $/kWh and 0.3 $/kWh, optimal replacement schedules range from 5 to 2 years, depending on the operational mode. Furthermore, a flexible operational mode yields additional improvements in LCOH over traditional galvanostatic and potentiostatic modes.

Numerical study on heat restoration cycle performance of energy pile with backfilling PCM

The numerical analysis of energy pile backfilled with phase change material (PCM) was performed for the renewable geothermal energy utilization in building energy savings. Different operation modes and the melting temperature, latent heat, thermal conductivity of the PCMs within the energy piles were discussed to obtain the optimal parameters. Further, the restoration and heat transfer performance of energy piles were also analyzed for the prolonged operation. It was concluded that relatively higher latent heat and thermal conductivity were preferable to enhance the heat transfer rate per meter (Qm) of the PCM-backfilled energy pile. However, a relatively lower PCM latent heat may help to full utilization and restoration of PCMs during every cycle of cooling and heating when energy pile works. An ideal melting temperature of PCM is probably close to the initial soil temperature to achieve preferred restoration and heat transfer performance, rather than the inlet fluid temperature. In heating 12 h and cooling 12 h alternate mode, taking continuous operation as a reference, the Qm and the restoration rate of pile wall temperature of the PCM-backfilled energy pile were increased by 32.7 % and 52.5 % after operating 720 h.

Causes and predictors of unplanned reoperations within 30 days post laparoscopic pancreaticoduodenectomy: a comprehensive analysis.

To delineate the risk factors and causes of unplanned reoperations within 30 days following laparoscopic pancreaticoduodenectomy (LPD). A retrospective study reviewed 311 LPD patients at Ningbo Medical Center Li Huili Hospital from 2017 to 2024. Demographic and clinical parameters were analyzed using univariate and multivariate analyses, with P < 0.05 indicating statistical significance. Out of 311 patients, 23 (7.4%) required unplanned reoperations within 30 days post-LPD, primarily due to postoperative bleeding (82.6%). Other causes included anastomotic leakage, abdominal infection, and afferent loop obstruction. The reoperation intervals varied, with the majority occurring within 0 to 14 days post-surgery. Univariate analysis identified significant risk factors: diabetes, liver cirrhosis, elevated CRP on POD-3 and POD-7, pre-operative serum prealbumin < 0.15 g/L, prolonged operation time, intraoperative bleeding > 120 ml, vascular reconstruction, soft pancreatic texture, and a main pancreatic duct diameter ≤3 mm (all P < 0.05). Multivariate analysis confirmed independent risk factors: pre-operative serum prealbumin < 0.15 g/L (OR = 3.519, 95% CI 1.167-10.613), CRP on POD-7 (OR = 1.013, 95% CI 1.001-1.026), vascular reconstruction (OR = 9.897, 95% CI 2.405-40.733), soft pancreatic texture (OR = 5.243, 95% CI 1.628-16.885), and a main pancreatic duct diameter ≤3 mm (OR = 3.462, 95% CI 1.049-11.423), all associated with unplanned reoperation within 30 days post-LPD (all P < 0.05). Postoperative bleeding is the primary cause of unplanned reoperations after LPD. Independent risk factors, confirmed by multivariate analysis, include low pre-operative serum prealbumin, elevated CRP on POD-7, vascular reconstruction, soft pancreatic texture, and a main pancreatic duct diameter of ≤3 mm. Comprehensive peri-operative management focusing on these risk factors can reduce the likelihood of unplanned reoperations and improve patient outcomes.

An implantable sensor based on shape memory polymers and triboelectric nanogenerators: Monitoring ureteral peristalsis to assess bladder volume

Urinary diseases affect the quality of life of millions of patients around the world, and the monitoring of bladder volume is an essential indicator for the evaluation of urinary system performance. By introducing shape memory polymers and biocompatible materials, this study designed an implantable sensor based on triboelectric nanogenerator (TENG) and implanted it into the outer wall of the ureter of a large animal, enabling real-time monitoring of ureteral peristalsis. In addition, the incorporation of a shape memory polymer gives the implantable triboelectric nanogenerator (iTENG) the ability to recover its shape at body temperature, which ensures that the sensor always retains its shape even after prolonged operation in the body. The addition of biocompatible materials allows the sensors to be implanted into living organisms for extended periods without biotoxicity. The experiments reveal that the designed iTENG exhibits outstanding sensitivity and durability, accompanied by some anti-interference capabilities. The iTENG is expected to improve patient comfort as a novel approach to urological monitoring.

Bioaugmentation with Clostridium pasteurianum for high-yield continuous bio-hydrogen production in a dynamic membrane bioreactor

This study demonstrated the feasibility of achieving high-yield continuous bio-H2 production through bioaugmentation with Clostridium pasteurianum. C. pasteurianum was introduced during the initial granulation stage in a dynamic membrane bioreactor (DMBR) inoculated with heat-treated digester sludge. Following bioaugmentation, the average hydrogen yield (HY) reached 3.07 ± 0.13 mol H2/mol hexoseconsumed, with a hydraulic retention time (HRT) of 2 h. This high-yield and high-rate hydrogen production performance was achieved alongside a high concentration of suspended and granular biomass as 21.02 ± 1.01 g VSS/L. The DM played a crucial role in prolonging the solid retention time of the suspended biomass to 12.15 h. C. pasteurianum emerged as the predominant species, constituting 92.3 % of the total bacterial population. This dominance significantly contributed to achieving the high HY, reaching 77 % of the theoretical maximum HY (4 mol H2/mol hexoseconsumed) by shifting the metabolic pathway from non-H2 production pathways to hydrogen-producing acetate. However, during further continuous operation, the hydrogen production pathway was gradually shifted towards the butyrate pathway, resulting in a decreased HY of 2.26 mol H2/mol hexoseconsumed along with the decreased population of C. pasteurianum. Additional bioaugmentation of C. pasteurianum during the maturational granulation stage did not impact the metabolic pathways or microbiome significantly, as the added strain was supposed to be washed out. This study provides insights into achieving high-yield continuous bio-H2 production through bioaugmentation with C. pasteurianum during the initial granulation stage. Further studies are necessary to sustain C. pasteurianum-dominated high HY with the acetate pathway during prolonged operation.

Influence of NR/MWCNT Blending on Rotor Metal Friction and Wear during Mixing Process.

Mixing involves blending raw rubber or masticated rubber with additives using a rubber mixer, which is the most critical process in rubber production. The internal mixer, as the most important mixing equipment, experiences rotor wear during prolonged operation, affecting the gap between the mixer rotor and the chamber wall. This wear reduces mixing effectiveness, weakens filler dispersion, and ultimately impacts rubber performance. In recent years, as research on multi-walled carbon nanotubes (MWCNTs) and nanomaterials has deepened, their broad application prospects have become increasingly apparent. The objective of the present study is to understand and quantify rotor wear in rubber blends during the mixing process as influenced by multi-walled carbon nanotubes. This study found that with the increase in MWCNT content, the proportion of abrasive wear rises, while the proportion of corrosive wear decreases, leading to reduced overall wear. Compared to rubber without MWCNTs, the Payne effect decreased by 6.78%, 9.57%, 13.03%, 20.48%, and 26.06% with the addition of 1 phr, 3 phr, 5 phr, 7 phr, and 9 phr of MWCNTs, respectively. The friction coefficients between the rubber and metal increased by 6.31%, 8.57%, 25.43%, 39.31%, and 47.61%, while the metal wear rate decreased by 9.08%, 10.73%, 13.41%, 17.46%, and 25%. Conversely, the friction coefficients were reduced by 19.39%, 22.42%, 33.94%, 66.06%, and 76.36%.

Audiological results of myringoplasty performed by trainee surgeons (ENT residents) under supervision—analytic study

BackgroundMyringoplasty is one of the most common surgeries performed in otology centers, with many factors influencing the success rate, including the size and site of perforation, function of the Eustachian tube, revision surgery, and expertise of the surgeons. It is well established that the perforation closure rate is lower when performed by trainee surgeons than by senior otologists. Myringoplasty performed by trainees tends to pose more iatrogenic trauma to middle ear mucosa, less gentle manipulation of ossicles, and prolonged operation time compared with operations performed by experienced surgeons, all of which might produce more damage to middle ear structures and consequently negatively affect the closure rate of TM and audiological outcome. This study aimed to assess the audiological outcomes of successfully closed perforation myringoplasty performed by a trainee under supervision.MethodsThe study design was an analytic cross-sectional study of 35 patients aged between 6 and 62 years diagnosed with safe TM perforation. All patients had two audiograms, one before surgery and the other 3 months after surgery. The exclusion criteria included any case with cholesteatoma, tumor, tympanosclerosis, or ossicular erosion/fixation because this study aimed to study the sole effect of closing TM perforation without any other confounding factor.ResultsThe results indicate a mean hearing improvement of 12.25 dB of ABG and 10.6 dB of AC thresholds at the four frequencies of 500, 1000, 2000, and 4000 Hz. The mean of the residual ABGs at the four frequencies is 14.2 dB. There were no correlations between the amount of air conduction threshold improvement and age, gender, side of the affected ear, area of perforation, or duration of disease (p > 0.05 for all tests).ConclusionAlthough the rate of perforation closure in myringoplasties performed by trainees is lower than that of experienced surgeons, the audiological outcomes of myringoplasties performed by trainees under supervision were acceptable; however, further research is recommended.

In Situ Electrochemical Recovery: Sediment Transformation under Chromium Poisoning in Reversible Solid Oxide Cells with La0.6Sr0.4Co0.2Fe0.8O3-σ-Based Oxygen Electrodes.

Reversible solid oxide cells (RSOCs) are an all-solid-state electrochemical device, which can convert H2 into electricity in the fuel cell (SOFC) mode and electrolyze H2O into fuel gas in the electrolytic cell (SOEC) mode, exhibiting good application prospect in the development of carbon neutrality. However, the degradation of the air electrode caused by Cr-containing steel interconnects is a major obstacle that limits the broader application of RSOCs. Herein, the Cr poisoning effect on La0.6Sr0.4Co0.2Fe0.8O3-σ (LSCF)-based oxygen electrodes under the electrolysis mode was systematically investigated. The phase transition of the sediment during the chromium poisoning process was captured and monitored. When tested under the presence of Fe-Cr interconnects at 800 °C for 40 h, SrCrO4 on the surface of LSCF was clearly identified through XRD and Raman analysis as the main deposition, and with the prolonged operating time, LaCrO3 slowly emerged. Due to the much higher electrical conductivity of LaCrO3 compared to SrCrO4, the negative effect induced by Cr poisoning was offset along with test progressing due to the deposition transition phenomenon. Inspired by the interesting discoveries, transition from SrCrO4 to LaCrO3 can be artificially facilitated by switching the operating mode to the SOEC mode, which can partially recover the dramatic degradation caused by the Cr poisoning effect under the SOFC mode. The feasibility of the in situ electrochemical recovery method was also verified by the experimental results. The peak power density of the cells decreased from 0.829 to 0.505 W/cm2 when operating under the SOFC mode with an Fe-Cr metal connector, and after in situ electrochemical recovery in the SOEC mode, the peak power density recovered to 0.630 W/cm2. This study provides a new strategy for achieving high performance and stability of RSOCs.

Evaluating the Performance of an All-Aqueous Copper Trab through 200 Hours of Discharge Cycling

Thermally regenerative ammonia batteries (TRABs) have the potential to serve as a viable solution for energy storage and electricity generation by harnessing low-grade heat. A TRAB discharge closely resembles that of a conventional flow battery, where electrochemical reactions are used to produce electrical power and aqueous electrolytes are stored in external tanks. However, the key distinction of a TRAB from a conventional flow battery lies in the recharging process, where thermal energy is used to separate ammonia from the negolyte, referred to as thermal recharging. During thermal recharging, the exhausted negolyte is converted into a fresh posolyte through the thermal separation of ammonia that was dissolved into the solution. This separated ammonia is subsequently added into the depleted posolyte, turning it into a fresh negolyte thereby completing the recharging process. Although there are many types of TRABs, the all-aqueous copper TRAB (Cuaq-TRAB) has produced some of the largest power densities and energy storage densities observed from a TRAB discharge. Building on these recent successes with Cuaq-TRABs, our investigation seeks to assess the performance of the Cuaq-TRAB during prolonged operation. Previous investigations with TRABs have typically lasted 0.5-7 hours, with the longest lasting 20 hours, which does not provide sufficient data to demonstrate the stability of the technology as thousands of hours of operation will be required. To address this gap, we operated an Cuaq-TRAB for 200 hours with a constant discharge current density of 10 mA cm-2 to examine battery performance and material degradation over time. Throughout the 200-hour test period, we measured an average power density of 7.2 mW cm⁻², which increased by 0.01% during the test. Additionally, the average energy density was 2.7 Wh L⁻¹, with a degradation of only 0.03% over the 200-hour timeframe. These results are the first to provide valuable information about the stability of the Cuaq-TRAB system during extended operation.

Development of High-Performance Bipolar Membranes with Optimal Junction Properties for Efficient Electro-Membrane Processes

A bipolar membrane (BPM) is a special type of ion-exchange membrane in which an anion-exchange layer (AEL) and a cation-exchange layer (CEL) are combined. Water molecules can be easily dissociated at the interface of the BPM by the strong electric field generated when a reverse bias voltage is applied through the membrane. Such dissociation leads to the generation of proton and hydroxide ions, which are then transported through the CEL and AEL, respectively, resulting in the production of acid and base solutions. Under a forward bias, these ions are drawn back to the bipolar interface, where they neutralize each other. The energy derived from this neutralization process, represented as a junction potential (JP) value, is a key factor in the BPM's efficiency. BPMs with ideal JP values are critical for achieving high separation and energy efficiencies in electro-membrane processes. Furthermore, for the prolonged operation of these processes, BPMs must possess a highly adhesive bipolar junction. Our work includes the development of a novel BPM with an ideal JP and a highly adhesive bipolar junction. This BPM has been applied to various electro-membrane processes, including an acid-base flow battery and direct seawater electrolysis. The BPMs are fabricated using poly(phenylene oxide) (PPO)-based ionomers, and incorporates an iron-based catalyst and a reinforcing material. These additions enhance the water-splitting performance and the durability of the interface between the ion-exchange layers. The prepared BPMs not only demonstrated excellent interfacial adhesiveness and mechanical properties but also achieved a water-splitting efficiency of 98% or higher. In comparison to commercial BPM, the electro-membrane processes utilizing the prepared BPM exhibited superior performance. This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korean government (MEST) (NRF-2022M3C1A3081178 & NRF-2022M3H4A4097521).

Advancing Sustainable Direct Contact Membrane Distillation: Performance and Stability of Novel Polymer Inclusion Membranes

Novel hydrophobic membranes for direct contact membrane distillation (DCMD) were developed using poly(1,1-difluoroethylene) (PVDF) loaded with the ionic liquid methyltrioctylammonium bis(2-ethylhexyl) phosphate (MTOA-DEHP). These polymer inclusion membranes (PIMs) were fabricated via non-solvent induced phase separation (NIPS). Detailed characterization revealed that MTOA-DEHP significantly enhances the morphological and physicochemical properties of the PIMs. Through a series of DCMD experiments, the membrane’s flux, salt rejection, and stability under varying conditions, including different feed solutions (i.e., synthetic NaCl solution and real seawater from the Atlantic Ocean), were assessed. Our results demonstrate that the PVDF/20 %MTOA-DEHP membrane exhibits superior performance, maintaining consistent transmembrane flux values (8.98 ± 0.61 kg·m−2·h−1) over multiple cycles and achieving high salt rejection rates (>99.9 %). Furthermore, the membrane demonstrates excellent stability, with minimal degradation observed even after prolonged operation. The results affirm the viability of PIMs as a promising avenue for achieving sustainable and efficient desalination via DCMD, particularly in real-world operational scenarios.

An investigation of shaft voltage in synchronous generators under SAGE and variable load condition

Abstract Synchronous generators are widely used in power generation systems. Static air-gap eccentricity (SAGE) often occurs in synchronous generators due to the component wear over prolonged operation. This paper presents a comprehensive mathematical model specifically tailored for SAGE fault, incorporating for the influence of stator slotting. The study thoroughly examines the impacts of both eccentricity and varying loads on the shaft voltage using the developed model. Furthermore, a novel method for detecting SAGE is introduced, leveraging the mathematical model of shaft voltage. This detection method proves effective for identifying eccentricity in synchronous generators across different load conditions by reasonably combining shaft voltage and phase current. The mathematical model of shaft voltage and the proposed detection method are validated through three-dimensional finite-element calculations and experimental studies. The work is helpful to manage and predict the shaft voltage. This paper contributes to the prevention of shaft voltage damage and real-time monitoring of the SAGE fault in synchronous generators.

Detection of defects in composite insulators based on laser‐induced plasma combined with machine learning

AbstractDue to Prolonged operation and external environmental factors, composite insulators may develop various defects, which can potentially lead to serious accidents in power systems. Detecting and analyzing these defects is critically important. In this study, we combine machine learning with laser‐induced breakdown spectroscopy (LIBS) to identify defects in composite insulators and obtain spectral data from both defective and nondefective samples. The Uniform Manifold Approximation and Projection algorithm was employed to reduce the dimensionality of the data, thereby enhancing detection accuracy and efficiency. Decision tree, random forest (RF), K‐nearest neighbor, and support vector machine algorithms were used to classify the dimensionality‐reduced data. The results indicate that the RF algorithm achieved the best classification performance, with accuracies of 100% and 95.46% for the training and test sets, respectively. Furthermore, the precision, recall, and F1 scores, which reflect model performance, also showed superior results with the RF algorithm. These findings suggest that the combination of LIBS technology and machine learning can rapidly and accurately detect and analyze defects in composite insulators, offering new insights and methods for defect detection in composite insulators.

Unveiling clinicopathologic features and outcomes for endoscopic submucosal dissection of early gastric cancer at gastric angulus in China

BackgroundWith advances in endoscopic submucosal dissection (ESD) technique, an increasing number of the Chinese population are being diagnosed with early gastric cancers (EGCs) at gastric angulus. However, the relationship between gastric angulus and EGCs remains obscure.ObjectivesWe aimed to unveil the unreported location characteristics of gastric angulus in Chinese EGC patients and the correlation between the degree of submucosal fibrosis and ESD outcomes.MethodsWe retrospectively reviewed the medical records of EGC patients treated with ESD from January 2010 to March 2023. We retrospectively investigated and analyzed 740 EGC patients using multiple analyses.ResultsFollowing gastric antrum (53.1%), the gastric angulus (21.8%) emerged as the second-most prevalent site for EGCs. It had highest incidence of severe submucosal fibrosis and ulceration than the other parts. Multivariate analysis showed independent associations of submucosal fibrosis at the angulus with ulceration (OR: 3.714, 95% CI: 1.041–13.249), procedure duration (OR: 1.037, 95% CI: 1.014–1.061), and perforation complication (OR: 14.611, 95% CI: 1.626-131.277) (all P < 0.05).ConclusionsThe gastric angulus demonstrates the highest incidence of severe submucosal fibrosis and ulceration for EGCs identified by ESD. This condition is linked to unfavorable outcomes, typically increased perforation risks and prolonged operation duration. Therefore, meticulous dissection is crucial for patients with EGCs in the gastric angulus.

Molybdenum sulfide modified with nickel or platinum nanoparticles as an effective catalyst for hydrogen evolution reaction

In this study, we investigate the catalytic performance of molybdenum sulfide (MoS2) modified with either nickel (Ni) or platinum (Pt) nanoparticles as catalysts for the hydrogen evolution reaction (HER). The MoS2 was prepared on the TiO2 nanotube substrates via a facile hydrothermal method, followed by the deposition by magnetron sputtering of Ni or Pt nanoparticles on the MoS2 surface. Structural and morphological characterization confirmed the successful incorporation of Ni or Pt nanoparticles onto the MoS2 support. Electrochemical measurements revealed that Ni- and Pt-modified MoS2 catalysts exhibited enhanced HER activity compared to pristine MoS2. Obtained catalysts demonstrated a low onset potential, reduced overpotential, and increased current density, indicating efficient electrocatalytic performance. Furthermore, the Ni or Pt-modified MoS2 catalyst exhibited remarkable stability during prolonged HER operation. The improved catalytic activity can be attributed to the synergistic effect between metal nanoparticles and MoS2, facilitating charge transfer kinetics and promoting hydrogen adsorption and desorption. Incorporating Ni and Pt nanoparticles also provided additional active sites on the MoS2 surface, enhancing the catalytic activity.

Unsupervised Transfer Learning Method via Cycle-Flow Adversarial Networks for Transient Fault Detection under Various Operation Conditions.

The efficient fault detection (FD) of traction control systems (TCSs) is crucial for ensuring the safe operation of high-speed trains. Transient faults (TFs) can arise due to prolonged operation and harsh environmental conditions, often being masked by background noise, particularly during dynamic operating conditions. Moreover, acquiring a sufficient number of samples across the entire scenario presents a challenging task, resulting in imbalanced data for FD. To address these limitations, an unsupervised transfer learning (TL) method via federated Cycle-Flow adversarial networks (CFANs) is proposed to effectively detect TFs under various operating conditions. Firstly, a CFAN is specifically designed for extracting latent features and reconstructing data in the source domain. Subsequently, a transfer learning framework employing federated CFANs collectively adjusts the modified knowledge resulting from domain alterations. Finally, the designed federated CFANs execute transient FD by constructing residuals in the target domain. The efficacy of the proposed methodology is demonstrated through comparative experiments.

Electrolysis of CuCl/HCl aqueous system in Cu–Cl thermochemical cycle for green hydrogen production: Investigations on alternative to platinum anode

The ICT-OEC Cu–Cl cycle is a six-step thermochemical copper-chlorine (Cu–Cl) closed-loop cycle to produce green hydrogen via water splitting. One of the critical steps in this cycle involves the electrolysis of CuCl to generate copper (Cu) and cupric chloride (CuCl2). Using platinum as the anode material in this system is economically disadvantageous and expensive. Consequently, this work investigates the feasibility of alternative anode materials to replace platinum. Mixed Metal Oxide (MMO) coated on Ti mesh (MMO mesh) and Pt coated on Ti mesh (Pt mesh) were evaluated as suitable anode alternatives to pure Pt sheet based on their performance metrics at different voltages. The integration of MMO mesh for a 100-h Time on Stream (TOS) study at a mini-pilot scale demonstrated promising current density and efficiency values. However, performance variations were observed over prolonged operation, potentially due to changes in membrane resistance. After 100 h, the MMO mesh remained undamaged, indicating its durability for extended use. Characterization studies revealed the electrodeposited copper to have a dendritic structure with an FCC phase. The findings suggest that MMO mesh and Pt mesh are viable alternatives to platinum at operating voltages above 0.7 V in this system.

Atomic-level quantum well degradation of GaN-based laser diodes investigated by atom probe tomography

Gallium nitride (GaN)- based lasers are extensively employed in display, lighting, and communication applications due to their visible laser emission. Despite notable advancements in their performance and reliability, sustained device functionality over extended periods remains a challenge. Among the diverse mechanisms contributing to degradation, the deterioration of quantum wells poses a persistent obstacle. In this study, we investigated the atomic-level degradation of quantum wells within GaN-based laser diodes utilizing atom probe microscopy. Our analysis revealed a substantial increase in indium fluctuation, accompanied by the formation of indium protrusions at the quantum well interfaces, which provides a credible explanation for the observed increase in FWHM (full width at half maximum) of the spontaneous spectra of lasers following prolonged operation. Additionally, magnesium analysis yielded no evidence of diffusion into the quantum well region. Combined with prior studies, we attribute the degradation of quantum wells primarily to the formation of indium-related non-radiative recombination centers.