Short-term Processes Research Articles

Local ablation disrupts immune evasion in pancreatic cancer

BackgroundPancreatic cancer (PC) is characterised by late diagnosis, tumour heterogeneity, and a peculiar immunosuppressive microenvironment, leading to poor clinical outcomes. Local ablative techniques have been proposed to treat unresectable PC patients, although their impact on activating the host immune system and overcoming resistance to immunotherapy remains elusive. MethodsWe dissected the immune-modulatory abilities triggered by local ablation in mouse and human PC models and human specimens, integrating phenotypic and molecular technologies with functional assays. ResultsLocal ablation treatment performed in mice bearing orthotopic syngeneic PC tumours triggered tumour necrosis and a short-term inflammatory process characterised by the prompt increase of HMGB1 plasma levels, coupled with an enhanced amount of circulating and tumour infiltrating myeloid cells and increased MHCII expression in splenic myeloid antigen-presenting cells. Local ablation synergised with immunotherapy to restrict tumour progression and improved the survival of PC-bearing mice by evoking a T lymphocyte-dependent anti-tumour immune response. By integrating spatial transcriptomics with histological techniques, we pinpointed how combination therapy could reshape TME towards an anti-tumour milieu characterised by the preferential entrance and colocalization of activated T lymphocytes and myeloid cells endowed with antigen presentation features instead of T regulatory lymphocytes and CD206-expressing tumour-associated macrophages. In addition, treatment-dependent TME repolarization extended to neoplastic cells, promoting a shift from squamous to a more differentiated classical phenotype. Finally, we validated the immune regulatory properties induced by local ablation in PC patients and identified an association of the short-term treatment-dependent increase of neutrophils, NLR and HMGB1 with a longer time to progression. ConclusionTherefore, local ablation might overcome the current limitations of immunotherapy in PC.

A clustering-based approach to scenario-driven planning for EV charging with autonomous mobile chargers

The main goal of this paper is long-term planning for electric vehicle (EV) charging infrastructure using autonomous mobile chargers (AMCs). The proposed method employs a clustering-based strategy to group EVs based on similar charging patterns, thereby reducing the number of scenarios and simplifying the planning problem. This reduces the number of possible scenarios and simplifies the planning problem. Each cluster then undergoes a short-term scheduling process to determine the optimal allocation of AMCs among its EVs. The program evaluates the probability of each scenario as well as the corresponding time results. Eventually, it formulates an ideal long-term strategy for the deployment and operation of AMC. This plan incorporates the concept of confidence level to address uncertainty in forecasting vehicle behavior and charging requirements. It ensures that the number and capacity of chargers are sufficient to meet system requirements at various confidence levels. The concept of confidence level strikes a balance between the cost of deploying mobile chargers and the risk of failing to satisfy the charging demand. This approach leads to optimal and reliable planning for EV charging infrastructure.

Evaluating inverse modeling methods for measurement and verification of chiller energy efficiency measures

A commonly budget and time constrained yet crucial measurement and verification process for chiller energy efficiency measures often requires rarely trended chiller performance data for the pre-retrofit or post-retrofit chiller necessitating chiller modeling for year-round performance prediction. This study evaluates chiller inverse modeling methods for measurement and verification applications. Variable speed drive-controlled centrifugal chillers operating in a hot and humid climate are used as case studies. Two scenarios are explored: one where full-range metered chiller data are available and another with limited data that requires a short-term metering process. The biquadratic black-box and Gordon-Ng with a variable entropy term models perform exceptionally well when full-range chiller performance data is available, displaying a coefficient of variation of approximately 5 % for both training and test datasets. However, in situations that use short-term metered data not covering the full range, the fundamental and Foliaco reformulated Gordon-Ng models outperform other models. These models show minimal degradation in average statistical performance when trained with one-month metering data instead of four-month data, indicating their potential to capture the year-round chiller performance variation with short-term metered data. Furthermore, the optimal metering period for an accurate modeling process is identified as one containing data from at least one shoulder month like April, May, or October for a hot and humid climate. These findings provide valuable guidance for practitioners involved in chiller efficiency measure assessments, emphasizing the significance of proper model selection and an appropriate metering period for a reliable measurement and verification process.

Excellent combinations of strength-ductility and corrosion resistance in SAF 2205 duplex stainless steel with multi-scale grain distribution

In this work, a multi-scale grain structure was obtained in SAF 2205 duplex stainless steel (DSS) by severe deformation and short-term annealing process. The influence of this structure on the mechanical properties and electrochemical behavior is systematically investigated. Experimental results indicate that the sample subjected to short-term annealing at 1000 °C (SA-1000 °C) exhibits the best comprehensive properties, with a yield strength (YS) of 652.6 MPa and an elongation (EL) of 39.9 %. Both strength and ductility surpass those of the original sample and long-term annealed (LA-1000 °C) samples. The strength-ductility product is increased by 32 % compared to the original sample and by 18 % compared to the LA-1000 °C sample. The increase in YS is predominantly attributed to dislocation strengthening and grain refinement strengthening, and the heterogeneous microstructure leads to good ductility. Moreover, the multi-scale distribution of the grain structure exhibits enhanced corrosion resistance due to the increased low-Σ grain boundaries and the promotion of stable passivation film formation by a limited number of defects, thereby mitigating the corrosion rate.

Becoming European: Mid- and Short-Term Development of a European Identity Among Adolescents

ABSTRACT European identity formation is a component of political identity and linked to the support of European institutions and values. To understand how it develops, we examined three processes of identity formation (commitment, in-depth exploration, and reconsideration of commitment) on a short- and mid-term time scale, and their interrelations. A total of 371 German adolescents (M age = 14.24, SD age = 0.55, 60.37% females) participated in a longitudinal study and in a ten-day daily diary study. We conducted latent growth curve analysis (LGCM) and assessed rank-order stability and profile similarity for both time scales. Next, conditional LGCMs were run to examine associations of both time scales. We found a significant increase of all identity processes from the beginning to the middle of the school year and a significant decrease from the middle to the end of the school year. Across 10 days, growth curves varied according to the identity process. Stabilities were high for both time scales. Commitment at the beginning of the school year was negatively associated with fluctuations in commitment. Our results highlight the importance of examining different time scales and focusing on specific domains for understanding identity development in adolescence. They further indicate that short-term processes are associated with long-term development.

Adsorption behavior of asphaltene aggregates generated by self-association at the oil/water interface

The formation of emulsions is undesirable yet unavoidable in petroleum production. Researchers suggest that asphaltenes adsorb at the oil/water interface, forming a protective film that stabilizes emulsions. This study investigates how asphaltene aggregates, formed through intermolecular interactions, affect emulsion stability and the properties of the oil/water interface. First, the effects of asphaltene concentrations, components, and temperatures on emulsion stability and the association state of asphaltenes were explored using the bottle test method and dynamic light scattering, respectively. The promotion of asphaltene aggregation by higher asphaltene concentrations and liquid paraffin content was confirmed by comparing the average size of aggregates, while higher temperatures were found to inhibit aggregation. Higher temperatures destabilize emulsions containing asphaltenes by increasing water droplet collisions, whereas higher asphaltene concentrations and liquid paraffin content stabilize emulsions. Subsequently, the effects of these conditions on expansion modulus were thoroughly investigated using the pendant drop technology. Pendant drop experiments demonstrate that increasing asphaltene concentration, along with the introduction of liquid paraffin, enhances asphaltene aggregation, thereby reinforcing the structural stability of the interfacial film. Spinning drop experiments were conducted to obtain dynamic interfacial tension (IFT) and analyze the adsorption behavior of aggregates at the oil/water interface. The adsorption process of asphaltenes driven by intermolecular interactions, occurs in three regimes: a short-term diffusion-controlled process, a transition process, and a long-term low-speed descent process, referred to as Regimes I, II, and III. The diffusion coefficient in Regime I increases with temperature, while the equilibrium IFT in Regime III decreases with temperature. In Regime II, adsorbed asphaltene aggregates from Regime I tend to prevent further adsorption, reducing the rate of dynamic IFT decrease. In Regime III, dynamic IFT decreases slowly, primarily due to the continued adsorption of asphaltene aggregates into the sublayer and their subsequent reconfiguration. These findings have significant implications for improving the understanding of oil/water interface properties and emulsion behavior in oil production, transportation, and refining systems.

Modulation of retrogradation properties by removal and retention of starch granule-associated lipids: A case study on buckwheat and wheat starches

The objective of this research was to investigate the influence of starch granule-associated lipids (SGALs) on retrogradation properties of buckwheat and wheat starches. According to the results, the removal of SGALs led to remarkable increase in the retrogradation enthalpy change of all starches and the strength of starch gels, as well as the density and short-range ordered structure of starch aggregates. The strength of starch gel experienced a rise from 3139.39 g to 3718.18 g in Tartary buckwheat, 2924.12 g to 3551.13 g in common buckwheat, and 1887.55 g to 2555.24 g in wheat, respectively. The removal of SGALs contributed to a decrease in the thermal stability of starches and an augmentation of amylose leaching during gelatinization process, which would strengthen the hydrogen bond interaction between starch molecules during cooling process, and promoting the rearrangement of the order structure of starch molecules. In general, these results indicated that the retention of SGALs could limit amylose leaching, then inhibited rearrangement and recrystallization of dissolved starch molecules, and ultimately delayed the short-term and long-term retrogradation process. This work further supplemented theoretical knowledge about SGALs in buckwheat and wheat starches, also provided a new perspective for regulating the physicochemical properties of starches.

Adsorption behavior of non-ionic demulsifiers at the oil/water interface stabilized by asphaltenes: Experiments, adsorption kinetics, and mechanisms

Formation of emulsions containing asphaltenes is both undesirable and unavoidable in petroleum production. Chemical demulsifiers, such as non-ionic surfactants, have long been applied as the cheapest and most effective method of breaking emulsions by altering the oil/water interfacial properties. In this study, the association state of the asphaltenes, the dehydration rate, and the interfacial rheology under various demulsifier concentrations were used to analyze the contributions of non-ionic demulsifiers to the breaking of the asphaltene-containing emulsions. Additionally, the dynamic interfacial tension (DIFT) data over time were used to investigate the adsorption kinetics of the asphaltenes and the demulsifier at the oil/water interface. Results indicate that liquid paraffin enhanced the association of the asphaltene molecules, while the non-ionic demulsifier rendered asphaltene aggregate sizes smaller. The addition of the demulsifiers reduced the interfacial strength, leading to an unstable interface. The oil-soluble demulsifiers reduced IFT more effectively than the water-soluble ones, due to their faster migration rate and low interfacial tension gradient to the oil–water interface. The adsorption process of the asphaltenes, influenced by the demulsifier concentration, could be divided into three stages: a short-term diffusion-controlled process, a transition process, and a slow descent process (referred to as Regimes I, II, and III). In Regime I, the diffusion coefficient of asphaltenes increased with the demulsifier concentration, indicating that the demulsifier aided the dispersing of the asphaltenes in the solution. The equilibrium IFT and the maximum surface excess concentration of the asphaltenes in the long-term adsorption process decreased with the demulsifier concentration, indicating that the asphaltene-containing emulsions generally became unstable after adding the demulsifiers. Our results offer valuable insights into the adsorption kinetics and the mechanisms of alterations by the asphaltenes and demulsifiers of the oil/water interface, with implications for various interfacial phenomena (e.g., emulsion stability) involving surfactants in oil production, transportation, and processing.

Commuting-driven competition between transmission chains shapes seasonal influenza virus epidemics in the United States.

Despite intensive study, much remains unknown about the dynamics of seasonal influenza virus epidemic establishment and spread in the United States (US) each season. By reconstructing transmission lineages from seasonal influenza virus genomes collected in the US from 2014 to 2023, we show that most epidemics consisted of multiple distinct transmission lineages. Spread of these lineages exhibited strong spatiotemporal hierarchies and lineage size was correlated with timing of lineage establishment in the US. Mechanistic epidemic simulations suggest that mobility-driven competition between lineages determined the extent of individual lineages' geographical spread. Based on phylogeographic analyses and epidemic simulations, lineage-specific movement patterns were dominated by human commuting behavior. These results suggest that given the locations of early-season epidemic sparks, the topology of inter-state human mobility yields repeatable patterns of which influenza viruses will circulate where, but the importance of short-term processes limits predictability of regional and national epidemics.

Enhancing E-learning effectiveness: a process mining approach for short-term tutorials

AbstractThe rise of e-learning systems has revolutionized education, enabling the collection of valuable students’ activity data for continuous improvement. While existing studies have predominantly focused on prolonged learning paths, short-term tutorials offer a flexible and efficient alternative that is recently gaining increasing popularity. This article presents a methodology for investigating e-learning systems for short-term tutorials leveraging user behavior tracking and process mining techniques. A case study involving a web-based tutorial with approximately one hour of learning explores the learning processes of 250 students in Italy. The study analyzes learning outcomes and investigates the impact of different learning paths on student progress. The research questions concern i) the extraction of activity flows in short-term tutorials; ii) the prediction of outcomes in the early stages of short-term learning process. The proposed approach provides descriptive insights into the learning process which can also be used to offer prescriptive guidance.

The role of executive functions in long-term memory: case report

The role of executive functions in long-term memory has been studied. We describe a single-case study, consisting of a 45-year-old male patient, hospitalized for right frontal stroke. After the stroke, the patient had memory alterations in everyday activities. However, performance in short-term memory tests was not significantly altered. Long-term memory assessments included pre- and post-stroke episodic, semantic, and procedural memories. Specific skills involved in the acquisition of new learning (auditory-verbal and visual reproduction) were also evaluated, as well as executive functions. The results evidence that short-term memory was not affected. Regarding long-term memory, significant differences were observed between pre- and post-stroke knowledge, the former being better preserved, which reveals anterograde amnesia. Pre-stroke long-term memory was also affected, but only with respect to episodic knowledge, with semantic and procedural memories preserved (episodic retrograde amnesia). Executive functions were altered as well, which could have been a factor affecting the acquisition and consolidation of new learning, despite the fact that short-term memory was not significantly altered. Therefore, executive functions might be a determinant factor in the acquisition of new learning, regardless of short-term memory processes, at least partially. According to the results of the present study, alterations in these functions might lead to anterograde amnesia. This entails the need to evaluate executive functions as an intrinsic part of memory evaluation.

Potential of Cation Exchange Resin as a Carrier for Anaerobic Consortia in Biohydrogen Fermentation

Cation exchange resin (CER) has been reported to promote sludge fermentation. However, previous studies have typically focused on the effects of CER on sludge properties to enhance fermentation, and the role of CER as a biocarrier for anaerobic consortia during fermentation has been overlooked. Thus, in this study, the potential of gel-type and macro-reticular type CERs to serve as biocarriers in fermentation was investigated. A significant number of anaerobes appeared to be attached to the surfaces of CER during 2-day fermentation. However, an extended fermentation time negatively affected the attachment of anaerobic consortia, suggesting that CER may be a suitable carrier for short-term fermentation processes, such as biohydrogen fermentation. Electrochemical analyses revealed that the electron transfer capacities of CER with attached anaerobes were enhanced after both 2-day and 28-day fermentation periods, with the macro-reticular type CER exhibiting higher electron transfer capacity than the gel-type CER. Fermentation experiments using mixing model substrates with macro-reticular and gel-type CERs with attached anaerobes showed that the macro-reticular type CER was more beneficial for biohydrogen fermentation than the gel-type CER. Further analyses of microbial communities revealed that hydrogen-producing bacteria (i.e., Caloramator, unclassified_f_Caloramatoraceace, and Sporanaerobacter) were more likely to adhere to the macro-reticular type CERs. This outcome confirmed that macro-reticular type CERs have significant potential as a carrier for anaerobic consortia to promote the generation of hydrogen and volatile fatty acids. These findings are expected to provide a reference for using materials as biocarriers to enhance the biohydrogen fermentation of sludge.

Robust bioprocess design and evaluation of commercial media for the serial expansion of human induced pluripotent stem cell aggregate cultures in vertical-wheel bioreactors

BackgroundWhile pluripotent stem cell (PSC) therapies move toward clinical and commercial applications at a rapid rate, manufacturing reproducibility and robustness are notable bottlenecks in regulatory approval. Therapeutic applications of PSCs require large cell quantities to be generated under highly robust, well-defined, and economically viable conditions. Small-scale and short-term process optimization, however, is often performed in a linear fashion that does not account for time needed to verify the bioprocess protocols and analysis methods used. Design of a reproducible and robust bioprocess should be dynamic and include a continuous effort to understand how the process will respond over time and to different stresses before transitioning into large-scale production where stresses will be amplified.MethodsThis study utilizes a baseline protocol, developed for the short-term culture of PSC aggregates in Vertical-Wheel® bioreactors, to evaluate key process attributes through long-term (serial passage) suspension culture. This was done to access overall process robustness when performed with various commercially available media and cell lines. Process output variables including growth kinetics, aggregate morphology, harvest efficiency, genomic stability, and functional pluripotency were assessed through short and long-term culture.ResultsThe robust nature of the expansion protocol was demonstrated over a six-day culture period where spherical aggregate formation and expansion were observed with high-fold expansions for all five commercial media tested. Profound differences in cell growth and quality were revealed only through long-term serial expansion and in-vessel dissociation operations. Some commercial media formulations tested demonstrated maintenance of cell growth rates, aggregate morphology, and high harvest recovery efficiencies through three bioreactor serial passages using multiple PSC lines. Exceptional bioprocess robustness was even demonstrated with sustained growth and quality maintenance over 10 serial bioreactor passages. However, some commercial media tested proved less equipped for serial passage cultures in bioreactors as cultures led to cell lysis during dissociation, reduction in growth rates, and a loss of aggregate morphology.ConclusionsThis study demonstrates the importance of systematic selection and testing of bioprocess input variables, with multiple bioprocess output variables through serial passages to create a truly reproducible and robust protocol for clinical and commercial PSC production using scalable bioreactor systems.

Optimizing short-term in-class process evaluation: analyzing the effectiveness of teaching interventions in pharmaceutical education using repeated measures analysis

BackgroundThe assessment of the effectiveness of teaching interventions in enhancing students’ understanding of the Pharmaceutical Care Network Europe (PCNE) Classification System is crucial in pharmaceutical education. This is especially true in regions like China, where the integration of the PCNE system into undergraduate teaching is limited, despite its recognized benefits in addressing drug-related problems in clinical pharmacy practice. Therefore, this study aimed to evaluate the effectiveness of teaching interventions in improving students’ understanding of the PCNE Classification System in pharmaceutical education.MethodsUndergraduate pharmacy students participated in a series of sessions focused on the PCNE system, including lectures (t1), case analyses (t2), and practical implementation (t3). The levels of understanding were evaluated using time-course questionnaires. Initially, paired samples t-Tests were used to compare understanding levels between different time points. Subsequently, Repeated Measures Analysis (RMA) was employed. Pearson correlation analysis was conducted to examine the relationship between understanding levels and the usability and likelihood of using the PCNE system, as reported in the questionnaires.ResultsThe paired samples t-Tests indicated insignificant differences between t2 and t3, suggesting limited improvement following the practical implementation of the PCNE system. However, RMA revealed significant time effects on understanding levels in effective respondents and the focused subgroup without prior experience (random intercept models: all p < 0.001; random slope models: all p < 0.001). These results confirmed the effectiveness of all three teaching interventions. Pearson correlation analysis demonstrated significant positive correlations between understanding levels and the usability and likelihood of using the PCNE system at all examined time points. This finding highlighted the reliability of the understanding levels reported in the questionnaires. The homework scores were used as external calibration standards, providing robust external validation of the questionnaire’s validity.ConclusionThe implementation of RMA provided robust evidence of the positive impact of time on understanding levels. This affirmed the effectiveness of all teaching interventions in enhancing students’ comprehension of the PCNE Classification System. By utilizing RMA, potential errors inherent in common statistical methods, such as t-Tests, were mitigated. This ensured a more comprehensive and accurate assessment of the effectiveness of the teaching interventions.

Research on the Preparation and Performance of Biomimetic Warm-Mix Regeneration for Asphalt Mixtures

To determine the formula for biomimetic warm-mix regeneration and fulfill the requirements of a “high waste asphalt mixture content, high quality, and high level” for its usage in reclaimed asphalt pavement (RAP), this paper first determined the suitable preparation process and formula for biomimetic warm-mix regeneration based on orthogonal experiments and a gray correlation analysis. Then, the optimum dosage of the warm-mix regenerant was determined by a uniaxial penetration test, low-temperature splitting test, and freeze–thaw penetration test. The rutting test was conducted to characterize the high-temperature performance of the asphalt mixture. The Immersion Marshall Test and the freeze–thaw splitting test were used to characterize the water stability of the recycled asphalt mixture. The low-temperature small beam test was employed to study the low-temperature performance of the recycled asphalt mixture. The asphalt’s short-term and long-term aging processes were simulated using the rotary thin-film oven test (RTFOT) and the pressure aging test (PAV). The action mechanism of biomimetic warm-mix regeneration was revealed by Fourier-transform infrared spectroscopy (FTIR). Finally, a comprehensive thermal performance test was conducted on the aged asphalt after biomimetic warm-mix regeneration. The results showed that the self-made biomimetic warm-mix regeneration agent exhibited an excellent regenerative effect on RAP and significantly reduced the mixing temperature of the styrene–butadiene–styrene (SBS)-modified asphalt mixture. In addition, the self-made biomimetic warm-mix regeneration agent effectively improved the high- and low-temperature performance of the recycled asphalt mixture, but had no noticeable effect on the water stability. The suggested dosage of the biomimetic warm-mix regeneration agent was 6%, and the mixing temperature was 130 °C. The microscopic chemical analysis revealed that biomimetic warm-mix regeneration restored the performance of aged asphalt by supplementing the light component. The change rules of the chemical functional groups and the comprehensive thermal properties of the recycled mixture showed a good correlation with the change rules of its high- and low-temperature performance.

Determination of dynamic component reactions in support bearings of rotor saws for cutting hot rolled (message 2)

For modern rolling production, the issue of strength and reliability of rotary saw designs, which are designed for cutting hot rolled products, is relevant. One of the factors that reduces the reliability of a rotary saw is the insufficient durability of the bearings of the shaft of the high-speed disk, which perceives the cutting forces. Practice shows that the applied methods of calculating the strength of support bearings do not allow taking into account all possible factors that affect the reliability of bearings in the cutting process. First, as it turned out, during operation, the saw blade has a radial beat, possibly due to an error when cutting the teeth of the blade and the eccentric landing of the blade on the seat when replacing it. Also, due to the fact that the process of cutting with a rotary saw is very short-term, the cutting force is considered to be the impact force. The purpose of this work is to determine the durability of the bearings of the disc shaft of a rotary saw, considering such factors as the radial beating of the disc and the shock load during the cutting process. As you know, during long-term operation of the object, the place for landing the cutting disc on the faceplate wears out, sometimes there is an error in the hole when making a new disc. Therefore, there is an eccentricity of the center of gravity of the disc. The presence of this eccentricity is considered in the work when determining the required forces using D'Alembert's principle of conditional balancing of forces. Given that the duration of cutting is a short-term process (lasts 0.105 sec.), when determining the reactions in the supports of the disk shaft that occur under the action of cutting forces, it is possible to consider the cutting process as an impact phenomenon. Due to the fact that the process of cutting with a circular saw is very short-term, the cutting force is considered the impact force. The magnitudes of the reaction forces in the bearings are determined during cutting using the theorems of impact dynamics: the theorem of impulses and the change of kinetic moment. For the possibility of theoretical determination of the effect of disk beating on the reaction in the bearings of the bearing shaft, experimental studies of disk beating and determined cutting forces were carried out

Tempering Procedure Effects On the Impact Toughness in Simulated Haz of Grade 22 Steel

Abstract Welding of thick low alloy steel components without elevated preheat imposes rapid cooling rates that may promote martensite formation in the CGHAZ. Freshly formed martensite contains a distorted and supersaturated matrix with high dislocation densities. As a result, impact toughness properties of these regions are inherently low and post weld tempering procedures are typically required. Conventional PWHT involves extended isothermal holds at elevated temperature which allows for considerable softening of the martensitic structure but has been found to have less effect on improving impact toughness. In contrast, short-term tempering processes with rapid heating and cooling rates and short exposures to elevated temperatures have been shown to greatly improve impact toughness through a shift in the kinetics of martensite tempering that produces high number densities of refined carbides. Temper bead welding (TBW) was developed for in-service repair of thick steel components where PWHT is impractical or not possible. With TBW, the heat-affected-zone is tempered by one or more rapid re-heat cycles from overlapping weld beads or weld layers. This study compares the CVN impact toughness and fracture morphology of the CGHAZ in the as-welded condition, with conventional PWHT, with a single TBW reheat, and with multiple TBW reheats for an SA-387 Grade 22 alloy steel.

An adaptive and interpretable SOH estimation method for lithium-ion batteries based-on relaxation voltage cross-scale features and multi-LSTM-RFR2

Accurate estimation of state of health (SOH) is crucial for ensuring reliable and safe operations of lithium-ion batteries across diverse engineering scenarios. However, current SOH estimation methods face challenges of reliance on specific working conditions, inadequate quality of degradation features, and limited precision and interpretability of estimation models. To address these issues, this paper presents an adaptive and interpretable SOH estimation method based on cross-scale features and a framework with multiple long short-term memory processes and two-level random forest regression (Multi-LSTM-RFR2). First, relaxation voltage, adapting to multiple charging-discharging conditions, is utilized as a source for degradation feature construction. In this aspect, multiple value features, variation features, statistic features, and parameter features are created from four scales: point data, local data, global data, and extended data. Then, the Multi-LSTM-RFR2 interpretable framework employs multi-LSTM processes to handle time-series inputs from multiple features, incorporating a two-level RFR mechanism to fuse and optimize pre-estimated SOH results. Finally, the importance of features is studied from both single and category feature perspectives for interpretability analysis. Degradation experiments with 24 commercial 18,650 battery cells under multiple charging-discharging conditions are used to validate effectiveness of the proposed method. The average values of four evaluation indicators in terms of mean absolute error, mean absolute percentage error, root mean squared error, and R-squared are 1.07 %, 1.33 %, 1.28 %, and 0.9654, respectively.

Optical characterization and thermal analysis of rare earth-doped PbO-GeO2-Ga2O3 glasses embedded with gold nanoparticles

This study investigated the optical properties of PbO-GeO2-Ga2O3 glasses doped with Er3+ and Yb3+ rare earth ions, deposited with gold nanoparticles and annealed at different times (1 h, 12 h, 28 h, and 52 h). By varying the annealing times, we can understand how these thermal processes influence the position of the energy bands, which in turn affects the material’s optical properties such as the energy gap and Urbach energy. The study found that the sample annealed for 52 h had the lowest Eg value and the highest Eu value, indicating significant structural changes due to prolonged thermal treatment. The study aimed to determine the energy gap (Eg) and Urbach energy (EU), Judd-Ofelt parameters (Ω2, Ω4, Ω6), oscillator strength (fexp and fcal), and root mean square (RMS) deviation. Additionally, the study reports on the linear absorption and heat transfer results, which were used to evaluate temperature changes during Z-scan experiments. The data obtained indicate that the sample subjected to 52-hour annealing has the smallest Eg value, suggesting that intense thermal processes and crystallisation affect the positions of the material’s energy bands, increasing its ability to absorb light. Consequently, the EU value for this sample is the highest at 0.312 eV, decreasing to 0.203 eV for the sample annealed for 1 h. This indicates that longer annealing times result in more significant structural changes in the glass matrix, thereby modifying its optical properties. The analysis of the obtained results, leads to the conclusion that the lowest values of both experimental (fexp) and calculated (fcal) oscillator strength occur at 546 nm and 811 nm, indicating the potential energy properties of the 4S3∕2 and 4I9∕2 levels in the atomic structure. It was observed that the J-O parameters did not exhibit significant changes with increased annealing time, suggesting that short-term thermal processes may be sufficient to achieve a stable energy configuration. This finding is of significant practical importance, as it indicates that the material can maintain its optical properties even with shorter annealing times, thereby enhancing the efficiency of the production process.

Heterostructure mediated high strength and large ductility in novel medium-Mn steels with low Mn content

Medium-Mn steels (MMnS) exhibit superior strength and ductility via the transformation-induced plasticity (TRIP) of retained austenite. However, to realize the partitioning of Mn atoms into retained austenite for thermal stability optimization, long-term intercritical annealing is required. In addition, the high Mn content of MMnS also causes other issues, e.g., high cost, welding, etc. In this work, instead of utilizing the TRIP effect of retained austenite, heterostructure consisting of alternatively distributed lamellar martensite zones and lamellar ultrafine dual-phase (martensite + ferrite) zones was engineered in a MMnS with low Mn content by a conventional rolling and short-term intercritical annealing process. The formation of the heterostructure was attributed to the heterogeneous distribution of Mn, the formation of highly dispersed martensite-austenite (MA) islands in Mn-poor zones and the low diffusion rate of Mn atoms at the intercritical annealing temperature. Tensile test results show that the steel exhibits superb synergy of a high ultimate tensile strength of 1452 MPa, a large ductility of 17 % and a high work hardening capability. The high work hardening capability and large ductility were mainly attributed to the apparent microhardness difference between the lamellar martensite zones and the ultrafine dual-phase zones that caused a strong hetero-deformation induced (HDI) strengthening effect. This study proposes a novel approach to developing high-performance steels, which provides an effective paradigm for addressing the long-established conflicts between mechanical performance, high Mn content and long intercritical annealing period of MMnS.