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In this work, we investigate the microstructures and mechanical properties evolution on a novel carbon-based maraging steel with the compositions of Fe–10Mn-0.25C–1Cr–2Mo wt%, through hot and cold rolling following by heat treatment. The composition was designed through thermodynamic modelling to achieve a combination of high strength and high tensile elongation through the development of fine tempered martensite with carbide strengthening, and the transformation induced plasticity (TRIP) from the reverted austenite. After hot and cold deformation, a solution treatment at 870 °C followed by quenching gave a martensitic structure with 5% retained austenite. The microstructure and tensile properties were then investigated in detail as a function of ageing time at 510 °C. The kinetics of austenite reversion were much more rapid, with a peak in austenite content after only 5h, giving a maximum volume fraction of ∼26%, with a sharp reduction for longer ageing times. The best tensile properties were obtained after an 8 h age with only ∼16.5% of reverted austenite, which provided a UTS of 1560 MPa (220 MPa contributed by TRIP) and an elongation of 14.5%. While the smallest grain size was attained after 16 h of aging, accompanied by an exceedingly low volume fraction of reverted austenite (∼2.1%) for the TRIP effect, the UTS decreased to 1356 MPa, with a slightly improved elongation of 15.7%. The results show that achieving the optimal mechanical properties requires balancing the volume fraction of reverted austenite for the TRIP effect with the grain size to enhance both strength and ductility.

Finite element models of the burnishing process for galvanized Advanced High-Strength Steels (AHSS) sheets were developed. To reduce the number of points that describe a real surface profile, optimization algorithms were implemented, considering three sequential stages: (1) surface profile filter, (2) mean line determination and, (3) eight roughness parameters validation. The finite element models developed accurately reproduce the experimental roughness profile, obtained with different burnishing forces. Also, the effect of the real surface roughness on the residual stress distribution was numerically investigated by considering the interaction between the coating layer present on the steel. The simulation showed that considering the real surface strongly influences the residual stress profile on the surface and to a certain depth.

This paper examines the issues of studying decision support systems for passenger travel in terms of identifying patterns of such behavior, their classification and clustering. A review of the literature of domestic and foreign authors concerning the analysis of patterns of transport behavior of the population and their recognition is given. The relevance of studying the transport behavior of the population using the theory of patterns is substantiated. An approach to describing patterns of behavior from the point of view of the theory of macrosystems has been formed. Examples of mobile applications for route planning, modern models for studying transport behavior based on BigData technologies, neural networks, and parsing theory are given. The problem of formalizing the description of transport behavior has been solved in order to obtain a tool for analyzing the influence of control actions on transport behavior. The conclusion is made about the need for a generalized representation of transport behavior, and, consequently, its pattern, in the form of logical models. The purpose of the study is to compile a generalized representation of transport behavior and its patterns within the framework of the theory of macrosystems by compiling a digital pattern that can be displayed as a set of graphical schemes and as a subsequent logical description. The results obtained consist in a detailed review of the literature on the topic of decision support systems when making a trip, determining patterns of passenger behavior, and the influence of individual behavior on the behavior of the entire transport system as a whole. A toolkit for determining patterns based on the theory of macrosystems has been developed. The analysis of various methods of data processing and visualization of results used by researchers is carried out, which additionally serves to determine the possibilities of qualitative and quantitative description of transport behavior. At the same time, the set of states of the elements of the transport system, specific measurable and/or calculated values, their relation to the micro- or macro-levels of the description of the transport system were determined. It is determined that the most convenient and comprehensive tool for representing and studying patterns is the theory of transport macrosystems.

Abstract Background Falls due to stumbling are prevalent for transfemoral prosthesis users and may lead to increased injury risk. This preliminary case series analyzes the transfemoral prosthesis user stumble recovery response to highlight key deficits in current commercially-available prostheses and proposes potential interventions to improve recovery outcomes. Methods Six transfemoral prosthesis users were perturbed on their prosthetic limb at least three times while walking on a treadmill using obstacle perturbations in early, mid and late swing. Kinematic data were collected to characterize the response, while fall rate and key kinematic recovery metrics were used to assess the quality of recovery and highlight functional deficits in current commercially-available prostheses. Results Across all participants, 13 (54%) of the 24 trials resulted in a fall (defined as > 50% body-weight support) with all but one participant (83%) falling at least once and two participants (33%) falling every time. In contrast, in a previous study of seven young, unimpaired, non-prosthesis users using the same experimental apparatus, no falls occurred across 190 trials. For the transfemoral prosthesis users, early swing had the highest rate of falling at 64%, followed by mid-swing at 57%, and then late swing at 33%. The trend in falls was mirrored by the kinematic recovery metrics (peak trunk angle, peak trunk angular velocity, forward reach of the perturbed limb, and knee angle at ground contact). In early swing all four metrics were deficient compared to non-prosthesis user controls. In mid swing, all but trunk angular velocity were deficient. In late swing only forward reach was deficient. Conclusion Based on the stumble recovery responses, four potential deficiencies were identified in the response of the knee prostheses: (1) insufficient resistance to stance knee flexion upon ground contact; (2) insufficient swing extension after a perturbation; (3) difficulty initiating swing flexion following a perturbation; and (4) excessive impedance against swing flexion in early swing preventing the potential utilization of the elevating strategy. Each of these issues can potentially be addressed by mechanical or mechatronic changes to prosthetic design to improve quality of recovery and reduce the likelihood a fall.

The mechanical properties of ausferritic ductile iron are strongly influenced by the ability of the austenite to undergo martensite formation. Strain-induced martensite formation occurring under the right circumstances results in transformation induced plasticity (TRIP) that improves ductility and strength. TRIP has been shown to depend on the austenite's stacking fault energy (SFE), which describes the crystals micromechanical behaviour. In austenitic FeMnAlSi-TRIP steels, TRIP as a reaction to mechanical load only occurs for SFE <20 mJ/m2. For carbon-stabilised austenite as in ADI, the relationship between stacking faults, mechanical properties and martensitic transformation has not yet been established. To investigate the TRIP-effect in ADI, unalloyed ADI with 3.43 wt% C, 2.52 wt% Si and 0.21 wt% Mn was ausferritised and subjected to tensile tests at temperatures between −180 °C and 200 °C. The amount of martensite produced by thermal and mechanical activation, crystalline microstrain and stacking fault density were measured on deformed and undeformed regions of the specimen by XRD and the resulting SFE calculated. Between −70 and 20 °C, the elongation at fracture exceeded 10 % compared to below 2 % in the temperature range of −130 to −180 °C. At temperatures above 80 °C, elongation at fracture gradually decreased to 4.5 % at 200 °C. High sample ductility was associated with lower SFEs as low as 35 mJ/m2, indicating a correlation of stacking fault formation and strain-induced martensite formation in ADI. [ABSTRACT FROM AUTHOR]

Copyright of Magazine of Historical Studies & Archaeology is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Laser surface texturing is a promising technique for improving the surface properties of metals. In this study, a nanosecond pulsed laser was used to perform surface texturing on a metastable austenitic stainless steel AISI 301LN. The effects of the number of laser passes (from 1 to 1000 passes) on the surface morphology, microstructure, and mechanical properties were investigated. The results show that the depth of laser tracks increases with the number of passes due to thermal accumulation. Increasing the number of laser passes produces a rougher surface, but beyond a certain value, a smoother texture is observed. The amount of α'-martensite phase induced by the laser increases with the number of passes, producing augments in hardness. However, again, this trend changes after a certain number of laser passes, and hardening saturates and even decreases. Therefore, selecting the appropriate laser processing parameters and number of passes is essential to control the dimensions of laser tracks and thus the desired surface texture and also to achieve the level of hardening. [ABSTRACT FROM AUTHOR]

Fall injury and fatality claims and legal cases involving ordinary pedestrians as well as employees/contractors at work sites have increased dramatically over the course of the author's 43-year engineering career. As a result, forensic engineers are frequently being contacted by insurers and attorneys to analyze these incidents. The need is to determine probable cause(s) and ascertain as to whether location features were designed, constructed, installed, manufactured, and/or maintained in accordance with the standard of care, including requirements specified in applicable codes and standards. The proper contemporary analysis techniques for these incidents are addressed in this paper as well as what constitutes proper basis for establishing a standard of care for involved installations and/or equipment. It will also expand on and update information provided in approximately two dozen past NAFE papers on various aspects of fall incident analysis, most of which are more than 10 to 30 years old. [ABSTRACT FROM AUTHOR]

The ride-sharing trend is booming because of modern technologies and plays a significant role in transitioning to sustainable transportation methods. This study utilizes a comprehensive dataset collected from an online survey administered to over 1300 individuals in Bangladesh in 2023. Its specific focus is to examine the usage patterns of ride-sharing applications, such as Pathao and Uber. It builds upon previous research to analyze the factors influencing the use of these services and current trends in shared transportation. Additionally, it investigates the challenges associated with utilizing shared transportation amenities and proposes potential improvements to make ride-sharing or pooling more attractive. The study diligently worked to establish an inclusive framework and terminology to enhance policies and gain a more detailed understanding of the transportation choices and requirements of communities. To bridge the gap between theory and practice, we adopted an implementation-oriented research approach and conducted a comprehensive quantitative and inferential analysis of the survey data. The inclination of an individual to opt for or perceive collective or merged services depends on several demographic, geographical, and built-environment factors. The findings highlight the necessity of enhanced security measures, increased public awareness of ride-sharing benefits, and the formulation of legislative measures to promote sustainable mobility. Two examples of potential measures we have found to improve and encourage the use of ride-sharing services include reducing uncertainty about shared rides and minimizing passenger discomfort. These measures can be implemented through operational adjustments, government regulations, and employer programs. An essential conclusion was reached regarding the importance of prioritizing improvements in ride-sharing operations, rather than relying solely on cash incentives to promote behavioral change. Furthermore, it was determined that regardless of the changes, policies, or programs implemented, it is imperative to enhance public awareness and education.

Understanding why falls during pregnancy occur at over 25% rate over gestation has clinical impacts on the health of pregnant individuals. Attention, proprioception, and perception of the environment are required to prevent trips and falls. This research aimed to understand how the changes to these neurocognitive processes control obstacle avoidance through gestation. Seventeen pregnant participants were tested five times in 6-week intervals. Participants walked an obstacle course (OC), and we analyzed the crossings over obstacles that were set to 10% of participants' body height. Participants also performed an attentional network test (ANT: performance of specific components of attention), an obstacle perception task (OP: ability to visually define an obstacle and translate that to a body posture), and a joint position sense task (JPS: ability to recognize and recreate a joint position from somatosensation). In the OC task, average leading and trailing foot crossing heights significantly reduced by 13% and 23% respectively, with no change in variation, between weeks 13 and 31 of pregnancy, indicating an increased risk of obstacle contact during this time. The variability in minimum leading foot distances from the obstacle was correlated with all three neurocognition tasks (ANT, OP, and JPS). Increased fall rates in the second and third trimesters of pregnancy may be driven by changes in attention, with additional contributions of joint position sense and environmental perception at various stages of gestation. The results imply that a holistic examination on an individual basis may be required to determine individual trip risk and appropriate safety modifications. [ABSTRACT FROM AUTHOR]

Malaria is caused by Plasmodium parasites that multiply inside host cells and can be lethal when P. falciparum is involved. We identified tRip as a membrane protein that facilitates the import of exogenous transfer RNA (tRNA) into the parasite. tRip encompasses a tRNA binding domain exposed on the parasite surface. We used the SELEX approach to isolate high-affinity and specific tRip-binding RNA motifs from a library of random 25 nucleotide-long sequences. In five rounds of combined negative and positive selections, an enriched pool of aptamers was obtained; sequencing revealed that they were all different in their primary sequence; only by comparing their structure predictions did most of the selected aptamers reveal a conserved 5-nucleotide motif sequence. We showed that the integral motif is essential for tRip-binding while the rest of the molecule can be significantly reduced or mutated as long as the motif is presented in a single-stranded region. Such RNA aptamers bind in place of the original tRNA substrate and act as an efficient competitor, suggesting that they can block tRip function and slow parasite development. [Display omitted] • tRip is a conserved protein located on the surface of Plasmodium parasites. • tRip is a promising target for the development of new antimalarial drugs. • RNA aptamers were selected to interact specifically with tRip. • Most of the selected aptamers share a 5-nucleotide single-stranded motif. • The selected aptamers compete with tRNAs for binding to tRip. [ABSTRACT FROM AUTHOR]

The variations of the microstructure and mechanical properties of medium-Mn steel after vanadium (V) microalloying with different contents were investigated. After a one-step intercritical annealing (IA) at 730 °C, the steel containing 0.04 wt.% of V exhibited excellent comprehensive properties. The steel maintained an ultimate tensile strength (UTS) of 1000 MPa while also exhibiting a total elongation (TEL) of 37% and a product of strength and plasticity (PSE) of 37.7 GPa%. V-microalloying improved the yield strength (YS) and UTS of the experimental steel by refining ferrite grains and precipitation strengthening, however, it deteriorated its plasticity, which is difficult to compensate for through grain refinement and due to the TRIP effect of retained austenite (RA). The largest amount of RA and the appropriate stability also make a significant contribution to the outstanding UTS of the steel containing 0.04 wt.% of V through the TRIP effect. However, the further increase of V content led to decreased RA content and stability, weakening the TRIP effect and resulting in a weaker strength ductility balance. [ABSTRACT FROM AUTHOR]

Successful recovery following a perturbation during walking depends on a quick well-coordinated response from the body. As such, lower limb joint power and work provide critical information characterizing the success of the recovery after a perturbation. Therefore, this study aimed to investigate lower-limb joint power and the relative contribution of each joint to the total leg work during the recovery following a trip-induced perturbation. Twenty-four young male volunteers walked at 1.1 m/s for 2 min, followed by two unexpected perturbations induced by rapidly decelerating the right belt of the split-belt treadmill. Joint moments and powers were calculated using an inverse dynamic approach. Joint work was found as the integral of joint power with respect to time. Statistical parametric mapping (SPM) and paired-sample t-tests were used to compare joint power and work between recovery and unperturbed steps. Compared to normal walking, recovery from the trip required a significant increase in both positive (+27 %, p < 0.05) and negative(+28 %,p < 0.05) leg work. During unperturbed walking, the ankle was the key contributor to both positive (ankle=50 %, hip=34 %, and knee=15 %) and negative (ankle=62 %, knee=32 %, and hip=6 %) leg work. During recovery, the knee eccentric work significantly increased (+83 %,p < 0.05) making it the main contributor to the negative leg work (knee=46 %, ankle=45 %, and hip=9 %). The hip positive work also increased during recovery (+62.7 %, p < 0.05), while ankle and the knee positive work remained unchanged. These findings highlight the importance of eccentric work of the knee, and concentric work of the hip joint during recovery from trip-induced perturbations. The additional mechanical demand of producing and absorbing more power during recovery is primarily imposed on the knee and hip, rather than the ankle. This new insight into the specific functions of lower-limb joints during recovery from trip-induced perturbations has important implications for the design of targeted fall prevention interventions. • Trip perturbations altered lower-limb joints contribution to leg work. • Knee joint played the most crucial role in absorbing energy during recovery. • The excessive demand of producing more power was mainly imposed on the hip joint. [ABSTRACT FROM AUTHOR]

The aim of this research is to determine the views of 6th-grade students regarding historical site trips organized within the context of out-of-school learning environments in social studies courses. The research was conducted with a case study, one of the qualitative research methods. The study group of the research consisted of 12 students attending the 6th grade in a secondary school affiliated with the Muş Provincial Directorate of National Education during the 2022-2023 academic year. In the research, “Open-Ended Questionnaire Form”, “Semi-Structured Interview Form”, and “Student Trip Diary” were used as data collection tools. The data obtained was evaluated through content analysis in the research. It was determined that students were willing to visit out-of-school learning environments such as historical sites or museums to gain knowledge, to see different places, and to learn lessons in these environments. It was concluded in the study that the school trips organized to out-of-school learning environments and the activities carried out during these trips provided benefits in terms of evoking emotions such as excitement, happiness, pride, and enjoyment in students. Furthermore, it was observed that the activities conducted during these visits to the historical sites were liked by students due to being both fun and educational. The research revealed that students’ level of knowledge about historical sites in their local environment increased. In addition, it was concluded that out-of-school learning environments contributed to students’ experiential learning, facilitating permanent and effective learning, and fostering students’ enjoyment of the subject. [ABSTRACT FROM AUTHOR]

This study proposes a machine-learning (ML) model combining ab initio calculations and an experimental dataset of 201 alloys (in addition to pure Ti) to predict the activated plasticity mechanisms in β-Ti alloys. This methodology is shown to be more efficient than the so-called Bo¯-Md¯ approach, achieving 82% prediction accuracy while the Bo-Md approach leads to 52% correct predictions on the same dataset. In addition, four new alloy compositions were produced to verify the model validity. Specific cases where the present model disagreed with the Bo-Md predictions were chosen to increase the benefits of the produced results. The plasticity mechanisms of the four alloys experimentally confirmed the validity of the ML model. This approach particularly helps the design of specific Ti alloys exhibiting a high work hardening rate owing to the simultaneous activations of the Transformation-Induced Plasticity (TRIP) and mechanical twinning (TWIP) effects. Indeed, the class corresponding to the combination of TRIP and TWIP effects reach a prediction accuracy of 88%.

This article, published in Clinical Pediatric Endocrinology, discusses a case of adrenal crisis (AC) in a young child with septo-optic dysplasia (SOD) during a trip. The patient, a 16-month-old Japanese child with SOD and intellectual disability, developed AC after a long-distance trip. The authors suggest that prolonged periods in unfamiliar environments during trips may be a potential precipitating factor for AC in susceptible individuals. They recommend considering prophylactic administration of a stress dose of hydrocortisone during trips to prevent AC. However, further research is needed to determine the effectiveness of this approach. [Extracted from the article]

The variations of the microstructure and mechanical properties of medium-Mn steel after vanadium (V) microalloying with different contents were investigated. After a one-step intercritical annealing (IA) at 730 °C, the steel containing 0.04 wt.% of V exhibited excellent comprehensive properties. The steel maintained an ultimate tensile strength (UTS) of 1000 MPa while also exhibiting a total elongation (TEL) of 37% and a product of strength and plasticity (PSE) of 37.7 GPa%. V-microalloying improved the yield strength (YS) and UTS of the experimental steel by refining ferrite grains and precipitation strengthening, however, it deteriorated its plasticity, which is difficult to compensate for through grain refinement and due to the TRIP effect of retained austenite (RA). The largest amount of RA and the appropriate stability also make a significant contribution to the outstanding UTS of the steel containing 0.04 wt.% of V through the TRIP effect. However, the further increase of V content led to decreased RA content and stability, weakening the TRIP effect and resulting in a weaker strength ductility balance.

The applicability of metastable β titanium alloys is frequently constrained by their relatively low yield strength. This study has successfully designed a metastable β titanium alloy with heterogeneous microstructures (HS) comprising both deformed and recrystallized grains, achieved through simple cold rolling followed by short-term annealing. Compared to traditionally coarse-grained (CG) specimen that is entirely crystallized and equiaxed, the HS specimen exhibit not only a postponed initiation of double yielding but also superior yield strength (enhanced by 27.8 %) and ductility (enhanced by 7 %). The delayed double yielding and enhanced strength in the HS specimen are ascribed to the restriction of dislocation motion by α" martensite and the heterogeneous deformation induced (HDI) strengthening mechanisms. The ductility of the HS specimen exceeds that of the CG specimen, owing to the combined effect of HDI hardening and the transformation-induced plasticity (TRIP) effects. The more pronounced TRIP effect in the HS specimens results from the synergistic effect of the elevated HDI stress and the applied external stress, which promotes the occurrence of stress-induced martensitic phase transformation. This study offers a novel strategy for the development of high-performance metastable β titanium alloys. [ABSTRACT FROM AUTHOR]

This study produces a Ni-containing ductile iron with a matrix consisting of lamellar α and γ phases, along with nanoscale Mg 6 Si 7 Ni 16 phases. The interface of fine α and γ phases and the nanoscale Mg 6 Si 7 Ni 16 phases impede dislocation mobility, contributing to high yield strength. During the tensile test, the transformation-induced plasticity (TRIP) phenomenon is etected because Ni addition effectively endows appropriate carbon concentration in γ phase of ductile iron. The TRIP effect significantly augments the strain-hardening capacity of ductile iron, resulting in an excellent plasticity with an elongation of ∼21 % and a considerable ultimate tensile strength of ∼900 MPa. Consequently, the ductile iron achieves an exceptional strength-plasticity synergy, characterized by the product of tensile strength and elongation (PSE) of 19 GPa%. [Display omitted] • A ductile iron composed of graphite, lamellar α and γ phases was produced. • Nanoscale Mg 6 Si 7 Ni 16 phases were observed in the tempered sample. • TRIP effect was observed during the deformation of the tempered sample. • An excellent strength and plasticity with a PSE of 19 GPa% was obtained. [ABSTRACT FROM AUTHOR]

Metallic materials or alloys consisting of single face-cubic centered (FCC) phases typically face difficulties in obtaining high strength without sacrificing ductility. The introduction of different crystalline defects via pre-straining and the activation of multiple deformation mechanisms have been shown to be effective in achieving superior strength–ductility synergy. In this work, we investigated the role of varying rolling conditions and subsequent annealing on the mechanical response in an established twinning- and transformation-induced plasticity dual phase high-entropy alloy (TWIP-TRIP-DP HEA). We found that all of the annealed samples exhibited similar nano-twinned structures. Furthermore, phase transformation from FCC γ to hexagonal close-packed (HCP) ε prevailed along the nano-twins under mechanical loading. With increasing rolling temperature, the phase stability of the matrix revealed a downward trend, resulting in a significant increase in TWIP/TRIP effects along with a prominent change in the deformation microstructure. Our study presented a simple and feasible strategy for manipulating mechanical performance by modulating the microstructural characteristics and associated deformation modes. [Display omitted] • Metastable Fe 50 Mn 30 Co 10 Cr 10 C 0.5 high-entropy alloys with single FCC matrix are successfully fabricated. • The structural stability can be adjustable by altering rolling temperature. • The origins for fantastic mechanical properties together with good work-hardening capability were elucidated. [ABSTRACT FROM AUTHOR]

With the surge of electric vehicles, accurate estimation of their energy consumption becomes increasingly critical. Data-driven models have been widely used for estimating the energy consumption of electric vehicles; however, their applications often face limitations due to inadequate training data, resulting in over-fitting and poor generalizability. In this paper, a physically rational data augmentation approach is proposed to expand the driving trip dataset. By incorporating physical coherence into the augmentation process, new driving trips are synthesized with rational physical context. The effectiveness of the proposed approach is validated by applying it to three data-driven models for estimating the energy consumption of electric vehicles across different validation scenarios. Compared with two baseline data augmentation approaches, our proposed approach demonstrates superior model training performance with less data synthesized. In the best case, the proposed approach achieved a 34% accuracy improvement over the raw data and an 11% improvement over the best-performing baseline. This proposed approach shows considerable promise in facilitating the effective adoption of advanced machine learning algorithms in industrial applications by significantly reducing the data collection requirements. [Display omitted] • The requirements of small-scale data for BEV data-driven models are discussed. • An approach that synthesizes physically rational BEV trip samples is proposed. • Experiments show that conventional data augmentation may produce invalid samples. • The proposed approach effectively improves the performance of data-driven models. [ABSTRACT FROM AUTHOR]

The mechanical performance and multi-step TRIP/TWIP behaviors in a metastable Fe 55 Mn 25 Co 10 Cr 10 were systematically investigated at room temperature (RT) and 77 K. The deformation behaviors and mechanically induced ε-martensite, fcc twin and hcp twin bands in Fe 55 Mn 25 Co 10 Cr 10 were studied based on the thermodynamics and nanostructural analyses. Deformation-induced nanostructural evolutions were found to vary greatly as the temperture decreases from RT to 77K. Deformation induced ε-martensite and fcc deformation twins (fcc) carrying more strain developed at RT. On the other hand, bi-directional ε-martensite bands were favored to accommodate the increased strain at 77K instead of fcc deformation twins because of the increased stability of hcp phase. Complicated hcp ε-martensite twins developed adjacent to the crossed region of two ε-martensitec bands at 77K. The tensile stress developed perpendicular to the original hcp ε-martensite band because of its intrinsic smaller c/a ratio (1.615–1.620) than the ideal ratio (1.633) in hcp ε-martensite, inducing {10Ī2} twins with (0001) basal plane approximately perpendicular (86.0°) to that of the original ε-martensite band. Hcp twinning in the ε-martensite band at 77K is suggested to be driven by the structural and electronic relaxations associated with the c/a distortion of the hcp ε-martensite bands. Excellent strength-ductility combinations were also obtained at RT (861MPa/73.2 %) and 77 K (1.42GPa/61.8 %) because of the enhanced hardening rates due to TRIP/TWIP(fcc) at RT and/or TRIP/TWIP(hcp) at 77 K in this study. [ABSTRACT FROM AUTHOR]

Additively-manufactured metastable high entropy alloys are emerging as promising alternatives for energy absorption in protective equipment due to their exceptional ductility. In this study, an elongation of over 50 % was achieved in a directed energy deposition fabricated Fe 45 Mn 35 Co 10 Cr 10 metastable high entropy alloys (MHEAs). The inherent high cooling rate and repeated heat treatment in the directed energy deposition process were harnessed to deliberately induce an uneven distribution of Mn elements, forming a cellular structure with chemical boundary. The unique heterogeneity stacking fault energy results in a synergistic interplay of multiple deformation mechanisms such as, dislocation slip, transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP). In the initial stage of deformation, dislocation slip and TRIP contribute to the main plasticity. Stacking faults/martensite are confined within the cellular structure with low stacking fault energy (SFE). As strain increases, TWIP and TRIP are activated in the high SFE regions. Twins and martensite across the cell wall were observed. As strains exceed 40 %, primary martensite variant and twinning with a particular intersection angle take place to further enhance the deformation ability. The chemical boundary with stacking fault energy heterogeneity not only simultaneously activates both TRIP and TWIP, but also maintains the martensite and twins at the nanoscale. • Fe 45 Mn 35 Co 10 Cr 10 MHEAs were manufactured by DED with high ductility. • The uneven distribution of Mn elements results in stacking fault energy heterogeneity. • The stacking fault energy heterogeneity enables the simultaneous activation of TRIP and TWIP. • Chemical discontinuity maintains the width of martensite and twins consistently at the nanoscale. • Monoclinic structure MnO particles do not influence the TRIP/TWIP processing. [ABSTRACT FROM AUTHOR]

Internal combustion engines contribute significantly to global warming and air pollution in urban areas with high population densities and abundant vehicular movement. Alternative energy vehicle, such as hybrid and electric vehicles, are being developed to address these concerns. However, a gradual transition to electrification while maintaining the existing fuel infrastructure appears more feasible than the rapid proliferation of battery-powered electric vehicles. Hybrid electric vehicles are recognized as an important means of improving vehicle fuel efficiency and reducing carbon emissions by introducing changes in driving modes to enhance energy consumption efficiency. Catalyst activation does not occur in cold starts, making it challenging to control exhaust emissions. In Korea, urban driving patterns characterized by speeds below 60 km/h often results in insufficient catalyst activation. Therefore, research on the characteristics of urban driving and cold-start conditions is essential. This study analyzed the urban driving characteristics of domestic hybrid vehicles reflecting urban conditions through chassis tests and examined the variations in the external temperature and engine contribution to assess the control capability of the hybrid system. Confirming that minimizing the engine preheating time during cold starts and efficiently utilizing energy stored in the motor can enhance fuel efficiency and reduce exhaust emission rates. • Fuel consumption and exhaust emissions are predominantly generated during vehicle operation. • Hybrid electirc vehicles have the best fuel efficiency. • The hybrid system is controlled and operated by the state of charge. • Enhancing both fuel efficiency and emission control is achieved through hybrid systems. [ABSTRACT FROM AUTHOR]

The protein known as PI3K-interacting protein (PIK3IP1), or transmembrane inhibitor of PI3K (TrIP), is highly expressed by T cells and can modulate PI3K activity in these cells. Several studies have also revealed that TrIP is rapidly downregulated following T cell activation. However, it is unclear how this downregulation is controlled. Using a novel monoclonal antibody that robustly stains cell-surface TrIP, we demonstrate that TrIP is lost from the surface of activated T cells in a manner dependent on the strength of signaling through the T cell receptor and specific downstream signaling pathways, in particular classical PKC isoforms. TrIP expression returns by 24 h after stimulation, suggesting that it may play a role in resetting T cell receptor signaling at later time points. We also provide evidence that ADAM family proteases are required for both constitutive and stimulation-induced downregulation of TrIP in T cells. Finally, by expressing truncated forms of TrIP in cells, we identify the region in the extracellular stalk domain of TrIP that is targeted for proteolytic cleavage., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

• In-situ tensile testing is performed up to failure under synchrotron X-ray diffraction. • Stress/strain level dependent strengthening mechanisms are exhibited in terms of diffraction peaks change. • The microstructure evolution, phase transformation, and strengthening mechanisms occurring during loading on a dual-phase high entropy alloy are detailed. The present research focuses on analyzing the deformation mechanisms associated with tensile loading of the Fe 50 Mn 30 Co 10 Cr 10 high entropy alloy (HEA) using synchrotron x-ray diffraction (SXRD). This novel material is comprised by two major phases: γ-FCC and ε-HCP, where transformation induced plasticity (TRIP) effectively transforms the first into the latter, upon the application of an external stress. However, the presence of thermally stable ε-HCP prior to loading will also influence the deformation mechanism of the material during mechanical solicitation. As such, here we investigate the activation of different strain accommodation mechanisms and the consequent microstructural evolution. Four stages were identified in the mechanical response of this novel HEA, where the TRIP and the twinning induced plasticity (TWIP) deformation modes are the main events granting this HEA its outstanding properties. Such sequence of events allows to evidence the effectiveness of the collaboration between the transformative capability of the γ-FCC phase and the work hardening potential of the ε-HCP phase. This analysis is performed via quantitative and qualitative analysis of the SXRD data, allowing also to investigate the response behavior of specific crystallographic planes to the increasing stress throughout the experiment. [Display omitted] [ABSTRACT FROM AUTHOR]

We investigated the temperature-dependent mechanical properties and deformation mechanisms of the Fe 49.5 Mn 30 Co 10 Cr 10 C 0.2 Ti 0.1 V 0.1 Mo 0.1 alloy from room temperature to cryogenic temperatures. As the deformation temperature decreased, both the strength and strain-hardening rate increased, while ductility tended to decrease. The higher strength of the material deformed at 123 K, compared to that deformed at 223 K, can be attributed to the larger number of multivariant HCP plates and higher hetero deformation induced (HDI) strengthening in the former. Multivariant deformation-induced HCP plates were the primary deformation mechanisms at all deformation temperatures, and cryogenic deformation activated intersecting shear, defined as the primary HCP plate being sheared by the secondary HCP plate. This mechanism contributed to stress relaxation and enhanced deformation accommodation. The reduced ductility observed in the material deformed at 123 K may be attributed to coarse edge and grain boundary cracks, which were more pronounced when the TRIP effect was enhanced. • Temperature-dependent mechanical properties of an FCC high entropy alloy. • Increased HCP plates and back stress after cryogenic deformation led to high strength. • Cryogenic deformation activated intersecting shear. • Grain boundary cracks formed during cryogenic deformation limit ductility. [ABSTRACT FROM AUTHOR]

This study reports the grain-size-dependent deformation-induced face-centered cubic (FCC)–hexagonal close-packed (HCP) transformation behavior of Fe 49.5 Mn 30 Co 10 Cr 10 C 0.2 Ti 0.1 V 0.1 Mo 0.1 (at. %) high-entropy alloy in the medium grain size range (10–20 μm), their mechanical properties, and deformation mechanisms. The materials annealed at 900 °C for 1 h (A900-1) and 10 h (A900-10) showed a fully FCC, recrystallized microstructure with a larger grain size in the latter owing to grain growth during annealing. The A900-1 sample exhibited a larger strength–ductility balance and a higher strain hardening rate than the A900-10 sample. The A900-1 sample, with a larger number of grain boundary nucleation sites of the deformation-induced HCP phase, exhibited a higher HCP transformation rate than the A900-10 sample in the early stage of deformation below 10 % strain, whereas both materials showed similar HCP transformation rates at strain levels higher than 30 %. The emission of deformation-induced HCP plates in both neighboring grains from the same grain boundary (A900-1) and the activation of the deformation-induced HCP phase in a single grain and only dislocations in the neighboring grains (A900-10) suggest the importance of grain boundary stress in the observed phenomena. The observed additional mechanisms other than dislocation slip and deformation-induced HCP phase, that is, reverse FCC-HCP transformation, HCP { 10 1 ‾ 2 } twinning, and kink banding, could contribute to deformation accommodation and stress relaxation, thereby leading to the excellent ductility of the investigated materials. [ABSTRACT FROM AUTHOR]

Background: Falls due to stumbling are prevalent for transfemoral prosthesis users and may lead to increased injury risk. This preliminary case series analyzes the transfemoral prosthesis user stumble recovery response to highlight key deficits in current commercially-available prostheses and proposes potential interventions to improve recovery outcomes., Methods: Six transfemoral prosthesis users were perturbed on their prosthetic limb at least three times while walking on a treadmill using obstacle perturbations in early, mid and late swing. Kinematic data were collected to characterize the response, while fall rate and key kinematic recovery metrics were used to assess the quality of recovery and highlight functional deficits in current commercially-available prostheses., Results: Across all participants, 13 (54%) of the 24 trials resulted in a fall (defined as > 50% body-weight support) with all but one participant (83%) falling at least once and two participants (33%) falling every time. In contrast, in a previous study of seven young, unimpaired, non-prosthesis users using the same experimental apparatus, no falls occurred across 190 trials. For the transfemoral prosthesis users, early swing had the highest rate of falling at 64%, followed by mid-swing at 57%, and then late swing at 33%. The trend in falls was mirrored by the kinematic recovery metrics (peak trunk angle, peak trunk angular velocity, forward reach of the perturbed limb, and knee angle at ground contact). In early swing all four metrics were deficient compared to non-prosthesis user controls. In mid swing, all but trunk angular velocity were deficient. In late swing only forward reach was deficient., Conclusion: Based on the stumble recovery responses, four potential deficiencies were identified in the response of the knee prostheses: (1) insufficient resistance to stance knee flexion upon ground contact; (2) insufficient swing extension after a perturbation; (3) difficulty initiating swing flexion following a perturbation; and (4) excessive impedance against swing flexion in early swing preventing the potential utilization of the elevating strategy. Each of these issues can potentially be addressed by mechanical or mechatronic changes to prosthetic design to improve quality of recovery and reduce the likelihood a fall., (© 2024. The Author(s).)

The ride-sharing trend is booming because of modern technologies and plays a significant role in transitioning to sustainable transportation methods. This study utilizes a comprehensive dataset collected from an online survey administered to over 1300 individuals in Bangladesh in 2023. Its specific focus is to examine the usage patterns of ride-sharing applications, such as Pathao and Uber. It builds upon previous research to analyze the factors influencing the use of these services and current trends in shared transportation. Additionally, it investigates the challenges associated with utilizing shared transportation amenities and proposes potential improvements to make ride-sharing or pooling more attractive. The study diligently worked to establish an inclusive framework and terminology to enhance policies and gain a more detailed understanding of the transportation choices and requirements of communities. To bridge the gap between theory and practice, we adopted an implementation-oriented research approach and conducted a comprehensive quantitative and inferential analysis of the survey data. The inclination of an individual to opt for or perceive collective or merged services depends on several demographic, geographical, and built-environment factors. The findings highlight the necessity of enhanced security measures, increased public awareness of ride-sharing benefits, and the formulation of legislative measures to promote sustainable mobility. Two examples of potential measures we have found to improve and encourage the use of ride-sharing services include reducing uncertainty about shared rides and minimizing passenger discomfort. These measures can be implemented through operational adjustments, government regulations, and employer programs. An essential conclusion was reached regarding the importance of prioritizing improvements in ride-sharing operations, rather than relying solely on cash incentives to promote behavioral change. Furthermore, it was determined that regardless of the changes, policies, or programs implemented, it is imperative to enhance public awareness and education., Competing Interests: The authors declare that they have no competing interests.The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)

Trips and falls are a major concern for older adults. The resulting injury and loss of mobility can have a significant impact on quality of life. An emerging field of study, known as Perturbation Training, has been shown to reduce injury rates associated with trips and falls in older adults. Treadmills traditionally used for Perturbation Training are large, expensive, and immobile, forcing users to travel long distances to receive care. A portable treadmill would serve a larger portion of the at-risk population than current methods. We developed a portable, low-cost, twin-belt perturbation treadmill capable of high-intensity Perturbation Training. Belt speeds are controlled by a custom mechanical and software interface, allowing operators with no programming experience to control the device. The treadmill can accommodate users up to 118 kg and provides a maximum acceleration and speed of 12 m/s 2 and 3.3 m/s, respectively, under full load. The total weight is 180 kg, and the treadmill can be moved like a wheelbarrow, with handles in the back and wheels in the front. The prototype was validated with mechanical and human participant testing, showing it as a viable device for Perturbation Training. In this paper, we will go over the design, fabrication, and validation processes used to create the Portable Perturbation Treadmill., (Copyright © 2024 by ASME.)

• A cyclic plasticity constitutive model containing a three-phased microstructure of austenite, martensite, and ferrite is constructed by the two-leveled homogenization method, into which a kinetics equation for the strain-induced martensitic transformation and a modified nonlinear kinematic hardening equation are introduced. • Effect of martensitic transformation on ratchetting of the medium-manganese steel was systematically investigated. • The ratchetting behavior of medium-manganese steel is further predicted for different austenite contents and different phase transformation rates by the proposed model. Transformation-induced plasticity (TRIP) behavior and related cyclic plasticity model of medium-manganese steel subjected to uniaxial cyclic loading were studied. Cyclic loading tests were conducted at different mean stresses and stress amplitudes. The results show that medium-manganese steel exhibits two different ratchetting evolution characteristics. Moreover, microscopic characterizations reveal that martensitic transformation occurs in medium-manganese steel during asymmetrical cyclic stressing, and the higher the applied stress amplitude, the greater the ratchetting strain and the more likely the martensitic transformation will occur. The interaction between TRIP and ratchetting leads to accelerated accumulation of plastic strain. Based on the existing meso-mechanics cyclic elastoplastic constitutive model, a kinetic equation for the strain-induced martensitic transformation and a modified nonlinear kinematic hardening equation are introduced. Subsequently, the two-leveled homogenization method was used to construct a homogenized cyclic plasticity model containing a three-phase microstructure of austenite, martensite, and ferrite. By comparing the predicted results with the experimental results, the proposed model can reasonably describe the evolutionary features of each phase and the effect of the phase transformation on the ratchetting of medium-manganese steel. Finally, ratchetting is further predicted and discussed for different austenite contents and phase transformation rates using the proposed model. [ABSTRACT FROM AUTHOR]

• It successfully detects the fracture initiation time by using DCPD and DIC methods. • The maximum stress exhibits a positive strain rate dependency, and the maximum strain exhibits a negative strain rate dependency. • The fracture toughness can be evaluated by J -integral and shows negative strain rate dependency. • SZD and θ show negative strain rate dependencies, while SZW shows positive strain rate dependency. • Mixed-mode fracture can be found near the crack for impact tension. Utilizing transformation-induced plasticity (TRIP) steel with strain-induced martensitic transformation (SIMT) on automotive steel plates and developing products which have exceptional energy absorption capabilities can be used to reduce weight. For this purpose, it is important to clarify the fracture toughness of TRIP steels and its strain rate dependency to ensure the use of impact-absorbing members over a wide range of deformation rates. However, inconsistent rate dependent trends were observed in the previous studies, possibly as a result of the transition of the fracture mode. Therefore, the effect of fracture modes and strain rate on the fracture toughness values needs to be examined sufficiently. In the present study, the fracture toughness of the specimens made of SUS304 metastable austenitic stainless steel, which is a kind of TRIP steel, is evaluated by tensile tests at various strain rates. Direct current potential difference and digital image correlation methods are introduced to detect the time of fracture initiation during deformation, especially at high deformation rates by using the developed impact tensile tests based on the split Hopkinson pressure bar. The fracture surfaces of the fractured specimens are observed by using an electron scanning electron microscopy to determine not only the fracture modes and their rate dependent effects but also the reinforcement mechanism of SIMT in mixed modes. The results demonstrate that fracture toughness shows negative strain rate dependency, and mixed-mode fracture can be found near the crack in the case of the impact tensile test. [ABSTRACT FROM AUTHOR]

[Display omitted] • A hybrid machine-learning algorithm combining ab initio calculations and an experimental dataset is proposed. • The proposed model, available online, better predicts the activated plasticity mechanisms of β-titanium alloys. • The prediction accuracy is improved, particularly in the case of the simultaneous activations of the TRIP and TWIP effects. This study proposes a machine-learning (ML) model combining ab initio calculations and an experimental dataset of 201 alloys (in addition to pure Ti) to predict the activated plasticity mechanisms in β-Ti alloys. This methodology is shown to be more efficient than the so-called Bo ¯ - Md ¯ approach, achieving 82% prediction accuracy while the Bo-Md approach leads to 52% correct predictions on the same dataset. In addition, four new alloy compositions were produced to verify the model validity. Specific cases where the present model disagreed with the Bo-Md predictions were chosen to increase the benefits of the produced results. The plasticity mechanisms of the four alloys experimentally confirmed the validity of the ML model. This approach particularly helps the design of specific Ti alloys exhibiting a high work hardening rate owing to the simultaneous activations of the Transformation-Induced Plasticity (TRIP) and mechanical twinning (TWIP) effects. Indeed, the class corresponding to the combination of TRIP and TWIP effects reach a prediction accuracy of 88%. [ABSTRACT FROM AUTHOR]

• Time-resolved quantifications of strain-induced martensitic transformation (SIMT) and stresses at phase scale were determined in three ferrite-austenite-martensite medium Mn steels during tensile tests. • Evidences are found that Lüders and PLC instabilities originates respectively from ferrite and austenite. • An innovative mean field micromechanical model was developed which simulates the local behavior of each phase and the SIMT. • The model is microstructure-based, sensitive to the grain size and composition of the constituting phases. • A new framework is proposed to model the unique mechanical behavior of strain-induced martensite. Medium Mn steels belong to a new generation of advanced high-strength steels whose superior mechanical properties are explained by their ultrafine-grained ferrite/austenite/martensite microstructures and a possible transformation induced plasticity (TRIP) related to the stability of retained austenite. The mechanical behaviour of a set of model medium Mn steels is investigated during tensile testing using a combination of high-energy X-ray diffraction (HEXRD) and digital image correlation (DIC) measurements. HEXRD allows for the time-resolved determination of transformation kinetics and in situ stress partitioning among the different constituting phases. DIC provides precise spatiotemporal information on the strain evolution along the gauge length, particularly at the position of the diffracting volume. These experiments served to calibrate an innovative mean field micromechanical model which accounts for the local behaviour of each phase, as well as the strain-induced martensitic transformation (SIMT) of retained austenite. The work-hardening of both austenite and ferrite is modeled using a dislocation-based size-sensitive approach which includes kinematic hardening contributions. The behaviours of fresh and strain-induced martensite are predicted using a genuine model derived from the continuous composite approach. The model for SIMT is based on a thermodynamic assessment of the stability of retained austenite. The overall model is thus sensitive to the size of the microstructure components, their local chemistry, and their respective stability. [ABSTRACT FROM AUTHOR]

A novel transformation induced plasticity (TRIP) Ti alloy with the composition of Ti-4.7Al-6.26Mo-2.85Cr was designed. The tensile and Charpy impact behaviors of the alloy with single β and α + β dual phase were comparably investigated. Compared to the single β microstructure, the α + β dual microstructure exhibited the higher yield strength (YS) and impact absorbed energy. This suggests the YS of the metastable β Ti alloys has a significant influence on the impact toughness, i.e., the disadvantage of the low YS in single β microstructure become more prominent in the impact deformation. Because the β matrix in the α + β dual microstructure was more stable than that in the single β microstructure due to the elemental partitioning effect, the primary impact deformation mechanism changed from the stress induced martensite in the single β microstructure to dislocation slip in the α + β dual microstructure. Correspondingly, the cracking mechanism changed from β/α" interface cracking to β retained /α lath interface cracking. These findings provide guidance for the simultaneous improvement of YS and Charpy impact absorbed energy of TRIP Ti alloys by microstructural regulation. [Display omitted] • Compared to the single β microstructure, the double α + β microstructure exhibited the higher yield strength and impact absorbed energy. • The disadvantage of the low yield strength of the single β microstructure under static tensile deformation became more prominent under the impact deformation. [ABSTRACT FROM AUTHOR]

Competing Interests: All authors declare no relevant financial relationships.