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Abstract This study investigated the corrosion and oxidation mechanism of the Cr-free Fe-40Ni-15Co superalloy with exposure to a tropical marine atmosphere for one year and a subsequent high temperature of 650 °C for 300 h. The degradation behavior of the samples was evaluated based on surface characterization and analysis. In the tropical marine atmospheres, the corrosion process of the Fe-40Ni-15Co superalloy presented an initial localized type after one month of exposure and gradually developed into uniform. The corrosion products were mainly comprised of Fe2O3 and NiO, suppressing the pitting process. During the high-temperature oxidation process, all samples presented super-parabolic oxidation kinetics. Except for the initial active oxidation due to salt deposits, the corrosion products after atmospheric exposure could significantly enhance the oxidation resistance at 650 °C. An explanation for the degradation mechanism of the Fe-40Ni-15Co superalloy was developed based on the synergistic effects of atmospheric corrosion and high-temperature oxidation.

Unified constitutive equations have been developed to model the behaviour of metallic materials under various processing conditions. These constitutive equations usually take the form of a set of ordinary differential equations (ODEs), which must be solved thousands of times in a finite element (FE) process simulation. Thus, an efficient and reliable numerical integration method for large systems is crucial for solving this problem. However, in many constitutive equations, numerical stiffness is often present. This means that the stability requirements, rather than the accuracy, constrain the step size. Therefore, certain numerical methods become unsuitable when the required step size becomes unacceptably small. In this study, a series of mathematical analyses was performed to investigate the difficulties in the numerical integration of three sets of unified viscoplastic/creep constitutive equations. Based on an analysis of the current stiffness assessment methods, a novel index was introduced, that enables an accurate assessment of the stiffness of the ODE-type unified constitutive equations. A computational study was also conducted to benchmark several promising implicit numerical integration methods for viscoplastic/creep constitutive equations. This study can assist researchers in metal forming and other fields in choosing appropriate numerical methods when dealing with stiff ODEs.

Digital image correlation (DIC) outperforms other strain measurement technologies due to its versatility, accuracy, non-contact nature, and capability to capture full-field strains. However, for aluminium alloys like AA6082 under high-temperature and large-deformation conditions, the shiny effects observed in the gauge area degrade the quality of the captured deformation images, leading to failures in the DIC analyses. In this study, the source of the shiny effects was investigated by analysing the evolution of AA6082 specimen surfaces painted with speckle patterns during hot stamping deformation. It was found that the shiny effects were attributed to the exposure of the reflective base material due to paint peeling and cracking. To overcome these problems, the DIC method was improved by developing a novel procedure for generating more effective speckle patterns and utilising a cross-polarisation optical system (XPOL) to mitigate the shiny effects. The improved DIC method was applied to AA6082 in both uniaxial and biaxial tensile tests under diverse hot stamping conditions, along with applications to boron steel for comparison. These improvements significantly reduced the shiny effects and increased the time over which full-field strains can be measured for AA6082, reaching over 96% (up from 75%) of the fracture time in the uniaxial tests and even 100% in the biaxial tests. The improved DIC method enables the full-field strain measurement for aluminium alloys under hot stamping conditions, allowing for the accurate determination of their thermomechanical properties.

Abstract Background Ischemic heart disease is one of the leading causes of mortality worldwide, and thus calls for development of more effective therapeutic strategies. This study aimed to identify potential therapeutic targets for coronary heart disease (CHD) and myocardial infarction (MI) by investigating the causal relationship between plasma proteins and these conditions. Methods A two-sample Mendelian randomization (MR) study was performed to evaluate more than 1600 plasma proteins for their causal associations with CHD and MI. The MR findings were further confirmed through Bayesian colocalization, Summary-data-based Mendelian Randomization (SMR), and Transcriptome-Wide Association Studies (TWAS) analyses. Further analyses, including enrichment analysis, single-cell analysis, MR analysis of cardiovascular risk factors, phenome-wide Mendelian Randomization (Phe-MR), and protein-protein interaction (PPI) network construction were conducted to verify the roles of selected causal proteins. Results Thirteen proteins were causally associated with CHD, seven of which were also causal for MI. Among them, FES and PCSK9 were causal proteins for both diseases as determined by several analytical methods. PCSK9 was a risk factor of CHD (OR = 1.25, 95% CI: 1.13–1.38, P = 7.47E-06) and MI (OR = 1.36, 95% CI: 1.21–1.54, P = 2.30E-07), whereas FES was protective against CHD (OR = 0.68, 95% CI: 0.59–0.79, P = 6.40E-07) and MI (OR = 0.65, 95% CI: 0.54–0.77, P = 5.38E-07). Further validation through enrichment and single-cell analysis confirmed the causal effects of these proteins. Moreover, MR analysis of cardiovascular risk factors, Phe-MR, and PPI network provided insights into the potential drug development based on the proteins. Conclusions This study investigated the causal pathways associated with CHD and MI, highlighting the protective and risk roles of FES and PCSK9, respectively. FES. Specifically, the results showed that these proteins are promising therapeutic targets for future drug development.

As a promising solution to the growing demand for lightweighting, hot stamping has gained considerable applications in the automotive industry. Over the past few decades, the market for hot stamping has experienced explosive growth, with ongoing advancements offering potential for further expansion of its applications. This paper provides a historical overview of hot stamping alongside an in-depth analysis of future trends. Scientific publications, patents and industrial applications of hot stamping are systematically reviewed, with major developments in materials, processes, tools, and other relevant aspects being highlighted. Through data analysis, the current state of hot stamping is comprehensively depicted, and the trends in the development of hot stamping are revealed. Additionally, the future of extending hot stamping technologies to a broader range of materials is discussed, with suggestions furnished from both academic and industrial perspectives.

With the growing concern about climate issues and the urgent need to reduce carbon emissions, hydrogen has attracted increasing attention as a clean and renewable vehicle energy source. However, the storage of flammable hydrogen gas is a major challenge, and it restricts the commercialisation of fuel cell electric vehicles (FCEVs). This paper provides a comprehensive review of common on-board hydrogen storage tanks, possible failure mechanisms and typical manufacturing methods as well as their future development trends. There are generally five types of hydrogen tanks according to different materials used, with only Type III (metallic liner wrapped with composite) and Type IV (polymeric liner wrapped with composite) tanks being used for vehicles. The metallic liner of Type III tank is generally made from aluminium alloys and the associated common manufacturing methods such as roll forming, deep drawing and ironing, and backward extrusion are reviewed and compared. In particular, backward extrusion is a method that can produce near net-shape cylindrical liners without the requirement of welding, and its tool designs and the microstructural evolution of aluminium alloys during the process are analysed. With the improvement and innovation on extrusion tool designs, the extrusion force, which is one of the most demanding issues in the process, can be reduced significantly. As a result, larger liners can be produced using currently available equipment at a lower cost.

Aluminium extrusion profiles are widely utilised due to their potential to enhance energy efficiency and reduce costs. In this paper, two advanced tool designs for a novel sideways extrusion technique, the Unified design and the Guided design, were proposed. These designs facilitate the production of three-dimensional curved profiles with marked asymmetry and large-scale cross-sections. Numerical simulations of the initial designs revealed considerable variations in bending shapes compared to the target profile. Employing the Taguchi method combined with grey relational analysis, the study identified that the extrudate's bending shape are influenced by the die orifice position and the speed ratio of two rams with different sensitivities. Following this, optimal designs were derived for both design types. For the particular profile in this study, the simulation results showed that the optimal Unified design permitted better welding quality and lower extrusion force. However, the optimal Guided design achieved a bending shape more aligned with the target shape. It can also provide enhanced stability in the extrusion system and higher production yield compared to the optimal Unified design.

Developing reusable and easy-to-operate biocatalysts is of significant interest in biodiesel production. Here, magnetic whole-cell catalysts constructed through immobilizing recombinant Escherichia coli cells (containing MAS1 lipase) into Fe3O4–chitosan magnetic microspheres (termed MWCC@MAS1) were used for fatty acid methyl ester (FAME) production from waste cooking oil (WCO). During the preparation process of immobilized cells, the effects of chitosan concentration and cell concentration on their activity and activity recovery were investigated. Optimal immobilization was achieved with 3% (w/v) chitosan solution and 10 mg wet cell/mL cell suspension. Magnetic immobilization endowed the whole-cell catalysts with superparamagnetism and improved their methanol tolerance, enhancing the recyclability of the biocatalysts. Additionally, we studied the effects of catalyst loading, water content, methanol content, and reaction temperature on FAME yield, optimizing these parameters using response surface methodology and Box–Behnken design. An experimental FAME yield of 89.19% was gained under the optimized conditions (3.9 wt% catalyst loading, 22.3% (v/w) water content, 23.0% (v/w) methanol content, and 32 °C) for 48 h. MWCC@MAS1 demonstrated superior recyclability compared to its whole-cell form, maintaining about 86% of its initial productivity after 10 cycles, whereas the whole-cell form lost nearly half after just five cycles. These results suggest that MWCC@MAS1 has great potential for the industrial production of biodiesel.

In this study, laser-cladding technology was used to create Cu-based amorphous-crystalline composite coatings on the surface of Nickel-aluminum bronze (NAB), and the microstructure, mechanical properties, corrosion and wear resistance of the coatings were systematically investigated. The coatings consisted of a combination of amorphous and intermetallic compounds, with a positive correlation observed between the amorphous content and the laser scanning speed. Microstructural observations confirmed excellent metallurgical bonding between the coatings and substrate without any noticeable defects. Furthermore, electron back-scatter diffraction testing demonstrated a gradient structure from the substrate to the coating, confirming its composition as an amorphous- crystalline composite. At a laser scanning speed of 20 mm/s, the volume fraction of the amorphous phase of the coating reached 68.8%, with a microhardness approximately 4.5 times higher than that of the substrate and an average friction coefficient half that of the substrate. Moreover, the coatings showed a shift in corrosion potential by 149 mV with nearly an order-of-magnitude decrease in corrosion current density. [ABSTRACT FROM AUTHOR]

Unified constitutive equations have been developed to model the behaviour of metallic materials under various processing conditions. These constitutive equations usually take the form of a set of ordinary differential equations (ODEs), which must be solved thousands of times in a finite element (FE) process simulation. Thus, an efficient and reliable numerical integration method for large systems is crucial for solving this problem. However, in many constitutive equations, numerical stiffness is often present. This means that the stability requirements, rather than the accuracy, constrain the step size. Therefore, certain numerical methods become unsuitable when the required step size becomes unacceptably small. In this study, a series of mathematical analyses was performed to investigate the difficulties in the numerical integration of three sets of unified viscoplastic/creep constitutive equations. Based on an analysis of the current stiffness assessment methods, a novel index was introduced, that enables an accurate assessment of the stiffness of the ODE-type unified constitutive equations. A computational study was also conducted to benchmark several promising implicit numerical integration methods for viscoplastic/creep constitutive equations. This study can assist researchers in metal forming and other fields in choosing appropriate numerical methods when dealing with stiff ODEs. [ABSTRACT FROM AUTHOR]

Background Earlier studies have investigated the association between overweight/obesity and an elevated risk of breast cancer in women. However, some studies have found that it may not be scientifically accurate to solely analyze the association between overweight/obesity and breast cancer in women for overweight/obesity can be classified into different metabolic phenotypes. The current findings on the association of different metabolic phenotypes with breast cancer remain inconsistent. Objective To prospectively analyze the associations of different metabolic obesity phenotypes with the risk of breast cancer in women. Methods In this prospective cohort study, female employees (n=23 406) of Kailuan Group who participated in physical examinations for the first time in Kailuan General Hospital and its 11 affiliated hospitals from 2006 to 2008 were selected as the study subjects and received questionnaire investigation, physical examination and laboratory tests. The study subjects were divided into the four groups based on the types of metabolic syndrome and BMI, including metabolically healthy normal weight (MHNW) group (n=12 739), metabolically unhealthy normal weight (MUNW) group (n=1 060), metabolically healthy overweight/obese (MHO) group (n=6 394), and metabolically unhealthy overweight/obese (MUO) group (n=3 213). The subjects were followed up, with the first physical examination attended as the starting point, and new onset breast cancer, death, or the end of follow-up time (2020-12-31) as the endpoints. Multivariate Cox proportional hazard regression model was used to estimate the association of the four groups with the risk of breast cancer. Results During an average follow-up of (13.26±1.85) years, with 353 new cases of breast cancer and an incidence density of 11.38 cases per 10 000 person-years in the total population. The incidence cases in the MHNW, MUNW, MHO, and MUO groups were 154, 21, 113, and 65, respectively, with the incidence density of 9.08, 15.37, 13.27, and 15.49 per 10 000 person-years, and the cumulative incidence of 1.22%, 2.01%, 1.67%, and 1.93%, respectively. Multivariate Cox proportional hazard regression model analysis, after adjusting for confounders, showed that compared with the MHNW group, the risk of breast cancer was increased by 42% (HR=1.42, 95%CI=1.11-1.82) and 59% (HR=1.59, 95%CI=1.17-2.17) in the MHO group and MUO group, respectively. Stratified analysis by menopausal status showed that compared to the MHNW group, the MUO group was associated with a 69% increase in risk of premenopausal breast cancer (HR=1.69, 95%CI=1.01-2.83). The risk of postmenopausal breast cancer was increased by 85% (HR=1.85, 95%CI=1.09-3.14), 50% (HR=1.50, 95%CI=1.06-2.13), and 55% (HR=1.55, 95%CI=1.05-2.28) for the MUNW, MHO, and MUO groups, respectively, compared to the MHNW group. Conclusion Overweight/obesity is a risk factor for female breast cancer, and overweight/obesity with metabolic abnormalities further increases the risk of breast cancer. Additionally, normal weight postmenopausal women who are metabolically unhealthy may be at an increased risk of postmenopausal breast cancer.