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Alcohol-related liver fibrosis (ALF) is a form of alcohol-related liver disease (ALD) that generally occurs in response to heavy long-term drinking. Ecto-5'-nucleotidase (NT5E), also known as CD73, is a cytomembrane protein linked to the cell membrane

A new forming process for magnesium alloy sheet, namely, electromagnetic impacting medium forming (EIMF), is proposed. Medium is compressed by strong magnetic force which is produced from varied magnetic field between coil and driver sheet. Magnesium alloy sheet can be deformed by a strong force from medium. In EIMF, once impacting or more times impacting is easily implemented, that is difficulty in conventional electromagnetic forming. Effects of different discharge energy and temperature were investigated. Peak forming heights increased linearly with increasing discharge energy and temperature. Distribution of contour and thickness had been revealed. Strains could be improved by increasing temperature and discharge energy. Twice impacting process was carried out. The forming height was enhanced obviously in contrast with results obtained at once impacting. Fracture morphology and optical microstructure were analyzed. It is found that brittle fracture at room temperature and ductile fracture at 200 °C appeared. Due to high strain rate forming process, deformation mechanism (non-basal slip systems) has limit effect. And at 200 °C, twinning is also a main mechanism for AZ31 sheet deformation in EIMF. In further work, EIMF for formability of AZ31 sheet will be improved by affected the deformation mechanism.

We conducted a series of experimental investigations on the mechanical properties of DP600 dual-phase steel under strain rates from 0.001 to 3000 s−1 at room temperature. A split Hopkinson tensile bar was used to capture a high strain rate response. A comparison of the quasi-static and dynamic experiment results showed that the yield strength and ultimate tensile strength increased significantly under dynamic conditions. Fractographs were analyzed by scanning electron microscopy, which indicated a better ductility at a high strain rate. Based on the experimental results, the Johnson–Cook constitutive model was applied to describe the tensile deformation behavior under various strain rates. A reasonable agreement was observed between the experimental data and the Johnson–Cook model. A metallographic analysis of tensile specimens showed that the average ferritic grain size of the fractured specimens at a high strain rate was smaller than that of the fractured specimens under quasi-static conditions. Ferritic grain refinement proved that high-speed forming could enhance the forming ability of the DP600 steel.

Magnetic pulse forming is high velocity forming technology, which requires the workpiece with better conductivity. However, high-strength steel with lower conductivity is difficult to deform by magnetic pulse forming. In this paper, AA1060 sheet was employed to drive DP600 sheet which was used to solve the forming problem of high-strength steel in magnetic pulse forming. Experimental tests and numerical method were used to investigate the deformation characteristic of DP600 sheet. Effects of drive sheet and discharge voltage for DP600 sheet deformation were analyzed. Forming height increases with increasing discharge voltage and optimal thickness of driver sheet is 2 mm. Forming profile and thickness of deformed DP600 sheet were provided. Distribution of magnetic field line and magnetic force were presented by numerical simulation. Higher magnetic flux density and magnetic force can be produced by 2 mm Al driver sheet. Deformation process, velocity, strain rate, and principal strain were investigated. During the driving process, DP600 sheet was accelerated and got higher velocity about 252 m/s with 2 mm driver sheet and C = 615 μF/U = 3.38 kV. Principal strain increases with discharge voltage increasing. And the varied trend can be described by quadratic equation.

A novel design and manufacturing method, dubbed “precast,” of the cooling system and tools for a hot forming process was proposed in this paper. The integrated structures of the punch and blank holder were determined by analyzing the bending and reverse-bending deformation of the forming parts. The desired crashworthiness performance of an automotive front bumper constructed with this process was obtained by a tailored phase transformation, which generated martensite-bainite in the middle and full martensite transformation in the corner areas. Varying cooling effects in the formed parts caused the highest temperature to be located in the bottom and the lowest on the end of the formed parts. Moreover, the microstructural distributions demonstrated that the bottom possessed a relatively lower content of martensite, while, conversely, the end possessed a higher content. This was precisely the most desired phase distributions for the hot formed parts. For the six-process cycle stamping, the temperatures reached a stable status after an initial rapid increase in the first three process cycles. The microstructural results verified the feasibility of the hot forming tools under multiprocess cycles.

This paper presents experimental studies of rubber-pad forming process of AA5182 aluminum alloy sheet. The influences of load velocity and rubber pad height for characteristic of polyurethane rubber are investigated firstly by compression tests. It can be concluded that the load force increases quickly with decreasing of rubber pad height. The expansion diameter of polyurethane rubber is insensitive to load velocity at 40 and 60 mm height. Then the deformation characteristic of rubber-pad forming, states of strain, and stress is analyzed to compare with conventional drawing. Furthermore, AA5182 aluminum alloy sheets with thickness of 0.8 and formed target part with diameter of 80 mm and height of 15 mm are investigated under different load velocity varying from 50 to 500 mm/min. The load velocity, load force, and distribution of thickness are analyzed in detail. Results show that the maximum thickness reduction occurs at the bottom corner of the formed part. And the maximum thinning decreases to 20.0% for v = 50 mm/min, 20.0% for v = 100 mm/min, 17.5% for v = 300 mm/min, and 17.5% for v = 500 mm/min. At last, the forming process for target part with diameter of 80 mm and height of 20 mm is also investigated under different load velocity. The results confirmed that it is difficult to form the desired shape.

Thermal effect from warm temperature is always used to improve the formability of AZ31 magnesium alloy sheet. However, it is seldom employed to deform AZ31 sheet in magnetic pulse forming process, due to increasing resistivity and decreasing effect of high strain rate. In this study, Al driver sheets without heating were used to strength effect of high strain rate and drive AZ31 sheet with warm temperature to deform. Method of numerical simulation was used to analyze magnetic pulse forming of AZ31 sheet with driver sheet and temperature. Magnetic flux density and magnetic force with and without Al driver sheet (thickness of 1, 1.5, and 2 mm) and different temperature (25, 100, 150, 200, and 250°C) were investigated. Deformation processes and velocity with Al driver sheet and different temperature were analyzed. The results indicate that it is better for formability of AZ31 sheet to adopt 1-mm Al driver sheet at higher discharge energy and warm temperature.

Hot deformation in 6063 aluminum alloys was investigated by hot compression testing over the temperature range of 573–723 K with strain rates of 0.01–10 s−1 using a Gleeble 3500 thermal-mechanical simulator. Based on the experimental results, constitutive equations compensated with strain were developed to model the hot deformation behavior. The intrinsic workability was further analyzed by establishing three-dimensional processing maps. These maps were constructed based on dynamic materials model to delineate variations in power dissipation efficiency and flow instability domains. Combined with microstructure observation, recommended processing domains are predicated to be within the temperatures range of 673–723 K and strain rates range of 0.01–0.1 s−1. Under such conditions, the main softening mechanism is dynamic recrystallization. The results from these processing maps agree well with microstructure observation.

Using a controlled thermal simulator system, hybrid carbon nanotube-aluminum reinforced ZA27 composites were subjected to hot compression testing in the temperature range of 473-523 K with strain rates of 0.01-10 s−1. Based on experimental results, a developed-flow stress model was established using a constitutive equation coupled with strain to describe strain softening arising from dynamic recrystallization. The intrinsic workability was further investigated by constructing three-dimensional (3D) processing maps aided by optical observations of microstructures. The 3D processing maps were constructed based on a dynamic model of materials to delineate variations in the efficiency of power dissipation and flow instability domains. The instability domains exhibited adiabatic shear band and flow localization, which need to be prevented during hot processing. The recommended domain is predicated to be within the temperature range 550-590 K and strain rate range 0.01-0.35 s−1. In this state, the main softening mechanism is dynamic recrystallization. The results from processing maps agree well with the microstructure observations.

In this paper, forming behavior of AZ31 sheet in rubber pad forming with warm temperature was investigated by experimental method. Rubber pad is always considered as it is temperature resistant. However, some types of rubbers can endure warm temperature, such as polyurethane for 120 °C and silica gel for 250 °C. Thus, forming for coupling with effects of temperature and flexible of rubber pad is proposed in this paper. The forming process of AZ31 sheet experienced bulging first and then gradually contacting with die, which was different from conventional forming. Fracture presented flat at room temperature and fracture became dentation obviously at 100 °C. When the temperature elevated to 200 °C, the fracture does not occur but the polyurethane was melted. The AZ31 sheet could fill the die successfully with silica gel as rubber pad at 200 °C. The effects of different load velocity for forming of AZ31 sheet were investigated. Thickness increased at bottom of deformed part, due to pressure stress acted from surrounding area. The thickness deceased at the bottom corner. Microstructure of deformed AZ31 sheet was also analyzed. It was indicated that dynamic recrystallization and twinning deformation mechanics were activated which had positive influence for improving formability of AZ31 sheet.

Microstructure and mechanical properties of the welding zone highly depend on the thickness of inner tube for jointing two tubes using magnetic pulse welding (MPW). In this study, the critical thickness of inner 20Fe tube for the Al–Fe welding tubes is investigated by combining the theoretical calculation and experiments. Theoretical analysis demonstrates that plastic deformation zone of the inner tube expands from its inner surface to its outer surface. With equilibrium equations and modified Tresca yield criterion, the critical thicknesses of inner tube under various collision velocities are derived so as to assure the high quality of the welding. The results show that the critical thickness of inner tube increases linearly with the discharge voltage. With the discharge voltage increases by every 2 kV, the critical thickness increases by 0.5 mm accordingly. The theoretical predictions agree well experiments with an error of less than 2.5%. Furthermore, effects of thickness of inner tube on the mechanical properties of welding zone are also investigated.

Thermal effects in magnetic pulse forming of magnesium alloy sheet were investigated by finite element software ANSYS. The adiabatic temperature produced in magnetic pulse forming was due to the high forming velocity. Distribution of adiabatic temperature is affected by discharge parameters, such as voltage and capacitance. Distribution of adiabatic temperature is predicted by C-P model and J-C model which are always used to describe the forming behaviors of material in high velocity forming. Predicted distribution of adiabatic temperature by C-P model and J-C model increases with increasing of discharge voltage, but decreases clearly with capacitance increasing, particularly at the center position of the deformed part. The highest temperature is 77.7 and 94 °C at C = 1152 μF/U = 2.75 kV (limit forming parameters) predicted by C-P model and by J-C model, respectively. The relationship between velocity and adiabatic temperature is also analyzed. Preliminary study for the effect of adiabatic temperature on the micro-structure of AZ31 sheet in magnetic pulse forming is explored by the analysis for fracture morphology of the deformed sheet.

The magnetic pulse forming process of AZ31 magnesium alloy shell using uniform pressure coil at room temperature was investigated. ANSYS FEA software was used to analyze the distribution of magnetic flux density of the uniform pressure coil and magnetic pressure for loading on the AZ31 sheet. The characteristic of forming process of AZ31 shell was revealed, and magnetic pulse forming process of AZ31 shell and effect of Al alloy sheet with different thickness were presented by experiments. Due to impact between sheet and die, the rebound profiles on the bottom of deformed sheets were observed. In order to remove the rebound profile, AA5052 sheets were employed to drive the deformed AZ31 sheets. The section contour of R = 30 mm (R means bottom radius of die) shell deformed by 0.5-mm thickness of driver sheet driving once and R = 15 mm shell deformed by 1-mm thickness of driver sheet driving twice are good agreement with die, not only width direction (AB direction) but also length direction (CD direction). However, there was a big obstacle to deform the AZ31 shell with R = 2 mm, because the die had small bottom radius and sidewall section. Variation of effective strain and velocity with width direction and length direction during magnetic pulse forming without driver sheet and with Al driver sheet were analyzed by simulation.

In this work, the formability of AZ31 magnesium alloy sheets was investigated by electromagnetic bulging experiments with driver sheet. Al (0.5 mm, 1 mm, and 2 mm thick) and Cu (1 mm thick) driver sheets were used to accelerate the AZ31 sheet in electromagnetic forming (viz magnetic pulse forming) process. In order to evaluate the effect of impact induced by driver sheet, the electromagnetic bulging experiments with gap between AZ31 sheet and driver sheet were investigated. Compared with quasi-static forming limit results, increases in the major and minor principal strains (with 0.5 mm, 1 mm driver sheet, and without driver sheet) of approximately 68 % and 72 % were achieved, respectively. However, the major and minor principal strains with 2 mm Al driver sheet increased about 148 % and 184 %. When the energy is up to 2.788 kJ after the first crack (with 1 mm Al driver sheet) producing, the major and minor strains increase about four times compared to the quasi-static condition.

In this paper, the formability of magnetic pulse uniaxial tension of AZ31magnesium alloy sheet at room temperature were investigated by the numerical simulation and experimental method. The numerical simulation for the magnetic pulse uniaxial tension of AZ31 sheet is performed by means of the ANSYS FEA software. The changes in velocity and strain rate were analyzed by simulation. The approximate rectangular flat spiral coil was employed to carry out the magnetic pulse uniaxial tensile experiments. The forming process was recorded by the high-speed camera, and the simulation result was consistent with it. The experimental results indicate that the total elongation of AZ31 sheet improves about 37 % compared with the quasi-static case. The major and minor principal strains at most increase by approximately 112 and 96 % under 5.12 kJ energy, respectively.

Access management in transportation planning can save travel time, reduce crashes, and increase route capacities. The planning literature suggests a need for performance metrics and a decision-aiding framework to guide access management programs across large corridor networks and diverse time horizons. This paper describes a quantitative framework to support access management programs, applying multicriteria analysis and cost-benefit analysis with parameter uncertainties. The metrics used to assess relative priorities at existing access points include the following: travel time delay index, traffic exposure, value of time, and costs of typical access management activities. Uncertain parameters that influence the estimates of the potential benefits and costs are identified and treated via a numerical interval analysis. The framework is demonstrated at several geographic scales and locations including 7,000 km of highway arterials of a 110,000 square-kilometer region and several sub-regions. The results assist decision makers to identify route segments that should be addressed sooner by eliciting additional information, reserving right-of-way, closing access points, planning new alignments, facilitating development proffers, etc. The approach is transferable to other topics involving resource allocation for preservation and improvement of multiscale infrastructure systems.

Formability of magnesium alloys at room temperature or slightly elevated temperatures is low, and exhibiting poor resistance to strain localization and failure. However, it is possible to improve the formability of AZ31 magnesium alloy sheet at high strain rate such as by electromagnetic forming (or magnetic pulse forming). In this study, experimental investigation of uniaxial tension of AZ31 sheet by magnetic pulse forming at room temperature was presented. The approximate rectangular flat spiral coil was employed to carry out the experiments. The specimens used in the tension test by magnetic pulse forming were same as the quasi-static uniaxial test. The samples were placed close to the outside of coil where an approximately homogenous magnetic field distribution prevailed. The experimental results indicate that the total elongation of AZ31 sheet improves about 37% compared with the quasi-static case. Non-uniform deformation occurs in the specimen. The maximum strain takes place on the area C, where is plotted on the specimen. The major and minor principal strains at most increase by approximately 112 and 96% under 5.12 kJ energy. The experimental results obtained in this study provide the fundamentals for the investigation of high speed forming of AZ31 magnesium alloy sheets.

In this work, the effects of process parameters on AZ31 magnesium alloy sheets were investigated by electromagnetic bulging experiments. The bulging height increases with increasing discharging energy, which is adjusted by tuning discharge voltage and capacitance. The limit dome height of electromagnetic forming is markedly improved as compared to quasi-static forming. In order to improve the efficiency of the energy, 0.5- and 1-mm thick Al driver sheet were used to accelerate the magnesium alloy sheets. For rupturing the AZ31 sheet, the discharging energy can be reduced from a maximum value of 4.356 kJ (no driver) to 2.304 kJ (with1-mm Al driver sheet). The numerical simulation for the electromagnetic forming of AZ31 sheet is performed by means of ANSYS FEA software. The change of velocity, strain rate, and plastic strain energy were analyzed by simulation. Compared with quasi-static forming limit results, increases in the major and minor principal strains of approximately 68 and 72 % were achieved, respectively.

The current pilot study examined the hypothesis that cigarette smokers who developed an emphysematous phenotype of Chronic Obstructive Pulmonary Disease (COPD) were associated with distinctive patterns in their corresponding metabolomics profile as compared to those who did not. Peripheral blood plasma samples were collected from 38 subjects with different phenotypes of COPD. They were categorized into three groups: healthy non-smokers (n=16), smokers without emphysema (n=8), and smokers with emphysema (n=14). Ultra High Performance Liquid Chromatography/quadrupole–time-of-flight mass spectrometry techniques were used to identify a large number of metabolite markers (3,534). Unsupervised clustering analysis accurately separated the smokers with emphysema from others without emphysema and demonstrated potentials of this metabolomics data. Subsequently predictive models were created with a supervised learning set, and these predictive models were found to be highly accurate in identifying the subjects with the emphysematous phenotype of COPD with excellent sensitivity and specificity. Our methodology provides a preliminary model that differentiates an emphysematous COPD phenotype from other COPD phenotypes on the basis of the metabolomics profiles. These results also suggest that the metabolomics profiling could potentially guide the characterization of relevant metabolites that leads to an emphysematous COPD phenotype.