Influence of stamping parameters on stamping characteristics of SAF2205 bidirectional stainless steel

SAF2205 bidirectional stainless steel is an excellent material for multiple corrugated diaphragms. It is necessary to study its stamping forming characteristics and provide a theoretical basis for stamping forming of multiple corrugated diaphragms. In this paper, the detailed V-bending process parameters are formulated. The effects of bending speed, relative fillet radius, temperature, and alignment time on spring-back behavior of SAF2205 bidirectional stainless steel are systematically studied to reveal the positive and negative spring-back mechanism. The range of process parameters suitable for stamping of SAF2205 bidirectional stainless steel was obtained. Article Highlights The detailed V-bending process parameters are formulated. The effect of SAF2205 parameters on the spring-back behavior was studied. The range of process parameters suitable for stamping of SAF2205 was obtained.

Response Surface Approach to Optimize the Conditions of Foam Mat Drying of Plum in relation to the Physical-Chemical and Antioxidant Properties of Plum Powder

This research was done to optimize the influence of various egg albumin (EA) concentrations of 2, 4, and 6% as a foaming agent and whipping times of 5, 10, and 15 minutes, on physicochemical and antioxidant properties of plum powder produced using response surface methodology (RSM). Physical properties of the foam such as density, porosity, and expansion were determined. After drying and powder manufacturing, physical properties, namely, the water absorption index (WAI) and water solubility index (WSI), as well as chemical characteristics such as pH, titratable acidity, and browning index, were assessed. Finally, antioxidant capabilities such as the total phenol content (TPC), DPPH scavenging activity, beta carotene, and total flavonoid content (TFC) were measured. According to the findings, both whipping duration and EA concentration had a substantial effect on the foam forming characteristics. Foam expansion increased significantly with EA concentration and whipping time increase, but foam density exhibited an inverse relationship as expected. Increases in EA concentration and whipping duration both raised pH values whereas titratable acidity exhibited an inverse tendency as variable quantity rose. The browning index dropped as EA concentration increased. Antioxidant qualities were retained in dried sample powder as compared with the fresh sample, and they were also altered by variable changes. Overall, a 4% EA concentration for 10 to 15 minutes produced the best dehydration effects with the most antioxidant retention.

Analysis of Metal Transfer and Weld Forming Characteristics in Triple-wire Gas Indirect Arc Welding

Triple-wire gas indirect arc welding (TW-GIA) has the advantages of low heat input and high deposition rate. However, the simultaneous melting of triple wires makes the metal transfer mode complicated. The unknown of the metal transfer mode restricts the development of this technology. In this paper, high-speed camera systems and electrical signal acquisition sensors were used to explore the TW-GIA metal transfer mode. The static force model and the arc conductive channel model were used to discuss the droplet force and energy conversion characteristics respectively. Results showed that the TW-GIA metal transfer modes can be divided into: short-circuit transfer (SCT), main wire projected transfer + side wire globular transfer (PGT), main wire streaming transfer + side wire projected transfer (SPT) and main wire streaming transfer + side wire streaming transfer (SST). Moreover, the process parameter ranges corresponding to the four modes were summarized. Due to the stable arc and the uniform metal transfer process, SPT and SST can form desirable weld seam. The gravity and z-axis components of electromagnetic force are the main forces that promote metal transfer. The x-axis and y-axis components of the electromagnetic force deviate the metal transfer path from the arc coverage. Due to the change of arc conductive channel, the energy transferred from TW-GIA to the base metal is less than that of GMAW, showing the advantages of small welding deformation, narrow heat affected zone and grain refinement.

Study on the Influence of Initiation Model on the Forming Characteristics of MEFP Warhead

To study the influence of different initiation modes on the forming characteristics of the MEFP warhead, numerical simulations were carried out on three types of initiation modes. The numerical simulation results showed that the number of EFPs was the least by double-column multipoint synchronous initiation, the number of EFPs was the largest by the central single-point (multipoint) initiation, and single-column single-point (multipoint synchronous) detonation forms the number of EFPs between central single-point (multipoint synchronous) detonation and double-column multipoint synchronous detonation. For the MEFP warhead of a small-caliber grenade, whether it is center detonation or eccentric detonation, the EFP velocity of multipoint detonation is higher than that of the single-point detonation, the velocity of double-column multipoint eccentric synchronous detonation is 2%–9% higher than that of the single-column single-point (multipoint eccentric synchronous) detonation, the velocity of double-column multipoint eccentric synchronous detonation is 10%–17% higher than that of the central single-point (multipoint synchronous) detonation, and the velocity of single-column single-point (multipoint eccentric synchronous) detonation is 5%–17% higher than that of the central single-point (multipoint synchronous) detonation. Research results show that although the number of EFPs is reduced during eccentric single-point (multipoint simultaneous) detonation of MEFP warheads, a higher velocity can be obtained.

Effects of Various Mineral Trioxide Aggregates on Viability and Mineralization Potential of 3-Dimensional Cultured Dental Pulp Stem Cells

Three-dimensionally (3D) cultured dental pulp stem cells (DPSCs) reportedly exhibit superior multi-lineage differentiation capacities and have a higher expression in regeneration-related gene categories compared to conventionally cultured DPSCs. This study aimed to evaluate the effects of various mineral trioxide aggregates (MTAs) on DPSCs cultured in 3D, assessing their cell viability and tissue mineralization properties. We examined the morphology, cell viability, alkaline phosphate (ALP) activity and qualitative alizarin red S staining assay of the DPSCs that reacted with various MTAs, which included ProRoot (PRM), Biodentine (BIO), and Well-Root PT (WRP), in two different culture plates, an ultra-low attachment plate (ULA) and a conventional monolayer plate (2D). As a control, MTA-free and IRM samples were prepared. None of the MTA groups affected the microsphere-forming characteristics of DPSCs that had been cultured in ULA. The DPSCs that were cultured in ULA showed high cell viability in all MTA groups compared to IRM. The mineralization potential was favorable in all MTA groups, with a significantly higher ALP activity among the DPSCs that were cultured in ULA. Among MTAs, the PRM group showed substantially higher ALP activity than the other MTA groups. In conclusion, our results indicate that 3D-cultured DPSCs with various MTAs showed comparable viability and mineralization capacity similar to those cultured without reacting with MTA cement.

Effect of Polar Molecule Aggregation on the Stability of Crude Oil/Water Interface: A Molecular Simulation Study

To ensure the efficient operation of crude oil dehydration and sewage treatment technology in oilfield surface production system, the effect mechanism of polar components represented by asphaltene and resin on the formation and stability of oil-water emulsion needs to be revealed at nanoscale. In this paper, the molecular dynamics simulation method was used to construct the crude oil/polar component/water system models with different molar ratios of asphaltene to resin by adjusting the number of asphaltene and resin molecules, so as to reveal the molecular arrangement and aggregation process and film forming characteristics of asphaltene, resin, and their mixture at the oil-water interface. The simulated results showed that the aggregation process of asphaltene molecules under the influence of hydrogen bonds can be divided into three stages. The addition of resin molecules enhanced the connection between molecules of all polar components at the interface. The π−π stacking and T-shaped stacking structures were found in all aggregations, and the higher the molar ratio of asphaltene molecules, the higher the proportion of π−π stacking structure. With the increase of the molar ratio of asphaltene to resin increases from 0 : 1 to 1 : 0, the interfacial film thickness and interface formation energy increase from 2.366 nm and -143.89 kJ/mol to 3.796 nm and -304.09 kJ/mol, respectively, which indicated that asphaltene molecules play a more significant role in promoting the formation of interfacial film and maintaining its structural stability than resin molecules. The investigations in this study provide theoretical support for demulsification of the crude oil emulsion.