The corrosion behavior of an Inconel 718 alloy fabricated using the selective laser melting (SLM) technique in a 3.5 wt.% NaCl solution is determined. The corrosive effect of the NaCl solution on the ...Inconel 718 alloy is investigated using potentiodynamic polarization curve measurements, Mott-Schottky plots, electrochemical impedance spectroscopy, atomic force microscopy, and x-ray photoelectron spectroscopy (XPS) and is compared with that on a commercially rolled Inconel 718 alloy (R 718). Electrochemical results suggest that the application of SLM to the Inconel 718 alloy lowers its corrosion resistance. The passive films formed on both alloys show p-type and n-type semiconductor behaviors. However, the concentrations of the defects in the passive films formed on the surface of the SLM Inconel 718 alloy are higher than those on the surface of the commercially rolled R 718. XPS shows that the passive film formed on the SLM Inconel 718 alloy has a higher NiO content, leading to the deterioration of its protective properties.
This study aimed to investigate the impact of building planes on the microstructure and corrosion behaviors of 316L stainless steel (SS) manufactured using selective laser melting (SLM) when ...subjected to a 0.1 M HCl solution. The investigation of material corrosion behavior involved the utilization of a wide array of surface characterization techniques, as well as various electrochemical measurements. The findings were subjected to a comparison with those obtained from a commercially rolled 316L SS (R 316L SS). The analysis revealed that the XZ and YZ planes displayed a distinctive fish scale melt pool structure, while the XY plane exhibited a columnar melt pool structure. The densities of the low-angle grain boundaries for different building planes were observed as YZ < XY < XZ. SLM 316L SS showing a broader passivation region and a higher breakdown potential compared to the commercially available R 316L SS, especially the XZ and XY planes. Meanwhile, the passive film on the XZ plane was the more compact and had a lower carrier density. The observed factors contributing to these findings could be attributed to the SLM sample containing an increased proportion of O2−/OH− and Cr2O3 in the passive film. This resulted in the formation of a thick and dense passive film, which is particularly evident on the XY and XZ planes. In addition, it was observed that the nucleation mechanism of the passive films remained unchanged following the SLM process.
The pore structure characteristic parameters of vuggy carbonate reservoirs were extracted, and matrix resistivity of vuggy reservoir was calculated by the percolation network simulation. A segmented ...cross-scale resistivity calculation method was established, in which the finite element method was used to simulate the resistivity of vuggy reservoirs. The mathematical models of vug porosity and water saturation with rock resistivity in vuggy carbonate reservoir were established, and the relationships between them were obtained. Experimental results verified the reliability of the simulation results. The method presented provides new technical means and research method for the resistivity log interpretation of vuggy carbonate reservoirs. The matrix porosity, vug porosity and matrix pore water saturation are the key factors determining the resistivity of reservoir rocks.
A series of clinical trials support the effectiveness of monoclonal antibodies for generalized myasthenia gravis (MG) compared to the placebo, but the priority among drugs remains unclear. Therefore, ...we conduct a frequentist network meta-analysis (NMA) to compare the relative effects of different drugs for generalized MG.
PubMed, Embase, Cochrane Library, and clinicaltrials.gov were systematically searched for eligible studies up to 1 June 2023. The primary outcome was efficacy (Myasthenia Gravis Activities of Daily Living MG-ADL score and Quantitative Myasthenia Gravis QMG score) and safety (adverse events AEs). Mean difference (MD) and risk ratio (RR) with their 95% credible intervals (95%CrIs) were used to show the effect size of continuous and categorical variables, respectively. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.
Thirteen studies involving 1167 individuals were identified for NMA. For efficacy outcomes, belimumab, efgartigimod, mezagitamab 600mg, and nipocalimab 60mg/kg were inferior to rozanolixzumab 7mg/kg (MD ranged from 2 to 3.69) and rozanolixzumab 10mg/kg (MD ranged from 2.04 to 3.72) in MG-ADL score, and rozanolixzumab had the highest rank probability (83%) according to the subjective surface under the curve ranking area (SUCRA). For QMG score, batoclimab 340mg (MD ranged from 4.32 to 8.52) and batoclimab 680mg (MD ranged from 4.11 to 9.31) were more effective than placebo and other monoclonal antibodies except for rozanolixzumab, with the highest SUCRA value (93% and 97% respectively). For safety outcomes, belimumab achieved the highest SUCRA value (89.8%) with significant statistical difference compared to rozanolixzumab 7mg/kg (RR 0.08, 95%CrI 0.01 to 0.94) and rozanolixzumab 10mg/kg (RR 0.08, 95%CrI 0.01 to 0.86).
While all monoclonal antibodies were superior to the placebo, rozanolixzumab and batoclimab might be the most effective for generalized MG. However, rozanolixzumab was associated with higher incidence of AEs. Given the limitations inherent in indirect comparisons, further head-to-head and extensive observational studies are necessary to confirm our findings.
https://inplasy.com/?s=202370112, identifier 202370112.
During the storage and transportation of crude oil, volatile organic vapors (VOCs) are generated. International organizations and relevant countries have formulated relevant regulations for VOCs ...emissions. This article introduces four kinds of oil and gas recovery technologies and their combined processes: absorption method, adsorption method, membrane separation method and condensation method. The advantages and disadvantages of different oil and gas recovery technologies are analyzed and the process performance is compared. It lists examples of the application of oil and gas recovery technology in ships, points out its shortcomings, and puts forward relevant suggestions for the research of marine VOCs recovery technology.
Recently, sound-based diagnosis systems have been given much attention in many fields due to the advantages of their simple structure, non-touching measurement style, and low-power dissipation. In ...order to improve the efficiency of coal production and the safety of the coal mining process, accurate information is always essential. It is indicated that the sound signal produced during the cutting process of the coal mining shearer contains much cutting pattern identification information. In this paper, the original acoustic signal is first collected through an industrial microphone. To analyze the signal deeply, an adaptive Hilbert–Huang transform (HHT) was applied to decompose the sound to several intrinsic mode functions (IMFs) to subsequently acquire 1024 Hilbert marginal spectrum points. The 1024 time-frequency nodes were reorganized as a 32 × 32 feature map. Moreover, the LeNet-5 convolutional neural network (CNN), with three convolution layers and two sub-sampling layers, was used as the cutting pattern recognizer. A simulation example, with 10,000 training samples and 2000 testing samples, was conducted to prove the effectiveness of the proposed method. Finally, 1971 testing sound series were recognized accurately through the trained CNN and the proposed method achieved an identification rate of 98.55%.
The corrosion behavior of pure Fe under a Na₂SO₄ deposit in an atmosphere of O₂ + H₂O was investigated at 500 °C by thermo gravimetric, and electrochemical measurements,
. potentiodynamic ...polarization, electrochemical impedance spectroscopy (EIS), and surface characterization methods
. X-ray diffraction (XRD), and scanning electron microscope (SEM)/energy dispersive spectroscopy(EDS). The results showed that a synergistic effect occurred between Na₂SO₄ and O₂ + H₂O, which significantly accelerated the corrosion rate of the pure Fe. Briefly, NaFeO₂ was formed in addition to the customary Fe oxides; at the same time, H₂SO₄ gas was produced by introduction of water vapor. Subsequently, an electrochemical corrosion reaction occurred due to the existence of Na₂SO₄, NaFeO₂, and H₂O. When this coupled to the chemical corrosion reaction, the progress of the chemical corrosion reaction was promoted and eventually resulted in the acceleration of the corrosion of the pure Fe.
The results of this work prove that electrochemical reactions are involved in the whole corrosion process of pure Fe with a solid NaCl deposit in water vapor at 600
°C. The interaction of chemical ...and electrochemical reactions accelerates the corrosion rate of pure Fe significantly. The electrochemical reaction is coupled with a preceding chemical reaction process (ce), in which Fe first reacts chemically with NaCl and water vapor to generate HCl
(g). And then, the electrochemical reaction proceeds via a one-electron electrochemical reduction to form H
2.
Development and application of solid rockets have put forward new requirements for the combustion performance of AP/HTPB propellants. Herein, carbon-supported Ti/Co bimetallic oxide (MTiCo) ...nanocomposites with carbon skeleton and porous structure were proposed to use as catalysts for improving the combustion performance of AP/HTPB propellants. For AP decomposition, MTiCo-2 (2.0 wt%) reduced the AP HD temperature by 93.1 °C and enhanced heat release by about 356.3 %. Simultaneously, MTiCo-2 (2.0 wt%) significantly decreased Ea of AP HD stage by 51.4 %. MTiCo-2 (2.0 wt%) also reduced the ignition delay of AP/HTPB propellant by 78.3 % and enhanced combustion rate by 192.0 %. The synergistic effect of catalysis and combustion support of MTiCo-2 provided by the structure of carbon-supported Ti/Co bimetallic oxide was the main mechanism for improving the combustion performance of AP/HTPB propellants.
•Carbon-supported Ti/Co bimetallic oxide nanocomposites have been prepared.•MTiCo-2 exhibited carbon skeleton and porous structure.•MTiCo-2 (2.0 wt%) enhanced heat release of AP decomposition by about 356.3 %.•M-TiO-2 could shortened the ignition delay time of AP/HTPB propellants by 78.3 %.•M-TiO-2 could also enhance combustion rate of AP/HTPB propellants by 192.0 %.
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