The COVID-19 pandemic triggered the widespread use and need for respirators face masks healthcare workers public. In this study, several generally available mask designs were fit tested, their materials evaluated filtration efficiency using 250 nm polystyrene latex particles. Efficiency testing was performed 2 0.5 h at low (2.6 L min–1) high (7.4 airflows, respectively, ~17.4 cm2 material area....

Assessment of a corroded pipe is crucial to determine when it must be repaired or replaced. However, the conventional corrosion assessment codes for failure pressure predictions pipes with circumferentially aligned interacting defects are conservative (underestimations more than 40%), resulting in premature repair replacements pipelines. Alternatively, numerical approaches may used, but they ti...

Low-temperature embrittlement in the heat-affected zone (HAZ) of heavy-wall X80 weld joints is a primary challenge for arctic oil & gas exploitation. In this paper, influence intercritically reheated coarse-grained HAZ (ICCGHAZ) on low-temperature toughness joint 22 mm thick spiral submerged arc welded pipe was studied through instrumented Charpy V-notch impact test at ?80~20 °C and corresp...

Conventional pipeline failure pressure assessment codes do not allow for prediction of interacting defects subjected to combined loadings. Alternatively, numerical approaches may be used; however, they are computationally expensive. In this work, an analytical equation based on finite element analysis the API 5L X52, X65, and X80 corroded pipes with a longitudinal corrosion defect loadings is p...

Thick-walled X80 pipelines for oil and gas transportation are difficult to relocate due their large size. In the process of narrow-gap overhead welding, welding defects, such as bulges lack sidewall fusion, can appear easily. To avoid these defects improve quality thick-walled pipelines, GMAW method is adopted in this paper. The formation characteristics weld influence arc oscillation parameter...

Abstract In this paper, the failure mechanism of Zn-rich epoxy coating under AC interference in alkaline environment was revealed based on EIS tests. Using X80 steel as matrix, coated sample formed by hand-brushing with thickness 25 ± 5 μ m determined five-point test. The curves 3 wt% NaOH solution immersion time studied (no) interference, and evolution established through fitting parameters. r...

The surface morphology of X80 steel with hydrophilic underwater oleophobic characteristic is described greater comprehensively and quantitatively in this work by combining fractal dimension multifractal. characteristics was constructed using a chemical etching method. Then, the aid three wettability parameters—contact angle, rolling adhesion work—this study investigated relationship between sta...