Metagenomics, the study of genetic material recovered directly from environmental samples, has the potential to provide insight into the structure and function of heterogeneous microbial communities. There has been an increased use of metagenomics to discover and understand the diverse biosynthetic capacities of marine microbes, thereby allowing them to be exploited for industrial, food, and h...

Abstract Existing natural gas pipelines provide an economic alternative for the transport of hydrogen (H 2 ) in envisioned economy. Hydrogen can dissolve steel and cause embrittlement (HE), compromising pipeline structural integrity. HE causes subcritical cracking, decreases ductility fracture toughness, increases fatigue crack growth rate (FCGR). This work analyzes testing standards gaseous us...

The purpose of this paper was to investigate the effects of Nb on the microstructure and elevated-temperature mechanical properties of Alloy 690-SUS 304L dissimilar welds. The results show that the welds were dominant with dendrites and interdendritic phases. In the low Nb welds, the main interdendritic phases were Nb-rich and Al-Ti-rich phases. Cr-carbides were precipitated along the grain bou...

For the long-term service of X65/Incoloy 825 bimetallic composite pipe girth welds in H 2 S environment, corrosion damage behavior was investigated. Characterizations welded joints were conducted by OM, SEM, XRD, and EDS. The pitting corrosion’s 3D surface morphology NACE-B solution saturated with results show that composition segregation occurs welding process, Laves phase appears between dend...

There are two laser welding mechanisms, keyhole mode and conduction mode. Keyhole welding is widely used because it produces welds with high aspect ratios and narrow heat affected zones. However keyhole welding can be unstable, as the keyhole oscillates and closes intermittently. This intermittent closure causes porosity due to gas entrapment. Conduction welding, on the other hand, is more stab...

This paper presents an experimental characterisation of fatigue at welded connections for the next-generation high-strength low-alloy offshore riser steel, X100Q. An instrumented girth weld is conducted with a parallel programme physical-thermal simulation (Gleeble) to develop heat affected zone (HAZ) test specimens. X100Q shown exhibit superior performance current state art X80. Significant di...