The review presented herein is regarding the stress corrosion cracking (SCC) phenomena of carbon steel pipelines affected by the corrosive electrolytes that comes from external (E) and internal (I) environments, as well as the susceptibility and tensile stress on the SCC. Some useful tools are presented including essential aspects for determining and describing the E-SCC and I-SCC in oil and gas pipelines. Therefore, this study aims to present a comprehensive and critical review of a brief experimental summary, and a comparison of physicochemical, mechanical, and electrochemical data affecting external and internal SCC in carbon steel pipelines exposed to corrosive media have been conducted. The SCC, hydrogen-induced cracking (HIC), hydrogen embrittlement, and sulfide stress cracking (SSC) are attributed to the pH, and to hydrogen becoming more corrosive by combining external and internal sources promoting cracking, such as sulfide compounds, acidic soils, acidic atmospheric compounds, hydrochloric acid, sulfuric acid, sodium hydroxide, organic acids (acetic acid, mainly), bacteria induced corrosion, cathodic polarization, among others. SCC growth is a reaction between the microstructural, chemical, and mechanical effects and it depends on the external and internal environmental sources promoting unpredictable cracks and fractures. In some cases, E-SCC could be initiated by hydrogen that comes from the over-voltage during the cathodic protection processes. I-SCC could be activated by over-operating pressure and temperature at flowing media during the production, gathering, storage and transportation of wet hydrocarbons through pipelines. The mechanical properties related to I-SCC were higher in comparison with those reviewed by E-SCC, suggesting that pipelines suffer more susceptibility to I-SCC. When a pipeline is designed, the internal fluid being transported (changes of environments) and the external environment concerning SCC should be considered. This review offers a good starting point for newcomers into the field, it is written as a tutorial, and covers a large number of basic standards in the area.

• Highest heavy crude oil biodegradation of marine oil-spill Micrococcus bacteria. • Roughness and development dynamics of Micrococcus biofilms by SEM and AFM microscopy. • Responses to salinity, temperature, and hydrocarbon depend on Micrococcus species. • Environmental stressors induced the expression of uspA gene biomarker. • uspA expression: increased by up to 3-fold at high salinity and crude oil concentration.

Modern microbial mats are relictual communities mostly found in extreme environments worldwide. Despite their significance as representatives of the ancestral Earth and their important roles in biogeochemical cycling, research on microbial mats has largely been localized, focusing on site-specific descriptions and environmental change experiments. Here, we present a global comparative analysis of non-lithifying microbial mats, integrating environmental measurements with metagenomic data from 62 samples across eight sites, including two new samples from the recently discovered Archaean Domes from Cuatro Ciénegas, Mexico. Our results revealed a notable influence of environmental filtering on both taxonomic and functional compositions of microbial mats. Functional redundancy appears to confer resilience to mats, with essential metabolic pathways conserved across diverse and highly contrasting habitats. We identified six highly correlated clusters of taxa performing similar ecological functions, suggesting niche partitioning and functional specialization as key mechanisms shaping community structure. Our findings provide insights into the ecological principles governing microbial mats, and lay the foundation for future research elucidating the intricate interplay between environmental factors and microbial community dynamics.

The effect of milling energy on the phase evolution of mechanically alloyed Ti–Ni powders is reported. Alloys were produced by low-energy and high-energy mechanical alloying (LEMA and HEMA, respectively). Powders milled for different times were characterised by X-ray diffraction and scanning electron microscopy. The phase transformations of powders milled by LEMA and HEMA before amorphisation are presented. During LEMA, TiNi, TiNi₃, Ti₃Ni₄, and Ti₂Ni were formed at 50 and 100 h. At these times, the results were consistent with the Ti–Ni equilibrium phase diagram. Up to 7.27 wt% of TiNi with a crystallite size of 32.63 ± 0.01 nm appeared at 50–75 h. During HEMA, iron contamination inhibited the formation of the TiNi phase at short milling times, and up to 47.9% of Fe_0.2Ni_4.8Ti₅ was generated. These results indicate that amorphisation and heat treatment are not the only methods of promoting phase transformation in Ti–Ni alloys.