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Stress Corrosion Cracking (SCC) process through which cracks occur in a variety of susceptible materials is a result of a combination of residual or applied stresses and corrosion. In oil and gas field, buried pipeline steels are made of low-alloy steels with a ferritic-pearlitic structure, such as X70. In dilute solutions, these materials are prone to SCC failure. The Near-neutral simulated soil solution (NS4) solution is established to imitate SCC conditions and subsequently became the industry requirement for crack growth experiments in the majority of laboratories. The strainassisted active crack pathways are considered while modelling SCC growth as an oxide film rupture and anodic dissolution process. It's been hypothesized that increasing the strain concentration can help with dissolution at the filmfree crack tip. This research focuses on estimating the SCC crack growth rate under various environmental conditions in oil and gas pipelines using finite element modelling. The simulation is carried out using the J-integral theory in the COMSOL Multiphysics program. Simulations are performed to model the crack growth rate (CGR) using slip anodic dissolution (film rupture) mechanism. The plastic strain gradient is required to compute the SCC CGR (da/dt). Because the plastic strain located at crack tip increases proportionally to the crack length as it propagates, the CGR increases as the stress intensity factor (SIF) increases. The crack growth rates increase when constant loads are applied and as the temperature rises, and elevating the cathodic potential has a minimal influence on the propagation rate of cracks but raises the material yield strength and imparts brittle behavior to it.

As a component of the urban fabric system, zero-emission neighborhood (ZEN) projects represent an opportunity to boost the sustainable performance of cities. However, overlooking the potential of different actors or underestimating the complexity of interactions among them may threaten the projects themselves. Public procurement is a powerful tool that potentially enables national and local authorities to achieve sustainable development goals while procuring necessary products and services. This paper aims to understand the potential of innovative public procurement (IPP) to reduce some of the project complexity in ZEN. Besides literature on sustainable neighborhoods (SN), empirical insights are drawn from an ongoing ZEN project to map the primary sources of complexity in such projects. Afterward, the potential for dialogue with suppliers is mainly discussed in light of these sources. Our findings suggest that using IPP may assist in reducing the complexity imposed on ZEN projects.

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In a rapidly urbanizing world, cities form the key context for a sustainable transition. The neighborhood scale is suggested as a successful scale to realize cross-sector, inter-organizational collaborations. The multifaceted goals and resulting interdependencies in sustainable neighborhood (SN) developments seem to render them complex. Neighborhood scale can be understood as a program of related projects encompassing a wide range of actors interacting in a non-simple way. The added complexity comprised at the neighborhood scale challenges the promise of sustainable transition, creating a gap between what is promised as SN and what is delivered. While filling this gap is deemed pivotal to boost the performance and success of SNs, this study focuses on the practice of procurement. Green procurement has a prominent role in fostering the sustainable transition and alleviate the projects’ poor performance in energy consumption and carbon emissions. However, green procurement is complicated and often hampered by the complex nature of the programs and projects required to realize SNs. Using an in-depth case study of an ongoing SN development in Norway, we seek to explore green procurement in SN programs. The present study has several contributions. First, we provide a fresh look at SNs using the notion of program management and the principles of nearly decomposable systems. Second, the study demonstrates that green procurement can support coordination in programs, and propose several implications for purchasers to consider when devising a green procurement strategy for SN programs, laying the groundwork for new procurement research focusing on structural complexity. Furthermore, our study encourages purchasers to think like architects to grasp the various levels and make better decisions in complex projects and programs.