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The purpose of this paper is to assess a phenomenological zero‐dimensional model (0‐D model) in order to evaluate both the in‐cylinder tumble motion and turbulence in high‐performance engine, focusing on the capability and sensitivity of the model.

The study was performed using a four‐valve pentroof engine, testing two different intake ports. The first one was a conventional port and the second one was design in such a way to promote tumble. CFD simulations for admission and compression strokes under different engine conditions were carried out. Then, the in‐cylinder entrance mass and mean velocities from CFD were imposed as boundary conditions in the 0‐D model.

Marked discrepancies between 0‐D model and CFD results were found. As expected, for the original port, CFD results displayed a poor tumble generation during the admission period. It was followed by a fast degradation of the tumble momentum along the compression stroke due to it was not dominant over the other two momentum components. 0‐D model overestimated the entrance‐tumble but underestimated the vortex degradation along the compression stroke, resulting in higher tumble predictions, thereby it is not recommended for low‐tumble engines. As for the modified port, 0‐D model assumptions were closer to the in‐cylinder flow field from CFD, but results underestimated the entrance‐tumble during the intake stroke and predicted excessive tumble at the end of the compression stroke. Summarizing, 0‐D model neither showed sensitivity to changes in the intake port because of the scarce information about the entrance‐flow field nor it was not suitable to evaluate the tumble degradation.

The limitations of the current model were highlighted, given possible guidelines in order to improve it.

The authors revisit the notion of co-production, highlight more critical and re-politicized forms of co-production and introduce three principles for its operationalization. The paper’s viewpoint aims to find entry points for enabling more equitable disaster research and actions via co-production.

The authors draw insights from the authors’ reflections as climate and disaster researchers and literature on knowledge politics in the context of disaster and climate change, especially within critical disaster studies and feminist political ecology.

Disaster studies can better contribute to disaster risk reduction via political co-production and situating local and Indigenous knowledge at the center through three principles, i.e. ensuring knowledge plurality, surfacing norms and assumptions in knowledge production and driving actions that tackle existing knowledge (and broader sociopolitical) structures.

The authors draw out three principles to enable the political function of co-production based on firsthand experiences of working with local and Indigenous peoples and insights from a diverse set of co-production, feminist political ecology and critical disaster studies literature. Future research can observe how it can utilize these principles in its respective contexts.

This paper aims to deal with the issue of shareholder activism of private equity investors in public companies. The study identifies characteristics of target firms and investors related to the likelihood of private equity activism. The research also examines whether shareholder activism strategy of private equity investors is associated with the better performance in future and value creation of target firms.

The paper applies econometric modeling to hand-collected data on private equity investments in listed companies, in the form of private investment in public equity and open-market share purchases, from eight Continental Europe’s countries for the period 2005–2014.

The findings indicate that the probability of shareholder activism is higher if the target firm’s industry corresponds to the private equity investor’s industry specialization, if the private equity firm is older, if the target is larger and the average ownership share purchased by the investor is higher. Conversely, the probability of shareholder activism is lower where a private equity firm invests in the target for the first time. A target firm with an activist investor has poorer operational performance results one year following the investment compared to a target firm with a passive private equity investor.

Results from the analysis of transactions in Continental Europe countries with French and German legal origin may be not generalizable to other markets with the different legal tradition and institutional environment.

This research provides new empirical evidence on private equity activism in listed companies of Continental Europe. By distinguishing between active and passive investments, testing rarely considered characteristics to provide valuable insights and analyzing the effect of activism on the target firm’s performance, the study contributes variously to the still-limited body of literature on private equity activism in public companies with a governance structure based on concentrated ownership. The findings emphasize the relationship between shareholder activism and both target and investor’s characteristics from perspective of mitigating agency problem and value creation in target firms. By simultaneously investigating investments in public companies from several European markets, the study complements empirical evidence mostly obtained from studies of a single national market.