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The purpose of this paper is to review cases of artificial reefs built through additive manufacturing (AM) technologies and analyse their ecological goals, fabrication process, materials, structural design features and implementation location to determine predominant parameters, environmental impacts, advantages, and limitations.

The review analysed 16 cases of artificial reefs from both temperate and tropical regions. These were categorised based on the AM process used, the mortar material used (crucial for biological applications), the structural design features and the location of implementation. These parameters are assessed to determine how effectively the designs meet the stipulated ecological goals, how AM technologies demonstrate their potential in comparison to conventional methods and the preference locations of these implementations.

The overview revealed that the dominant artificial reef implementation occurs in the Mediterranean and Atlantic Seas, both accounting for 24%. The remaining cases were in the Australian Sea (20%), the South Asia Sea (12%), the Persian Gulf and the Pacific Ocean, both with 8%, and the Indian Sea with 4% of all the cases studied. It was concluded that fused filament fabrication, binder jetting and material extrusion represent the main AM processes used to build artificial reefs. Cementitious materials, ceramics, polymers and geopolymer formulations were used, incorporating aggregates from mineral residues, biological wastes and pozzolan materials, to reduce environmental impacts, promote the circular economy and be more beneficial for marine ecosystems. The evaluation ranking assessed how well their design and materials align with their ecological goals, demonstrating that five cases were ranked with high effectiveness, ten projects with moderate effectiveness and one case with low effectiveness.

AM represents an innovative method for marine restoration and management. It offers a rapid prototyping technique for design validation and enables the creation of highly complex shapes for habitat diversification while incorporating a diverse range of materials to benefit environmental and marine species’ habitats.

The objective of this study is to investigate the impact of longitudinal forces on extreme-long heavy-haul trains, providing new insights and methods for their design and operation, thereby enhancing safety, operational efficiency and track system design.

A longitudinal dynamics simulation model of the super long heavy haul train was established and verified by the braking test data of 30,000 t heavy-haul combination train on the long and steep down grade of Daqing Line. The simulation model was used to analyze the influence of factors on the longitudinal force of super long heavy haul train.

Under normal conditions, the formation length of extreme-long heavy-haul combined train has a small effect on the maximum longitudinal coupler force under full service braking and emergency braking on the straight line. The slope difference of the long and steep down grade has a great impact on the maximum longitudinal coupler force of the extreme-long heavy-haul trains. Under the condition that the longitudinal force does not exceed the safety limit of 2,250 kN under full service braking at the speed of 60 km/h the maximum allowable slope difference of long and steep down grade for 40,000 t super long heavy-haul combined trains is 13‰, and that of 100,000 t is only 5‰.

The results will provide important theoretical basis and practical guidance for further improving the transportation efficiency and safety of extreme-long heavy-haul trains.

This study aims to focus on a specific project marketing concept, i.e. “discontinuity,” and analyzes how this concept emerged in project marketing, becoming its key scholarly embodiment, how it became decoupled from the increasingly service-intensive project business practice and what the relevance of discontinuity is for project marketers moving forward.

This study is built on a systematic literature review of 31 years (1993–2023) of publishing data from major marketing and management journals.

This study provides three findings. First, the author reveals the risks related to marketing scholars and practitioners losing sight of each other as business practices evolve much faster than scholarly research can keep up. Second, the author highlights the role of interdisciplinary collaboration in advancing conceptual innovations. Finally, the research elucidates the need for broader metatheoretical reflection to keep this research tradition on an upward trajectory.

The aim of this study is not to criticize project marketing, as many strands of business-to-business (B2B) marketing face the same challenge, but to elucidate a need for conceptual innovations, collaboration with practitioners and other disciplines and broader metatheoretical reflection to keep this research tradition on an upward trajectory.

This study makes several contributions to the project marketing research tradition. First, it reviews the emergence and dissipation of the concept of discontinuity, drawing on semantical, etymological and epistemological insights. It also reflects on recent disruptions in the marketplace and envisions future research trajectories for this elusive concept. In addition, the author develops a conceptual framework that combines project types with exchange elements in project and service businesses. This conceptual framework helps elucidate what part of the exchange is continuing and what is discontinuing in the resulting business relationships. Furthermore, the research contributes to B2B marketing more broadly by highlighting the fleeting correspondence between theory and the real world. It underscores the need for constant updates to maintain relevance.