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[Display omitted] • This study proposes novel auxetic medical stents. • Two-dimensional metamaterials were fabricated through additive manufacturing technique. • Finite element analysis was employed to investigate the mechanical behaviour. • An excellent correlation was observed between the FEA and experimental results. • The modifications made to the rib-unit cells had a significant effect on the stent's recoil behaviour. Due to the significant mortality rate associated with atherosclerosis-induced cardiovascular disease, the utilization of advanced intravascular stents with superior mechanical performance is imperative for the restoration of obstructed arteries. This study proposes novel auxetic medical stents that aim to enhance critical parameters of biomedical stents. This includes load-bearing capacity, expanded opening percentage, and reduced recoil percentage. On this matter, the missing rib auxetic unit cell has been considered and geometrically modified to achieve these objectives. Two-dimensional (2D) metamaterials were fabricated through additive manufacturing technique and subjected to experimental testing. Then, finite element analysis (FEA) was employed to gain comprehensive insights into the mechanical behaviour of the proposed medical stents. Remarkably, an excellent correlation was observed between the FEA and experimental results, validating the high precision of the analysis. The findings reveal that the stents classified as "E-category" exhibit the highest final opening percentage while concurrently demonstrating the lowest recoil percentage. The base stent exhibited a relatively high recoil percentage of 15.56%, indicating a significant amount of recoil or spring-back after deformation. In contrast, the modified "E-category" stent displayed a substantially lower recoil percentage of 1.62%. This notable reduction in recoil percentage indicates that the modifications made to the rib-unit cells had a significant and beneficial effect on the stent's recoil behaviour and minimizing potential damage to arterial tissue during stent deployment (angioplasty) and balloon pressure. The modified design likely enhances the stent's ability to maintain its shape and resist recoil, making it more effective and reliable in its intended application. Additionally, more aspects of biomedical stents such as foreshortening, and dog-boning of the modified missing rib stents were meticulously examined through FEA. [ABSTRACT FROM AUTHOR]

One of the most important dimensions of cooperative systems, which have existed in Iran since 1974, is cooperative rural production enterprises. In this study, the performance of rural production cooperatives in Iran is examined in relation to the social capital components of the members. This study's statistical population consisted of 16,870 members from 41 cooperatives. 217 samples of cooperative members and 98 samples of the cooperative's management and board of directors were selected using the Cochran formula, and questionnaires were filled out for each group. The results showed that from the viewpoint of the members of rural cooperatives, the most important factor in improving the performance of cooperatives was the use of effective extension training (model-extension sites). The results also showed that members' satisfaction and training members of cooperatives can play an important role in improving the performance of cooperatives. The results of this research, while emphasizing the role of education (especially extension activities), can help rural development planners in improving the performance of rural cooperatives in their regions. [Display omitted] • The study identified the impacts of social capitals on the performance of rural production cooperatives. • The most important factor in improving the performance was the use the extension trainings. • Members' satisfaction and training play an important role in improving the performance. • The level of education in production cooperatives has a direct relationship with trust and satisfaction. • Cooperatives do not perform well in the fields of sales, marketing and insurance. [ABSTRACT FROM AUTHOR]