Dorcas Kaweesa, Lourdes Bobbio, Allison M. Beese and Nicholas Alexander Meisel
This study aims to investigate the tensile strength and elastic modulus of custom-designed polymer composites developed using voxel-based design. This study also evaluates…
Abstract
Purpose
This study aims to investigate the tensile strength and elastic modulus of custom-designed polymer composites developed using voxel-based design. This study also evaluates theoretical models, such as the rule of mixtures, Halpin–Tsai model, Cox–Krenchel model and the Young–Beaumont model and the ability to predict the mechanical properties of particle-reinforced composites based on changes in the design of rigid particles at the microscale within a flexible polymer matrix.
Design/methodology/approach
This study leverages the PolyJet process for voxel-printing capabilities and a design of experiments approach to define the microstructural design elements (i.e. aspect ratio, orientation, size and volume fraction) used to create custom-designed composites.
Findings
The comparison between the predictions and experimental results helps identify appropriate methods for determining the mechanical properties of custom-designed composites ensuring informed design decisions for improved mechanical properties.
Originality/value
This work centers on multimaterial additive manufacturing leveraging design freedom and material complexity to create a wide range of composite materials. This study highlights the importance of identifying the process, structure and property relationships in material design.
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Vitus Mwinteribo Tabie, Chong Li, Wang Saifu, Jianwei Li and Xiaojing Xu
This paper aims to present a broad review of near-a titanium alloys for high-temperature applications.
Abstract
Purpose
This paper aims to present a broad review of near-a titanium alloys for high-temperature applications.
Design/methodology/approach
Following a brief introduction of titanium (Ti) alloys, this paper considers the near-α group of Ti alloys, which are the most popular high-temperature Ti alloys developed for a high-temperature application, particularly in compressor disc and blades in aero-engines. The paper is relied on literature within the past decade to discuss phase stability and microstructural effect of alloying elements, plastic deformation and reinforcements used in the development of these alloys.
Findings
The near-a Ti alloys show high potential for high-temperature applications, and many researchers have explored the incorporation of TiC, TiB SiC, Y2O3, La2O3 and Al2O3 reinforcements for improved mechanical properties. Rolling, extrusion, forging and some severe plastic deformation (SPD) techniques, as well as heat treatment methods, have also been explored extensively. There is, however, a paucity of information on SiC, Y2O3 and carbon nanotube reinforcements and their combinations for improved mechanical properties. Information on some SPD techniques such as cyclic extrusion compression, multiaxial compression/forging and repeated corrugation and straightening for this class of alloys is also limited.
Originality/value
This paper provides a topical, technical insight into developments in near-a Ti alloys using literature from within the past decade. It also outlines the future developments of this class of Ti alloys.
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Diqian Ren, Jun-Ki Choi and Kellie Schneider
Because of the significant differences in the features and requirements of specific products and the capabilities of various additive manufacturing (AM) solutions, selecting the…
Abstract
Purpose
Because of the significant differences in the features and requirements of specific products and the capabilities of various additive manufacturing (AM) solutions, selecting the most appropriate AM technology can be challenging. This study aims to propose a method to solve the complex process selection in 3D printing applications, especially by creating a new multicriteria decision-making tool that takes the direct certainty of each comparison to reflect the decision-maker’s desire effectively.
Design/methodology/approach
The methodology proposed includes five steps: defining the AM technology selection decision criteria and constraints, extracting available AM parameters from the database, evaluating the selected AM technology parameters based on the proposed decision-making methodology, improving the accuracy of the decision by adopting newly proposed weighting scheme and selecting optimal AM technologies by integrating information gathered from the whole decision-making process.
Findings
To demonstrate the feasibility and reliability of the proposed methodology, this case study describes a detailed industrial application in rapid investment casting that applies the weightings to a tailored AM technologies and materials database to determine the most suitable AM process. The results showed that the proposed methodology could solve complicated AM process selection problems at both the design and manufacturing stages.
Originality/value
This research proposes a unique multicriteria decision-making solution, which employs an exclusive weightings calculation algorithm that converts the decision-maker's subjective priority of the involved criteria into comparable values. The proposed framework can reduce decision-maker's comparison duty and potentially reduce errors in the pairwise comparisons used in other decision-making methodologies.
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Antonella Francesca Cicchiello, Amirreza Kazemikhasragh and Stefano Monferrà
The purpose of this paper aims to understand whether gender disparity has an impact on the likelihood of obtaining equity crowdfunding financing in Latin America.
Abstract
Purpose
The purpose of this paper aims to understand whether gender disparity has an impact on the likelihood of obtaining equity crowdfunding financing in Latin America.
Design/methodology/approach
The paper uses a unique database of 492 projects from different equity crowdfunding platforms in Latin America over a period of 2013–2017.
Findings
Results indicate that the involvement of at least one woman in the board of firms seeking equity financing increases campaigns' success significantly. Team gender has no impact on the project's likelihood to experience overfunding.
Originality/value
The paper sheds light on women's access to crowdfunding financing in Latin America, not yet considered so far.
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Ning Shen and Zhiyi Zhuo
Based on upper echelons (UE) theory, the purpose of this study is to investigate a conceptualized moderated mediation model for examining the effects of top management team (TMT…
Abstract
Purpose
Based on upper echelons (UE) theory, the purpose of this study is to investigate a conceptualized moderated mediation model for examining the effects of top management team (TMT) heterogeneity and firm value in China through the mediating effect of product diversification, the moderating effect of ownership type between TMT heterogeneity and product diversification and the moderating effect of executive shareholding between product diversification and firm value.
Design/methodology/approach
Unbalanced panel data were collected over 5 years with a total of 6,597 observations, organized through the WIND (Wind Economic Database) and CSMAR (China Stock Market and Accounting Research) Database. The hypotheses were tested using structural equation modeling and analyzed with stata15.0 software.
Findings
The results indicated that product diversification plays a mediating role between TMT heterogeneity and firm value. In China, TMT heterogeneity of non–state-owned enterprises plays a more significant role in promoting product diversification than that of state-owned enterprises; executive shareholding strengthens the relationship between product diversification and firm value.
Research limitations/implications
The characteristic dimension of TMT is seen as a relatively static factor, and it is worth looking at whether a more dynamic system of evaluation and measurement can be established.
Originality/value
This study enriches theoretical research on TMT and contributes to UE theory in several ways. First, we studied the mediation effect of product diversification between TMT heterogeneity and firm value. This extends research on UE theory to possible process variables. Second, considering the influence of the unique institutional environment in China on corporate strategic decisions, the study investigates state-owned and non–state-owned enterprises. Specifically, it looks at the influence of ownership type as a moderating variable between TMT heterogeneity and product diversification. Third, the paper discusses the moderating effect of executive shareholding on the product diversification–firm value relationship. The research contributes to agency theory and expands research on different economic systems by implementing agency theory.
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Gijeong Seo, Md. RU Ahsan, Yousub Lee, Jong-Ho Shin, Hyungjun Park and Duck Bong Kim
Due to the complexity of and variations in additive manufacturing (AM) processes, there is a level of uncertainty that creates critical issues in quality assurance (QA), which…
Abstract
Purpose
Due to the complexity of and variations in additive manufacturing (AM) processes, there is a level of uncertainty that creates critical issues in quality assurance (QA), which must be addressed by time-consuming and cost-intensive tasks. This deteriorates the process repeatability, reliability and part reproducibility. So far, many AM efforts have been performed in an isolated and scattered way over several decades. In this paper, a systematically integrated holistic view is proposed to achieve QA for AM.
Design/methodology/approach
A systematically integrated view is presented to ensure the predefined part properties before/during/after the AM process. It consists of four stages, namely, QA plan, prospective validation, concurrent validation and retrospective validation. As a foundation for QA planning, a functional workflow and the required information flows are proposed by using functional design models: Icam DEFinition for Function Modeling.
Findings
The functional design model of the QA plan provides the systematically integrated view that can be the basis for inspection of AM processes for the repeatability and qualification of AM parts for reproducibility.
Research limitations/implications
A powder bed fusion process was used to validate the feasibility of this QA plan. Feasibility was demonstrated under many assumptions; real validation is not included in this study.
Social implications
This study provides an innovative and transformative methodology that can lead to greater productivity and improved quality of AM parts across industries. Furthermore, the QA guidelines and functional design models provide the foundation for the development of a QA architecture and management system.
Originality/value
This systematically integrated view and the corresponding QA plan can pose fundamental questions to the AM community and initiate new research efforts in the in-situ digital inspection of AM processes and parts.
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Antonella Francesca Cicchiello, Amirreza Kazemikhasragh and Stefano Monferra
Women’s entrepreneurial activity can significantly impact economic and social development globally, particularly in developing countries. The significant challenges…
Abstract
Purpose
Women’s entrepreneurial activity can significantly impact economic and social development globally, particularly in developing countries. The significant challenges entrepreneurial women face draw the attention of researchers and policymakers. This paper aims to analyse the impact of gender disparity on the likelihood of obtaining equity financing through crowdfunding. The equity crowdfunding industry was selected because it is a non-traditional financial market where gender bias may act differently for women.
Design/methodology/approach
To investigate the relationship between gender and equity financing through crowdfunding, this paper applies ordinary least squares regression. The analysis is based on a unique data set of 492 equity crowdfunding campaigns launched between 2013 and 2017 on all existing platforms in Brazil, Chile and Mexico.
Findings
The analysis reveals that the involvement of at least one woman on the board of firms seeking equity financing increases campaign success rates in terms of the investors’ average pledge, the target amount reached at the end of the campaign and the percentage raised at the end of the campaign exceeding the initial fundraising goal. Altogether, this suggests that equity crowdfunding campaigns should be based on gender equality in the firms’ boards. The research finds evidence that there is no gender disparity in the likelihood of a campaign being financed by a greater number of investors.
Practical implications
These findings have implications for Latin American female entrepreneurs when selecting funding sources and policymakers when defining political actions to remove the barriers at the root of this historic inequality in female entrepreneurs’ access to finance.
Originality/value
To the best of the authors’ knowledge, this document analyses the gender disparity in the Latin American equity crowdfunding market, shedding light on women’s access to crowdfunding financing for the first time.