scholarly journals Casting of complex structures in aluminum using gypsum molds produced via binder jetting

2021 ◽  
Vol 27 (11) ◽  
pp. 13-23
Author(s):  
Luca Giorleo ◽  
Michele Bonaventi

Purpose The purpose of present paper is to enlarge the knowledge about the performance of gypsum powder to realize complex molds or cores for aluminum casting. Design/methodology/approach The research was divided into two activities: simple; and complex-part production capability. In the simple-part step, the performance of gypsum powder and the minimum mold thickness that would withstand the casting process. In the complex-part step, the authors first investigated the powder removability as a function of geometry complexity and then binder jetting performance was evaluated for the case of lattice-structure fabrication. Findings All the geometries tested withstand the casting process demonstrating the benefits in terms of complexity part design; however, the process suffers of all the typical defect of casting as misrun, porosity and cold shut. Originality/value The results found in this research improve the benefits related to additive manufacturing application in industrial environment and in particular to the binder jetting technology and the rapid casting approach.

2017 ◽  
Vol 23 (5) ◽  
pp. 954-963 ◽  
Author(s):  
Eduardo Castro e Costa ◽  
José Pinto Duarte ◽  
Paulo Bártolo

Purpose In this paper, the authors aim to address the potential of mass personalization for ceramic tableware objects. They argue that additive manufacturing (AM) is the most adequate approach to the production of such objects. Design/methodology/approach The authors review the manufacturing of ceramic tableware objects, both traditional techniques and AM processes, and assess which available AM technologies are suitable for the research purpose. Findings The authors consider binder jetting and material extrusion as the most suitable processes for the production of ceramic objects to be integrated into a mass personalization system of ceramic tableware. Originality/value This paper provides an original overview of traditional and innovative techniques in ceramic manufacturing, exposing not only its differences but also its commonalities. Such overview supports the conceptual design of original equipment.


2020 ◽  
Vol 14 (3) ◽  
pp. 543-557
Author(s):  
Aliaa AlSadaty

PurposeThis paper investigates urban potentials of historic covered market buildings. Generally, these structures witnessed the apex of construction during the turn of the 20th century in Europe and beyond. They thrived until the second half of the 20th century when they started to decline and their existence became threatened due to several factors. This research focuses on recent regeneration attempts that consider the qualities of these structures, not only as individual buildings but also as an important tool for the revitalization of their surrounding contexts.Design/methodology/approachThis paper focuses mainly on the Egyptian network of historic indoor markets with special reference to Port Said markets which are currently in decay and in urgent need for intervention. Through the consultation of the Barcelona Model for Markets, Spain and the survey of Port Said historic markets; the present study suggests a framework through which the network of local markets can regain their positive role and contribute to the revitalization of their surrounding context.FindingsFindings reveal that historic indoor markets are complex structures that cannot be regenerated in isolation from their usually fast changing contexts. Intervention in this prototype needs to balance between traditional imaginary of these buildings, including the protection of their historic features and the protection of vulnerable local trades; and at the same time, the adaptation of market buildings to contemporary needs to improve their competitiveness on the commercial level.Originality/valueThe present study suggests a two-level framework and approach through which the network of local markets in Egyptian cities can regain their positive role and hence contribute to the revitalization of their surroundings.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abdulwahed Fazeli ◽  
Mohammad Saleh Dashti ◽  
Farzad Jalaei ◽  
Mostafa Khanzadi

PurposeAnalyzing different scenarios at the design stage of construction projects has always been a challenging task. One of the main parameters that helps owners in making better decisions in designing their buildings is to look after the cost perspective on different design scenarios. Thus, this study aims to propose a semi-automated BIM-based cost estimation approach that enables practitioners to estimate the cost of projects based on different design scenarios by an accurate and agile system.Design/methodology/approachThis study proposes an integrated framework, through which the cost estimation standard of Iran (FehrestBaha) is linked to the materials quantity take-offs (QTO) from BIM models. The performance of the system is based on connecting the classification standards of UniFormat and MasterFormat to the cost estimation standard of FehrestBaha. A BIM-based extension in the Revit environment is developed to automate the cost estimation process.FindingsTo evaluate the efficiency of the proposed approach in cost estimation, it is implemented to estimate the cost of the architectural discipline in a real construction project. The results indicate that the proposed BIM-based approach estimated the cost of the architectural discipline with an acceptable level of accuracy.Practical implicationsThe proposed approach could be used by practitioners to have an agile and accurate BIM-based cost estimation of different scenarios during design process. The semi-automated system considerably reduces the time of cost estimation in comparison to the traditional manual approaches, particularly in complex structures. Owners are able to easily trace changes in project cost according to any changes in components and materials of the BIM model. Furthermore, the proposed approach provides a practical roadmap for BIM-based cost estimation based on cost estimation standards in different countries.Originality/valueUnlike the traditional manual cost estimation approaches, the proposed BIM-based approach is not highly dependent on the knowledge of experienced estimators, which therefore facilitates its implementation. Furthermore, automating both QTO process and the required calculations in this approach increases the accuracy of cost estimation while decreasing the probability of human errors or omission occurrence.


2019 ◽  
Vol 22 (1) ◽  
pp. 5-8
Author(s):  
Ian Cummins

Purpose The purpose of this paper is to discuss the recent National Appropriate Adult Network (NAAN) report on the role of the appropriate adult. Design/methodology/approach This paper is based on the NAAN report and a review of relevant policy and research literature. Findings There to Help 2 highlights that there are still significant gaps in the provision of appropriate adult schemes across England and Wales. These gaps potentially place vulnerable adults at increased risk. Originality/value This paper is a review of recent research.


2019 ◽  
Vol 41 (4) ◽  
pp. 740-757 ◽  
Author(s):  
Sophie Hennekam ◽  
Subramaniam Ananthram ◽  
Steve McKenna

Purpose The purpose of this paper is to investigate how individuals perceive and react to the involuntary demotion of a co-worker in their organisation. Design/methodology/approach The authors draw on 46 semi-structured in-depth interviews (23 dyads) with co-workers of demoted individuals. Findings The findings suggest that an individual’s observation of the demotion of a co-worker has three stages: their perception of fairness, their emotional reaction and their behavioural reaction. The perception of fairness concerned issues of distributive, procedural, interpersonal and informational justice. The emotional responses identified were feelings of disappointment/disillusion, uncertainty, vulnerability and anger. Finally, the behavioural reactions triggered by their emotional responses included expressions of voice, loyalty, exit and adaptation. Originality/value Perceptions of (in)justice perpetrated on others stimulate emotional and behavioural responses, which impacts organisational functioning. Managers should therefore pay attention to the way a demotion is perceived, not only by those directly concerned, but also by co-workers as observers.


2019 ◽  
Vol 32 (4) ◽  
pp. 455-471
Author(s):  
Jorge Cruz-Cárdenas ◽  
Jorge Guadalupe-Lanas ◽  
Ekaterina Zabelina ◽  
Andrés Palacio-Fierro ◽  
Margarita Velín-Fárez ◽  
...  

Purpose The purpose of this paper is to understand in-depth how consumers create value in their lives using WhatsApp, the leading mobile instant messaging (MIM) application. Design/methodology/approach The study adopts the perspective of customer-dominant logic (CDL) and uses a qualitative multimethod design involving 3 focus groups and 25 subsequent in-depth interviews. The research setting was Ecuador, a Latin American country. Findings Analysis and interpretation of the participants’ stories made it possible to identify and understand the creation of four types of value: maintaining and strengthening relationships; improving role performance; emotional support; and entertainment and fun. In addition, the present study proposes a conceptual model of consumer value creation as it applies to MIM. Practical implications Understanding the way consumers create value in their lives using MIM is important not only for organizations that offer MIM applications, but also for those companies that develop other applications for mobile phones or for those who wish to use MIM as an electronic word-of-mouth vehicle. Originality/value The current study is one of the first to address the topic of consumer behavior in the use of technologies from the perspective of CDL; this perspective enables an integrated qualitative vision of value creation in which the consumer is the protagonist.


2019 ◽  
Vol 25 (3) ◽  
pp. 378-396 ◽  
Author(s):  
Arian Razmi-Farooji ◽  
Hanna Kropsu-Vehkaperä ◽  
Janne Härkönen ◽  
Harri Haapasalo

Purpose The purpose of this paper is twofold: first, to understand data management challenges in e-maintenance systems from a holistically viewpoint through summarizing the earlier scattered research in the field, and second, to present a conceptual approach for addressing these challenges in practice. Design/methodology/approach The study is realized as a combination of a literature review and by the means of analyzing the practices on an industry leader in manufacturing and maintenance services. Findings This research provides a general understanding over data management challenges in e-maintenance and summarizes their associated proposed solutions. In addition, this paper lists and exemplifies different types and sources of data which can be collected in e-maintenance, across different organizational levels. Analyzing the data management practices of an e-maintenance industry leader provides a conceptual approach to address identified challenges in practice. Research limitations/implications Since this paper is based on studying the practices of a single company, it might be limited to generalize the results. Future research topics can focus on each of mentioned data management challenges and also validate the applicability of presented model in other companies and industries. Practical implications Understanding the e-maintenance-related challenges helps maintenance managers and other involved stakeholders in e-maintenance systems to better solve the challenges. Originality/value The so-far literature on e-maintenance has been studied with narrow focus to data and data management in e-maintenance appears as one of the less studied topics in the literature. This research paper contributes to e-maintenance by highlighting the deficiencies of the discussion surrounding the perspectives of data management in e-maintenance by studying all common data management challenges and listing different types of data which need to be acquired in e-maintenance systems.


2020 ◽  
Vol 72 (10) ◽  
pp. 1153-1158 ◽  
Author(s):  
Yafei Deng ◽  
Xiaotao Pan ◽  
Guoxun Zeng ◽  
Jie Liu ◽  
Sinong Xiao ◽  
...  

Purpose This paper aims to improve the tribological properties of aluminum alloys and reduce their wear rate. Design/methodology/approach Carbon is placed in the model at room temperature, pour 680°C of molten aluminum into the pressure chamber, and then pressed it into the mold containing carbon felt through a die casting machine, and waited for it to cool, which used an injection pressure of 52.8 MPa and held the same pressure for 15 s. Findings The result indicated that the mechanical properties of matrix and composite are similar, and the compressive strength of the composite is only 95% of the matrix alloy. However, the composite showed a low friction coefficient, the friction coefficient of Gr/Al composite is only 0.15, which just is two-third than that of the matrix alloy. Similarly, the wear rate of the composite is less than 4% of the matrix. In addition, the composite can avoid severe wear before 200°C, but the matrix alloy only 100°C. Originality/value This material has excellent friction properties and is able to maintain this excellent performance at high temperatures. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0454/


2020 ◽  
Vol 27 (3) ◽  
pp. 755-770
Author(s):  
Maria Krambia-Kapardis

Purpose The purpose of this study is to develop a profile of whistleblowers and to determine whether whistleblowing legislation would encourage those individuals to bring to light some illegal or unethical behaviour that otherwise would remain in the shadows. Design/methodology/approach Having identified whistleblowing correlation, a survey was carried out in Cyprus of actual whistleblowers and could-have-been whistleblowers. Findings Males between 46 and55 years of age, regardless of whether they have dependents or hold senior positions in organizations are significantly more likely to blow the whistle. However, could-have-been whistleblowers did not go ahead because they felt that the authorities would not act on their information. Research limitations/implications Because of the sensitive nature of the research topic and the fact that only whistleblowers or intended whistleblowers could participate in the study, the sample size is limited as a result. This, in turn, limits both the number of respondents in each category (actual and intended) as well as constrains the statistical analysis that could be carried out on the data. Practical implications It remains to be seen whether EU Member States shall implement the European Directive 2019/1937 on the protection of persons who report breaches of Union Law, in its entirety by the due date, namely December 2021. Originality/value This study provides a literature review of whistleblowing and reports an original survey against the backdrop of the European Directive.


2019 ◽  
Vol 37 (1) ◽  
pp. 134-142
Author(s):  
Alberto Bueno-Guerrero

Purpose This paper aims to study the conditions for the hedging portfolio of any contingent claim on bonds to have no bank account part. Design/methodology/approach Hedging and Malliavin calculus techniques recently developed under a stochastic string framework are applied. Findings A necessary and sufficient condition for the hedging portfolio to have no bank account part is found. This condition is applied to a barrier option, and an example of a contingent claim whose hedging portfolio has a bank account part different from zero is provided. Originality/value To the best of the authors’ knowledge, this is the first time that this issue has been addressed in the literature.


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