Search results

1 – 10 of 12
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Article
Publication date: 8 March 2022

Jared Allison, John Pearce, Joseph Beaman and Carolyn Seepersad

Recent work has demonstrated the possibility of selectively sintering polymer powders with radio frequency (RF) radiation as a means of rapid, volumetric additive manufacturing…

182

Abstract

Purpose

Recent work has demonstrated the possibility of selectively sintering polymer powders with radio frequency (RF) radiation as a means of rapid, volumetric additive manufacturing. Although RF radiation can be used as a volumetric energy source, non-uniform heating resulting from the sample geometry and electrode configuration can lead to adverse effects in RF-treated samples. This paper aims to address these heating uniformity issues by implementing a computational design strategy for doped polymer powder beds to improve the RF heating uniformity.

Design/methodology/approach

Two approaches for improving the RF heating uniformity are presented with the goal of developing an RF-assisted additive manufacturing process. Both techniques use COMSOL Multiphysics® to predict the temperature rise during simulated RF exposure for different geometries. The effectiveness of each approach is evaluated by calculating the uniformity index, which provides an objective metric for comparing the heating uniformity between simulations. The first method implements an iterative heuristic tuning strategy to functionally grade the electrical conductivity within the sample. The second method involves reorienting the electrodes during the heating stage such that the electric field is applied in two directions.

Findings

Both approaches are shown to improve the heating uniformity and predicted part geometry for several test cases when applied independently. However, the greatest improvement in heating uniformity is demonstrated by combining the approaches and using multiple electrode orientations while functionally grading the samples.

Originality/value

This work presents an innovative approach for overcoming RF heating uniformity issues to improve the resulting part geometry in an RF-assisted, volumetric additive manufacturing method.

Details

Rapid Prototyping Journal, vol. 28 no. 8
Type: Research Article
ISSN: 1355-2546

Keywords

Access Restricted. View access options
Article
Publication date: 20 September 2021

Jared Allison, John Pearce, Joseph Beaman and Carolyn Seepersad

Additive manufacturing (AM) of thermoplastic polymers for powder bed fusion processes typically requires each layer to be fused before the next can be deposited. The purpose of…

133

Abstract

Purpose

Additive manufacturing (AM) of thermoplastic polymers for powder bed fusion processes typically requires each layer to be fused before the next can be deposited. The purpose of this paper is to present a volumetric AM method in the form of deeply penetrating radio frequency (RF) radiation to improve the speed of the process and the mechanical properties of the polymer parts.

Design/methodology/approach

The focus of this study was to demonstrate the volumetric fusion of composite mixtures containing polyamide (nylon) 12 and graphite powders using RF radiation as the sole energy source to establish the feasibility of a volumetric AM process for thermoplastic polymers. Impedance spectroscopy was used to measure the dielectric properties of the mixtures as a function of increasing graphite content and identify the percolation limit. The mixtures were then tested in a parallel plate electrode chamber connected to an RF generator to measure the heating effectiveness of different graphite concentrations. During the experiments, the surface temperature of the doped mixtures was monitored.

Findings

Nylon 12 mixtures containing between 10% and 60% graphite by weight were created, and the loss tangent reached a maximum of 35%. Selective RF heating was shown through the formation of fused composite parts within the powder beds.

Originality/value

The feasibility of a novel volumetric AM process for thermoplastic polymers was demonstrated in this study, in which RF radiation was used to achieve fusion in graphite-doped nylon powders.

Access Restricted. View access options
Article
Publication date: 12 April 2022

Jared France, Julie Milovanovic, Tripp Shealy and Allison Godwin

This paper aims to explore the differences in first-year and senior engineering students’ engineering agency beliefs and career goals related to sustainable development. The…

592

Abstract

Purpose

This paper aims to explore the differences in first-year and senior engineering students’ engineering agency beliefs and career goals related to sustainable development. The authors also sought to understand how topics related to sustainable development in engineering courses affect senior engineering students’ goals to address these issues in their careers. This work provides evidence of how students’ agency beliefs may be shaped by higher education, which is essential to workforce development.

Design/methodology/approach

Findings stem from two national surveys of engineering first-year (Sustainability and Gender in Engineering, n = 7,709) and senior students (Student Survey about Career Goals, College Experiences, n = 4,605). The authors compared both groups using pairwise testing by class standing.

Findings

The results indicate that undergraduate studies tend to reinforce students’ engineering agency beliefs to improve their quality of life and preserve the environment. Significantly more senior students selected career goals to address environmental issues compared to first-year students. In general, students undervalue their roles as engineers in addressing issues related to social inequities. Those topics are rarely addressed in engineering courses. Findings from this work suggest discussing sustainability in courses positively impact setting career goals to address such challenges.

Research limitations/implications

The study compares results from two distinct surveys, conveyed at different periods. Nonetheless, the sample size and national spread of respondents across US colleges and universities are robust to offer relevant insights on sustainable development in engineering education.

Practical implications

Adapting engineering curriculum by ensuring that engineering students are prepared to confront global problems related to sustainable development in their careers will have a positive societal impact.

Social implications

This study highlights shortcomings of engineering education in promoting social and economic sustainability as related to the engineering field. Educational programs would benefit from emphasizing the interconnectedness of environmental, social and economic dimensions of sustainable development. This approach could increase diversity in engineering education and the industry, and by ripple effect, benefit the communities and local governance.

Originality/value

This work is a first step toward understanding how undergraduate experiences impact students’ engineering agency beliefs and career goals related to sustainability. It explores potential factors that could increase students’ engineering agency and goals to make a change through engineering.

Details

International Journal of Sustainability in Higher Education, vol. 23 no. 7
Type: Research Article
ISSN: 1467-6370

Keywords

Access Restricted. View access options
Book part
Publication date: 22 February 2013

Shauna A. Morimoto

Purpose – This paper aims to provide insight into high school students’ understanding and experience of citizenship and civic engagement in the United States today.Methodological…

Abstract

Purpose – This paper aims to provide insight into high school students’ understanding and experience of citizenship and civic engagement in the United States today.Methodological approach – To supplement literature that reports the causes and correlates of youth civic engagement, this qualitative study explores the form and meaning of citizenship to young Americans. Drawing on observations and interviews with 116 high school students aged 14–19 years, this study explores how youth construct the meaning of citizenship and civic engagement.Findings – I find that race and racial identity are emergent in young people's construction of citizenship. Youth articulate the status of citizen on the basis of “privilege” and feel fortunate to be American. Forms of civic engagement vary by race with white students positioning themselves as helpers and delineating lower income minorities as “others” while also engaging in civic activity out of individual motivations and weak community connections. Minority youth express a desire to stay out of trouble, but also contest the boundaries of citizenship through forms of engagement that connect them to community.Value of paper – This paper contributes to understanding how race is emergent for young people's definitions of citizenship and civic actions. In addition to demonstrating how the categories of race and citizen are mutually constructed, it shows the value of looking beyond simple measurements of civic activity and exploring the meaning of youth civic work to gain insight into contemporary youth and democracy.

Details

Youth Engagement: The Civic-Political Lives of Children and Youth
Type: Book
ISBN: 978-1-78190-544-9

Keywords

Access Restricted. View access options
Article
Publication date: 4 June 2021

Luis Lisandro Lopez Taborda, Heriberto Maury and Jovanny Pacheco

There are many investigations in design methodologies, but there are also divergences and convergences as there are so many points of view. This study aims to evaluate to…

1256

Abstract

Purpose

There are many investigations in design methodologies, but there are also divergences and convergences as there are so many points of view. This study aims to evaluate to corroborate and deepen other researchers’ findings, dissipate divergences and provide directing to future work on the subject from a methodological and convergent perspective.

Design/methodology/approach

This study analyzes the previous reviews (about 15 reviews) and based on the consensus and the classifications provided by these authors, a significant sample of research is analyzed in the design for additive manufacturing (DFAM) theme (approximately 80 articles until June of 2017 and approximately 280–300 articles until February of 2019) through descriptive statistics, to corroborate and deepen the findings of other researchers.

Findings

Throughout this work, this paper found statistics indicating that the main areas studied are: multiple objective optimizations, execution of the design, general DFAM and DFAM for functional performance. Among the main conclusions: there is a lack of innovation in the products developed with the methodologies, there is a lack of exhaustivity in the methodologies, there are few efforts to include environmental aspects in the methodologies, many of the methods include economic and cost evaluation, but are not very explicit and broad (sustainability evaluation), it is necessary to consider a greater variety of functions, among other conclusions

Originality/value

The novelty in this study is the methodology. It is very objective, comprehensive and quantitative. The starting point is not the case studies nor the qualitative criteria, but the figures and quantities of methodologies. The main contribution of this review article is to guide future work on the subject from a methodological and convergent perspective and this article provides a broad database with articles containing information on many issues to make decisions: design methodology; optimization; processes, selection of parts and materials; cost and product management; mechanical, electrical and thermal properties; health and environmental impact, etc.

Details

Rapid Prototyping Journal, vol. 27 no. 5
Type: Research Article
ISSN: 1355-2546

Keywords

Available. Content available
Book part
Publication date: 31 January 2024

Abstract

Details

Data Curation and Information Systems Design from Australasia: Implications for Cataloguing of Vernacular Knowledge in Galleries, Libraries, Archives, and Museums
Type: Book
ISBN: 978-1-80455-615-3

Available. Content available
Book part
Publication date: 6 September 2016

Abstract

Details

Advances in Accounting Education: Teaching and Curriculum Innovations
Type: Book
ISBN: 978-1-78560-969-5

Available. Content available
Book part
Publication date: 14 December 2023

Filippo Marchesani

Free Access. Free Access

Abstract

Details

The Global Smart City
Type: Book
ISBN: 978-1-83797-576-1

Access Restricted. View access options
Book part
Publication date: 26 November 2019

Patricia Arend and Katherine Comeau

This chapter studies the social reproduction of the traditional heterosexual engagement ritual in which men propose marriage to women, even as many women now occupy positions of…

Abstract

This chapter studies the social reproduction of the traditional heterosexual engagement ritual in which men propose marriage to women, even as many women now occupy positions of power, surpass men in educational attainment, and provide their own incomes. We draw from 37 semi-structured interviews with middle-class, heterosexual women in which they discussed their marriage proposals. We argue that three related types of socioeconomic incentives encourage women to participate in traditional proposals: (1) the social status of being chosen to marry, (2) the value of gifts, especially an engagement ring, which also reflects the fiancé’s implied taste, and (3) the proposal story itself as scrip for inclusion in heterosexual women’s social groups. By considering social factors that mediate relationships among women, we show that economic and status incentives are important explanations for the perpetuation of the traditional engagement ritual. Specifically, the middle-class, heterosexual women in our study exchange socioeconomic status in their female-centered reference groups for their participation in gender-normative relations with their male partners.

Details

The Challenge of Progress
Type: Book
ISBN: 978-1-78714-572-6

Keywords

Access Restricted. View access options
Article
Publication date: 1 April 1977

THE Reference Department of Paisley Central Library today occupies the room which was the original Public Library built in 1870 and opened to the public in April 1871. Since that…

432

Abstract

THE Reference Department of Paisley Central Library today occupies the room which was the original Public Library built in 1870 and opened to the public in April 1871. Since that date two extensions to the building have taken place. The first, in 1882, provided a separate room for both Reference and Lending libraries; the second, opened in 1938, provided a new Children's Department. Together with the original cost of the building, these extensions were entirely financed by Sir Peter Coats, James Coats of Auchendrane and Daniel Coats respectively. The people of Paisley indeed owe much to this one family, whose generosity was great. They not only provided the capital required but continued to donate many useful and often extremely valuable works of reference over the many years that followed. In 1975 Paisley Library was incorporated in the new Renfrew District library service.

Details

Library Review, vol. 26 no. 4
Type: Research Article
ISSN: 0024-2535

1 – 10 of 12
Per page
102050