Gabriel Antonio Mendible, Nabil Saleh, Carol Barry and Stephen P. Johnston
Rapid tooling has numerous advantages when prototyping injection molded components, but the effects of the tooling on the resulting part properties are often overlooked. The…
Abstract
Purpose
Rapid tooling has numerous advantages when prototyping injection molded components, but the effects of the tooling on the resulting part properties are often overlooked. The purpose of this paper is to consider the effect of tooling on the final part properties and morphology.
Design/methodology/approach
Digital polyacrylonitrile-butadiene-styrene (ABS) tooling and aluminum tooling were used to mold test specimens from isotatic polypropylene (iPP). Tensile behavior, impact strength, shrinkage, surface roughness and porosity were evaluated for both sets of samples. Additionally, differential scanning calorimeter (DSC) and wide-angle X-ray scattering (WAXS) were used to assess the crystallinity of the samples.
Findings
Characterization of the molded parts showed that slower cooling rates in the Digital ABS inserts promoted the formation of ß-PP, while this crystal structure was not found in the parts molded using aluminum tooling. Additionally, parts molded on the digital ABS inserts exhibited higher mold shrinkage and SEM images identified microscopic shrinkage voids within the material. The change in morphology and the presence of voids significantly affected the tensile behavior with the parts molded in Digital ABS, which broke with little cold drawing and exhibited higher tensile moduli and higher yield strengths.
Practical implications
The results show that the choice of rapid tooling technique plays an important role on determining the properties of the final parts.
Originality/value
Previous studies have not characterized the effect of rapid tooling on the morphology of the molded articles fully or over a variety of processing conditions. This study builds on prior work by using both WAXS and DSC to characterize morphological changes over a wide range of processing conditions and comparing results to mechanical property and shrinkage data.
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Gabriel Antonio Mendible, Jack A. Rulander and Stephen P. Johnston
This study aims to evaluate the performance of injection molding inserts produced via rapid and conventional manufacturing techniques considering the mechanical and thermal…
Abstract
Purpose
This study aims to evaluate the performance of injection molding inserts produced via rapid and conventional manufacturing techniques considering the mechanical and thermal performance of the tools as well as the resulting molded part quality.
Design/methodology/approach
Three insert materials and manufacturing techniques were evaluated, jetted photopolymer (PolyJet) 3D printing using digital ABS, direct metal laser sintering (DMLS) using bronze and machining using stainless steel. Molding trials were performed, and the insert surface temperature, longevity and part properties were evaluated. Complementary information was acquired using computer simulation.
Findings
Similar behavior and part quality were observed in machined and DMLS inserts. The latter were used for 500 cycles without any signs of failure. PolyJet inserts had increased cycle time and slower rate of cooling which increased shrinkage and crystallinity in the molded parts. PolyJet inserts could be produced quickly at a lower cost than machined or DMLS inserts.
Research limitations/implications
Cooling within the insert was not studied; inserts were cooled indirectly by the mold plates behind them. Subsequent studies will incorporate cooling lines directly into the inserts.
Originality/value
Little research has been done to understand the thermal behavior of inserts manufactured via rapid tooling techniques. This study provides a direct comparison between rapid tooling techniques, which is supported by simulation results and analysis of the actual molding properties.
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This chapter examines the current higher (tertiary) education system in Aotearoa/New Zealand, drawing specifically on Maori (indigenous people) endeavours to engage at that level…
Abstract
This chapter examines the current higher (tertiary) education system in Aotearoa/New Zealand, drawing specifically on Maori (indigenous people) endeavours to engage at that level. I outline historically key practices and their underlying philosophies, which limited Maori access to higher education, especially those based on colonial views about race that positioned Maori at the lower end of the social structure in New Zealand society. The loss of language and culture, a monocultural education system, and the impact on Maori in terms of educational underachievement will be further outlined.
The chapter then examines Maori educational initiatives as a means to outline how Maori have attempted to address educational underachievement and the redress of their language, knowledge and culture. The engagement of Maori in universities, research and education will be discussed including new tertiary developments, an indigenous tertiary institution – Te Whare Wananga o Awanuiarangi.
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How do transnational social movements organize? Specifically, this paper asks how an organized community can lead a nationalist movement from outside the nation. Applying the…
Abstract
How do transnational social movements organize? Specifically, this paper asks how an organized community can lead a nationalist movement from outside the nation. Applying the analytic perspective of Strategic Action Fields, this study identifies multiple attributes of transnational organizing through which expatriate communities may go beyond extra-national supporting roles to actually create and direct a national campaign. Reexamining the rise and fall of the Fenian Brotherhood in the mid-nineteenth century, which attempted to organize a transnational revolutionary movement for Ireland’s independence from Great Britain, reveals the strengths and limitations of nationalist organizing through the construction of a Transnational Strategic Action Field (TSAF). Deterritorialized organizing allows challenger organizations to propagate an activist agenda and to dominate the nationalist discourse among co-nationals while raising new challenges concerning coordination, control, and relative position among multiple centers of action across national borders. Within the challenger field, “incumbent challengers” vie for dominance in agenda setting with other “challenger” challengers.
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In recent years, school districts have faced numerous questions surrounding accommodations of transgender students. Strong objections to accommodations have been voiced in public…
Abstract
In recent years, school districts have faced numerous questions surrounding accommodations of transgender students. Strong objections to accommodations have been voiced in public argument and litigation, primarily in the areas of athletics, bathrooms, and dress codes. As younger transgender students express their gender identity at school, however, the existing objections are weakened by considering the context of elementary rather than high school students. Greater numbers of young transgender students will likely encourage accommodation of trans students of all ages, as well as challenge the gender binary unconsciously taught in school.
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The purpose of this paper is to explore the professional biography of Ethel A. Stephens, examining her career as an artist and a teacher in Sydney between 1890 and 1920. Accounts…
Abstract
Purpose
The purpose of this paper is to explore the professional biography of Ethel A. Stephens, examining her career as an artist and a teacher in Sydney between 1890 and 1920. Accounts of (both male and female) artists in this period often dismiss their teaching as just a means to pay the bills. This paper focuses attention on Stephens’ teaching and considers how this, combined with her artistic practice, influenced her students.
Design/methodology/approach
Using a fragmentary record of a successful female artist and teacher, this paper considers the role of art education and a career in the arts for respectable middle-class women.
Findings
Stephens’ actions and experiences show the ways she negotiated between the public and private sphere. Close examination of her “at home” exhibitions demonstrates one way in which these worlds came together as sites, enabling her to identify as an artist, a teacher and as a respectable middle-class woman.
Originality/value
This paper offers insight into the ways women negotiated the Sydney art scene and found opportunities for art education outside of the established modes.
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In the last four years, since Volume I of this Bibliography first appeared, there has been an explosion of literature in all the main functional areas of business. This wealth of…
Abstract
In the last four years, since Volume I of this Bibliography first appeared, there has been an explosion of literature in all the main functional areas of business. This wealth of material poses problems for the researcher in management studies — and, of course, for the librarian: uncovering what has been written in any one area is not an easy task. This volume aims to help the librarian and the researcher overcome some of the immediate problems of identification of material. It is an annotated bibliography of management, drawing on the wide variety of literature produced by MCB University Press. Over the last four years, MCB University Press has produced an extensive range of books and serial publications covering most of the established and many of the developing areas of management. This volume, in conjunction with Volume I, provides a guide to all the material published so far.
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Stephen Cope, Frank Leishman and Peter Starie
Explores the links between processes of globalization and new public management (NPM), and examines their effects on the management of the police in particular. Assesses whether…
Abstract
Explores the links between processes of globalization and new public management (NPM), and examines their effects on the management of the police in particular. Assesses whether managerial unity or managerial disunity will characterize the future of police management. Looks at the effects of globalization on academic disciplines; the role of the State in an era of globalization; the rise of NPM; the effects of NPM on the management of the British police; the implications of police management reform for the police; and future scenarios of police management.
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Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some…
Abstract
Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some legal aspects concerning MNEs, cyberspace and e‐commerce as the means of expression of the digital economy. The whole effort of the author is focused on the examination of various aspects of MNEs and their impact upon globalisation and vice versa and how and if we are moving towards a global digital economy.
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The concept and practice of e-services has become essential in business transactions. Yet there are still many organizations that have not developed e-services optimally. This is…
Abstract
The concept and practice of e-services has become essential in business transactions. Yet there are still many organizations that have not developed e-services optimally. This is especially relevant in the context of Indonesian Airline companies. Therefore, many airline customers in Indonesia are still in doubt about it, or even do not use it. To fill this gap, this study attempts to develop a model for e-services adoption and empirically examines the factors influencing the airlines customers in Indonesia in using e-services offered by the Indonesian airline companies. Taking six Indonesian airline companies as a case example, the study investigated the antecedents of e-services usage of Indonesian airlines. This study further examined the impacts of motivation on customers in using e-services in the Indonesian context. Another important aim of this study was to investigate how ages, experiences and geographical areas moderate effects of e-services usage.
The study adopts a positivist research paradigm with a two-phase sequential mixed method design involving qualitative and quantitative approaches. An initial research model was first developed based on an extensive literature review, by combining acceptance and use of information technology theories, expectancy theory and the inter-organizational system motivation models. A qualitative field study via semi-structured interviews was then conducted to explore the present state among 15 respondents. The results of the interviews were analysed using content analysis yielding the final model of e-services usage. Eighteen antecedent factors hypotheses and three moderating factors hypotheses and 52-item questionnaire were developed. A focus group discussion of five respondents and a pilot study of 59 respondents resulted in final version of the questionnaire.
In the second phase, the main survey was conducted nationally to collect the research data among Indonesian airline customers who had already used Indonesian airline e-services. A total of 819 valid questionnaires were obtained. The data was then analysed using a partial least square (PLS) based structural equation modelling (SEM) technique to produce the contributions of links in the e-services model (22% of all the variances in e-services usage, 37.8% in intention to use, 46.6% in motivation, 39.2% in outcome expectancy, and 37.7% in effort expectancy). Meanwhile, path coefficients and t-values demonstrated various different influences of antecedent factors towards e-services usage. Additionally, a multi-group analysis based on PLS is employed with mixed results. In the final findings, 14 hypotheses were supported and 7 hypotheses were not supported.
The major findings of this study have confirmed that motivation has the strongest contribution in e-services usage. In addition, motivation affects e-services usage both directly and indirectly through intention-to-use. This study provides contributions to the existing knowledge of e-services models, and practical applications of IT usage. Most importantly, an understanding of antecedents of e-services adoption will provide guidelines for stakeholders in developing better e-services and strategies in order to promote and encourage more customers to use e-services. Finally, the accomplishment of this study can be expanded through possible adaptations in other industries and other geographical contexts.