Search results

To demonstrate, through numerical models, that it is possible to simulated low‐gravity phase change (melting), of an electrically conducting material (gallium), in terrestrial conditions via the application of electromagnetic fields.

A complete three‐dimensional mathematical formulation governing a phase change process in the presence of an electromagnetic field has been developed. In addition a comprehensive parametric study has been completed to study the various effects of gravity, Stefan number, Hartmann number and electromagnetic pressure number upon the phase change process.

The results show that the application of an electromagnetic filed can be used to simulate key melting characteristics found for actual low‐gravity. However, the resulting three‐dimensional flow field in the melted region differs from actual low‐gravity. The application of an electromagnetic field creates a flow phenomenon not found in actual low‐gravity or previously seen in two‐dimensional problems.

Future work may include the use of oscillating electromagnetic fields to enhance convection in energy storage systems in a low‐gravity environment.

The ability to suppress unwanted convective flows in a phase change process without the high magnetic fields necessary in magnetic field only suppression systems.

This work fills a void in the literature related to conducting fluids and the effects of magnetic and electromagnetic fields.

Tuber crops are extremely important for humans, being extensively used in many cultures and mainly in poor and developing countries. Tanias (Xanthosoma Schott) belong to the Aracea family and have been commonly used as a staple food since pre‐Columbian times. Nowadays, tanias are integrated in the staple diet of several countries in the Americas, West Africa, Asia and the Pacific. In order to shed light on their potential and possible risks for human nutrition, nutritional and anti‐nutritional evaluations of different compounds synthesized by tania corms were carried out by using seven tropical species.

Classical analyses for non‐structural carbohydrates and nitrogenated compounds as well inhibitory assays towards α‐amylases and proteases were employed.

Tests for quantitation of reducing sugars, soluble polysaccharides, free amino acid content and total protein amounts presented variable scores among studied species. Nevertheless, the amounts of non‐starchy polysaccharides and sugars were less than those observed in other tuber crops, such as potato, cassava, sweet potato and yam. Otherwise, when anti‐nutritional compounds were evaluated, no digestive enzyme inhibitory activity was detected in performed assays. Moreover, Xanthosoma atrovirens, Xanthosoma brasiliense and Xanthosoma mafaffa showed agglutination activity towards blood type B, probably due to the presence of lectins.

In summary, data here presented suggest that it is not possible to indicate a single tania candidate as the best choice for human consumption.

The paper presents a pioneer comparison of nutritional and antinutritional compounds between different species of tania corms.

The Mechanical Engineering course at the University of Campinas is composed of different disciplines in the areas of materials, mechanical design, manufacturing (production and manufacturing), computational systems, thermal and fluids. In the manufacturing area, in particular, there is a discipline entitled Productive Systems whose main objective is to offer to the student a global vision about operations management. In the field of operations management, sustainability is gaining more and more importance; thus, it is important to develop in the students a critical sense about social and environmental aspects. Thus, this paper aims to present the main initiatives developed in the discipline to promote sustainability in engineering students.

Since 2015, the professors responsible for the Productive Systems discipline, assisted by post-graduate students and professors from other universities, have begun to redesign the discipline, including debates, lectures, projects and other initiatives to provide a critical view concerning the traditional concepts taught. The discipline has been performed three times with this new conception. The methodology to structure this research was literature review, documental analyses of the discipline records and meetings with professors that participated in the initiatives. An Action Research approach was performed by two professors and a graduate student. The authors of this paper also compared the results with those obtained by initiatives performed at Chalmers University of Technology (Sweden).

This study allowed to reinforce some results from initiatives performed at Chalmers University of Technology (Sweden); however, some differences were identified. For example, similar to the initiatives mentioned, the professors of University of Campinas had problems with didactic books, as they loosely integrate the basic operations management concepts with sustainable development fundamentals. On the other hand, debates related to social sustainability were considered positive from the point of view of the professors and students, differing from initiatives performed at Chalmers University of Technology.

Results come from one field study (University of Campinas) when professors of the Mechanical Engineering course try to integrate operations management concepts and sustainable development. Different results may be observed by other higher education institutions.

The authors of this paper believe that the diffusion of these initiatives can stimulate other professors and researchers in the field to broaden the academic debate about the insertion of sustainability into engineering courses.

There are few papers presenting didactic experiences and empirical results about the integration of operations management concepts and sustainable development. Results of this paper reinforce some good practices and they also present other ones, in a way that extend the debate about educational engineering.

In a context where human–machine interaction is growing, understanding the limits between automated and human-based methods may leverage qualitative research. This paper aims to compare human and machine analyses, highlighting the challenges and opportunities of both approaches.

This study applied qualitative secondary analysis (QSA) with machine learning-based text mining on qualitative data from 25 interviews previously analyzed with traditional qualitative content analysis.

By analyzing both techniques' strengths and weaknesses, this study complements the results from the original research work. The previous human model failed to point to a particular aspect of the case, while the machine analysis did not recognize the sequence of time in the interviewee's discourse.

This study demonstrates that combining content analysis with text mining techniques improves the quality of the research output. Researchers may, therefore, better handle biases from humans and machines in traditional qualitative and quantitative research.

This study aims to analyze the practices and relationships of companies established in Science and Technology Parks (STPs) as drivers of the quadruple and quintuple helix (QQH) and the determinants for aligning with the future vision of STPs.

The authors conducted a survey of companies associated with consolidated STPs and used the Structural Equation Model technique to predict such relationships.

The results showed a positive relationship between the QQH and the Future Vision of STPs, in addition to the relevance of collectives as representatives of the quadruple helix (QH).

Collectives are a recent phenomenon and require longitudinal studies on their performance in innovation environments.

Companies that are part of collectives are the actors of the QH.

The role of collectives in aligning with the future vision of STPs should be considered. Collectives reflect people’s vision and can help STPs from being a closed environment and expand their performance, with a key role in connecting innovation environments. The authors found that collectives are promising in practices related to sustainability, thus contributing to STPs with their ability to mobilize the ecosystem.

The research emphasizes the role of companies as agents of QQH in innovation environments, strengthening the increasing and distinct role of collectives in their relationships with STPs.

The purpose of this paper is to analyze the difficulties observed during implementation of quality management systems (QMSs) in Brazilian manufacturing companies.

The methodological strategy used was a literature review, a panel of experts and a survey. Through the literature review, 15 difficulties associated with the implementation of QMS were raised; these were organized into latent variables by specialists in the subject and served as the basis for a survey. In total, 123 professionals working with quality management in manufacturing companies participated in the research and the data collected were analyzed by means of second-order confirmatory factorial analysis.

The results allowed the validation of the 15 difficulties observed in the literature, and it was evidenced that these difficulties are structured in four latent variables as follows: difficulties associated with employees; difficulties associated with QMS structuration; difficulties associated with integration; and difficulties resulting from the planning.

The main limitation of this research is the sample size, because 123 professionals that work with quality management in manufacturing companies participated in the research. It should be noted, however, that all parameters evaluated through the second-order confirmatory factorial analysis were validated.

The findings have great value for both quality management professionals, who may use those findings to guide the pre-implementation phase of a QMS, and researchers, who may use those findings as a foundation for future studies, in the development of models or tools related to QMS implementation.

No other paper was found on the scientific basis with the same focus for Brazilian manufacturing companies, thus demonstrating originality. The value of the research lies in the fact that the results presented here, statistically validated, may be used by other researchers and market professionals.

We present a critical literature review debating Brazilian research on social and environmental accounting (SEA). The aim of this study is to understand the role of politics in the construction of hegemonies in SEA research in Brazil. In particular, we examine the role of hegemony in relation to the co-option of SEA literature and sustainability in the Brazilian context by the logic of development for economic growth in emerging economies. The methodological approach adopts a post-structural perspective that reflects Laclau and Mouffe’s discourse theory. The study employs a hermeneutical, rhetorical approach to understand and classify 352 Brazilian research articles on SEA. We employ Brown and Fraser’s (2006) categorizations of SEA literature to help in our analysis: the business case, the stakeholder–accountability approach, and the critical case. We argue that the business case is prominent in Brazilian studies. Second-stage analysis suggests that the major themes under discussion include measurement, consulting, and descriptive approach. We argue that these themes illustrate the degree of influence of the hegemonic politics relevant to emerging economics, as these themes predominantly concern economic growth and a capitalist context. This paper discusses trends and practices in the Brazilian literature on SEA and argues that the focus means that SEA avoids critical debates of the role of capitalist logics in an emerging economy concerning sustainability. We urge the Brazilian academy to understand the implications of its reifying agenda and engage, counter-hegemonically, in a social and political agenda beyond the hegemonic support of a particular set of capitalist interests.

This study aims to investigate the influence of the theory of planned behavior (TPB), innovation and sustainability, through environmental awareness, in the formation of entrepreneurial intention (EI).

Based on the alignment between theoretical axes, such as the theory of planned behavior, adaptation–innovation theory and the environmental axis of sustainability, quantitative research was developed with students from Brazilian and Spanish universities. We obtained a sample of 686 university students enrolled in courses related to management in both countries. Data analysis included exploratory factor analysis and logistic regression.

Our results revealed that the constructs of TPB (personal attitudes and perceived behavioral control) influenced EI, excluding subjective norms. Innovation had an influence on the EI of students from both countries. In Brazilians, valuing change predicts EI, highlighting the importance of flexibility. Conversely, Spaniards emphasize originality, valuing uniqueness and creativity as drivers of EI. Sustainability, via environmental awareness, did not influence EI.

With this study, we aim to encourage policies and practices aimed at higher education institutions globally, to broaden the understanding about the importance of environmental, innovative and social studies and practices aligned with the context of entrepreneurship. The final aim is to enhance social and environmental benefits generated by future entrepreneurs.

Increased competition and access to information are forcing companies to provide quality to their products and services, aligned with a growing society pressure for less harmful environmental practices. The purpose of this paper is to demonstrate how the adoption of reverse logistics (RL) may contribute to the generation of competitive advantage and improved quality in a part substitution process of a household appliance company.

This paper carried out a single case study in a household appliance company. The study collected data through semi-structured interviews in addition to document analysis and observation.

The implemented practices enhanced service maintenance and customer services and provided a more effective monitoring of defective parts. Moreover, such practices reduced unnecessary part substitutions, consumer dissatisfaction and undesired disposal in the environment. RL in the studied company has offered a potential contribution to the company quality strategies by providing more part returns, assuring cost savings, and reducing time to solve field problems.

The study was limited to a single case study. Thus, the study findings are not subject to generalization for other similar organizations.

This paper is one of the few studies on RL in a household company in the context of an emerging economy. Such feature denotes in a singular scenario in RL investigations about recovering defective parts.