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This paper aims to present a proposal for evaluating the coefficient of friction (COF), under a reciprocating test that considers the energy dissipated by the friction force. In addition, this new parameter is compared to average COF, which is often used to evaluate COF in reciprocating tests.

Samples of compacted graphite iron were extracted directly from an internal combustion engine block. The piston ring used was a nitrided martensitic stainless steel with an asymmetrical profile, and the lubricant oil was the SAE 30 CF, controlled at 40°C. Different testing conditions were carried out in a CETR-UMT-Bruker tribometer, varying loads between 25-125 N, frequencies between 1-12.5 Hz and track length between 3-10 mm. Three maps comparing the average COF and the energetic definition were built, allowing to discuss their similarities.

In general, both parameters had similarities especially for low frequencies and small tracks. However, for test conditions that imposed higher accelerations (i.e. longer track lengths and higher frequencies), the energetic COF (COFe) was lower than the average COF (COFa) and presented better agreement in Stribeck-like curves – independent on the experienced lubrication regime along the stroke. As the COFe can be interpreted as a weighted average of instantaneous COF in relation to in-track displacements, an immediate consequence is that instantaneous COF closest to mid-stroke is considered more significant. Furthermore, perturbations associated with the intrinsic accelerations of the movement test are minimized in the COFe formulation.

The energetic COF parameter (COFe) is presented and compared to the average COF. The new parameter presented less data dispersion and is attractive to evaluate the COF behavior in reciprocating tests, as its formulation minimizes perturbations associated with the intrinsic accelerations of the movement (mainly in the initial and final part of the track where the acceleration has its greatest magnitude).

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2019-0324

The purpose of this article is to discuss the tribological behavior of polytetrafluoroethylene (PTFE) and property changes imposed by wear tests.

Long-duration dry wear tests were carried out in a sliding bearing on shaft tribometer. Differential Scanning Calorimetry (DSC) and Fourier Transformed Infrared Spectroscopy (FTIR) analyses were performed in the PTFE in its original condition and after the tests.

The wear products merged in multilayer films and were expelled out of the test sequence. Through DSC and FTIR analyses in the polymeric material, before and after tests, it was possible to verify an increase of the crystallinity degree of PTFE, as well as absence of crystalline fusion of the material. The wear products presented changes in the infrared spectra, which suggests the occurrence of some bonds of hydrogen and oxygen.

It was verified on correlation that fibril mechanism, which occurred during PTFE wear, and its crystallinity degree increase. Also, analysis of PTFE wear products showed CO and CH bonds, which were imposed by wear test.

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 paper aims to analyze what Samarco and Brazilian magazines speak and say about Mariana’s environmental crime. Discover their doxa in this subject. Interpret the speakings, sayings and doxas through the theories of the treadmills of production, crime and law.

It is a qualitative and documental research and a narrative analysis. Regarding the documents: 45 were from public authorities, 14 from Samarco Mineração S.A. and 73 from Brazilian magazines. Theoretically, the authors resorted to Bourdieusian sociology (speaking, saying and doxa) and the treadmills of production, crime and law theories.

Samarco: speaking – mission statements; saying – detailed information and economic and financial concerns; doxa – assistance discourse. Brazilian magazines: speaking – external agents; saying – agreements; doxa – attribution, aggravations, historical facts, impacts and protests.

The absence of discussions that addressed this fatality, with its respective consequences, from an agenda that exposed and denounced how it exacerbated race, class and gender inequalities.

Regarding Mariana’s environmental crime: Samarco Mineração S.A. speaks and says through the treadmill of production theory and supports its doxa through the treadmill of crime theory, and Brazilian magazines speak and say through the treadmill of law theory and support their doxa through the treadmill of crime theory.

To provoke reflections on the relationship between the mining companies and the communities where they settle to develop their productive activities.

Concerning environmental crime in perspective, submit it to a theoretical interpretation based on sociological references, approach it in a debate linked to environmental criminology, and describe it through narratives exposed by the guilty company and by Brazilian magazines with high circulation.

To address the absence of Lean in transportation logistics in the digital era, this study aims to investigate the application of Lean transportation (LT) tools to reduce waste and facilitate the digital transformation of dedicated road transportation in the offshore industry.

The study adopts action research with a multimethod approach, including a scoping review, focus groups (FG) and participant observation. The research is conducted within the offshore supply chain of a major oil and gas company.

Implementing LT’s continuous improvement tools, particularly value stream mapping (VSM), reduces offshore transportation waste and provides empirical evidence about the intersection of Lean and digital technologies. Applying techniques drawn from organisational learning theory (OLT), stakeholders involved in VSM mapping and FGs engage in problem-solving and develop action plans, driving digital transformation. Waste reduction in loading and unloading stages leads to control actions, automation and process improvements, significantly reducing downtime. This results in an annual monetary gain of US$1.3m. The study also identifies waste related to human effort and underutilised digital resources.

This study contributes to theory and practice by using action research and LT techniques in a real intervention case. From the lens of OLT, it highlights the potential of LT tools for digital transformation and demonstrates the convergence of waste reduction through Lean and Industry 4.0 technologies in the offshore supply chain. Practical outputs, including a benchmarking questionnaire and a plan-do-check-act cycle, are provided for other companies in the same industry segment.

Universities, as providers of knowledge and technology, have a key role in society based on knowledge. The purpose of this paper is to identify and describe the technological innovation centers (TICs) of the federal universities of Minas Gerais, Brazil, verifying if federal institutions of higher education in the state are meeting the attributions outlined in the Innovation Act.

In order to achieve the proposed objective, each one of the public and federal universities in the state of Minas Gerais, Brazil, was outlined as analysis units. The data sources used for this study are intrinsically secondary and were collected from the websites and TICs of each university.

As a result, it was found that all universities have TICs, and are inserted into the State Intellectual Property Network. Those aspects show that the universities have been searching for structure themselves by the new entrepreneurial mission of today’s educational institutions.

As noted in the literature, more research is needed to examine the efficiency and professionalism of TICs in the entrepreneurial activity of universities because the institutionalization of TICs is still recent and many TICs are currently in an improvement phase of their activities.

This paper seeks to analyze the relationship between China and the Northeast region of Brazil, aiming to identify how the renewable energy sector is being developed.

The authors analyzed secondary data from the official databases from China-Brazil chambers of commerce to establish the main points related to renewable energy in Brazil's Northeast.

It is possible to notice the main investments, highlighting the wind energy as a more prominent source recently. The authors also point the huge influence from China on Brazil's Northeast energy sector.

It is difficult to identify the amount of Chinese capital due to the large number of mergers and acquisitions that has been taking place in recent years.

Identification of regions that have been receiving investments and the main interests of Chinese investors in the renewable energy sector.

Demonstration of how the renewable energy sector has taken an important turn in Brazil due to Chinese investment.

To evaluate a regional consortium, analyzing its strategies for partnerships with China to help each other in global questions, as is the case of renewable energy.