María José Pujol, Francisco A. Pujol, Fidel Aznar, Mar Pujol and Ramón Rizo
In this paper the authors aim to show the advantages of using the decomposition method introduced by Adomian to solve Emden's equation, a classical non‐linear equation that…
Abstract
Purpose
In this paper the authors aim to show the advantages of using the decomposition method introduced by Adomian to solve Emden's equation, a classical non‐linear equation that appears in the study of the thermal behaviour of a spherical cloud and of the gravitational potential of a polytropic fluid at hydrostatic equilibrium.
Design/methodology/approach
In their work, the authors first review Emden's equation and its possible solutions using the Frobenius and power series methods; then, Adomian polynomials are introduced. Afterwards, Emden's equation is solved using Adomian's decomposition method and, finally, they conclude with a comparison of the solution given by Adomian's method with the solution obtained by the other methods, for certain cases where the exact solution is known.
Findings
Solving Emden's equation for n in the interval [0, 5] is very interesting for several scientific applications, such as astronomy. However, the exact solution is known only for n=0, n=1 and n=5. The experiments show that Adomian's method achieves an approximate solution which overlaps with the exact solution when n=0, and that coincides with the Taylor expansion of the exact solutions for n=1 and n=5. As a result, the authors obtained quite satisfactory results from their proposal.
Originality/value
The main classical methods for obtaining approximate solutions of Emden's equation have serious computational drawbacks. The authors make a new, efficient numerical implementation for solving this equation, constructing iteratively the Adomian polynomials, which leads to a solution of Emden's equation that extends the range of variation of parameter n compared to the solutions given by both the Frobenius and the power series methods.
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Keywords
Izabela Simon Rampasso, Osvaldo Luiz Gonçalves Quelhas, Gilberto Miller Devós Ganga, Milena Pavan Serafim, Victor Gomes Simão, Luiz Felipe M. Costa and Rosley Anholon
Considering the high impacts caused by manufacturers on sustainability, this research aims to analyse how Brazilian manufacturing companies deal with sustainability issues. To do…
Abstract
Purpose
Considering the high impacts caused by manufacturers on sustainability, this research aims to analyse how Brazilian manufacturing companies deal with sustainability issues. To do this, sustainability parameters are analysed to verify possible improvement opportunities.
Design/methodology/approach
This research uses Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and grey relational analysis (GRA) to analyse data from a survey with Brazilian professionals regarding aspects of sustainability in Brazilian manufacturers. The average score levels and the ranking of these aspects are evaluated.
Findings
Through the analysis performed, it was possible to verify that manufacturers in Brazil still have a long path to travel in the search for sustainability. Comparatively, it was observed that practices related to local communities received the lowest scores, on average. In contrast, on average, practices related to productivity and efficiency, occupational accidents and diseases, and compliance with environmental legislation received the highest scores.
Practical implications
The results presented in this paper show that there are several improvement opportunities to be sought by Brazilian manufacturing companies regarding sustainability aspects. Particular attention should be given to local community practices. Besides companies, policymakers can also use this analysis to guide their future actions, encouraging manufacturing companies to better support the local community. Researchers can use the instrument of analysis (TOPSIS and GRA) to analyse other realities and compare them with the findings presented.
Originality/value
The analysis of Brazilian manufacturing companies’ reality regarding sustainability practices and considering a model based on Global Reporting Initiative (GRI) and Brazilian Institute of Corporate Governance (IBGC) is novel in the literature. The use of TOPSIS and GRA, as well as comparing their findings, generated interesting insights for companies, policymakers and researchers. The analysis presented shows the need for more significant concern for local communities and can be used to support further debates and action plans to minimise this gap.
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Eva M. García-Granero, Laura Piedra-Muñoz, Emilio Galdeano-Gómez and Yolanda Sorroche-del-Rey
This study aims to propose a comprehensive framework for assessing circular economy (CE) performance in the agri-food sector. It identifies those indicators that should be used to…
Abstract
Purpose
This study aims to propose a comprehensive framework for assessing circular economy (CE) performance in the agri-food sector. It identifies those indicators that should be used to measure circularity regarding CE strategies, applies them at a microeconomic level and examines the impact of key business determinants (financial, internalization, knowledge, awareness and digitalization).
Design/methodology/approach
A literature review was conducted with a focus on CE strategies and related indicators. The framework obtained is applied on a Spanish agri-food sector survey to provide an empirical CE analysis at firm level. A partial least squares based-structural equation modelling method is applied.
Findings
The research suggests a set of circularity indicators to assess CE strategies at micro level. The findings reveal the heterogeneity of CE sub-indicators related to narrowing, slowing, closing and regenerating strategies. It also highlights the strong effects that the drivers tested have on CE, especially awareness and knowledge.
Practical implications
This study provides a framework that can guide public policies and business decisions in sectors with significant environmental impacts. It provides a conceptual framework that explains which CE indicators should be considered by governments and regulators when developing policies that seek to promote circular strategies.
Social implications
In the case of companies, the results show that acquiring more environmental awareness and knowledge is essential for promoting more sustainable work habits that enhance CE.
Originality/value
The paper offers a novel contribution to the CE literature by introducing a multidimensional indicator framework comprehensively applied to the agri-food sector, integrating miscellaneous pillars of circular strategies and business determinants.
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Marian Buil Fabregá, Núria Masferrer, Josep Patau and Albert-P. Miró Pérez
The purpose of this research is to analyse the relationship between entrepreneurial skills and innovation commitment and entrepreneurial skills and environmental commitment as…
Abstract
Purpose
The purpose of this research is to analyse the relationship between entrepreneurial skills and innovation commitment and entrepreneurial skills and environmental commitment as drivers of awareness on sustainable development of higher education students.
Design/methodology/approach
A sample of 1,318 business and management students out of the 3,535 students of Tecnocampus Pompeu Fabra University in Spain during the 2017-2018 academic year was selected to conduct a survey regarding their entrepreneurial skills and sustainability commitment, resulting in a total number of responses of 515. A structural equation model is proposed to contrast the hypothesis.
Findings
The statistical analysis showed the existence of a positive relation between the entrepreneurial skill of self-consciousness, innovation and environmental commitment to foster sustainability and sustainable development. It is one of the few studies related to the self-conciousness competence of the entrepreneurial skills which found, as a novelty, that the entrepreneurial skill of self-consciousness is the skill with the greater impact on innovation and environmental commitment.
Research limitations/implications
The limitations of the study are that it is based on a sample of students taking entrepreneurship courses at a specific Spanish University that is not representative of all entrepreneurs in all universities.
Practical implications
The research proposes including entrepreneurial skills programmes in higher education and research programmes as a way to assure commitment to innovation and environmental sustainability.
Originality/value
Promoting entrepreneurial skills among higher education students could act as drivers for sustainable development.