Bauru - FEB - Faculdade de Engenharia

URI Permanente para esta coleçãohttps://hdl.handle.net/11449/253742

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A macro-level circular economy index: theoretical proposal and application in European Union countries
(2023-01-01) de Oliveira Frascareli, Fernanda Cortegoso ; Furlan, Marcelo ; Mariano, Enzo Barberio ; Jugend, Daniel ; Centro Universitário Sagrado Coração (UNISAGRADO) ; Universidade Estadual Paulista (UNESP) ; Aeronautics Institute of Technology (ITA)
The objective of this study was to propose a circular economy index applicable at a macro-level (i.e., countries). To achieve this objective, the snowball approach to literature reviews was adopted to find possible macro-level circular economy dimensions and indicators. Then, 10 indicators relating to these dimensions were identified in international databases. Finally, it was applied the benefit of the doubt (BoD) approach for data envelopment analysis (DEA), social network analysis (SNA) and principal component analysis (PCA) to build a macro-level circular economy index (MaCEI) for 18 European Union countries. The main results were as follows: (i) the identification of 52 potential indicators related to the circular economy at a macro-level were divided into 10 dimensions, (ii) a ranking of the performance of the 18 European countries in terms of their circular economy, (iii) the identification and analysis of the best circular economy practices at a national level (benchmarks), and (iv) the establishment of targets for each country. By offering a circular economy indicator and a well-established country ranking, this study contributes to the effective development of environmental standards that support public policies and national programs on the circular economy, in addition to guiding policy managers in driving the adoption of the circular economy at a macro-level.
Modeling quality, satisfaction and perceived crowding in public healthcare: A study with low-income Brazilian patients
(2023-01-01) Marcato, João Guilherme ; Da Silva, Hermes Moretti Ribeiro ; Luiz, Octaviano Rojas ; Mariano, Enzo Barberio ; Paro, Carlos Eduardo ; Universidade Estadual Paulista (UNESP) ; Universidade de São Paulo (USP)
This paper is one of the first to propose a research model to assess the quality and satisfaction perceived by low-income Brazilian patients using public healthcare services, under the moderating effect of perceived crowding. The model was evaluated from data obtained from 417 patients, and its proposed relationships and statistics were tested through Structural Equation Modeling using a Partial Least Squares approach (PLS-SEM). To explore the moderating effect of perceived crowding, the sample was divided into two groups and tested by employing multi-group analysis (MGA). The results show that Reliability, Safety, Tangibles, Empathy and Responsiveness have a positive effect on Perceived Healthcare Quality (PHQ), which, in turn, has a marked effect on patient satisfaction (PS), ergo, PHQ acts as antecedent of PS. However, perceived crowding has no moderating effect on any relationship in the model.
Sem título
(2023-04-01) Silveira, Marcos Paulo Motta ; Ramos, Nathália de Carvalho ; Lopes, Guilherme da Rocha Scalzer ; Tribst, João Paulo Mendes ; Bottino, Marco Antonio ; Universidade Estadual Paulista (UNESP) ; University of Taubaté (UNITAU) ; The University of Amsterdam and Vrije Universiteit
Error in Figure In the original publication [1], there was a mistake in Figure 2 as published. “Aging” labels referring to “Yes” and “No” on the figure were switched. The corrected Figure 2 appears below. The authors state that the scientific conclusions are unaffected. This correction was approved by the Academic Editor. The original publication has also been updated.
Estimation of Toughness as a Function of Compression Strength Parallel to the Grain of Tropical Woods
(2023-01-01) Ruthes, Heloiza Candeia ; Dos Santos, Herisson Ferreira ; De Araujo, Victor Almeida ; Azambuja, Maximiliano Dos Anjos ; Aquino, Vinicius Borges de Moura ; Chahud, Eduardo ; Branco, Luiz Antônio Melgaço Nunes ; Favarim, Higor Rogério ; de Campos, Cristiane Inácio ; Lahr, Francisco Antonio Rocco ; Christoforo, André Luis ; Universidade Federal de São Carlos (UFSCar) ; Universidade Estadual de Maringá (UEM) ; Universidade Estadual Paulista (UNESP) ; Federal University of Southern and Southeastern Pará ; Universidade Federal de Minas Gerais (UFMG) ; Universidade de São Paulo (USP)
Tropical species are widely used in construction, and their physical and mechanical properties have been important characteristics with direct impact on the design of structures, especially the strength and stiffness of wood applied in them. Tests to obtain both parameters are conducted under ABNT NBR 7190 (1997) guidelines in Brazil, being rarely found in some research centers because of the higher costs of testing equipment. For instance, the toughness test depends on equipment with a pendulum, whose device requires accuracy and maintenance for reliable analyses. This paper aims to estimate toughness through another property more easily found, given by the compression strength parallel to the grain. For this, 20 tropical wood species of the South American region were used to obtain initial values of these properties. The characteristic values of the compression strength parallel to the grain as well as linear and quadratic regression models were obtained. Statistical analysis was performed and confirmed that a linear model gave better predictions than a quadratic model.
Crossing actors' boundaries towards circular ecosystems in the organic food sector: Facing the challenges in an emerging economy context
(2023-06-25) Ferrari, Aline Gabriela ; Jugend, Daniel ; Armellini, Fabiano ; Barbalho, Sanderson César Macedo ; Carvalho, Marly Monteiro de ; Universidade Estadual Paulista (UNESP) ; Polytechnique Montréal ; University of Brasília (UnB) ; Universidade de São Paulo (USP)
The demand for organic food is increasing worldwide. Studies have shown that the circular economy can bring environmental and operational improvements to the food sector. However, little is known about how the circular economy can contribute to organic food. From the perspective of circular ecosystems, this exploratory study aims to contribute to the emerging debate by identifying and analyzing the relationships between different actors in an ecosystem of organic food producers. Addressing this objective, a case study was carried out involving seven actors from an organic food ecosystem in Brazil. The main results revealed: (i) that the production of organic food is aligned with the principles of the circular economy; (ii) that the common goal of using and disseminating organic agriculture facilitates alignment between the actors in an ecosystem; (iii) the important role of the orchestrator, mainly to coordinate the different actors and technically support small producers/farmers; and (iv) that collaboration in an ecosystem favors the reuse of “waste” between farmers. In addition, our results identified that ecosystems face bureaucratic barriers to obtaining resources, and there is little collaboration between the actors and universities.
Identifying Collapsible Soils from Seismic Cone (SCPT): A Qualitative Approach
(2023-03-01) Rocha, Breno Padovezi ; Silveira, Isabela Augusto ; Rodrigues, Roger Augusto ; Lodi, Paulo Cesar ; Giacheti, Heraldo Luiz ; Science and Technology of São Paulo (IFSP) ; Universidade Estadual Paulista (UNESP)
Collapsible soils are unsaturated low-density soils that undergo abrupt settlement when flooded without any increase in the in-situ stress level. The first stage of the site characterization is identifying collapsible soils, since these are problematic soils. Seismic cone testing (SCPT) has been increasingly used for site characterization, because it allows combining stratigraphic logging with the maximum shear modulus (G0) determination. In this paper, laboratory and in-situ tests carried out at 21 sites with collapsible and non-collapsible soils are interpreted to differentiate between such soils, based on the seismic cone test (SCPT). Collapsible soils have G0/qc values greater than 23 and qc1 values less than 70, while non-collapsible soils have G0/qc values less than 23 and qc1 values greater than 70. The investigated collapsible soils have microstructure (bonding/cementation), but the classical approach cannot be sufficient to identify collapsible soils alone. An approach was used to identify collapsible soils based on maximum shear modulus (G0), normalized cone resistance (qc1), and cone resistance (qc). The chart G0/qc versus qc1 and boundaries is an alternative for distinguishing between collapsible and non-collapsible soils in the early stage of site investigation. This qualitative approach should be used in the preliminary investigation phase to select potentially collapsible soils and helps guide the sampling of potentially collapsible soils for laboratory testing. Further SCPT data from different soil types, particularly the collapsible ones, are valuable to adjust or confirm the boundary equations suggested.
Suction Influence on Load–Settlement Curves Predicted by DMT in a Collapsible Sandy Soil
(2023-02-01) Saab, Alfredo Lopes ; Rodrigues, André Luís de Carvalho ; Rocha, Breno Padovezi ; Rodrigues, Roger Augusto ; Giacheti, Heraldo Luiz ; Universidade Estadual Paulista (UNESP) ; Federal Institute of São Paulo
The plate load test (PLT) is the most reliable in situ testing for studying the load–settlement behaviour of footings on unsaturated collapsible soils. In these soils, the suction profile is not constant along the depth, and the scale effect between the prototype and footing leads to different suction averages and, consequently, different data. One method to eliminate the effect of soil suction on the test data is to fully saturate the soil prior to the test, which is also recommended at the design process for footing on collapsible soils. However, the inundation process on PLTs is expensive and time-consuming, which makes this procedure difficult to incorporate into engineering practice. This study presents a device that can be attached to flat dilatometer (DMT) to allow local inundation of the soil as part of the in situ test campaign and obtain the DMT-constrained modulus (MDMT) for both natural and inundated conditions. The MDMT presented an average reduction of 56% from natural to inundated condition. This parameter can be used in a model to predict load–settlement curves by DMT data considering the suction influence on this behaviour. The curves obtained from the prediction model were compared to curves determined by PLT conducted under the same in situ conditions. Good agreement was found between the curves predicted by DMT and those measured by PLT for both conditions. The proposed procedure, which uses a device attached to the DMT blade, provides an investigation method to obtain the load–settlement curve under different suction conditions, which can help in the selection and performance prediction of shallow foundations, taking into account suction and collapse phenomenon-related problems.
Sem título
(2023-03-01) Juarez, Mariana Barbosa ; Mondelli, Giulliana ; Giacheti, Heraldo Luiz ; Universidade Estadual Paulista (UNESP)
Equations 10 and 11 should be interchanged. The Original article has been corrected.
Editorial: Financial and trade globalization, greener technologies and energy transition
(2023-01-10) Mariano, Enzo Barberio ; Ferraz, Diogo ; Radulescu, Magdalena ; Shahzadi, Irum ; Universidade Estadual Paulista (UNESP) ; Federal University of Ouro Preto (UFOP) ; University of Hohenheim ; Faculty of Economic Studies and Law ; University Lucian Blaga of Sibiu
Aeroelastic energy harvesting in flutter condition increases with combined nonlinear stiffness and nonlinear piezoelectrical coupling
(2023-02-01) Amaral, Ana Carolina Godoy ; De Marqui, Carlos ; Silveira, Marcos ; Universidade Estadual Paulista (UNESP) ; Universidade de São Paulo (USP)
The dynamic behaviour of an aeroelastic energy harvester using a piezoelectric transducer is studied. An important question in applications of energy harvesting is how to increase the efficiency of energy conversion. The study of both mechanical and electrical nonlinear terms has proven important in this context, both to provide more accurate models and to aid the design of purposely nonlinear systems. Here, the influence of plunge cubic nonlinear stiffness and nonlinear piezoelectrical coupling is investigated with respect to flutter speed, mechanical and electrical power. Different combinations of nonlinear terms are explored and compared to the linear case. The influence of the nonlinear coefficients and of the parameters of the electrical domain on the behaviour of the system are analysed analytically via the method of multiple scales (MMS) and numerically via a fourth-order Runge–Kutta method (RK). A Poincaré section method is proposed to determine the period of oscillations of the nonlinear systems at flutter. The results indicate that nonlinear stiffness has more influence in increasing flutter speed, and nonlinear piezoelectrical coupling has more influence in increasing electrical power. More energy is transferred from the pitch motion than from the plunge motion. Flutter speed, mechanical and electrical power increase with nonlinear stiffness, indicating that neglecting this characteristic can lead to underestimation of flutter speed and harvested energy.
An overview of in situ testing and geophysical methods to investigate municipal solid waste landfills
(2023-02-01) Juarez, Mariana Barbosa ; Mondelli, Giulliana ; Giacheti, Heraldo Luiz ; Universidade Estadual Paulista (UNESP)
Municipal solid waste (MSW) management is challenging as a whole. Global waste generation is expected to continue to increase in the coming years, and landfills are currently the primary destination. Therefore, the stability of these structures must be carefully evaluated to prevent failures and associated health and pollution risks, which implies the determination of waste properties using more reliable approaches. This paper presents a scoping review of field data from MSW landfills and outlines suggestions for future work. Studies published in the past twenty years were selected following a systematic search process in databases. Aspects discussed include (1) strength parameters and soil behavior type from in situ testing, (2) elastic moduli from seismic wave propagation, and (3) moisture content from geoelectrical measurements. Although the values of geotechnical parameters have varied due to waste heterogeneity and applied methods, the trends observed with depth and age could be compared. Research opportunities involve the spatial analysis of mechanical properties at a given site, seismic response of landfills with high organic content and saturation degree, interpretation of long-term resistivity monitoring, and combination of electrical properties to assess the degradation stages within the waste mass.
Models for Predicting Velopharyngeal Competence Based on Speech and Resonance Errors and Velopharyngeal Area Estimation
(2023-01-01) Scarmagnani, Rafaeli Higa ; Lohmander, Anette ; Salgado, Manoel Henrique ; Fukushiro, Ana Paula ; Trindade, Inge Elly Kiemle ; Yamashita, Renata Paciello ; Universidade de São Paulo (USP) ; Karolinska University Hospital ; Universidade Estadual Paulista (UNESP)
Objective: To develop tools for predicting velopharyngeal competence (VPC) based on auditory-perceptual assessment and its correlation with objective measures of velopharyngeal orifice area. Design: Methodological study. Participants and Methods: Sixty-two patients with repaired cleft palate, aged 6 to 45 years, underwent aerodynamic evaluation by means of the pressure-flow technique and audiovisual recording of speech samples. Three experienced speech-language pathologists analysed the speech samples by rating the following resonance, visual, and speech variables: hypernasality, audible nasal air emission, nasal turbulence, weak pressure consonants, facial grimacing, active nonoral errors, and overall velopharyngeal competence. The correlation between the perceptual speech variables and velopharyngeal orifice area estimates was analysed with Spearman's correlation coefficient. Two statistical models (discriminant and exploratory) were used to predict VPC based on the orifice area estimates. Sensitivity and specificity analyses were performed to verify the clinical applicability of the models. Results: There was a strong correlation between VPC (based on the orifice area estimates) and each speech variable. Both models showed 88.7% accuracy in predicting VPC. The sensitivity and specificity for the discriminant model were 92.3% and 97.2%, respectively, and 96.2% and 94.4% for the exploratory model. Conclusion: Two predictor models based on ratings of resonance, visual, and speech variables and a simple calculation of a composite variable, SOMA (Eng. “sum”), were developed and found to be efficient in predicting VPC defined by orifice estimates categories based on aerodynamic measurements. Both tools may contribute to the diagnosis of velopharyngeal dysfunction in clinical practice.
Sensors Applied to Bearing Fault Detection in Three-Phase Induction Motors†
(2021-01-01) Lucas, Guilherme Beraldi ; de Castro, Bruno Albuquerque ; Serni, Paulo José Amaral ; Riehl, Rudolf Ribeiro ; Andreoli, André Luiz ; Universidade Estadual Paulista (UNESP)
Three-Phase Induction Motors (TIMs) are widely applied in industries. Therefore, there is a need to reduce operational and maintenance costs since their stoppages can impair production lines and lead to financial losses. Among all the TIM components, bearings are crucial in the machine operation once they couple rotor to the motor frame. Furthermore, they are constantly subjected to friction and mechanical wearing. Consequently, they represent around 41% of the motor fault, according to IEEE. In this context, several studies have sought to develop monitoring systems based on different types of sensors. Therefore, considering the high demand, this article aims to present the state of the art of the past five years concerning the sensing techniques based on current, vibration, and infra-red analysis, which are characterized as promising tools to perform bearing fault detection. The current and vibration analysis are powerful tools to assess damages in the inner race, outer race, cages, and rolling elements of the bearings. These sensing techniques use current sensors like hall effect-based, Rogowski coils, and current transformers, or vibration sensors such as accelerometers. The effectiveness of these techniques is due to the previously developed models, which relate the current and vibration frequencies to the origin of the fault. Therefore, this article also presents the bearing fault mathematical modeling for these techniques. The infra-red technique is based on heat emission, and several image processing techniques were developed to optimize bearing fault detection, which is presented in this review. Finally, this work is a contribution to pushing the frontiers of the bearing fault diagnosis area.
Application of MQL with cooled air and wheel cleaning jet for greener grinding process
(2023-03-01) Daniel, Douglas Maiochi ; Moraes, Douglas Lyra de ; Garcia, Mateus Vinicius ; Lopes, José Claudio ; Rodriguez, Rafael Lemes ; Ribeiro, Fernando Sabino Fonteque ; Sanchez, Luiz Eduardo de Angelo ; Bianchi, Eduardo Carlos ; Universidade Estadual Paulista (UNESP)
Metalworking fluids (MWF) or flooded process based on mineral oil are widely used in industry, which is unsustainable and causes damage to employees and the environment, in addition to making up a significant part of the machining cost. On the other hand, abrasive machining methods, such as grinding, are increasingly used for their excellent finish and geometric precision but use large quantities of metalworking fluids. This work evaluates the alternative methods Minimum Lubricant Quantity (MQL), MQL + Cooled Air (CA), MQL + Wheel Cleaning Jet (WCJ), and MQL + Cooled WCJ in the grinding of AISI 4340 steel compared to the application of flooded process. Surface roughness, roundness error, G ratio, grinding power, specific energy, microhardness, cost per piece, and carbon emission tests were applied. From the results, MQL reduced the cost of grinding around 90% and carbon emission by 67% compared to grinding with flooded process. The MQL + CWCJ produced the best results of surface quality compared to other alternative techniques, significantly approaching the results of the flooded process.
Dynamic analysis of an electromagnetic vibration absorber in a non-ideal system
(2023-01-01) Petrocino, Eduardo Abuhamad ; Balthazar, José Manoel ; Tusset, Ângelo Marcelo ; Gonçalves, Paulo José Paupitz ; Silveira, Marcos ; Universidade Estadual Paulista (UNESP) ; Federal University of Technology – Paraná
A dynamic system usually used in engineering are rotating machines fixed to flexible structures, and an excessive vibration known as the Sommerfeld effect may occur in the passage of the resonance. This research aims to analyze an electromagnetic absorber in a non-ideal system, a simple model for the analysis of the first mode of a beam. In this context, an investigation of the dynamic behavior of a cantilever beam with a dc motor coupled to its free end, having an unbalanced mass on its axis, providing a non-ideal energy source. A permanent magnet is attached to this same free end, which is immersed inside a coil attached to the base. In this step, an analysis of the dynamic behavior is carried out by means of an analytical solution approximated by the averaging method and by numerical computational simulations. The absorber reduces the phenomena caused by the Sommerfeld effect and reduces the region of instability.
Digital transformation in school management: the legacy that strategic actions in the 2020s leave for future pandemics
(2022-01-01) de Almeida Barbosa Franco, Jacqueline ; Espuny, Maximilian ; da Motta Reis, José Salvador ; Diogo, Gabriel Miranda Monteiro ; Paes, Luis Alberto Bertolucci ; Costa, Ana Carolina Ferreira ; Nunhes, Thaís Vieira ; Barbosa, Luís César Ferreira Motta ; Rodrigues, Andréia Marize ; Battistelle, Rosane Aparecida Gomes ; de Oliveira, Otávio José ; Universidade Estadual Paulista (UNESP) ; Universidade do Estado do Rio de Janeiro (UERJ) ; Centro Federal de Educação Tecnológica Celso Suckow da Fonseca - CEFET-RJ
With the outbreak of social withdrawal due to the pandemic, many countries have undergone drastic transformations in various spheres. In education, face-to-face classes were transformed into distance learning. However, this sudden change caused several problems for students and teachers. Given these events, the purpose of this article was to propose exceptional actions to improve the transition from face-to-face classes to virtual classes. For this, the elements that positively and negatively impacted education in the Covid-19 pandemic were identified in the literature. These elements were then clustered into four strategies, these being: redesign of pedagogical practices, psychological and social support, technological infrastructure in virtual teaching, and school management to cope with the pandemic scenario. The multiple case study method was used, investigating five technical schools located in the state of São Paulo (Brazil). With this, it was possible to propose 10 exceptional actions aimed at the transition from face-to-face classes to virtual classes. The main novelty of this article was the proposition of actions to motivate the school community against the impacts of the pandemic, building memory in its agents, making them more prepared for unexpected events.
Geomechanical parameters in the active zone of an unsaturated tropical soil site via laboratory tests
(2022-10-01) Fernandes, Jeferson Brito ; Saab, Alfredo Lopes ; Rocha, Breno Padovezi ; Rodrigues, Roger Augusto ; Lodi, Paulo César ; Giacheti, Heraldo Luiz ; Universidade Estadual Paulista (UNESP) ; Instituto Federal de São Paulo
The seasonal variability of geotechnical parameters in the unsaturated zone is typically neglected in the design of geotechnical works. In most of the geotechnical projects the parameters are determined only for the saturated condition. Although it is known that this condition is the most critical to soil strength and deformability, this conservative approach may neglect a possible important contribution of the unsaturated condition, resulting in an increase in the cost of the geotechnical solution. This paper presents and discusses the site characterization of the active zone of an unsaturated sandy soil profile under different suction conditions. Laboratory tests with controlled suction (retention curves, triaxial compression with bender elements and oedometer tests) were carried out on undisturbed samples collected from 1.0 to 5.0 m depth. The results show that strength and deformability parameters are strongly affected by soil suction and are less influenced by confinement stress up to 5.0 m depth. All the investigated subsoil profile shows a collapsible behavior, more pronounced closer to the ground surface and under the effect of higher suction values. The findings highlight the importance of incorporating the suction influence in the site investigation, parameter determination, and geotechnical design for more economical, reliable, and environmentally sustainable solutions.
Assessment of Partial Discharges Evolution in Bushing by Infrared Analysis †
(2021-01-01) de Castro, Bruno Albuquerque ; Lucas, Guilherme Beraldi ; Fernandes, Gabriel Scota ; Fraga, José Renato Castro Pompéia ; Riehl, Rudolf Ribeiro ; Andreoli, André Luiz ; Universidade Estadual Paulista (UNESP)
The quality of power systems is related to their capability to predict failures, avoid stoppages, and increase the lifetime of their components. Therefore, science has been developing monitoring systems to identify failures in induction motors, transformers, and transmission lines. In this context, one of the most crucial components of the electrical systems is the insulation devices such as bushings, which are constantly subjected to dust, thermal stresses, moisture, etc. These conditions promote insulation deterioration, leading to the occurrence of partial discharges. Partial discharges are localized dielectric breakdown that emits ultra-violet radiation, heat, electromagnet, and acoustics waves. The most traditional techniques to identify these flaws on bushings are based on the current, ultra high frequency, and acoustic emission analysis. However, thermal analysis stands out as a noise-resistant technique to monitor several components in the power systems. Although the thermal method is applied to detect different types of faults, such as bad contacts, overloads, etc, this technique has not been previously applied to perform partial discharge detection and evaluate its evolution on bushings. Based on this issue, this article proposes two new indexes to characterize the discharge evolution based on the infrared thermal analysis: the area ratio coefficient and the Red, Green, and Blue (RGB) ratio coefficient. Seven discharge levels were induced in a contaminated bushing, and an infrared thermal camera captured 20 images per condition, totalizing 140 images. New coefficients were used to perform the identification of discharge evolution. Results indicated that values of the new indexes increase with the partial discharge activity. Thus, the new imaging processing approach can be a promising contribution to literature, improving the reliability and maintenance planning for power transmission systems.
Strain Energy Approach for Nonlinear Stiffness Coeffcients in the Design of Periodic Structures
(2023-01-01) Cruz, Rodrigo dos Santos ; Silveira, Marcos ; Universidade Estadual Paulista (UNESP)
In this work, we explore the dynamic behaviour of a discrete model of a periodic structure under harmonic input with nonlinear stiffness. The periodic structure has a unit cell with three degrees of freedom. We devise an approach that replaces the linear stiffness characteristic of the structure with a nonlinear one in which the nonlinear stiffness coefficients provide the same strain energy. The effect of this approach on the frequency response is analysed using numerical simulation, focusing on band gaps. The approach to determining nonlinear stiffness coefficients is based on the concept of equivalent elastic strain energy. This is different from the common approach found in the literature of adding a cubic term to the linear one, resulting in an increase in the elastic deformation energy of the system. Once the strain energy of the linear system is determined, a family of possible nonlinear stiffness coefficients is found, parameterised by the ratio between the linear and cubic coefficients. This approach can be used with hardening or softening stiffness characteristics. With the nonlinear stiffness coefficients defined, the dynamic response of the metastructure shows the usual shift to high and low frequencies. In addition, some frequency ranges are shown where vibration levels can be greatly reduced when the ratio of nonlinear stiffness coefficients is increased, compared to the case where there are only linear springs. Also, it is shown that the addition of the nonlinear component in the structure can increase or decrease the distance between the resonant frequencies.
Prospects for a circular bioeconomy in urban ecosystems: Proposal for a theoretical framework
(2022-12-20) Paes, Luis Alberto Bertolucci ; Stolte Bezerra, Barbara ; Jugend, Daniel ; Liar Agudo, Fabiana ; Universidade Estadual Paulista (UNESP) ; Science and Technology of Sao Paulo (IFSP)
The interconnectedness of value chains, the different motivations of actors, and the complexity of urban ecosystems (UE) have given rise to calls for more comprehensive approaches to diagnosis urban sustainability. In this regard, the circular bioeconomy (CBE) is attractive for, in theory, it ensures regenerative capacity and offers the possibility of improving the resilience of ecosystem services. However, there is a risk that the delineation of the narrative will be limited to issues narrowly defined by key actors, without considering value creation beyond financial. This paper explores how the alignment of CBE principles can support the services provided by UE, considering their socio-ecological needs. To this end, we propose an adaptive theoretical framework supported by a qualitative and comparative analysis of the current scientific literature. The main contributions of the paper are: (i) propose an original structure using the nature-based solutions (NbS) concept as background and (ii) provide a new typology built from the biophysical boundaries, drivers, barriers, strategies, and indicators identified. The framework presents itself as an instrument capable of guiding further research in the thematic area, facilitating the identification of trade-offs, benefits, and co-benefits, and represents a step forward in the search toward generalisation, reducing uncertainties and utopian notions that mould the CBE.

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