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The purpose of this paper is to present the implementation in a finite element (FE) code of a recently developed material model for the analysis of cracked reinforced…
The purpose of this paper is to present the implementation in a finite element (FE) code of a recently developed material model for the analysis of cracked reinforced concrete (RC) panels. The model aims for the efficient nonlinear analysis of large‐scale structural elements that can be considered as an assembly of membrane elements, such as bridge girders, shear walls, transfer beams or containment structures.
In the proposed constitutive model, the equilibrium equations of the cracked membrane element are established directly at the cracks while the compatibility conditions are expressed in terms of spatially averaged strains. This allows the well‐known mechanical phenomena governing the behaviour of cracked concrete elements – such as aggregate interlock (including crack dilatancy effects), tensile fracture and bond shear stress transfer – to be taken into account in a transparent manner using detailed phenomenological models. The spatially averaged stress and strain fields are obtained as a by‐product of the local behaviour at the cracks and of the bond stress transfer mechanisms, allowing the crack spacing and crack widths to be obtained directly from first principles. The model is implemented in an FE code following a total formulation.
The fact that the updated stresses at the cracks are calculated explicitly from the current spatially averaged total strains and from the updated values of the state variables that are used to monitor damage evolution contributes to the robustness and efficiency of the implementation. Some application examples are presented illustrating the model capabilities and good estimates of the failure modes, failure loads, deformation capacity, cracking patterns and crack widths were achieved.
While being computationally efficient, the model describes the complex stress and strain fields developing in the membrane element, and retrieves useful information for the structural engineer, such as concrete and reinforcement failures as well as the crack spacing and crack widths.
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…
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.
The purpose of this study is to evaluate the effect of Hibiscus sabdariffa ethanolic extract (HsE) on protein levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6…
The purpose of this study is to evaluate the effect of Hibiscus sabdariffa ethanolic extract (HsE) on protein levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, adiponectin and leptin in adipose tissue, as well as on the lipid and glycemic profiles of high-fat/sugar diet-induced obese (DIO) rats.
Obesity was induced in male Wistar rats through a high-fat/sugar diet provided for eight weeks. Control rats received a standard diet. The high-fat/sugar DIO animals were subsequently randomized into DIO (n = 8) and DIO treated with HsE (DIO + HsE, n = 8, 150 mg/kg/day) by gavage, for additional eight weeks. Oral glucose tolerance test was performed, and blood samples and epididymal adipose tissue were collected for biochemical analysis and adipokine protein level evaluation, respectively.
Compared to the DIO rats, HsE treatment decreased weight gain (50.6%) and mesenteric fat (42%), indicated as diminished visceral fat (22.5%). HsE did not affect the lipid profile and TNF-α levels in adipose tissue; however, it effectively prevented a 13% increase in fasting glucose levels and improved glucose tolerance. Compared with the C group, HsE normalized the adiponectin levels and leptin/adiponectin ratio and decreased the IL-6 (55%) and leptin (18.6%) levels in adipose tissue of obese rats.
HsE improves adipokine protein levels in high-fat/sugar DIO rats, demonstrating the clinical efficacy of HsE in the treatment of obesity and obesity-related diseases.