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The paper deals with the rheological‐dynamical analogy in which the three‐dimensional stress‐strain relations are defined under cyclic variation of stress for Hencky’s total strain theory. In many practical visco‐elasto‐plastic problems, like as multiaxial fatigue under loading at constant stress amplitude and constant stress ratio, the load‐carrying members are subjected to proportional loading. The classical Hencky’s theory has the advantage of mathematical convenience but its disadvantage is that the deformations predicted for the volume element are independent of the loading path. The existing formulations of the constitutive models for metals are mainly based on the Prandtl‐Reuss incremental theory of elasto‐plasticity, slip theory of plasticity or continuum damage mechanics. They have been shown capable of reproducing satisfactorily most experimental results available for metallic specimens. However, from the theoretical viewpoint little has been said about how these formulations relate to realistic predicting many different inelastic and time dependent problems of two‐ or threedimensional solids, such as fatigue, discontinuous plastic deformation etc. In this paper, fundamentally new aspect of isochronous constitutive relations for Hencky’s theory, which are dependent of the each loading path, is achieved by systematically introducing RDA concept into the continuum framework. Specific inelastic and fatigue formulation of triaxial state of stress is developed and discussed within the new theoretical tool and related to von Mises plasticity..

This paper is concerned with a new proposal regarding the analysis of visco‐elastoplasticity and fatigue and is based on rheological‐dynamical theory. Due to the analogy between rheological model and dynamical model with viscous damping, it becomes obvious that inelastic response of members is essentially a dynamical problem. An analytical rheological‐dynamical viscoelasto‐ plastic solution of one‐dimensional longitudinal continuous vibration under loading and solution for the stress relaxation as unloading have been developed and used to obtain the fatigue limit of thin long bars. Rheologic behavior of the bar can be characterized by one parameter, like in a single‐degree‐of‐freedom spring mass system. In all inelastic strains time rate effects are always present to some degree. Whether or not their exclusion has a significant influence on the prediction of the material fatigue behavior depends upon several factors like: maximum absolute stress in the cycle, coefficient of asymmetry of cycle, creep coefficient, slope of the strain hardening portion of the stress‐strain curve, relative frequency and uniaxial yield stress. This paper provides description of dynamic magnification factor, relaxation of stress, stress concentration and the fatigue limit of thin long symmetrical bars.

The purpose of this paper is to contribute to the solution of the fatigue damage problem of reinforced concrete frames in bending.

The problem of fatigue damage is formulated based on the rheological–dynamical analogy, including a scalar damage variable to address the reduction of stiffness in strain softening. The modal analysis is used by the finite element method for the determination of modal parameters and resonance stability of the selected frame cross-section. The objectivity of the presented method is verified by numerical examples, predicting the ductility in bending of the frame whose basic mechanical properties were obtained by non-destructive testing systems.

The modal analysis in the frame of the finite element method is suitable for the determination of modal parameters and resonance stability of the selected frame cross-section. It is recommended that the modulus of elasticity be determined by non-destructive methods, e.g. from the acoustic response.

The paper presents a novel method of solving the ductility in bending taking into account both the creep coefficient and the aging coefficient. The rheological-dynamical analogy (RDA) method uses the resonant method to find material properties. The characterization of the structural damping via the damping ratio is original and effective.

The problems of inelastic instability (buckling) and dynamic instability (resonance) have been the subject of extensive investigation and have received wide attention from the structural mechanics community. This paper aims to tackle these problems in thin-walled structures, taking into account geometrical and/or material non-linearity.

The inelastic buckling mode interactions and resonance instabilities of prismatic thin-walled columns are analysed by implementing the semi-analytical finite strip method (FSM). A scalar damage parameter is implemented in conjunction with a material modelling named rheological-dynamical analogy to address stiffness reduction induced by the fatigue damage.

Inelastic buckling stresses lag behind the elastic buckling stresses across all modes, which is a consequence of the viscoelastic behaviour of materials. Because of the lag, the same column length does not always correspond to the same mode at the elastic and inelastic critical stress.

This paper presents the influence of mode interactions on the effective stresses and resonance instabilities in thin-walled columns due to the fatigue damage. These mode interactions have a great influence on damage variables because of the fatigue and effective stresses around mode transitions. In its usual semi-analytical form, the FSM cannot be used to solve the mode interaction problem explained in this paper, because this technique ignores the important influence of interaction of the buckling modes when applied only for undamaged state of structure

The purpose of this paper is to describe various aspects of the visco-elastoplastic (VEP) behavior of porous-hardened concrete samples in relation to standard tests.

The problem is formulated on the basis of the rheological-dynamic analogy (RDA). In this study, changes in creep coefficient, Poisson's ratio, damage variables, modulus of elasticity, strength and angle of internal friction as a function of porosity are defined by P and S wave velocities. The RDA model provides a description of the degradation process of material properties from their peak state to their ultimate values using void volume fraction (VVF).

Compared to numerous versions of acoustic emission tracking developed to analyze the behavior of total wave propagation in inhomogeneous media with density variations, the proposed model is comprehensive in interpretation and consistent with physical understanding. The comparison of the damage variables with the theoretical variables under the assumption of spherical voids in the spherical representative volume element (RVE) shows a satisfactory agreement of the results for all analyzed samples if the maximum porosities are used for comparison.

The paper presents a new mathematical-physical method for examining the effect of porosity on the characteristics of hardened concrete. Porosity is essentially related to density variations. Therefore, it was logical to define the limit values of porosity using the strain energy density.

The purpose of this paper is to contribute to the solution of the buckling and resonance stability problems in inelastic beams and wooden plane trusses, taking into account geometric and material defects.

Two sources of non-linearity are analyzed, namely the geometrical non-linearity due to geometrical imperfections and material non-linearity due to material defects. The load-bearing capacity is obtained by the rheological-dynamical analogy (RDA). The RDA inelastic theory is used in conjunction with the damage mechanics to analyze the softening behavior with the scalar damage variable for stiffness reduction. Based on the assumed damages in the wooden truss, the corresponding external masses are calculated in order to obtain the corresponding fundamental frequencies, which are compared with the measured ones.

RDA theory uses rheology and dynamics to determine the structures' response, those results in the post-buckling branch can then be compared by fracture mechanics. The RDA method uses the measured P and S wave velocities, as well as fundamental frequencies to find material properties at the limit point. The verification examples confirmed that the RDA theory is more suitable than other non-linear theories, as those proved to be overly complex in terms of their application to the real structures with geometrical and material defects.

The paper presents a novel method of solving the buckling and resonance stability problems in inelastic beams and wooden plane trusses with initial defects. The method is efficient as it provides explanations highlighting that an inelastic beam made of ductile material can break in any stage from brittle to extremely ductile, depending on the value of initial imperfections. The characterization of the internal friction and structural damping via the damping ratio is original and effective.

The purpose of this review is to summarize new research indicating that high-dose supplements of the antioxidant vitamin C can interfere with the benefits of physical exercise for athletic performance and the risk for chronic disease.

This article reviews current original literature on the regulation of human metabolism by oxidants and antioxidants and evaluates the role of exercise and high-dose vitamin C in this context. The presentation in this article aims to be informative and accessible to both experts and non-experts.

The evidence reviewed here indicates that single, high-dose supplements of the antioxidant vitamin C abolish the beneficial effects of athletic training on muscle recovery and strength as well as abolishing the benefits of exercise in lowering the risk for chronic disease. In contrast, an antioxidant-rich diet based on regular foods apparently enhances the benefits of exercise. These findings are consistent with an updated understanding of the critical importance of both oxidants and antioxidants in the regulation of human metabolism. While more research is needed to address the role of timing and level of antioxidant consumption, it is clear that a balance between oxidants and antioxidants is essential.

The information presented in this review is important for both athletes and the public at large in their efforts to choose nutrition and exercise regimes appropriate to maximize the outcome of their training efforts and lower their risk for chronic disease.

This article provides accessible and comprehensive information to researchers, nutritionists, and consumers interested in optimal nutrition during athletic training and for obtaining the full benefit of physical exercise in lowering the risk for chronic disease.

Over the last few years, sportsmen and women have begun to realise the potential role of nutrition in relation to improving performance. As sporting standards get higher and higher, competitors often experiment with new diets, protein supplements and megavitamin doses in an attempt to achieve the ‘competitive edge’. There is, however, no conclusive evidence that such practices do improve performance. The whole area of nutrition in sport is currently receiving much interest within the nutrition and dietetic profession. It was one of the major topics discussed at the recent annual conference of the British Dietetic Association and the Sports Nutrition Foundation has recently been established to provide a focal point for the professional development of all those involved in the field of sports nutrition.

As the development and vaccination of the COVID 19 vaccine is accelerating worldwide, it is important to investigate the ways to improve immunity and immune responses to vaccines. This study aims to investigate the association between history of nutritional supplements intake and body mass index (BMI) in the severity of COVID-19 vaccine side effects after vaccination.

A total of 465 vaccinated participants with the Sinopharm vaccine (females and males in the 18–65 age range) participated in the study. Anthropometric measurements were taken on the first visit. In addition, nutrient supplement history and demographic information were collected. Moreover, the participants’ phone numbers were collected and they were contacted. Participants were asked to report if they experienced systemic (whole-body) and/or local side effects after vaccination, in the following eight days. Then, participants were grouped into four categories: no symptoms (n = 232), mild symptoms (n = 121), moderate symptoms (n = 55) and severe symptoms (n = 57).

There was a significant difference between the consumption of nutritional supplements by different groups of participants in the last six months (considering the severity of the symptoms) (p < 0.001). The odds ratio (OR) and 95% confidence intervals (CI) for the incidence of side effects from the COVID-19 vaccine increased in the Q3 of BMI (range 22.94–26.34) in Modes 2 and 3: [OR: 1.85, (95% CI: 1.14– 3.00), p-for trend = 0.08] and [OR: 1.89, (95% CI: 1.16– 3.09), p-for trend = 0.09] based on logistic regression models.

In this study, the history of nutrient supplement intake affects the severity of side effects after the vaccination with COVID-19. Furthermore, based on logistic regression models, side effects were more prevalent in the BMI range 22.9–26.3 when compared to BMI < 20.2 so further study is necessary.

There are significant health inequalities experienced by women in prison. They face distinct challenges and have particular and complex needs, specifically with regard to their physical and mental health. The purpose of this paper is to describe the approach taken to develop a set of health and wellbeing standards for the women’s prison estate in England, which can be applied elsewhere.

A structured literature review of standard healthcare databases and grey literature was used to inform development of suggested standards. A multidisciplinary expert panel provided consensus on the standards through an online survey and women with a history of contact with the criminal justice system were consulted through consensus groups.

A total of 549 papers were included in the final review. From this, 127 standards were identified for inclusion in the Delphi process. Consensus was achieved on all standards; this, combined with the analysis of qualitative feedback provided by both the survey and the consensus groups, resulted in the development of 6 overarching principles and 122 standards, across ten topic areas.

These standards are the most extensive that are known to exist for health and wellbeing of women in prison and the first to be developed in England. The process used ensures the standards have high validity, acceptability and feasibility and can be used to support those developing similar methodologies. There are few papers which document the development of standards to improve health and to the authors knowledge, only one other paper has been published detailing the development of health standards in prison settings specifically.