Search

The meshless displacement error-recovery parametric investigation in finite element method-based incompressible elastic analysis is presented in this study. It investigates key parameters such as interpolation schemes, patch configurations, dilation indexes, weight functions, and meshing patterns. The study evaluates error recovery effectiveness (local and global), convergence rates, and adaptive mesh improvement for triangular/quadrilateral discretization schemes. It uses meshless moving least squares (MLS) interpolation with rectangular and circular support regions and solves benchmark plate and cylinder problems. It is observed that a circular influence region, a cubic spline weight function, and regular mesh patterns yield a better performance of than an MLS-based error recovery method. The study also concludes that lower dilation index values with rectangular influence regions are preferable for regular meshes, while higher dilation index values with radial influence regions are suitable for preferable meshes to enhance MLS error recovery. [ABSTRACT FROM AUTHOR]

The meshless displacement error-recovery parametric investigation in finite element method-based incompressible elastic analysis is presented in this study. It investigates key parameters such as interpolation schemes, patch configurations, dilation indexes, weight functions, and meshing patterns. The study evaluates error recovery effectiveness (local and global), convergence rates, and adaptive mesh improvement for triangular/quadrilateral discretization schemes. It uses meshless moving least squares (MLS) interpolation with rectangular and circular support regions and solves benchmark plate and cylinder problems. It is observed that a circular influence region, a cubic spline weight function, and regular mesh patterns yield a better performance of than an MLS-based error recovery method. The study also concludes that lower dilation index values with rectangular influence regions are preferable for regular meshes, while higher dilation index values with radial influence regions are suitable for preferable meshes to enhance MLS error recovery.

In this article, a goal-oriented adaptive scheme is proposed for Fredholm partial integro-differential equations (FPIDEs). The aim of this work is to obtain higher accuracy approximations for the unknown function and its derivative at a given fixed point. In the proposed goal-oriented scheme, as opposed to the typical energy norm, the finite element approximated error is computed based on the quantities of interest. These designated quantities are identified by linear goal functions. The formula of the goal error and the a priori estimate of its upper bound are derived. An a posteriori error estimate is formulated and then approximated by using the recovered gradient. Some numerical tests are presented to show the efficiency of the proposed scheme in hastening the achievement of regional aspects of the solution.

Neodymium is critically scarce and is often used in supportable technologies such as permanent magnets, batteries, and catalysts. The extraction of it from virgin ores causes environmental degradation and recycling of end‐of‐life (EOL) products proves to be an alternative to meet its future criticality. From an environmental and economic point of view, magnets produced from recovered neodymium perform better than the ones produced from virgin neodymium. In this review various technologies such as hydro metallurgy, pyro metallurgy, supercritical CO2 extraction, desalination, and adsorption have been discussed for the recovery of this metal from different EOL sources. The advantages and limitations of these methods are summarized. Different experimental status like sources, temperature, aqueous phase composition, organic phase make up, and maximum recovery efficiency are also looked upon. This review may prove beneficial for the researchers to design recovery road maps under different circumstances. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Academic Finance is the property of Academic Finance Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Stroke is a significant disability and death cause worldwide and is conventionally defined as a neurological impairment relating to the intense focal harm of the central nervous system (CNS) by vascular causative components. Although the applicability of robotic rehabilitation is a topic with considerable practical significance because it has produced noticeably higher improvements in motor function than regular (physical and occupational) therapy and exempted the therapists, most of the existing bibliometric papers were not focused on stroke survivors. Additionally, a modular system is designed by joining several medical end-effector devices to a single limb segment, which addresses the issue of potentially dangerous pathological compensatory motions. Searching the Web of Science database, 31,930 papers were identified, and using the VOSviewer software and science mapping technology, data were extracted on the most prolific countries, the connections between them, the most valuable journals according to certain factors, their average year of publication, the most influential papers, and the most relevant topical issues (bubble map of term occurrence). The most prolific country in the analyzed field and over the entire period evaluated (1975–2022) is the United States, and the most prolific journal is Neurorehabilitation and Neural Repair, observing a marked increase in the three periods of scientific interest for this field. The present paper assesses numerous scientific publications to provide, through statistical interpretation of the data, a detailed description of the use of robotic rehabilitation in stroke survivors. The findings may aid scientists, academics, and clinicians in establishing precise goals in the optimization of the management of stroke survivors via robotic rehabilitation, but also through easier access to scientifically validated literature. [ABSTRACT FROM AUTHOR]

Copyright of Turkiye Klinikleri Journal of Sports Sciences is the property of Turkiye Klinikleri and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The displacement and stress-based error estimates in a posteriori error recovery of compressible and nearly-incompressible elastic finite element solutions is investigated in the present study. The errors in the finite element solutions, i.e., in displacement and stress, at local and global levels are computed in L2-norm of quantity of interest, namely, displacements and gradients. The error estimation techniques are based on the least square fitting of higher order polynomials to stress and displacement in a patch comprising of node/elements surrounding and including the node/elements under consideration. The benchmark examples of compressible and incompressible elastic bodies, with known solutions employing triangular discretization schemes, are implemented to measure the finite element errors in displacements and gradients. The mixed formulation involving displacement and pressure is used for incompressible elastic analysis. The performance of error estimation is measured in terms of convergence properties, effectivity and mesh required for predefined precision. The error convergence rate, in FEM original solution, recovered solution using displacement recovery-based and stress-based error recovery technique for stresses, are obtained as (1.9714, 2.8999, and 2.5018) and (0.9818, 1.7805, and 1.4952) respectively for compressible and incompressible self-loaded elastic plate benchmark example using higher order triangular elements. It is concluded from the study that displacement fitting technique for extracting higher order derivatives shows a very effective technique for recovery of compressible and nearly-incompressible finite element analysis errors. [ABSTRACT FROM AUTHOR]

Behavioral changes are signs of pain in animals. Understanding the physiological mechanisms of pain is essential for the development of new drugs. Currently, analgesia is obtained through systemic techniques associated with peripheral analgesia techniques. Pain is monitored by evaluating hemodynamic and respiratory parameters but especially by clinical parameters. Thus it remains an extremely subjective assessment. Adequate analgesia improves the clinical and biological condition of patients, inefficiency of pain control can often delay the healing process. In this paper are presented the main entities associated with the phenomenon of pain in the musculoskeletal system and veterinary therapeutic techniques for recovery in dogs.

The present work focuses on assessing bacterial profiles of microbiota existing on technological equipment applied in food products manufacturing, objects located inside medical and preventive facilities, and water objects in recreation zones; another goal was to examine phenotypic properties of opportunistic pathogenic bacteria isolates as hazard identification factors within the framework of risk assessment concept. Our research objects were strains of Escherichia, Klebsiella, Enterobacter, Staphylococcus, Pseudomonas, Citrobacter and Serratia families that were detected and extracted due to hygienic monitoring activities performed in 2013–2017. Samples were taken via washing, direct inoculation, membrane filtration, and instrumental aspiration technique. Microbial status was analyzed with cultural and biochemical techniques on nutrient and differential-diagnostic media with subsequent confirmation with polymerase chain reaction (PCR). Phenotypic peculiarities were examined in vitro with conventional biochemical and microbiological techniques in conformity with the requirement fixed in Good Laboratory Practice. We revealed peculiarities of microbial profiles belonging to opportunistic pathogenic microbiota on different objects in habitats. The greatest groups included staphylococci detected in the air inside medical organizations with 1–4 cleanness degree (44%); Enterobacteriaceae family bacteria, in washes off objects located in manufacturing and medical and prevention facilities (64% and 69% accordingly); Pseudomonas family bacteria, in water objects (46%). 60 (36%) isolates out of 167 examined ones had modified morphological and tinctorial signs regarding those typical for a family. Most isolates had a set of modified or atypical metabolomic signs such as hemolytic and lecithinase activities, apparent persistent factors, and ability to create biofilms. Opportunistic pathogenic bacteria strains extracted from washes off objects located inside food products manufacturing and medical and preventive facilities were the most potentially aggressive. Isolates from the same families extracted from water objects in recreation zones and air inside medical and preventive facilities had less apparent phenotypic properties that characterized their pathogenic potential. Our experimental data provide useful materials for examining a phenomenon related to changes in phenotypic properties; they can be applied during revealing and drawing up a hazard profile and for minimizing uncertainty within the concept of microbiological risk analysis.

In this study, techniques for mesh dependent and independent displacement recovery for an a posteriori error estimation are presented. The error recovery of the field variable is made by fitting a higher order polynomial to the displacement over a mesh independent patch (support domain) using the moving least square (MLS) interpolation procedure. The mesh dependent recovery procedure is based on the recovery of the displacement over an element patch that consists of all elements surrounding the element under consideration using the least square (LS) interpolation procedure. The two-dimensional benchmark examples are analysed using linear and quadratic triangular elements to demonstrate the effectiveness and reliability of error estimations. Global and elemental errors of a finite element solution in the energy and L2 norms are calculated directly from the post-processed displacement. The quality of error estimation obtained using the mesh independent displacement recovery technique in terms of convergence properties, effectivity and adaptive meshes under different error norms has been compared with that of the mesh dependent displacement recovery using the MLS interpolation and least square (LS) interpolation procedures. The performance of an adaptive scheme based on a mesh independent error estimator is compared with the adaptive scheme based on a mesh dependent error estimator. The numerical results show that the finite element analysis based on mesh independent recovery is very effective in converging to a predefined accuracy in a solution with a significantly smaller number of degrees of freedom. [ABSTRACT FROM AUTHOR]

The displacement and stress-based error estimates in a posteriori error recovery of compressible and nearly-incompressible elastic finite element solutions is investigated in the present study. The errors in the finite element solutions, i.e., in displacement and stress, at local and global levels are computed in L2-norm of quantity of interest, namely, displacements and gradients. The error estimation techniques are based on the least square fitting of higher order polynomials to stress and displacement in a patch comprising of node/elements surrounding and including the node/elements under consideration. The benchmark examples of compressible and incompressible elastic bodies, with known solutions employing triangular discretization schemes, are implemented to measure the finite element errors in displacements and gradients. The mixed formulation involving displacement and pressure is used for incompressible elastic analysis. The performance of error estimation is measured in terms of convergence properties, effectivity and mesh required for predefined precision. The error convergence rate, in FEM original solution, recovered solution using displacement recovery-based and stress-based error recovery technique for stresses, are obtained as (1.9714, 2.8999, and 2.5018) and (0.9818, 1.7805, and 1.4952) respectively for compressible and incompressible self-loaded elastic plate benchmark example using higher order triangular elements. It is concluded from the study that displacement fitting technique for extracting higher order derivatives shows a very effective technique for recovery of compressible and nearly-incompressible finite element analysis errors.

Behavioral changes are signs of pain in animals. Understanding the physiological mechanisms of pain is essential for the development of new drugs. Currently, analgesia is obtained through systemic techniques associated with peripheral analgesia techniques. Pain is monitored by evaluating hemodynamic and respiratory parameters but especially by clinical parameters. Thus it remains an extremely subjective assessment. Adequate analgesia improves the clinical and biological condition of patients, inefficiency of pain control can often delay the healing process. In this paper are presented the main entities associated with the phenomenon of pain in the musculoskeletal system and veterinary therapeutic techniques for recovery in dogs. [ABSTRACT FROM AUTHOR]

The mesh-free interpolation method-based recovery of finite element discretization error is presented in this study. Two interpolation schemes, namely radial point interpolation method and moving least squares method, are taken for the recovery of finite element solution error. The global and elemental errors of finite element solution are evaluated in energy norm. The two-dimensional benchmark elastic problems are analysed using triangular/quadrilateral meshing schemes to prove the proposed mesh-free error estimation techniques validity and the effectiveness. The results of the mesh-less interpolation recovery-based error estimation are also compared with mesh-dependent least squares interpolation method-based error estimation. The mesh-free recovery is based on the fitting of a higher-order polynomial to the field variable over a mesh-less patch (radial support domain) using RPI and MLS interpolation method, while the mesh-dependent recovery is based on recovery of the field variable over a patch of nodes surrounding the particular given node using RPI, MLS and LS interpolation method. The study presents the effect of polynomial basis function (LS), polynomial basis function along with radial basis function (RPI)-based interpolation method and weighted polynomial basis function (MLS) on the recovery of finite element solution error. The quality of error estimation under different interpolation schemes is compared in terms of convergence characteristics, local/global effectivity, error distribution patterns and adaptively refined meshes. It can be concluded that weighting function of least squares interpolation affects considerably the mesh-free error estimation. [ABSTRACT FROM AUTHOR]

Most onshore oil fields in China are in the later stage of development, and the water content is more than 90%, which increases the difficulty of remaining oil mining. In order to improve the oil production, it is necessary to develop a variety of oil recovery technologies, increase the oil field space pressure, weaken the oil viscosity, and improve the recovery factor. Taking L oilfield as an example, the paper briefly expounds the characteristics of extra-high water cut period, and on this basis, puts forward recovery technology, grasps development rules, and realizes technological innovation. The accumulative oil production reaches 2.32 million tons, and the recovery factor increases by 9%, thus providing reference for related workers.

The paper presents a parametric study on interpolation techniques based postprocessed error estimation in finite element elastic analysis by varying important parameters of recovery, interpolation scheme and type of patch construction. The quality of error estimation with recovery parameters is compared in terms of local and global effectivity of error estimation, rate of error convergence, and adaptively refined meshes. A mesh free moving least square interpolation technique with proven reliability and effectivity is introduced for improving the recovery of finite element solution errors. The post-processed finite element solutions of elastic problems are presented for performance study under different parameters of recovery technique. The study concludes that recovery parameters of interpolation method have pronounced effect on the recovery of finite element solution error and analysis in adaptive environment. [ABSTRACT FROM AUTHOR]

International Journal of Exercise Science 12(2): 714-725, 2019. Heart rate recovery (HRR) and blood pressure recovery (BPR) from exercise are both important indicators of health and fitness and are strongly associated with cardiovascular disease. The purpose of this study was to compare the effects of a slow-breathing technique, upright passive recovery (PASS), and active recovery (ACT) on HRR and BPR from exercise. Nine moderately trained, college-aged (20.22 ± 0.97 yrs) female participants cycled three times on an ergometer for 15 mins at 70% of their heart rate maximum (HRmax), each of which was followed by one of three 5 min recovery interventions with heart rate (HR) and blood pressure (BP) objectively measured. Each participant completed all three recovery protocols. One recovery protocol consisted of breathing at a rate of 6 breaths per minute (BRE), another involved PASS and the third was ACT at 60 RPM and 25 W. A repeated measures ANOVA revealed there was a significant effect of protocol (p = 0.00, np2 = 0.67) with HRR. BRE resulted in the fastest HRR of 69 ± 9.31 bpm (40.12%) at the end of the 5 min recovery compared to 63 ± 10.60 bpm (36.57%) and 47 ± 12.54 bpm (27.34%) for PASS and ACT, respectively. A second repeated measures ANOVA indicated there was no effect of protocol (P = 0.43), nor was there a significant interaction with time (p = 0.68), for BPR. The results indicated that BRE increased HRR after exercise more rapidly than PASS or ACT with no influence on BPR. These findings lead to future research needed to explore different breathing protocols following exercise in at-risk populations, such as individuals with cardiovascular disease. [ABSTRACT FROM AUTHOR]

In this article, a goal-oriented adaptive scheme is proposed for Fredholm partial integro-differential equations (FPIDEs). The aim of this work is to obtain higher accuracy approximations for the unknown function and its derivative at a given fixed point. In the proposed goal-oriented scheme, as opposed to the typical energy norm, the finite element approximated error is computed based on the quantities of interest. These designated quantities are identified by linear goal functions. The formula of the goal error and the a priori estimate of its upper bound are derived. An a posteriori error estimate is formulated and then approximated by using the recovered gradient. Some numerical tests are presented to show the efficiency of the proposed scheme in hastening the achievement of regional aspects of the solution. [ABSTRACT FROM AUTHOR]

Our objective is to determine the optimal undeformed workpiece geometry (material configuration) within forming processes when the prescribed deformed geometry (spatial configuration) is given. For solving the resulting shape optimization problem—also denoted as inverse form finding—we use a novel parameter-free approach, which relocates in each iteration the material nodal positions as design variables. The spatial nodal positions computed by an elasto-plastic finite element (FE) forming simulation are compared with their prescribed values. The objective function expresses a least-squares summation of the differences between the computed and the prescribed nodal positions. Here, a recently developed shape optimization approach (Landkammer and Steinmann in Comput Mech 57(2):169-191, 2016) is investigated with a view to enhance its stability and efficiency. Motivated by nonlinear optimization theory a detailed justification of the algorithm is given. Furthermore, a classification according to shape changing design, fixed and controlled nodal coordinates is introduced. Two examples with large elasto-plastic strains demonstrate that using a superconvergent patch recovery technique instead of a least-squares (L2)-smoothing improves the efficiency. Updating the interior discretization nodes by solving a fictitious elastic problem also reduces the number of required FE iterations and avoids severe mesh distortions. Furthermore, the impact of the inclusion of the second deformation gradient in the Hessian of the Quasi-Newton approach is analyzed. Inverse form finding is a crucial issue in metal forming applications. As a special feature, the approach is designed to be coupled in a non-invasive fashion to arbitrary FE software. [ABSTRACT FROM AUTHOR]

Microscopic considerations are drawing increasing attention for modern simulation techniques. Micromorphic continuum theories, considering micro degrees of freedom, are usually adopted for simulation of localization effects like shear bands. The increased number of degrees of freedom clearly motivates an application of adaptive methods. In this work, the adaptive FEM is tailored for micromorphic elasticity. The proposed adaptive procedure is driven by a goal-oriented a posteriori error estimator based on duality techniques. For efficient computation of the dual solution, a patch-based recovery technique is proposed and compared to a reference approach. In order to theoretically ensure optimal convergence order of the proposed adaptive procedure, adjoint consistency of the FE-discretized solution for the linear elastic micromorphic continua is shown. For illustration, numerical examples are provided. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

As cyber physical system (CPS) is often used in safety critical areas, dependability of the system is an important issue that needs to be analysed. Any failure on the components of the CPS could result in a degradation of the physical state, which then causes major harm to life and/or property. Since the concept of dependence leads to that of trust, the subsystems of the CPS should be dependable to each other to deliver the requested services as specified without failing during its operation. In this study, the authors apply Markov chain to model and analyse the component dependability of CPSs and propose the recovery techniques to guarantee a high level of dependability so as to take care of assuring the continuity of system operation. [ABSTRACT FROM AUTHOR]

The research field of model adaptivity is well established, aiming at adaptive selection of mathematical models from a well defined class of models (model hierarchy) to achieve a preset level of accuracy. The present work addresses its application to a class of linear elastic composite problems. We will show that the classical bounding theories can provide a model hierarchy in a natural and theoretically consistent manner, without combination of different methods using a priori knowledge. To arrive at computable higher order bounds, the classical singular approximation is made. As a new finding, this may, under certain circumstances, give rise to an overlap effect. To overcome this, a correction is proposed. Additionally, the model adaptivity is coupled to the well established adaptive finite element method (FEM), such that both macro model and macro discretization errors are controlled. The proposed adaptive procedure is driven by a goal-oriented a posteriori error estimator based on duality techniques. For efficient computation of the dual solution, a patch-based recovery technique is proposed and compared to existing methods. For illustration, numerical examples are presented. [ABSTRACT FROM AUTHOR]

Coral disease literature has focused, for the most part, on the etiology of the more than 35 coral afflictions currently described. Much less understood are the factors that underpin the capacity of corals to regenerate lesions, including the role of colony health. This lack of knowledge with respect to the factors that influence tissue regeneration significantly limits our understanding of the impact of diseases at the colony, population, and community level. In this study, we experimentally compared tissue regeneration capacity of diseased versus healthy fragments of Gorgonia ventalina colonies at 5 m and 12 m of depth. We found that the initial health state of colonies (i.e., diseased or healthy) had a significant effect on tissue regeneration (healing). All healthy fragments exhibited full recovery regardless of depth treatment, while diseased fragments did not. Our results suggest that being diseased or healthy has a significant effect on the capacity of a sea fan colony to repair tissue, but that environmental factors associated with changes in depth, such as temperature and light, do not. We conclude that disease doesn’t just compromise vital functions such as growth and reproduction in corals but also compromises their capacity to regenerate tissue and heal lesions.

This study examined the effects of antioxidant vitamins, ibuprofen, cold water submersion, and whey protein administered simultaneously on short-term recovery. Competitive athletes (n = 22) performed the protocol in 2 occasions (treatment and control) separated by 1 5 days in counterbalanced crossover design. Each occasion consisted of morning and afternoon sessions (AM and PM). In each session, participants performed 2 bouts of high-intensity anaerobic cycling separated by 30 minutes of rest. Each bout consisted of 3 Wingate tests (3 x 30-second Wingate tests) with 3 minutes of active recovery in between. Power output, rated perceived exertion (RPE), and pain scores were averaged and compared between the 2 sessions (AM vs. PM) and between the treatment vs. control (4 bouts). Creatine kinase (CK) levels were also measured 24 hours after the AM bout. Power output, CK, muscle soreness, and RPE were measured as recovery indices. Creatine kinase increased (p < 0.001) in both treatment and control 24 hours after the AM session. Performance results in the PM session for treatment/control were 832.5±1 98.7/813.3±1 87.6 W for peak power (PP), and 497.85±120.7/486.1±115 W for mean power (MP). Treatment was effective in maintaining MP (p = 0.034) in the PM sessions, but there was no significant effect of treatment on PP (p = 0.1 93), CK (p = 0.08), pain (p = 0.1 2), or RPE (p = 0.45). Treatment was helpful in protecting performance, but this was apparently not due to reduced muscle soreness or damage. [ABSTRACT FROM AUTHOR]