Parametric variation of a coupled pendulum-oscillator system using real-time dynamic substructuring

In this paper, we present results from real-time dynamic substructuring tests used to model the dynamics of a coupled pendulum–oscillator system. The substructuring technique is particularly suitable for systems where the nonlinear and linear parts of the system can be separated. The nonlinear part is built full size and tested physically (the substructure) while the linear part is simulated numerically. Then, in order to replicate the dynamics of the complete system the substructure and the numerical model must be coupled in real time. In this study, we demonstrate how real-time dynamic substructure testing can be used to model systems with strongly nonlinear behaviour using parametric variation. We show that the substructuring results give good qualitative and quantitative agreement with purely numerical simulations of the complete system for a range of parameters values. This includes single parameter bifurcation diagrams, some of which cannot be obtained from a full physical experiment. We also briefly discuss the effects of delay and noise on the stability of the substructured system, and how these effects can be mitigated. Copyright © 2006 John Wiley & Sons, Ltd

The Risk Factors Of Fall And Their Correlation With Balance, Depression, Cognitive Impairment And Mobility Skills In Elderly Nursing Home Residents

Objectives: The purpose of this study was to investigate risk factors of fall and to examine their correlations with balance, depression, cognitive impairment and mobility skills in elderly nursing home residents. Methods: This study included 30 elderly people living in Seyranbaglari Nursing Home in Ankara City Centre, Turkey and was carried out in 2004. Risk factors for fall were obtained through individual interviews and observation. Cognitive function was assessed by Mini Mental State Examination (MMSE). The Geriatric Depression Scale (GDS) was used for determining the depression status of the elderly. Balance of the subjects was evaluated by the Berg Balance Scale (BBS) and the Get Up and Go Test (GUGT). In addition, mobility skills were assessed by Rivermead Mobility Index (RMI). The correlation analysis was used for establishing the correlations of the total number of risk factors with the other parameters. In addition, the correlations among all parameters were evaluated. Results: At the end of the study, it was found that the correlation among all parameters was significant (p < 0.01, p < 0.05). For example, there was a significant correlation of MMSE score with the total number of risk factor for falls, GDS, BBS, GUGT and RMI. The RMI score was also correlated with GDS, MMSE, BBS and GUGT scores. Conclusion: The results of the present study confirm that impairment of cognitive function, balance and mobility skills, and depression increases the risk of falling. In addition, all the parameters affect each other, too. There is a vicious circle among these parameters. If this vicious circle is not broken, an increasing risk of fall will be inevitable. That is why this information will be useful for patients' therapy, and for development of fall prevention programs for elderly people.Wo

Functional Mobility, Depressive Symptoms, Level of Independence, and Quality of Life of the Elderly Living at Home and in the Nursing Home

WOS: 000272150400014PubMed ID: 19883891Objectives: To compare functional mobility, depressive symptoms, level of independence, and quality of life of the elderly living at home and in the nursing home. Design: A prospectively designed, comparative study Setting: A nursing home and a university hospital department. Participants: In this study, 33 elderly living in a nursing home and 25 elderly living at home, who fulfilled the inclusion criteria and volunteered to participate, were included. Measurements: Sociodemographic characteristics were recorded. Functional mobility (Timed Up & Go Test), depressive symptoms (Geriatric Depression Scale), level of independence (Kahoku Aging Longitudinal Study Scale), and quality of life (Visual Analogue Scale) scores were compared between the groups. Results: Functional mobility and independence level of the nursing home residents were higher than the home-dwelling elderly (95% CI: -4.88, -0.29 and 0.41, 6.30, respectively), but they had more depressive symptoms (95% CI: 0.30, 5.45), and their level of QoL was lower (95% CI: -15.55, -2.93). Conclusion: These findings are thought to be important and of benefit for health care professionals and caregivers as indicating the areas that need to be supported for the elderly living at home (functional mobility and independence) and in the nursing home (depressive symptoms and quality of life). (J Am Med Dir Assoc 2009; 10: 662-666

Influence of heat treatment on the wear resistance of the ZnAl40Cu1.5Ti1.5 alloy

Zn-Al-Cu alloys are predominantly used due to their tribological properties. One of the crucial issues related to the use of Zn-Al alloys is their dimensional instability. Partial replacement of copper with titanium greatly contributes to the reduction of the dimensional instability issue. The study involved the ZnAl40Cu1.5Ti1.5 alloy. In this work, microstructure and wear properties of ZnAl40Cu1.5Ti1.5 alloy were studied in both as-cast and heat treated conditions. The heat treatment was performed by solution treatment at a temperature of 385°C for 24 hours, quenching in cold water and artificial aging at 125°C for 3 hours. The hardness tests enabled to specify the optimum ageing time span, which amounts to 3 hours. Wear tests indicated that the ZnAl40Cu1.5Ti1.5 alloy is characterized with high wear resistance. It was also observed that the applied heat treatment increases the wear resistance of the experimental alloy

Effectiveness and safety of direct-acting antiviral therapies in chronic hepatitis C infections patients with cirrhosis in Turkey

International Liver Congress (ILC) -- APR 11-15, 2018 -- Paris, FRANCEWOS: 000461068601206…European Assoc Study Live