Background The association among psychological, neuropsychological dysfunctions and functional/clinical variables in Chronic Heart Failure (CHF) has been extensively addressed in literature. However, only a few studies investigated those associations in the older population. Purpose To evaluate the psychological/neuropsychological profile of older CHF patients, to explore the interrelation with clinical/functional variables and to identify potential independent predictors of patients' functional status. Methods This study was conducted with a multi-center observational design. The following assessments were performed:
Wood exhibits anisotropic swelling and shrinking upon changes of wood moisture content (MC). By manufacturing bi-layered structures with adapted grain orientation in the two bonded layers, humidity-driven actuators are generated, which have the potential to be used for autonomous climate adaptive building with tile. The present study deals with design principles for upscaling the size of the bilayers and for increasing the rate of MC change and, thus, rate of shape change. Wood bilayers with widths of up to half a meter were subjected to changes of relative humidity (RH). Moisture and curvature changes were recorded. Bilayers with different widths showed curvature exclusively along their length. Next to this, the performance was compared between bilayers with and without milled-in grooves. These grooves lead to shorter diffusion paths along fibre direction for increasing the rate of MC change. The highest rates of MC change were visible for the samples with the smallest width within the first hours after change of RH. Later on, all samples showed similar rates. The milling of grooves increased the moisture change rate substantially compared to the non-milled samples resulting in a higher rate of curvature change. The increase is especially pronounced for cyclic changes of RH. This study shows that, by applying material specific design principles, the shape change of wood bilayers can be adapted and the rate of the MC change can be increased by keeping diffusion paths short along fibre direction. These principles may facilitate the use of large-scale wood bilayers as lamellae in shading systems.
The bending of wooden bilayers in response to the change of relative humidity can be utilized to build autonomous actuation devices. For bending, the properties of the adhesive may play a crucial role in terms of humidity transfer and mechanical performance. Hence, the type of the adhesive may have an impact on the bilayer responsiveness upon humidity changes. In this study, bilayers with various sizes were fabricated and glued with five different adhesives. The same samples were exposed at first to a single desorption phase for 48 h and in a second experiment to ten de-/adsorption cycles with a cycle length of 24 h. The initial moisture contents (MC) of the bilayers differed depending on the type of adhesive. Due to the additional water uptake of the wood layers bonded with water introducing adhesives (PVAC, MUF and PRF), these bilayers had a higher initial MC than those bonded with non-water introducing adhesives (PUR and Epoxy). During the de-/adsorption cycles, the overall amplitude of bending stayed relatively constant. However, the start-and the endpoints of the movement were shifted in the first three cycles, since here, the cycle length was not sufficiently long to reach an equilibrated MC state. However, after this initial adjustment phase, the bending of the wooden bilayers was reversible and repeatable. No significant differences in the kinetics of bilayers manufactured with the different adhesive systems could be observed. Thus, the specific adhesive properties do not seem to influence the responsiveness and performance of the wooden bilayers.
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