A Computational Model for Early Assessment of Padded Furniture Comfort Performance

Seating comfort has always been a primary issue in the design of padded furniture pieces. This paper proposes a computational model‐based methodology to assist the designer willing to take comfort into account as a primary requirement for padded furniture design. The methodology is based on a virtual mannequin, which can be tailored to reproduce the average target user, and the complete assembly of the main elements composing a typical armchair. Since contact pressure distribution is recognized to be strictly related to seating comfort perception, the contact occurring between these components, during the seating act, was simulated by means of a finite element solver and the resulting contact pressure distribution was computed. Several simulations were carried out with reference to a set of different armchair layout and materials; the obtained results showed a reasonable agreement with the experimental data recorded by means of a capacitive mat. Finally, by using an exemplificative criterion based on comfort‐related pressure distribution parameters, the authors demonstrate the possibility of selecting the best‐performing configurations prior to building a physical prototype. The proposed approach, tested on a complex seat and a wide range of possible materials, can be considered of general applicability since 1) the virtual mannequin, as opposed to what is reported in a number of scientific works, is not requested to closely resemble a single test subject, and 2) the selected seat structure and seat components encompass the most commonly used ones for this kind of product so that a few generally applicable considerations can be drawn.     

Flat-band add-drop FIR lattice filter design

A finite impulse response design method has been successfully applied to flatten and shape the pass bandwidth of resonant coupler add-drop filters. A comparison between a binomial and flat-band design has been presented. Measurements and improvements in filter performance have been highlighted     

A stable and adaptive semi-Lagrangian potential model for unsteady and nonlinear ship-wave interactions

We present an innovative numerical discretization of the equations of inviscid potential flow for the simulation of three-dimensional, unsteady, and nonlinear water waves generated by a ship hull advancing in water.The equations of motion are written in a semi-Lagrangian framework, and the resulting integro-differential equations are discretized in space via an adaptive iso-parametric collocation boundary element method, and in time via implicit backward differentiation formulas (BDF) with adaptive step size and variable order.When the velocity of the advancing ship hull is non-negligible, the semi-Lagrangian formulation (also known as Arbitrary Lagrangian Eulerian formulation or ALE) of the free-surface equations contains dominant transport terms which are stabilized with a streamwise upwind Petrov–Galerkin (SUPG) method.The SUPG stabilization allows automatic and robust adaptation of the spatial discretization with unstructured quadrilateral grids. Preliminary results are presented where we compare our numerical model with experimental results on a Wigley hull advancing in calm water with fixed sink and trim.     

Statins (HMG-CoA reductase inhibitors), cholesterol and stroke

The HMG-CoA reductase inhibitors (known as statins) have been shown to reduce morbi-mortality of vascular origin, including transitory ischemic accidents and cerebral infarcts, in a large group of patients. The implications, both clinical and of costs, oblige us to consider analysis of the existing evidence and the answers to a number of questions arising in a field which has not yet received much attention from neurologists.     

Leg bone pain syndrome due to cyclosporine in a renal transplant patient

A leg bone pain syndrome of unclear etiology has been recently described in renal transplant patients receiving cyclosporine A. Herein we report a 54-year-old woman treated with cyclosporine A (CsA), corticosteroids and azathioprine who developed two months after renal transplantation severe symmetric pain with periarticular soft tissue swelling in the knees and metatarsophalangeal joints. Scintigraphy showed periarticular radionuclide activity. Clinical onset was associated with both the high dosage and with the plasma levels of CsA. Symptoms improved when the dosage of CsA was reduced and the plasma levels declined to less than 150 ng/ml.