this paper studies a maintenance policy for a system composed of two components, which are subject to continuous deterioration and consequently stochastic failure. the failure of each component results in the failure of the system. the components are inspected periodically and their deterioration degrees are monitored. the components can be maintained using different maintenance actions (repair...

This paper studies a maintenance policy for a system composed of two components, which are subject to continuous deterioration and consequently stochastic failure. The failure of each component results in the failure of the system. The components are inspected periodically and their deterioration degrees are monitored. The components can be maintained using different maintenance actions (repair...

Abstract The paper presents the results of vibration tests carried out on pedestrian bridge accessing Civita di Bagnoregio, Italy. structure was in bad health condition. external beams were damaged due to deterioration exacerbated by combined actions rain and wind. circular piers also with several cracks where concrete cover spliced reinforcement bars exposed. analysis presented focuses highest...

It is now more than ten years since the introduction of mitral valvotomy. The initial results (Baker, Brock, and Campbell 1950; Baker et al., 1952) and a three-year follow-up of the first 45 Guy's cases (Baker et al., 1955) have been published. We now report a larger group of 200 patients followed up for over five years, which allows a more complete assessment of the long-term benefits of mitra...

Twenty-two patients underwent cardiac catheterization before and an average of five months after aorto-coronary bypass operation (ACBO). Two groups were examined: 10 patients with all grafts patent, and 12 patients with one or more grafts occluded. All patients improved symptomatically, regardless of graft patency. However, in the occluded group, left ventricular enddiastolic pressure (LVEDP) i...

in this paper, an analytical model is introduced to show the cyclic behavior of the structures, considering degradation phenomena including pinching, stiffness degradation, strength deterioration and sliding effects. this model is based on well-known mostaghel’s model though some essential modifications as well as sliding effect are also taken into account. this model is developed based on a si...

the present paper investigates the advantages of a new class of composite grid structures over conventional grids. thus far, a known grid structure such as orthogrid or isogrid has been used as an orthotropic layer with at most in-plane anisotropy. the present laminated grid is composed of various numbers of thin composite grid layers. the stiffness of the structure can be adjusted by choosing ...

One of the most famous methods to predict the stiffness of short fiber composites is micromechanical modeling. In this study, a Representative Volume Element (RVE) of a beech wood flour natural composite has been designed and the orientation averaging approach has been utilized to predict its stiffness tensor. The novelty of this work is in finding the proper fiber orientation distribution func...

in this paper, a production inventory model is developed for the business enterprise which consists of three wings. the first wing is for manufacturing new items, the second wing is for collecting the returned items, while third wing is for remanufacturing the returned item. in this model we consider the fact that the storage item is deteriorated during storage periods and salvage value is inco...

conclusions male gender, history of hypertension, high nyha score, and the presence of cad predict lvef deterioration in patients with lbbb. objectives the present study aimed to identify underlying factors that predict left ventricular ejection fraction (lvef) deterioration in patients suffered from complete lbbb. patients and methods in a retrospective case-control study, the data of 220 cons...