This paper presents a signal analysis technique for machine health monitoring based on the Hilbert-Huang Transform (HHT). The HHT represents a time-dependent series in a two-dimensional (2-D) time-frequency domain by extracting instantaneous frequency components within the signal through an Empirical Mode Decomposition (EMD) process. The analytical background of the HHT is introduced, based on ...

Background: Autogenous osteochondral grafting of articular defect in weight-bearing surface of large joints has proven to be a proper biomechanical and physiological solution for localized full-thickness defects.Objective: To study the gross and histopathological results of mosaicplasty in an animal model (sheep’s medial femoral condyle), evaluating the factors of defect and graft size, assessi...

The nonlinear dynamic model of rotor-bearing-seal system with crack in shaft is set up based on the coupling model of nonlinear oil-film force and Muszyska’s nonlinear seal fluid force. The dynamic vibration characteristics of the rotor-bearing-seal system and the effects of physical and structural parameters of labyrinth seal and crack fault on movement character of the rotor were analyzed. Th...

The purpose of this paper is to apply adaptive fuzzy sliding mode control for structurally controlling buildings with sliding bearing isolation. Combining fuzzy control and robust control such as sliding mode control, reduces fuzzy rule bases complexity and ensures stability and robustness. We use Lyapunov theory to develop a self-tuning law. Stiffness uncertainty and time delay is used to demo...

Bearing stiffness, as one of the most important service characteristics for ball bearing, plays a crucial role in bearing design and rotor dynamic analysis. To rapidly accurately calculate stiffness matrix under arbitrary load conditions, 5-DOF analytical model analysis has been established by ball–raceway contact analysis, implicit/explicit differential method, operations. The validated compar...

Structural Fe in clay minerals is an important, albeit poorly characterized, redox-active phase found in many natural and engineered environments. This work develops an experimental approach to directly assess the redox properties of a natural Fe-bearing smectite (ferruginous smectite, SWa-1, 12.6 wt % Fe) with mediated electrochemical reduction (MER) and oxidation (MEO). By utilizing a suite o...

Health monitoring of engineering structures has gained a lot of interest over the last few years. Many engineering structures suffer damage and deterioration when exposed to various loading and environmental changes during their lifetime. This seriously affects structural performance and may even lead to catastrophic structural failures. Thus, inspection and testing of structural components for...

Analysis of sperm chromosomes by G-banding and two-colour fluorescence in-situ hybridization (FISH) was carried out in the father of a child with a de-novo reciprocal translocation t(11;15)(q12;q22). Sperm chromosome complements were obtained after in-vitro fusion of zona-free hamster oocytes and donor spermatozoa. A total of 112 sperm complements was first analysed by G-banding. The frequency ...

functionalized indeno[1,2-b]chromene derivatives have been synthesized via condensation reaction of 1h-indene-1,3(2h)-dione with benzaldehyde and cyclization with 2-hydroxynaphthalene-1,4-dione in the presence of a catalytic amount of triethylamine (et3n) in etoh at room temperature. it was observed that benzaldehyde bearing electron donating group gave high yield of product, whereas, benzaldeh...