Mooring and flow lines involved in offshore systems for oil production are submitted to various solicitations. Among them the effects of current are dominating. Vortex-Induced Vibrations (VIV) and Wake-Induced Oscillations (WIO) on closely spaced marine risers may lead to fatigue, clashes and structural failures. Extended studies have been conducted to describe and explain them for spring mount...

introduction: noradrenergic cells in lc participate in the process of cortical activation and behavioral arousal. the evidence suggests that locus ceoruleus (lc) plays an important role in the sleep-wake cycle. the aim of this study was stereological estimation of cavity caused by lesion and assessment of sleep stages after bilateral lesion of the lc. materials and methods: male wistar rats wei...

duffing harmonic oscillator is a common model for nonlinear phenomena in science and engineering. this paper presents he´s energy balance method (ebm) for solving nonlinear differential equations. two strong nonlinear cases have been studied analytically. analytical results of the ebm are compared with the solutions obtained by using he´s frequency amplitude formulation (faf) and numerical solu...

This paper proposes a generalized model for vortex shedding around static cylinder. is first step to bridge the gap between two existing families of Vortex Induced Vibration (VIV) models , namely (1) stochastic spectral and (2) wake-oscillator with coupled fluid structural equations. The family experimentally-based while second typically rely on theoretical phenomenological concepts. These use ...

Duffing harmonic oscillator is a common model for nonlinear phenomena in science and engineering. This paper presents He´s Energy Balance Method (EBM) for solving nonlinear differential equations. Two strong nonlinear cases have been studied analytically. Analytical results of the EBM are compared with the solutions obtained by using He´s Frequency Amplitude Formulation (FAF) and numerical solu...

This work proposes a novel demodulation circuit to address the implementation of Wake-Up Receivers (Wu-Rx) in Wireless Sensor Nodes (WSN). This RF demodulator, namely Modulated Oscillator for envelOpe Detection (MOOD), is compatible with both FSK and OOK/ASK modulation schemes. The system embeds an LC oscillator, an envelope detector and a base-band amplifier. To optimize the trade-off between ...