Resonance as a Design Strategy for AI and Social Robots

Resonance, a powerful and pervasive phenomenon, appears to play a major role in human interactions. This article investigates the relationship between the physical mechanism of resonance and the human experience of resonance, and considers possibilities for enhancing the experience of resonance within human–robot interactions. We first...

Is intermittent control the source of the non-linear oscillatory component (0.2-2Hz) in human balance control

Objective: To explain the 0.2-2Hz oscillation in human balance. Motivation: Oscillation (0.2-2 Hz) in the control signal (ankle moment) is sustained independently of external disturbances and exaggerated in Parkinson's disease. Does resonance or limit cycles in the neurophysiological feedback loop cause this oscillation? We investigate two...

Higher-order phenomena in nanomechanics of two-dimensional material membranes

This thesis studies higher-order material properties* and effects in van der Waals crystals, such as anisotropic Young’s modulus, magnetostriction, and non-trivial thermal expansion effects near magnetic and electronic phase transitions, that can affect the nanomechanical motion ofmultilayer two-dimensional (2D) material membranes. These...

Transversal waves and vibrations in axially moving continua

Effective stiffness method for rigid monopile foundations of offshore wind turbines and in-situ validation

It is widely accepted that the initial stiffness derived with the p-y methodology as prescribed by the American Petroleum Institute does not capture the true small-strain stiffness for rigidly behaving piles. We present an alternative method, capturing the 3D effects in the soil-pile interaction, in which the soil is characterized with in-situ...

A versatile Lock-In digital Amplifier (LIdA): The case of mechanical resonances

The assembly of a Lock-In digital Amplifier (LIdA) from widely accessible ready-made modules is presented. This equipment, which does not require any advanced knowledge of electronics or programming, may introduce the experimenter to resonant techniques by registering mechanical resonances. The freely available control program allows for...

Microwave Field Applicator Design in Small-Scale Chemical Processing

Ever since the first experiments nearly three decades ago, microwave enhanced chemistry has received incessant scientific attention. Many studies report improved process performance in terms of speed and conversion under microwave exposure and therefore it is recognized as a promising alternative method of process activation. It has also raised...

A resonating rainfall and evaporation recorder

We propose a novel, accurate quantification of precipitation and evaporation, as needed to understand fundamental hydrologic processes. Our system uses a collection vessel placed on top of a slender rod that is securely fixed at its base. As the vessel is deflected, either by manual perturbation or ambient forcing (for example, wind), its...

Q-factor control of a microcantilever by mechanical sideband excitation

We demonstrate the coupling between the fundamental and second flexural modes of a microcantilever. A mechanical analogue of cavity-optomechanics is then employed, where the mechanical cavity is formed by the second vibrational mode of the same cantilever, coupled to the fundamental mode via the geometric nonlinearity. By exciting the cantilever...

Resonance in Low-Temperature Oxidation Waves for Porous Media

This paper analyzes traveling wave profiles possessing an internal resonance point for a class of systems of partial differential equations describing oxidation and vaporization of liquid fuel in a porous medium when an oxidizer (air) is injected. It is shown that the resonance is characterized by a saddle point of an associated vector field...

High Frequency Combustion Instabilities of LOx/CH4 Spray Flames in Rocket Engine Combustion Chambers

Ever since the early stages of space transportation in the 1940’s, and the related liquid propellant rocket engine development, combustion instability has been a major issue. High frequency combustion instability (HFCI) is the interaction between combustion and the acoustic field in the combustion chamber. It destroys the thermal boundary layer...

Influence of topography on tide propagation and amplification in semi-enclosed basins

An idealized model for tide propagation and amplification in semi-enclosed rectangular basins is presented, accounting for depth differences by a combination of longitudinal and lateral topographic steps. The basin geometry is formed by several adjacent compartments of identical width, each having either a uniform depth or two depths separated...

Insect-inspired wing actuation structures based on ring-type resonators

In this paper, we illustrate and study the opportunities of resonant ring type structures as wing actuation mechanisms for a flapping wing Micro Air Vehicle (MAV). Various design alternatives are presented and studied based on computational and physical models. Insects provide an excellent source of inspiration for the development of the wing...

A new elastic model for ground coupling of geophones with spikes

Ground coupling are terms that describe the transfer from seismic ground motion to the motion of a geophone. In previous models, ground coupling was mainly considered as a disk lying on top of a half-space, not considering the fact that in current practice geophones are spiked and are buried for optimal response. In this paper we introduce a new...

Steady-State Response of Periodically Supported Structures to a Moving Load

Steady-state vibrations of periodically supported structures under a moving load are analytically investigated. The following three structures are considered: an overhead power line for a train, a long suspended bridge and a railway track. The study is based on the application of so-called 'periodicity condition', which implies that the shape of...

Effect of tidal resonance on the morphology of Wadden and Estuaries

Contains basic paper plus background supplements. Areas like the Western Wadden area have a length of approximately 1/4 of a tidal wave length. Therefore tidal motion is sensible for resonance. It is investigated, under which circumstances morphological instabilities may occur. Instabilities are defined in this way, that small depth increments...