A novel continuously adjustable hydrodynamic bearing

A novel form of adjustable fluid film bearing has been devised whereby the hydrodynamic conditions can be changed in a continuously controlled manner during operation. The principle can be applied to conventionally orientated journal bearings, i.e. a shaft rotating within a stationary bearing housing; to inverse orientations, i.e. a rotor on a stationary shaft; and to thrust bearings. A theoretical model and computerised solution technique were developed in which the fluid film profile, temperature, viscosity and pressure fields were simultaneously solved. Experiments were conducted on journal bearing versions for which recently developed measurement techniques demonstrated stable operation at zero eccentricity, and the ability to move the rotational centre whilst in operation. Performance characteristics predicted by the computer model have been demonstrated in practice. The novel bearing has shown significant improvements over conventional designs in tems of stiffness, damping, rotational accuracy, power losses and temperature rise

Fluid Film Bearings

A hydrodynamic fluid film bearing in which a plurality of circumferentially spaced bearing elements are provided, defining areas of support for the rotating part of the bearing. At least some of the bearing elements are adjustable during operation to vary lubrication conditions in the fluid film. The bearing elements are of sufficiently high stiffness that the position of the entire bearing surface of each element is essentially independent of the pressure in the fluid film encountered during operation. The bearing allows complete control of the lubrication conditions and can be adjusted for optimum performance over a wide range of speed and load

Single cold atom as efficient stationary source of EPR-entangled light

The Stokes and anti-Stokes components of the spectrum of resonance fluorescence of a single trapped atom, which originate from the mechanical coupling between the scattered photons and the quantized motion of the atomic center of mass, exhibit quantum correlations which are of two-mode-squeezing type. We study and demonstrate the build-up of such correlations in a specific setup, which is experimentally accessible, and where the atom acts as efficient and continuous source of EPR-entangled, two-mode squeezed light

CTRL+ALT+DEL: De keuring van technische hulpmiddelen

In deze bijdrage gaan wij in op het begrip technisch hulpmiddel en twee daaraan gekoppelde discussiepunten, te weten de definitie van technisch hulpmiddel en de voorafgaande keuring van software. Op basis daarvan beantwoorden wij in deze bijdrage de vraag wat het toekomstige recht moet regelen met betrekking tot de keuring van technische hulpmiddelen

2019-2020 Master Class - Members of the Eroica Trio

https://spiral.lynn.edu/conservatory_masterclasses/1201/thumbnail.jp

Time-separated entangled light pulses from a single-atom emitter

The controlled interaction between a single, trapped, laser-driven atom and the mode of a high-finesse optical cavity allows for the generation of temporally separated, entangled light pulses. Entanglement between the photon-number fluctuations of the pulses is created and mediated via the atomic center-of-mass motion, which is interfaced with light through the mechanical effect of atom-photon interaction. By means of a quantum noise analysis we determine the correlation matrix which characterizes the entanglement, as a function of the system parameters. The scheme is feasible in experimentally accessible parameter regimes. It may be easily extended to the generation of entangled pulses at different frequencies, even at vastly different wavelengths.Comment: 17 pages, 5 figures. Modified version, to appear in the New Journal of Physic

Development of a low-power wireless acoustic emission sensor node for aerospace applications

Acoustic emission (AE) is the spontaneous release of energy caused by the growth of damage, the monitoring of which gives an indication of the presence of damage within a structure. The current standard for AE localisation is difficult to apply in a low‐power system as sensors must either be wired together or Node's time synchronised, which is power intensive. This paper proposes the use of a method of bonding three piezoelectric sensors in a small triangular array, which has previously been shown by Aljets et al. to be capable of locating sources in simple structures. In this prior work the wave's A0 mode was used to predict the angle of arrival and the distance the wave has travelled through single sensor modal analysis. This paper presents the development of hardware to apply this technique and testing that showed artificial sources could be located in simple plates to a good level of accuracy. The addition of complexity to structures significantly reduced accuracy. This prompted hardware modifications to use the S0 mode for angle prediction. Testing showed that this significantly improved performance in a complex composite structure. The power consumption of the device is very low, consuming 0.33 mW in sleep mode, 17.44 mW whilst waiting for an event and 38 mW to record, process and transmit an event. This level of consumption has the potential to be self‐powered via energy harvesting

Entanglement transfer from dissociated molecules to photons

We introduce and study the concept of a reversible transfer of the quantum state of two internally-translationally entangled fragments, formed by molecular dissociation, to a photon pair. The transfer is based on intracavity stimulated Raman adiabatic passage and it requires a combination of processes whose principles are well established.Comment: 5 pages, 3 figure

Continuous variable entanglement and quantum state teleportation between optical and macroscopic vibrational modes through radiation pressure

We study an isolated, perfectly reflecting, mirror illuminated by an intense laser pulse. We show that the resulting radiation pressure efficiently entangles a mirror vibrational mode with the two reflected optical sideband modes of the incident carrier beam. The entanglement of the resulting three-mode state is studied in detail and it is shown to be robust against the mirror mode temperature. We then show how this continuous variable entanglement can be profitably used to teleport an unknown quantum state of an optical mode onto the vibrational mode of the mirror.Comment: 18 pages, 10 figure