The measurement of lubricant-film thickness using ultrasound

Ultrasound is reflected from a liquid layer between two solid bodies. This reflection depends on the ultrasonic frequency, the acoustic properties of the liquid and solid, and the layer thickness. If the wavelength is much greater than the liquid-layer thickness, then the response is governed by the stiffness of the layer. If the wavelength and layer thickness are similar, then the interaction of ultrasound with the layer is controlled by its resonant behaviour. This stiffness governed response and resonant response can be used to determine the thickness of the liquid layer, if the other parameters are known. In this paper, ultrasound has been developed as a method to determine the thickness of lubricating films in bearing systems. An ultrasonic transducer is positioned on the outside of a bearing shell such that the wave is focused on the lubricant-film layer. The transducer is used to both emit and receive wide-band ultrasonic pulses. For a particular lubricant film, the reflected pulse is processed to give a reflection-coefficient spectrum. The lubricant-film thickness is then obtained from either the layer stiffness or the resonant frequency. The method has been validated using fluid wedges at ambient pressure between flat and curved surfaces. Experiments on the elastohydrodynamic film formed between a sliding ball and a flat surface were performed. Film-thickness values in the range 50-500 nm were recorded, which agreed well with theoretical film-formation predictions. Similar measurements have been made on the oil film between the balls and outer raceway of a deep-groove ball bearing

A supercritical series analysis for the generalized contact process with diffusion

We study a model that generalizes the CP with diffusion. An additional transition is included in the model so that at a particular point of its phase diagram a crossover from the directed percolation to the compact directed percolation class will happen. We are particularly interested in the effect of diffusion on the properties of the crossover between the universality classes. To address this point, we develop a supercritical series expansion for the ultimate survival probability and analyse this series using d-log Pad\'e and partial differential approximants. We also obtain approximate solutions in the one- and two-site dynamical mean-field approximations. We find evidences that, at variance to what happens in mean-field approximations, the crossover exponent remains close to $\phi=2$ even for quite high diffusion rates, and therefore the critical line in the neighborhood of the multicritical point apparently does not reproduce the mean-field result (which leads to $\phi=0$) as the diffusion rate grows without bound

In vivo immunological toxicity in mice of carbon nanotubes with impurities

ArticleCarbon. 47(5):1365-1372 (2009)journal articl

Thin Ice Target for 16^{16}O(p,p') experiment

A windowless and self-supporting ice target is described. An ice sheet with a thickness of 29.7 mg/cm$^2$ cooled by liquid nitrogen was placed at the target position of a magnetic spectrometer and worked stably in the $^{16}$O$(p,p')$ experiment at $E_{p}=392$ MeV. Background-free spectra were obtained.Comment: 14 pages, 4 figures, Nucl. Instr. & Meth. A (in press

Strong Approximation of Empirical Copula Processes by Gaussian Processes

We provide the strong approximation of empirical copula processes by a Gaussian process. In addition we establish a strong approximation of the smoothed empirical copula processes and a law of iterated logarithm

DESIGN METHOD FOR BUCKLING AMPLIFIED PIEZOELECTRIC ACTUATOR USING FLEXURE JOINT AND ITS APPLICATION TO AN ENERGY EFFICIENT BRAKE SYSTEM

ABSTRACT This paper shows a practical design method for a displacement amplification mechanism for a piezoelectric actuator which employs a buckling INTRODUCTION Energy efficiency is a major concern these days. Energy efficiency not only reduces energy consumption, but also affects the crucial value of various products. For example, more efficient motors require smaller energy reservoirs which result in enhanced performance, especially in mobile machines such as cars and robots. Electro-magnetic (EM) motors are arguably the most popular actuators in many machines. Their properties are based on the inductive energy transformation principle, which suits work conditions which need continuous motion regardless of force outputs required. EM motors consume energy depending on the output force regardless of their mechanical work. Hence, in load conditions which requir

The facial nucleus of cat: Antidromic and synaptic activation and peripheral nerve representation

The facial nucleus (FN) of the cat was studied by electrophysiological method for (1) general characteristics of the FN neurons during antidromic activation, (2) topographical representation of the peripheral branches of the facial nerve and (3) synaptic activities induced in the FN neurons following peripheral facial nerve stimulation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46540/1/221_2004_Article_BF00233995.pd

Patient-specific Conditional Joint Models of Shape, Image Features and Clinical Indicators

We propose and demonstrate a joint model of anatomical shapes, image features and clinical indicators for statistical shape modeling and medical image analysis. The key idea is to employ a copula model to separate the joint dependency structure from the marginal distributions of variables of interest. This separation provides flexibility on the assumptions made during the modeling process. The proposed method can handle binary, discrete, ordinal and continuous variables. We demonstrate a simple and efficient way to include binary, discrete and ordinal variables into the modeling. We build Bayesian conditional models based on observed partial clinical indicators, features or shape based on Gaussian processes capturing the dependency structure. We apply the proposed method on a stroke dataset to jointly model the shape of the lateral ventricles, the spatial distribution of the white matter hyperintensity associated with periventricular white matter disease, and clinical indicators. The proposed method yields interpretable joint models for data exploration and patient-specific statistical shape models for medical image analysis.Comment: Supplementary material: https://www.youtube.com/watch?v=gPoHP_iFQI