Nanometer stepping drives of surface acoustic wave motor

High resolution (from nanometer to subnanometer) stepping drives of a surface acoustic wave motor are presented. It was shown that step displacement was easily controlled by adjusting a number of driving waves, using a steel ball slider equipped with permanent magnet for preload. By means of this open loop control, the step displacement was controlled from centimeter-order to submicrometer-order. In this paper, using a silicon slider equipped with a ball bearing linear guide, the stepping motions of a surface acoustic wave motor were investigated. A laser interferometer equipped with a 2-picometer resolution displacement demodulator was introduced. Motions of the slider ranging from several hundreds of nanometers to several nanometers in each step displacement were observed. Reduction of the driving waves down to 25 cycles, under a 100 V/sub peak/ driving voltage and a 30 N preload condition, generated about 2 nm stepping motion using our experimental setup under an open loop condition. We also demonstrated subnanometer step movements. These experimental results indicated that the surface acoustic wave motor has an ability of subnanometer positioning with a centimeter-level stroke.     

Stabilizing effect of artificial stabilizers for binding activity of QCM immunosensors

We compare stabilizing effects of artificial and natural stabilizers for maintenance of binding activity of immobilized antibody on the gold surface of quartz crystal microbalance (QCM). Binding activity between immobilizing antibody and specific antigen was measured and considered as a calculated frequency shift with QCM-immunosensor after temperature increasing and long-term storage. According to the experimental results, one stabilizer among eight samples shows the best stabilizing effect for QCM-immunosensor.     

Simple, real-time method for removing the cyclic error of a homodyne interferometer with a quadrature detector system

The cyclic error of a homodyne interferometer is caused mainly by phase mixing due to the imperfection of polarizing optical components such as polarizing beam splitters. In Appl. Opt. 43, 2443 (2004), we concentrated on the relationship between these imperfect optical characteristics and the cyclic error and found the preamplifier-gains condition for removing the cyclic error. Here we demonstrate the cyclic error correction method experimentally and show that the method can be applied in real time. We obtained 0.04-nm cyclic errors, with a standard deviation above 5 microm.     

Preparation of aqueous dispersible polyurethane: Effect of acetone on the particle size and storage stability of polyurethane emulsion

An aqueous dispersible polyurethane was prepared by the reaction of hydroxyl‐terminated poly(ethylene adipate), dimethylol propionic acid, 4,4′‐diphenylmethane diisocyanate, and ethylene glycol. Formation of the dispersion was achieved by phase inversion of an acetone solution of the polyurethane with water, utilizing carboxylate anion groups as the internal emulsifying sites. The amount of acetone added has a large effect on the particle diameter (0.08 to 8.61 μm) and particle size distribution of the polyurethane emulsion. The storage stability was evaluated in terms of particle size distribution breadth. The aqueous emulsion obtained with no use of acetone was sufficiently stable in storage for at least 6 months. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3455–3461, 2004     

Energy Problems and Energy Control System in the Japanese Steel Industry

With the second oil crisis as a turning point, energy issues have come to occupy a most vital position in business. For the steel industry in particular, which is a heavy oil consumer, energy conservation is as vital as it is anywhere. Steelmakers are therefore committed to a variety of energy-conserving measures, including (1) the installation of waste heat recovery facilities, (2) the organization of elaborate economizing campaigns, (3) the orientation toward continuous operations (continuous casting, etc.) by integrating indispensable processes and excluding dispensable ones, and (4) the increased use of hot rolling and direct rolling, etc.

On the other hand, the steel industry has energy-generating facilities and by-product energy-generating processes that form a complicated energy supply-demand structure. Energy balance is intimately related to the operating rate and the operating method of each steel works, and this so much so that the minimization of specific energy costs does not necessarily entail total cost minimization.

Because of this, there is a rapidly expanding need for a scientifically built “software system” within which the aforementioned relationships are quantitatively analyzed to minimize overall plant costs in relation to the changing external environment. This paper discusses this system by referring to the developments and achievements made so far by the Yawata works of Nippon Steel Corporation.     

Overview of secondary neutron production relevant to shielding in space

An overview of experimental secondary neutron measurements relevant to space-related activities is presented. Stopping target yields and cross section measurements conducted at particle accelerators using heavy ions with energies > 100 MeV per nucleon are discussed.     

Polarization properties of the flint glass fiber

To realize stable characteristics of a current sensor using the Faraday effect in an optical fiber, it is necessary to prevent the influence of birefringent effect on light passing the fiber, which is caused by photo-elastic effect and/or lack of axial symmetry of its structure. The flint glass fiber manufactured from flint glass with very small photo-elastic constant, which has circular core and satisfies the single ode condition,has been developed to solve this problem. This paper reports results of a study to clarify polarization properties of the fiber and to consider a method for highly stabilizing the polarization. From experiments to investigate the relationship between state of polarization of light inserted to the fiber and that emitted from another end, it was confirmed that the birefringence due to the photo-elastic effect and the lack of symmetry are negligibly small. It also became known that the azimuth angle of polarization of the emitted light depends on the shape of the curve of the fiber. Namely, a rotation of the polarization plane is equal to the amount of line integral of the torsional rate along the curve. A countermeasure is necessary for this phenomenon, because characteristics of the current sensor may be influenced if the flint glass fiber coil is deformed by environmental factors. From a consideration of the mechanism of the phenomenon, it is inferred that the problem can be solved by reciprocating light in the fiber to stabilize the polarization. The effect of this method is confirmed experimentally