1010‐cycle fatigue properties of 1800 MPa‐class JIS‐SUP7 spring steel

10¹⁰‐cycle fatigue tests were conducted at 100 Hz for three years and at 20 kHz for one week on 1800 MPa‐class JIS‐SUP7 spring steel. Uniaxial tests up to 10⁸ cycles were also conducted at 120 and 600 Hz. The 120 Hz tests had larger control volumes. The fatigue limit at 10¹⁰ cycles was lower than at 10⁸ cycles, and any frequency effect was shown to be negligible. A size effect was found; the tests with larger control volumes showed results of lower fatigue strength.     

DISPERSION STATE OF PROTEIN-STABILIZED EMULSIONS Dependence of Globule Size and Size Distribution upon pH in Concentrated Oil-in-Water Systems

Concentrated benzene-in-water emulsions were prepared with various proteins such as lysozyme, bovine serum albumin, ovalbumin, casein and gluten. The emulsions consisted of coarse globules whose size distribution could be approximated to the log-normal distribution function, while the adsorbed film of protein molecules seemed to contribute to the stabilization of the globules. These properties were influenced by the pH of the aqueous phase. The mean globule size increased progressively up to the isoelectric point of the proteins. Both the interfacial tension and the rate of coalescence between the globules were minimized as the isoelectric point of the proteins was approached.     

Novel guidelines for the development of pM-selective glass electrodes from oxide glasses

There have been no guidelines for developing pM-selective (M = alkali metal ions) glass membrane electrodes. One of the key points for developing pM-selective glasses is to make glasses not responsive to changes in pH, since pM-measurements can be disturbed by the pH of the solution. As hydrogen-bonded protons in glasses are mobile and their mobility is thought to be responsible for pH-sensitivity, glasses for pM-selective electrodes should contain no hydrogen-bonded protons and no non-bridging oxygen. In this paper, guidelines for developing pH-selective glasses are proposed by using pNa-selective glasses in the Na₂O–Al₂O₃–SiO₂ system as examples. This revised version was published online in November 2006 with corrections to the Cover Date.     

A statistical approach to strength evaluation incorporating porosity effect for porous ceramics

ABSTRACT It has not been clear whether the conventional effective volume proposed for dense brittle materials can be applied satisfactorily to the strength evaluation of porous ceramics. In the present study, a modified effective volume was proposed by incorporating the porosity effect in the statistical evaluation of strength properties of porous ceramics. The modified effective volume was derived as the conventional effective volume multiplied by a function of porosity p. In this work, a power function of (1 + p)^a was adopted as the simplest porosity function. To clarify the applicability of the modified effective volume, bending tests were conducted using smooth and notched specimens of 3 wt% MgO partially stabilised zirconia with six different porosities. The porosity dependence appeared in the relation between the conventional effective volume and the mean strength of various zirconia ceramics with different porosities. The exponent a of the porosity function was determined from experimental data obtained by using identically shaped specimens with distinct porosities, and the modified effective volume was calculated for several types of specimens used in the experiments. It was revealed that the mean strength was almost uniquely correlated with the modified effective volume independent of porosity. The experimental correlation verified the applicability of the modified effective volume to strength evaluation of porous ceramics.     

Study on Rotary Loop Flow Controller for the Next‐Generation Distribution System

This paper describes two types of rotary loop flow controller, one is series type and the other is unified power flow controller (UPFC) type. Both of them can maintain the suitable voltage level of distribution system even with a large and uneven penetration of distributed generation. The configurations of proposed controllers are essentially same as wound rotor induction machine with no slip rings. The proposed controllers are less costly, more efficient, and more tolerant to overvoltages/currents as compared to power electronics‐type controllers. Further, UPFC‐type rotary loop flow controller has additional advantages like relatively smaller capability and ability to control reactive power than the series type of rotary loop flow controller. The proper functioning of the proposed controllers is confirmed through simulations and experiments.     

Development of Tri‐Stable Rotary Solenoid Actuator

We have designed and developed a tri‐stable rotary solenoid actuator, which has a simple structure and simple operation. The plunger has two stabilities at the extreme positions along an angular stroke and the third stability at the center of it. The third has been successively achieved by using the electromagnetic restoring torque, which is designed to be larger than the inertia torque. The dynamic characteristics were determined by utilizing an optimal design program that is specially constructed based on the response surface method in order to design the coil winding and the power supply for the coil excitation. A prototype solenoid was constructed and used to verify the tri‐stable motions and accuracy of the previously constructed design program.     

Electromotive Manipulator Control by Detection of Proximity,Contact, and Slipping Using MEMS Multiaxial Tactile Sensor

In this paper, we have demonstrated usefulness of the electromotive manipulator system with a developed single element MEMS sensor which can detect proximity, contact, and slipping to skillful gripping of the object. This MEMS sensor can detect proximity as impedance change of Si substrate by reflected light from the object due to the photoconductive effect. In addition, both normal and shear load can be also detected as resistance change of strain gage on cantilevers located threefold symmetry and embedded in polydimethylsiloxane (PDMS). By attaching the sensor on the electromotive manipulator, accurate control of gripping force was enabled by feedback of the sensor output.