Uncertainty analysis of calibration of geometrical gauges

On the calibration of geometrical gauges, such as a ball plate, using a coordinate measuring machine, a gauge block is simultaneously used for compensating the scale error and maintaining traceability to the length standard. A mathematical model of this calibration procedure is presented in accordance with Guide to the Expression of Uncertainty in Measurement (GUM). By considering uncertainty of the calibration, the danger of using a single gauge block is pointed out both theoretically and experimentally, and a solution to avoid the danger is also presented.     

Continuous extraction and separation of Am(III) and Cm(III) using a highly practical diamide amine extractant

A highly practical diamide-type extractant, which is an alkyl diamide amine with 2-ethylhexyl alkyl chains (ADAAM(EH)), was investigated for the mutual separation of Am(III) and Cm(III). ADAAM(EH) is a multidentate ligand with one soft N-donor atom and two hard O-donor atoms as part of its central frame. This tridentate arrangement of donor atoms provides selective binding to Am(III) compared to that with Cm(III) in highly acidic media (1.5 M HNO₃), resulting in separation factors of up to 5.5. A continuous liquid–liquid extraction and stripping test was conducted using a multistage countercurrent mixer-settler extractor with ADAAM(EH) in n-dodecane. In this test, the separation of Am(III) and Cm(III) was achieved with very high yield.     

Tag-KEM/DEM: A New Framework for Hybrid Encryption

This paper presents a novel framework for the generic construction of hybrid encryption schemes which produces more efficient schemes than the ones known before. A previous framework introduced by Shoup combines a key encapsulation mechanism (KEM) and a data encryption mechanism (DEM). While it is sufficient to require both components to be secure against chosen ciphertext attacks (CCA-secure), Kurosawa and Desmedt showed a particular example of KEM that is not CCA-secure but can be securely combined with a specific type of CCA-secure DEM to obtain a more efficient, CCA-secure hybrid encryption scheme. There are also many other efficient hybrid encryption schemes in the literature that do not fit into Shoup’s framework. These facts serve as motivation to seek another framework. The framework we propose yields more efficient hybrid scheme, and in addition provides insightful explanation about existing schemes that do not fit into the previous framework. Moreover, it allows immediate conversion from a class of threshold public-key encryption to a threshold hybrid one without considerable overhead, which may not be possible in the previous approach.     

Mechanism of color breakup in field-sequential-color projectors

Abstract— To investigate color breakup in field-sequential-color projectors, we measured the threshold of color fusion frequency relative to retinal velocity of the moving edge on the color flicker field. The characteristic changed as the velocity approached saccade. The result suggests that the mechanism of color breakup differs according to the velocity of the image on the retina.     

Changes in the specificity of antibodies against steroid antigens by introduction of mutations into complementarity-determining regions of the V(H) domain

An attempt was made to change the specificity of antibodies (Abs) by introduction of mutations. A monoclonal Ab specific for 17alpha- hydroxyprogesterone (17-OHP) was used as the starting Ab. On the basis of a model that was generated by a computer-driven model-building system, we constructed a phage-display library of Abs in which 16 residues were mutated in three complementarity-determining regions of the heavy chain that appeared to form the steroid-binding pocket. We screened the library with 17-OHP and cortisol that had been conjugated with bovine serum albumin, and we isolated many clones that had retained 17-OHP-binding ability as well as clones with the newly developed ability to bind cortisol in addition to 17-OHP. We compared the amino acid sequences between 17-OHP-specific and cortisol-binding Abs, and then constructed several additional Abs. Our results indicated that a change in specificity could be achieved by changing only a single, critical amino acid residue. Models of the 17-OHP-and cortisol- binding pockets formed by the mutated Abs could explain these observations.      

Simulation of surface acoustic wave motor with spherical slider

The operation of a surface acoustic wave (SAW) motor using spherical-shaped sliders was demonstrated by Kurosawa et al. (1994). It was necessary to modify the previous simulation models for usual ultrasonic motors because of this slider shape and the high frequency vibration. A conventional ultrasonic motor has a flat contact surface slider and a hundredth driving frequency; so, the tangential motion caused by the elasticity of the slider and stator with regard to the spherical slider of the SAW motor requires further investigation. In this paper, a dynamic simulation model for the SAW motor is proposed. From the simulation result, the mechanism of the SAW motor was clarified (i.e., levitation and contact conditions were repeated during the operation). The transient response of the motor speed was simulated. The relationships between frictional factor and time constant and vibration velocity of the stator and the slider speed were understood. The detailed research regarding the elastic deformation caused by preload would be helpful to construct an exact simulation model for the next work.     

An Approach to Flux Control of Induction Motors Operated with Variable-Frequency Power Supply

A new speed control system for induction motors has been developed which is capable of controlling with quick field weakening and superior response and stability. This method is to control the stator current as a vector quantity on the basis of slip frequency control. More specifically, it is designed to calculate the commanded stator current of the induction motor by corresponding to flux and torque commands on the basis of motor constants and use the calculated commands to control the stator current.     

Angle dependence of signal currents from cylindrical ionisation chambers

A signal current from a cylindrical ionisation chamber with an ionisation volume of 62.7 cm3, 40 mm in diameter and 50 mm long, peaked when the chamber was lixed at 0 degrees and at 90 degrees in 137Cs and 60Co gamma ray fields for source-chamber distances of 1 m and 2 m. A smaller ionisation chamber showed a small peak at 0 degrees in both fields but not at 90 degrees. However, calculations indicated that the signal current from the smaller chamber would also show a peak at 90 degrees in a 137Cs point-source gamma ray field. Peaks occur because gamma rays attenuate along the cylindrical side wall or along the end walls when a chamber is tilted slightly from 0 degrees or 90 degrees and the direction of the gamma ray beam agrees with the plane of one of these walls. These facts suggest the need for care in the common practice of measuring and calculating responses for cylindrical ionisation chambers fixed perpendicular to gamma ray beams.     

A cylindrical micro ultrasonic motor using PZT thin film deposited by single process hydrothermal method (phi2.4 mm, L=10 mm stator transducer)

A micro ultrasonic motor using PZT (lead zirconate titanate) thin film has been improved by a single process hydrothermal method. The hydrothermal method is a unique method for depositing PZT thin film in a solution. An earlier reported hydrothermal method consisted of two linked processes. Our new method, however, has only a single process. Hence, less distribution of chemical components of the PZT film contributes to a higher efficiency of the stator transducer. The piezoelectric factor d(31) was -30 pC/N for this new method, which is six times larger than that of the previous method. The output torque of the micro ultrasonic motor fabricated by the single process hydrothermal method was measured. The output torque was 7.0 muNm, and the maximum revolution speed was 880 rpm at 15 Vp-p driving voltage.     

Applications of electrostatic stretch-and-positioning of DNA

The authors have previously reported that the electrostatic orientation and the dielectrophoresis (DEP) of DNA occur under ≈1 MHz, >1×10⁶ V/m field, by which DNA strands are stretched straight along field lines and positioned onto electrode edges. This paper presents some application of this stretch-and-positioning method to genetic engineering. It is shown that the DNA size distribution, as well as the activities of nuclease, can be determined by the measurement of the apparent length of stretched DNA. Several methods are developed to immobilize stretched DNA onto a substrate, including: (1) immobilization onto a conducting substrate for observations with the scanning tunneling microscopy, (2) anchoring onto a substrate only at both ends of the DNA using special electrode configuration, and/or molecular binding between avidin and biotin. The DNA can be held without contact to the substrate in the latter method, so that it does not cause steric hindrances to the DNA-binding enzymes. A novel fluid integrated circuit (FIC) device is proposed in which stretched DNA is cut by laser beam for the successive sequencing. A method to obtain unidirectionally oriented DNA is developed. The spatial resolution, and the small number of molecules required, are the advantages of the assays and measurements using electrostatic DNA manipulations over conventional biochemical methods. It is hoped that the methods may open a way to a novel category of “molecular biochemistry with spatial resolution.”