Inactivation of Lactobacillus fructivorans in physiological saline and unpasteurised sake using CO2 microbubbles at ambient temperature and low pressure

The ability of carbon dioxide microbubbles (MB‐CO₂) to inactivate Lactobacillus fructivorans suspended in physiological saline and unpasteurised sake at ambient temperature and a pressure lower than 2.0 MPa was investigated. The number of L. fructivorans cells in physiological saline solution containing 15% ethanol showed a 6‐log reduction following MB‐CO₂ treatment at 40 °C and 2.0 MPa for 50 min. The effectiveness of the treatment increased concomitantly with temperature, pressure and ethanol concentration of the sample solution but was unaffected by the glucose concentration in the sample solution. Furthermore, the number of L. fructivorans cells showed a 5‐log reduction in sake after MB‐CO₂ treatment at 40°C and 2.0 MPa for 60 min. Sensory evaluation revealed no significant difference between MB‐CO₂‐treated sake and unpasteurised sake. These results indicated that MB‐CO₂ treatment was highly effective for the inactivation of L. fructivorans and might become a practical method for pasteurising sake at ambient temperature.     

16 Kb/s high quality voice encoding for satellite communication networks

This paper describes applications of adaptive predictive coding (APC) with maximum likelihood quantization (MLQ) which can cover a wide range of coding rates from 4.8 to 16 kb/s for low C/N satellite communication systems, such as maritime, aeronautical mobile and thin-route satellite communication systems, and also for speech and data integration, including digital circuit multiplication equipment (DCME) in business communication systems, such as INTELSAT business services (IBS). A 16 kb/s APC–MLQ hardware codec has been implemented by NEC–7720 DSP chips and the performance has been confirmed in subjective quality of speech through conversational tests. The objective performance has also been evaluated for non-voice signals, such as single and multi-frequency tones, and 1200 and 2400 b/s voiceband data signals. The APC-MLQ codec can transmit the voice-band data at 1200 b/s over two asynchronous tandem links and at 2400 b/s over one link. It was noted that the APC-MLQ codec is superior in speech performance at 16 kb/s to a narrow-band companded FM and meets requirements for low C/N satellite communication systems. For voice and data integration into 16 kb/s for 64 kb/s links, we propose a multi-media multiplexing for low C/N digital satellite communication systems and also a small-scale circuit multiplication system for business use. In these systems, a variable rate coding of APC-MLQ from 4.8 to 16 kb/s can be effectively introduced for voice and data integration.     

Improvement of convergence behavior for adaptive feed-forward control with initial values design in hard disk drives

This paper introduces an improvement method of convergence behavior for adaptive feed-forward control in hard-disk-drives (HDDs). To increase a data capacity of HDDs, head-positioning-control system must compensate for any disturbances which worsen the positioning accuracy. Especially, it is important to compensate for external disturbances in the head positioning system of 2.5 type HDDs. Previous studies proposed an adaptive feed-forward control method to compensate for the external disturbances. However, the control method have problems with respect to convergence in the adaptive algorithm. To overcome the problems, we have developed design method of initial values for the adaptive feed-forward control by using data-driven design method. The initial values designed by proposed method can improve the convergence behavior for the adaptive algorithm.     

A 13.5‐in. Quad‐FHD flexible CAAC‐OS AMOLED display with long‐life OLED device structure

In this study, the device structure of a white tandem organic light‐emitting diode (OLED) was changed to control the emission area and thereby achieve less luminance decay. A long‐life 13.5‐inch 4 K flexible c‐axis‐aligned crystal oxide semiconductor (CAAC‐OS) active‐matrix OLED with less color shift and high resolution was fabricated using this long‐life white OLED, transfer technology, and a CAAC‐OS field‐effect transistor.     

Simple timing generation along workspace paths for nonredundant robotic limbs

This article focuses on the relation between workspace path geometry and the timing along the path, obtained via simple timing generators yielding constant end-link speed motion, natural motion, and two types of globally optimized joint velocity motions. The generators are designed within the Singularity-Consistent framework developed originally to tackle motion control in the vicinity of kinematic singularities. A comparative study highlights how performance expressed in terms of various kinematic and dynamic criteria of local (peak joint velocity and torque) and global (joint velocity/torque uniformity and total mechanical power) nature is influenced by the curvature of the path image in configuration space and by the vicinity of singular configurations. Results from simulations with a simple planar 2R limb and a spatial 3R positioning limb following linear and circular paths are presented.     

A Versatile and Simple Approach to Generate Light Emission in Semiconductors Mediated by Electric Double Layers

The light‐emitting device is the primary device for current light sources. In principle, conventional light‐emitting devices need heterostructures and/or intentional carrier doping to form a p–n junction. This junction formation is, however, very difficult to achieve for most emerging semiconductors, and the fabrication of light‐emitting devices is invariably a significant challenge. This study proposes a versatile and simple approach to realize light‐emitting devices. This proposed device requires only a semiconducting film with two electrodes that are covered with an electrolyte. This unique structure achieves light emission at a voltage slightly larger than the bandgap energy of materials. This study applies this concept to emerging direct bandgap semiconductors, such as transition metal dichalcogenide monolayers and zinc oxide single crystals. These devices generate obvious light emission and provide sufficient evidence of the formation of a dynamic p–i–n junction or tunneling junction, presenting a versatile technique to develop optoelectronic devices.     

Polyolefin fibers with chemically fixed active ester for the solid phase synthesis of an amide derivative

Reactive fibers having chemically fixed active ester were derived from chloromethylstyrene grafted polyethylene-coated polypropylene staple fiber and non-woven cloth. First, chlorine atoms in each fiber were substituted by mercapto groups, and the resulting fibers were reacted with N-hydroxymaleimide to obtain fibers containing chemically fixed N-hydroxysuccinimide moieties. These fibers were converted into reactive fibers having chemically fixed active ester by reaction with a model carboxylic acid (3-(2-bromophenyl)propionic acid) in the presence of a condensing reagent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride) in excess. Performances of both reactive fibers in the model amide synthesis were compared by their reaction with 2-phenylethylamine. Although the reactive non-woven cloth gave an amide contaminated with unknown organic impurities, the reactive staple fiber yielded highly pure product. Possible causes of this difference are discussed on the basis of SEM observation of both fibers.     

Three-component photo radical initiating system—the effect of 2-mercaptobenzothiazole as a co-initiator in polymer matrix

We studied the sensitization mechanism in a photo initiating system that consists of an aminostyryl sensitizing dye, 2-[p-(diethylamino)styryl]naphto[1,2-d]thiazole (NAS), and a radical generator, 2,2′-bis(2-chlorophenyl)-4,4′,5,5′-tetraphenyl-1, 1′-bi-1H-imidazole (HABI). In a photopolymer bearing NAS/HABI system, an improvement of the photosensitivity was observed by the addition of co-initiator, 2-mercaptobenzothiazole (MBT), to the initiating system. Photochemical and photophysical behavior of the three-component initiating system, NAS/HABI/MBT, in the PMMA film was studied by means of a nanosecond laser flash photolysis method employing a total reflection sapphire plate. It is considered that MBT can enhance to generate the triplet state of NAS, which is hardly observed by the direct excitation, and the mechanism of both singlet and triplet electron transfer from NAS to HABI is suggested.     

Bonding strength of DLC film on zirconia coating prepared by gas tunnel type plasma spraying

Bonding strength of diamond-like carbon (DLC) films on zirconia coatings prepared using a novel gas tunnel plasma spraying method has been studied and discussed. The emphasis is on the getting better characteristics of such doubly structured coatings (DSC) as comparing compared with properties of both components involved in the coatings. For the study of various failure mechanisms zirconia coatings of different thicknesses on aluminum substrates were prepared. The as-sprayed coatings were firstly polished and then subjected to deposition of DLC films. Adhesion of the DSC has been evaluated using a scratch test method. It has been found that the thicker coatings have higher hardness and lower porosity. The adhesion failures of DLC films on zirconia coatings (DSC) are caused by two different main mechanisms: (i) DLC films separation from the zirconia coatings, and (ii) DLC films breaking under stress load due to the brittleness of the material. In addition the adhesion failures are due to flaking of DLC films on the thinner zirconia coatings caused by a distortion of the aluminum alloy substrate coatings; and, chipping of DLC films themselves on the thicker zirconia coatings.     

Separation mechanism for double cylinder with shrink fitting system used for ceramics conveying rollers

Steel conveying rollers used in hot rolling mills must be exchanged frequently at great cost because hot conveyed strips induce wear and deterioration on the surface of roller in short periods. In previous studies, new roller structure was considered which has a ceramics sleeve connected with two steel shafts at both ends by shrink fitting. Here, although the ceramics sleeve can be used for many years, the steel shafts sometimes have to be exchanged for maintenance and reconstruction under the corrosive atmosphere. Since the thermal expansion coefficient of steel is about five times larger than that of ceramics, it is necessary to investigate how to separate the shrink fitting system by heating outside of sleeve and cooling inside of the shaft. Although how to separate the real roller has been discussed in the previous study, the separation mechanism has not been clarified yet. Therefore, in this study, several types of more fundamental models are investigated to understand the separation mechanism of real roller by the application of the finite element method. The results may be useful for designs of new rollers.