High coercivity in Sm5Fe17 melt-spun ribbon

Sm–Fe binary alloy with the hard magnetic Sm₅Fe₁₇ phase was produced by melt-spinning followed by heat treatment. The magnetic properties of the Sm–Fe melt-spun ribbon depended on the annealing temperature. The highest coercivity, _iH_c = 1.90 MA m⁻¹, was obtained by annealing the Sm–Fe melt-spun ribbon for 1 h at 923 K. The coercivity of the Sm₅Fe₁₇ melt-spun ribbon was attributed to the grain size of the hard magnetic Sm₅Fe₁₇ phase.     

The Fatty Acid Composition in Tuna (Bonito,Euthynnus pelamis) Caught at Three Different Localities from Tropics to Temperate

The present paper describes the effect of habitat on the fatty acid composition of the lipid of bonito (Euthynnus pelamis), which was caught at three different localities, Philippine Sea (the tropical zone; seawater temperature at the fishing ground was 27·8°C), East China Sea (the subtropical zone; seawater temperature was 29·7°C), and the Pacific coast of Japan (the temperate zone; sea-water temperature was 20·3°C). The total lipids of various organs and stomach contents were extracted and their fatty acid composition analysed by gas chromatography (GC). Docosahexaenoic acid (DHA; 22: 6n-3) was the major unsaturated fatty acid in the lipid of all specimens examined from all localities. The mean DHA content accounted for more than 25% (mean±standard error: 26·0±0·6%) of the total fatty acids (TFA) in the lipids of all organs, a lipid profile markedly different from that of other fish species whose fatty acid composition is generally variable. Particularly, the mean DHA content of lipids in bonito caught in the northern sea-area sample (the temperate zone) was always high (28·4±0·7% TFA) in the lipid of every organ. Because the DHA contents of lipids of the stomach contents fluctuated between 9·9 and 31·9% TFA, bonito did not simply incorporate the fatty acid profile of the lipids of its prey fishes, but selectively accumulated the DHA. Though the mean DHA content in the lipid of all bonito from the tropical to the temperate zone was markedly higher than other marine fish species such as sardines and herrings, there was a small difference between those in the northern (28·4±0·7% TFA) and southern samples (the subtropical and tropical samples, 24·7±0·8% TFA) (P<0·05). It is suggested that the difference between them may be due to environmental effects, for example, the temperature of the seawater and the fatty acid composition of the lipids of prey organisms. © 1997 SCI.     

A novel variable-reluctance N-speed synchro and its application for synchronous reluctance motor drive

The authors have previously presented a control scheme for synchronous reluctance motors in which the motor current is controlled to keep the MMF (magnetomotive force) phase angle constant, and have shown that a simpler control scheme is possible by using an N-speed synchro for a 2N pole motor. However, conventional brushless synchros are expensive and bulky due to the intricate construction, where a rotary transformer supplies current to the exciting winding on the rotor core. The authors have therefore developed a novel VR (variable reluctance) synchro without the rotary transformer. This paper describes the theory of the novel VR synchro and presents measured waveforms of the output voltages of a prototype VR four-speed synchro. In addition, a variable speed drive system for eight-pole reluctance motors which uses the new control scheme is introduced. In this system, the VR synchro is directly connected to the motor shaft, whose output voltages are demodulated and directly used as the current phase command for the inverter current supplied to the motor. Experimental results show a satisfactory speed response for four-quadrant drive. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120 (3): 54–63, 1997     

Practical use of the statistically modified laminate model for injection moldings. Part 1: Method and verification

The fibers in injection molded FRP provide the material's strength and stiffness; however, they also supply many of the problems. Preferential orientation of fibers during molding can reduce strength and stiffness below expected values in critical directions, or induce warpage in thin walled sections. Makers of short fiber reinforced injection molded products typically use computer aided engineering packages to optimize product performance and manufacturing variables. However, the reliability of the fiber orientation simulation can be limited, and the method is not easily understood, making an assessment of accuracy for a given situation difficult. In addition, the structural module of flow analysis packages is often a basic package with many features missing. This paper presents a structural analysis system for injection molded parts made of short fiber reinforced plastics. A full-featured commercial structural analysis code is interfaced with a flow analysis program using a practical material model that takes into account the effects of local fiber orientation. The system is completely open to the user, and can be modified as required.     

Comparative studies on color preference in Japan and other Asian regions,with special emphasis on the preference for white

The results of three surveys are presented. The first survey was carried out in four large cities in Japan, and the findings were analyzed by factor analysis and cluster analysis. The second survey was carried out in Seoul, Korea and Tokyo, Japan to determine color preference in the two countries, focusing on the preference for white. The last survey compared color preference in Taipei and Tokyo, also with emphasis on the preference for white. In these successive studies on color preference in Japan and other Asian cities, the subjects were mainly asked to choose from a color chart the three colors they liked most and the three they liked least, and to state the reasons for their choices. The results of Survey 1 showed that color preference could be influenced by differences in age, sex, and geographical region. Also factor analysis and cluster analysis indicated some relation between color preference and the subjects' life styles. Dual scaling analysis of the results of Surveys 2 and 3 indicated that each Asian area has unique color preference tendencies and that there are statistically significant differences in the frequency of selection of colors of certain hues and tones. However, a high preference for white was common to all areas, along with preferences for some other colors. These results thus demonstrated a common strong preference for white in three neighboring Asian areas. The reasons given for the choices suggested that besides the factors of age and sex, associative images based on environmental and cultural aspects may be an important factor influencing color preference. © 1996 John Wiley & Sons, Inc.     

Fabrication of high-power electric double-layer capacitors

The electrochemical behavior of activated carbon/carbon (AC/C) composite electrodes was investigated for high-power electric doublelayer capacitors (EDLCs). It was found that high-rate charge/discharge characteristics are affected by the resistance of the electrolyte phase in the pores of the electrode. The charge/discharge characteristics were improved by optimizing the pore-size distribution of the electrodes. The size and total volume of the macro-pores in the electrodes were controlled by mixing and burning out polymer spheres. A high-power EDLC (15V, 470 F), which can discharge as much as 500 A, was fabricated by using improved AC/C composite electrodes.     

Preparation of silver-ion-loaded nonwoven fabric by radiation-induced graft polymerization

Sulfonic acid (SO₃H) groups were appended to three nonwoven fabrics made of polyethylene (PE), polypropylene (PP), and a hybrid of PP and PE by radiation-induced graft polymerization of glycidyl methacrylate (GMA) and subsequent ring-opening with sodium sulfite. Silver ion was loaded onto the resultant SO₃H-type cation-exchange nonwoven fabric at a density of 2.0 mmol g⁻¹, where the molar ratio of Ag ions to SO₃H groups was unity.     

Carbon nanotube-dependent synthesis of armchair graphene nanoribbons

Sub-nanometer armchair graphene nanoribbons(GNRs)with moderate band gap have great potential towards novel nanodevices.GNRs can be synthesized in the confined t...     

Visual simulation of water currents using a particle-based behavioural model

Several CG researchers have simulated impressive ocean waves so far. Recently, other researchers have succeeded in simulating waterfalls by employing a mass of particles. However, visual simulation of water currents having complex surfaces, such as mountain streams and turbulent water, still remains a challenging problem thanks to their complicated patterns of behaviour. Effective simulation methods for water currents are expected to have abilities to represent the following remarkable behavioural visual features of water: the appearance of a pool, an obstacle avoidance flow, a fluent flow, a flow into an open space, the collision and the confluence of flows and the occurrence of splashes. In this paper, we present a new type of particle-based simulation method for complex water currents which is not based on strict fluid dynamics but rather classified into a ‘quasi-physically-based’ simulation method constructed on the basis of algorithmic approaches. We first present a simple behavioural model of a ‘water-particle’. Next, we propose a method for generating CG images of water currents from a set of water-particles. Finally, we demonstrate the ability of our method by showing several examples of the simulation.     

Natural Killer T Cells Are Involved in Atherosclerotic Plaque Instability in Apolipoprotein-E Knockout Mice

The infiltration and activation of macrophages as well as lymphocytes within atherosclerotic lesion contribute to the pathogenesis of plaque rupture. We have demonstrated that invariant natural killer T (iNKT) cells, a unique subset of T lymphocytes that recognize glycolipid antigens, play a crucial role in atherogenesis. However, it remained unclear whether iNKT cells are also involved in plaque instability. Apolipoprotein E (apoE) knockout mice were fed a standard diet (SD) or a high-fat diet (HFD) for 8 weeks. Moreover, the SD- and the HFD-fed mice were divided into two groups according to the intraperitoneal injection of α-galactosylceramide (αGC) that specifically activates iNKT cells or phosphate-buffered saline alone (PBS). ApoE/Jα18 double knockout mice, which lack iNKT cells, were also fed an SD or HFD. Plaque instability was assessed at the brachiocephalic artery by the histological analysis. In the HFD group, αGC significantly enhanced iNKT cell infiltration and exacerbated atherosclerotic plaque instability, whereas the depletion of iNKT cells attenuated plaque instability compared to PBS-treated mice. Real-time PCR analyses in the aortic tissues showed that αGC administration significantly increased expressional levels of inflammatory genes such as IFN-γ and MMP-2, while the depletion of iNKT cells attenuated these expression levels compared to those in the PBS-treated mice. Our findings suggested that iNKT cells are involved in the exacerbation of plaque instability via the activation of inflammatory cells and upregulation of MMP-2 in the vascular tissues.