Optimum design of a long-stroke thin linear DC motor

Computers have been more widely used in recent years. Researchers are now able to analyze a magnetic field using the finite element method. A motor can be designed more effectively and rationally. It is important to understand design space. Design space means the limit of the thrust or design variables within constraints. Within these limited dimensions, a linear dc motor (LDM) for a pen recorder is designed. This LDM is very thin with long strokes. It is described as follows: (1) the thickness of the permanent magnet and the length of the gap are selected as the design variables in the magnetic circuit of the LDM; (2) the effective magnetic flux density of LDMs using the 3-D finite element method is compared; (3) the design space of thin LDM with long strokes is clarified. The LDM measurement value (thrust constant) was increased at 0.60 N/A from the first LDM. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 118 (4): 84–93, 1997     

Alkali decomposition of poly(ethylene terephthalate) with sodium hydroxide in nonaqueous ethylene glycol: A study on recycling of terephthalic acid and ethylene glycol

Pellets of poly(ethylene terephthalate) (PET; 0.48–1.92 g) were heated in anhydrous ethylene glycol (EG; 5 mL) with 2-equivs of NaOH at 150°C for 80 min or 180°C for 15 min to convert them quantitatively to disodium terephthalate (Na₂-TPA) and EG. The disodium salt was precipitated quantitatively in pure state from the EG solution and separated readily. The other product EG, being the same component to the solvent, remains in the solution and can be obtained after distillation as a part of the solvent. The rate of decomposition was significantly accelerated by the addition of ethereal solvents to EG, such as dioxane, tetrahydrofuran, and dimethoxyethane. The reaction system is simple; no water and no extra reagent other than NaOH and EG are used. A few recycling systems of PET can be designed on the basis of the present alkali decomposition reaction. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 595–601, 1997     

Stability against tilt of a glass sheet submerged in molten metal with electromagnetic force

In one of the glass sheet tempering processes in which a glass sheet is submerged in molten metal with electromagnetic force by a linear induction motor (LIM), it is necessary to keep the glass sheet vertical in the center of the molten metal tank, because a glass sheet warps unless both sides are uniformly cooled. This paper describes the concept of the center of the buoyancy force on a glass sheet in molten metal, introduced in order to discuss its stability against tilt. If the center of the buoyancy force of a glass sheet is higher than its center of gravity, it is stable against tilt. Numerical simulation of electromagnetic fluid flow is performed to evaluate the center of the buoyancy force. The stability conditions are the following (where τ is the pole pitch of the LIM): (1) The shortest length of a glass sheet is 2τ/3 shorter than that of the LIM. (2) The lowest limit of the center of gravity of a glass sheet is τ/3 higher than the center of the LIM. © 1999 Scripta Technica, Electr Eng Jpn, 126 (3): 64–72, 1999     

Effect of surface treatment of pitch-based carbon fiber on mechanical properties of polyethernitrile composites

The effect of surface treatment of pitch-based carbon fiber on a new engineering thermoplastic resin, polyethernitrile, was investigated. Pitch-based carbon fiber (CF) was treated in two separate oxidizing solutions. In the first method, a nitric acid solution was used as an oxidizing agent. In the second method, a hydrogen peroxide solution was used. Both methods demonstrated that each of these solutions was a satisfactory oxidizing agent for the pitch-based CF. These treated fibers were combined with polyethernitrile polymer by the powder impregnation method, and unidirectional laminates were obtained. Improvements in both interlaminar shear strength and transverse flexural strength were achieved. The laminates fabricated from the treated CF maintained the same longitudinal flexural strength as laminates from the untreated control. In addition, scanning electron micrographs of composite fracture surfaces also showed excellent bonding of the treated fiber.     

Study on Interactions of Corn Starch and γ-Cyclodextrin with Lipid Peroxide

The deterioration of corn starch and γ-cyclodextrin (γ-CD) as a model compound by coexisting of methyl linolate (ML) has been studied in the solid system. With the elapse of oxidation time of ML, the reducing values of above the sugars increased and the value of γ-CD with Silica Gel done more largely than without the one. The molecular weight of corn starch may decrease slightly, the glycosidic linkages of amylopectin and amylose molecules in the starch may be cleaved partially and the crystalline structure of the starch will be deteriorted a little by some active radicals formed by the autoxidation of ML. The propagative autoxidation of ML induced the deterioration of γ-CD giving the two processes of the hydrolysis and the depolymerization in the similar way as observed in the reaction of γ-CD with OH radicals.     

Lactobacillus paracasei KW3110 Prevents Inflammatory-Stress-Induced Mitochondrial Dysfunction in Mouse Macrophages

Lactobacillus paracasei KW3110 (KW3110) has anti-inflammatory effects, including the prevention of blue light exposure induced retinal inflammation and ageing-related chronic inflammation in mice. The mechanism involves the promotion of anti-inflammatory cytokine interleukin (IL)-10 production by KW3110, leading to reduced pro-inflammatory cytokine IL-1β production. Although various stress-induced mitochondrial damages are associated with excessive inflammatory responses, the effect of KW3110 on inflammatory-stress-induced mitochondrial damage remains unknown. In this study, we investigated the effect of KW3110 on inflammatory stress-induced mitochondrial damage using the murine macrophage-like cell line J774A.1. KW3110 treatment suppressed lipopolysaccharide (LPS)-induced mitochondrial dysfunction, including downregulation of membrane potential, induction of reactive oxygen species, and respiratory dysfunction. In addition, KW3110 prevented LPS-induced disruption of mitochondrial morphology including cristae structures. IL-10 treatment also ameliorated LPS-induced mitochondrial dysfunction and morphology disruption. These results suggest that KW3110 prevents LPS-induced mitochondrial dysfunction, potentially via promoting IL-10 production in mouse macrophages. We are the first to reveal a suppressive effect of lactic acid bacteria on mitochondrial morphology disruption in inflammatory-stressed macrophages. Our findings contribute to understanding inflammatory-stress-induced mitochondrial damage and developing food ingredients with preventive effects on mitochondrial-damage-derived inflammatory conditions.     

Comparative Study on Structural Redundancy of Cable-Stayed and Extradosed Bridges Through Safety Assessment of Their Stay Cables

This study provides new insights into the comparison of cable-stayed and extradosed bridges based on the safety assessment of their stay cables.These bridges ar...     

Components of the Porous Maize Starch Granule Prepared by Amylase Treatment

Porous starch granules were prepared from normal and waxy maize starch with amylase (from Aspergillus sp.) treatment, but we failed to make it from amylostarch under the same condition. The porous normal starch samples of some digestive stage were analyzed to X-ray diffraction, DSC and GPC after debranching process. The X-ray diffraction patterns were changed following with proceed of digestion, but the values obtained from DSC and GPC were not changed. These observations suggest that crystal region may be more sensitive to the amylase than amorphous one, and amylose may be homogeneously distributed in the both regions.     

High efficiency fine boring of monocrystalline silicon ingot by electrical discharge machining

This article deals with high efficiency and high accuracy fine boring in a monocrystalline silicon ingot by electrical discharge machining (EDM). In manufacturing process of integrated circuits, a plasma-etching process is used for removing oxidation films. This process has recently been examined for use of monocrystalline silicon as the electrode to minimize the contamination. However, it is difficult to machine silicon accurately by the conventional diamond drilling method, because the material removal is due to brittle fracture. The machining force in the EDM process is very small compared with that in conventional machining, therefore, the possibility of high efficiency and high accuracy boring holes in silicon ingot by EDM is experimentally investigated. The removal rate of monocrystalline silicon by EDM is much higher than that of steel, while the electrode wear is extremely small. The improvement method leads to a better hole without chipping at the exit of hole or sticking of the insulator on the wall of hole. Furthermore, it is proved that even a high aspect ratio of about 200 boring is possible.     

Crystalline Copolymer Approach for Melting Behaviour of Starch

The melting behaviour of starch-water systems are analysed from the standpoint of the melting point depression of a block copolymer-diluent system, since the major component of starches, amylopectin is a son of crystalline copolymer. Flory's lattice theory is applied and an equation for the melting temperature is derived. Comparison of the melting temperature extrapolated to volume fraction of water v₁ ζ 0 for both starch and amylose crystal of type A or B, which have the same crystallite sequence length ∼ the equation allows to evaluate the branched chain length CL as 16∼118, which is in reasonable agreement with the value evaluated by chromatography and light scattering.