Mass measuring instrument for use under microgravity conditions

A prototype instrument for measuring astronaut body mass under microgravity conditions has been developed and its performance was evaluated by parabolic flight tests. The instrument, which is the space scale, is applied as follows. Connect the subject astronaut to the space scale with a rubber cord. Use a force transducer to measure the force acting on the subject and an optical interferometer to measure the velocity of the subject. The subject's mass is calculated as the impulse divided by the velocity change, i.e., M=integral Fdt/delta v. Parabolic flight by using a jet aircraft produces a zero-gravity condition lasting approximately 20 s. The performance of the prototype space scale was evaluated during such a flight by measuring the mass of a sample object.     

An efficient numerical technique for bioheat simulations and its application to computerized cryosurgery planning

As a part of ongoing efforts to develop computerized planning tools for cryosurgery, the current study focuses on developing an efficient numerical technique for bioheat transfer simulations. Our long-term goal is to develop a planning tool for cryosurgery that takes a 3D reconstruction of a target region, and suggests the best cryoprobe layout. Toward that goal, a planning algorithm, termed "force-field analogy," has been recently presented, based on a sequence of bioheat transfer simulations, which are by far the most computationally expensive part of the planning method. The objective in the current study is to develop a finite difference numerical scheme for bioheat transfer simulations, which reduces the overall run time of computerized planning, thereby making it clinically relevant. While the general concept of variable grid size and time intervals is not new, its application to the phase change problem of cryosurgery is the unique contribution of the current study.     

High pressure synthesis and electrical properties of BaTiO3−xFx

The substitution of fluorine for oxygen in BaTiO₃ was investigated by the reaction of BaO₂, BaF₂, TiO₂ and Ti under the conditions of 3.0 GPa and 1300° C for 2 H. Batio_3–x F _x solid solutions were obtained as a single phase in the region of 0 x0.1. The X-ray diffraction data showed that the symmetrical change from tetragonal to cubic form occurred atx=0.08 at room temperature. Also, the solid solutions were characterized by TG-DTA analysis, ESCA spectroscopy and diffusion reflectance spectroscopy. As a result, the existence of Ti³⁺ was verified. The electrical resistivities of BaTiO_3–x F _x were in the range from 4cm for x=0.05 to 3Ocm forx=0.1 at 300 K and the relationship between In and 1000 T^–1 was linear. The thermoelectric powers at 300 K were –250V K^–1 forx=0.05 and –130VK^–1 forx=0.1. The electrical property of the solid solution was discussed on the basis of a conventional band model which involved localized donor levels associated with oxygen vacancies.     

Primary cell culture of esophageal cancer as an indicator of biological malignancy

The predictability of the monolayer culture patterning of primary cell culture as an indicator of biological malignancy was described. The prognosis of patients whose cancer cells could grow in monolayer epithelial pattern were significantly lower than that of the "no tumor growth" group. Multivariate analysis indicated that monolayer culture status best correlated with a mortality rate nearly equivalent to the number of lymph node metastasis, and Akaike's information criterion revealed that monolayer epithelial growth is a predictive factor of hematogenous recurrence. The relation of oncogenes and suppressor genes to cell culture was also described. Monolayer epithelial growth may be indicative of such general characteristics as adhesion, motility, invasion and reproduction of cancer cells.     

Structures and dehydrogenation activities of vanadium oxide overlayers on supports

A method has been devised to prepare reduced Co clusters in zeolite Y. Sodium acetate is impregnated after exchanging Co²⁺ ions into the zeolite. During calcination the acetate is partially or completely oxidized to sodium oxide. This not only stabilizes Co²⁺ ions in supercages, impeding their migration to smaller cages, but it also neutralizes the protons that are formed during the reduction of the Co²⁺ ions with H₂. As a result, the temperature of effective reduction is lowered by up to 350 °C, depending on the calcination program. In unmodified zeolites, Co reduction requires a temperature above 750 °C, which inevitably induces partial destruction of the zeolite lattice; this novel method permits complete reduction of Co without damaging the zeolite lattice. It is predicted that this novel method should be applicable to other zeolite encaged metals of low reducibility such as Ni.     

Synthesis of MAG of CLA with Penicillium camembertii lipase

CLA has various physiological activities, and a FFA mixture containing almost equal amounts of cis-9,trans-11 and trans-10,cis-12 CLA (named FFA-CLA) has been commercialized. We attempted to produce MAG of CLA by a two-step successive reaction. The first step was esterification of FFA-CLA with glycerol. A mixture of FFA-CLA/glycerol (1∶5, mol/mol), 2 wt% water, and 200 units/g of Penicillium camembertii mono-and diacylglycerol lipase was agitated at 30°C to form a homogeneous emulsion. The esterification degree reached 84% after 10 h. To further increase the degree, the reaction was continued with dehydration at 5 mm Hg. The esterification degree reached 95% after 24 h (34 h in total), and the reaction mixture contained 50 wt% MAG and 44 wt% DAG. The second step was glycerolysis of the resulting DAG. The reaction mixture in the first-step esterification was transferred from the reactor to a beaker and was solidified by vigorous agitation on ice. When the solidified mixture was allowed to stand at 5°C for 15 d, glycerolysis of DAG proceeded successfully, and MAG content in the reaction mixture increased to 88.6 wt%. Hydrolysis of the acylglycerols was not observed during the second reaction. FA composition in the synthesized MAG was completely the same as that in the original FFA-CLA, showing that Penicillium lipase does not have selectivity toward FA in the FFA-CLA preparation.     

Sensorless suppression control for frame vibration of PMSM

It is well known that frame vibration occurs in driving permanent magnet synchronous motors (PMSM). The authors have suggested a method for suppression of frame vibration by means of Fourier series and repetitive control. The method requires an acceleration sensor and a position sensor. However, the use of such a sensor is not desirable from the point of view of system cost. Therefore, this paper proposes a method of sensorless suppression control of frame vibration. The effectiveness of the proposed method is illustrated by experiments. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(3): 53–61, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21048     

Chaperone‐Polymer‐Assisted,Photodriven DNA Strand Displacement

Photodriven DNA strand displacement by using a 2′,6′‐dimethylazobenzene‐tethered strand and poly(l ‐lysine)‐graft‐dextran (PLL‐g‐Dex) as a chaperone is reported. Rapid strand displacement was reversibly induced by UV and visible‐light irradiation without any toehold portion. To further improve the method, the concentration of PLL‐g‐Dex and the number of equivalents of the photoresponsive strand were optimised. Optimally, 64 % strand displacement was reversibly induced by alternating UV and visible‐light irradiation.     

Enzymatic conversion of waste edible oil to biodiesel fuel in a fixed-bed bioreactor

The conversion of waste edible oil to biodiesel fuel in a fixed-bed bioreactor was investigated. Three-step methanolysis of waste oil was conducted using three columns packed with 3 g of immobilized Candida antarctica lipase. A mixture of waste oil and 1/3 molar equivalent of methanol against total fatty acids in the oil was used as substrate for the first-step reaction, and mixtures of the first- and second-step eluates and 1/3 molar equivalent of methanol were used for the second- and third-step reactions, respectively. Ninety percent of waste oil was converted to the corresponding methyl esters (ME) by feeding substrate mixtures into the first, second, and third reactors at flow rates of 6, 6 and 4 mL/h, respectively. We also attempted one-step methanolysis of waste oil. When a mixture of waste oil and 90% ME-containing eluate (1∶3, wt/wt) and an equimolar amount of methanol against total fatty acids in the waste oil was fed into a reactor packed with 3 g of immobilized C. antarctica lipase at a flow rate of 4 mL/h, the ME content in the eluate reached 90%. The immobilized biocatalyst could be used for 100 d in the two reaction systems without significant decrease in its activity. Waste oil contained 1980 ppm water and 2.5% free fatty acids, but these contaminants had little influence on enzymatic production of biodiesel fuel.     

Use of thermostable Fusarium heterosporum lipase for production of structured lipid containing oleic and palmitic acids in organic solvent-free system

A newly developed 1,3-positionally specific thermostable lipase from Fusarium heterosporum (named R275A lipase) was immobilized on Dowex WBA for the production of structured lipid by acidolysis of tripalmitin (PPP) with oleic acid (OA). The immobilized catalyst was fully activated by pretreatment at 50°C in a PPP/OA mixture containing 2% water. The pretreatment caused concomitant hydrolysis, but the hydrolysis was repressed using a substrate without water in the subsequent reactions. The optimal reaction conditions were determined as follows: A mixture of PPP/OA (1∶2, w/w) and 8% immobilized lipase catalyst was incubated at 50°C for 24 h with shaking at 130 oscillations/min. The acidolysis reached 50% under these conditions, and the contents of triolein, 1,3-dioleoyl-2-palmitoyl-glycerol, 1(3),2-dioleoyl-3(1)-palmitoyl-glycerol, 1(3),2-palmitoyl-3(1)-oleoyl-glycerol, 1,3-dipalmitoyl-2-oleoyl-glycerol, and PPP in the reaction mixture were 8, 36, 4, 28, 1, and 6 mol%, respectively. The stabilities of immobilized R275A lipase catalyst and two immobilized catalysts containing Rhizopus delemar or Rhizomucor miehei lipases were compared under the conditions mentioned above, with the catalysts being transferred to fresh substrate every 24 h. The half-life of the R275A lipase catalyst was 370 d, which was significantly longer than those of Rhizopus and Rhizomucor lipase catalysts.