Cooling action of grinding fluid in shallow grinding

A new method is proposed for measuring the heat transfer coefficient in the vicinity of the wheel-workpiece contact zone. The accuracy of measurement is estimated by using a finite element method and the factor for correcting the measured results is derived. The experiments are performed in a number of conditions where grinding fluid is supplied and the following measures are consequently recommended for increasing the cooling efficiency: (1) set the velocity of coolant to more than the critical value to penetrate the air flow layer formed around the wheel periphery; (2) use a nozzle with a thin throat, about 1 mm in height, and attach a scraper plate above the nozzle outlet; (3) choose a wheel of large grain size and dress roughly, or form shallow grooves on the wheel periphery; and (4) set a higher wheel speed.     

Application of an ecosystem model for aquatic ecological risk assessment of chemicals for a Japanese lake.

The Lake Suwa version of the comprehensive aquatic systems model (CASM-SUWA) was developed using field data from Lake Suwa and evaluated to examine the utility of CASM-SUWA for assessing the ecological risk of chemicals for aquatic ecosystems. The calibration of the parameters for the model provided that the established reference model simulation could reproduce complex seasonal biomass behavior of populations that were not significantly different from the general seasonal pattern for the Lake Suwa ecosystem. The sensitivity analyses revealed the potential importance of indirect effects and demonstrated that the parameter values of all the trophic levels were important in determining the biomass of each trophic level in the model. The risk estimation of linear alkylbenzene sulfonates (LAS) demonstrated that the model estimated the risks of direct toxic effects on each population and the indirect ecological effects that propagate through the food-web in the model ecosystem. The CASM-SUWA-derived benchmark levels were approximately one order of magnitude less than the field-derived NOECs in literature. The analyses of the comparison implied that the model could provide a good basis in determining an ecological protective level of a chemical of concern in aquatic ecosystem. This modeling study demonstrated that the model can be used to provide additional information for the decision-making process in the management of the aquatic ecological risk of chemicals.     

Radical high polymerization of di-tert-butyl fumarate and novel synthesis of high molecular weight poly(fumaric acid) from its polymer

Summary Di-tert-butyl fumarate (DtBF) was found to homopolymerize easily with 1,1-azobisisobutyronitrile and benzoyl peroxide as radical initiators at 50~80°C to give a nonflexible rod-like polymer, poly(tert-butoxycarbonylmethylene) with number-average molecular weight of more than 100,000. The colorless powderlike polymer thus obtained was soluble in benzene, toluene, carbon tetrachloride and tetrahydrofuran, and gave a transparent film or fiber from its toluene solution. This polymer did not melt, but it underwent degradation with a quantitative elimination of isobutene at 180~190°C. The remaining polymer was confirmed to be a pure poly(fumaric acid), poly(hydroxycarbonylmethylene). Therefore, the degradation of poly(DtBF) in solution at 180~190°C was found to be a new route for synthesizing of a high molecular weight poly(fumaric acid).Polymers from 1,2-Disubstituted Ethylenic Monomers. XI. Parts I~X of this series are Refs. 1~10.     

名古屋丰田每日大厦的制振设计

本建筑为250m高超高层智能型办公商业综合大楼,建造于日本名古屋市,竣工于2006年9月。地上为外围框架 中央核心筒 伸臂桁架的综合钢结构体系,地下为型钢钢筋混凝土结构,主楼的中央核心筒由高强钢钢板墙构成,伸臂桁架内设置了油阻尼器,主楼和裙房之间也设置了油阻尼器。在大地震和强风频发的名古屋设计这样一栋超高层建筑时,需要对地震影响和风的影响进行全面、综合考虑。本文具体介绍了结构设计师是如何思考并解决这些影响的。