The microwave dielectric properties and microstructures of (Mg 0:95 Zn 0:05 )TiO 3 ceramics, prepared by a mixed oxide route, were investigated. The ceramics could be sintered at temperatures as low as 1250 C and their microwave dielectric properties were found to be strongly correlated with sintering temperature. The quality factor (Q Â f ) of (Mg 0:95 Zn 0:05 )TiO 3 increased with temperature up to 1300 C and decreased thereafter. The decrease in Q Â f was coincident with the observed abnormal grain growth. A maximum Q Â f of 264000 GHz associated with an " r of 17.1 and a f of À40:3 ppm/ C was achieved for the samples at 1300 C/4 h. Thus, (Mg 0:95 Zn 0:05 )TiO 3 is proposed as a very promising dielectric material for low-loss microwave applications.

Abstract. Experiments were conducted to investigate the optimum concentration of nutrient solution for strawberry 'Maehyang' bred domestically for exportation in hydroponics. Nutrient solutions for strawberry, which was made by Yamazaki, were supplied electrical conductivity (EC) 0.6, 0.8, 1.2, and 1.8 dS·m -1 after planting on cocopeat medium during the experiment period. Growth of shoot of strawberries did not show any statistical differences among treatments. Fruit length showed the longest in EC 0.8 and 1.2 dS·m , followed by 0.6 and 1.8 dS·m -1 in the first and third cluster. It showed the shortest in EC 1.8 dS·m -1 in the second cluster but there were no significant differences among treatments in the fourth cluster. Fruit diameter did not show significant differences among treatments in the first and second cluster but was the longest in the lowest concentration EC 0.6 dS·m -1 in the third cluster. The shortest was in EC 1.8 dS·m -1 in the fourth cluster. The heaviest mean fruit weight appeared in EC 0.8 and 1.2 dS·m -1 , and the lightest was in EC 1.8 dS·m -1 in the first cluster and also lightest in EC 1.8 dS·m -1 but no significant differences was found among other treatments in the second & third cluster. Also the fruit weight was significantly light in plants grown in EC 1.8 dS·m -1 than 0.6 dS·m -1 in the fourth cluster. Soluble solids content of fruit was the highest in EC 0.6 dS·m -1 in all cluster. As a result, we came to the conclusion that the optimum EC for strawberry 'Maehyang' was EC 0.8 -1.2 dS·m -1 during low temperature season. This result will be utilized as an indicator for strawberry hydroponics.

Abstract. Experiments were conducted to evaluate the effect of low temperature-darkness treatment on floral initiation in four kinds of Korean strawberry cultivars. Mother plants were planted on March 29 and daughter plants were raised for the experiment. Temperature treatment was done for 7, 14, and 21 days keeping 13°C in cooling storage from August 29, September 5 and September 14 to September 21. After the treatment, flower bud initiation was examined by a microscope, and the seedlings were transplanted on hydroponic system with Yamazaki's strawberry solution of EC 0.8 dS･m -1 to check the flowering. 'Ssanta' and 'Maehyang' showed early flower bud initiation in 7 days treatment than 'Seolhyang' by microscope check. 'Ssanta', 'Daewang', and 'Maehyang' showed early flower bud initiation in 14 days treatment than 'Seolhyang'. There were no differences among the treatments in 21 days treatment. Percentage of flowering of 'Seolhyang' and 'Maehyang' by low temperature-darkness treatment didn't show any difference but 'Daewang' and 'Ssanta' showed high percentage of flowering. It suggested that low temperature-darkness treatment technique can be use for improving early flowering and yield of 'Ssanta' and 'Daewang' cultivars. Additional key words:

The changes in moisture, cyanogen, crude protein and fat content of para-rubber seed at post-harvest from 0 to 27 days in August and 0-48 days in November were studied. After a short storage, 3 days in August and 6 days in November, the cyanogen content reaches its peak 230-250 mg/100g dry wt, then it decreases during the whole storage. Results show that reducing the initial drying rate promote cyanogen removal. Cyanogen content reduces more effectively in proper storage and processing, while crude protein content and fat content change little during storage.