A characterization of the permeation and separation using single salt solution was carried out with charged composite membranes. Various charged composite membranes were fabricated by blending an ionic polymer with a nonionic polymer in different ratios. In this study, sodium alginate, chitosan and poly(vinyl alcohol) were employed as anionic, cationic and nonionic polymers, respectively. The permeation and separation behaviors of the aqueous salt solutions have been investigated through the charged composite membranes with various charge densities. As the content of the ionic polymer increased in the membrane, the hydrophilicity of the membrane increased, and pure water flux and the solution flux increased correspondingly, indicating that the permeation performance through the membrane is determined mainly by its hydrophilicity. Electrostatic interaction between the charged membrane and ionic solute molecules, that is, Donnan exclusion, was observed to be attributed to salt rejection to a greater extent, and molecular sieve mechanism was effective for the separation of salts under a similar electrostatic circumstance of solutes.

Among the developed bío-degradable polymer fílms as compared wíth transparent fílm(Whíte), black polymer fílm was sígnífícantly more effectíve for controllíng weeds ín red pepper. Also, we found that whíte and black polymer mulchíng had 81.8% and 97.9% of managing weed controllíng effects in rice, respectively. Compared to nonmulched rice paddy with water supply, the non-mulched rice paddy wíthout any water supply has stopped its growth at 41 days after transplantíng, whíle polymer -mulched rice paddy without water supply had about 60% of normally growing rice plants. This shows the polymer treatment has a remarkable effect on water and power saving, solution of herbicidal resistance, avoidance of herbícidal influence to eco-system etc. When the naturally decomposíng polymer was used, a temperature was elevated as high as 4.7 ℃ on maximum and 2.6 ℃ on average. Also the naturally decomposing polymer accelerated rooting by 7 days and lowered a stress level from transplanting. The weed control effect mulched by polymer was remarkable as 98. 7%. The p이ymer now, after 294 days treated on the rice paddy, has been completely decomposed.

An in vtro nucellar polyembryo propagation method was established with mature seed of the Citrus junos Sieb. 7-8 nucellar polyembryos per seed were induced on MS basal medium without plant growth regulators. The polyembryos developed to complete plantlets on teatment with IBA. These shoots grew further in MS medium without plant growth regulators. Rooting of shoots occurred on MS medium supplemented with IBA. These plantlets were successfully transplanted to small plastic pot containing soil mixture. Somatic embryos were induced from nucellar polyembryo and maturation occurred spontaneously from proliferating cultures on MS medium without growth regulators. Random Amplified Polymorphic DNA (RAPD) marker analysis of in vitro and in vivo grown junos orange showed identical polymorphism indicative of their genetic stability. The RAPD polymorphism produced revealed same banding pattern in each regenerant. Hence, propagaton of junos orange by nucellalr polyembryos was efficient and produced in genetically stable plants under in vitro conditions.