Using Landsat TM Image of the Kimhae Delta Plain, Korea, this study clarifies the reason why paddy fields make different tones after harvest. In order to examine the brightness difference, the study collected soil samples from areas and analyzed a soil grain size and chemical contents. According to the analyses, the brightness difference could not be explain by the soil moisture, grain size composition and the quantity of organic matters. However, two sample areas showed a clear difference in their saline contents, and the distribution pattern of saline soil and non-saline soil corresponded with the landform development of delta. Therefore, the study concluded that the saline difference is the cause of the bright difference.

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Polar amino groups of the waste silk sericin (SS) were modified by isocyanate compounds : 2- (methacryloyloxy)ethyl isocyanate (MOI) or 2-(acryloyloxy)ethyl isocyanate (AOI). By hot-pressing the MOImodified silk sericin (MOISS) or the AOI-modified silk serisin (AOISS), vinyl groups in the MOI or AOI were polymerized and the flexible and transparent films were obtained. Tensile moduli and strengths of the MOISS films were significantly enhanced as the MOI content increased. By the addition of the isocyanate compound, sericin films exhibited the lower solubility to the distilled water (80℃) and also the lower swell ratio to the distilled water (room temperature). For the enhancement of tensile properties and to restrain the water swelling, MOI was more effective than AOI. Biochemical oxygen demand (BOD) / theoretical oxygen demand (TOD) of the pure sericin film was almost 100% after 10days immersion into the activated sludge. By adding the isocyanate compound, BOD/TOD was decreased and delayed. When more than 50mol% of polar amino groups remained unreacted, sericin films retained the biodegradability. From the viewpoint of biodegradability, AOI was more effective than MOI.

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