• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.443-450
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• 2006

For understanding sludge concentration profile as a function of time, sludge was sampled at each sampling port. When sludge concentration was 3g/L, the vertical sludge concentration distribution was similar to that of 2g/L of sludge concentration. During the early stage of sludge settling, sludge concentration increased remarkably as the sludge interface height in batch column became lower. The higher sludge concentration became, the worse sludge setteability became. Also, the type of sludge settling was influenced with sludge concentration gradient in batch column. In the same concentration, the greater sludge concentration gradient was, the faster sludge interface settled down. And the changing sludge concentrations in a batch settling or a continuous settling were simulated by using the equation of sludge interface height change model.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.18-22
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• 1998

A mutant strain which hyperproduced thermostable ${\alpha}-amylase$ was obtained by chemical mutagenesis of Bacillus licheniformis. The mutant strain, SK-5, produced the enzyme about 50 times higher than the original strain. The mutant was longer and slimmer in shape, slower in growth compared to the original strain. Nucleotide sequence analysis of the SK-5 ${\alpha}-amylase$ gene revealed no changes in the the structural gene. The changes found in the promoter region might be responsible for the hyperproduction of the enzyme by the mutant. No structural changes in the enzyme structure could be observed when the secreted enzymes at various culture times were analyzed by Western blot.

• Korean Journal of Food Science and Technology
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• v.18 no.1
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• pp.31-37
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• 1986

Seven cultivars of hard and soft wheat were evaluated by regression analysis for five bread quality characteristics to determine varietal response to environments. The regression coefficients were used as the measure of adaptability, and determination coefficients were used as the measure of stability by models of Eberhart and Russell. Phenotypic, genotypic and environmental correlation coefficient estimated for 6 characters tested in this experiments. Statistical analyses confirmed the strong influence of environment on five bread quality. A significant positive correlation exists between protein content, sedimentation value, pelshenke value and specific loaf volume. High heritability was found for sedimentation value ($h^2=0.747$), protein content ($h^2=0.557$) and specific loaf volume ($h^2=0.551$).