• Title/Summary/Keyword: modified reproductive number

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The Analysis on Patterns of Questions in Elementary School Science Textbooks under the 2007 Revised Curriculum (2007년 개정교육과정에 따른 초등 과학교과서에 제시된 발문의 유형 분석)

  • Choi, Yoon-mi;Lee, Hyeong Cheol
    • Journal of Science Education
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    • v.36 no.1
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    • pp.120-129
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    • 2012
  • The purpose of this study is to provide informations for developing next elementary school science textbooks and educational implications for a spot of science class through analyzing patterns of questions in the elementary school science textbooks under the 2007 revised curriculum. To get a meaningful results, the 2,446 questions extracted by operation definition from 3~6 grade science text books were analyzed by modified analysis frame work based on Blosser's classified system. The findings of this study were as follows: First, among 2,446 questions, the propositional pattern element had the highest rate, 49.2%, the appreciable pattern element had the lowest rate, 1.4%, of all pattern elements. Second, from the results of comparing patterns of questions in each grade's science textbook, as the grade went higher, the rate of the applicable and the divergent pattern element tended to increase, and that of the other elements tended to decrease. Third, as the results of comparing patterns of questions of 4 each field in elementary science textbooks, the energy field questions were the largest in number, followed by the substance field. The rate of the propositional pattern element was the highest of all question elements in common in each field. In the reproductive and the propositional pattern element, the energy and the substance field had a little higher rate than the other fields. On the other hand, in the applicable and the divergent pattern element, the earth and the life field had a little higher rate than the other fields.

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Influence of NO3-:NH4+ Ratios in Fertilizer Solution on Growth and Yield of Hot Pepper (Capsicum annuum L.) in Pot Cultivation (배지경 포트재배에서 비료용액의 NO3-:NH4+ 비율이 고추의 생장 및 수량에 미치는 영향)

  • Yi, Ho Jin;Choi, Jong Myung;Jang, Sung Wan;Jung, Suk Ki
    • Horticultural Science & Technology
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    • v.31 no.1
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    • pp.65-71
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    • 2013
  • This research was conducted to evaluate the influence of $NO_3{^-}:NH_4{^+}$ ratios in fertilizer solution on the vegetative growth and fruit yield of hot pepper (Capsicum annuum L.) through pot cultivation. The Hoaglad's solution was modified to contain various $NO_3{^-}:NH_4{^+}$ ratios such as 100:0 (A), 73:37 (B), 50:50 (C), 27:73 (D), 0:100 (E), and no nitrogen (F). Plants were transplanted into root substrates and the modified solutions were applied as plant needed in plastic house. There were no statistical significances among the treatments from A through D in the fresh and dry weights, and number of leaves 31 days after transplanting, but elevation of $NH_4{^+}$ ratios in the solution decreased the fresh fruit weight 62 days after transplanting with statistical differences. In the results of inorganic element analysis based on the dry weight of fully expanded mature leaves, N and P contents as well as micro cations such as Fe, Mn, Zn, and Cu increased as $NH_4{^+}$ ratios were elevated 62 days after transplanting. However, those of macro cations such as K, Ca, and Mg resulted in decreasing tendency. The elevation of $NH_4{^+}$ ratios in fertilizer solution resulted in the increase of EC and total N concentrations ($NO_3{^-}+NH_4{^+}$), but this decreased the pH as well as Ca and Mg concentrations in soil solution 62 days after transplanting. The K concentration in soil solution was the highest in the treatments of C and followed by D, B, E, and A. The above results indicate that the proper $NO_3{^-}:NH_4{^+}$ ratio in the nutrient solution is 73:27 (B) or 100:0 (A) and the B solution is proper for the vegetative growth and that of A is proper for reproductive growth stage.