합성 wustite 의 흑연에 의한 환원속도론

김선효,윤종규 대한금속재료학회(대한금속학회) 1979 대한금속·재료학회지 Vol.17 No.4

反應中 생기는 氣媒介體 CO와 CO₂를 通해 일어나는 合成 wu¨stite의 黑鉛에 의한 還元反應이 950℃∼1075℃ 溫度範圍에서 示差熱分析裝置에 의해 Ar분위기中의 등온 條件下에서 行해졌다. 還元反應에 대한 機構와 速度는 Rao에 의해 제시된 modified physico-chemical model에 의해 조사되었으며 아울러 이의 妥當性에 대한 硏究가 이루어졌다. 黑鉛함량 및 wu¨stite 粒子크기와 混合體에 加한 壓力이 還元反應速度에 미치는 영향도 分析검토하였다. 反應의 초기단계와 끝部分을 제외한全 還元反應은 Rao의 modified model에 잘 들어맞고 있음이 나타났다. 氣相媒介體를 通한 wu¨stite의 黑鉛에 의한 還元反應에 必要한 活法化에너지는 57Kcal/㏖임이 얻어졌고 이 값은 文獻과 잘 일치하고 있는 것으로 밝혀졌다. 還元反應速度式은 X=2au[1-exp(-kt)〕이 됨이 나타났다. Reduction reaction of synthetic Wustite by graphite through the gaseous intermediates CO and CO₂occuring during the reaction was carried out isothermally within the temperature range 950℃ to 1075℃ in an inert Ar atmosphere with T.G.-D.T.A. analysis technique. The mechanism and the rate of reduction reaction were investigated with modified physico-chemical model derived by Rao and the suitability of Rao's model to this reaction system was studied, too. The effects of variables such as C/FeO molar ratio, Wustite powder size to the rate of reduction reaction and the compactness of mixed powder were discussed. The overall reduction reaction but the initial stage and the tail part of reaction was considered to be well fitted to the modified physico-chemical model. The activation energy for the Wustite reduction by graphite through the gaseous intermediates is calculated to be 57Kcal/㏖ and this value is reasonably in good agreement with the literature. The rate equation of reduction reaction through the gaseous intermediates was found to be X=2av [1-exp (-kt).〕.

중학교 가정교과서의 우유 교육 내용 분석과 중학생의 우유・유제품 섭취 실태 및 영양지식 조사 - 충남 공주시 중학생을 중심으로 -

김선효 한국가정과교육학회 2017 한국가정과교육학회지 Vol.29 No.4

This study was performed to analyze education contents related to milk in current home economics textbooks of middle school, and to investigate intake status, consumption behaviors, perception and nutritional knowledge of milk and dairy products among 364 middle school students in Gongju for improvement of milk education in home economics subjects and milk intake of adolescents. As a result, education contents of milk and dairy products in home economics textbooks currently applied in middle school were major nutrients, consumption method for balanced diet, and selection and storage of milk and dairy products, thus it tended not to match current food trend. Only 30.5% of subjects met 2 cups of milk a day, the recommended level. The main reason for drinking milk was to 'be taller' and 'to quench thirst' and there was a difference by gender(p<0.01). The rate of not participating in school milk program was 23.1% of total and its satisfaction was moderate. The most popular dairy products by subjects were ice cream, followed by yogurt and cheese, and the choice of milk was focused on 'taste' or 'expiration date'. The rate of knowing certification mark of K-MILK was low at 28.8%, and most subjects knew as 'domestic milk use'. In home economics class, experience-based learning such as cow ranch experience was the most preferred instruction method for milk followed by laboratory practice and lecture, and there was a difference by gender(p<0.001). Perception degree of milk and dairy products was moderate and male subjects were more positively perceived than female subjects(p<0.01). Nutritional knowledge level of milk and dairy products was moderate and female subjects were higher than male subjects(p<0.01). Therefore, education contents of milk and dairy products of home economics textbooks of middle school should be centered on real life in accordance with food trend, and applied student participation-based instruction methods such as experience-based learning. In addition, it is necessary to enhance taste and merchandise of milk and to provide them with preferred milk and dairy products in school milk program for improvement of milk intake of adolescents. 본 연구는 충남 공주지역 중학교에 재학 중인 1∼3학년 남녀 학생 364명을 대상으로 중학교 현행 가정교과서의 우유 교육 내용을 분석하고 우유・유제품 관련 섭취 실태, 소비행동, 인식 및 영양지식을 조사함으로써 가정교과서의 우유 내용이 우유를 바르게 섭취하도록 돕고 중학생의 우유 섭취 향상을 위한 기초자료를 제공하고자 실시하였다. 현재 중학교에서 적용 중인 가정교과서의 우유 교육 내용은 우유의 영양성분, 식단작성을 위한 우유・유제품 섭취 방법, 선택과 보관방법에 대한 일반적 내용이어서 청소년의 우유・유제품 소비 실태를 반영하지 못하는 것으로 파악되었다. 조사대상자에서 우유 권장수준인 하루에 2컵을 충족하는 비율은 30.5%뿐이었으며 성별에 따른 차이가 없이 전체적으로 우유 섭취량이 낮았다. 우유를 마시는 주된 이유는 ‘키 크게 하려고’가 가장 많았고, 그 다음으로 ‘갈증을 해소하려고’, ‘맛이 있어서’가 많았으며 성별에 따른 차이가 있었다(p<0.01). 우유를 마시는 방법은 우유만 마신다는 비율이 66.8%로 높았으나 그 외에 시리얼이나, 제티 등을 섞어 마시고 있었으며 성별에 따른 차이가 있었다(p<0.05). 학교우유급식에 참여하지 않는 비율이 23.1%이었으며, 만족하는 비율은 58.9%로 높지 않았다. 유제품 중 가장 즐겨 먹는 것은 아이스크림이었고 그 다음으로 요구르트, 치즈로 나타났다. 우유 선택시 ‘맛’, ‘유통기한’을 중시하였고 ‘영양’을 중시하는 비율은 낮았으며 성별에 따른 차이는 없었다. 우유・유제품 소비촉진을 위해 ‘더 엄격한 위생관리’를 원하는 비율이 가장 높았고, 이어서 ‘맛의 개선’, ‘제품 종류의 다양화’ 등이 높았으며 성별에 따른 차이가 있었다(p<0.05). 좋아하는 우유 용기는 종이팩이 59.3%로 높았고 그 다음이 플라스틱병, 유리병이 높았으며 성별에 따른 차이가 있었다(p<0.001). K-MILK 인증마크를 안다는 비율은 28.8%뿐으로 낮았다. 그 의미를 ‘국내산 우유 사용’으로 알고 있는 비율이 높았으며 성별에 따른 차이는 없었다. 중학교 가정교과에서 우유 관련해 원하는 수업방법은 목장체험 등 체험학습이 가장 높았고 그 다음으로 실험실습, 강의식 등으로 나타났으며 성별에 따른 차이가 있었다(p<0.001). 우유・유제품에 대한 인식은 보통 정도이었으며 남자가 여자보다 긍정적이었다(p<0.01). 우유・유제품에 대한 영양지식은 양호한 수준이었으며 여자가 남자보다 높았다(p<0.01). 따라서 중등학교 가정교과서의 우유 교육 내용을 청소년의 소비 흐름을 고려해 구성하고 실생활 중심의 학습이 될 수 있도록 돕는 수업방법을 적용함으로써 청소년의 바른 우유・유제품 이용으로 연결되도록 지원하는 것이 필요하다고 하겠다. 또한 설문 조사 결과 우유 섭취량을 늘리는 것이 시급하였으며 이를 위해 우유 맛의 개선, 우유와 동반간식을 제공하는 다양한 상품 개발, 우유 용기 및 용량 개선, 우유 섭취에 기여도가 높은 학교우유급식의 참여 제고를 위한 독려 및 선호도 높은 우유・유제품의 병행・제공 등이 필요하다고 하겠다.

우유 섭취와 건강과의 관련성 고찰

김선효 공주대학교 과학교육연구소 2015 과학교육연구 Vol.45 No.1

Milk is a rich source of health functional component, thus milk is helpful for preventing various diseases such as osteoporosis, hypertension, cancer, cardiovascular disease and diabetes. This study was performed to review the relationship between milk and health to provide a scientific evidence for appropriate use of milk.

우유의 영양성분과 영양적 가치 고찰

김선효 공주대학교 과학교육연구소 2015 과학교육연구 Vol.45 No.1

Milk is a rich source of fat, protein, amino acids, vitamins and minerals, thus we should consume 1-2 cups/day of milk for nutrition and health. However, anti-milk information is spreaded recently and this trend prevents right consumption of milk. This study was performed to review the nutritional values of milk to provide a scientific evidence of milk and support the reasonable consumption of milk.

GaAs 바랙터다이오드를 이용한 마이크로파 동조형 대역통과 필터의 설계에 관한 연구 ( A Study on the Design of Microwave Tunable Bandpass Filter Using GaAs Varactor Diode )

김선효,임광호,신철재,정상구 대한전자공학회 1987 대한전자공학회 학술대회 Vol.1987 No.5

-적'형의 통사적 범주와 의미

김선효 서울대학교 국어국문학과 2002 冠嶽語文硏究 Vol.27 No.-

우리나라 고등학생의 식품 및 영양소 섭취 변화 추이 - 2007~2015 국민건강영양조사를 이용하여 -

김선효,Kim, Sun Hyo 한국식품영양학회 2020 韓國食品營養學會誌 Vol.33 No.5

This study assessed yearly trends of food and nutrient intake among high school students aged 16 to 18 years (n=2,377) using the 2007~2015 Korea National Health and Nutrition Examination Survey (KNHANES). Yearly trends of food or nutrient intake were analyzed via logistic regression analysis. The results showed that consumption of sugars & sweets, and beverages & alcohols was increased rapidly during this period (p<0.0001). Intake of meat & meat products, and fish & shellfish also was increased (p=0.0008). Intake of grains and grain products was increased until year 2011 but declined after 2012 (p=0.0025). Consumption of vegetables, and milk & milk products was decreased (p=0.0395). Intake of protein, fat, thiamin, riboflavin, niacin, and iron was increased (p=0.0445). Carbohydrate energy ratio was decreased, whereas fat energy ratio was increased (p=0.0235). Most nutrient intakes satisfied the dietary reference intakes for Koreans except dietary fiber (19.6~26.2%), calcium (46.9~55.2%) and sodium (more than 221.4%) during this period. There was a significant positive correlation between most food group intakes and most nutrient intakes (p=0.0468). Therefore, it is crucial to increase dietary fiber and calcium intake and decrease consumption of sugars, fats and sodium through diverse eating of food groups to ensure balanced nutrition of subjects.

22.9kV 중 전압 전력선 통신을 위한 금속귀로 채널과 대지귀로 채널의 특성분석

김선효,이원태,이영철,신철재 한국통신학회 2002 韓國通信學會論文誌 Vol.27 No.9B

CaO-SiO2-Al2O3-MgOsat-FetO (〈10wt%) 계 래이들 슬래그중 MgO 및 FetO 가 재산화반응과 탈황정련능에 미치는 영향

김선효,서정도 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.4

The effect of MgO and Fe_tO on the reoxidation and sulfide capacity of CaO-SiO₂ Al₂O₃ MgO_(sat)-Fe_t O( <10 wt% )slag system was investigated through the slag/metal equilibrium technique using MgO crucible at 1873 K for clean steel technology in ladle refining process. The MgO added into a slag to prevent the dissolution of refractory gives the high possibility to cause reoxidation of aluminum in liquid iron and deteriorates sulfide capacity of slag system. The CaO-SiO₂ Al₂O₃ MgO_(sat) slag system containing around 5 wt% Fe_tO is superior to that containing Fe_t O less than 2 wt% from the standpoint of both reoxidation of aluminum in liquid iron and sulfide capacity. The sulfide capacity as a function of slag composition could be obtained at 1873 K. logC_(S^(2-))=X_(CaO)-5.59X_(SiO₂)-5.30X_(Al₂O₃)+0.29X_(Mgo)+7.42X_(Fe₃O)-1.33.

우리나라 청소년의 칼슘 섭취 실태와 가정교과에서 우유 섭취 교육의 필요성

김선효 공주대학교 과학교육연구소 2016 과학교육연구 Vol.46 No.1

The purpose of this study was to provide basic material for the milk intake education of adolescents by discussing the current status of calcium intake in Korean adolescents and the necessity of milk intake education in the home economics for improving calcium intake. This study was conducted by searching the literature using domestics and foreign engine with the combination of searching words such as milk, calcium, nutrient intake, body weight, height, bone mineral density, and adolescents. As a result, nutritional intake of adolescents was found to be the most vulnerable among the whole life cycle even though adolescents' nutritional management is very important because of rapid growth and high burden of study. In particular, calcium intake in adolescents was very low and there was concern that lack of calcium intake was reported to inhibit body growth. Milk intake, on the other hand, has been studied to improve overall nutrient intake as well as calcium intake in adolescents. However, most Korean adolescents did not meet the recommended level of milk intake, 2 cups a day, and it was urgent to increase milk intake. For this, it was thought that it is necessary to educate about milk intake in the secondary school home economics and to increase the participation rate of school milk program as the adolescents spend most of the day at school. This increase in milk intake not only improves the overall nutrient intake of the adolescents including calcium, but also reduces the intake of sweetened beverages, resulting in healthy eating habits, positively affecting body growth and health throughout adolescence and later adulthood. It is necessary for the government, the school, and the family to work together so that the milk intake training for the adolescents can work systematically and the school milk program can be improved. Also, the adolescents should try to practice the knowledge of the milk which is acquired.