• 제목/요약/키워드: science content

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Relationship of Physicochemical Characteristics and Ethanol Yield of Korean Barley (Hordeum vulgare L.) Cultivars

  • Lee, Mi-Ja;Kim, Yang-Kil;Park, Jong Chul;Kim, Young-Jin;Kim, Kyeong-Hoon;Choi, Induck;Choi, Jae-Seong;Kim, Kee-Jong;Kim, Hyung-Soon
    • 한국작물학회지
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    • 제57권4호
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    • pp.401-408
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    • 2012
  • The grain and agronomic characteristics of Korean barley cultivars were investigated with respect to ethanol yield. Test weight, grain yield, and starch yield showed noticeable variation among the cultivars. Grain yields were higher in covered barley and non-waxy barley. Starch yield was higher in non-waxy barley than waxy barley. Protein, ${\beta}$-glucan, and starch content of tested cultivars ranged in 10.0-12.9%, 4.4-7.5% and 49.7-65.3%, respectively. Naked barley cultivar had higher starch content than covered barley cultivar. However, covered barley had high starch yield because it has higher grain yield than naked barley. Covered barley cultivar had higher husk content, ranging 7.6-14.0%, than that of naked barley cultivar, ranging 5.3-8.0%. Starch content was positively correlated with amylose content, test weight, ethanol yield and negatively correlated with protein, husk, ${\beta}$-glucan content. Ethanol yield per ton was positively correlated with starch content, but negatively correlated with husk content. Ethanol yield per hectare was positively correlated with starch yield, grain yield, grain weight and negatively correlated with protein, test weight. From this research, the important characteristics of barley cultivar as a bioethanol producing material were starch content and grain yield. Optimum barley genotype was non-waxy naked barley that had low protein, ${\beta}$-glucan, husk content, and high starch content and grain yield.

2007 개정 교육과정에 의한 초등학교 과학 교과서의 STS 내용 분석 (An Analysis of the STS Content in the Elementary Science Textbooks Developed under the 2007 Revised National Curriculum)

  • 양찬호;이주석;노태희
    • 한국초등과학교육학회지:초등과학교육
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    • 제31권2호
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    • pp.154-163
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    • 2012
  • In this study, we analyzed the proportions of STS content, components, topics, and types of the activities of STS content in the elementary science textbooks developed under the 2007 Revised National Curriculum. The analyses of the results revealed that the percentage of STS content included was 15.9% by the number of pages, and 13.5% by the lesson hour. By the components of the STS content, the proportion of 'application of science', 'science-technology and our life' and 'social problems and issues' were large. Most STS topics were related to the 'effects of technological developments' and 'environmental issue', and the topics of 'family and population' and 'human engineering' were few. By the types of the activities, reading was the most, and investigation and writing were also found. Compared with those of the science textbooks developed under the 7th National Curriculum, the variety of components of the STS content increased, but the proportion of STS content and the variety of activities of STS content decreased in the science textbooks developed under the 2007 Revised National Curriculum.

국민학교 과학내용의 분석과 발전적 모색 (An innovative investigation of science content in the elementary school)

  • 김효남
    • 한국과학교육학회지
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    • 제8권2호
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    • pp.23-32
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    • 1988
  • This study analyzed the specific science content involved in 'the 5th curriculum in the elementary school' in Korea and four Kinds of 'Science in the elementary school' books. And innovative science content is investigated for children's living in the scientific, technological, and informationized society. As results, biology is emphasized much more than other areas. Chemistry is less emphasized than other areas. The innovative science content should inchudethe S. T.S problems, the recent developments and the value or religious problems related to science. This study suggested several innovative science contents.

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Relationship of Phenolic Compounds and Free-radical Scavenging Activity in Black and Red Rice Extract

  • Hu, Gao-Sheng;Xu, Kai-Xiu;Jeong, Soon Jae;Kim, Doh-Hoon
    • 한국육종학회지
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    • 제42권2호
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    • pp.129-138
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    • 2010
  • Total phenolic content, total anthocyanin content and antioxidant activity were analyzed from rice samples collected in Korea, Japan and China. The results showed that the total phenolic content and free-radical scavenging activity differed significantly in these rice lines. The correlation between content and activity was subsequently investigated. The results showed that in black rice, anthocyanin was the major phenolic component and that both phenolic content and anthocyanin content were closely correlated with free-radical scavenging activity. Reverse Phase High Performance Liquid Chromatography (RP-HPLC) data showed that cyanidin-3-O-glucoside and peonidin-3-O-glucoside composed about 90% of the total anthocyanin content in black rice and in red rice. In the red rice extract, the total phenolic content produced a high correlation coefficient with antioxidant activity but correlated very poorly with the total anthocyanin content. The $OD_{458}$ and the $OD_{500}$ values which represent the proanthocyanidin content of the rice extract, produced high correlation coefficients with antioxidant activity and total phenolic content. These results suggest that the $OD_{458}$ and the $OD_{500}$ values can be used to evaluate the quality of red rice. In addition, based on the data obtained, a competitive accumulation model of anthocyanin and proanthocyanidin in black and red rice was proposed.

Effects of Extrusion Conditions on the Physicochemical Properties of Extruded Red Ginseng

  • Gui, Ying;Gil, Sun-Kuk;Ryu, Gi-Hyung
    • Preventive Nutrition and Food Science
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    • 제17권3호
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    • pp.203-209
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    • 2012
  • The effects of variable moisture content, screw speed and barrel temperature on the physicochemical properties of red ginseng powder extrudates were investigated. The raw red ginseng powders were processed in a co-rotating intermeshing twin-screw extruder. Primary extrusion variables were feed moisture content (20 and 30%), screw speed (200 and 250 rpm) and barrel temperature (115 and $130^{\circ}C$). Extruded red ginseng showed higher crude saponin contents (6.72~7.18%) than raw red ginseng (5.50%). Tested extrusion conditions did not significantly affect the crude saponin content of extrudates. Increased feed moisture content resulted in increased bulk density, specific length, water absorption index (WAI), breaking strength, elastic modulus and crude protein content and decreased water solubility index (WSI) and expansion (p<0.05). Increased barrel temperature resulted in increased total sugar content, but decreased reducing sugar content in the extrudate (p<0.05). Furthermore, increased barrel temperature resulted in increased amino acid content and specific length and decreased expansion and bulk density of extrudates only at a higher feed moisture content. The physicochemical properties of extrudates were mainly dependent on the feed moisture content and barrel temperature, whereas the screw speed showed a lesser effect. These results will be used to help define optimized process conditions for controlling and predicting qualities and characteristics of extruded red ginseng.

In Vitro Sugar Accumulation in Juice Sacs of 'Shiranuhi' Mandarin

  • Moon, Doo-Gyung;Han, Sung-Gap;Joa, Jae-Ho;Kim, Chun-Hwan;Seong, Ki-Cheol
    • 원예과학기술지
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    • 제31권3호
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    • pp.269-274
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    • 2013
  • To further our understanding of sugar accumulation in 'Shiranuhi' mandarin [(C. unshiu ${\times}$ C. sinensis) ${\times}$ C. reticulate], we investigated the patterns of sugar uptake in juice sacs exposed to different concentrations of sucrose, fructose and glucose in vitro. Data was also collected on the change in weight and shape of the in vitro juice sacs over time. Soluble solids content, sugar content and acidity content were highest at 20% sucrose, fructose and glucose solution content; while fructose content was highest at 5% sucrose concentration. Furthermore, the juice sac's fresh weight was highest at 5% sucrose and lowest at 20% fructose content. The shape of the juice sacs also differed in different sugar concentration and type. Overall, sucrose, fructose and glucose content in juice sacs increased with the sugar concentration. These results suggest that sugar translocation into juice sacs is actively induced by high sugar concentration in the medium. Thus, it can be concluded that sugar and acid accumulation in juice sacs increased with sugar concentration in vitro culture.

Adhesion Properties of Urea-Melamine-Formaldehyde (UMF) Resin with Different Molar Ratios in Bonding High and Low Moisture Content Veneers

  • Xu, Guang-Zhu;Eom, Young-Geun;Lim, Dong-Hyuk;Lee, Byoung-Ho;Kim, Hyun-Joong
    • Journal of the Korean Wood Science and Technology
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    • 제38권2호
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    • pp.117-123
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    • 2010
  • The objective of this research was executed to investigate the effect of molar ratio of formaldehyde to urea and melamine (F/(U+M)) of urea-melamine-formaldehyde (UMF) resin on bonding high and low moisture content veneers. For that purpose, UMF resin types with 5 different F/(U+M) molar ratios (1.45, 1.65, 1.85, 2.05, and 2.25) synthesized were used in present study. First, their curing behavior was evaluated by differential scanning calorimetry. Second, their adhesion performance in bonding high and low moisture content veneers was evaluated by probe tack and dry and wet shear strength tests. Curing temperature and reaction enthalpy decreased with the increase of F/(U+M) molar ratio. And the dry and wet shear strengthsof plywood manufactured from low moisture content veneers were higher than thoseof plywood manufactured from high moisture content veneers. Also, the maximum initial tack force on the low moisture content veneer was higher than that on the high moisture content veneer.

Effects of Strawberry Puree and Red Pepper Powder Contents on Physicochemical Properties of Kochujang Analyzed Using Response Surface Methodology

  • Lee, Jun-Ho;Kim, Hui-Jeong
    • Preventive Nutrition and Food Science
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    • 제13권3호
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    • pp.231-236
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    • 2008
  • Response surface methodology (RSM) was used for the analysis and optimization of the production process of strawberry Kochujang. Experiments were carried out according to a central composite design, selecting strawberry puree content and red pepper powder content as independent variables and soluble solids content, moisture content, water activity, color characteristics ($L^*-$, $a^*-$, and $b^*$-values) as response variables. The polynomial models developed by RSM were highly effective for describing the relationships between the study factors and the responses. Kochujang containing a higher amount of red pepper powder had a higher soluble solids content; on the contrary, soluble solids content decreased with the increase in the strawberry puree content in the sample. Moisture content increased with increased strawberry puree content but decreased with increased red pepper powder content. Water activity increased with the increase in strawberry puree content in the sample but was less affected by the amount of red pepper powder content. Decreases in $L^*$-values with increasing amount of red pepper powder were noted. $a^*$-values decreased with the increases in red pepper powder content but increased with the increase in strawberry puree content in the Kochujang formulation. $b^*$-values decreased with the increases in red pepper powder content but was less affected by the strawberry puree content. Overall optimization, conducted by overlaying the contour plots under investigation, was able to point out an optimal range of the independent variables within which the six responses were simultaneously optimized. The point chosen as representative of this optimal area corresponded to strawberry puree content=14.36% and red pepper powder content=11.33%, conditions under which the model predicted soluble solids content=$59.31^{\circ}Brix$, moisture content=45.30% (w.b.), water activity=0.758, $L^*$-value=24.81, $a^*$-value=7.250, and $b^*$-value=10.19.

보육교사의 소진, 과학교수불안 및 과학교수효능감 간의 관계에서 과학교과교육학지식의 매개효과 (The Mediating Effect of Pedagogical Content Knowledge of Science Teaching on the Relations Among Child Care Teachers' Burnout, Science Teaching Anxiety, and Science Teaching Efficacy)

  • 백영숙;김동례
    • 한국보육지원학회지
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    • 제12권6호
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    • pp.189-206
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    • 2016
  • The purpose of this study was to analyze the mediating effect of pedagogical content knowledge of science teaching on the relations among child care teachers' burnout, science teaching anxiety, and science teaching efficacy. For this study, questionnaires were distributed to 355 teachers working at child care centers in Jollanam-do. The analysis of data was conducted with SPSS WIN 18.0. The results of this study were as follows. First, child care teachers' burnout lowered their science teaching efficacy, and child care teachers' pedagogical content knowledge, as a mediating variable, reduced the negative effect of child care teachers' burnout on their science teaching efficacy. Second, child care teachers' science teaching anxiety lowered their science teaching efficacy, and child care teachers' pedagogical content knowledge, as a mediating variable, reduced the negative effect of child care teachers' science teaching anxiety as an independent variable on their science teaching efficacy. These findings imply there is a need to boost pedagogical content knowledge during in-service teacher education programs.

Effect of cooking methods on the phytosterol content in nine selected vegetables

  • Shin, Jung-Ah;Park, Jong-Min;Lee, Ki-Teak
    • 농업과학연구
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    • 제43권1호
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    • pp.87-99
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    • 2016
  • Phytosterol contents in nine vegetables such as paprika (red, yellow, and orange), kohlrabi, bamboo shoot, cherry tomato, cucumber, Chinese chive, and corn were analyzed by gas chromatography. Individual contents of ${\beta}$-sitosterol, campesterol, and stigmasterol in fresh and cooked vegetables (boiling, grilling, stir-frying, deep-frying, steaming, roasting, and microwaving) were determined and compared. Total phytosterol content of paprika, cucumber, Chinese chive and cherry tomato ranged from 23.19 to 46.51 mg/kg (0.002-0.005%) of fresh weight of raw vegetables. Total phytosterol content variation (%) was obtained as follows: [(the content of phytosterol after cooking) - (the content of phytosterol before cooking)] / (the content of phytosterol before cooking) ${\times}100$. Total phytosterol content was found to be high in raw kohlrabi at 138.99 mg/kg fw (0.01%), in corn at 302.86 mg/kg fw (0.03%), and in bamboo shoot at 443.15 mg/kg fw (0.04 %). Total phytosterol content variation (%) in orange paprika ranged from 27.5 to 267.3 while that in cherry tomato ranged from -11.0 to 337.5. Generally, high content variation of total phytosterol was found in stir-fried and deep-fried vegetables. Therefore, higher phytosterol levels were obtained from cooked vegetables than raw vegetables. We suggest that these data will be useful to investigate cooking methods for increased intake of phytosterols.