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Environmental Life Cycle Assessments on Nano-silver Inks by Wet Chemical Reduction Process (습식환원법으로 제조한 은나노 잉크의 환경 전과정 평가)

  • Lee, Young-Sang;Hong, Tae-Whan
    • Clean Technology
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    • v.21 no.2
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    • pp.85-89
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    • 2015
  • Utilized in a variety of electronic components, electronic components industry with metallic ink technology was established itself as a major technology research and development was gradually increasing, silver ink that is excellent in conductivity and stability, have long been used in the industry of electronic components in recent years and silver ink has been the size of nanoscale particles dispersed by developing display, an electronic tag, a flexible circuit board or the like used in the semiconductor and electronics as has been highlighted in, however industry modernization of equipment by increasing the production and consumption of products generated during the production process and environmental pollutants by use of waste products is expected to bring a serious environmental problem. In this study, prepared by a wet reduction method, the manufacturing process of the silver nano-ink to the entire process of the environmental impact assessment (LCA) was evaluated using the techniques. Life cycle assessment software GaBi 6 was used as received from the relevant agencies of the silver nano-ink data with reference to the manufacturing process, building inventory was international organization for standardization (ISO) 14040, 14044 compliant LCA conducted over four stages.

Relationship between Perception of Facial Asymmetry and Posteroanterior Cephalometric Measurements (안면비대칭에 대한 주관적 인지도와 정모두부방사선사진 분석치의 연관성)

  • Ahn, Jeong-Soon;Hwang, Hyeon-Shik
    • The korean journal of orthodontics
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    • v.31 no.5 s.88
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    • pp.489-498
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    • 2001
  • This study was aimed at how posteroanterior cephalometric measurements affect the perception of the patient about his/her facial asymmetry. One hundred orthodontic patients, over the age of 12, who required a posteroanterior cep-halogram in the Department of Orthodontics of Chonnam National University Hospital were used as the subjects. They were asked if they thought their faces were asymmetrical. Their responses were classified into 5 groups based on the level of asymmetry as follows : Definitely No, Probably No, Don't Know, Probably Yes, and Definitely Yes. Nine linear and low angular measurements from each posteroanterior cephalometric radiographs were analysed on the standard of the line between crista galli and anterior nasal spine to show the extent of asymmetry. Through this comparative study, the following results were obtained. 1. As the deviation of menton and the midline discrepancy of the upper and lower jaws were greater, the perception of patients about their facial asymmetry was higher. 2. All the measurements from the group 'Don't Know' showed no statistical difference from those of the groups 'Definitely No' or 'Probably No.' 3. All the measurements from the group 'Probably Yes' showed no statistical difference from those of the group 'Definitely yes.' .

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Comparison of Performances of Forward Osmosis and Membrane Distillation Processes for Shale Gas Plant Water Treatment (셰일가스 플랜트 용수 처리를 위한 정삼투(FO)와 막증발(MD) 공정의 성능 비교)

  • Koo, Jaewuk;Lee, Sangho;Shin, Yonghyun;Yun, Taekgeun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.3
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    • pp.279-284
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    • 2015
  • As non-conventional oil resources such as shale gas have been widely developed, proper treatment of flowback and produced water is becoming important. However, application of conventional water treatment techniques is limited due to high concentration of pollutants such as oil and grease, organics, harmful chemicals, and inorganic ions. In this study, we examined the feasibility of using forward osmosis (FO) and air gap membrane distillation (AGMD) as novel treatment options for shale gas wastewater. Laboratory-scale FO and MD devices were fabricated and used for the experiments. Results showed that FO could be used to treat the synthetic wastewater. Using 5 M NaCl as the draw solution, the flux was approximately $6L/m^2-hr$ during the treatment of low range wastewater (TDS: 66,000 mg/L). Nevertheless, AGMD was more effective to treat high range wastewater (Total Dissolved Solid: 260,000 mg/L) than FO.

A Scheme of the Instruction of Prism Definition for 5th Grade Students (각기둥의 정의 만들기에 관한 지도 사례 연구 -초등학교 5학년을 대상으로-)

  • Cho, Young-Mi;Park, Ha-Na
    • Journal of Elementary Mathematics Education in Korea
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    • v.15 no.2
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    • pp.317-332
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    • 2011
  • The purpose of this study is to suggest an effective plan for teaching the definition of prism by integrating and analyzing the theories related to the instruction of definitions. The subjects in this study to realize these objectives were as follows. First, it looks to theoretical backgrounds regarding the instruction of the definition of solid by functions of definition in mathematics education. Second, it explores the instructional way to form the definition of solid through function of definition, by analyzing the unit of solid in the 6th grade. Third, after conducting the real practice with the 5th graders who before learn solid in 6th curriculum, according to plan of instruction, it examined student's response and testify its effectiveness, and then propose a teaching scheme which is designed to be useful based on the outcomes. In terms of theoretical background, it investigated the precedent research in relation to the instruction of the definition that mathematical definition is not given perfectly but the process of making knowledge that mathematization activity is necessary. It investigated the effects of the instruction of definitions, based on the effects of teaching and interviews with the 5th graders, and analysis of student's handout. The followings were the results of this study. First, 'Making Definitions' activities through remove counterexample process was possible to analytic thinking not intuitively thinking, and it effects the extend of awareness in definition that definition is not fixed but various. Second, it need the step of organize terms that is useful on solid's definition through activate of background knowledge. Third, it is effective that explore characters of the solids after construct the solids. Fourth, interactive discussion that students correct their mistakes each other through mathematical communication and they can think developmental is useful on making definition more than individual study.

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Growth of Li2B4O7 Single Crystal and Its Thermoluminescent Properties (Li2B4O7 단결정 성장과 열형광 특성)

  • Park, Kang-Soo;Ahn, Jung-Keun;Kim, Dong-Jin;Hwang, Yoon-Hwae;Kim, Hyung-Kook;Park, Myeong-Hwan;Kang, Hee-Dong;Kim, Do-Sung
    • Journal of Sensor Science and Technology
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    • v.12 no.1
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    • pp.16-23
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    • 2003
  • Thermoluminescent properties of $Li_2B_4O_7$ single crystal grown by Czochralski method have been investigated. The high quality $Li_2B_4O_7$ single crystal without core was obtained at rotation speed of 10 rpm for seed crystal and pulling speed below $0.18\;mm{\cdot}h^{-1}$. The structure of $Li_2B_4O_7$ single crystal was classified as tetragonal by XRD analysis. The TL glow curve was composed with three overlapped peaks which can be easily deconvoluted and the TL response of $Li_2B_4O_7$ single crystal TLD to X-ray radiation is linear within the range of $50\;mGy{\sim}1.5\;Gy$. Activation energies of three TL glow peaks analyzed by the various heating rates method and PL spectrum were 0.93, 1.78 and 2.25 eV, respectively.

The Study on Didactic Transposition for Teaching Statistical Graphs - The comparison between the Korean and MiC's textbooks (그래프의 교수학적 변환 방식 비교 -우리나라 교과서와 MiC 교과서의 초등 통계 내용을 중심으로-)

  • Lee, Kyung-Hwa;Ji, Eun-Jeung
    • Journal of Educational Research in Mathematics
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    • v.18 no.3
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    • pp.353-372
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    • 2008
  • This study looks around the goals of teaching statistical graphs that are introduced in the seventh Korean Curriculum for Elementary School and in the Principles and Standards for School Mathematics(NCTM, 2000), and these are compared. We compare how to transpose statistical graphs didactically between the Korean and MiC textbooks. For it, it examines the types of statistical graphs, the methods defining them, and the making connections and comparing among them, which are content components in the chapters on statistical graphs. The results show that in contrast to the Korean textbooks, NCTM(2000) has allowed students to develop their own expression for data, to compare results analysed within different graphs, and to consider a graph as a whole in the goals of teaching statistical graphs. MiC textbooks have introduced the number-line plot and the box plot more than Korean. Although both of Korean and MiC textbooks usually use extensive methods for defining individual graphs, the former use extensive methods together with synonymic methods and the latter use extensive methods with the characteristics of graphs. Also, the number-line plot is defined using operative method in the MiC textbooks. MiC textbooks contain various activities for connecting and comparing graphs, but there are comparatively few comparing activities in the Korean textbooks.

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The Effect of Drug Release from Osmotic Pellet Related to the Various Ratio of $Eudragit^{(R)}$ RL and RS ($Eudragit^{(R)}$ RL과 RS의 비에 따른 삼투정 펠렛의 약물방출에 미치는 영향)

  • Youn, Ju-Yong;Ku, Jeong;Lee, Soo-Young;Kim, Byung-Soo;Kim, Moon-Suk;Lee, Bong;Khang, Gil-Son;Lee, Hai-Bang
    • Polymer(Korea)
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    • v.31 no.4
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    • pp.329-334
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    • 2007
  • Osmotic pellet system, which is one of the oral drug delivery systems, has been developed to improve manufacturing process, reduce product cost and other problems of osmotic tablet systems. Osmotic pellet is consisted of water swellable seed layer, drug layer, and membrane layer. Among them, the membrane layer plays an important role in a control of the drug release. In this work, we examined the effect of ratio for Eudragit RL and RS on the drug release behavior. Osmotic pellet with nifedipine as a model drug was easily obtained in a good yield by fluidized bed coater. Osmotic pellet showed round morphology with a range of size $1300{\sim}1500\;{\mu}m$. In the experiment of nifedipine release, the release amount increased with the increase of the ratio of Eudragit. This is due to the fact that Eudragit RL contains more hydrophilic quaternary ammonium group than Eudragit RS. Additionally, the release amount was retarded with increasing the membrane thickness. There are no differences in the release amount measured at the different pH 1.2, 6.5, 6.8, and 7.2. In conclusion, it was found that the drug release from osmotic pellets depended on the composition ratio and coating thickness of membrane layer.

Quality Characteristics of Sansapyun with various amounts of Crataegi fructus concentrate (산사 첨가량을 달리한 산사편의 품질특성)

  • Shin, Soo-Jung;Yoon, Hye-Hyun
    • Culinary science and hospitality research
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    • v.17 no.3
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    • pp.181-190
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    • 2011
  • This study analyzed the quality characteristics of the Sansapyun products, which were manufactured by mixing with 0, 5, 10, 20, and 30% of Crataegi fructus concentrate and 9% of mung bean starch. The moisture content and pH in Sansapyun decreased significantly(p<0.001) as the concentration of Crataegi fructus concentrate increased. Sweetness increased as the amount of Crataegi fructus concentrate increased in both Before/After cases. As for the L value of the color characteristics of Sansapyun, it turned out that the control group, which had 0% of Crataegi fructus concentrate, was higher. Meanwhile, the a and b values were the strongest with 30% of Crataegi fructus concentrate. As the concentration increased, the hardness, springiness, chewiness, gumminess, cohesiveness all decreased significantly(p<0.001), while adhesiveness became higher as the concentration increased. The preference test showed that the increase of the concentration resulted in the increase of red color, fruity flavor, sour flavor, Chinese (herb) medicine flavor, sour taste, sweetness, Chinese (herb) medicine taste, stickiness, and aftertaste. However, the sleekness, transparency, hardness and springiness decreased as the concentration increased. The survey on the preference showed that the preferences for flavor, taste and overall preference were the highest at the 10% sample group, but the preferences for color and texture were the highest at the 20% sample group.

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On the Relation Between Cloud-to-Ground Lightning and Rainfall During 2006 and 2007 Summer Cases (2006-2007년 여름 사례로 본 구름-지면 낙뢰와 강우의 관계)

  • Oh, Seok-Geun;Suh, Myoung-Seok;Lee, Yun-Jeong
    • Journal of the Korean earth science society
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    • v.31 no.7
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    • pp.749-761
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    • 2010
  • A relationship between cloud-to-ground lightning and rainfall was investigated by using the two-years (2006-2007) summer lightning data and the automatic weather stations (AWSs) data of the Korea Meteorological Administration. The negative lightning occurred at the core of highly concentrated convection, which is often accompanied with heavy rains. Whereas most positive lightning occurred at the anvil cloud with low density and light rains. The rainfall intensity is strongest when the negative and positive lightning occurred concurrently, and one with lightning is much stronger than that without lightning. A portion of the positive lightning of the total lightning was less than 10% during summer seasons, and the lightning without rains was about 34%. The rain rate was strongly correlated with the negative flash rate, and the correlation coefficients varied between 0.87 and 0.94 according to the co-location radius (5-15 km) of AWSs. Most of the lightning occurred 10 minutes before and/or concurrently occurred with rains. A portion of the convective rainfalls of the total rainfalls was at least 20% when we define the rainfalls with lightning as convective. The convective rainfall was greater during August than in June and July. In general, the portion of convective rainfalls showed a maximum diurnal variation during late afternoon as in the rains and lightning.

A Study on the effect of Shared Leadership on the Organizational Well-being (공유리더십이 조직웰빙에 미치는 영향)

  • Kim, Jin-Wook;Chang, Young-Chul;Kim, Young-Hunl
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.3
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    • pp.197-208
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    • 2016
  • The study showed that directional Shared Leadership and transformational Shared Leadership positively influences the relationship between Shared Leadership and interpersonal relationships in the view of organizational wellbeing. In addition, in the relationship between Shared Leadership and rewarding job experience of organizational wellbeing, three leadership types excluding directional Shared Leadership had positive effects. In addition, transformational Shared Leadership and empowering Shared Leadership had a positive impact on the relationship between Shared Leadership and organizational mood of organizational wellbeing. In the relationship between Shared Leadership and a sense of fulfillment in the view of organizational wellbeing, transformational Shared Leadership only had a positive effect. As is the case with the sense of fulfillment, the transformational Shared Leadership, of and itself, positively influenced the relationship between Shared Leadership and leisure of life of organizational wellbeing. A analysis of the study showed that transformational Shared Leadership has an impact on both organizational wellbeing and personal wellbeing. Transformational Shared Leadership helps set up mutual vision or strategies, or to challenge each other to enhance existing processes and procedures. On the other hand, directional Shared Leadership influences the interpersonal relations only, whereas transactional Shared Leadership impacts rewarding job experience only. Presenting clearer ideas on what to do to each other and sharing the reward for performance implies that the members of an organization can feel much more rewarded through job engagement.