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Kinetics of Photocatalytic Reactions with Porous Carriers Coated with Nano-$TiO_2$ Particles (나노-$TiO_2$ 입자로 코팅된 다공성 담체의 광촉매 반응에 관한 동력학)

  • Park, Seong-Jun;Rittmann, Bruce E.;Bae, Woo-Keun
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.10
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    • pp.927-932
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    • 2009
  • Toxic and recalcitrant organic pollutants in wastewaters can be effectively treated when advanced oxidation and biodegradation are combined, ideally with intimate coupling, in which both processes occur simultaneously in the same system. One means to achieve intimate coupling is to coat nanoscale $TiO_2$ on the outside of macroporous biofilm carriers. This study investigated the kinetics of photocatalysis with $TiO_2$-coated porous carriers. The carriers were made of polyvinyl alcohol (PVA) and coated with $TiO_2$ using a low-temperature sol-gel process. The $TiO_2$-coated carriers catalyzed the oxidation of methylene blue (MB) effectively under irradiation of UV light. The overall reaction rate with adsorption and photolysis saturated at high MB concentration, and approached the adsorption rate, which was first order for all MB concent rations. This result indicates that adsorbed MB may have slowed photocatalysis by blocking active sites for photocatalysis. The overall kinetics could be described by a quasi-Langmuir model. The estimated maximum specific (per unit mass of $TiO_2$) transformation rate of MB by the $TiO_2$-coated carriers was four times larger than that obtained from slurry-$TiO_2$ reactors. This observation demonstrated that the $TiO_2$ present as a coating on the carriers maintained high efficiency for transforming recalcitrant organic matter via photocatalysis. These findings serve as a foundation for advancement of an intimate coupling of photocatalysis to biodegradation.

Geochemical Characteristics of the Jurassic Chunyang Granites in Northeastern Part of the Yeongnam Massif (영남육괴에 분포하는 쥐라기 춘양화강암의 지화학적 특성)

  • Kang, Minyoung;Kim, Yunji;Wee, Soomeen
    • Journal of the Korean earth science society
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    • v.38 no.1
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    • pp.49-63
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    • 2017
  • The geochemical results of the Chunyang granites located in the northeastern part of the Yeongnam Massif, indicate that these rocks have characteristics of calc-alkaline series in the sub-alkaline field, I-type and peraluminous. Most of the geochemical features in major and trace elements show systematic trends, which are similar to differentiation trends of the general Jurassic granitoids in South Korea. The Chunyang granite is largely enriched in mobile LILE (Sr, K, Rb and Ba) relatively immobile HFSE. They show LREE enriched patterns [$(La/Lu)_{CN}=41.8-73.2$] with a slightly negative Eu anomaly [$(Eu/Eu^*)_{CN}=0.89-1.10$]. There are no meaningful correlations in major and trace elements between the Chunyang granites and the Buseok plutonic rock which is the main unit of the Yeongju batholith. This result may suggest that these two plutonic rocks be not derived from the same parent magma. Tectonic discrimination diagrams indicate that the Chunyang granite was formed in volcanic arc environments. These geochemical characteristics results suggest that the Chunyang granite must have been generated at the active continental margin during the subduction of the Jurassic proto-Pacific plate.

The Development and Its Application of Teaching and Learning Plan for Making Class of Natural Dyeing and Jogakbo (천연염색과 조각보 만들기 수업을 위한 교수-학습 지도안 개발 및 적용)

  • Park, Hee-Soon;Lee, Hye-Ja
    • Journal of Korean Home Economics Education Association
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    • v.20 no.2
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    • pp.61-73
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    • 2008
  • The purpose of this study was to improve interest and attitude of student's Technology-Home Economics Curriculum and to recognize the change of recognition on Traditional image through Natural Dyeing and Jogakbo making on the unit of making living goods with fabrics in Technology-Home Economics curriculum on first year high school. The abridged result of study following this: First, in Natural Dyeing and Jogakbo making, teaching-learning plan applying LT cooperative studying and learning materials have been developed. Second, after applying the developed lesson plan, the result showed that the change in learning interest and attitude about Technology-Home Economics curriculum was positively improved. After executing the class on Natural Dyeing and Jogakbo making, the interest and concern about tradition were very positively upgraded through the result analyzing the change of recognition on traditional image. Through these results, The Teaching-learning plan and learning materials would show high possibility of application as educational contents about traditional culture in the field of education. After executing the class on making of Natural dyeing and Jogakbo, the learning interest degree and attitude was very positively upgraded, and the recognition on traditional image had been changed to the active and positive recognition.

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Dutch Touch : Mobile Application with Easy Dutch Pay (더치 터치: 더치페이를 쉽게 해주는 모바일 어플리케이션 구현)

  • Song, Yoojeong;Moon, Yeeun;Eom, Jiyeon;Lee, Jongwoo
    • Journal of Digital Contents Society
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    • v.19 no.1
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    • pp.11-18
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    • 2018
  • The Dutch treat culture, which pays for the cost of having meetings with a large number of people, is located in the daily life of many modern people. In particular, the execution of Kim Young-ran is a more active Dutch treat. However, when going dutch, there is a case where the amount of money to be paid per person is not divided equitably and there is an ambiguous situation about who should pay more. Also if one person have to pay all of the payments because of the different payment method such as a cash or card, there is inconvenience to keep a record of the financial relationship each time. In this paper, we introduce an application that allows several people to easily calculate the amount of money to pay per person when eating together or calculating something. From our service, you can easily access with web-based service, manage the user's debts more conveniently through forming the group. In addition, we focused on convenient calculation of cost by setting remaining unit and reserve function which is a function to overcome the disadvantages of existing application. Also, we maintain fairness through games in situations where the users need to make a choice.

The Development and Application of Strategies using Fairy Tales in Elementary School Science Instruction (초등학교 과학수업에서 동화를 활용하는 전략의 개발과 적용)

  • Kwon, Nan-Joo;Lee, Kyong-Mi
    • Journal of The Korean Association For Science Education
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    • v.30 no.1
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    • pp.1-12
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    • 2010
  • The purpose of this study was to investigate the development and application of strategies using fairy tales in elementary school science. For this study, many fairy tales were searched in terms of various characteristics and educational value of the tales. Five fairy tales were selected and reconstructed to suit the 'mirrors and lenses' unit of 5th graders' school science, and teaching strategies using the fairy tales were developed to be used in six lessons. To investigate the effects of instruction using fairy tales, pre/post tests for scientific attitude were administered. To analyze students' perception of their classes, a simple survey was administered through questionnaires. We found from this study that the students related the fairy tales with their own experiences and took an active part in the class that used them. Also, instruction using fairy tales had positive effects on their scientific attitude. Many students said that the science classes were interesting, and the method using fairy tales encouraged students to study hard as well as helped them to understand the context. It was concluded that instruction using fairy tales was an effective method in terms of enhancing learning motivation, encouraging more inquiries, more opportunities to apply the scientific concept, and more positive scientific attitude. We discussed the strategies using fairy tales for implementation in elementary science classes as well.

Purification of a Protease Produced by Bacillus subtilis PCA 20-3 Isolated from Korean Traditional Meju (전통 메주로부터 분리한 Bacillus subtilis PCA 20-3 유래 Protease 의 정제)

  • Lim, Seong-Il;Yoo, Jin-Young
    • Korean Journal of Food Science and Technology
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    • v.31 no.6
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    • pp.1635-1641
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    • 1999
  • Bacillus subtilis PCA20-3 was isolated from meju and was found to produce a protease. The strain produced the maximum amount of enzyme in the medium containing soytone (0.2%), soluble starch (2%), $(NH_4)_2SO_4\;(0.1%),\;CaCl_2(0.1%),\;yeast\;extract\;(0.01%),\;K_2HPO_4\;(0.1%),\;and\;KH_2PO_4\;(0.1%)$. Protease was first concentrated by ammonium sulfate (80% saturation, w/v) precipitation of culture supernatant. Then the enzyme was purified by column chromatography using CM Sephadex C-50. The collected proteins were rechromatographed using Sephadex G-100 gel filtration column. The fraction with protease active from Sephadex G-100 gel chromatography was found to be pure when examined by SDS-polyacrylamide gel electrophoresis and YMC-pak reverse phase chromatography. Specific activity, yield and purity were 76 U/mg. 2.7%, and 7.6 fold, respectively. The molecular weight of the enzyme was estimated to be 31.5 kDa by SDS-PAGE. The number of amino acids calculated from molecular weight was evaluated about 321 residues. N-terminal sequence of the enzyme was $Val^1-Pro^2-Tyr^3-Gly^4-Val^5-Ser^6-Gln^7-Gly^8-Lys^9-Ala^{10}$.

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A Study on The Family Life Education(II) -special Reference to marital life education- (가족생활 교육 프로그램 개발을 위한 기초연구(II)-부부교육을 중심으로-)

  • 오윤자
    • Journal of Families and Better Life
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    • v.10 no.2
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    • pp.209-229
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    • 1992
  • The purpose of this study is to develop Family Life Education program for Marital education in Korea. In order to realize the about research purpose, this study is divided into three sections. First, nature conception and contents f Family Life Education, second, patterns and models for Family Life Education Program in USA and Korea, and Third, the future of Family Life Education. Family Life Education (FLE) is an education originated in reaction to changing social conditions, industrialization and urbanization, it deals with the perceived inadequacies of families to cope with these changes, thereby reduction social problems involved with, and improving family life. With and assumption that the studies about FLE have not been so active in Korea, the present thesis examines the FLE in Korea. The necessity of marital education in Korea Is based upon the theories of FLE in the United States of America. Also, it atempts to formulate a tentative plan for the promotion of a FLE program in Korea. The concept of FLE in Korea was manifested in the social educational law and life-span education. specified as 4th among ten presidential regulations. It is defined as " the Life-span developmental education to enhance the quality of human life, to solve family problems, to develop an individual's potentiality and to strengthen the family relations. of the FLE programs, the marital education is considered one of the furcial wubjects becaused it is the core of the family life. With this premise, FLE tries to wupport the healthy mrital relations. subsequently helping to explore the family potentiality and to strengthen family ties. The objects of the FLE program are unmarried, pre-marred , and married persons. For the married persons, the FLE program should be arranged in accordance with their rrital status divided by the family life cycle so that they may prevent possible family problems at each stage of the family life. Also, to prevent the problems occurred in the course of carrying out family functions, the FLE program should be provided with on the basis of a family unit, thereby improving the quality of the family functions. The FLE is to hep persons begin smoothly the adaption process for a successful marital relations. For the FLE to be practised more widely systematically, research on family education--that is basic study, research and production and evaluation or the FLE to be carried out by research institute wholly responsible for it-- should be done first.

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Characteristics and Action Pattern of Polygalacturonase from Rhizopus oryzae CJ-2114 (Rhizopus oryzae CJ-2114가 생성하는 Polygalacturonase의 특성 및 작용양상)

  • Chung, Yung-Gun;Cho, Young-Je;Kwon, Oh-Jin;Choi, Cheong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.21 no.2
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    • pp.195-200
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    • 1992
  • Rhizopus oryzae CJ-2114 was selected for its strong polygalacturonase activity among various strains of mold found in soil. The optimum pH for the enzyme activity was 4.0 and optimum temperature was 4$0^{\circ}C$. The activation energy for the polygalacturonase was calculated by Arrhenius equation was 2.048㎉/㏖. The reaction of this enzyme followed typical Michaelis-Menten kinetics with the Km value of 54.05mM with the $V_{max}$ of 13.9m mole/min. The enzyme is relatively stable in acidic condition. The activity of polygalactur-onase was inhibited completely by C $u^{2+}$, P $b^{2+}$ and Z $n^{2+}$, $_Mn^{2+}$ at concentration of 1 mM. The enzyme can be inactivated by the treatment with maleic anhydride and iodine. The results indicate the possible involvement of histidine at active site. When polygalacturonase from Rhizopus oryzae CJ-2114 was reacted with poly-galacturonic acid as a substrate mono-, di-, and oligogalacturonic acid were produced at early and mono-, digalacturonic acid produced at late incubation time. time.

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A Design and Fabrication of a Compact Ka Band Transmit/Receive Module Using a Quad-Pack (쿼드팩을 이용한 소형 Ka 대역 송수신(T/R) 모듈의 설계 및 제작)

  • Oh, Hyun-Seok;Yeom, Kyung-Whan;Chong, Min-Kil;Na, Hyung-Gi;Lee, Sang-Joo;Lee, Ki-Won;Nam, Byung-Chang
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.3
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    • pp.389-398
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    • 2011
  • In this paper, the design and fabrication of a transmit/receive(T/R) module for Ka-band phased array radar is presented. A 5bit digital phase shifter and digital attenuator were used in common for both transmitter and receiver considering unique Ka-band characteristic. The circulator was excluded in the T/R module and was placed outside T/R module. The transmitting power per element antenna is designed to be about 1 W and the noise figure is designed to be below 8 dB. The designed T/R module RF part has a compact size of $5\;mm{\times}4\;mm{\times}57\;mm$. In order to implement the T/R module, MMICs used in T/R module was separately assessed before assembly of the designed T/R module. The transmitter of the fabricated T/R module shows about 1 W at 5 dBm unit module input power and the receiver shows a gain of about 20 dB and a noise figure of below 8 dB as expected in the design stage.

A Study on the Safety Handling Method of KCG's Water Jet Propulsion Ship (해양경찰 Water Jet 추진함정의 안전 조함법 연구)

  • Yun, Chong-Gum;Pak, Chae-Hong;Park, Deuk-Jin;Jung, Cho-Yeong
    • Journal of Navigation and Port Research
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    • v.41 no.6
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    • pp.373-380
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    • 2017
  • Operational errors caused by human factors, which is the major cause of marine accidents, include lack of knowledge, misunderstanding knowledge, and inadequate procedures. Recently, the type of propulsion mounted on KCG cutters has been diversified. In particular, the water jet propulsion unit, which was mainly installed in small boats, have been gradually expanded to medium and large size Coast Guard cutters, reaching 50% of the total. Axes types are divided into 2 to 4, and the bucket types are divided into Double Reverse Bucket(DRB) and Single Reverse Bucket(SRB); in these, the backward and steering control methods are completely different. Diversification of these operating systems can increase factors causing human error by the ships' operators. However, there is a lack of research on the maneuvering methods, considering the inherent active characteristics of each type of water jet. In this paper, we analyze the sideway method suitable for the condition of Coast Guard Exclusive wharf without assistance, based on the astern performance of each type. Then, a ship handling simulator was used for the experiment; they compared and verified through interviews of captains.