This study proposes a method of separating uranium (U) and minor actinides from rare earth (RE) elements in the LiCl-KCl salt system. Several RE metals were used to reduce UCl3 and MgCl2 from the eutectic LiCl-KCl salt systems. Five experiments were performed on drawdown U and plutonium (Pu) surrogate elements from RECl3-enriched LiCl-KCl salt systems at 773 K. Via the introduction of RE metals into the salt system, it was observed that the UCl3 concentration can be lowered below 100 ppm. In addition, UCl3 was reduced into a powdery form that easily settled at the bottom and was successfully collected by a salt distillation operation. When the RE metals come into contact with a metallic structure, a galvanic interaction occurs dominantly, seemingly accelerating the U recovery reaction. These results elucidate the development of an effective and simple process that selectively removes actinides from electrorefining salt, thus contributing to the minimization of the influx of actinides into the nuclear fuel waste stream.

Two commonly used ceramics in molten salt research are alumina and mullite. The two ceramics were exposed to a combination of rare earth chlorides (YCl3, SmCl3, NdCl3, PrCl3, and CeCl3; each rare earth chloride of 1.8 weight percent) in LiCl-KCl at 773 K for approximately 13 days. Scanning electron microscopy with wave dispersion spectra was utilized to investigate a formation layer or deposition of rare earths onto the ceramic. Only the major constituents of the ceramics (Al, Si, and O2) were observed during the wave dispersion spectra. X-ray fluorescence was used as well to determine concentration changes in the molten salt as a function of ceramic exposure time. This study shows no evidence of ionic exchange or layer formation between the ceramics and molten chloride salt mixture. There are signs of surface tension effects of molten salt moving out of the tantalum crucible into secondary containment.

In this study, we analyzed the development of high school students’ argumentation through their writings on socio-scientific Issues (SSI) related to the Climate Change Unit in the Earth Science I curriculum. Pre- and post-writing assignments on the two main causes of global warming were analyzed and compared. In addition, an in-depth interview of the focus group was conducted with 7 students who showed a distinct change in the level of argumentation. According to the results, 16 of 52 students remained at the same argumentation level in pre- and post-writing assignments, and students remaining at Level 2 among five levels had difficulty in understanding the Toulmin’s argument pattern (TAP) structure. Using the TAP structure, 29 of 52 students demonstrated increased argumentation levels in the post-writing assignments. The conclusions include that writing lessons on SSI using the TAP in Earth science classes can improve the level of high school students’ argumentative writing, and that the level of students’ argumentation can develop with the elaboration of their level of falsification. Also, it is suggested that the science curriculum should increase students' science writing competencies by specifying science writing as one of the goals.

This study identified and examined earth science education department programs in Korea. Major courses provided by 11 universities and their course requirements were analyzed, and the main research results are as follows. First, many basic courses, other major requisite, and elective courses are provided in geology, astronomy, and atmospheric science. oceanography, geophysics, earth environmental science, and natural disaster and energy resources had fewer major requisite courses provided in addition to basic courses, and few elective courses were offered. Second, many courses in science education focused on earth science, while others focused on general science and there were few courses that covered education theory regarding the specific subject. Third, science course application requirements emphasized the understanding of science in general or of earth science specifically. From the above results, additional studies are proposed to reflect on the current state and supplement these programs.

SrMoO4:RE3+ (RE=Dy, Sm, Tb, Eu, Dy/Sm) phosphors are prepared by co-precipitation method. The effects of the type and the molar ratio of activator ions on the structural, morphological, and optical properties of the phosphor particles are investigated. X-ray diffraction data reveal that all the phosphors have a tetragonal system with a main (112) diffraction peak. The emission spectra of the SrMoO4 phosphors doped with several activator ions indicate different multicolor emissions: strong yellow-emitting light at 573 nm for Dy3+, red light at 643 nm for Sm3+, green light at 545 nm for Tb3+, and reddish orange light at 614 nm for Eu3+ activator ions. The Dy3+ singly-doped SrMoO4 phosphor shows two dominant emission peaks at 479 and 573 nm corresponding to the 4F9/2→6H15/2 magnetic dipole transition and 4F9/2→6H13/2 electric dipole transition, respectively. For Dy3+ and Sm3+ doubly-doped SrMoO4 phosphors, two kinds of emission peaks are observed. The two emission peaks at 479 and 573 nm are attributed to 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions of Dy3+ and two emission bands centered at 599 and 643 nm are ascribed to 4G5/2→6H7/2 and 4G5/2→6H9/2 transitions of Sm3+. As the concentration of Sm3+ increases from 1 to 5 mol%, the intensities of the emission bands of Dy3+ gradually decrease; those of Sm3+ slowly increase and reach maxima at 5 mol% of Sm3+ ions, and then rapidly decrease with increasing molar ratio of Sm3+ ions due to the concentration quenching effect. Fluorescent security inks based on as-prepared phosphors are synthesized and designed to demonstrate an anticounterfeiting application.

희토류(Rare Earth) 함량이 높은 TRU 생성물 중의 RE 원소를 감소시키기 위하여 RE 원소와 UCl3의 산화반응을 이용한 RE 제거 공정의 타당성을 HSC Chemistry 코드를 이용하여 검토하였다. 사용후핵연료에 포함된 TRU 원소 및 RE 원소의 조성 및 열역학적 자료를 검토하였으며, UCl3와의 산화 반응에 따른 평형 자료를 계산하여 공정 가능성을 검토하였다. 실제 파이로 프로세싱 처리를 가정한 물질수지로부터 TRU 생성물의 RE 함량이 다른 두 가지 경우에 대하여 RE 원소 제거율과 TRU 회수율을 평가하였다. TRU 생성물을 산화제인 UCl3와 반응시켰을 때 각 원소의 Gibbs free energy의 차이에 의한 선택적 산화 반응이 일어났다. 투입된 UCl3 양을 조절하여 TRU 회수율을 최대로 유지하면서도 RE 원소를 제거하여 최종생성물의 TRU/ RE 비를 증가시킬 수 있는 가능성을 계산 결과로 확인하였다. 본 연구의 결과들은 열역학적 평형 자료에 기반한 결과이므로 실제 공정에 적용하기에는 많은 차이점이 존재한다. 그러나 TRU 물질을 취급하기 어려운 환경에서 파이로프로세싱의 TRU 생성물을 고속로의 핵연료로 공급하기 위한 공정 설계에 중요한 자료로 활용될 것으로 기대된다.

The purpose of this study was to determine whether there are differences in the verbal interactions of earth science gifted depending on their communications structures and group status in small group activities. To this end, a small group activity was conducted to measure the density of the earth, and 8 small groups were selected, including 4 coownership type and 4 monopolistics type groups with different communication structures. And then, the framework was developed for analyzing verbal interactions to compare the differences in characteristics between small groups. The results are as follows. First, regardless of the communication structures, there were showing a simple pingpong-type communication structures for all small groups. Second, negative interactions such as ‘restraint’, ‘command’, ‘complaint’, and ‘lack of confidence’ predominantly appeared in all small groups. Third, the students in the status of out-lookers in small groups were mainly verbal interactions, such as instructing the other person, acting against the other person’s actions, and expressing dissatisfaction with the attitudes and abilities of members. Therefore, teachers should guide students to use higher-level verbal interactions in their group activities in small group activities, and engage in students communication to prevent negative interactions from occurring. The teachers also need to check the level of achievement for students in the status of out-lookers in advance and guide them to participate more actively in small group activities. This study is meaningful in that it can be sued to design teaching and learning to improve students’ problem solving and communication skills.

The purpose of this study was to compare the earth science curriculums of South Korea and North Korea. Aspects such as the content of the curriculums and the timing of learning were analyzed, in order to provide basic data that can be used to design a revised and integrated Korean curriculum. The objects of this study were South Korean Science textbooks from grades 5-9, and the high school Unity of Science and Earth Science I and II textbooks. Additionally, from North Korea, the junior middle school Natural Science 1 and 2 textbooks and the senior middle school Chosun Geography 2 and Geography 1 textbooks were analyzed. The results of this study obtained through an analysis that used the Trends in International Mathematics and Science Study (TIMSS 2019) grade 8 earth science assessment framework were as follows. First, South Korea needs to adopt iterative learning. Repetitive learning, which is effective for understanding what is being learned, is applied to only 1 by 8th grade. Second, South Korea needs to adjust the time when certain content is learned. This is because there is a disparity between when content is learned in comparison to North Korea, and the timing of learning of about 50% of the TIMSS standards have not been followed. Third, it is necessary to reflect the content present within the TIMSS that have not been learned. This can be a way to increase the nations’ educational competitiveness in the international community. This paper proposed a comparative analysis of South korean and North Korean approaches to the earth science curriculum and conducted practical research to facilitate the construction of an integrated curriculum.

Oceanic current maps introduced in science and earth science textbooks can offer a valuable opportunity for students to learn about rapid climate change and the role of currents associated with the global energy balance problem. Previously developed oceanic current maps in middle and high school textbooks under the 2007 and 2009-revised national curriculum contained various errors in terms of scientific accuracy. To resolve these problems, marine experts have constructed a unified oceanographic map of the oceans surrounding the Korean Peninsula. Since 2010, this process has involved a continuous, long-term consultation procedure. By extensively gathering opinions and through verification process, a representative and scientific oceanic current map was eventually constructed. Based on this, the educational oceanic current maps, targeting the comprehension of middle and high school students, were developed. These maps were incorporated into middle and high school textbooks in accordance with the revised 2015 curriculum. In this study, we analyzed the oceanic current maps of five middle school science textbooks and six earth science textbooks that were published in high school in 2019. Although all the oceanic current maps in the textbooks were unified based on the proposed scientific oceanic current maps, there were problems such as the omission of certain oceanic currents or the use of a combination of dotted and solid lines. Moreover, several textbooks were found to be using incorrect names for oceanic currents. This study suggests that oceanic current maps, produced by integrating scientific knowledge, should be visually accurate and utilized appropriately to avoid students’ misconception.

절대 습도와 이슬점 온도의 관계에 대한 예비 교사들의 인식을 조사하기 위하여 설문지를 투입하였다. 설문 결과 예비 교사들이 “절대 습도와 이슬점 온도는 비례한다.”, “이슬점 온도는 공기 중의 수증기의 질량에 비례한다.”와 같은 견고한 오개념을 갖고 있음을 발견하였다. 예비 교사들이 갖는 이러한 오개념은 절대 습도와 이슬점 온도의 관계에 대한 7차 교육과정과 2007 개정 교육과정 중학교 과학 교과서의 부정확한 서술 내용에서 기인하는 것으로 사료된다. 한편, 2015 개정 교육과정 중학교 1학년 과학 교과서는 증발, 응결, 압력과 온도 변화에 따른 기체의 부피 변화를 분자 운동의 관점에서 다루기 때문에, 중학교 교육과정에서 이러한 관점을 유지하기 위해 수증기량과 이슬점 온도의 척도로서 수증기압의 도입은 예비 교사와 학습자의 오개념을 방지할 수 있으며, 과학 교육과정을 보다 일관되고 논리적으로 만들 수 있을 것으로 사료된다.

본 연구는 현직 및 예비 지구과학교사의 H-R도와 별의 진화에 대한 개념 이해 상태를 알아보기 위해 개념 지위 분석틀을 활용하여 수행하였다. 이해 가능성 영역에서 현직교사의 비과학적 용어 사용이 다수 발견되었고, 그래프 작성에서 낮은 과학적 탐구 능력과 개념에 대한 비과학적 비유가 발견되어 교수 과정에서 잘못된 개념 전달의 가능성이 확인되었다. 예비교사는 중등교육과정 연계 문항에서 다수의 오류를 보였으며, 이와 관련하여 학교 현장에 적용이 더 잘될 수 있도록 예비교사 교육 과정의 개선이 필요하겠다. 개연성 영역에서, 두 집단 모두 별의 진화가 갖는 우주론적 의미를 이해하고 있었으나, 예비교사의 별의 실제기작에 대한 설명이 구체적이지 않았다. 유용성 영역에서, 현직교 사는 지구과학의 학문적 특성을 반영한 교육적 고민을 하고 있었고, 지식을 현실 문제해결에 활용, 적용하려는 경향이 높았다. 반면, 예비교사는 높은 무응답률을 보여 H-R도와 별의 진화를 실용적 개념으로 파악하지 않는 것으로 확인되었다. 결과적으로, 두 집단 모두에서 H-R도와 별의 진화에 대한 비과학적 개념이 다수 발견되어 교사 교육 및 교수 학습 계획 수립 시 주의가 필요함을 확인할 수 있었다.

본 연구는 중학교 교육과정에서 수학과 연계된 지구과학 실험 중 지구의 크기 측정을 중심으로 총 30시간 동안 지구과학 교육봉사 활동에 참여한 예비 지구과학교사와 중학생들에게 본 프로그램이 주는 의미를 살펴보고 혁신적 수업으로의 가능성을 탐색해 보았다. 중학교 과학 교과서에 소개된 고대 그리스 시대 에라토스테네스의 그림자 길이를 이용한 지구 크기 측정 실험에서 나타나는 오차를 최소화하기 위하여, 멀리 떨어진 수도권과 지방의 두 개의 중학교에서 삼각비를 이용한 탐구 활동을 수행 한 후, 실측한 자료를 두 학교 학생들이 공유하여 지구의 크기를 최종적으로 계산하였다. 이 과정을 통해 실측 자료를 효과적으로 표현하는 수학적 방법을 배우며, 반복적이고 정확한 자료 획득 과정의 중요성과 어려움을 체험하고, 도출된 결과에 포함된 오차의 원인들에 대해 토론하였다. 본 연구 결과는 학생들이 지구과학 탐구의 특성을 이해하고, 2015 개정 교육과정에서 과학과 수학교과에서 공통적으로 강조하고 있는 교과 역량인 문제 해결력, 사고력, 의사소통 능력을 함양할 수 있는 수학·과학 통합 프로그램 개발에 기초 자료를 제공할 것이다.

The traditional earth wall structure consists of a Joongkit(a small reinforcing post inside a wall) and a Oe(a miscellaneous tree, rendered laths) based on the space between the columns and applying the soil. The members who act as the base layer before applying soil used joongkit, sakmok, and oemok, which are known to correspond to the current joongkit, gasisae, and lath strips. This study was designed to understand the following through an analysis of the ancient texts, such as uigwe. Through a study on the usage and specifications of joongkit recorded on the uigwe, I wanted to reveal that joongkit is a material that has different specifications, functions, and installation techniques from current joongkit. The purpose of this study was to present the differences and technical features of the components of use for two types of oeyeokki technique of traditional wall. In addition, the items to be considered at the actual cultural heritage repair site were reviewed in the restoration of the earth wall weaving technique.

Since the ISO decided to deal with rare-earth elements at the 298th Technical Committee (TC) in 2015, Korea has participated in four plenary meetings and proposed four standards as of June 2019. The status of ISO TC 298, the standards covered by the TC, and the standardization strategies of Korea are summarized. Korean delegations are actively engaged in WG2, which deals with recycling, proposing four standards for fostering the rare-earth recycling industry. However, the participation of domestic experts is still low compared with the increase in the number of working groups and the number of standards in TC 298. The aim of this article is to summarize the current status of ISO international standards related to rare-earth elements, to encourage relevant experts to participate in standardization, and to develop international standards that accurately reflect the realities of the industry.

대기 대순환을 결정하는 주요 인자로는 남북방향 온도 경도와, 지구 자전으로 인한 코리올리 힘이 있다. 남북방향 온도 경도에 따른 경압성 차이로 인한 대기 대순환의 변화는 지금까지 많이 연구되어 왔으나, 자전속도에 따른 대기 대순환의 반응은 크게 연구되어 오지 않았다. 때문에 본 연구에서는 현 지구보다 느리거나 빠른 자전속도 범위를 모두 포괄하여 이에 따른 해들리 순환과 제트의 변화를 확인하였다. 이 연구에서 우리는 지구의 자전속도가 빨라질수록 해들리 순환 경계와 제트의 위치가 적도에 가까워지고, 제트와 해들리 순환의 세기가 약해진다는 것을 발견하였다. 해들리 순환 경계와 제트의 위치는 자전속도가 매우 빠르거나 느린 경우를 제외하면 준선형적인 관계를 가졌다. 특히, 해들리 순환 경계는 자전속도가 현재보다 1/8에서 8배의 자전속도 범위에서 자전속도보다 그 제곱근에 더 잘 반비례하는 경향성을 보였다. 단, 이러한 자전속도에 따른 변화는 해들리 순환 세기와 제트의 세기에 대해서는 뚜렷하지 않았다. 이는 대기 대순 환의 위치 구조 변화는 지구 자전속도와 관련이 큰 반면, 세기의 변화는 자전속도로 설명되지 않음을 의미한다.