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Content Diversity Analysis of Elementary Science Authorized Textbooks according to the 2015 Revised Curriculum: Focusing on the "Weight of an Object" Unit (2015 개정 교육과정에 따른 초등 과학 검정 교과서 내용 다양성 분석 - '물체의 무게' 단원을 중심으로 -)

  • Shin, Jung-Yun;Park, Sang-Woo;Jeong, Hyeon-Ji;Hong, Mi-Na;Kim, Hyeon-Jae
    • Journal of Korean Elementary Science Education
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    • v.41 no.2
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    • pp.307-324
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    • 2022
  • This study examined the content diversity of seven authorized science textbooks by comparing the characteristics of the science concept description and the contents of inquiry activities in the "weight of objects" unit. For each textbook, the flow of concept description content and the uniqueness of the concept description process were analyzed, and the number of nodes and links and words with high connections were determined using language network analysis. In addition, for the inquiry activities described in each textbook, the inquiry subject, inquiry type, science process skill, and uniqueness were investigated. Results showed that the authorized textbooks displayed no more diversity than expected in their scientific concept description method or their inquiry activity composition. The learning elements, inclusion of subconcepts, and central words were similar for each textbook. The comparison of inquiry activities showed similarities in their contents, inquiry types, and scientific process skills. Specifically, these textbooks did not introduce any research topics or experimental methods that were absent in previous textbooks. However, despite the fact that the authorized textbook system was developed based on the same curriculum, some efforts were made to make use of its strengths. Since the sequence of subconcepts to explain the core contents differed across textbooks, this explanation process was divided into several types, and although the contents of inquiry activities were the same, the materials for inquiry activities were shown differently for each textbook to improve and overcome the difficulties in the existing experiments. These findings necessitate the continuation of efforts to utilize the strengths of certified textbooks.

Plant Regeneration via Adventitious Shoot Formation from Hypocotyl Explants of Groundcherry (Physalis angulata L.) (땅꽈리(Physalis angulata L.) 하배축 절편으로부터 신초 형성을 통한 식물체 재분화)

  • Koh, Seok Chan
    • Korean Journal of Plant Resources
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    • v.35 no.4
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    • pp.502-507
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    • 2022
  • In the present study, plant regeneration through adventitious shoot formation from hypocotyl segments of in vitro seedlings of groundcherry (Physalis angulata L.) was investigated to determine the optimum culture conditions for highly efficient regeneration of the species. Adventitious shoots in hypocotyl segments were efficiently induced on MS media with low concentrations of BAP, specifically, with 0.5-1.0 mg/L BAP singly or in combination with 0.1-0.5 mg/L NAA. The 1.0 mg/L BAP single treatment was most effective for forming multiple adventitious shoots. When the induced shoots were transferred to the root induction media, low concentrations of NAA, IBA, and IAA enhanced the development of adventitious roots from adventitious shoots, suggesting that low concentrations of auxins were optimal for producing regenerated plantlets. The number of roots per shoot was large (> 2.0), and the root length exceeded 8.0 cm. In particular, the development and the overall shape of the roots were ideal. Furthermore, the number and length of shoots exceeded 2 and 6.0 cm, respectively. When the regenerated plantlets were transferred to compost soil, the root and shoot systems had developed well to the point that all of the regenerated plantlets acclimated successfully, resulting in normal morphology and growth characteristics, similar to those of the mother plant. Therefore, plant regeneration via adventitious shoot formation is expected to be one of the main methods for producing groundcherry on a large scale for a stable supply of the raw materials.

Metallurgical Study of Iron Artifacts from Guryong-ri Site in Ungcheon, Boryeong

  • Choi, Eun Young;Cho, Nam Chul
    • Journal of Conservation Science
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    • v.38 no.4
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    • pp.289-300
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    • 2022
  • In the 6th and 7th centuries, 5 iron artifacts excavated form the Baekje Stone Tomb in Guryong-ri site, Ungcheon, Boryeong, were studied. The sample were metal microscopic observation, SEM-EDS analysis and Raman micro-spectroscopy analysis were conducted to understand the metallurgical characteristics. The microstructure observation showed the presence of ferrite and pearlite throughout, and differences in carbon content existed depending on the direction. Non-metallic inclusions were in the form of long lines, and most of them were wüstite, fayalite. It is indicated that the artifacts were forge welded using hypoeutectoid steel, with signs of carburizing and decarburizing processes. Some crystals with high P2O5, TiO2, CaO content were identified as sarcopside, ulvöspinel, and perovskite, respectively, through Raman spectroscopy. A comparison of the results with previous studies on the sites of Bujang-ri site in Seosan and Bongseon-ri site in Seocheon, which are adjacent sites in the coastal area, revealed that, while heat treatment technology was available, the artifacts were not heat-treated considering the purpose for use for these artifacts. The chemical composition of the non-metallic inclusions P2O5, TiO2, CaO were plotted in proportions to SiO2 and compared with adjacent sites. Considering that the P2O5/SiO2 ratio was widely distributed, the refining technology was not uniform. In addition, the TiO2/SiO2 ratio was found to be higher than that of other sites, meaning that a titanium-containing ore was used to manufacture the artifacts, unlike in surrounding sites, but it is not detected in all artifacts, so it may have been affected by various factors such as furnace walls in addition to raw materials. Although slag formers were used, considering the CaO/SiO2 ratio and the (Al2O3/SiO2)/(CaO/SiO2) ratio, which appear to be similar to the surrounding sites, but it is possible that CaO containing raw ore was used because it is also affected by the components of raw ore. As a result of the study, it is highly likely that ore different from that of the surrounding sites was used for production, but a more comprehensive comparative study with the surrounding sites is needed in the future.

Current Status and Perspectives of Quality Improvement in Sesame (참깨 품질 연구의 현황과 문제점 및 전망)

  • Lee, Bong-Ho;Lee, Jung-Il;Park, Rae-Kyeong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.33 no.s01
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    • pp.86-97
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    • 1988
  • Sesame(Sesamum indicum L.) is probably the most ancient oilseed crop known in the world. The seed of sesame is used in a variety of ways as food. The whole seed may be eaten raw, either roasted or parched, or fed to birds and stock. Sesame oil is used as a salad or cooking oil, in shortening, margarine and in the manufacture of soap. Minor uses are as a fixative in the perfume industry and formerly as a carrier for fatsoluble substances in pharmaceuticals such as penicillin. One of the minor constituents of sesame oil, sesamin, is used for its synergistic effect in pyrethrin insecticides, in addition of a small quantity of this substance markedly increases the effectiveness of fly sprays. The meal remaining after oil extraction can be used as and animal feed-stuff or as manure. In general sesame meal is considered to be equal to cottonseed or soybean meal as a protein supplement for livestock and poultry. It is especially high in certain amino-acids such as methionine, which is low in soybean meal, and thus can be combined with it or similar meal to form a more balanced ration. An attempt to summarize the literature review on quality improvement of sesame was made to discuss the accomplishments of the past and perspectives in the future. The reviews on quality improvement of sesame were mainly discussed in connection with the cultural practices and genetic informations in current status. The emphasis focussed on environmental variation of quality in cultural practices, such as harvest time, variety by location, climatic condition, fertilizer application, and growth regulator treatment. On the genetic variation of quality, it was discussed on variety background, mutation breeding, correlations, and inheritance of quality related characteristics. It also was discussed on relationship between quality and plant traits, storage condition or period, and seed coat color. Moreover, current research status were reviewed on some minor elements such as sesamin, oxalic acid, and trypsin inhibitor. As a results of the review, the lack of an effort to quality improvement in each utilization area was indicated as a problem area. More active efforts for the improvement of quality were also insufficient to incorporate the available genes for quality in breeding method or collection and analysis of breeding materials. Therefore, researches in the future would be recommended to emphasize on these problem areas.

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Taste Compounds of Small Black Bean Chungkugjang Added with Kiwi and Radish (키위와 무를 첨가한 소립 검정콩 청국장의 정미성분)

  • Shon, Mi-Yae;Kwon, Sun-Hwa;Seo, Kwon-Il;Park, Seok-Kyu;Park, Jeong-Ro
    • Journal of Life Science
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    • v.11 no.6
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    • pp.517-522
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    • 2001
  • To Confirm the repression of off-odor and improvement of food quality in small black bean chungkugjang (SBC), some taste compounds of SBC added with kiwi and radish homogenate and fermented fro 3 days at 42$^{\circ}C$ were investigated. Contents of free amino acids in SBC were lower than that of soybean chungkugjang (SC) and were increased by adding kiwi and radish homogenate to black bean, indicating that two materials were effective to the enzymatic digestibility of soy protein. Of organic acids, citric acid was the most abundant, followed by acetic acid and lactic acid. Fatty acid composition was high in the order of linoleic acid (50.82~54.51%), oleic acid (17.76%~22.10%) and plamitic acid(12.13~13.79%). There were no significant difference in compositions of organic acids and fatty acids of chungkugjang. Major volatile compounds of SBC were indole , 2-5-dimethyl pyrazine and trimethyl pyrazine. Contents of alkyl pyrazines that contribute the characteristic aroma and flavor of SBC added and fermented with kiwi and radish homogenate were 3 times lower than those of SC. Uracil and UMP were major nucleic acie-drlated compounds in all four chungkugjangs. Contents of the other nucleic acid-related compounds were a similar trend in all chungkugjangs.

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Analysis of the Effect of Intralesional Steroid Injection on the Voice During Laryngeal Microsurgery (후두 미세수술 중 병변 내 스테로이드 주입이 음성에 미치는 효과 분석)

  • Jae Seon, Park;Hyun Seok, Kang;In Buhm, Lee;Sung Min, Jin;Sang Hyuk, Lee
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.33 no.3
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    • pp.166-171
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    • 2022
  • Background and Objectives Vocal fold (VF) scar is known to be the most common cause of dysphonia after laryngeal microsurgery (LMS). Steroids reduce postoperative scar formation by inhibiting inflammation and collagen deposition. However, the clinical evidence of whether steroids are helpful in reducing VF scar formation after LMS is still lacking. The purpose of this study is to determine whether intralesional VF steroid injection after LMS helps to reduce postoperative scar formation and voice quality. Materials and Method This study was conducted on 80 patients who underwent LMS for VF polyp, Reinke's edema, and leukoplakia. Among them, 40 patients who underwent VF steroid injection after LMS were set as the injection group, and patients who had similar sex, age, and lesion size and who underwent LMS alone were set as the control group. In each group, stroboscopy, multi-dimensional voice program, Aerophone II, and voice handicap index (VHI) were performed before and 1 month after surgery, and the results were statistically analyzed. Results There were no statistically significant differences in the distribution of sex, age, symptom duration, occupation and smoking status between each group. Both groups consisted of VF polyp (n=21), Reinke's edema (n=11), and leukoplakia (n=9). On stroboscopy, the lesion disappeared after surgery, and the amplitude and mucosal wave were symmetrical on both sides of the VFs in all patients. Acoustic parameters and VHI significantly improved after surgery in all patients. However, there was no significant difference between the injection and control group in most of the results. Conclusion There was no significant difference in the results of stroboscopy, acoustic, aerodynamic, and subjective evaluation before and after surgery in the injection group and the control group.

Effect of Growth and Nitrogen Use Efficiency to Chinese Cabbage under Fermented Organic Fertilizer Treatment with Domestic Resource (국내 자원으로 제조한 발효 유기질비료가 배추의 생육 및 질소이용효율에 미치는 영향)

  • You-Jin Kim;So-Hui Kim;Sang-Min Lee;Cho-Rong Lee
    • Journal of the Korea Organic Resources Recycling Association
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    • v.31 no.3
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    • pp.83-91
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    • 2023
  • This study investigate growth responses of Chinese cabbage and nitrogen use efficiency (NUE) to application of fermented organic fertilizer produced from domestic organic resources for developing alternative materials instead of imported castor oil meal. Two types of fermented fertilizers (Fermented Organic Fertilizer A (OFA) and Fermented Organic Fertilizer B (OFB)) were produced by mixing distillers dried grains 30%, sesame cake 30%, rice bran 20% and fish meal 20% under different fermentation conditions. Treatment consisted of OFA is fermented for 21 days on plastic greenhouse, OFB is fermented for 5 days on 40℃, and MOF (Mixed Organic Fertilizer) is a fertilizer made with castor bean as the main ingredient. OFA, OFB and MOF were applied at the rate of 320 kg N/ha. Chinese cabbages were cultivated from Aug. to Nov. in 2022. Growth and yield of Chinese cabbage were no significant differences among all treatments except control (non-fertilized, NF). However, NUE of Chinese cabbage was higher the fermented fertilizer treatment (OFB: 81.4%, OFA: 79.1%) than the MOF (65.3%). It was observed that urease activity in the fermented fertilizer treatment was significantly higher than the MOF. This result confirmed that fermented fertilizers have similar effect on growth and yield with the MOF and could improve the NUE of crop.

A Study on the Numerical Analysis Methods for Predicting Strength Test Result of Box Girder under Bending Moment (휨 모멘트를 받는 박스거더 구조 강도 실험에 대한 수치해석 방법에 관한 연구)

  • Myung-Su Yi;Joo-Shin Park
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.5
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    • pp.488-496
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    • 2023
  • Ship and bridge structures are a type of long box-shaped structure, and resistance to vertical bending moment is a key factor in their structural design. In particular, because box girders are repeatedly exposed to irregular wave loads for a long time, the continuous collapse behavior of structural members must be accurately predicted. In this study, plastic collapse behavior, including buckling according to load changes of the box girder receiving pure bending moments, was analyzed using a numerical analysis method. The analysis targets were selected as three box girders used in the Gordo experiment. The cause of the difference was considered by comparing the results of the structural strength experiment with those of non-linear finite element analysis. This study proposed a combination of the entire and local sagging shape to reflect the effect of the initial sagging caused by welding heat that is inevitably used to manufacture carbon steel materials. The procedures reviewed in the study and the contents of the initial sagging configuration can be used as a good guide for analyzing the final strength of similar structures in the future.

The Analysis of Characteristics and Plan to Activate the Small Wedding Reported in Internet News (인터넷 뉴스에 보도된 작은 결혼식의 특징 분석 및 활성화 방안)

  • Kim, Hyun-Mi
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.3
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    • pp.43-54
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    • 2019
  • This study has purpose in analyzing the characteristics of small weddings reported in the internet news, and suggesting the plan to activate it. The materials are about 248 internet news from 2012 to 2018, and frequency analysis and chi-square test were conducted for it. The research result is like the following. 1. It was reported that the saving type was higher in 2016 and the money gift improving type was higher rate in 2015. 2. As a venue for wedding, it was reported the saving type and free type choose the public institution, the small size type hotels, the peculiar type outdoor and house, money gift improving type hotel and public institutions. 3. The saving type, peculiar type and free type were likely to be reported as information transfer, and the small size type and the money gift improving type were likely to be reported to suggest the case of small weddings. 4. Case type showed high rate for public institutions and hotels for small weddings, and information type showed high rate for public institution for small wedding venue. 5. Case type and information type showed favorable rate for small wedding, and opinion type appeared similar favorable rate and unfavorable rate for small weddings. 6. Ordinary people showed high rate to be reported with saving type, celebrities were with small size type. And also the ordinary people showed high rate public institutions, celebrities with hotel as small wedding venue. 7. The items to save the cost in small wedding included more of venue renting cost, reception cost, wreath/decoration cost, photo filming cost than marriage expenses and wedding gifts, house.

A Study on the Performance Variations of Liquid-crystal Aqueous Cleaning Agents with their Formulating Components and Mixing Ratios (액정 세척용 수계 세정제의 배합성분과 혼합비에 따른 성능 변화)

  • Jeong, Jae-Yong;Lee, Min-Jae;Bae, Jae-Heum
    • Clean Technology
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    • v.16 no.2
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    • pp.103-116
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    • 2010
  • It has been reported that the LCD panel market in the FPD industry is become growing and its panel size and production capacity are increasing, and its manufacturing technique is improved every year. FPD manufacturing process requires high cleanliness in its overall process. Especially, FPD cleaning process which accounts for 30~40% of total manufacturing process is very important in its technological and productivity aspects. It is difficult to remove residual liquid-crystal in the fine gap after liquid-crystal injection process in the cell. In this study, aqueous cleaning agents with excellent cleaning, rinsing, and penetrating abilities, but minimum ion content for LCD panel were formulated through mixing glycol ether-type and glycol dimethyl ether-type solvents and nonionic surfactants which are widely used as raw materials for alternative cleaning agents because of environmental regulation at home and abroad. And the formulated cleaning agents were applied to clean FPD liquid crystal after its injection in the cell. Physical properties, cleaning efficiencies, and rinsabilities of the formulated cleaning agents with different combination ratios of solvents, surfactants and additives were measured. As experimental results, the formulated cleaning agents showed higher wetting indices and cloud point than the traditional commercial cleaning agent. And it was found that cleaning efficiencies of the formulated cleaning agents were influenced by the structure of main solvents in them and the types of liquid crystal as soil for cleaning. The best cleaning agents among the formulated cleaning agents showed similar cleaning efficiencies and better rinsabilities compared to the conventional cleaning agent.