• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.4
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• pp.31-36
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• 2019

Concrete is a material generally used to build structures and it is exposed to various environment conditions. In particular, a medium such as water lets noxious factors flow into concrete, causing a lot of damage. Therefore, different kinds of materials are being developed to increase the durability of concrete. Among such materials, silane and siloxane compound are known to have a high utilization as an absorption inhibitor. However, if aged or deteriorated reinforced concrete is treated with those compounds, they easily come off the concrete and lose their function since the basic material is weak. This study conducted an experiment to provide concrete with both an absorption-inhibiting effect and surface strengthening by using melamine-formaldehyde resins that are surface-treated with siloxane compound. In addition, a study on the porosity and surface hardness characteristics of a concrete was conducted to check the absorption-inhibiting effect and surface strengthening.

• Korean Journal of Plant Taxonomy
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• v.49 no.3
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• pp.261-264
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• 2019

Eupatorium rugosum Houtt. is known to be an alien invasive species and is listed as an ecosystem disturbance species in Korea. There is also an eastern North American species Ageratina altissima (L.) R. M. King & H. Rob. similarly dispersed in Korea. This article aims to clarify the taxonomic confusion regarding the species. The two names refer to the same species originally described as Ageratum altissimum by Linnaeus in his Species Plantarum. Ageratum altissimum was transferred to the genus Eupatorium and later to Ageratina. Eupatorium rugosum is the replacement name in Eupatorium because of E. altissimum L., an existing name based on the different type. When the species was transferred to Ageratina, A. altissima was published based on its basionym, as the epithet "altissima" was available in the genus. It seems that taxonomic confusion regarding the species in Korea is due to the recognition of the names as different taxa. Ageratina altissima is the correct name for the species based on morphological and molecular data.

• The Journal of the Petrological Society of Korea
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• v.28 no.3
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• pp.217-225
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• 2019

This study describes a large recumbent fold, which occurs at the north entrance slope of the Batjae tunnel, Pyeongchang-gun, Gangwon-do, and interprets its formation mechanism. The several-hundred-meter scale fold, developed in the Jeongseon Limestone of the Paleozoic Joseon Supergroup, has a nearly horizontal axial plane and its head is facing north. Stretching lineations ($L_1$) observed on the composite foliations of bedding and axial plane cleavage plunge southward at about $10^{\circ}$. Small A-type or eye-shaped sheath folds together with S-shaped asymmetrical folds are often observed in the fold limbs and their axes are nearly parallel to the lineations ($L_1$) within center and rear parts of the fold. It is thus interpreted that the recumbent fold is a large sheath fold produced by the top-to-the-north ductile shearing due to the Songrim orogeny during the late Paleozoic to Triassic.

• Korean Journal of Optics and Photonics
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• v.30 no.4
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• pp.146-153
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• 2019

The exposure system is a device that transfers a circuit pattern to a desired location. To display patterns on a substrate without deforming the optical characteristics, the characteristics of the optical exposure system are very important. Therefore, to form a microcircuit pattern, a small divergence angle should impinge on the irradiation area. Also, since the light from the source must react uniformly with the photosensitizer, it must have high luminance efficiency and uniformity of illumination. In this paper a parabolic reflector and an aspherical lens were designed to solve the problem of narrow-angle implementation, and it was confirmed by simulation analysis after their arrangement that the beam angle, uniformity, and maximum illuminance satisfied the target performance.

• The Journal of Engineering Geology
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• v.28 no.4
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• pp.593-603
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• 2018

The most of groundwater with high U-concentration occur in the Jurassic granite of Gyeonggi massif and Ogcheon belt, and some of them occur in the Cretaceous granite of Ogcheon belt. On the contrary, they do not occur in the Jurassic granite of Yeongnam massif and the Cretaceou granite of Gyeongsang basin. The Jurassic and Cretacous granite, the host rock of high U-groundwater, were resulted from parental magma with high ratio of crustal material and highly differentiated product of fractional crystalization. These petrogenetic characteristics explain the geological evidence for preferential distribution of uraniferous groundwater in each host rock. It were reported recently that high U-content, low Th/U ratio and soluble mineral occurrence of uraninite in the two-mica granite of Daejeon area which have characteristics of S-type peraluminous and highly differntiated product. It is the mineralogical-geochemical evidences supporting the fact that the two-mica granite is the effective source of uranium in groundwater. The biotite granite and two-mica granite of Jurassic age were reported as biotite granite in many geological map even though two-mica granite occur locally. This fact suggest that the influence of two-mica granite can not be ignored in uraniferous groundwater hosted by biotite granite.

• Journal of Korean Society of Forest Science
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• v.108 no.1
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• pp.109-115
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• 2019

The objectives of this study was to analyze the importance and satisfaction (ISA) of forest healing instructor training program, targeting on the students educated in 2018. As a result, it was found that students older than forties are the majority as 81 %, and they preferred forest healing instructors as their second future job. When comparing the importance and satisfaction, the students evaluated satisfaction with low grade compared to importance with high grade in all questions. In ISA analysis, it was needed to improve the updated textbook information, to list the example problems by subject, to expose the test subjects in the textbooks, to disclose the test questions and answers, to control the test difficulty, to adjust the test pass rate, to expand the number of test and test sites, to increase the effort for making students understand, to prepare lectures appropriate to practice for forest healing instructor training program by priority.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.1
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• pp.67-73
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• 2019

We presented detailed morphological descriptions of the eggs, larvae and juvenile of Acanthaphritis unoorum based on specimens collected with bongo nets from Korean waters during the period May 2017-July 2018. We collected 18 individuals including eggs (n= 4, 0.77-0.85 mm in egg diameter), preflexion larvae (n= 6, 4.11-6.31 mm in standard length, SL), flexion larvae (n= 4, 6.60-7.82 mm SL), postflexion larvae (n= 3, 8.94-13.46 mm SL), and one juvenile (n= 1, 14.67 mm SL). The mitochondrial (mt) DNA 16S rRNA sequences of the eggs, and the cytochrome c oxidase subunit I (COI) sequences of the larvae were identical to those of A. unoorum adults (genetic distances <0.01). The A. unoorum larvae and the juvenile that we collected were morphologically similar to those of Dactylopsaron dimorphicum, but the A. unoorum specimens were readily distinguishable by the presence of lateral melanophores. This is the first record of A. unoorum in Korean waters. We propose a new Korean name for A. unoorum: "O-ri-bu-ri-nuntung-i".

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.559-564
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• 2019

Cyrtomium yamamotoi Tagawa is an unrecorded species of perennial Pteridophyta that belongs to the genus Cyrtomium of Dryopteriaceae. It is known as native to Taiwan, China and Japan, but we found it in Jeju-si, Jeju-do and Haenam-gun, Jeollanam-do, Republic of Korea in 2018. This species is very similar to C. fortunei J.Sm. having characters such as 1 pinnate compound leaves, globular indusium, but distinguished from the latter by its lanceolate or lanceolate-ovate shaped lateral pinnates of less than 12 pairs, bicolor indusium with dark brown or blackish in center, and margin incised teeth. Here, we provide its description, photographs and a key of related taxa in Korea.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.6-6
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• 2019

대마는 인류가 이용해 온 가장 오래된 약제 중 하나로 그 원산지는 중앙아시아와 남아시아이다. 식물분류학적으로 대마속 일년생 식물로서 Cannabis sativa, Cannabis indica, Cannabis ruderalis 3종이 있으며, 우리나라에서 재배되고 있는 종은 Cannabis sativa이다. 대마 재배의 역사는 인류의 시작과 그 궤를 같이하며, 동 서양을 막론하고 고대 문명에서 대마에 대한 기록을 쉽게 찾아볼 수 있다. 기록에 의하면 병의 치료나 심리적 치유 및 신에게 제사를 올릴 때 제사장이 사용한 것으로 알려져 있다. 대마의 약효에 대하여는 B.C. 2737년 중국의 신농황제시대의 기록에 관절염과 통증등 의료목적으로 사용했던 최초의 기록이 있으며 본초강목과 동의보감에 저술되어 있다. 우리나라의 대마에 관한 문헌 기록은 삼국지 '위지동이전', 삼국사기 '동성왕편'과 삼국유사에 삼베를 사용한 기록이 있는 것으로 미루어 봤을 때 대마재배의 역사는 삼국시대 이전으로 볼 수 있다. 우리 민족은 생활 속에서 대마를 즐겨 사용하였으며 삼베로 의복과 멍석, 행주 그리고 칠공예품이나 신발등을 만들어 사용하였으며, 죽음에 이르러 삼베옷을 수의로 사용하였다. 대마의 용도는 뿌리, 줄기, 잎, 꽃대 그리고 씨앗까지 다양하게 이용된다. 전통적으로 줄기의 껍질을 이용한 섬유제품이 있으며 실, 의복 및 밧줄등이 있다. 대마 줄기의 속대는 종이, 건축자재, 연료로 사용된다. 씨앗의 경우 식품과 조류의 먹이, 생약으로 이용되고 씨앗의 기름은 연료, 화장품, 맛사지 오일등으로 사용되고 있다. 환각성분이 있어 마리화나 원료로 사용되는 꽃대와 잎은 의약품의 원료로 주목받고 있다. 대마에 관한 최초의 논문은 1843년에 Cannabis indica의 약효에 관한 것으로 보고되었다. 1850년부터 1937년까지 미국의 약전은 대마를 100가지 이상의 질병에 효과가 있는 주요 의약품으로 기재하고 있다. 세계적으로 여러 가지 이유로 대마를 의료 응용과 연구 및 사용을 제한하여 대마에 관한 연구가 침체되었다. 대마의 의학연구는 대마의 약효성분인 칸나비노이드의 발견과 그 구조 및 약효에 관한 연구가 시작되면서 1960년대부터 증가하였으며 2000년 이후에는 칸나비노이드 및 칸나비디올의 다양한 의학적 효과가 밝혀지면서 급격히 증가하고 있다. 대마에 포함된 성분의 의학적 효과가 입증되면서 대마 사용을 합법화한 국가가 증가하면서 대마 산업이 급부상하고 있으며, 의료용뿐만 아니라 기호용, 식품용, 그리고 주류 및 음료시장까지 확대되고 있다. 우리나라도 2019년 3월 질병 치료 목적 대마성분 의약품을 제한적으로 허용하는 마약류 관리에 관한 법률 일부 개정안이 시행되면서 의료용 대마에 관한 연구와 산업화에 관심이 증가하는 추세이다.

• Korean Journal of Plant Taxonomy
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• v.50 no.4
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• pp.395-402
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• 2020

A new species, Carex brevispicula G. H. Nam & G. Y. Chung (Cyperaceae), was found in Korea. Carex brevispicula is similar to the related species C. chungii Z. P. Wang and C. genkaiensis Ohwi in that its achenes are constricted in the middle part. However, C. brevispicula is distinguished from C. chungii as the plants, staminate, and pistillate spikes are shorter and its pistillate scales are pale green; C. brevispicula is distinguished from C. genkaiensis by its awned staminate and pistillate scales. The scientific name of this new species was based on the fact that its inflorescence is shorter than that of C. chungii. The corresponding Korean name, "Jom-mok-po-sa-cho," means that the plants of this species are smaller than the "Mok-po-sa-cho" types (C. genkaiensis). We hereby provide a description of C. brevispicula, with corresponding illustrations and photographs, a distribution map, and a key of related taxa.