• Nuclear Engineering and Technology
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• 제54권6호
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• pp.1947-1953
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• 2022

As the plasma facing material in the nuclear fusion reactor, tungsten has to bear the irradiation impact of high energy particles. The surface quality of tungsten may affect its irradiation resistance, and even affect the service life of fusion reactor. In this paper, tungsten samples with different surface quality were polished by mechanical processing, subsequently conducted by D₂⁺ implantation and thermal desorption. D₂⁺ implantation was performed at room temperature (RT) with the irradiation dose of 1 × 10²¹ D₂⁺/m² by 5 keV D₂⁺ ions, and thermal desorption spectroscopy measurements were done from RT to 900 K. In addition, He irradiation was also performed by 50 eV He⁺ ions energy with the fluxes of 5.5 × 10²¹ m^-2s^-1 and 1.5 × 10²² m^-2s^-1, respectively. Results reveal that the hydrogen/helium irradiation behavior are both related to surface quality. Samples with high surface quality has superior D₂⁺ retention behavior with less D₂ retained after implantation. However, such samples are more likely to generate fuzzes on the surface after helium irradiation. Different morphologies (smooth, wavy, pyramids) after helium irradiation also demonstrates that the surface morphology is related to tungsten crystallographic orientation.

• 항공우주의학회지
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• 제30권2호
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• pp.75-79
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• 2020

This study focuses on the comparative and quantitative analysis of the epidemiologic trends and aspects of severe fever with thrombocytopenia syndrome (SFTS) outbreaks between Korea and Japan from 2013 to 2017. The following factors were analyzed; cumulative incidence rate (CIR), cases-fatality rate (CFR), and the epidemic aspects, including cases related to gender, male-to-female morbidity ratio (MFMR), age, seasonal, and geographical distributions. We observed 607 SFTS cases with CIR in Korea during the period 2013 to 2017 were as 0.24 per 100,000 populations and with a 127 fatal-cases (F.C.s), corresponding to a CFR of 20.9%, respectively. During the same period in Japan, 319 SFTS cases with a CIR of 0.05 and with 60 F.C.s to a CFR of 18.8% observed. When compared, the CIR of SFTS in Korea was significantly higher than in Japan (P<0.01), but there were no significant differences levels of the CFR and MFMR between Korea and Japan. Also, a higher incidence of SFTS was observed in people aged over 50-years or elders in Korea and those of 60-years or elders in Japan (P<0.01). The seasonal distribution of SFTS outbreak cases showed that the incidence in summer through autumn in Korea (92.4% of total cases) was higher than in Japan (65.2%), while the outbreaks of SFTS in spring was much higher in Japan (31.0%) than in Korea (7.4%), (P<0.01). The regional distribution revealed no significant difference between the eastern area (44.8%) and the western area (46.8%) of the Korean peninsula except Jeju-island (8.4%). However, in Japan, the incidence only occurred in Chubu-Kinki-Chugoku (30.3%), Shikoku (25.7%), Kyushu (42.6%) and Okinawa (0.3%), which are the western and southern areas of Japan. These differences in SFTS occurrence may reflect the influences of vector/hosts, climate, and geographical and cultural characteristics between the two countries.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.141.1-141
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• 2003

Forty six isolates of bean common mosaic virus (BCMV) collected from azuki bean, mungbean, kidney bean, cowpea, broad bean and peanut were classified into three groups based on biological, serological, cytopathological, and molecular characteristics. Group I induced vein-banding symptoms in cowpea which was similar to those produced by the BCMV-cowpea strain. Group II caused mosaic symptoms in azuki bean but not in peanut and tobacco. Since this character was different from that of previously described BCMV strain, group II may not belong to BCMV GroupIII induced vein-clearing symptoms in azuki bean, kidney bean and peanut, which are typical symptoms for BCMV-peanut stripe virus strain. Virus inclusion patterns of BCMV groups were similar to those of Potyvirus subdivision III with the scroll, pinwheel and long laminated inclusions. However, the inclusions of laminated aggregates were never observed in mungbean isolates. Multiple alignment as well as cluster dendrograms of 3'noncoding region (3'-NCR) and a part of coat protein gene (CP) suggested that group I belongs to the BCMV-cowpea strain, group II to the BCMV-azuki bean strain, and group III to the BCMV-peanut stripe virus strain. Since molecular phylogenesis of BCMV based on nucleotides of 3'-NCR and coat protein differed from the grouping based on virulence differentiation, and BCMV groups are more closely related to each other with the same host origin, other characteristics of those strains are under investigation.

• 한국지구과학회지
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• 제43권6호
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• pp.680-690
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• 2022

테프라연대학은 광역테프라를 연대측정과 층서대비에 이용하는 연구이다. 광역 테프라층은 층서적 건층으로 사용될 수 있기 때문에 제4기지질학과 고고학 분야에서 매우 중요하다. 이 논평에서는 테프라의 동정 방법과 연대측정 방법에 대해 정리하였다. 또한 한반도의 육상퇴적층에서 발견되는 광역테프라층의 종류와 산출 특성에 대해 정리하였고, 광역테프라층의 지질학적 활용 방법과 한계점에 대해서도 토의하였다. 지금까지 한반도 육상의 고토양층, 해안단구 퇴적층, 호수퇴적층에서는 일본 큐슈 기원의 AT와 Ata, Kb-Ks 테프라가 발견되었다. 또한 공식적으로 발견되지는 않았지만 Aso-4 테프라도 발견될 가능성이 높은 것으로 판단된다. 광역테프라층은 제4기 퇴적층, 특히 방사성탄소연대측정의 범위를 넘는 5만년 이상 퇴적층의 연대측정과 층서대비에 유용하며, 활성단층의 연대측정과 화산재해에 대한 대응책 마련에도 유용한 정보를 제공한다. 하지만 테프라층을 지질학적으로 이용하기 위해서는 퇴적학적 연구를 통해 일차퇴적 여부에 대한 확인이 필요하다.

• Animal Bioscience
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• 제36권4호
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• pp.671-678
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• 2023

Objective: Previous studies isolated the thermophilic ammonium-tolerant (TAT) bacterium Bacillus sp. TAT105 that grew in composting swine manure with the assimilation of ammonium nitrogen and reduced ammonia emissions during composting. Those studies also investigated the potential for applications of TAT105 to composting. It was observed that the concentration of TAT bacteria, phylogenetically close to TAT105, increased during composting. The objectives of this study were to identify the phylogenetic placement of these TAT bacteria and investigate their distribution in various composts. Methods: The phylogenetic placement of TAT105 was examined based on the sequence of 16S ribosomal RNA gene. The genomic DNA homology between TAT105 and the type strains of bacterial species that were phylogenetically close to TAT105 were examined by DNA-DNA hybridization. Moreover, the tolerances of these strains to NH₄Cl and NaCl were analyzed using a cultivation method. Concentrations of TAT bacteria in various composts were evaluated using an agar medium specific to TAT bacteria and polymerase chain reaction followed by restriction fragment length polymorphism analysis. Results: TAT105 was most closely related to Bacillus thermolactis and Bacillus kokeshiiformis. Many variants of these species have been detected in various environments, including composts. The type strains of these species displayed TAT characteristics that were similar to those of TAT105. Among the composts examined in this study, TAT bacteria were detected at high concentrations (10⁵ to 10⁹ colony forming units per gram of dry matter) in most of the composts made from cattle manure, swine manure, bark, and excess sludge. Conclusion: TAT bacteria comprised B. thermolactis, B. kokeshiiformis, and their phylogenetically close relatives. They were considered to be adaptable to composting of some certain materials, and a favorable target for searching for strains with some useful function that could be applied to composting of these materials.

• Composites Research
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• 제22권6호
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• pp.45-51
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• 2009

치아의 와동에 수복된 치과용 복합레진을 광(LED) 조사를 통해 경화 수축시키면서 음향방출(acoustic emission, AE)법을 이용하여 와동 벽면과 복합레진 사이의 계면상태를 실시간 해석하였다. 복합레진의 중합 수축에 의해 AE 신호들이 검출되었는데 계면 접착 상태가 나쁜 경우, 경화 수축률이 큰 초기 1분 동안 많은 AE 사상들이 관측되었으며, 이들 AE는 주파수범위가 주로 100-200kHz인 돌발형이었다. 인간치아 재질의 시편에서 발생된 AE 사상수는 스테인리스 스틸 시편보다 적었으나, PMMA 시편보다는 많았고 접착제의 도포 상태가 양호할수록 검출되는 AE 사상수는 적었다. AE 파라미터의 특성은 복합레진과 링재 사이의 접착부에서 발생하는 인장형 균열전파 및 복합레진의 수축에 따른 링재의 압축거동과 관련되었으며, 음향방출법이 치아 수복물의 접착성에 대한 비파괴 검사법으로써 유효함을 알았다.

• Clinics in Shoulder and Elbow
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• 제26권3호
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• pp.296-301
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• 2023

Background: A supervised physiotherapy program (SPP) is a standard regimen after surgical rotator cuff repair (RCR); however, the effect of a home-based exercise program (HEP), as an alternative, on postoperative functional recovery remains unclear. Therefore, the purpose of this meta-analysis was to compare the functional effects of SPP and HEP after RCR. Methods: We searched electronic databases including Central, Medline, and Embase in April 2022. The primary outcomes included the Constant score, American Shoulder and Elbow Surgeons score, University of California Los Angeles shoulder score, and pain score. Secondary outcomes included range of motion, muscle strength, retear rate, and patient satisfaction rate. A meta-analysis using random-effects models was performed on the pooled results to determine the significance. Results: The initial database search yielded 848 records, five of which met our criteria. Variables at 3 months after surgery were successfully analyzed, including the Constant score (mean difference, -8.51 points; 95% confidence interval [CI], -32.72 to 15.69; P=0.49) and pain score (mean difference, 0.02 cm; 95% CI, -2.29 to 2.33; P=0.99). There were no significant differences between the SPP and HEP. Other variables were not analyzed owing to the lack of data. Conclusions: Our data showed no significant differences between SSP and HEP with regard to the Constant and pain scores at 3 months after RCR. These results suggest that HEP may be an alternative regimen after RCR. Level of evidence: I.

• Asian-Australasian Journal of Animal Sciences
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• 제18권12호
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• pp.1727-1734
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• 2005

The fermentation characteristics and mono- and di-saccharides compositions during the early stage of ensiling were studied with a temperate grass, Italian ryegrass (Lolium multiflorum Lam.) and a tropical grass, guineagrass (Panicum maximum Jacq.). The laboratory silos were kept in the room set at 25$^{\circ}C$, and then were opened on 0.5, 1, 2, 3, 5 and 7 days (14 days in Italian ryegrass) after ensiling, respectively. The Italian ryegrass silage showed a fast and large pH decrease caused by a fast and large production of lactic acid during the first 5 days of ensiling and succeeded to achieve lactic acid type fermentation; high lactic acid/acetic acid and lactic acid content at the end of ensiling (14 days), low values of pH (3.74), acetic acid, ethanol and ammonia-N/total nitrogen, none or only small amounts of Butyric acid, valeric acid and propionic acid. The guineagrass silage showed a slow decrease in pH and a slow increase in lactic acid content during the full ensiling period, causing a high final pH value, low contents of lactic acid, acetic acid, total volatile fatty acids and total organic acids. In Italian ryegrass silage, mono- and di-saccharides compositions decreased largely within the initial 0.5 day (12 h) of ensiling. Sucrose disappeared rapidly within the initial 0.5 day of ensiling, but fructose and glucose contents showed an initial rise by the activity of enzymes in plant tissues, and then decreased gradually. On the other hand, the contents of monoand di-saccharides in guineagrass showed the largest decreases due mainly to plant respiration within the initial 0.5 day of ensiling, and no initial rises in fructose and glucose contents during the early stage of ensiling because of the absence of fructans which are hydrolyzed into fructose and glucose in temperate grasses. In both silages, the rate of reduction in mono- and di-saccharides compositions within the initial 5 days of ensiling was ranked in the order of glucose>fructose>sucrose, suggesting that glucose and fructose might be more favorably utilized than sucrose by microorganisms and glucose is the first fermentation substrate. It was concluded that the silage made from Italian ryegrass with high moisture content had a good fermentation quality owing to the dominance of lactic acid bacteria and active lactic acid fermentation during the initial stage of ensiling. These results can be explained by rapid plant sap liberation and the high activity of plant enzyme hydrolyzed fructans into fructose and glucose within the initial 2 days of ensiling, which stimulate the homofermentative lactic acid bacteria growth. In ensiling a temperate grass, the physical characteristics may ensure the rapid onset of fermentation phase, which results from the smaller losses of water-soluble carbohydrates during the initial stage of ensiling and providing sufficient water-soluble carbohydrates for lactic acid bacteria. The silage made from guineagrass with intermediate dry matter and high initial mono- and di-saccharides content was stable silage. This could be explained by the higher incorporation of air during the very early stage of ensiling and the restriction of cell breakdown and juice release due to the properties of a tropical grass with coarse porosity and stemmy structures. These physical characteristics delayed the onset of lactic acid bacteria fermentation phase by extending the phases of respiration and aerobic microorganisms activity, causing the higher loss of water-soluble carbohydrates and the shortage of lactic acid bacteria fermentation substrates.

• 한국토양비료학회지
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• 제17권1호
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• pp.67-76
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• 1984

CNP 제초제시용(除草劑施用)이 논토양(土壤)의 미생물상(微生物相)에 미치는 영향(影響)을 구명(究明)코져 유기물(有機物) 함량(含量)이 극(極)히 낮은 사양토(砂壤土)를 공시(供試)하여 유기물(有機物)의 종류(種類)를 달리하고 제초제무시용(除草劑無施用) 및 시용조건(施用條件)(1,080ppm)에서 수도무재배(水稻無栽培) 담수상태(湛水狀態)로 초자온실(硝子溫室)에 정치(靜置)하면서 미생물상(微生物相)을 조사(調査)한 결과(結果)는 다음과 같다. 1. 호기성(好氣性) 전세균(田細菌)의 균수(菌數)는 담수후(湛水後) 50일(日)째까지는 제초제시용(除草劑施用)으로 증가(增加)되었으나, 이후(以後)는 현저(顯著)한 차이(差異)를 볼 수 없었다. 유기물(有機物) 종류별(種類別)로는 제초제시용(除草劑施用) 유무(有無)에 관계(關係)없이 볏짚시용시(施用時) 호기성(好氣性) 세균수(細菌數)가 제일 많았고, glucose 시용구(施用區)는 다소(多少) 감소(減少)하는 경향(傾向)이었다. 2. 사상균수(絲狀菌數)는 제초제(除草劑) 및 유기물(有機物) 시용(施用) 유무(有無)에 관계(關係)없이 전담수기간(全湛水期間) $8{\sim}20{\times}10^3$의 수준(水準)으로 유지(維持)되었다. 3. 방선균수(放線菌數)는 제초제시용(除草劑施用)으로 감소(減少)하는 경향(傾向)이 있고 유기물시용(有機物無施用) 및 볏짚시용시(施用時)는 균수(菌數)를 현저(顯著)하게 감소(減少)시켰다. 한편 유기물시용(有機物施用)에 의한 방선균수(放線菌數)의 증가(增加)는 볼 수 없었다. 4. 혐기성(嫌氣性) 전세균(全細菌) 및 gram-음성세균수(陰性細菌數)는 제초제(除草劑) 및 유기물(有機物) 시용간(施用間)에 큰 차이(差異)를 볼 수 없었다. 5. 사상균(絲狀菌)에 대(對)한 세균(細菌)의 비(比)(B/F) 및 방선균(放線菌)에 대(對)한 세균(細菌)의 비(比)(B/A)는 제초제(除草劑) 및 유기물(有機物) 시용시(施用時) 높은 치(値)를 보였다. 6. 방선균(放線菌)의 생리적(生理的) 성질(性質)을 기준(基準)으로 분류(分類)한 결과(結果) 1) 전방선균(全放線菌)에 대(對)한 농갈색(濃褐色) 색소생산장성균(色素生産陽性菌)의 비율(比率)은 제초제시용(除草劑施用)으로 다소(多少) 높았다. 특(特)히 제초제시용(除草劑施用) 유무(有無)에 관계(關係)없이 볏짚시용시(施用時)가 현저(顯著)히 높았다. 2) Cellulase 양성균(陽性菌)의 비율(比率) 역시 제초제무시용(除草劑無施用)에 비(比)해 제초제시용(除草劑施用)으로 높았으나, 유기물(有機物) 종류간(種類間)에는 현저(顯著)한 차이(差異)가 없었다.

• 자원환경지질
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• 제39권5호
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• pp.555-566
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• 2006

주성분원소, 미량원소 및 희토류원소에 대한 지화학적 연구를 통하여 진동화강암의 성인과 마그마 근원물질의 지화학적특징 및 지구조적 환경을 살펴보았다. 진동화강암은 비알칼리암 중에서 칼크-알칼리계열의 화강암류이며, 마그마의 특성이 metaluminous에서 분화가 진행됨에 따라 peraluminous한 쪽으로 진행됨을 알 수 있다. 이들의 주성분 및 미량원소의 변화경향은 체계적인 연속성을 나타내며, 콘드라이트에 표준화한 희토류원소의 패턴은 일반적으로 경희토류원소가 부화되어 나타나며((La/Yb)c=4.2-12.8), Eu의 이상이 거의 나타나지 않는다. 진동화강암체의 Rb-Sr전암연대는 $114.6{\pm}9.1\;Ma$이며 $^{87}Sr/^{86}Sr$의 초생값은 0.70457로 나타났다. 낮은 $^{87}Sr/^{86}Sr$의 초생값은 경상분지 남부의 마산, 김해, 부산지역에 분포하는 백악기 화강암류들($^{87}Sr/^{86}Sr=0.7049-0.707$)과 유사하다. 이는 진동화강암체의 관입시기가 경상분지내에 분포하는 백악기 화강암류 중에서 가장 오래된 백악기 초기였으며 근원물질이 상부맨틀과 관련이 있음을 지시한다. 진동화강암체는 경상분지내의 다른 백악기 화강암류에 비해 상대적으로 높은 $Al_{2}O_{3},\;Na_{2}O$ 및 Sr과 낮은 $K_{2}O$와 Y의 함량을 보인다. 이들의 주성분원소($Al_{2}O_{3},\;K_{2}O,\;Na_{2}O,\;MgO$) 및 미량원소(Sr, Y, Rb) 함량범위는 adakite의 범주에 포함되며 남서부 일본의 큐슈(Kyushu)섬에서 나타나는 화강암체와 유사한 adakitic한 지화학적 특성을 나타낸다. 지구조 판별도 및 AUK vs. ACNK도에 점시해본 결과 I-type의 화강암으로 지구조적 환경은 화산호화 강암(VAG) 영역에 해당된다. 이 결과로 미루어 진동화강암류는 중생대 백악기 이자나기판의 섭입과 관련되어 관입한 대륙주변부 환경에서 생성되었음을 시사한다.