• Journal of Forest and Environmental Science
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• 제37권2호
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• pp.163-167
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• 2021

Mushroom survey and collection were conducted in the Dong Hua Sao National Biodiversity Conservation Area (DHSNBCA), which is located about 30 km east of Pakse and about 10 km south of the town of Paksong, Champasak Province of Lao-PDR, from from at the early July to October in 2019. During this periods, mushroom specimens were collected from 6 different locations, and then they were identified and classified into 103 species, 74 genera, 37 families, 15 orders and 6 classes by morphological and molecular analyses. The mushrooms belongs to Ascomycota were classified into 10 species, 6 genera, 4 families, 3 orders and 2 classes, while those belongs to Basidiomycota were classified into 92 species, 67 genera, 32 families, 11 orders, and 3 classes, respectively. In addition, 1 species of Myxomycota was also identified. Among these mushrooms, the most species-rich families are Marasmiaceae (17.3%), Polyporaceae (13.1%), Mycenaceae (8.9%), Agricaceae (8.3%), Xylariaceae (6.5%), Auriculariaceae (4.8%), Ganodermtaceae (3.6%), Dacrymycetaceae (3.0%), Meruliaceae (3.0%), Russulaceae (3.0%) and comprised 71.4% of the total specimens identified.

• Journal of Ecology and Environment
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• 제45권4호
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• pp.182-189
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• 2021

Background: Organism body size is a basic characteristic in ecology; it is related to temperature according to temperature-size rule. Butterflies are affected in various aspects by climate change because they are sensitive to temperature. Therefore, this study was conducted to understand the effect of an increase in temperature due to global warming on the wing of butterflies. Results: A total of 671 butterflies belonging to 9 species were collected from 1990 to 2016 in Seoul (336 specimens) and Mokpo (335 specimens). Consequently, as the mean temperature increased, the wing length of the species increased. However, there are exceptions that the Parnassius stubbendorfii, Pieridae canidia, and Pieris rapae wing length of Seoul increased, but the butterfly wing length of Mokpo decreased. Conclusions: The positive correlations between the butterfly wing length and mean temperature showed that the change of mean temperature for about 26 years affects the wing length of butterfly species. The exception is deemed to have been influenced by the limited research environment, and further studies are needed. We would expect that it can be provided as basic data for studying effect of climate change.

• 한국가구학회지
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• 제26권2호
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• pp.138-144
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• 2015

Among several thermal wood modification methods German oil heating technology was applied for color changing larch and paulowniawood specimens. They were heat treated at $200^{\circ}C$ for 3 hours in an autoclave filled with linseed oil. The CIE $L^*a^*b^*$ color indexes of the shells and cores of the oil heated specimens were measured. The color difference indexes between the oil heated and the control specimens of larch and paulowniawood were in the range of 6 and 12, which implies considerably different. The color difference indexes between the core layers of the larch and paulowniawood specimens were 4.3 and 1.7, respectively. It could be concluded that the specimens of the two species were color changed uniformly by oil heating.

• Steel and Composite Structures
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• 제25권1호
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• pp.93-104
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• 2017

In the present work, the effect of hygrothermal aging on the glass fibre and epoxy matrix interface has been investigated by destructive and non-destructive techniques. The glass fiber reinforced polymer (GFRP) composite laminates were prepared using Vacuum Assisted Resin Infusion Molding (VARIM) technique and the specimens were immersed in simulated seawater, followed by quantitative measurement. Besides this, the tensile tests of GFRP specimens revealed a general decrease in the properties with increasing aging time. Also, exposed specimens were characterized by a non-destructive ultrasonic guided Lamb wave propagation technique. The experimental results demonstrate a correlation between the drop in ultrasonic voltage amplitude and fall in tensile strength with increasing time of immersion. Hence, the comparison of the transmitted guided wave signal of healthy vis-a-vis specimens subjected to different extents of hygrothermal aging facilitated performance evaluation of GFRP composites.

• Applied Microscopy
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• 제52권
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• pp.4.1-4.11
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• 2022

Field emission scanning electron microscopy (FESEM) is an essential tool for observing surface details of specimens in a high vacuum. A series of specimen procedures precludes the observations of living organisms, resulting in artifacts. To overcome these problems, Takahiko Hariyama and his colleagues proposed the concept of the "nanosuit" later referred to as "NanoSuit", describing a thin polymer layer placed on organisms to protect them in a high vacuum in 2013. The NanoSuit is formed rapidly by (i) electron beam irradiation, (ii) plasma irradiation, (iii) Tween 20 solution immersion, and (iv) surface shield enhancer (SSE) solution immersion. Without chemical fixation and metal coating, the NanoSuit-formed specimens allowed structural preservation and accurate element detection of insulating, wet specimens at high spatial resolution. NanoSuit-formed larvae were able to resume normal growth following FESEM observation. The method has been employed to observe unfixed and uncoated bacteria, multicellular organisms, and paraffin sections. These results suggest that the NanoSuit can be applied to prolong life in vacuo and overcome the limit of dead imaging of electron microscopy.

• 대한미생물학회지
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• 제15권1호
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• pp.47-54
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• 1980

Exoenzymes, protease(P) and elastase(E) produced by Pseudomonas aeruginosa are reported to have close relationship with pathogenicity of Pseudomonas aeruginosa. Productibility of exoenzymes P and E were studied and compared in environmental isolates from hospital environments and clinical isolates from various clinical specimens, also, the relationship between their enzyme production and serotype were reviewed. 1. Clinical isolates were typed into nine serotypes A, B, C, D, E, F, G, H and I. Serotype E had the highest incidence of 24%, followed by B with 16.8%, G, 15.1% and C, 9.3%. 2. Environmental isolates were, typed as serotype B, C, E, F, G, H, I, K and M. Serotype I had the highest incidence of 26.6%, followed by C, F and M each incidence of 14.3%. 3. In the typing of the above two groups, serotypes A and D were found only in the clinical isolates and serotypes K, and M were found only in the environmental isolates. Serotypes J and L were found in neither clinical isolates nor environmental isolates. 4. In the distribution of serotypes from various clinical specimens, serotype G among isolates from pus showed incidence of 20.4%, and serotypes E and B were 19.5% separately. Serotype E had incidence of 22.6% and 20.0% in urine and sputa respectively, showing a high rate compared to the other serotypes. 5. The incidence of strains producing both exoenzymes P and E was 77.8% in the preserved strains of clinical isolates and 76.2% in the environmental isolates. There were no significant difference between the two groups. 6. Serotypes A and H, which are preserved strains from clinical isolates showed productibility of both exoenzymes P and E, the other serotypes showed productibility of various combination of exoenzymes. Among the environmental isoaltes, production of both exoenzymes P and E were seen in serotypes E, F, G, H, I and K and no serotype produced only P or E. 7. In ability to produce exoenzymes of isolates from sources of various clinical specimens, strains producing both exoenzymes P and E were found most frequently in pus with incidence rate of 82.0%, followed by 80.0% in sputum and urine. 8. Almost all the fresh strains of clinical isolates were producers of both exoenzymes P and E.

• Composites Research
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• 제30권1호
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• pp.71-76
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• 2017

본 연구에서는 환경인자에 노출된 탄소섬유/에폭시 복합재의 층간전단강도를 이용하여 장기 성능을 예측하였다. 필라멘트와인딩 공법으로 제작된 층간전단시편은 분위기 온도가 $50^{\circ}C$, $70^{\circ}C$, $100^{\circ}C$인 건조 조건과 분위기 온도가 $25^{\circ}C$, $50^{\circ}C$, $70^{\circ}C$인 침수 조건에 각각 3000시간까지 노출시켰다. 연구결과에 따르면 분위기 온도가 $50^{\circ}C$와 $70^{\circ}C$인 건조 상태에서는 층간전단강도가 노출시간에 따라 크게 변하지 않지만 분위기 온도가 $100^{\circ}C$인 건조 상태에서는 노출시간이 길어지면 후경화로 인해 다소 증가한다. 그러나 분위기 온도가 $25^{\circ}C$인 침수 상태의 경우 층간전단강도는 노출 초기에 크게 변하지 않다가 노출시간이 길어지면 감소하고 감소 정도는 분위기 온도가 높아지면 커진다. 각 분위기 온도에 대한 층간전단강도 선형회귀식은 침수 상태에 3000시간까지 노출된 시편에서 얻은 층간전단강도에서 구할 수 있었다. 이들 선형 회귀식을 이용하면 층간전단강도는 분위기 온도가 $25^{\circ}C$와 $50^{\circ}C$인 경우 측정값의 5.5% 이내, 분위기 온도가 $70^{\circ}C$인 경우 측정값의 2.3% 이내로 예측이 가능하였다. 따라서 제시된 성능 예측 절차는 환경인자에 노출된 탄소섬유/에폭시 복합재의 장기 층간전단강도를 잘 예측할 수 있다.

• 콘크리트학회논문집
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• 제23권4호
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• pp.511-520
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• 2011

최근 국내에서는 고분자 화합물인 폴리우레아를 이용하여 보강 성능의 향상을 위한 연질형 폴리우레아를 개발하여 구조물에 적용하였지만 보강 성능은 미비한 것으로 나타났다. 따라서, 이 연구에서는 폴리우레아를 구조물의 보강재로 사용하기 위하여 연질형 폴리우레아의 구성 요소를 변화시켜 경질형 폴리우레아를 개발하였다. 개발된 경질형 폴리우레아는 연질형 폴리우레아에 비해 경도와 인장강도가 향상된 성능을 나타내었다. 경질형 폴리우레아를 일반 구조물의 보강재로 사용하기 위하여 RC 슬래브 시험체를 제작하여 보강 성능을 평가하였으며, 현재 보강재로 사용되는 섬유 시트와 적층하여 보강한 후 성능을 평가하였다. 실험 결과 경질형 폴리우레아만으로 보강한 시험체가 무보강 시험체보다 우수한 강성 증진 효과와 연성 증진 효과를 나타내는 것으로 나타났다. 또한, 섬유 시트를 부착한 후 경질형 폴리우레아를 외부에 도포하여 보강한 시험체는 섬유 시트만으로 보강한 시험체보다 보강 성능이 매우 우수한 것으로 나타났다. 그러나 경질형 폴리우레아를 도포한 후 섬유 시트를 부착한 시험체는 경질형 폴리우레아의 변형을 강성이 높은 섬유 시트가 억제하여 하중이 가해지며 생기는 응력이 한곳에 집중되어 취성적인 파괴 거동을 보이는 것으로 나타났다.

• 한국지반공학회논문집
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• 제24권2호
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• pp.87-97
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• 2008

단단한 모래 입자와 연약한 고무 입자로 이루어진 Engineered soils을 고결화 시킨 후 $K_o$ 상태에서의 거동 특성을 분석하였다. 고결화 효과에 따른 영향 및 모래부피비에 따른 영향을 파악하기 위하여 다양한 모래부피비를 가지는 비고결화 및 고결화 시료를 준비하여, 수직 응력에 따른 변형 및 탄성파 속도를 측정하였다. 탄성파 속도 측정은 벤더 엘리먼트와 PZT 엘리먼트를 이용하였다. 고결화 이 후 응력에 따른 수직 변형율의 기울기는 이중 선형 관계를 보이며 고결화 결합 파괴 이후에는 비고결화 시료와 비슷한 기울기를 가진다. 정규화된 수직 변형량은 응력에 따라 capillary force, cementation, decementation 구간으로 나눌 수 있다. 근접장 내에서 측정된 전단파 신호의 첫 번째 움직임은 압축파의 도달과 일치하였다. 고결화에 의해 탄성파 속도는 수직 응력의 증가 없이 급격한 증가를 보였으며, 고결화 이후 추가적인 응력 증가에도 일정한 값을 보였다. 고결화 파괴 후 지속적인 수직 응력의 증가에 따라 탄성파속도는 증가하였다. 고결화는 비고결화 시료에서 나타나는 유사고무, 유사모래, 전이 3가지의 거동을 방해한다. 고무-모래 혼합재의 고결화 결합의 파괴 메커니즘은 모래부피비에 따라 다르며 낮은 모래부피비의 시료는 입자 모양의 변화가, 높은 모래부피비 시료에서는 입자 구조의 변화가 고결화 결합의 파괴가 주요한 원인이다. 본 연구를 통해 연약한 고무 입자와 단단한 모래 입자의 혼합재인 Engineered soils의 거동은 고결화 및 고결화 파괴에 따라 비고결화 시료와 구분됨을 알 수 있었다.

• 환경생물
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• 제27권3호
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• pp.237-243
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• 2009

The giant crab spider genus Sinopoda in Korea is reviewed with detailed illustrations of male palpal organs. Three species, S. forcipata, S. stellatops, S. koreana are recognized with newly collected specimens. The first species is recorded newly in Korean spider fauna. A key to the species of the Korean Sinopoda spiders are also provided.