Estuary is important in terms of biodiversity because it has the characteristics of transition waters, created by the mixing of fresh- and seawater. The estuarine water circulation provides a variety of habitats with different environments by inducing gradients in the chemical and physical environment, such as water quality and river bed structure, which are ultimately the main factors influencing biological community composition. If the water circulation is interrupted, the loss of brackish areas and the interception of migration of biological communities will lead to changes in the spatial distribution of biodiversity. In this study, among the sites covered by the Estuary Aquatic Ecosystem Health Assessment, we selected study sites where changes in biodiversity can be assessed by spatial gradient from the upper reaches of the river to the lower estuarine area. The α-, γ- and β-diversity of diatom, benthic macroinvertebrates, and fish communities were calculated, and they were divided into open and closed estuary data and compared to determine the trends in biodiversity variation due to estuarine circulation. As results, all communities showed higher γ-diversity at open estuary sites. The benthic macroinvertebrate community showed a clear difference between open and closed estuaries in β-diversity, consequently the estuarine transects were considered as a factor that decreases spatial heterogeneity of their diversity among sites. The biodiversity trends analyzed in this study will be used to identify estuaries with low γ- and β-diversity by community, providing a useful resource for further mornitoring and management to maintain estuarine health.

1. 열대아시아지역에 적응하는 수출용 일대잡종 벼 품종을 육성할 목적으로 2013년에 미얀마에서 수집한 도열병과 흰잎 마름병에 저항성인 ‘MY1B’를 국제미작연구소(IRRI)에서 육성 된 일대잡종 벼 웅성불임친인 ’IR68897A’에 4회 여교배하여 2016년에 불임친인 ‘KR1A’와 유지친인 ‘KR1B’를 육성하였으며 육성된 불임친 ‘KR1A’를 회복친유전자를 가진 우량계통들과 검정교배한 결과 베트남 지역 적응성이 높고 도정특성이 우수한 OM052와 교배한 조합이 우수하여 교배번호 KR0695H을 부여한 후 생산력 검정에 필요한 F1종자를 생산하였고 선발된 일대잡종 벼 계통에 대해 2년간의 지역적응시 험을 통해 우수성이 인정되어 2019년 농촌진흥청 직무육성 신 품종선정위원회에서 신품종으로 선정되면서 ‘KGHR1’으로 명명되었음 2. ‘KGHR1’의 F1 종자생산을 위해 육성된 불임친과 유지친, 회복친의 농업형질을 조사한 결과 불임친인 ‘KR1A’의 임실율이 0%인 완전불임을 보였고 불임친인 ‘KR1A’과 유지친인 ‘KR1B’을 1% potassium iodide-iodine(I-KI)에 염색해 본 결과 ‘KR1A’는 염색이 되지 않은 완전불임을 나타내어 일대잡종벼의 특성에 부합되었음 3. ‘KGHR1’는 중부평야지 보통기 재배에서 평균 출수기가 8월 13일로 대비품종 ‘다산’보다 5일 늦은 중생종이었고 간장은 103 cm로 다산의 82 cm보다 21 cm 큰 장간이고, 이삭길이는 28 cm로 ‘다산’ 보다 길고 이삭당 벼알수는 202개로 ‘다산’ 보다 69개 많았고 등숙비율은 76.3%로 대비품종 ‘다산’ 83.7% 보다 낮게 조사되었음 4. ‘KGHR1’는 도열병과 줄무늬잎마름병에 저항성이었고 흰 잎마름병은 K1, K2, K3 균계에 저항성을 보였지만, 오갈병 및 멸구류에 대한 저항성은 없었으며 도복에는 강하며, 수발 아와 내냉성은 ‘다산’과 비슷한 수준을 보였음 5. ‘KGHR1’의 입형은 현미장폭비가 3.37로 장원립이고 백미외관은 심복백이 0/1로 맑고 투명하였으며 단백질함량은 6.3%로 ‘다산’ 보다 낮은 반면 아밀로스함량은 22.7%로 ‘다산’ 보다 높았음 6. ‘KGHR1’의 제현율과 현백률은 대비품종 ‘다산’과 차이가 없었고 완전미도정수율은 40.5%로 ‘다산’ 보다 낮았으나 베트남 현지 일대잡종 벼 품종인 IIA838 보다 높았음 7. ‘KGHR1’의 쌀수량은 ‘수원’ 등 3개 지역에서 실시한 지역적응시험 보통기 보비재배 평균 6.60 MT/ha로 ‘다산’의 6.59 MT/ha와 차이가 없는 수량성을 보였고 수원에서 3년간 실시한 생산력 검정에서는 ‘다산’ 보다 23% 증수하였으며 특히 2019년에 7.59 MT/ha로 베트남 대조품종인 IIA838 보다 도 11% 증수하였으나 베트남 하이하우에서 2018년에서 2019 년까지 2년간 2작기씩 현지 관행재배로 4회 실시한 생산력검 정시험에서는 8.25 MT/ha로 대조품종인 IIA838 보다 12% 떨어지는 수량을 나타내었음 8. ‘KGHR1’는 국내 종자산업 육성과 수출경쟁력을 높이기 위해 2014년부터 수행한 골든시드프로젝트(Golden Seed Project, GSP)의 결과로 개발된 첫 번째 일대잡종 벼 품종으로 우리나라 벼 종자수출산업의 발전을 위한 밑거름이 될 것임

In order to establish optimal double cropping system for getting the maximum annual productivity, we investigated annual fresh and dry yields of winter forage crops (WFC), Italian ryegrass (IRG) ‘Kowinearly’, triticale ‘Joseong’ and summer forage crop (SFC), ‘Jonong’ and ‘Jowoo’ as whole crop silage rice in the paddy field of Yeongseo of Gangwon Province. The double cropping of each crops was applied with 2 standard cultivation method of WFC and SFC from 2018 to 2020. For the WFC, the average percentage of dry matter (29.6%) of IRG ‘Kowinearly’ was lower than that (35.5%) of triticale ‘Joseong’. The average fresh matter yield of IRG ‘Kowinearly’ was 2,662kg/10a that there was no significant difference from the 2,836kg/10a of triticale ‘Joseong’. The average dry matter yield (996kg/10a) of triticale ‘Joseong’ was more than that (696kg/10a) of IRG ‘Kowinearly’. For the summer forage crops, the average percentage of dry matter of whole crop silage rice, ‘Jonong’ was 34.5% that there was no significant difference from the 35.0% of ‘Jowoo’. The average fresh matter yield (5,367kg/10a) of ‘Jowoo’ was more than that (3,966kg/10a) of ‘Jonong’. And the average dry matter yield (1,936kg/10a) of ‘Jowoo’ was more than that (1,433kg/10a) of ‘Jonong’. The total maximum dry matter yield was 2,982kg/10a with the combination of the WFC triticale, ‘Joseong’ and the SFC whole crop silage rice, ‘Jowoo’. In conclusion, the combination of crops that can obtain the maximum yield of high quality forage for double cropping is sowing the WFC triticale, ‘Joseong’ in mid-October, harvesting ‘Joseong’ around the end of May and then SFC whole crop silage rice, ‘Jowoo’, to be transplanted in early June.

In this study, three kinds of bainitic steels are fabricated by controlling the contents of vanadium and boron. High vanadium steel has a lot of carbides and nitrides, and so, during the cooling process, acicular ferrite is well formed. Carbides and nitrides develop fine grains by inhibiting grain growth. As a result, the low temperature Charpy absorbed energy of high vanadium steel is higher than that of low vanadium steel. In boron added steel, boron segregates at the prior austenite grain boundary, so that acicular ferrite formation occurs well during the cooling process. However, the granular bainite packet size of the boron added steel is larger than that of high vanadium steel because boron cannot effectively suppress grain growth. Therefore, the low temperature Charpy absorbed energy of the boron added steel is lower than that of the low vanadium steel. HAZ (heat affected zone) microstructure formation affects not only vanadium and boron but also the prior austenite grain size. In the HAZ specimen having large prior austenite grain size, acicular ferrite is formed inside the austenite, and granular bainite, bainitic ferrite, and martensite are also formed in a complex, resulting in a mixed acicular ferrite region with a high volume fraction. On the other hand, in the HAZ specimen having small prior austenite grain size, the volume fraction of the mixed acicular ferrite region is low because granular bainite and bainitic ferrite are coarse due to the large number of prior austenite grain boundaries.

In this study, effects of carbon and nickel on microstructure and low temperature Charpy impact properties of HSLA (high strength low alloy) steels are investigated. To understand the complex phase transformation behavior of HSLA steels with high strength and toughness before and after welding processes, three kinds of HSLA steels are fabricated by varying the carbon and nickel content. Microstructure analysis, low temperature Charpy impact test, and Vickers hardness test are performed for the base metals and CGHAZ (coarse-grain heat affected zone) specimens. The specimens with the lowest carbon and nickel content have the highest volume fraction of AF, the lowest volume fraction of GB, and the smallest GB packet size. So, the low temperature Charpy absorbed energy of the CGHAZ specimen is the highest. The specimens with increased carbon and nickel content have the lowest volume fraction of AF, the highest volume fraction of GB, and the largest GB packet size. So, the low temperature Charpy absorbed energy of the CGHAZ specimen is the lowest.

In this study, two types of thick steel plates are prepared by controlling carbon equivalent and nickel content, and their microstructures are analyzed. Tensile tests, Vickers hardness tests, and Charpy impact tests are conducted to investigate the correlation between microstructure and mechanical properties of the steels. The H steel, which has high carbon equivalent and nickel content, has lower volume fraction of granular bainite (GB) and smaller GB packet size than those of L steel, which has low carbon equivalent and nickel content. However, the volume fraction of secondary phases is higher in the H steel than in the L steel. As a result, the strength of the L steel is higher than that of the H steel, while the Charpy absorbed energy at -40 °C is higher than that of the L steel. The heat affected zone (HAZ) simulated H-H specimen has higher volume fraction of acicular ferrite (AF) and lower volume fraction of GB than the HAZ simulated L-H specimen. In addition, the grain size of AF and the packet sizes of GB and BF are smaller in the H-H specimen than in the L-H specimen. For this reason, the Charpy absorbed energy at -20 °C is higher for the H-H specimen than for the L-H specimen.

수생태계 생물학적 온전성을 평가하기 위하여 국내 하천 및 하구 923개 지점의 자료를 근거로 한국형 다중형 돌말지수 (KMDI)를 개발하고, 이를 금강수계 233개 지점을 대상으로 온전성평가를 실시하여 단일형 돌말지수들과 비교 검토하였다. KMDI의 개발은 1) 먼저 선행문헌들을 참고로 300개 이상의 메트릭을 추출하고, 2) 이 중 설명력이 높은 46개 후보 메트릭을 선택하며, 3) 각 메트릭 값들의 변이성, 중복성, 변별력, 환경에 대한 민감성 등을 검증하고, 최종적으로 5가지의 메트릭을 선정하였다. KMDI는 매트릭의 단순합으로 표현하고, 환경요인들에 대한 신뢰성 검토 결과, 토지이용, BOD, TN, 전기전도도 등에 대해 높은 민감성 및 설명력을 보였으나 단일형 돌말지수들 보다는 동일 지점의 생물학적 온전성은 다소 높게 평가되는 특성을 보였다. 추후 국내는 물론 지역에 상관없이 적용가능한 설명력 높은 매트릭의 발굴 및 정확한 돌말류 분석 연구가 뒷따라야 될 것으로 판단되었다.

1. ‘아세미’는 열대 아시아지역 적응 다수성이며 자포니카 품종을 육성할 목적으로 1993년 필리핀에 소재한 국제미작연구소에서 우리나라에서 파견된 육종팀에 의해서 인공교배 하였고, 국제미작연구소 육종포장에서 계통을 육성하며 열대기후에서 생육이 안정적인 IR68333-B-B-B-22계통을 선발하여 2001~2002년간 필리핀에서 지역적응시험을 실시하고, 그 이후 농가실증시험을 거쳐서 2008년에 필리핀 벼 품종심의위원회에서 ‘MS11’로 장려품종에 선정되었다. 2. 우리나라의 지적재산권 보호 차원에서 ‘MS11’을 2012년에 ‘수원574호’로 계통명을 부여하여 2013년에 지역적응시험을 실시한 결과 그 우수성이 인정되어 2013년 12월 농촌진흥청 직무육성 신품종선정위원회에서 신품종으로 선정됨과 동시에 ‘아세미’로 명명되었다. 3. ‘아세미’는 이앙부터 성숙기까지 본답의 생육일수가 113일로 조생종이고, 벼 키는 82cm, 이삭길이는 21cm, 주당 이삭수 12개였으며, 현미 천립중이 22.5g으로 중소립종이다. 4. ‘아세미’는 도열병에 중정도 저항성을 보였고, 줄무늬잎 마름병, 퉁그루에 저항성을 보였지만, 흰빛잎마름병, 오갈병 및 멸구류에 대한 저항성은 없었다. 5. ‘아세미’의 쌀수량은 보통기보비재배에서 5.23MT/ha으로 대비품종 ‘화성’보다 13% 증수되는 수량성을 보였다.

PURPOSES : The frequency and severity of natural disasters such as torrential rain or typhoons have become increasingly significant worldwide. Events such as summer typhoons and localized torrential downpour can cause severe damages to a residential area and road networks, resulting in serious harm to the daily lives of people, especially in rural areas by isolating residents from road networks. An immediate and emergency repair technology for the collapsed road networks is urgently needed. This study introduces a new technology to repair road bases or slopes. METHODS: The development of new technology for emergency and permanent repair consists of first, packing of cement paste-coated gravel, second, combining appropriate equipment, and third, conducting a field applicability test. In this research, the compressive strength of cement pastecoated gravel, gravel-netting concrete properties, and packing efficiency were determined, and a full scale field mock-up test was carried out. RESULTS : The compressive strength of the cement paste-coated gravel concrete satisfied the required limit for road base of 5 MPa after 7 days. With appropriate netting materials and packing size, gravel-netting concrete was successful up to a slope of 1:1.5. The full scale field mockup test showed efficiency in the field and penetration resistance performance. CONCLUSIONS: The new technology of emergency and permanent repair for damaged road bases and slopes, introduced in this study, showed satisfactory performance. The technology is expected to be applied in the field when construction procedures and quality specifications are made.

With land-use (cover) and water quality, the distributional characteristics of epilithic diatom communities were studied with 193 samples from estuaries of Korean peninsula between 2015 and 2016. Of total 394 taxa classified, Nitzschia perminuta (19.6%) and N. inconspicua (14.0%) were the 1st and 2nd dominant species. Using a cluster analysis, the epilithic diatom communities of Korean estuaries were divided into four groups (G1-G4). Ecological characteristics of each group were followed: G1 was located in estuaries of the East Sea, and characterized by high forest land-use and high DO and low nutrients; G2 was the eastern part of the South Sea, and characterized by low turbidity and nutrients; G3 was the western part of the South Sea, and characterized by high agriculture, low electric conductivity and low salinity; G4 was the Yellow Sea, and characterized by high nutrients. The environmental factors having significant correlation with diatom distributions were as follows: TN to G1, turbidity to G2, agriculture to G3, and TP to G4. Moreover, the important factors affecting the occurrence of indicator species were forest land-use for Fragilaria construens var. venter in G1, turbidity for Rhoicosphenia abbreviata in G2, urban land- use and total phosphorus (TP) for Bacillaria paradoxa and Hantzschia amphioxys of G3, and TP and turbidity for N. ovalis and Stephanodiscus invistatus of G4. These results collectively indicate that the distribution of epilithic diatom communities in Korean peninsula was largely effected by water quality and land cover/use.

This study was carried out in Suwon-central plain, and Cheorwon, mid-northern plain of Korea to evaluate agricultural characteristics including heading date and yield component for North Korean rice germplasm. The difference between two regions of the heading dates of germplasm was recognized the significance and early matured group growing in Cheorwon tended to flower earlier than that of Suwon while mid-early matured group showed an opposite result. The other agricultural characteristics such as culm length, panicle length, number of panicles per hill, number of grains per panicle, and ripened grain ratio, of the two regions of all traits were highly significant, especially culm length and panicle length in Suwon were longer than those were growing in Cheorwon. Number of panicles per hill and number of grains per panicle in Suwon were more than that were growing in Cheorwon, and ripened grain ratio in Suwon was higher than that of Cheorwon. The another difference between both the regions, of 1000-grain weight was not significant while the effect of interaction between the regions and variety was highly significant. Whereas brown/rough rice ratio and milled rice yield were highly significant; higher in Cheorwon for brown/rough rice ratio and in Suwon of milled rice yield. Additionally, the results concluded that, the North Korean rice germplasm showed susceptible response to bacterial leaf blight(BLB) races such as K2. K3, and K3a but more than mid-range resistant response to rice blast.

PURPOSES: The occurrence of unexpected disasters, including fire events, increases as the road network becomes complicated and traffic volume increases. When a fire event occurs on and under bridges, the damage extensively influences direct damage to structures, vehicles, and human life and secondary socioeconomic issues owing to traffic blockage. This study investigated potential fire-hazard risks on bridges of the Korean national route roadMETHODS: The investigation was conducted using field investigation and analysis with satellite pictures and road views from commercial websites and the Bridge Management System (BMS). From the filed investigation, various potential fire resources were identified. The satellite pictures and road views were helpful in measuring and recognizing conditions underneath bridges, stowage areas, etc.RESULTS : There are various potential fire resources underneath bridges such as piled agricultural products, parked petroleum tanks, construction equipment, and attached high-voltage cables. A total of 94.6% of bridges have underneath clearances of less than 15 m. A bridge underneath volume that can stow a potential fire hazard resource was 7,332 m3 on average, and most bridges have about 4,000 m3 of space. Based on the BMS data, the amounts of PSC and steel girders were 29% and 25%, respectively.CONCLUSIONS : It was found that the amount of stowed potential fire hazard resources was proportional to the underneath space of bridges. Most bridges have less than 15 m of vertical clearance that can be considered as a critical value for a bridge fire. The fire risk investigation results should be helpful for developing bridge fire-protection tools.

Palatability and texture analysis of nine Korean rice cultivars were investigated to select the most appropriate rice variety for the cooked-rice processing. The rice cultivars studied consisted of Samkwang, Seonpum, Wolbaek, Andabyeo, Dasan-1, Ilpum, Haiami, Jungsanggold and Chindle. They revealed the moisture, protein, amylose and starch contents of 10~12, 5~6, 12~19, and approximately 90%, respectively. Among the evaluated rice varieties, WB exhibited the lowest amylose content (12.7%) and Jungsanggold the next (17.2%). In the rapid-visco analyzer test, Jungsanggold, Chindle, Wolbaek and Seonpum revealed a low value of final and setback viscosities than other varieties. Using a toyo meter analyzer, Chindle, Haiami, Samkwang were selected as having high toyo palatability values, while Dasan-1, Wolbaek and Andabyeo revealed low values. Toughness and adhesiveness of all nine cooked rice varieties were highest in Jungsanggold, Chindle and Ilpum. Also, palatability of cooked rice was highest in the following order: Chindle (80.03) > Samkwang (76.21) > Jungsanggold (74.08). The results of this study suggest that Chindle may be effectively used to produce processed cooked rice.

최근 호우 및 산사태 등 자연재해로 인한 도로유실 피해가 증가하고 있으며, 특히 지역특성상 산림이 많이 분포된 지역은 피해가 큰 실정이다. 또한, 유실부 긴급복구 방법은 일시적 교통개방이며, 지속된 교통개방이 어려운 상태이다. 이에 본 연구에서는 도로유실 긴급복구를 위한 연구의 일환으로 골재망을 활용한 다공질 콘크리트 긴급복구 공법의 장비조합을 제안하고자 하였으며, 최소한의 장비로 현장배합 및 도로유실 긴급복구에 활용하고자 한다. 장비, 재료 운반 및 하차수단으로 카고크레인 및 일반 적재트럭으로 2식의 차량을 제안하며, 운반 구성은 현장배합용으로 시멘트, 몰탈믹서, 1㎥물통과 유실부 복구를 위한 골재망, 시멘트페이스트 적재 박스와 골재망 적치는 카고크레인으로 대처하며, 현장지반정리용 0.2B/H, 다공질콘크리트 일부다짐용 콤펙터를 활용하였다. 그림1 및 그림2는 제안한 2식의 차량으로 활용되는 계획을 각각 나타내며, 그림3은 제시한 장비조합의 긴급복구 계획을 나타내고 있다. 도로유실 긴급복구 골재망 활용 다공질 콘크리트의 현장배합 및 시공을 위한 장비조합을 제시하고자 하였으며, 이에 따른 결과는 다음과 같다. 1) 제시한 장비조합은 대형 중장비가 아닌 중 · 소형 장비, 재료로써 운반 및 사용이 용이하며, 신속하고 항구적인 골재망 활용 다공질콘크리트 긴급복구 공법에 적합하다 판단된다. 2) 제시한 장비조합은 Mock-up시험 등을 통한 검증필요가 예상되며, 유실위치 및 규모에 따른 추가 장비구성 및 시공방법 변경에 대한 추가적인 계획이 필요할 것으로 사료된다.