This study evaluated the management priority of small catchments in the Nam River basin, comprehensively considering the impact of non-point pollution sources for water quality improvement. Water quality data from the Water Environment Measurement Network and additional field survey data were collected to understand the water quality status at the small catchment level. The management priority was calculated by integrating data on pollution sources, land cover, and runoff using a weighted method. As a result, the E08-2 small catchment, located downstream of the Nam River, showed the highest priority, followed by A18, B09, E04, and A19. The main factor influencing the water quality improvement priority was the pollution source characteristics within the small catchment, especially the influence factor and land use condition. This study contributes to the efficient water quality management of the Nam River basin by identifying the priority by small catchment through analysis that simultaneously considers point and non-point pollution sources.

Microalgae are efficient fatty acid producers owing to their high photosynthetic activities. They can act as sources of biofuel, feed, and various bioactive compounds. This study aimed to determine optimal culture conditions, including culture medium, temperature, and light intensity, to enhance the biomass and fatty acid content of the indigenous freshwater microalga, Tetradesmus obliquus. Evaluation using a high-throughput photobioreactor revealed that the optimal culture temperature and light intensity were 25°C and 300 μmol m-2 s-1, respectively. Additionally, we optimized components (N, P, and Mg) of the BG-11 medium to enhance the microalgal biomass. Modified BG-11 medium increased the T. obliquus biomass by 37% compared to the standard BG-11 medium. Subsequently, the culture medium was replaced with N- and P-depleted media to determine the abiotic stress factor that could increase the cellular fatty acid content. Notably, fatty acid content was significantly increased from 8.5% up to 14.6% on day 7 of culture in N-deficient (N-P+ and N-P-) media. Sequential optimization effectively increased the biomass by 83% and fatty acid content by >76% in T. obliquus. Our optimization method can be used to enhance the biomass and fatty acid contents of various other microalgae.

This study aims to see if task-based flipped learning (TBFL) can be effective in developing university students’ self-regulated learning. The specific research question is: Does TBFL have a positive impact on learners’ self-regulated learning attitude in cognitive, motivational, and behavioral domains? The research took place at a university English class where a total of 12 students participated for 15 weeks in the fall semester of the year 2023. In order to answer the research question, the self-regulated learning attitude inventory was used along with focus-group interviews and class observation. Due to the limited number of participants, frequency analysis was made for the quantitative data. Major findings were revealed as follows: Firstly, a high level of self-regulated learning attitude was found in all factors in the cognitive domain except for ‘Planning and Monitoring.’ Secondly, positive responses shown in the entire factors in the motivational domain led to greater interest and self-efficacy. Lastly, in the behavioral domain, positive responses were revealed except for ‘Time Management & Environment Setting,’ which seems to be related to the problems found in the cognitive domain’s ‘Planning and Monitoring.’

본 연구에서는 신선 채소의 병원성 미생물 제어를 위해 phytic acid (PA)가 포함된 30 mg/L slightly acidic electrolyzed water (SAEW)의 세척 효과를 평가하였다. 로메인 상추, 방울토마토, 당근에 Escherichia coli O157:H7 및 Salmonella spp.를 접종하고 수돗물 또는 SAEW-PA 소 독수로 5분간 세척하였다. 전반적으로, 시료를 SAEW-PA 로 처리하였을 때 병원균이 유의적으로 감소하였으며, E. coli O157:H7 및 Salmonella spp. 모두 방울토마토와 당근 보다 로메인 상추에서 더 효과적으로 감소하였다. 본 연 구는 또한 식품 접촉 표면인 고무, 플라스틱 및 스테인리 스 스틸의 S. Typhimurium 바이오 필름에 대한 SAEW-PA 소독수의 세척 효과를 평가하였다. S. Typhimurium 바이 오 필름은 고무 재질에서 가장 잘 형성되었고, 플라스틱 과 스테인리스 스틸이 그 뒤를 이었다. 세척 효과는 식품 접촉 표면 및 세척 시간에 따라 다르게 나타났는데, SAEWPA 소독수로 1분간 세척하는 것이 스테인리스 스틸에 가 장 효과적이었으며 고무 및 플라스틱에 미치는 영향은 적 었다. 세척 시간을 5분으로 연장하면 모든 표면에서 바이 오 필름 제거 효과가 향상되었다. 특히 고무 재질에서 NaClO에 비해 SAEW-PA 소독수가 바이오 필름을 더 효 과적으로 감소시켰으며, 이는 식품 산업에서 고무 장갑과 같은 고무 표면을 소독하는 데 SAEW-PA 소독수를 활용 할 수 있음을 시사한다.

The purpose of this study is to examine the characteristics of the change by diachronically investigating the construction period, horizontal arrangement and vertical positional relationship with the burial mound, and architectural composition of shrines built together in cemetery, focusing on cases of domestic sanctification projects. The research method was organized chronologically after selecting the cemeteries through definition of terms and scope. I conducted a literature search, including historical records and newspaper articles, as well as the websites and on-site inspections of each cemetery. The results of the study are as follows. 1) In the sanctification project, it can be seen that placing the shrine at the bottom of the burial mound, similar to the relationship between Neung(royal tomb) and Jeongja-gag(pavilion), was judged to be a traditional arrangement. 2) The inverted relationship between burial mounds and shrines that appeared in the 1990s, that is, the mortuaries located above cemeteries, can be seen as a characteristic unique to democratized cemeteries. 3) As shrines are visited by the public, there is a tendency for them to be built on a majestic scale befitting a national sanctuary.

본 연구는 강릉 소나무 친환경벌채지 산림식생(벌채지, 산림영향권, 군상잔존구, 수림대, 대조구)을 대상으로 산림군집구조를 구명하고 조림학적 갱신 정보를 제공하고자 수행되었다. 2020년 7월 75개소의 방형구를 Braun-Blanquet 방법으로 식생조사를 실시한 후 중요치, 종다양도, 군락유사도, DCA를 분석하였다. 그 결과, 벌채지와 산림영향권에서 큰기름새의 중요치가 높은 것으로 나타났다. 종다양도는 대조구가 1.733로 가장 높게 나타났고, 벌채지가 1.237로 가장 낮게 나타났다. 군락유사도는 벌채지와 산림영향권이 0.706로 가장 높게 나타났고, 벌채지와 대조구가 0.452로 가장 낮게 나타났으며, Sørensen의 유사계수와 더불어 조사위치별 거리를 정량적으로 확인해 보고자 DCA분석을 실시한 결과 군락유사도와 유사한 결과를 나타내었다. 본 연구는 단기적인 연구결과이므로 추후 장기적인 모니터링을 통해 변화되는 친환경벌채지 산림식생에 대한 지속적인 식생 정보의 축적을 통해, 산림영향권이 포함된 친환경벌채지 산림식생의 회복과정에 대한 연구가 필요할 것으로 판단된다.

딤프로피리다즈는 pyrazole carboxamide 계열 살충제로 활성형은 TRPV 상류 부위를 표적으로 하여 신호전달을 차단하며 진딧물 등의 해충 방제에 효과적이다. 사이클로 뷰트리플루람은 phenethyl pyridineamide 계열 살충제로 미 토콘드리아 전자 수송 사슬복합체 II의 호흡작용을 저해 한다. 딤프로피리다즈와 사이클로뷰트리플루람에 대한 국 내 잔류물의 정의는 모화합물이며, 각각 수박, 호박잎 등 29품목에 대하여 0.03-7.0 mg/kg, 배추 등 6품목에 대하여 0.03 mg/kg으로 잔류허용기준이 설정되어 있다. 본 연구 에서는 농산물 중 딤프로피리다즈와 사이클로뷰트리플루람 의 잔류량을 분석하기 위한 공정시험법을 마련하고자 하였 다. 딤프로피리다즈 및 사이클로뷰트리플루람을 분석하기 위하여 아세토니트릴을 추출용매로 사용하는 QuEChERS법 을 이용하여 추출 및 정제조건을 확립한 후, LC-MS/MS 를 분석기기로 선정하였다. 딤프로피리다즈 및 사이클로 뷰트리플루람의 결정계수(R2)는 모두 0.99 이상으로 우수 하였으며, 정량한계는 0.01 mg/kg으로 나타났다. 대표 농 산물 5종(현미, 감자, 대두, 감귤, 고추)에 대하여 정량한 계, 정량한계 10배, 정량한계 50배 수준으로 처리하여 회 수율 실험을 한 결과 딤프로피리다즈의 평균 회수율은 85.5-101.5%, 사이클로뷰트리플루람은 86.8-108.5%을 보였 으며, 변이계수(coefficient of variation, CV)는 각각 10.9%, 13.7% 이하로 나타났다. 본 연구의 결과는 국제식품규격 위원회 농약 분석법 가이드라인25)의 잔류농약 분석 기준 및 식품의약품안전평가원의 식품 등 시험법 마련 표준절 차에 관한 가이드라인24)에 적합한 수준이다.

This paper presents a finite-difference method (FDM)-based heat-transfer model for predicting black-ice formation on asphalt pavements and establishes decision criteria using only meteorological data. Black ice is a major cause of winter road accidents and forms under specific surface temperature and moisture conditions; however, its accurate prediction remains challenging owing to dynamic environmental interactions. The FDM incorporates thermodynamic properties, initial pavement-temperature profiles, and surface heat-transfer mechanisms, i.e., radiation, convection, and conduction. Sensitivity analysis shows the necessity of a 28-d stabilization period for reliable winter predictions. Black-ice prediction logic evaluates the surface conditions, relative humidity, wind speed, and latent-heat accumulation to assess phase changes. Field data from Nonsancheon Bridge were used for validation, where a maximum prediction accuracy of 64% is indicated in specific cases despite the overestimation of surface temperatures compared with sensor measurements. These findings highlight the challenges posed by wet surface conditions and prolonged latent-heat retention, which extend the predicted freezing duration. This study provides a theoretically grounded methodology for predicting black ice on various road structures without necessitating additional measurements. Future studies shall focus on enhancing the model by integrating vehicle-induced heat effects, solar radiation, and improved weather-prediction data while comparing the FDM with machine-learning approaches for performance optimization. The results of this study offer a foundation for developing efficient road-safety measures during winter.

Fishways, particularly installed at the estuary, have a purpose to encourage fluent migration for migratory fishes, as well as amphidromous and even freshwater species. Not choosing the laborious traditional method of using traps, we assessed the efficiency of the two fishways installed at the west and east barrage of the Nakdong River estuarine barrage respectively, by analyzing the videos recorded through automatic monitoring system. We randomly selected 30 videos monthly at each fishways and identified what kind of fishes were using the fishways and categorised their behaviour such as size, time and whether they passed the monitoring system or not. As a result, a total 8 families 14 species were recorded by monitoring system, with the most dominance of Erythroculter erythropterus (Relative Abundance: 59.5%), followed by Micropterus salmoides (R.A: 19.9%) and Mugil cephalus (R.A: 9.9%). The monitoring system can capture passing fishes during night but the number of appearances of fish species at each hour of a day indicated significant diurnal activities (p<0.05). When fishes pass the monitoring system, approximately 70% of them passed through the monitoring device, while 17% of them showed fallback movement. Our finding indicates that species-specific characteristics of each fish are well represented through video monitoring method. In order to maximise advantages of using video monitoring, it is necessary to consider the installation point properly so that the monitoring system does not interfere with the movement of fish. Also, the utilisation of AI technology in the future is also necessary.

This study investigated the annual change and distribution of flora, including endangered species, Korean Red List species, and invasive plants, in the Nakdong River Estuary Ecological Park over a 10-year period (2013~2023). The park was established in 2009 as part of the Four Major Rivers Restoration Project. The investigation identified a total of 704 taxa, comprising 137 families, 401 genera, 631 species, 18 subspecies, 38 varieties, 11 forms, and 6 hybrids. Eulsukdo Ecological Park exhibited the highest plant diversity with 531 taxa, followed by Hwamyeong (404 taxa), Samnak (387 taxa), Daejeo (369 taxa), and Maekdo (356 taxa). The endangered wildlife survey identified three endangered plant species (Class II): Euryale ferox, Brasenia schreberi, and Saururus chinensis. Following the endangered species restoration project, E. ferox has been consistently observed both within the restoration area and the riparian of main channel. The Urbanization Index (UI) was highest in Eulsukdo Ecological Park (24.1%), followed by Hwamyeong (20.0%), Samnak (18.1%), Maekdo (17.8%), and Daejeo Ecological Parks (16.7%). Twelve invasive plants were identified: Sicyos angulatus, Lactuca scariola, Ambrosia trifida, Ambrosia artemisiifolia, Solanum carolinense, Aster pilosus, Hypochaeris radicata, Rumex acetosella, S. altissima, Paspalum disticum, Paspalum distichum var. indutum, and Humulus japonicus. Notably, S. altissima showed a significant decrease in its total distribution area, shrinking from 741,092 m2 in 2021 to 241,396 m2 in 2024. Continuous monitoring and management are necessary to prevent invasive plants, including ecosystem-disturbing species, from forming large colonies and hindering the growth of native plants.

This study used text mining to analyze public interest and research trends related to the Nakdong River. We examined news articles (1990~2024) and academic publications (1960~2024) to understand the evolving relationship between societal concerns and scientific research. Main findings reveal growing public interest towards the Nakdong River, with initial focus on pollution related to the industrial development shifting to large-scale river modification projects and water quality issues. This increased awareness mirrored trends in research, where early emphasis on classic ecology and water quality expanded to include sociocultural, educational aspects and advanced methodologies. The study highlights a dynamic interplay between public discourse and scientific inquiry, with research priorities aligning with societal concerns like water pollution, algal blooms, and biodiversity loss, underscoring the need for integrated, multidisciplinary research that addresses emerging environmental challenges and promotes sustainable management of the Nakdong River ecosystem under climate change and other societal shifts.

The present study was undertaken to ascertain the temperature development characteristics of Phthorimaea operculella (Lepidoptera: Gelechiidae) across its various developmental stages. To this end, the insect was subjected to six constant temperature conditions (13, 17, 25, 27, 32, 34±1°C), relative humidity (RH) levels of 65±5%, and photoperiods of 16 : 8 h light/dark. The developmental time of larvae was longest at 13°C, and as the temperature increased up to 35°C, the developmental time tended to become shorter. At the pupal stage, all individuals developing at 13°C perished and were excluded from the calculation of the development period for the development model. To ascertain the relationship between temperature and development, a regression model was employed for analysis. The lower threshold temperature of the total immature stage was determined to be 9.4°C, and the thermal constant was found to be 454.5DD. In the analysis of the temperature-development experiment, the Lactin 2 model exhibited an optimal fit (R 2=0.90-0.98) for the total immature stage of P. operculella.

본 연구는 합성 아질산염 대체 천연보존료로 개발하고자 천연물 유래 복합추출물(NP-NAP, NP-NAMR)의 성분 특성 과 소시지에의 적용 시 품질 특성을 규명하였다. NP-NAP 와 NP-NAMR 0.5-1.0% (w/v)는 90.1-100%의 ABTS 라디 칼 저해능과 10 mg/mL에서 각각 811 μM 및 770 μM trolox 상당의 FRAP 활성을 보였다. NP-NAP와 NP-NAMR은 S. aureus와 L. monocytogenes, E. coli 및 S. Typhimurium에 대 해 0.1% (w/v)에서 99.99-100%의 감소율을 보였고 C. perfringens에 대해 1%와 2% (w/v)에서 각각 89.0-91.4%와 84.7-100% 이상의 감소율을 보였다. 천연 복합추출물 첨가 소시지 시제품의 냉장 중 품질 특성에서 4주 차 pH (6.43- 6.57)와 NP-NAMR 첨가 시 높은 a 값(23.54% 및 28.81)을 확인하였다. Springiness와 cohesiveness는 NP-NAP 1%가 높 았으나 다른 모든 시험구는 양성 대조구와 유의적 차이가 없었다(P<0.05). 냉장 중 평균 MDA (0.87-1.183 μM)는 양 성 대조구(0.93-0.96 μM)와 유사하였으며(P<0.05) 총 증가 균수(log CFU)는 1% 첨가(1.10-1.32) 시 nitrite pickling salt (NPS) 0.08% (1.31)과 유사하였고 2% 첨가 시(0.17-0.49)는 commercial product from Spain (CPS) 1% (0.53)보다 적었 다. 종합적 기호도는 NP-NAMR 2% 제외한 모든 시험구는 통계적 유의차가 없었다. 이상의 결과, 과채 추출물 유래 NP-NAP와 NP-NAMR은 항산화, 항균 활성과 안정적인 적 색도와 함께 식약처 고시 소시지류의 기준 및 규격을 만족 하여 합성 아질산염과 시판 수입품을 대체하는, 유효한 소 재가 될 수 있을 것으로 사료된다.

본 연구에서는 국내 유통 유제품 중 안식향산, 소브산, 프로피온산 함량을 HPLC와 GC로 분석하였다. 분석 결과 유제품 25건 중 안식향산은 7건, 소브산은 2건, 프로피온 산은 1건에서 검출되었으며, 검출률은 각각 28%, 8%, 4% 였다. 안식향산, 소브산, 프로피온산은 각각 최고 농도 14.19, 416.91, 244.03 mg/kg까지 검출되었다. 소르빈산 칼 륨이 표기가 된 시료는 총 3건으로 그 중 2건에서 소브산 이 검출되었으나 국내 유제품 중 소브산 사용 기준에 모 두 적합한 수치였고 프로피온산이 첨가되었다고 표기된 시료는 없었다. 안식향산과 프로피온산이 검출된 시료의 경 우 천연에서 유래할 수 있는 메커니즘이 알려져 있고 미생 물 최소 저해 농도 이하의 수치로 검출되어 보존 효과를 나타낼 수 없기 때문에 의도적으로 첨가되지는 않았을 것 으로 사료된다. 본 연구는 향후 유제품 중 보존료 사용에 대한 소비자의 불안감 해소와 보존료의 안전성 관리 및 천연유래를 판단하기 위한 중요한 기초자료로 사용될 수 있을 것으로 사료된다.

국내 유통 중인 과·채류음료 64건을 대상으로 비타민 C, 폴리페놀, 무기질 함량에 대해 분석하였다. 분석 결과 비 타민 C는 1.851-251.108 mg/100 mL의 범위를 나타냈고, 비 가열 처리 사과주스에서 평균 함량 89.646 mg/100 mL로 가장 높게 나타났다. 폴리페놀은 260.767-1895.095 mg GAE/L의 범위를 나타냈으며 비가열 처리 사과주스에서 평균 함량이 1042.311 mg GAE/L로 가장 높게 나타났다. 무기질의 경우에는 100 mL 당 평균 함량이 가열 처리 오 렌지주스에서 셀레늄, 구리가 각각 0.101 μg, 22.875 μg으 로 가장 높게 나타났다. 비가열 처리 딸기주스에서 마그 네슘, 인, 철의 평균 함량이 각각 4.281 mg/100 mL, 16.085 mg/100 mL, 0.400 mg/100 mL으로 가장 높게 나타 났으며, 가열 처리 딸기주스에서 아연의 평균함량이 149.344 μg/100 mL으로 가장 높게 나타났다. 성인남성기준 일일권장섭취량과 비교해보았을 때, 200 mL의 주스 한 컵 을 마실 경우, 비타민 C는 하루 권장섭취량의 최대 5배 섭 취가 가능했고, 무기질 중 철은 50% 이상 충족이 가능했다.

본 연구에서는 열유도상분리법으로 제조한 polyvinylidene fluoride (PVDF) 중공사막의 오염성과 화학적 세척에 대한 실험을 진행하였다. 오염수는 소 혈청 단백질(bovine serum albumin, BSA)과 카올린(kaolin)을 이용해 제조하였으며, 차아 염소산나트륨(NaOCl), 구연산(citric acid), 황산(H2SO4)으로 화학적 세척을 진행한 후 뒤 표면 전하 분석기, 주사전자현미경 (scanning electron microscope, SEM) 그리고 에너지 분산 X선 분광법(energy dispersive X-ray spectroscopy, EDX)을 통해 세 척 효율을 평가하였다. PVDF 분리막은 높은 내화학성과 열적 안정성을 가지는 분리막으로 화학적 세척을 진행한 결과 가장 좋은 효율은 차아염소산나트륨으로 세척한 것으로 그 결과 투과도는 793.2 L/(m2.h.bar)로 초기 투과량인 945.3 L/(m2.h.bar) 값과 비교하였을 때 약 84% 회복률을 보여주었다. 이는 수처리 공정에서의 막 오염 방지 및 세척의 중요성을 제시한다.

본 연구에서는 이온성 물질 제거와 재생을 동시 수행하는 바이폴라막에 대한 운전 조건에 따른 성능 영향과 고회 수율을 위한 재생 조건을 연구하였다. 유입수의 농도와 유량이 증가할수록 제거율이 빠르게 감소하였으며 제거율 80% 지점 까지 유입수 농도 300 mg/L에서 최대의 TDS 제거용량을 나타내었고, 유입수 유량은 낮을수록 더 많은 TDS 제거용량을 나 타내었다. 낮은 전압에서는 제거율이 급격하게 감소하였고 전압이 높아질수록 제거율이 증가하지만, 일정 수준 이상의 전압 에서는 추가적인 제거율 향상을 보이지 않았다. 한편 재생을 위한 전압은 75 V로 선정하였는데, 이 이상의 재생 전압에서는 온도의 급격한 상승 및 이로 인한 바이폴라막의 손상이 관찰되었다. 재생 시 재생수의 공급을 최소화하기 위한 다양한 운전 모드가 평가되었고 70%의 고회수율을 구현할 수 있는 재생모드를 제안하였다.

This study aimed to estimate the rumen fermentation characteristics and greenhouse gas emissions of major domestic feed sources for Hanwoo. Five feed sources mainly used in South Korea were selected: corn meal (CM), soybean meal (SM), wheat flour (WF), palm kernel cake (PKC), and corn distiller’s dried grains with soluble (DDGS). These feed sources were purchased from a commercial feed company. For 24 h rumen incubation, each feed source (0.3 g) was placed into the incubation bottle with the rumen mixture (30 mL) in quadruplicates. After incubation, total gas production was measured and sub-sampled for CO2 and CH4 analyses, and the bottle content was centrifuged for rumen fermentation characteristics and in vitro dry matter digestibility (IVDMD). Crude protein content was highest in SM and lowest in CM. Ether extract content was highest in DDGS and lowest in SM, while neutral detergent fiber and acid detergent fiber contents were highest in PKC and lowest in CM. Propionate content was highest in DDGS, and butyrate and A:P ratio contents were highest in PKC (p<0.05). Total gas emission (mL/g DMD) was lowest in SM and DDGS, while CH4 emission (mL/g DMD) was lowest in DDGS (p<0.05). Therefore, this study concluded that DDGS could be an alternative feed source to reduce methane emissions.

Objectives: The main purpose of this study was to identify problems such as cooking fumes and lack of ventilation in school cafeterias and evaluate the improvement in the reduction of indoor pollutants in the cooking rooms through renovation. Methods: Three schools were selected for renovation and the spatial structures and air conditioning system of the cafeterias and cooking rooms wre investigated after renovation. The air conditioning systems were improved by the renovation work according to the characteristics of each school, and the concentration of indoor pollutants was measured and evaluated through CFD analysis. Results: The concentration of indoor pollutants in the cafeterias and cafe rooms was decreased after renovation. Conclusion: Air conditioning systems in the schools cafeterias and cooking rooms were improved in order to solve the problems of ventilation, and the indoor air quality improvement rate ranged from a minimum of 11% to a maximum of 40%. The renovation of cafeterias and cooking rooms was conducted to optimize the ventilation systems and this contributed to indoor air quality improvement by preventing the inflow of pollutants.