This study conducted field surveys targeting benthic macroinvertebrates and fish in Andong Dam and Yeongsan River, with the specific aim of analyzing bluegill stomach contents. Bluegills in Andong Dam ranged from 40-220 mm, with 93.0% between 80-220 mm, while those in Yeongsan River ranged from 50-210 mm, with 71.4% between 120-210 mm. The highest feeding rates in both sites were for Chironomidae spp., with findings of 72.6% in Andong Dam and 80.4% in Yeongsan River. In Andong Dam, H. nipponensis and Baetidae sp. were also significant at 17.5% and 6.5%, respectively, while in Yeongsan River, Baetidae sp. (7.5%) and Hymenoptera sp. were the next most common at 3.8%. The EI index showed that bluegills generally avoided H. nipponensis and S. tsuchigae (-0.373 and -0.975) whereas they preferred Chironomidae spp. (0.759, 0.892) and Baetidae sp. (0.723). The parameter b values of the total length-weight relationship of bluegill were calculated as 3.452 in Andong Dam and 3.449 in the Yeongsan River, respectively. The slope values of the condition factor were 0.0067 in Andong Dam and 0.0065 in the Yeongsan River. Both values were positive, indicating that the nutritional status of bluegill was good. Aquatic insects constituted the primary food source, particularly in Yeongsan River. Feeding patterns did not significantly differ by habitat orientation groups, but Yeongsan River bluegills consumed more diverse food sources. In Andong Dam, larger bluegills likely consume food sources with larger biomass, while Yeongsan River’s diverse and abundant food sources support opportunistic feeding tailored to the water ecological environment.
This study investigated the characteristics of personal PM2.5 exposure among 109 participants residing in Seoul over a two-month period, from February 2024 to April 2024. The participants were categorized into four sub-populations, and personal exposure to PM2.5 was assessed using portable monitors, GPS, and time-activity diaries. To understand the time-activity patterns, the daily occupancy rate for different microenvironments was calculated. Additionally, daily PM2.5 exposure contribution and integrated exposure were quantified. A time series analysis was conducted to identify differences in time-activity patterns and PM2.5 exposure among the sub-populations. ANOVA analysis indicated statistically significant differences in PM2.5 concentrations across populations and microenvironments (p<0.05). However, post-hoc analysis revealed specific microenvironments within certain sub-populations where PM2.5 concentration differences were not significant (p>0.05). All sub-populations spent more than 90% of their time indoors, and the results for exposure contribution and integrated exposure indicated that the home, which had the highest occupancy rate, was the most significant contributor to PM2.5 exposure. This study is expected to serve as foundational data for future indoor air quality management and the development of personalized strategies for reducing PM2.5 exposure.
Volatile organic compounds (VOCs) can adversely affect human and plant health by generating secondary pollutants such as ozone and fine particulate matter, through photochemical reactions, necessitating systematic management. This study investigated the distribution characteristics of gaseous VOCs in ambient air, with a focus on interpreting data from a photochemical pollution perspective. This paper analyzed the presence and concentration distribution of VOCs in industrial areas, identifying toluene, m-xylene, p-xylene, and n-octane as the most frequently detected components. Particularly, toluene was found to significantly contribute to the formation of ozone and fine particulate matter, highlighting the need for stricter regulation of this compound. Although n-octane and styrene were present in relatively low concentrations overall, their significant contributions to ozone generation and secondary organic aerosol formation, respectively, emphasize their importance in air pollution management.
This study was conducted to secure basic data for developing technologies to reduce the generation of odor substances by investigating the effects of environmental temperature on growth performance and the generation of odor substances from feces in growing pigs. A total of 16 pigs (Landrace × Yorkshire × Duroc, average body weight 56.49±0.47kg) were randomly assigned to two treatments: thermal-neutral (TN) and heat stress (HS) conditions. The experiments were conducted for two weeks, with average temperature-humidity indices of 68.91±0.09 for TN and 85.98±0.08 for HS. The results showed that HS significantly decreased average daily feed intake (ADFI, 33.3%) and average daily gain (ADG, 25.8%) compared with TN (p<0.05). Non-esterified fatty acid in serum was lower (36.2%) in HS compared with TN (p<0.05). However, protein, blood urea nitrogen, cholesterol, triglyceride, glucose, and IgG in serum showed no difference between HS and TN. Phenol (350.0%) and skatole (416.3%) were significantly higher in HS than in TN (p<0.05). The decrease in growth performance is attributed to reduction in ADFI. The increase in phenol and skatole in HS is presumed to be due to the effect of HS on the metabolism of intestinal microbial composition. Digestion rate, intestinal microbial composition, and urine emissions are known to affect odor substances. Further research on the content of odor substances in urine, nutrient digestion rate, and intestinal microbial composition is considered necessary to determine the exact associations.
In this study, the operating performance of the heat pump dryer using the PF heat exchanger was experimentally studied. The capacity, COP, drain, SMER and operating status of the cooling cycle of the heat pump dryer were investigated according to the temperature, relative humidity and flow rate of the indoor air. Heat pump dryers are refrigerant-air system. For the dryer performance experiment, an air enthalpy calorimeter was used. From the experimental results, as the temperature, relative humidity, and flow rate of the inlet air increased, the capacity, COP, drain, SMER of the dryer increased. The change in the performance of the dryer was most affected by temperature. The P-h diagram of the cooling system showed that the operation status of the dryer was greatly affected by the indoor temperature. In addition, the SMER of the dryer showed a drying performance of about 3.38 kg/kWh or more within all experimental ranges.
The Climate chamber system is an essential facility for aerodynamic performance development of commercial vehicles to investigate air flow field characteristics in different climatic conditions. In particular, the analysis of airflow fields within the chamber system is an essential consideration for optimal design. In this study, the pressure characteristics and velocity uniformity in the test section area were predicted with blower impeller rotational speed using CFD. The velocity uniformity is affected by the distance from the blower nozzle outlet, reaching up to 72.7% at 695 RPM. The pressure differential between 300 RPM and 740 RPM shows an approximate difference of 2651 Pa, with a high-pressure distribution observed along the right side wall of the blower. These results are expected to be used as design data applicable for improving the performance of environmental chamber systems.
황해 식물플랑크톤의 계절별 군집 구조와 해양환경 요인과의 상관관계를 파악하기 위하여 2019년 계절별로 15개 정점에 대해 조사하였다. 동계와 춘계에는 규조류가 높은 출현율을 나타내었으며, 하계와 추계에는 20μm 이하의 미동정 미소편모조류가 높은 출현율 을 나타내었다. 이는 낮은 농도의 영양염류로 인한 것으로, 특히 인산염의 경우 검출 한계까지 낮게 나타남에 따라 식물플랑크톤 성장에 심각한 저해 현상을 가져온 것으로 판단된다. 성층이 강화되는 하계와 추계 표층 혼합층에서 초미소형 크기의 식물플랑크톤 기여도가 높 았으며, 중복분석 결과 초미소형 크기의 식물플랑크톤은 영양염(질산염, 인산염) 및 수심에 대해 강한 음의 상관성을 나타내고 있었다. 결 론적으로 하계와 추계 성층 강화로 인한 표층 혼합층 내에서의 영양염 감소는 영양염류의 요구량이 낮은 상대적으로 크기가 작은 식물플 랑크톤 성장에 유리한 환경을 제공하며, 식물플랑크톤 군집 구조는 소형화가 진행된 것으로 판단된다.
퍼스널 모빌리티는 친환경 1인용 교통수단으로, 공유 서비스 도입 이후 이용자가 급격히 증가하였다. 연관 정책이 미비한 상태에서 이용자가 급증하였고, 이에 따라 서울시를 중심으로 퍼스널 모빌리티 사고가 증가하고 있으나 관련 연구가 부족한 실정이 다. 본 연구는 서울시를 중심으로 퍼스널 모빌리티 사고에 영향을 미치는 도시환경 요인을 파악하였다. 사고의 공간자기상관을 제거하기 위해 음이항 회귀모형 및 음이항 아이겐벡터 필터링 모형을 적용하였고, 각 모형을 비교한 후 최적 모형인 음이항 아이겐벡 터 필터링 모형의 결과를 바탕으로 사고 결과를 해석하였다. 본 연구는 인구, 교통, 사회 지표를 이용해 퍼스널 모빌리티 사고가 많이 일어나는 서울시 행정동의 특징을 확인하고 분석했다는 점에서 의의를 갖는다.
본 연구는 외부환경조건이 콘크리트 보도블록의 백화특성에 미치는 영향을 검토하였다. 콘크리트 보 도블록의 외부환경조건으로 양지 및 음지에서의 옥외폭로, 온도 20℃, 습도 55%의 항온항습 및 -5℃ ∼5℃의 저온환경 조건에서 시간경과에 따른 콘크리트 보도블록의 백화특성을 검토하여 외기환경조건 이 백화발생에 미치는 영향을 분석하였다.
In this study, infrared thermometry techniques were used to conduct surface wetting performance tests (wicking tests) on micropillar structures with good fluid supply capabilities to enhance the critical heat flux. Wicking tests were conducted based on various micropillar shapes (i.e., diameter and spacing) to investigate the surface wetting performance near the boiling point of the fluid(~100°C). The surface temperature was increased from 20°C to 95°C, to examine the wicking performance The shape of the micropillars were quantified by the roughness and the effect of the roughness and temperature on the wicking performance was analyzed. As a result, we confirmed that the roughness of the micropillars increases the capillary pressure, improving the wicking performance. The sample D04 G10 with the highest roughness coefficient at room temperature (r=2.51) exhibited the highest wicking coefficient, showing a 170% improvement in wicking performance compared to D04G20 with the smallest roughness coefficient at room temperature(r=1.51). Additionally, the D04 G10 sample (r=2.51) recorded a 50% improvement in the wicking coefficient at the highest temperature(95°C) compared to room temperature(20°C). The wicking coefficient data will be utilized as a database for developing a new correlation for critical heat flux.
Although interest in eco-friendly fashion products is increasing among scholars and industry leaders, the concept of eco-friendly products remains unclear, preventing consistent assessment of which fashion products are eco-friendly. This study conducted a content analysis of eco-friendly product information from 87 domestic and 102 foreign brands to reveal key standards for categorizing eco-friendly fashion products. Product characteristic information was coded according to the four material-based standards (i.e., organic material, regenerative material, alternative material, and sustainably produced/upcycled material). Consistency between coders was confirmed by Cohen’s kappa. In results, eco-friendly fashion products are categorized by four material-based standards and two certification standards (i.e., certified, not certified). Among the four material-based categories, the greatest number of domestic and foreign companies produced eco-friendly products that were classified as the regenerative material group. In addition, companies acquired eco-friendly certifications related to the use of organic, regenerative, and alternative materials. The greatest number of eco-friendly material brands used for eco-friendly fashion products belonged to the regenerative material group. Based on the study results, a typology of eco-friendly products was suggested. This typology can benefit practitioners and academics by highlighting a need for classification system for the eco-friendly fashion products, as well as by providing insight into the categorization of eco-friendly fashion products.
항만 내 선박과 부두의 사고를 예방하기 위하여 통항 및 접안 안전성 평가를 통하여 안전한 부두가 건설되어 관리하고 있으나, 선 박의 접안 및 계류 과정에서 선박이 부두에 충돌하거나 로프로 인한 인명사고의 발생 등 예측할 수 없는 사고들이 종종 발생한다. 자동계류장 치는 선박의 신속하고 안전한 계류를 위한 자동화된 시스템으로 로봇 매니퓰레이터와 흡착 패드로 구성된 탈/부착 메커니즘을 가지고 있다. 본 논문은 자동계류장치의 흡착 패드의 위치 및 속도제어에 필요한 선체와의 변위 및 속도 측정 시스템을 다룬다. 자동계류장치에 적합한 측 정 시스템을 설계하기 위하여, 본 논문은 우선 센서의 성능 및 실외 환경적 특성 분석을 수행한다. 다음으로 이러한 분석 결과를 토대로 실외 부두환경에서 설치되는 자동계류장치에 적합한 변위 및 속도 측정시스템의 구성 및 설계 방법에 대해 기술한다. 또한 센서의 측정상태 감지 및 속도 추정을 위한 알고리즘을 제시한다. 제안된 방법은 다양한 속도 구간에서의 변위 및 속도 측정 실험을 통해 그 유용성을 검증한다.
This study was performed to investigate immune changes by comparing the proportion and function of immune cells in the blood under high-temperature period and convalescence temperature period in Holstein dairy cows. The experiment was conducted using Holstein dairy cows of five animals per group (60 ± 20 months old, 175 ± 78 non-day) from the National Institute of Animal Science at high-temperature period (THI: 76 ± 1.2) and convalescence temperature period (THI: 66 ± 1.3). Complete blood count results showed no change in the number of immune cells between groups. In the analysis using Flow Cytometry of PBMCs, no significant differences were observed among B cells, Helper T cells, cytotoxic T cells, and γδ T cells between groups. However, there was an increase in Th17 cells producing IL-17a, while Th1 cells decreased during the convalescence temperature period. The results of gene expression analysis using qRT-PCR in PBMCs revealed an increase in IL-10 during the convalescence temperature period, while a decrease in HSP70 and HSP90 was observed. In conclusion, the increased expression of IL-10 and the decrease in HSP expression suggest the possibility of a weak recovery from heat stress. However, the lack of observed changes in B cells, T cells, and other immune cells indicates incomplete recovery from heat stress during the convalescence temperature period.
이 연구는 1세대 스마트 온실의 재배환경 데이터와 장미 절 화의 품질 특성 데이터를 수집하고 그 요인들 간의 상관 관계 를 분석하여 절화수명 예측 및 최적 환경 조성의 기초 자료를 얻고자 수행되었다. 이를 위해, 토경재배(SC) 및 암면배지경 양액재배(RWH) 하우스 각 1개소를 선정하여 1년간 기온, 상 대습도(RH) 및 수증기압차(VPD), 일적산광량(DLI), 근권온도 등의 환경 데이터와 매월 말 수확된 장미 ‘Miss Holland’ 절 화의 품질 특성 데이터를 수집하였으며, 이 데이터와 절화수 명과의 상관관계를 분석하였다. 절화수명은 10월과 11월을 제외하고는 SC 하우스에서 RWH 하우스보다 더 길었다. 절 화수명과 환경 및 생육 특성 간의 상관관계 분석에서 SC 하우 스의 상관계수는 RWH 하우스보다 조금 더 높았으며, 절화수 명 예측을 위한 요소들도 두 하우스 간에 차이가 있었다. SC 하우스의 절화수명 Y=0.848X1+0.366X2-0.591X3+2.224X4- 0.171X5+0.47X6+0.321X7+9.836X8-110.219(X1-X8: 최고 RH, RH 일교차, DLI, pH, Hunter’s b value, EC, 절화 장, 잎 두께; R2=0.544)로 예측되었고, RWH 하우스의 절화수명 Y=-1.291X1+52.026X2-0.094X3+0.448X4-3.84X5+0.624X6 - 8.528X7+28.45(X1-X7: 경경, 야간 VPD, 최고 근권온도, 최 저 근권온도, 기온 일교차, RH 일교차, 최고 VPD; R2=0.5243) 로 예측되었다. 이 두 모델식으로부터 SC 하우스에서는 RH, EC 및 pH가, 그리고 RWH 하우스에서는 근권 온도가 절화수명에 더 큰 영향을 미친다는 것을 추론할 수 있다. 따라서 각 재배 방법에 따라 장미의 절화수명에 더 큰 영향을 미치는 환경적 요인을 효율적으로 관리할 필요가 있다.
도로 건설로 인한 서식지 파편화에 대한 저감방안으로 육교형 생태통로가 건설되고 있기는 하지만 효과성에 대해서는 아직도 논쟁이 있다. 생태통로의 효과성 평가를 위해 족적트랩, 카메라트랩과 같은 모니터링 방법이 실시되고는 있으나 얼마나 많은 개체가 이용하는지 정량적으로 평가하기에는 한계가 있다. 이에 본 연구에서는 생태통로와 인근 지역을 서식지로 이용할 가능성이 큰 소형포유류인 등줄쥐를 대상으로 포획-재포획 방법으로 개체 위치 파악을 통해 생태통로 이용 정도를 도출하고, 트랩 주변 환경 특성을 이용하여 등줄쥐의 생태통로 이용에 미치는 요인을 확인하였다. 등줄쥐의 생태통로 이용도는 격자 단위의 포획지점을 연결하여 이동 거리와 경로를 확인하였고, 생태통로 이용에 미치는 환경 특성은 트랩당 포획 횟수를 종속변수로 한 일반화 선형 모형(Generalized linear model)을 이용하였다. 연구결과, 등줄쥐의 이동 거리는 선행연구와 유사하게 나타났으며, 생태통로를 횡단하는 개체가 나타나지 않음에 따라 등줄쥐는 생태통로를 통로보다는 서식지로 이용함을 확인하였다. 등줄쥐가 생태통로를 이용하는 데 영향을 미친 환경 특성은 층위별 식생피복량(1~2m, 2~8m, 8m 이상), 교목 식생, 트랩 주변 최대 수목 흉고직경, 경사도가 유의하게 나타났다. 이에 따라 생태통로 조성 시 더 많은 교목과 관목을 식재하고, 높은 경사와 절토사면 생성을 방지하여 생태계 내 먹이원으로 이용될 수 있는 등줄쥐 이용도를 높인다면 생태통로의 효과성을 더 높일 수 있을 것으로 예상된다.
Microphysogobio rapidus is designated as endangered species class I by Ministry of Environment, and its distribution and population have been gradually declining, and it is now limited to the Nam River and some tributary streams of the Nakdong River Watershed. For the restoration of this highly endangered species, it is important to identify the causes of the decline and establish appropriate restoration plans. However, due to lack of basic data and ecological research, most steps are stagnant. Therefore, in this study, we identified the differences in the physical, biological, and sociological habitats between current and past distributed sites through field surveys and literature reviews. As a result of the field survey, there were differences in conductivity between the current and past distributed sites, and fish communities were also showed differences. The literature data also showed that the physico-chemical values of the past distributed sites were generally unfavorable, which generated negative consequences on biological factors. In particular, the effects of urbanization were found to be a major factor affecting the habitat of M. rapidus. Habitat stabilization is crucial for the recovery of this endangered species. However, in the past distributed sites, disturbances such as stream development and weir construction have altered streams physico-chemically and result in changes of M. rapidus. Therefore, a comprehensive plan that considers both stream connectivity and water quality is needed to manage and restore the habitat of M. rapidus.
Hymenobacter 속(genus)은 Bacteroidota 문(phylum), Hymenobacteraceae 과(family)의 대 표 속(type genus)이다. 이 속에 속하는 세균들은 붉은색 색소를 함유하는 그람 음성 간균으로서, 자연 계의 다양한 환경에서 분리되고 있다. 본 연구에서 붉은색 색소를 함유하는 그람 음성 간균이 경남 창 원시 소재 창원대학교 교내의 연못에서 분리되었고, 이 세균은 균주 B2로 명명되었다. 균주 B2를 계통 분석 및 생화학적으로 분석한 결과, Hymenobacter 속에 속하는 것으로 밝혀졌다. 이 세균의 16S rRNA 유전자 염기서열을 genbank의 BLAST로 분석해 본 결과, 다른 어떠한 세균과도 16S rRNA 유전 자 염기서열의 상동성이 새로운 미생물로 인정되는 기준인 98.7%보다 낮은 것으로 나타났다. 균주 B2 의 지방산을 분석해 본 결과, 주된 지방산은 summed feature 3(C16:1 ω7c and/or C16:1 ω6c, 22.8%), iso-C15:0(16.2%), anteiso-C15:0(12.9%), C16:1ω5c(12.4%) 및 summed feature 4 (iso-C17:1 I/anteiso-C17:1)(9.5%)인 것으로 밝혀졌는데, 결과적으로 균주 B2의 지방산 함량은 다른 Hymenobacter 종들의 지방산 함량과 뚜렷한 차이가 있는 것을 알 수 있었다. 이 세균의 16S rRNA 유전자 염기서열 은 genbank에 accession number OQ318247로 등록되었다.