Purpose This study aimed to develop and evaluate a simulation-based autotransfusion device training program to enhance the clinical performance, performance confidence, and educational satisfaction of post-anesthesia care unit (PACU) nurses. Methods: A single-group pretestposttest study was conducted with 30 PACU nurses. The program, based on the ADDIE model, included orientation, simulation training, and debriefing. Data were collected using validated tools before and after the program and analyzed using the Wilcoxon signed-rank test. Results: Clinical performance improved from a median of 30.00 to 43.00 (Z =−4.78, p < .001). Performance confidence increased from 31.00 to 47.50 (Z =−4.71, p < .001), while educational satisfaction rose from 26.00 to 40.00 (Z =−4.73, p < .001). Conclusions: The simulation-based program effectively enhanced the clinical performance, performance confidence, and education satisfaction of PACU nurses. These findings underscore the value of simulation-based training for enhancing nurses’ competence in using complex, high-risk medical devices.

Dietary fiber plays a important role in improving gut micriobiome and reproductive performance in gestating sows. This study aimed to evaluate effects of dietary supplementation with domestically produced alfalfa, provided in pelleted or mashed form, on body weight, body condition, litter performance, fecal score and fecal microbiome in gestating sows. A total of nine crossbred F1 gilts (Yorkshire × Landrace) with an average body weight of 230.33 ± 12.63 kg at 50 days of gestation were randomly assigned to three dietary treatments (n = 3 per treatment): (1) control (CON, basal diet), (2) Pellet (basal diet + 10% pelleted alfalfa), and (3) Mash (basal diet + 10% mashed alfalfa). Results indicated that alfalfa supplementation had no significant effect on weight gain during gestation (p>0.05), although sows in both alfalfa-supplemented groups showed numerically reduced weight loss during lactation compared to the control. The mashed alfalfa improved average daily weight gain of piglets during lactation (p<0.05). Moreover, the pelleted alfalfa alleviated constipation and numerically increased the relative abundance of positive microbes such as Firmicutes (phylum level), Lactobacillaceae and Ruminococcaceae (family level), and Clostridium_sensu_stricto_1, Lactobacillus, and Ruminococcaceae_UCG_002 (genus level) (p<0.05). On the other hands, it numerically decreased the relative abundance of negative microbes such as Proteobacteria in phylum level and Escherichia_Shigella in genus level. These findings suggest that domestically grown alfalfa, particularly in pellet or mash form, may be a valuable dietary fiber source for gestating sows to support piglet performance, gut health, and welfare. However, further studies with larger sample sizes are warranted to confirm these effects.

어선은 다른 어선들과 근접 운항하는 경우가 많아 선회 반경이 작고 빠른 방향 전환이 가능해야 한다. 어선은 또한 파도와 조류 의 영향을 많이 받기에 순간적인 조종이 필요한 경우가 많다. 해양교통안전정보시스템에 따르면 10톤 미만의 소형 선박에 대한 사고는 전 체 사고의 69%에 해당하며 접촉, 충돌, 좌초가 주요인인 사고는 낮은 조종성능으로 인한 사고이다. 이에 소형 어선에 대한 조종성능 평가가 필요하다. 본 연구에서는 4.99톤급 소형 어선을 대상선으로 선정하여 CFD 기반 수치해석 프로그램인 STAR-CCM+을 활용하여 주요 제원 변 화에 따른 조종성능 시뮬레이션을 구축하였다. 조종 성능 평가로는 ∘ /∘ zig-zag test, ∘ /∘ zig-zag test, ∘ portside turning test를 진행 하였다. zig-zag test에서는 L/B가 우세한 선형들이 B/D가 우세한 선형들과 Overshoot angle에서는 큰 차이를 보이지 않았지만 빠른 변침 속도 를 보였다. 반대로 Turning test에서는 B/D가 우세한 선형들이 L/B가 우세한 선형들보다 비교적 작은 선회 반경을 보였다. 이를 바탕으로 4.99톤급 어선의 초기설계 단계에서 조종성능을 고려한 주요 제원을 선정할 수 있는 기초자료로 사용될 수 있을 것으로 기대한다.

This study aims to evaluate traffic safety facilities in school zones in Busan Metropolitan City through Importance-Performance Analysis. This study investigated the traffic safety facilities in nine school zones, which have relatively more traffic accidents in Busan Metropolitan City from 2020 to 2022, through a field study and an Analytic Hierarchy Process(AHP). It identified their performance(i.e., compliance rate) and importance to derive measures for the improvement of traffic safety facilities in school zones. The field study showed that the compliance rate of starting points among traffic safety signs was low, and no speed limits were complied with the installation regulations among traffic road markings, but road safety facilities were generally well managed and operated. As a result of AHP, the order of importance was road safety facilities, traffic safety signs, and traffic road markings. More specifically, speed bumps, safety signs, and crosswalks were found to be more important than others in road safety facilities, traffic safety signs, and traffic road markings, respectively. Importance- Performance(compliance) Analysis revealed that the traffic safety facilities necessary to be most urgently improved are starting points. This result can be resorted to underlying measures to determine priorities for installing and operating traffic safety facilities in school zones.

기후변화로 인해 전 세계적으로 수온이 상승하는 추세이며, 그에 따른 수계 내 유기물의 농도 증가에 따라 정수 처리 과정에서의 소독부산물 생성량 역시 상승하고 있다. 이 중 총트리할로메탄(Trihalomethanes, THMs)은 발암물질로 분류되며, 먹는 물 수질 기준이 0.1 mg/L로 설정되어 있다. 소독부산물 생성량 증가와 취수원에서의 수질 문제가 지속적으로 제기됨에 따라 안정적 수돗물 공급을 위한 대책이 필요한 상황에서 본 연구는 여름철 경기도와 경상북도 지역의 수도꼭지에서 THMs 농도를 모니터링 하였다. 또한, 과거 THMs 측정 자료와 더불어 다양한 자료를 비교ㆍ분석하여 THMs 농도 변화의 원인을 파악했다. 그 결과, 조사 지역들의 THMs 생성에는 원수의 종류, 그로 인한 용존유기탄소 (Dissolved organic carbon, DOC), 클로로필-a 인자와 더불어 계절적 요인들 중 기온과 강우량이 종합적으로 기여하는 것으로 나타났다. 특히, 선형 회귀분석을 통해 용존유기탄소와 THMs간의 상관관계가 높으며 수돗물의 용존유기탄소 농도가 2.7 mg/L 이상일 경우 THMs 농도가 법정 먹는 물 수질 기준을 초과할 가능성이 높다는 결과를 도출하였다. 이를 통해 여름철 강우가 집중되는 시기와 갈수기 THMs 관리를 위해 원수의 유기물 농도를 관리하는 노력이 필수적임을 확인하였다. 해당 결과는 정수장에서의 유기물 농도 관리를 통해 THMs 생성을 억제하는 것이 매우 중요함을 시사하며, 앞으로 먹는 물 수질 기준과 정수장 운영 관리에 용존유기탄소 수질 항목을 추가하는 방안의 검토가 필요하다 판단된다.

Reinforced concrete (RC) columns exhibit cyclic damage, such as strength degradation, under cyclic lateral loading, such as earthquakes. Considering the cyclic damage, the nonlinear load-deformation response of RC columns can be simulated using a lumped plasticity model. Based on an experimental database, this study calibrates lumped plasticity model parameters for 371 rectangular and 290 circular RC columns. The model parameters for adequate flexural rigidity, plastic rotation capacity, post-capping rotation capacity, moment strength, and cyclic strength degradation parameter are adjusted to match each experimentally observed load-deformation response. We have developed predictive equations that accurately relate the model parameters to the design characteristics of RC columns through regression analyses, providing a reliable tool for engineers and researchers. To demonstrate their application, the proposed and existing models numerically simulate the earthquake response of a bridge pier in a metropolitan railway bridge. The pier is subjected to several ground motions, increasing intensity until collapse occurs. The proposed lumped plasticity model showed about 41% less vulnerable to collapse.

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 investigated benthic macroinvertebrates and fish in the Yeongsangang River weir and analyzed stomach contents of Squalidus chankaensis tsuchigae. Length distribution of individuals varied by site, with 91.3% and 72.7% falling within the 70-90 mm range in SC-U (upstream location of Seungchon weir) and SJ (location between Seungchon and Juksan weirs), respectively, and 77.5% within 70-80 mm and 100 mm range in JS-D (downstream location of Juksan weir). Chironomidae spp. (nonred type) were the most abundant food sources, comprising 46.3%, 76.9%, and 88.3% of the diet at SC-U, SJ, and JS-D, respectively. The Electivity Index (EI) indicated a strong preference for Chironomidae spp. (non-red type) (0.927) and avoidance for the red type (-0.929) and Limnodrilus gotoi (-0.995). The proportion of burrowers (BU) increased downstream, while swimmers (SW) decreased. The condition factor (K) varied by site, decreasing in SC-U and increasing in SJ and JS-D, showing a significant positive influence on the number of food sources (p<0.05). Among food sources, Chironomidae spp. and Baetidae sp. were predicted to be utilized across a broad range of lengths and weights, with strong connectivity observed among Tanypodinae sp., Hymenoptera sp., and Baetiella tuberculata.

Cool-season grasses are currently widely used in South Korea, but their productivity and quality may decline due to global warming associated with climate change. Warm-season grasses have shown greater adaptability to heat stress and drought conditions, making them potential alternatives for summer pasture establishment in central and southern Korea. This study aimed to compare the growth characteristics, productivity, and forage value of warm-season grasses bermudagrass and crabgrass for pasture establishment in the central region of South Korea. The experiment was conducted from May 2023 to October 2024 at the National Institute of Animal Science, Cheonan, South Korea. Crabgrass exhibited superior initial establishment and faster growth rates, whereas bermudagrass had poor initial growth, placing it at a competitive disadvantage against weeds. However, after the first cutting, bermudagrass successfully established itself and maintained a stable botanical composition. The annual dry matter productivity of crabgrass (8,586 kg/ha in 2023 and 12,013 kg/ha in 2024) was 32.62% and 40.18% higher, respectively, than that of bermudagrass (5,785 kg/ha in 2023 and 8,570 kg/ha in 2024). In forage value, crabgrass tended to show higher feed value at the initial harvest, while bermudagrass showed higher quality at the later harvests. In conclusion, these results suggest that both crabgrass and bermudagrass have potential for pasture establishment, with carbgrass being more suitable for short-term due to its rapid growth and high productivity, and bermudagrass being more appropriate for long-term due to its stable productivity in regions where overwintering in possible.