This study investigated the effect of Lactiplantibacillus plantarum JSA22-fermented rice drinks on dextran sodium sulfate (DSS)-induced colitis in mice. Twenty-four mice were randomly assigned; No colitis (Con), colitis with tap water (DSS-only), colitis with unfermented rice (DSS-UFR), and colitis with fermented rice (DSS-FR). After inducing colitis with 2% DSS for 5 days, they were given Tap water, UFR drink, or FR drink for an additional 6 days. The DSS-FR group had significantly lower Disease Activity Index (DAI) scores compared to the DSS-only group, but no significant difference with the DSS-UFR group. Colon length was reduced in the DSS-only group. The DSS-only group had significantly higher IL-6 mRNA levels compared to the Con group, while the DSS-FR groups showed significantly lower IL-6 mRNA levels compared to the DSS-only group. These results suggest that rice drinks fermented with Lactiplantibacillus Plantarum JSA22 ameliorate the severity of DSS-colitis, by potentially reducing proinflammatory cytokines.

The conservation of wetland ecosystems has a significant role in climate change. Notably, the Han River Protected Area, including the Siam-ri wetland and Janghang wetland, provides high biodiversity value. Thus, it is necessary to comprehensively evaluate the function and value of wetland ecosystems. This study evaluated the ecosystem services of Siam-ri and Janghang Wetlands located in the Han River Protected Area using the Rapid Assessment Wetland Ecosystem Services approach, a function-oriented ecosystem analysis. The results were calculated using the Ecosystem Services Index formula to analyze wetland ecosystem services. We also assessed the key ecosystem services based on a focus group interview. We identified that the supporting and cultural services index scores were relatively high in the study area. The results can provide helpful information for sustainable wetland conservation, conservation planning as primary data, and raising awareness for the Han River Protected Area.

Aluminum alloys, known for their high strength-to-weight ratios and impressive electrical and thermal conductivities, are extensively used in numerous engineering sectors, such as aerospace, automotive, and construction. Recently, significant efforts have been made to develop novel aluminum alloys specifically tailored for additive manufacturing. These new alloys aim to provide an optimal balance between mechanical properties and thermal/ electrical conductivities. In this study, nine combinatorial samples with various alloy compositions were fabricated using direct energy deposition (DED) additive manufacturing by adjusting the feeding speeds of Al6061 alloy and Al-12Si alloy powders. The effects of the alloying elements on the microstructure, electrical conductivity, and hardness were investigated. Generally, as the Si and Cu contents decreased, electrical conductivity increased and hardness decreased, exhibiting trade-off characteristics. However, electrical conductivity and hardness showed an optimal combination when the Si content was adjusted to below 4.5 wt%, which can sufficiently suppress the grain boundary segregation of the α- Si precipitates, and the Cu content was controlled to induce the formation of Al2Cu precipitates.

In this study, the biogeochemistry management (BGC-MAN) model was applied to North and South Korea pine and oak forest stands to evaluate the Net Primary Productivity (NPP), an indicator of forest ecosystem productivity. For meteorological information, historical records and East Asian climate scenario data of Shared Socioeconomic Pathways (SSPs) were used. For vegetation information, pine (Pinus densiflora) and oak (Quercus spp.) forest stands were selected at the Gwangneung and Seolmacheon in South Korea and Sariwon, Sohung, Haeju, Jongju, and Wonsan, which are known to have tree nurseries in North Korea. Among the biophysical information, we used the elevation model for topographic data such as longitude, altitude, and slope direction, and the global soil database for soil data. For management factors, we considered the destruction of forests in North and South Korea due to the Korean War in 1950 and the subsequent reforestation process. The overall mean value of simulated NPP from 1991 to 2100 was 5.17 Mg C ha-1, with a range of 3.30-8.19 Mg C ha-1. In addition, increased variability in climate scenarios resulted in variations in forest productivity, with a notable decline in the growth of pine forests. The applicability of the BGC-MAN model to the Korean Peninsula was examined at a time when the ecosystem process-based models were becoming increasingly important due to climate change. In this study, the data on the effects of climate change disturbances on forest ecosystems that was analyzed was limited; therefore, future modeling methods should be improved to simulate more precise ecosystem changes across the Korean Peninsula through processbased models.

This study was to evaluate the values of Korean native sweet sorghum as a new feed crop for ruminants. Sweet sorghum was the Muan native species (Bioenergy Crop Research Center, National Institute of Crop Science), and cultivated from May to October 2021 at Sangji University (Wonju-si, Gangwon-do, Korea). There were a non-treated group (Con), a recommended amount treatment (RD) and a treatment with double the recommended amount (Double RD) by an oil cake fertilizer. Plant height was measured at weekly intervals for 12 weeks after planting sweet sorghum seedlings, and was a significant difference in the order of Double RD, followed by RD and Con in 7 weeks (p<0.05). Feed values and sugar contents were measured in 7, 9, and 11 weeks. Crude protein of Double RD was higher than that of the other treatments in 7 and 9 weeks (p<0.05). Crude fat was higher at Double RD than the other one in 9 weeks (p<0.05). ADF and NDF of Double RD were higher than the other one (p<0.05). When it was compared to corn and sudangrass hybrids grown on farms, Crude protein was lower in sweet sorghum than other crops (p<0.05), and crude fat was higher in sweet sorghum than corn (p<0.05). Crude fiber, ADF and NDF were higher in sweet sorghum compared to corn and sudangrass (p<0.05). The sugar contents of sweet sorghum were 4.07 ± 0.12∼7.63 ± 0.21 brix, and showed higher than corn and sudangrass hybrid (p<0.05). The rumen in situ digestibility of sweet sorghum was 30.73∼38.13% at the 9th and 11th weeks, and showed higher than that of corn and sudangrass hybrids (p<0.05). Therefore, it is considered that Korean native sweet sorghum has sufficient value as a new forage crop for ruminants, and good value as yield, nutrients and digestibility, when the grass height is 273.33~332.50 cm.

본 연구는 복잡한 도심주변의 지형과 다양한 배출원이 존재하고 있는 세종시 부강면과 조치원읍 일원을 대상으 로 대기오염 확산의 물리적인 특성을 분석하여 오염 물질의 확산을 가정했을 때의 특징을 분석하였다. 부강면의 경우 토지의 기복이 심한 전형적인 분지형지역으로서, 대기오염물질의 확산이 불량하여 대기 오염이 심화되는 지형상의 특성을 내포하고 있다. 지형조건의 특성상 강한 풍속으로 이류된 대기오염물질의 확산이 용이하지 않아 국지적으로 정체되 어 대기오염물질의 공간적 확산 보다는 정체에 의한 대기 환경 악화의 간접 요인이 될 수 있음을 나타낸다. 또한 이러 한 경우 지형적 가열율의 차이 등에 의한 급속한 온도 상승 경향이 나타날 가능성이 있어 향후 먼지 돔현상(dust dome) 등과 관련하여 오염물질의 확산과 관련한 정책제안에 있어서 세심한 논의가 필요하다. 고농도와 비고농도 사례 일을 분석했을 때 조치원읍의 경우 부강면에 비하여 주변 배출원의 영향이 다소 높은 상태이다. 또한 고농도과 비고농 도의 사례에 대한 분석에서 특정한 풍계에 따라 고농도일의 사례가 됨과 동시에 지형적으로 경사지에 속해 서쪽에서 이류된 오염물질이 쉽게 유입되는 상황으로 분석된다. 이러한 국지 지형에 따른 난류특성 변수들인 마찰속도(friction velocity), 확산속도(convective velocity), 현열 속(sensible heat flux) 등에 의한 연직 혼합고는 대기오염물질의 확산강도 에 중요한 요인임을 알 수 있었다. 이와 관련하여 배출원관리에 따른 논의가 부강면 사례에서 보다는 조치원읍에서 상 대적으로 필요함을 분석하였다.

In this study, non-destructive technologies that can be applied to evaluate the integrity of valve materials, safety against internal pressure caused by corrosion, and the blocking function of large-diameter water valves during operation without requiring specimen collection or manpower entering the inside of the valve were tested to assess the reliability of the technologies and their suitability for field application. The results showed that the condition of the graphite structure inside the valve body can be evaluated directly through the optical microscope in the field without specimen collection for large-diameter water butterfly valves, and the depth of corrosion inside the valve body can be determined by array ultrasound and the tensile strength can be measured by instrumented indentation test. The reliability of each of these non-destructive techniques is high, and they can be widely used to evaluate the condition of steel or cast iron pipes that are significantly smaller in thickness than valves. Evaluation of blocking function of the valves with mixed gas showed that it can be detected even when a very low flow rate of mixed gas passes through the disk along with the water flow. Finally, as a result of evaluating the field applicability of non-destructive technologies for three old butterfly valves installed in the US industrial water pipeline, it was found that it is possible to check the material and determine the suitability of large-diameter water valves without taking samples, and to determine the corrosion state and mechanical strength. In addition, it was possible to evaluate safety through the measurement results, and it is judged that the evaluation of the blocking function using mixed gas will help strengthen preventive response in the event of an accident.

The aim of this study was to compare the antioxidant activities and functional contents of Korean conventional and Chinese seed gingers from the Jeollabuk-do Wanju and Chungcheongnam-do Seosan regions. Ginger samples were subjected to steaming treatments for different durations (2–8 h) at 121oC using an autoclave. The antioxidant activity was evaluated by measuring total polyphenol and flavonoid contents and ABTS and DPPH radical scavenging activities, while functional ingredient contents were analyzed for gingerols and shogaols. The results showed that Wanju conventional seed ginger (WO-2) had the highest total polyphenol (85.24 mg GAE/g) and flavonoid (98.14 RE/100 g) contents, surpassing that of the control in all steamed groups at 6 h. ABTS radical scavenging activity showed a strong correlation with total polyphenol and flavonoid contents. The control groups indicated that Korean conventional seed ginger had 1.0–1.3 times higher gingerol contents compared to Chinese seed ginger. Furthermore, the content of shogaols, considered major functional ingredients, increased significantly with longer steaming durations, reaching the highest content (1,793 mg/kg) at 8 h, which was 1.0–1.8 times higher in Korean conventional seed ginger than that in Chinese seed ginger. These experiments provide valuable data supporting the excellence of Korean conventional seed ginger in the future.

Boron carbide (B4C) is highly significant in the production of lightweight protective materials when added to aluminum owing to its exceptional mechanical properties. In this study, a method for fabricating Al-B4C composites using high-energy ball milling and directed energy deposition (DED) is presented. Al-4 wt.% B4C composites were fabricated under 21 different laser conditions to analyze the microstructure and mechanical properties at different values of laser power and scan speeds. The composites fabricated at a laser power of 600 W and the same scan speed exhibited the highest hardness and generated the fewest pores. In contrast, the composites fabricated at a laser power of 1000 W exhibited the lowest hardness and generated a significant number of large pores. This can be explained by the influence of the microstructure on the energy density at different values of laser power.

Aluminum alloys are widely utilized in diverse industries, such as automobiles, aerospace, and architecture, owing to their high specific strength and resistance to oxidation. However, to meet the increasing demands of the industry, it is necessary to design new aluminum alloys with excellent properties. Thus, a new method is required to efficiently test additively manufactured aluminum alloys with various compositions within a short period during the alloy design process. In this study, a combinatory approach using a direct energy deposition system for metal 3D printing process with a dual feeder was employed. Two types of aluminum alloy powders, namely Al6061 and Al-12Cu, were utilized for the combinatory test conducted through 3D printing. Twelve types of Al-Si-Cu-Mg alloys were manufactured during this combinatory test, and the relationship between their microstructures and properties was investigated.

Metal additive manufacturing (AM) has transformed conventional manufacturing processes by offering unprecedented opportunities for design innovation, reduced lead times, and cost-effective production. Aluminum alloy, a material used in metal 3D printing, is a representative lightweight structural material known for its high specific strength and corrosion resistance. Consequently, there is an increasing demand for 3D printed aluminum alloy components across industries, including aerospace, transportation, and consumer goods. To meet this demand, research on alloys and process conditions that satisfy the specific requirement of each industry is necessary. However, 3D printing processes exhibit different behaviors of alloy elements owing to rapid thermal dynamics, making it challenging to predict the microstructure and properties. In this study, we gathered published data on the relationship between alloy composition, processing conditions, and properties. Furthermore, we conducted a sensitivity analysis on the effects of the process variables on the density and hardness of aluminum alloys used in additive manufacturing.

Machine learning-based data analysis approaches have been employed to overcome the limitations in accurately analyzing data and to predict the results of the design of Nb-based superalloys. In this study, a database containing the composition of the alloying elements and their room-temperature tensile strengths was prepared based on a previous study. After computing the correlation between the tensile strength at room temperature and the composition, a material science analysis was conducted on the elements with high correlation coefficients. These alloying elements were found to have a significant effect on the variation in the tensile strength of Nb-based alloys at room temperature. Through this process, a model was derived to predict the properties using four machine learning algorithms. The Bayesian ridge regression algorithm proved to be the optimal model when Y, Sc, W, Cr, Mo, Sn, and Ti were used as input features. This study demonstrates the successful application of machine learning techniques to effectively analyze data and predict outcomes, thereby providing valuable insights into the design of Nb-based superalloys.

건설공사도급계약 체결 시 도급인과 수급인 간에 지체상금약정을 체결하는 것 이 일반적이고, 그에 대한 구체적인 내용은 국토교통부 고시상 ‘민간건설공사 표준도급계약 일반조건’이나 공정거래위원회 ‘건설공사도급계약 표준약관’에 의하고 있다. 지체상금은 건설공사 진행 단계 중 공기지연 등으로 인한 문제가 발생할 경우를 대비하여 건설공사도급계약 체결 시 수급인(시공사 및 계약상 대자)이 건설공사도급계약상 이행의무를 지연할 경우 지급하여야 할 배상금액 을 미리 정하고 있는 것인데, 분쟁의 사전 예방과 공사이행의 담보 등 많은 역 할을 해 줄 것이라는 기대에도 불구하고 실제 건설공사도급계약에서는 지체상 금 약정과 관련한 분쟁이 끊임없이 발생하고 있다. 무엇보다도 지체상금 관련 조건이 제대로 이행되지 않아 그로 인한 조건 구비 여부 자체가 문제되는가 하면, 보다 강력한 이행 강제를 부담지우려는 목적으 로 발주자가 미리 지체상금액을 과다하게 책정하거나 청구할 수 있도록 함으 로써 도급계약 자체가 수급인 쪽에 불리하게 이루어지는 경우도 많아 논란이계속되고 있다. 이러한 현실에서 본 연구에서는 지체상금에 관한 그동안의 판 례 및 선행연구들을 분석하고 정리함과 동시에 현재 지체상금 약정 운용 시에 나타나고 있는 몇 가지 주요 문제들인 지체상금의 면책사유 및 구체적 운영 과정에서의 지체상금 부과와 관련한 판단기준이나 당사자 귀책사유에 따른 지 체상금의 적절한 분배 문제 등에 대하여 판례 및 그에 대한 해석론을 중심으로 고찰하였다.

본 논문에서는 우리나라 경제성장과 연구수행 주체별 공공 연구개발투자, 기업 연구개발투자, 대학 연구개발 투자 간의 장·단기 인과관계를 실증 분석하였다. 이를 위해 1976년부터 2020년 동안의 시계열 자료를 바탕으로 단위근 검정, 공적분 검정, 백터오차수정 모형(VECM)을 통한 인과성 검정을 실시하였다. 분석결과, 우리나라 경제성장과 공공 연구 개발투자, 기업 연구개발투자, 대학 연구개발투자 간에는 장기적으로 인과관계가 존재하는 장기균형관계가 있다는 것을 도출하였다. 그러나, 공공 연구개발투자가 경제성장에 단기적으로 영향을 미치는 데에 비해 기업 및 대학 연구개발투자는 경제성장에 단기적으로 영향을 미치지 않는 것으로 나타났다. 더불어, 경제성장 및 공공 연구개발투자, 기업 연구개발투자와 공공 연구개발투자, 대학 연구개발투자와 공공 연구개발투자 간에 단기적으로 양방향의 인과관계가 있는 것으로 도출되었다. 마지막으로 단기적으로 공공 연구개발에 인과관계가 있는 것은 GDP 경제성장이며, 대학의 연구개발에 단기적으로 인과관계가 있는 것은 공공 및 기업의 연구 개발투자인 것으로 나타났다. 이상의 연구를 통해서 공공 연구개발투자, 기업 연구개발투자, 대학 연구개발 투자와 경제성장 간에는 높은 상호 유기적인 관계가 존재한다는 것을 실증적으로 도출하였다. 향후 연구개발투자가 경제성장에 미치는 파급효과를 높이기 위해서는 대학과 기업의 연구개발투자가 상호 촉진되고, 기업의 연구개발투자가 공공 연구개발투자에 긍정적 영향을 미쳐 공공 연구개발투자가 향후 경제성장에 기여할 수 있도록 하는 정책개발이 필요할 것이다.

This study aimed to investigate the effect of a coating agent on pork storage. Pork was coated with a coating agent containing sodium carboxymethyl cellulose (CMC) and mandarin peel powder (M). The treatments were divided into control, a 0.1% CMC treatment, and a 0.1% CMC +5% M treatment, and pH, color, 2-thiobarbituric acid reactive substances (TBARS), volatile basic nitrogen (VBN), and the number of viable cell counts were measured. In the case of redness (a), it was found that the reduction over the storage period was less in the 0.1% CMC + 5% M treatment than in the control and the 1% CMC treatment. When stored at 4oC and 25oC, TBARS of pork tended to increase during the storage period, followed by control, 0.1% CMC treatment, and 0.1% CMC + 5% M treatment, indicating that lipid oxidation was most suppressed in pork coated with mandarin peel powder. As a result of measuring the VBN of pork stored at 4oC and 25oC, the 0.1% CMC + 5% M treatment showed lower values than the control and 0.1% CMC treatment. When the film-coated pork was stored at 4oC, the number of viable cell counts in the 0.1% CMC +5% M treatment area was 7.13±0.96 log CFU/g on the 12th day of storage, delaying the growth of viable cell counts for approximately 3 d more than other treatments. Therefore, coating pork with a film containing CMC and mandarin peel powder has been confirmed to delay the increase in the number of viable cell counts while reducing the quality change during pork storage, which is an effective alternative to improving the storage of fresh food as an edible film.