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        검색결과 958

        1.
        2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To utilize pepper (Piper nigrum) as an immunostimulatory agent, we isolated macrophage stimulating polysaccharides from pepper and investigated their macrophage activating activities. Hot-water extracts (HW) of black pepper (BP) and white pepper (WP) were prepared, and their macrophage stimulating activities were evaluated using RAW 264.7 cells. BP-HW significantly promoted the secretion of macrophage stimulating factors such as nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-12 compared to WP-HW. When BP and WP-HW were fractionated into crude polysaccharides (CP) and low molecules (LM) by ethanol precipitation, BP-CP demonstrated significantly more potent activity. Furthermore, BP-CP not only induced mRNA gene expression of macrophage activation factors, but also promoted nuclear localization of p65 and c-Jun. In addition, component sugar analysis revealed that glucan-type polysaccharides in BP-CP played a crucial role in macrophage activation. Taken together, these findings suggest that black pepper has industrial applicability not only as a spice, but also as an immunostimulatory functional material.
        4,200원
        2.
        2024.10 구독 인증기관·개인회원 무료
        2019년 12월, 상주-영천 고속도로 상행선에서 도로 노면 결빙에 의한 연쇄추돌사고로 48명의 사상자가 발생하였다. 이에, 국토교통부 는 2020년 1월 결빙 취약구간 선정기준을 마련하여 결빙 취약구간 403개소를 지정하고, 결빙 취약구간을 대상으로 2022년까지 1,699억 원의 예산을 투입하여 결빙사고 예방사업을 계획하였다(BAI, 2021). 하지만, 결빙 취약구간 선정기준에 대해 적정성 검토가 이루어지 지 않아 그 신뢰성과 실효성이 충분히 검증되지 않았다. 본 연구에서는 국가교통정보센터의 노드·링크(Node·Link) 체계를 기반으로 전국 고속국도 및 일반국도의 특성정보(시설, 선형구조, 기상, 교통 등)를 GIS(Geographic Information System) 데이터로 구축하였다. 최근 5년 결빙사고 발생이력이 있는 도로구간(Link)을 확인하고 Random Forest 알고리즘을 통해 도로 특성정보의 결빙사고에 대한 변수 중요도(Feature Importance)를 분석했다. 이를 통해 결빙사고와 각 인자의 상관성을 파악하여 ‘결빙 취약구간 평가 세부 배점표’의 항목별 배점을 수정, 보완함으로써 평가표의 신뢰성을 제고한다.
        3.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Present study investigated fish community at 12 sites within Yudeungcheon Stream in October 2018 and May 2019 to understand the inhabit status of the endangered species Pseudopungtungia nigra. We collected 39 species and 2,554 individuals of fish, and the Fish Assessment Index (FAI) was evaluated as “Good (B)” with an average score of 66.8. Among collected fishes, 15 endemic and 2 invasive species, Micropterus salmoides and Lepomis macrochirus were identified. In the distribution survey of P. nigra, it appeared in a range of approximately 12 km from Maebawiyuwonji Park (St. 5) to Budnaedari Bridge (St. 10). Based on population collected in May, the age of P. nigra (female) were divided into three groups by the length-frequency distribution method: 1 year old (60~76 mm), 2 years old (82~99 mm), and more than 3 years old (100~117 mm). Total length of the minimum maturity individual was 60 mm, and was a 1 year old. The estimated average population size using the Jolly-Seber method was 5,804 individuals in the Suryeongyo Bridge. Our study provides fundamental information about the fish community and River health assessment in Yudeungcheon Stream. Furthermore, we are expected to provide ecological information of the P. nigra, consequently helping to establish conservation and restoration plans for endangered species.
        4,600원
        4.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Black ice, a thin and nearly invisible ice layer on roads and pavements, poses a significant danger to drivers and pedestrians during winter due to its transparency. We propose an efficient black ice detection system and technique utilizing Global Positioning System (GPS)-reflected signals. This system consists of a GPS antenna and receiver configured to measure the power of GPS L1 band signal strength. The GPS receiver system was designed to measure the signal power of the Right-Handed Circular Polarization (RHCP) and Left-Handed Circular Polarization (LHCP) from direct and reflected signals using two GPS antennas. Field experiments for GPS LHCP and RHCP reflection measurements were conducted at two distinct sites. We present a Normalized Polarized Reflection Index (NPRI) as a methodological approach for determining the presence of black ice on road surfaces. The field experiments at both sites successfully detected black ice on asphalt roads, indicated by NPRI values greater than 0.1 for elevation angles between 45o and 55o. Our findings demonstrate the potential of the proposed GPS-based system as a cost-effective and scalable solution for large-scale black ice detection, significantly enhancing road safety in cold climates. The scientific significance of this study lies in its novel application of GPS reflection signals for environmental monitoring, offering a new approach that can be integrated into existing GPS infrastructure to detect widespread black ice in real-time.
        4,000원
        5.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Supplementing feed components is becoming increasingly difficult for various reasons, including increased shipping costs, decreased capture efficiency, and global warming. For this reason, much research has been conducted globally to find alternative protein sources. The black soldier fly (BSF; Hermetia illucens) is an important feed item for nutritional accumulation and has environmental consequences. Few studies have been conducted to determine the nutritional level of the substrate, but most of these studies have involved modifying the substrate material. The aim of this study was to determine the ideal crude protein(CP) content of a substrate for BSF rearing. The experimental treatment was separated into three CP levels (low, 13.5%; medium, 20%; high, 26.5%) in the substrate. The results showed that the BSF weight (6.46%) and protein conversion ratio (1.13%) increased as the substrate CP level increased (p<0.05). In addition, protein (14.38%) and lipid (13.12%) yields were significantly increased (p<0.05). The BSF CP level increased as the substrate CP level increased (p<0.05). CP levels in the substrate upregulated the levels of certain fatty acids, essential amino acids, and non-essential amino acids (p<0.05). In conclusion, the potential values of BSF as feed were improved as the CP level of the substrate increased; However, no difference was found between medium and high CP levels in the rearing substrate. These results suggested that the substrate CP level should be at the medium level for optimal product quality. In conclusion, BSF quality is influenced by substrate nutrient levels, necessitating the development of specialized substrates for effective rearing.
        4,000원
        6.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        For sustainable livestock industry, black soldier fly as eco-friendly animal protein source is spotlighted for swine and poultry. However, most of black soldier fly is reared in dirty condition like food waste. In this study, we investigated the effects of fiber level on the growth performance and nutrient composition of black soldier fly reared in specific substrate. Treatments were divided in two as Low (fiber level: 7.1%), and High (fiber level: 14.2%) with a total of 50,000 eggs each. The rearing box had a dimension with 1064 × 507 × 320 cm (length × width × height). Black soldier fly survival rate (72.24 vs. 76.48) and substrate consumption (77.43 vs. 80.37) were greater in High than Low. However, bioconversion (10.59 vs. 9.80) and protein conversion (8.97 vs. 8.00) were increased in Low than High. Gross energy was higher in High compared with Low (4,133 vs. 4,208). Some of essential amino acid (Isoleucine, leucine, phenylalanine, threonine, tryptophan) were significantly higher in High compared with Low, and non-essential amino acid (alanine, aspartate, glycine, proline, serine, tyrosine) were higher in High compared with Low. Acids such as C12:0, C14:0, C15:0, and C20:1 were higher in High compared with Low, while C18:4 was higher in Low compared with High. As a result, black soldier fly reared in high fiber substrate might be a preferred option for rearing and producing a reliable animal protein source for monogastric animal.
        4,000원
        8.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Black soldier fly (BSF, Hermetia illucens) has been noted as an excellent feed ingredient. However, there is limited information on rearing and processing technology. Thus, this study was conducted to evaluate the substrates for rearing BSF and the optimal processing method for BSF performance. Study separated as 2 experiment, BSF rearing and drying method(Exp 1.) and EP-processing method(exp 2.). During the study, 30 clutches were reared, with 10 per substrate. Three substrates, namely food waste (FW), tofu by-product (TF), and vegetable waste with two drying methods, namely hot air dry (AD) and microwave dry (MW) at expanding (EP) ratios of 5:5 and 7:3, were examined by evaluating their rearing performance, nutrient contents, in vitro digestibility and lipid oxidation stability during storage (0, 14 and 28 days). In experiment 1, the rearing substrates and drying methods were evaluated. Compared with that of conventional methods (FW, AD), the TF substrates and MW method showed higher dry matter contents (3.43%) and in vitro digestibility (1.62%) but lower ether extract contents(3.53%; p<0.05). However, the malondialdehyde (MDA) concentration under MW treatments decreased during storage (5.77%, 4.69% and 3.24%; p<0.05). In experiment 2, compared with that of the 7:3 EP-BSF ratio, the 5:5 EP-BSF ratio showed higher in vitro digestibility (2.70%) and lower MDA concentration during storage (19.19%, 7.96% and 6.42%; p<0.05). In conclusion, the optimal conditions for BSF rearing and ensuring product quality were TF substrates, MW methods and a 5:5 corn:BSF ratio. Therefore, the optimal conditions for producing EP-BSF can present an excellent feed ingredient alternative for swine feed.
        4,000원
        9.
        2024.03 구독 인증기관·개인회원 무료
        최근 국내 겨울철 블랙아이스(Black Ice)로 인해 발생하는 교통사고가 증가하는 추세이며, 한국 도로교통공단 조사 결 과 2016~2020년 겨울철까지 블랙아이스로 인한 사고는 총 4,868건이며, 사상자는 8,938명인 것으로 조사 되었다. 도로상 태에 따라 건조대비 동결상태에서 교통사고 발생시 치사율이 43%로 높게 나타났다. 이러한 사고는 기온이 떨어지는 12 월부터 급증하여, 최저기온이 가장낮은 1월까지 증가한다. 블랙아이스는 도로에 쌓인 눈이 융해(해설)과 동시에 도로 위 각종 이물질과 결합 후 재동결하여 흑색 동결막을 형성하는 것을 말한다. 그 특성상 운전자가 차량내부에서 도로의 상태 를 쉽게 파악할 수 없으며 대부분의 운전자가 차량이 미끄러지기 시작함과 동시에 인지하여 사고가 발생하게 된다. 이에 본 연구에서는 기존 포장체의 미끄럼 저항도를 상태별로 비교 분석하였다. 포장체의 미끄럼 저항성 정도를 파악하기 위 해 영국식 미끄럼저항 시험기 (British Pendulum Tester ; BPT)를 사용하였으며, 포장체의 종류로는 일반적인 밀입도 아스팔트 포장, 배수성 아스팔트 포장, 그루빙(포장 표면에 일정한 규격의 홈을 형성)을 적용한 콘크리트 포장, 그루빙이 없는 콘크리트 포장을 적용하였다. 미끄럼저항 실험은 관련 KS규격 및 ASTM규격에 준하여 실시하되 블랙아이스를 모 사하기위하여 표면온도 영하 2~3℃ 샘플에 강우를 모사한 물을 분사하며 영하 9℃로 10분 동결 후 2mm강수량을 모사 한 수분을 재 분사한 후 시험을 실시하였다.
        10.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문은 회분식 반응기에서 습식 산화법으로 합성한 칼륨 페레이트(VI)에 의한 난분해성 아조 염료Reactive Black 5의 분해 과정을 연구하는 것을 목적으로 한다. 수용액에서 RB5의 분해는 pH, Ferrate (VI) 투입량, 초기 농도, 수용액 온도 등 다양한 변수의 조건에서 연구되었다. RB5 경우에는 최대 분해 효율은 pH 7.0에서 63.2%가 달성되었으며, 이 실험 조건에서 얻은 kapp 값은 190.49 M-1s-1 으로 나타났다. 온도 또한 가장 중요한 매개 변수 중 하나로 연구되었으며, 그 결과로부터 온도(45°C까지)를 증가시키면 페레이트(VI)에 의한 아조 화합물 염료의 분해 효율이 증가하고, 온도가 45°C를 초과하면 분해 효율이 저하되는 것으로 나타났다.
        4,200원
        11.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Black chestnut (BC) was obtained through aging of fresh chestnut (FC) at 80℃ for 15 days. Proximate and mineral compositions along with colors of FC and BC were evaluated. With aging, moisture contents decreased by 50%, whereas sugar contents, carbohydrate contents, and calories increased. Contents of minerals (Fe, P, Ca, Na, Mg, K) were significantly higher in FC than in BC, showing an order of Mg < Ca < P < K in both FC and BC. Using a Hunter color system, it was found that lightness (L), redness (a), and yellowness (b) values of FC were higher than those of BC. Antioxidant and cytotoxic activities of hot water and ethanol (50, 80, 100%) extracts prepared from FC and BC were evaluated. Extraction yields were lower with FC than with BC. Among water and ethanol extracts, water extract showed the highest DPPH radical scavenging activity for both FC and BC. IC50 values for ABTS+ radical scavenging activities increased after aging. Cytotoxicities of FC and BC extracts were similar to each other. They were different against various cell lines (3T3, HeLa, and Sarcoma-180). These results suggest that BC could be used as a new processed food using chestnut.
        4,000원
        12.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Black phosphorus (BP) is incorporated in the electrochemical detection of uric acid (UA) to form few layers of BP nanosheets (BPNS)-modified glassy carbon electrodes (BPNS/GCE), investigated by means of ultrasound-assisted liquid-phase exfoliation. We find a significant increase in the peak current magnitude and positive potential shift in the electrochemical response of BPNS/GCE, which may be attributed to the larger specific surface area and good charge transfer ability of BPNS. Further, the electrochemical response of BPNS/GCE is evaluated under different conditions to achieve the optimal conditions. UA detection using differential pulse voltammetry (DPV) shows linear response within the range of 1–1000 μM with a detection limit of 0.33 μM. This work reveals new applications of BP nanomaterials in the electrochemical sensing, thereby promoting further advancement in terms of practical applications of two-dimensional nanomaterials.
        4,000원
        13.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study explores modern portfolio theory by integrating the Black-Litterman portfolio with time-series clustering, specificially emphasizing K-shape clustering methodology. K-shape clustering enables grouping time-series data effectively, enhancing the ability to plan and manage investments in stock markets when combined with the Black-Litterman portfolio. Based on the patterns of stock markets, the objective is to understand the relationship between past market data and planning future investment strategies through backtesting. Additionally, by examining diverse learning and investment periods, it is identified optimal strategies to boost portfolio returns while efficiently managing associated risks. For comparative analysis, traditional Markowitz portfolio is also assessed in conjunction with clustering techniques utilizing K-Means and K-Means with Dynamic Time Warping. It is suggested that the combination of K-shape and the Black-Litterman model significantly enhances portfolio optimization in the stock market, providing valuable insights for making stable portfolio investment decisions. The achieved sharpe ratio of 0.722 indicates a significantly higher performance when compared to other benchmarks, underlining the effectiveness of the K-shape and Black-Litterman integration in portfolio optimization.
        4,200원
        14.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The insecticidal activities of 27 different commercial products with environmentally friendly organic material (EFOM) against Scotinophara lurida, a major rice pest, were evaluated in the laboratory using spraying methods on plants and insects. Seven plant-derived organic farming materials (EFOM-8, -10, -12, -13, -19, -20, and -26) with high insecticidal effects when sprayed directly on the insect’s body rather than on the plant were selected. In the indoor rice pot test, all 7 EFOMs showed an insecticidal rate of over 73.3% under irrigated conditions. Notably, EFOM-13 and EFOM-20 demonstrated much higher insecticidal rates, ranging from 1.5 to 1.8 times, in irrigated conditions compared to drained conditions. In the semi-paddy field test, EFOM-10 (80% garlic extract), EFOM- 13 (62% neem extract), and EFOM-26 (70% sophora extract+28% ethyl alcohol+2% pyrethrum extract) exhibited a higher control value of 88.9% in the irrigated paddy on the 7th day, surpassing the control values in the drained paddy by 1.4 to 1.9 times. The control value in the irrigated rice paddy field sprayed with EFOM-10 reached 86.2% on the 7th day, which was 1.4 times higher than 61.9% in the drained paddy. Taken together, the findings suggest that direct contact of the insect’s body with sufficient amounts of spray solution and the maintenance of paddy irrigation can enhance the controlling effect of EFOMs. These findings will be valuable in developing an optimal S. luridacontrol strategy for application in rice paddy fields in the near future.
        4,000원
        15.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon black is a material in the form of fine black powder obtained by incomplete combustion or pyrolysis of hydrocarbons, and is composed of 90-99% carbon, and the rest is composed of hydrogen and oxygen. In the event of an emergency during the manufacture of carbon black, the generated tail gas should be safely discharged through an emergency line to prevent fire, explosion, and environmental pollution accidents caused by the tail gas. If the pressure continues to rise, the pressure control valve shall operate and the rupture plate shall be ruptured sequentially and the tail gas shall be discharged to the vent stack through the emergency line. As an emergency emission system, even if some untreated substances in the tail gas are released into the atmosphere, they are lighter than air, so it is safe to discharge them to a safe place through the Vent Stack. If the gas pressure is rising or worse, it is discharged from the Vent Stackine, and discharging fuel.
        4,000원
        19.
        2023.11 구독 인증기관·개인회원 무료
        Pt/C catalysts were prepared using black carbon (CB), and evaluated for their potential application as a catalyst of liquid-phase catalystic exchange for tritium treatment. CB was treated with 10% H2O2 solution for 0 and 2 hours at 105°C, Ethylene glycol and 40wt% Pt were added to the dried treated sample to prepare a Pt/C catalyst. The physical and chemical properties of the prepared catalysts were evaluated by BET, XRD, elemental analysis (EA), and TEM analyses. As a result of BET analysis, the surface area of CB without 10% H2O2 was 237.2 m2·g-1, and after treatment with 10% H2O2, it decreased to 181.2 m2·g-1 for 2 hours. However, the internal surface area increased, indicating the possibility that more Pt could be distributed inside the CB treated with 10% H2O2. In the XRD analysis results, the presence of Pt was confirmed by observing the Pt peak in the prepared Pt/C catalyst, and it was also observed through TEM analysis that Pt was evenly distributed within the CB. The elemental analysis (EA) results showed that the ratio of S and N decreased and the ratio of O increased with increasing 10% H2O2 treatment time. The H2O2 treated carbon supported Pt catalysts and polytetrafluoroethylene were then loaded together on a foamed nickel carrier to obtain hydrophobic catalysts. Our hydrophobic Pt catalyst using H2O2 treated black carbon are expected to be usefully used in the tritium treatment system.
        20.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this research, synergetic and separate influence of nano-carbon black (C.Bn) and SiC on the microstructure and flexural strength of ZrB2 were investigated. So, ZrB2 and ZrB2- 30vol%-based composites containing 10 and 15 vol% C.Bn as well as ZrB2- 15 vol% SiC were fabricated via spark plasma sintering at 1850 °C for soaking time of 8 min under the applied pressure of 35 MPa. Relative density was measured by Archimedes method. Microstructural evaluation was carried out by applying the field emission electron microscopy (FESEM), and flexural strength was measured by three-point bending test. It was found the relative density improves in the presence of C.Bn and SiC especially in synergetic state so that the full densification was gained in Z30Si10C.Bn and Z30Si15C.Bn composites through their reactions with impurities at 1850 °C. In the monolithic ZrB2 system, the C.Bn addition improves the flexural strength slightly to 300 MPa and 315 MPa from 290 MPa. However, co-doped 10 vol% C.Bn with 30 vol% SiC resulted to achieve maximum flexural strength of 486 MPa in comparison with individually applying each of them (395 MPa for Z30Si and 300 MPa for Z10 C.Bn).
        4,000원
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