• 제목/요약/키워드: Smart concentrations

검색결과 64건 처리시간 0.028초

반순환여과양식시스템에서 오존 유래 잔류산화물이 넙치(Paralichthys olivaceus) 사육수의 수질과 미생물에 미치는 영향 (Ozone-produced Oxidants Improve Water Quality Parameters and Microbial Colony Counts in the Semi-Recirculating Aquaculture System for Olive Flounder Paralichthys olivaceus)

  • 정상명;박우근;박성덕;박정환;김재원;김병기
    • 한국수산과학회지
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    • 제54권5호
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    • pp.751-760
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    • 2021
  • This study investigated the changes in water quality parameters and microbial colonies when ozone was applied to a semi-recirculating aquaculture system (semi-RAS) for the olive flounder Paralichthys olivaceus (500 g in average weight). Concentrations of ozone-produced oxidants (OPO) in rearing tanks were maintained at 0, 0.014, 0.025 mg/L as Cl2 for 26 days. Except total ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, phosphate phosphorus, chemical oxygen demand, and total suspended solids decreased significantly with increasing OPO concentration in daily and weekly monitoring (P<0.05). Colony forming unit (CFU) counts of heterotrophic marine bacteria decreased in an OPO concentration-dependent manner. Overall reduction rates of microbial colonies in the treatments were 80% higher than those of the control (P<0.05). During the experiment, the OPO concentration-driven ozonation was reliably practiced without any adverse effects on the animals cultured in semi-RAS. Considering the biohazard, operating cost, and stability of ozonation, an OPO concentration of 0.014 mg/L would be sufficient to control water quality parameters and microbial colonies in a semi-RAS.

스마트버스정류장 유형에 따른 미세먼지 농도 저감효과 (Types of Smart Bus Stop and Their Impacts on Reducing Fine Dust Concentrations in Seoul)

  • 서정기;김형규
    • 토지주택연구
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    • 제12권3호
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    • pp.39-50
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    • 2021
  • 본 연구는 미세먼지 농도 저감을 위해 스마트버스정류장 도입 유형에 대한 가이드라인을 제안하고자 한다. 이를 위해 스마트버스정류장 유형을 밀폐형 및 개방형으로 구분하고, 서울 강남구에 위치한 스마트버스정류장 내부와 외부 5개 지점에서 PM10 및 PM2.5를 5일간 실측하여 저감효과를 비교·분석하였다. 분석 결과 외부공간에 대한 저감효과는 두 유형에서 모두에서 미비하게 나타났으나, 밀폐형 버스정류장(PM10 26.0㎍/m3, PM2.5 20.2㎍/m3 내·외부 농도차이) 내에서 개방형 버스정류장(PM10 2.4㎍/m3, PM2.5 1.8㎍/m3 내·외부 농도차이) 내에서보다 상대적으로 우수한 농도 저감효과를 나타내었다. 이를 바탕으로 미세먼지 저감을 고려한 스마트버스정류장 도입을 검토할 경우 밀폐형을 권장한다. 또한 스마트버스정류장 외부의 미세먼지 저감효과가 미비하기 때문에 스마트버스정류장 내부 용량을 초과하는 서비스 수요 발생 시 스마트버스정류장 추가 구축이 필요하다.

Luteolin and Chicoric Acid, Two Major Constituents of Dandelion Leaf, Inhibit Nitric Oxide and Lipid Peroxide Formation in Lipopolysaccharide-Stimulated RAW 264.7 Cells

  • Park, Chung-Mu;Park, Ji-Young;Song, Young-Sun
    • Preventive Nutrition and Food Science
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    • 제15권2호
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    • pp.92-97
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    • 2010
  • Luteolin and chicoric acid are the most abundant phytochemicals in dandelion (Taraxacum officinale) leaf. In this study, four kinds of extraction methods [hot water, ambient temperature (AT) water, ethanol, and methanol] were applied to analyze the contents of both phytochemicals and verify their anti-inflammatory and antioxidative activities. The methanol extract showed the most potent nitric oxide (NO) inhibitory effect. The luteolin and chicoric acid concentrations were 3.42 and $12.86\;{\mu}g/g$ dandelion leaf in the methanol extract. The NO-suppressive effect of luteolin and chicoric acid was identified in a dose-dependent manner with $IC_{50}$ values of $21.2\;{\mu}M$ and $283.6\;{\mu}M$, respectively, in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells without cytotoxicity. Malondialdehyde (MDA) concentration, as an index for free radical injury on cell membrane, was also dose-dependently inhibited by the two compounds. The suppressive effect was further examined using mRNA and protein expression levels, which were attributable to the inhibition of inducible nitric oxide synthase (iNOS). These results suggest that two phytochemicals in dandelion leaf, luteolin and chicoric acid, may play an important role in the amelioration of LPS-induced oxidative stress and inflammation.

직접 수소화붕소나트륨/과산화수소 연료전지의 산화극 연료 조성에 관한 연구 (A Study on Anode Fuel Composition of Direct Borohydride/Hydrogen Peroxide Fuel Cell)

  • 이태훈;유수상;오택현
    • 한국수소및신에너지학회논문집
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    • 제32권6호
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    • pp.514-523
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    • 2021
  • This study investigated the effect of anode fuel composition on the performance of direct borohydride/hydrogen peroxide fuel cells (DBHPFCs). The effect of sodium borohydride (NaBH4) and sodium hydroxide (NaOH) concentrations on fuel cell performance was determined through fuel cell tests. Fuel cell performance increased with an increase in the NaBH4 concentration, whereas it decreased with an increase in the NaOH concentration. The anode fuel composition was selected as 10 wt% NaBH4+10 wt% NaOH+80 wt% H2O based on the fuel viscosity, electrochemical reaction rate, and decomposition reaction rate. DBHPFCs were also tested to analyze the effect of operating temperature and operation time on fuel cell performance. The present results can be used as a reference basis to determine operating conditions of DBHPFCs.

순환여과양식시스템에서 광주기 및 어체 크기가 대서양연어(Salmo salar)의 Off-season Smolt 생산에 미치는 영향 (Effects of Photoperiods and Body Size on the Off-season Smolt Production of Atlantic Salmon Salmo salar in a Recirculating Aquaculture System)

  • 김유희;김병기
    • 한국수산과학회지
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    • 제55권6호
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    • pp.894-902
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    • 2022
  • This study investigated the effects of photoperiod (NL 12L:12D and LL 24L:0D) and body sizes (30 g and 50 g) on parr-smolt transformation, post-smolt growth and blood properties in the off-season parr-smolt stage of Atlantic salmon reared in a recirculating aquaculture system (RAS). Potential off-season salmon smolt were reared in a freshwater RAS for 80 days and then all experimental fish were transferred to seawater. In both LL groups (LL-30 and LL-50), we recorded and increase in specific growth rate and reduction in feed conversion, although there were no significant difference in body size. The values of osmolality, and serum Na+, Cl- and cortisol concentrations in the LL groups were maintained at lower levels than in NL group fish, and LL group fish were observed to recover to the pre-seawater adaptation state more rapidly than those in the NL group. ID chips were inserted in all smolts reared in freshwater. These fish were subsequently transferred to full-strength seawater and thereafter individual growth rates were monitored for 120 days. The results indicated that compared with smolt reared under natural photoperiodic condition, 24 h lighting in freshwater contributed to enhancing post-smolt specific growth rate in seawater.

철근 콘크리트의 Zwitterion 및 인산염 기반 하이브리드 부식 억제제: 염화물 임계값 및 사용 수명 결정 (Hybrid Corrosion Inhibitor-Based Zwitterions and Phosphate in Reinforced Concrete: Determining Chloride Threshold and Service Life)

  • 트란 득 탄;정민구;이한승;양현민;싱 지텐드라 쿠마
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
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    • pp.33-34
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    • 2023
  • Corrosion of reinforcement steel is a major cause of deterioration in reinforced concrete (RC) structures. In order to protect these structures from corrosion, corrosion inhibitors are added to the concrete mix. In recent years, zwitterionic compounds have shown promising results as corrosion inhibitors in concrete due to their ability to form a protective layer on the surface of the reinforcement steel. The experimental study involves preparing concrete samples with different concentrations of adding the hybrid corrosion inhibitor at a high concentration of chloride ions. This study aims to determine the chloride threshold value and service life of hybrid corrosion inhibitors in reinforced concrete based on zwitterions. The samples are subjected to accelerated corrosion tests in a chloride environment to determine the threshold value and service life of the corrosion inhibitor. The effect of hybrid inhibitor on mechanical properties is guaranteed in allowable range. The chloride threshold concentration and service life of hybrid inhibitor containing samples perform greater than those of plain RC.

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Study on Fire Simulation in College Dormitories Based on Pyrosim

  • Zechen Zhang;Hasung Kong
    • International journal of advanced smart convergence
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    • 제13권3호
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    • pp.321-327
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    • 2024
  • In recent years, the frequency of fires in college dormitories has been increasing, primarily due to outdated electrical wiring and improper use of electrical appliances. Given the high population density in such buildings, fires can cause significant damage to life and property. To better understand the dynamics of dormitory fires, this study uses Pyrosim fire simulation software to model fire scenarios in a six-story male dormitory. The study focuses on analyzing key factors such as heat release rates, smoke spread, temperature changes, and carbon monoxide concentrations during a fire. Simulation results indicate that smoke spreads rapidly after a fire breaks out, significantly reducing visibility and hindering evacuation efforts. Simultaneously, temperatures near the fire source rise quickly, exceeding safe levels, and carbon monoxide concentrations reach dangerous thresholds in a short time, greatly increasing the risk of poisoning. Based on these findings, the study proposes several recommendations to improve fire prevention in dormitories, including installing smoke barriers, improving evacuation routes, adding mechanical smoke extraction systems, and enhancing students' fire safety awareness and skills through regular training. These measures are crucial for reducing fire risks and enhancing fire safety in college dormitories.

$\beta$-Glucan Suppresses LPS-stimulated NO Production Through the Down-regulation of iNOS Expression and $NF{\kappa}B$ Transactivation in RAW 264.7 Macrophages

  • Yang, Jeong-Lye;Jang, Ji-Hyun;Radhakrishnan, Vinodhkumar;Kim, Yang-Ha;Song, Young-Sun
    • Food Science and Biotechnology
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    • 제17권1호
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    • pp.106-113
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    • 2008
  • The antioxidant and anti-inflammatory protective effects of $\beta$-glucan from barley on RAW 264.7 murine macrophage cells induced by lipopolysaccharide (LPS) were examined. The RAW 264.7 murine macrophages were preincubated with various concentrations ($0-200\;{\mu}g/mL$) of $\beta$-glucan and stimulated with LPS to induce oxidative stress and inflammation. The $\beta$-glucan treatments were found to reduce thiobarbituric acid-reactive substance (TBARS) accumulation, and enhance glutathione levels and the activities of antioxidative enzymes, including superoxide dismutase (SOD), catalase, glutathione reductase, and glutathione peroxidase (GSH-px) in the LPS-stimulated macrophages as compared to the LPS-only treated cells. Nitric oxide (NO) production was significantly suppressed in a dose-dependent manner (p<0.05) with an $IC_{50}$ of $104\;{\mu}g/mL$. Further treatment with $\beta$-glucan at $200\;{\mu}g/mL$ suppressed NO production to 2% of the LPS-control, and suppressed the levels of inducible nitric oxide synthase (iNOS) protein and mRNA in a dose-dependent manner. The specific DNA binding activity of nuclear factor ${\kappa}B\;(NF{\kappa}B)$ was significantly suppressed by $\beta$-glucan treatment with an $IC_{50}$ of $220\;{\mu}g/mL$ in a dose-dependent manner. Finally, barley $\beta$-glucan ameliorates NO production and iNOS expression through the down-regulation of $NF{\kappa}B$ activity, which may be mediated by attenuated oxidative stress in RAW 264.7 macrophages.

스마트팜과 노지에서 재배한 병풀의 생약학적 비교 (Comparison of Bioactivities from Centella asiatica Cultivated in Smart Farm and Field)

  • 박진홍;이다희;조성민;최정환;김남준;김민수;박영민;이기만
    • 생약학회지
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    • 제53권4호
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    • pp.192-201
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    • 2022
  • This study aimed to compare bioactivities of Centella asiatica (CA) cultivated in smart farms and fields. Component analysis, cell viability, anti-inflammatory activity, neuroprotection activity, and antioxidant activity were examined with 70% ethanol extracts of CA cultivated in smart farm (SEE) and field (FEE), respectively. Asiaticoside was analyzed by high performance liquid chromatography (HPLC) and as a result, SEE had more asiaticoside content than FEE. After treatment of RAW 264.7 cells with SEE and FEE, there was no cytotoxicity within the treated concentrations. SEE and FEE showed nitric oxide (NO), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 inhibitory activities in a dose-dependent manner in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Moreover, SEE inhibited more NO, TNF-α, and IL-6 production levels than FEE. SEE and FEE reversed the H2O2-induced SH-SY5Y cell death. Especially, SEE was more effective in changing the H2O2-induced SH-SY5Y cell death than FEE. The antioxidant activity was confirmed by various methods such as total phenol content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and superoxide dismutase (SOD). As a result, SEE showed the most potent antioxidant activities about TPC, DPPH, and SOD methods. This study suggested that SEE has higher bioactivities such as effect of anti-inflammation, neuroprotection, and antioxidation than FEE.

황색 포도상구균과 대장균에 대한 은나노 입자의 항균활성 (Antibacterial Activity of Silver-nanoparticles Against Staphylococcus aureus and Escherichia coli)

  • 김수환;이형선;류덕선;최수재;이동석
    • 한국미생물·생명공학회지
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    • 제39권1호
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    • pp.77-85
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    • 2011
  • 본 연구는 은나노 입자의 항균활성을 알아보기 위하여, 그람 양성세균인 황색포도상구균과 그람 음성세균인 대장균에 대한 은나노 입자(Ag-NPs)를 처리 후, 세균세포 생장곡선측정, 활성산소생성능 측정, 세포질 단백질 누출량 측정, 젖산탈수소효소 활성측정 및 고분해능 임계방사 주사전자현미경 관찰이 수행되었다. 세균세포의 생장곡선 측정은 다양한 농도, 배양시간, 배양온도 및 pH에서 수행되었다. 결과적으로 황색 포도상구균과 대장균은 배양온도와 pH에 영향을 받지않고 은나노 입자에 의해 효과적으로 생장억제가 이루어지는 것을 관찰할 수 있었다. 또한 활성산소의 생성에 의하여 세포막의 파괴로 세포질내 물질의 유출을 세포질 유래 단백질 측정으로 확인할 수 있었으며, 젖산탈수소효소 활성측정을 통하여 은나노 입자에 대한 세포호흡억제활성 또한 확인할 수 있었다. 임계방사 주사전자현미경 관찰결과 은나노 입자에 의한 세균 세포표면의 형태학적 변화 또한 관찰되었다. 이러한 결과를 통하여 은나노 입자를 효과적인 항균활성소재로 활용 가능함이 입증되었다.