• 제목/요약/키워드: Condensation Prevention

검색결과 47건 처리시간 0.024초

이층커튼 온풍난방 플라스틱온실의 겨울철 포차 및 결로량 변화 (Variation of Vapor Pressure Deficit and Condensation Flux of Air Heating Plastic Greenhouse Installed with Two Layers Thermal Curtain in Winter)

  • 이현우;김영식;심상연;이종원
    • 생물환경조절학회지
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    • 제22권1호
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    • pp.35-41
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    • 2013
  • 본 연구는 우리나라 온실 피복재의 결로 발생을 억제하는데 필요한 기초자료를 제공하기 위하여 토마토 재배용 실험온실의 포차변화 및 피복재에 발생하는 결로량의 변화를 분석하였으며 결과를 요약하면 다음과 같다. 실험온실의 경우 포차가 병 발생을 유발하기 쉬운 한계포차인 0.2kPa보다 더 크게 유지되어 온습도환경이 양호한 것으로 판단되었고 제습여부 결정을 위한 임계포차인 0.5kPa보다는 작게 나타나 제습은 필요한 것으로 판단되었다. 내부피복재의 표면온도는 외부온도와 커튼상부온도의 평균값 보다 약간 더 큰 것으로 나타났으며, 대체로 외부온도의 변화에 비례하여 변화하는 것으로 나타났다. 외부의 온도 및 습도 변화에 상관없이 커튼 상부의 습도는 거의 100%에 가까운 상대습도를 유지하여 결로 발생이 용이한 조건인 것으로 나타났다. 커튼하부의 습도는 내부습도의 큰 변화에도 불구하고 75~90% 정도로 안정된 값을 유지하였으며, 이는 온풍난방을 실시하여 온도를 $15^{\circ}C$로 유지하였기 때문으로 판단된다. 실험조건 및 피복재의 종류에 따라 결로 발생량은 많은 차이가 있는 것으로 알려져 있다. 실험온실의 결로 발생량은 Seginer와 Kantz(1986)의 연구결과와 가장 잘 일치하는 것으로 나타났으나 다른 온실실험 결과들과는 약간의 차이를 보여주고 있기 때문에 앞으로 실험을 통해서 더 자세한 검증을 거친다면 우리나라 온실 피복재에 발생하는 결로량을 분석하는데 유용하게 활용될 수 있을 것으로 기대된다.

외단열 벽체에서 창호 설치 위치에 따른 단열성능 및 냉난방 에너지 소비량 (Insulation Performance and Heating and Cooling Energy Consumption depending on the Window Reveal Depth in External Wall Insulation)

  • 이규남;정근주
    • 대한건축학회논문집:구조계
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    • 제33권12호
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    • pp.91-98
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    • 2017
  • In this study, the effect of window installation position in the residential building with the external insulation was numerically investigated in terms of insulation performance and heating/cooling energy consumption. For different window positions, 2-D heat transfer simulation was conducted to deduce the linear thermal transmittance, which was inputted to the dynamic energy simulation in order to analyze heating/cooling energy consumption. Simulation results showed that the linear thermal transmittance ranges from 0.05 W/mK to 0.7 W/mK, and is reduced as the window is installed near the external finish line. Indoor surface temperature and TDR analysis showed that the condensation risk is the lowest when the window is installed at the middle of the insulation and wall structure. It was also found that the window installation near the external finish can reduce the annual heating/cooling energy consumption by 12~16%, compared with the window installation near the interior finish. Although the window installation near the external finish can achieve the lowest heating/cooling energy consumption, it might lead to increased condensation risks unless additional insulation is applied. Thus, it can be concluded that the window should be installed near the insulation-wall structure junction, in consideration of the overall performance including energy consumption, condensation prevention and constructability.

Momordica cochinchinensis Aril Extract Induced Apoptosis in Human MCF-7 Breast Cancer Cells

  • Petchsak, Phuchong;Sripanidkulchai, Bungorn
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권13호
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    • pp.5507-5513
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    • 2015
  • Momordica cochinchinensis Spreng (MC) has been used in traditional medicine due to its high carotenoid content. The objective of this study was to investigate mechanisms underlying apoptotic effects of MC on human MCF-7 breast cancer cells. A lycopene-enriched aril extract of MC (AE) showed cytotoxicity and antiestrogenicity to MCF-7 cells. On DAPI staining, AE induced cell shrinkage and chromatin condensation were evident. With flow cytometric analysis, AE increased the percentage of cells in an early apoptosis stage when compared with the control group. RT-PCR analysis showed AE to significantly increase the expression of the proapoptotic bax gene without effect on expression of the anti-apoptotic bcl-2 gene. Moreover, AE enhanced caspase 6, 8 and 9 activity. Taken together, we conclude that AE of MC fruit has anticancer effects on human MCF-7 breast cancer cells by induction of cell apoptosis via both intrinsic and extrinsic pathways of signaling.

서중기 2중버블시트로 단열처리된 옹벽의 온도이력 특성 (Temperature History of the Concrete for Retaining Wall Insulated with Double Layered Bubble Sheet in Summer)

  • 정은봉;김경훈;장덕배;경영혁;한민철;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
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    • pp.45-46
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    • 2012
  • This study is intended to use the insulation effect of the dual bubble sheet to review the freezing prevention capability of underground walls by pouring the dual bubble sheet on the retaining walls before the concrete pouring to contemplate the temperature profile for each area of installation and the area of non-installation of the dual bubble sheet, and as a result, the temperature of the concrete was heightened than the ground due to the insulation effect in using the bubble sheet.

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온돌을 이용한 바닥복사냉방의 제어성능에 관한 실험적 연구 (An Experimental Study on Control Performance of Radiant Floor Cooling Using Ondol)

  • 김용이;임재한;한여명;김광우
    • 설비공학논문집
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    • 제13권11호
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    • pp.1165-1173
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    • 2001
  • The objectives of this study are to analyze the application of radiant floor cooling and to evaluate the control methods through experiments when the radiant heating system is used for cooling. Through the experiment analysis the control methods such as on/off control, variable flow control and outdoor reset with indoor temperature feedback control are evaluated and compared. The cooling curve (reset ratio) is found for radiant cooling, which shows tole relation between outside air temperature and supply water temperature. Comparison of cooling methods shows that outdoor reset with indoor temperature feedback control is more appropriate than on/off control and variable flow control with regard to prevention of the condensation and thermal comfort.

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화재 예방을 위한 태양광 접속반의 지능형 진단 시스템 (Intelligent Diagnostic System of Photovoltaic Connection Module for Fire Prevention)

  • 안재현;양오
    • 반도체디스플레이기술학회지
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    • 제20권3호
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    • pp.161-166
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    • 2021
  • To prevent accidents caused by changes in the surrounding environment or other factors, various protection facilities are installed at the photovoltaic connection module. The main causes of fire are sparks due to foreign substances inside the photovoltaic connection module through high temperature rise and dew condensation in the photovoltaic connection module, and fire due to heat from the power diode. The proposed method can predict the fire by measuring flame, carbon dioxide, carbon monoxide, temperature, humidity, input voltage, and current on the photovoltaic connection module, and when the fire conditions are reached, fire alarm and power off can be sent to managers and users in real time to prevent fire in advance.

석조문화재 보호각 현황과 사례연구 (The present situation of shelter and case study of stone cultural heritage)

  • 신은정;김사덕;엄두성
    • 보존과학연구
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    • 통권31호
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    • pp.103-120
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    • 2010
  • Most of the important stone cultural heritage (National treasures and Treasures) in Korea are mainly located outdoor and considerably affected by the changes of the temperature, humidity and rainfalls. 541 of the stone cultural heritage are preserved as National treasure and Treasure. The pagodas occupy 187 remains and next 127 Buddha statues, 68 monuments, 60 stupas, and the others 74 stone cultural heritages. The shelter has been installed for one pagoda, 60 Buddha statues, 36 monuments and two stupas. The shelters are categorized in three shapes as traditional shape, modern shape, and others (tradition+modern). Approximately 100 of shelters that have constructed in traditional ways, and about nine of shelters have modern ways, and the only one has the combination shape of tradition and modern, which has been constructed since mid 1900s and repaired from the 1980s~2000s. Many researchers are studying for improvement of manners such as repairing, remodeling or removing of the shelter because problems have occured on shelters. Architectural form of traditional style of Korean timber building is respected, but it has problems on importing natural sunlight to the inside as well as ventilation and spacial problems. However, it needs to supplement policies to improve the positive roles of shelters such as prevention of artificial damage, blocking acid rain, and so on. For instance, the rock-carved Buddha Triad in Seosan, it had problems with viewing, contamination, and dew condensation on the surface. These problems decreased after dismantling the shelter, the space was made for improvement of viewing and dew condensation, and moisture problems were in better conditions. The velocity wind is an important factor in drying conditions on the surface of the rock, therefore the condition has improved after dismantling the shelter.

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Neuroprotective effects of hesperetin on H2O2-induced damage in neuroblastoma SH-SY5Y cells

  • Ha-Rin Moon;Jung-Mi Yun
    • Nutrition Research and Practice
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    • 제17권5호
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    • pp.899-916
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    • 2023
  • BACKGROUND/OBJECTIVES: Oxidative stress is a fundamental neurodegenerative disease trigger that damages and decimates nerve cells. Neurodegenerative diseases are chronic central nervous system disorders that progress and result from neuronal degradation and loss. Recent studies have extensively focused on neurodegenerative disease treatment and prevention using dietary compounds. Heseperetin is an aglycone hesperidin form with various physiological activities, such as anti-inflammation, antioxidant, and antitumor. However, few studies have considered hesperetin's neuroprotective effects and mechanisms; thus, our study investigated this in hydrogen peroxide (H2O2)-treated SH-SY5Y cells. MATERIALS/METHODS: SH-SY5Y cells were treated with H2O2 (400 µM) in hesperetin absence or presence (10-40 µM) for 24 h. Three-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays detected cell viability, and 4',6-diamidino-2-phenylindole staining allowed us to observe nuclear morphology changes such as chromatin condensation and apoptotic nuclei. Reactive oxygen species (ROS) detection assays measured intracellular ROS production; Griess reaction assays assessed nitric oxide (NO) production. Western blotting and quantitative polymerase chain reactions quantified corresponding mRNA and proteins. RESULTS: Subsequent experiments utilized various non-toxic hesperetin concentrations, establishing that hesperetin notably decreased intracellular ROS and NO production in H2O2-treated SH-SY5Y cells (P < 0.05). Furthermore, hesperetin inhibited H2O2-induced inflammation-related gene expression, including interluekin-6, tumor necrosis factor-α, and nuclear factor kappa B (NF-κB) p65 activation. In addition, hesperetin inhibited NF-κB translocation into H2O2-treated SH-SY5Y cell nuclei and suppressed mitogen-activated protein kinase protein expression, an essential apoptotic cell death regulator. Various apoptosis hallmarks, including shrinkage and nuclear condensation in H2O2-treated cells, were suppressed dose-dependently. Additionally, hesperetin treatment down-regulated Bax/Bcl-2 expression ratios and activated AMP-activated protein kinase-mammalian target of rapamycin autophagy pathways. CONCLUSION: These results substantiate that hesperetin activates autophagy and inhibits apoptosis and inflammation. Hesperetin is a potentially potent dietary agent that reduces neurodegenerative disease onset, progression, and prevention.

Mechanism of Action of Nigella sativa on Human Colon Cancer Cells: the Suppression of AP-1 and NF-κB Transcription Factors and the Induction of Cytoprotective Genes

  • Elkady, Ayman I;Hussein, Rania A;El-Assouli, Sufian M
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권17호
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    • pp.7943-7957
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    • 2015
  • Background and Aims: Colorectal cancer is one of the leading causes of death in the world. The aim of this study was to investigate the growth-suppression potentiality of a crude saponin extract (CSENS) prepared from medicinal herb, Nigella sativa, on human colon cancer cells, HCT116. Materials and Methods: HCT116 cells were subjected to increasing doses of CSENS for 24, 48 and 72 h, and then harvested and assayed for cell viability by WST-1. Flow cytometry analyses, cell death detection ELISA, fluorescent stains (Hoechst 33342 and acridine orange/ethidium bromide), DNA laddering and comet assays were carried out to confirm the apoptogenic effects of CSENS. Luciferase reporter gene assays, quantitative reverse transcription-polymerase chain reaction and Western blot analyses were performed to assess the impact of CAERS and CFEZO on the expression levels of key regulatory proteins in HCT116 cells. Results: The results demonstrated that CSENS inhibited proliferation and induced apoptosis. Apoptosis was confirmed by flow cytometry analyses, while CSENS-treated cells exhibited morphological hallmarks of apoptosis including cell shrinkage, irregularity in cellular shape, cellular detachment and chromatin condensation. Biochemical signs of apoptosis, such as DNA degradation, were observed by comet assay and gel electrophoresis. The pro-apoptotic effect of CSENS was caspase-3-independent and associated with increase of the Bax/Bcl-2 ratio. CSENS treatment down-regulated transcriptional and DNA-binding activities of NF-${\kappa}B$ and AP-1 proteins, associated with down-regulation of their target oncogenes, c-Myc, cyclin D1 and survivin. On the other hand, CSENS up-regulated transcriptional and DNA-binding activities of Nrf2 and expression of cytoprotective genes. In addition, CSENS modulated the expression levels of ERK1/2 MAPK, p53 and p21. Conclusions: These findings suggest that CSENS may be a valuable agent for treatment of colon cancer.