• Title/Summary/Keyword: High humidity

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Characterization of odourous compounds in air, leachate, stream and well in and around Taju-Bello Dumpsite, Lagos, Nigeria

  • Azeez, L.;Oyedeji, O.A.;Abdulsalami, I.O.;Adewuyi, S.O.
    • Advances in environmental research
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    • v.2 no.2
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    • pp.143-153
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    • 2013
  • This study investigated the concentrations of odourous compounds in air, leachate, stream and well in and around Taju-Bello dumpsite. Meteorological parameters (temperature, relative humidity, wind velocity) and six odour families comprising sulphur ($H_2S$), ammonia ($NH_3$), aromatic (benzene, toluene, ethylbenzene, styrene, p-xylene, m-xylene), aliphatic (hexane), oxygenated (formaldehyde, acetaldehyde) and halogenated (tetrachloroethene, trichloroethene, carbontetrachloride) compounds were measured. Meteorological parameters suggested low dispersal of pollutants at L1 with possible perspiration and suffocation from exposure to high temperature, relative humidity and low wind velocity. The trend of abundance of odourous compounds at studied locations is of the order dumpsite (L1) > leachate (L4) > 100 m away from dumpsite (L2) > 200 m away from dumpsite (L3) > stream (L5) > well (L6). $H_2S$, Oxygenated and aromatic compounds were the major contributors to odour strength in these locations. Correlation, factor and cluster analyses of the data revealed similarities of sources as biogenics and xenobiotics inherent in the wastes as the main sources of these odourous compounds.

Electrochemical Study on PVDF-HFP/Silylated Al2O3-coated PE Separators using the Electron Beam Irradiation for Lithium Secondary Battery (전자선을 이용한 PVDF-HFP/Silylated Al2O3가 코팅된 리튬 이차 전지용 폴리에틸렌 분리막의 전기화학적 특성 연구)

  • Sohn, Joon-Yong;Shin, Junhwa;Nho, Young-Chang
    • Journal of Radiation Industry
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    • v.4 no.4
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    • pp.359-364
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    • 2010
  • PVDF-HFP (binder)/silylated alumina (inorganic particle)-coated PE (polyethylene) separators were with various compositions of binder and inorganic particle were prepared by a dip-coating process with humidity control (R.H. 25% and 50%) using electron beam irradiation. The morphology of the coated PVDF-$HFP/Al_2O_3$ layer with various compositions of PVDF-HFP and $Al_2O_3$, and humidity condition was found to be an important factor in determining ionic conductivity of the prepared separators. The PVDF-$HFP/Al_2O_3$ (5/5)-coated PE separator prepared at R.H. 50% followed by electron beam irradiation at 200 kGy was applied for lithium-ion polymer battery and the cell test results showed improved high-rate discharge performance and better cyclic stability compared to the cells with the bare PE and the PVDF-HFP-coated PE separators.

Comparison Analysis of Machine Learning for Concrete Crack Depths Prediction Using Thermal Image and Environmental Parameters (열화상 이미지와 환경변수를 이용한 콘크리트 균열 깊이 예측 머신 러닝 분석)

  • Kim, Jihyung;Jang, Arum;Park, Min Jae;Ju, Young K.
    • Journal of Korean Association for Spatial Structures
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    • v.21 no.2
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    • pp.99-110
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    • 2021
  • This study presents the estimation of crack depth by analyzing temperatures extracted from thermal images and environmental parameters such as air temperature, air humidity, illumination. The statistics of all acquired features and the correlation coefficient among thermal images and environmental parameters are presented. The concrete crack depths were predicted by four different machine learning models: Multi-Layer Perceptron (MLP), Random Forest (RF), Gradient Boosting (GB), and AdaBoost (AB). The machine learning algorithms are validated by the coefficient of determination, accuracy, and Mean Absolute Percentage Error (MAPE). The AB model had a great performance among the four models due to the non-linearity of features and weak learner aggregation with weights on misclassified data. The maximum depth 11 of the base estimator in the AB model is efficient with high performance with 97.6% of accuracy and 0.07% of MAPE. Feature importances, permutation importance, and partial dependence are analyzed in the AB model. The results show that the marginal effect of air humidity, crack depth, and crack temperature in order is higher than that of the others.

Analysis and Monitoring of Environmental Parameters in a Single-span Greenhouse during Strawberry Cultivation

  • Park, Minjung;Kang, Taegyeong;Yun, Sung-wook;Lim, Ryugap;Son, Jinkwan;Kang, Donghyeon
    • Journal of Environmental Science International
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    • v.30 no.11
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    • pp.907-914
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    • 2021
  • In this study, strawberry cultivation environment in a greenhouse located in Jeonju was monitored and internal environmental parameters were analyzed. Temperature, humidity, RAD, and PPF sensors were installed to monitor environmental conditions in the test greenhouse. Data were collected every 10 minutes during four winter months from sensors placed across the greenhouse to assess its permeability and environmental uniformity. Temperature and humidity inside the greenhouse were relatively uniform with negligible deviations among the center, south, and north; however, it was judged that further analysis of gradients of these parameters from the east to the west of the greenhouse would be needed. Both RAD (Total solar radiation) and PPF (Photosynthetic photon flux) had high values on the south and were low on the north and the reduction rate of these parameters was 54% and 61%, respectively, indicating that a significant amount of light could not be transmitted. This implied a significant decrease in the amount of light entering the greenhouse during winter. Therefore, it is concluded that environmental control devices and auxiliary lighting are needed to achieve uniform greenhouse environment for efficient strawberry cultivation.

Effect of Solid-State Fermented Brown Rice Extracts on 3T3-L1 Adipocyte Differentiation

  • Su Bin Ji;Chae Hun Ra
    • Journal of Microbiology and Biotechnology
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    • v.33 no.7
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    • pp.926-933
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    • 2023
  • Aspergillus oryzae KCCM 11372 was used to enhance the production of β-glucan using humidity control strategies. Under conditions of 60% humidity, solid-state fermentation (SSF) increased the yields of enzymes (amylase and protease), fungal biomass (ergosterol), and β-glucan. The maximum concentrations obtained were 14800.58 U/g at 72 h, 1068.14 U/g at 120 h, 1.42 mg/g at 72 h, and 12.0% (w/w) at 72 h, respectively. Moreover, the β-glucan containing fermented brown rice (β-glucan-FBR) extracts at concentrations of 25-300 ㎍/ml was considered noncytotoxic to 3T3-L1 preadipocytes. We then studied the inhibitory effects of the extracts on fat droplet formation in 3T3-L1 cells. As a result, 300 ㎍/ml of β-glucan-FBR extracts showed a high inhibition of 38.88% in lipid accumulation. Further, these extracts inhibited adipogenesis in the 3T3-L1 adipocytes by decreasing the expression of C/EBPα, PPARγ, aP2, and GLUT4 genes.

Analysis of Water Balance in Closed Transplants Production System (폐쇄형 묘생산 시스템의 수분 수지 분석)

  • Kim, J.K.;Kim, Y.H.;Choi, Y.H.;Lee, M.G.
    • Journal of Bio-Environment Control
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    • v.12 no.3
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    • pp.152-159
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    • 2003
  • This study was conducted to analyze the water consumption in closed transplants production system (CTPS) for the production of quality transplants and to investigate the effect of relative humidity on the water balance in CTPS. Potato (Solanum tuberosum L. cv. Dejima) plug seedlings were grown for 15 days at air temperature of 20$^{\circ}C$, relative humidity of 70%, photoperiod of 16/8 h, and photosynthetic photon flux (PPF) of 200 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-l}$ following rooting for 5 days in CTPS. Amount of humidified, dehumidified, irrigated and evapotranspirated water were 67.9 kg${\cdot}m^{-2},\;196.9{\cdot}m^{-2},\;44.3\;kg{\cdot}m^{-2},\;33.5\;kg{\cdot}m^{-2}$, respectively. Water content of media and plants were 1.2 kg${\cdot}m^{-2},\;6.9\;kg{\cdot}m^{-2}$, respectively. Three relative humidity levels of 60, 70, and 80% were provided to analyze the effect of humidity on the water balance in CTPS. Amount of humidified, dehumidified, irrigated, evapotranspiratad water and water contents of media and plants increased with increasing relative humidity. Since the water consumption required to produce plug seedlings in CTPS dec1eased with decreasing relative humidity, the available water utilization efficiency of CTPS increased with decreasing relative humidity. CTPS showed high available water utilization efficiency of 0.92 - 0.97 if dehumidified water in CTPS was recycled. The development of CTPS with recycling system of dehumidified water will not only reduce the water consuming for the production of transplants but contribute to the establishment of plant production economizing in water consumption.

The effect of air quality and humidity on aged characteristics of beeswax-treated paper during artificial aging (인공열화 시 공기질 및 습도가 밀랍지의 열화에 미치는 영향)

  • Yang, Eun Jeong;Choi, Kyoung Hwa;Kang, Yeong Seok;Cho, Jung hye;Jeong, Hye Young
    • 보존과학연구
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    • s.33
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    • pp.45-55
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    • 2012
  • A beeswax-treated paper has no air permeability but has the water repellency compared with a general Hanji. Because of these properties, the differences of the aging factors and mechanisms between the outer partition of beeswax-treated paper that is affected by the surrounding conservation environment and the inner partition of it that is not affected are bigger than general books. In this research, we analyzed and compared the aging characteristics through the accelerated aging of the beeswax-treated paper by some air and humidity conditions. The results of the physical and optical analysis after the artificial aging, it was shown that the oxygen accelerates the aging of the beeswax-treated paper and the condition with the humidity 50% RH is more stable than the condition with the humidity 0% RH. The results of the CG/MS analysis that was conducted to figure out the decomposition charateristics of the beeswax according to the air quality and the humidity, a low molecular weight compound that the number of carbon is C9-C20 including a fatty acid such as a palmitic acid was increased as the aging was progressed. However, under the same environment, a compound that the number of carbon is C21-C36 including a hydrocarbon and a aliphatic alcohol and a high molecular weight compound that the number of carbon is more than C34 including a wax ester were decreased. A rate of change according to the air quality and the humidity was similar to the beeswax-treated papers.

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A Study on the Characteristic of Variable High Voltage Power Source for Laser Printer (Laser 프린터용 고압 가변 전원특성에 관한 연구)

  • Chae Y.m;Cho J.h.;Kwon J.g.
    • Proceedings of the KIPE Conference
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    • 2003.07a
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    • pp.110-114
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    • 2003
  • In this paper, a new self-oscillated type high voltage charger controller circuit is proposed, which has variable constant current source characteristics to improve charge characteristic of charger roller. The proposed control method enables high quality printing characteristics regardless of the circumstance change such as ambient temperature or humidity by changing the current reference signal. To verify the proposed control method various experiments are performed.

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Water Absorption and Charge Formation in PCB (PCB 절연체에서 전하 형성과 수분 흡수)

  • Lee, Jung-Soo;Hwang, Jong-Sun
    • Proceedings of the KIEE Conference
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    • 2008.09a
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    • pp.233-234
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    • 2008
  • We observed internal space charge behavior for two types of epoxy composites under dc electric fields to investigate the influence of water at high temperature. In the case of glass/epoxy specimen, homocharge is observed at water-treated specimen, and spatial oscillations become clearer in the water-treated specimens. Electric field in the vicinity of the electrodes shows the injection of homocharge. In aramid/epoxy specimens, heterocharge is observed at water-treated specimens, i.e. negative charge accumulates near the anode, while positive charge accumulates near the cathode. Electric field is enhanced just before each electrode. In order to further examine the mechanism of space charge formation, we have developed a new system that allows in situ space charge observation during ion migration tests at high temperature and high humidity. Using this in situ system.

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An apt material model for drying shrinkage and specific creep of HPC using artificial neural network

  • Gedam, Banti A.;Bhandari, N.M.;Upadhyay, Akhil
    • Structural Engineering and Mechanics
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    • v.52 no.1
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    • pp.97-113
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    • 2014
  • In the present work appropriate concrete material models have been proposed to predict drying shrinkage and specific creep of High-performance concrete (HPC) using Artificial Neural Network (ANN). The ANN models are trained, tested and validated using 106 different experimental measured set of data collected from different literatures. The developed models consist of 12 input parameters which include quantities of ingredients namely ordinary Portland cement, fly ash, silica fume, ground granulated blast-furnace slag, water, and other aggregate to cement ratio, volume to surface area ratio, compressive strength at age of loading, relative humidity, age of drying commencement and age of concrete. The Feed-forward backpropagation networks with Levenberg-Marquardt training function are chosen for proposed ANN models and same implemented on MATLAB platform. The results shows that the proposed ANN models are more rational as well as computationally more efficient to predict time-dependent properties of drying shrinkage and specific creep of HPC with high level accuracy.