• Title/Summary/Keyword: surface protection

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A study on Mechanical Properties of Acrylic-casein Hybrid Resins for Surface Protection (표면 보호용 수용성 Acrylic-casein Hybrid Resin의 합성 및 기계적 물성에 관한 연구)

  • Lee, Joo-Youb;Kim, Ki-Jun
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.4
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    • pp.618-625
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    • 2012
  • In this study, prepared synthesis waterborne acrylic resin and water soluble milk casein resin. And than extent of casein contents in acrylic resin. We measured property of these samples by Lamb leather which is coated by acrylic-casein resins. According to measure data for solvent resistance, WAR resin and Hybrid resins had good property. Among this result knew that increase of casein constant did not influence to big change of hybrid resin property. As test of tensile strength, WAR had lowest strength($1.399kg_f/mm^2$) and WAC-3 had highest strength($1.426kg_f/mm^2$). Also we knew that best property of abrasion was WAC-3(69.774 mg.loss). In elongation case, WAR had best property(820%) in this experiment.

A Theoretical Study on the Characteristics of Fire Resistance for the Concrete Filled Tubular Steel Columns (콘크리트충전 강관기둥의 내화특성에 관한 이론적 연구)

  • Chung, Kyung Soo;Choi, Sung Mo;Kim, Dong Kyu
    • Journal of Korean Society of Steel Construction
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    • v.9 no.4 s.33
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    • pp.649-658
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    • 1997
  • When steel tube as a column is filled with concrete, it is common that the load-bearing capacities of CFST(Concrete Filled Steel Tube) column are increased substantially, And the CFST column can obtain a capacity of fire resistance without any additional detail on the surface of the steel tube for fire protection. In order to clarify the behavior of CFST column during fire occurrence, a theoretical study is performed, that is, a thermal analysis is used to find temperature gradient dependent on the time on the steel tube and the infilled concrete. N-M (axial force-moment) interaction curves are summarized under the consideration for time dependent variation. The material properties of concrete and steel in accordance with a temperature variation are referred to the existing general data. Thermal transient analyses are performed by finite element method through ANSYS and then these results are verified by comparing with the existing test results. On the basis of analytical results, load-carrying capacities (N-M interaction curves) are calculated by numerical analysis method.

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Protective efficacy of vaccination with Neospora caninum multiple recombinant antigens against experimental Neospora caninum infection

  • CHO Jung-Hwa;CHUNG Woo-Suk;SONG Kyoung-Ju;NA Byoung-Kuk;KANG Seung-Won;SONG Chul-Yong;KIM Tong-Soo
    • Parasites, Hosts and Diseases
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    • v.43 no.1 s.133
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    • pp.19-25
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    • 2005
  • Protective efficacy of vaccination with Neospora caninum multiple recombinant antigens against N. caninum infection was evaluated in vitro and in vivo. Two major immunodominant surface antigens (NcSAG1 and NcSRS2) and two dense granule proteins (NcDG1 and NcDG2) of N. caninum tachyzoites were expressed in E. coli, respectively. An in vitro neutralization assay using polyclonal antisera raised against each recombinant antigen showed inhibitory effects on the invasion of N. caninum tachyzoites into host cells. Separate groups of gerbils were immunized with the purified recombinant proteins singly or in combinations and animals were then challenged with N. caninum. Following these experimental challenges, the protective efficacy of each vaccination was determined by assessing animal survival rate. All experimental groups showed protective effects of different degrees against experimental infection. The highest protection efficacy was observed for combined vaccination with NcSRS2 and NcDG1. Our results indicate that combined vaccination with the N. caninum recombinant antigens, NcSRS2 and NcDG1, induces the highest protective effect against N. caninum infection in vitro and in vivo.

Study on Estimation and Application of Discharge Coefficient about Nonpoint Source Pollutants using Watershed Model (유역모형을 이용한 유량조건별 배출계수 산정 및 활용방안 연구)

  • Hwang, Ha-Sun;Rhee, Han-Pil;Park, Jihyung;Kim, Yong-Seok;Lee, Sung-Jun;Ahn, Ki Hong
    • Journal of Korean Society on Water Environment
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    • v.31 no.6
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    • pp.653-664
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    • 2015
  • TPLMS (Total water pollutant load management system) that is the most powerful water-quality protection program have been implemented since 2004. In the implementation of TPLMS, target water-quality and permissible discharged load from each unit watershed can be decided by water-quality modeling. And NPS (Non-point sources) discharge coefficients associated with certain (standard) flow are used on estimation of input data for model. National Institute of Environmental Research (NIER) recommend NPS discharge coefficients as 0.15 (Q275) and 0.50 (Q185) in common for whole watershed in Korea. But, uniform coefficient is difficult to reflect various NPS characteristics of individual watershed. Monthly NPS discharge coefficients were predicted and estimated using surface flow and water-quality from HSPF watershed model in this study. Those coefficients were plotted in flow duration curve of study area (Palger stream and Geumho C watershed) with monthly average flow. Linear regression analysis was performed about NPS discharge coefficients of BOD, T-N and T-P associated with flow, and R2 of regression were distributed in 0.893~0.930 (Palger stream) and 0.939~0.959 (Geumho C). NPS Discharge coefficient through regression can be estimated flexibly according to flow, and be considered characteristics of watershed with watershed model.

Occurrence of Fruit Rot of Pumpkin Caused by Sclerotium rolfsii (Sclerotium rolfsii에 의한 호박 흰비단병 발생)

  • Kwon, Jin-Hyeuk;Shen, Shun-Shan;Chae, Yun-Seok;Park, Chang-Seuk
    • Research in Plant Disease
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    • v.13 no.1
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    • pp.53-56
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    • 2007
  • The fruit rot of pumpkin caused by Sclerotium rolfsii occurred sporadically at Gyeongsangnam-do Agricultural Research and Extension Services, Korea in 2004 and 2005. The typical symptom of the disease included water-soaking, fruit rotting and wilting. White mycelial mats were spread over infected fruits and then sclerotia were formed on the lesions and near soil surface. The sclerotia were globoid in shape, 1$\sim$3 mm in size and white to brown in color. The optimum temperature for mycelial growth and sclerotia formation was at $30^{\circ}C$ on PDA and the hyphal width ranged from 4 to 8 ${\mu}m$. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. On the basis of mycological characteristics and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report on the fruit rot of Cucurbita spp. caused by S. rolfsii in Korea.

Health Risks to Children and Adults Residing in Riverine Environments where Surficial Sediments Contain Metals Generated by Active Gold Mining in Ghana

  • Armah, Frederick Ato;Gyeabour, Elvis Kyere
    • Toxicological Research
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    • v.29 no.1
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    • pp.69-79
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    • 2013
  • The purpose of this study was to investigate the current status of metal pollution in the sediment from rivers, lakes, and streams in active gold mining districts in Ghana. Two hundred and fifty surface sediment samples from 99 locations were collected and analyzed for concentrations of As, Hg, Cr, Co, Cu, Fe, Zn, Pb, Cd, Ni, and Mn using inductively coupled plasma-mass spectroscopy (ICP-MS). Metal concentrations were then used to assess the human health risks to resident children and adults in central tendency exposure (CTE) and reasonable maximum exposure (RME) scenarios. The concentrations of Pb, Cd, and As were almost twice the threshold values established by the Hong Kong Interim Sediment Quality Guidelines (ISQG). Hg, Cu, and Cr concentrations in sediment were 14, 20, and 26 times higher than the Canadian Freshwater Sediment Guidelines for these elements. Also, the concentrations of Pb, Cu, Cr, and Hg were 3, 11, 12, and 16 times more than the Australian and New Zealand Environment and Conservation Council (ANZECC) sediment guideline values. The results of the human health risk assessment indicate that for ingestion of sediment under the central tendency exposure (CTE) scenario, the cancer risks for child and adult residents from exposure to As were $4.18{\times}10^{-6}$ and $1.84{\times}10^{-7}$, respectively. This suggests that up to 4 children out of one million equally exposed children would contract cancer if exposed continuously to As over 70 years (the assumed lifetime). The hazard index for child residents following exposure to Cr(VI) in the RME scenario was 4.2. This is greater than the United States Environmental Protection Agency (USEPA) threshold of 1, indicating that adverse health effects to children from exposure to Cr(VI) are possible. This study demonstrates the urgent need to control industrial emissions and the severe heavy metal pollution in gold mining environments.

Study on the NiAl Coating for Corrosion Resistance of Stainless Steel in Molten Carbonate Salt (용융탄산염에 대한 스테인레스강의 내식성 향상을 위한 NiAl 피복에 관한 연구)

  • Hwang, Eung-Rim;Gang, Seong-Gun
    • Korean Journal of Materials Research
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    • v.7 no.1
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    • pp.76-80
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    • 1997
  • '4 NiAl coating process was applied on 316 stainless steel to retard the corrosion of the wet- seal area of separator for the molten carbonate fuel cell. The Nit11 phasc on the stainless steel substrate could be formed by pre-coating with Ni, plated with A1 and ther, heat treated at $800^{\circ}C$ for 3 hr in $H_2/N_2$ gas atmosphere. The corrosion protection behavior of YiAl coating layer was stuilied under immersion condition in molten cxhonate salt($62^{m}/_{o}Li_2CO_3-38^{m}/_{o}/K_{2}CO_{3}$) at $650^{\circ}C$. The NiAl coating layer ticposited on the AiSi 316 stainless steel had high corrosion resistance in molten carbor. dte salt. The corrosion resistance of XiAl (~~jpoared to be associated with the .A1 oxide formed on the surface of coating layer.

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Assessment of the Radiological Inventory for the Reactor at Kori NPP Using In-Situ Measurement Technology (In-Situ 측정법을 이용한 고리 원자로 방사선원항 평가)

  • Jeong, Hyun Chul;Jeong, Sung Yeop
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.2
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    • pp.171-178
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    • 2014
  • After the expiration of operating license of a plant, all infrastructures within the plant must be safely dismantled to the point that it no longer requires measures for radiation protection. Despite the fact that Kori 1 and Wolsong 1 are close to the expiration of their operating license, sufficient technologies for radiological characterization, decontamination and dismantling is still under development. The purpose of this study is to develop one of methods for radiological inventory assessment on measuring object by using direct measure of large component with In-Situ measurement technique. Radiological inventory was assessed by analyzing nuclide using portable gamma spectroscopy without dismantling reactor head, and the result of direct measurement was supplemented by performing indirect measurement. Radiochemical analysis were performed on surface contamination samples as well. During the study, radiological inventory of reactor vessel calculated expanding the result. Based on the result and the radioactivity variation of each radionuclides time frame for decommissioning can be decided. Thus, it is expected that during the decommissioning of plants, the result of this study will contribute to the reduction of radiation exposure to workers.

The Drying of Plasticized Pasta (가소화(可塑化)된 파스타의 건조(乾燥))

  • Schwartzberg, Henry G.;Kim, Kong-Hwan
    • Applied Biological Chemistry
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    • v.24 no.1
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    • pp.29-39
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    • 1981
  • Cooked spaghetti soaked in 10%, 20%, and 40% aqueous glycerine solutions for ten minutes absorbed sufficient glycerine to plasticize that spaghetti during and after subsequent drying. The plasticizing action of the glycerine prevented fissuring(checking) and surface corrugation of the spaghetti at elevated drying temperature and large wet-bulb dry-bulb temperature difference. The drying temperature and the wet-bulb dry-bulb differences up to which such protection was provided as the glycerine soak concentration increased. Despite the reduction in drying rate, the drying time required to produce spaghetti with a water activity of 0.65 (the level normally required for stability) decreased as glycerine content increased. At high frying temperatures glycerine addition increased the extent of browning and shortened the period required to induce detectale browning, but in all instances browning started well after the product $a_w$ reached the 0.65 value required for the completion of drying. Because glycerine addition reduced drying times at any given set of drying conditions and permitted the use of higher drying temperatures, relatively low levels of glycerine addition (e.g. 0.15 kg glycerine/kg dry spagetti) can shorten spagnetti drying times by roughly 80% and perhaps by as much as 93%.

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Using Artificial Neural Networks for Forecasting Algae Counts in a Surface Water System

  • Coppola, Emery A. Jr.;Jacinto, Adorable B.;Atherholt, Tom;Poulton, Mary;Pasquarello, Linda;Szidarvoszky, Ferenc;Lohbauer, Scott
    • Korean Journal of Ecology and Environment
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    • v.46 no.1
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    • pp.1-9
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    • 2013
  • Algal blooms in potable water supplies are becoming an increasingly prevalent and serious water quality problem around the world. In addition to precipitating taste and odor problems, blooms damage the environment, and some classes like cyanobacteria (blue-green algae) release toxins that can threaten human health, even causing death. There is a recognized need in the water industry for models that can accurately forecast in real-time algal bloom events for planning and mitigation purposes. In this study, using data for an interconnected system of rivers and reservoirs operated by a New Jersey water utility, various ANN models, including both discrete prediction and classification models, were developed and tested for forecasting counts of three different algal classes for one-week and two-weeks ahead periods. Predictor model inputs included physical, meteorological, chemical, and biological variables, and two different temporal schemes for processing inputs relative to the prediction event were used. Despite relatively limited historical data, the discrete prediction ANN models generally performed well during validation, achieving relatively high correlation coefficients, and often predicting the formation and dissipation of high algae count periods. The ANN classification models also performed well, with average classification percentages averaging 94 percent accuracy. Despite relatively limited data events, this study demonstrates that with adequate data collection, both in terms of the number of historical events and availability of important predictor variables, ANNs can provide accurate real-time forecasts of algal population counts, as well as foster increased understanding of important cause and effect relationships, which can be used to both improve monitoring programs and forecasting efforts.