• Title/Summary/Keyword: Dust-particles

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Ecological Characteristics of White Stain Symptom on the Grape in Korea (포도흰얼룩증상의 발생생태적 특성)

  • Oh, Soh-Young;Nam, Ki-Woong;Yoon, Deok-Hoon
    • Korean Journal of Environmental Agriculture
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    • v.33 no.3
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    • pp.178-183
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    • 2014
  • BACKGROUND: The white stain symptom of grape clusters and canes by dust-like particles occurred in many vineyards recently. This study was conducted to investigate the ecological characteristics of white stain symptom in grapevines and vineyards. METHODS AND RESULTS: Optimal climate condition for white stain symptom was $25^{\circ}C{\sim}30^{\circ}C$ with 60% of humidity. Moreover, closed condition with same humidity showed higher incidence rate of white stain symptom than ventilation condition. Grape varieties with black berry skin such as Campbell-Early and Kyoho were more sensitive to white stain symptom compare to varieties with green and red berry skin. Although the pathogens were not detected until March, they increased from April, and increased sharply from mid of July. The pathogens may overwinter in the infected stems and/or on the bark as a mycelium. According to the increase of sugar content of grape from August to September, the mycelium which was parasitic on the bark grew to move to the fruits through the stems, and finally reached the fruit stalk to detach berries from the clusters. CONCLUSION: Well ventilation is recommended inside the vineyard since mid-July with roll up an insect net. In addition, infected stems and fruits should be removed out from grapevines infected with pathogens in the vineyards.

Hydrophilic Finish of Polyester Fabrics using Sericin Finishing Agents (세리신 가공제에 의한 폴리에스터 직물의 친수화 가공)

  • Park, In-Woo;Hwang, Gye-Soon;Hong, Young-Ki;Bae, Han-Soo;Bae, Kie-Seo
    • Textile Coloration and Finishing
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    • v.21 no.1
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    • pp.38-45
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    • 2009
  • First of all, the properties imparted to PET fabrics are resistance to and recovery from creasing or wrinkling when wet or dry; high resistance to stretch in the filament yarns but not in the staple; high abrasion resistance; good texture and appearance; resistance to heat ageing; good chemical resistance and good resistance, behind glass, to sunlight. But, the low moisture regain of PET fabric conduces to static troubles in textile processing. Furthermore, garments made from PET may, during wear, develop electric charges which attract to the fabric particles of soil(dirt, swarf, dust) flying in the air, so that the cuffs of shirts, for example, become soiled quickly and are not easily laundered clean. The sericin constitutes 25$\sim$30% of silk protein and surrounds the fibroin fiber with sticky layer that supports the formation of a cocoon. The useful biochemical properties of sericin protein are oxidation resistant, antibacterial, UV resistant, hydrophilic property, and good affinity with hydrophobic material. These properties can be used as an improving reagent or a coating agent for natural and synthetic fibers, fabrics, and other intermediate products. The sericin is also applied to cross-link, and can be blended with other materials. In this study, we modified the surface of PET fabric by mixture of sericin finishing agent; sericin, polyuretane binder and 1,2,3,4-butanetetracarboxylic acid (BTCA) cross-link agent. Also, we investigated the finshing effect; moisture regain, stiffness, handle, drape and electrostatic. The moisture regain of PET fabric treated with sericin finishing agent was higher than that of untreated PET fabric. As a result of evaluating influence about handle of PET fabrics treated with sericin finishing agent, it was confirmed that the sericin finishing agent could be use as a linen like finishing agent.

Control of Algal Blooms in Eutrophic Water Using Porous Dolomite Granules

  • Huh, Jae-Hoon;Choi, Young-Hoon;Lee, Shin Haeng;Cheong, Sun Hee;Ahn, Ji Whan
    • Journal of the Korean Ceramic Society
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    • v.54 no.2
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    • pp.108-113
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    • 2017
  • The use of aluminum-based coagulants in water pretreatment is being carefully considered because aluminum exposure is a risk factor for the onset of Alzheimer's disease. Lightly burned-dolomite kiln dust (LB-DKD) was evaluated as an alternative coagulant because it contains high levels of the healthful minerals calcium and magnesium. An organic pore forming agent (OPFA) was incorporated to prepare porous granules after OPFA removal through a thermal decomposition process. A spray drying method was used to produce uniform and reproducible spherical granules with low density, since fine dolomite particles have irregular agglomeration behavior in the hydration reaction. The use of fine dolomite powder and different porosity granules led to a visible color change in raw algae (RA) containing water, from dark green to transparent colorlessness. Also, dolomite powders and granules exhibited a mean removal efficiency of 48.3% in total nitrogen (T-N), a gradual increase in the removal efficiency of total phosphorus (T-P) as granule porosity increased. We demonstrate that porous dolomite granules can improve the settling time and water quality in summer seasons for the emergent treatment of excessive algal blooms in eutrophic water.

IAQ improvement effect analysis in Dynamic Breathing Building(DBB) (숨쉬는 벽체를 적용한 건물에서의 실내공기질(IAQ) 개선 효과 분석)

  • Park, Yong-Dai;Lee, Jin-Sook;Kang, Eun-Chul;Lee, Euy-Joon
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.748-753
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    • 2008
  • In modern buildings, the air-tightness and insulation for energy saving resulted in degradation of Indoor Air Quality(IAQ). It has brought out new diseases such as New Building Syndrome(NBS) and Sick Building Syndrome(SBS) to the tenants of such buildings. As a result, researches on the Dynamic Breathing Building(DBB) are being undertaken to minimize energy loss as well as to improve IAQ. DBB is a state-of-the-art technology to build channels inside the wall so that air migrates between indoor and outdoor, which improves insulation performance and IAQ. This study attempts to evaluate the improvement of DBB employed in real buildings. As analyzing tools, IAQ improvement and particle degradation while were evaluated while the required indoor ventilation rate was satisfied. DBB were installed in the twin test cells at Korea Institute of Energy Research(KIER). From the test, IAQ was compared with outdoor air base on the concentration of particle matter(PM10). As a results, the concentration of particle dust (PM10) within the breathing walls was reduced by 80% at 0.7 ACH, 67% at 2 ACH, 63% at 3 ACH respectively. As ACH is higher, Dnamic Isulation(DI) and normal wall permit more PM10 particles being infiltrated.

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Characteristics of Cyclone-Bag Filter with Bottom Inlet (하부유입식 원심 여과집진장치의 특성)

  • Yoa, Seok-Jun
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.4
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    • pp.639-650
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    • 2000
  • The main object of this study was to investigate experimentally the characteristics of cyclone-bag filter with bottom inlet to decrease the high pressure drop which was one of main problems of fabric bag filter. The experiment was executed for the analysis of collection efficiency and pressure drop(specially, pressure drop of fabric filter) characteristics of the cyclone-bag filter in comparison with those of general fabric bag filter with various experimental parameters such as the inlet velocity, dust loading and variation of vortex region, etc. In the results, the tangential inlet type showed higher collection efficiency for submicron particles below $1{\mu}m$ in diameter than of center inlet, and over 99% for overall collection efficiency. For the inlet particle concentration $100mg/m^3$, pressure drop reduction ratios were shown as 15~38% with the inlet velocity in case of large bag, while 30~48% for small bag due to the increase of vortex region.

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Spatial Analysis of Major Atmospheric Aerosol Species Using Earth Observing Satellite Data (지구관측 위성자료를 이용한 주요 대기 에어러솔 성분의 공간분포 분석)

  • Lee, Kwon-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.2
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    • pp.109-127
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    • 2011
  • Atmospheric aerosols, small particles in the atmosphere, are one of the important parameters in climate change and human health. Additionally, accurate estimates of aerosol species are increasingly important in environmental impact assessment studies. Recent advances in global satellite remote sensing provide powerful tool for air quality monitoring. This study explores the potential usage of satellite derived data such as atmospheric aerosols for air quality monitoring as well as climate change study. The objectives of this study is to understand the general features of the global distribution of type dependent aerosols. A detailed spatio-temporal variability of the each different satellite dataset shows the variation of the global zonal average and specific geographical regions where the strong emission sources are located. Especially, significantly large aerosol amounts are observed in Asia and Africa because of the desert dust storm, anthropogenic and biomass burning emissions.

A study on bulk deposition flux of dustfall and insoluble components by the wind intensity in Busan, Korea (바람의 강도에 따른 강하먼지와 불용성 성분의 조성특성)

  • 황용식;김유근;박종길;문덕환
    • Journal of Environmental Science International
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    • v.11 no.7
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    • pp.651-662
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    • 2002
  • Weather elements were observed by the AWS (Automatic Weather System) and dustfall particles were collected by the modified American dust jar (wide inlet bottle type) at 4 sampling sites in Busan area from March. 1999 to February, 2000. Thirteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Si, and Zn) were analyzed by AAS and ICP. The purposes of this study were to estimate qualitatively various bulk deposition flux of dustfall and insoluble components by applying regional and seasonal wind intensity. Frequency of wind speed were found in order of low(1-3m/s), very low(<1m/s), medium(3-8m/s) and high(>8m/s), and annual mean had higher range at low(1-3m/s) for 56.3%. Strong negative linear correlation were observed between dustfall and wind direction (northeastern and eastern), but strong positive linear correlation were observed between dustfall and wind direction (western and northwestern) at industrial, commercial and coastal zone(p<0.05). While a negative correlation were observed between wind speed frequency of very low(<1 m/s) and dustfall, and positive correlation were observed between wind speed frequency of low(1-3m/s) and dustfall in coastal zone(p<0.05). The correlation coefficient was observed 0.556 between wind speed frequency of low(1-3m/s) and Ni by commercial zone(p<0.05). The correlation coeffcient show well-defined insoluble trace metals (Al, Ca, Cr, Cu, Fe, Pb, and Zn) and wind speed frequency of low(1-3m/s) at coastal zone, which was found significant difference(p<0.01).

Fabrication and Properties of Reaction Bonded SiC Hot Gas Filter Using Si Melt Infiltration Method (용융 Si 침윤방법에 의한 반응소결 탄화규소 고온가스 필터의 제조 및 특성)

  • 황성식;김태우
    • Journal of the Korean Ceramic Society
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    • v.40 no.9
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    • pp.891-896
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    • 2003
  • Novel fabrication technique was developed for high strength Reaction-Bonded SiC (RBSC) hot gas filter for use in IGCC (Integrated Gasification Combined Cycle) system. The room and high temperature fracture strengths for Si-melt infiltrated reaction-bonded SiC were 50-123, and 60-66 MPa, respectively. The average pore size was 60-70 $\mu\textrm{m}$ and the porosity was about 34 vol%. RBSC infiltrated with molten silicon showed improved fracture strength at high temperature, as compared to that of clay-bonded SiC, due to SiC/Si phase present within SiC phase. The thickness for SiC/Si phase was increased with increasing powder particle size of SiC from 10 to 34 $\mu\textrm{m}$. Pressure drop with dust particles showed similar response as compared to that for Schumacher type 20 filter. The filter fabricated in the present study showed good performance in that the filtered powder size was reduced drastically to below 1 $\mu\textrm{m}$ within 4 min.

A Study on Long Range Image Monitoring and Tracking System Using Laser Range-Gate Method in Inclement Weather Conditions (악천후 상황에서 Laser Range-Gate 방식을 이용한 원거리 영상 감시 및 추적 시스템에 대한 연구)

  • Oh, Sung-Kwun;Yoo, Sung-Hoon;Ku, Kyong-Wan;Kim, Su-Chan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.2
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    • pp.257-263
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    • 2013
  • In case of image observation equipments, CCTV for short distance visual field is usually installed and operated mostly as the means of crime-prevention. However, the extensive demand for monitoring problems in case of the increase in intelligent crimes and disasters has led to the necessity of the development of long-distance observation equipments embedded with Night View functions. In case of the Night View equipments, the relevant market is set up to be focused mostly on Thermal Observation Device(hereinafter, TOD), but some shortcomings such as the limitation of image visibility and excessive maintenance cost, etc. have actually caused the necessity of new long distance Night View equipment. Moreover there might follow lots of difficulties in long-distance visualization in the event that irregular reflection is generated by minute particles in the atmosphere such as fog, smog, and dust, etc. These factors are motivate the work presented in this study. Our study is aimed at the realization of Pulsed Laser Illuminator and newly proposed Range-Gated image acquisition technology. And also the implementation of Tracker for continuous trace of the objects of interest from the obtained sequence images.

A Study on Simulation of Asymmetric Doppler Signals in a Weather Radar (기상 레이다에서의 비대칭 도플러 신호 모의구현에 관한 연구)

  • Lee, Jong-Gil
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.10
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    • pp.1737-1743
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    • 2008
  • A weather radar extracts the weather information from the return echoes which consist of scattered electromagnetic wave signals from rain, cloud and dust particles, etc. The characteristics of Doppler weather signal and ground clutter should be analyzed to extract the accurate weather information. However, the conventional symmetric weather Doppler model is somewhat inappropriate in representing various weather situations. Therefore, the improved model is suggested to describe the skewness in the Doppler spectrum model. Using the suggested model, many various weather signals can be simulated efficiently in time and spectral domain according to weather situations, operation environment and system characteristics. This simulation method may be very helpful in verifying the accuracy of the weather information extraction algorithms and developing the new system for further performance improvement.