• Title/Summary/Keyword: Mixing region

Search Result 479, Processing Time 0.025 seconds

Spatial Distribution and Variation of Long-range Transboundary Air Pollutants Flux during 1997~2004 (장거리이동 대기오염물질 이동량의 공간적 분포와 변화 추이(1997~2004))

  • Han J. S.;Kim Y. M.;Ahn J. Y.;Kong B. J.;Choi J. S.;Lee S. U.;Lee S. J.
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.22 no.1
    • /
    • pp.99-106
    • /
    • 2006
  • Aircraft measurements have been executed for the purpose of monitoring the long range transported air pollution and estimation of air pollutant in/out-flux over the Yellow sea. Total 74 missions of measurements have been done since 1997, mainly in spring and fall. The main study domain was over $124^{\circ}$E $/sim$ $124^{\circ}$E, $35^{\circ}$N $/sim$ $37^{\circ}$N below 3,000m. In long-term trends, mixing ratios of $SO_{2}$N were around 2 ppbv expect in summer ( < 1 ppbv). NOx exhibited 24 ppbv and have no clear annual trends over the Yellow Sea. The concentrations of 03 were 51, 58, 41 ppbv in spring, summer and fall-winter, respectively. Backward trajectory was performed for three days to investigate the source regions of the air mass. Six regions were divided around Korea peninsular centering at $36^{\circ}$N, $126^{\circ}$E. I, II, III, IV and V regions represents in sequence northeast China and Siberia, Sandong peninsula and Balhae gulf, Sanghi and southern China, the south Pacific included Jeju island and the East sea included Japan. L region correspond to the airmass from Korea peninsula. Influx of $SO_{2}$N was approximately five times higher than outflux in yearly flux variation and showed a decreasing long-term trend since 1998. NOx outflux was average 0.095 ton/km/hr and three times higher than $SO_{2}$ outflux. In/out flux of 03 showed even distribution in yearly basis except 2002 (influx 5.45 ton/km/hr). The transported amounts from I, II, III regions were much higher than those from other region. In seasonal flux variation, influx levels of gas phases were the lowest in summer and the levels gradually increased from fall toward spring. As a result, transport of pollutants begins from fall and prevails in winter and spring.

The Genealogy of Trousers in the Eurasian Region (유라시아 지역 바지 구조의 계보)

  • 김문영;조우현
    • Journal of the Korean Society of Costume
    • /
    • v.53 no.7
    • /
    • pp.95-109
    • /
    • 2003
  • The style of different styles of clothing have been developed by not only the natural environment and social effects. but also by various variables such as the peculiar cultures and religions of different ethnic groups. It is naturally accepted without question that the origin of trousers was derived from the Skytie race in the modern style of dress. And the style of those trousers has changed and developed throughout a long history in different environments and surroundings. As part of the research of the process in this styles of clothing, it is essential to know how the fabric of trousers has been developed and how the styles have been changed because of different weather conditions and different religions. Nowadays, Eurasian countries was scattered from western and eastern Asian countries to middle Asian countries such as Russia, Uzbekistan, Kazakistan, Turkey, Turkmenistan, Iran and China. These countries are located on the way to the Silk Road. They are fully developed in a cultural area among the different religions. In terms of cultural aspects within the different religions, men's trousers had developed the traditional style of this dress as one of the importnat items on the cultural basis. The ranges and types of these traditional trousers are divided by the regions, such as west and southern Asia, central Asia and China. Pakistan, Afghanistan, Iran, Iraq, Syria, Lebanon, Turkey. Jordan, Saudi Arabia, Kuwait and Israel was a part of the west and southern Asian countries which were located between western countries and eastern countries. This tribes wore Shalwar trousers which is a wide style of trousers. Shalwar in the western and eastern Asian region has a specific feature by the each nation but has the same distinctions such as by using very wide and loose style and tying a fine thread around the waist. Some central Asian countries consisted of part of China, Turkmenistan. the Republic of Tajikistan. the Republic of Kyrgyzstan and the Republic of Afganistan. These style of trousers are compound types which appeared with mixing Draperian Greek culture. So it can be inferred from this data that the horse-riding nomadic trousers which had been handed down from Skytie tribe through Persia. The style of the trousers in those regions has small pieces. The style of the trousers in China, which is located on the way to the far eastern countries, has developed new trousers put together two pieces of the textile. These widen trousers can be worn by using a sash belt. So we can find out that those trousers of countries which mentioned above have a common point and a rule.

Investigation of Water Leakage in Seosan A-Region Sea Wall using Integrated Analysis of Remote Sensing, Electrical Resistivity Survey, Electromagnetic Survey, and Borehole Survey (원격탐사, 전기탐사, 전자기탐사 및 시추공영상의 융합적 분석을 통한 서산지역 방조제 누수구역 판별)

  • Hong, Seong-In;Lee, Dongik;Baek, Gwanghyun;Yoo, Youngcheol;Lim, Kookmook;Yu, Jaehyung
    • Economic and Environmental Geology
    • /
    • v.46 no.2
    • /
    • pp.105-121
    • /
    • 2013
  • This study introduces integrated approach on detection of a leakage in a sea wall based on remote sensing, electric resistivity survey, electromagnetic survey, and borehole survey for the Seosan A-Region sea wall. The satellite temperature distribution from Landsat ETM+ data identifies water leakage distribution and period by analyzing temperature mixing patterns between sea water and fresh water. Electric resistivity survey provides both horizontal and vertical anomaly distributions over the sea wall showing below average electric resistivity. Electromagnetic survey(electrical conductivity survey) reveals the potential possible leakage areas with minimal background impact by comparing electrical conductivity values between high and low tides. Borehole image processing system confirmed the locations of anomalies identified from the other survey methods and distributions of vertical fracture zones. The integrated approach identified 41.7% of the sea wall being the most probable area vulnerable to water leakage and effectively approximated both horizontal and vertical distribution of water leakage. The integrated analysis of remote sensing, electric resistivity survey, electromagnetic survey and borehole survey is considered to be an optimal method in identifying water leakage distribution, period, and extent of fractures knowledged from the boreholes.

A Study on Feasibility of Cloud Seeding in Korea (한반도에서의 인공증우 가능성에 대한 연구)

  • Chung, Kwan-Young;Eom, Won-Geun;Kim, Min-Jeong;Jung, Young-Sun
    • Journal of Korea Water Resources Association
    • /
    • v.31 no.5
    • /
    • pp.621-635
    • /
    • 1998
  • The feasibility of cloud seeding in Korea is presented from analyses of precipitation, cloud amount, satellite data, and upper air data. The daily mean precipitation over Dae-Kwan-Ryong is the largest(~4.5 mm/day), while the intensity of precipitation (amount of yearly rainfall divided by the frequency of rain days) over Southern area is above 14 mm/day, which shows the largest in Korea. Both the daily mean and the intensity of precipitation over Andong area are the smallest with values of ~2.7 mm/day and ~11 mm/day, respectively. In the meanwhile, the occurrence frequency of appropriate cloud top temperature (-10'~-30') for cloud seeding over the region has a large value (~130 days/year). The precipitation patterns of the region vary with wind direction and intensity calculated from 43 AWSs(Automatic Weather Station) and the additional 7 rain guages which were installed along Northern and Southern part of the Sobaek mountain. The Sc(Stratocumulus) cloud type over Andong is frequently observed, and Cirrus and Altostratus next. From the results, it is estimated that the feasibility of cloud seeding over the area would be high if a proper strategy of cloud seeding is set up. LCL (Lifting Condensation Level) and CCL (Convective Condensation Level) have the most frequency in 1000-950 hPa being occupied 4/9 of total analysis period and in 400-500 hPa, respectively, with both small variations from season to season. The correlation between vapor mixing ratio and CCL is the highest in Summer and the lowest in Winter. It means that the height of cumulus in Summer is high with an abundant water vapor but vice versa in Winter, and that the strategy of cloud seeding should be different with seasons.

  • PDF

A Shallow Water Front and Water Quality in Chinhae Bay (진해만에 형성되는 천해전선과 수질분포)

  • Kum, Cha-Kyum
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.9 no.2
    • /
    • pp.86-96
    • /
    • 1997
  • In order to investigate the formation of a shallow water front and its relation to water quality distributions, oceanographic measurements were made, and the numerical computations of the Simpson-Hunter stratification parameter log(H/U$^3$) were performed. It is shown from satellite image and hydrographic data that the shallow water front is formed near the northern Kaduk channel, and the stratification parameter log(H/U$^3$) near the front is in a range of 2.0-2.5. Measured COD (Chemical Oxygen Demand) concentrations in offshore region of the front and in the western part of the bay are below 2.0 mg/1. whereas the concentrations in Masan Bay located in the northern inside of the frontal zone are high as 3.0-5.5 mg/1. COD concentrations decrease gradually from Masan Bay toward the offshore due to the dilution by strong water mixing. Anoxic and hypoxic water masses at the bottom layer in summcr occur in the western part of Chinhae Bay and in Masan Bay, and DO (Dissolved Oxygen) concentrations become low with increasing the stratification parameter. DO concentrations outside the front are more than about 4.0 mg/1, whereas the concentrations inside the front are low. The shallow water front plays a significant role for material transport from coastal area to oceanic area, and the frontal region seems to be important physical and chemical boundaries.

  • PDF

Surface Micelle Formation of Polystyrene-b-Poly(2-vinyl pyridine) Diblock Copolymer at Air-Water Interface

  • Park, Myunghoon;Bonghoon Chung;Byungok Chun;Taihyun Chang
    • Macromolecular Research
    • /
    • v.12 no.1
    • /
    • pp.127-133
    • /
    • 2004
  • We have studied the surface micelle formation of polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) at the air-water interface. A series of four PS-b-P2VPs were synthesized by anionic polymerization, keeping the PS block length constant (28 kg/㏖) and varying the P2VP block length (1, 11, 28, or 59 kg/㏖). The surface pressure-area ($\pi$-A) isotherms were measured and the surface morphology was studied by atomic force microscopy (AFM) after Langmuir-Blodgett film deposition onto silicon wafers. At low surface pressure, the hydrophobic PS blocks aggregate to form pancake-like micelle cores and the hydrophilic P2VP block chains spread on the water surface to form a corona-like monolayer. The surface area occupied by a block copolymer is proportional to the molecular weight of the P2VP block and identical to the surface area occupied by a homo-P2VP. It indicates that the entire surface is covered by the P2VP monolayer and the PS micelle cores lie on the P2VP monolayer. As the surface pressure is increased, the $\pi$-A isotherm shows a transition region where the surface pressure does not change much with the film compression. In this transition region, which displays high compressibility, the P2VP blocks restructure from the monolayer and spread at the air-water interface. After the transition, the Langmuir film becomes much less compressible. In this high-surface-pressure regime, the PS cores cover practically the entire surface area, as observed by AFM and the limiting area of the film. All the diblock copolymers formed circular micelles, except for the block copolymer having a very short P2VP block (1 kg/㏖), which formed large, non-uniform PS aggregates. By mixing with the block copolymer having a longer P2VP block (11 kg/㏖), we observed rod-shaped micelles, which indicates that the morphology of the surfaces micelles can be controlled by adjusting the average composition of block copolymers.

Discharge header design inside a reactor pool for flow stability in a research reactor

  • Yoon, Hyungi;Choi, Yongseok;Seo, Kyoungwoo;Kim, Seonghoon
    • Nuclear Engineering and Technology
    • /
    • v.52 no.10
    • /
    • pp.2204-2220
    • /
    • 2020
  • An open-pool type research reactor is designed and operated considering the accessibility around the pool top area to enhance the reactor utilization. The reactor structure assembly is placed at the bottom of the pool and filled with water as a primary coolant for the core cooling and radiation shielding. Most radioactive materials are generated from the fuel assemblies in the reactor core and circulated with the primary coolant. If the primary coolant goes up to the pool surface, the radiation level increases around the working area near the top of the pool. Hence, the hot water layer is designed and formed at the upper part of the pool to suppress the rising of the primary coolant to the pool surface. The temperature gradient is established from the hot water layer to the primary coolant. As this temperature gradient suppresses the circulation of the primary coolant at the upper region of the pool, the radioactive primary coolant rising up directly to the pool surface is minimized. Water mixing between these layers is reduced because the hot water layer is formed above the primary coolant with a higher temperature. The radiation level above the pool surface area is maintained as low as reasonably achievable since the radioactive materials in the primary coolant are trapped under the hot water layer. The key to maintaining the stable hot water layer and keeping the radiation level low on the pool surface is to have a stable flow of the primary coolant. In the research reactor with a downward core flow, the primary coolant is dumped into the reactor pool and goes to the reactor core through the flow guide structure. Flow fields of the primary coolant at the lower region of the reactor pool are largely affected by the dumped primary coolant. Simple, circular, and duct type discharge headers are designed to control the flow fields and make the primary coolant flow stable in the reactor pool. In this research, flow fields of the primary coolant and hot water layer are numerically simulated in the reactor pool. The heat transfer rate, temperature, and velocity fields are taken into consideration to determine the formation of the stable hot water layer and primary coolant flow. The bulk Richardson number is used to evaluate the stability of the flow field. A duct type discharge header is finally chosen to dump the primary coolant into the reactor pool. The bulk Richardson number should be higher than 2.7 and the temperature of the hot water layer should be 1 ℃ higher than the temperature of the primary coolant to maintain the stability of the stratified thermal layer.

Development of Traditional Doenjang Improved in Color (색상이 개선된 재래식 된장 개발)

  • Lee, Si-Kyung;Kim, Nam-Dae;Kim, Hyoun-Jin;Park, Jong-Sung
    • Korean Journal of Food Science and Technology
    • /
    • v.34 no.3
    • /
    • pp.400-406
    • /
    • 2002
  • In case of doenjang, solution of browning problem might be an important remedy in order to dissolve consumers' dissatisfaction, therefore this study was performed to develop traditional doenjang which has improved in color aspect for consumers' needs. Physicochemical compositions and color values of commercialized traditional doenjang which was processed by history references of our country, were analyzed. doenjang used as samples were processed with traditional meju, which were made with soybean and mixed with various rates after following process such as soaking, steaming, cooling, chopping and grinding. The doenjang processed were storaged at $30^{\circ}C$ for 27 days, and their amino-N, pH, color values and sensory evaluation were analyzed with fermentation period. Furthermore, nitrogen results analyzed were compared with that of commercialized traditional doenjang. In the comparison with control, treated with only traditional meju, and doenjang treatments processed with different mixing rates of traditional meju and steamed soybean, the content of amino-N in control were higher than the others, and the contents of amino-N decreased with increasing contents of steamed soybean. Their pH were changed weak alkalic region into weak acidic region with fermentation period. In the aspect of color, traditional doenjang having the rate of traditional meju and steamed soybean (1:4) was most improved and also, in comparison of result of sensory evaluation with commercial traditional doenjang, its color, taste and falvor were evaluated predominent, therefore it might be thought to have competition on the market.

Comparison of Sea Surface Temperature from Oceanic Buoys and Satellite Microwave Measurements in the Western Coastal Region of Korean Peninsula (한반도 서해 연안 해역에서의 해양 부이 관측 수온과 위성 마이크로파 관측 해수면온도의 비교)

  • Kim, Hee-Young;Park, Kyung-Ae
    • Journal of the Korean earth science society
    • /
    • v.39 no.6
    • /
    • pp.555-567
    • /
    • 2018
  • In order to identify the characteristics of sea surface temperature (SST) differences between microwave SST from GCOM-W1/AMSR2 and in-situ measurements in the western coast of Korea, a total of 6,457 collocated matchup data were produced using the in-situ temperature measurements from marine buoy stations (Deokjeokdo, Chilbaldo, and Oeyeondo) from July 2012 to December 2017. The accuracy of satellite microwave SSTs was presented by comparing the ocean buoy data of Deokjeokdo, Chilbaldo, and Oeyeondo stations with the AMSR2 SST data more than five years. The SST differences between the microwave SST and the in-situ temperature measurements showed some dependence on environmental factors, such as wind speed and water temperature. The AMSR2 SSTs were tended to be higher than the in-situ temperature measurements during the daytime when the wind speed was low ($<6ms^{-1}$). On the other hand, they showed positive deviation increasingly as the wind speed increased for nighttime. In addition, increasing tendency of SST differences was related to decreasing sensitivity of microwave sensors at low temperatures and data contamination by land. A monthly analysis of the SST difference showed that unlike the previous trend, which was known to be the largest in winter when strong winds were blowing, the SST difference was largest in summer in Deokjeokdo and Chilbaldo buoy stations. This seemed to be induced by differential tidal mixing at the collocated matchup points. This study presented problems and limitations of the use of microwave SSTs with high contribution to the SST composites in the western coastal region off the Korean peninsula.

Occurrence and Chemical Composition of Minerals from the Pallancata Ag Mine, Peru (페루 Pallancata 은 광산에서 산출되는 광물들의 산상 및 화학조성)

  • Yoo, Bong Chul;Acosta, Jorge
    • Journal of the Mineralogical Society of Korea
    • /
    • v.32 no.2
    • /
    • pp.87-102
    • /
    • 2019
  • Pallancata Ag mine is located at the Ayacucho region 520 km southeast of Lima. The geology of mine area consists of mainly Cenozoic volcanic-intrusive rocks, which are composed of tuff, andesitic lava, andesitic tuff, pyroclastic flow, volcano clasts, rhyolite and quartz monzonite. This mine have about 100 quartz veins in tuff filling regional faults orienting NW, NE and EW directions. The Ag grades in quartz veins are from 40 to 1,000 g/t. Quartz veins vary from 0.1 m to 25 m in thickness and extend to about 3,000 m in strike length. Quartz veins show following textures including zonation, cavity, massive, breccia, crustiform, colloform and comb textures. Wallrock alteration features including silicification, sericitization, pyritization, chloritization and argillitization are obvious. The quartz veins contain calcite, chalcedony, adularia, fluorite, rutile, zircon, apatite, Fe oxide, REE mineral, Cr oxide, Al-Si-O mineral, pyrite, sphalerite, chalcopyrite, galena, electrum, proustite-pyrargyrite, pearceite-polybasite and acanthite. The temperature and sulfur fugacity ($f_{s2}$) of the Ag mineralization estimated from the mineral assemblages and mineral compositions are ranging from 118 to $222^{\circ}C$ and from $10^{-20.8}$ to $10^{-13.2}atm$, respectively. The relatively low temperature and sulfur-oxygen fugacities in the hydrothermal fluids during the Ag mineralization in Pallancata might be due to cooling and/or boiling of Ag-bearing fluids by mixing of meteoric water in the relatively shallow hydrothermal environment. The hydrothermal condition may be corresponding to an intermediate sulfidation epithermal mineralization.