• Journal of the Korean Institute of Gas
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• v.18 no.5
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• pp.6-11
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• 2014

To optimize the design of fuel cylinder for LNG vehicles, we introduced the design parameters of the inner and the outer tank of the vessel support structure by analyzing the structural characteristics of conventional design. We selected the inner and outer diameter of the hollow support bars and a dimension of the inner structure of the vessel among the design parameters for design optimization. In this study the temperature distribution and thermal stress of the support structure were evaluated by using the utility program as MSC/MARC. The evaluation criteria are first mode natural frequency, total transferred energy through support structure and thermal stress. The developed design satisfied the design criteria and it was made of prototype. The prototype was verified through three-dimensional vibration testing and thermal performance test.

• Korean Journal of Remote Sensing
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• v.31 no.6
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• pp.583-598
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• 2015

This paper presents derivation of background temperature from geostationary satellite and its validation based on ground measurements and Geographic Information System (GIS) for future use in weather and surface heat variability. This study only focuses on daily and monthly brightness temperature in 2012. From the analysis of COMS Meteorological Data Processing System (CMDPS) data, we have found an error in cloud distribution of model, which used as a background temperature field, and in examining the spatial homogeneity. Excessive cloudy pixels were reconstructed by statistical reanalysis based on consistency of temperature measurement. The derived Brightness temperature has correlation of 0.95, bias of 0.66 K and RMSE of 4.88 K with ground station measurements. The relation between brightness temperature and both elevation and vegetated land cover were highly anti-correlated during warm season and daytime, but marginally correlated during cold season and nighttime. This result suggests that time varying emissivity data is required to derive land surface temperature.

• Polymer(Korea)
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• v.32 no.6
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• pp.549-554
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• 2008

In order to synthesize polymer particle containing inorganic material, styrene and n-butylmethacrylate were copolymerized with alumina by dispersion polymerization. The weight ratio of styrene to n-butylmethacrylate was 3 : 1. A poly(N-vinyl pyrrolidon) was added as stabilizer. 2,2'-AzobisCisobutyronitrile) and 3-methacryloxypropyl trimethoxysilane were used as initiator and coupling agent, respectively. The weight ratio of 70 : 30 of isopropanol to distilled water was used as dispersion medium. According to the TEM measurement, we could confirm that alumina was dispersed into the polymer particle. The increase 'of concentration of alumina resulted in enhancement of particle size, but decreased its distribution. By the XRD method, it was found that the increase of alumina concentration showed the increase of intensity in peak and the increased 2$\theta$ value. From the TGA measurement, the increase of alumina concentration caused high heat resistance of the polymer. With respect to the type of initiator, the longer half life of initiator, the smaller particle size. We also found that the increase of particle stabilizer concentration made the decreased of particle size due to the accelerated generation of polymer particle in the early stage of reaction.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.14 no.2
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• pp.207-223
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• 2001

The Wonyenaejang is equivalent to the (senile)cataract in western medicine. The word cataract is used to describe the natural lens that has turned cloudy. As the natural lens of the eye becomes cloudy, it does not allow light to pass through it. Cataracts usually start as a slight cloudiness that progressively grows more opaque. As the cataract becomes more mature(increasingly opaque and dense), the retina receives less and less light. The light that does reach the retina becomes increasingly blurred and distorted. This causes gradual impairment of vision. If left untreated, cataracts can cause needless blindness. Although there are many kinds of cataracts, a senile cataract is the most common one. We chose the oriental medicine textbooks and the oriental medicine journals that were dealing with the symptoms, etiology, and internal/external treatments. The results were as follows : 1. The main causes of this disease are weak liver and kidney, burning up of the wind and heat in the liver and gall, weak spleen and stomach. 2. As the internal treatment of the Cataract, Geegukjihwangtang is mostly prescribed. 3. As the external treatment of the Cataract, (l) In the field of medicine for external application is commonly prescribed (2) In the field of drug action, frequently used treatments are as follows. emission of the evil, alleviation of fever, removal of lump of blood, and the medicine for external applications. (3) In the field of four Qi, cold medicine is commonly prescribed. (4) In the field of five tastes, bitter/hot/sweet mdicine are commonly prescribed. (5) In the field of toxicity, non-togic medicine is commonly prescribed. (6) In the field of channel distribution, most of the medicine belong to liver channel.

• Applied Chemistry for Engineering
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• v.19 no.3
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• pp.310-315
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• 2008

Herein, we synthesized silica-coated chrome yellow particles having improved chemical resistance. The intermediate with a good dispersion stability was prepared and the chemical resistance of the final product was investigated. The effects of pH and temperature, as the main parameters influencing the formation of particles, the reduced particle size by homogenizer on the silica coating were investigated. The change in the particle morphology by temperature and pH was also studied. As the results, small and monodisperse particles were achieved at low pH and high temperature. Good silica coating was obtained when used reduced size of the particles by homogenizer. Furthermore, the sufficient silica coating by microencapsulation was obtained at 9~10 pH and the temperature above $90^{\circ}C$.

• Resources Recycling
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• v.25 no.6
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• pp.3-12
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• 2016

In this study, Au distribution in F-PGA chip and W-BGA chip were examined to recover Au effectively from CPU chips. The result showed that 80.8% and 89.8% of Au exist in terminal of F-PGA chip and bare die of W-BGA chip, respectively. Based on the fact that Au exists in specific parts of the chips, an CPU chip dismantling apparatus was developed. The experimental variables were roller rotating speed, heat temperature of IR heater and heating time. Terminals of F-PGA chips were completely recovered under the temperature of $300^{\circ}C$ and the residence time of 90 s. Bare dies of W-BGA chips were completely recovered as well under the temperature of $300^{\circ}C$, the roller rotating rate of 90 rpm and the residence time of 90 s.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.7
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• pp.402-408
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• 2009

In this paper, the effects of ventilation and humidification on thermal comfort and indoor air quality(IAQ) were evaluated in a classroom when a heat pump system was operated in winter. Thermal comfort parameters, such as temperature, relative humidity, globe temperature and air velocity, were measured at 9 points in the classroom. The concentration of $CO_2$ and total suspended particles(TSP) in the classroom were measured in order to analyze IAQ. Temperature distribution in the classroom was decreased by $2{\sim}5^{\circ}C$ when the ventilation system and the humidifier were operated. When the relative humidity was adjusted to 60% by operating the humidifier and the ventilation system, the predicted mean vote(PMV) in the classroom was within the comfortable range of $-0.5{\sim}0.5$. When the ventilation system was operated, the average concentration of $CO_2$ and TSP were decreased by 645 ppm and 0.17 $mg/m^3$, respectively. This paper suggests the humidification and ventilation conditions to maintain the comfortable environment in the school classroom in winter experimentally.

• Journal of Integrative Natural Science
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• v.4 no.1
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• pp.44-57
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• 2011

In general, heavy rainfall in Korea is mostly associated with inflow of 850hPa low-level jet. It transports abundant heat and moisture flux to the Changma front. In this study, synoptic characteristics of heavy rainfall in Korea from a case study is examined by classifying heavy rainfall cases with synoptic patterns, in particular distribution of upper- and low-level jets, western North Pacific high, and moisture flux. The surface and upper-level weather charts including auxiliary analysis chart and radar and satellite images obtained from the Korea Meteorological Administration, and 500hPa geopotential heights from NCEP/NCAR are used and then KLAPS is applied to understand the local atmospheric structure associated with heavy rainfall. Results show that maximum frequency in 60 heavy rainfall cases with more than 150mm/day appears in the Changma type of 43 cases (a proportion in relation to a whole is 52%) including the combined Changma types with typhoon and cyclone. As indicated in previous studies, most heavy rainfall cases are related to inflow of low-level jet. In addition, synoptic characteristics based on the analyses of weather charts, radar and satellite images, and KLAPS in heavy rainfall case of 12 July, 2009 reveal that the atmospheric vertical structure in particular equivalent potential temperature favorable for effective inflow of warm and moist southwesterly into the Changma front is linked to large potential instability and the strong convergence accompanied with low-level jet around Suwon contributes to atmospheric upsliding along the Changma front, producing heavy rainfall.

• Elastomers and Composites
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• v.15 no.3
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• pp.147-154
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• 1980

The cellular rubber products for industrial purpose have been applied in many fields such as auto-motive parts, ship-building, machinery, sports goods, diving suit or interior housings etc. The purpose of this dissertation is to study the physical properties of celluar rubber products particulary for those elastomers such as EPDM, CR and NBR with heat resistance property, weather proofness, and oil resistance characteristics respectively, aiming at improving their quality, and renovating the manufacturing know-how which is beyond our technical power at the present time in Korea. In order to meet this requirement an ideal recipe is being shown for the three elastomers, and also a practical recipe which is easily available in terms of compounding ingredients in domestic market has set up as shown in Table 1. for the investigation of vulcanization characteristics by means of Rheometer. The optimum Mooney viscosity of compounded rubber was found to be approximately $ML_{1+4}(100^{\circ}C)$ $30\sim45$. Excess mustication makes a dispersion of ingredients worse, consequently it causes deformation of shapes and heterogenous cell distribution. In other words the articles are rejected because of its insufficient workmanship. The results of physical properties of the products are indicated in Table 3. It has shown that the quality meet requirement when tested in accordance with ASTM D572, 573 and D 395. The test results o CR/IR blends in terms of hardness, volume change by blowing, tensile strength and elongation have been shown.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.245-251
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• 2006

The main idea of this study is to turn attention on the question of good cooling ability of customer substations in large district heating networks. The main reason for that is based on our experience that the optimization of district heating very often is directed toward production, whereas questions of optimal distribution are neglected if only the necessary load can be supplied and the customer's request for comfort is met. Our view is that low return temperature(operational temperature differences, ${\Delta}T$) in district heating systems is an Important feature for efficient net operation and gives both economic and operational benefits to the district heating supplier Furthermore, it is as well a prerequisite for meeting the customers demand for reliable supply of the heat load. However, in many practical cases we have seen that district heating return temperatures are higher than necessary. Hence, the aim of the study is to propose and verify a method for detection of the most critical consumers of the net and to identify the reasons for resulting high return temperature. From the results, temperature control system is presented as one of the most important reason of high return temperature in DH networks.