• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.665-668
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• 1999

Thin films of Pb(Zr,Ti)O$_3$ were fabricated by means of the sol-gel spin-coating method and the multi-coating of eight coating numbers. The thin films were dried on the temperature range of 250 ~ 400($^{\circ}C$), whenever the specimens were dried after each coating Processing. The fabricated ferroelectric thin films of lead zirconate titanate(PZT) were treated with the rapid thermal annealing(RTA) at 650($^{\circ}C$),or 3(min), and direct insertion thermal annealing(DITA) at 650($^{\circ}C$), for 30(min). The measured properties of dielectric thin films were following: The good results of dielectric properties were shown by the RTA specimen. The saturation polarization(Ps), remanent polarization(Pr), coercive field (Ec), dielectric constant and dielectric loss factor of the RTA specimen were estimated to be about 27.1[ $\mu$ C/$\textrm{cm}^2$], 13.7[ $\mu$ C/$\textrm{cm}^2$], 55.6(kV/cm), 786 and 6.4(%) respectively.

• 한국자원식물학회지
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• 제27권6호
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• pp.635-641
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• 2014

Scutellaria baicalensis $G_{EORGI}$ (Scutellariae Radix) has been used to clear heat and to dry dampness in the stomach or intestines, which manifests as diarrhea or dysenteric disorder. In this study, we investigated the effective preparation of active components in Scutellariae Radix using the methods of solvent extraction and absorption fractionation for the development of new functional food or pharmaceuticals. The marker substances, baicalin, baicalein, wogonoside, and wogonin were directly isolated from the Scutellariae Radix. There chemical structures were elucidated by spectroscopic analysis. The Scutellariae Radix was extracted with hot water. To enhance yield of flavonoids in Scutellariae Radix, the hot water extract was dissolved in ethanol with concentration dependent manner. The precipitates were separated using centrifugal techniques at 10,000 rpm. Supernatant liquid was applied to the HPLC for quantification of major compounds. Separately, the hot water extract was absorbed on Diaion HP-20 resin. And then, the absorbed fraction was eluted with methanol for HPLC. The contents of baicalin, baicalein, wogonoside and wogonin in different treatment methods were analyzed by HPLC. Total amount of four major components were 16.9% in 50% ethanol extract, 21.7% in 70% ethanol extract, 20.5% in 90% ethanol extract, and 39.3% in absorbed fraction of Diaion HP-20 resin. In these results, we found that resin absorption method is suitable for the extraction of enriched flavonoids from Scutellariae Radix.

• Corrosion Science and Technology
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• 제23권4호
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• pp.266-277
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• 2024

Due to its good corrosion and heat resistance with excellent mechanical properties, 304L stainless steel is commonly used in the fabrication of spent nuclear fuel dry storage canisters. However, welds are sensitive to stress corrosion cracking (SCC) due to residual stress generation. Although SCC resistance can be improved by stress relieving the weld and changing the chloride environment, it is difficult to change corrosion environment for certain applications. Stress control in the weld can improve SCC resistance. Ultrasonic shot peening (USP) needs further research as compressive residual stresses and microstructure changes due to plastic deformation may play a role in improving SCC resistance. In this study, 304L stainless steel was welded to generate residual stresses and exposed to a chloride environment after USP treatment to improve SCC properties. Effects of USP on SCC resistance and crack growth of specimens with compressive residual stresses generated more than 1 mm from the surface were studied. In addition, correlations of compressive residual stress, grain size, intergranular corrosion properties, and pitting potential with crack propagation rate were determined and the improvement of SCC properties by USP was analyzed.

• 한국분말재료학회지
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• 제9권6호
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• pp.441-448
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• 2002

Dispersions of non-soluble ceramic particles in a metallic matrix can enhance the strength and heat resistance of materials. With the advent of mechanical alloying it became possible to put the theoretical concept into practice by incorporating very fine particles in a flirty uniform distribution into often oxidation- and corrosion- resistant metal matrices. e.g. superalloys. The present paper will give an overview about the mechanical alloying technique as a dry, high energy ball milling process for producing composite metal powders with a fine controlled microstructure. The common way is milling of a mixture of metallic and nonmetallic powders (e.g. oxides. carbides, nitrides, borides) in a high energy ball mill. The heavy mechanical deformation during milling causes also fracture of the ceramic particles to be distributed homogeneously by further milling. The mechanisms of the process are described. To obtain a homogeneous distribution of nano-sized dispersoids in a more ductile matrix (e.g. aluminium-or copper based alloys) a reaction milling is suitable. Dispersoid can be formed in a solid state reaction by introducing materials that react with the matrix either during milling or during a subsequent heat treatment. The pre-conditions for obtaining high quality materials, which require a homogeneous distribution of small dis-persoids, are: milling behaviour of the ductile phase (Al, Cu) will be improved by the additives (e.g. graphite), homogeneous introduction of the additives into the granules is possible and the additive reacts with the matrix or an alloying element to form hard particles that are inert with respect to the matrix also at elevated temperatures. The mechanism of the in-situ formation of dispersoids is described using copper-based alloys as an example. A comparison between the in-situ formation of dispersoids (TiC) in the copper matrix and the milling of Cu-TiC mixtures is given with respect to the microstructure and properties, obtained.

• 한국한의학연구원논문집
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• 제14권2호
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• pp.101-106
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• 2008

Objective: The purpose of this study is to examine the characteristics and the improvement in the symptoms of the patients who showed improvement after the administration of Yeoldahanso-tang and Cheongpyesagan-tang. Methods: The patients whose Sasang Constitution were examined by an expert at six Oriental medical hospitals and three regional Oriental-medicine clinics, 89 showed a predetermined symptom improvement when Yeoldahanso-tang and Cheongpysagan-tang were administered to them from November 2007 to July 2008. The traits of the patients and the effects of their treatment were examined. Results and Conclusions: 1. There were about as many male patients as there were female patients, but 21.3% of the patients who were female and who were in their 40's showed the most improvement, which makes them the biggest category in this study. 2. The main syndromes in which the patients showed improvement were hemi-paralysis, vertigo, and headache, and the ordinary symptoms in which the patients showed improvement were diarrhea, fatigue, and dry mouth. 3. The average food intake of the patients was highest and their feces had intermediate hardness (semi-soft). 4. The amount of the patients' sweat was either high(38.2%) or appropriate(38.2%) and they showed a dislike of heat over coldness. 5. Among the diseases that the patients previously had, high blood pressure. The above results show that Yeoldahanso-tang and Cheongpyesagan-tang can be considered beneficial to females in their 40's and to stroke patients whose food intake is normal, whose sweat level is either copious or appropriate, who dislike heat and who are suffering from high blood pressure.

• Animal Bioscience
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• 제37권7호
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• pp.1303-1315
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• 2024

Objective: This study aimed to determine the effects of increasing energy and protein levels in diets by including protected fat (PF), glycerol (GL), and soybean meal (SBM) on growth performance, physiological parameters, carcass characteristics, and behavioral measurements of late-fattening Hanwoo steers under heat stress conditions. Methods: Thirty-six steers (initial body weight, 724.9±58.3 kg; age, 25.5±0.4 month) were assigned into control (total digestible nutrient [TDN] 76%, crude protein [CP] 15%), PF (TDN 83.6%, CP 15%), PF+GL (TDN 83.6%, CP 15%) and PF+GL+SBM (TDN 83.6%, CP 16.5%) by randomized complete block design for a total of 16 weeks with division of 4-week periods. The average temperature-humidity index was 87.0 (1st period; severe), 82.8 (2nd; moderate), 71.4 (3rd; comfort), and 68.1 (4th; comfort). Results: The dry matter intake (DMI) showed no treatments differences during the whole experiment. However, DMI in 1st and 2nd period decreased by approximately 30% and 10% compared to 4th period, respectively. Higher average daily gain and feed conversion ratio were noted for treatments compared to control at both 1st and 2nd period (p<0.05). There were no treatment effects on rectal temperature (RT), cortisol, and behaviors during the entire experiment. However, both RT and cortisol in 0, 1st and 2nd period were higher than those of 3rd and 4th period (p<0.05). Carcass yield and grade remained unaffected by increasing TDN and CP levels. Behavioral changes in the hot season (1st period) included reduced lying (43%), increased standing (48%), decreased walking (62%), and decreased eating (38%) (p<0.05), with an increase in drinking by 54%. Rumination during standing was 53% higher, while rumination during lying was about 33% lower compared to the post-hot season (3rd period) (p<0.05). Conclusion: Dietary supplementation of protected fat in late-fattening Hanwoo steers under heat stress had a positive effect on preventing a reduction in performance.

• 한국해양공학회지
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• 제24권6호
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• pp.76-80
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• 2010

Oil hydraulic piston pumps are being extensively used around the world, because of their simple design, light weight, effective cost, etc. An oil hydraulic pump is likely to have the serious problems of high leakage, friction, and low energy efficiency after a long period of use. In an oil hydraulic piston pump, the clearance between the valve block and piston plays an important role for volumetric and overall efficiency. In this study, the wear property of the SACM645 material with DLC coating used for a hydraulic piston pump was determined by experimentation with variable heat treatment. To investigate the effect according to the piston surface condition, five different types of specimens were prepared. The maximum tensile strengths of the QT and QT Nitration specimens had similar values of about 800 MPa, but the strains indicated a big difference. In a wear test, the wear characteristic of the DLC coating specimen was shown to be excellent. The QT, QT + IH, QT + Nitration, and matirx specimen showed similar wear characteristics. In the case of a dry condition without oil, the DLC coating specimen had good wear resistance, with no wear shown.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.131.1-131.1
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• 2010

This study was conducted for engineering optimization for the gasification process which is the key factor for success of Taean IGCC gasification plant which has been driven forward under the government support in order to expand to supply new and renewable energy and diminish the burden of the responsibility for the reduction of the green house gas emission. The gasification process consists of coal milling and drying, pressurization and feeding, gasification, quenching and HP syngas cooling, slag removal system, dry flyash removal system, wet scrubbing system, and primary water treatment system. The configuration optimization is essential for the high efficiency and the cost saving. For this purpose, it was designed to have syngas cooler to recover the sensible heat as much as possible from the hot syngas produced from the gasifier which is the dry-feeding and entrained bed slagging type and also applied with the oxygen combustion and the first stage cylindrical upward gas flow. The pressure condition inside of the gasifier is around 40~45Mpg and the temperature condition is up to $1500{\sim}1700^{\circ}C$. It was designed for about 70% out of fly ash to be drained out throughout the quenching water in the bottom part of the gasifier as a type of molten slag flowing down on the membrane wall and finally become a byproduct over the slag removal system. The flyash removal system to capture solid particulates is applied with HPHT ceramic candle filter to stand up against the high pressure and temperature. When it comes to the residual tiny particles after the flyash removal system, wet scurbbing system is applied to finally clean up the solids. The washed-up syngas through the wet scrubber will keep around $130{\sim}135^{\circ}C$, 40~42Mpg and 250 ppmv of hydrochloric acid(HCl) and hydrofluoric acid(HF) at maximum and it is turned over to the gas treatment system for removing toxic gases out of the syngas to comply with the conditions requested from the gas turbine. The result of this study will be utilized to the detailed engineering, procurement and manufacturing of equipments, and construction for the Taean IGCC plant and furthermore it is the baseline technology applicable for the poly-generation such as coal gasification(SNG) and liquefaction(CTL) to reinforce national energy security and create new business models.

• 대한한의학원전학회지
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• 제37권2호
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• pp.49-76
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• 2024

Objectives : The purpose of this paper is to examine the mechanism and treatment of the Zangfu warm disease in the Beijiqianjinyaofang. Methods : This study examined the Zangfu warm disease content in the Beijiqianjinyaofang, Shanghanzongbinglun, Saninfang, based on the Neijing explanation of the pathological mechanism. Treatment was analyzed among the three texts in terms of their similarity and difference. Results & Conclusions : 1. Zangfu warm disease is caused by seasonally inappropriate qi, which is infectious, epidemic, and seasonal. 2. While the Qingjinqian disease pattern was explained in terms of the relationship between Shaoyin and Shaoyang, the actual disease pattern happened more in the Taiyang channel, and partly in the Shaoyang channel. For treatment of Fu deficiency pattern, the Chaihudihuangtang was listed in the Qianjinyaofang and the Shanghanzongbinglun, while in the Sanyinfang, the formula was modified to extinguish heat and thin phlegm, while reinforcing healthy qi. 3. The Chimaifei disease pattern was explained in terms of the relationship between Shaoyin and Taiyang that is deeply associated with Wei qi. For treatment of Fu deficiency the Qianjinyaofang and Shanghanzongbinglun used the Shigaodihuangtang, while the Sanyinfang reinforced healthy qi and eliminated pathogenic qi. 4. The Huangrousui disease pattern was explained as being caused by problems in the Taiyin and Yangming, in which the Triple Burner fails to control and manage cold dampness. In treating Zang excessiveness, the Qianjinyaofang and Shanghanzongbinglun used the Xuanshenhanshuishitang, while the Sanyinfang instructed to reinforce healthy qi and eliminate pathogenic qi. In treating Fu deficiency, the Sanyinfang instructed to warm the center and dry dampness, tonifying the Spleen and reinforcing qi. 5. The Baiqili disease pattern was explained within the relationship between Taiyin and Taiyang. In treating Fu deficiency, the Qianjinyaofang and Shanghanzongbinglun used the Shigaoxingrentang, while the Sanyinfang instructed to reinforce healthy qi and eliminate pathogenic qi. In treating Zang excessiveness, the Qianjinyaofang and Shanghanzongbinglun used the Shigaocongbaitang, while the Sanyinfang instructed to reinforce healthy qi and eliminate pathogenic qi. 6. The Heiguwen disease pattern was explained as being caused by stagnation and obstruction in the Triple Burner due to clash between Taiyang and Shaoyin. In treating Zang excessiveness, the Qianjinyaofang and Shanghanzongbinglun used the Kushenshigaotang, while the Sanyinfang instructed to reinforce healthy qi and eliminate pathogenic qi. The Zangfu Warm Disease is a infectious disease concept which is based on the Five Zang that integrates the meridian aspect together with the Six Fu with which there is an external/internal relationship. This concept and treatment could be considered in dealing with COVID-19.

• 한국작물학회지
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• 제64권1호
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• pp.18-24
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• 2019

콩 발아기간 중 몇 가지 물리적 요인(열 처리, 수분공급 제한, 조명 처리, 초음파 처리)이 이소플라본 함량 증대에 미치는 영향에 대하여 알아보았다. 1. 대조군과 함께 4가지 처리는 모두 발아시간이 경과함에 따라 이소플라본 함량이 높아졌다. 2. 초음파 처리가 이소플라본 함량 증대에 가장 큰 효과가 있었으며, 발아기간 중 조명 처리도 유의성이 인정되었다. 3. 열처리도 이소플라본 함량 증대에 유의적인 효과가 있었으나 발아기간 중 부패립이 많이 발생하는 문제가 있었으며, 수분제한은 대조군에 비해 이소플라본 함량이 떨어지는 경향이었다. 4. 이소플라본 종류별 함량을 분석한 결과 malonyl-glucoside가 대체로 총 이소플라본 함량의 85% 이상을 차지하였고 다음으로는 glucoside > aglycone > acetyl-glucoside 순서로 함량이 높았으며, 발아가 진행되면서 aglycone 함량이 증가하는 경향이었다. 이와 같은 결과를 볼 때 발아기간 중 외부의 물리적 요인 처리가 콩 종자의 이소플라본 함량을 증대시킴을 확인할 수 있었다.