• Title/Summary/Keyword: A/W

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Thermal Properties of Granite for Installation of Underground Heat Exchanger (지중 열교환기 설계를 위한 화강암의 열물성 연구)

  • Kim, Jong-Chan;Lee, Young-Min;Koo, Min-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.456-459
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    • 2007
  • Thermal conductivities (TC) of 57 Jurassic muscovitic granite samples (KIGAM) and 149 porphyritic granite samples (Yeonki: BE-2, BE-3) were measured with LFA-447. Ranges of TC values are $2.429{\sim}3.878$ W/mK (KIGAM), $2.220{\sim}3.767$ W/mK (Yeonki, BE-2) and $2.019{\sim}3.990$ W/mK (Yeonki, BE-3); arithmetic means are 2.924 W/mK (KIGAM), 2.907 W/mK (Yeonki, BE-2), and 2.881 W/mK (Yeonki, BE-3), respectively. In this study, harmonic mean values were calculated to estimate the average value of TC. Harmonic mean values are 2.883 W/mK (KIGAM), 2.886 W/mK (Yeonki, BE-2), and 2.866 W/mK (Yeonki, BE-3), respectively. Heat extraction rates of a borehole heat exchanger strongly depend on TC values. Heat-extraction rates from re values are expected to be a little lower than 84 W/m in all sites. However, considering ground water flow, it is expected that actual heat extraction rate would be higher than the expected value.

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Optimization of Sugar Replacement with Date Syrup in Prebiotic Chocolate Milk Using Response Surface Methodology

  • Kazemalilou, Sahar;Alizadeh, Ainaz
    • Food Science of Animal Resources
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    • v.37 no.3
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    • pp.449-455
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    • 2017
  • Chocolate milk is one of the most commonly used non-fermentative dairy products, which, due to high level of sucrose, could lead to diabetes and tooth decay among children. Therefore, it is important to replace sucrose with other types of sweeteners, especially, natural ones. In this research, response surface methodology (RSM) was used to optimize the ingredients formulation of prebiotic chocolate milk, date syrup as sweetener (4-10%w/w), inulin as prebiotic texturizer (0-0.5%w/w) and carrageenan as thickening agent (0-0.04%w/w) in the formulation of chocolate milk. The fitted models to predict the variables of selected responses such as pH, viscosity, total solid, sedimentation and overall acceptability of chocolate milk showed a high coefficient of determination. The independent effect of carrageenan was the most effective parameter which led to pH and sedimentation decrease but increased viscosity. Moreover, in most treatments, date syrup and inulin variables had significant effects which had a mutual impact. Optimization of the variables, based on the responses surface 3D plots showed that the sample containing 0.48% (w/w) of inulin, 0.04% (w/w) of carrageenan, and 10% of date syrup was selected as the optimum condition.

Enhancement of Microstructural Homogeneity of W-Cu Pseudo-alloy by Adding W-Cu Composite Powder in Infiltration Process

  • Hong, Moon-Hee;Choi, Jae-Ho;Lee, Seong;Kim, Eun-Pyo;Noh, Joon-Woong;Lee, Sung-Ho;Kim, Young-Moo
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.948-949
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    • 2006
  • An infiltration technique using W-Cu composite powder has been developed to enhance microstructural uniformity of W-Cu pseudo-alloy. W-Cu composite powder, manufactured by reduction from $WO_3$ and CuO powder mixtures, were blended with W powder and then cold iso-statically pressed into a cylindrical bar under 150 MPa. The pressed samples were pre-sintered at $1300^{\circ}C$ for 1 hour under hydrogen to make a skeleton structure. This skeleton structure was more homogeneous than that formed by using W and Cu powder mixtures. The skeleton structures were infiltrated with Cu under hydrogen atmosphere. The infiltrated W-Cu pseudo-alloy showed homogeneous microstructure without Cu rich region

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The Effect of Water-Filtered Infrared-A (wIRA) on Body Core and Body Surface Temperatures in Anesthetized Rabbits Maintained with Isoflurane

  • Geonho Choi;Dongseok Kim;Eungmo Tae;Ilgwon Jung;Sang-Kwon Lee;Won-Jae Lee;Sung-Ho Yun;Young-Sam Kwon;Min Jang
    • Journal of Veterinary Clinics
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    • v.40 no.1
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    • pp.44-49
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    • 2023
  • The purpose of this study was to evaluate body temperature changes in rabbits anesthetized using water-filtered infrared-A (wIRA). Ten rabbits were used for this study. For the experimental group (wIRA group; wG, n = 5), the experimental equipment was used and irradiated using wIRA. The control group (CG, n = 5) did not have any warming device. There were no significant differences in heart rate, respiration rate, and end tidal CO2 (EtCO2) between wG and CG. After 80 min, the core body temperature of wG rabbits was significantly higher than that of CG rabbits. The surface body temperature was significantly higher while receiving wIRA support at all time points after 5 min. In conclusion, in rabbits under inhalation anesthesia, the surface body temperature was better maintained than the core body temperature when using wIRA.

A Movability Support for Execution Engine of Browser-based Softwares (이동성을 지원하는 브라우저 기반 SW 실행 엔진)

  • Ku, Kyong-I;Nam, Ki-Hyuk;Chung, Moon-Young;Kim, Won-Young;Choi, Wan
    • Annual Conference of KIPS
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    • 2007.11a
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    • pp.482-484
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    • 2007
  • YouFree 는 이동형 SW 플랫폼을 기반으로 개인 맞춤형 지식 관리 및 개발 환경을 제공하고자 한다. YouFree 내의 브라우저 기반 SW 실행 엔진은 사용자가 이동한 곳에서 YouFree 가 실행될 수 있도록 이동성을 지원한다. 본 논문에서 제안하는 브라우저 기반 SW 실행 엔진은 설치 시 레지스트리의 변경하지 않으며, 실행을 위해 사용자의 추가적인 구성을 필요로 하지 않는다. 또한, 먼저 실행된 엔진이 존재하더라도 충돌 없이 새로운 엔진을 실행하여 사용자가 편리하게 브라우저 기반 SW 를 사용할 수 있도록 한다. 따라서 사용자는 YouFree 를 이용해 브라우저 기반 SW 를 서비스하거나, 또는 SW 의 개발도구, 개인 컨텐츠 관리 도구로 YouFree 를 이용할 수 있다.

A Study on Performance Improvement of a PHC-W Pile for PHC-W Retaining Wall (PHC-W 흙막이용 PHC-W말뚝의 성능개선에 관한 연구)

  • Kim, Chae Min;Kim, Sung Su;Jeon, Byeong Han;Choi, Yongkyu
    • Journal of the Korean Geotechnical Society
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    • v.33 no.2
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    • pp.27-34
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    • 2017
  • Various earth retaining wall methods were used on the domestic construction sites and a cast in place pile (C.I.P) method was mostly applied at deep excavation. Because of a lot of shortcomings in the C.I.P method, a new method using PHC-W earth retaining wall was developed. The earth retaining wall method using PHC-W piles has a lot of advantages including that it is safer than other earth retaining wall methods due to uniform quality and high rigidity. PHC-W was designed to effectively resist lateral earth pressure by alternating cross section of PHC pile. And increment of bending moment and shear strength were verified through KS F 4306 tests, and were increased by 42% and 98% more than KS standards.

Effect of Phospholipid Zwitterionic Surfactant CDP-W on the Characteristics of Liposome (인지질계 양쪽성 계면활성제 CDP-W 첨가가 리포좀 특성에 미치는 영향)

  • Jeong Min Lee;Jong Choo Lim
    • Applied Chemistry for Engineering
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    • v.35 no.3
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    • pp.230-238
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    • 2024
  • In the present work, the interaction of lipid-based zwitterionic surfactant CDP-W with the vesicle membrane of phospholipids was investigated. For this purpose, interfacial properties such as critical micelle concentration (CMC) and surface tension were measured for the zwitterionic surfactant CDP-W and lecithin S100-3. The zeta potential of 1 wt% aqueous surfactant solutions was also measured as a function of pH to determine the iso-electric point of CDP-W surfactant, where the characteristic of CDP-W surfactant changes from a cationic surfactant to an anionic surfactant. Based on the iso-electric point measurement of CDP-W surfactant, the effects of pH change and CDP-W addition on the stability of S100-3 liposome systems were studied, such as average particle size, polydispersity index (PDI), and zeta potential. The effect of CDP-W on the fluidity characteristics of liposome membranes such as fluorescence anisotropy ratio, deformability, and melting point was investigated at pH 6 where the most stable liposomes were prepared to understand the effect of the fluidity of the liposome membrane on the encapsulation efficiency of active materials and the stability of liposome systems.

DYE PENETRATION AND SURFACE CHANGE OF ROOT CANAL WALL BY Nd : YAG LASER IRRADIATION (Nd:YAG 레이저 조사에 의한 근관벽의 색소 침투도 및 표면 변화에 관한 연구)

  • Lee, Kyoung-Beom;Shin, Dong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.21 no.1
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    • pp.300-310
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    • 1996
  • Recently, there have been attempts to obstruct the dentinal tubules and remove the smear layer by way of laser irradiation in the root canal during endodontic treatment. This treatment was designed to make the root canal to be nonporous. Using 33 extracted single rooted teeth, 30 teeth were divided into 3 groups (10 each), and 3 teeth were used as samples for SEM. Using Nd : YAG laser, the control group was not irradiated, experimental group l(1W group) was irradiated with 1W, 15pps, 15sec., 3 times, 6.7mJ and experimental group 2(3W group) was irradiated with 3W, 15pps, 15sec., 3 times 20mJ. Thereafter the roots were immersed in methylene blue for 8 hours, and the dye infiltration pattern was observed under stereomicroscope and canal wall surface change was observed under SEM. The results are as following ; 1. As a result of evaluating the dye infiltration rate of the apical and middle 1/3, there was significant difference between control group and 1W group, control group and 3W group and there was no significant difference between 1 W group and 3W group. 2. In each group, as a result of comparing the dye infiltration rate of the apical and middle 1/3, there was no significant difference in control and 1W group but significant difference in 3W group. 3. In the control group smear layer was scarecely found and many dentinal tubules were found to be open. 4. In the 1W group, the number of dentinal tubules were decreased and gradual changes of the dentin surface could be seen and 3W group, almost no dentinal tubules could be found and the dentin surface was changed a little more and showed signs of partial fusion.

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Development of a Generalized Software for IR Image Generation and Analysis (적외선 영상 생성 및 분석을 위한 종합 소프트웨어 개발)

  • Han, Kuk-Il;Kim, Do-Hwi;Choi, Jun-Hyuk;Ha, Nam-Koo;Jang, Hyun-Sung;Kim, Tae-Kuk
    • KIISE Transactions on Computing Practices
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    • v.23 no.3
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    • pp.141-147
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    • 2017
  • Recently there has been an increasing demand for developing a domestic software (S/W) for infrared signature generation to prevent technology leakage and match the domestic operating environment. In this study, we developed a S/W for infrared signature generation and presented its structures and functions for creating and analyzing the IR images of designated spectral bands. The proposed S/W generates IR images of an object through calculations of surface temperatures and IR signals including the self-emitted, surface reflected and path dependent radiances. Moreover, the proposed S/W includes the features of infrared threat analyses from the generated IR images including the infrared contrast radiant intensity (CRI), detection ranges or detection probability analyses, unlike the imported, commercial infrared signature generation S/W.

DEVELOPMENT OF A S/W SYSTEM FOR RELATIVE POSITIONING USING GPS CARRIER PHASE (GPS의 반송파 위상을 이용한 상대측지 S/W의 개발)

  • 안용원;김천휘;박필호;박종옥;조정호
    • Journal of Astronomy and Space Sciences
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    • v.14 no.2
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    • pp.347-354
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    • 1997
  • We developed a GPS phase data processing S/W system which calculates baseline vectors and distances between two points located in the surface of the Earth. For this development a Double-Difference mothod and L1 carrier phase data from GPS(Global positioning System) were used. This S/W system consists of four main parts: satellite position calculation, Single-Difference equation, Double-Difference equation, and correlation. To verify our S/W, we fixed KAO($N36^{circ}.37,E127^{circ}.37,H77.61m$), one of the International GPS Services for Geodynamics, which is located at Tae-Jon, and we measured baseline vectors and relative distances with data from observations at approximate baseline distances of 2.7, 42.1, 81.1, 146.6km. Then we compared the vectors and distances with the data which we obtained from the GPSurvey S/W system, with the L1/L2 ION-Free method and broadcast ephemeris. From the comparison of the vectors and distances with the data from the GPSurvey S/W system, we found baseline vectors X, Y, Z and baseline distances matched well within the extent of 50cm and 10cm, respectively.

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