• Title/Summary/Keyword: Hall effects

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A Study on How Baekje delivered Stylobate-Constructing Techniques to Silla Counterpart (백제(百濟) 기단(基壇) 축조술(築造術)의 대신라(對新羅)의 전파(傳播))

  • Cho, Won-Chang
    • Journal of architectural history
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    • v.14 no.2 s.42
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    • pp.57-69
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    • 2005
  • A stylobate, part of the foundation for hardening soil below the floor, has been built with a variety of materials, such as stone, tile and brick, in several kinds of combined constructions of soil, stone, and brick. In particular, Baekje used a tile-piled stylobate that could not be found in Goguryeo and Silla counterparts, thus showing outstanding performance in the construction culture. Archeological excavations up to now evidence the stylobate played a role in building the magnificent structures or enhancing the decorative effects. It can be enough inferred that such features are reflected on dual footing stylobate, framed stylobate and tile-piled stylobate. Baekje had delivered its techniques for constructing stylobate to Silla from about the middle of 6th century. They can be traced down back from the dual stylobate that has been identified in Hwangryong-sa temple lastly built in the old site of Silla, those constructed with broken stones at Najeong, tile-piled stylobate of the mode of vertical-horizontal rows which had been established in Inwang-dong, Gyeongju, the capital of the kingdom, and a framed stylobate at Hall enshrining Buddha (Golden Hall) site of Gameun-sa temple site. Recently, relics of structures, including temple sites, are intermittently being unearthed in the old sites of Baekje and Silla. However, studies linking archeology with architecture can be rarely found up to now. It is, therefore, necessary that the relics should be correctly construed in archeological as well as architectural aspects. We expect that further studies can graft architectural insight into archeological analysis.

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Manufacture of Water-Resistant Corrugated Board Boxes for Agricultural Products in the Cold Chain System(II) - Application Methods of Chemicals for Improving Water and Moisture Resistance of Corrugated Boards - (농산물 저온유통용 내수 골판지 상자의 제조(제2보) - 골판지의 내수 및 내습성 향상을 위한 약품 적용 방법 -)

  • Jo, Jung-Yeon;Min, Choon-Ki;Shin, Jun-Seop
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2004.04a
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    • pp.192-210
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    • 2004
  • Application methods of chemicals were investigated tn minimize strength reduction of corrugated boards under the high humidity environment encountered in the cold chain system. Starch insolubilizers were introduced in the starch solution preparation of the Stain hall method and their insolubilization effect of starch binder were estimated. The performance of water repellent agents(WRA) and moisture proof agents(MPA) were evaluated in terms of water and moisture resistance. And effects of the combination of the chemicals and the coating method were also examined. Addition of the polyamine polyamide insolubilizer to the main part in the Stain hall process improved the binding force and water resistance of starch, which contributed to minimize the strength reduction of paper under the high humidity environment. AZC and Glyoxal type insolubilizers could not be used in the experiment due to an excessively increased viscosity of starch solution and the poor stability. Conventional WRA treatment to the base paper enhanced water and moisture resistance very slightly even though water repellency of the paper reached R10 by the treatment. MPA showed excellent performance than WRA not only in water and moisture resistance but in water repellency. Double coating on paper with MPA was more effective than the single coating at the same coating weight. A newly developed MPA showed excellent performance and runnability only by a single coating instead of a double coating.

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Thermodynamic Analysis of Vapor Explosion Phenomena (증기폭발 현상의 열역학적 해석)

  • Bang, Kwang-Hyun
    • Nuclear Engineering and Technology
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    • v.25 no.2
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    • pp.265-275
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    • 1993
  • A vapor explosion has been a concern in nuclear reactor safety due to its potential for a destructive mechanical energy release. In order to properly assess the hazard of a vapor explosion, it is necessary to accurately estimate the conversion efficiency of the thermal energy to mechanical energy. In the absence of a complete model to determine the explosive energy yield, one may have to rely on a simpler upper bound estimate such as a thermodynamic model. This paper discusses various thermodynamic models and presents a clarification of each model in their mathematical formulation and the thermodynamic work conversion. It is shown that the work release in the shock adiabatic model of Board and Hall is essentially equal to that of Hicks-Menzies thermodynamic model. The effect of coolant void fraction on the explosion efficiency is also predicted based on these thermodynamic models. Finally, the Hicks-Menzies model is modified to account for the chemical reaction between a metallic fuel and water and the resultant effects on the explosion expansion work are discussed.

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Property Variation of Diamond-like Carbon Thin Film According to the Annealing Temperature (열처리에 따른 Diamond-like Carbon (DLC) 박막의 특성변화)

  • Park, Ch.S.;Koo, K.H.;Park, H.H.
    • Journal of the Microelectronics and Packaging Society
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    • v.18 no.1
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    • pp.49-53
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    • 2011
  • Diamond-like carbon (DLC) films is a metastable form of amorphous carbon containing a significant fraction of Sp3 bond. DLC films have been characterized by a range of attractive mechanical, chemical, tribological, as well as optical and electrical properties. In this study DLC films were prepared by the RF magnetron sputter system on $SiO_2$ substrates using graphite target. The effects of the post annealing temperature on the Property variation of the DLC films were examined. The DLC films were annealed at temperatures ranging from 300 to $500^{\circ}C$ using rapid thermal process equipment in vacuum. The variation of electrical property and surface morphology as a function of annealing treatment was investigated by using a Hall Effect measurement and atomic force microscopy. Raman and X-ray photoelectron spectroscopy analyses revealed a structural change in the DLC films.

Effects of Doping Concentrations and Annealing Temperatures on the Electrical and Optical Properties of Ga-doped ZnO Thin Films by Sol-gel Method (Sol-gel 법으로 제작한 Ga-doped ZnO 박막의 도핑 농도와 열처리 온도가 전기적 및 광학적 특성에 미치는 효과)

  • Kang, Seong-Jun;Joung, Yang-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.3
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    • pp.558-564
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    • 2012
  • We fabricated Ga doped ZnO (GZO) thin films on the glass substrate (Eagle 2000) with various of Ga doping concentration and annealing temperatures using sol-gel method, electrical and optical properties were investigated. When the GZO thin films doped with 1 mol% of Ga and annealed at $600^{\circ}C$, the excellent (002) orientation was observed. In the results of Hall measurement, carrier concentration decreased and resistivity increased due to segregation effect with increasing of the Ga doping concentration. The largest carrier concentration and lowest resistivity were $9.13{\times}10^{18}cm^{-3}$ and $0.87{\Omega}cm$, respectively, in the GZO thin films doped with 1 mol% Ga and annealed at $600^{\circ}C$. All films is higher than 80 % in the visible light region. Energy band gap narrowing due to Burstein-Moss effect was observed with increasing of Ga doping concentration from 1 to 4 mol%.

Manufacture of Water-Resistant Corrugated Board Boxes for Agricultural Products in the Cold Chain System(II). -Application Methods of Chemicals for Improving Water and Moisture Resistance of Corrugated Boards- (농산물 저온유통용 내수 골판지 상자의 제조(제2보) - 골판지의 내수 및 내습성 향상을 위한 약품 적용 방법 -)

  • 조중연;민춘기;신준섭
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.36 no.2
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    • pp.60-69
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    • 2004
  • Application methods of chemicals were investigated to minimize strength reduction of corrugated boards under the high humidity environment encountered in the cold chain system. Starch insolubilizers were introduced in the starch solution preparation of the Stein hall method and their insolubilization effect of starch binder were estimated. The performance of water repellent agents(WRA) and moisture proof agents(MPA) were evaluated in terms of water and moisture resistance. And effects of the combination of the chemicals and the coating method were also examined. Addition of the polyamine polyamide insolubilizer to the main part in the Stein hall process improved the binding force and water resistance of starch, which contributed to minimize the strength reduction of paper under the high humidity environment. AZC and Glyoxal type insolubilizers could not be used in the experiment due to an excessively increased viscosity of starch solution and the poor stability. Conventional WRA treatment to the base paper enhanced water and moisture resistance very slightly even though water repellency of the paper reached R10 by the treatment. MPA showed excellent performance than WRA not only in water and moisture resistance but in water repellency. Double coating on paper with MPA was more effective than the single coating at the same coating weight. A newly developed MPA showed excellent performance and runnability only by a single coating instead of a double coating.

Effects of Bilayer Period on the Microhardness and Its Strengthening Mechanism of CrN/AlN Superlattice Coatings

  • Kim, SungMin;Kim, EunYoung;Kim, DongJun;La, JoungHyun;Lee, SangYul
    • Journal of Surface Science and Engineering
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    • v.45 no.6
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    • pp.257-263
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    • 2012
  • CrN/AlN multilayer coatings with various bilayer periods in the range of 1.8 to 7.4 nm were synthesized using a closed-field unbalanced magnetron sputtering method. Their crystalline structure, chemical compositions and mechanical properties have been investigated with Auger electron spectroscopy, X-ray diffractometry, atomic force microscopy, nanoindentation, scratch tests. The properties of the multilayer coatings varied strongly depending upon the magnitude of the bilayer period. The multilayer coating with a bilayer period of 1.8 nm showed the maximum hardness and an elastic modulus of approximately 37.6 and 417 GPa, respectively, which was 1.54 times higher than the hardness predicted by the rule of mixture from the CrN and AlN coatings. The hardness of the multilayer coating increased as the bilayer period decreased, i.e. as the rotation speed increased. The Hall-Petch type relationship, hardness being related to (1/periodicity)$^{-1/2}$, suggested by Lehoczky was confirmed for the CrN/AlN multilayer coatings with bilayer period close to the 5-10 nm range. With decreasing bilayer period, the surface morphology of the films became rougher and the critical load of films for adhesion strength gradually decreased.

The Effects of Agricultural Experience Program on Agricultural Literacy and Hand Function Improvement of Adolescents Living in Self-reliance Residence Hall

  • Ryu, Ja Yeong;Kim, Mi Jin;Yun, Suk Young
    • Journal of People, Plants, and Environment
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    • v.24 no.3
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    • pp.277-283
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    • 2021
  • Background and objective: This study was conducted to increase understanding of agriculture through agricultural experience programs for adolescents living in self-reliance residence hall, and to investigate changes in work performance ability through changes in hand function. Methods: There were 11 subjects, and the average age was 18.2 years, all males without disabilities. The agricultural experience program consists of a total of 10 sessions including orientation and watching videos on future agriculture, creating vegetable gardens, planting, managing each crop, harvesting, visiting the processing room, and selling at a local food store. Results: The change in agricultural literacy by the agricultural experience program positively improved from a score of 113.73 to 127.91 (p = .008). The changes by sub-item are as follows. The value and safety of agri-foods (p = .020) and agriculture and natural environment (p = .007) were significantly improved. The function and value of rural areas (p = .050), production of agricultural products (p = .160), processing and distribution of agricultural products (p = .248), and agricultural policies (p = .058) were not significantly changed. The simple function of the hands was measured by the number of pegs inserted during 30 seconds, and the assembly function was measured by the number of pegs inserted during 60 seconds. In the case of simple function, the dominant hand was improved from 14.82 to 15.83 (p = .014), andthe non-dominant hand was also significantly improved from 13.79 to 15.01 (p = .002). There was no significant improvement in the simple function (p = .153) and assembly function (p = .770) of both hands. Conclusion: It is considered that the agricultural experience program will enable youths living in self-reliance residence halls to enhance their understanding of agriculture as an occupation, and enable them to play a role as wise consumers by positively affecting improvements in their agricultural literacy and simple hand functions.

Electrical and Optical Properties of BZO Thin Films Deposited by RF Magnetron Sputtering with Various Annealing Temperatures (열처리 온도에 따른 BZO 박막의 전기적 및 광학적 특성)

  • Seong-Jun Kang;Yang-Hee Joung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.19 no.1
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    • pp.47-52
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    • 2024
  • The effects of annealing temperature on the optical and electrical properties of BZO thin films, grown on glass substrate, have been investigated. Analysis of the XRD shows that regardless of the annealing temperature, all BZO thin films indicate the c-axis orientation. The full width of half maximum (FWHM) decreases from 1.65 to 1.07° as the annealing temperature increases from 400 to 600℃. The average transmittance in the visible light region showed a high value of 85% without significantly affecting the annealing temperature. The results of Hall effect measurements indicate that the carrier concentration and mobility increased and the resistivity decreased as the annealing temperature increased. The resistivity and the carrier concentration of the BZO thin films annealed 600℃ were 9.75×10-2 Ω·cm and 4.21×1019 cm-3 respectively, showing the best value. The optimization of deposition and annealing conditions will certainly make the BZO thin films promising materials for the application to the next generation of optoelectronic devices.

Optimum Design of Braced Steel Framed Structures Considering Soil Condition Under Earthquake Loads (지반조건을 고려한 브레이스된 강골조 구조물의 내진 최적설계)

  • Park, Moon-Ho;Kim , Ki-Wook;Lee , Seung-Jo;Park , Jung-Hwal
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.4
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    • pp.97-107
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    • 2006
  • This study is structural analysis and continuous, discrete optimum design of braced steel frame structures under earthquake loads considering soil condition. The program which is able to perform simultaneously structural analysis and continuous, discrete optimum design, it is applied steel frame structures using unbraced, Z-braced, and X-braced types and analyze the program about static loads and seismic loads. The purpose of this study is to present proper braced type for seismic effects by comparing and analyzing results of analytic method about various cases using specially Newmark-Hall design spectrum, ATC design spectrum and ATC equivalent static analysis and finding minimum weight and design variables which satisfy the ultimate strength requirements of AISC-ASD specifications, the serviceability requirements and allowable story drift requirements of ATC-3-06 and various constraints.