• Title/Summary/Keyword: Light induction

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A Study on the Architectural Characteristics of Mount Angel Abbey Library (마운트 엔젤 수도원 도서관의 건축 특성에 관한 연구)

  • Chung, Tae-Yong
    • Korean Institute of Interior Design Journal
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    • v.20 no.1
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    • pp.71-79
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    • 2011
  • Mount Angel Abbey library shows not only the general characteristics which Aalto had shown in his 60s but also special features of his last library project. Special features of Mount Angel library are the result of considering geography and existing context of the site. General characteristics of the library mainly come from the Aalto's concept for library especially considering light. Due to steep site, Mount Angel Abbey library has multi-layered and dynamic spatial configuration. Aalto considered the importance of daylight in the library and applied various kinds of openings to induce natural light. Therefore, Mount Angel Abbey library is the final result of his library type that developed from the Viipuri library of 1930s and his architectural thoughts of 1960s. As a combination of space and light, Mount Angel Abbey library is the outcome of Aalto's unique functional thoughts which maximize the function of the library through efficient induction of natural light.

Crystallization Characteristics of Metallocene Low Density Polyethylene (메탈로센 선형 저밀도 폴티에틸렌의 결정화 거동)

  • 김경룡;한정우;조봉규;강호종
    • Polymer(Korea)
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    • v.25 no.6
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    • pp.833-839
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    • 2001
  • The crystallization characteristics of metallocene linear low density polyethylene was investigated by small angle light scattering and comparison was made with Ziegler-Natta linear low density polyethylene. The special efforts were made to find out the effects of branching number, length of branching and co-monomer content of m-LLDPE on the crystallization behavior of m-LLDPE. It was found that m-LLDPE has longer induction time to start crystallization from the amorphous state than that of conventional LLDPE with similar branching number, but the rate of crystallization seems not change much in both LLDPEs. Lowering of branching number in m-LLDPE resulted in both increasing of rate of crystallization and reducing induction time to crystallize. In general, the maximum size of spherulites of m-LLDPE is bigger than that of conventional LLDPE.

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Process Design for the Tubular Hydroforming at Elevated Temperatures (온간 하이드로포밍 공정을 위한 시스템 설계)

  • Kim, B.J.;Park, K.S.;Sohn, S.M.;Lee, M.Y.;Moon, Y.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2006.05a
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    • pp.226-229
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    • 2006
  • Process design has been performed for the warm hydroforming of light weight alloy tubes. For the heating of tubes, specially designed induction heating system has been adopted to ensure rapid heating of tubes. The induction heating system uses 30kHz frequency induction coil in order to concentrate the energy in the tube and prevent the energy loss. But the induced heat by the integrated heating system, consisting of induction coil, tube, pressure oil and dies, was normally not equally distributed over the length and circumference of the tube specimen, and consequent temperature distribution was non-uniform. So additional heating element has been inserted into the inside of the tube to maintain the forming temperature and reduce temperature drop due to heat loss to the molds. And for that heat loss, a heat insulation system has also been installed. The drop in flow stress at elevated temperatures results in lower internal pressure for hydroforming and lower clamping forces. The proposed warm hydroforming process has been successfully implemented when applying 6061 aluminum extruded tubes.

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Improvement of Regeneration Efficiency from Mature Embryo and Leaf Base Segment in Korean Oat Genotypes

  • Kim Kyung-Hee;Moon Jung-Hun;Lee Sang-Kyu;Lee Byung-Moo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.49 no.4
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    • pp.349-353
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    • 2004
  • Mature embryo and leaf base segment of Korean oat were used as materials in an experiment to check plant regeneration efficiency. MS media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D), kinetin, and picloram were used for callus induction from mature embryos and leaf base segments. Three mg/l of 2,4­D and 3 mg/l of picloram in callus induction medium showed high frequency for plant regeneration from mature embryos. Leaf base segments were transferred to callus induction medium and incubated at $25^{\circ}C$ in 16/8 hr light/dark cycle for 3 weeks. Callus induction from leaf base segments of Malgwiri showed high efficiency in medium containing 3 mg/l of 2,4-D and 1 mg/l of kinetin $(91.8\%)$. In case of Samhangwiri, the combinations of phytohormones did not show significant difference. Regeneration from leaf base segments showed high frequency in shoot medium containing 1 mg/l of antiauxin, tri-iodobenzoic acid (TIBA) and 1 mg/l of 6-benzyladenine (BA). Calli induced from leaf base segments of Samhangwiri and Malgwiri in media containing 3 mg/l of 2,4-D and 3 mg/l of picloram showed high regeneration frequency. It appears that the callus initiation medium may be an important factor for subsequent plant regeneration.

Efficiency Improvement of Inverter Fed Induction Machine System Using Neural Network (신경망을 이용한 유도전동기-인버터 시스템의 효율향상)

  • Ryu, Joon-Hyoung;Lee, Seung-Chul;Choy, Ick;Kim, K.B.;Lee, K.W.
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.1984-1986
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    • 1998
  • This paper presents an optimal efficiency control for the inverter fed induction machine system using neural network. The motor speed and the load torque vary the efficiency characteristics of an induction motor. The optimal slip frequency has nonlinearity varied by the load torque as well as the motor speed. The induction motor is driven using the inverter system and the indirect vector control method which input is slip frequency. The neural network for estimating the optimal slip frequency has two input layer(the motor speed and the load torque) and one output layer(the optimal slip frequency that minimize the input power). Learning algorithm of the neural network is the back-propagation. Using the equivalent circuit including the nonlinearity of the induction motor, the loss reduction is analyzed quantitatively. Experimental results are shown noticeable power savings by proposed scheme in high speed and light load conditions.

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Study on Damage Mechanism Analysis and Recovery Characteristic of the Large Scale Steam Turbine Cased by Water Induction (대형 증기터빈 물유입에 의한 손상메커니즘 분석과 원상복구특성 연구)

  • Kim, D.Y.;Park, G.H.;Lee, B.H.
    • Journal of Power System Engineering
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    • v.15 no.5
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    • pp.22-29
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    • 2011
  • In this study, the damage mechanism of large scale steam turbine due to water induction was analyzed and recovery characteristics were reviewed. A turbine consists of the rotating rotor and the stationary casing, and the clearance between them is very small for the efficiency enhancement. If water induction, while relatively cold steam or water is introduced into turbine, occurs, the considerable humping is caused at the casing near the initial water induction point and that induces the rubbing between rotor and casing. Finally, it leads to the catastrophic failure. Bowed rotor has the different characteristics in the recovery depending on damage degree. The elastic deformation due to light rubbing is recovered by turning the rotor with 3 rpm under normal operation condition, but most plastic deformation due to rubbing deforms the local microstructure and that results in permanent deformation which could not be recovered under normal operation condition. Bowed rotor has diverse characteristics depending on the recovery method, and the method is empirical and needs the cutting edge technology. Careful recovery treatment of the rotor will eliminate the risks and secure the high quality rotor similar to new rotor. If any critical error is made during the recovery, the rotor would not be recovered permanently and it should be scrapped.

Effect of Salt Type and Concentration on the Growth of Lactic Acid Bacteria Isolated from Kimchi (소금의 종류와 농도가 배추김치에서 분리한 유산균의 생육에 미치는 영향)

  • Hahn, Young-Sook
    • Korean Journal of Food Science and Technology
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    • v.35 no.4
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    • pp.743-747
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    • 2003
  • Tests show that the growth of lactic bacteria in kimchi varies according to the type and concentration of salt used. Weissella confusa, the early stage bacteria in kimchi fermentation, increased sharply after 5 hr of induction with 3% light salt and refined salt. However, the induction period lengthened to 12 hr with 3% sea salt and bamboo salt. Lactobacillus delbrueckii ss lactis and L. pentosus which grow in the middle stage of fermentation, and L. hamsteri, which grows at the end stage of fermentation, were found after 12 hr of induction with 3% salt of all kinds. When 5% light salt was added to the culture medium, the induction period of bacteria other than W. confusa lengthens to 12 hr. The trend is similar for sea salt, bamboo salt, and refined salt, with a higher NaCl concentration resulting in less growth. W. confusa showed salt tolerance, but L. hamsteri was affected by the type and concentration of salt. With 5% sea salt, bamboo salt, and refined salt, the growth of bacteria was inhibited by up to 24 hr.

Enhancing Astaxanthin Accumulation in Haematococcus pluvialis by Coupled Light Intensity and Nitrogen Starvation in Column Photobioreactors

  • Zhang, Wen-wen;Zhou, Xue-fei;Zhang, Ya-lei;Cheng, Peng-fei;Ma, Rui;Cheng, Wen-long;Chu, Hua-qiang
    • Journal of Microbiology and Biotechnology
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    • v.28 no.12
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    • pp.2019-2028
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    • 2018
  • Natural astaxanthin mainly derives from a microalgae producer, Haematococcus pluvialis. The induction of nitrogen starvation and high light intensity is particularly significant for boosting astaxanthin production. However, the different responses to light intensity and nitrogen starvation needed to be analyzed for biomass growth and astaxanthin accumulation. The results showed that the highest level of astaxanthin production was achieved in nitrogen starvation, and was 1.64 times higher than the control group at 11 days. With regard to the optimization of light intensity utilization, it was at $200{\mu}mo/m^2/s$ under nitrogen starvation that the highest astaxanthin productivity per light intensity was achieved. In addition, both high light intensity and a nitrogen source had significant effects on multiple indicators. For example, high light intensity had a greater significant effect than a nitrogen source on biomass dry weight, astaxanthin yield and astaxanthin productivity; in contrast, nitrogen starvation was more beneficial for enhancing astaxanthin content per dry weight biomass. The data indicate that high light intensity synergizes with nitrogen starvation to stimulate the biosynthesis of astaxanthin.

Proposal of the Track Layout Criterion for the Light Rail Transit (경량전철 선로선형기준에 대한 제안)

  • 오지택;한승용;윤태양;성택룡
    • Proceedings of the KSR Conference
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    • 2000.11a
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    • pp.111-118
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    • 2000
  • This paper proposes the track layout criterion for the LRT(light rail transit). All criterions established concerning dimension and performance of LRT vehicles that are three types. Types of vehices are AGT(automated guided train) steel wheel. AGT rubber tire and LIM(linear induction motor). Using theoritical approach, adaptation and validity of criterions are verified. Proposed criterions may provide a standard scheme for design and construction of the infrastructure on LRT.

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A Study on Improvement of Operation Characteristics and Inspection Method of Standby Power Supply such as Emergency Induction Light using Li-ion Capacitor (리튬이온커패시터를 활용한 비상유도등 예비전원장치의 동작 특성 및 점검방법 개선에 관한 연구)

  • Jung, Jun-Chea
    • Journal of the Society of Disaster Information
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    • v.16 no.2
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    • pp.392-401
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    • 2020
  • Purpose: This study analyzes the operating characteristics of a lithium ion capacitor that can be used as a standby power supply in an emergency, and determines whether the standby power supply is abnormal even by measuring the voltage using a linear proportionality characteristic during charging and discharging. The aim is to provide an experimental basis that can be done. Method: As a method for this study, first, analyze the operation principle and characteristics of the existing backup power supply and lithium ion capacitor, and then measure the voltage of the lithium ion capacitor according to the configuration and system block diagram of the induction lamp used in the experiment. We proceed with the test of the measured value of discharge power for each voltage band to check the amount of power held by the battery and the operation test experiment using induction lamps. Results: Just by checking the charging voltage using the linear proportional characteristics of lithium ion capacitors, it provides a basis for accurately inferring the effective operating time of induction lamp lamps. Conclusion: In the event of a disaster, the lithium ion capacitor is used as a spare power supply for emergency induction lamps to prevent complete discharge of emergency induction lamps, to prevent the problem of performing normal operation of the standby power supply, and to use only a simple voltage measurement to reserve power. It was intended to suggest many uses for evacuation equipment application in the future by making it possible to check whether the device is abnormal.