• 한국초전도ㆍ저온공학회논문지
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• 제23권4호
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• pp.25-29
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• 2021

For the application of HTS wire to AC power equipment, a conductor with high current capacity and low loss is required. CORC^®, one of the high-current conductors manufactured using several HTS wires, is made by winding the wires in a spiral on a cylindrical former. Because the magnetization loss of a CORC^® conductor depends on the degree of magnetic coupling between the wires constituting the CORC^®, it is necessary to know the value of the magnetization loss of the CORC^® itself. In order to obtain an accurate loss value, it is necessary to know the effect of the ratio of the winding pitch of the CORC^® conductor in the pickup coil region sampling the magnetization loss signal. To confirm this effect, we prepare CORC^® samples having various winding pitches, and measure and compare the magnetization losses. In addition, the magnetization loss was measured while rotating the CORC^® samples and it was examined whether there was a difference in the magnetization loss according to the rotation.

• 한국초전도ㆍ저온공학회논문지
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• 제25권4호
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• pp.45-49
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• 2023

CORC, which is being studied as one of the conductors for large currents, is manufactured by symmetrically arranging several strands of high-temperature superconducting wires on a cylindrical former. It allows current to flow evenly between wires and has the advantage of being manufactured in a multi-layer structure to increase current capacity. In order to apply CORC to AC power devices, it is necessary to review the material of the former, which is the frame around which the superconducting wire is wound. In the case of metal formers, they are difficult to apply because eddy currents are generated in the former, and they do not have the flexibility to be manufactured into coils by winding them with CORC. In this paper, we compare and analyze the magnetization loss caused by an external alternating magnetic field of Litz wire, which is being considered as a former material for CORC, with the results from formers made of other materials. In addition, we experimentally examine the effect of reducing magnetization loss due to an external magnetic field in CORC using a split wire made by dividing a high-temperature superconducting wire into two using an etching method, and in CORC made with a non-split wire.

• 한국도서관정보학회지
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• 제33권1호
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• pp.193-210
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• 2002

이 연구에서는 전자정보원(electronic resources)을 효율적으로 정리해서 제공하기 위해 웹사이트에서 양질의 인터넷 정보원의 위치를 확인하기 위한 참고도구로써 실험하고 있는 OCLC의 CORC (Cooperative Outline Resource Catalog)의 역사와 특징, 운영 등에 대해 종합적으로 분석하였다. 또한 이를 바탕으로 국내 도서관이 당면한 관련문제를 해결하고 유사한 시스템을 도입하기 위한 제안을 제시하였다.

• 한국초전도ㆍ저온공학회논문지
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• 제24권4호
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• pp.46-49
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• 2022

Since CORC^®(Conductor on Round Core) is made of multiple strands of a superconducting tape to conduct a large current, it is difficult to measure the critical current due to the limitation of a capacity of a power supply. The magnetization loss of a superconductor is dependent on the full penetration field. The full penetration field corresponds to the inflection point of the magnetization loss graph with respect to the external magnetic field. We propose a method to predict the critical current of CORC^® indirectly. This method uses the measured magnetization losses of various CORC^® samples for the prediction of the critical currents.

• 한국초전도ㆍ저온공학회논문지
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• 제25권4호
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• pp.40-44
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• 2023

For high-temperature superconducting power applications that need large current capacity, a large current conductor manufactured using multiple superconducting tape is required. Conductors being studied for large currents capacity such as CORC, TSTC, and RACC have advantages and disadvantages, and in order to use these conductors in coil form and apply them to AC power devices, research on magnetization loss occurring in superconductors due to external magnetic fields is essential. To accurately measure magnetization loss in a conductor that is twisted by stacking straight conductors like TSTC, the correlation between the measuring system and the shape of the sample must be clearly known to accurately measure the loss. In this paper, we will confirm the difference in magnetization loss measurement values according to the correlation between the length of the pickup coil and the twist pitch of the sample in CORC and TSTC shapes, and review considerations for accurate magnetization loss measurement from the results.

• 한국도서관정보학회지
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• 제35권1호
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• pp.237-256
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• 2004

최근 활발하게 제기되고 있는 전자자료의 목록작업은 전자자료의 여러 가지 특성으로 인해 많은 문제점을 가지고 있다. 이 연구에서는 특히 인터넷자료를 중심으로 여러 유형의 전자자료와 이들 전자자료에 대한 협동목록의 필요성을 살펴보고, 대표적인 전자자료 협동목록 시스템으로서 OCLC의 CORC과 LC의 POC에 대하여 전반적인 상황을 분석하였다. 또한 이를 바탕으로 국내 온라인 전자자료 협동목록 시스템을 제안하였다.

• 한국초전도ㆍ저온공학회논문지
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• 제24권1호
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• pp.1-7
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• 2022

So far, large-scale scientific devices such as nuclear fusion tokamaks and high energy circular accelerators were constructed using high-current conductors made of metallic superconducting wires. Recently, as REBCO superconducting wires usable in high magnetic fields have been developed by several companies, researchesto apply high current cable type REBCO conductors to next-generation large superconducting magnets were also started. High critical currents of several kA or more in high magnetic fields have been successfully demonstrated on test samples of REBCO cable conductors by several research groups. In this review article, the main features and properties of the representative high current REBCO conductors such as CORC(Conductor On Round Core), TSTC(Twisted Stacked-Tape Cable) and RACC(Roebel-Assembled Coated Conductor), which are currently being developed at abroad are briefly introduced. Research activities of high-current density REBCO MHOS(Multi HTS layers on One Substrate) conductor at KERI, whose structure is different from other cable type REBCO conductors are also shortly introduced.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권2호
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• pp.140-148
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• 2000

In this paper, using surface micromachining technology with thick photoresist and aluminum, an SLM(Spatial Light Modulator), which is applied to the fields of adaptive optics and pattern recognition system, was fabricated and the electromechanical properties of the fabricated micro SLM are measured. In order to maximize fill-factor and remove mechanical coupling between micro SLM actuators, the micro SLM is composed of three aluminum layers so that spring structure and upper electrode are placed beneath the mirror plate, and $10\times10$ each mirror plate is individually actuated. Also, the micro SLM was designed to be able to modulate phase and amplitude of incoming light in order to have a continuity of phase modulation of incoming light. In the case of amplitude and phase modulation, maximum vertical displacement is 4$\mum$, and maximum angular displacement is $\pm4.6^{\corc}$ respectively. The height difference of the fabricated mirror plate was able to be reduced to 1100A with mirror plate planarization method using negative photoresist(AZ5214). The electromechanical properties of the fabricated micro SLM were measured with the optical measurement system using He-Ne laser and PSD(position sensitive device).

• 한국초전도ㆍ저온공학회논문지
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• 제23권4호
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• pp.10-13
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• 2021

Recently, cable conductors composed of numerous coated conductors have been developed to transport huge current for large-scale applications, for example accelerators and fusion reactors. Various cable conductors such as CORC (Conductor on round core), Roebel Cable, and TSTC (Twisted stacked tape cable) have been designed and tested to apply for large-scale applications. But, these cable conductors cannot improve the engineering critical current density (J_e) because they are made by simple stacking of coated conductors. In this study, multi-HTS (High temperature superconductor) layers on one substrate (MHOS) wire was fabricated to increase the engineering critical current density by using the exfoliation of superconducting layer from substrate and silver diffusion bonding method. By the repetition of these processes, the 10 m long 6-layer MHOS conductor was successfully fabricated without any intermediate layers like buffer or solder. 6-layer MHOS conductor exhibited a high critical current of 2,460A/12mm-w. and high engineering critical current density of 1,367A/mm² at liquid nitrogen temperature.

• 환경위생공학
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• 제6권2호
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• pp.109-121
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• 1991

For the analysis of mercury in blood and urine, many literatures have been reffered and many kinds of reducing agents for mercury reduction and many acids for pretreatmr are known to be varied. $So HNO_{3}$ and $H_{2}SO_{4}$ among acids and $SnCl_{2}$ and $NaBH_{4}$ as a reducing agent being chosen for the establishment of more efficient and less erroneous analysis, and comparing the absorbance by using vapor generator, the results are followings. 1. The difference of absorbance from concentration of $HNO_{3}$ and $H_{2} SO_{4}$ was not nearly found when mercury reduced by $NaBH_{4}$ after pretreatment. But for more precise analysis, conc acid treatment need to be used. 2. Higher absorbance was shown by using conto acid treatment (P<0.005) when mercury reduced by $NaBH_{4}$ after treating acid primer. And sample which has 99.5% reliability in T-test, treated by conc $H_{2}SO_{4}$(P<0.005) was shown higher absorbance than treat by CORC $HNO_{3}$. 3. The difference of absorbance was not in the slightest in higher 0.1 w/v% $NaBH_{4}$ proved by uruskal-wallis H-Test 4. Some difference of absorbance in $SnCl_{2}$(P<0.005) having 99.5% reliability was found but there was no difference in these 20 w/v% , 25 w/v% and 30 w/v% SnCl$_{2}$ by the experiment of T-test. 5. According to these test results, organic materials were much affect the absorballce when reducing mercury by using $SnCl_{2}$ rather than by $NaBH_{4}$. For bio sample which is contained various organic substances, reduclng agent $NaBH_{4}$ is a lot more efficient to reduce the error then $SnCl_{2}$. 6. analytic method for this study is as following. 7. As the recovery test was done by this, the rate of recovery was shown form 94% to 100.7% .