• Advances in nano research
• /
• 제1권3호
• /
• pp.153-158
• /
• 2013

An approach to achieving of spatially homogeneous, ordered ensemble of semiconductor quantum rods in polymer film of polyvinyl butyral is reported. The CdSe/ZnS quantum rods are embedded to the polymer film. Obtained film is stretched up to four times to its initial length. A concentration of quantum rods in the samples is around $2{\times}10^{-5}$ M. The absorption spectra, obtained in the light with orthogonal polarization, confirm the occurrence of spatial ordering in a quantum rod ensemble. Anisotropy of the optical properties in the ordered quantum rod ensemble is examined. The presented method can be used as a low-cost solution for preparing the nanostructured materials with anisotropic properties and high concentration of nanocrystals.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
• /
• pp.358-360
• /
• 2004

To reduce the earth resistance, earth electrode are installed horizontally or vertically in the earth. There are two kinds of vertical earth electrode methods, one is a deep-driven rod and another is slight-driven parallel rods. Bibliography have so far analyzed the earth resistance calcalation of a rod type electrode and parallel rods type for the multi-layered earth. Befor long, We are going to study earth resistance of deep-driven rod and slight-driven parallel rods in the multi-layered earth with reference to bibliography.

• Restorative Dentistry and Endodontics
• /
• 제6권1호
• /
• pp.133-139
• /
• 1980

In this experiment, etching was performed on the incisor enamel surfaces of 13 Albino rats, weighted about 130gm, with both 30% and 50% concentrations of the phosphoric, citric acids, and EDTA solution for 60 seconds. Immediately after extraction of the animal teeth, laboratory procedures for scanning electron microscopic observations were made and the author derived the following conclusions: 1. On the enamel surface treated with 30% and 50% phosphoric acids, all of the periphery, center of the enamel rods, and the enamel matrices were severely etched. 2. In the etched with 30% citric acid group, only the small part of the enamel rods were etched out. In case of 50% citric acid the periphery, center of enamel rods were partially or entirely etched, and the intermatrix spaces were widened. 3. In the 30% and 50% of the EDTA etched groups, the periphery of the enamel rods explicitely were etched, and the spaces between matrices were widened.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 C
• /
• pp.1858-1860
• /
• 2003

Ground rods as the discharge path are commonly installed to ensure the safety of human beings and facilities from the surge. Accordingly, proper grounding resistance are specified by the grounding types, and the specified resistance are also required to install the lightning protective facilities. it is needed to analyze the difference between these two resistance through the field test. Therefore, in this paper, the impulse response behavior of the ground rods is analyzed by constructing the test facilities and by testing the ground rods in multi-ground power distribution systems. The impulse responses were analyzed, in transient state, by testing the concrete poles as well since the grounding wires are installed in the concrete poles.

• 대한미생물학회지
• /
• 제22권3호
• /
• pp.219-224
• /
• 1987

A strain of Leptospira interrogans(UM-19) was isolated in 1984 from a patient with epidemic pulmonary hemorrhagic fever. The bacteria has been characterized morphologically by a polymorphism showing spiral forms, short and long rods in culture. In order to study the biological relatedness among these forms of the bacteria, the short rods were separated from others by means of continuous sucrose density gradient centrifugation, and cultured at various temperatures such as $10^{\circ}C$, $15^{\circ}C$, $30^{\circ}C$ and $37^{\circ}C$. It was revealed that cultivation or subcultivation of the short rods has resulted in morphological changes observed by darkfield examination, silver stain, and scanning electron microscope showing spiral forms as well as short and long rods.

• 비파괴검사학회지
• /
• 제19권2호
• /
• pp.79-84
• /
• 1999

영상처리 방법에 의한 핵연료봉의 제원을 측정하기 위하여 영상처리 소프트웨어를 개발하고 핵연료봉의 직경을 측정하였다. 카메라와 시험체간의 거리, 카메라 위치, 조명세기 및 조명종류와 같은 요소가 핵연료봉 제원 측정에 영향을 미침을 확인하였다. 영상처리 방법에 의한 핵연료봉 직경의 백분율 측정 상대오차는 4.88%이고 백분율 측정 표준편차는 ${\pm}3.34%$였다. 한편 영상처리 방법이 아닌 기존 방법에 의한 백분율 측정 상대오차는 12.77%이고 백분율 측정 표준편차는 ${\pm}9.72%$였으며, 영상처리 방법에 의한 직경 측정 정확도가기존 방법에 의한 결과보다 약 3배정도 향상되었다.

• 대한조선학회지
• /
• 제6권1호
• /
• pp.35-42
• /
• 1969

Penetrations of arc welding electrades are different by changing welding conditions, welding speed of travel and current, even though quite same ones. Changing status of penetration is studied by changing welding speed of travel keeping welding current constant, at first, and by changing welding current keeping welding speed of travel which was obtained prior experiment constant, afterward. The F-100 4mm $\phi$ rods, E4301 class, which covering substance is mainly ilmenite and a domestic representative product of this class electrode, are used for this experiment. The Marquette's No.130 5/32"(4mm)$\phi$ rods, E6011 class, and No. 140 5/32"(4mm)$\phi$, E6013 class, which were produced in the United Stated, are used to compare penetration with F-100 at same welding conditions. The covering substance of Marquette's No. 130 rods is mainly cellulose, and belong to deep penetration arc welding electrodes, the covering material of another rods is titania, and a kind f shallow penetration rods. The result of this study is as follow : penetration of F-100, domestic ilmentite covering electrade, E4301 class, is between E6011 and E6013 of the United States products. At the lower range of welding current, penetration is closer to E6013 than E6011, at the higher range, closer to E6011 than another; and the value of penetration ranges $1.65{\sim}2.70mm$ for 4mm$\phi$ rods in the adequate current range. The changing status of penetration is showed by following experimental formula. $P=KE_v^{-\frac{2}{5}}1^{\frac{3}{2}}$

• Nuclear Engineering and Technology
• /
• 제55권9호
• /
• pp.3260-3267
• /
• 2023

Zr-Nb alloy have been widely used as fuel rods in nuclear power plants. However, from the Fukushima nuclear accident, the weakness of the rod was revealed under harsh conditions, and research on the safety of these types of rods was conducted after the disaster. The method of depositing chromium onto the existing Zr-Nb alloy fuel rods is being considered as a means by which to compensate for the weakness of Zr-Nb alloy rods because chromium is strong against oxidation at high temperatures and has high strength. In order to secure these advantages, it is important to maintain the Cr thickness of the rods and properly inspect the rods before and during their use in power generation. Eddy current testing is a typical means of evaluating the thickness of thin metals and detecting surface defects. Depending on the size and shape of the inspected object, various eddy current sensors can be applied. In particular, because pancake sensors can be manufactured in very small sizes, they can be used for inspections even in narrow spaces, such as a nuclear fuel assembly. In this study, an eddy current technique was developed to confirm the feasibility of Cr coating thickness evaluations. After determining the design parameters of the pancake sensor by means of a FEM simulation, a FPCB pancake sensor was manufactured and the optimal frequency was selected by measuring minute changes in the Cr-coating thickness using the developed sensor.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
• /
• 제16권8호
• /
• pp.825-836
• /
• 2010

정보통신의 발전으로 인한 전자 기록물의 등장은 기록물 관리 체계에 많은 변화를 가져 왔다. 전자 기록물의 등장으로 인한 기록물관리의 가장 큰 변화는 종이기록물 등의 물리적인 기록물에 대한 수동적인 관리체제에서 컴퓨터 시스템을 통한 전자형식 기록물의 자동화된 기록 관리체제로의 전환과 대량 대용량으로 발생하는 전자 기록물에 대한 효율적인 관리이다. 데이터 그리드 소프트웨어인 iRODS(Integrated Rule-Oriented Data System)는 규칙 기반 데이터 그리드 시스템으로서 지리적으로 분산된 컴퓨팅 자원을 네트워크로 연동하여 가상화를 통해 대용량 저장 인프라를 구성한다. 특히, 이 시스템은 규칙을 정의함으로써, 입력되는 전자 기록물에 대한 데이터를 분산 및 백업하는 등의 조작이 가능하다. 따라서 iRODS는 대량, 대용량으로 발생하는 전자기록물을 자동적으로 관리하는 전자기록물 관리시스템의 구축에 적합한 기술이다. 본 논문은 규칙 기반의 그리드 시스템인 iRODS를 이용하여 전자 기록물 관리 시스템을 설계 및 구현하였다. 본 논문에서 구축한 전자 기록물 관리 시스템은 iRODS의 규칙을 이용하여 기록물 유형에 따라 데이터를 자동 분산하며 데이터를 자동으로 백업한다. 그리고 iRODS의 메타데이터를 관리하는 iCAT DB를 이용하여 전자 기록물의 메타 데이터 저장 및 검색 기능을 제공한다.

• 한국결정성장학회지
• /
• 제6권2호
• /
• pp.121-128
• /
• 1996

Floating zone법으로 $LiNbO_3$ 단결정올 육성하는데 있어서 원료분말 합성과 원료봉 소결 과정의 최척의 조건을 설험적으로 조사하였다. 원료분말 합성사 낮은 고상반응 온도(700, $800^{\circ}C$)에서는 미량의 $Li_2CO_3$와 $Nb_2O_5$가 미반응상태로 남아있고, 고상반응 온도가 높을 때 ($1000^{\circ}C$)에는 입자성장이 일어나 후속공정인 원료봉 소결에 악영향을 미침이 확인되었다. $950^{\circ}C$에서 12시간 고상반응시킨 원료분말이 $LiNbO_3$의 결정상을 가지면서 미세한 결정립 크기와 균일한 크기분포를 보여 $950^{\circ}C$, 12시간이 최적의 원료분말 합성조건이었다. 원료봉 소결시 소 결온도가 높아질수록, 또 소결시간이 늘어날수록 치밀도가 증가하고 업자성장 양상이 급격히 증가함을 알 수 었었다. $1100^{\circ}C$에서 2시간 동안 소결한 원료봉이 치밀하고, 작은 결정립 크기 와 균얼한 크기분포를 나타내어 floating zone법에 의한 $LiNbO_3$ 단결정성장에 가장 적합한 최적 의 소결 조건은 $1100^{\circ}C$, 2시간엄이 확인되었다.