PLSI 위상차 제어기에 의한 초음파 모터의 점탄성 특성

김동옥,김원배,성도생,고낙용,최한수,김영동 조선대학교 생산기술연구소 1996 生産技術硏究 Vol.18 No.1

As an actuator for direct drive(DD) manipulator. the travelling-wave type ultrasonic motor(USM) has many excellent performances and good advantages over conventional servo motors such as compact size, light weight, silent motion, low rotation-speed, high torque, low magnetic noise, high speed response, flexible free forms, large holding torque and so on. So it has been expected to be used as servo motor. This paper presents a design method of USM controller to adjust the phase difference of USM power using PLSI (Programmable Large Scale Intersration). we can control the elastic coefficient and the viscous coefficient of the USM by adjusting the phase difference of the motor power. By controlling the elasticity and viscosity, a robot can work in compliance with external environment. To use the result, we will be able to control the robot to reach its goal with compliance motion. It remains for further research to develop the impedance control of USM and to make cooperative robots.

Determination of Impurities in Uranium Dioxide by Neutron Activation Analysis

Nak Bae Kim,Hae-Ill Bak,Chul Lee Korean Nuclear Society 1981 Nuclear Engineering and Technology Vol.13 No.4

이산화우라늄중의 미량불순물원소들의 중성자 방사화분석을 위하여 이들 원소들의 사전농축에 음이온교환수지를 사용하였다. 황산에 녹인 우라늄 시료용액의 산도를 pH 2.7에 맞춘다음 음이온교환수지통에 얹었다. 이 음이온교환수지통으로 부터 미량분순물 원소만을 정량적으로 회수할 수 있었다. 이 사전농축법과 알미늄중 미량불순물 원소의 정량을 위하여 개발한 방사화학적인 분리법을 이용하므로서 원자로급 이산화우라늄 중의 21개 미량불순물을 정량할 수 있었다. The preliminary concentration of trace elements in uranium dioxide using an anion exchange resin is presented for neutron activation analysis. The uranyl solution in sulfuric acid is adjusted to the acidity of about pH 2.7 and loaded on a column of the anion exchange resin. An appropriate volume of eluates obtained from the column shows good recoveries of trace elements. By combining this preconcentration with a radiochemical separation scheme, which was developed for the determinations of impurities in aluminum, it is possible to determine 21 trace elements in reactor grade uranium dioxide.

A Single Comparator Method Using Reactor Neutron and Its Errors

Nak Bae Kim,Keung Shik Park,Hae-Ill Bak Korean Nuclear Society 1986 Nuclear Engineering and Technology Vol.18 No.2

원자로 중성자 방사화 분석법으로 다중 원소들을 분석하기 위한 단일 비교체법을 그에 따른 오차와 함께 조사하였다. 각 시료의 조사 위치에서 스펙트럴 지수는 Au와 Co 두개의 모니터를 이용하여 결정하였으며 이중 한개는 단일 비교체로 사용하였다 18개 원소에 대하여 이 방법에 사용된 핵 자료의 불확실도를 조사하였으며, 이 값들에 의한 분석 결과의 오차는 6% 이하이었다. 4개의 USGS 표준시료의 분석 결과는 USGS에서 평가한 분석결과와 15%의 편차 이내에서 잘 일치하였다. A single comparator method with its accuracy has been studied for determining multielement by reactor neutron activation analysis. Spectral index at the irradiation position of each sample was determined using two flux monitors of Au and Co, one of which was used as a single comparator. The uncertainties of nuclear data related to the method were investigated for 18 elements and the error of the analytical result due to the uncertainties of nuclear data related is found to be less than 6%. The analytical results of 4 USGS reference samples agree well within 15% deviation with the results evaluated by USGS.

Some Improvements of Gamma-ray Measurement for the Determination of the Boron Content

Nak Bae Kim,Hae-Ill Bak Korean Nuclear Society 1984 Nuclear Engineering and Technology Vol.16 No.1

붕소의 사전 농축후 포획감마선 계측법에서 자연 리티움 벽돌을 Ge(Li) 검출기 앞에 설치하므로서 붕소의 검출한계를 더욱 낮출 수 있었다. 실험상 검출한계는 알루미늄, 철강, 이산화우라늄 그리고 그라파이트 시료에 대해서 각각 0.30ppm, 0.18ppm, 0.045ppm 고리고 0.090ppm이었다. 또한 계측 중 중성자 속의 변화에 의한 오차를 없애기 위하여 교대로 계측하는 방법을 사용하였다. The detection limit of boron has been lowered further in the capture gamma-ray measurement after preconcentration of boron by placing natural lithium brick in front of Ge(Li) detector. The experimental detection limit is found to be 0.30ppm, 0.18ppm, 0.045ppm and 0.090ppm for the samples of aluminum, steel, uranium dioxide and graphite, respectively. An alternate counting technique kas been also used for neglecting the error caused by the fluctuation of neutron flux during counting.

A Study on the Present Levels of Mercury and other Trace Elements in Fresh-water Fish by Neutron Activation Analysis

Kim, Nak-Bae,Lee, Chul,Bak, Hae-Ill Korean Nuclear Society 1976 JOURNAL- KOREAN NUCLEAR SOCIETY Vol.8 No.1

Ge(Li) 검출기를 사용한 비파괴 방사화분석법을 이용하여 담수어중 수은 및 기타 미량원소들의 현재 함량 준위를 조사하다. 분석결과에 의하면 지역에 따라 수은의 함량이 크게 변하였으며 이 변화는 아마 지역적인 오염원에 의한 것으로 생각된다. 그리고 분석결과로 부터 미량원소들 중 어떤 원소들 사이에는 뚜렷한 상관관계가 있음을 알았다. 수은 오염의 중요한 원인으로 무연탄 연소가 고려될 수 있을 것으로 생각되어 수종의 무연탄을 분석하였다. A nondestructive, instrumental neutron activation analysis using a Ge(Li) detector is applied to investigate the present levels of mercury and other trace elements in some fresh-water fish. The results show large variations of mercury content which are indicative of important local sources and indicate the inter-dependence relations between two of some trace elements. Analytical results for mercury in antracites are also given with the concern for their combustion as one of major causes of the mercury pollution.

A Study of Boron Determination in High Purity Aluminum by Capture Gamma-Ray Measurement

Nak Bae Kim,Hae-Ill Bak Korean Nuclear Society 1981 Nuclear Engineering and Technology Vol.13 No.4

중성자포획 감마선 방사화분석법을 이용하여 원자로급 알루미늄중 붕소를 분석하였다. 실험에 의한 검출한계는 10% 불확실도의 경우 5.7ppm 이었다. 함량이 더욱 미량인 경우를 위하여 양이온 교환수지를 이용하며 알루미늄으로 부터 붕소를 사전분리하는 농축법을 개발하였다. 이 두 방법 즉 직접 측정하는 방법과 농축후 측정하는 두가지 방법의 정확도를 첨가법으로 조사하였다. 그 결과 5% 편차 이내에서 잘 일치하였다. The boron content in reactor grade aluminum has been determined by means of a capture gamma-ray counting method. The experimental detection limit is found to be 5.7% ppm with 10% uncertainty. In order to improve the sensitivity, the boron is preconcentrated from aluminum by cation exchange resin system. The accuracies of both methods, i.e., one by the direct measurement and the other by the measurement after preconcentration, are checked by an additive method. The results show good agreements with less than 5% deviation.

A Study on the Present Levels of Mercury and other Trace Elements in Fresh-water Fish by Neutron Activation Analysis

Kim, Nak-Bae,Lee, Chul,Bak, Hae-Ill Korean Nuclear Society 1976 Nuclear Engineering and Technology Vol.8 No.1

Ge(Li) 검출기를 사용한 비파괴 방사화분석법을 이용하여 담수어중 수은 및 기타 미량원소들의 현재 함량 준위를 조사하다. 분석결과에 의하면 지역에 따라 수은의 함량이 크게 변하였으며 이 변화는 아마 지역적인 오염원에 의한 것으로 생각된다. 그리고 분석결과로 부터 미량원소들 중 어떤 원소들 사이에는 뚜렷한 상관관계가 있음을 알았다. 수은 오염의 중요한 원인으로 무연탄 연소가 고려될 수 있을 것으로 생각되어 수종의 무연탄을 분석하였다. A nondestructive, instrumental neutron activation analysis using a Ge(Li) detector is applied to investigate the present levels of mercury and other trace elements in some fresh-water fish. The results show large variations of mercury content which are indicative of important local sources and indicate the inter-dependence relations between two of some trace elements. Analytical results for mercury in antracites are also given with the concern for their combustion as one of major causes of the mercury pollution.

Determination of Impurities in Aluminum by Neutron Activation Analysis

Kim, Nak-Bae,Bak, Hae-ill,Lee, Chul Korean Nuclear Society 1980 Nuclear Engineering and Technology Vol.12 No.1

A radiochemical separation scheme for the neutron activation analysis is developed for the determination of 28 elements in aluminum. The scheme is based on a group separation using ion-exchange resin and mineral exchanger. Present work has employed mineral acids and their partly organic mixture excluding HF as the media as well as common glass wares. For the determination, gamma-ray spectroscopy using $3"\times3"\;Nal(TI)$ detector and a single comparator method are used.

Magnesium phosphate ceramics incorporating a novel indene compound promote osteoblast differentiation <i>in vitro</i> and bone regeneration <i>in vivo</i>

Kim, Ju Ang,Yun, Hui-suk,Choi, Young-Ae,Kim, Jung-Eun,Choi, So-Young,Kwon, Tae-Geon,Kim, Young Kyung,Kwon, Tae-Yub,Bae, Myung Ae,Kim, Nak Jeong,Bae, Yong Chul,Shin, Hong-In,Park, Eui Kyun IPC Science and Technology Press 2018 Biomaterials Vol.157 No.-

<P><B>Abstract</B></P> <P>Incorporating bioactive molecules into synthetic ceramic scaffolds is challenging. In this study, to enhance bone regeneration, a magnesium phosphate (MgP) ceramic scaffold was incorporated with a novel indene compound, KR-34893. KR-34893 induced the deposition of minerals and expression of osteoblast marker genes in primary human bone marrow mesenchymal stem cells (BMSCs) and a mouse osteoblastic MC3T3-E1 cell line. Analysis of the mode of action showed that KR-34893 induced the phosphorylation of MAPK/extracellular signal-regulated kinase and extracellular signal-regulated kinase, and subsequently the expression of bone morphogenetic protein 7, accompanied by SMAD1/5/8 phosphorylation. Accordingly, KR-34893 was incorporated into an MgP scaffold prepared by 3D printing at room temperature, followed by cement reaction. KR-34893-incorporated MgP (KR-MgP) induced the expression of osteoblast differentiation marker genes <I>in vitro</I>. In a rat calvaria defect model, KR-MgP scaffolds enhanced bone regeneration and increased bone volume compared with MgP scaffolds, as assessed by micro-computed tomography and histological analyses. In conclusion, we developed a method for producing osteoinductive MgP scaffolds incorporating a bioactive organic compound, without high temperature sintering. The KR-MgP scaffolds enhanced osteoblast activation <I>in vitro</I> and bone regeneration <I>in vivo</I>.</P>

A Chemical Route to Activation of Open Metal Sites in the Copper-Based Metal–Organic Framework Materials HKUST-1 and Cu-MOF-2

Kim, Hong Ki,Yun, Won Seok,Kim, Min-Bum,Kim, Jeung Yoon,Bae, Youn-Sang,Lee, JaeDong,Jeong, Nak Cheon American Chemical Society 2015 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.137 No.31

<P>Open coordination sites (OCSs) in metal–organic frameworks (MOFs) often function as key factors in the potential applications of MOFs, such as gas separation, gas sorption, and catalysis. For these applications, the activation process to remove the solvent molecules coordinated at the OCSs is an essential step that must be performed prior to use of the MOFs. To date, the thermal method performed by applying heat and vacuum has been the only method for such activation. In this report, we demonstrate that methylene chloride (MC) itself can perform the activation role: this process can serve as an alternative “chemical route” for the activation that does not require applying heat. To the best of our knowledge, no previous study has demonstrated this function of MC, although MC has been popularly used in the pretreatment step prior to the thermal activation process. On the basis of a Raman study, we propose a plausible mechanism for the chemical activation, in which the function of MC is possibly due to its coordination with the Cu<SUP>2+</SUP> center and subsequent spontaneous decoordination. Using HKUST-1 film, we further demonstrate that this chemical activation route is highly suitable for activating large-area MOF films.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2015/jacsat.2015.137.issue-31/jacs.5b06637/production/images/medium/ja-2015-06637g_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja5b06637'>ACS Electronic Supporting Info</A></P>