• Title/Summary/Keyword: Magnetic System

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Shock Metamorphism of Plagioclase-maskelynite in the Lunar Meteorite Mount DeWitt 12007 (달운석 Mount DeWitt 12007의 마스컬리나이트 충격 변성 특성 연구)

  • Kim, Hyun Na;Park, Changkun
    • Journal of the Mineralogical Society of Korea
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    • v.29 no.3
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    • pp.131-139
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    • 2016
  • Detailed knowledge on maskelynite, a glassy phase of plagioclase found in shocked meteorites and impact craters, is essential to understand a shock metamorphism. Here, we explore an inhomogeneous shock metamorphism in the lunar meteorite Mount DeWitt (DEW) 12007 with an aim to understand the formation mechanism of maskelynite. Most plagioclase grains in the DEW 12007 partially amorphized into maskelynite with a unidirectional orientation. Back-scattered electron (BSE) images of maskelynite show a remnant of planar deformation fracture possibly indicating that the maskelynite would be formed by solid-state transformation(i.e., diaplectic glass). Plagioclase with flow texture is also observed along the rim of maskelynite, which would be a result of recrystallization of melted plagioclase. Results of Raman experiments suggest that shock pressure for plagioclase and maskelynite in the DEW 12007 is approximately 5-32 GPa and 26-45 GPa, respectively. The difference in shock pressures between plagioclase and maskelynite can be originated from 1) external factors such as inhomogeneous shock pressure and/or 2) internal factors such as chemical composition and porosity of rock. Unfortunately, Raman spectroscopy has a limitation in revealing the detailed atomic structure of maskelynite such as development of six- or five-coordinated aluminum atom upon various shock pressure. Further studies using nuclear magnetic resonance spectroscopy are necessary to understand the formation mechanism of maskelynite under high pressure.

Lower Motor Weakness and Complex Regional Pain Syndrome of Lower Limb in the Patient of Frontotemporal Dementia: A Case Report (이마관자엽 치매 환자에서 나타난 하지 근력 저하와 복합부위 통증증후군에 대한 증례 보고)

  • Lee, Kwang Min;Noh, Se Eung;Joo, Min Cheol;Hwang, Yong;Kim, Ji Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.12
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    • pp.352-358
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    • 2017
  • Frontotemporal dementia, the second most common cause of early onset dementia, is a neurodegenerative clinical syndrome characterized by progressive deficits in behavior, executive function and language. Although motor symptoms in frontotemporal dementia are represented by motor neuron disease, parkinsonism and progressive supranuclear palsy syndrome, there have been no reports of motor weakness caused by the direct involvement of central motor nervous systems in frontotemporal dementia. Moreover, no association between clinical dementia groups and complex regional pain syndrome has been reported. We diagnosed a rare case with motor weakness and complex regional pain syndrome of lower limbs due to central nervous system lesion in a patient with frontotemporal dementia by magnetic resonance imaging, electrodiagnostic study and three phase bone scan. Following steroid therapy for complex regional pain syndrome, pain was improved. Functional improvement was noted after rehabilitation therapy, including functional electrical stimulation, muscle strengthening exercise and gait training during hospitalization. This case report suggests that rehabilitation therapy for motor weakness in frontotemporal dementia could be effective for improving overall function.

Application of Gamma Ray Densitometry in Powder Metallurgy

  • Schileper, Georg
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2002.07a
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    • pp.25-37
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    • 2002
  • The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

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Deterioration and Microclimate in the Shelter for the Gaetaesajiseokbulibsang (Standing Triad Buddha Statues in Gaetaesaji Temple Site), Nonsan, Korea (논산 개태사지석불입상의 손상도와 보호각 내부의 미기후 환경)

  • Kim, Ji-Young;Park, Sun-Mi;Lee, Chan-Hee
    • Journal of Conservation Science
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    • v.25 no.2
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    • pp.179-196
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    • 2009
  • The Gaetaesajiseokbulibsang (Treasure No. 219) consists of light gray and coarse to medium-grained granodiorite with feldspar phenocrysts in part. Magnetic susceptibility of the rock material was measured as 12.06(${\times}10^{-3}$ SI unit), being different from the granite($0.19{\times}10^{-3}$ SI unit) in the Mt. Cheonho. This indicates the raw material has been supplied from the outside. As a result of deterioration assessment, exfoliation of the Right Buddha, cement and dust of the Main Buddha were estimated as 35.2%, 21.1% and 25.0%. The ultrasonic velocity was measured as 2850.2m/s(Main Buddha), 2648.4m/s(Left Buddha) and 2644.5m/s(Right Buddha). The compressive strength calculated from the velocity showed low in the Right Buddha among three and the all pedestal parts which corresponds to the result of deterioration assessment. The indoor mean temperature and relative humidity of the shelter were $13.7^{\circ}C$ and 79.0%. It is evaluated that the indoor microclimate was stable and the shelter functioned to reduce climatic fluctuation of the outdoor. However, water condensation was occurred on the surface of the pedestal part during spring and summer, and freezing in winter season might also be done. These factors were probable to be a main cause of the surface exfoliation of the Triad Buddha Statues. Therefore, dehumidification and heating system in the shelter should be applied to prevent further deterioration.

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Developing a Korean Standard Brain Atlas on the basis of Statistical and Probabilistic Approach and Visualization tool for Functional image analysis (확률 및 통계적 개념에 근거한 한국인 표준 뇌 지도 작성 및 기능 영상 분석을 위한 가시화 방법에 관한 연구)

  • Koo, B.B.;Lee, J.M.;Kim, J.S.;Lee, J.S.;Kim, I.Y.;Kim, J.J.;Lee, D.S.;Kwon, J.S.;Kim, S.I.
    • The Korean Journal of Nuclear Medicine
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    • v.37 no.3
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    • pp.162-170
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    • 2003
  • The probabilistic anatomical maps are used to localize the functional neuro-images and morphological variability. The quantitative indicator is very important to inquire the anatomical position of an activated legion because functional image data has the low-resolution nature and no inherent anatomical information. Although previously developed MNI probabilistic anatomical map was enough to localize the data, it was not suitable for the Korean brains because of the morphological difference between Occidental and Oriental. In this study, we develop a probabilistic anatomical map for Korean normal brain. Normal 75 blains of T1-weighted spoiled gradient echo magnetic resonance images were acquired on a 1.5-T GESIGNA scanner. Then, a standard brain is selected in the group through a clinician searches a brain of the average property in the Talairach coordinate system. With the standard brain, an anatomist delineates 89 regions of interest (ROI) parcellating cortical and subcortical areas. The parcellated ROIs of the standard are warped and overlapped into each brain by maximizing intensity similarity. And every brain is automatically labeledwith the registered ROIs. Each of the same-labeled region is linearly normalize to the standard brain, and the occurrence of each legion is counted. Finally, 89 probabilistic ROI volumes are generated. This paper presents a probabilistic anatomical map for localizing the functional and structural analysis of Korean normal brain. In the future, we'll develop the group specific probabilistic anatomical maps of OCD and schizophrenia disease.

Performance of Beam Extractions for the KSTAR Neutral Beam Injector

  • Chang, D.H.;Jeong, S.H.;Kim, T.S.;Lee, K.W.;In, S.R.;Jin, J.T.;Chang, D.S.;Oh, B.H.;Bae, Y.S.;Kim, J.S.;Cho, W.;Park, H.T.;Park, Y.M.;Yang, H.L.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.240-240
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    • 2011
  • The first neutral beam injector (NBI-1) has been developed for the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. A first long pulse ion source (LPIS-1) has been installed on the NBI-1 for an auxiliary heating and current drive of KSTAR core plasmas. Performance of ion and neutral beam extractions in the LPIS-1 was investigated initially on the KSTAR NBI-1 system, prior to the neutral beam injection into the main plasmas. The ion source consists of a JAEA magnetic bucket plasma generator with multi-pole cusp fields and a set of KAERI prototype-III tetrode accelerators with circular apertures. The inner volume of plasma generator and accelerator column in the LPIS-1 is approximately 123 liters. Final design requirements for the ion source were a 120 kV/ 65 A deuterium beam and a 300 s pulse length. The extraction of ion beams was initiated by the formation of arc plasmas in the LPIS-1, called as an arc-beam extraction method. A stable ion beam extraction of LPIS-1 has been achieved up to an 100 kV/42 A for a 4 s pulse length and an 80 kV/25 A for a 14 s pulse length. Optimum beam perveance of 1.21 microperv has been found at an accelerating voltage of 80 kV. Neutralization efficiency has been measured by using a water flow calorimetry (WFC) method of calorimeter and an operation of bending magnet. The full-energy species of ion beams have been detected by using the diagnostic method of optical multichannel analyzer (OMA). An arc efficiency of the LPIS was 0.6~1.1 A/kW depending on the operating conditions of arc discharge.

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Precisely Nondestructive Diagnosis and Slope Stability of the Bonghwa Bukjiri Maaeyeoraejwasang (Rock-Carved Seated Buddha Statue), Korea (봉화 북지리마애여래좌상의 비파괴 정밀진단과 사면안정성 분석)

  • Cho, Ji-Hyun;Jo, Young-Hoon;Chun, Yu-Gun;Choi, Joon-Hyun;Lee, Chan-Hee
    • Journal of Conservation Science
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    • v.26 no.2
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    • pp.121-132
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    • 2010
  • The Bukjiri Maaeyeoraejwasang (National Treasure No. 201) consists of two-mica granite in medium size, which was the simbol of power in the region of the Silla period. Magnetic susceptibility of the host rock was measured as 0.41(${\times}10^{-3}$ SI unit), which has the similar range with surrounding outcrop. The Buddha developed parallel discontinuous plane of NE to SW strike and damaged seriously by exfoliation, granular disintegration and brown discoloration as 41.5%, 16.7% and 40.0%, respectively. As a result of the ultrasonic velocity, which was relatively weak values as 1,629m/s (Buddha area) and 1,549m/s (surrounding outcrop), improved about 900m/s compared to last treatment. From the results of the evaluation for slope stability, identified the possibility of toppling failure in the Buddha, and planar and wedge failure in host rock. Therefore, we suggest for the safely conservation of the Buddha, continuance monitoring for understand behavior of discontinuity system of the surface, and necessitate foundation reinforcement method for the rock which has the danger of collapse.

A Novel Method to Measure Superior Migration of the Humeral Head: Step-off of the C-line

  • Park, Kyoung Jin;Eun, Hyeon Jun;Kim, Yong Min;Yoo, Jun Il;Lim, Chae Ouk
    • Clinics in Shoulder and Elbow
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    • v.19 no.3
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    • pp.125-129
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    • 2016
  • Background: Superior migration of humeral head has been conventionally determined by measuring the acromiohumeral distance (AHD), We sought to devise a novel measurement system more reliably and accurately than AHD. We described a structural landmark called 'C-line'. In this study, we investigated the clinical usefulness of 'step-off of the C-line (SOC)' compared to that of AHD. Methods: The C-line formed from the medial margin of the proximal humeral head continuing up to the inferior margin of the articular glenoid and then to the lateral border of the scapula. The superior migration of the humeral head triggered by a rotator cuff tear introduces a discontinuity in this C-line. We measured the distance of this discontinuity. We enrolled 144 patients who underwent a rotator cuff repair. We selected 58 controls who didn't have any cuff lesions apparent on magnetic resonance imaging. Using radiographs derived from standardized true anteroposterior views of the shoulder, we measured the SOC and the AHD. We used t-tests for statistical analyses. Results: A rotator cuff tear was associated with an increase in SOC and a decrease in AHD. In control group, the mean SOC was $1.29{\pm}1.71mm$ and AHD was $9.71{\pm}2.65mm$. In cuff tear group, the mean SOC was $3.15{\pm}3.41mm$ and AHD was $8.28{\pm}1.76mm$. The mean SOCs of the patient group in relation to the mean SOC of the control group according to tear size, the SOCs of medium tear and lager groups showed statistically significant increase (p<0.05). Conclusions: The SOC may be a similarly effective to diagnose cuff tears of medium size and larger compared with AHD.

Isolation and Purification of Berberine in Cortex Phellodendri by Centrifugal Partition Chromatography (Centrifugal Partition Chromatography에 의한 황백으로부터 Berberine의 분리 및 정제)

  • Kim, Jung-Bae;Bang, Byung-Ho
    • The Korean Journal of Food And Nutrition
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    • v.27 no.3
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    • pp.532-537
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    • 2014
  • Cortex Phellodendri (CP) is derived from the dried bark of Phellodendron amurense. It has been widely used as a drug in traditional Korea medicine for treating diarrhea, jaundice, swelling pains in the knees and feet, urinary tract infections, and infections of the body surface. Many analytical methods have been used to study oriental herbal medicines, such as thin-layer chromatography, column liquid chromatography, and high performance liquid chromatography (HPLC). In this study, preparative centrifugal partition chromatography (CPC) was successfully carried out in order to separate pure compounds from a CP methanol extract. The optimum two-phase CPC solvent system was composed of n-butanol: acetic acid: water (4:1:5 v/v/v). The flow rate of the mobile phase was 3 mL/min in ascending mode with rotation at 1,000 rpm. The CPC-separated fraction and purification procedures were carried out by preparatory HPLC. The $^1H$ NMR spectrum revealed that the resonances at ${\delta}$ 4.10 and 4.20 ppm corresponded to three protons ($-OCH_3$), whereas those at ${\delta}$ 6.10 ppm corresponded to two protons ($-OCH_2O-$). Further, two aromatic protons (H-11 and H-12) conveys a doublet-doublet pattern. The H-11 doublet and H-12 doublet appear at ${\delta}$ 7.98 and 8.11, respectively. The $^{13}C$ NMR. spectrum showed a tetrasubstituted with a methylenedioxy group at C2 and C3, and two methoxy groups at C9 and C10. The chemical structure of the berberine was identified by $^1H$, $^{13}C$-nuclear magnetic resonance and electrospray ionization-mass spectroscopy spectral data analysis.

Analysis of Images According to the Fluid Velocity in Time-of-Flight Magnetic Resonance Angiography, and Contrast Enhancement Angiography

  • Kim, Eng-Chan;Heo, Yeong-Cheol;Cho, Jae-Hwan;Lee, Hyun-Jeong;Lee, Hae-Kag
    • Journal of Magnetics
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    • v.19 no.2
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    • pp.185-191
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    • 2014
  • In this study we evaluated that flow rate changes affect the (time of flight) TOF image and contrast-enhanced (CE) in a three-dimensional TOF angiography. We used a 3.0T MR System, a nonpulsatile flow rate model. Saline was used as a fluid injected at a flow rate of 11.4 cm/sec by auto injector. The fluid signal strength, phantom body signal strength and background signal strength were measured at 1, 5, 10, 15, 20 and 25-th cross-section in the experienced images and then they were used to determine signal-to-noise ratio and contrast-to-noise ratio. The inlet, middle and outlet length were measured using coronal images obtained through the maximum intensity projection method. As a result, the length of inner cavity was 2.66 mm with no difference among the inlet, middle and outlet length. We also could know that the magnification rate is 49-55.6% in inlet part, 49-59% in middle part and 49-59% in outlet part, and so the image is generally larger than in the actual measurement. Signal-to-noise ratio and contrast-to-noise ratio were negatively correlated with the fluid velocity and so we could see that signal-to-noise ratio and contrast-to-noise ratio are reduced by faster fluid velocity. Signal-to-noise ratio was 42.2-52.5 in 5-25th section and contrast-to-noise ratio was from 34.0-46.1 also not different, but there was a difference in the 1st section. The smallest 3D TOF MRA measure was $2.51{\pm}0.12mm$ with a flow velocity of 40 cm/s. Consequently, 3D TOF MRA tests show that the faster fluid velocity decreases the signal-to-noise ratio and contrast-to-noise ratio, and basically it can be determined that 3D TOF MRA and 3D CE MRA are displayed larger than in the actual measurement.