• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.26-30
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• 2020

This study was undertaken to determine the characteristics of xanthoangelol, the major chalcone constituent derived from the extracts of different parts of Lespedeza bicolor. Xanthoangelol was isolated from the root extract using column chromatography and used as a standard for quantitative analysis. The structure of the isolated compound was established based on spectroscopic evidence. The HPLC-DAD method was validated for specificity, linearity, precision, accuracy, limit of detection, and limit of quantitation. The calibration curve of xanthoangelol had significant linearity (R²>0.9999). Limit of detection and limit of quantitation 0.018 and 0.059 ㎍/mL, respectively. The relative standard deviation values of precision test, and intra- and inter-day tests were less than 0.22 and 0.40%, respectively. In the recovery test, the accuracy ranged from 98.98-102.78% with RSD values less than 0.13%. The method validation parameters indicate the applicability of the HPLC method for quality control of food or drug formulations containing L. bicolor.

• Economic and Environmental Geology
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• v.11 no.3
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• pp.89-98
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• 1978

Mineralogy, beneficiation, and processes of titanium ores are reviewed from petrographic viewpoints. The most important titanium minerals are ilmenite ($FeTiO_3$) and rutile ($TiO_2$). Ilmenite will play major role :for raw material, because rutile are rapidly diminishing. Thus, there is a need to develope a successful process for producing high grade Ti02 from ilmenite. Commercial, as well as R and D processes to treat more abundant ilmenite ores fall in three general classess: 1. Iron in ilmenite is partially or completely reduced and separated either physically or chemically. 2. Iron is reduced to ferrous state and chemically leached away from the titanium. 3. Ore is treated to make chlorides either selectively or with subsequent separation and purification of $TiC_4$. Routes and efficiencies of these process technologies are primarily influenced by the particular ore deposit to be mined and secondly by environmental considerations. One deposit parameters which influence ilmenite process technologies are: 1. Complexity of microtextures of ilmenite intergrown with Fe-oxide minerals. 2. Composition of concentrates; ilmenites contain minor amounts of substituted Mg, Mn, and V. These elements plus iron and gangue minerals can cause difficulties to complete reactions, substantial acid consumption, difficulties of removing waste solids, and waste disposal problems. Major contributions to be made by petrologists for process optimization are: characterization and interpretation of compositional and physical changes of raw materials and solids derived from process streams. These informations can play significant role in selecting and improving process steps for titania production.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1043-1052
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• 1996

Supercritical fluid chromatographic method was recommended as an alternative separation method of fatty acids of the conventional method such as distillation or extraction. Although diffusion characteristics are varied by the carbon numbers and the degree of unsaturation of fatty acids, the quantitative data were so rare that the commercialization of supercritical fluid chromatographic method has been hindered. In this study, diffusion coefficients of fatty acids which are differently unsaturated are measured by CPB method in the range of 308.15K to 328.15K and 13MPa to 17MPa in supercritical carbon dioxide. A decrease in the binary diffusion coefficient was observed with an increase in temperature and pressure. Also, the decrease in the binary diffusion coefficient with increasing fluid density and viscosity. Wilke-Chang equation, Funazukuri empirical equation, and Matthews-Akgerman equation are used to correlate the experimental diffusion coefficients of fatty acids in supercritical carbon dioxide. Among the various theoretical equations, Matthews-Akgerman equation based on RHS theory was suggested as a more successful correlation model with experimental data.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.3
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• pp.70-78
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• 2000

In this study, a new method for canceling MRI artifacts through the motion translation of image plane is presented Breathing often makes problems in a clinical diagnosis. Assuming that the head moves up and down due to breathing, rigid translational motions in only y(phase encoding axis) direction are treated Unlike the conventional Iterative phase retrieval algorithm, this method is based on the MRI imaging process and analyzing of Image property A new constraint condition with which the motion component and the true image component in the MRI signal can be separated by a simple algebraic operation is extracted After the x(read out) directional Fourier transformation of MRI signal is done, the y(phase encoding) directional spectrum phasing value is Just an algebraic sum of the Image component and the motion component Meanwhile, as It is known that the density of subcutaneous fat area is almost uniform in the head tomographs, the density distribution along a y directional line on this fat area is regarded as symmetric shape If the density function is symmetric, then the phase of spectrum changes linearly with the position Hence, the departure component from the linear function can be separated as the motion component Based on this constrant condition, the new method of artifact cancellation is presented Finally, the effectiveness of this algorithm IS shown by using a phantom with simulated motions.

• The Journal of the Acoustical Society of Korea
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• v.43 no.5
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• pp.570-583
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• 2024

The supply of inverter-type air conditioners for cooling in summer and heating in winter is increasing. In addition, since the operating speed of the compressor has been continuously increased for higher efficiency and higher performance, the flow speed of the refrigerant has also increased. As a result, it results in the increase of the relative contribution of flow-born noise to total noise generated from outdoor unit, and this highlights the importance of designing for the noise reduction to addressing flow-borne noise and requires necessary to analyze noise generation mechanisms by flow borne noise. Therefore, in this paper, the noise generation mechanisms by flow borne noise from air conditioner outdoor unit was numerically investigated. The wall pressure field was predicted using Large Eddy Simulation(LES) for the refrigerant flow inside the pipe, and the vibration and radiated noise were predicted using structure and acoustic coupled scheme based Finite Element Method (FEM). In this step, the compressible/in-compressible pressure field were separated using Wavenumber-Frequency Analysis(WFA) for inner pipe wall, and this results were used in analyzing the noise source due to refrigerant flow.

• Economic and Environmental Geology
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• v.50 no.2
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• pp.97-104
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• 2017

Here we present the timings of reactivated events from a fault in the northern Pohang area, which should be located at the northern-end of Yangsan fault line, the major fault in the southeastern Korean Peninsula. Recently developed illite-age-analysis (IAA) approach was employed for determining the fault-activated timing, combined with illite-polytype quantification using the optimized full-pattern-fitting (FPF) method, and K-Ar age-dating for each size fraction($<0.1{\mu}m$, $0.1-0.4{\mu}m$, and $0.4-1.0{\mu}m$) of 4 fault clay samples. Two chronological records of brittle fault-activation events were recognized at $19.6{\pm}1.86Ma$ and $26.1{\pm}2.55-27.9{\pm}3.46Ma$. The ages are much younger than those of fault clays from Sangcheon-ri area (41.5~43.5 and 50.7 Ma), the southern part of Yangsan fault line, and are close to the timing of East Sea-opening event. Further chronological analysis for additional sites of the Yangsan fault should be needed to reveal the time-scheme of the tectonic events and their spatial distributions along the fault line.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.845-856
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• 2020

This study proposes a bridge evaluation system for indivisible permit vehicles such as hydraulic cranes. The permit loads for the bridge evaluation are divided into three categories: routine permit loads, special permit 1 loads, and special permit 2 loads. Routine permit and special permit 1 vehicles are allowed to cross a bridge with normal traffic. For these two permits, the standard lane model in the Korean Highway Bridge Design Code was adopted to consider normal traffic in the same lane. Special permit 2 vehicles are assumed to cross a bridge without other traffic. Structural analyses of two prestressed-beam bridges and two steel box girder bridges were conducted for the proposed permit loads. The rating factors of the four bridges for all permit loads were calculated as sufficiently large values for the moment and shear force so that crossing the bridges can be permitted. A reliability assessment of the bridges was performed to identify the reliability levels for the permit vehicles. It was confirmed that the reliability level of the minimum required strength obtained by the load-resistance factors yields the target reliability index of the design code for the permit vehicles.

• The Korean Journal of Nuclear Medicine
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• v.7 no.2
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• pp.43-46
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• 1973

이 논문(論文)은 1969년(年) 9월(月) 부터 시작된 IAEA, Internal Society of Hematology 후원(後援)인 ICSH(International Committee for Standardization of Haematology 주최로 열린 제5차 ICSH Panel에서 거론된 Ferrokinetics에 관한 몇 가지 문제점을 초록한 것이다. 1973년 11월 19일 IAEA/ICSH는 Ferrokinetics의 수기(手技)상의 문제점에 관한 토론이 있었다. 즉 혈청철(血淸鐵)이나 총철결합능(總鐵詰合能)을 검사용 혈액 채취시마다 매번 측정해야 되는지에 관한 문제, 환자(患者)의 총철결합능(總鐵詰合能)이 낮을 때 $^{59}Fe$를 주사(注射)하기전 직업적 공혈자(供血者)의 혈장(血漿)과 미리 incubation한 후 주어야 하는지의 문제, 검사용 혈액채취시 그 혈액양, 주입하는 방사성동위원소의 양(量), 항응고제(抗凝固劑)로 Heparin 대신 ACD를 사용할 수 있는지 여부, 통상(通常)의 주사기(注射器)를 사용할 때 그 오차를 줄이는 방법에 관한 문제 방사능(放射能) 계측시(計測時) 혈장(血漿) 대신 전혈(全血)을 사용채도 좋은가에 관한 문제점등이 토론되었다. 여기서 대체로 의견이 일치된 점으로는 주입(注入)하는 $^{59}Fe$는 비방사능(比放射能)이 $5{\mu}Ci/{\mu}g$이상일 것, 이의 양(量)은 체중당(體重當) 얼마로 표시할 것, 방사능계측(放射能計測)에 사용되는 혈액(血液)은 반드시 혈장(血漿)으로 통일할 것, 혈청철(血淸鐵)의 측정(測定)에는 첫번째 및 네번째의 검사용 혈액(血液)을 사용할 것, 혈액(血液)채취후 즉시 혈장(血漿)을 분리(分離)하여 보관할 것, 등(等)에 의견을 모았으며 앞으로 이에 관한 상보(詳報)를 마련하기로 하였다.各) 검사(檢査)에서 계산(計算)된 측정치(測定値)에 차이(差異)가 있어 그 결과(結果)의 해석(解釋) 및 비교(比較) 검토(檢討)에 적지않은 난점(難點)이 생겨 표준화(標準化)된 공통적(共通的)인 방법(方法)의 사용(使用)이 중요(重要)하다는 사실(事實)이 인식(認識)되게 되었다. 1966년(年) 호주(濠洲)의 Sydney에서 개최(開催)되었든 제11차(第11次) 국제혈액학회(國際血學會)때 열린 제4차(第4次) International Committee for Standardization in Haematology(ICSH)에서 Diagnostic Applications of Radioisotopes in Haematology에 관(關)한 expert panel을 갖을것을 의결(議決)하여 다음과 같은 12명(名)의 위원(委員)이 결정(決定)되었으며 위원회(委員會)의 의장(議長)에 Dr. Szur, 총무(總務)에 Dr. Glass가 각각(各各) 선임(選任)되었다. 그간(間) 1967년(年) 영경(英京) London에서 첫 회합(會合)이 있은후(後) New York, Vienna(IAEA후원(後援)) Brthesda(NIH후원(後援))에서 전문위원회(專門委員會)를 갖고 적혈구수명측정법(赤血球壽命測定法)에 관(關)한 의견(意見)의 일치(一致)를 보았다. ICSH와 국제혈액학회(國際血學會)에서는 이번에 결정(決定)된 적혈구수명측정법(赤血球壽命測定法)을 널리 소개(紹介)하며, 측정법(測定法)과 얻어진 결과(結果)의 해석(解釋)에 표준화(標準化)를 기(期)할 목적(目的)으로 이에 연관성(聯關性)있는 전문지(專門誌)에 게재(揭載)할 것을 요청(要請) 받었기에 이에 전문(全文)을 소개(紹介)하는 바이다. 이들은 방사성(放射性) chromium 법(法)의 모든 세부적(細部的)인 면(面)을 표준화(標準化)하고 있으며 그간(間) 가장 논란(論難)의 대상(對象)이 되었던,

• Korean Journal of Materials Research
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• v.9 no.10
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• pp.970-977
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• 1999

Effect of Mo interlayer on the relaxation of residual stress in AlN/Cu pint bonded by active-metal brazing method was investigated. The stress analyses by finite-element-method, the measurement of pint strength and the observation of fracture surface were carried out and their results were compared with each other. From the results of stress analysis it is confirmed that a Mo interlayer led to a shift of maximum stress concentration site from AlN/insert-metal interface$\rightarro$ insert-metal/Mo$\rightarro$Mo interlayer. Additionally, with increase of the Mo interlayer thickness the stress concentration with tensile component was separately built both at the interface of Cu/Mo and AlN/Mo. whereby the residual stress in the free surface of AlN close to the bonded interface was drastically reduced. The AlN/Mo/Cu pints with Mo interlayer thickness of above 400$\mu\textrm{m}$ showed the strengths higher than 200 MPa. upto max. 275 MPa, while the AlN/Cu pint only max. 52 MPa.

• Food Science and Preservation
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• v.24 no.1
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• pp.145-152
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• 2017

In this study, near infrared (NIR) spectroscopy known as a non-destructive analysis technique was applied to investigate peptide cleavage and consequent release of amino acids in soybean lumps as affected by its moisture content and incubation time during fermentation at 25 for 3 weeks. The NIR spectra of the soybean lump semi-dried and soaked in saline water showed that absorption intensity around 1,400 nm originating from hydrogen bonds of water decreased and absorption band shifted to 1,430 nm as moisture content decreased during incubation at 25 for 3 weeks. In addition, absorption around 2,050 nm which was assigned to amino groups increased as incubation time increased. NIR spectra data from 1,000 to 2,250 nm showed higher accuracy in the discriminant analysis between outside and inside parts of fermented soybean lumps than visible spectra result. NIR spectroscopy for the amino acid and moisture contents in traditional fermented soybean lumps showed relatively good accuracy with the multiple correlation coefficient ($R^2$) of 0.91 and 0.81, respectively, and root mean square error of cross validation (RMSECv) of 0.23 and 0.83%, respectively, in partial least square regression (PLSR). These results indicate that NIR spectral observations could be applicable to control the fermentation process for preparation of soybean products.