• 제목/요약/키워드: 김용하

검색결과 1,770건 처리시간 0.031초

HPLC를 이용한 감초 추출물의 당 분석법 연구 (The Study of Sugar Analysis in Licorice Extract by HPLC)

  • 권영주;장기철;나효환;김용하;이문수
    • 한국연초학회지
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    • 제27권1호
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    • pp.114-119
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    • 2005
  • The study was carried out to develope quantitative analysis method of individual sugars in licorice extract. Individual sugars were analyzed by HPLC equipped with Refractive Index(RI) Detector. R values of sucrose and glucose were 1.0000 and R values of fructose and maltose were 0.9999. Standard calibration curve showed good linearity. Detection limit of sugars was in the range of 1.58 to 3.92 ${\mu}g$. Recovery rate of fructose, glucose, sucrose and maltose was $99.4\~102.2\%,\;92.3\~97.9\%,\;99.4\~102.0\%,\;91.1\~101.0$ respectively. Measure uncertainty was calculated to confirm trust and accuracy of analytical results. Main uncertainty factors were standard purity and HPLC replication injection. In $95\%$ trust level expanded uncertainty of sugars in licorice extract were fructose $1.98\pm0.047,\;glucose\;1.32\pm0.065,\;sucrose\;11.69\pm1.177,\;maltose\;1.06\pm0.042\;g/100\;g$.

GC/MS를 이용한 잎담배 중 알칼로이드 함량 분석 (Determination of Nicotine and Other Minor Alkaloids in Tobacco Leaves by GC/MS)

  • 이정민;민혜정;김용하;이문수
    • 한국연초학회지
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    • 제27권1호
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    • pp.100-106
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    • 2005
  • To obtain the optimum condition for analysis of 10 alkaloids in tobacco leaves, such as nicotine, nornicotine, anatabine, anabasine, myosmine, cotinine, 2,3'-dipyridyl, $\beta-nicotyrine,\;\beta-nornicotyrine\;and\;\beta-formylnornicotin$, 5 types of extraction method were investigated by GC-FID and GC/MS. The optimum condition of alkaloid extraction was achieved by using methanol:dichloromethane(1:3, v/v) after NaOH treatment. The use of mass selective detector (MSD) provided unambiguous nicotine related alkaloid analysis. Alkaloids in various tobacco leaves were extracted with the optimum extraction condition and quantified by GC/MS/SIM mode. Compared with concentrations of alkaloids among the various tobacco leaves, the concentration of alkaloids was generally in the order burley > flue-cured > oriental tobacco. In flue-cured tobacco leaves, the order of concentration of alkaloids was nicotine > anatabine > nornicotine > $\beta-nicotyrine\;>\;\beta-formylnornicotine\; >\;myosmine\;>\;2,3'-dipyridyl\;>\;cotinine\;>\;anabasine\;>\;\beta-nornicotyrine$. However, in the case of burley and oriental tobacco leaves, the concentration of nornicotine was higher than that of anatabine.

EERS시행을 위한 천연가스 에너지절감 추이분석 (Analysis of LNG Perspectives for EERS)

  • 김용하;우성민;박화용;김의경;유정희
    • 에너지공학
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    • 제23권3호
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    • pp.7-12
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    • 2014
  • 본 논문에서는 천연가스 도 소매 에너지공급자의 적정 목표량 설정을 위해 가스도입부터 최종 공급까지의 흐름 분석 및 관련 통계자료 구축을 통해 절감잠재량을 도출하였다. 천연가스 에너지절감 전망 추이 분석을 위해 용도별 천연가스 공급자별 천연가스 절감 잠재량 전망과 천연가스 이용기술 및 기기에 대한 잠재량 분석은 가스분야를 더욱 세밀화한 도구개발의 결과를 기반으로 도출하였다. 또한 가스사용기기의 효율향상과 보조금 조건 등을 고려하여 여러 가지 시나리오를 적용하여 각 시나리오에 따른 에너지 절감량을 산출하였다.

자세성 사두증의 진단과 치료 (Diagnosis and Treatment of Deformational Plagiocephaly)

  • 정규진;김용하
    • 대한두개안면성형외과학회지
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    • 제14권2호
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    • pp.73-80
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    • 2013
  • It is important to distinguish deformational plagiocephaly from craniosynostosis, the two conditions are different with respect to clinical progression and treatment options. Deformational plagiocephaly is diagnosed based on the patient's medical history and physical examination. Until recently, there has been no standardized method of evaluation. Visual assessment, anthropometric assessment, digital scanning, and radiologic evaluation are mostly commonly used modalities for diagnosis and assessment. Treatment of deformational plagiocephaly requires an understanding of natural progression of the disease. Deformational plagiocephaly should be classified according to its severity before the proper method and time for treatment are determined. Treatment includes repositioning, physiotherapy and remodeling with the use of orthotic devices. In general, repositioning is preferred for patients younger than six months old while treatment with the use of orthotic devices such as helmet is preferred for patients over six months old. Moreover, treatment with the use of orthotic devices is also favored for severe plagiocephaly. There is continuing research on the relation between deformational plagiocephaly and developmental delay.

한반도 상공 고층대기의 중간 자외선 대기광 모델 (A MODEL FOR MUV AIRGLOW FROM THE UPPER ATOMOSPHERE ABOVE THE KOREAN PENINSULA)

  • 문봉곤;김용하;이유;김준
    • 천문학회지
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    • 제34권1호
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    • pp.35-40
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    • 2001
  • For the planned experiments of Korea Sounding Rocket-III (KSR-III), we have constructed a model of MUV dayglow in the mid-latitude. The model computes relative intensities of individual emission lines in the Vegard-Kaplan and 2PG band systems of $N_2$ in the wavelength range of 2500-3500${\AA}$. In addition to the emission lines, solar scattered continuum was computed by an extended LOWTRAN7 code, in which we have included solar scattering in altitudes higher than 100 km by using MSIS90 thermosphere model. Ratios among vibrational bands of VK and 2PG system, were computed from the observed MUV dayglow spectra of Cleary et al. (1995). The model provides MUV dayglow intensitiy profiles with a wavelength resolution of 3.13${\AA}$ as a function of altitude. The computed intensity profiles have been utilized in designing the KSR-III airglow photometers.

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안와 파열 골절의 분류 (Classification of Blowout Fracture)

  • 이준호;류민희;김용하
    • Archives of Plastic Surgery
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    • 제34권6호
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    • pp.719-723
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    • 2007
  • Purpose: Blowout fracture can lead to functional impairments and esthetic deformities such as impairment of ocular movement, diplopia, visual loss and enophthalmos. The object of this study is to present a classification and its analysis according to the computed tomographic scan in blowout fractures. We classified blow out fractures into three types according to the anatomical location of fracture, the size of the bone defect and the degree of periosteal injury by using the computed tomography scan. Each progress and complications were analyzed more than mean 1 year. Methods: Among the 155 cases during 4 years, there were 11 cases of medial orbital wall fracture, 97 cases of inferior orbital wall fracture, 47 cases of combined type. The mean age of patients was 31.2 years, ranged from 8 to 84 years. Results: According to our classification, surgical treatments through the nasoendoscopic approach, the subciliary approach, the transconjunctival approach or their combinations were performed in 116 patients, and conservative treatments were done in 46 patients. Presurgical clinical findings of diplopia, impairment of ocular movement, enophthalmos of more than 2 mm were present in 62 patients. After surgical treatment, clinical findings were remained in 7 patients. Conclusion: We think that our classification according to computed tomographic scan is helpful for the indication and it may decrease the complications such as impairment of ocular movement, diplopia, visual loss and enophthalmos.

수요예측에 오차를 고려한 신뢰도 지수 산정에 관한 연구 (A STUDY ON THE GENERATING SYSTEM RELIABILITY INDEX EVALUATION WITH CONSIDERING THE LOAD FORECASTING UNCERTAINTY)

  • 송길영;김용하;차준;오광해
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1991년도 하계학술대회 논문집
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    • pp.402-405
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    • 1991
  • This paper represents a new method for computing reliability indices by using Large Deviation method which is one of the probabilistic production cost simulations. The reliability measures are based on the models used for the loads and for the generating unit failure states. In computing these measures it has been tacitly assumed that the values of all parameters in the models are precisely known. In fact, however, some of these values must often be chosen with a considerable degree of uncertainty involved. This is particularly true for the forecast peak loads in the load model, where there is an inherent uncertainty in the method of forecasting, which are frequently based on insufficient statistics. In this paper, the effect of load forecasting uncertainty on the LOLP(Loss of Load Probability), is investigated. By applying the Large Deviation method to the IEEE Rilability Test System, it is verified that the proposed method is generally very accurate and very fast for computing system reliability indices.

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Y형 밸런싱 트랜스포머를 적용한 AC초퍼 LED 구동 시스템 (The AC Chopper LED Driving System Using The Y Type Balancing Transformer)

  • 김진구;유진완;김용하;박종연
    • 조명전기설비학회논문지
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    • 제29권3호
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    • pp.22-29
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    • 2015
  • The AC-LED driving system which is connected directly to alternative current source is suitable for commercialization because of it's simple structure and low cost. However, it requires additional circuits compensating for current differences between the parallel connected LED strings. In this paper, we proposed the circuit compensating for current error of the three LED strings using the Y type balancing transformer. The proposed Half-bridge AC Chopper LED driving system used the ferrite material's balancing transformer. at the same time, it is able to dimming control. The proposed system is applied to 80W AC-LED module consist of three parallel strings. Experiment results present that Power factor and THD measured with power analyzer are 0.958 and 26.473% respectively satisfied with IEC61000-3-2 harmonics standard.