• Title/Summary/Keyword: Optimal flow-rate

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Development Cut-off Value for Yin-deficiency Questionnaire and Diagnostic Ability of Yin-deficiency in Xerostomia (구강건조증 환자에서 음허 측정 설문지 절단점 개발 및 진단능 평가)

  • Jang, Seung-Won;Kim, Jin-Sung
    • The Journal of Internal Korean Medicine
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    • v.35 no.4
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    • pp.483-497
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    • 2014
  • Objectives: The aims of study were developing cut-off value of Yin-deficiency questionnaire (YDQ) for diagnosis of Yin-deficiency (YD) and compare diagnostic ability between YDQ and Yin-deficiency scale score (YDS) in xerostomia patients. Methods: We recruited 58 xerostomia patients. They were diagnosed YD or non-YD by 3 Korean medicine doctors (KMD). We assessed YD using YDQ and YDS. We evaluated xerostomia using VAS, Dry Mouth Symptom Questionnaire (DMSQ), Salivary Flow Rate (SFR), oral moisture on buccal mucosa and tongue surface (OMB and OMT). We surveyed tongue coatings using Winkel Tongue Coating Index (WTCI). Results: We diagnosed 23 patients YD and 35 patients non-YD. There were no significant differences of age, sex and body mass index between the YD and non-YD groups. Using receiver operating characteristic curve analysis, the optimal cut-off value of YDQ was defined as 304. Sensitivity, specificity and Youden index of YDQ were 86.96%, 71.43% and 1.5839 respectively. Using Cohen's coefficient of agreement, we found that degree of agreement between KMD and YDQ diagnosis was moderate (${\kappa}$=0.524, p<0.001). Using Pearson's correlation analysis, we found concurrent validity of YDQ and YDS were significant correlated. Using area under curve value, we found diagnostic ability between YDQ and YDS were not significantly different (p=0.505), but there were more strong correlations between DMSQ-symptoms and YDQ (r=0.731, p<0.001) than correlations between DMSQ-symptoms and YDS (r=0.418, p<0.01). Conclusions: The cut-off value of YDQ can diagnose YD in xerostomia and diagnostic ability of YDQ in xerostomia is better than YDS.

Shape Characteristics of Exhaust Plume of Dual-Stage Plasma Thruster using Direct-Current Micro-Hollow Cathode Discharge (직류 마이크로 할로우 음극 방전을 이용한 이단 마이크로 플라즈마 추력기의 배기 플룸의 형상 특성)

  • Ho, Thi Thanh Trang;Shin, Jichul
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.3
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    • pp.54-62
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    • 2016
  • Micro plasma thruster (${\mu}PT$) was studied experimentally with a dual-stage micro-hollow cathode discharge (MHCD) plasma. Electrostatic-like acceleration exhibiting more directional and elongated exhaust plume was achieved by a dual layer MHCD at the total input power less than 10 W with argon flow rate of 40 sccm. V-I characteristic indicated that there was an optimal regime for dual-stage operation where the acceleration voltage across the second stage remained constant. Estimated exhaust plume length showed a similar trend to the analytic estimate of exhaust velocity which scales with an acceleration voltage. ${\mu}PT$ with multiple holes exhibited similar performance with single-hole thruster indicating that higher power loading is possible owing to decreased power through each hole. Boltzmann plot of atomic argon spectral lines showed average electron excitation temperature of about 2.6 eV (~30,170 K) in the exhaust plume.

Characteristics for Sludge Removal Nozzle in Steam Generator (증기 발생기 슬러지 제거용 노즐 특성 연구)

  • Lee Sam-Goo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.8 no.3
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    • pp.37-43
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    • 2004
  • Water-jet trajectory visualization and velocity deficits from a high pressurized steam-generator nozzles were experimentally observed. In order to find an optimal nozzle configuration. several parameters affecting plugging and erosion onto the steam generator tube were quantitatively analyzed. For the experiments, a high-pressurized pump (pressure in use: 200 kg/$\textrm{cm}^2$, 15 HP, 11 kW, output flow Q : 301/min) was utilized. Visualization, velocity distribution, and spray growth rate with different nozzle configurations have been mainly focused using a 2-D PDPA system. The results indicated that trajectories along the centerline regardless of their configurations has its potential core region. However, the phenomena from the peripheral part need to be meticulously considered. Accordingly, it is evident that quantitative velocity deficits at the outer region are outstanding due to the aerodynamical drag and entrainment.

A Study of Cutting Methods by Comparing the Contents of Cinnamic acid and Cinnamaldehyde in Different Parts of Cinnamomi Ramulus (Cinnamic acid, Cinnamaldehyde의 부위별 정량을 통한 계지(桂枝)의 음편(飮片) 규격 연구)

  • Kim, Young-Sik;Lee, Guem-San;Kim, Jung-Hoon;Choi, Go-Ya;Jeong, Seung-Il;Cho, Su-In;Ju, Young-Sung;Kim, Hong-Jun
    • The Korea Journal of Herbology
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    • v.26 no.2
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    • pp.11-15
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    • 2011
  • Objectives : In the present study, the contents of cinnamic acid and cinnamaldehyde in three different parts of Cinnamomi Ramulus (CR) (the whole body, the bark part, and the wood part) was evaluated using UPLC (ultra performance liquid chromatography) in order to investigate a suitable cutting method. Methods : Analysis was performed on SMART LC with UV detector. Reference compounds were separated on Inertsil ODS-4 column ($2.1mm{\times}50mm$, $3{\mu}m$, GL Science, Japan) using isolation elution with water and acetonitrile each containing acetic acid at a flow rate of $500{\mu}L/min$. Additionally, samples of CR were purchased from pharmacy of medicinal herb. Results : The correlation coefficients of the cinnamic acid and cinnamaldehyde levels showed good linearity ($r^2{\geq}0.9999$) over the linear ranges. Furthermore, the bark part exhibited higher concentration levels of reference compounds than the wood part in all samples. In addition the bark exfoliation rates in oblique and perpendicular-long cut samples of CR were lower than the perpendicular-short cut samples. Conclusions : These results suggested that the optimal cutting method would be able to reduce the bark exfoliation. Therefore, the oblique or perpendicular-long cutting method is considered to be a better cutting type than the perpendicular-short cutting method.

Optimization of Culture Conditions for the Production of Diphtheria Toxin (디프테리아 toxin 생산을 위한 발효조건 최적화)

  • Cho, Min;Ryu, Yeon-Woo
    • KSBB Journal
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    • v.14 no.2
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    • pp.241-247
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    • 1999
  • Experimental studies were carried out to optimize the culture conditions of Corynebacterium diphtheriae for the production of diphtheria toxin. A new media which does not contain any meat digest products was selected. The main ingredient of new medium was enzymatic digests of casein known as NZ-Case. In fermenter experiments, the toxin production was increased with the increase of cell growth. The optimum initial pH of media, air flow rate and agitation speed were 7.0, 0.22, vvm and 400 rpm, respectively. The contents of iron and calcium-phosphate precipitate were important for maximal cell growth and toxin production. The optimum concentration of iron was 0.3 mg/L and calcium-phosphate precipitate could serve in gradual supply of iron to maintain the optimal culture condition which is required for enhanced yield of toxin production. In potency test, the potency of toxoid from fermentor culture was higher than that from static culture. When diphtheria toxin is produced by fermentor culture, it is possible to produce higher levels of toxin and better toxoid quality in terms of safety, yield, productivity and immunity.

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CFD Performance Analysis and Design of a 8kW Class Radial Inflow Turbine for Ocean Thermal Energy Conversion Using a Working Fluid of Ammonia (암모니아 작동유체를 이용한 해수온도차발전용 8kW급 구심터빈의 설계 및 CFD 성능해석)

  • Mo, Jang-Oh;Cha, Sang-Won;Kim, You-Taek;Lim, Tae-Woo;Lee, Young-Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.8
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    • pp.1030-1035
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    • 2012
  • In this research, we analysed design and CFD analysis of an inflow radial turbine for OTEC with an output power of 8kW using an working fluid of ammonia. The inflow radial turbine consists of scroll casing, vain nozzle with 18 blade numbers and rotor blade with 13 blade numbers. Mass flow rate, and inlet temperature are 0.5kg/s and $25^{\circ}C$ respectively, and variable rotational speeds were applied between 12,000 and 36,000 with 3,000 rpm intervals. As the results according to the rotational speeds, the designed speed is 24,000 rpm where maximum efficiency exists. The maximum efficiency and output power are 88.66% and 8.52kW, respectively. Through this study, we expect that the analysed results will be used as the design material for the composition of the turbine optimal design parameters corresponding to the target output power under various working material conditions.

The Comparison of Morphological and Constituents of the Leaves of Magnolia officinalis, M. biloba and M. obovata (중국 및 일본산 후박 잎의 형태 및 성분 비교)

  • Park, Seo-Hee;Yun, Ui-Jung;Shin, Jong-Hun;Kwon, Byoung-Mok;Bae, Ki-Hwan
    • Korean Journal of Pharmacognosy
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    • v.37 no.4 s.147
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    • pp.278-282
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    • 2006
  • In this study, we analyzed and quantified the contents of magnolol (1), honokiol (2), and obovatol (3) in the leaves of Magnolia species by HPLC. HPLC methods were developed and validated by ICH guide lines comparing the linearity, intraday precision, inter-day precision. The optimal conditions were as follows; wavelength: 288 nm, column: Zorbax Eclipse XDBC18 $(2.1\times150\;mm,\;5{\mu}m)$, mobile phase: Acetonitril - 0.1 % $H_3PO_4$ (45:55, v/v) buffer, flow rate: 0.5 ml/min. The contents of magnolol, honokiol and obovatol were 1.08%, 2.37%, and 0.57% in the leaves of M. officinalis, 0.50%, 0.03%, and 1.54% in the leaves of M. biloba, 0.37%, 0.03%, and 0.76% in the leaves of M. obovata. The contents of effective ingredients in the leaves of M. officinalis and M biloba were higher than that of M. obovata. Especially, the content of obovatol in the leaves of M. biloba was remarkably high. This result showed that the shapes of leaves have a certain relationship with the content of obovatol.

Anti-inflammatory Activities of Lupane-triterpenoids In Vitro and Their Phytochemical Fingerprinting from Leaves of Acanthopanax gracilistylus

  • Li, Xiao Jun;Dai, Ling;Li, Zhi;Zhang, Xiao Dan;Liu, Xiang Qian;Zou, Qin Peng;Xie, Xia
    • Natural Product Sciences
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    • v.21 no.2
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    • pp.104-110
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    • 2015
  • The activities on the inhibition of NO on LPS-induced RAW 264.7 macrophages were investigated in this work. A simple and sensitive method has been developed and validated for fingerprinting analysis of leaves of Acanthopanax gracilistylus W.W. Smith (AGS). The cytotoxicity and inhibition of NO on LPS-induced RAW 264.7 cells of the extract and triterpenoids were determined. Optimal conditions of HPLC analysis were established as follows. The separation was performed with an ODS-C18 column at $30^{\circ}C$, the detected wavelength was 210 nm, the flow rate was 1 mL/min, and the mobile phase consisted of acetonitrile (0.05% phosphoric acid)-0.05% phosphoric acid solution with gradient elution. Our results showed that impressic acid and acankoreaogenin was more effective on the inhibition of NO than the methanol extract and other compounds. There were seventeen peaks coexisted with similarities above 0.95 and nine lupane-triterpenoids including acankoreaogenin and impressic acid detected and identified. The result of anti-inflammatory activities provides a potential explanation for the use of AGS leaves as a herbal medicine in the treatment of inflammatory diseases. Our results also show that acankoreanogenin and impressic acid may be potentially useful in developing new anti-inflammatory agents. In addition, the fingerprint chromatography clearly illustrated and confirmed the material basis for the anti-inflammatory activities of this plant.

An Optimal Design of a Pedestrian Safety System Using a Design Scenario (설계방법론을 이용한 보행자 보호 시스템의 최적설계)

  • Yun, Yong Won;Park, Gyung Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.9
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    • pp.1019-1027
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    • 2014
  • Vehicle-into-pedestrian traffic accidents show a very high mortality rate compared to their frequency of occurrence. Throughout the world, governments and insurance companies tend to establish and implement new safety standards for pedestrian protection. In order to improve the performance of pedestrian protection, the Korean government has evaluated the pedestrian safety of vehicles under the Korea New Car Assessment Program (K-NCAP) since 2007. The pedestrian protection performance has improved gradually, but it remains insufficient. A pedestrian protection system consisting of a hood lift system and a pedestrian airbag can be a solution to pedestrian safety. A pedestrian airbag design procedure based on a newly defined design scenario is introduced to reduce the head injury criterion of pedestrians. The proposed design scenario is discussed from a practical viewpoint and applied to manufacture pedestrian protection systems.

Comparative Analyses of Bioactive Constituents from Forsythia suspensa and Forsythia viridissima by HPLC-DAD

  • Won, Tae-Hyung;Liao, Lijuan;Lee, Seung-Ho;Son, Jong-Keun;Shin, Jong-Heon
    • Natural Product Sciences
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    • v.17 no.4
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    • pp.328-336
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    • 2011
  • A high-performance liquid chromatography (HPLC) with diode array detector (DAD) method was established for the discrimination of a folk medicine Forsythia suspensa and Forsythia viridissima. Five and three representative metabolites of the lignan and phenolic glycoside classes were selected for the analysis from F. suspensa and F. viridissima, respectively. The optimal chromatographic conditions were obtained on an ODS column (5 ${\mu}m$, $4.6{\times}250$ mm) with the column temperature at $40^{\circ}C$. The mobile phase was composed of methanol and 0.3% acetic acid using an isocratic elution with the flow rate 1 mL/min. Detection wavelength was set at 280 nm. All calibration curves showed good linear regression ($r^2$ > 0.996) within test ranges. Limits of detection (LOD) and limits of quantitation (LOQ) values were lower than 0.096 and 0.291 ${\mu}g/mL$, respectively. The developed method provided satisfactory precision and accuracy with overall intra-day and inter-day variations of 0.07-0.63% and 0.14-0.62%, respectively, and the overall recoveries of 97.79-102.46% for all of the compounds analyzed. In addition, effectiveness of diverse extraction methods was compared to each other for the development of standard analytical method. The verified method was successfully applied to the quantitative determination of representative metabolites in fifty-three commercial F. suspensa samples and fifteen commercial F. viridissima samples from diverse sources. The overall analytical results showed the unequivocal differences in bioactive constituents between F. suspensa and F. viridissima.