• Bulletin of the Korean Chemical Society
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• 제29권1호
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• pp.33-37
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• 2008

A phenomenological theory of viscosity previously proposed by the present authors8 is applied to the corresponding state theory for the viscosity of liquid. Through the process of the formulation of the corresponding state equation, we can find the simple viscosity equation with no parameters in a reduced form. The liquid viscosities of various substances can be calculated using this equation when we know only the values of the molecular weight and critical constant of substances. A corresponding state equation for the viscosity of liquid from this theory may be applicable to predicting viscosities of various substances under varying temperature and pressure. As a result, this equation may be widely applied to chemical engineering.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.655-659
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• 2001

Resident time of the continuous and Instantaneous centrifugal separator using that separates the light and heavy liquids by use of density difference is the orptical factor that affects significantly the chemical metial extraction and the productivity in the chemical and mechanical process. In this paper, the overflow of the device is investigated under consideration of the relationships between inclination angle of liquid feeding screw and the centrifugal force. From the design of the length of a centrifugal separator, the radiuses of rotor and housing, theoretical formulation on the contact radius of separation weir is established through the experiments. From the experiments, it is identified that how much the capacity of inlet impeller and the emulsion phenomenon depend on the screw angle of inlet impeller. Also, we investigate the separation condition and the resident times that are functions of the phase ratio and density.

• Journal of Mechanical Science and Technology
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• 제14권12호
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• pp.1365-1375
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• 2000

Two phase flows have been numerically calculated to analyze plume characteristics and liquid circulation in gas injection through a porous plug. The Eulerian approach has been for formulation of both the continuous and dispersed phases. The turbulence in the liquid phase has been modeled using the standard $textsc{k}$-$\varepsilon$ turbulence model. The interphase friction coefficient has been calculated using correlations available in the literature. The turbulent dispersion of the phase has been modeled by the "dispersion Prand시 number". The predicted mean flows is compared well with the experimental data. The plume region area and the axial velocities are increased with the gas flow rate and with the decrease in the inlet area. The turbulent intensity also shows the same trend. Also, the space-averaged turbulent kinetic energy for various gas flow rates and inlet areas has been obtained. The results are of interest in the design and operation of a wide variety of materials and chemical processing operations.

• 대한화장품학회지
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• 제19권1호
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• pp.108-126
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• 1993

유화, 가용화, 겔화 등의 화장품 제형에서 폴리옥시에칠렌 토코페릴에테르의 기능에 대해 연구하였다. Liquid paraffin의 유화에 있어서 POE(10)TE는 O/W 유화에서 우수한 유화능을 나타내었다. W/o 및 O/W 유화에서 oil 과 polyol 류의 함량 증가가 점도에 미치는 영향에 대해서도 연구하였다. O/W 유화에서 점도는 liquid paraffin 약 70% 함량에서 급격히 증가하기 시작하였으며, propylene glycol 첨가시는 약간의 증가만 나타내었다. 그러나 W/O 유화에서 점도는 liquid paraffin의 함량 증가에 따라 감소하였고, propylene glycol함량 증가에 대해서도 감소하는 경향을 나타내었다. Perfume oil의 가용화에 있어서 POE(18)TE는 우수한 가용화능을 나타내었다. Poe(n)TE의 gelling effect는 폴리옥시에칠렌의 사슬의 증가에 따라 50 mol 까지는 상승하는 현상을 나타내었다.

• Parasites, Hosts and Diseases
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• 제55권4호
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• pp.409-416
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• 2017

The high prevalence of pediculosis capitis, commonly known as head lice (Pediculus humanus capitis) infestation, has led to the preparation of a community-based pediculicidal ointment, which is made of common household items and the extract of Tinospora crispa stem. The present study aimed to evaluate the safety, efficacy, and physicochemical characteristics of the T. crispa pediculicidal ointment. The physicochemical properties of the ointment were characterized, and safety was determined using acute dermal irritation test (OECD 404), while the efficacy was assessed using an in vitro pediculicidal assay. Furthermore, the chemical compounds present in T. crispa were identified using liquid-liquid extraction followed by ultra-performance liquid chromatography quadruple time-of-flight mass spectrometric (UPLC-qTOF/MS) analysis. The community-based ointment formulation was light yellow in color, homogeneous, smooth, with distinct aromatic odor and pH of $6.92{\pm}0.09$. It has spreadability value of $15.04{\pm}0.98g{\cdot}cm/sec$ and has thixotropic behavior. It was also found to be non-irritant, with a primary irritation index value of 0.15. Moreover, it was comparable to the pediculicidal activity of the positive control $Kwell^{(R)}$, a commercially available 1% permethrin shampoo (P>0.05), and was significantly different to the activity of the negative control ointment, a mixture of palm oil and candle wax (P<0.05). These findings suggested that the community-based T. crispa pediculicidal ointment is safe and effective, having acceptable physicochemical characteristics. Its activity can be attributed to the presence of compounds moupinamide and physalin I.

• Journal of Pharmaceutical Investigation
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• 제41권5호
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• pp.309-315
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• 2011

A sensitive and specific liquid chromatographic method coupled with tandem mass spectrometry (LC-MS/MS) was developed for the analysis of ambroxol (active moiety of acebrophylline). After acetonitrile precipitation of proteins from plasma samples, ambroxol and the domperidone (internal standard, IS) were eluted on a C18 column. The isocratic mobile phase was consisted of 10 mM ammonium acetate and methanol (10 : 90, v/v), with flow rate at 0.2 mL/min. A tandem mass spectrometer, as detector, was used for quantitative analysis in positive mode by a multiple reaction monitoring mode to monitor the m/z 379.2${\rightarrow}$264.0 and the m/z 426.2${\rightarrow}$175.1 transitions for ambroxol and the IS, respectively. Twenty four healthy Korean male subjects received two capsules (100 mg ${\times}$ 2) of either the test or the reference formulation of acebrophylline HCl in a 2 ${\times}$ 2 crossover study, this was followed by a 1week washout period between either formulation. $AUC_{0-t}$ (the area under the plasma concentration-time curve) was calculated by the linear trapezoidal rule. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. The 90% confidence intervals for the log transformed data were acceptable range of log 0.8 to log 1.25 (e.g., log 0.8964 - log 0.9910 for $AUC_{0-t}$ log 0.8690 - log 1.0750 for $C_{max}$). The major parameters, $AUC_{0-t}$ and $C_{max}$ met the criteria of Korea Food and Drug Administration for bioequivalence indicating that Acephyll$^{(R)}$ capsule (test) is bioequivalent to Surfolase$^{(R)}$ capsule (reference).

• 농약과학회지
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• 제14권2호
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• pp.138-147
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• 2010

소나무재선충에 대한 살선충 활성을 나타내는 Micromonospora sp. AW050027 균주를 최적의 배지에서 배양한 미생물배양액을 제제하여 포트 및 포장에서 살선충 효과를 확인하였다. 최적화된 배지조성은 리터당 glycerol 10 g, soybean meal 10 g, NaCl 1 g, $CaCO_3$ 2 g, $K_2HPO_4$ 0.125 g 이었으며, 활성균주를 배양하여 농축한 후 액상 및 분말 미생물제제를 제조하였다. 제제에는 소나무재선충 공생미생물에 대하여 가장 효과적으로 항균활성을 나타내는 kanamycin을 첨가하여 사용하였다. 포트시험, 예비포장 시험 및 본포장 시험을 통하여 소나무재선충 방제효과를 확인한 결과, 액상제제를 수간수사하여 처리한 경우 1회처리시 고사율 53%, 5회 분할처리시 28%로 분할처리가 1회처리보다 2배 가량 효과적이었고, 배양농축액을 분할처리한 경우에서는 대조구의 고사율 100%에 대하여 고사율 10% 이내로 가장 낮게 나타났다.

• 한국환경보건학회지
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• 제50권3호
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• pp.169-180
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• 2024

Background: CAPSS missing evaporate emissions of volatile organic compounds (VOCs) from liquid cargo loading and unloading at ports. It needs to be supplemented to improve air quality management and allow more effective policy formulation. Objectives: In this study, the VOC emissions from the loading and unloading of liquid cargo at ports, which are not included in CAPSS, were estimated. The results of this study were compared and analyzed with the emission levels as described by CAPSS, confirming the need for managing VOC emissions from the loading and unloading of liquid cargo. Methods: Methodology provided by the U.S. Environmental Protection Agency (EPA) was applied to estimate the VOC emissions from the loading and unloading of liquid cargo at ports. The types of liquid cargo loaded at unloaded at ports are diverse, but for this study emissions were estimated for 37 VOCs designated by the Ministry of Environment. Results: The estimated results for VOC emissions from liquid cargo loading and unloading at domestic ports was 112,079 tons/yr, which was confirmed to be 11% of the known CAPSS emissions. The highest emissions were found from the loading and unloading of naptha, and the port with the highest emissions was Ulsan Port. Conclusions: The results of the estimated VOC emissions from liquid cargo loading and unloading at ports confirmed the high emission levels. To protect the health of port workers and nearby residents, it is essential to manage the emission sources and undertake continuous research.

• 혜화의학회지
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• 제23권1호
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• pp.93-104
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• 2014

Glycyrrhizae Radix et Rhizoma has been extensively used by human beings as a medicinal herb as well as natural sweetener. In this study, we performed quantification analysis of three major constituents including liquiritin, glycyrrhizin, and glycyrrhetinic acid in the 70% ethanol extracts of non-processed Glycyrrhizae Radix et Rhizoma and processed Glycyrrhizae Radix et Rhizoma using a high-performance liquid chromatography coupled with photodiode array detector. The analytical column for separation of the 3 constituents used a Gemini C18 column kept at $40^{\circ}C$ by the gradient elution of two mobile phase. The amounts of liquiritin, glycyrrhizin, and glycyrrhetinic acid in non-processed Glycyrrhizae Radix et Rhizoma were 2.57%, 3.52%, and not detected. After processing by roasting, the best roasting temperature and time of iquiritin, glycyrrhizin, and glycyrrhetinic acid were $160^{\circ}C$-15 min (2.46%), $160^{\circ}C$-15 min (3.67%), and $240^{\circ}C$-15 min (0.76%), respectively.

• 생약학회지
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• 제47권4호
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• pp.360-365
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• 2016

The aim of this study was to compare the amount of spinosin in the 70% ethanol extracts of non-processed Zizyphi Semem (ZS) and processed ZS by roasting using a high-performance liquid chromatography equipped with photodiode array detector. Separation of the spinosin was used $SunFire^{TM}$ $C_{18}$ analytical column ($5{\mu}m$, $4.6{\times}150mm$) using two mobile phase consisting of distilled water and acetonitrile, both with 1.0% (v/v) acetic acid. The flow rate was 1.0 mL/min and injection volume was $10{\mu}L$. Calibration curve of the spinosin was y = 22339.45x+483.99 in tested concentration range ($1.28-20.00{\mu}g/mL$) and correlation coefficient was 1.0000. In non-processed ZS sample, the amount of the spinosin was 0.94 m/g, while, the amount of the marker compound in processed ZS samples were 0.66-1.10 mg/g.