• Nuclear Engineering and Technology
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• v.31 no.3
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• pp.267-275
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• 1999

This paper deals with the industrial problem of thermal striping damage on the French prototype fast breeder reactor, Phenix and it was studied in coordination with the research program of IAEA. The thermomechanical and fracture mechanics evaluation procedure of thermal striping damage on the tee-junction of the secondary piping using Green's function method and standard FEM is presented. The thermohydraulic(T/H) loading condition used in the present analysis is the random type thermal loads computed by T/H analysis on the turbulent mixing of the two flows with different temperatures. The thermomechanical fatigue damage was evaluated according to ASME code section 111 subsection NH. The results of the fatigue analysis showed that fatigue failure would occur at the welded joint within 90,000 hours of operation. The assessment for the fracture behavior of the welded joint showed that the crack would be initiated at an early stage in the operation. It took 42,698.9 hours for the crack to propagate up to 5 mm along the thickness direction. After then, however, the instability analysis, using tearing modulus, showed that the crack would be arrested, which was in agreement with the actual observation of the crack. An efficient analysis procedure using Green's function approach for the crack propagation problem under random type load was proposed in this study. The analysis results showed good agreement with those of the practical observations.

• Natural Product Sciences
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• v.17 no.4
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• pp.315-320
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• 2011

Routinely applicable HPLC assay procedures for the ganglioside content in various deer antler preparations were established through the creation of a UV-absorbing chromophoric substance - trans-${\alpha},{\beta}$-unsaturated-hexadecene-aldehyde - from the sphingosine moiety in ganglioside molecules by two step chemical reactions. In order to guarantee the assay's accuracy and sensitivity, the HPLC-assay procedure adopted internal reference procedures by mixing cis-${\alpha},{\beta}$-unsaturated-hexadecene aldehyde[V] or cis-3-heptadecene- 1,2-diol[IV] to assay samples. The internal reference compound [IV] or [V] was synthesized in our laboratory starting from mannitol-diacetonide through three or four step organic reactions. This new HPLC-assay procedure was successfully applied to deer antler extracts with good dose-dependent calibration curves at the picomole level of gangliosides.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.226-233
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• 2023

To create an environmentally sustainable fuel with a low sulfur concentration, requires alternative sulfur removal methods. During the course of this study, a high surface gamma alumina-supported ZnO nanocatalyst with a ZnO/-Al₂O₃ ratio of 12% was developed and tested for its ability to improve the activity of the oxidative desulfurization (ODS) process for the desulfurization of kerosene fuel. Scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) were used to characterize the produced nanocatalyst. In a digital batch baffled reactor (20~80 min), the effectiveness of the synthesized nanocatalyst was tested at different initial concentrations of dibenzothiophene (DBT) of 300~600 ppm, oxidation temperatures (25~70 ℃), and oxidation periods (0.5, 1, and 2 hours). The baffles included in the digital baffled batch reactor resist the swirling of the reaction mixture, thus facilitating mixing. The ODS procedure yielded the maximum DBT conversion (95.5%) at 70 ℃ with an 80-minute reaction time and an initial DBT level of 600 ppm. The most precise values of kinetic variables were subsequently determined using a mathematical modelling procedure for the ODS procedure. The average absolute error of the simulation findings was less than 5%, demonstrating a good degree of agreement with the experimental results acquired from all runs. The optimization of the operating conditions revealed that 99.1% of the DBT can be removed in 140 minutes.

• Archives of Pharmacal Research
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• v.16 no.1
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• pp.57-61
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• 1993

Based on the turbidimetric response of protein with 50% trichloroacetic acid (TCA), this study aims to introduce an assay method for protein in solution. The standard procedure consists of mixing equal volume of sample solution (standard or unknown) with 50%-TCA solution and measuring the absorbance at 450 nm after 20 min. The absorbances of the solutions were almost stable over 120 min at room temperature. This assy method is simple, reproducible, and tolerant to many interfering substances. It can detect less amount than $10\mu$g/ml of bovin serum albumin. The assay method has low protein-to-protein variability over wide range of molecular weight.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.549-554
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• 2002

In Powder System, SCC demands high dosage of superplasticizer and a lage amout of powder for suitable fluidity and viscosity. Okamura's method of most representative mixing design method in SCC of Powder-System is unfavorable economically because of using a large amount of powder. In addition, many ready-mixed concrete plants do not use his mix design method and procedure due to complexity for practical application. Therefore, Nan Su proposed more simple mix design method than Okamura's. It had an advantage in simplicity in practical application and required a smaller amount of powders compared with Okamura's method. This paper proposed an optimal mixture proportion of SCC with consideration of Nan Su's method. The new and modified mix design method required a smaller amount of powder than that of Nan Su's. To check the properties of SCC, considered with the requirements specified by the Japanese Society of Civil Engineering.(JSCE)

• Journal of Environmental Science International
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• v.8 no.2
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• pp.241-248
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• 1999

The photocatalytic decolorization and photodegradation of wastewater contamininated with dyes such as methyleneblue tetrahydrate(MBT), methyl orange(MO), phenol red(PR) and the mixed dyes have been studied using a batch reactor in the presence of aerotropic and titania. Degussa P25 titanium oxide was used as the photocatalyst and proved to be effective for the dyes-degradation when irradiated with UV-light source emitting the wavelength of 253.7 nm in the presence of air. In addition to removing the color from the wastewater, the photocatalytic reaction simultaneously reduced the COD and optical density which suggests that the dissolved organic compounds have been photooxidized. The reaction rate of disappearance of the dyes were measured as a function of the irradiation times. The photooxidative procedure of the aquatic solution have the first order reaction-kinetics. The rate constants were increased in the order of PR < MBT < $gL^{-1}-TiO_2$ powder were irradiated with the UV -light source.

• Journal of the Korean Magnetic Resonance Society
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• v.12 no.2
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• pp.81-88
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• 2008

Solid HETCOR (Hetero-Correlation) requires homo-dipolar decoupling between proton spins during the evolution and the mixing period in 2D-NMR. There are two different ways of achieving it with pulse sequences. One is based on the multiple pulse (MP) sequence where thousands of intense radio frequency (rf) pulses are used to remove the homo-dipolar interaction between protons. The other is utilizing the so-called Lee-Goldburg (LG) off-resonance scheme where a continuous rf-irradiation is used. In this report, the advantage of one technique to the other, is analyzed. LG version is evaluated better in S/N and easier in setup procedure with the same experimental time.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.4 no.4
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• pp.253-262
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• 1992

A numerical procedure is introduced to calculate local ventilation effectiveness using the definitions of local decay rate and local mean age. A low Reynolds number $k-{\varepsilon}$ model is implemented to calculate steady state turbulent velocity distributions, and a step-down method is used to calculate transient concentration distributions. Simulations are carried out for several different values of air change rates and several different diffuser angles in a two-dimensional model of a half scale office room. The results show that the local ventilation effectiveness within a room could vary significantly from one location to another. The nominal air change rate based on the assumption of complete mixing of room air does not provide the local ventilation effectiveness information. It is numerically proved that the local mean age distribution obtained from the transient calculation is equivalent to the steady state concentration distribution with homogeneously distributed contaminant sources.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.1087-1093
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• 1996

Current processing and packaging of anchovy sauce was reviewed and a new method of anchovy sauce processing was proposed for standardized production and quality management. The proposed procedure for liquid type anchovy sauce involves mixing of anchovy fishes and salt(20%), stored aging and fermentation under controlled temperature condition, filtration/centrifuge, secondary fermentation and filtration of residue added with brine solution, combining of first and second filtrates, packaging into container, and pasteurization. Treatment of residue waste was also considered.

• 한국전산유체공학회:학술대회논문집
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• 1995.10a
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• pp.246-252
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• 1995

The transient incompressible flow behind the bluffbody is numerically simulated using the random vortex method(RVM). Based on the vorticity formulation of the unsteady Navier-Stokes equations, the Lagrangian approach with the random walk technique is employed to account for the transport processes of the vortex elements. The random walk procedure for the diffusion process has been validated against the exact solutions. The present simulation focuses on the transition flow regime where the recirculation zone behind the bluffbody becomes highly unsteady and large-scale vortex eddies are shed from the bluffbody wake. The unsteady flow structures and the mixing characteristics behind the bluffbody are discussed in details.