• Korean Journal of Soil Science and Fertilizer
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• v.46 no.4
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• pp.296-302
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• 2013

This study was carried out to investigate the effect of organic content level on ultimate methane potential and anaerobic biodegradability of substrate by biochemical methane potential assay. Three organic matters (whole sludge and liquid and solid fraction of sludge) of the same origin, which had different organic contents, were fermented at the batch anaerobic reactor for 70 days. Ultimate methane potential and anaerobic biodegradability were determined by the terms of volatile solid (VS) and chemical oxygen demand (COD). Volatile solid contents of whole sludge and solid and liquid fraction of sludge were 2.4, 18.8, and 0.2% and COD were 5.3, 30.4, and 0.5%, respectively. Ultimate methane potentials ($B_u$-COD) and anaerobic biodegradability ($D_{VS}$) determined by VS content were $0.5Nm^3kg^{-1}-VS_{added}$, 76.3% for whole sludge, $0.5Nm^3kg^{-1}-VS_{added}$, 76.3% for the liquid fraction of sludge, and $0.6Nm^3kg^{-1}-VS_{added}$, 77.0% for the solid fraction of sludge. Ultimate methane potentials ($B_u$-COD) and anaerobic biodegradability ($D_{COD}$) determined by COD were $0.2Nm^3kg^{-1}-COD_{added}$, 73.4% for whole sludge, $0.2Nm^3kg^{-1}-VS_{added}$, 74.0% for the liquid fraction of sludge, and $0.33Nm^3kg^{-1}-COD_{added}$, 99.1% for the solid fraction of sludge. In conclusion, ultimate methane potential and anaerobic biodegradability given by the VS term showed more reasonable results because COD might be underestimated by the interference of $NH_4{^+}$ in the case of highly concentrated organic material.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.328.2-328.2
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• 2014

Semiconductor nanowires (NWs) have attracted research interests due to the distinct physical properties that can lead to variousoptical and electrical applications. In this paper, we have grown InAs NWs viagold (Au)-assisted vapor-liquid-solid (VLS) and catalyst-free vapor-solid (VS) mechanisms and investigated on the p-type doping profile of the NWs. Metal-organic chemical vapor deposition (MOCVD) is used for the growth of the NWs. Trimethylindium (TMIn) and arsine (AsH3) were used for the precursor and diethyl zinc (DEZn) was used for the p-type doping source of the NWs. The effectiveness of p-type doping was confirmed by electrical measurement, showing an increase of the electron density with the DEZn flow. The structural properties of the InAs NWs were examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In addition, we characterize atomic distribution of InAs NWs using energy-dispersive X-ray spectroscopy (EDX) analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.777-781
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• 1997

In this study, the effect of strain-rate and inital solid fraction on the deformation behaviour of semi-solid material is investigated, when semi-solid forging is performed by the process of closed-die compression using A356 alloy of which the above results can be practically applied for industrical purpose. In order to simulate densification in the deformation of semi-solid material, the semi-solid material is assumed to be composed of solid region following rigid visco-plastic material, the liquid region following Darcy's law for the liquid flow saturated in the interstitial space. Simulation results of closed-die compression and simple upsetting under different strain-rate and initial solid fraction are compared.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.98-105
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• 1997

The behaviour of alloys in the semi-solid state strongly depends on the imposed stress state and on the morphology of the phase which can very from dendritic to globular. The estimation of behaviour characteristic in the compression simulation with seim-solid materials are calculated by finite element method with proposed algorithm. The proposed theoretical model and a various boundary conditions for compression process is investigated with the coupling calculation between the liquid phase flow and the solid phase deformation. The simulation process considering soldification phenomena is performed to the isothermal conditions of two dimensional problems. To analysis of compression process by using semi-solid materials, a new stress-strain relationship is described, and compression analysis is performed by viscoelastic model for the solid phase and the Darcy's law for the liquid flow. The calculated results for compression force and ram displacement will be compared to experimental data.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.440-444
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• 2015

Effects of operating variables on the solid circulation rate were investigated in a three-phase circulating fluidized bed, of which inside diameter was 0.102m and height was 3.5m, respectively. Gas velocity, primary and secondary liquid velocities, particle size and height of solid particles piled up in the solid recycle device were chosen as operating variables. The solid circulation rate increased with increasing primary and secondary liquid velocities and height of solid particles piled up in the solid recycle device, but decreased with increasing particle size. The value of solid circulation rate decreased only slightly with increasing gas velocity in the riser. The values of solid circulation rate were well correlated in terms of dimensionless groups within the experimental conditions.

• Structural Engineering and Mechanics
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• v.65 no.5
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• pp.557-572
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• 2018

The academic research works about liquid storage tanks are reviewed for the purpose of providing valuable reference to the engineering practice on their aseismic design. A summary of the performance of tanks during past earthquakes is described in this paper. Next, the seismic response of tanks under unidirectional earthquake is reported, supplemented with the dynamic response under multidirectional motions. Then, researches on the influence of soil-structure interaction are brought out to help modify the seismic design approach of tanks in different areas with variable properties of soils. Afterwards, base isolation systems are reported to demonstrate their effectiveness for the earthquake-resistant design of liquid storage tanks. Further, researches about the liquid-structure interaction are reviewed with description of simplified models and numerical analytical methods, some of which consider the elastic effect of tank walls. Moreover, the liquid sloshing phenomenon on the hydrodynamic behaviors of tanks is presented by various algorithms including grid-based and meshfree method. And then the impact of baffles in changing the dynamic characteristics of the liquid-structure system is raised, which shows the energy dissipation by the vortex motion of liquid. In addition, uplifting effect is given to enhance the understanding on the capacity of unanchored tanks and some assessment of their development. At last, the concluding remarks and the aspects of extended research in the field of liquid storage tanks under seismic loads are provided, emphasizing the thermal stress analysis, the replaceable system for base isolation, the liquid-solid interaction and dynamic responses with stochastic excitations.

• The Journal of Pediatrics of Korean Medicine
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• v.17 no.1
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• pp.71-86
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• 2003

Objectives : The aim of this study was to investigate the classification methods of the external treatments of atopic dermatitis for Children. Methods: We surveyed the oriental medical book concerning the atopic dermatitis for Children. Results : 1. The oriental herbal medications for the atopic dermatitis used with Ryuhwang(硫?), WoongHwang(雄黃), KyoungBun(輕粉), WhangBaek(黃栢), SeokGo(石膏) and so on. 2. The frequently used type of external prescription is solid or liquid. 3. The external preparations were frequently painted or washing with to the lesion of dermatitis. For the wet type of atopic dermatitis, the solid prescription were sprinkled on the lesion or irrigated with the liquid. For the dry type, the mixed prescription of the solid and liquid were painted on the lesion.

• Journal of Korea Foundry Society
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• v.9 no.1
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• pp.73-79
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• 1989

Microstructural characteristics of Al-3.63wt.%Pb hyper-monotectic alloy rapidly-solidified by melt spinning were examined. Possibility of forming a planar liquid -solid interface during rapid solidification of this alloy was also considered with a morphological stability theory, and a mechanism of forming banded structure observed at the bottom parts of melt-spinned specimens was considered as well. Application of the absolute stability criterion predicts the liquid-solid interface of the primary aluminium phase to be able to maintain a planar interface during the early stage of rapid solidification. Formation of banded structure was supposed to be resulted from the release of latent heat during solidification, which affect the stability of a planar liquid-solid interface.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.2
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• pp.73-81
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• 1999

Shake mixing has been widely used in cell culture. The mixing performance for shake mixing, however, has not been reported quantitatively. The critical circulating frequency and the power consumption for complete suspension of particles, based on the definition of Zwietering, were measured in a shaking vessel containing a solid-liquid system. The critical suspension frequency was correlated by the equation from Baldi's particle suspension model modified with the physical properties of the particles. Critical suspension frequency was correlated as following ; $$N_{JS}={\frac{0.58\;d{_p}^{0.06}(g{\Delta}{\rho}/{\rho}_L)^{0.004}X^{0.03}}{D^{0.35}d^{0.17}{\upsilon}^{0.04}}}$$ The power consumption at the critical suspension condition in the shaking vessel was less than that in an agitated vessel with impeller.

• Journal of the Korean Applied Science and Technology
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• v.12 no.1
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• pp.1-11
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• 1995

In this outline, the stability of solid/liquid dispersion was theoretically investigated the matter from all angles by using the modified DLVO theory. The stability was handled various considerations such as a production and characteristics of electrical double layer, total interaction$(V_T)$ that consisting of attractive force$(V_A)$ and repulsion$(V_R)$. coagulation, the stability ratio(W), critical flocculation concentration (cfc) and zeta potential$(\zeta)$ etc. It was possible for us to examine with the stability ratio(W), critical flocculation concentration (cfc) and zeta potential$(\zeta)$ that may estimation of stability of solid/liquid dispersion experimentally.