• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.95-97
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• 2001

This paper deals with cryogen, which is used solid nitrogen to keep the operating temperature of High Temperature Superconducting (HTS) synchronous machine. To make the solid nitrogen of liquid nitrogen, liquid helium (LHe) passes into and cools the heat exchanger to its own temperature. Two types of heat exchangers are designed and manufactured to make the solid nitrogen, and temperature characteristics of those compare with each other. The rotor cooled by latent heat of solid nitrogen and it is kept under 40K during 2 hours and 30 minutes without LHe.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 추계 학술대회논문집
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• pp.27-31
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• 2007

Glass particle distribution in a stirred solid/liquid systems was investigated using computational fluid dynamics(CFD). The numerical results were compared to experimental data from the available literature which investigated the local dispersed phase volume fraction by means of an endoscope technique. Eulerian multi-phase model and applications considered high loading of solid particle was used to investigate the influence of the particle concentration and mixing tank size on the solid distribution. A good agreement was obtained between the experimental data and simulation results. The results showed different solid particle distribution in an agitator by particle concentration and mixer size.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 학술대회
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• pp.171-175
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• 2008

In the present study, a numerical simulations are investigated in a stirred solid/liquid system by using Eulerian multi-phase model. The transient flow field of liquid phase and distribution of solid particles are predicted in stirred tanks consisting of 4-pitched paddles impeller and baffles. The effects of number and width of baffles on the mixing time and the quality of solid suspension in a stirred tank are presented numerically. The result shows that the mixing time decreases as the width and number of baffles increase.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.369-372
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• 2008

An experimental study is carried out to study two-phase vertically upward hydraulic transport of solid particles by water in a vertical and inclined (0${\sim}$60 degree) concentric annulus with rotation of the inner cylinder. Rheology of particulate suspensions in shear-thinning fluids is of importance in many applications such as particle removal from surfaces, transport of proppants in fractured reservoir and cleaning of drilling holes, and so on. Annular fluid velocities varied from 0.2 m/s to 1.5 m/s for the actual drilling operational condition. Macroscopic behavior of solid particles, averaged flow rate, and particle rising velocity are observed. Main parameters considered in this study were radius ratio, inner-pipe rotary speed, fluid flow regime, and particle injection rate. For both water and CMC solutions, the higher the concentration of the solid particles is, the larger the pressure gradients become

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.728-736
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• 1996

Solid/Liquid(S/L) separation is crucial for biological treatment of animal wastewater. Liquid portion from S/L separation has less BOD-load and proper post-strip treatment can be obtained . Screen or declined sieve was normally used to separate the solid parts. For better separating efficiency a vibration and a cylindrical separator were constructed and tested. The results are summarized as follows : Solids removal efficiency and moisture content of separated solid were 15-26% and 85-88%, respectively for the vibration separator. For the cylindrical separator, solid removal efficiency and moisture content of solid were 16-39% and 86-89% , respectively. The greatest amount of drymatter was obtained when operating vibration separator with 10。 inclination and 100% vibrating power. For the cylindrical separator maximum efficiency was obtained with 40rpm and 19 inclination . The vibration and the cylindrical separator have shown 21% and 26% in BOD removal, respectively. These two types of separator were proved to be applicable methods for animal wastewater separation.

• 한국주조공학회지
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• 제21권4호
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• pp.246-252
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• 2001

Variation in the microstructure of Mg-5%Al semi-solid slurry during isothermal heating was investigated in relation to initial microstructure, holding time, and holding temperature. Specimens with three different initial microstructures were isothermally heated. Dendritic structure in as-cast ingot was decomposed into solid globules in the semi-solid slurry during isothermal holding, while in the recrystallized specimens prepared by extrusion or rolling the size of solid particles was continuously increased during the heating. Effects of mold temperature and liquid fraction of slurry on the mold filling ability were also studied. Very thin section (0.4 mm) could be successfully filled up to 50 mm by 60% liquid slurry when the mold was heated to $600^{\circ}C$.

• 한국전산유체공학회지
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• 제14권4호
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• pp.1-6
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• 2009

In the present study, numerical simulations were performed in a stirred solid/liquid system by using Eulerian multi-phase model. The transient flow field of liquid and distribution of solid particles were predicted in the stirred tank with pitched paddle impeller and baffles. The Frozen rotor method is adopted to consider the rotating motion of the impeller. The effects of number and width of baffles on the mixing time and the quality of solid suspension in the stirred tank are presented numerically. The result shows that the mixing time decreases as the width and number of baffles increase. The present numerical methodology can be applied to optimizing mixing condition of industrial mixer.

• 한국주조공학회지
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• 제22권2호
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• pp.82-88
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• 2002

Al-5.5Zn-2.5Mg-l.5Cu semi-solid slurry was prepared by cooling the liquid metal with a low superheat to a solid and liquid co-existing temperature. Relatively round solid particles could be obtained in the slurry through the simple process. The prepared slurry was deformed into the metallic mold by a press and the mechanical properties of obtained specimens were investigated. Mold filling ability of the alloy slurry was also investigated and compared with that of A356 alloy. Al-Zn-Mg-Cu alloy showed lower mold filling ability than A356 alloy probably because small amount of eutectic phase is present and the heat of fusion generated during solidification is smaller than that of A356 alloy.

• Journal of Microbiology and Biotechnology
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• 제32권3호
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• pp.317-323
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• 2022

Solid-state fermentation using hulled barley was carried out to produce enzymes and β-glucan. The one-factor-at-a-time experiments were carried out to determine the optimal composition of the basal medium. The modified synthetic medium composition in liquid-state fermentation was determined to be 70 g/l hulled barley, 0 g/l rice bran, 5 g/l soytone, and 6 g/l ascorbic acid. Optimal pretreatment conditions of hulled barley by solid-state fermentation were evaluated in terms of maximum production of fungal biomass, amylase, protease, and β-glucan, which were 1.26 mg/g, 31310.34 U/g, 2614.95 U/g, and 14.6% (w/w), respectively, at 60 min of pretreatment condition. Thus, the solid-state fermentation process was found to enhance the overall fermentation yields of hulled barley to produce high amounts of enzymes and β-glucan.

• Asian-Australasian Journal of Animal Sciences
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• 제31권5호
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• pp.763-772
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• 2018

Objective: Swine manure in Korea is separated into solid and liquid phases which are composted separately and then applied on land. The nutrient accumulation in soil has been a big issue in Korea but the basic investigation about nutrient input on arable land has not been achieved in detail. Within the nutrient production from livestock at the national level, most values are calculated by multiplication of the number of animals with the excreta unit per animal. However, the actual amount of nutrients from swine manure may be totally different with the nutrients applied to soil since livestock breeding systems are not the same with each country. Methods: This study investigated 15 farms producing solid compost and 14 farms producing liquid compost. Composting for solid phase used the Turning+Aeration (TA) or Turning (T) only methods, while liquid phase aeration composting was achieved by continuous (CA), intermittent (IA), or no aeration (NA). Three scenarios were constructed for investigating solid compost: i) farm investigation, ii) reference study, and iii) theoretical P changes (${\Delta}P=0$), whereas an experiment for water evaporation was conducted for analyzing liquid compost. Results: In farm investigation, weight loss rates of 62% and 63% were obtained for TA and T, respectively, while evaporation rates for liquid compost were 8.75, 7.27, and $5.14L/m^2{\cdot}d$ for CA, IA, and NA, respectively. Farm investigation provided with the combined nutrient load (solid+liquid) of VS, N, and P of 117.6, 7.2, and $2.7kg/head{\cdot}yr$. Nutrient load calculated from farm investigation is about two times higher than the calculated with reference documents. Conclusion: The nutrient loading coefficients from one swine (solid+liquid) were (volatile solids, 0.79; nitrogen, 0.53; phosphorus, 0.71) with nutrient loss of 21%, 47%, and 29%, respectively. The nutrient count from livestock manure using the excretion unit has probably been overestimated without consideration of the nutrient loss.