• Journal of the Korean Society of Combustion
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• v.18 no.3
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• pp.38-43
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• 2013

In this study, we tested the absorption of $CO_2$ in combustion gas into an alkaline wastewater to simultaneously control $CO_2$ and wastewater. During the experiment, we investigated the effects of operating parameters on neutralization characteristics of the wastewater by using $CO_2$ in a bench-scale semi-batch jet loop reactor (0.1 m diameter and 1.0 m in height). The operating parameters investigated in the study are gas flow rate of 1.0-2.0 L/min, liquid recirculation flow rate of 4-32 L/min, and liquid temperature of $20-25^{\circ}C$. It was shown that the initial pH of wastewater rapidly decreased with increased gas flow rate for a given liquid recirculation flow rate. This was due to the increase in the gas holdup and the interfacial area at higher gas flow rate in the reactor. At constant gas flow rate, the time required to neutralize the wastewater initial pH of 10.1 decreased with liquid recirculation flow rate ($Q_L$), reached a minimum value in the range of $Q_L$ = 16-24 L/min, and then increased with further increase in $Q_L$. Further, the time required to neutralize the wastewater was shortened at higher temperatures.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.284.2-284.2
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• 2003

Using a column-switching technique. highly sensitive and selective semi-micro high-performance liquid chromatographic (HPLC) method has been developed for the determination of baclofen in human plasma. Following precipitation of plasma sample containing baclofen with zinc sulfate-acetonitrile, samples were directly injected on to the system. (omitted)

• Transactions of Materials Processing
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• v.14 no.4 s.76
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• pp.338-350
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• 2005

Recently, in the field of automobile industry, to solve the problem of reducing the weight of automobile for the improvement of fuel efficiency and the protection of environment, the aluminum alloy parts have been substituted for the steel parts. However, the aluminum alloy does not have as good mechanical property as the steel part. To improve the mechanical property, the semi-solid die casting process is performed to make automobile parts. In the fabrication of semisolid material the control of the liquid segregation is very important to improve the material properties of aluminum alloy. In the present paper we examine the influence of the liquid segregation by the injection conditions in the semi-solid die casting has been investigated.

• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.193-198
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• 2012

The following results are from the test of semi-gel electrolyte to store energy efficiently and use advanced VRLA batteries by photovoltaic and wind power generation. Semi-Gel electrolyte with Silica 5% became Gel after 1 and half hour. It shows it is the most suitable time that the electrolyte can be absorbed into the separator and active material of plate to be gel. The test also says that semi-gel electrolyte shows the much better performance for low-rate discharge and the liquid electrolyte is good for high-rate discharge because the reaction rate of gel electrolyte is slower than liquid one for high-rate discharge performance. The test with DOD10% and DOD100% says that 5% silica electrolyte shows much better performance for life efficiency than liquid one. Because semi-gel electrolyte increase the efficiency of gas recombination at the chemical reaction of VRLA battery and it makes minimizing the reduction of electrolyte. Using the 5% silica electrolyte in order to improve the stroage efficiency and life performance for photovoltic and wind power generation, it causes improving by 4.8% for DOD100% and 20% for DOD10%.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.10
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• pp.2034-2043
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• 2002

The process design to produce a near net shape home-appliance compressor component using semi-solid die casting process is performed. In order to obtain a good component without defects such as liquid segregation and porosity, the relationship between pressure and time, and plunger tip displacement and injection velocity are proposed with repeated trial and error. The effect of the velocity variation in the process parameters on liquid segregation and extraction is investigated to produce the aluminum frame part(a kind of compressor part) with good mechanical properties. The mechanical characteristic of semi-solid die casting formed parts for AlSi7Mg0.65r(A357) and AlSi17Cu4Mg(A390) are investigated with a view to minimizing the occurrence of defects. To investigate of application possibility at industry field, A380 aluminum alloy with 8∼9% silicon contents used for the squeeze casting process. The obtained mechanical properties is compared with semi-solid die casting.

• Wind and Structures
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• v.9 no.4
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• pp.271-296
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• 2006

The frequency of a traditional tuned liquid column damper (TLCD) depends solely on the length of liquid column, which imposes certain restrictions on its application to long span cable-stayed bridges during construction. The configuration of a cable-stayed bridge varies from different construction stages and so do its natural frequencies. It is thus difficult to apply TLCD with a fixed configuration to the bridge during construction or it is not economical to design a series of TLCD with different liquid lengths to suit for various construction stages. Semi-active tuned liquid column damper (SATLCD) with adaptive frequency tuning capacity is studied in this paper for buffeting response control of a long span cable-stayed bridge during construction. The frequency of SATLCD can be adjusted by active control of air pressures inside the air chamber at the two ends of the container. The performance of SATLCD for suppressing combined lateral and torsional vibration of a real long span cable-stayed bridge during construction stage is numerically investigated using a finite element-based approach. The finite element model of SATLCD is also developed and incorporated into the finite element model of the bridge for predicting buffeting response of the coupled SATLCD-bridge system in the time domain. The investigations show that with a fixed container configuration, the SATLCD with adaptive frequency tuning can effectively reduce buffeting response of the bridge during various construction stages.

• Earthquakes and Structures
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• v.27 no.3
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• pp.165-176
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• 2024

In this study, a direct Lagrangian-based three-dimensional computational procedure is developed to evaluate the seismic performance of reinforced concrete liquid-containing circular tanks (RC-LCT). In this approach, fluid-structure interaction (FSI), material nonlinearity, and liquid-structure large deformations are formulated realistically. Liquid is modeled using Mie-Grüneisen equation of state (EOS) in compressible form considering the convective and impulsive motions of fluid. The developed numerical framework is validated based on a previous study. Further, nonlinear analyses are carried out to assess the seismic performance of RC-LCT with various diameter-to-liquid height ratios ranging from 2.5 to 4.0. Based on observations, semi-deep tanks (i.e., D/H_l=2.5) show low collapse ductility due to their shear failure mode while shallow tanks (i.e., D/H_l=4.0) behave in a more ductile manner due to their dominant wall membrane action. Furthermore, the semi-deep tanks provide the least over-strength and ductility due to their catastrophic failure with little energy dissipation. This study shows that LCTs can be categorized as between immediately operational and life safety levels and therefore a drift limiting criterion is necessary to prevent probable damages during earthquakes.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.164-170
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• 2019

The absorption and release capacities, survival efficiency, and recovery rates of five kinds of transport media were evaluated based on the swab elution method (Quantitative) of CLSI (Clinical and Laboratory Standards Institute) M40-A2. Liquid media showed mostly better results than semi-solid media in the three evaluations. The flocked swabs had better ability to absorption and discharge bacteria than the standard swabs. The liquid medium (S4) had the best survival efficiency. Pneumococcal strains with poor growth had a higher survival efficiency and recovery rate in liquid media (S4, S5). The results of microbial recovery showed that S. pyogenes met all the CLSI standards in all media. S. pneumoniae was inadequate in the semi- solid media (S2, S3) and all the remaining media met the criteria. H. influenzae was unsuitable in semi-solid media (S1, S3) and met the criteria in semi-solid medium (S2) and liquid medium (S4, S5). The viability of the H. influenzae, pneumococcal strain causing respiratory disease, was poor in most media. Overgrowth of P. aeruginosa was observed at room temperature. The combination of liquid medium and flocked swab confirmed the best results in the three evaluation methods.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.79-82
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• 2006

Fueled by ballooning oil prices, waste plastics are now regarded as being cheap and abundant renewable sources, removing their stigma of dirty wastes Catalytic pryolysis of plastics in liquid phase allows recovery of light fuel oil as well as green treatment of polymerics wastes, and therefore significant efforts have been devoted to this research field. In this study, catalytic Pyrolysis of LDPE was carl ied out in semi-batch reactor which equipped a unit of separation and recirculation. The effect of react ion conditions were examined by analyzing liquid oil yield and carbon number distribution of products

• Journal of Korea Foundry Society
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• v.21 no.4
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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 $600^{\circ}C$.