• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.4-8
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• 2003

Cucumber mosaic virus (CMV) belongs to genus Cucumovirus. The Cucumovirus group contains three distinct members： CMV, Tomato aspermy virus (TAV), and Peanut stunt virus (PSV). The type member, CMV is the most widespread and most studied. CMV is isometric particles about 30 nm in diameter. The genome of CMV is divided into three RNAs. In addition, RNA extracted from virus particles contains a fourth RNA that is a subgenomic RNA generated from RNA3. RNA1 and RNA2 are each encapsidated in separate particles, whereas RNAs3 and 4 are coencapsidated in a third particle. Hence, inoculation by three particles, transmitted either mechanically or by the aphid vector, is required to infect plants.(중략)

• Journal of the Korean Geosynthetics Society
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• v.12 no.3
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• pp.87-94
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• 2013

As sediment contamination problems have recently been raised in Korea, the need for technologies to remove contaminants in sediments has increased. Contaminated sediments in Korea has been annually dredged and treated using processes of coagulation/flocculation, sedimentation on barges, dewatered and dried at prepared site, and then disposed at a landfill site, which is very costly, and only a limited landfill space available in Korea. Contaminants in media containing a high percentage of silt and clay sized particles, typically, are strongly adsorbed on the particles and difficult to remove. Particle separation processes that separate the fine clay and silt particles from the coarser sand and gravel and concentrate the contaminants into a smaller volume of sediment that can be further treated of disposed of, are very effective in the post step processes. In this study are to test the feasibility of treating dredged sediments using a hydrocyclone process, and to estimate design parameters for a pilot scale test. A hydrocyclone was operated to separate larger particles from the sediments. It was found that the particle separation was greatly affected by the solid contents and inlet pressure in the hydrocyclone.

• Progress in Superconductivity and Cryogenics
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• v.25 no.3
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• pp.13-17
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• 2023

Magnetic separation technology for small paramagnetic particles has been desired for the volume reduction of contaminated soil from the Fukushima nuclear power plant accident and for the separation of scale and crud from nuclear power plants. However, the magnetic separation for paramagnetic particles requires a superconducting high gradient magnetic separation system applied, hence expanding the bore diameter of the magnets is necessary for mass processing and the initial and running costs would be enormous. The use of high magnetic fields makes safe onsite operation difficult, and there is an industrial need to increase the magnetic separation efficiency for paramagnetic particles in as low a magnetic field as possible. Therefore, we have been developing a magnetic separation system combined with a selection tube, which can separate small paramagnetic particles in a low magnetic field. In the previous technique we developed, a certain range of particle size was classified, and the classified particles were captured by magnetic separation. In this new approach, the fluid control method has been improved in order to the selectively classify particles of various diameters by using a multi-stage selection tube. The soil classification using a multi-stage selection tube was studied by calculation and experiment, and good results were obtained. In this paper, we report the effectiveness of the multi-stage selection tube was examined.

• Journal of Magnetics
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• v.21 no.4
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• pp.635-643
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• 2016

Improvements were made in the study for the design of the conventional Eddy Current Separator (ECS) used for separating small sized non-ferrous particles in the waste. These improvements include decreasing the air gap between the material and magnetic drum, making the drum position adjustable and placing the splitter closer to the drum. Thus, small particles were separated with high efficiency. The magnetic drum was removed from inside the ECS conveyor belt system as design change and was placed as a separate unit. Hence, the force generated on the test material increased by about 5.5 times while the air gap between the non-ferrous materials and drum decreased from 3 mm to 1 mm. The non-metal material in the waste is separated before the drum in the novel design. Whereas non-ferrous metal particles are separated by falling into the splitter as a result of the force generated as soon as the particles fall on the drum. Every material that passes through the drum can be recycled as a result of moving the splitter closer to the contact point of the drum. In addition, the drum can also be used for the efficient separation of large particles since its position can be adjusted according to the size of the waste material. The performance of the novel design ECS was verified via analytical approaches, finite element analysis (FEA) and experimental studies.

• Journal of Korean Society on Water Environment
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• v.37 no.1
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• pp.10-19
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• 2021

In the flotation process to remove microplastic (MP) particles, the attachment and separation efficiency is determined by the basic physicochemical characteristics of MP particles as well as bubbles. To evaluate the flotation characteristics of MP particles, we carried out a series of simulations using the population balance (PB) model. The initial attachment coefficient (αo) of MP particles was in the range of 0.2-0.275, and it was slightly lower than that of typical particles, such as clay, debris and algae particles, which exist in water bodies, αo, 0.3-0.4. The relative bubble number (RBN) attached to the surface of the typical number of bubbles was 0.30 and 0.32 for MP 30 ㎛ and MP 58 ㎛, respectively. In comparison, the RBN of larger MP particles (138 ㎛) was as high as 0.53. Furthermore, smaller microbubbles were required to separate properly or additional treatment needed to be applied to enhance collision and attachment efficiency since the flotation of MP particles was found to be difficult to treat as high-rate. As a result of comparing the removal rate (experimental value) of MP particles obtained from the batch-type flotation apparatus and the flotation removal rate (predicted value) of MP obtained through the PB model, the final particles by the particle size of MP overall except for the initial separation time area. With respect to the removal efficiency, the observed and predicted values were similar, and it was confirmed that the floating separation characteristics and evaluation of the MP particles through the PB model could be possible.

• Journal of the Korean Society of Visualization
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• v.7 no.2
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• pp.56-63
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• 2010

In this work, a dielectrophoresis-based particle-separation device is developed which is to be used to continuously separate particles in microchannels. We fabricated the particle-separation device with combining the benefits of electrode-based DEP and insulator-based DEP. The DEP forces are generated by an array of electrodes located in both sidewalls of a main channel. According to the magnitude and frequency of electrical signals, particles with different dielectric properties experience different DEP forces, and therefore, continuously move along different streamlines in the main flow channel without need of pre-focusing process. Based on this mechanism, we examined the performance of the device by controlling the trajectory of polystyrene particles. This device is applicable to the investigation of dielectric properties of biological cells as well as the continuous separation of biological cells.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.3
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• pp.1-8
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• 2002

Clayey paddy soils should be mixed with other good coarse soils to be used as a material for the lining, or, embankment. However, it has been difficult to separate soil particles from each other because of the internal cohesion in the soil gradation(separation) characteristics of the fine soil were investigated by various laboratory tests including the slaking durability test. Degradation rate of the soil were dependent upon the clay content and the initial water content before the submergence. The amount of degradations decreased as initial water content increased with exponential functions. The dried specimens separated into the particles after 24 hours of the submergence and specimens which water contents were less than 10% also separated into the particles after 2, or 3 days of the submergence. Compaction curves and the unconfined strength were not varied before and after the submergence. However, unconfined strength decreased as water content increased.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.4
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• pp.281-287
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• 2017

Mill scale, an iron waste, was used to separate magnetite particles for the adsorption of phosphate from aqueous solution. Mill scale has a layered structure composed of wustite (FeO), magnetite ($Fe_3O_4$), and hematite ($Fe_2O_3$). Because magnetite shows the highest magnetic property among these iron oxides, it can be easily separated from the crushed mill scale particles. Several techniques were employed to characterize the separated particles. Mill scale-derived magnetite particles exhibited a strong uptake affinity to phosphate in a wide pH range of 3-7, with the maximum adsorptive removal of 100%, at the dosage of 1 g/L, pH 3-5. Langmuir isotherm model well described the equilibrium data, exhibiting maximum adsorption capacities for phosphate up to 4.95 and 8.79 mg/g at 298 and 308 K, respectively. From continuous operation of the packed-bed column reactor operated with different EBCT (empty bed contact time) and adsorbent particle size, the breakthrough of phosphate started after 8-22 days of operation. After regeneration of the column reactor with 0.1N NaOH solution, 95-98% of adsorbed phosphate could be detached from the column reactor.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.425-427
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• 1994

A manipulator which can separate dielectric particles (biological cells) was fabricated on a silicon wafer using polyimide and n-type electroplating. It consists of 1024 electrode arrays ($60{\mu}m{\times}60{\mu}m$) and spacing insulator. Positive dielectrophoresis is used for attracting particles. We have the solution of 3-D laplace equation about this device and calculate the force acting on the particles. The solution has spatial periodicity in the x, y directions and decays exponentially in the z direction.

• Proceedings of the Korean Society for Language and Information Conference
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• 2007.11a
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• pp.182-191
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• 2007

This paper gives a thorough investigation into Mandarin sentence-final particles (henceforth SFPs). First I induce core grammatical functions and semantic interpretations of SFPs. Based on Rizzi's (1997) Split CP hypothesis, I make some modifications to accommodate Mandarin SFPs and map them onto separate functional heads within a proper hierarchy. I also examine some empirical evidence of head directionality and tentatively assume Mandarin C is head-initial. To explain the surface head-final order, in light of Chomsky's (2001) Phase Theory and Hsieh's (2005) revised Spell-out hypothesis, I pose a CP complement to Spec movement. Following Moro's (2000) idea, I further claim the motivation behind is to seek for antisymetry.