• Membrane and Water Treatment
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• v.8 no.6
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• pp.553-562
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• 2017

In the present study, the water desalination across the penta-graphene has been explored by using molecular dynamics simulation. The penta-graphene, a new carbon allotrope, introduced theoretically in 2015. It was shown that this carbon nanostructure is slightly stiffer against buckling in comparison with the graphene nanoribbons. The effect of radius of curvature (ROC) of the membrane, pore size, and applied pressure, on water flow rate, and salt rejection is investigated. It is shown that salt rejection, and the shape of the oxygen density distribution inside the pore can be influenced by the ROC of membrane. Finally, it is shown that the ROC, and pore size of 2D membranes, play an important role in the salt rejection.

• Journal of the Korean Wood Science and Technology
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• v.30 no.2
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• pp.87-94
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• 2002

This study was carried out to evaluate bending property on principal domestic species such as sargent cherry(Prunus sargentii), bitter wood(Picrasma quassioides), horn beam(Carpinus laxiflora), cork oak(Quercus variabilis), birch(Betula schmidtii), painted maple(Acer mono), basswood(Tilia amurensis), red pine(Pinus densiflora), pitch pine(Pinus rigtda), royal pawlonia(Paulownia tomentosa) by microwave heating. In this study, radius of curvature(ROC) for bending process was classified by radius of curvature(ROC) of bending plate such as 4 cm, 6 cm, and 10 cm, and thickness of metal-strap(TMS) was 0.6 mm and 0.8 mm. Bending process was successfully operated for 100 percent in bitter wood, horn beam, birch and painted maple. On the other hand, there was a success rate of 58 percent in sargent cherry and 83 percent in cork oak and 29 percent in basswood and 8 percent in royal pawlonia which is the worst bending property. All specimens of basswood and royal pawlonia were broken at 4 cm of ROC. Success rate of bending property was shown 44 percent in red pine and 56 percent in pitch pine. TMS has an effect on only drying speed in drying process than difficulty and facility of bending property. It was considered that the thinner TMS in drying process is the faster in drying speed of bent wood.

• Journal of the Korean Wood Science and Technology
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• v.30 no.3
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• pp.85-90
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• 2002

This study was carried out to investigate the dimensional stability of bentwoods by three treatments: steaming, urethane varnish coating, and polyethylene glycol (PEG) treatment. Bentwood processing employed a bending-jig with only 4 cm radius of curvature (ROC). The used species were bitter wood (Picrasma quassioides), painted maple (Acer mono), and birch (Betula schmidtiii). The bending properties of these are well-known in bentwood production (Jung et al., 2002). The bentwoods were treated repeated at room temperature [20℃, RH 80% (12 hours) and 40℃ under RH 10% (12 hours)]. To estimate the dimensional stability of bentwoods, we measured the radius of curvature and end-distance. The best results could be attained with PEG treatment. Steaming was the worst treatment. Comparing the properties of the different species, the dimensional stability of bitter wood was excellent. It was concluded that the steaming treatment was unsuitable for dimensional stability of bentwoods.

• Journal of the Korea Furniture Society
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• v.18 no.4
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• pp.275-281
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• 2007

This study was carried out to know bending process property of bentwood by treatment methods such as microwave and ammonia solution treatment. Bentwood processing was operated on bending-jig form with 60mm and 100mm radius of curvature (ROC). The species was used to Korean red pine (Pinus densiflora). No significant difference was shown in bentwood processing method on ROC. In treatment method, ammonia solution treatment for bentwood was better in dimensional stability and working ability than that of microwave treatment. However, bentwood stress was reduced with ammonia solution treatment. Color of bentwood surface appearance has a dark tendency in ammonia solution treatment. But it seems to beautiful effect of apparent annual ring is rising esthetically by ammonia solution treatment. To utilize wood as a exterior material for living amenity, it has to be closely examined from various angles including surface property, degree of swelling and shrinkage, drying state, retaining strength, durability, safety, and insect damage.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.491-492
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• 2009

We have fabricated a microlens integrated silicon (Si) structure for optical interconnects. To form microlenses, the Si wafer was wet-etched with $SiN_x$ mask in a HF:$HNO_3:C_2H_4O_2$ solution and then the holes were filled with a AZ9260 photoresist. The focal length of microlens increased in proportional to its radius of curvature (ROC). For the ROC of $100-161{\mu}m$, the focal lengths were obtained approximately between $160{\mu}m$ and $310{\mu}m$, in an agreement with the simulated values using a ray tracing method.

• Journal of the Korean Wood Science and Technology
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• v.29 no.3
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• pp.14-20
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• 2001

On the bending process, metal-strap plays an important role in dispersing the stress generated in wood. Therefore, the metal-strap has more influence on the property of bentwood materials. The effect of the metal-strap thickness for bentwood was examined. The effect of metal-strap on the bending properties of Korean red pine(Pinus densiflora Sieb. et Zucc.)was investigated in this research. The metal-strap thickness is divided into 4 kinds such as 1.0, 0.8, 0.6, 0.4 mm. The specimens were selected by grain such as annual ring angles, flat grain and half-edge grain specimens. As a result of this study, the bending ability of 1.0, 0.8 mm, thickness of half-edge grain specimens was better than flat grain specimens but the result of 0.6, 0.4 mm were reversed. The bending ability of half-edge grain was better than flat grain and the grade was higher. When the processed specimens were dried, the radius of curvature(ROC) was decreased became drying-stress was not perfectly dispersed. An optimum drying-condition would deminish this phenomenon.