• Journal of Magnetics
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• v.15 no.1
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• pp.12-16
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• 2010

Combined study of in-situ stress measurements and atomic force microscopy (AFM) revealed drastic stress relaxation in the CoCrPt and PS(styrene)-PVP(vinyl pyridine) polymer hybrid structure that was closely related to the growth structure of the film. We have observed not only no large initial growth stress at the initial stages of film growth but also twice smaller stress in magnitude with opposite sign in the CoCrPt/PS-PVP/Si sample. The microstructural studies using AFM at the various film growth stages revealed that the film growth structure plays an important role in the stress relaxation mechanism of CoCrPt films on a corrugated polymer surface.

• Journal of Mechanical Science and Technology
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• v.20 no.2
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• pp.212-226
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• 2006

This paper is a continuation of the authors' previous work on spiral coil heat exchangers. In the present study, the heat transfer characteristics and the performance of a spirally coiled finned tube heat exchanger under wet-surface conditions are theoretically and experimentally investigated. The test section is a spiral-coil heat exchanger which consists of a steel shell and a spirally coiled tube unit. The spiral-coil unit consists of six layers of concentric spirally coiled finned tubes. Each tube is fabricated by bending a 9.6 mm diameter straight copper tube into a spiral-coil of four turns. The innermost and outermost diameters of each spiral-coil are 145.0 and 350.4 mm, respectively. Aluminium crimped spiral fins with thickness of 0.6 mm and outer diameter of 28.4 mm are placed around the tube. The edge of fin at the inner diameter is corrugated. Air and water are used as working fluids in shell side and tube side, respectively. The experiments are done under dehumidifying conditions. A mathematical model based on the conservation of mass and energy is developed to simulate the flow and heat transfer characteristics of working fluids flowing through the heat exchanger. The results obtained from the present model show reasonable agreement with the experimental data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.747-754
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• 2017

The Concrete-Filled Tube (CFT) system was developed for its excellent structural performance, such as its good stiffness, stress and ductility, which is derived from the mechanical advantages of its composite structure. However, it is known that the flat type of reinforcing plates need stiffeners placed at a certain distance from each other to avoid buckling failure, which increases the cost accordingly. This paper investigates the contribution of the rib elements placed inside the steel tube for the purpose of increasing the bond strength between the steel and concrete and fire performance with no additional protection. The test results also demonstrate the effectiveness of the corrugated rib's shape against fire. The results of this study showed that the buckling prevention and fire resistance performance criteria were satisfied by the application of the inner surface attachment rib, due to the resulting increase in the strength of the CFT column. Therefore, it is considered that the CFT method using the corrugated rib structure reinforcement developed through this study satisfies the structural and fire resistance performance criteria without the need for a refractory coating. Future studies will be needed to make the process efficient and economical for factory production.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.522-527
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• 1997

To find out the optimum seeding rate in corrugated water seeded rice, field experiment was carried out at Yeongdeog Substation of the National Yeongnam Agricultural Experiment Station for two years, 1994 and 1995. A rice cultivar Donghaebyeo, was seeded on May 15 with five seeding rate from 3kg /10a to 7kg /10a. The number of seedling stand per unit area was curvilinearly increased with seeding rate. In characteristics of rice plant associated with lodging, the plant height, fresh weight per tiller, Culm wall thickness and ratio of gravity center were not significantly different among seeding rates, but the breaking strength of 4th internode was slightly decreased with increasing seeding rate and thus, lodging index was generally greater at higher seeding rate than lower seeding rate. Field lodging was observed at 1~3 degree in seeding rate of 5~7kg /10a. Panicle number per unit area was generally increase with increase of seeding rate, while ratio of ripened grain was decreased with increase of spikelet number. Milled rice yield was curvilinearly increased with seeding rate. The optimum seeding rate in the highest rice yield was 4.8kg /10a in 1994, and 4.3kg /a in 1995, respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.1
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• pp.30-36
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• 2009

Cracking of scored or creased lines on boards is a serious problem in converting process of corrugated fiberboard. It is important to reduce the possibility of score crack in advance by controlling the related quality factors of linerboard. To find out the key properties affecting score crack, we carried out the correlation analysis between score crack and physical properties of linerboards. Score crack was evaluated by visual rating on surface crack after folding a linerboard using laboratory folding resistance tester. Thickness of linerboard was the most important factor to score crack. The critical limits of thickness and strain can be determined by correlation analysis for reducing the possibility of score crack.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1046-1051
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• 2004

A plate-fin-tube heat exchanger used for a $SF_{6}$ gas-insulated transformer is extremely important since the dissipation of the heat generated from inside coils has a significant effect on the performance as well as the durability of the transformer. The heat exchanger consists of corrugated plate fins and staggered array tube bundles for coolant. In order to find out heat transfer and pressure drop characteristics, series of numerical analyses for plate fins with enhanced surface geometries were conducted. Based on the results of the numerical analyses, an improved model of the plate fin has been proposed.

• Archives of Plastic Surgery
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• v.33 no.4
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• pp.503-505
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• 2006

Purpose: Cutis verticis gyrata(CVG) is a morphologic syndrome, typically occurring on the scalp, characterized by varing development of permanent folds and furrows conferring a corrugated or convoluted appearance which resembles the outer surface of the cerebrum. Cutis verticis gyrata can be categorized into primary and secondary types according to various etiologic factors and associated conditions which cause disease process. Methods: We report a case of essential primary cutis verticis gyrata in a 24-year-old male who did not have any other underlying or associated conditions. Results: After we made an incision to the galea aponeurotica of patient's scalp four times under local anesthesia, we dissected along the subapponeurotic layer and adjusted the flaps each other, and then sutured the flap. Conclusion: After the operation, the clear margin disappeared and it did not recur.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.729-733
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• 2012

Frame structures of High speed train are constructed from corrugated panel and aluminum extruded panel, which have high bending stiffness. Transmission loss of those panels, however, is less satisfactory than other panels with same mass per unit area. Therefore, this study predicted transmission loss of aluminum extruded panels using Finite element method. Specifically, we modeled acoustic cavity above a radiation surface and analyzed correlation between T-slot and transmission loss. Moreover, we examined the effect of boundary condition changes of the structure on transmission.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.3
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• pp.48-52
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• 2008

Waste paper plastic composites were prepared with old newspaper and old corrugated containers and mixed office waste and those properties were evaluated. The results were summarized as fellows. 1. The strength properties like as tensile and Young's modulus reveled most high level in MOW composite. 2. The coagulation of fibers in paper particle should interrupt equal dispersion of polymer and paper particle. 3. The micrograph of the surface of composites showed the most high dispersion in ONP composite.

• Journal of the Korean Graphic Arts Communication Society
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• v.19 no.1
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• pp.64-74
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• 2001

This study is to find the effect of the molecular weight distribution of components on the freeness and physical properties of paper by observing the change of properties according the modification of fibers by using production technology and process technology together to develop additives which can effectively control according to the purpose of paper-making process and by combining low molecular weight cellulase (below MW 20,000; CMC activity 400 unit) with different enzyme's molecular weight and activity and high molecular weight cellulase(MW 20,000∼80,000;CMC activity 90,000 unit) and then process them in Sw-BKP(Softwood Bleached Kraft Pulp) and Hw-BKP(Hardwood Bleached Kraft Pulp) and Cotton Linter Pulp and OCC(Old Corrugated Container) with different properties of pore of surface of fibers respectively, since it is judged that making the appropriate composition ratio of components is necessary in consideration of the properties of fibers and paper-making process.