• Bulletin of the Korean Chemical Society
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• v.27 no.9
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• pp.1459-1462
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• 2006

• Journal of Ocean Engineering and Technology
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• v.4 no.1
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• pp.25-34
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• 1990

케이싱과 배관 연결(connection)의 구조적이고 기능적인 능력은 가스와 기름을 안전하고 효과적으로 발견하고 개발하는데 매우 중요하다. 이 글에서는 이러한 연결에 관한 일반적이고 기술적인 정보를 소개하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.883-884
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• 2010

• Bulletin of the Korean Mathematical Society
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• v.43 no.2
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• pp.411-418
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• 2006

In this paper, we show that a short simple closed geodesic in quaternionic hyperbolic 2-manifold has an embedded tubular neighborhood whose width only depends on the length of the geodesic.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3115-3118
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• 2014

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1331-1332
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.601-602
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• 2010

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.7
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• pp.829-835
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• 2010

This paper presents a disposable power generator for microfluidic devices; the power generator has a tubular PEMFC and a $H_2$ generator. The tubular PEMFC has a tubular MEA (diameter: 1.52 mm) that is supported by a spiral wire electrode. The $H_2$ generator supplied $H_2$ to the tubular PEMFC; $H_2$ was generated via the reaction of Al foil (27 mg) and 5 M NaOH (0.12 ml). The open circuit voltage and power density of a unit cell of the tubular PEMFC were 0.81 V and $16.4\;mW/cm^2$ (0.35 V), respectively. The $H_2$ generator generated 11.6 ml $H_2$ for 15min. The power generator was continuously operated for 15 min at 0.64 mW (0.71 V) and for 10 min at 1.06 mW (0.46 V). We experimentally verified that it is feasible to use the proposed power generator as a power source for microfluidic devices; in the experiment, an LED (2.5 mW; 1.8 V) was lit for 10 min by using three serially connected TPEMFCs and one $H_2$ generator.

• The KSFM Journal of Fluid Machinery
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• v.11 no.5
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• pp.44-49
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• 2008

As the alternative energy, renewable energy should have been developing by many techniques, in order to substitute the fossil fuel which will be disappeared in the near future. One of the small hydropower generator, main concept of tubular turbine is based on using the different water pressure levels in pipe lines, energy which was initially wasted by using a reducing valve at the end of the pipeline, is collected by turbine in the hydro power generator. A propeller shaped hydro turbine has been used in order to use this renewable pressure energy in order to acquire basic design data of tubular type hydraulic turbine, output power, head, efficiency characteristics due to the guide vane opening angle are examined in detail. First, it ensures the reliance of CFD by that of compared with experiment data. After all, the results of performance characteristics of the CFD and experiment show to confirm the data that power, head and efficiency of less than 4%, 2% and 5% respectively. Moreover influences of pressure, tangential and axial velocity distributions on turbine performance are investigated.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.267-274
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• 2011

The effect of internal ring stiffeners is numerically evaluated for reinforcement of tubular K-joints. Finite element analyses are performed to compute stress of un-stiffened and ring-stiffened K-joints subjected to axial loading. The influence of loading condition and geometrical parameters of ring stiffener on joint behavior is assessed to determine the installation effect of single and double ring stiffeners. The arrangement effect of ring stiffener are evaluated using quantitative analysis compared single ring with double ring stiffeners. Based on the numerical results, practical size of ring stiffener is proposed for design of tubular K-joints.