• Korean Chemical Engineering Research
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• v.54 no.5
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• pp.630-635
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• 2016

In the prior work, we studied a ballast water treatment apparatus, which is secondary pollution free by using physical treatment of shear stress. The principle of this apparatus is smashing various microorganisms by shear stress generated between stationary outer cylinder and revolving inner cylinder. Because of various magnitude of shear stress according to the inner cylinder surface type and revolution speed, an appropriate surface type and optimum revolution speed should be studied by consecutive experiment to determine the reference data for commercial apparatus. Through a comparative study of disk type and cylinder type of ballast water treatment apparatus, cylinder type is turned out to be superb to disk type. In this study, we studied to determine the superior collaboration of cylinder type, groove type and knurling type of inner cylinder to non patterned outer cylinder, and to optimize the revolution speed and flow rate according to the gap between inner cylinder and outer cylinder. As a result, we could get perfect sterilization effect at groove type under the conditions of 250 mL/min of flow rate at 8,000 rpm and 500 mL/min of flow rate at 10,000 rpm respectively.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.616-622
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• 2015

Current ballast water treatment technologies are applying chemical or electrical treatment technology which are not free from secondary environmental pollution. The purpose of this study is to treat the ballast water by shear stress without an additional environmental pollution and to find out the optimal treatment apparatus. We tried to treat ballast water by applying shear stress with two different type of combination of inner and outer cylinder, such as non-pattern type and groove type. In the case of non-pattern type of inner and outer cylinder, sterilization effect was comparatively low because of a slip between inner and outer cylinder. But in the case of groove type of inner and outer cylinder, sterilization effect was superior to the non-pattern type. With a same revolutional speed of 8000rpm, an extinction effect was acquired in the gap of 1 mm of inner and outer cylinder at non-pattern type, but 3mm of that of groove type.

• Journal of the Korean Institute of Gas
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• v.16 no.1
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• pp.46-50
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• 2012

The performance of the Type3 hydrogen composite cylinder whose pressure is 70 MPa using hydrostatic cycling test equipment was evaluted in this study. It also includes the finite element method analysis on the performance of the cylinder when the pressure is applied. As a result, cylinder body parts of the Type3 hydrogen composite cylinder, which draws attention with its safe status and the lightness, was ruptured first and the same result has been found out through the finite element method. The dome knuckle and the cylinder body were proved as the weakest parts since the cylinder body parts was expanded under the pressure.

• ALGAE
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• v.22 no.4
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• pp.253-259
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• 2007

This study deals with the taxonomy of the marine diatom Ditylum brightwellii (West) Grunow: shape, size and ratio, marginal ridge, labiate process, areolation, and seasonal distribution are all considered. Ditylum brightwellii were divided into two type; prism- and cylinder-shaped. Comparisons between specimens from the Yellow Sea were made on, (1) shape- prism types are prismatic-shaped and/or regular square or right-angled tetragon, cylinder types are cylinder-shaped and/or long right-angled tetragon in the girdle view, respectively; (2) size and ratiodiameters of prism types are 82.1 ± 2 μm, while those of cylinder types are 21.2 ± 5 μm and ratio of pervalvar axis/diameter- prism types cells are 1.0-1.5, but cylinder types are 3.9-5.5; (3) marginal ridges- prism types have dotted, while those of the cylinder-type cells have piece, slotted or fimbriated on the marginal ridge; (4) labiate process- both prism- and cylinder-types are central part in valve face, but length of labiate processes of prism types are longer than those of cylinder types; (5) cell margin- the girdle margin show many shallow furrows in prism type and smooth in cylinder type; (6) areolation- both prism- and cylinder-types are a radial pattern in the valve center, but areolae of prism types are larger than those of cylinder types; (7) seasonal distribution- cylinder types are dominated in summer and prism types in the other seasons.

• Journal of Drive and Control
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• v.9 no.3
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• pp.29-36
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• 2012

The hydraulic cylinder is used for actuating the roller-link type rotating floodgate which controls the volume of water in the reservoir. The locating points of hydraulic cylinder are restricted to the limited space and determined to minimize the cylinder force necessary for actuating the floodgate. Generally, the head end point of cylinder is fixed at underground and the rod end point of cylinder is connected to the support link. Therefore there exist three design variables to be determined to minimize the cylinder force within the rotating range of floodgate. First, the mathematical model of the roller-link type rotating floodgate is derived to find the cylinder force corresponding to the floodgate angle. Then, the optimal locating point of hydraulic cylinder is searched using the complex method that is one kind of constrained direct search method.

• Tribology and Lubricants
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• v.20 no.4
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• pp.209-217
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• 2004

Lubrication characteristics between a cylinder block and a valve plate for high speed bent-axis type hydraulic pump play an important role in volumetric efficiency and durability of pump. In this paper, a finite element method is presented for the computation of the pressure distribution between a cylinder block and a valve plate for high speed bent-axis type hydraulic pump. Also, a Runge-Kutta method is applied to simulate the cylinder block dynamics of three-degrees of freedom motion. From the results of computation, we can draw two major conclusions. One is related to the fluid film characteristics between a cylinder block and a valve plate and the other is related to the average leakage that is determined by the pressure gradient and the clearance near the discharge port. The numerical results of cylinder block dynamics were compared with the experimental results using eddy-current type gap sensors those are fixed at a pump housing.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1798-1800
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• 1997

Object of this paper is to find the best shape of cylinder, flowing velocity of gas and state of pole with the cylinder wire magnet type. Also it is to analysis phenomena arising in the cylinder. So that general program FLUX2D has used for magnetic and electric field analysis at the cylinder wire magnet type. General program PHOENICS has used for cold or hot gases flowing analysis at the cylinder wire type with magnet.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.77-83
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• 2006

A PIV(Particle Image Velocimetry) was applied to measure in-cylinder velocity field according to inlet valve angle during compression stroke. Two engines, one is conventional DOHC 4 valve and the other is narrow valve angle, were used to compare real compression flow. The results show that the flow patterns are well arranged compared with intake flow and the basic tumble flow structures are maintained until end compression stage regardless of valve angle. Also the results show that the tumble motion is intensified by momentum conservation during compression in normal engine. In the normal engine, the bulk shape of flow pattern is "Y" type at the top of cylinder and reverse "Y" type at the bottom of cylinder and weak reverse flow exists at the top of cylinder along cylinder center line. Otherwise, the other engine's flow pattern changes from "Y" type to "T" type at the top of cylinder during compression.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.192-198
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• 2006

The real-time simulator of a turning-type sluice gate actuated by the hydraulic cylinders is developed using a PC and a visual C++ program language. The real-time simulator receives the directional control valve signal selected by the operator using the mouse, updates the state variables of the turning-type sluice gate system responding to the control signal, and draws the moving figures of the sluice gate, cylinder, reserved water every drawing time on the PC monitor. Also, the operator can observe the sluice gate angle, cylinder force, cylinder pressures, and hydraulic power representing the operation of sluice gate system through the PC monitor every drawing time. The simulator can be a very useful tool to design and improve the turning-type sluice gate system.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.644-647
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• 2009

In this paper, the study is researched for related safety standards having experiments concerning temperature changes in type IV cylinder of the Hydrogen fuel cell vehicle. Experiments were performed to acquire temperature data of type IV cylinder according to filling time. The experimental results are shown that internal temperatures of type Ⅳ vessel are over $85^{\circ}C$ at all measured points after 5 minutes at filling 35 MPa and the highest temperature is getting lower when the residual gases are more remained. Consequently, the safety standards need properly limited value through further study for filling flow rate and filling time.