In this study, a numerical analysis study was conducted on the flow characteristics according to the internal flow path change and differential pressure of the hydrogen shut-off valve, and through this, the pressure loss characteristics and flow coefficient of the hydrogen shut-off valve were predicted. ANSYS CFX program was used to predict the flow characteristics of the hydrogen shut-off valve. When the flow path gap was 1.3 mm, the design conditions of the hydrogen shut-off valve were satisfied, and the value of the flow coefficient of the valve was about 1.53. As the inlet pressure of the hydrogen shut-off valve increases, the outlet flow rate increases, but regardless of the inlet pressure, the flow coefficient of the valve is almost constant, ranging from 1.53 to 1.56, indicating that it is the inherent flow coefficient of the designed hydrogen shut-off valve.

In wastewater treatment, an emulsion polymer automatic dissolving system is used to mix and dissolve the polymer used as a polymer coagulant with water before it is put into the dissolution tank. In this study, a disperser is developed to mix water and emulsion polymer better in the dissolving system. For this purpose, the flow analysis of the three disperser models was performed to select the disperser for the emulsion polymer automatic dissolving system with the best performance. The excellence of mixing was evaluated by grasping the flow uniformity and the vorticit in the disperser, and it was confirmed that the TYPE3 disperser was excellent.

고하목은 연갑강에 속하는 갑각류 목의 하나로 지하수의 간극에 서식한다. 지하수는 수계별로 구분되며, 과거 지질변 동 이후에는 수계가 격리되어, 지역적 고유성이 매우 높아 지표종으로 활용하기에 유용한 분류군이다. 고하목의 서식 지는 지하수인데, 이들은 서식지에 대한 적응력이 매우 높다. 따라서, 지각변동 등 어떠한 요인으로 인한 수계의 혼합 또는 단절이 일어났을 경우 형태적으로 수렴진화하거나 종분화 과정 중에 있는 형태적으로 식별이 어려운 complex종의 출현 빈도가 높은 것으로 알려져 있다. 형태적 식별이 어려운 종들 에 대하여 유전정보를 활용하여 해당 종들의 분류학적 위치 를 바로 잡아야 할 필요가 있다. 유전정보를 활용한 연구를 하여, 형태적으로 혼란이 많은 종들의 위치를 바로잡는 동시 에 새로운 종의 발굴 가능성을 높일 수 있다. 본 연구를 통하여, 총 13개 지역에서 채집한 한반도 서식 너도고하과 (Parabathynellidae) 20종에 대하여 74개의 염 기서열을 획득하여 계통학적연구를 진행하였다. 전반적으 로 너도고하과에 속하는 종들은 속 수준으로 잘 나뉘어지는 것을 볼 수 있다. 예를 들면 현재까지 채집한 종들은 4개의 속 (Allobathynella, Arisubathynella, Hangangbathynella, Eobathynella)에 속하는데 이들이 각기 다른 그룹으로 묶이 는 것으로 보았을 때 너도고하과는 단계통으로 여겨진다. 또한 종간 변이의 최대값은 37.5 %로 이는 대전 서구 흑석 동 Allobathynella와 경상북도 예천군 용궁면 대은리의 Eobathynella 와의 차이다. 또한 종간 변이의 평균값은 26.5 %였다. 추후 더 다양한 채집지역과 다른 속들의 종이 포함 된 이후 분석한다면 더욱 해상도 높은 연구가 될 것이라 예상한다.

This is a thesis about the experiment of comparison characteristic of exhaust gas in the same condition between diesel engine that is equipped turbocharger to increase effectiveness of the engine which is recently used in a lot of industry which requires high power. Resulting of the experiment turbocharger diesel engine according to response power, difference in low speed is not significant, but in high speed, effectiveness of turbocharger diesel engine is almost the same in four turbocharger. In other hand, in exhaust gas experiment, high response power turbocharger model exhausts less NOX, but it doesn’t significantly affect the result when it comes with decreasing of CO2 and effectiveness of similar power characteristic. As a result, the high response power turbocharger diesel engine is economically effective comparing with the low response power turbocharger diesel engine

The purpose of this study is to develop the flowmeter of high viscosity paint spraying system. In this study, the numerical flow analysis of the flowmeter was performed. The velocity and the pressure distributions were obtained using the turbulent SST(Shear Stress Transport) model. The ICEM-CFD13 and CFXMesher, reliable grid generation software was also adapted to secure high quality grid necessary for the reliable analysis. According to the simulation results, the flow rate of flowmeter is 6.49l/min in case of Δp=45bar. This result was in good agreement with design result and could be applied to the actual design of the high viscosity paint spraying system

In this paper, the response of graphite/epoxy laminated composite beams subjected to impact loads without damage, is studied by the use of the developed finite element program. The modified Hertzian contact law considered elasto-plastic process is used to calculate the dynamic responses between the impactor and laminated target. Numerical results are presented to demonstrate the effects on the histories of contact force, deflection, damage energy, strain and stress through the thickness due to stacking sequence. In view of the kinetic energy response, [0/30/0/-30]2S laminate is faster than that of other two laminates due to its flexural stiffness. In special, the distribution of stress through the thickness shows nearly linear despite its discontinuity of stacking sequences for dynamic analysis unlike static analysis in a laminated composites.

As a result of an analysis of a damper system, a solution to a fire damper is developed using the continuity equation of damper control and orthogonal array. The fire damping device is made with a CAE software. Additionally, new H-120 grade fire damper is designed for the optimal offshore structure. This device will soon be tested on an actual offshore structure. An optimized fire temper is finally achieved using an orthogonal array. Using the result of present study will provide an environment friendly fire damper for offshore plants by choosing the optimum fire damper conditions

The monolithic glass, without damage, under impact loading, is studied by the use of the coded finite element program. To predict the impact energy of monolithic glass like annealed glass and tempered glass, a finite element approach based on Sun's higher-order beam finite element and impact energy equation is proposed. For this purpose, the contact force-displacements, energy-displacement histories and velocity-acceleration histories etc. are calculated during all impact processes. And, also, by the calculations of the coded FEM program, the geometric parameter like thickness is investigated to determine their impact energy prediction of monolithic glass.

The monolithic glass, without damage, subjected to ballistic impact, is studied by the use of the coded finite element program. To analyze the impact response of monolithic glass like ordinary annealed glass and tempered glass, a finite element approach based on the Hertzian contact law and Sun's higher-order beam finite element is proposed. For verifying effectiveness of this finite element program, the contact force history is analyzed in conjunction with the loading and unloading processes. And, also, the time history of the impact responses such as the strain and stress according to the thickness changes due to transverse impact at the center are calculated