• The KSFM Journal of Fluid Machinery
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• v.5 no.3 s.16
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• pp.33-39
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• 2002

The head-capacity corves for pumps developed by the pump manufacturer are based on tests of a single pump operating in a semi-infinite pool with no nearby walls or floors and with no stray currents. Hence, flow into the pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. However, various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found in pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface, side-wall, and back-wall due to different clearances from back-wall to vortical intake pipe. Moreover, the locations and patterns of the various types of vortices that were found in the examinations are discussed.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.95-101
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• 2002

The head-capacity curves for pumps developed by the pump manufacturer are based on tests of a sin91e pump operating in a semi-infinite pool with no nearby walls or floors and no stray currents. Hence, flow into the pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. But various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found within a sump of pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface due to different clearances from back-wall to vertical intake pipe with bell mouse and without. Moreover, the locations and vorticities of the various types of vortices that were found in the examinations are discussed.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.13-19
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• 2014

Urea-SCR system is the selective catalytic reduction to reduce nitrogen oxides ($NO_x$) emitted from diesel vehicles. The objective of this study is numerical analysis of 3-dimensional unsteady melting problems of frozen urea by using an electric heater. It can be applied to determine capacity of power with respect to time and the location of the urea suction pipe in urea storage tank. The study includes the change of liquid volume fraction, temperature profiles and a influence of natural convection by using the commercial software STAR-CCM+(v7.06). The accuracy of the numerical analysis is estimated by comparisons with experimental data. After validation, a numerical analysis for freezing urea is conducted with four different heating power. From the results, it was found that relation of velocity of phase interface and amount of melting urea by increasing heating power in a container. There is also a difference in trend between velocity of phase interface and amounts of melting urea because of effect of natural convection.

• Journal of Chest Surgery
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• v.26 no.4
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• pp.255-259
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• 1993

The efficacy of the autotransfusion system is a reducing the need of intraoperative and postoperative transfusion in cardiovascular surgery. Between January 1990 and December 1991, we experienced 23 cases of autotransfusion using Haemonetic Cell Saver in cardiovascular surgery [Experimental group]. Another 13 cases which were taken similiar operations without Cell Saver during same period [Control group]. The amounts of blood transfused are 4.23 1.84 units in Control group, 2.82 1.84 units in Experimental group. Postoperatively, both groups showed decreased platelet counts, mild prolongation of prothrombin and partial thromboplastin time compred to preoperative value [P<0.001], but there were no significant differences between two group [P=NS]. Plasma hemoglobin was markedly increased in Experimental group compared with Control group [p<0.05]. In Experimental group, amount of average processed blood by Cell Saver was 700ml of which composition was hemoglobin 17mg/dl, hematocrit 50.0%, RBC 5,590,000/ml, WBC 7500/ml, and platelet 40,000/ml. The culture of the processed blood revealed no growth of the organisms. Conclusively, Cell Saver autotransfusion system is a simple, safe, and cost effective method especially in the cases associated with massive bleeding. However, it requires familiarity with system, gentle manipulation of suction tip, and careful selection of candidates to obtain maximal benefits .

• Computers and Concrete
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• v.17 no.2
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• pp.189-199
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• 2016

Chloride penetration is considered as a most crucial factor for the determination of the service life of concrete. A lot of experimental tools for the chloride penetration into concrete have been developed, however, the mechanism was based on only diffusion, although permeability is also main driving forces for the chloride penetration. Permeation reacts on submerged concrete impacting for short to long term durability while capillary suction occurs on only dried concrete for very early time. Furthermore, hydrostatic pressure increases in proportional to measured depth from the surface of water because of the increasing weight of water exerting downward force from above. It is thought, therefore, that the water pressure has a great influence on the chloride penetration and thereby on the service life of marine concrete. In this study, new experiment is designed to examine the effect of water pressure on chloride penetration in concrete quantitatively. As an experiment result, pressure leaded a quick chlorides penetration by a certain depth, while diffusion induced chlorides to penetrate inward slowly. Therefore, it was concluded that chloride should penetrates significantly by water pressure and the phenomena should be accelerated for concrete exposed to deep sea. The research is expected as a framework to define the service life of submerged concrete with water pressure and compute water permeability coefficient of cementitious materials.

• Structural Engineering and Mechanics
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• v.61 no.6
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• pp.737-746
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• 2017

The touch down zone (TDZ) and top connection point of the vessel are most critical part of fatigue damage in the steel catenary riser (SCR). In general, the linear soil model has been used to evaluate fatigue performance of SCRs because it gives conservative results in the TDZ. However, the conservative linear soil model shows the limitation to accommodate real behavior in the TDZ as water depth is increased. Therefore, the riser behavior on soft clay seabed is investigated using a nonlinear soil model through time domain approach in this study. The numerical analysis considering various important parameters of the nonlinear soil model such as shear strength at mudline, shear strength gradient and suction resistance force is conducted to check the adoptability and applicability of nonlinear soil model for SCR design.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.2
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• pp.89-96
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• 2018

This study aimed to investigate the feasibility of improving dewaterability and settleability of sewage sludge using coagulation sludge. When mixed with sewage sludge and coagulation sludge at 1:1 ratio, capillary suction time(CST) and specific resistance to filtration(SRF) decreased by about 56% and 68%, respectively. It is found that total solids(TS) and volatile solids(VS) of mixing sludge are increased by about 59% and 53%, respectively. Also, the turbidity of the mixing sludge supernatant was reduced from 99 to 16 NTU. It is observed that the mixing of sewage sludge and coagulation sludge at 1:1 showed better effect than using poly-aluminum chloride(PAC) coagulant at 25 mg/L.

• Journal of Korean Academy of Nursing
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• v.28 no.3
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• pp.650-661
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• 1998

The purpose of this study was to provide fundamental data for determining contents of Fundamental Nursing Practice and developing desirable bedside nursing techniques for clinical nursing areas. Subjects for this study were 86 nurses who were employees of two university hospitals located in Seoul and a district area. Data were collected by questionnaires. Items of Fundamental Nursing Practice were classified into 72 items according to the result from content analysis of 9 textbooks of Fundamental Nursing. The results are as follows : 1) Items which above 80% of respondents practiced during the school inside practice or clinical nursing practice course were axillary temperature measurement, radial pulse measurement, respiratory rate measurement, application of oral hygiene, hand-washing technique, application of hot and cold bags, intramuscular injection technique, open bed-making, soap enema method, application of nelaton catheterization and oral and nasal suction methods. 2) Above 90% of respondents replied that all items except temperature measurement and bed-making were requisite contents for Fundamental Nursing Practice. Above 10% of respondents replied oral and rectal temperature measurement and bed-making were unnecessary content. 3) Above 90% of respondents replied that operating methods of all items except isolation technique, admission and discharge procedures, and retention enema in the Fundamental Nursing Practice course and clinical situation were consistent. The main reasons that respondents did not apply methods which they learned in the Fundamental Nursing Practice course to the clinical situation were 'insufficient time', 'colleagues were using different methods', 'insufficient supply of instuments' or 'inappropriate appliances'.

• Journal of Ocean Engineering and Technology
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• v.26 no.1
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• pp.70-77
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• 2012

In this study, a numerical analysis of offshore installation using a floating crane with heave compensator is carried out in time domain. The motion analysis of crane vessels is based on floating body dynamics using convolution integral and the crane wire is treated as simple spring. The lifted structure is assumed as a rigid body with 3 degree-of-freedom translational motion. The heave compensator is numerically modelled by the generalized spring-damper system. Firstly, forced motion simulations of crane wire system are carried out to figure out the basic principle of heave compensator. The transfer function of crane wire system is obtained and effective wave period of heave compensator are found. Then, coupled analysis of crane vessel, crane wire, and lifted structure are performed in regular and irregular sea conditions. Two different crane vessels and two lifted structures (suction pile and manifold) are considered in this study. Through a series of numerical calculations, the effective zone of heave compensator is investigated with respect to wave period and crane wire length.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.209-215
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• 2001

The head-capacity curves for pumps developed by the pump manufacturer are based on tests of a single pump operating in a semi-infinite pool with no nearby walls or floors and no stray currents, Hence, flow into the Pump suction is symmetrical with no vortices or swirling. Pump station designers rely on these curves to define the operating conditions for the pump selected. But various constraints such as size, cost, and limitations on storage time require walls, floors, and pump intakes to be close proximity to each other. From this background, the authors are carrying out a systematic study on the flow characteristics of intakes within a sump found in pump stations. Model pump intake basin is designed and PIV is adopted as a measuring tool to capture the instantaneous flow patterns. Special attention is paid to investigate the flow patterns near the free surface, side-wall and back-wall due to different clearances from back-wall to vertical in take pipe. Moreover, the locations and vorticities of the various types of vortices that were found in the examinations are discussed.