• The KSFM Journal of Fluid Machinery
• /
• v.3 no.4 s.9
• /
• pp.52-58
• /
• 2000

The numerical study on the waterhammer was carried out for the intake pumping station of the metropolitan water supply 6th stage project. Because the waterhammer problems as a result of the pump power failure were the most important, these situations were carefully investigated. The surge tank and the stand pipes effectively protected the tunnels md the downstream region of pipeline from the pressure surge. In case the moment of inertia of the pump and motor was above $5080\;kg{\cdot}m^2$, the column separation did not occur in the pipeline between the pumping station and the inlet of 1st tunnel. As the moment of inertia increased, the pressure surges decreased in the pipeline conveying raw water. The pump control valve was chosen as the main surge suppression device for the intake pumping station. After power failure, the valve disc should be rapidly closed in 2.5 seconds and controlled the final closure to 15 seconds by the oil dashpot. If the slamming happened to the pump control valve, there was some danger of this system damaging. As the reverse flow through the valve increased, the upsurge extremely increased.

• Journal of Advanced Marine Engineering and Technology
• /
• v.33 no.3
• /
• pp.373-377
• /
• 2009

It is well known that SOx and NOx concentration has a considerable influence on the $N_2O$ emission of the greenhouse gas properties. The quantity of SOx generated during combustion, on fuel specific basis, is directly related to the sulfur content of the fuel oil. However, restricting the fuel oil sulfur content is only a partial response to limiting the overall quantity of SOx emissions, as there remains no over control on the fuel oil consumption other than the commercial pressure which have always directed the attention. This study was carried out as a new basic experiment method of emission control, manly targeted to the vessel. In the experiment, where the scrubbing was achieved through spray tower with high alkaline water made from the electrolysis of seawater, the combined action was to neutralize the exhaust gases (SOx, PM, CO etc.), dilute it, and wash it out. The results showed that SOx reduction of around 95 percent or over could be achieved when using in the high alkaline water, and also leaded to a reduction in the stability of the each pollutant components including the PM (Particulate Matter). The results suggest that the seawater electrolysis method has a very effective reduction of emissions without heavy cost, or catalysts particularly on board.

• Water for future
• /
• v.28 no.4
• /
• pp.171-183
• /
• 1995

The Snyder's Unit Hydrograph Method is applied to simulate the November 1985 Flood of the Cheat River Basin, which is located in the North-East region of West Virginia in United States. The entire basin is divided into many subareas according to the hydrologic and geologic characteristics. The overland flows are computed on each subarea and combined together along the streams. The flows are also routed by the Normal Depth Storage and Outflow Method in Modified Pulse option. The several structural flood control alternatives are examined. The study shows the OPTION III which has the three moderately sized dam is ultimately suitable to control the flood. The HEC-1 computer model is used to analyze the flood.

• The Journal of Pediatrics of Korean Medicine
• /
• v.25 no.1
• /
• pp.40-48
• /
• 2011

Objectives: The purpose of this study is to evaluate the effect of Gonjadaesungchimjoongbang on spatial learning abilities and memories in ischemic brain injury. Methods: Rats were separated into three groups; (1) Normal, (2) Saline medication after ischemic brain injuries (control), (3) Gonjadaesungchimjoongbang medication after ischemic brain injuries (experiment). Ischemic brain injuries was induced by MCA occlusion and reperfusion. Morris water maze test was conducted for spatial learning and memory tests. Then, the change of BDNF in the hippocampus($7^{th}$, $14^{th}$ day) was examined by immunohistoche- mistry. Results: In Morris water maze test, spatial learning abilities and memory functioning were considerably increased in the experiment group as oppose to control group on $7^{th}$ and $14^{th}$ day(p<0.01). Moreover, immunohistochemistric response of BDNF in the hippocampus indicated that the more increased immune reaction was found in the experiment group as oppose to the control group on $7^{th}$ and $14^{th}$ day. Conclusions: Gonjadaesungchimjoongbang can improve the learning abilities and memories in ischemic brain injury.

• Korean Journal of Hydrosciences
• /
• v.10
• /
• pp.73-83
• /
• 1999

The intake towers of Buyeo W.T.P. in Keum river have being suffered from the sedimentation problems since the beginning of the operation. Impellers of the intake pumps have to the frequently changed due to the serious surface erosion. Thousands tons of sands are entrapped in the intake towers and equalization chambers of W.T.P. every year. Site surveying and numerical analysis were carried out to suggest an appropriate solution by understanding the general sedimentation regime of Keum river and causes of the sedimentation in the intake towers. Origin of the sediment could be found by the desk and site inspections. The validity of the used numerical models was examined by comparisons between the calculated bydraulic values and the measured ones during the specific periods. The design flow rate for the prediction of the future sedimentation regime of the rever was studied. The efficiency of the sediment control measures was also examined with the verified numerical models. Finally, it was found that the best solution could be a combination of three sediment control measures; increase the clearance between river bed and inlet, construct jetties at 2 kilometers upstream from the intake towers, and put vanes at the right side of the intake towers.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.37 no.1
• /
• pp.49-54
• /
• 1995

Three types of floating-type automatic inlet were developed for the purpose of reduc- ing farmer's working hours required for water management and saving irrigation water. The point of automation is to use a float within the inlet which is floated and sinked by the ponding depth of paddy field, Thus opens and closes the control gate of irrigation. Suitability of each inlet may depend on production cost, applicability to paddy field condi- tions, and feasibility to farmers, etc. The first model was composed of three parts : chamber for irrigation control gate, chamber for float controlled by ponding depth, and connection bar between the two parts. It was designed to open and close the control gate gradually as the ponding depth drops and rises to a certain level. The second model was designed to improve the weak point of the first model which is the imperfect-closing of gate when it approaches to the end of ir- rigation. A switch-spring was equipped above the connection bar for perfect opening and closing of gate when the ponding depth reaches to a certain level. The third model was designed by combining the two chambers, that is, cut in halves the inlet volume of the above two models. Magnets were equipped above the float for perfect opening and closing gate. The functional experiment for three developed inlets was successfully carried out and the rating curves were derived.

• Korean journal of food and cookery science
• /
• v.24 no.4
• /
• pp.412-418
• /
• 2008

In this study, Sulgidduk samples were prepared with substitutions of 1, 2, 3, and 4% tomato powder, along with a control, and were then analyzed for quality characteristics such as moisture content, water activity, color, textural characteristics, and sensory qualities, in order to determine the optimal ratio of tomato powder in the formulation. According to the results, moisture content and water activity were not significantly different among the Sulgidduk samples. In terms of color, as the level of tomato powder content increased, lightness decreased, while the a-value (+redness/-greenness), and yellowness increased. For the textural characteristics, the samples showed significant differences for hardness, adhesiveness, and gumminess, while fracturability was not significantly different. In addition, the samples containing tomato powder presented significantly higher springiness, cohesiveness(except the 1% substitution level), chewiness, and resilience than the control group. In the sensory evaluation, the control group had significantly higher scores for color and flavor as compared to the tomato powder samples. Furthermore, flavor and overall acceptability decreased, while tomato flavor, sourness, and off-flavor increased with increasing tomato powder content. Sweetness and after-taste were not significantly different among the samples. In conclusion, the results indicate that substituting 2${\sim}$3% tomato powder in Sulgidduk is optimal for quality, and provides a product with reasonably high overall acceptability.

• Fisheries and Aquatic Sciences
• /
• v.12 no.1
• /
• pp.49-53
• /
• 2009

We conducted a histological analysis to investigate the influence of nutritional changes on melano-macrophages (MMs) accumulation in the kidney of sub-adult rock bream (Oplegnathus fasciatus). Four experimental groups were established (initial control, control, fed and starved), and fed commercial feed amounting to 1-3% of their body weight for 2 weeks prior to initiation of experiments. Kidney MMs with dark brown pigment were randomly observed in the kidneys of starved fish, increasing rapidly after 4 weeks, while deposition levels remained low throughout the experiment in the control and fed groups. These results suggest that catabolic tissue breakdown is a major factor contributing to the formation of pigments within MMs. Results also suggest that the degree of MMs deposition in the kidney can be used as alternative indicators in identifying starvation in wild and cultured rock bream.

• The Journal of Korean Medicine
• /
• v.28 no.1 s.69
• /
• pp.187-197
• /
• 2007

Objectives : We examined the effect of Jiyutaug(JYT) on the experimental ulcerative colitis induced by dextran sulfate sodium(DSS). Methods : Experimental colitis was induced in mice by daily treatment with 3% DSS in the drinking water for 5days. Afterward, the mice were divided into two groups: the control group was administered water and the sample group was administered JYT for 7 days. Results : The sample group provided JYT for 7 days demonstrated faster recovery of body weight compared with the control group. Histologic change showed faster regeneration of crypt and surface epithelial cells, decreased edema of the submucosa, and decreased Iymphatic follicles of mucosa compared with the control group. immunohistochemical stain using COX-2 gene was decreased. Regeneration of surface epithelial cells and goblet cells in mucosa was observed by transmission electron microscope. Conclusion : These results indicate therapeutic effect of JYT on DSS-induced colitis in mice.

• YAKHAK HOEJI
• /
• v.37 no.4
• /
• pp.408-419
• /
• 1993

Subacute toxicities of DWH-Ol(Ranitidine : Bismuth : Sucralfate=1.5:2:6) were inverstigated in Sprague-Dawley rats. After oral administration of DWH-01 with different dosages of 5 g/kg, l g/kg, and 0.2 g/kg, we examined the number of deaths, general signs, food intake, water intake, body weight and histopatholgical changes for both sexes of rats. During the adminstration period, urinalysis and opthalmological examination were also performed in the treated animals. 1) Animals were all survived for 4 weeks. 2) There were no significant differences in pathological and opthalmological findings between the control and treated animals. 3) There were no significant changes in body weight, food intake and water intake compared with control group. 4) In hematological examination and blood chemical analysis, there was no significant change compared with control group. 5) In histopathological examinations of organs and tissues, there was some hemorrhage in a lung tissue of low dose group, but it was thought to be caused by environmental factor. These data suggest that DWH-01 is not subacutely toxic in Sprague-Dawley rats.