• 상하수도학회지
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• 제32권3호
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• pp.211-220
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• 2018

The water containing soluble manganese may cause problems such as discolored water, unpleasant taste, fouling or scaling of pipes in water distribution system, and so on. Conventional water treatment processes using sand filtration or sedimentation after oxidation, however, cannot often meet manganese standard for drinking water. Two types of oxidants, potassium permanganate ($KMnO_4$) and sodium hypochlorite (NaOCl), were utilized at the same time for manganese oxidation, and then the precipitated manganese oxides were removed by low pressure membrane filtration in this study. In batch experiments, the multiple injection of both oxidants showed more effective manganese removal than did the single injection using either of them. Moreover, the deterioration of manganese removal at low temperature was less serious for the multiple injection than that for the single injection. Manganese removal by the continuous system of oxidation by multiple injection combined with membrane filtration was higher than those by batch experiments at the same oxidation conditions. In addition, less membrane fouling was observed for membrane filtration with oxidation during continuous membrane filtration than membrane filtration without oxidation. These results indicate that the oxidation by multiple injection coupled with membrane filtration was efficient and applicable to actual water treatment for manganese removal.

• 대한기계학회논문집B
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• 제27권10호
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• pp.1435-1441
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• 2003

Combustion characteristics on diesel-water emulsion are analyzed in high pressure injection for several variables such as water content, injection pressure and injection timing. As a fact of well-known, maximum combustion pressure was decreased and ignition delay was elongated in accordance with increasing of water content. But these characteristics were enhanced with increase of injection pressure to high pressure. It was shown that combustion of neat diesel in case of injecting with 600bar is similar to that of 20 % diesel-water emulsion was injected at 1200 bar.

• 지구물리와물리탐사
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• 제7권1호
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• pp.25-32
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• 2004

We have carried out laboratory measurements of P-wave velocity and deformation strain during $CO_2$ injection into a porous sandstone sample, in dry and water-saturated conditions. The rock sample was cylindrical, with the axis normal to the bedding plane, and fluid injection was performed from one end. Using a piezoelectric transducer array system, we mapped fluid movement during injection of distilled water into dry sandstone, and of gaseous, liquid, and supercritical $CO_2$ into a water-saturated sample. The velocity changes caused by water injection ranged from $5.61\;to\;7.52\%$. The velocity changes caused by $CO_2$ injection are typically about $-6\%$, and about $-10\%$ for injection of supercritical $CO_2$, Such changes in velocity show that the seismic method may be useful in mapping $CO_2$ movement in the subsurface. Strain normal to the bedding plane was greater than strain parallel to the bedding plane during $CO_2$ injection; injection of supercritical $CO_2$ showed a particularly strong effect. Strain changes suggest the possibility of monitoring rock mass deformation by using borehole tiltmeters at geological sequestration sites. We also found differences associated with $CO_2$ phases in velocity and strain changes during injection.

• Asian-Australasian Journal of Animal Sciences
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• 제31권2호
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• pp.278-286
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• 2018

Objective: Two experiments were conducted to evaluate vitamin $D_3$ administration to nursery pigs by injection or in drinking water on serum 25-hydroxycholecalciferol ($25-OHD_3$) concentrations. Methods: At weaning, 51 pigs (27 and 24 pigs in experiments 1 and 2, respectively) were allotted to vitamin $D_3$ treatments. Treatments in experiment 1 were: i) control (CON), no vitamin administration beyond that in the diet, ii) intramuscular (IM) injection of 40,000 IU of vitamin $D_3$ at weaning, and iii) water administration, 5,493 IU of vitamin $D_3/L$ drinking water for 14 d post-weaning. Treatments in experiment 2 were: i) control (CON), no vitamin administration, and ii) water administration, 92 IU of $d-{\alpha}-tocopherol$ and 5,493 IU of vitamin $D_3/L$ drinking water for 28 d post-weaning. The lightest 2 pigs within each pen were IM injected with an additional 1,000 IU of $d-{\alpha}-tocopherol$, 100,000 IU of retinyl palmitate, and 100,000 IU of vitamin $D_3$. Results: In both experiments, serum $25-OHD_3$ was changed after vitamin $D_3$ administration (p<0.05). In experiment 1, injection and water groups had greater values than CON group through d 35 and 21 post-administration, respectively (p<0.05). In experiment 2, serum values peaked at d 3 post-administration in the injection groups regardless of water treatments (p<0.05) whereas CON and water-only groups had peaks at d 14 and 28 post-administration, respectively (p<0.05). Even though the injection groups had greater serum $25-OHD_3$ concentrations than the non-injection groups through d 7 post-administration regardless of water treatments (p<0.05), the water-only group had greater values than the injection-only group from d 21 post-administration onward (p<0.05). Conclusion: Serum $25-OHD_3$ concentrations in pigs increased either by vitamin $D_3$ injection or drinking water administration. Although a single vitamin $D_3$ injection enhanced serum $25-OHD_3$ concentrations greater than water administration in the initial period post-administration, a continuous supply of vitamin $D_3$ via drinking water could maintain higher serum values than the single injection.

• 한국분무공학회지
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• 제17권2호
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• pp.64-70
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• 2012

Water mist fire suppression systems which use relatively small droplets of water with high injection pressure are increasingly being used in wider applications because of its greater efficiency, low flooding damage and low toxicity. However, the performance of the system significantly relies on the water mist characteristics and it requires better understanding of fire suppression mechanism of water mist. In the present study, computational fluid dynamics simulations were carried out to investigate cooling performance of water mist in heated chamber. The gas phase was prepared with natural convection heat transfer model for incompressible ideal case and then the effects of water mist injection characteristics on cooling capabilities were investigated upon the basis of the pre-determined temperature field. For the simulation of water mist behavior, Lagrangian discrete phase model was employed by using a commercial code, FLUENT. Smaller droplet sizes, greater injection angles and higher flow rates provided relatively higher cooling performance.

• Nuclear Engineering and Technology
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• 제47권6호
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• pp.719-728
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• 2015

Following the Fukushima accident, a special safety inspection was conducted in Korea. The inspection results show that Korean nuclear power plants have no imminent risk for expected maximum potential earthquake or coastal flooding. However long- and short-term safety improvements do need to be implemented. One of the measures to increase the mitigation capability during a prolonged station blackout (SBO) accident is installing injection flow paths to provide emergency cooling water of external sources using fire engines to the steam generators or reactor cooling systems. This paper illustrates an evaluation of the effectiveness of external cooling water injection strategies using fire trucks during a potential extended SBO accident in a 1,000 MWe pressurized water reactor. With regard to the effectiveness of external cooling water injection strategies using fire engines, the strategies are judged to be very feasible for a long-term SBO, but are not likely to be effective for a short-term SBO.

• Design & Manufacturing
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• 제9권2호
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• pp.10-15
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• 2015

The water has been the suitable for the cooling medium until now. But the water as cooling medium seem to have the limit for high speed injection. The steam plastic molding injection use the steam as the medium when raise the mold temperature. The weld line has been the major quality problems in a plastic injection parts to be difficult to be solved. These problems in injection-molded plastic parts are difficult to find the reason because these issues are usually in tradeoff realtions with each other. The purpose of this paper is to obtain the optimum injection moulding condition for improving the quality of plastic injection parts and to inquire the productivity improvement with the measured cycle time by steam plastic moluding injection. Based on these numerical results, the guidelines of mould design and injection processing condition were established. As a result, the improvement of quality and the reduction of cycle time was achieved.

• 자원환경지질
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• 제43권4호
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• pp.371-379
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• 2010

연안지역 염수와 담수가 혼재하는 전이대에서 해수침투 피해개선을 목적으로 균열암반을 통한 담수주입시험을 수행하고 그 효과를 모니터링하였다. 담수주입은 절대적으로 그 지역의 지질학적, 수리학적 특성에 따라 좌우되며, 특히 파쇄대나 투수성 미고결 지층 등의 특성 파악이 중요하다. 연구 지역의 염담수 분포특성을 고려하여 두 개의 주요 연안 대수층인 충적층과 균열암반 구간을 통한 담수주입이 가능하도록 시추공을 설계 및 굴착하였으며, 균열암반 대수층 내 담수주입을 위하여 현장에서의 시험 준비, 이동, 조립 및 장비의 유지보수가 간단하도록 착탈식인 모듈화되어 있는 주입시스템을 제작하여 적용하였다. 시추공영상화검층을 통해 전체적인 균열의 특성을 파악하였고, 이를 바탕으로 주입공 및 관측공 간 투수성 파쇄대의 확인을 위한 구간별 담수주입 및 모니터링을 실시하여 담수주입 구간을 선정하였다. 담수주입시험 결과, 관측공의 일정 심도에서 담수가 유입되어 시간이 경과함에 따라 상부 구간의 전기전도도도 점진적으로 감소함을 보였으며, 담수주입 중단 및 패커를 해지한 후에도 유입된 심도에서 점진적으로 전기전도도값이 증가하기는 하지만 그 증가폭이 전체적으로 낮아 담수주입의 효과가 있음을 확인하였다. 또한 장기적으로 전기전도도값을 모니터링함으로써 담수주입의 효과가 수개월 후에도 지속됨을 확인하였으며, 이는 담수주입에 의해 일정 정도의 해수침투 피해에 대한 개선효과를 기대할 수 있음을 시사한다.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2005년도 연구개발 발표회 논문집
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• pp.273-277
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• 2005

The large particles of suspended matter in raw water can be removed by allowing them to settle out in a presedimentation basin. But there are smaller particles in almost all surface water and some groundwater that will not settle out within a reasonable time without some help to accelerate the process, In the coagulation and flocculation processes, nonsettleable solids are converted into large and heavier settleable solids by physical-chemical changes broght about by adding and mixing coagulant chemicals into the raw water. The object of this research was to improve corrective injection method for low dissolution liquid in the water treatment plant. A sort of chemical feed equipment are diaphram pump, flow control in combined magnetic flowmeter md control valve, roto dipper wheel system and tube pump. Particularly low dissolution liquid (Calcium Hydroxide) put in a bit by feed equipment, tube pump is very useful method for corrective injection method in the water treatment plant.

• 한국농촌건축학회논문집
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• 제24권2호
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• pp.45-52
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• 2022

Of the 17,106 domestic reservoirs(as of December 2020), 14,611 are older than 50 years, and these old reservoirs will gradually increase over time. The injection grouting method is most applied to the reinforcement method of the aging reservoir. However, the injection grouting method is not accurate in uniformity and reinforced area. An laboratory model test was conducted to evaluate the applicability of the deep mixing method, which compensated for these shortcomings, as a reservoir reinforcement method. As a result of calculating the hydraulic conductiveity for each method through the model test results, the injection grouting method was calculated as a hydraulic conductiveity value that was about 7.5 times larger than that of the deep mixing method. As a result of measuring the water level change in the laboratory model test, it was found that the water level change decreased in the injection method and deep mixing method compared to the non-reinforcement method. In addition, deep mixing method showed a water level change of about 15% based on 40 hours compared to the injection method, indicating that the water-reducing effect was superior to that of the injection method.