• 한국지하수토양환경학회지:지하수토양환경
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• 제11권4호
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• pp.10-17
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• 2006

본 연구에서는 실험실 규모의 2D air/bio-sparging 장치를 이용하여 공기주입량과 공기주입방식이 디젤오염 토양/지하수의 복원에 미치는 영향을 평가하고 최적 조건을 도출하였다. 최적의 공기주입량과 공기주입방식은 1,000 ml/min의 공기주입과 15 min 간격의 간헐적인 공기주입 패턴이 효율적으로 관찰되었고, 실험기간동안 TPH와 DO 감소, $CO_2$ 생성은 오염원인 디젤이 효과적으로 생분해에 의해 제거가 이루어지고 있음 보여주었다. 즉, 최소한의 공기주입으로도 포화층에서의 디젤 분해를 효과적으로 증진시킬 수 있었으며, 간헐적인 공기주입방식은 대수층내에서의 공기 전달을 증진시킬 수 있었다. 또한 Air/bio-sparging공법의 대부분의 운전비가 blower와 off-gas 처리 시스템에 사용되는 전력비라는 것을 감안 할 때, 최적의 공기주입량과 간헐적인 공기주입방식은 운전비 절감의 효과를 가져다 줄 것으로 판단된다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제27회 추계학술대회논문집
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• pp.319-322
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• 2006

초음속 연소가 성공하려면 1 ms의 시간 안에 충분한 연료-공기 혼합이 이루어져야 한다. 본 실험은 마하 1.92유동에서 헬륨을 수직 분사하여 연료-공기 혼합이 어떻게 이루어지는지 살펴보았다. 평판과 공동 두 가지 모델로 실험을 수행하였고, 슐리렌 가시화를 통해 사진을 찍었다. 압력은 초음속 덕트 내에서 충격파가 어떻게 생성되는지에 영향이 많았고, 침투 거리는 J가 커질수록 두꺼워졌다. 공동이 있는 경우 평판일 때보다 침투 거리가 더 컸다.

• Water Engineering Research
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• 제2권2호
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• pp.123-138
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• 2001

An injection experiment was carried ut to investigate the pressure domain within which hydromechanical coupling influences considerably the hydrologic behavior of a granite rock mass. The resulting database is used for testing a numerical model dedicated to the analysis of such hydromechanical interactions. These measurements were performed in an open hole section, isolated from shallower zones by a packer set at a depth of 275 m and extending down to 840 m. They consisted in a series of flow meter injection tests, at increasing injection rates. Field results showed that conductive fractures from a dynamic and interdependent network, that individual fracture zones could not be adequately modeled as independent systems, that new fluid intakes zones appeared when pore pressure exceeded the minimum principal stress magnitude in that well, and that pore pressures much larger than this minimum stress could be further supported by the circulated fractures. These characteristics give rise to the question of the influence of the morphology of the natural fracture network in a rock mass under anisotropic stress conditions on the effects of hydromechanical couplings.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3529-3533
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• 2007

The advantages of the SITVC(secondary injection thrust vector control) technique over mechanical thrust vector systems include a reduction in both the nozzle weight and complexity due to the elimination of the mechanical actuators that are used in conventional vectoring. Computational study is performed to understand the fluidic thrust vectoring control of an axisymmetric nozzle, in which secondary gas injection is made in the divergent section of the nozzle. The nozzle has a design mach number 3. The effect of injection hole number and shape of secondary jet on the mach number distribution of SITVC were investigated. The standard ${\kappa}$ - ${\epsilon}$ turbulence model solved the complex three-dimensional nozzle flows perturbed by the secondary gas jet. The numerical code was validated by experiment. The results showed that the mach number distribution of circular and square nozzle are similar each other. As number of second injection hole increasing, a effect of deflection was decreased.

• 대한기계학회논문집B
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• 제20권9호
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• pp.2924-2932
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• 1996

As the environmental pollution can be greatly reduced and the waste heat can be also recovered through a combustion of municipal solid waste, the incineration begins to be highlighted recently in our country. But it is very difficult to be operated with constant combustion conditions for a long time as the domestic waste is composed of various components, contains a large percentage of water, and has a low heating value. Therefore, the cold flow test and partial hot flow test were conducted in the incinerator by use of injection angles of a secondary air affecting fluid flow as the first action to maintain the optimum combustion conditions. A model to a scale of 1:10 was designed and manufactured through the similarity of model and prototype flows. Velocities and temperatures were measured through the experiment. From the results, fluid flows of secondary air obtained from partial hot flow test correspond almost well with those of main flow obtained from cold flow test. Consequently, injection angles of secondary air are proved to affect main flow decisively.

• The Korean Journal of Physiology and Pharmacology
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• 제8권5호
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• pp.281-288
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• 2004

The present study was undertaken to confirm whether melittin, a major constituent of whole bee venom (WBV), had the ability to produce the same nociceptive responses as those induced by WBV. In the behavioral experiment, changes in mechanical threshold, flinching behaviors and paw thickness (edema) were measured after intraplantar (i.pl.) injection of WBV (0.1 mg & 0.3 mg/paw) and melittin (0.05 mg & 0.15 mg/paw), and intrathecal (i.t.) injection of melittin $(6{\mu}g)$. Also studied were the effects of i.p. (2 mg & 4 mg/kg), i.t. $(0.2{\mu}g\;&\;0.4{\mu}g)$ or i.pl. (0.3 mg) administration of morphine on melittin-induced pain responses. I.pl. injection of melittin at half the dosage of WBV strongly reduced mechanical threshold, and increased flinchings and paw thickness to a similar extent as those induced by WBV. Melittin- and WBV-induced flinchings and changes in mechanical threshold were dose- dependent and had a rapid onset. Paw thickness increased maximally about 1 hr after melittin and WBV treatment. Time-courses of nociceptive responses induced by melittin and WBV were very similar. Melittin-induced decreases in mechanical threshold and flinchings were suppressed by i.p., i.t. or i.pl. injection of morphine. I.t. administration of melittin $(6{\mu}g)$ reduced mechanical threshold of peripheral receptive field and induced flinching behaviors, but did not cause any increase in paw thickness. In the electrophysiological study, i.pl. injection of melittin increased discharge rates of dorsal horn neurons only with C fiber inputs from the peripheral receptive field, which were almost completely blocked by topical application of lidocaine to the sciatic nerve. These findings suggest that pain behaviors induced by WBV are mediated by melittin-induced activation of C afferent fiber, that the melittin-induced pain model is a very useful model for the study of pain, and that melittin-induced nociceptive responses are sensitive to the widely used analgesics, morphine.

• 한국지반환경공학회 논문집
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• 제24권1호
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• pp.15-23
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• 2023

그라우팅 공법은 연약지반의 차수 및 보강을 목적으로 시공되는 공법이다. 그라우트가 지반 내에 주입될 때, 지반을 구성하는 지반의 형태, 토립자의 크기, 공극율 및 지하수의 유무에 따라 그라우트가 침투 및 확산하는 형태가 다양하게 나타나고 있으나, 그라우팅 설계 시에는 이러한 요인을 적용하기 어려운 실정이다. 따라서, 본 연구에서는 전도성 재료를 함유한 그라우트를 지반내로 주입하는데 있어서 전도성 재료 첨가에 따른 그라우트의 침투 성능을 파악하기 위하여 실내시험을 수행하였다. 주입시험에서는 전도성 재료를 혼합수의 0%, 3% 및 5%를 그라우트에 첨가하고, 원지반 조건을 자갈과 규사로 구성된 다양한 지반으로 조성하였다. 전도성 그라우트는 전용주입장치를 사용하여 모형지반 내로 압력에 의해 주입되면서 주입시간(t), 압력(p), 유속(v) 및 주입량(q)를 계측하고, 모형지반 내 주입된 경화체를 채취하여 침투성능을 평가하였다. 그라우트 주입실험 결과에서는 전도성 재료의 사용량과 그라우트 주입율은 역의 관계를 나타내었으며, 모형지반 토립자 크기에 따라 침투형태가 변화되는 것을 확인하였다. 전도성 재료를 함유한 그라우트는 지반 내 침투가 비교적 양호하고 경화체의 강도 및 내구성이 우수하여 그라우트의 침투범위 측정을 위한 첨가제로 사용하는 것이 가능하다고 판단하였다.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.321-327
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• 2003

[ $CO_2$ ] sequestration in oil reservoirs can be one of the most effective strategies for long-term removal of greenhouse gas from atmosphere. This paper presents an advantage of the localized nonlinear approximation of integral equation solutions for inverting crosswell electromagnetic data, which are observed as a part of pilot project of $CO_2$ flooding at the Lost Hills oil field in central California, U.S.A. To monitor the migration of $CO_2$, we have used 2-D cylindrically symmetric and 2.5-D tomographic inversion methods. These two schemes produce nearly the same images if the borehole separation is large compared with the skin depth. However, since the borehole separation is much less than five skin depths in this $CO_2$ injection experiment, the 2.5-D model seems to be more reliable than the 2-D model. In fact, the pre-injection 2.5-D image is more successfully compared with induction logs observed in the two wells than the 2-D model. From the time-lapse crosswell imaging, we can confirm the replacement of brine with $CO_2$ makes a decrease of conductivity.

• 대한금속재료학회지
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• 제48권5호
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• pp.424-429
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• 2010

In the RH process, it is possible to obtain quicker processing times by enhancing the decarburization rates at a low carbon range of steel melt through Ar gas injection into the vacuum vessel. The RH decarburization reaction was simulated through a dissolved oxygen removal reaction by injecting nitrogen into a 1/8 scale RH water model system. The gas nozzles for the N$_{2}$ injection into the vacuum vessel were located at the lowest level of the vessel's outer wall. The nitrogen bubbling in the vacuum vessel resulted in an increase in the reaction rate constant, which rose in accordance with an increase in the bubbling flow rate and number of nozzles used. However, there was almost no variation in the reaction rate constant, which depended on the horizontal positions of the bubbling nozzles.

• 한국안전학회지
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• 제20권3호
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• pp.71-77
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• 2005

This study aims to find the safe vent area to prevent a destruction of building by gas explosion in a building. Explosion vessel which used in this experiment is 1/5 scale down model of simple livingroom and its dimension is 100cm in length 60cm in width and 45cm in height. Liquified petroleum gas(LPG) was injected to the vessel to the concentration of 4.5vol%, and injection rate were varied in 1L/min or 4L/min. Gas mixture was ignited by the 10kV electric spark. For analysis the characteristics of vented explosion pressure according to the vent size and vent shape, its size and shape were varied. From the experiment, it was found that explosion pressure in the vented explosion :in affected by the gas injection rate, vent area and vent shape. And the vent area to volume ratio(S/V) to prevent the building destruction by explosion pressure, it is recommended that the design of vent area happened by the explosion should be above 1/500cm in S/V. And if the vent area has complicate structure in same area, vented explosion pressure will be higher than a single vent, and possibility of building destruction will increase. Therefore to effectively vent the explosion pressure for protect a building and residents from the gas explosion hazards, the same vent area should have a singular and constant shape in the cross-sectional area of the vessel.