• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2022년도 춘계학술대회
• /
• pp.314-316
• /
• 2022

수도계량기는 사용자가 사용하는 물의 양을 계측하는 기기로 계량안정성 관리가 필요하다. 하지만 겨울철 한파로 인해 계량기 내부의 물이 얼음으로 상변화하며 약 9%의 체적이 커지게 되며 계량기의 파손이 발생된다. 기존 동파방지용 수도미터 동파방지 기술은 크게 세 가지로 보호통 내부에 열을 공급하는 방법, 단열을 위한 수도미터 외부 보호방법, 수도계량기에 동파방지 장치를 설치하는 방법으로 나뉜다. 기술개발 제품의 상용화를 위하여 구조를 최대한 변형시키지 않으며 외부전원이 필요하지 않은 기술을 개발하는데 목적이 있다. 따라서, 영하의 온도에서 수도계량기에 가해지는 내부압력을 해석하여 동파 취약부위를 확인하고 파손을 방지하기 위해 내부 압력을 감소시킬 수 있는 동파방지 효과가 우수한 수도계량기를 개발하고자 한다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2018년도 추계 학술논문 발표대회
• /
• pp.27-28
• /
• 2018

In this study, water vapor pressure and restrained stress were evaluated by ring-type restrained condition for compressive strength 60 and 80MPa concrete. Experimental results show that the 80MPa concrete has higher water vapor pressure and restraint stress than the 60MPa concrete, resulting in spalling occurrence. It is because, the higher the compressive strength of the concrete, the more dense the internal structure is formed.

• 멤브레인
• /
• 제17권4호
• /
• pp.318-328
• /
• 2007

본 연구에서는 호소수의 정수처리공정 중 폴리술폰계 중공사막을 이용한 침지형(흡인압)과 외압형을 동시에 적용한 분리막 공정으로 압력 및 공경에 따른 투과플럭스의 변화에 관한 성능을 평가하고자 하였다. 침지형(흡인압) 공정의 압력에 따른 최대 투과 플럭스는 공경이 $0.3{\mu}m$에서 평균 282 LMH, $0.05{\mu}m$에서는 234 LMH를 나타내었으며 외압형(외압) 공정의 압력에 따른 최대 투과 플럭스는 공경이 $0.3{\mu}m$에서 평균 443 LMH, $0.05{\mu}m$에서는 522 LMH를 나타내었다. 또한, 흡인압과 외압을 동시에 적용한 공정의 압력에 따른 최대 투과 플럭스는 공경이 $0.3{\mu}m$에서 평균 674 LMH $0.05{\mu}m$에서는 648 LMH를 나타내었다. 따라서, 호소수를 이용한 정수처리공정에서 분리막으로 흡인압과 외압을 동시에 이용할 경우 단위 면적당 생산수를 최대로 할 수 있을 것으로 사료된다.

• 동력기계공학회지
• /
• 제18권5호
• /
• pp.80-87
• /
• 2014

The pipelines are apt to erosion or corrosion because of the high-speed flow of water and steam with high temperatures or high pressures. This study was carried out a finite element analysis (FEA) and an experimental for the fracture behavior of T-joint pipes with local wall thinning under internal pressure. Local wall thinning was machined on the pipes in order to simulate erosion and corrosion of the metal. The configurations of the eroded area included an eroded ratio of d/t=0.80~0.963 and an eroded length of l=25 mm, 50 mm, and 102 mm. Three-dimensional elastic-plastic analyses were also carried out using FEA, which accurately simulates failure behaviors. In regards to the relationship between pressure and eroded, the criterion that indicates what can be used safely under operating pressure and design pressure were obtained from FEA. The FEA results were in relatively good agreement with that of the experiment.

• 동의생리병리학회지
• /
• 제16권6호
• /
• pp.1263-1269
• /
• 2002

To evaluate the effect of Choakwiyeum(CKY) and Yukmijihwang-tang(YJT) water extract on the renal function and the levels of plasma aldosterone, this experiment was performed in the rabbbits. These result indicate that increase in urine volume(UV) after administration of CKY and YJT water extract is related to increase in glomerular filtration rate(GFR), free water clearance(FWC) and renal plasma f1ow(RPF) and also to decrease in plasma aldosterone concentration(PAC), which seems to be affected by renin-angiotensin-aldosterone system, and that reduced blood pressure seems to be caused by reduced peripheral resistance.

• 농업과학연구
• /
• 제47권4호
• /
• pp.1159-1168
• /
• 2020

The conduits of agricultural reservoirs undergo deterioration over a considerable period of time and this is highly likely to cause structural problems such as cracks. It is therefore important to consider the effects of structural defects on the body from the viewpoint of stability and maintenance of the embankment. In this study, basic data on the effects of the crack location on the stability of the embankment is obtained by identifying, comparing, and analyzing the erosion characteristics and pore water pressure behavior through a large-scale model experiment that involves classifying the location of the conduit cracks. From the results of the experiment, it was confirmed that when a crack occurred, the amount of leakage increased as the location of the crack portion was closer to the water level, and the internal erosion phenomenon accelerated, thereby increasing the possibility of piping. It was also found that an upstream conduit crack affects the erosion and water pressure change of the central and downstream conduit of the embankment, and the conduit crack has a very large effect on the pore water pressure despite the low upstream water level. Therefore, the seepage behavior of the embankment for each conduit crack identified in this study is considered to be useful basic data for preparing a repair and reinforcement plan according to the crack location in the future.

• 대한한방내과학회지
• /
• 제17권1호
• /
• pp.8-33
• /
• 1996

The present experiment was designed to understand the effect of Boganhwan on the cardiovascular system in experimental animals. And thus the Blood pressure, isometric movement of atrium,Mg++-Ca++-ATPasc activity of sarcoplasmin reticulum. liver function, prothrombin time, and changes of blood composition were measured in the presence of Boganhwan. The results obtained here were as following: 1. The blood pressure decreased in the presence of SAMOOLTANG, and the decreasing effect was more stimulated by adding Bangpoong and Ganghwa(Boganhwan) 2. The oral administration of the drug for 7days also demonstrated the decreasing of blood pressure and the effect was stimulated by adding Bangpoong and Kanghwal. 3. The autonomic nerve blocking agents such as atropine and regitine did not demonstrate the effect on the drug action. 4. Boganhwan inhibited the cardiac isometric movement and rate by stimulating the Mg++-Ca++-ATPase activity of the heart sarcoplasmins reticulum. 5. Boganhwan increased the number of red blood cell, hematocrit percentage, hemoglobin concentration, and prothrombin time. 6. The drug stimulated the liver metabolism by stimulating the total ATPase activity. According to the results. Boganhwan demonstrated the decreased blood pressure and it also increased the hemoglobin concentration and the hematocrit percent. These effects stanches the hypertension. anemia, and cerebrovascular accident.

• 대한한방내과학회지
• /
• 제31권4호
• /
• pp.880-891
• /
• 2010

This study is about a comparison of controlled and uncontrolled hypertension groups regarding comprehensive diagnosis of Qi blood water and quality of life. We surveyed "controlled and uncontrolled hypertension patients" using questionnaires for comprehensive diagnosis of Qi blood water, SF-36 and HTN QoL (Measurement Scale for the quality of life in hypertensive patients). There was no difference in comprehensive diagnosis of Qi blood water between the controlled and uncontrolled hypertension groups. Within the controlled hypertension group, the patients diagnosed with a Qi deficiency, Qi stagnation, Qi counterflow, blood deficiency, and water retention received lower total scores in SF-36 and HTN QoL than in undiagnosed patients. Within the uncontrolled hypertension group, the patients diagnosed with Qi deficiency, blood deficiency, and water retention got lower total scores in SF-36 and HTN QoL than in undiagnosed patients. These results were statistically significant. These results are insufficient that we and use comprehensive diagnosis of Qi blood water for a diagnosis tool of hypertension. But if we have better studies that make up for weak points, these results will help to make a diagnosis tool for hypertension.

• 한국화재소방학회논문지
• /
• 제32권4호
• /
• pp.17-24
• /
• 2018

본 논문은 화재의 발생 및 전파를 억제하기 위해 방수총의 내부 유체유동특성을 파악하는 것을 목적으로 한다. 본 연구를 위해 개발 중인 워터노즐을 모델링하였고, 필드실험에서 얻은 경계조건(펌프의 가압력 : 4 bar, 방수총 출구압력 : 대기압)을 적용하였으며, 유동에 대한 운동량 지배방정식을 이용하여 방수총 내부 유동에 대한 속도 및 압력분포를 얻었다. 서브파이프의 유무와 길이를 기준으로 방수총 출구의 노즐에서의 성능 특성에 영향을 미치는 2가지 주요 인자로 고려하였다. 해석 결과 기존 모델의 경우에는 서브파이프의 길이가 변하더라도 방수총의 출구영역에서 성능특성에 그다지 영향을 미치지 않았다. 이에 반해서, 서브파이프를 단관형으로 교체한 경우에는 서브파이프의 입구에서 역류가 발생하였고, 이를 제거하기 위해 서브파이프의 길이를 2배로 변화시켜 역류를 제거할 수 있었다.

• Corrosion Science and Technology
• /
• 제3권6호
• /
• pp.233-239
• /
• 2004

Primary water stress corrosion cracking of steam generator tubings occur on many tubes in pressurized water reactors(PWRs), and they are repaired using sleeves or plugs. In order to develop proper repair criteria, it is necessary to know the leak behavior of the tubes, which have stress corrosion cracks. Crack development tests were carried out on the tubes at room temperature, and leak rate and burst pressure were measured on the degraded tubes at room temperature and a high temperature. No leakage was detected on the tubes where 100 % through wall crack developed, at 1560 psi, which is an operating pressure difference of pressurized water reactors(PWRs). In some tests, leak rates of the tubes increased with time at a constant internal water pressure. A test tube showed a very small amount of leakage at 2700 psi in a high temperature pressure test at $282^{\circ}C$, but it disappeared after the pressure increased slightly. Even cracks are 100 % through wall, they need to open in order to reach a certain amount of leak rate at the operating pressure difference.