• Title/Summary/Keyword: Air-bleeding

Search Result 143, Processing Time 0.037 seconds

Studies on the Environmental Factors for Sap Exudation of Acer mono and the Resource Development of its Community (2): Environmental Factors and Tree Recovery (고로쇠나무(Acer Mono)의 수액출수에 미치는 환경요인과 그 군락의 자원화에 관한 연구 (2): 환경요인 및 공시목의 회복)

  • Kim, Chul-Soo;Kwak, Ae-Kyung
    • The Korean Journal of Ecology
    • /
    • v.17 no.4
    • /
    • pp.533-545
    • /
    • 1994
  • The bleeding of 39 Acer mono trunks by wounding was investigated at the altitudes of 400m, 500m, 800m, and 1100m on Wangsirobong (1,214m), Mt. Chiri area (127°34'E., 35°14'N.) from February 4 to March 21, 1993 and from February 23 to March 23, 1994. The amount of sap in a day was clodely related to the change of air temperature and wind speed. Especially, the abundant sap was exudated at the ranges of -4~13℃ in the daily range of temperature and it was below 0.14m/s in wind speed. The most abundant bleeding was exudated from Acer mono trunk located south facing slope in 800m altitude. Also the amount of sap increased with incereasing suface area of crown. The maximum bleeding of sap was collected from the hole punctured at 80cm height from the ground surface at southern part of the trunks. And the number of exudation holes had an important effect on bleeding of sap but the number of holes should be controlled by DBH of trunks. These results suggested that the exudation was influenced by the daily range of temperature and wind speed. And the altitude, direction of sloped where the trees occurred, surface area of crown, the number of exudation holes, height form the ground surface and the direction of the hole was 91.6% when germicide (Dimethyl-4,4' -ophenylene bis 3-thio alonate) was treated from April to October after bleeding of sap in the year.

  • PDF

Analysis of the Influence of Anti-icing System on the Performance of Combined Cycle Power Plants (가스터빈 결빙방지 시스템이 복합화력발전 시스템의 성능에 미치는 영향)

  • Moon, Seong Won;Kim, Jeong Ho;Kim, Tong Seop
    • The KSFM Journal of Fluid Machinery
    • /
    • v.19 no.6
    • /
    • pp.19-25
    • /
    • 2016
  • Anti-icing is important in gas turbines because ice formation on compressor inlet components, especially inlet guide vane, can cause performance degradation and mechanical damages. In general, the compressor bleeding anti-icing system that supplies hot air extracted from the compressor discharge to the engine intake has been used. However, this scheme causes considerable performance drop of gas turbines. A new method is proposed in this study for the anti-icing in combined cycle power plants(CCPP). It is a heat exchange heating method, which utilizes heat sources from the heat recovery steam generator(HRSG). We selected several options for the heat sources such as steam, hot water and exhaust gas. Performance reductions of the CCPP by the various options as well as the usual compressor bleeding method were comparatively analyzed. The results show that the heat exchange heating system would cause a lower performance decrease than the compressor bleeding anti-icing system. Especially, the option of using low pressure hot water is expected to provide the lowest performance reduction.

An Experimental Study on the Properties of Concrete using High Volume of Coal Ash

  • Kim, Moo Han;Choi, Se Jin
    • Architectural research
    • /
    • v.4 no.1
    • /
    • pp.39-44
    • /
    • 2002
  • Recently, the coal-ash production has been increased by increase of consumption of electric power. So it is important to secure a reclaimed land from pollution and develop practical application of coal ash. This is an experimental study to compare and analyze the properties of concrete using high volume of coal ash (including fly ash and bottom ash) as a part of fine aggregate. For this purpose, the mix proportions of concrete according to replacement ratio of coal ash (10, 20, 35, 50%) were selected. And then air content, slump, setting time, bleeding content, chloride content, compressive strength and carbonation test were performed. According to test results, it was found that the bleeding content of concrete using the coal ash decreased according to increase of replacement ratio. And the chloride content of concrete using the bottom ash as a part of fine aggregate increased as the replacement ratio of bottom ash increased, but it is satisfied with the total chloride content of concrete recommended by KCI - $0.3kg/m^3$ below. Also, the compressive strength of concrete using the bottom ash was similar to that of plain concrete(BA 0) after 28days of curing and the carbonation depth of concrete increased as the replacement ratio increased. However, the carbonation depth of concrete using the fly ash decreased as the replacement ratio of fly ash increased.

Effects of Animal Additives on the Fundamental Properties of Mortar and Concrete (동물성 첨가제가 모르타르 및 콘크리트의 기초 물성에 미치는 영향)

  • Song, Jin-Woo;Moon, Seung-Kwon
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.7 no.1
    • /
    • pp.69-75
    • /
    • 2012
  • The study was conducted to determine the effects of adding pig blood as an admixture to both mortar and concrete. The mortar tests included the determination of its unit weight, flow and its compressive strength. Moreover, the concrete test includes the determination of air content, slump, bleeding, setting time compressive strength and freeze-thaw resistance of the material. As the test result, the utilization of pig blood, as an additive to both mortar and concrete mixtures causes air entrainment. The mortar flow increased and both the unit weight and the compressive strength of mortar decreased. As the blood replacement rate increases, the air content decreases over time, the setting and amount of bleeding showed a tendency to decline and reduced compressive strength, and the freeze-thaw resistance of the concrete increased.

  • PDF

Influence of Particle Properties of Crushed Sand on the Qualities of Concrete (부순모래의 입자특성이 콘크리트의 품질에 미치는 영향)

  • Yoo Seung-Yeup;Sohn Yu-Shin;Lee Seung-Hoon;Lee Gun-Cheol;Yoon Gi-Won;Han Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2005.05a
    • /
    • pp.89-92
    • /
    • 2005
  • This study investigates influence of particle properties of crushed sand on the duality of concrete. The test shows that an increase of fineness modulus(FM) resulted in high slump and air contents, while compressive strength decreased due to decreased adhesion with reduction of surface area. As grain shape become rounder, the slump of concrete increased, due to reduction of internal friction, and increased air contents. The reduction of adhesion by abrasion of surface declined compressive strength during the process of manufacturing crushed sand. Increase of powder contents decreased slump and it also decreased air contents due to the effect of filling air void. In addition. using powder contents increased compressive strength, but could not find any difference of bleeding and tensile strength with particle properties.

  • PDF

Wound Probing in Neck Trauma Patients (경부 손상 환자에서의 상처 탐침)

  • Ye, Jin Bong;Sul, Young Hoon;Mun, Yun Su;Go, Seung Je;Kwon, Oh Sang;Ku, Gwan Woo;Lee, Min Koo
    • Journal of Trauma and Injury
    • /
    • v.28 no.3
    • /
    • pp.198-201
    • /
    • 2015
  • Neck trauma is a relatively uncommon but can be a life-threatening injury. Several guidelines for neck trauma is established to recommend a proper management such as no clamping of bleeding vessels, no probing of wounds, Trendelenberg position for preventing venous air embolism. Here, we present a regretful case of 49-year-old man with neck trauma presenting undesired bleeding after probing of wound, and then discuss about treatment guildeline for neck trauma with a review.

  • PDF

The Animal Experiments of Total Artificial Heart at the National Cardiovascular Center in Japan (일본국립순환기병센터형 완전 인공심장을 이용한 동물실험)

  • 박영환
    • Journal of Chest Surgery
    • /
    • v.27 no.10
    • /
    • pp.824-832
    • /
    • 1994
  • Recently we developed the concept of totally implantable electrohydraulic artificial heart. We tested the artificial heart which was drived by external compressive air in the calves. All three calves had pneumonia before surgery, so postoperative course was not only bad but also the results was not good. The first calf died severe pneumonia on 76th day, the second calf died from troublesome bleeding and uncertain allergic like reaction, and the third died because of bleeding. However, the performance of the artificial heart was good, and especially the blood contacting surface showed excellent hemocompatibility. The anatomic fitting was also very good even in the 35 Kg small newborn calf. During treadmill test, the first calf did not well tolerate for 1 minute but by the Full Fill Full Empty control method the artificial heart responsed well to the physiologic needs. In conclusion, the artificial heart had the very good hemocompatible surface, however, the volume of the artificial heart was a little deficient for the calf and the control algorithm needed further development.

  • PDF

Idiopathic Cystic Medial Necrosis -A Case Report- (특발성 낭포성 중층 괴사 -1례 보고-)

  • 장병철
    • Journal of Chest Surgery
    • /
    • v.12 no.3
    • /
    • pp.183-190
    • /
    • 1979
  • A 23-year-old male patient complained dyspnea on exertion and orthopnea since December 1977. On examination, he was tall and slender. There was grade IV/VI to-and-fro murmur on the left sternal border especially on Erb`s point. The liver was descended 2 fingers breadth below right costal margin. There were no signs of Marfan`s syndrome. Echocardiography demonstrated partial closure of aortic valve and dilated aortic root with enlargement of ascending aorta. Left heart cardiac catheterization revealed moderately elevated pulmonary wedge pressure and right ventricular pressure. The left ventricular end diastolic pressure was markedly elevated to 26 mmHg. On aortography, the aortic regurgitation was severe and it was belonged to angiographically Grade IV. The aortic valve was replaced with Carpentier-Edwards valve without excision and replacement of ascending aorta, under the impression of rheumatic valvular heart disease. After closure of aortotomy, blood pressure was transiently elevated and bleeding from the site of inserting air vent needle of ascending aorta was developed. The bleeding was not controlled by any means. On postmortem microscopic study, the histologic changes were strikingly limited to the ascending aorta from the region of the aortic valve ring.

  • PDF

Change in Risk of Dropout Due to Bleeding during Bloodletting-Cupping Therapy (습식 부항 시술시 사혈량에 따른 부항 탈락 위험도 탐색)

  • Kim, Daehyeok;Bae, Eunkyung;Park, Jeonghwan;Kim, Soyoung;Lee, Sanghun
    • Korean Journal of Acupuncture
    • /
    • v.35 no.1
    • /
    • pp.41-45
    • /
    • 2018
  • Objectives : To investigate minimum pressure by verifying changes in pressure due to bleeding amount during bloodletting-cupping therapy. Methods : (1) We compared adhesion performance of four different cupping cups of same size: two disposable cupping cups(A, B) and two reusable cupping cups(A, B) each were vacuumed three times and kept in place for 10 minutes. (2) We vacuumed two different sized disposable cupping cups(A), size.1(InnerDiameter 48.8 mm) and size.3(InnerDiameter 39.1 mm), twice each(-200 mmHg) on silicon plate. We injected water and air at regular intervals in cupping cups by using a syringe, and then measured change of pressure in cupping cups and pressure at the time of dropout. Results : (1) Pressure reduction was $4.75{\pm}2.78%$ on average in the order of 'Disposable[A]>reusable[B]>Disposable[B]>reusable[A]', so that pressure retention performance of disposable cups can't be regarded as inferior to that of reusable cups. (2) Pressure of disposable cupping B(size.1) decreased by an average of -40.08 mmHg per 5 ml of water. At -24.8 mmHg, when 22 ml of water has been injected, cup has come off. Pressure of disposable cupping B(size. 3) decreased by an average of -99.4 mmHg per 5 ml of water. At -48.6 mmHg, when 13 ml of water was injected, cupping came off. Conclusions : Considering reduction rate of pressure due to water injection, in case of bleeding more than 15 ml, size.3 cup always comes off, therefore it needs to be re-operated at least once. Meanwhile, size.1 cup does not always come off in the same condition, depending on the initial pressure and therefore, re-operation may be considered.

Comparison of the Oral Health Education Effect of Air Force Personnel according to the Use of Disclosing Solution (치면 착색제 사용 유무에 따른 공군장병의 구강 보건 교육 효과 비교)

  • Lee, Hye-Rim;Jung, Gyu-Un;Pang, Eun-Kyoung
    • The Journal of the Korean dental association
    • /
    • v.54 no.1
    • /
    • pp.57-66
    • /
    • 2016
  • This study was to evaluate the effects of oral health education conducted on air force personnel according to the use of disclosing solution. They were divided into 3 groups: Group A: oral health education was not conducted, Group B: oral health education was conducted without using disclosing solution, and Group C: oral health education was conducted using disclosing solution. The subjects who had not participated in the education at least once were excluded, and the remaining 83 subjects received oral health education four times and one time each week. The probing depth, plaque index, gingival index, and bleeding on probing were measured one week before the implementation of the first oral health education and one week after the implementation of the fourth oral health education. The results of verifying the homogeneity of the clinical indices before the oral health education showed statistically significant differences in bleeding on probing among the three groups. The results of comparing the clinical indices among the three groups after the oral health education exhibited statistically significant differences in the plaque and gingival indices among the three groups. Groups B and C showed lower values than Group A. The comparison of the clinical indices before and after the oral health education showed statistically significant improvements in all clinical indices after the education in Group C. The results suggested that the oral health education using disclosing solution could maximize that visual effects and encourage self-motivation, consequently improve the oral hygiene of the patients.

  • PDF