• 제목/요약/키워드: low leakage

검색결과 1,336건 처리시간 0.036초

Occupational Exposure during Intraperitoneal Pressurized Aerosol Chemotherapy Using Doxorubicin in a Pig Model

  • Wongeon Jung;Mijin Park;Soo Jin Park;Eun Ji Lee;Hee Seung Kim;Sun Ho Chung;Chungsik Yoon
    • Safety and Health at Work
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    • 제14권2호
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    • pp.237-242
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    • 2023
  • Background: This study evaluated occupational exposure levels of doxorubicin in healthcare workers performing rotational intraperitoneal pressurized aerosol chemotherapy (PIPAC) procedures. Methods: All samples were collected during PIPAC procedures applying doxorubicin to an experimental animal model (pigs). All procedures were applied to seven pigs, each for approximately 44 min. Surface samples (n = 51) were obtained from substances contaminating the PIPAC devices, surrounding objects, and protective equipment. Airborne samples were also collected around the operating table (n = 39). All samples were analyzed using ultra-high performance liquid chromatography-mass spectrometry. Results: Among the surface samples, doxorubicin was detected in only five samples (9.8%) that were directly exposed to antineoplastic drug aerosols in the abdominal cavity originating from PIPAC devices. The telescopes showed concentrations of 0.48-5.44 ng/cm2 and the trocar showed 0.98 ng/cm2 in the region where the spraying nozzles were inserted. The syringe line connector showed a maximum concentration of 181.07 ng/cm2, following a leakage. Contamination was not detected on the surgeons' gloves or shoes. Objects surrounding the operating table, including tables, operating lights, entrance doors, and trocar holders, were found to be uncontaminated. All air samples collected at locations where healthcare workers performed procedures were found to be uncontaminated. Conclusions: Most air and surface samples were uncontaminated or showed very low doxorubicin concentrations during PIPAC procedures. However, there remains a potential for leakage, in which case dermal exposure may occur. Safety protocols related to leakage accidents, selection of appropriate protective equipment, and the use of disposable devices are necessary to prevent occupational exposure.

Investigation of the Antifungal Activity and Mechanism of Action of LMWS-Chitosan

  • Park, Yoon-Kyung;Kim, Mi-Hyun;Park, Seong-Cheol;Cheong, Hyeon-Sook;Jang, Mi-Kyeong;Nah, Jae-Woon;Hahm, Kyung-Soo
    • Journal of Microbiology and Biotechnology
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    • 제18권10호
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    • pp.1729-1734
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    • 2008
  • Chitosan, a cationic polysaccharide, has been widely used as a dietary supplement and in a variety of pharmacological and biomedical applications. The antifungal activity and mechanism of action of low molecular weight water-soluble chitosan (LMWS-chitosan) were studied in fungal cells and vesicles containing various compositions of fungal lipids. LMWS-chitosan showed strong antifungal activity against various pathogenic yeasts and hyphae-forming fungi but no hemolytic activity or cytotoxicity against mammalian cells. The degree of calcein leakage was assessed on the basis of lipid composition (PC/CH; 10:1, w/w). Our result showing that LMWS-chitosan interacts with liposomes demonstrated that chitosan induces leakage from zwitterionic lipid vesicles. Confocal microscopy revealed that LMWS-chitosan was located in the plasma membrane. Finally, scanning electron microscopy revealed that LMWS-chitosan causes significant morphological changes on fungal surfaces. Its potent antibiotic activity suggests that LMWS-chitosan is an excellent candidate as a lead compound for the development of novel anti-infective agents.

Closed Thoracostomy of Spontaneous Pneumothorax : Clinical Comparison of Suction with No Suction (자연기흉의 흡인법 치료 효과)

  • Im, Seung-U;Lee, Dong-Hyeop;Lee, Jeong-Cheol
    • Journal of Chest Surgery
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    • 제24권9호
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    • pp.890-894
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    • 1991
  • We have performed a prospective study to assess the efficacy of suction drainage in 45 patients with primary spontaneous pneumothorax and 15 patients with secondary spontaneous pneumothorax, treated by closed chest tube drainage with underwater seal during the period Jan. 1990 to Dec. 1990 at the Department of Thoracic and Cardiovascular Surgery, Yeungnam University Hospital. The patients were divided randomly into two groups, 28 cases receiving suction and the other 32 cases no suction. The success rate was 82.1% for the former and 87.5% for the latter with the overall success rate of 85.0% and there was no significant difference in success rate between the two groups According to the causes and the extent of pneumothorax, the difference between the success rates of the two groups was also not significant statistically. But according to the duration of air leakage, suction group under 2 days showed a high success rate[46.4%] and the same group with 3-4 days, a relatively low success rate[21.4%] compared with that of the former. We conclude that the suction treatment is somewhat valuable in shortening the tubing time in patients with small amounts of air leakage, but it doesn`t seem to increase the success rate in all patients.

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Study of Failure Examples for Fuel Coagulation, Leakage, Low Grade Gasoline and Fuel Additives in Automotive Fuel System (자동차 연료 시스템에관한 연료 응고, 누설, 불량 휘발유 및 연료 첨가제에 의한 고장 사례 고찰)

  • Lee, IL Kwon;Kim, Young Gyu;Ko, Young Bae;Kim, Seung Chul
    • Tribology and Lubricants
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    • 제28권4호
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    • pp.178-183
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    • 2012
  • The fuel system of a vehicle is a very important compotent, as it provides the firing resources to the combustion chamber of the engine. However, improper operation of the system can generate bad condition or start-off during engine revolution. This study analyzed several examples of failure that had originated in the field. In the first example, the driver operated a vehicle containing both gasoline and LPG in the fuel tank, but the gasoline fuel remained unused for a few months. Therefore the fuel pump was clogged because of gasoline congelation. The second example, dealt with fuel leakage that occurred from the slightly torn O-ring connecting the fuel lines. The third example, pertained to engine damage and power-down owing to the usage of proor-quality fuel and ingredient. Therefore, it is necessary to take adequate measures to prevent the failure of the fuel system of vehicle.

The comparative risk assessment of LNG tank designs using FTA (고장수목분석법을 이용한 액화천연가스 저장탱크 형식별 위험성 비교 평가)

  • Lee, Seung Rim;Kim, Han Sang
    • Journal of the Korean Institute of Gas
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    • 제16권6호
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    • pp.48-54
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    • 2012
  • Building above-ground membrane LNG storage tanks have been recently actively reviewed because they have advantages in ease of large capacity, environmental friendliness, and low possibility of gas leakage of the inner tank (slow increase of leakage speed). In this paper, the safety of membrane LNG storage tanks was ensured through comparative risk assessment of full-containment LNG storage tanks and membrane LNG storage tanks by using Fault Tree Analysis (FTA). Risk assessment results showed that both types of tanks have very similar level of risk except for the membrane storage tanks without additional safety equipments (early model).

Electrical charateristics of MIS BST thin films

  • Park, C.-S.;Mah, J.-P.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • 제14권3호
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    • pp.90-94
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    • 2004
  • The variation of electrical properties of (Ba,Sr)$TiO_3$ [BST] thin films for Metal-Insulator-Semiconductor (MIS) capacitors was investigated. BST thin films were deposited on p-Si(100) substrates by the RF magnetron sputtering with temperature range of 500~$600^{\circ}C$. The dielectric properties of MIS capacitors consisting of AUBST/$SiO_2$/Si sandwich structure were measured for various conditions. We examined the characteristics of MIS capacitor with various oxygen pressure, substrate temperature and (Ba+Sr)/Ti ratio. It was found that the leakage current was reduced in MIS capacitor with high quality $SiO_2$ layer was grown on bare p-Si substrate by thermal oxidation. The BST MIS structure showed relatively high capacitance even though it is the combination of high-dielectric BST thin films and $SiO_2$ layer. The charge state densities of the MIS capacitors and Current-voltage characteristics of the MIS capacitor were investigated. By applying $SiO_2$ layer between BST thin films and Si substrate, low leakage current of $10^{-10}$ order was observed.

The X-ray Detection and morphology Characteristics on Evaporation Temperature of amorphous Selenium based digital X-ray detector (비정질 셀레늄의 박막 제조공정에 따른 미세구조와 IV특성)

  • Gong, H.G.;Cha, B.Y.;Lee, G.H.;Kim, J.H.;Nam, S.H.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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    • pp.51-54
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    • 2002
  • Recently, due to its better photosensitivity in X-ray, the amorphous selenium based photoreceptor is used on digital direct method conversion material. Compared to other photoconductive material, amorphous selenium has good X-ray response characteristic and low leakage current. It has many parameters of detecting X-ray response on selenium. Among of them, it is well known that manufacture of a-Se is the most basic element. In this paper, we fabricated two types of amorphous selenium sample which had time variable. The one was fabricated continuous deposition sample and the other was step by step sample. Thickness of sample was $300{\mu}m$ and top electrode was evaporated gold. We investigated the leakage current and photo current of them and analysed their electrical characteristics. For analyzing morphology of samples, SEM and surface was pictured. We found that step by step deposition method could be applied for novel fabricating amorphous selenium film.

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Study of the Effects of the Antisite Related Defects in Silicon Dioxide of Metal-Oxide-Semiconductor Structure on the Gate Leakage Current

  • Mao, Ling-Feng;Wang, Zi-Ou;Xu, Ming-Zhen;Tan, Chang-Hua
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제8권2호
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    • pp.164-169
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    • 2008
  • The effects of the antisite related defects on the electronic structure of silica and the gate leakage current have been investigated using first-principles calculations. Energy levels related to the antisite defects in silicon dioxide have been introduced into the bandgap, which are nearly 2.0 eV from the top of the valence band. Combining with the electronic structures calculated from first-principles simulations, tunneling currents through the silica layer with antisite defects have been calculated. The tunneling current calculations show that the hole tunneling currents assisted by the antisite defects will be dominant at low oxide field whereas the electron direct tunneling current will be dominant at high oxide field. With increased thickness of the defect layer, the threshold point where the hole tunneling current assisted by antisite defects in silica is equal to the electron direct tunneling current extends to higher oxide field.

Electrical and Dielectric Characteristics of Zn-Pr-Co-Er-M(M=Ni, Mg, Cr) Oxides-Based Varistors (Zn-Pr-Co-Er-M(M=Ni, Mg, Cr)산화물계 바리스터의 전기적, 유전적 특성)

  • 남춘우;김명준
    • Journal of the Korean Ceramic Society
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    • 제41권8호
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    • pp.605-609
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    • 2004
  • The microstructure, electrical and dielectric characteristics of ZnO varistors were investigated at various metal oxide (NiO, MgO, and Cr$_2$O$_3$) additives. The average grain size was increased with addition of NiO while that was decreased with addition of Cr$_2$O$_3$-Thereby, the varistor voltage was higher in Cr$_2$O$_3$-added composition. Among varistors, the varistor added with Cr$_2$O$_3$ exhibited the highest nonlinearity, with 40.5 in the nonlinear exponent and 2.7 ${\mu}$A in the leakage current and its dielectric dissipation factor was relatively low value of 0.0589.

Behavior of Tip Vortex in a Propeller Fan (프로펠러팬에서의 Tip Vortex 거동)

  • Kim, Sung-Hyup;Furukawa, Masato;Inoue, Masahiro
    • Proceedings of the KSME Conference
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.1377-1382
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    • 2004
  • Flow fields in a half ducted propeller fan have been investigated by three-dimensional Reynolds-averaged Navier-Stokes (RANS) simulations and a vortex core identification technique. The simulation at the design operating condition shows that the tip vortex onset point is located at 30 percent tip chord of the suction surface on the blade tip. There is no interaction between the tip vortex and the adjacent blade, so that the tip vortex smoothly convects to the rotor exit. However, the high vorticity in the tip vortex causes the wake and the tip leakage flow to be twined around the tip vortex and to interact with the pressure surface of the adjacent blade. This flow behavior corresponds well with experimental results by Laser Doppler Velocimetry. On the contrary, the simulation at the low-flowrate operating condition shows that the tip vortex onset point is located at the 60 percent tip chord of the suction surface. In contrast to the design operating condition, the tip vortex grows almost tangential direction, and impinges directly on the pressure surface of the adjacent blade.

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