• 제목/요약/키워드: Manufacturing pressure

검색결과 1,615건 처리시간 0.029초

우수방사성의약품 생산시설 개발 (Development of Good Manufacturing facility for Radiopharmaceuticals)

  • 신병철;정원명;박상현;이규일;박경배;박진호
    • Journal of Pharmaceutical Investigation
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    • 제33권2호
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    • pp.145-149
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    • 2003
  • Manufacturing facilities of the pharmaceuticals must meet certain level of the cleanness required so that foreign substances such as dust, moisture, heat, microorganism, or virus do not contaminate the product. In case of radiopharmaceuticals for medical treatment and diagnosis, not only should the operators and environment be protected from radiation but also need to be isolated from the foreign contaminant. Therefore, manufacturing facilities for radiopharmaceuticals must satisfy the design standards of both hot cell and clean room which are specified by GMP. However, standards of maintaining negative pressure for preventing spread of radioactive contaminant in isolated facilities conflict with the standards of maintaining positive pressure for keeping cleanness. To solve this problem, air pressure of hot cell was designed lower than in the adjacent area to meet standards of the radiation safety. To keep higher cleanness in certain part of the hot cell for filling, minimal relative positive pressure allows. In order to effectively maintain the cleanness that is required for production of Tc-99m generator, which takes 70% of whole demand of radiopharmaceuticals, the rooms placed in each side of production room are used as a buffer area and three lead hot cells are installed in production room. In this research, we established the appropriate engineered design concept for Tc-99m generator manufacturing facility, which satisfies both GMP cleanness standard for preventing particles, bacteria, other contaminants and the regulations of radiation safety for supervising and controlling the amount of radiation exposure and exhausted radioactivity. And the concept of multi-barrier buffer zones is introduced to apply negative air pressure for hot cell with first priority and to continue relative positive air pressure for clean room.

점화기관 배기계의 압력과 전파특성에 관한 연구 (A Study on the Characteristics of Pressure Wave Propagation in Spark Ignition Engine Exhaust System)

  • 박진용
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1996년도 춘계학술대회 논문집
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    • pp.72-78
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    • 1996
  • Based on experimental analysis, the characteristics of pulsating pressure wave propagation is clarified by testing of 4-stroke gasoline engine. The pulsating pressure wave in exhaust system is generated gyulsating gas flow due the working of exhaust valve. The pulsating pressure wave is closely concerned to the loss of engine power according to back pressure and exhaust noise. It is difficult to exactly calculate pulsating pressure wave nonlinear effect. Therefore, in the first step for solving these problems, this paper contains experimental model and analysis method which are applied two-port network analysis. Also, it shows coherence function, frequency response function. back pressure, and gradient of temperature in exhaust system.

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대칭형 보에 의해 보강된 등방성 평판의 음향방사에 관한 연구 (A Study on Sound Radiation from Isofropic Plates Stiffened by Symmetrical Reinforced Beams)

  • 김택현
    • 한국생산제조학회지
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    • 제7권1호
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    • pp.41-50
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    • 1998
  • The detemination of sound pressure radiated from peoriodic plate structures is fundamental in the estimation of noise levels in aircraft fuselages and ship hull structures. As a robust approach to this problem, here a very general and comprehensive analytical model for predicting the sound radiated by a vibrating plate stiffened by periodically spaced orthogonal symmetric beams subjected to a sinusoidally time varying point load is developed. The plate is assumed to be infinite in extent, and the beams are considered to exert both line force and moment reactions on it. Structural damping is included in both plate and beam materials. A space harmonic series representation of the spatial variables is used in conjunction with the Fourier transform to find the sound pressure in terms of harmonic coefficients. From this theoretical model. the sound pressure levels on axis in a semi-infinite fluid (water) bounded by the plate with the variation in the locations of an external time harmonic point force on the plate can be calculated efficiently using three numerical tools such as the Gauss-Jordan method, the LU decomposition method and the IMSL numerical package.

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연료 압력 조절기용 가이드 밸브의 냉간 단조 개발에 관한 연구 (A Study on the Cold Forging Development of Guide Valve for the Fuel Pressure Regulator)

  • 송승은;권혁홍
    • 한국생산제조학회지
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    • 제21권2호
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    • pp.331-336
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    • 2012
  • This study was aimed at the design of the dies for the guide valve for the fuel pressure regulator using the computer simulation to shorten the period of production, on the basis of the process planning which was designed by the field experts. In the computer simulation, 'Deform-3d' and 'Eesy-DieOpt' have been used, which are the commercial process analysis and die design program. Through the process analysis, we could know the propriety of the forming process, the inner pressure of the die and the suitable fitting pressure between the insert and the sleeve which was not showing any positive tangential stresses in the insert. Through the simulation of die design, we could know the number of the stress ring, the diameter ratios, the stresses of the die, the shrink fitting tolerance and temperature in the condition of the already determined maximum outer die diameter of the multi-stage former. The validity of the die design using the computer simulation was analyzed by the experiments and the results were satisfactory. As the results of this study, the new and easy die design system for multi-forging has been developed.

속도 감응형 가변 오리피스를 갖는 쇽업저버 개발 (Development of a Shock Absorber with an Orifice Sensitive to Velocity)

  • 문사현;김옥현
    • 한국생산제조학회지
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    • 제22권3호
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    • pp.447-451
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    • 2013
  • In this study, a shock absorber whose orifice area changes according to the oil pressure inside the absorber is developed. The orifice widens and narrows when the oil pressure is high and low, respectively; thus, the orifice area changes according to the oil pressure, in other words, according to the extension/compression velocity. It is well known that the damping force can be expressed as $C{\cdot}v^{\alpha}$. For fluid film damping, the force is proportional to velocity, i.e., ${\alpha}=1$, and for orifice damping, it is proportional to the square of velocity, i.e., ${\alpha}=2$. The shock absorber proposed in this paper can exhibit different relationships between the damping force and velocity because the orifice area changes according to the induced oil pressure. The motivation of this study is to develop a method for designing a shock absorber with desired values of C and ${\alpha}$ which is not just 1 or 2. Theoretical and experimental studies have been conducted to verify the damping characteristics of the shock absorber. The effect of some major design parameters on damping characteristics has been also examined to relate the design parameters to the damping characteristics.

전단간섭계를 이용한 압력용기 내부 결함 측정시 전단량 변화에 따른 오차분석 (Analysis of Error Rate in the Variations of Shearing Amount in Measuring the Internal Defect using a Shearography)

  • 홍경민;강영준;최인영;안용진;윤석범
    • 한국생산제조학회지
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    • 제21권5호
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    • pp.726-732
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    • 2012
  • Pipe and Pressure Vessels that is used in power plant and chemical industry have many Internal Defects that is corrosion caused by the flow of fluid. These Internal Defects that have possibility of explosion are very dangerous because it can not see from the outside. This days many companys using NDT method to find an Internal Defect. Most of the NDT methods have limitations that are constraint of shape and materials. But Sheargoraphy have many advantages compared conventional NDT method. It has very fast measuring speed, non-destructive and non contacting measurement. As well as it hasn't constraint of shape and materials. As a paper on the analysis of measurement of error, the important factors were the Shearing Amount and pressure, and discovered measurement of the Internal Defect of the object by using shearography. The optimal Shearing Amount and pressure was discovered and utilized.

미세유체시스템의 유체이송을 위한 탄성체의 복원력을 이용한 흡입형 미세유체펌프 (Microfluidic Suction Pump based on Restoring Force of Elastomer for Liquid Transportation in Microfluidic System)

  • 변강일;한의돈;김병희;서영호
    • 한국생산제조학회지
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    • 제24권1호
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    • pp.81-86
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    • 2015
  • This paper presents a disposable passive suction pump that uses the restoring force of an elastomeric chamber for liquid transportation in a microfluidic system. The proposed suction pump can be operated by finger pressure without any peripheral equipment. To adjust the generated suction pressure, five different displacements of the suction chamber ceiling, two different chamber shapes, and five different elastic moduli of the elastomer were considered. For a cylindrical chamber with a 5 mm height and 5 mm radius, the generated suction pressure and flow rate increased almost linearly up to about 31 kPa and $160.8{\mu}L/min$, respectively, depending on the chamber deformation. A maximum suction pressure of $42.9{\pm}0.7kPa$ was obtained for a hemispherical chamber with a 2.1 mm height and 5 mm radius.

제조기업의 환경혁신에 대한 원인요인과 촉진요인 (The Influence Factors on the Activation of Environmental Innovations in Manufacturing Firms)

  • 최종민
    • 경영과학
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    • 제32권3호
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    • pp.71-89
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    • 2015
  • This research empirically investigated the influence factors on the activation of environmental innovations (EI) in Korean manufacturing firms. In this study, external factors (compulsory demand, government regulation, normative pressure and imitative pressure) and internal factors (environmental resources, top management support, integration of environmental tasks, capabilities of environmental personnel, and environmental strategy/environmental management systems) were totally considered. The results of a multiple regression analysis showed that influence factors such as top management support, environmental resources and integration of environmental tasks have a significant and positive impact on levels of EI. However, the effects of external factors were not statistically significant. We also examined whether capabilities of environmental personnel as well as environmental resources, which are directly related with degrees of EI, have a moderating impact on relationships between other internal factors and levels of EI. With a subgroup analysis, the moderating role of abilities of environmental personnel were empirically confirmed. Through a multiple regression analysis, the direct effects of external factors on the adoption or construction of internal factors were demonstrated. The effects of government regulation, normative pressure and imitative pressure on internal factors were significant and positive. It was also found that external factors have indirect effects on EI through internal factors. Finally, the results of multiple regression analyses indicated that EI positively influences the achievement of environmental competitive benefits, and environmental competitive advantages can improve the organizational performance of a firm.

SM45C 중실축의 마찰용접 기계적 특성에 관한 연구 (A Study on the Mechanical Properties of the Friction Welding with Solid Shaft of SM45C)

  • 구건섭
    • 한국생산제조학회지
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    • 제21권6호
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    • pp.932-937
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    • 2012
  • In the presented study, SM45C carbon steel parts were joined by friction welding. The welding process was carried out under optimized conditions using statistical approach. The study of SM45C is conducted with various combinations of process parameters. Parameter optimization, microstructure and mechanical property correlation are the major contribution of the study. The welded joints were produced by varying spindle revolution speed, friction pressure, upset pressure and burn-off length. Tension tests were applied to welded parts to obtain the strength of the joints. Fracturs properties were additionally obtained experimentally under fluctuated tensile loads. Microstructures using microphotographs were examined in the weld interface and weld region and heat affected zone and base metal and flash zone of welded parts. Finally, Hardness variations in welding zone and base metal were also obtained. Through these tests, the optimum conditions of parameters for ${\phi}20$ SM45C in friction welding were obtained when the friction spindle revolution was 1,950 rpm, the friction pressures was 30 MPs, upset pressures was 50 MPs.

Optimization of Preparation Variables for Trimyristin Solid Lipid Nanoparticles

  • Choi, Mi-Hee;Lee, Mi-Kyung
    • Journal of Pharmaceutical Investigation
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    • 제37권1호
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    • pp.51-55
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    • 2007
  • Solid lipid nanoparticles (SLNs) have been regarded to behave similar to the vegetable oil emulsions because emulsions of lipid melts are formed before lipid droplets being solidified to turn into SLNs. Compared to lipid emulsion, however, it has been more difficult to obtain stable SLNs and needs more extensive considerations on stabilizer and manufacturing process. In the present study, we tried to prepare phosphatidylcholine-based trymyristin (TM) SLNs using high pressure homogenization method and optimize the manufacturing variables such as homogenization pressure, number of homogenization cycles, cooling temperature, co-stabilizer and freeze-drying with cryoprotectants. Nano-sized TM particles could be Prepared using egg Phosphatidylcholine and pegylated phospholipids ($PEG_{2000}$PE) as stabilizers. Based on the optimization study, the dispersion was manufactured by homogenization under the pressure of 100 MPa for more than 5 cycles, and solidifying the intermediately formed lipid melt droplets by dipping in liquid nitrogen followed by thawing at room temperature. In addition, TM SLNs could be freeze-dried and then redispersed easily without significant particle size changes after freeze drying with 10% and 12.5% sucrose or trehalose. The TM SLNs established in this study can be used as delivery system for drugs and cosmetics.