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  • Title/Summary/Keyword: Double chamber

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치료중 실시간 모니터링을 위한 투과형 빔측정장치 개발

  • Kim, Jae-Hong;Swanepoel, M.W.;Dekock, E.A.;Park, Yeon-Su;Yang, Tae-Geon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.315-315
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    • 2010
  • 양성자 빔을 이용하여 두경부 암 치료를 South Africa의 iTHEMBA에서 시행하고 있다. 200 MeV의 양성자 빔라인으로부터 진공에서 대기로 인출하여 노즐을 통과하여 종양세포에 조사된다. 치료계획에 적합하게 빔에너지와 모양을 변환하고, 빔을 모니터링하는 기계적 장치들이 노즐에 구성된다. 빔라인에는 이온챔버, Steering Magnet, Multi-wire 이온챔버, Range trimmer plates, lead scattering plate, Double-wedge energy degrader, Multi-layer Faraday cup, Range modulator, Range monitor, occluding ring, Shielding collimators, Quadrant and monitor ionization chamber, Treatment collimator, 그리고 Wellhofer dosimetry tank로 구성되어 있다. 총길이는 6.6m이며 노즐 끝에서 환자의 isocenter 까지는 30cm 정도 아래에 위치한다. 상기의 배치를 갖는 시스템의 양성자 scattering system의 성능을 MCNPX v2.5.0 Monte Carlo simulation을 실시하였다. 또한 정확한 선량을 실시간으로 측정하는 방법인 투과형 검출기를 개발하여 치료와 빔 특성을 동시에 수행하는 기술개발연구가 보고되고 있다. 본 연구에서는 Multileaf Faraday Cup (MLPC) 검출기 설계구조와 데이터 측정방법에 관한 연구를 수행하고자 한다. 빔의 전송 방향으로 3개층의 4×4 배열의 구조로 48 channel의 전류값을 측정하여 입자빔의 분포를 실시간으로 관측하고, 측정된 전류는 ADC를 거쳐 치료계획에 의해 선택된 영역의 SOBP를 유지하도록 range modulation propeller를 조절하는 feed-back system을 갖춘 방사선치료빔 실시간 측정장치 개발에 관한 결과를 보고하고자 한다.

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Effects of Parameters of Combustion and Fuel Injection System on Performance and Exhaust Emissions in a Diesel Engine (연소계 및 연료분사계의 구성인자가 디젤엔진의 성능 및 배기 배출물에 미치는 영향)

  • Lee, Joon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.2
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    • pp.166-173
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    • 2006
  • This study investigates a heavy duty diesel engine with swept vol. 12.6L, 4cycle-OHC type to verify the effects of the performance and exhaust gas emission according to the variable specifications of both swirl ratio and flow coefficient in inlet port, combustion bowl and fuel injection system. To meet the high BMEP and stringent exhaust emission standard, a turbocharger with wastegate and an intercooler were installed in the engine. Helical port, major design parameters for combustion chamber and electronic fuel injection pump with 1,000bar were reviewed and applied. Confirmation tests were also performed to meet the target value, NOx 5.0g/kWh and PM 0.1g/kWh of Euro3 exhaust emission legislation. The results of this study show that not only is it effective to use a relatively bigger bowl size for controlling rapid burning condition due to the decreased in-bowl swirl, but also to use a concave cam with double injection rates to decrease NOx.

Study on Bead-based Microbiochip and Analytical System for Protein Detection

  • Kim, Min-Soo;Chung, Woo-Jae;Cho, Su-Hyung;Park, Sung-Soo;Kim, Byung-Gee;Lee, Young-Sik;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 2002.11a
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    • pp.60-63
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    • 2002
  • This paper presents bead-based microbiocihps to detect and separate target proteins. Micro beads coated with capture proteins were introduced into a microchamber, and target proteins flowing across the chamber were bound and concentrated. The chip was connected with an external fluid system. Bead surfaces were double-coated with photo-cleavable linkers and capture proteins. The proteins bound on the beads were photo-separated under UV irradiation, and excited to be measured in fluorescence. 3850μm sized polystyrene beads were used. SOGs(silicon-on-glass) were used to fabricate the microchip having glasses bonded on both sides. 100 μm thick silicon channel was formed through silicon deep RIE process. The upper glass cover had holed through to have inlets and outlets fabricated by powder-blastings. In this study, biotin and streptavidin were used as capture proteins and detection proteins, respectively. The protein mixtures of streptavidin, HSA(human serum albumin) and ovalbumin were applied for selective detection test.

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Surgical Treatment of Ruptured Sinus of Valsalva Aneurysm (발살바동 동맥류 파열의 외과적 치료 - 10례 보고 -)

  • 김우찬;윤정섭;김치경;조규도;왕영필;곽문섭
    • Journal of Chest Surgery
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    • v.29 no.11
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    • pp.1207-1211
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    • 1996
  • During the recent 10 years, ten patients with ruptured sinus of Valsalva were operated on our institute. Eight patients were congenital but two patients were proved acquired lesions due to bacterial endocarditis. Coexistent cardiac lesions were 4 aortic regurgitations, 2 atrial septal defects, 1 ventricular septal defect, 1 tricuspid regurgitation and 1 mitral regurgitation. In all cases, aneurysms of sinus of Valsalva arose from the right coronary sinus, and they ruptured to right ventricle in 8 patients and to right atrium in 2 patients. We preferred double approach, through both the aorta and the involver. cardiac chamber, The repair of ruptured site was performed Dacron patch graft in 8 patients and simple closure in 2 patients. Operative results were very good in all cases with no surgical mortality.

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A Case of Alagille Syndrome (Alagille 증후군 1례)

  • Kim, Eun-Soo;Lee, Dong-Woo;Chung, Ki-Sup;Kim, Soon-Il;Park, Young-Nyun
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.5 no.2
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    • pp.192-198
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    • 2002
  • Alagille syndrome is characterized by paucity of interlobular bile ducts, chronic cholestasis, characteristic facial abnormalities, cardiovascular abnormalities, posterior embryotoxon, vertebral arch defects, skeletal abnormalities, and glomerular renal involvement. We experienced a case of Alagille syndrome in a 10 month-old male presenting with jaundice. He had chronic cholestasis, characteristic face, cardiovascular abnormalities (aortic stenosis, dextrocardia, double chamber of left ventricle), and situs inversus. Histological examination of liver biopsy specimen revealed paucity of interlobular bile ducts with septal fibrosis, cirrhotic transformation and severe cholestasis. He underwent liver transplantation, but died of cardiopulmonary arrest associated with cardiac anomaly.

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Characteristics of the Inlet with the Pressure Perturbation in the Ramjet Engine

  • Shin, Dong-Shin;Kang, Ho-Chul
    • Journal of Mechanical Science and Technology
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    • v.20 no.2
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    • pp.286-294
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    • 2006
  • Flows in a ramjet inlet is simulated for the study of the rocket-ramjet transition. The flow is unsteady, two-dimensional axisymmetric, compressible and turbulent. Double time marching method is used for the unsteady calculation and HLLC method is used as a higher order MUSCL method. As for turbulent calculation, κω SST model is used for more accurate viscous calculations. Sinusoidal pressure perturbation is given at the exit and the flow fields at the inlet is studied. The cruise condition as well as the ground test condition are considered. The pressure level for the ground test condition is relatively low and the effect of the pressure perturbation at the combustion chamber is small. The normal shock at the cruise condition is very sensitive to the pressure perturbation and can be easily detached from the cowl when the exit pressure is relatively high. The sudden decrease in the mass flux is observed when the inlet flow becomes subcritical, which can make the inlet incapable. The amplitude of travelling pressure waves becomes larger as the downstream pressure increases, and the wavelength becomes shorter as Mach number increases. The phase difference of the travelling perturbed pressure wave in space is 180 degree.

Study on Combustion Stability and Flame Structure of Injectors Through Subscale Combustion Tests (모델 연소시험을 통한 분사기 연소안정성과 화염구조에 대한 연구)

  • Song Ju-Young;Lee Kwang-Jin;Seo Seonghyeon;Han Yeoung-Min;Seol Woo-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.10a
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    • pp.245-250
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    • 2004
  • The objective of the present study is to conduct model combustion tests for various injectors to identify their combustion stability characteristics. Three different double swirl coaxial injectors with variation of a recess number have been tested for the comparative study of stability characteristic and flame structure. Gaseous oxygen and mixture of gaseous methane and propane have been employed for simulating actual propellants used for a fullscale thrust chamber. Upon test results, the direct comparison between various types of injectors can be realized for the selection of the best design among prospective injectors.

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Effects of Barley Straw Management Practices on Greenhouse Gases(GHGs) Emission During Rice Cultivation in Rice-barley Double Cropping System (벼보리 이모작 재배에서 보리짚 처리 방법이 벼재배시 온실가스 배출에 미치는 영향)

  • Ko, Jee-Yeon;Lee, Jae-Saeng;Jung, Ki-yul;Choi, Young-Dae;Ramos, Edwin P;Yun, Eul-Soo;Kang, Hwang-Won;Park, Seong-Tae
    • Korean Journal of Soil Science and Fertilizer
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    • v.41 no.1
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    • pp.65-73
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    • 2008
  • Because main barley straw management is changing these days from off-fields to burning that may relate to air quality concerning the global warming, this study was conducted to investigate the effects of barley-straw management practices on greenhouse gas emissions during rice cultivation in rice-barley double cropping system. The treatments were barley straw burning, off-field usage of barley straw and incorporation of barley straw in paddy fields. Laboratory experiment showed that burning of barley straw at the rate of 4.5Mgha1 emitted GHGs in the amounts of 4,607, 19.5, and 0.9kgha1 of CO2, CH4, and N2O, respectively. During the rice cultivation of the rice-barley double cropping system, the highest GHG emission by evaluated close-static chamber method was observed from the soil incorporation of barley straw with 387 and 1.0kgha1 of CH4 and N2O, respectively. The GHGs emissions from the barley straw burning and off-field usage treatments were 233 and 160kgha1 for CH4 and 0.80 and 0.79kgha1 for N2O, respectively. The barley straw burning treatment showed the greatest GHGs emission among barley straw management practices in rice-barley double cropping system when considering GHGs emissions both during burning and from paddy fields during the cropping seasons. As a result, the GHGs emissions recorded in the barley straw incorporation to soil and off-field usage treatments were 22.4 and 66.8%, respectively, less than sum of GHGs emissions from the burning of barley straw and from paddy fields during rice cultivation.

A Prediction Model for Removal of Non-point Source Pollutant Considering Clogging Effect of Sand Filter Layers for Rainwater Recycling (빗물 재활용을 위한 모래 정화층의 폐색특성을 고려한 비점오염원 제거 예측 모델 연구)

  • Ahn, Jaeyoon;Lee, Dongseop;Han, Shinin;Jung, Youngwook;Choi, Hangseok
    • Journal of the Korean Geotechnical Society
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    • v.30 no.6
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    • pp.23-39
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    • 2014
  • An artificial rainwater reservoir installed in urban areas for recycling rainwater is an eco-friendly facility for reducing storm water effluence. However, in order to recycle the rainwater directly, the artificial rainwater reservoir requires an auxiliary system that can remove non-point source pollutants included in the initial rainfall of urban area. Therefore, the conventional soil filtration technology is adopted to capture non-point source pollutants in an economical and efficient way in the purification system of artificial rainwater reservoirs. In order to satisfy such a demand, clogging characteristics of the sand filter layers with different grain-size distributions were studied with real non-point source pollutants. For this, a series of lab-scale chamber tests were conducted to make a prediction model for removal of non-point source pollutants, based on the clogging theory. The laboratory chamber experiments were carried out by permeating two types of artificially contaminated water through five different types of sand filter layers with different grain-size distributions. The two artificial contaminated waters were made by fine marine-clay particles and real non-point source pollutants collected from motorcar roads of Seoul, Korea. In the laboratory chamber experiments, the concentrations of the artificial contaminated water were measured in terms of TSS (Total Suspended Solids) and COD (Chemical Oxygen Demand) and compared with each other to evaluate the performance of sand filter layers. In addition, the accumulated weight of pollutant particles clogged in the sand filter layers was estimated. This paper suggests a prediction model for removal of non-point source pollutants with theoretical consideration of the physical characteristics such as the grain-size distribution and composition, and change in the hydraulic conductivity and porosity of sand filter layers. The lumped parameter θ related with the clogging property was estimated by comparing the accumulated weight of pollutant particles obtained from the laboratory chamber experiments and calculated from the prediction model based on the clogging theory. It is found that the lumped parameter θ has a significant influence on the amount of the pollutant particles clogged in the pores of sand filter layers. In conclusion, according to the clogging prediction model, a double-sand-filter layer consisting of two separate layers: the upper sand-filter layer with the effective particle size of 1.49 mm and the lower sand-filter layer with the effective particle size of 0.93 mm, is proposed as the optimum system for removing non-point source pollutants in the field-sized artificial rainwater reservoir.

Commercialization of Ion Exchange Fiber System for Recovering Valuable Metals in Plating Wastewater (도금 폐수 중 유가 금속 회수를 위한 이온교환섬유의 상용화기술)

  • You, Seong-sik
    • Korean Chemical Engineering Research
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    • v.55 no.4
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    • pp.535-541
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    • 2017
  • On the basis of 200 ppm of Ag and 120 l/h of feed flow rate, we built a pilot plant of an ion exchange fiber system having an double tube type ion exchange chamber with strong base ion exchange fiber (FIVAN A-6) which was designed to replace fibers easily and to eliminate the need for a fixture. The following results were obtained for the double tube type of ion exchange fiber system with an ion exchange capacity of 4.6 meq/g for Ag. The adsorption process was operated in the range of 40~90 l/h after confirming the effect of the flow rate and, pH did not affect formation of complex ion of Ag in the range of pH 7~12. In the case of backwash process, the recovery rate of Ag was tested in the range of 60~120 l/h and comparative experiments were carried out using NaOH, NH4Cl, and NaCl as the chemicals for backwash. Although the desorption time was shortened at higher concentration, the desorption efficiency per mol was lowered. Therefore, it was confirmed that the desorption time and the concentration should be well balanced to operate economically. The desorption pattern of the backwash process is slower than the adsorption process and takes a lot of time. The results showed that the Ag adsorption ratio was 99.5% or more and the Ag recovery ratio was 96% or more, and commercialization was possible.