• Title/Summary/Keyword: Effective Flow Area

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Lymphatic Delivery of Oral Anticancer Tegafur by Emulsion Formulations

  • Lee, Yong-Bok;Koh, Ik-Bae
    • Journal of Pharmaceutical Investigation
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    • v.23 no.3
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    • pp.19-30
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    • 1993
  • The influence of emulsion type of tegafur, an oral anticancer agent, on lymphatic transport was studied in rats. The water-in-oil-type of emulsion and the oil-in-water-type emulsion of tegafur each in 50 mg, calculated in terms of tegafur, were prepared by adding tegafur aqueous solution to sesame oil containing hydrogenated castor oil following ultrasonic treatment, and then the prepared emulsions and aqueous solution as a comparative formulation were administered orally to rats (50 mg/5 ml/kg). The concentration levels of tegafur in plasma of femoral artery and lymph from thoracic duct cannula were measured simultaneously along a time course after administration and the pharmacokinetic parameters were investigated. At the same time, we examined the above described factors of 5-FU which is known as an active metabolite of tegafur. In comparison with tegafur solution, AUC and mean residence time of plasma tegafur were significantly increased in w/o-emulsion but significantly decreased in o/w-emulsion. Lymph flow rates were similar in both solution and w/o-emulsion but half in o/w-emulsion. Ratios between area under the lymph and plasma concentration time curves were always less than 1 reflecting the passive lymphatic delivery after oral administration of the prepared tegafur emulsions, but those to the 5-FU in the case of w/o-emulsion were more than 1. These results suggested that lymphatic delivery of tegafur by w/o-emulsion was more effective than that by o/w-emulsion due to its differences of formation ability of chylomicrons.

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Effect of building volume and opening size on fluctuating internal pressures

  • Ginger, John D.;Holmes, John D.;Kopp, Gregory A.
    • Wind and Structures
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    • v.11 no.5
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    • pp.361-376
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    • 2008
  • This paper considers internal pressure fluctuations for a range of building volumes and dominant wall opening areas. The study recognizes that the air flow in and out of the dominant opening in the envelope generates Helmholtz resonance, which can amplify the internal pressure fluctuations compared to the external pressure, at the opening. Numerical methods were used to estimate fluctuating standard deviation and peak (i.e. design) internal pressures from full-scale measured external pressures. The ratios of standard deviation and peak internal pressures to the external pressures at a dominant windward wall opening of area, AW are presented in terms of the non-dimensional opening size to volume parameter, $S^*=(a_s/\bar{U}_h)^2(A_W^{3/2}/V_{Ie})$ where $a_s$ is the speed of sound, $\bar{U}_h$ is the mean wind speed at the top of the building and $V_{Ie}$ is the effective internal volume. The standard deviation of internal pressure exceeds the external pressures at the opening, for $S^*$ greater than about 0.75, showing increasing amplification with increasing $S^*$. The peak internal pressure can be expected to exceed the peak external pressure at the opening by 10% to 50%, for $S^*$ greater than about 5. A dominant leeward wall opening also produces similar fluctuating internal pressure characteristics.

Bio-filters for the Treatment of VOCs and Odors - A Review

  • Vikrant, Kumar;Kim, Ki-Hyun;Szulejko, Jan E.;Pandey, Sudhir Kumar;Singh, R.S.;Giri, B.S.;Brown, Richard J.C.;Lee, S.H.
    • Asian Journal of Atmospheric Environment
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    • v.11 no.3
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    • pp.139-152
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    • 2017
  • Excessive amounts of volatile organic compounds (VOCs) and odorants discharged into the environment are highly dangerous to human health as well as to ecological systems. Biological treatments of waste gas streams, called biofiltration, containing VOCs and odorous compounds has gained much attention because biofilters are more cost effective and environmentally friendly than conventional air pollution control technologies. This review provides an overview of biotrickling filtration, which is a type of biofiltration including continuous trickled-water flow inside filter media, for VOC and odor abatement. The configuration, design, cost effectiveness, removal capacity and environmental impact of this techniques and the future research and development needs in this area are all considered.

Analysis of Spatial Structures and Central Places of Gwangju and Jeonnam Region using Social Network Analysis (사회네트워크 분석을 이용한 광주 전남지역의 공간 구조 변화 및 중심지 분석)

  • Lee, Jimin
    • Journal of Korean Society of Rural Planning
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    • v.23 no.2
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    • pp.43-54
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    • 2017
  • When an age of low growth and population decline, population migration plays an important role in spatial structure of region. There have been many researches on migration and regional spatial structure. The purpose of this study is to examine the changes of Gwangju and Jeonnam region's spatial structure and central area using social network analysis methods. For analysis it was used that population and migration data and passenger OD(Origin and Destination) travel data released by Statistics Korea and Korea Transport Database(KTDB). Using Gephi 0.8.2, migration and passenger OD networks were visualized, and this describe network flow and density. The results of the network centrality analysis show that the most populated village is not always network center though population mass is an important factor of central places. The average eigenvector centrality of 2010 migration is the lowest during 2005-2015, and it means few regions have high centralities. When comparing migration and travel networks, travel data is more effective than migration data in determining the central location considering spatial functions.

A STUDY ON THERMAL ANALYSIS OF HORIZONTAL FILLET JOINTS BY CONSIDERING BEAD SHAPE IN GMA WELDING

  • Cho, Si-Hoon;Kim, Jae-Woong
    • Proceedings of the KWS Conference
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    • 2002.10a
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    • pp.151-155
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    • 2002
  • In GMA(Gas Metal Arc)Welding, the weld size that is a locally melted area of a workpiece is one of the most important considerations in determining the strength of a welded structure. Variations in the weld power and the welding heat flux may affect the weld pool formation and ultimately the size of the weld. Therefore, an accurate prediction of the weld size requires a precise analysis of the weld thermal cycle. In this study, a model which can estimate the weld bead geometry and a method for thermal analysis, including the model, are suggested. In order to analyze the weld bead geometry, a mathematical model was developed with transformed coordinates to apply to the horizontal fillet joints. A heat flow analysis was performed with a two dimensional finite element model that was adopted for computing the base metal melting zone. The reliability of the proposed model and the thermal analysis was evaluated through experiments, and the results showed that the proposed model was very effective for predicting the weld bead shape and good correspondence in melting zone of the base metal.

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Noninvasive assessment of pressure gradients across prosthetic heart valve by doppler ultrasound -A comparative studyof the duromedics bileaflet valves in mitral position and normal mitral valves- (도플러 초음파를 이용한 인공판막 상하의 압력차 측정에 관한 연구 -승모판막 치환에 사용한 Duromedics 인공판막과 정사인의 승모판막과의 비교연구-)

  • Jin, Seong-Hun;Seo, Gyeong-Pil
    • Journal of Chest Surgery
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    • v.20 no.2
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    • pp.223-229
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    • 1987
  • Doppler echocardiography provides valuable information regarding prosthetic heart valve function rather than structure. There are three methods of expressing the severity of mitral valve obstruction: the transvalvular pressure gradient, effective valve area, and pressure half-time. Of these, the transvalvular pressure gradient [~p] can be determined by the measurement of maximum transvalvular blood flow velocity [V] according to the modified Bernoulli`s equation [gp=4V*]. Eleven patients, who underwent mitral valve replacement with Duromedics mechanical prostheses, and 17 normal persons were investigated. There were significantly higher calculated pressure gradients in prosthetic than normal mitral valves [9.*10*2.22mmHg-vs-3.26*0.99mmHg:p<0,01], and there was a inverse relationship between pressure gradient and prosthetic valve size [11.17*0.%mmHg in size 27mm and 29mm -v- 7.38*1.12mmHg in size 31mm and 33mm; r=0.85, p<0.01] The noninvasive Doppler technique should be useful in the diagnosis of prosthetic valve obstruction.

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Adsorption of volatile organic compounds using activated carbon fiber filter in the automobiles

  • Moon, Hyung Suk;Kim, In Soo;Kang, Sin Jae;Ryu, Seung Kon
    • Carbon letters
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    • v.15 no.3
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    • pp.203-209
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    • 2014
  • The adsorption of volatile organic compounds (VOCs) was carried out using an activated carbon fiber (ACF) filter in an automobile. The adsorption capacities of formaldehyde, toluene, and benzene on an ACF filter were far better than those of a polypropylene (PP) mat filter and combined (PP+activated carbon) mat filter by batch adsorption in a gas bag. In a continuous flow of air containing toluene vapor through an ACF packed bed, the breakpoint time was very long, the length of the unused bed was short, and sharp "S" -type breakthrough curve was plotted soon after breakpoint, showing a narrow mass transfer zone of toluene on the ACF. The adsorption amount of toluene on the ACF filter was proportional to the specific surface area of the ACF; however, the development of mesopores 2-5 nm in size on the ACF was very effective with regard to the adsorption of toluene. The ACF air clarifier filter is strongly recommended to remove VOCs in newly produced automobiles.

Pressure Drop in a Circular Pipe of Waste Collection Piping System (쓰레기 관로 이송 시스템의 관로 압력강하 평가)

  • Jang, Choon-Man;Lee, Sang-Yun;Suh, Sang-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.10 no.4
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    • pp.55-60
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    • 2007
  • This paper describes an evaluation method of pressure drop in a circular pipe of waste collection piping system. Accurate pressure drop in a piping system is very important to determine the capacity of turbo blower, which is one of the main elements in the system. Three-dimensional Navier-Stokes analysis is introduced to analyze the pressure drop in the piping system. Organic waste is selected and modeled using the result of site survey performed in an apartment area. Evaluation method of pressure drop used In the present numerical simulation is performed in the shortened pipe line prior to the calculation of the real system. Throughout the numerical simulation, pressure drop in a waste pipe is obtained and compared to the value determined by analytical method. The pressure drop obtained by numerical simulation has a good agreement with that of the analytic method. It is noted that present evaluation method is effective to determine a pressure drop in the piping system. Detailed flow characteristics inside the pipe line are also analyzed and discussed.

In-Service Identification of the Heterogeneous Zone in Petrochemical Pipelines by Using Sealed Gamma-Ray Sources $(^{60}Co,\;^{137}Cs)$

  • Kim, Jin-Seop;Jung, Sung-Hee;Kim, Jong-Bum
    • Journal of the Korean Society for Nondestructive Testing
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    • v.26 no.3
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    • pp.169-173
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    • 2006
  • In-service diagnoses of pipeline facilities are important for a systematic maintenance of them. Field applications by using sealed gamma-ray sources $(^{60}Co,\;^{137}Cs)$ were performed to identify the heterogeneous zone in the pipelines of a distillation tower and a flare stack respectively. From the results, the heterogeneous zones in the pipelines were successfully identified. In the case of the pipeline connected to the distillation tower, a vapor pocket was detected in the fluid under hydrodynamic conditions, which could explain the reason for a decrease of the flow rate. In another case, an area with some amount of catalyst deposits was found at the bottom of the gas pipeline which was connected to the flare stack. And these findings provided important information for the process operators. Diagnosis technique by using gamma radiation sources has been proven to be an effective and reliable method for providing information on a media distribution in a facility.

A Study on Cargo Handling Accident Analysis and Prevention for irregular employee in Incheon Port (인천항 비상용 근로자의 재해분석 및 예방대책에 관한 연구)

  • Nam, Young-Woo;Jho, Yong-Chul;Lee, Chang-Ho
    • Journal of the Korea Safety Management & Science
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    • v.11 no.2
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    • pp.1-8
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    • 2009
  • The port, differently from general working place, is a closed area to execute security, customs, and quarantine procedures. The loading and unloading is being done differently by cargoes, ships, berths, and equipments. To load and unload a lot of equipments and different types of labor are required, in which work flow is very complicated. As above mentioned the port is very unique and deteriorated working place including danger. Now frequency of cargo handling accidents in port is highest for the second time among all industries. The purpose of this study is to propose ways to analyze and establish the preventive measure for cargo handling accidents in port. We have collected 45 accidents happened at Incheon Port during the period from 2007 to 2009. And the result of analysis, we proposed the new safety management system and safety education to reduce cargo handling accidents and to promote the quality of cargo handling in Incheon Port. Within the framework of effective safety management of cargo handling in port, this study will help to revise and establish system, education, and standard working manual with respect to the port loading and unloading system.