• 제목/요약/키워드: Clearance rate

검색결과 452건 처리시간 0.03초

Effects of Temperature and Body Size on the Clearance Rate of a Tidal Flat Bivalve, Coecella chinensis (Deshayes)

  • Ryu, Tae-Kwon;Lee, Chang-Hoon;Park, Jin-Woo
    • 한국어업기술학회:학술대회논문집
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    • 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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    • pp.391-392
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    • 2003
  • There were many studies on the dependence of clearance rate on temperature and the body size of bivalves (Winter, 1973; Bayne et al., 1976; Yukihira et al., 1998), Most of these studies dealt with relatively large species, especially commercially important species. Studies with smaller but ecologically important species were relative rare(Werner and Hollibaugh, 1993). (omitted)

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No Effect of Diltiazem on the Hepatic Clearance of Indocyanine Green in the Rats

  • Joo, Eun-Hee;Lee, Yong-Bok
    • Archives of Pharmacal Research
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    • 제21권4호
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    • pp.411-417
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    • 1998
  • In order to investigate the effect of the pretreatment with various doses of diltiazem (DTZ) on the pharmacokinetics of indocyanine green (ICG) at steady state, especially the hepatic blood clearance due to the change of hepatic blood flow, the following experiments were carried out with ICG, a hepatic function test marker, not metabolized in liver and only excreted in bile. The intravenous bolus injection ($3,780\mu\textrm{g}$/kg) and the constant-rate infusion ($10,100\mu\textrm{g}$/kg/hr) of ICG into the left femoral vein were made in order to check the steady-state plasma concentration ($C_{ss} of $10\mu\textrm{g}$/ml) of ICG at 20, 25 and 30 min. Following a 90-min washout period, the intravenous bolus injection (108, 430, 860 and $1,720\mu\textrm{g}$/kg) and the constant-rate infusion (108, 433, 866 and $1,730\mu\textrm{g}$/kg/hr) of DTZ into the right femoral vein were made and the achievement of the steady-state plasma levels ($C_{ss} of 50, 200, 400 and 800 ng/ml) of DTZ were conformed at 60, 70 and 80 min. During the steady state of DTZ, the intravenous bolus injection ($3,780\mu\textrm{g}$/kg) and the constant-rate infusion ($10,200\mu\textrm{g}$/kg/hr) of ICG into the left femoral vein were made and also the steady-state plasma concentration of ICG was checked at 20, 25 and 30 min. The plasma concentrations of DTZ and ICG were determined using a high performance liquid chromatographic technique. At the steady state, the hepatic blood clearance of ICG was obtained from the plasma concentration and blood-to-plasma concentration ratio ($R_B$) of ICG. The pretreatment with various doses of DTZ did not influence the plasma concentrations, $R_B$ and plasma free fraction ($f_p$) of ICG. So the hepatic blood clearance of ICG was independent of concentration of DTZ. The hepatic blood clearance of ICG could be affected by both hepatic bood flow and hepatic intrinsic clearance. But there was no change of the hepatic blood clearance of ICG between the control and the DTZ-pretreated rats in this study. So it may be suggested that DTZ does not influence hepatic blood flow.

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모헤어 개수, 틈새 길이 및 축소된 길이의 창문 기밀성 및 개폐력에 대한 실험적 연구 (Experimental Research of Window Air Tightness and Opening Force with Respect to Mohair Number, Clearance and Shortened Length)

  • 김승재;박종준;김영일
    • 설비공학논문집
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    • 제30권4호
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    • pp.195-203
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    • 2018
  • Mohair is widely used as an airtight material for filling the gap between a window frame and sash. The purpose of this study is to investigate infiltration rate and opening force of sliding windows according to the mohair installation conditions. Infiltration experimental apparatus was set up, and the experimental results were applied to windows to find a correlation between infiltration rates and opening forces. When 4 rows of mohair were installed, the infiltration rate increase became 27.1% per clearance length increase of 1 mm, and the infiltration rate decrease became 5.7% per shortened length increase of 0.1 mm. For 4 rows of mohair, the opening force decreased by 28.2% as the clearance increased by 1 mm, and it increased by 9.3% as the shortened length increased by 0.1 mm.

시메티딘이 설프이소미딘의 약물동태에 미치는 영향 (Effect of Cimetidine Pretreatment on the Pharmacokinetics of Sulfisomidine Administered Intravenously in Rabbits)

  • 이진환;최준식;범진필
    • 약학회지
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    • 제29권6호
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    • pp.362-366
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    • 1985
  • These paper was attempted to investigate the mechanism of increased blood level of sulfisomidine by cimetidine pretreatment pharmacokinetically. Especially, effect of cimetidine pretreatment on both renal clearance and biliary clearance of sulfisomidine was studied in rabbits. The results are as follows. The blood level of sulfisomidine administered intravenously in dose of 25mg/kg was elevated significantly by cimetidine pretreatment. Relative bioavailability and biological half-life were increased significantly by cimetidine pretreatment. Overall elimination rate constant ($betha$) and distribution rate constant ($K_{13}$) of sulfisomidine were decreased significantly by cimetidine pretreatment. The renal and biliary clearance of sulfisomidine were decreased significantly compared with those of control rabbits by cimetidine pretreatment. The results may be also related to the inhibition of sulfisomidine metabolism enzyme activity or reduction of blood flow in the liver.

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핀칼라와 튜브의 간극에 따른 열교환기의 열전달 특성 (Heat Transfer Characteristic of Finned-tube Heat Exchangers with Different Clearance between Fin Collar and Tube Surface)

  • 박영민;정영만;이재근;박내현
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.1073-1078
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    • 2009
  • Finned-tube heat exchangers are often made with aluminum fins and copper tubes. Usually the contact between fin collar and tube surface for finned tube heat exchanger is secured by mechanical expansion of the tubes. The objective of the present study is to apprehend how much effect clearance has on the performance of heat exchanger. This effect is studied using an experimental approach. The thermal fluid measurements are made using a psychometric calorimeter. Frontal air velocity varies in the range from 1.0m/s to 3.0 m/s. The heat transfer rate of sample which has bigger clearance is only 27% compare with the other's in dry condition. In wet condition, its heat transfer rate is 78% compare with the other's.

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Effect of 2-Methylaminoethyl-4,4'-Dimethoxy-5, 6, 5' ,6'-Dimethyl­enedioxybiphenyl-2-Carboxylic Acid-2'-Carboxylate Monohydro­chloride (DDB-S) on Indocyanine Green (ICG) Clearance in Rats

  • Lee Kyoung-Jin;Kim Jae-Ryung;Lee Chi-Ho
    • Archives of Pharmacal Research
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    • 제28권1호
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    • pp.115-119
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    • 2005
  • The clearance of ICG, a known hepatic blood flow marker was investigated in rats in order to examine whether DDB-S influences hepatic blood flow. The effect of DDB-S on the protein binding and blood-to-plasma partition of ICG was measured. The steady-state plasma concentration of ICG was monitored before and after co-administration of various concentration of DDB-S, and ICG clearance was estimated from the steady-state concentration and the infusion rate of ICG. There was no significant difference in protein binding and blood-to-plasma partition of ICG with and without addition of DDB-S (10, 20, and 40 ${\mu}g/mL)$. When ICG was infused into DDB-S pretreated rats, the steady-state concentrations of ICG decreased and the calculated ICG clearance increased. However, no dose-dependency of ICG Css on DDB-S Css was observed. Since DDB-S did not affect the protein binding and blood-to-plasma partition of ICG, the increased clearance of ICG with co-administration of DDB-S seems to be due to the increased hepatic blood flow by DDB-S.

Thickness and clearance visualization based on distance field of 3D objects

  • Inui, Masatomo;Umezun, Nobuyuki;Wakasaki, Kazuma;Sato, Shunsuke
    • Journal of Computational Design and Engineering
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    • 제2권3호
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    • pp.183-194
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    • 2015
  • This paper proposes a novel method for visualizing the thickness and clearance of 3D objects in a polyhedral representation. The proposed method uses the distance field of the objects in the visualization. A parallel algorithm is developed for constructing the distance field of polyhedral objects using the GPU. The distance between a voxel and the surface polygons of the model is computed many times in the distance field construction. Similar sets of polygons are usually selected as close polygons for close voxels. By using this spatial coherence, a parallel algorithm is designed to compute the distances between a cluster of close voxels and the polygons selected by the culling operation so that the fast shared memory mechanism of the GPU can be fully utilized. The thickness/clearance of the objects is visualized by distributing points on the visible surfaces of the objects and painting them with a unique color corresponding to the thickness/clearance values at those points. A modified ray casting method is developed for computing the thickness/clearance using the distance field of the objects. A system based on these algorithms can compute the distance field of complex objects within a few minutes for most cases. After the distance field construction, thickness/clearance visualization at a near interactive rate is achieved.

사판식 액시얼 피스톤 펌프의 가변용량 시스템의 특성에 관한 연구 (A Study on Characteristics of a Compensator System for Swash Plate Type Axial Piston Pump)

  • 김신;오석형;정재연
    • Tribology and Lubricants
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    • 제14권4호
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    • pp.15-22
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    • 1998
  • Recently, the importance of variable displacement piston pump is increasing in industrial world. Especially, most consumers require various range of pressures and flow rates. Pressure compensator is a system controlling flow rate in piston pump at low cost and, therefore, satisfies the need of consumers. However, the system has serious problems, such as response and leakage. The response and leakage are affected by clearance between actuator piston and cylinder, roughness of surface, and spool overlap. In this paper, these effects are investigated experimentally, and optimal clearance and chamfer is obtained. While diameter of cylinder is fixed and diameter of actuator piston is changed in this experiment, response and leakage are measured. Also parameters such as roughness and processing accuracy are changed for piston of fixed clearance. Experimental setup modelled into several parts of actuator piston, cylinder, spool, and swash plate. Input pressure is changed by function generator and proportional valve. The result of this experiment shows that leakage increases very much in proportion to the increase of clearance, and especially leakage occurs enormously when clearance is more than 0.002. The response is not good because as clearance increases leakage increases and as clearance decreases viscous damping effect increases. Accordingly, it is found out that optimal clearance range exists for tile response, within about 0.0012∼0.0014, at this time. Futhermore, the better roughness and geometrical accuracy of actuator piston are, the smaller are leakage and friction. The paper informs that response and leakage are influenced by and geometrical accuracy of actuator piston, roughness of surface, and the clearance between actuator piston and cylinder, and that optimal design of actuator piston in the pressure compensator is possible.

The Effect of Energy Supplementation on Intake and Utilisation Efficiency of Urea-treated Low-quality Roughage in Sheep II. Rumen Kinetics and Acetate Clearance Rate

  • Migwi, P.K.;Godwin, I.;Nolan, J.V.
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권6호
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    • pp.774-780
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    • 2011
  • Inadequate supply of glucose or glucogenic substrates to the body tissues can affect metabolism of absorbed acetogenic metabolites from the gut and therefore, influence feed intake in ruminants. This study investigated the effect of energy supplementation on rumen kinetics in the gut, and the acetate clearance rate in the body tissues of sheep fed low quality basal roughage. A basal diet consisting of urea-treated mixture of wheaten chaff and barley straw (3:1 DM) containing 22.2 g N/kg DM was used. Four Merino cross wethers weighing $45{\pm}4.38\;kg$ fitted with permanent rumen and abomasal cannulae were allocated to four treatments in a $4{\times}4$ LSD. The treatments were basal diet ($E_0$), or basal diet supplemented with sucrose (112.5 g/d) administered intraruminally ($E_R$), abomasally ($E_A$), or via both routes (50:50) ($E_{RA}$). There was no difference (p>0.05) in the rumen liquid kinetics parameters between the four dietary treatments. However, there was a trend of animals supplemented with sucrose wholly or partly through the abomasum having lower faecal DM and therefore poor pellet formation, and low pH. Although the glucogenic potential of the fermentation products absorbed from the rumen was increased (p<0.001) by intra-ruminal supplementation with sucrose ($E_R$ and $E_{RA}$), there was no significant difference (p<0.05) in acetate clearance rate between the four dietary treatments.