• 약학회지
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• 제31권5호
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• pp.308-314
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• 1987

In cardiovascular disease the flow adaptation of erythrocytes can be affected by reduced shear stresses and metabolic influences on red cell fluidity as a consequence of tissue hypoxia. In addition there are indications that risk factors of cardiovascular diseases are able to decrease the intrinsic red cell deformability. Erythrocyte deformability was studied by the filtration technique of Reid et al. to investigate the relationship between blood pressure chances and erythrocyte deformability. In this experiment normotensive rats, spontaneously and DOCA-salt treated hypertensive rats were used. Erythrocyte deformability was significantly reduced by blood pressure elevation in hypertensive rats but was not fully recovered by normalization of blood pressure after antihypertensive drug treatment. Therefore other factors than blood pressure may be involved in erythrocyte deformability reduction during blood pressure elevation.

• Archives of Pharmacal Research
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• 제16권4호
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• pp.295-299
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• 1993

Human renal dipeptidase (RDPase) was purified from surgically removed kdneys of renal stone aptients by affinity chromatography using its specific inhibitor, cilastain, as the ligand. The partial purified RDPase of 6 mg exhivited specific activity of 99.4 unit/mg with 2, 029 fold purification. it was composed of a slow moving major band (96%) and a fast moving minor band (4%). The minor band was not a contaminant as it showed a dipeptidase-specific activity. The kinetic parameters determined with glycyldehydrophenylalanine (Gdp) as synthetic substrate were Vmax, $322.6\;\mu{mol/min/mg}$ and km, 0.120 mM. This experiment provided biochemical evidences that sugically removed, nonfunctional kidneys in respect of glomerular filtration still retained high activity of renal dipeptidase.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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• pp.347-352
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• 2000

Before investigating the performance of NA-Q additive oil, we have studied the properties of the commercial reference oil by using an engine dynamometer. Experimemts were conducted for 300 hours with 2,950rpm and 22kw and every 50 hours the used oil was sampled for analyzing its physical and chemical propreties. The reference oil shows stable but slightly increasing viscosities during the experiment. It has good agreements with the change of its TAN and TBN. Friction coefficients and anti-wear characteristics are compared with its ZDTP depletion factor and the diameters of wear scar. The concentrations of metal particles are analyzed with the results of ICP and spectrometer, However it is found that the concentrations by filtration method shows large difference with those by standard method in spectrometer.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.429-435
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• 2006

In this study multi-zone modeling program CONTAM 2.4 which is developed by NIST is used for modeling the air disinfection system which is consist of dilution, filtration, ultra violet germicidal irradiation (UVGI) for removing the indoor microorganism such as bacteria and fungus. Developed models those protect occupants against indoor microorganism generated in our daily life are enable to use for immune building simulation tool. Also, results indicate that those models are enable to compute the real situation that is almost impossible of carrying out experiment and identify the disinfection rate with highly reliance. Results also suggest that engineers will use these models as a design tool for the immune building system.

• 한국임상수의학회지
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• 제7권2호
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• pp.471-487
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• 1990

Present experiment was performed in order to establish the optimum conditions for quantitation of ${\gamma}$-GTP and AGS activities in rat urine and investigate the applicability of the these enzymes in experimental assessment of nephrotoxicity in rats. The results obtained were as follows. 1. The optimal pH of Tris-BCI buffer containing glycylglycine for determination of urinary ${\gamma}$-GTP activity was 7.6(37$^{\circ}C$). 2. The Michaelis constant of urinary ${\gamma}$-GTP ranged from 1.1 to 1.2 mmol/$\ell$. 3. The optimal pH of citrate buffer for determination of urinary AGS activity was 3.6(37$^{\circ}C$). 4. The Michaelis constant of urinary AGS ranged from 0.8 to 0.9mmo1/$\ell$. 5. Coefficient of variance for within-run imprecision of urinary ${\gamma}$-GTP ranged from 3.8 to 6.4％ and that of urinary AGS ranged from 2.5 to 4.1％. 6. There was no significant difference between gel-filtered samples and crude samples in the mean activity of urinary ${\gamma}$-GTP and the intra-individual differences by gel-filtration were either increased or decreased. Mean values of ${\gamma}$ -GTP activities in gel-filtered samples and crude samples were 1570 and 1590 U/$\ell$, repectively. 7. The mean activity of urinary AGS increased significantly after gel-filtration and all the individual urines revealed higher activities after gel-filtration. 8. ${\gamma}$-GTP and AGS activities were linear to 135 and 7U/$\ell$, respectively. 9. Urinary ${\gamma}$-GTP and AGS excretion before administration of potassium dichromate were 22.1 ${\pm}$ 11.2 and 0.5${\pm}$0.2 U/24hrsㆍkg body weight respectively and increased significantly to 102.3${\pm}$44.5 and 5.8${\pm}$3.30/24hrsㆍkg body weight respectively within 24 hours after administration. 10. BUN increased continuously from 24 hours following exposure to potassium dichromate in all 10 rats. From these findings it is concluded that the urinary ${\gamma}$-GTP and AGS excretions are early and sensitive indicators for nephrotoxicity assessment in rat.

• 자원환경지질
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• 제52권6호
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• pp.595-604
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• 2019

본 연구 목적은 비-가시성 금 정광을 마이크로웨이브-질산용출 시키고, 여과지를 이용하여 금을 단순하게 얻고자 하였다. 본 실험에서 사용된 시료의 경우 질산농도별로 마이크로웨이브-질산용출실험을 수행한 결과 Fe, Te, Ag 등은 완전용출(100%) 되었지만, Au는 용해되지 않았다. 용출용액을 3장의 여과지로 여과하여 SEM/EDS 분석한 결과 첫 번째, 두 번째 및 세 번째 여과지의 표면 및 단면 모두에서 Au가 검출되었다. 고체-잔류물이 포함된 여과지 3장을 모두 납-시금법에 사용한 결과 질산농도 모두에서 금 입자들이 회수되었다. 최대 금 입자(452.50g/t)가 얻어진 용출조건은 질산농도 6M에서 그리고 마이크로웨이브 조사시간 12분에서였다.

• 수산해양기술연구
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• 제47권1호
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• pp.1-9
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• 2011

In order to investigate the cause and magnitude of scale effect occurring in the model experiments of fishing nets, five pairs of Nylon pyramid nets and one pair of PE ones in which all the two nets paired were equal each other in the factors determining their flow resistance, i. e., the ratio d/l of diameter d to length l of bars, the angle f between two adjacent bars, the attack angle q of nettings to the water flow, and the wall area S of nets, and different in the values of d and l were prepared. Then, the nets were attached to the circular steel frame alternately and their flow resistances with shapes in water were measured on the sea ascribing no turbulent flows by using the tension meter made of a block bearing for the experiment. All the Nylon nets were spreads out easily in water to form a circular cone at relatively low velocity of water and showed the resistance smaller a little in the nets with larger d and l than them with smaller d and l, because the filtration of water through meshes become easier in nets especially with larger l. But PE nettings were not spread out sufficiently on account of their small flexibility and showed higher resistance especially in them with thicker twines. Therefore, the difference in bar length or mesh size and flexibility of nettings between prototype and model nets are regarded to become factors ascribing scale effect. Especially the influence of the difference in mesh size may become large significantly in actual model experiments because the mesh size of model nets is decided at much larger value than that given by scale ratio and so the difference of mesh size between the two nets become much larger than that between nets used in this experiment.

• 한국수자원학회논문집
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• 제49권9호
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• pp.741-748
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• 2016

개착식 하상여과에 대해서 실험실 규모의 모형을 구축하고 중사, 왕사, 화산석, 자갈에 대한 단일 여재를 구성하였다. 실험을 통해 투수계수 및 하상 여과에 대한 취수량을 추정하고, 지하수 유동 모델링인 Visual MODFLOW를 통해 탁도 변화에 따라 수정된 투수계수를 적용하고 미치는 영향을 분석하였다. 각 여재마다 22개의 수정 투수계수 시나리오가 적용되었다. 전체 모델링에서 최소 오차는 화산석(2~5 mm)을 여재로 한 경우 상부에서부터 3개 지층에 대해서 20% 감소된 투수계수를 적용한 시나리오다. 이는 화산석의 특성상 탁도를 유발하는 황토가 여재에 흡착되어 상부에서 3번째 지층까지 영향을 미치는 것으로 추정되었다. 또한 입자의 크기가 작은 중사의 경우 5% 감소된 투수계수를 상부에서 두 번째 지층까지 적용한 시나리오에서도 작은 오차 값을 나타냈다.

• 생태와환경
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• 제41권2호
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• pp.237-246
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• 2008

서로 다른 물리-화학적 성격이 다른 저온기 두 부영양수계에서 우점하는 규조류 중심의 현장수에 대한 한국산 말조개(Unio douglasiae)의 섭식특성-여과능 및 배설물 생산을 각각 비교 조사하였다. 두 실험수 모두 패류밀도가 증가할수록 뚜렷한 엽록소 $\alpha$ 감소를 보였으며, 한강시료는 1시간 이후부터, 일감호 시료는 패류 처리와 함께 즉시 감소였다. 한강시료는 고밀도 처리에서 감소율이 높았으며 (약 90%), 일감호시료는 패류밀도 간에 다소 차이는 보였으나 고밀도군에서도 50% 정도 감소하였다. 조류 현존량의 변화경향는 엽록소와 유사하였으며, 시료와 조류종에 따라 차이를 보였다. 패류의 조류여과능은 패류적용 1시간째 시료 간에는 큰 차이를 보였으나 시간이 경과할수록 유사한 수준에 도달하였다. 배설물 생산은 한강시료에서는 밀도간에 차이가 적었으며 일감호의 높은 전도도와 탁도, 낮은 DO 포화도에서는 밀도 간에 100배 이상의 큰 차이를 나타냈다. 특히 일감호에서 고밀도 패류 적용시, 낮은 엽록소(조류)감소 및 높은 배설물 생산 등은 소화가 어려운 고형물의 축적효과가 높아 저온기 동안 탁도가 높은 하천 및 호수의 수질개선에 매우 효과적일 것으로 사료되었다.

• 대한환경공학회지
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• 제22권5호
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• pp.959-970
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• 2000

본 연구는 실험실 규모의 침지형 막분리 활성오니법을 이용하여 생물 대사 성분이 막투과 유속에 미치는 영향에 대해 고찰하였다. SMP와 분리막의 fouling과의 관계를 살펴보기 위해 연속 실험과 회분 실험으로 나누어 운전하였다. 합성 폐수로는 단일 탄소원으로서 phenol을 사용하였다. 생물 반응조의 체류 시간과 MLSS농도는 각각 12hr과 9.000mgVSS/L로 유지하였다. 연속 장치에 있어서 회분 여과 실험을 통해 SMP농도가 증가할수록 막투과 유속은 감소하였고, cake와 gel층이 형성을 증가시켰다. Cake의 저항은 $2.9{\sim}4.0{\times}10^{10}$으로 측정되어 다른 여과 저항보다 막투과 유속의 감소에 중요한 영향을 나타냈다. 회분 페놀 분해 실험에서 SMP종들 중에 $SMP_{nd}$와 $SMP_{e}$가 난분해성 고분자 물질로서 막투과 감소에 중요한 역할을 하였다. 또한, SMP농도는 막투과 유속의 감소에 대한 HRT의 증가로서 생물 반응조 내에 축적되었다.