• 한국패류학회지
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• 제13권2호
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• pp.203-210
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• 1997

As a prioiminary study on usage of metabolic charateristics of the indicator species for indirect estimation of environmental water quality, effects of environmental pollutants on survival, filtration and oxygen consumption rates in Corbicula aeana were investigated at 17$^{\circ}C$ and $25^{\circ}C$ in 10 day afrer treatmint of pollutants. In case of glucose and complex fertilizer, the survival rates of the clams were 100% without any relation to individual sizes and water temperatures. In small sizes at $25^{\circ}C$, the survival rates of the clams by NH$_{4}$CI concentration were shown 95% at 10 mg/1 and 15mg/1, and 90% at 20mg/1, respectively. But the survival rate was 95%at 20 mg/1 of NH$_{4}$CI concentration in small size at 17$^{\circ}C$. The higher filtration and oxygin consumption rates were shown in small size at higher water timperatures(over $25^{\circ}C$), and generally filtration and oxygen consumption rates decreased with increase of glucose, complex fertilizer and NH$_{4}$CI concentrations, respectively. In general, effects of filtration and oxygen consumption rates at NH$_{4}$CI concentrations were shown slightly larger than those of glucose and complex fertilizer.

• Clinical and Experimental Pediatrics
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• 제48권6호
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• pp.614-618
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• 2005

목 적 : Cystatin C는 최근 사구체 여과율의 정확한 지표로 제시되고 있다. 본 연구에서는 소아 및 청소년에서 연령에 따른 혈청 cystatin C 농도의 변화, 혈청 cystatin C 농도의 정상 범위, 혈청 cystatin C 농도와 사구체 여과율의 연관성을 분석하여 소아 및 청소년에서 사구체 여과율의 지표로서 혈청 cystatin C 농도의 유용성을 알아보고자 하였다. 방 법 : 2004년 5월부터 7월까지 중앙대학교 용산병원을 방문하여 혈액 검사를 시행받은 환아들 중에서 신질환의 증거가 없는 276명의 환아들을 대상으로 혈청 cystatin C와 creatinine을 측정하였고, 사구체 여과율은 Schwartz's formula로 추정하였다. 결 과 : 1) 혈청 cystatin C 농도는 1세 이상보다 1세 미만에서 유의하게 높았다. 2) 혈청 cystatin C 농도는 1세 미만에서 연령과 음의 상관관계를 보였으나, 1세 이상에서는 유의한 상관관계를 보이지 않았다. 3) 1세 이상에서 혈청 cystatin C 농도의 정상 범위는 0.46-1.05 mg/L였다. 4) 1/cystatin C은 Schwartz's formula로 추정된 사구체 여과율과 양의 상관관계를 보였다. 결 론 : Cystatin C는 소아 및 청소년에서 사구체 여과율의 지표로 유용하게 사용될 수 있을 것으로 생각된다.

• 한국환경보건학회지
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• 제23권4호
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• pp.57-66
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• 1997

Successful energy conservation and good indcfor air quality (IAQ) are highly dependent on ventilation system. Air filtration is a primary solution of indoor air control strategies in terms of reducing energy consumption and improving ihdoor air quality. A conventional system with bypass filter, as it is called variable-air-volume/bypass filtration system (VAV/BPFS), is a variation of the conventional variable air volume (VAV) systems, which is designed to eliminate indoor air pollutant and to save energy. Bypass filtration system equipped with a high-efficiency particulate filter and carbon absorbent provides additional cleaned air into indoor environments and maintain good IAQ for human health. The objectives of this research were to compare the relative total decay rate of indoor air pollutant concentrations, and to develop a mathematical model simulating the performance of VAV/BPFS. All experiments were performed in chamber under the controlled conditions. The specific conclusions of this research are: 1. The VAV/BPFS system is more efficient than the VAV system in removing indoor air pollutant concentration. The total decay rates of aerosol, and total volatile organic compound (TVOC) for the VAV/BPFS system were higher than those of the conventional VAV system. 2. IAQ model predictions of each pollutant agree closely with the measured values. 3. According to IAQ model evaluation, reduction of outdoor supply air results in decreased dilution removal rate and on increased bypass filtration removal rate with the VAV/BPFS. As a results, we recommends the VAV/BPFS as an alternative to conventional VAV systems.

• 약학회지
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• 제22권3호
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• pp.138-147
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• 1978

Bethanidine, which is known as a sympathetic blocking agent, was injected into the vein of a dog in an attempt to investigate the influence on renal funciton. Bethanidine resulted in an increased urine flow and glomerular filtration rate, and it produced an increase of urinary sodium and potassium excretion and a decrease of reabsorption rate of sodium and potassium in renal tubules, whereas renal plasma flow showed no significant changes. After pretreatment of phentolamine, a specific alpha adrenergic blocking agent, bethanidine did not significantly increase glomerular filtration rate and diuresis, significantly increased urinary sodium and potassium excretion although the magnitudes were reduced when compared with that of bethanidine alone. In conclusion, bethanidine-induced diuresis appears to be the result of an inhibited tubuler reabsorpting of electrolytes within the kidney through its sympathetic blockade of renal nerves and of an increased glomerular filtration rate, which was caused by the constriction of vas efferense in the glomeruli.

• 상하수도학회지
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• 제33권1호
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• pp.79-86
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• 2019

In order to measure the filtration characteristics of a cotton ball shape filter, the experiments of suspended solids(SS) surrogate material selection and filtration performance have been carried out in this study. Between the two materials of powdered activated carbon(PAC) and powdered red-clay, PAC is more suitable surrogate material in terms of experimental criteria and particle size distribution in the non-point source pollutants removal system. As a result of the filtration experiments with the cotton ball shape filter, the initial headloss was about 8 cm, and the headloss slightly increased over filtration time. The Kozeny-Carman equation was used to analyze the changes of pressure and porosity during the filtration. The initial porosity was calculated as 0.945 and it decreased to 0.936 at the end of design filtration time. As the filtration continued, the SS concentration of the filtered water gradually increased and the SS removal rate gradually decreased. When the SS target removal efficiency is assumed to be 80%, the cumulative SS removal capacity is expected as $28.8kg/m^2$. This means the volume loading rate of the cotton ball shape filter can be $115m^3/m^2$ when the typical SS concentration of non-point source water pollution is assumed as 250 mg/L.

• 상하수도학회지
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• 제24권2호
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• pp.231-236
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• 2010

A compressible media filtration process with synthetic fiber media was studied for combined sewer overflows (CSOs) treatment. Since the operation performance of fiber media filtration was dependent on the pattern of CSOs, the flow rate of CSOs was investigated and it was characterized by a big fluctuation. Thus, in this study, the fiber media filtration process was tested with wide range of filtration velocity. The removal efficiency was proportion to the increase in compressibility. As the filtration velocity was increased, the treatment efficiency was decreased and consequently leveled off when the velocity exceeded 750 $m^3/m^2$/d. An exponential equation was introduced to express the relationship between the removal efficiency and up-flow velocity. At columm test, six repetition of filtration and backwash cycle did not after the filtering velocity under the constant pressure condition.

• 상하수도학회지
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• 제31권6호
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• pp.501-510
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• 2017

In this study, it is estimated that ceramic membrane process which can operate stably in harsh conditions replacing existing organic membrane connected with coagulation, sedimentation etc.. Jar-test was conducted by using artificial raw water containing kaolin and humic acid. It was observed that coagulant (A-PAC, 10.6%) 4mg/l is the optimal dose. As a results of evaluation of membrane single filtration process (A), coagulation-membrane filtration process (B) and coagulation-sedimentation-membrane filtration process (C), TMP variation is stable regardless of in Flux $2m^3/m^2{\cdot}day$. But in Flux $5m^3/m^2{\cdot}day$, it show change of 1-89.3 kpa by process. TMP of process (B) and (C) is increased 11.8, 0.6 kpa each. But, the (A) showed the greatest change of TMP. When evaluate (A) and (C) in Flux $10m^3/m^2{\cdot}day$, TMP of (A) stopped operation being exceeded 120 kpa in 20 minutes. On the other hand, TMP of (C) is increased only 3 kpa in 120 minutes. Through this, membrane filtration process can be operated stably by using the linkage between the pretreatment process and the ceramic membrane filtration process. Turbidity of treated water remained under 0.1 NTU regardless of flux condition and DOC and $UV_{254}$ showed a removal rate of 65-85%, 95% more each at process connected with pretreatment. Physical cleaning was carried out using water and air of 500kpa to show the recovery of pollutants formed on membrane surface by filtration. In (A) process, TMP has increased rapidly and decreased the recovery by physical cleaning as the flux rises. This means that contamination on membrane surface is irreversible fouling difficult to recover by using physical cleaning. Process (B) and (C) are observed high recovery rate of 60% more in high flux and especially recovery rate of process (B) is the highest at 95.8%. This can be judged that the coagulation flocs in the raw water formed cake layer with irreversible fouling and are favorable to physical cleaning. As a result of estimation, observe that ceramic membrane filtration connected with pretreatment improves efficiency of filtration and recovery rate of physical cleaning. And ceramic membrane which is possible to operate in the higher flux than organic membrane can be reduce the area of water purification facilities and secure a stable quantity of water by connecting the ceramic membrane with pretreatment process.

• 상하수도학회지
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• 제19권3호
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• pp.338-347
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• 2005

Horizontal-Flow Roughing Filtration (HRF) is one of altemative pretreatment methods e.g. prior to Slow Sand Filtration (SSF). However, some of its limitations are that the effluent quality drops drastically at higher turbidity (>200 NTU) and at higher filtration rate (>1 m/h). To overcome these drawbacks, we suggested Direct Horizontal-Flow Roughing Filtration (DHRF), which is a modified system of Horizontal-Flow Roughing (HRF) by addition of low dose of coagulant prior to filtration. In this study to optimize the DHRF configuration, a conceptual and mathematical model for the coarse compartment has been developed in analogy with multi-plate settlers. Data from simple column settling test can be used in the model to predict the filter performance. Furthermore, the model developed herein has been validated by successive experiments carried out. The conventional column settling test has been found to be an handy and useful to predict the performance of DHRF for different raw water characteristics (e.g. coagulated or uncoagulated water, different presence of organic matter, etc.) and different inital process conditions (e.g. coagulant dose, mixing time and intensity, etc.). An optimum filter design for the coarse compartment (grain size 20mm) has been found to be of 3 m/h filtration rate with filter length of 4-4.5 m.

• Journal of Pharmaceutical Investigation
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• 제7권1_4호
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• pp.28-37
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• 1977

The pharmacological actions to methanol extract(PME) obtained from Plantaginis semen were examined in the rabbit. 1) PME, when administered into the vein of rabbit, produced the fall of blood pressure and stimulation of respiration. The former action was inhibited by atropine but the latter not affected by atropine. 2) PME caused contraction in both isolated intestinal and uterus strips, atropine blocked the contraction of intestinal strips while did not the uterus contraction. 3) PME decreased the heart rate of rabbit anesthetized with urethane. 4) PME elicited antidiuresis with doses ranging from 10mg/kg. The antidiuresis appeared to be related to the hemodynamic changes decreases in the renal plasma flow and glomerular filtration rate. Urinary sodium and potassium decrease in the renal plasma flow and glomerular filtration rate. Urinary sodium and potassium decrease in relation to the diminished filtration.

• 약학회지
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• 제31권6호
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• pp.376-393
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• 1987

This study was performed in order to investigate the effect of nifedipine, a vasodilating drug which acts through calcium antagonism, on renal function using mongrel dog. Nifedipine, when given interavenously in doses ranging from 1.5 to 5.0$\mu\textrm{g}$/kg, elicited diuresis along with less changes of glomerular filtration rate and significant increases of renal plasma flow, so that the filtration fraction(FF) decreased significantly, at the same time both osmolar and free water clearances increased, and amount of sodium, potassium and calcium excreted in urine increased significantly. Nifedipine, when infused into a renal artery in doses from 0.05 to 0.15$\mu\textrm{g}$/kg/min, exhibited identical responses to the actions of intraveneous nifedipine except significant increase of glomerular filtration rate and no change of FF, which was confined only to the infused kidney. The renal action of nifedipine into a renal artery were not influenced by renal denervation, decreased significantly by ouabain, Na$^+$-K$^+$-ATPase inhibitor, which was given into a renal artery. Nifedipine infused into a renal artery in dog pretreated with propranolol i.v. produced diuresis associated with the increase of electrolytes excretion by reduction of electrolyte reabsorption and with no changes of glomerular filtration rate and renal plasma flow. Thus, it is concluded that nifedipine infused into a renal aretery produces diuretic action along with both improvement of hemodynamics and inhibition of electrolytes reabsorption, which may be related to sympathetic $\beta$-receptor or Na$^+$-K$^+$-ATPase activity because the action of nifedipine in kidney is blocked by propranolol or ouabain.