• 대한의생명과학회지
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• 제23권2호
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• pp.111-117
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• 2017

Leukocytes in blood components are involved in diverse adverse transfusion reactions such as febrile non-hemolytic transfusion reactions. Therefore, leukocyte reduction is required to reduce these adverse reactions. The objective of this study was to compare the efficiency of pre-storage filtration and post-storage filtration. Filtration time, residual leukocyte count, RBC recovery, and hemolysis were assessed after pre-storage or post-storage filtration. Compared to pre-storage filtration, filtration time was prolonged and hemolysis was dramatically increased when post-storage filtration was performed. Residual leukocytes count and RBC recovery after post-storage filtration were similar with those obtained after pre-storage filtration. These results suggest that pre-storage filtration has better efficiency than post-storage filtration. These are thought to contribute to the production of better quality of leukoreduction blood components.

• 상하수도학회지
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• 제14권3호
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• pp.260-270
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• 2000

The objective of this study is to evaluate the effect of filter aids in the dual-media rapid filtration. Paper-filter tests were conducted to determine the proper dosages of coagulant and filter aid, and pilot plant tests using two dual-media filter columns were performed for a variety of filtration rates. Using a filter aid (non-ionic polymer), the maximum feasible filtration rate is 480m/day, while turbidity is less than 0.3 NTU and filter run-time is about 70 hours. It is possible to increase the filtration rate up to 360 m/day for keeping the turbidity less than 0.1 NTU. Turbidity increases for the filtration rate greater than 360m/day. In general, the quality of filtered water with a filter aid is stable, while the filter maintains a sufficient filter run-time for a maximum allowable head loss. Particularly, the initial breakthrough can be effectively controlled. The use of a filter aid may be one of the methods applicable if the turbidity of filtered water is required to be improved or if the filter breakthrough limits filter run-time.

• 한국입자에어로졸학회지
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• 제15권1호
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• pp.15-25
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• 2019

The influences of corona charging parameters on collection efficiency and surface potential of air filters were investigated. A polypropylene filter medium was electrically charged using a corona charger, and the resulting surface potential and filtration efficiency against neutralized KCl particles were measured. The filter media was charged under different conditions of applied voltage, voltage polarity, charging time, and distance between electrodes. In addition, we considered charging both sides of the filter as well as charging one side of the filter. As a result, electrical force obtained by charged fiber affected filtration efficiency when the apply voltage strength was higher than 7 kV. Negatively charged filter had higher filtration efficiency than positively charged filter while the surface potential of the negatively charged filter was slightly lower than those of positively charged filter. Moreover, the filtration efficiency increased as the charging time of filter fiber increased and the distance between electrodes decreased. The filtration efficiency was more sensitive to changes of charging time than to those of electrode distance, and the efficiency of both sides charged filter was higher than that of single side charged filter.

• 상하수도학회지
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• 제23권2호
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• pp.207-214
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• 2009

This study examines the optimum filtration conditions in pretreatment of seawater desalination by reverse osmosis. For this purpose, Masan bay seawater is treated through a gravity filter column while $FeCl_3$ is added as coagulant. The conditions of coagulantd osage, media depth, filtration rate, and backwash time are evaluated. The study results show that the filtrate quality improved with increasing coagulant dosage, but head loss rapidly increased. After 4mg/L, the unit filter run volume reduced to less than $200m^3/m^2$. Considering the head loss development, 4mg/L is determined as the optimum dosage. The better filtrate qualities are obtained with depth of 100cm than that of 80cm. The two stage filtration, which outperformed the single stage filtration, is suggested for treatment of Masan bay. The filtration rate of 5m/h is decided as the optimum condition considering the head loss development. At 10m/h, the filtrate quality deteriorated even though the extent was minimal, and head loss increased rapidly. The backwash time of 10 min is decided appropriate.

• 한국임상수의학회지
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• 제22권3호
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• pp.228-232
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• 2005

Damaged spermatozoa are supposed to be trapped in glass wool. In the respect of this, two glass wool filtration spermatozoa groups (0.5 cm, 1 cm depth) were compared with control group to assay sperm motility, HOS values, and vital rate by CFDA/PI staining method following glass wool filtration. The motility of canine sperm extended with PBS+PVP after glass wool filtration was lower in both filtrated groups than that of the control group (p<0.01) and the same significant difference was also shown in canine semen extended with Tris buffer (p<0.01). The motility of canine sperm diluted with PBS+PVP was higher than that diluted with Tris buffer in the same experimental groups (p<0.05). The motility of control group was not significantly decreased until 2 hours immediately after extending, however, the motility of both glass wool filtrated spermatozoa were significantly decreased as time passed until 2 hours after filtration (p<0.01). At each time for assay (immediately, 30 min, 2 hours after filtration), the motility of canine sperm of control group was higher than the filtrated groups (p<0.05), whereas the motility of 0.5 cm depth group was higher than 1 cm depth group at the immediate time after filtration (p<0.05), 30 minutes later (p<0.05) with no difference at 2 hours. No difference was shown among the experimental groups in HOS values of canine sperm after glass wool filtration. The vital rate assayed by CFDA/PI staining of both filter groups was higher than the control group (p<0.05).

• Journal of Acupuncture Research
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• 제23권6호
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• pp.85-101
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• 2006

Objectives : This study was designed to find out correlation of filtration rate of herbal-acupunctures and pain score of herbal acupuncture stimulation. Methods : Filtration rate of Hwangryunhaedoktang herbal acupuncture, Kidney yang deficiency number two herbal acupuncture, Hominis Placenta herbal acupuncture, Cervus Elaphus herbal acupuncture, BUM herbal acupuncture and Carthami Flos herbal acupuncture were measured at the korean institute of herbal acupuncture. And Hwangryunhaedoktang herbal acupuncture, Kidney yang deficiency number two herbal acupuncture, Hominis Placenta herbal acupuncture, Cervus Elaphus herbal acupuncture, BUM herbal acupuncture and Carthami Flos herbal acupuncture were injected at Xie points of the subjects. Results : Ranking of herbal acupunctures filtration rates is the same as ranking of pain score and duration time of herbal acupuncture. Correlation analysis result of herbal acupunctures filtration rates and herbal acupuncture VAS with a simple linear regression analysis is that correlation coefficient of Hwangryunhaedoktang herbal acupuncture, Kidney Yang Deficiency Number Two herbal acupuncture, Hominis Placenta herbal acupuncture, Cervus elaphus herbal acupuncture, BUM herbal acupuncture. Carthami Flos herbal acupuncture is 0.44, 0.53, 0.58, 0.76, 0.47 and 0.54. Correlation analysis result of herbal acupuncture's filtration rates and herbal acupuncture stimulation's duration time is that correlation coefficient of Hwangryunhaedoktang herbal acupuncture, Kidney Yang Deficiency Number Two herbal acupuncture, Hominis Placenta herbal acupuncture, Cervus Elaphus herbal acupuncture, BUM herbal acupuncture, Carthami Flos herbal acupuncture is -0.09, 0.11, -0.07, 0.28, -0.11 and -0.09. Conclusion : We found the correlation of filtration rate of herbal-acupunctures and pain score of herbal-acupuncture stimulation. This study help to control pain amount and pain duration time of herbal acupuncture treatment. And this study improve acupuncture theory of herbal acupuncture.

• 상하수도학회지
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• 제21권4호
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• pp.485-491
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• 2007

The fluctuation of inlet flow to a water treatment plant makes a serious problem that it can change the filtration rate abruptly, and ultimately occur the breakthrough of the detained particles inside filter media. Also, since it takes very short time (about 10 minutes) for the surface wave occurred from the fluctuation of inlet flow to reach the filtration process, it is impossible to control the filtration rate stably. Therefore, this study was conducted to evaluate the effect of daily flow-rate fluctuation on the performance of sand filtration process, and to suggest the dual media composition for coping with that effect. Comparative column tests have been carried out for various dual media (sand and anthracite) compositions. From the results of column tests, dual media, especially in the case of sand 45cm/anthracite 30cm, is more effective to cope with the effect of flow-rate fluctuation on the performance of filtration than single media (only sand). In addition, irrespective of dual media composition, managing ability to cope with that fluctuation tends to be weak at the end of allowable filtration duration time,

• 한국수자원학회논문집
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• 제35권2호
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• pp.213-220
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• 2002

하수 처리수의 재이용을 위하여 표준활성슬러지법에 의한 생물학적 처리 후 최종침전지 유출수를 급속여과공정으로 처리하기 위한 Pilot Plant 실험연구가 수행되었다. 또한, 활성슬러지와 연계된 급속여과공정과 포기조 후단에 응집제를 주입하는 활성슬러지 이후 급속여과 처리하는 공정과의 비교 실험도 행해졌다. 최종침전지 유출수를 급속여과공정으로 처리한 경우 여과속도는 100m/day, 여과지속시간은 40시간 이하로 운전하는 것이 타당한 것으로 나타났으며, 여과지의 역세척 주기는 여과속도 100m/day일 때 40시간에 1회 정도가 되었다. 여과지 역세척 시 역세척 방법은 공세 1분, 공세+수세 30초, 수세 1분, 공세·수세 2분, 수세 3분, 안정 30초, 배수 10분의 순으로 행하는 것이 효과적이었으며, 수세속도는 10LPM으로 전체 여과수량의 2%정도였다. 표준활성슬러지 시스템에 의한 2차 처리수를 잡용수로 재이용 하기 위해서는 폭기조 후단에 응집제를 첨가하여 여과 공정을 후속공정으로 하는 시스템으로 유용하게 사용할 수 있을 것으로 판단된다.

• 상하수도학회지
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• 제18권5호
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• pp.673-679
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• 2004

Particle breakthrough can occur by either the breakoff of previously captured particles (or flocs) or the direct passage of some influent particles through the filter. Filtration experiments were performed in a laboratory-scale filter using spherical glass beads with a diameter of 0.55 mm as collectors. A single type of particle suspension (Min-U-Sil 5, nearly pure $SiO_2$) and three different destabilization methods (pH control, alum and polymer destabilization) were utilized. The operating conditions were similar to those of standard media filtration practice: a filtration velocity of 5 m/h. To assess the possibility of particle detachment during the normal filtration, a hydraulic shock load (20% increase of flow rate) was applied after 4 hours of normal filtration. The magnitude of particle detachment was proportional to the particle size for non-Brownian particles. At the same time, less favorable particles, i.e., particles with larger surface charge, were easily detached during the hydraulic shock load. Therefore, proper particle destabilization before filtration is crucial for maximum particle removal as well as minimum particle breakthrough.

• 한국물환경학회지
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• 제20권6호
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• pp.652-656
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• 2004

Both surface wash and backwash are considered as one of the most important methods that can improve the filtration efficiency in the existing water treatment plant. This study has mainly focused on the improvement of filtering efficiency by controlling surface wash and backwash time, and water level before backwash (when drained up to the trough, when drained up to 10 cm above filter bed, and when drained below 10 cm filter bed). Filtration efficiency was shown a little bit of differences depending on the operating conditions like surface wash injection pressure, the distance control between filter bed and the facility, and the types of surface wash. When the water level before backwash was reached up to 10 cm below filter bed after draining, however, the filtration velocity and the turbidity removal efficiency in the filter bed was improved. When the surface wash followed by backwash is longer, it showed a similar result. Because the proper adjustment of surface washing time makes filtration efficiency higher, therefore, it is necessary to set up the backwash time moderately.