• 대한환경공학회지
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• 제30권11호
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• pp.1139-1145
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• 2008

응집-막분리 공정의 적용시 전처리 응집공정에서 응집조건에 따라 발생하는 플럭 생성특성을 파악하고 생성된 플럭 특성에 따른 막투과 플럭스의 영향을 살펴본 결과 인공시수와 낙동강 원수에서 전처리 응집공정을 적용시 급속교반 후 용존성 유기물질(자연유기물질)이 미세 플럭의 형성으로 인하여 입자상 유기물질로 전환이 발생하였으며 급속교반초기 10초 사이에 용존성 유기물이 입자상 물질로 전환되었다. 또한 응집제 주입량이 0.025 mM as Al (7.5 mg/L Alum) 이었을 경우 입자 전환율 K값이 크게 나타나고 있었으나 0.05 mM (15 mg/L Alum)이상으로 응집제 주입량이 증가할 경우 K값은 감소하였으며 0.15 mM까지 유사한 값을 보이고 있었다. 낙동강 원수를 이용하여 전처리 공정으로 응집 공정을 적용시 UF 단독공정에 비하여 투과 flux 감소는 상당히 낮게 나타났으며 투과 flux 변화는 응집공정에 의하여 형성되는 입자크기 분포에 의존하였으며 응집조건에 따른 투과 flux 실험결과 급속교반-UF공정과 급속교반-완속교반-UF공정의 투과 flux는 유사하게 나타났다. 막의 재질에 따른 투과 flux 실험결과 소수성 재질의 막에 비하여 친수성 재질의 막이 투과 flux가 높게 유지되었으며 응집제 자체의 금속성분에 의한 막오염 영향은 나타나지 않았다.

• 대한한방부인과학회지
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• 제19권1호
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• pp.139-154
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• 2006

Objective : This experimental study was carried out to investigate anti-coagulation effects and mechanism of Hongdeung-tang on the dissentimenated intravascular coagulation Methods : Each 10 rats were classified as normal gorup, control group and treated group. The control group was given a 0.5mg/ml endotoxin intra-vein injection and was occurred Disseminated Intravascular Coagulation(DIC). The treated group were orally administrated 1ml Hongdeung-tang concentration once a day for 6 days and then it was treated the same as the control group. We took the blood from heart and were investigated number of Platelet and white blood cell(WBC), fibrinogen concentration, prothrombin time(PT), activated partial thromboplastin time(APTT), interleukin-6(IL-6), Tumor Necrosis $Factor-{\alpha}(TNF-{\alpha})$, Prostaglandin $E2(PGE_2)$ from them. Results : There were a statistically significant increase of platelet and fibrinogen concentration in the treated group compared to the treated group. The PT was a significantly reduced in treated group compared to the control group. There was no significant change in numbers of WBC and APTT between control and treated group. On the contrary, the number of PT, IL-6, $TNF-{\alpha}$, $PGE_2$ were significantly decreased in treated group compared to the control group. Conclusion : DIC which was occurred by endotoxin intravenous injection seems to related to the increase of IL-6, $TNF-{\alpha}$, $PGE_2$ and Hongdeung-tang has an effect that supress those factors. we can assume Hongdeung-tang has an anti-coagulation effect by those supressing effect.

• 상하수도학회지
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• 제9권3호
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• pp.65-77
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• 1995

The kinetics of flocculation of heterodisperse suspension like those in water treatment plants and natural water system are usually described by the Smoluchowski equation, which incorporates collision frequency functions for particle collisions by Brownian motion, fluid shear, and differential sedimentation. These collisionfrequeney functions have been based on a rectilinear view of collisions, i.e., one that ignores short-range forces and changes in fluid motion as particles approach one another. In this research, a curvilinear approach, i.e., one that accounts for hydrodynamic forces and particle interaction in the collision of two different size particles is developed. Collision efficiency factors of each mechanism can be calculated by trajectory analysis (fluid shear and differential sedimentation) or the solution of diffusion equation (Brownian motion). The results are presented as a set of corrections to the rectilinear collision frequency functions for each mechanism.

• Korean Chemical Engineering Research
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• 제46권3호
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• pp.639-645
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• 2008

십자형 응집-한외여과 막분리 공정 운전시 응집조건에 따른 영향을 살펴보면 급속교반-UF 공정과 응집-침전-UF 공정에서 투과 flux의 변화는 크게 나타나지 않았으며 UF막의 막오염 억제 측면에서는 응집전처리공정으로서 1분간의 짧은 급속혼화만으로도 충분한 것으로 나타났다. 교반강도에 따른 투과 flux의 변화결과 교반강도에 따라 형성되는 floc의 크기가 거의 유사하게 형성되어 교반강도에 따른 영향은 나타나지 않았다. 응집제 주입량에 따른 투과 flux변화를 살펴보면 응집제 주입량이 증가함에 따라 유기물의 제거가 크게 일어나 유기물 부하의 감소와 floc의 크기가 증가함에 따라 다공성 케이크층의 형성에 따른 막저항의 감소로 인하여 투과 flux가 향상되었다. 막의 재질과 전처리 응집공정적용에 따른 여과메카니즘 분석결과 막의 재질에 따라서는 친수성 재질의 막에 비하여 소수성 재질의 막의 경우 막의 공극속으로 입자의 침투가 발생하여 침적 흡착되는 현상과 막의 표면에서 형성되는 cake층에 의한 투과 flux 감소가 주원인이 되었으며 응집공정을 전처리공정으로 적용시 UF단독공정에 비하여 막오염 발생이 저감되었다.

• Journal of Trauma and Injury
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• 제34권1호
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• pp.57-60
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• 2021

Warfarin is used as part of the treatment of various diseases, and laboratory monitoring of its effects is required. Airway hematoma secondary to warfarin is rare, but can be fatal because of potential airway obstruction. Rapid definitive airway establishment is crucial if airway obstruction is suspected. This complication is more likely to occur in those with elevated coagulation laboratory values. However, we experienced a patient in whom a massive retropharyngeal hematoma caused airway obstruction after a non-severe motor vehicle collision. The patient had been taking warfarin, and had coagulation parameter values within the normal ranges. A major fracture or hemorrhage was not anticipated. Upon examination, a massive retropharyngeal hematoma was noted. Orotracheal intubation failed due to an airway obstruction. Emergency tracheostomy and an operation for hematoma removal were performed. Physicians must always consider the possibility of airway hematoma in warfarin-taking patients with normal coagulation values regardless of the severity of mechanism of injury.

• 한국물환경학회지
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• 제22권5호
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• pp.958-967
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• 2006

The overall objective of this research was to find out the role of rapid mixing conditions in the species of hydrolyzed Al(III) formed by Al(III) coagulants and to evaluate the distribution of hydrolyzed Al(III) species by coagulant dose and coagulation pH. When an Al(III) salt was added to water, monomers, polymers and solid precipitates may form. Different Al(III) coagulants (alum and PSOM) show to have different Al(III) species distribution over a rapid mixing condition. During the rapid mixing period, for alum, formation of dissolved AI(III) (monomer and polymer) increases, but for PSOM, precipitates of $Al(OH)_{3(S)}$ increases rapidly. During the rapid mixing period, for high coagulant dose, Al-ferron reaction increases rapidly. The kinetic constants, Ka and Kb, derived from AI-ferron reaction. The kinetic constants followed very well the defined tendencies for coagulation condition. For pure water, when the rapid mixing time increased, the kinetic constants, Ka and Kb showed lower values. Also, for raw water, when the rapid mixing time increased, the kinetic constants, Ka and Kb showed lower values. At A/D(Adsorption and Destabilization) and sweep condition, both $Al(OH)_{3(S)}$ and dissolved Al(III) (monomer and polymer) exist, concurrent reactions by both mechanism appear to cause simultaneous precipitation.

• 대한약침학회지
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• 제18권4호
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• pp.7-11
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• 2015

Objectives: Bee venom (BV) is a complex mixture of proteins and contains proteins such as phospholipase and melittin, which have an effect on blood clotting and blood clots. The mechanism of action of honey bee venom (HBV, Apis mellifera) on human plasma proteins and its anti-thrombotic effect were studied. The purpose of this study was to investigate the anti-coagulation effect of BV and its effects on blood coagulation and purification. Methods: Crude venom obtained from Apis mellifera was selected. The anti-coagulation factor of the crude venom from this species was purified by using gel filtration chromatography (sephadex G-50), and the molecular weights of the anti-coagulants in this venom estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Blood samples were obtained from 10 rabbits, and the prothrombin time (PT) and the partial thromboplastin time (PTT) tests were conducted. The approximate lethal dose (LD) values of BV were determined. Results: Crude BV increased the blood clotting time. For BV concentrations from 1 to 4 mg/mL, clotting was not observed even at more than 300 seconds, standard deviations $(SDs)={\pm}0.71$; however, clotting was observed in the control group 13.8 s, $SDs={\pm}0.52$. Thus, BV can be considered as containing anti-coagulation factors. Crude BV is composed 4 protein bands with molecular weights of 3, 15, 20 and 41 kilodalton (kDa), respectively. The $LD_{50}$ of the crude BV was found to be $177.8{\mu}g/mouse$. Conclusion: BV contains anti-coagulation factors. The fraction extracted from the Iranian bees contains proteins that are similar to anti-coagulation proteins, such as phospholipase $A_2(PLA_2)$ and melittin, and that can increase the blood clotting times in vitro.

• 상하수도학회지
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• 제9권3호
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• pp.99-107
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• 1995

Various humic substances are widely distributed in natural water body, such as rivers and lakes and cause the yellowish or brownish color to water. The evidence that humic substances are precursors of THMs formation in chlorinated drinking water has been reported m the Jiteratures. For the reason of public health as well as aesthetics, needs for humic substances removal have been increased in the conventional water treatment processes. In this research, the characteristics of aluminium coagulation of humic acids and humic acids were investigated. The optimum pH and coagulants dosage to remove these materials simultaneously by coagulation were alto studied. The results are as followed; 1. UV-254 absorptiometry for measuring the concentration of aquatic humic acids showed good applicability and stable results. 2. The optimal pH range for humic acids removal by aluminium coagulation was 5 to 5.5, however, an increase in aluminium coagulant dosage could enhance the removal rate of humic acids in the wide pH range. 3. Coprecipitation of humic acids in the typical pH range of 6.5 to 8 in water treatment processes may require the sweep coagulation mechanism with the excess aluminium coagulant dosage. 4. Using PAC(poly aluminium chloride) or PASS(poly aluminium silica sulfate) as coagulants was able to expand the operating range for removing humic acids. 5. From the coagulation of humic substances(UV-254) and turbidity at pH range of 5.5 - 6.0 and alum dose of 86 ppm, the removal efficiency of turbidity from the reservoir water was above 90% and that of UV-254 was above 70%. 6. By using the reservoir water, the optimum condition of rapid mixing for simultaneous removal of turbidity and UV-254 absorbance was pH of 5.8 and LAS dose of 86 ppm, in this study.

• 대한기계학회논문집B
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• 제22권12호
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• pp.1691-1701
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• 1998

Fly ash produced in coal combustion is a fine-grained material consisting mostly of spherical, glassy, and porous particles. A study on the formation mechanism of the fly ash from coal particles in the pulverized coal power plant is investigated with a physical, morphological, and chemical characteristic analysis of fly ash collected from the Samchonpo power plant. This study may contribute to the data base of domestic fly ash, the improvement of combustion efficiency, fouling phenomena and ash collection in the electrostatic precipitator. The physical property of fly ash is determined using a particle counter for the measurement of ash size distribution. Morphological characteristic of fly ash is performed using a scanning electron micrograph. The chemical components of fly ash are determined using an inductively coupled plasma emission spectrometry(ICP). The distribution of fly ash size was bi-modal and ranged from 12 to $19{\mu}m$ in mass median diameter. Exposure conditions of flue gas temperature and duration within the combustion zone of the boiler played an important role on the morphological properties of the fly ash such as shape, particle size and chemical components. The evolution of ash formation during pulverized coal combustion has revealed three major mechanisms by large particle formation due to break-up process, gas to particle conversion and growth by coagulation and agglomeration.

• 한국산학기술학회논문지
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• 제19권8호
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• pp.105-114
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• 2018

전기응집 (Electro-coagulation)을 활용한 분리 막 생물반응기 (Membrane Bio-Reactor) 공정의 막 오염 저감 현상을 확인하고 이를 해석하고자 하였다. 전기응집의 주요 운전 인자인 전류밀도와 접촉시간 변화가 활성슬러지 혼합액의 막 여과에 미치는 영향을 관찰하고 전기응집 과정에서 발생하는 수산화금속염이 막 오염에 미치는 역할에 대해 연구하였다. 전류밀도를 $10A/m^2$으로 높게 유지한 경우에는 전기응집 시간이 증가하여도 막 오염 감소 효과가 크지 않은 반면 $2.5A/m^2$의 낮은 전류밀도 하에서는 전기응집 시간이 증가하면 추가적인 막 오염 감소가 관찰되었다. 즉, 막 오염을 감소시키는 전류밀도와 접촉시간의 곱이 전체 막 오염 저감 정도를 지배하고 있음을 확인하였다. 또한 주어진 전류밀도와 인가시간에서 입도분포는 크게 변화하지 않은 것으로 나타나 콜로이드 입자와 막 오염 저감과는 큰 관련성이 없는 것으로 판단되었다. 그러나 전기응집을 통해 생성된 수산화알루미늄 (인산알루미늄)이 막 여과 과정에서 동적 막 (Dynamic Membrane)을 형성하여 막 오염 현상을 완화하는 것으로 확인되었다. 전기응집에서 발생한 수산화금속염이 막 표면에 동적 막을 형성하고 이로 인해 유입수의 입자성분이 직접 막 표면과 내부에 침적되는 것을 방해하고 동적 막에 주로 쌓이게 함으로써 막 오염이 감소된 것이다. 본 연구에서 밝힌 수산화금속염에 의한 동적 막의 역할은 전기응집을 활용한 MBR 공정의 후 막 오염 감소 메커니즘을 해석하는데 중요한 역할을 한다고 결론지을 수 있다.