• 제목/요약/키워드: Coagulation control

검색결과 220건 처리시간 0.027초

응집침전에 의한 제철공장 냉각수질향상 (Improvement of Cooling Water Quality by Coagulation and Sedimentation in Steel Mill)

  • 조관형;우달식;황병기;이선주;박덕원
    • 한국환경보건학회지
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    • 제35권5호
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    • pp.411-416
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    • 2009
  • This study was initiated to improve the cooling water quality by chemical coagulation and sedimentation in steel mills. Due to the inefficient flocculation in the settling tanks of blast furnace cooling water systems, the solid particles in the cooling water overflow accumulate and clog the cooling system. To protect the cooling water system from such fouling, proper flocculants must be continuously used. Laboratory tests were performed for the indirect cooling water system of a plate mill. The batch test in the gas scrubbing cooling water system of a blast furnace showed that the proposed coagulant was more effective for the improvement of coagulation and sedimentation than the existing one. During the tests, cationic flocculants were more effective than use of only an anionic flocculant. The suggested combination of anionic and cationic flocculants can probably improve the turbidity removal efficiency of the cooling water. Proper control of the overflow rate by the designed residence time would help turbidity removal efficiency in the settling tank. In addition, the settling can be enhanced by adopting rapid and slow mixing alternatively. Scale problems in blast furnace cooling water system were reduced to some extent by efficient settling.

오존산화에 의한 수처리공정에서 VOCs의 제거 특성 (VOCs Removal in Drinking Water Treatment Process by Ozonation)

  • 한명호;최준호;임학상
    • 상하수도학회지
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    • 제11권2호
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    • pp.65-75
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    • 1997
  • Removal characteristics of volatile organic carbons(VOCs) by ozone oxidation and other processes in the raw water of the 1st Nakdong water treatment plant were investigated. Dichrolomethane, toluene and other 7 compounds were detected in the raw water. With regard to detected 4 compounds in finally treated water, it was found that VOCs could not be removed effectively by traditional water treatment process. Benzene, 1,2-dichlorobenzne were not detected in the raw water but they were detected in the process of treatment. The compound of highest detection frequency was dichloromethane. When the raw water was controlled at pH 7, temperature $20^{\circ}C$, 5 minutes as contact time, 10 minutes as reaction time, the removal rate of THMFP, $KMnO_4$ demand, TOC, $UV_{254nm}$ and $NH_3-N$ were 46.4%, 22%, 19.6%, 31% and 8%, respectively. From estimating the finally treated water qualities in 7 kinds of treatment processes, P-6 process(raw water-chlorination-coagulation-ozonation) was most effective for organics removal and THMs control. Removal efficiencies for $KMnO_4$ demand and TOC by the process which combined preozonation with coagulation was twice better than only preozonation. $NH_3-N$ removal rate was shown as 10% by P-3 process(raw water-coagulation-ozonation), but 83% of $NH_3-N$ was removed by P-4 process(raw water-coagulation-chlorination). It was found that the chlorination is more effective than the ozonation for the NH3-N removal as commonly known.

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A Comparative Analysis of the Metabolic and Coagulative Profiles in Patients with Idiopathic Scoliosis, Congenital Scoliosis and Healthy Controls: A Case-Control Study

  • Ahuja, Kaustubh;Garg, Bhavuk;Chowdhuri, Buddhadev;Yadav, Raj Kumar;Chaturvedi, Pradeep Kumar
    • Asian Spine Journal
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    • 제12권6호
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    • pp.1028-1036
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    • 2018
  • Study Design: Single-center, observational, case-control study. Purpose: Comparison and analysis of the metabolic and coagulative profiles in patients with idiopathic scoliosis, patients with congenital scoliosis, and healthy controls. Overview of Literature: Serum melatonin deficiency has been a controversial topic in the etiopathogenesis of scoliosis. Low bone mineral density, low vitamin D3 levels, and high parathyroid hormone levels are common metabolic abnormalities associated with scoliosis that may be responsible for its pathogenesis. In addition to metabolic defects, several studies have shown coagulation defects that either persist from the preoperative period or occur during surgery and usually lead to more than the expected amount of blood loss in patients undergoing deformity correction for scoliosis. Methods: The study population (n=73) was classified into those having congenital scoliosis (n=31), those with idiopathic scoliosis (n=30), and healthy controls (n=12). After detailed clinicoradiological evaluation of all the subjects, 10-mL blood samples were collected, measured, and analyzed for various metabolic and coagulation parameters. Results: The mean serum melatonin levels in patients with idiopathic scoliosis were significantly lower than those in the healthy controls. Although the mean serum melatonin level in the congenital group was also low, the difference was not statistically significant. Serum alkaline phosphatase and parathyroid hormone levels were higher in the scoliosis groups, whereas the vitamin D level was lower. No differences were observed in the coagulation profiles of the different groups. Conclusions: Low serum melatonin levels associated with scoliosis can be a cause or an effect of scoliosis. Moreover, low bone mineral density, high bone turn over, and negative calcium balance appear to play an important role in the progression, if not the onset, of the deformity.

Testicular Degeneration and Sperm Loss Induced by Chronic Administration of CocaineiIn Mice

  • Suh, Jeong-Hye;Yang, Boo-Keun;Lim, Dong-Koo;Jhoo, Wang-Kee;Kim, Hyoung-chun
    • Archives of Pharmacal Research
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    • 제17권4호
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    • pp.213-217
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    • 1994
  • The effect of ccocaine on reproductive system were studied in male ICR mice. daily injection of cocaine HCL (10, and 40 mg/kg s.c for 15 days) disrupted epididymal sperm levels and testicular morphology. These disruptions were manifested in a decreased number of sperum, an increased number of dead sperm as compared with control vehicle, and wre evidenced by vacuolations, multinucleated giant cell formations and coagulation necrosis in the testicular seminiferous tubules. Responses in the current study were trended in dose dependent pattem. These results suggest that thronic cocaine intoxication can perturb on male reproductive organ functioning.

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TiO₂/H₂O₂/UV 공정을 이용한 염색폐수처리에 관한 연구 (A Study on the Treatment of Dyeing Wastewater Using TiO₂/H₂O₂/UV Processes)

  • 조일형;정효준;박경렬;성기석;이용규;이홍근
    • 환경위생공학
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    • 제15권4호
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    • pp.27-27
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    • 2000
  • In order to treat the dyeing wastewater, the UV/TiO₂/H₂O₂ system was investigated, and proper pretreatment methods were examined to reduce the load on the system considering economical and technical efficiency. The results of this study were as follows: 1.UV/TiO₂/H₂O₂ system with pretreatment process was adopted, the result of Chemical coagulation and pH control units was pH 11→ coagulation → pH 4 and the optimum dosage of FeCl₃ was 600㎎/ℓ 2. Proper dosage of TiO₂in the UV/TiO₂/H₂O₂ system with pretreatment process was 2g/ℓ and H₂O₂ was 1000㎎/ℓ, UV contact time was 20min to get below 200㎎/ℓ of $COD_{Cr}$

$TiO_2/H_2O_2/UV$ 공정을 이용한 염색폐수처리에 관한 연구 (A Study on the Treatment of Dyeing Wastewater Using $TiO_2/H_2O_2/UV$ Processes)

  • 조일형;정효준;박경렬;성기석;이용규;이홍근
    • 환경위생공학
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    • 제15권4호
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    • pp.26-34
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    • 2000
  • In order to treat the dyeing wastewater, the $UV/TiO_2/H_2O_2$ system was investigated, and proper pretreatment methods were examined to reduce the load on the system considering economical and technical efficiency. The results of this study were as follows: 1. $UV/TiO_2/H_2O_2$ system with pretreatment process was adopted, the result of Chemical coagulation and pH control units was $pH{\;}11{\;}{\rightarrow}{\;}coagulation{\;}{\rightarrow}{\;}pH{\;}4$ and the optimum dosage of $FeCl_3$ was $600mg/{\ell}$. 2. Proper dosage of $TiO_2$ in the $UV/TiO_2/H_2O_2$ system with pretreatment process was $2g/{\ell}$ and $H_2O_2$ was $1000mg/{\ell}$, UV contact time was 20min to get $200mg/{\ell}$ of $COD_{Cr}$.

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Changes in Functional Properties of Casein by Different Chemical Modifications

  • Kim, Il-Sung;Choi, Jin-Ho;Hong, Jeong-Hwa
    • Preventive Nutrition and Food Science
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    • 제2권1호
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    • pp.17-22
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    • 1997
  • Casein was chemically modified with acetic, succinic, and maleic anhydride and changes in functional pro-perties were evaluated as affected by the degree of modification. Chemical modification resulted in casein with unique functional properties depending upon the type of anhydrid used and the degree of modification. It was possible to control heat coagulation, calcium precipitability, forming and emulsion capacity and stability. At pH 4.5 heat coagulation was 0% in the case 74.1% acetylated casein; on the contrary, succinylation and maleyation resulted in highly heat sensitive protein. Foaming properties were improved markedly by suc-cinylation and maleylation at pH 4.5. However, emulsifying properties were enhanced only by maleylation.

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마이크로파를 이용한 수술기의 개발 (The Development of Microwave Tissue Coagulator)

  • 박병욱;정병선;박민용;이상배;손우정;정동균;양성화
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1989년도 춘계학술대회
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    • pp.81-83
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    • 1989
  • In surgery the hemostatic control is very important for the parenchymatous organs. These organs consist of the fragile and the blood content tissues such as liver, spleen and kidney, etc.. One of the control methods to solve this problem is to insert the mono polar typed needle electrode, which gathers the thermal effect of microwave, directly into tissues so as to coagulate and stop the hemorrhage. This method has same advantages: First, the range of the heat energy is limited. Second, the coagulation, the hemostatic characteristic, and stability are excellent. Third, more convenient operation is possible. This paper is aimed to manufacture the microwave tissue coagulation system and to suggest the new direction for development, hereafter.

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Purification and Characterization of Anticoagulant Protein from Ark Shell, Scapharca broughtonii

  • Jung, Won-Kyo;Park, Pyo-Jam;Kim, Se-Kwon
    • 한국어업기술학회:학술대회논문집
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    • 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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    • pp.90-91
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    • 2000
  • The physiological systems that control blood fluidity are both complex and elegant. Blood must remain fluid within the vasculature and yet clot quickly when exposed to nonendothelial surfaces at sites of vascular injury. There are two principle mechanisms to control a delicate balance in higher organisms (Davie & Ratnoff, 1964). Present evidence suggests that the intrinsic pathway play an important role in the growth and maintenance of fibrin formation in the coagulation cascade while a second overlapping mechanism, called the extrinsic pathway, is critical in the initiation of fibrin formation. Coagulation factors is in two mechanisms, and in order to clot blood, they are activated by a cooperation with $Ca^{2+}$, phospholipid and vitamin K etc. For example, the human placental anticoagulant protein (PAP of PAP- I), which is a $Ca^{2+}$ -dependent phospholipid binding protein (Funakoshi et al., 1987) inhibited the activity of factor Xa, so that it prolonged fibrin formation. We wondered whether any other protein was involved in regulation of the coagulant system as an anticoagulant protein from natural organisms. Natural agents would have not harmful side-effects in comparision with chemically synthesized materials such as warfarin, aspirin, phenindione, etc.. But anticoagulant agents from natural, especially marine organisms have hardly been researched except for polysaccharides from marine algae. (omitted)

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