• 제목/요약/키워드: urea treatment

검색결과 733건 처리시간 0.036초

선박디젤기관용 SCR 시스템의 NOx 저감율에 관한 연구 (Investigation of NOx Reduction Ratio on SCR System for a Marine Diesel Engine)

  • 최재성;조권회;이재현;이진욱;김정곤;양희성;고준호;박기용;장성환
    • Journal of Advanced Marine Engineering and Technology
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    • 제27권7호
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    • pp.832-838
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    • 2003
  • IMO NOx levels are generally possible to meet by means of primary on-engine measures. Nevertheless further significant follow-on reductions are likely to require a secondary after-treatment technique. SCR system is currently the only available technology proven at full scale to meet the 90% NOx reduction levels. Accordingly, maybe the use of an SCR system on board ship provides the solution to minimize this primary pollutant without increasing fuel consumption. In order to develop a practical SCR system for marine application on board ship, a primary SCR system using urea was made. The SCR system was set up on the ship. employed a two-stroke diesel engine as a main propulsion. which is a training ship in KMU (Korea Maritime Univ.). The purpose of this paper is to report the results about the basic effects of the above system parameters which is investigated from practical application through its trial use. The degree of NOx removal depends on some parameters. such as the amount of urea solution added, space velocity. reaction gas temperature and activity of catalyst. The preliminary results from trial run are presented.

산화양모의 효소처리에 의한 양모섬유의 개질(제1보)-화학적 성질의 변화- (Modification of Oxidation Wool Treated with Protease(Part I)-Changes of chemical properties)

  • 김영리;유효선
    • 한국의류학회지
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    • 제22권7호
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    • pp.843-850
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    • 1998
  • The purpose of this study is the investigation of chemical properties of wool treated with oxidants and protease at low temperature. The chemical degradation of the fibers were investigated by measuring $\alpha$-amimo acid contents and FT-IR analysis. In addition, urea-hydrogensulfite solubility was measured to compare to the oxidation and protease treated wool. The results were as follows. 1) By the oxidation of wool, cystine is oxidised to cysteic acid by way of the intermediate oxides, cystine-S-monooxide and cystine-S-dioxide, in the case hydrolysis catalysed by the protease catalyse. Also, $\alpha$-amimo acid contents is increased, and urea-hydrogensulfite solubility was lower than that of untreated wool. This chemical degradation of wool was occurred due to oxidate hydrolysis in the order of permonosulfate>dichloroisocyanuric acid$\geq$chlorine. 2) The chemical degradation of wool was accelerated by the protease treatment of oxidized wool. Oxidation of wool is considered to make the fiber more susceptibled to enzymatic attact by opening disulphide bond within wool. Enzymatic attact was effectively directed to the wool oxidised by permonosulfate.

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Preparation of Molecularly Imprinted Polymers Using Photocross-linkable Polyphosphazene and Selective Rebinding of Amino Acids

  • Lee, Seung-Cheol;Chang, Ji-Young
    • Macromolecular Research
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    • 제17권7호
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    • pp.522-527
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    • 2009
  • A photocrosslinkable polyphosphazene was used for molecular imprinting. We synthesized polyphosphazene (3) having urea groups for complexation with N-carbobenzyloxyglycin (Z-Gly-OH, template) and chalcone groups for cross-linking reaction. As substituents, 4-hydroxycha1cone (1) and N-(4-hydroxyphenyl)-N'-ethylurea (2) were prepared. Choloro groups of poly(dichlorophosphazene) were replaced by the sequential treatment with sodium salts of compounds 1 and 2, and trifluoroethanol. The template molecule was complexed with the urea groups on the polymer chains via hydrogen bonding. A thin polymer film was prepared by casting a solution of the complex of polymer 3 and the template in dimethylformamide on a quartz cell and irradiated with 365 nm UV light to yield a cross-linked film with a thickness of about $16{\mu}m$. The template molecules in the film were removed by Soxhlet extraction with methanol/acetic acid. The control polymer film was prepared in the same manner for the preparation of the imprinted polymer film, except that the template and triethylamine were omitted. In the rebinding test, the imprinted film exhibited much higher recognition ability for the template than the control polymer. We also investigated the specific recognition ability of the imprinted polymer for the template and its structural analogues. The rebinding tests were conducted using Z-Glu-OH, Z-Asp($O^tBu$)-OH, and Z-Glu-OMe. The imprinted film showed higher specific recognition ability for the template and the lowest response for Z-Asp($O^tBu$)-OH.

모기유충에 살충력이 있는 Bacillus thuringiensis subsp. darmstadiensis 73E10-2의 delta-endotoxin의 화학적 처치에 따른 안정성 (Stability on Chemical Treatment of Niosquitocidal delta-endotoxin from Bacillus thuringiensis subsp. darmstadiensis 73E10-2)

  • 김광현;조경순;이광배
    • 한국미생물·생명공학회지
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    • 제19권3호
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    • pp.308-312
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    • 1991
  • B.thuringiensis subsp. darmstadiensis 73E10-2의 내독소에 대한 화학적 처리에서 고농도의 중성염(4M NaBr), 유기용매(50% acetone), 변성제(4M urea) 및 중성 계면활성제(10% triton X-100)로 내독소를 처리하였을 때 모기유충에 대한 독력의 소실이 거의 나타나지 않았으나, guanidine HCL이나 $CCl_4$ 또는 양이온 및 음이온 계면활성제로 처리함으로써 그 독력이 크게 소실되었다. 또한, 내독소의 sulfhydryl기의 변형은 모기유충에 대한 독력에 영향을 나타내지 못하였으나, lysine기 변형으로 내독소의 독력이 거의 완전히 소실되었다.

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An Experiment of SCR System On-board Ship

  • Choi Jae-Sung;Cho Kwon-Hae;Lee Jae-Hyun;Lee Jin-Wook;Kim Jeong-Gon;Jang Sung-Hwan;Yang Hee-Sung;Ko Jun-Ho;Park Ki-Yong
    • Journal of Advanced Marine Engineering and Technology
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    • 제29권3호
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    • pp.306-312
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    • 2005
  • IMO $NO_x$ levels are generally possible to meet by means of primary on-engine measures. Further significant follow-on reductions are likely to require a secondary after-treatment technique. SCR(Selective Catalytic Reduction) technology is used almost exclusively for $NO_x$ removal in stationary combustion systems. In order to develop a practical SCR system for marine application on board ship, a primary SCR system using urea was made. The SCR system was set up on the ship, 'HANNARA' as a test vessel. employed a two-stroke cycle diesel engine as main propulsion, which is a training ship of Korea Maritime University. The purpose of this paper is to report the results about the basic effects of the below system parameters, The degree of $NO_x$ removal depends on some parameters, such as the amount of urea solution added, space velocity, reaction gas temperature and activity of catalyst.

Effect of supplementation with brewer's yeast hydrolysate on growth performance, nutrients digestibility, blood profiles and meat quality in growing to finishing pigs

  • Zhang, Jian Ying;Park, Jae Won;Kim, In Ho
    • Asian-Australasian Journal of Animal Sciences
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    • 제32권10호
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    • pp.1565-1572
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    • 2019
  • Objective: This study was aimed to investigate the effects of brewer's yeast hydrolysate (YH) on growth performance, nutrients digestibility, blood profiles and meat quality of growing pigs. Methods: A total of 200 growing pigs ($[Landrace{\times}Yorkshire]{\times}Duroc$) (initial body weight, $25.31{\pm}1.29kg$) were allotted to 5 treatments as follow: CON, basic diet; and YH treatment, CON+0.05%, 0.1%, 0.5%, and 1.0% of YH, respectively. Results: On wk 11, 16 and overall phase, pigs fed YH diet showed a linear improvement in average daily body gain and gain/feed (p<0.05). The pigs that received YH linearly increased the digestibility of dry matter, nitrogen, and energy on wk 11 and 16. The concentration of serum urea nitrogen was linearly increased in YH treatments on wk 16. However, the carcass weight, back fat and lean muscle percentage of pigs receiving YH had no significant change. Besides, no difference was observed in creatinine and total protein in the blood among treatments. Conclusion: The pigs fed a graded YH diet had improved growth performance and nutrient digestibility, meanwhile, the YH increased the serum urea nitrogen in the growing pigs.

본초학적 접근을 통해 본 국내에서 연구된 한약재의 사염화탄소로 유발된 간손상에 대한 간보호 효과 (Domestic review of Korean medical treatment on Carbon Tetrachloride-induced Hepatotoxicity - Focusing on Treatment of Korean Herbal Medicine)

  • 김나현;김수일;신민규;김진주
    • 동의생리병리학회지
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    • 제25권5호
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    • pp.919-926
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    • 2011
  • The purpose of this study is to inspect trends of the paper of Korean medical treatment on Carbon Tetrachloride-induced Hepatotoxicity and try to establish the future direction for development of Korean herbal medicine. We reviewed 79 papers which had been published from 1981 to 2010 in journals published in Korea. According to these studies, Carbon Tetrachloride-induced hepato-celluar degeneration and necrosis induced to increase in serum aspartate amintransferase (AST), alanine aminotransferase (ALT), Alkaline phosphatase (ALP), ${\gamma}$-Glutamyl transferase (${\gamma}$-GTP), lactate dehydrogenase (LDH), bilirubin, blood urea nitrogen (BUN) and albumin levels. In biochemical analyses, antioxidant enzymes such as superoxide dismutase (SOD), Glutathione S-transferase (GST) and catalase in hepatic tissue were remarkably incresed by Carbon Tetrachloride treatment. We found that some of the herbal extracts have a protective effect against Carbon Tetrachloride-induced Hepatotoxicity. More studies of oriental medicinal herbs are required for developing a treatment of hepatotoxicity.

클로렐라 및 수산부산물 발효 비료의 들깻잎 시비효과 (Perilla Leaf Fertilization Effect of Fertilizer by Chlorella and Seafood By-product Fermentation)

  • 안승원;이재면;조용구
    • 한국환경과학회지
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    • 제29권4호
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    • pp.423-434
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    • 2020
  • The effects of amino acid and/or urea liquid fertilizer application on the growth and phytochemicals of Perilla leaves were summarized as follows; The fresh weight of the perilla leaves was in the order of CF, CL, KLF, and control, and 39.7 g, 37.4 g, 36.5 g and 32.3 g were measured. The plant height increased by 71.6 cm in the CF treatment than in the control(54.6 cm). The number of nodes was 14.3 node in CF treatment and 19% more than control(12 node). The vitamin C content tends to be increased by fertilizing the amino acid solution in the perilla leaf. The components of polyvalent unsaturation of n-6 origin were measured in CF treatment, KLF treatment, and control in 10.19 mg, 10.18 mg, and 9.38 mg per 100 g, respectively. Glutamic acid, aspartic acid, leucine, arginine, alanine and lysin were contained in perilla leaf amino acid. Glutaminic acid content was found to be 455.1 mg, 495.6 mg, and 478.8 mg in the control, KLF and CF treatment per 100 g, respectively. Effective nutrition management using amino acid fertilizer optimizes crop yield and profitability, it is important to reduce the negative environmental risks of using fertilizer.

Effect of Route of Trihalomethanes (THM) Administration on Renal Toxicity in Male Rat

  • Chung, Jin-Ho;Lee, Soo-Hwan
    • Archives of Pharmacal Research
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    • 제14권2호
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    • pp.188-192
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    • 1991
  • Single non-lethal doses of chloroform $(CHCL_3)$ dichlorobromomethane $(CHCL_2Br)$, dibromochloromethane $(CHCIBr_2)$, or bromoform $(CHBr_3)$ were administered to male rats. Routes of exposure including single intraperitional (ip) and subcutaneous (sc) injection were used in order to permit comparison of severity of THM effects and renal toxicity was assessed at varied times following treatment. On an equimolar basis, sc administration of $CHBr_3$ (either 12 or 3 mmoles/kg) is more effective at increasing KW/BW than ip $CHCI_3$ treatment. Plasma urea nitrogen (BUN) following ip THM injections are markedly increased with all four THM at 24 hours post treatment. BUN response to $CHCL_2Br$ and $CHCIBr_3$-effected BUN levels have essentially returned to those of vehicle control. THM sc treatment results in a BUN response similar to that seen following ip treatment, with only the time course being different. With the exception of $CHCL_3$, sc and ip-treatments appear to be equally effective in evoking absolute BUN elevations. These results suggest that THM administration induce renal toxicity dependent upon the route or exposure.

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Effects of Dandelion (Taraxzcum coreanum) Supplementation on Milk Yield, Milk Compositions and Blood Characteristics in Lactating Dairy Cows

  • Cho, Jung Youl;Kim, Eun Joong;Lee, Sang Moo
    • 한국초지조사료학회지
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    • 제35권3호
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    • pp.217-224
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    • 2015
  • This study aimed to investigate the effects of Dandelion (Taraxzcum coreanum) supplementation on milk yield, milk composition and blood characteristics in lactating dairy cows. Eight lactating dairy cows were divided into two groups (control: TMR supplementation, treatment: TMR with Dandelion supplementation). The milk yield, milk fat, lactose, solids not fat (SNF) and somatic cells counts (SCC) were not significantly different between the control group and the treatment group, whereas milk protein, milk urea nitrogen (MUN) and free fat acid (FFA) were significantly higher in the treatment group compared to the control (p<0.05). The blood components of the treatment group were compared with those of the control group and only aspartate aminotransferase (AST) appeared significantly high (p<0.05). The other blood components were not significantly different in the two groups. Blood corpuscle components in the groups were not significantly different. Especially, all blood corpuscle components in the treatment group were within the normal range. However, the white blood cells (WBC), lymphocytes (LYM) and hematocrits (HCT) in the control group exceeded the normal range. Based on the above results, the addition of Dandelion to feed increased milk protein, MUN and FFA, but did not significantly affect the composition of the blood and corpuscle in Holstein milking cows.