• Title/Summary/Keyword: Acid and Alkali

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Purification and Characterization of Alkali-resistant Amylases from Pseudomonas sp. (Pseudomonas sp.로부터 알칼리내성 amylase의 정제 및 특성 확인)

  • Lee, Jeong-Eun;Jhon, Deok-Young
    • Korean Journal of Food Science and Technology
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    • v.40 no.1
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    • pp.70-75
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    • 2008
  • Two extracellular amylase isozymes were purified and characterized from alkalophilic Pseudomonas sp. KFCC 10818 for the production of maltooligosaccharides. The molecular weights of the homogeneous proteins were 50 kDa and 75 kDa, respectively. The 50 and 75 kDa amylases showed optimum temperatures at 35 and $40^{\circ}C$, respectively. The optimum pH of the enzymes ranged from pH 6-8, and the enzymes were resistant to an alkaline condition of pH 12. Via the enzyme's actions, the final products from maltooligosaccharides or soluble starch were maltose and maltotriose. Calcium was a potent activator of the 50 kDa amylase. Finally, the N-terminal amino acid sequences of the 50 and 75 kDa amylases were QTVPKTTFV and DTVPGNAFQ, respectively.

Synthesis of Co(II), Ni(II) and Cu(II) Complexes from Schiff base Ligand and Reactivity Studies with Thermosetting Epoxy Resin

  • Lakshmi, B.;Shivananda, K.N.;Prakash, Gouda Avaji;Rama, Krishna Reddy K.;Mahendra, K.N.
    • Bulletin of the Korean Chemical Society
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    • v.32 no.5
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    • pp.1613-1619
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    • 2011
  • A hybrid thermosetting maleimido epoxy compound 4-(N-maleimidophenyl) glycidylether (N-MPGE) containing Co(II), Ni(II) and Cu(II) ions was prepared by curing N-MPGE and tetradentate Schiff base Co(II), Ni(II) and Cu(II) complexes. The curing polymerization reaction of N-MPGE with metal complexes as curing agents was studied. The cured samples were studied for thermal stability, chemical (acid/alkali/solvent) and water absorption resistance and homogeneity of the cured systems. The tetradentate Schiff base, 3-[(Z)-2-piperazin-1-yl-ethylimino]-1,3-dihydro indol-2-one was synthesized by the condensation of Isatin (Indole-2, 3-dione) with 1-(2-aminoethyl)piperazine (AEP). Its complexes with Co(II), Ni(II) and Cu(II) have been synthesized and characterized by microanalysis, conductivity, Uv-Visible, FT-IR, TGA and magnetic susceptibility measurements. The spectral data revealed that the ligand acts as a neutral tetradentate Schiff base and coordinating through the azomethine nitrogen, two piperazine nitrogen atoms and carbonyl oxygen.

모발(毛髮)의 Carotinoid계(係) 색소(色素) 염색(染色)에서 Chitosan 처리순서(處理順序)가 모발(毛髮)의 염색성(染色性)과 역학적(力學的) 특성(特性)에 미치는 영향(影響)

  • Kim, Kyung-Sun;Jeon, Dong-Won;Kim, Jong-Jun;Ahn, Byung-Tae
    • Journal of Fashion Business
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    • v.11 no.5
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    • pp.79-89
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    • 2007
  • The effect of chitosan treatment on the dyeing and dye fastness, and mechanical properties of hair was investigated in this study when the carotinoid dyestuffs extracted from African Marigold(Tagetes erecta L.) were applied to the hair. The sequences of the chitosan treatment were changed in dyeing and mordanting procedures, i.e., pre-treatment, mid-treatment, and post-treatment. While the effect of chitosan application on the color shade change was not significant, the pre-treatment of the chitosan increased the dye uptake. Discoloration and fading was observed in the lightfastness test when chitosan was mid-treated. Alkali perspiration and acid perspiration fastness test results showed that chitosan post-treatment gave lower tendency. Washing fastness results showed that chitosan post-treatment and mid-treatment gave lower values, which indicates that chitosan deters the direct formation of insoluble complex among fiber-dyestuff-mordant. In the mechanical characteristics results, however, initial modulus and breaking strength increased significantly in the post-treatment and pre-treatment of chitosan.

Effective Functionable Water Generation Characteristics of a Slit Type Parallel Plate Electrode System in Water (수중 슬릿형 평행평판전극계에 의한 효과적인 기능수 발생특성)

  • Lee, Dae-Hee;Kim, Jin-Gyu;Moon, Jae-Duk
    • Proceedings of the KIEE Conference
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    • 2000.07e
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    • pp.26-28
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    • 2000
  • A novel oxidant generation and ion precipitation cell with slits on parallel plate electrodes system has been proposed and an effect of the number and size of slits on ion precipitation and oxidant generation characteristics. As a result, with the electrodes with 48 slits($S=200{\times}60[mm^2]$. d = 1.5, 5.0 [mm]), it is found that the oxidant contained waters of 17.0 [ppmm] and 23.5 [ppmm] in acid water were obtained with 0.1 [wt%] NaCl dissolved tap water fed. And oxidant contained waters of 0.5 [ppmm] and 1.5 [ppmm] in alkali water were obtained with 0.1 [wt%] NaCl dissolved tap water fed. And the oxidant contained waters of 7.0 [ppmm] and 11.5 [ppmm] in mixed water were obtained with tap water and 0.1 [wt%] NaCl dissolved tap water fed. Consequently, very high ion precipitation and dense oxidant generation characteristics can be realized by having slits on the electrodes of conventional cells as these slits increase the electric fields and decrease the space charge limiting actions in interelectrode space.

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Roles of polypropylene beads and pH in hybrid water treatment of carbon fiber membrane and PP beads with water back-flushing

  • Song, Sungwon;Park, Yungsik;Park, Jin Yong
    • Membrane and Water Treatment
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    • v.10 no.2
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    • pp.155-163
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    • 2019
  • The roles of polypropylene (PP) beads and pH on membrane fouling and treatment efficiency were investigated in a hybrid advanced water treatment process of tubular carbon fiber membranes (ultrafiltration (UF) or microfiltration (MF)) and PP beads. The synthetic feed including humic acid and kaolin flowed inside the membrane, and the permeated contacted the PP beads fluidized in the space between the membrane and the module with UV irradiation and periodic water back-flushing. In the hybrid process of UF ($0.05{\mu}m$) and PP beads, final resistance of membrane fouling ($R_f$) after 180 min increased as PP beads increased. The turbidity treatment efficiency was the maximum at 30 g/L; however, that of dissolved organic matters (DOM) showed the highest at PP beads 50 g/L. The $R_f$ strengthened as pH of feed increased. It means that the membrane fouling could be inhibited at low alkali condition. The treatment efficiency of turbidity was almost constant independent of pH; however, that of DOM showed the maximum at pH 5. For MF ($0.1{\mu}m$), the final $R_f$ was the minimum at PP beads 40 g/L. The treatment efficiencies of turbidity and DOM were the maximum at PP beads 10 g/L.

Two Cases of Inhalation Injury Caused by An Explosion of Two Different Chemical Disinfectants(Sodium Dichloroiso Cyanurate & Calcium Hypochlorite) in a Swimming Pool (수영장에서 소독제 분말 가스 폭발에 의한 흡입화상 2례)

  • Lee, Su Jin;Park, Eun Young;Kim, Mi Ran;Lee, Kon Hee;Kim, Kwang Nam
    • Clinical and Experimental Pediatrics
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    • v.46 no.2
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    • pp.198-202
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    • 2003
  • Of all toxic inhalant exposures, chlorine is one of the most common toxic chemical inhalants. When acutely inhaled, it can be responsible for symptoms ranging from upper air way irritation to more serious respiratory effects. It can also deteriorate lung function and lead to death. Chlorine and its compounds such as chlorinated cyanurates and hypochlorites are commonly used in water disinfection. The chemical agents discussed in this article are sodium dichloroiso cyanurate and calcium hypochlorite which are the two most popular products for swimming pool chlorination. They are both strong oxidizing agents which are soluble in water. Between the above two alkali agents, acid-base interaction occurred and generated heat. And the acid drove the combination of hypochlorous and chloride ions to form chlorine gas. We have experienced, two boys who had inhalation injuries caused by an accidental explosion which occurred in a swimming pool by mixing two different chlorinating agents : sodium dichloroiso cyanurate and calcium hypochlorite. The children suffered from respiratory difficulties after the exposure. They both required intensive care management and one needed the support of mechanical ventilation.

Preparation of Mook with Sea Mustard and Sea Tangle 2. Calcium Contents and Histochemical Changes during Processing Mooks (미역과 다시마를 주원료로 한 묵 제조 2. 묵 제조 과정중 칼슘 함량 및 조직학적 변화)

  • 정용현;국중렬;장수현;김종배;최선남;강영주
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.23 no.1
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    • pp.164-169
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    • 1994
  • $Ca^{++}$ content and histochemical changes during processing Mooks prepared with sea mustard (Undaria pinnatifida) and sea tangle (Laminaria japonica) were studied. $Ca^{++}$ content of sea mustard Mook during gelation in $CaCl_2$ solution was not only increased fast, but also decreased fast during soaking in distilled water as comparing with that of sea tangle Mook. Both solubilization of the seaweeds by 1 % $K_2HPO_4$ and filtration of solubilized seaweed were decreased the extruding amount of $Ca^{++}$ from Mooks during soaking. The cell walls in sea mustard were likely irregular and ling, but those in sea tangle were regular and round shape. alginic acid was mainly occurred around cell walls. The alginic acid was gradually solubilized depending on heating and alkali treatment. Thus, the fillament cells in sea tangle were cut finely during processing Mook, while those in sea mustard were remained tolerably.

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Enzymatic Bleaching of Kraft-pulp with Horseradish Peroxidase and Radical Mediator (Horseradish Peroxidase와 라디칼 전달체를 이용한 Kraft 펄프의 표백)

  • 류근갑;권오열
    • KSBB Journal
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    • v.16 no.2
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    • pp.179-182
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    • 2001
  • The use of 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid)(ABTS) as a radical mediator enhanced the bleaching efficiency of kraft pulp by horseradish peroxidase(HRP) and $H_2O_2$. High concentrations of up to 20 mM $H_2O_2$. were used. The bleaching of the kraft pulp increased as the amount of HRP and ABTS concentration were inceased up to 0.3 mg/90 mL and 2 mM, respectively. The bleaching of the kraft pulp was closely related with the HRPs activity and its adsorption onto the pulp. The activity of HRP and bleaching of kraft pulp were maximum at pH 7 and were reduced either in a acidic or alkaline solutions. The adsorption of HRP onto pulp was low in solutions of pH 6-8 and high in an acidic(pH5) and an alkaline solutions(pH 9). The adsorption of the enzyme was greater for alkali-lignin than for crystalline cellulose, the two major components of pulp.

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Purification and Characterization of the Gelatin from the Bone of Cod, Gadus macrocephalus (대구뼈로부터 젤라틴의 추출정제와 특성)

  • Kim, Se-Kwon;Jeon, You-Jin;Lee, Byoung-jo;Lee, Chang-Kook
    • Journal of Life Science
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    • v.6 no.1
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    • pp.14-26
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    • 1996
  • In order to effectively utilize fish(Cod, Gadus macrocephalus) bone obtained as fish waste in fish manufactory, the preparation of the fish bone gelatin were attempted by heat extracting method from collagen protein contained in the fish bone. The methods of two kinds pretreatments (the B-type by alkali pretreatment and the E-type by enzyme pretreatment) for fish bone and the optimal extraction conditions to prepare gelatin from pretreated fish bone were investigated. Physical properties and functionalities of the two type fish bone gelatins obtained were compared with the commercial gelatin and the fish skin gelatin. The optimal extraction conditions of the B-type and the E-type gelatins were 5 folds of added water with material(w/w), pH 5.0, 3 hrs of extraction time and 60$\circ$C of extraction temperature. The yield of the B-type and the E-type gelatins were 32.6% and 28.1 %, respectively. The B-type gelatin was superior to the E-type un all physical properties. Molecular weight of the B-type was larger than that of the E-type due to its pretreatment method. Among the composition of amino acids, the amino acids such as glycine, alanine, glutamic acid and imino acids(proline and hydroxyproline) were responsible for 68$\sim$70% of the total amino acids. Functionalities of the fish bone gelatin were almost similar to commercial gelatin.

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Isolation of Methylotrophic Actionmycetes Capable of Producing Antagonistic Activity Against Oral Resident Bacteria and Screening of Mutants (구강상재균을 중심으로 항균력을 나타내는 메탄올 자화방선균의 분리 및 변이주 생산)

  • Park, Myoung-Ho;Lee, Hwa-Sik;Bae, Bong-Jin;Kim, Joung
    • Journal of Technologic Dentistry
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    • v.22 no.1
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    • pp.145-152
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    • 2000
  • In order to select an effective antibiotic substance against oral resident bacteria, we were isolated from soil and texonomically analyzed. Seven hundred and eighteen strains were isolated on humic acid- vitamin agar(HV agar) and 220 strains were on methanol medium from three each paddy forest, field and riverside soil samples. So, during the screening of antibiotics from soil, we isolated microorganisms showing powerful antagonistic activity against oral resident bacteria. Microorganism was tested against 25 strains of bacteria, yeast and fungi. Among them, No. 248 strain exhibited the most strongly growth inhibition. So, the taxonomical analysis the isolated strain was found to be unknown Actinomyces sp. and was named No 248. A production of the antibiotics from No. 248 begins at the early exponential phase developed at the 72th hour under the optinum conditions. The property of No. 248 antimicrobial compound was very stable under acid(pH 3.0) and alkali(pH 10.0) treatment, but it was instable in heat treatment at $120^{\circ}C$. For the improvement of antibiotic activity, two mutants were isolated from strain No. 248 by the treatment of mutagenic agents, NTG and hydroxylamine. As a result, the mutant strains excreted the potent antibiotics to inhibit the growth of Candida albicans.

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