• Title/Summary/Keyword: alkaline agent

Search Result 210, Processing Time 0.024 seconds

Manufacturing of Korean Traditional Handmade Paper with Reduced Fiber Damage(III)-Potassuim Carbonate Cooking of Paper Mulberry (Broussonetia Kazinoki Sieb) (섬유의 손상이 적은 한지 제조(제 2보) -닥나무 백피의 K2CO3 증자 특성)

  • 문성필;임금태
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.31 no.3
    • /
    • pp.83-89
    • /
    • 1999
  • Bast fibers of paper mulberry ( Broussonetia Kazinoki Sieb) were cooked with a weak alkaline salt, potassium carbonate which has been known as a major inorganic component of the traditional lye, and its cooking characteristics were investigated . The bast fiber was easily cooked by potassium carbonate. The pulp yield was rapidly decreased up to 20-30 mol of potassium carbonate, but the Kappa number was slowly decreased with increasing of potassium carbonate. The potassium carbonate pulps were easily defibered at low cooking chemical charge of 25mm on and high pulp yield of about 80%. These results were confirmed that pectin was easily removed during the potassium carbonate cooking. In contrast, when sodium carbonate was used as a cooling agent, the bast fiber was only partially defibered. Thus, sodium carbonate was a less effective cooling chemical of the bast fiber. The results of this experiment indicated that potassium carbonate could not only be used as a good cooling agent of bast fiber, but also as an alternative agent of sodium hydroxide.

  • PDF

Studies on the Production of Protease by Aspergillus oryzae KC-15 and Characteristics of the Enzymes (Aspergillus oryzae KC-15에 의한 protease의 생산 및 그 효소의 특징에 관한 연구)

  • 이미자;정만재
    • Microbiology and Biotechnology Letters
    • /
    • v.8 no.2
    • /
    • pp.77-85
    • /
    • 1980
  • This experiment was conducted to investigate the conditions for production and the characteristics of pretenses. Aspergillus oryzae KC-15, which is selected as a superior strain for the production of the protease, was used in this study. The results obtained were as follows: 1. The optimum culture time for the production of acid, neutral and alkaline protease on wheat bran medium were about 48, 48 and 72hr, respectively. The protease-produced by the strain were mainly alkaline and neutral one, but the production of acid protease was feeble extremely. 2. The addition of NaH$_2$PO$_4$, Na$_2$HPO$_4$, glucose, rice powder and Na-glutamate respectively to wheat bran media were effective for the production of alkaline and neutral protease, and the addition of (NH$_4$)$_2$HPO$_4$, glucose and rice powder respectively were effective for the production of acid protease. 3. Characteristics of professes(equation omitted) 4. As a heat resistance agent, NaH$_2$PO$_4$was the most effective one. The optimum amount of NaH$_2$PO$_4$was 10mg for alkaline and neutral protease, and 5mg for acid protease. 5. The heat resistance of the Protease by NaH$_2$PO$_4$was not recognized mostly above 6$0^{\circ}C$. 6. After the treatment of enzyme solution with 10mg of NaH$_2$PO$_4$for 30 minutes at 55$^{\circ}C$, the residual activities measured for alkaline, neutral and acid protease were 58, 57 and 55% respectively.

  • PDF

Effects of Coal Fly Ash as a Bulking Agent under Co-composting with Swine Manure and Saw Dust

  • Lee, Chang Hoon;Park, Seong Jin;Kim, Myung Sook;Yun, Sun Kang;Sonn, Yeon Kyu
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.47 no.5
    • /
    • pp.356-361
    • /
    • 2014
  • The coal fly ash (CFA) may be utilized as an extender for organic waste composting at the same time fully expected to solve all industrial waste disposal and sawdust tribe. The main objective in this study was to evaluate the effect of CFA addition as a bulking agent for swine manure composting. To determine the suitable addition rate of CFA as a bulking agent, 0, 10, 20 and 30% of saw dust were mixed with 30, 20, 10 and 0% of coal fly ash, respectively. Compost quality for swine manure composting was to evaluate temperature, pH, C/N ratio, and phytotoxicity as germination index. Stability of compost increased with increasing levels of CFA as bulking agent during swine manure composting due to the high alkaline materials including CFA. C to N ratio in treatment added CFA was higher than that of the control without CFA. After finishing composting, germination index of lettuce and cabbage in swine manure compost added 10% of CFA was similar to the control, all the heavy metal contents were far below the stipulated standard for organic farming. These results indicated tahr coal fly ash as bulking agents might be alternative materials to save saw dust and apply industrial products for swine manure composting.

The Adsorption Properties of Heavy Metal Ions on to Cotton Fabrics Treated with Reactive Anionic Agent (반응형 음이온화제 처리 면직물에 대한 중금속 이온의 흡착특성)

  • Kim Mi-Kyung;Yoon Seok-Han;Kim Tae-Kyeong;Lim Yong-Jin
    • Textile Coloration and Finishing
    • /
    • v.17 no.1
    • /
    • pp.20-29
    • /
    • 2005
  • Cotton fabric was treated with a reactive anionic agent in order to have anionic sites(-S03-) on it, which made it possible for the fabric to adsorb various cationic materials. In this study, the adsorptivity of various heavy metal ions such as Pb(II), Cd(II), Cr(III), Co(II), Cu(II), Ni (II) and Cr(VI) on the cotton fabrics treated with anionic agent was examined at the various conditions; concentrations of heavy metal ions, pHs of solution, reaction time and temperature. As a result, the adsorptivity of the heavy metal ions on the cotton fabrics treated with the anionic agent was highly increased comparing to that of untreated cotton fabrics. The order of the adsorptivity was as follows: $Pb(II)>Cd(II)>Cu(II)\geqNi(II)\geqCo(II)>Cr(III)\ggCr(VI)$. The adsorption amounts of most heavy metal ions were increased in weak alkaline conditions and were reached to an adsorption equilibrium within 10 ~ 30 minutes. The maximum adsorption ratios of Pb(II) and Cd(II) were respectively 99% and 80% of the initial concentration of heavy metal ions. Therefore the anionized cotton fabrics seem to be utilized as an adsorption fabrics for the removal of heavy metal ions in the waste water.

Evaluation of Ciclopirox as a Virulence-modifying Agent Against Multidrug Resistant Pseudomonas aeruginosa Clinical Isolates from Egypt

  • Zakaria, Azza S.;Edward, Eva A.;Mohamed, Nelly M.
    • Microbiology and Biotechnology Letters
    • /
    • v.47 no.4
    • /
    • pp.651-661
    • /
    • 2019
  • Targeting the pathogen viability using drugs is associated with development of drug resistance due to selective pressure. Hence, there is an increased interest in developing agents that target bacterial virulence. In this study, the inhibitory effect of ciclopirox, an antifungal agent with iron chelation potential, on the microbial virulence factors was evaluated in 26 clinical MDR Pseudomonas aeruginosa isolates collected from Alexandria Main University Hospital, a tertiary hospital in Egypt. Treatment with 9 ㎍/ml ciclopirox inhibited the hemolytic activity in 70% isolates, reduced pyocyanin production, decreased protease secretion in 46% isolates, lowered twitching and swarming motility, and decreased biofilm formation by 1.5- to 4.5-fold. The quantitative real-time PCR analysis revealed that treatment with ciclopirox downregulated the expression levels of alkaline protease (aprA) and pyocyanin (phzA1). Ciclopirox is used to treat hematological malignancies and the systemic administration of ciclopirox is reported to have adequate oral absorption with a satisfactory drug safety profile. It is important to calculate the appropriate clinical dose and therapeutic index to reposition ciclopirox from a topical antifungal agent to a promising virulence-modifying agent agent against P. aeruginosa, a problematic Gram-negative pathogen.

Effects of Hydroxide and Silicate ions on the Plasma Electrolytic Oxidation of AZ31 Mg Alloy (AZ31 마그네슘 합금의 플라즈마전해산화 피막 형성에 미치는 수산화 이온 및 규산 이온의 영향)

  • Moon, Sungmo;Yang, Cheolnam;Na, Sangjo
    • Journal of the Korean institute of surface engineering
    • /
    • v.47 no.4
    • /
    • pp.147-154
    • /
    • 2014
  • Formation behavior of PEO (Plasma Electrolytic Oxidation) films on AZ31 Mg alloy was studied in aqueous solutions containing various concentrations of hydroxide ion ($OH^-$) and silicate ion ($SiO_3{^{2-}}$) by voltage-time curves, and corrosion resistance of the PEO film-covered specimen was investigated by immersion test in 0.5 M NaCl solution. From the analyses of the voltage-time curves, it is suggested that two different types of anions are essentially needed for the formation of PEO films on AZ31 Mg alloy: film formation agent and local film breakdown agent. $SiO_3{^{2-}}$ ion acts only as a film formation agent but $OH^-$ ion acts not only as a film formation agent but also film breakdown agent. The PEO films prepared on AZ31 Mg alloy in alkaline silicate solution showed very good corrosion resistance without any pitting or filiform corrosions up to 480 h of immersion in 0.5 M NaCl.

Extracellular Novel Metalloprotease from Xenorhabdus indica and Its Potential as an Insecticidal Agent

  • Pranaw, Kumar;Singh, Surender;Dutta, Debjani;Singh, Nirpendra;Sharma, Garima;Ganguly, Sudershan;Kalia, Vinay;Nain, Lata
    • Journal of Microbiology and Biotechnology
    • /
    • v.23 no.11
    • /
    • pp.1536-1543
    • /
    • 2013
  • Proteases produced by Xenorhabdus are known to play a significant role in virulence leading to insect mortality. The present study was undertaken to purify and characterize protease from Xenorhabdus indica, an endosymbiont of nematode Steinernema thermophilum, and to decipher its role in insect mortality and its efficacy to control Helicoverpa armigera. A set of 10 strains of Xenorhabdus isolated from different regions of India were screened for protease activity on the basis of zone of clearing on gelatin agar plates. One potent strain of Xenorhabdus indica was selected for the production of protease, and the highest production (1,552 U/ml) was observed at 15-18 h of incubation at $28^{\circ}C$ in soya casein digest broth. The extracellular protease was purified from culture supernatant using ammonium sulfate precipitation and ion-exchange chromatography. The enzyme was further characterized by SDS-PAGE and zymography, which confirmed the purity of the protein and its molecular mass was found to be ~52 kDa. Further MALDI-TOF/TOF analysis and effect of metal chelating agent 1,10-phenanthrolin study revealed the nature of the purified protease as a secreted alkaline metalloprotease. The bioefficacy of the purified protease was also tested against cotton bollworm (Helicoverpa armigera) and resulted in $67.9{\pm}0.64%$ mortality within one week. This purified protease has the potential to be developed as a natural insecticidal agent against a broad range of agriculturally important insects.

Improvement of the Early Age Strength of Low Cement Concrete Using High Volume Mineral Admixture

  • Park, Jong-Ho;Kim, Yong-Ro;Song, Young-Chan;Song, Dong Yub;Kim, Gyu-Yong
    • Journal of the Korea Institute of Building Construction
    • /
    • v.12 no.6
    • /
    • pp.566-574
    • /
    • 2012
  • To address the problem of global warming, consumption of cement, the main material of concrete, should be decreased. Unfortunately, when industrial by-products are used in large quantities as admixture, the early age strength of concrete will be decreased, reducing its viability for use in concrete structures. Therefore, in this study, the application of an ionization accelerator and alkaline activator as addition agent of superplasticizer were investigated to secure a similar early age strength to that of normal concrete, thus increasing the viability of low cement concrete. Through the investigation, it was found that specimens that used a combination of Alkaline-activator (Na2Sio3) and ionization accelerator (Amine) had the highest early and long-age compressive strength. From this, we can determine an appropriate range of application of superplasticizer to improve early-age compressive strength of low cement concrete.

Preparation and Analysis of Alkaline Powder Cleaning Agents for Steel (철강용 알칼리 분말세정제의 제조 및 세정해석)

  • Lee, Ae-Ri;Chung, Dong-Jin;Park, Hong-Soo;Im, Wan-Bin
    • Journal of the Korean Applied Science and Technology
    • /
    • v.20 no.4
    • /
    • pp.283-288
    • /
    • 2003
  • Alkaline powder cleaning agents (APCAs) were prepared by blending of $Na_2CO_3$ tetrasodium pyrophosphate (TSPP). sodium orthosilicate (Na-OSi), Na-dioctyl sulfosuccinate (303C), Demol C, and MJU-100A (100A). The physical properties of APCAs tested with steel specimen showed the following results. The cleaning powers of APCA-6 ($Na_2CO_3$ 250g/TSPP 70g/Na-OSi 40g/303C 60g/Demol C 50g/100A 30g mixture) for press-rust preventing oil was 97% and 98% degreasing at 2wt%, $70^{\circ}C$ and $90^{\circ}C$, respectively; for Quenching oil, the cleaning power of APCA-6 was 95% degreasing at 2wt% and $70^{\circ}C$. From the results, it was ascertained that APCA-6 exhibited a good cleaning power. Also low foaming power tests proved that the APCA-6 maintained good defoaming effect.

The Effect of Temperature, Cooling and Surface Tension on the Fining in Alkali-Alkaline Earth-Silica Glassmelts Containing ZnO

  • Kim, Ki-Dong
    • The Korean Journal of Ceramics
    • /
    • v.4 no.3
    • /
    • pp.176-182
    • /
    • 1998
  • The effects of temperature, cooling surface tension on the fining were studied in alkali-alkaline earth-silica TV screen glassmelts containing ZnO. Sodium antimonate $(Na_2OSb_2O_5)$ was used as a fining agent. Viscosity and surface tension of the melts were determined. On the basis of these properties, fining tests for several batches were performed by "MF" (Melting and Fining) and "PMF" (Profiled melting and Fining) methods. The results of these tests showed an opposite behavior each other with increase in ZnO content. This hehavior has been discussed in terms of two fining processes-growth of bubbles and shrinkage of seeds. shrinkage of seeds.

  • PDF