• Fashion & Textile Research Journal
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• v.15 no.2
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• pp.302-308
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• 2013

This study is a preliminary investigation of the influence of surface characteristics of substrates on detergency of particulate soil. The surface of PET film was modified with NaOH and NaOH+ethylene diamine on different times. The surface morphology of the film was scanned by AFM and surface energies were calculated from measured contact angles between several solutions and film based on the geometric mean and a Lewis acid base method. The surface morphology of PET film treated with NaOH and NaOH+ethylene diamine became more etched, and the surface area, surface roughness and the coefficient of friction of film increased with treatment of NaOH and NaOH+ethylene diamine. The contact angle of film treated with NaOH and NaOH+ethylene diamine decreased in water and surfactant solution; in addition, the surface energy increased was largely attributed to the increased portion on the polar surface energy of film. However, the effect of the diamine addition to the NaOH treatment solution on surface characteristics of PET film was insignificant.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.232-237
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• 2005

This study was conducted to elucidate the effects of NaOH fusion treatment on Na-P1 zeolite synthesis from fly ash and to evaluate its optimal condition. NaOH fusion treatment of fly ash led to Na-P1 zeolite with shorter reaction time and higher quality compared that of simple hydrothermal method. Mixed zeolite phases of Na-P1 and hydroxy sodalite were formed by the fusion treatment below $450^{\circ}C$, whereas only Na-P1 zeolite was formed above $550^{\circ}C$. Ratio of NaOH/fly ash, reaction times, fusion temperature and solid/liquid ratio strongly affected the kind and crystallinity of the zeolite formed. The CEC of Na-P1 zeolite formed at the optimum reaction conditions of NaOH/fly ash ratio 0.9 and solid/liquid ratio $1/5.0{\sim}1/7.5$ after NaOH fusion treatment at $550^{\circ}C$ for 2 hours was about $398cmol^+kg^{-1}$ which was 40% higher than those of control products. Therefore, it is clear that NaOH fusion treatment of fly ash in open system could lead to Na-P1 zeolite with high purity.

• Membrane and Water Treatment
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• v.8 no.2
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• pp.149-160
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• 2017

This study investigated effects of NaOH cleaning on the intrinsic permeability of polyvinylidene fluoride (PVDF) membranes and flux recoveries and membrane resistances under various conditions encountered during ultrafiltration in water treatment plants. The NaOH cleaning using 10,000 mg/L NaOH led to discoloration of PVDF membranes and had little effect on water flux. The NaOH cleaning was efficient in removing the fouling layer caused by humic water. However, long filtration induced a fouling layer that was not removed easily by NaOH cleaning. The lower temperature during filtration yielded rapid increases in transmembrane pressure and decreases in NaOH cleaning efficiency. The alkaline cleaning of PVDF changed the membrane properties such as the hydrophobicity and morphology. Foulant properties, operational conditions such as temperature, and chemical agents should be considered for cleaning strategies for PVDF applied in water treatment.

• Journal of Sericultural and Entomological Science
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• v.42 no.1
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• pp.31-35
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• 2000

When insoluble sericin was hydrolyzed by treatment of NaOH solution, the solubility was increased with higher treatment temperature and longer treatment time. Whereas it was decreased in addition of NaHSO$_3$. As the results of electrophoresis in sericin powder obtained by the NaOH treatment, a distinguishable band was not confirmed. Average degree of polymerizations(A.D.P.) of sericin hydrolyzed by NaOH solutions were about 19.6∼22.1 and average molecular weight(M.W.) were about 2,200∼2,500. The longer hydrolysis time increased the whiteness of sericin powder. As the results of amino acid analysis, the contents of Thr., Tyr., and Ser. were decreased in NaOH hydrolysis as compared to HCl hydrolysis. In DSC analysis, thermal deformation and pyrolysis peak located at near 230$\^{C}$ and 320$\^{C}$, respectively.

• Tuberculosis and Respiratory Diseases
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• v.65 no.5
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• pp.379-384
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• 2008

Background: Sputum decontamination with NALC-NaOH (N-acetyl-L-cysteine-sodium hydroxide) is known to better detect Mycobacterium tuberculosis (M. tb) by culture than that with using NaOH, which is widely used in Korean hospitals. In this report, sputum samples collected from pulmonary tuberculosis (TB) patients were treated with either NaOH or NALC-NaOH, and we compared the results of smear and culture positivity to determine whether the NALC-NaOH treatment method improves culture positivity in the sputum samples, and especially for those sputum samples that are smear negative and scanty. Methods: For each decontamination method, 436 sputum samples from pulmonary TB patients in the National Masan Tuberculosis Hospital were collected for this study. Sputum from a patient was collected two times for the first and second day of sampling time, and these samples were employed for the decontamination process by performing the 4% NaOH and NALC-2% NaOH treatment methods, respectively, for detecting M. tb by an AFB (Acid Fast Bacilli) smear and also by culture in solid Ogawa medium. Results: The NaOH and NALC-NaOH treatment methods did not significantly affect the AFB smear positivity of the sputum samples (33.0% vs 39.0%, respectively, p=0.078). However, the culture positive percents of M. tb in the Ogawa medium treated with NALC-NaOH and NaOH were 39.7% and 28.0%, respectively, which was a significantly different (p=0.0003). This difference in culture was more prominent in the sputum samples that were smear negative (the positive percents with NALC-NaOH and NaOH were 15.8% and 7.2%, respectively, p=0.0017) and scanty (NALC-NaOH and NaOH were 60.8% and 42.9%, respectively, p=0.036), but not for a smear that was 1+ or higher (p>0.05). Conclusion: NALC-NaOH treatment is better than NaOH treatment for the detection of M. tb by culture, but not by smear, and especially when the AFB smear is negative and scanty.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.147-151
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• 2004

Antigenicities of ovomucoid (OM) and ovalbumin (OA) in chicken egg white (EW) before and after NaOH, heat, and pretense treatments were examined by competitive indirect enzyme-linked immunosorbent assay (ciELISA), using rabbit anti-OM and-OA antibodies, Enzymatic hydrolysis of EW did not effectively reduce antigenicity of OM, whereas that of OA was decreased to 1/5,000-1/100,000 by treatment of plant-derived or microbial pretenses. Heat treatment below $100^{\circ}C$ for 30min did not decrease antigenicity of OM, whereas that of OA in heated EW increased maximally to 100 times, Antigenicity of OM in EW effectively decreased by NaOH treatment, disappearing at over 1% NaOH, whereas that of OA increased. Additional heat treatment of NaOH-treated EW at $70^{\circ}C$ for 15min slightly reduced antigenicities of OM and OA.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.240-247
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• 2015

Zeolite A was prepared from coal fly ash upon NaOH fusion treatment, followed by hydrothermal treatment. The effects of treatment conditions such as NaOH/ash ratio, fusion temperature, the amount of sodium aluminate added, hydrothermal treatment temperature and time on the type and the crystallinity of zeolites were investigated. The optimal NaOH/ash weight ratio and fusion temperature to produce high crystalline zeolite A were 1.2 and $550^{\circ}C$, respectively. The dissolution of $Si^{4+}$ and $Al^{3+}$ from the fused fly ash was not affected by stirring time. The type of synthetic zeolites was found to be dependent on the amount of sodium aluminate added. The low amount of sodium aluminate favored zeolite X, while a single phase zeolite A was produced by increasing the amount sodium aluminate. Zeolite A was transformed into hydroxysodalite with increasing hydrothermal treatment time and temperature. A high crystalline zeolite A could be obtained by decreasing the temperature increasing time up to the reaction temperature.

• Journal of Sericultural and Entomological Science
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• v.39 no.2
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• pp.197-202
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• 1997

To hydrolyze silk fibroin was treated with NaOH solution on various concentrations and times. And it was examined that the addition effects of NaHSO3 solution on the solubility and colouring of silk fibroin. As obtained results are as follows; The more increasement of concentration and time of NaOH treatment, the more increasement of solubility but solubility was slight above 3% concentration of NaOH. Fibroin yield was decreased above 3% concentration. This was due to formation of peptide or amino acids below molecular weight 3,000. Most of molecular weight distribution came out to be under 3,000 in 2% concentration and 4hrs of NaOH treatment. The more increasement of adding concentration and 4hrs of NaOH treatment. The more increasement of adding concentration of NaHSO3, the more reduction of solubility but white index of powder increased. In the results of FT-IR spectras of silk fibroin powder obtained by various concentrations of NaHSO3 treatment, the absorbent peak at 3,400 cm-1 which was considered as -CH=N- (azomethine) was disappeared by the more addition of NaHSO3. It showed that absorbent peak of $\beta$-fibroin moved into low temperature region and transferred to $\alpha$- and random coil structure through the DSC experiment. In the results of amino acid analysis, alkali hydrolysis reduced the oxy amino contents acid like serine and tyrosine, but increased the glycine content by the more addition of NaHSO3.

• Textile Coloration and Finishing
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• v.6 no.3
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• pp.1-7
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• 1994

Cotton fiber and NaOH-mercerized cotton fiber had been treated by liquid ammonia and were dyed with two direct dyes, C.I. Direct Red 2 and Blue 1. The effect of the treatment on the rate of dyeing, dye adsorption isotherm, and affinity were studied. The rate of dyeing was increased in the order of NaOH-mercerized> NaOH/liquid ammonia-treated > liquid ammonia-treated>Untreated cotton irrespective of kind of dyes. The rate of dyeing for NaOH-treated fiber considerably increased, whereas liquid ammonia-treated or NaOH/liquid ammonia-treated did not because the structural transformation was not enough for the dyes to penetrate easily into the liquied ammonia-treated cottons. The time of half-dyeing was considerably reduced by mercerizing with NaOH, but lengthened by liquid ammonia treatment because of increased equilibrium dye exhaustion especially in dyeing with C.I. Dierect Red 2. In spite of a short time of the ammonia treatment for 4 seconds, the equilibrium exhaustions of both of direct dyes, C.I. Direct Red 2 and C.I. Direct Blue 1, were increased in proportion to internal volume of treated cotton under a condition of fixed affinity.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.3
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• pp.37-43
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• 2016

Various mechanical and chemical pretreatment methods including alkali treatment, pre-beating, enzyme treatment and oxidation treatment have been used to reduce the production energy of the microfibrillated cellulose (MFC). Among them, alkali swelling can be helpful to reduce the energy consumption because the internal bonding between fibrils could be weakened. In this study, dimethyl sulfoxide (DMSO) was used as a cosolvent to improve alkali pretreatment efficiency and the effects of NaOH concentration during NaOH-DMSO swelling on changes in fiber characteristics of softwood bleached kraft pulp (SwBKP) were elucidated. For alkali treatment in H2O-DMSO solvents, fiber length were decreased with increasing NaOH concentration while fiber width, curl and WRV were increased. WRV began to increase at 8% NaOH solution. In addition, above 8% concentration of NaOH, crystalline structure of pulp fibers converted from cellulose II to cellulose III by DMSO cosolvent. Comparing the previous results with this study, it was shown that DMSO cosolvent could promote swelling of pulp fibers and thus reduce NaOH concentration for the maximum swelling of fibers.