• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.276-280
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• 1987

Several chiral potassium B-alkyl-9-boratabicyclo[3.3.1]nonanes $(K\; B-R^*-9-BBNH)$ and potassium B-alkoxy-9-boratabicyclo[3.3.1]nonanes $(K \;B-OR^*-9-BBNH)$ were synthesized by treatment of the corresponding trialkylboranes and dialkylmonoalkoxyboranes with a small excess of potassium hydride. The chiral B-alkoxy derivatives generally reduce representative ketones, such as acetophenone and 3-methyl-2-butanone, with greater optical induction than the corresponding B-alkyl derivatives, suggesting the involvement of the oxygen atom in the control process for asymmetric synthesis.

• Corrosion Science and Technology
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• v.10 no.1
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• pp.24-29
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• 2011

The greatest purpose of chromate treatment is to improve anti-corrosion by stabilizing a metal surface. Because metal surface forms a compound by absorbing oxygen or water in the air by being generally unstable, it is necessary to improve anti-corrosion of the metal by forming the metal surface with a stable film. When considering the economical efficiency and requirements together because the film of the metal surface treated with chromate has good anti-corrosion and the stability also in the air by being compact and strong, Chromate treatment has been used most up to the electronics industry from the auto industry. However, these days, because hexavalent chromium is both a toxic agent to be able to cause cancers and deadly poisonous environmental pollutant, the strong legal controls on its use is being imposed all over the world. Because of this reason, a new anti-corrosion method is being required. Also, by users' various demands, the passivations that have recently been developed require various characteristics such as conductivity, chemical resistance, alkali cleaning resistance as well as anti-corrosion. We could confirm the results such as excellent anti-corrosion compared to chromate, conductivity, chemical resistance and detergent resistance as the result of analysis of various characteristics of the galvannealed sheet steels coated with Cr-Free solution developed in this research.

• Applied Chemistry for Engineering
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• v.20 no.2
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• pp.234-240
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• 2009

$Mg(OH)_2$ particles were prepared by precipitation and a hydrothermal treatment to examine the effect of $MgCl_2$ concentration, alkali type and concentration, temperature, hydrothermal treatment on the formation of $Mg(OH)_2$ particles using full factorial design, as one of DOE (Design of experiment) methods. The primary particle size is similar to the secondary particle size for the samples after the hydrothermal treatment, where the average particle size of $Mg(OH)_2$ increased with increasing the concentration of $MgCl_2$ and hydrothermal temperature and decreasing alkali/Mg molar ratio. On the other hand, for the samples prepared from precipitation, the secondary particle size is larger than the primary particles due to aggregation. The difference in alkaline source is that the particles prepared from $NH_4OH$ exhibit the larger size with better dispersion than those from NaOH. Low density polyethylene and ethylene-co-vinyl acetate (LDPE-EVA) resin composed of the smaller secondary particle size of $Mg(OH)_2$ shows a higher limited oxygen index (LOI) at 50 and 55% loading, but the smaller primary particle size may result in a better grade in UL-94 tests. At the high loading of 60%, all samples with any preparation methods exhibit V-0 grade but the LOI value depends on not only primary particle size but also dispersion state.

• Korean Journal of Food Science and Technology
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• v.17 no.3
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• pp.180-185
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• 1985

The alkali refined rice bran oil (ARBO) and the esterified rice bran oil (ERBO) with glycerol were compared for their thermal stabilities at $150^{\circ}C$ and $180^{\circ}C$, respectively. The acid value gradually increased in ARBO during heating period but increased slowly in ERBO-2 and declined gradually in ERBO-1. The peroxide value was somewhat fluctuated during heating period, and the maximum peroxide value in all samples was 13.3 meq/kg. TBA value was sharply increased for the first 10 hr. heating and slowed down thereafter for all samples but ERBO were intensely colored after the heat treatment. The TG ratio of the oils after 90 hr. heating was not different at $150^{\circ}C$ but ERBO was 2-7% higher ratio of TG than ARBO at $180^{\circ}C$. The oxidative stability of ARBO was twice higher than ERBO according to the result of active oxygen test.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.1
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• pp.71-77
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• 2012

In order to find a feasibility of applying an agricultural biomass to the anaerobic digestion system, the effects of pre-treatment of rice straw was investigated by different sizes,temperatures, ultrasonic frequencies, and with/without NaOH treatment on the change of soluble organic matter, which is generated most dominantly in Korea. It was observed that SCOD(soluble chemical oxygen demand) as the index for the decomposition of rice straw increased with the smaller particle size, higher reaction temperature and alkali treatment. With treatment of 5% NaOH, it was shown that the highest concentrations of SCOD were observed at 9,000 mg $L^{-1}$ and 6,000mg $L^{-1}$ at $35^{\circ}C$ and $55^{\circ}C$, respectively. Agitating with ultrasonic irradiation could be enhanced SCOD of rice straw less than 3 cm with 40 kHz of ultrasound. Optimal RPM in this study was at 150 rpm regardless of reaction temperatures.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.4
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• pp.362-367
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• 2006

Waste activated sludge(WAS) collected from domestic wastewater treatment plant is biomass that contains large quantities of organic matter. However, relevant literature show that the bio-hydrogen yield using WAS was too low. In this study, the effect of pretreatment of WAS on hydrogen yield was investigated. Pretreatment includes acid and alkali treatments, grinding, heating, ozone and ultrasound methods. After pretreatment organic matters of WAS were solubilized and soluble chemical oxygen demand(SCOD) was increased by 14.6 times. Batch experiments were conducted to investigate the effects of pre-treatment methods and buffer solution, hydrogen partial pressure, and sodium ion on hydrogen production from WAS by using heated anaerobic mixed cultures. Experimental results showed that addition of buffer solution, efficient pre-treatment method with alkali solution, and gas sparging condition markedly increased the hydrogen yield to 0.52 mmol $H_2/g$-DS.

• Membrane and Water Treatment
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• v.7 no.5
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• pp.417-431
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• 2016

Poly(vinylidene fluoride) (PVDF) powder was treated with aqueous sodium hydroxide to obtain partially defluorinated fluoropolymers with expected properties such as improving hydrophilicity and fouling resistance. Raman spectrum and FT-IR results confirmed the existence of conjugated carbon double bonds after alkaline treatment. As the concentration increased, the degree of defluorination increased. The morphology and structure of membranes were examined. The permeation performance was investigated. The results showed that membrane's hydrophilicity increased with increase of the percentage of alkaline treated PVDF powder. Moreover, in terms of the water contact angle, it decreased from $92^{\circ}$ to a minimum of $68^{\circ}$; while water up take increased from 128 to 138%. Fluxof pure water and the cleaning efficiency increased with the increase of alkaline treated PVDF powder. The fouling potential also decreased with the increase of the percentage of alkaline treated PVDF powder. The reason that makes blending PVDF show different characteristics because of partial defluorination, which led the formation of conjugated C = C bonds and the inclusion of oxygen functionalities. The polyene structure followed by hydroxide attack to yield hydroxyl and carbonyl groups. Therefore, the hydrophilicity of blending membrane was improved. The SEM and porosity measurements showed that no obvious variations of the pore dimensions and structures for blend membranes were observed. Mechanical tests suggest that the high content of the alkaline treated PVDF result in membranes with less tolerance of tensile stress and higher brittleness. TGA results exhibited that the blend of alkaline treated PVDF did not change membrane thermal stability.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.119-127
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• 1996

The effect of sodium hydroxide treatment on some physicochemical properties of zeolite mordenite mineral was studied with chemical analyses, powder X-ray diffraction, thermal analyses, infrared analysis, measurement of carbon dioxide adsorption and gas chromatography. Mordenite mineral from tuffaceous rocks in Yeongil and Wolsung area was used as a starting material and treated with 0.1-5N NaOH aqueous solution at about $95^{\circ}C$ in the water bath for three hours.At the concentration of sodium hydroxide below 0.5N, all chemical compositions in the tuff were virtually insoluble and the mordenite structure did not change. At the concentration above 1N, the chemical compositions such as silica, alumina, etc., were dissolved. The dissolution ratio of silica was lager than that of alumina, and the ratio of silica to alumina in the tuff decreased sharply in the concentration range of 2 to 3N. Intensity of X-ray diffraction peak of mordenite (202) plane and the adsorbed amount of carbon dioxide also decreased with the increasing concentration of sodium hydroxide above 1N. These decreases corresponded to the degree of mordenite structure collapsed.The separation of gas chromatography of nitrogen, oxygen and carbon monoxide was not affected by the sodium hydroxide treatment, but elution peaks of methane and krypton tended to be broadened and their retention time was shortened. The elution peaks of both methane and krypton tended to be overlapped with those of nitrogen and oxygen.

• Journal of Animal Environmental Science
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• v.18 no.3
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• pp.229-234
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• 2012

Disinfecting contaminated swine manure with FMD (Foot-and-Mouth Disease) and pathogenic viruses is very important for maintaining sanitized environment. However, very few research reported on this subject, especially post-disinfection to utilize the wastes as a renewable resource. This research is carried out to obtain basic information for chemical treatment in FMD SOP (Standard Operating Procedure, Korea) of contaminated swine manure. Using lime, sodium hydroxide, citric acid and hydrochloric acid, described in FMD SOP, the effects of chemical treatments on livestock manure were compared in this paper. Four combinations of alkali-acid treatments and four kinds of acid-alkali combinations were tested to find out the effective method. Total coliform bacteria in contaminated swine manure, $1.6{\times}10^4$ CFU/100 ml, decreased to the range of 1/1000~1/100 in all treatments. Some specific disinfectants increases BOD (Biochemical Oxygen Demand) and EC(Electric Conductivity), especially, alkaline treatments increases ammonia level than acid treatments. These findings suggest that the treatment methods should be considered as an important environmental factor in post-disinfection of contaminated animal manure with pathogenic microorganisms.

• Archives of Plastic Surgery
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• v.42 no.1
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• pp.59-67
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• 2015

Background Negative-pressure wound therapy (NPWT) induces angiogenesis and collagen synthesis to promote tissue healing. Although acetic acid soaks normalize alkali wound conditions to raise tissue oxygen saturation and deconstruct the biofilms of chronic wounds, frequent dressing changes are required. Methods Combined use of NPWT and acetic acid irrigation was assessed in the treatment of chronic wounds, instilling acetic acid solution (1%) beneath polyurethane membranes twice daily for three weeks under continuous pressure (125 mm Hg). Clinical photographs, pH levels, cultures, and debrided fragments of wounds were obtained pre- and posttreatment. Tissue immunostaining (CD31, Ki-67, and CD45) and reverse transcription-polymerase chain reaction (vascular endothelial growth factor [VEGF], vascular endothelial growth factor receptor [VEGFR]; procollagen; hypoxia-inducible factor 1 alpha [HIF-1-alpha]; matrix metalloproteinase [MMP]-1,-3,-9; and tissue inhibitor of metalloproteinase [TIMP]) were also performed. Results Wound sizes tended to diminish with the combined therapy, accompanied by drops in wound pH (weakly acidic or neutral) and less evidence of infection. CD31 and Ki-67 immunostaining increased (P<0.05) post-treatment, as did the levels of VEGFR, procollagen, and MMP-1 (P<0.05), whereas the VEGF, HIF-1-alpha, and MMP-9/TIMP levels declined (P<0.05). Conclusions By combining acetic acid irrigation with negative-pressure dressings, both the pH and the size of chronic wounds can be reduced and infections be controlled. This approach may enhance angiogenesis and collagen synthesis in wounds, restoring the extracellular matrix.