• Proceedings of the Korea Air Pollution Research Association Conference
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• 2007.10a
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• pp.208-209
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• 2007

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.324-325
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• 2000

대기 오염 성분에 대한 연구 뿐 만 아니라 반도체 가공 현장의 환경평가를 위한 미량 기체의 효과적인 포집 및 정량 방법이 요구되고 있다(Lue, S. J., 1999). 이들 오염원은 대부분 pub 이하의 농도로 존재하며 순간적으로 변화하므로 분석을 위해서는 연속적으로 여러 원소를 감시할 수 있는 장비가 효과적이다. 이러한 관점에서 스크러버 형태의 확산 포집기와 이온 크로마토그래피를 이용한 대기중 미량 기체의 연속 정량법이 가장 효과적이다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.372-373
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• 2003

오늘날 강수의 오염도는 대기오염의 중요한 지표가 되고 있으며, 특히 산성화된 강수는 생태계에 심각한 악영향을 주고 있어 전세계적으로 이에 대한 연구가 지속적으로 이루어지고 있다. 우리나라에서도 환경부 및 지방자치단체에서 산성비 측정망을 운영하면서 강수의 산성도 및 수용성 이온성분의 농도 측정을 수행하고 있으나 현재 강수자동채취장치와 수동채취장치를 같이 사용하고 있어 그 분석자료의 정도관리에 상당한 문제점이 있는 것으로 드러나고 있다. (중략)

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.645-648
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• 2011

Hydrazine which has been used as monopropellant shows high performance, but because of its high toxicity research for new green propellant that could replace hydrazine is going on. Ionic liquid propellant that is one of the green propellant has lower toxicity, higher specific impulse, and higher density than hydrazine. To design the thruster which use Hydroxylamine Nitrate (HAN), one of ionic liquid propellant, as a propellant, a quantity of catalyst for full decomposition of a propellant is needed. In this study, reference point for HAN thruster design could be suggested through a design of a small scale thruster which used HAN propellant, and propellant decomposition capability evaluation with characteristic velocity efficiency.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.1
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• pp.103-110
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• 2017

In Concentrated Animal Feeding Operations(CAFOs), emission of ammonia from stored manure contributes negatively on the wellness of livestock. In CAFOs facilities, indoor aerial ammonia concentration oftentime surpasses the critical level potentially harmful to livestock's immune system. Understandably, numerous researches to control aerial ammonia have been conducted in countries where CAFOs were practiced for many decades. Some innovative technologies, such as scrubber, bio-filter, and additives emerged, as a result. Among them, microbial additives became popular in Korea, due to an easiness of use and affordability. However, microbial additives still have some weaknesses. Their price is still high enough to discourage farmers who run a small scale farm and their effectiveness are still questioned by many users and researchers. In the present study, we found soluble carbohydrates, such as sugar, glucose, and molasses, when supplemented to pig slurry manure, can mitigate ammonia emission. To be more specific, pig manure slurry(120kg), stored in container(200L), was supplemented with sugar at 0.1%(w/w) and was, subsequently, monitored for pH and aerial ammonia for next 10 days. From this experiment, it was found that the sugar supplementation was effective in mitigating the aerial ammonia concentration (33% in average) when monitored daily. Also, the pH of manure slurry was maintained at relatively low level(8.2) in sugar-supplemented manure slurry while it was elevated to 8.5 in untreated slurry. Conclusively, the obtained data suggest that soluble carbohydrate can mitigate ammonia emission by acidifying manure slurry. Additionally, it can be suggested that soluble carbohydrates, such as sugar, glucose, and molasses, can be reasonable choices for animal farmers who have been looking for an alternative choice to replace expensive microbial additives.

• Microbiology and Biotechnology Letters
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• v.26 no.1
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• pp.55-60
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• 1998

For an ideal extractive bioconversion in aqueous two-phase systems, the product has to be preferentially partitioned into the phase opposite to the one in which the biocatalyst is located. Partitioning behaviors of Lactobacillus helveticus IAM 11090 and lactic acid in aqueous two-phase systems composed a polycation, poly(ethylenimine) (PEI), and an uncharged polymer (hydroxyethyl)cellulose (HEC) were investigated. L. helveticus cells were preferentially partitioned to the HEC-rich top phase while about 85% of lactic acid was partitioned to the PEI-rich bottom phase. These results indicate that extraction of charged, low molecular weight products in an aqueous two-phase systems can be promoted by using an oppositely charged polymer as one of the phase-forming polymer. By the ideal partitioning of the cells and lactic acid, an aqueous PEI/HEC two-phase system can be used as a potential system for the extractive lactic acid fermentation of cheese whey.

• Membrane Journal
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• v.25 no.2
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• pp.144-151
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• 2015

The water-soluble poly(vinyl alcohol) membranes with the addition of sulfosuccinic acid (SSA) were prepared and to assign the ion exchange capacity, poly(4-styrene sulfonic acid-co-maleic acid) (PSSA_MA) was added to PVA according to PSSA_MA contents of 70, 80 and 90 wt%. To characterize the resulting membranes, FT-IR, water contents, ion exchange capacity, proton conductivity and methanol permeability were measured. As PSSA_MA contents increased, water contents, ion exchange capacity, proton conductivity increased, but methanol permeability decreased. From these results, the best preparation component was known as PVA10/SSA9/PSSA_MA80.

• Elastomers and Composites
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• v.39 no.3
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• pp.209-216
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• 2004

Two types of polyurethane-acrylate polymer were synthesized by reaction of 2-hydroxyethyl methacrylate(HEMA), acrylamide(AA), and polyurethane prepolymer. Water-soluble cationic polyurethane/acrylate retention aids were prepared by using polyurethane-acrylate, benzyl chloride and distilled water. The retention, drainage and strength properties of the retention aids were investigated. The retention of cationic polyurethane/acrylate type retention aids maintained around 70 % regardless of nm. COD value of white water was much reduced by adding the retention aids to it. Drainage property was also improved by addition of the retention aids. In addition, specific compression strength of the paper was improved a little by addition of the retention aids. PU-HEMA type showed better performance than PU-AA in terms of compression strength of the paper.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.799-805
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• 2008

In general, anionic and cationic surfactants are incompatible because their mixtures form insoluble complexes and precipitate in the water. There are, however, some equimolar complexes of anionic and cationic surfactant that are soluble and behave like regular surfactants, specifically like nonionic surfactants, thus named pseudo-nonionic surfactant complexes. Pseudo-nonionic complexes are more effective and efficient in surface activities than their ionic surfactant components as shown by their equilibrium and dynamic surface tensions. They pack at the interface more than their ionic components. When a novel cationic surfactant, diglyceryl dodecyl dimethyl ammonium chloride(DGDAC), having the polyhydroxyl group at the hydrophilic head group, was mixed with a conventional anionic surfactant (sodium dodecyl sulfate; SDS) at equimolar ratio, we found that the aqueous equimolar mixture showed strong positive synergism in which molecular interaction parameter ${\beta}^M$ was very low, -17.2. According to the studies of equilibrium phase behavior and microscopy, this mixed system could form homogenous solutions containing vesicles.

• Journal of Conservation Science
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• v.21
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• pp.59-72
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• 2007

The relationship between soluble salts and microbial growth on stone surface was investigated. Samples from deteriorated surface layers of several stone monuments were collected, and the soluble salts in samples were chemically analysed. According to the results of chemical analyses, $Na_2SO_4$, $CaSO_4$ $2H_2O$, and NaCl and so on were added to isolation media. As a result of preliminary experiments, 15 bacteria were selected. They are all Gram positives and fourteen of them were rods. Every bacteria could grow not only in media without salts, but also in media with $CaCO_3$, $CaSO_4$ $2H_2O$, and $Ca(OH)_2$. Three bacteria, Bl6, B56, and B6l, secreted viscous substances in these $Ca^{2+}$ added media. $CaCl_2$ $2H_2O$ was the most hygroscopic among 11 soluble salts, but it seemed to interfere with bacterial growth. Ammonium ion was the inhibitor, too.