• 펄프종이기술
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• 제37권4호통권112호
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• pp.26-31
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• 2005

The purpose of this study was to confirm paper strengthening properties with recently commercialized polyvinylamine. Because of its high cationic charge density, polyvinylamine has been investigated as a size retention and surface coating aids. In this study, we tried to confirm polyvinylamine as wet-end additives to improve dry and wet strength using LBKP and BCTMP pulps. As a result, we found improvement of dry and wet tensile properties of polyvinylamine with BCTMP were much better than LBKP condition. This phenomena could be explained that ionic bonding of cationic charge of polyvinylamine with abundant anionic substances of BCTMP was a very important factor to improve dry and wet strength of paper.

• Ocean and Polar Research
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• 제43권4호
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• pp.353-363
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• 2021

Fluorescent dissolved organic matter (FDOM) is referred to organic matter which absorbs efficiently solar radiation energy and fluorescence in the water column. The component and molecular structure of marine organic matter can be changed depending on the various substances and origins of organic matter, and then the organic matter has unique fluorescent properties. As the cutting-edge analytical techniques of optical measurement continuously developing from last few decades, a study on FDOM has been applied as a biogeochemical tracer to quantify the organic matter concentration and to investigate the behaviors and origins of organic matter. Especially, the marine environment around the Korean Peninsula is an ideal research area to study FDOM because of various oceanographic characteristics and the origins of organic matter. This study describes the general properties of FDOM and introduces the cycling and behaviors of marine organic matter based on the domestic research studies.

• 펄프종이기술
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• 제31권1호
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• pp.10-16
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• 1999

Air froth flotation was applied to OCC recycling process as a new pulp fractionation method and the effects of strength and drainage properties of testliner were also investigated. Fines including inks, stickies, and inorganic substances in OCC stock furnish were efficiently separated by the flotation. After the flotation, selective enzymatic treatment on the flotation reject was separately preformed, and then, the refined long fiber(flotation accept) portion was combined again with the fines(flotation reject) fraction for papermaking. This combination process was found to be effective in improving strength and drainage properties of testliner based on 100% OCC.

• 센서학회지
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• 제26권4호
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• pp.228-234
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• 2017

Gas sensors based on metal-oxide-semiconductors are predominantly used in numerous applications including monitoring indoor air quality and detecting harmful substances such as volatile organic compounds. Nanostructures, e.g., nanoparticles, nanotubes, nanodomes, or nanofibers, have been widely utilized to improve the gas sensing properties of metal-oxide-semiconductors by increasing the effective surface area participating in the surface reaction with target gas molecules. Recently, 1-dimensional (1D) metal oxide nanostructures fabricated using glancing angle deposition (GAD) method with e-beam evaporation have been widely employed to increase the surface-to-volume ratio significantly with large-area uniformity and reproducibility, leading to promising gas sensing properties. Herein, we provide a brief overview of 1D metal oxide nanostructures fabricated using GAD and their gas sensing properties in terms of fabrication methods, morphologies, and additives. Moreover, the gas sensing mechanisms and perspectives are presented.

• 농약과학회지
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• 제12권4호
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• pp.421-428
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• 2008

Adjuvant 첨가에 의한 농약살포액의 이화학적 특성 및 약효증진 효과를 구명하기 위하여 시험한 결과, 농약살포액의 분무입경은 adjuvant의 첨가로 다소 작아지는 경향을 보였으며, 그 효과는 약제 및 보조제의 종류에 따라 상이하였다. 또한 보조제 첨가에 의한 농약의 작물체 부착량은 일정한 경향없이 살포 방법 및 살포량에 따라 상반된 효과를 나타냈다. Adjuvant에 의한 tricyclazole WP와 fenobucarb EC 희석액의 살포 6시간 후 강우처리시 내강우성은 벼의 부위에 따라 $1.5{\sim}4.1$배의 높은 증진효과를 보였다. 또한 보조제 첨가에 의한 Propanil EC의 피 방제효과는 무첨가에 비해 $8{\sim}30%$의 약효 증진 효과를 보여 적절한 보조제를 혼용함으로써 농약의 살포회수 및 사용량을 줄일 수 있는 가능성을 보였다.

• 한국응용과학기술학회지
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• 제30권4호
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• pp.635-648
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• 2013

This study was carried out to investigate the emulsifying properties of surface-active substances from defatted rapeseed cake by supercritical $CO_2$ extraction. Based on the interfacial tension data, a supercritical fluid extract (SFE) with the lowest value of 14.16 mN/m was chosen for evaluation which was obtained from No. 2 extraction condition (150 bar, $65^{\circ}C$, 250 g). For emulsions with SFE, some physicochemical properties (i.e., fat globule size, creaming stability, zeta potential etc) were investigated according to changes in SFE concentration, pH, and NaCl addition in an emulsion. It was found that fat globule size was decreased with increasing SFE concentration in emulsion, with showing a critical value at 0.5 wt%, thereby resulting in less susceptibility to creaming behavior. The SFE emulsion also showed instability at acidic conditions (pH<7.0) as well as by NaCl addition. This was coincided with zeta potential data of emulsion. In addition, SSL (sodium stearoyl lactylate) found to be suitable as a co-surfactant, as it helped considerably in decreasing fat globule size in emulsions and its optimum concentration to be over 0.03 wt%, based on 0.1 wt% SFE in emulsion.

• Transactions on Electrical and Electronic Materials
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• 제4권1호
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• pp.11-14
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• 2003

The regularities of immobilization of natural medicinal substances - alchidine on gels of poly(vinyl alcohol) - are investigated. It is shown that the polymer components of alchidine interact with nonionic polymer with formation of interpolymer complexes. The influence of the different factors on the properties of complexes is considered and the constants of alchidine distribution in the system gel - water are calculated.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.282.2-283
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• 2003

The carboxylated acidic non-steroidal antiinflammatory drugs (NSAIDs) constitute the principal class of agents for controlling the pain and inflammation of the rheumatic diseases. It is mostly administered as a racemic mixture like most other drugs with asymmetric carbon atoms. However enantiomers of many racemic drug substances have been shown to posses different pharmacological toxicological properties. (omitted)

• 한국작물학회지
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• 제48권
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• pp.24-30
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• 2003

Plant fats and oils contain phytosterols as naturally occurring constituents, which are present in pure or esterified form, or conjugated as glycosides. The predominant phytosterol is sitosterol and minor components are campesterol, stigmasterol, $\Delta^7$-avenasterol and brassicasterol. They play a key role in cell membrane function of plants as cholesterol in animals. Phytosterols have been known for many years for their properties for reducing blood cholesterol levels, as well as their other beneficial health effects for cancer preventive biological-active substances. The objective of this paper is to present a description of the recent advances in phytosterols for future research.

• 한국토양비료학회지
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• 제25권4호
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• pp.311-324
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• 1992

Polymeric substances in organic matter of soils aggregate soil particles into a crumb structure which greatly influences such properties as water movement, aeration and heat transfer. Poorly-structured soils may be improved by the incorporation of synthetic polymers where the main objects are : promoting germination or establishing crops, improving drainage, combating wind and water erosion, and reducing evaporation from the surface of soil under arid condition.