• 분석과학
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• 제5권1호
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• pp.63-71
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• 1992

역상 액체 크로마토그래피에 의한 몇 가지 금속-N-Alkylisonitrosoacetylacetone imine 킬레이트의 용리거동을 Novapak $C_{18}$ 분리관을 사용하여 조사하였다. 용리액은 Acetonitrile/Water로 하였으며, 각 금속의 킬레이트의 최적 용리액 조성은 각각 70:30(Pd의 경우), 60:40(Ni의 경우) 및 50:50(Co의 경우)이었으며, 리간드의 alkyl기 종류에 따른 금속 킬레이트의 용리순서는 methyl>ethyl>propyl>butyl 유도체 순이었다. 모든 금속 킬레이트의 log k'값은 $0{\leq}log\;k^{\prime}{\leq}1$의 범위였고, log k'값과 용리액 중 물의 부피분율을 도시한 결과 직선관계가 성립되었다. 또한 뱃치법으로 측정한 분포비(Dc)값의 크기는 금속 킬레이트의 용리순서와 비교적 잘 일치할 뿐만 아니라 Dc값과 k'의 직선관계를 나타냄으로써, 금속 킬레이트의 용리 메카니즘은 주로 소용매성 효과, 즉 소수성 효과에 기인함을 확인하였다.

• 한국수자원학회논문집
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• 제37권6호
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• pp.467-477
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• 2004

물이 부족한 우리나라는 최근 수자원의 효율적인 이용에 대한 중요성이 강조되고 있으며 특히 지금까지 개발된 저류시설을 통한 수자원의 효율적인 관리가 절대적으로 필요한 실정이다 효율적이고 합리적인 수자원관리와 그 이용 효과를 극대화하기 위해 경북지방의 농업용 저수지에 대한 저류용량과 퇴사량의 현황을 분석한 결과 농업용 저수지의 준설을 통하여 10% 이상에 이르는 저류용량을 추가적으로 확보할 수 있음을 확인하였다. 또한 GIS와 각종 토사발생량 예측기법을 활용하여 산정한 퇴사량을 실제 준설량과 비교 분석한 결과 분산모형과 다방향흐름알고리즘을 이용한 기법이 산지에 위치한 저수지 상류의 지형학적 특성을 잘 반영하며 타 기법에 비해 우수한 예측결과를 제시하는 것을 알 수 있었다.

• 생물환경조절학회지
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• 제21권3호
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• pp.213-219
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• 2012

과채류 공정육묘에서 접목작업 후 버려지는 재사용 상토의 이화학적 특성을 개선할 목적으로 재사용상토와 perlite의 혼합비율이 상토의 이화학적 특성과 과채류 묘소질에 미치는 영향을 조사하였다. 재사용 상토의 적정 혼합비율을 구명하기 위한 시험구는 신규상토(NPM: new plug media)와 1회 사용상토구(UPM: used plug media)및 용적대비 재사용상토의 첨가비율을 25, 50 및 75%로 첨가한 5개의 처리구를 설계한 뒤, 각 처리구별 이화학적 특성과 오이 및 토마토 묘의 묘소질에 미치는 영향을 조사하였다. 또, 재사용 상토의 물리성 개선을 위한 적정 펄라이트 첨가 비율을 구명하기 위한 시험구는 UPM에 용적대비 펄라이트를 0, 5, 10 및 20% 첨가구와 NPM과 UPM을 1 : 1(v : v)로 혼합한 혼합상토(Mixed Soil)에 펄라이트를 0, 5, 10 및 20%를 첨가한 8개의 처리구를 설계하여 각 처리구별 이화학적 특성과 오이 및 토마토 묘의 묘소질에 미치는 영향을 대조구(NPM)와 비교하였다. UPM에 NPM의 혼합비율이 증가할수록 상토의 물리적 특성이 개선되는 경향을 보여 50% 이상 첨가구에서는 신규상토와 공극율, 용적밀도, 보수력은 물론 전반적인 묘소질도 NPM과 유의적인 차이를 나타내지 않았다. 상토의 이화학적 특성, 플러그묘의 근권형성 정도, 묘소질 등을 종합적으로 고려한 UPM의 물리성 개선을 위한 펄라이트의 적정 혼합비율은 UPM 단용구에서는 20%, NPM과 UPM을 1 : 1(v : v)로 혼합한 상토에서는 10%인 것으로 판단되었다.

• 펄프종이기술
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• 제33권2호
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• pp.41-48
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• 2001

This paper was made to evaluate the effect of the type of latex for coating on the printability by investigating the structure of pore such as the pore fraction, the number of pores, pore size and distribution of coated paper. The coated structure is mainly depend on the results of interaction between pigment and binder. It means that the structure of pore formed is chiefly affected by the type of latex. This physical properties of pore have a close relation with ink set-off associated with the drying rate, the speed of penetration of ink into base paper and printing gloss. Therefore it was necessary to find out the relationship between pore structure and the performance of printability by modifying the type of latex to vary the pore structure of coated paper. Acrylic latex was superior to S/B latex in the sedimentation volume, compressibility, smoothness, pore fraction and its number, the weight of transferred ink onto the coated paper and ink repellance. In contrast, water retention and ink setting were not good. in the comparison of anionic and amphoteric latex, amphoteric latex showed better performance in the thickness, smoothness, pore fraction and its number, pore size, the weight of ink transmitted and K&N ink receptivity, etc.

• 동아시아식생활학회지
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• 제19권4호
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• pp.641-649
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• 2009

This study was conducted to investigate the effects of wheat germ on medium flour using falling number and RVA tests, as well as farinogram and rheofermentometer analyses. The wheat germ was added to the medium flour on a 3, 5, and 7% basis. Falling numbers increased with increasing amounts of wheat germ. Analysis of the RVA characteristics showed that the wheat germ additions did not have significant effects on the initial pasting temperature. In the farinogram, water absorption decreased with an increasing amount of wheat germ. Also, development time was longest in the control group and shortest in the group with the highest addition of wheat germ. The results of the effects of added wheat germ on fermentation by rheofermentometer analysis showed that the H'm value reached a maximum height at 3%. Finally, the volume of $CO_2$ lost was increased whereas the retention coefficient was decreased.

• Environmental Engineering Research
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• 제23권2호
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• pp.195-204
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• 2018

A pilot scale study was conducted on a down-flow hanging sponge (DHS) reactor installed at a sewage treatment plant in Banda Aceh, Indonesia for treatment of desludging septic tank wastewater. Raw wastewater with an average biochemical oxygen demand (BOD) and total suspended solids of 139 mg/L and 191 mg/L, respectively, was pumped into the reactor. Two different hydraulic retention times (HRTs, 3 h and 4 h) were investigated, equivalent to organic loadings of 1.11 and $0.78kg\;BOD/m^3/d$, respectively. The average BOD concentration in the final effluent was 46 and 26 mg/L at HRTs of 3 and 4 h, respectively. The concentration of retained sludge along the reactor height was 10.2-18.7 g VSS/L-sponge, and the sludge activities were 0.24-0.32 and 0.04-0.40 mg/g VSS/h for heterotrophs and nitrification, respectively. Values of water hold-up volume, dispersion coefficient, and number of tank in-series found from tracer studies of clean sponge and biomass-loaded sponge confirmed that growth of retained sludge on the sponge module improved hydraulic performance of the reactor. Adoption of the DHS reactor by this Indonesian sewage treatment plant would enhance the role of the current desludging septic tank wastewater treatment system.

• Membrane and Water Treatment
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• 제14권4호
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• pp.181-189
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• 2023

The Covid-19 pandemic has increased demand for chlorine-based sanitizing solutions, most of which contain hypochlorous acid (HOCl) as an active agent. Free chlorine (HOCl) in these sanitizers is crucial for their efficacy. Disposable test strips are affordable and convenient tools for determining various qualitative and quantitative parameters. In this study, disposable opto-chemical test strips were developed by physically immobilizing 3,3',5,5'-tetramethylbenzidine (TMB) and o-dianisidine (o-D) reagents on chromatography and filter paper-based test strips for the visualization and detection of free chlorine in the form of HOCl. The reagents undergo a rapid color change upon reaction with chlorine through a redox reaction. The paper-based test strips showed rapid color change within a minute and a low sample volume requirement (1 ml). This portable, disposable paper-based test strip is a simple and cost-effective way to rapidly detect the presence of HOCl sanitizers for home and field applications. Both TMB and o-D successfully detected chlorine. Chromatography paper proved to be the more efficient option among the two papers used as substrates for the reagents (TMB and o-D). It exhibited high retention capacity and high performance in terms of color transformation when reacting with HOCl, even after two months of storage.

• Food Science and Biotechnology
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• 제15권4호
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• pp.572-577
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• 2006

The physiochemical interactions of 1-methylcyclopropene (1-MCP) and adsorbing agents can be described using a very powerful tool, inverse gas chromatography (IGC). Sorption behavior of 1-MCP on various adsorbing agents was assessed using the profile peaks of 1-MCP at an infinite dilution concentration using the IGC technique. Chromatogram peaks of 1-MCP adsorption were not observed for the adsorbing agent activated carbon. The forms of sorption isotherms followed Henry's law, and behaved according to the binding site theory. Specific retention volume and distribution coefficients for 1-MCP on the adsorbing agents were determined at 50, 60, 70, and $80^{\circ}C$, respectively. Silica gel had a much higher number of binding sites for 1-MCP compared to Tenax-TA and activated clay agents. Meanwhile, activated carbon proved to be a very strong binding agent for 1-MCP based on 1-MCP efficiency experiments on the selected adsorbing agents. However, as a proper means of delivering 1-MCP molecules to fresh food products, activated carbon is not fit for the binding and release of 1-MCP gas under dry or high humidity conditions because activated carbon has a strong affinity for 1-MCP, even when treated with distilled water.

• 한국작물학회지
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• 제46권5호
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• pp.360-366
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• 2001

Flour physicochemical properties of six Korean waxy wheat lines and their parental plants, including Kanto 107 and BaiHuo, which have partially null in GBSS (granule bound starch synthase), were evaluated in this study. The very low amylose content (3.20%) of Korean waxy wheat lines, which had been influenced by the null in all three GBSS isoforms encoded by three Wx loci, could result in the higher starch swelling power (25.15%), lower starch and flour pasting temperature (61.37$^{\circ}C$; 65.85$^{\circ}C$), and higher starch pasting peak viscosity and breakdown (246.60 RVU; 161.50 RVU) than those of their parental plants. In addition to high swelling and pasting properties, Korean waxy wheat lines had the higher protein content (12.80%), alkaline water retention capacity (97.39%), SDS sedimentation volume (80.33 $m\ell$) and damaged starch content (4.35 %) than those of their parental plants.

• 한국토양비료학회지
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• 제33권3호
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• pp.175-181
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• 2000

논토양에서 퇴비 및 규산 등 동일비료 장기연용시 토양물리성변화를 구명하여 벼의 안전재배를 위한 논토양 관리기술의 기초자료로 활용코자 하성평탄지의 하성충적충을 모재(母材)로 한 미사식양질계(微砂埴壤質系)인 보통답 "평택통(平澤統)"에서 벼단작재배로 31년간('67~'97) 무비(無肥), NPK, 퇴비단용(堆肥單用), NPK+퇴비(堆肥), 17년간(年間)('81~'97) Npk+규산구(珪酸區)를 각각 처리하여 얻은 결과를 요약하면 다음과 같다. 내수성입단(耐水性粒團) 및 입단화도(粒團化度)는 NPK+퇴비구>NPK+규산구>퇴비단용구>NPK구>무비구 순으로 높았고 토심별로는 표토보다 심토에서 높았으며, 0.5mm이상 대입단율은 퇴비 및 규산연용구에서, 0.5mm이하 소입단비율은 무비 및 NPK구에서 높았다. 한편 입단화도(粒團化度)는 토양경도(土壤硬度), 용적밀도(容積密度)와 부(負)의 상관(相關)을, 수중심정용적(水中沈定容積)과는 정(正)의 상관(相關)을 보였다. 수중심정용적(水中沈定容積)은 NPK+퇴비구에서 가장 높았고 무비구에서 가장 낮았으며, 심토보다는 표토에서, 풍건토(風乾土)보다 미풍건토(未風乾土)에서 각각 높았다. 토양공극율 및 보수력은 퇴비연용구에서 가장 높았고 무비구에서 가장 낮았으며, 규산연용구와 대조구간에는 비슷하였다. 작열감량(灼熱減量)은 NPK+퇴비구>퇴비단용구>NPK+규산구>NPK구>무비구 순(順)으로 높았으며, 포장쇄토율(圃場碎土率)은 NPK+퇴비구, 퇴비단용구, NPK+규산구 순으로 높았다.