• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.231-239
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• 2006

In this study, we evaluated the efficiency of using sulfur-$CaCO_3$ complex pellet in the sulfur oxidizing autotrophic denitrification process for synthetic wastewater with high $CaCO_3$ concentration. The sulfur-$CaCO_3$ complex pellet was packed in reactor(R4). Influent ${NO_3}^--N$ loading rate was from 200 to $1,000g/m^3{\cdot}day$. During the operation, average denitrification efficiency of R4 was above 95%. Particularly, the denitrififation rate at $1,000g/m^3{\cdot}day$ loading was 98.96% for R4. High ${NO_3}^--N$ removal efficiency was determined in R4 compared with other reactors. Through $Ca^{2+}$ and alkalinity analyses, we calculated the supplied alkalinity from the packed $CaCO_3$ in the reactor. Sulfur-$CaCO_3$ complex pellet more effectively supplied alkalinity through the dissociation of $CaCO_3$ as compared with other media. Based on these results, sulfur-$CaCO_3$ complex pellet increased the pH buffering capacity while also providing the carbon source to the denitrifying bacteria. Denitrification efficiency of R4 was also higher than other reactors. ESEM pictures of sulfur-$CaCO_3$ complex pellet show higher porosity than that of the granular sulfur. Hence, more denitrifying bacteria attached on the sulfur-$CaCO_3$ complex pellet than on granular sulfur. It can be concluded that the sulfur-$CaCO_3$ complex pellet is a more suitable media for a sulfur oxidizing autotrophic denitrification process as it provides high denitrification efficiency.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.602-603
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• 2011

본 논문은 전체 수요반응의 결과를 예측하는데 필요한 개별 수용가의 수요반응 모델을 제시하는 것을 목표로 하였다. 이를 위해, 개별 수용가의 수요반응 결정이 투자결정 문제가 유사함을 보이고, 수요 반응의 결정에 있어서도 투자결정 문제에서 위험선호 성향에 따라 수익과 위험 사이에서 개별적인 결정이 이루어진다고 보았다. 개별 수용가의 수요반응 모델을 유도할 때는 수요반응의 결과로 이루어지는 전력사용량 조정이 잘못된 결정일 확률을 고려하였고, 위험선호 지수라는 파라미터를 정의하여 일반적인 식으로 수요반응 모델을 표현하였다. 마지막으로, 시뮬레이션을 통해 위험선호 지수 R의 값에 따라 수요반응의 전력요금 감소 효과와 변동성이 달라짐을 확인하였다. 본 논문의 모델을 이용하면 전체 수용가의 총 수요반응을 예측하는 것이 가능해지고, 그 결과는 수요반응 제도 시행을 위한 장비투자 결정이나 정책 결정에 있어 중요한 지표로 활용될 수 있을 것이다.

• Journal of Sericultural and Entomological Science
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• no.11
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• pp.23-29
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• 1970

This experiment is to improve the wrinkle recovery (W.R.) of silk fabrics. The silk fabrics is creased very well, and the crease is the serious defection of it. This experiment is to improve the nature by use of formaldehyde on fabrics. The reagents used were HCl, CH$_3$COOH, CaC$_2$, HCHO, Na$_2$CO$_3$, NH$_4$OH, NaOH and NaHCO$_3$. The silk fabrics was treated, to compare 1 he influence of conditions, by varying the quantities of reagents and the temperature of solution, and the reaction time. The cotton fabrics and the viscose rayon were sunk with the silk at the same condition to be compared the influence. 1) Those of the most suitable temperature to improve for the better W.R. are 75$^{\circ}C$ for silk, 35-45$^{\circ}C$ for cotton, and no particular temperature under 75$^{\circ}C$ for viscose rayon. 2) The W.R. improvements after treated at the temperature of 1) were 11％ for silk and 33.4％ for cotton. 3) There are the best treating time for every fabrics. They were 60 to 90 min. for viscose rayon when HAC Ras used for solvent. It took, however, 60min. of the best time for silk, 120 min. for cotton, and 40 min. for viscose rayon when acetic anhydride instead of HAC was used. 4) It was possible to improve 16.6％ of W.R. for silk at the most suitable treating time, 25.0％ for cotton, and 13.3％ for viscose rayon. 5) Acetic anhydride was rather more effective to improve W.R. of both silk and viscose rayon than HAC. 6) Treating time was also shorter in case of using acetic anhydride than HAC. 7) The improvement of W.R. were 8.3％ for silk at the 10 to 14 ml. of HCHO the best volume, 21. 5％ for cotton at 18m!. of HCHO, and 70％ of for viscose rayon at 14 to 18ml. of HCHO. 8) The most effective quantity of HCI is 14 ml. for both silk and cotton. The W.R. improvement of silk was 22.2％, and that of cotton 19.5％. 9) The W.R. of 83.3％ the best for silk and 61. 6％ for cotton were gained when 4.2gr. of NaHCO$_3$ brings down the percent of W.R. for both silk and cotton. 10) The more NaOH and NH$_4$OH as neutralizing agents, the less effectivity of W.R. until the quantities of the reagents are reached to a special range which are 3. 3m!. for silk and 3.3-6.6 ml. for cotton, and then we can see the W.R. increasing as the quantities of reagents are increased. These facts were evident in case of silk and cotton. We can also see with this fact that the reminder of 〔OH$\^$-/〕 neutralizing 〔CH$\^$+/〕in solution makes it possible to treat formaldehyde on fabrics. 11) Low curing temperature was comparatively better for silk, and high temperature better for cotton. 12) The result of this experiment shows that the Improvement of W.R. for silk was possible to 94％ which means 22％ W.R. increase compared to the untreated silk. This effect also shows that the improvement to W '||'&'||' W (wash and wear) of silk will be possible.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.247-248
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• 2005

본 연구는 서로 다른 조건에서 질산화를 유도한 반응기의 군집동태를 살피기 위해 RAPD, ARDRA, DGGE와 같은 기법들을 적용시켜 반응기 초기의 슬러지 구성 군집의 상태 와 질산화 유도후의 군집 변화를 살펴보고자 하였다. 결과적으로 1.5 kb정도의 165 rDNA를 이용한 RAPD와 ARDRA에서는 RAPD에 의한 군집 Patterns변화가 훨씬 다양했으며, 250 bP정도의 PCR산물로 분리를 시도한 DGGE에서도 비교적 예상했던 바와 같이 군집이 단순화되는 양상을 볼 수 있었다.

• Journal of the Korean Chemical Society
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• v.34 no.5
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• pp.430-437
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• 1990

Various tris (${\eta}^4$-diene) molybdenums were easily synthesized by the reaction of various 1,3-dienes and molybdenum metal vapors by using metal atom reactor. The methyl substituent effect of the tris (${\eta}^4$-diene) molybdenum produced were discussed. And some alkadiene-molybdenum complexes which were easily decomposed in the air at room temperature were also formed.(C$_6$H$_{10}$)$_2$(CO)$_3$Mo were synthesized and its molybdenum-diene bond type were discussed.

• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.153-161
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• 1993

Cathodic oxygen reduction kinetics on $La_{0.9}Sr_{0.1}MnO_3$ electrode have been examined at $700-900^{\circ}C$ under various oxygen partial pressures. AC impedance and current interruption techniques were employed for the determination of charge transfer resistances for electrochemical oxygen reduction. The $R_{ct}$ values obtained from two different methods were very close each other for $La_{0.9}Sr_{0.1}MnO_3$ electrode. Activation energy for the electrochemical oxygen reduction was found to be 174kJ/mol under atmospheric oxygen pressure. $R_{ct}$ measurements as a function of oxygen partial pressure indicate that the rate-determining step for the electrochemical oxygen reduction on $La_{0.9}Sr_{0.1}MnO_3$ electrode is the charge transfer process.

• Clean Technology
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• v.17 no.3
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• pp.238-243
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• 2011

We investigate new polyols based on castor oil for polyurethane. In order to introduce primary alcohol groups, which exhibit higher reactivity with isocyanate than secondary alcohol groups, the secondary alcohol groups on castor oil were modified with maleic anhydride and aminoalcohol derivatives ($H_2N$-R-OH). The reactions with various molar ratio of castor oil and maleic anhydride were done at relatively low reaction temperature in the absence of catalyst. The polyols based on castor oil with flexible side-chains exhibit better miscibility with conventional synthetic polyols.

• Journal of the Korean Chemical Society
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• v.20 no.4
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• pp.316-320
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• 1976

Based on the results of graft copolymerization to proteins, an attempt is made to derive the rate equations to explain the mechanism of Ce(IV) ion-initiated graft copolymerizations. In this system the oxidative termination by Ce(IV) $[R{\cdot}+ Ce(IV) ${\rightarrow}$ R(inert) + Ce(III) + H^+]$ is considered characteristic particularly in higher concentration of Ce(IV) ion. The change in the mode of termination reactions with change in Ce(IV) ion concentration makes possible the presence of an optimum Ce(IV) ion concentration for maximum graft copolymerization yield. This effect is reflected in presently derived equations.

• Journal of the Korean Electrochemical Society
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• v.13 no.2
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• pp.132-137
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• 2010

This study is concerned the electrocatalytic generation of oxygen gas at electrochemically deposited manganese oxide electrode in KOH solution. Manganese oxide nanoparticles electrodeposited onto relatively substrate, e.g glassy carbon, Au, Ti electrode. MnOx is electrodeposited in nanorod structure which cover the overall surface of the substrate. The $\gamma$-MnOOH that is kind of manganese oxide species plays a significant role as a catalytic mediator, which promote 4-electron reduction process. Modified electrodes with electrodeposited manganese oxide structures resulted in significant decrease in the anodic polarization compared with the unmodified electrodes in alkaline media.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.2
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• pp.251-258
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• 2017

The objective of this study was to analyze patient satisfaction and perception of nutritional counseling services quality. A patient satisfaction and perception survey was conducted for 1,095 patients from 43 tertiary hospitals and 20 general hospitals. The number of returned questionnaires was 656 (response rate: 60.0%). Data from 633 questionnaires were analyzed after the questionnaires with unanswered items were excluded. Five domains were identified from the result of the factor analysis using the maximum likelihood and oblique rotation. The five domains were named empathy, responsiveness, tangibles, reliability, and skill and specialty. Patient perception mean score of nutritional counseling was 4.54/5.00. Patient satisfaction scores were significantly higher in empathy (P<0.001), responsiveness, and skill and specialty (P<0.01) with a college or graduate school education than in patients with a middle school education. There was no statistically significant difference between satisfaction scores in tertiary hospitals and those in general hospitals, but patients in capital hospitals reported significantly higher scores than their local counterparts in empathy, responsiveness, reliability, skill and specialty (P<0.001), and tangibles (P<0.05). In responsiveness, significantly higher (P<0.01) scores were observed in patients who received nutritional counseling only once compared to patients who received counseling two times. Patients perception of nutritional counseling services was significantly correlated with their satisfaction of five domains, reliability (r=0.721), responsiveness (r=0.697), empathy (r=0.690), skill and specialty (r=0.678), and tangibles (r=0.622).