• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.81-84
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• 2005

We investigated the effect of inorganic impurities such as clay bricks and asphalt concrete in recycled aggregate on the properties of lean concrete. The optimized moisture content of lean concrete with clay bricks increased, because the absorption ratio of clay bricks is high. On the other hand, lean concrete with asphalt concrete produced an opposite result owing to low absorption ratio. The results showed that inorganic impurities did not have a significant effect on compressive .strength of lean concrete containing below 30$\%$ clay bricks and below 10$\%$ asphalt concrete.

• 한국세라믹학회지
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• 제29권2호
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• pp.127-135
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• 1992

It has been reported that natural petalite showed a low negative thermal coefficient and wide coefficient and wide coexisting region with liquid phase in Li2O-Al2O3-SiO2 system. Therefore, we investigated variation of microstructure and thermal and mechanical properties when the amount of SiO2 content in petalite compound and MgO addition to it compound were changed. As SiO2 content exceeded 80 wt%, crystal phases of $\beta$-cristobalite and $\beta$-spondumene solid solution were formed. Generally, the densification and bending strength were increased by the addition of MgO, but the positive thermal coefficient was found in the case of MgO 10 wt% addition because of second phase and glassy phase.

• 한국토양환경학회지
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• 제4권3호
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• pp.35-43
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• 1999

강둑여과의 적지로 판단되는 지역의 배후 농경지 표층토에 대한 무기질소 변환 활동도를 호흡량 측정기에서 소비한 산소량에 기준하여 조사하였다. 초기 표층토 pH(약 4.8~5.7)를 변화시키지 않고 수분함량을 약 20%로 조정한 상태에서 무기질소의 변환을 관찰한 결과 대조군과 실험군의 뚜렷한 호흡량 및 무기질소변환은 관찰할 수 없었고 조사한 실험조건에서 수분 25%, pH 8 정도에서 가장 활발한 미생물 활동도가 관찰되었다. 또한 초기 ${NH_4}_2$$SO_4$400 mg $NH_4$-N의 농도에서 98%정도의 질산화가 조사되었으나 탈질화는 거의 발생하지 않았다.

• 한국식품과학회지
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• 제50권2호
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• pp.138-142
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• 2018

재배조건에 따른 차이를 보기 위해 논에서 재배되는 논쌀 두종과 제주밭쌀의 특성과 중금속 함량을 비교하였다. 두 논쌀 중 아밀로오스 함량이 높은 논쌀 2와 제주밭쌀은 높은 페이스팅 온도와 낮은 최고 점성, 그리고 상대적으로 높은 셋백(setback)을 보였으나, 재배조건에 따른 차이를 보이지는 않았다. 제주밭쌀은 짙은 노란색과 낮은 점성을 보여 외관과 기계적 식미치에서 논쌀보다 낮게 평가되었다. 중금속 중 카드뮴과 납은 논쌀과 밭쌀의 차이를 보이지 않았으나, 총 비소함량의 경우 제주밭쌀은 논쌀의 10.1-17.9%에 해당하는 양을 보였다. 또한 제주밭쌀의 무기비소함량도 논쌀 2의 무기비소함량의 15% 정도에 불과한 것으로 나타났다. 논쌀을 침수, 취반, 뜨거운 물로 씻어내리기 등의 처리에 의해 무기비소 함량을 각각 34.1, 23.8, 17.5% 줄일 수 있는 것으로 나타났으나, 제주밭쌀의 경우 무기비소함량이 매우 적어 처리에 의한 유의적 차이는 발견되지 않았다.

• 한국식품조리과학회지
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• 제32권6호
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• pp.686-695
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• 2016

Purpose: This study aimed to investigate the quality characteristics of traditional and commercial soybean pastes (Doenjang) for development of traditional soybean pastes. Methods: Proximate compositions, amino acid nitrogen contents, pH, acidity, salt contents, chromaticity, viable bacteria and inorganic substance contents of nineteen traditional and three commercial Doenjang were investigated. Results: Analysis of proximate compositions indicated a significant difference between samples. In moisture content, D10 did not meet the standard of food codex. The contents of moisture, fat, protein and ash were slightly higher in traditional than commercial Doenjang. However, the carbohydrate content was 2-fold higher in commercial than traditional, and thus, the calories were also higher. The amino nitrogen content was lower in commercial than traditional Doenjang. pH, acidity and salt contents of Doenjang were pH 4.67-6.15, 1.53-3.29%, and 9.01-18.78%, respectively. pH and acidity showed no significant differences between traditional and commercial Doenjang, however, salt contents were significantly higher in traditional than commercial Doenjang. In case of chromaticity, the averages of L, a, b values were higher in traditional Doenjang. In microbiological analysis, total bacteria counts were higher in traditional than commercial Doenjang. The number of Bacillus cereus in D12 and D19 exceeded the standard of food codex. Staphylococcus aureust was undetected in all samples. The number of fungi varied widely between samples, with no detection in five traditional and all commercial Doenjang. Results of inorganic substance analysis indicated that contents of inorganic substances in Doenjang were in order of Na, K, Mg and Ca. Overall, Na content was higher in traditional Doenjang. Contents of inorganic substances showed wide variations in traditional Doenjang. Conclusion: For the development of traditional Doenjang, quality standardization and ensuring safety are considered necessary.

• 펄프종이기술
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• 제40권1호
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• pp.23-28
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• 2008

Functional hanji was manufactured using the bast fiber of Broussonetia kazinoki and various inorganic compounds such as kaolin, talc, elvan, and ocher, and the physical and optical properties were investigated. The residual percentages of kaolin, talc, elvan and ocher in the functional hanji were above 50%. The density of the hanji increased with the increase of the content of inorganic compounds. The hanji manufactured using ocher showed the highest density. The breaking length and burst factor decreased with the increase of inorganic materials, indicating that physical properties of hanji were not improved by adding inorganic materials. The emission rates of far-infrared radiation increased in the hanji manufactured using inorganic materials. The higher emission rates were observed in the hanji with elvan or ocher. Addition of inorganic compounds to hanji showed the flame retardative effect. The colorfastness to light of the hanji with elvan or ocher was the degree of 4, which explained by the characteristic color of the inorganics.

• 한국수소및신에너지학회논문집
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• 제32권6호
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• pp.524-533
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• 2021

In this study, a series of anion conductive organic/inorganic composite membranes with excellent ionic conductivity and chemical stability were prepared by introducing graphene oxide (GO) inorganic nanofiller into the quaternized poly(phenylen oxide (Q-PPO) polymer matrix. The fabricated organic/inorganic composite membranes showed higher ionic conductivity than the pristine membrane. In particular, Q-PPO/GO 0.7 showed the highest ionic conductivity value of 143.2 mS/cm at 90℃, which was 1.56 times higher than the pristine membrane Q-PPO (91.5 mS/cm). In addition, the organic/inorganic composite membrane showed superior dimensional stability and alkaline stability compared to the pristine membrane, and the physicochemical stability was improved as the content of inorganic fillers increased. Therefore, we suggest that the as-prepared organic/inorganic composite membranes are very promising materials for anion exchange membrane applications with high conductivity and alkaline stability.

• Membrane and Water Treatment
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• 제7권4호
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• pp.341-353
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• 2016

Papermaking reconstituted tobacco is an important strategy for recycling the waste tobacco residues. To indentify the influences of the inorganic components on harmful components delivery in cigarette smoke, a self-made electrodialysis stack was assembled to desalt the tobacco extract. The influences of the applied current and extract content on the removal rate of the inorganic ions were investigated. Results indicated that the applied current was a dominant impact on the desalination performance. High currents lower than the limiting current density could accelerate the desalting efficiency but cause higher energy consumption. A current of 2 A, or current density of ${\sim}11mA{\cdot}cm^{-2}$, was an optimal choice by considering both the energy consumption and desalting efficiency. A 20% tobacco extract was an appropriate content for the electrodialysis process. More than 90% of inorganic ions could be removed under the optimum condition. The preliminary result indicated that removal of inorganic components was beneficial to decrease the harmful component delivery in cigarette smoke. Naturally, ED is an environmentally friendly and high-effective technology for desalting the tobacco extract.

• 한국물환경학회지
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• 제32권5호
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• pp.458-464
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• 2016

This study evaluated the dewatering efficiency of inorganic dehydrating agents that contain oyster shells. A filter press dehydrator was used for this study. The experiments were performed by the single injection of calcium-based chemicals, the single injection of oyster shells, and the mixed injection of oyster shells and calcium-based chemicals. The moisture content of the dewatered cake generated after dehydration confirmed that the best dewatering efficiency was found at the mixing ratios of CaCO₃ to sludge, oyster shell to sludge, and inorganic dehydrating agent to sludge of 3:1, 10:1, and 1.5:2.5:1, respectively. The moisture contents exhibited less than 58% when the injection mixing ratio of inorganic dehydrating agent to sludge was 1.5:2.5:1. From EPS, SEM, and EDX analysis, it was found that the calcium adsorbed on the sludge surface could reduce extracellular polymeric substances (EPSs) and enhanced the dewaterbility. Based on the above results, it is considered possible to apply inorganic dehydrating agents containing recycled oyster shells in sludge dewatering in order to reduce sludge.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권4호
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• pp.165-170
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• 2005

A series of inorganic-organic hybrid membranes were prepared with a systematic variation of titanium dioxide nanoparticle content. Their water uptake, methanol permeability and proton conductivity as a function of temperature were investigated. The results obtained show that the inorganic oxide network decreases the proton conductivity and water swelling. It is also found that increase in inorganic oxide content leads to decrease of methanol permeability. In terms of the morphology, membranes are homogeneous and exhibit good adhesion between inorganic domains and the polymer matrix. The properties of the composite membranes are compared with the standard nafion membrane.