• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2011년도 추계학술발표회 논문집
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• pp.39-41
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• 2011

The recycling rate of recovered paper in Korea is the highest in the world, 92%, but remanufacturing yield is low due to the extremely poor quality of the paper. The poor quality, in turn, influences to the reject amount in deinking process. To increase the yield of old newspaper recycling process, hydrophobic degree of inorganic pigments of deinking stock must be reduced. To determine the hydrophobicity, Pitch Potential Deposit Tester (PDT) was newly designed and applied with respect to the SB latex property of various quality used in Korea; its hydrophobic degree according to Tg, gel content, charge and particle size of latex and optimum designing condition of SB latex. And below are the conclusions: 1. The reason of excessive reject from old newspaper deinking process for total amount of printed ink is loss of inorganic pigments. When lipase, a biochemical catalyst, was applied with the purpose of preventing inorganic pigments loss about more than 70% of total reject weight and promoting hydration of pulp for deinking, deinking process yield of pre flotation secondary stage increased remarkably without any changes of deinking efficiency. 2. Lipase improved deinking stock by cutting ester linkage on surface of hydrophobic materials to promote its hydration. From this, it reached the conclusion that hydration degree of stock exercises significant effect on flotation deinking process yield. 3. Inorganic alkali promotes hydration of deinking stock. But there have been needs for more fundamental measures other than inorganic alkali of promoting hydration for yield improvement. For this, this study intended to find out reasons of chemical properties change on surface of hydrophobic material by change of pH. 4. Pitch Deposit Test (PDT) was performed for understanding principle of why surface of coating flake from OMG is hydrophobic and why it becomes hydrophilic when pH of stock is alkaline. As a result of this test, it is determined that swelling property by change of pH of latex film, which were used as coating adhesive is the reason for hydrophobic change. 5. Hydrophilicity of coating flake increased with hydrophilic pigments. And as more of SB Latex adhesive was used and higher of calcium hardness of stock became, its hydrophilicity decreased. SB Latex adhesive film is reformed by mechanical friction. For having hydrophilicity under neutral pH, strong bruising action such as kneading is required. 6. Because swelling of adhesive film decreases as Tg of SB latex gets lower and mean diameter gets smaller, it shows hydrophobicity under neutral pH. This lowers hydrophilicity of coating flake, which leads to easy elimination with flotation reject on DIP process. Therefore, for improving future flotation yield, it is necessary to develop to use eco-friendly clean SB latex by raising Tg and increasing mean diameter for recycling, and as a result, to reduce excessive loss of coating flake as a reject from deinking process.

• 한국버섯학회지
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• 제20권4호
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• pp.270-273
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• 2022

느타리 재배에서 비트펄프를 대체하여 밀짚펠렛을 첨가한 결과는 다음과 같다. 처리 간 화학성은 pH 4.8~5.5, 총 탄소함량 45.9~46.5%, 총질소함량 1.5~1.7%로 밀짚펠렛의 대체첨가량이 증가할수록 pH는 높아지고 총탄소함량과 총질소함량은 대조구와 유사하거나 낮아지는 경향이 있었으며, 탄질비는 27.8~31.0로 대조구에 비해 유사하거나 높게 나타났다. 처리 간 균사생장은 '흑타리'의 경우 밀짚펠렛을 20% 대체첨가한 C처리구에서 88.2 mm로 대조구(83.7 mm)에 비해 빠른 균사생장을 보였고, '수한1호'는 모든 처리구에서 70.3~79.6 mm로 대조구(69.1 mm)에 비해 균사생장이 빨랐으며, 밀짚펠렛의 첨가량이 증가할수록 균사생장이 빠른 경향을 보였다. 균사밀도는 처리 간 뚜렷한 차이를 보이지 않았다. 자실체는 '흑타리'의 경우 밀짚펠렛을 10% 대체첨가한 A처리구에서 병 당 수량 177.1 g, 병 당 유효경수 22.5개로 대조구와 대등하였고, '수한1호' 또한 A처리구에서 병당 수량 151.2 g, 병 당 유효경수 14.0개로 대조구와 대등한 수준이었다. 따라서 느타리 재배 시 비트펄프를 대체하기 위한 밀짚펠렛의 첨가량은 10%가 적절함을 확인하였으며, 첨가비율을 높이기 위해 지속적인 연구가 필요할 것으로 판단된다.

• 멤브레인
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• 제27권2호
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• pp.199-204
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• 2017

본 연구에서는 펄프공정으로부터 배출되는 리그닌 추출물 내의 금속이온분리를 위한 연구를 진행하였다. ${\alpha}$-Alumina 분말에 DMAc (N,N-dimethylacetamide) 용매와 PESf (Polyethersulfone) 고분자를 혼합하고 PVP (Polyvinylpyrrolidone) 분산제를 첨가하여 슬립 캐스팅 방법으로 분리막을 제조하였다. 분리막은 CFP (Capillary Flow Porometer) 장치를 통해 기공크기를 측정하고 FE-SEM (Field Emission Scanning Electron Microscope) 장치를 이용하여 실제 분리막 표면과 단면을 관찰하였다. 플럭스는 분리 실험장치를 이용하여 시간당 여과된 무게를 측정하여 계산하였다. 기공크기측정은 0 psi에서 30 psi까지 서서히 증가하는 승압조건에서 진행하였다. 분리막의 기공크기는 $0.4{\mu}m$ 크기를 가지며 플럭스는 분리막의 파울링에 의해 초기 플럭스 값인 $6.36kg{\cdot}m^{-2}{\cdot}h^{-1}$에서 $1.98kg{\cdot}m^{-2}{\cdot}h^{-1}$으로 감소하여 3시간 이후부터 일정해지는 것을 확인하였다. 투과 실험 후 막 오염물질은 간단한 세척을 통해 제거 가능하였다. 분리실험을 통해 초기 리그닌 추출물 내에 포함되어 있던 Na은 69%만큼 줄었고, Fe은 87%, K은 95%, Ca은 93%, Mg은 96%만큼 제거됨을 보였다.

• Journal of the Korean Wood Science and Technology
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• 제44권4호
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• pp.571-588
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• 2016

Eucalyptus pellita F. Muell is one of pulp woods that is being developed through breeding plantation programs in Indonesia. The research aimed at exploring the chemical and morphological characteristics of fiber, and to determine the rank of plus trees from 4 provenances based on the suitability for pulps. The materials included the plus trees of E. pellita (9 years) from the 2nd generation of progeny tests in Pelaihari, South Borneo. Wood properties under investigation included the chemical properties and morphological fiber characteristics (fiber dimensions and its derived properties). In the present study, data were analyzed using descriptive statistic, Analytic Hierarchy Process (AHP) and Pearson's correlation. Results showed that the chemical properties of E. pellita, i.e. the contents of ethanol-toluene extractives, hot water soluble extractives, holocellulose, alphacelullose, and lignin were $3.08{\pm}1.00%$, $1.41{\pm}0.38%$, $75.26{\pm}2.58%$, $49.02{\pm}2.88%$, and $29.49{\pm}1.86%$, respectively. The average values of wood fiber morphology were $1.02{\pm}0.08$ mm (fiber length), $13.25{\pm}1.64{\mu}m$ (fiber diameter), of $6.94{\pm}1.70{\mu}m$ (lumen diameter), $3.15{\pm}0.52{\mu}m$ (fiber wall thickness), $0.97{\pm}0.30$ (Runkel ratio), $0.57{\pm}0.10$ (Luce's shape factor), $78.21{\pm}10.34$ (slenderness ratio) and $130.91{\pm}33.77{\times}10^3{\mu}m^3$ (solids factor). The AHP scoring rank indicated that the best individuals were 28.4.3.28 (Kiriwo Utara), 12.1.5.28 (North Kiriwo), 19.11.5.45 (Serisa Village), 3.8.4.9 (South Kiriwo), and 6.6.3.15 (South Kiriwo). Pearson correlation analysis showed significant correlations between the levels of fiber length with alpha-cellulose content (r = 0.39) as well as the fiber length with ethanol-toluene extractive contents (r = -0.41).

• 한국식품저장유통학회지
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• 제24권6호
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• pp.802-812
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• 2017

유자 종류 및 부위에 따라 품질특성을 조사하기 위하여 일반성분, 유리당, 유기산, 비타민C, hesperidin 및 naringin 함량과 항산화 활성을 분석하였다. 유리당을 분석한 결과 총 3종(fructose, glucose, sucrose)이 검출되었는데 과피 중 유리당 함량은 fructose > glucose > sucrose 순이었으며, 과육 중 유리당 함량은 sucrose > fructose > glucose 순이었다. 유자 씨에 함유되어 있는 유리당은 sucrose 뿐이었다. 유기산은 총 5종(oxalic acid, citric acid, malic acid, succinic acid, fumaric acid)이 검출되었는데 과피와 과육에서는 citric acid가 높은 함량을 나타내었으며, 씨에서는 fumaric acid가 높은 함량을 나타내었다. Hesperidin은 무농약 과피가 13.23 mg/g으로 가장 높은 함량을 나타내었으며, naringin은 세 부위 중 과피에서 높은 함량을 나타내었고 그 중 일반 과피(4.62 mg/g)가 가장 높은 함량을 나타내었다(p<0.05). Vitamin C를 분석한 결과 다른 부위에 비하여 과피에 많이 함유되어 있었으며 종류 및 부위에 따라 유의적 차이를 나타내었다(p<0.05). 유기농 과피는 770.02 mg/100 g으로 유의적으로 가장 높은 vitamin C 함량을 나타내었고 씨부분에 적게 함유되어 있는 것으로 분석되었다(p<0.05). 총 폴리페놀 함량은 일반 과피가 0.85 mg/g의 값으로 가장 높은 함량을 나타내었으며, 무농약 과피와 유기농 과피는 각각 0.76 mg/g, 0.68 mg/g으로 일반 과피에 비하여 유의적으로 낮은 함량을 나타내었다(p<0.05). 무농약 씨의 총 플라보노이드 함량은 0.89 mg/g 으로 유자 시료 중 유의적으로 가장 높은 함량을 나타내었으며(p<0.05), 씨가 다른 부위에 비하여 높은 함량을 나타내었다. 일반, 유기농 및 무농약 과피와 과육 간 총 플라보노이드 함량은 유의차를 나타내지 않았다. DPPH 라디컬 소거능에서는 세 부위 중 과피에서 비교적 높은 소거활성을 나타내었는데 그 중 무농약 과피가 101.07%로 가장 높은 소거활성을 나타내었다(p<0.05). 과피 다음으로 소거활성이 높은 부분은 씨로 32.78-33.48%의 값을 나타내었으며, 과육은 10.23-12.14%를 나타내었다(p<0.05). 유기농 과피의 ABTS 라디컬 소거능은 84.47%로 시료 중 유의적으로 높은 라디컬 소거능을 나타내었으며(p<0.05), 일반 과피는 84.04%로 유기농 과피(84.47%)와 일반 과육(83.30%)과 유의차를 보이지 않았다. 씨의 경우 13.53-14.62%로 다른 부분에 비하여 유의적으로 낮은 소거 활성을 나타내었다(p<0.05). 유자는 주로 과피 만을 이용한 유자차 형태로 많이 소비되고 있어 과피를 제외한 나머지 부분들이 폐기되어 왔으나, 본 실험 결과 유자 과피 외에 과육과 씨에도 많은 유용성분이 함유되어 있으므로 유자 생과를 효율적으로 이용한 다양한 식품소재화가 이루어질 것으로 기대하는 바이다.

• 에너지공학
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• 제29권3호
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• pp.34-41
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• 2020

Used disposable diapers have been considered for a long time as a type of waste difficult to recycle and valorize due to their composite nature including plastic, cellulose pulp, a super absorbent polymer and either urine, feces or both. Therefore, the fate of disposed diapers often is either incineration or landfill burial which both have various adverse environmental impacts. However, used disposable diapers contain nutrients: cellulose is an organic matter while urine and feces contain non negligible amounts of nitrogen, phosphorus and potassium which are primary nutrients included in most chemical fertilizers used in agriculture. In a scope of waste recycling and valorization, this study focuses on developing a method to achieve nutrient solution extraction from used disposable diapers. The experiment essentially consists in shredding the diapers and letting them macerate in solutions of sodium hydroxide with various concentrations to allow breaking down of the cellulose and super absorbent polymer and release of urine and feces before sterilizing the solutions in an autoclave to remove potential coliform bacteria. At the end of the experiment, a set of parameters is measured for the final solution to identify concentrations of nutrients as well as presence or absence of harmful substances. Results are discussed and directions for future studies are suggested, which include mechanization of the diapers shredding process or added aeration to enhance nitrification and absorption of extracted nutrients from plants.

• Macromolecular Research
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• 제12권2호
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• pp.213-218
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• 2004

We have performed dispersion polymerization of acrylamide in tert-butyl alcohol/water mixture-using hydroxypropyl cellulose and ammonium persulfate as the stabilizer and the initiator, respectively - to study the effects that the concentration of monomer, initiator, and stabilizer, the tert-butyl alcohol/water ratios as polymerization media, and the reaction temperature have on, among other things, the polymerization kinetics, particle sizes, and molecular weights. The polymerization rate increased upon increasing the concentration of the monomer, initiator, and stabilizer, the water content in the tert-butyl alcohol/water media, and the polymerization temperature. The average particle size of the lattices increased upon increasing the concentration of initiator, the polymerization temperature, and the water content in the tert-butyl alcohol/water media, but it decreased upon increasing the concentration of monomer and stabilizer. The viscosity-average molecular weight increased upon increasing the concentration of monomer and stabilizer and the water content in the tert-butyl alcohol/water media, but it decreased upon increasing both the concentration of initiator and the polymerization temperature.

• 설비공학논문집
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• 제28권11호
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• pp.434-443
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• 2016

The evaporation of water from an aqueous solution is widely used in the food, desalination, pulp, and chemical industries. Usually, a large amount of energy is consumed in the evaporation process to boil off water due to atmospheric pressure. As a way of improving the energy efficiency of the evaporation process, the combination of multiple effect evaporation and thermal vapor recompression has been proposed and has become a successful technique. In this study, 4 multiple-effect falling film type evaporators for sugar solution are designed and the energy efficiency of the system is analyzed in response to the selection of the steam ejector position. Energy efficiency is increased and vapor is more compressed in the steam ejector as the Thermal Vapor Recompression (TVR) is arranged in the rear part of the evaporator system. A simplified 0-dimensional evaporator model is developed using non-linear equations derived from mass balances, energy balances, and heat transfer equations. Steam economy is calculated to compare the evaporation performance of the 4 proposed evaporators. The entrainment ratio, compression ratio, and expansion ratio are computed to check the ejector performance.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.472-477
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• 2001

Spent catalysts containing platinum were generated in petroleum refinery and other chemical industries. The reclamation of precious metals from such wastes has long been attempted in view of their rare, expensive and indispensable nature. In this study, the recovery of platinum from petroleum catalysts was attempted by a method consisting mainly of dissolving alumina substrate with sulfuric acid thereby concentrating insoluble platinum. Also, platinum dissolved partially in sulfuric acid was recovered by a cementation method using aluminum metal as a reductive agent. The effect of temperature, time, concentration of sulfuric acid. and pulp density on the dissolution of substrate was investigated. When the substrate of platinum catalyst was ${\gamma}$-AI$_2$O$_3$ about 95% alumina was dissolved in 6.0M sulfuric acid at 10$0^{\circ}C$ for 2 hours. When the substrate was the mixture of ${\gamma}$-A1$_2$O$_3$and $\alpha$-A1$_2$O$_3$about 92% was dissolved after 4 hours. As a result, more than 99% of platinum could be recovered by this method and aluminum sulfate was obtained as byproduct.

• Journal of the Korean Wood Science and Technology
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• 제42권5호
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• pp.499-509
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• 2014

Wood filler is a porous and anisotropic material having different size, shape, and aspect ratio. The use of wood fillers such as wood particle, wood flour, and wood pulp in wood plastic composites (WPCs) are growing rapidly because these wood fillers give improved strength and stiffness to WPCs. However, the wood fillers have originally poor compatibility with plastic matrix affecting the mechanical properties of WPCs. Therefore, to improve compatibility between wood and plastic, numbers of physical and chemical treatments were investigated. While the various treatments led to improved performances in WPC industries using petroleum-based plastics, full biodegradation is still issues due to increased environmental concerns. Hence, bio-based plastics such as polylactide and polyhydroxybutyrate having biodegradable characteristics are being applied to WPCs, but relatively expensive prices of existing bio-based plastics prevent further uses. As conventional processing methods, extrusion, injection, and compression moldings have been used in WPC industries, but to apply WPCs to engineered or structural places, new processing methods should be developed. As one system, co-extrusion technique was introduced to WPCs and the co-extruded WPCs having core-shell structures make the extended applications of WPCs possible.