• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.3
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• pp.469-477
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• 2002

One of the major deficiencies of composite restorative resins is their insufficient resistance to wear. Of the multitude of factors that have been associated with wear, subsurface degradation within the restoration is considered to be one. The aim of this study was to evaluate the resistance to degradation of four commercial composite resins in an alkaline solution. The brands studied were Z100(3M), Clearfil AP-X(Kuraray), Tetric Ceram(Vivadent), Aelit flo(Bisco). Resistance to degradation was evaluated on the basis of the following parameters: (a) mass loss(%) - determined from pre-and post-exposure specimen weights: (b) Si loss(ppm) - obtained from ICP-AE analysis of solution exposed to specimens; and (c) degradation depth(${\mu}m$) - measured microscopically (SEM) from polished circular sections of exposed specimens. The results were as follows: 1. The sequence of the mass loss was in ascending order by AE, EL, TC, Z100. There was statistically significant difference of mass loss between AE, CL group and TC, Z100 group(p<0.05). 2. The sequence of the degree of degradation layer depth was in ascending order by AE, CL, TC, Z100. But there was no statistically significant difference of degree of degradation layer depth between AE and CL(p<0.05). 3. For the Si concentration, Z100 was the highest of all. 4. The correlation coefficient between mass loss and degradation depth was relatively high(r=0.71 p<0.05).

• Journal of Korean Society of Environmental Engineers
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• v.37 no.7
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• pp.387-395
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• 2015

Anaerobic mesophilic batch test of several organic wastes were carried out by a graphical statistic analysis (GSA) to evaluate their ultimate biodegradability and two distinctive decay rates ($k_1$ and $k_2$) with their corresponding degradable substrate fractions ($S_1$ and $S_2$). Each 3 L batch reactor was operated for more than 100 days at the substrate to inoculum ratio (S/I) of 0.5 as an initial total volatile solids (TVS) mass basis. Their Ultimate biodegradabilities were obtained respectively as follow; 69% swine waste, 45% dairy cow manure, 66% slaughterhouse waste, 79% food waste, 87% food waste leachate, 68% primary sludge and 39% waste activated sludge. The readily biodegradable fraction of 89% ($S_1$) of Swine Waste BVS ($S_o$) degraded with in the initial 31 days with $k_1$ of $0.116day^{-1}$, where as the rest 11% slowly biodegradable fraction ($S_2$) of BVS degraded for more than 100 days with the long term batch reaction rates ($k_2$) of $0.004day^{-1}$. For the Food Waste and Waste Activated Sludge, their readily biodegradable portions ($S_1$) appeared 89% and 80%, which degrades with $k_1$ of $0.195day^{-1}$ and $0.054day^{-1}$ for an initial 15 days and 28 days, respectively. Their corresponding long term batch reaction rates ($k_2$) were $0.003day^{-1}$ and $0.002day^{-1}$. Results from other organic wastes are addressed in this paper. The theoretical hydraulic retention times (HRTs) of anaerobic digesters treating organic wastes are easily determined by the analysis of multiple decay rate coefficients ($k_1$ and $k_2$) and their corresponding biodegradable substrate fractions ($S_1$ and $S_2$).

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.200-205
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• 2011

This study was conducted to find the physico-chemical properties and the amino acid content of the pigs hoof hydrolysate, keratin protein and to investigate its fertilizer effect on the growth of crops. The keratin proteins such as pigs hoof were alkali-hydrolyzed to produce the hydrolysates. The chemical properties of the hydrolysate of pigs hoof was 6~7 of pH and $10{\sim}15dS\;m^{-1}$ of EC. Total amino acid contents released from the pigs hoof were 10.18%, respectively. The pot experiment was carried out for the cultivation of lettuce. The treatment design of these pot cultivation was composed of Control (compost + NPK), PHH-0.5, PHH-1.0, PHH-2.0 (${\times}2,000$ ; 1,000 ; 500 diluted solution of pig hoof hydrolysate). After lettuce cultivation, the pH values in all treatment soils were decreased than those in initial soils, and the exchangeable cation value was higher than that of control. In all PHH treatments, lettuce growth was better in the leaf length by 6~16% and the leaf width by 4~15% than in control. Therefore, the PHH solutions manufactured by hydrolysis process had plenty of amino acids, and among them PHH had the most abundant nutrients and amino acids with highest growth and yield effect on lettuce.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.22 no.3
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• pp.127-134
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• 2016

In this study, Biodegradable masterbatch (M/B) was prepared by different kinds and content of biodegradable catalysts added to oxo biodegradable plastics. The bio film was prepared by adding biodegradable M/B to the polyethylene pellet, and the change of physical properties by UV and heat treatment and the stability as food packaging material were confirmed. As a result of the physical property change, Fe salt and Al salt bio film was superior to Ni salt bio film about a decrease in physical property. However, considering the raw material cost and industrial availability, M/B containing Fe salt was selected and additional experiments were conducted by concentration. The bio films prepared with Fe salt M/B 1.0, 1.5 and 2.0 wt% showed excellent physical properties.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2007.11a
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• pp.145-146
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• 2007

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.470-474
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• 2007

본 논문에서는 하천복원사업으로부터 발생하는 사회 경제적 편익의 측정 및 평가를 위한 기준 및 지표를 다루고자 한다. 하천복원사업의 목적 및 하천의 기능 및 사업의 영향을 기초로 선정된 평가 기준은 크게 생태적 측면과 사회 경제적 측면으로 나눌 수 있다. 본 연구에서 생태적 측면이 강조되는 것은 하천 생태의 다양한 측면을 파악하는 것이 사회 경제성 연구에 있어 풍부한 논의의 가능성을 제공해주는 측면이 있기 때문이다. 이는 하천복원사업이 가지는 복합적인 성격으로 인해 사업의 사회적, 경제적, 생태적 영향이 서로 고립되지 않고 영향을 주고받는 것에서 연유한다. 첫 번째 평가 기준인 생태적 측면에서는 세부기준으로 생태계 및 수문부문 등의 변화를 포함하며, 복원사업 전후의 서식처 및 생물 종 다양성의 변화, 하상의 다양화 등을 지표로 고려할 수 있다. 나머지 큰 평가 기준인 사회 경제적 측면에서는 홍수방지 효과나 수질개선 효과와 같은 우리가 생태계로부터 제공받는 직접적인 서비스나 토지 이용의 변화 및 그 변화에서 야기되는 영향(하천의 친수 기능이나 학습효과 등), 복원사업의 관리 및 비용 측면 등을 세부기준으로 고려할 수 있다. 하천복원사업의 구체적인 평가를 위해, 각 세부기준에 대한 지표는 현 복원사업에서 실시되는 평가기법, 하천복원관련 문헌조사 및 사례조사를 통해 검토하여 일차적으로 선정한다. 각 지표는 고려하고자 하는 특성에 따라 정량화가 용이한 지표와 정성적 측면이 강한 지표로 나뉜다. 이렇게 선정된 지표는 전문가 조사를 통해 지표에 대한 의견을 수렴하여 확정한다.한 치즈곤죽에서는 쓴맛 펩타이드가 형성되었다가 사라짐을 관찰할수 있었다. 한편 지질분해효소를 침가할 경우 총 휘발성산이 4일 이후에 급격히 증가함을 통해 사용한 효소는 유지방을 잘 분해함을 알 수 있었으며 GLC에 의한 유리 지방산의 분석 결과는 Cheddar치즈곤죽은 시판Cheddar 치즈와 비슷하고 Italian형 치즈곤죽은 시판 Italian치즈보다 약간 떨어졌다. Cheddar치즈의 중요한 품미성분인 활성 SH기는 glutathione을 첨가한 치즈곤죽에서 발효 4일부터 증가하였으며 단백질분해효소를 함께 첨가할 경우 그 증가현상이 현저하였다. 단백질분해요소의 첨가유무에 따라 점도 변화는 다른 두 가지 양상으로 나타나 효소를 첨가할 경우 단백질이 분해됨에 따라 점도가 급격히 감소하였다.>${\pm}0.36$) %, 0.34(${\pm}0.27$) %, 0.34(${\pm}0.18$) % 의 오차를 보였다 중간에 6 cm 의 PP 을 위치한 경우에는 에너지별로 1.15(${\pm}1.86$) %, 0.90(${\pm}1.43$)%, 0.86(${\pm}1.01$)% 의 오차를 나타내었다. 이 경우에는 PCD 10 cm 의 경우에 비교적 큰 오차를 보였으며 PCD 10 cm 인 경우를 제외하면 에너지별로 0.47(${\pm}1.17$) %, 0.42(${\pm}0.96$) %, 0.55(${\pm}0.77$0.

• Fire Science and Engineering
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• v.17 no.1
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• pp.33-39
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• 2003

The purpose of this study is to evaluate flame retardant performance, thermal stability and toxicity of combustion gases for some commercial wallpapers. ID evaluate flame retardant performance 45 degree combustion experiment method was used and thermal stability was evaluated using DSC and TGA apparatus (OSC-50/Shimadzu, TGA2050/TA Instruments Inc) . Concentrations of CO, $CO_2$, HCN and HCI were measured with (GASTEC/Japan, MSA400 Gas Monitor/Infitron Inc) and toxicity indices using NIST N-Gas Model were applied to evaluate the toxicity of combustion gases. The evaluation produced the following results : First, paper cork and PVC wallpaper treated with flame retardants were found to be suitable for flame retardant performance standards. Second, paper, cork and PVC wallpaper non-treated with flame retardants were shown to be relatively more hazardous because they had greater calorific values and a faster decomposition time than the flame retardant treated wallpapers. Third, the toxicity indices of non-treated wallpapers were found to be higher than those of treated wallpapers, and the toxicity index of PVC wallpapers was higher than those of paper and cork wallpapers.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.507-520
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• 2016

This research was performed to evaluate incineration facilities with different scale and type using performance index. Incineration facilities of 28 units, which occupying about 15% of 184 units in nationwide, were selected for questionnaire survey. The facilities were classified in scale with large(${\geq}100t/d$), middle(50~<100 t/d), small(<50 t/d) ones, and in type with stoker, pyrolysis, fluidized bed. Performance index was composed of technological, economical, and environmental items, which have 6, 10, and 30 kinds of questions, respectively. As a result of scale evaluation, large scale facility has higher score than small one in all technological, economical, and environmental items. In overall evaluation of the facilities with different type, stoker incinerator has higher score of 65.3 than 59.0 of fludized bed and 58.3 of pyrolysis. It was shown that there was significant difference in economical evaluation field, in all technological, economical, and environmental items.

• Food Science and Preservation
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• v.31 no.3
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• pp.444-451
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• 2024

This study aimed to investigate the characteristics of protein hydrolysates derived from defatted egg yolk using various proteolytic enzymes and compare the antioxidant activity of the resulting hydrolysates. The defatted egg yolk powder was subjected to enzymatic hydrolysis using four different proteases (alcalase, bromelain, flavourzyme and neutrase), and the resulting hydrolysates were evaluated for their antioxidant properties. Through analysis of available amino group contents and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, it was observed that the defatted egg yolk powder treated with alcalase, flavourzyme, and neutrase for 12 h exhibited a high degree of hydrolysis value. Based on the RC₅₀ values obtained from two different antioxidant analyses, all hydrolysates showed comparable antioxidant activity, except for the alcalase hydrolysate, which demonstrated notably higher scavenging activity against hydrogen peroxide than the other hydrolysates. These findings suggest the potential of protein hydrolysates from defatted egg yolk, a by-product of lecithin extraction, as natural antioxidants.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.30-35
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• 2011

Purpose: The Boramae Hospital are currently using Wide beam reconstruction (WBR: UltraSPECT, Israel) to improve the resolution. The Xact-bone belongs to the WBR. It has been reported that Xact-bone helps us to improve image resolution and contrast. This study will be evaluated clinical usefulness of Xact-bone method. Materials and Methods: The usefulness evaluation of Xact-bone method was analyzed in resolution test and contrast ratio. The resolution test in Planar image were obtained from Full width at half maximum (FWHM) by using capillary tube. And the contrast ratio was obtained from Bone and Soft tissue (B/S) ratio values that were acquired from bone scan study of 50 patients before and after using the Xact-bone method. We prepared the Triple Line Source Phantom, NEMA IEC Body Phantom and Standard Jaszczak Phantom to acquire the FWHM and Contrast Ratio values of Single photon emission computed tomography (SPECT) image. Subsequently we compared among the Filtered backprojection (FBP), Orderd subset expectation maximization (OSEM) and Xact-Bone image. Results: The results of the planar Xact-bone data improved resolution about 20% by using capillary tube. In addition it was improved B/S ratio about 15%. When using Triple Line Source Phantom, SPECT Xact-bone data improved resolution for both FBP, OSEM methods about 20% and 10%, respectively. Contrast ratio in each spheres has also been increased for both methods that using NEMA IEC body Phantom and Standard Jaszczak Phantom. Conclusion: When we were using Xact-bone method, we could see to improve the resolution and Contrast ratio as compared to do not use the Xact-bone method. Accordingly, by using WBR's Xact-bone method is expected to improve the image quality. However, when introducing new software, it is needed to match the characteristics of the hospital protocol and clinical application.