• Proceedings of the Korean Nuclear Society Conference
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• 1996.11b
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• pp.596-602
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• 1996

석탄화력발전소 폐기물인 석탄회로 포집한 세슘의 고온안정성 분석을 위하여 Cs/Al의 몰비를 0.1에서 1.5까지 변화시켜 제조한 시료를 TGA, XRD, SEM등으로 분석하였다. 몰비가 0.75이상에서부터 pollucite 상 이외에 CsAlSiO$_4$상이 나타나기 시작하였으며 몰비가 증가할수록 CsAlSiO$_4$상이 증가하였다. 몰비가 0.5까지 세슘의 휘발로 인한 무게감량은 없었고 0.75부터는 몰비가 증가할수록 무게감량이 증가하였다. 이는 몰비가 증가할수록 세슘 증기압이 큰 CsAlSiO$_4$상이 증가하기 때문인 것으로 사료된다.

• Polymer(Korea)
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• v.33 no.6
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• pp.581-587
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• 2009

PLA/PEG blend fibers composed of poly (lactic acid) (PLA) and poly (ethylene glycol) (PEG) were prepared via melt blending and spinning for bioabsorbable filament sutures. The blend fibers hydrolyzed with the immersion in a phosphate buffer solution at pH 7.4 and $37\;^{\circ}C$ for 1~8 weeks. The effects of blending time, blend composition, and hydrolysis time on the weight loss and tensile strength of the hydrolyzed blend fibers were investigated. After hydrolysis, the weight loss of the blend fibers increased with increasing PEG content, blending time, and hydrolysis time. The tensile strength and tensile modulus of the blend fibers decreased with increasing PEG content, blending time, and hydrolysis time. Therefore, it can be concluded that the weight loss of the PLA/PEG blend fibers was less than 0.9% even at hydrolysis time of 2 weeks and their strength retentions were over 90%.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.22 no.3
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• pp.163-168
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• 2016

In this study, we analyzed the empty body weight and nominal volume of different types of polyethylene terephthalate (PET) bottles commercialized in Korean market. Over 780 PET bottles were collected and classified into four types, heat resistance bottle, normal resistance bottle, pressure resistance bottle, and long period using bottle. Each PET bottle's lightness index was established using bottle weight and nominal volume. Based on the index value, "acceptable" and "optimum" criteria for design guideline of PET bottle were summarized for each PET bottle type. In this paper, we suggest the use of PET bottle lightness index as a design guideline for material resource reduction of PET bottle for Korean beverage industries and bottle makers. For example, we can achieve 2~4 g weight reduction in normal pressure bottle for 500 mL drinking water.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.4
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• pp.363-368
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• 2010

The overall indicator of microbial activity in the fermentation-extinction reaction of food waste by using bio wood-chips were investigated by considering adenosine tri-phosphate(ATP). Degradation rate of organic compounds, which was represented by chemical oxygen demand(COD) and total nitrogen(TN), was increased with the concentration of adenosine tri-phosphate during fermentation-extinction reaction of food waste by using bio-wood chips. With this view, the ATP would be one of the overall evaluation indicator of organic degradation in the species of bio-wood chip for the fermentation-extinction of food waste.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.329-334
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• 1997

석탄화력발전소 폐기물인 석탄회로 포집한 세슘의 환원분위기(He+4% H$_2$)하에서 고온안정성 분석을 위하여 몰비를 0.1에서 1.5까지 변화시켜 제조한 시료를 머플로에서 열처리 및 XRD로 분석하였다 Cs/Al의 몰비가 증가할 수록 세슘 포집량이 증가하였다. 세슘 포집량 0.48(g-Cs$_2$O/g-fly ash) 이상에서 부터 pollucite 상 이외에 CsAlSiO$_4$상이 나타나기 시작하였고 세슘 포집량이 증가할 수록 CsAlSiO$_4$ 상이 증가하였다. 세슘 포집량 0.15(g-Cs$_2$O/g-fly ash) 까지 세슘의 휘발로 인한 무게감량은 없었고, 포집량 0.32(g-Cs$_2$O/g-fly ash)부터는 포집량이 증가할 수록 무게감량이 증가하였다. 이는 세슘 포집량이 증가할 수록 세슘 증기압이 큰 CsAlSiO$_4$상이 증가하기 때문인 것으로 사료된다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.4 s.27
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• pp.253-259
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• 2006

This paper investigated on anti-corrosion characteristic in chemical decontamination at extremely severe condition{process model-2) of stainless steels used with reactor coolant pump. The electrochemical properties of stainless steel{STS) 304 with the lapse qf cycle is better than those of STS 415 and STS 431. The STS 304 in process model-1 and process model-2 present the lowest weightloss ratio. The experiment results for STS 304, STS 415, and STS 431 in process model-2 solution, it was ascertained that weightloss ratio of process model-2 solution for process model-1 solution show 2..908, 2.572, and 2.370 times, respectively. The reason suggests that process model-2 is higher concentration of chemical and temperature compare to process model-1.

• Resources Recycling
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• v.7 no.5
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• pp.19-25
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• 1998

High temperature thermal behaviors of EAF dust by coke at initial reaction stage were studied to obtain the fundamental data of EAF dust treatment process, that is Extended Arc Plasma Furnace System called RAPID system. In this study thermal behaviors including calcination of limestone, devolatilization of EAF dust itself, and reduction & devolatilization of mixture(EAF dust : coke : limestone = 80 : 10 : 10 wt.%) were investigated as functions of reaction temperature (1000~1300$^{\circ}C$) and reaction time (3~12 min), considering the 180% equivalence of carbon reduction and 1.7 bacisity for optimum reduction and melting of EAF dust in the RAPID system. Size of sample was about below 0.1 mm for these experiments. Limestone was completely calcined at above 1100$^{\circ}C$ within 1 minutes. In the case of devolatilization of EAF dust itself, weight loss of EAF dust was about 14% at 1300$^{\circ}C$ and 12 minutes, and partial sintering and melting were found in part of sample. Weight loss of mixtures increased with increasing reaction temperature and time, about 46% weight loss in it was occurred at 1300$^{\circ}C$ and 12 minutes. From these weight losses showing devolatilization and reduction of EAF dust, the treatment time of EAF dust inside.

• Applied Microscopy
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• v.40 no.3
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• pp.163-168
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• 2010

We investigated the burning process of the virgin hair and straight permed hair using thermal analyser and scanning electron microscopy. After the thermal analysis, we found that weight started to change from $100^{\circ}C$. Whereas straight permed hair has weight decrease rate of 2.6% higher than the virgin hair till $200^{\circ}C$, those were 64.9% and 64.4% for the virgin and straight permed hairs, respectively at $300^{\circ}C$. At $400^{\circ}C$, the weight decrease rate of the virgin hair became lower than the other; they were 32.3% and 33.4% for the virgin and straight permed hairs, respectively. Final values were 25.4% and 28.3% at $500^{\circ}C$, which showed that final weight of burnt straight permed hair was higher than the virgin hair by about 2.9%. In terms of morphological changes, the hair started to melt together with adjacent ones by burning till $300^{\circ}C$. The medulla and cortex were melt and the inside was empty like bamboo. The hair burnt till $500^{\circ}C$ was entirely carbonized and found as a clod. We found many blowholes at the surface of the hair clump.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.109-119
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• 2002

This study is to estimate that food waste bags with biodegradable plastic are really decomposed by microorganism in composting with food waste and to examinate how biodegradable plastic affects composting. 6 kinds of 30%, 4 kinds of 100% and 2 kinds of none biodegradable plastics were used in d1is study. In 30% biodegradable plastics the highest Degradation rare is 6% in meso-condition and 10% in thermal-condition. Srain at auto break decreased to 150% in meso-condition and 120% in thermal-condition. Stress at max load were also reduced to $180kgf/cm^2$ in mesocondition and $200kgf/cm^2$ in thermal-condition. Usually, LLDPE decreased larger than HDPE in physical characreristics but HDPE is higher in degradation rate. 1n stain at auto break and stress ar max load 100% biodegradable plastic declined to 230% and to $380kgf/cm^2$ in meso-condition and to 440% and to $400/cm^2$ in thermal-condition respectively. 100% biodegradable plastics showed higher biodegradation and decomposition then 30%. They appeared clearly through SEM observation. As a result, it was not appropriate to use 30% biodegradable plastics as food waste bag because they were not decomposed perfectly. It is possible to use 100% biodegradable plastic as it but cost is too high. So development of technique is needed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.5
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• pp.249-255
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• 2017

Using a magnetic separation process, pond ash generated in thermoelectric power plants was separated into magnetic materials and nonmagnetic materials in order to make it into a raw material of geopolymers and unburned carbon; screening characteristics according to the particle sizes and magnet strength levels of the pond ash were observed. Based on the results of magnetic separation into fine particle (0.15~0.84 mm) and rough particle (0.84~2.4 mm) pond ash using 3000 G magnets, the weight fraction and ignition loss of nonmagnetic materials were found to be higher than those of magnetic materials, regardless of the particle size. In the case of fine particle pond ash, when the magnet strength was increased from 3000 G to 10000 G, even those materials that were weakly magnetic were separated into magnetic materials, leading to drastic increases in the weight fraction of magnetic materials, such that the ignition loss accounted for 66.9 % (22.8 wt%) of the entire ignition loss of 32.6 wt%, despite of the low ignition loss. Based on the results of measurement of the compressive strength levels of geopolymers made of magnetic-separated rough particle pond ash, the compressive strength of geopolymers made of magnetic materials containing small amounts of unburned carbon was found to be 20 MPa.