• Journal of the Korean Geosynthetics Society
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• v.14 no.4
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• pp.11-21
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• 2015

The method to replace asphalt and cement is needed to reduce the carbon emission on road. Polymeric material which is light and easy to handle while having complex function with less carbon emission would be highly effective when it replaced soil pavement containing cement. This study is intended to identify the usability of soil pavement containing organic solidification agent only through the field test. Pavement on bike trail still satisfied required bearing capacity coefficient in 3 months. Pavement after passing 1.6 bil units of bike through pavement acceleration test that simulated a long-term serviceability during a short-time still remained unaffected, demonstrating a long-term serviceability of soil pavement.

• Journal of Digital Convergence
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• v.13 no.12
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• pp.285-290
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• 2015

The purpose of this study is to compare the status of eyesight according to the change of astigmatism axis in myopic astigmatism and to minimize errors in making astigmatic glasses based on accurate optometry and prescription. The subjects were 93 males and females(186 eyes) who have myopic astigmatism without any ocular disease or systemic disease. We performed comparative analysis on the status of visual acuity according to the change of astigmatism axis to 5, 10 and 15 degree in corrected eyesight 1.0. The direct astigmatism was the most common astigmatism type among the 186 eyes. After all subjects were perfectly corrected into 1.0, the change of astigmatism axis affected eyesight; The results suggested that the more change was made in astigmatism axis, the worse their eyesight would become. The main astigmatism type was changed from direct astigmatism to inverse astigmatism as age increased. The change of the astigmatism axis resulted in failing of corrected eyesight. Therefore, the convergence of examination and correction for astigmatism strength and axis is necessary when conducting refraction inspection for astigmatism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.5
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• pp.778-781
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• 2016

Sea urchin skeleton (SUS) generated from production of sea urchin eggs was used as a biodegradable film base material, and its composite film with gelatin was prepared. In addition, Robinia pseudoacacia flower extract (RFE) was incorporated into the film-forming solution to provide antioxidant and anti-microbial activities. The tensile strength (TS) of the SUS/gelatin composite films increased with increasing gelatin content, whereas elongation at break (E) decreased. Among the composite films, SUS/gelatin film at a ratio of 8:2 (w/w) exhibited the most desirable TS and E values. Furthermore, SUS composite film containing RFE showed a reduced TS and increased E compared to the control film. Based on 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays and disc diffusion results against growth of Listeria monocytogenes, antioxidant and anti-microbial activities of films increased with increasing RFE concentration. Consequently, SUS composite film containing RFE showed proper physical properties as well as antioxidant and anti-microbial activities. These results indicate that SUS can be used as a film base material while the SUS composite film containing RFE can be utilized as active packaging.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.11
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• pp.1239-1243
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• 2014

This paper presents the application of carbon-fiber-reinforced polymer (CFRP) for the damage absorption and optimal design of portable smart devices to close in life. CFRP specimens are subjected to a tensile test to estimate their mechanical properties in terms of the stacking angles. Further, the screw reverse torque and screw torque at each stacking angle are determined using a torque tester after tapping holes on the CFRP specimens. Two experiments are performed for comparing their results in order to determine optimal conditions. In the tensile test, a woven specimen is found to have the highest strength and stiffness. In the case of the woven specimen, no difference is observed even when it is applied to prevent loosening of the coating. And average result value was excellent.

• Journal of the korean Society of Automotive Engineers
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• v.4 no.3
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• pp.18-23
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• 1982

최근 자동차의 고속경향화 추세는 많은 진전을 보고 있으며 또 앞으로도 많은 연구와 노력이 경주되어야 하리라고 본다. 그 가운데 하나로 스프링의 경량화는 대략 다음과 같은 3방향에서 연구되고 있다. 1) 복합재료, 즉 GFRP(carbon fiber reinforced plastics), 나아가서는 BFRP(born fiber reinforced plastics)의 탄선과 경량성을 이용한 스프링. 2) 형상, 즉 구조적인 면에서 스프링소재를 후판으로 사용함으로서, 다매물에서 단매 또는 소수 매의 거물곡선 스피링(parabolic taper spring)으로의 변진. 3) 고응력 사용, 즉 종래의 스프링량보다 높은 탄성을 가진 재료로써 스프링 응력을 톺게 사용할 수 있는 강종의 개발 등이다. 특히 3)의 탄성한을 \ulcorner이는 문제는 2)의 후재화와 더불어 열처리성, 가공성 등이 문제가 되어 이에 따라 신강종으로서의 변천을 강요하게 된다. 그러므로 국제경쟁력을 강화하기 위하여 각국 들이 활발하게 연구 및 개발을 추진하고 있는 현상이다. 우리나라의 경우 현재 제작기술은 어느 정동 많이 축적되고 있으나, 아직 R&D면에서는 점진적으로 추진되고 있다. 이와 같은 실정에서 자동차산업의 국제화와 더불어 종래 사용된 스프링강재의 재검토가 우리나라에서도 긴급히 필 요하게 되었따. 그 예로서 KS SPS5(JIS SUP9)의 강종이 종래 일본에서 자동차용스프링의 대 종을 이루고 있던것이 최근에는 SUP9A로 전환되고 있다. 이것은 SUP9A는 SUP9보다 기계적 성질이 우수하며, 또한 자동차분야의 세계제일위인 미국의 SAE5160재와 일지되고 있다. 그러므로 국제화 경향과 더불어 SUP9종은 SUP9A로 전환되고 있으므로서 우리 나라의 경우에도 자동차 스프링의 수출용은물론이고, 국내용에도 SUP9A에 해당하는 규격이 제정되고, 또한 빠른 전환이 필요하다고 본다. 이와 같은 국제적인 추세는 SUP6을 SUP7H종으로 더욱 향상된 것이 실용 화되고 있다. 아래에서 이에 대한 기계적 특성을 중심으로 검토키로 한다.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.22 no.3
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• pp.119-125
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• 2016

Fresh-cut agricultural products provide convenience to consumers. However, quality changes or microbial growth can easily occur due to physical changes such as cutting and peeling etc. during processing. Therefore, efforts have been made to develop a functional packaging for extension of shelf life of fresh-cut agricultural products, food etc., and researches on prolongation of storage period have been actively developed. The shelf life is extended by antimicrobial, far infrared rays, air permeability, anti-fogging, weak current, ethylene gas adsorption or decomposition, gas composition changes such as MA (Modified Atmosphere) or CA (Controlled Atmosphere). The method of extending the shelf life by various complex factors. This paper based on the published literature to extend the shelf life of fresh-cut agricultural products, food etc., The paper has summarized the storage period extension packing method, packaging material for shelf life extension and comprehensive evaluation method.

• Korean Journal of Microbiology
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• v.43 no.1
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• pp.72-75
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• 2007

Using co-immunoprecipitation, we identified proteins interacting with Streptomyces coelicolor RNase ES, an ortholog of Escherichia coli RNase E that plays a major role in RNA decay and processing. Polyphosphate kinase and a homolog of exoribonuclease polynucleotide phosphorylase, guanosine pentaphosphate synthetase I that use inorganic phophate were co-precipitated with RNase E, indicating a possibility of S. coelicolor RNase ES to form a multiprotein complex called degradosome, which has been shown to be formed by RNase E in E. coli. Polynucleotide phophorylase proteins from these two phylogenetically distantly related bacteria species showed similar RNA cleavage action in vitro. These results imply the ability of RNase ES to form a multiprotein complex that has structurally and functionally similar to that of E. coli degradosome.

• Polymer(Korea)
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• v.25 no.5
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• pp.642-648
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• 2001

An attempt was made to synthesize an ammonia adsorbent by the photo-induced grafting of styrene (St) onto polypropylene (PP) nonwoven using benzoin ethyl ether (BEE) as a photosensitizer with urea and trimethylol propane triacrylate in methanol medium. As styrene concentration was increased, the graft yield was increased. It was also found that the graft yield increased with reaction time. The polypropylene grafted with styrene (PP-g-St) was sulfonated by chlorosulfonic acid in dichloroethane and complexed with several metal ion, such as $cO^{+2}$, $nI^{+2}$, $cU^{+2}$, $Zn^{+2}$. The amount of ammonia gas adsorbed by these sample was dependent on the degree of sulfonation, adsorption time, and ammonia gas pressure. The adsorption capacity of ammonia gas by the sulfonated PP-g-St(SPP-g-St) nonwoven with 4. 25 mmol $H^+$/g was 6.61 mmol/g. Metal ion complexed SPP-g-St nonwovens had higher adsorption capacity than SPP-g-St nonwoven and the $Co^{+2}$ complexed SPP-g-St showed 9.90 mmol $NH_3$/g, which was much higher than that of active carbon or silica gel.

• Applied Biological Chemistry
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• v.36 no.2
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• pp.80-85
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• 1993

Addition of the treated dietary fiber sources to wheat flour were generally decreased at Amylograph viscosity as the mixing ratio increased. Addition of the treated dietary fiber sources on the preparation of noodles increased weight and volume of cooked noodles but decreased extention force as the mixing ratio increased. The sensory test of the dietary fiber sources mixed noodles supplemented by treated soymilk residue 5% was excellent sensual properties. The properties of the dietary fiber sources mixed noodles supplemented by treated soymilk residue 10% and treated apple pomace 5% were nearly the same in the texture organoleptic properties compared with those of wheat flour noodle.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.2
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• pp.18-28
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• 1998

현재의 가축분뇨처리 형태와 축종별 적용대상은 표 3과 같이 분류되며, 축분 퇴비화 뇨오수 정화방식의 고액분리 형태에서 분뇨혼합물의 동시처리 즉, 깔감축사(소, 돼지), 슬러리 발효 퇴비화를 통한 무방류 시스템으로 변화되는 추세이다. 이러한 현상은 최근의 방류수질 규제강화에 따른 무방류화 저비용 단순화를 지향하고 있으며, 무방류화의 가장 큰 걸림돌은 톱밥과 같은 수분조절재 부족이라 할 수 있다. 현재 이용되고 있는 주요 시스템별 개선안은 다음과 같다. $\square$ 주요 처리 시스템 적용의 문제제기 $\circ$ 축분발효시설 - 톱밥 등 부자재 무이용을 위한 축분의 예비 건조시설 이용 - 교반식 발효기의 악취확산방지를 위하여 밀폐형 하우스 및 강제환기 장치 설치에 의한 악취 포집 및 탈취 - 중소규모 발효시설 개발 $\circ$ 화력건조 - 예비건조를 통한 톱밥, 연료비용 절감 - 악취방치 장치부착 의무화 $\circ$ 활성오니 정화시설 - 시설 운전관리 단순화 - 1차 고액분리를 통한 유입수 오염부하량 감소 및 균일화 $\circ$ 깔감축사 - 경제적으로 흡수를 극대화할 수 있는 수분조절재의 조합비 결정 및 혼합물을 깔감으로 재이용 기술개발 $\circ$ 슬러리 발효퇴비화 시설 - 톱밥 등 수분조절재 사용량 절감기술 - 증발량 극대화 기술개발 및 소요에너지 최소화기술개발 우리나라는 사계절이 뚜렷하여 외기상에 따라 편차가 심하며, 고밀도 사육 및 지역적 편중성, 경지면적 협소, 고비용 시장구조 등의 축산환경을 고려한다면 근원적으로 가축분뇨문제 해결한다는 것은 결코 쉬운 일이 아니다. 이는 저공해 사료개발에서부터 분뇨가 발생단계에서 분리, 수거할 수 있는 수거시설, 고효율 분뇨처리시스템의 정립, 액비 및 퇴비의 가공, 토양환원되었을 때 작물생장장애, 액비, 퇴비의 유통, 가축분뇨처리 정책 및 규제법 등의 각 분야에서 복합적 노력이 필요하다.