• 대한금속재료학회지
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• 제46권6호
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• pp.390-401
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• 2008

The objective of this study is to evaluate various machining characteristics of AlN-hBN machinable ceramics in micro end-milling process for its further application. First, AlN based machinable ceramics with hBN contents in the range of 10 to 20vol% were prepared by hot-pressing. Material properties of the composites, such as relative density, Vickers hardness, flexural strength, Young's modulus and fracture toughness were measured and compared. Then, micro end-milling experiments were performed to fabricate micro channels using prepared system. During the process, cutting forces, vibrations and AE signals were measured and analyzed using applied sensor system. Machined micro channel shapes and surface roughness were measured using 3D non-contact type surface profiler. From the experimental results, it can be observed that the cutting forces, vibrations and AE signal amplitudes decreased with increasing hBN contents. Also, measured surface roughness and profiles were improved with increasing hBN contents. As a result of this study, optimum machining conditions can be determined to fabricate desired products with AlN-hBN machinable ceramics based on the experimental results of this research.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.636-640
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• 2000

Cup-plant (Silphium perfoliatum L.) has potential to produce high biomass and highly digestible forage in the wetlands where other productive forages do not grow or produce well. However, high moisture content at harvest is a considerable disadvantage of cup-plant for the production of high quality silage. This study was conducted to determine the effect of moisture content on the characteristics of cup-plant silage. Harvested cup-plant was ensiled in farm scale plastic bag silos and laboratory silos. In the plastic bag silos, first growth (FG) and regrowth (RG) cup-plant was harvested, wilted and ensiled. Dry matter content of FG and RG was 280 g/kg and 320 g/kg after 48 hr of wilting. The silage made with FG had pH 5.3 and 5.63 g/kg DM of acetate as a major volatile fatty acid. The composition of lactate, butyrate and acetate production was 1.0: 0.9: 2.3. The pH of silage made with RG was 4.5 and lactate was a major fermentation end product (16.8 g/kg DM). In the laboratory silos, wilted and unwilted first growth cup-plant material was ensiled to compare the early fermentation end products at days 2, 4, 11, and 40. Wilting increased dry matter content by 42% in the harvested material. Wilted silage showed about one unit lower pH until day 11. The contents of ammonia nitrogen and acetate were higher in un wilted silage, while that of lactate was higher in wilted silage (p<0.05). Butyrate and propionate were not detected in the wilted silage until day 40. We conclude from the results that moisture control is essential for the production of high quality cup-plant silage and high pH of cup-plant silage is due to low concentrations of fermentation end products.

• 펄프종이기술
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• 제46권4호
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• pp.1-10
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• 2014

In papermaking industry, inorganic fillers are widely used for the purpose of improving opacity, brightness, printability, uniformity and dimensional stability. They are also useful for production costs and energy savings. In the past, inorganic fillers in papermaking industry only focused on micro-scale but recently, new trials on nano-powdered technology are applying. Even nano-powdered fillers are rapidly utilized for improving the optical and surface properties in coating and surface sizing, there still have some problems in wet-end process due to poor dispersibility and retention. In this study, nano-particled calcium carbonate was produced by milling the PCC and its applicability between micro sized and nano sized calcium carbonated was compared in wet-end process, and finally the sheet properties were evaluated. Nano-PCC was not retained in sheet structure without applying retention system, but with retention system nano-powdered PCC was absorbed on fiber surface with expanding the fiber networks. The application of PAM-bentonite system has resulted in high ash retention and bulky structure for copier paper, and good optical properties in brightness and opacity. However, it required to solve the weakness of low tensile property due to interruption of hydrogen bonding by nano fillers.

• Journal of Nutrition and Health
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• 제38권3호
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• pp.251-258
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• 2005

The purposes of this study were to conceptualize the Home Meal Replacement (HMR) in Korea and to gather professionals' opinions of prospect and task for HMR industry in Korea. A total of 67 experts participated in a three round survey by Delphi technique, which was used to integrate and share the each expert's professional idea. According to the result, HMR was translated into 'Gajeongsiksa daeyongsik' in Korean and given definition to 'a meal taken directly or through brief cooking process at home by purchasing ready to eat or ready to end-cook type of food'. As the result of categorizing HMR products of Korean food, 'I. Ready to eat' such as side dishes, kimchi, salad, sandwich, kimbab, and so on and 'II. Ready to heat' such as rice, porridge, retort food (soup, broth, curry, spaghetti, etc.), frozen pizza, grilled food, jabchae, instant soup, and so on were construed in a limited sense of the HMR. In addition, 'III. Ready to end-cook' such as frozen dumpling, frozen pork cutlet, seasoned meat, powder-type soup, and so on as well as these two kinds were interpreted in a broad sense of the HMR. In the prospect of HMR industry in Korea, the Korean HMR industry would develop continuously accompanied by increasing of consumers using HMR products. Introduction and generalization of HMRs would serve the convenience for meal preparation and then influence the change of home meal pattern. Nevertheless, it was concerned about that using HMRs might have limitation on solving the problems of dietary life including irregular meal, skipping a meal, and so on and influence the nutrition imbalance. For the development of HMRs, developing various menu and the packaging materials for HMR products, constructing the thorough sanitary management, and strengthening R & D for the HMR of Korean food were the future tasks in Korean HMR industry.

• 한국생활과학회지
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• 제24권3호
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• pp.423-436
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• 2015

Namdaemun Market is located in the heart of history and has the volume and the budget for nearly half of the total Namdaemun. But it has been undergoing the crisis of stagnation without reviving the merit of only the 'jewelry' wholesale industrial cluster in the nation. The purposes of this study were that analyzed the status and design of jewelry in Namdaemun and identified the characteristics of successful domestic jewelery brands and then the revitalized the way of the Namdaemun jewelry industry. Problems being currently facing the Namdaemun jewelry shopping are most likely caused by products' design did not respond to changes quickly, while China's jewelry products are in leaps of the quality and the affordable jewelry market in Korea has lost the large number of the customers by china's cheap jewelry products. The most feature of successful domestic jewelry companies, Red Eye, Naughty Cat and Jackie Moon. put the most effort to unique design development and then constantly develope new designs to meet the diverse needs of consumers. It is a conclusion that the Namdaemun jewelry market need to produced under the name of brand not by the traditional whole sale market style. Development unique jewelry brand requires a high-end commercial strategy of the logo, packaging and interior. The high-end quality require for the advanced designs as well as the study of new materials needed for the advanced materials.

• 청정기술
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• 제3권1호
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• pp.9-26
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• 1997

공해 유발형 산업기술/제품의 폐기 요구 점증, 배출된 오염 물질 제거를 위한 후처리기술(EOP 기술) 활용의 한계, Green Round에 의한 국제 무역 규제 및 환경 부담금 문제 가시화(PPMs 규제) 및 지속 가능한 환경조화형 산업기술 확보(Sustainable Development)요구 등에 능동적 대처를 위해 산업활동에서의 환경오염 발생을 원천 억제 또는 제거하는 미래형 청정기술개발에 대한 요구가 급증하고 있다. 미래청정기술은 산업활동에서의 환경오염 발생을 원천 억제 또는 제거하는 미래형 환경오염 방지 기술로 정의될 수 있다. 선진국에 비해 청정기술 개발이 늦은 국내 현실에서 청정기술의 예속화를 피하고 기술 자립을 위해서는 원천 기술의 확보가 필수 불가결하며, 이의 달성을 위한 효과적인 청정기술의 개발 전략이 요구된다. 현재 국내 외에서 진행 중인 연구개발 프로그램을 비교 분석하고, 원천 기술인 미래형 청정기술의 성격을 규명한 뒤 효과적인 연구 수행을 위한 전략을 소개한다.

• Korean Chemical Engineering Research
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• 제46권3호
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• pp.540-544
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• 2008

혼합플라스틱에 대한 열분해특성실험을 스테인레스 스틸의 회분식 미분반응기에서 수행하였으며, 혼합플라스틱의 혼합비율은 22 wt.% HDPE, 17 wt.% LDPE, 27 wt.% PP, 12 wt.% PS, 16 wt.% ABS, 6 wt.% PVC이었다. 열분해온도는 $410{\sim}450^{\circ}C$ 이었으며 각 열분해생성물의 수율은 무게측정을 통해 얻었으며, 액상생성물의 분자량분포는 GC-SIMDIS 방법을 통해 측정하였다. 혼합플라스틱 열분해의 경우 반응온도와 시간이 증가할수록 고상잔류물의 수율증가와 액상생성물의 수율감소 그리고 액상생성물의 평균 분자량 감소가 두드러졌다. 혼합플라스틱에 포함된 PVC의 약 20%가 염소가스형태로 배출됨을 알 수 있었다. 혼합플라스틱 열분해에서 말단절단의 속도계수인 활성에너지 값은 50.2 kcal/mole 이었다.

• 산업경영시스템학회지
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• 제32권2호
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• pp.120-131
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• 2009

Most world-leading companies are aware that Environment and Health and Safety Issues are critical to the product quality and sustainable growth of their company. Environment-friendly efforts are seen in almost all aspects of business operations in an advanced nation. The Extended Producer Responsibility(EPR) and EU Directive on Waste Electric and Electronic Equipment(WEEE) attempt to tackle the growing quantity of WEEE by making producers responsible for the costs of the collection and recycling of their products at the End-of-Life(EOL). To implement the RFID-based integration system for EOL household electric appliances, such as washing machines and refrigerators, we analyzed the process of collecting, recovering, and recycling the EOL products returned from the distribution points. Furthermore, we proposed a soon-to-be process using the RFID-based integration system in the metropolitan recycling center(MRC). This soon-to-be process model is composed of RFID tags, readers, ALEs, applications and several devices. Through the introduction of the RFID-based integration system, we are expecting to see increasing traceability and real-time management for EOL products from customers, and also improvements in valuable reusable materials(VRM) produced from recycling processes.

• 대한화장품학회지
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• 제45권1호
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• pp.19-25
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• 2019

최종당화산물은 환원당과 단백질, 지질 또는 핵산 사이의 당화반응에 의해서 생성되는 물질로 이물질은 피부 노화 과정에 밀접하게 연관되어 있다고 보고되어 있다. 본 연구에서는 항산화 활성, 최종당화산물 생성 저해, 콜라겐과 최종당화산물의 교차결합 저해 및 억제, 엘라스타제 활성 저해 효능 시험을 통해서 비자나무 유박 추출물의 항노화 효과를 평가하였다. 시험 결과, 비자나무 유박 추출물은 폴리페놀과 플라보노이드를 함유하고 있으며, DPPH와 ABTS 자유라디칼을 50% 소거할 수 있는 농도는 각각 $16.4{\mu}g$ (Dried materials, DM)/mL과 $16.7{\mu}g\;DM/mL$ 로 관찰되었다. 또한, 비자나무 유박 추출물은 농도 의존적으로 최종당화산물 생성과 엘라스타제 활성을 저해하였고, 콜라겐과 최종당화산물의 교차결합을 저해 및 억제하였다. 따라서 본 연구 결과를 바탕으로 비자나무 유박 추출물은 항노화 효능이 있는 화장품 소재로서 활용가치가 있음을 확인하였다.

• 펄프종이기술
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• 제42권1호
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• pp.41-47
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• 2010

Increasing ash content of the paper is one of the most effective methods for saving raw materials and steam consumption and improving optical properties and better print quality. However, the increase of filler loading or filler content using a conventional wet end system is limited due to severe loss in strength properties, affecting runnability and product quality. This is because the filler has no ability to make bonding with cellulosic fibers. Therefore, if the technology to give filler the bonding ability is developed, the ash content of the paper can be increased more than ever. This study was carried out to modify PCC by coating its surface with starch contributing to better bonding with fibers. To prepare the modified PCC, cationic starch was selected as a polymer and then pretreatment was done by mixing PCC and cationic starch. Consequently, the pretreated PCC contributed to higher tensile strength, stiffness and opacity than the conventional filler, such as GCC and untreated PCC. However, CIE whiteness and ISO brightness decreased slightly compared to conventional fillers.