• Title/Summary/Keyword: Chu-Na

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Characteristics of sPAES Membrane and sPEEK Membrane for Direct Formic Acid Fuel Cell (직접개미산 연료전지용 전해질막으로서 sPAES 막과 sPEEK 막의 특성)

  • Jeong, Jae-Hyeon;Song, Myung-Hyun;Chung, Hoi-Bum;Lee, Moo-Seok;Lee, Dong-Hoon;Chu, Cheun-Ho;Na, Il-Chai;Park, Kwon-Pil
    • Korean Chemical Engineering Research
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    • v.53 no.6
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    • pp.690-694
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    • 2015
  • Recently, direct formic acid fuel cells (DFAFC) among direct liquid fuel cells is studied actively. Economical hydrocarbon membranes alternative to fluorinated membranes for DFAFC's membrane are receiving attention. In this study, characteristics of sulfonated poly(ether ether ketone, sPEEK) and sulfonated poly(arylene ether sulfone, PAES) membranes were compared with Nafion membrane at DFAFC operation condition. Formic acid crossover current density of hydrocarbon membranes were lower than that of Nafion 211 fluorinated membrane. I-V performance of sPEEK MEA(Membrane and Electrode Assembly) was similar to that of Nafion 211 MEA due to similar membrane resistance each other. sPEEK MEA with low formic acid crossover showed higher stability compared with Nafion 211 MEA.

Effect of Fabrication Method of Anode on Performance in Enzyme Fuel Cells (효소연료전지의 Anode 제조조건이 성능에 미치는 영향)

  • Lee, Se-Hoon;Hwang, Byung-Chan;Lee, Hye-Ri;Kim, Young-Sook;Chu, Cheun-Ho;Na, Il-Chai;Park, Kwon-Pil
    • Korean Chemical Engineering Research
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    • v.53 no.6
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    • pp.667-671
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    • 2015
  • Enzyme fuel cells were operated with cells composed of enzyme anode and PEMFC cathode. Enzyme anodes was fabricated by compression of a mixture of graphite particle, glucose oxidase(Gox) as a enzyme and ferrocene as a redox mediator, and then coated with Nafion ionomer solution. Performances of enzyme unit cell were measured with variation of anode manufacture factors, to find optimum condition of enzyme anode. Optimum pressure was 8.89MPa for enzyme anode pressing process. Highest power density was obtained at 60% graphite composition in enzyme anode. Optimum glucose concentration was 1.7 mol/l in anode substrate solution. The enzyme anode was stabilized by two times of deeping in Nafion solution for 1 sec.

Quality Characteristics and Antioxidant Activity of Syrup Added with Maca (Lepidium meyenii) Extract (마카 추출액 첨가에 따른 시럽의 품질특성과 항산화성)

  • Chung, Hai-Jung;Park, Han-Na;Chu, Young-Ran;Jeon, In-Sook;Kang, Yong-Soo
    • Food Science and Preservation
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    • v.17 no.2
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    • pp.236-242
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    • 2010
  • This study was conducted to develop a functional syrup by using maca extract. Five different levels (0%, 7%, 14%, 21%, 28%) of maca extract was added and the physicochemical properties were investigated. The pH of control syrup was lower than that of syrup added with maca extract. Viscosity increased with increasing amount of maca extract. Hunter L value decreased while b value increased as maca extract level increased. Results of consumer acceptance test revealed that no significant differences in flavor, sweet taste and overall acceptability were observed among samples. Therefore, it is suggested that maca extract can be incorporated into syrup up to 28% without depressing the quality. Total polyphenol content and DPPH radical, superoxide anion radical and hydroxyl radical scavenging tests were conducted in view of estimating the functionality of maca syrup. Results showed that incorporation of maca extract into syrup exhibited higher polyphenol content and DPPH radical and superoxide anion radical scavenging activity than control syrup (p<0.05).

Effects of Supplemented Salt in the Diet on Survival, Growth and Body Fluid Composition of Juvenile Grey Mullet (Mugil cephalus) Reared in Freshwater (어린 숭어(Mugil cephalus)의 담수사육에서 염분흡착 사료가 성장, 생존율 및 체액의 조성에 미치는 영향)

  • Chu, Chung;Chang, Young-Jin;Hur, Jun-Wook
    • Journal of Aquaculture
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    • v.13 no.4
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    • pp.317-323
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    • 2000
  • Experimental cohorts of Mugil cephalus were divided into 5 groups : seawater~normal feed (SWN), acclimation to freshwater~normal feed (GFWN), acclimation to freshwater~salt feed (Gf\iVS), freshwater. normal feed (FWN) and freshwater-salt feed (f\iVS). Growth was faster in the SWN, Gf\iVS, and GFWN groups than in the f\iVS and FWN groups. Condition factor did not differ among the groups. Survival (92 %) of the juveniles was the highest in the Gf\iVS group; however, the others showed no significant difference. Moisture of FWN group was significantly higher than that of SWN group (P < 0.05). Potassium concentration was significantly higher in the SWN group than that of others (P < 0.05). It was highest (30 mmolfl) among the cohort of SWN.

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A Research Analysis of Current Trends in Manual Therapy for Low Back and Pelvic Girdle Pain as Regards Pregnancy (임신과 관련하여 발생한 요통 및 골반통에서 수기요법에 관한 국내외 연구동향)

  • Park, Na-Ri;Lee, Yun-Jin;Chu, Hui-Yeong;An, Hee-Duk;Yang, Doo-Hwa
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.15 no.1
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    • pp.101-114
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    • 2020
  • Objectives : This study aimed to determine the current trends in manual therapy for low back and pelvic girdle pain as regards pregnancy. Methods : Using 7 online databases, we searched for appropriate clinical studies. Results : Eighteen studies were selected from online databases. The included studies consisted of 8 randomized controlled trials, 6 uncontrolled trials, 4 case reports, and 1 non-randomized controlled trial. Four studies were performed in pregnant patients, while others were in postpartum patients. The majority of studies used relaxing or rubbing of soft tissue and some of the studies were manipulated. The visual analog scale (VAS) was the most frequently used outcome, with the effective rate second. Conclusions : This study demonstrates that manual therapy may be a promising therapeutic option low back and pelvic girdle pain for patients as regards pregnancy or postpartum.

The Effects of Drying Method and Spice Extracts Added to Beef Jerky on the Quality Characteristics of Beef Jerky (건조방법과 향신료 추출물 첨가가 육포의 품질특성에 미치는 영향)

  • Park, Chu-Ja;Park, Chan-Sung
    • Korean journal of food and cookery science
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    • v.23 no.6
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    • pp.800-809
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    • 2007
  • To develope Hanbang beef jerky as health food, six kinds of beef jerky were prepared by adding sugar (A), licorice (B) and three kinds of spice extracts (clove: C, fennel fruit: D and Chungyang green pepper extract: E) and mixture of all extracts (F). The effects of the drying method and added spice extracts on the quality characteristics of the beef jerky were evaluated. In general, the air-blast dried beef jerky contained $31{\sim}33%$ moisture, $50.0{\sim}51.2%$ crude protein, $7.2{\sim}7.8%$ crude lipid and $3.0{\sim}3.3%$ crude ash. For the mineral content of the air-blast dried jerky, the most prevalent mineral was Na $(1540.08{\sim}1838.17$ mg%), followed by K, P, Mg, and Ca. The Ca content of the beef jerky was highest in the mixed extract group (88.53 mg%), and the lowest content was in sugar-added group (53.12 mg%). For the color properties, the L-value (lightness), a-value (redness) and b-value (yellowness) were higher in the air-blast dried beef jerky than in the hot air dried samples. The drying methods showed their greatest affect on the redness (a) for all six jerkies (p<0.001). For the preference by sensory evaluation, the beef jerky samples with added sugar (A) and licorice extract (B) had significantly higher scores than the beef jerky samples with the added spice extracts, for both of air-blast drying and hot air drying (p<0.05). Preference for the air-blast dried beef jerkies with added clove (C) and fennel fruits (D) were significantly higher, in terms of taste, color, softness and aftertaste as compared to the respective hot air dried jerkies (p<0.01). Considering all the obtained results, we concluded that licorice and spice extracts can be used as natural preservatives in the development of health foods and the air-blast drying method is recommended to improve the quality characteristics of beef jerky.

Horse Riding Simulator Affect the Posture Alignment of Young Adults with Forward Head Posture

  • Hong, Chu-Yi;Jung, Nam-Jin;Na, Sang-Su;Hwangbo, Gak
    • Journal of the Korean Society of Physical Medicine
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    • v.11 no.4
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    • pp.19-26
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    • 2016
  • PURPOSE: The purpose of this study was to compare the effect of correction on posture parameters between a horse riding simulator exercise and a conventional exercise occurring in an open linear chain linking the head to the pelvis in the sagittal plane of young adults with a forward head posture. METHODS: In this study, 30 subjects were randomly divided into two groups of 15 subjects each, were assigned to the horse riding simulator exercise or the neck exercise group and they performed exercise 30 minutes per each round two times a week for six weeks. To determine the subjects' forward head posture, the three angles and three distances were measured. RESULTS: The forward head angle and head distance results showed a significant change between pre and post intervention in both group. The horizontal distance between acromion and tragus results showed a significant change between pre and post intervention in neck exercise group (CG), but no significant change in horse riding simulator exercise group (EG). The averages of each measured values of EG and CG before and after were compared, but there are no significant different between groups. CONCLUSION: Although the effects of the horse riding exercise were lower than those elicited by the neck exercise, the results demonstrated that the horse riding simulator exercise improved posture alignment for subjects with forward head posture. Therefore, the horse riding simulator exercise can constitute an appropriate alternative exercise for subjects with forward head posture.

Stretchable Transistors Fabricated on Polydimethylsiloxane Elastomers

  • Jung, Soon-Won;Choi, Jeong Seon;Park, Chan Woo;Na, Bock Soon;Lim, Sang Chul;Lee, Sang Seok;Cho, Kyoung Ik;Chu, Hye Yong;Koo, Jae Bon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.389.2-389.2
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    • 2014
  • Polydimethylsiloxane (PDMS) based electronic devices are widely used for various applications in large area electronics, biomedical wearable interfaces and implantable circuitry where flexibility and/or stretchability are required. A few fabrication methods of electronic devices directly on PDMS substrate have been reported. However, it is well known that micro-cracks appear in the metal layer and in the lithography pattern on a PDMS substrate. To solve the above problems, a few studies for fabrication of stiff platform on PDMS substrate have been reported. Thin-film islands of a stiff region are fabricated on an elastomeric substrate, and electronic devices are fabricated on these stiff islands. When the substrate is stretched, the deformation is mainly accommodated by the substrate, and the stiff islands and electronic devices experience relatively small strains. Here, we report a new method to achieve stiff islands structures on an elastomeric substrate at a various thickness, as the platform for stretchable electronic devices. The stiff islands were defined by conventional photolithography on a stress-free elastomeric substrate. This technique can provide a practical strategy for realizing large-area stretchable electronic circuits, for various applications such as stretchable display or wearable electronic systems.

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Characteristics of Microbial Fuel Cells Using Pig Waste and sPAES Membrane (돼지 분뇨와 sPAES 막을 이용한 미생물 연료전지의 특성)

  • Lee, Se-Hoon;Mun, Ji-Yoon;Kim, Young-Sook;Chu, Cheun-Ho;Na, Il-Chai;Lee, Jeong-Hoon;Lee, Moo-Seok;Lee, Dong-Hoon;Park, Kwon-Pil
    • Korean Chemical Engineering Research
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    • v.54 no.4
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    • pp.453-458
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    • 2016
  • Microbial fuel cells (MFC) were operated with pig wastes and PEMFC (Proton Exchange Membrane Fuel Cells) MEA (Membrane and Electrode Assembly). Performance of hydrocarbon membrane was compared with that of perfluoro membrane at MFC condition. Sulfonated-Poly(Arylene Ether Sulfone) was used as hydrocarbon membrane and Gore membrane was used as perfluoro membrane. OCV of sPAES MEA was 50mV higher than that of Gore MEA and power density of sPAES MEA was similar that of Gore MEA. Reinforcement of sPAES membrane stabilized the performance of MEA in MFC. The highest performance was obtained at temperature of $45^{\circ}C$ and with culture solution circulation rate of 50 ml/min. The highest power density was $1,100mW/m^2$ at optimum condition in MFC using pig waste.

A Study on Interior Design Planning of Long-Life Housing - Focus on Case Studies - (장수명 주택의 공간구성 분석에 관한 연구 - 국내.외 사례를 중심으로 -)

  • Kim, You-Na;Kong, Soon-Ku;Chu, Beom
    • Korean Institute of Interior Design Journal
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    • v.19 no.3
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    • pp.136-144
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    • 2010
  • Since most domestic apartment, built in bearing wall system limiting variability of space, in spite of its good durability, cannot accept life style change and is being wasted, dumped scraps of which cause environmental pollution and waste of resources. As a response for this, researches on sustainable housing, that is, 'long-life housing' which has high durability, and variability responding life style change of the resident are in progress in and out of country. Therefore, this article aims, in suggesting the various status appearing on apartment and the interior plan responding the problem, to research on the house plan in the future which can be used continuously instead consuming type of apartment shortly used and discarded with understanding of long-life housing developed in foreign countries, and grasping the factors of application plan. Various reports from previous researches were comparatively analyzed and the studies on the characteristics, the real examples and the types of the surfaces were performed on the experimental model of long-life housing and similar residential surfaces to find the concept to be applied to Long-Life Housing and the introduction method of such concept. This article tries not only to prevent 'scarp and build', the serious cause of environmental pollution, but also to be basic materials for interior construction plan afterwards through 'long-life housing interior design plan' as the new conception which can accept life style and life cycle change.