• Title/Summary/Keyword: 다소재

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The Thermal Conduction Property of Structural Concrete using Insulation Performance Improvement Materials (단열성능향상 재료를 사용한 구조용 콘크리트의 열전도 특성)

  • Park, Young-Shin;Kang, Min-Gi;Kim, Jung-Ho;Ji, Suk-Won;Jeon, Hyun-Kyu
    • Journal of the Korea Institute of Building Construction
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    • v.16 no.1
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    • pp.9-15
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    • 2016
  • The part of a building with the biggest energy loss is the exterior and many studies are actively conducted to reduce the energy loss on that part. However, most studies consider the window frames and insulation materials, but many studies do not discuss the concrete that takes more than 70% of the exterior. In order to minimize the energy loss of buildings, it is necessary to enhance the concrete's insulation performance and studies need to be conducted on this. Therefore, this study used a micro foam cell admixture, calcined diatomite powder, and lightweight aggregates as a part of a study to develop a type of concrete with improved insulation performance that has twice higher thermal conductivity compared to concrete. It particularly secured the porosity inside concrete to lower thermal conductivity. As a result of the experiment, the slump and air capacity showed fair results, but all mixtures containing micro foaming agent showed 14.3~35.1% lower mass per unit of volume compared to regular concrete. Compressive strength decreased slightly due to the materials used to improve the insulating performance, but it all satisfied this study's target strength(24MPa). Thermal conductivity was up to twice higher than that of regular concrete.

Fabrication and Evaluation of Si3N4-coated Organic/inorganic Hybrid Separators for Lithium-ion Batteries (Si3N4-코팅 유/무기 복합 분리막을 통한 리튬이온전지용 분리막의 제조 및 평가)

  • Yeo, Seung-Hun;Son, Hwa-Young;Seo, Myeong-Su;Roh, Tae-Wook;Kim, Gyu-Chul;Kim, Hyun-Il;Lee, Ho-Chun
    • Journal of the Korean Electrochemical Society
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    • v.15 no.1
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    • pp.48-53
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    • 2012
  • Polyethylene (PE) separator is the most popular separator for lithium-ion batteries. However, it suffers from thermal contraction and mechanical rupture. In order to improve the thermal/mechanical dimensional stabilities, this study investigated the effects of $Si_3N_4$ coating. SCS (Silicon-nitride Coated Separator) has been fabricated by applying 10 ${\mu}m$-thick $Si_3N_4$/PVdF coating on one side of PE separator. SCS exhibits enhanced thermal stability over $100{\sim}150^{\circ}C$: its thermal shrinkage is reduced by 10~20% compared with pristine PE separator. In addition, SCS shows higher tensile strength than PE separator. Employing SCS hardly affects the C-rate performance of $LiCoO_2$/Li coin-cell, even though its ionic conductivity is somewhat lower than that of PE separator.

Comparison of Storability on Film Sources and Storage Temperature for Fresh Japanese Mint in MA Storage (Japanese Mint의 MA 저장시 저장온도와 필름종류에 따른 저장성 비교)

  • 박권우;김충호;강호민
    • Journal of Bio-Environment Control
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    • v.9 no.1
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    • pp.40-46
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    • 2000
  • This study was conducted to investigate the comparison of storability on film sources and storage temperature and determine the proper condition for fresh Japanese mint in U storage. The fresh weight in storage was maintained well more than 40$\mu$m ceramic film(CE 40) thickness. The carbon dioxide, ethylene, and acetaldehyde contents in 80$\mu$m ceramic film(CE 80) was higher than those in CE 40. Those were not different among the storage temperatures, rather, those in 3$^{\circ}C$ and 1$^{\circ}C$ storage were higher than those in 1$0^{\circ}C$. The chlorophyll contents loss was promoted by above 5% water loss and 0.5ppm ethylene contents, but mote than 4% carbon dioxide contents restrained from degrading chiorophyll. The storage period in 3$^{\circ}C$ was 30 days that was twice longer than those in other storage temperatures. The visual quality was higher in CE 40 at 3$^{\circ}C$, and this plot was lowest in ion leakage that was shown the degree of chilling injury. It was concluded that storage temperature of at 3$^{\circ}C$ and packaged ceramic 40$\mu$m film to increase storability of Japanese mint would be favorable.

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Comparison of Storability of Some Sprout Vegetables in MA Storage (MA저장중 몇가지 싹기름 채소의 저장성 비교)

  • Kang, Ho-Min;Kim, Il-Seop
    • Journal of Bio-Environment Control
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    • v.16 no.4
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    • pp.415-419
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    • 2007
  • This study was conducted to compare the storability of some sprout vegetables; alfalfa, broccoli, radish, red-cabbage, and red-radish, packed with 50 low density polyethylene (LDPE) film in MA storage. Most of all 5 different sprout vegetable crops maintained the fresh weight higher than 99% until 10 days storage at 2 and $8^{\circ}C$. The carbon dioxide concentration in packages was higher at 8 than at $2^{\circ}C$. It was higher in radish and red-radish sprouts than other crops. As the oxygen concentration showed opposite trends to carbon dioxide, that of radish and red-radish sprouts decreased more than 3% after 3 days in 8 storage. Ethylene concentration in the packages of alfalfa was 0.1 ppm, significantly higher than other four crops with less than 1.0 ppm. Temperature treatment, however, did not influence the ethylene concentration in packages. The radish and red-radish sprouts, with lowest oxygen concentration in package, showed lowest off-flavor compared to the others. The visual quality of these sprouts in packages showed higher at $2^{\circ}C\;than\;at\;8^{\circ}C$ and was maintained the highest in radish sprouts, followed by red-radish, broccoli, red-cabbage, and alfalfa sprouts in that order. In conclusion, as the sprout vegetables have different shelf-life, of which radish was $4{\sim}5$ days longer than that of alfalfa the distributed condition of sprout vegetables should be differently controlled according to kinds of crops.

Efficiency of Yellow and White light Traps on Controlling Tobacco Whitefly in tomato Greenhouse (토마토 온실에서 담배가루이 성충에 대한 노란색 및 백색 트랩의 방제효과)

  • Lee, Jung-Sup;Lee, Jae-Han;Park, Kyung-Seob;Yeo, Kyung-Hwan;Kim, Jin-Hyun;Kweon, Jun-Kuk
    • Journal of Bio-Environment Control
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    • v.26 no.4
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    • pp.432-437
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    • 2017
  • Yellow sticky traps have been commonly used for monitoring tobacco whitefly populations in open-fields, as well as in greenhouses. However, the attractiveness depends on various factors such as the reflected intensity (brightness) and hues of yellow color (wavelength) of the trap surface, which is often influenced by environmental conditions and may sometimes affect tobacco whitefly capture. Therefore, the use of light-emitting traps can be a significant complementary tool to strengthen the attractiveness and selectivity of these traps. This research was carried out in tomato greenhouses to evaluate the light-emitting trap as potential attractants for Bemisia tabaci adults. The results showed that B. tabaci adults on average preferred (p>0.05) traps in yellow lights (590 nm) ($168{\pm}7.6adults/trap$) compared to traps in white lights ($106{\pm}4.6adults/trap$) and traps without lights ($60{\pm}4.8adults/trap$). The yellow light trap(590 nm) showed the most attractive to B. tabaci adults, followed by a little lower attraction to the white light trap(450-625 nm), whereas the control (no light trap) was little attractive to B. tabaci adults. These results suggested that yellow and white light traps could have a promising use in greenhouses for the identification, monitoring, and pest control tools of tobacco whiteflies.

Rural Amenity Contents in the Textbooks of Agricultural High School (농업계고등학교 교과서를 통해 살펴본 농촌어메니티 교과내용)

  • Kim, Eun-Ja;Ryu, Cheong-San;Kang, Bang-Hun;Yoon, Soon-Duck;Kim, Sang-Bum;Hwang, Jeong-Im;Rhee, Sang-Young
    • Proceedings of the Korean Society of Community Living Science Conference
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    • 2009.09a
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    • pp.93-93
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    • 2009
  • 본 연구는 농업 농촌의 미래세대 주역으로 활동하게 될 농업계 고등학교 학생들에게 교과서를 통한 학습기회 제공이 무엇보다 중요함에 따라, 그들이 배우고 있는 농업계고등학교 교과서를 대상으로 농촌어메니티 교과내용을 분석함으로써 농촌어메니티 및 녹색가치 구현에 대한 인식 중대를 도모하고 올바른 농업 농촌의 가치관을 형성시키는데 기여하고자 한다. 분석 교과서는 원예, 축산, 농기계, 식품가공 등 총 39종의 농업계 교과서를 대상으로, 농촌어메니티자원 37종을 활용한 어메니티 관점으로 내용분석이 이루어졌다. 그 결과 환경자원과 자연자원을 포함한 자연적 자원의 경우(대기질, 수질, 비옥한 토양, 미기후, 지형 등) 141개로 17.6%를 차지하고 있는 것으로 나타났으며, 역사자원, 경관자원을 포함한 문화적 자원(문화재, 전통건조물, 신앙공간 등)의 경우 219개로 27.4%를 나타내었다. 또한 시설자원, 경제활동자원, 공동체활동자원을 포함하는 사회적 자원(공동생활시설, 기반시설, 도농교류활동, 생활공동체활동 등)인 경우 440개, 55%인 것으로 나타나 전체 39종의 교과서를 대상으로 어메니티 관점으로 하여 교과내용을 분석한 결과 총 800개가 수록되어 있는 것으로 분석되었다. 내용분석은 제시유형(문장, 사진, 삽화, 그래프, 표), 교육적 성격(준비학습, 내용이해, 기능습득, 실습활동, 문제해결, 태도형성, 기타)을 기준으로 분석하여 해당 내용이 농촌어메니티를 적절하게 표현하였는지에 따라 판정 여부를 제시하였다. 또한 교과서를 유형별로 구분하여 분석해 본 결과 A유형의 교과서는 9권으로 351개의 내용분석이 이루어졌고, B유형의 교과서는 16권으로 322개의 내용분석이 이루어졌으며, C유형의 경우 14권으로 127개의 내용분석이 이루어졌다. A와 B유형 교과서는 농촌어메니티를 나타낼 수 있는 교과서 내용 요소가 많은 유형이고, C유형은 주로 기술 및 관리 기법 등과 관련된 내용의 교과서였다. 제시유형별 교과내용을 분석한 결과 A유형의 교과서에는 사진 185, 문장 125, 삽화 24 순으로 나타났으며, B유형에는 사진 144, 문장 136, 삽화 37개, C유형에는 사진 57, 문장 55, 삽화 11개의 순으로 나타났다. 교육적 성격별 분석결과 A유형, B유형, C유형 두 내용이해,에 대한 교과내용이 절대적으로 우선순위를 나타냈으며, B유형의 경우 기능습득에 대한 교육적 성격도 다소 높은 것으로 분석되었다.

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Effects of Different Body Color Strain and Improvement on Serium Cholesterol and Protein Contents in Chickens (닭의 체모색 계통별 및 개량상태가 혈중 Cholesterol과 Protein 함양에 미치는 영향)

  • 조성구
    • Korean Journal of Poultry Science
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    • v.17 no.1
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    • pp.7-15
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    • 1990
  • The present study was undertaken to determine the effect of different body hair color (Native type) and commercial white laying hen (Improvement, Nick Chick strain) on cholesterol, triglyceride and protein concentration in serium. Experimental hens were selected out of yellow-brown body hair color strain (10 heads), green-black body hair color strain (13 heads), white body hair color strain (7 heads), black-bone strain (10 heads) as native type and commercial white laying hen (30 head,3) as improved variety. Experimental diet was fed identically for 4 weeks in total groups. The results of the experiment obtained were summerized as follows:1. Serium cholesterol contents were the highest in commercial white laying hen ($172.50\pm$13.45 mg/100 $m\ell$) (p<0.01;, and higher in white color strains than body hair color strain groups. Body hair color strain groups were similar in serium cholesterol contents. 2, Serium triglyceride concentration also showed no response among native type groups, however commercial white laying hen group shelved significatly difference. (p<0.01) 3. Serium protein contents were the highest in commercial white laying hen group ($6.24\pm$0.23 mg/100 $m\ell$). (p<0,01) Increasing the serium cholesterol, triglyceride and protein contents in commercial white laying hen group than color strain group of native type was considered to improved grade.

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A Feature Point Extraction and Identification Technique for Immersive Contents Using Deep Learning (딥 러닝을 이용한 실감형 콘텐츠 특징점 추출 및 식별 방법)

  • Park, Byeongchan;Jang, Seyoung;Yoo, Injae;Lee, Jaechung;Kim, Seok-Yoon;Kim, Youngmo
    • Journal of IKEEE
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    • v.24 no.2
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    • pp.529-535
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    • 2020
  • As the main technology of the 4th industrial revolution, immersive 360-degree video contents are drawing attention. The market size of immersive 360-degree video contents worldwide is projected to increase from $6.7 billion in 2018 to approximately $70 billion in 2020. However, most of the immersive 360-degree video contents are distributed through illegal distribution networks such as Webhard and Torrent, and the damage caused by illegal reproduction is increasing. Existing 2D video industry uses copyright filtering technology to prevent such illegal distribution. The technical difficulties dealing with immersive 360-degree videos arise in that they require ultra-high quality pictures and have the characteristics containing images captured by two or more cameras merged in one image, which results in the creation of distortion regions. There are also technical limitations such as an increase in the amount of feature point data due to the ultra-high definition and the processing speed requirement. These consideration makes it difficult to use the same 2D filtering technology for 360-degree videos. To solve this problem, this paper suggests a feature point extraction and identification technique that select object identification areas excluding regions with severe distortion, recognize objects using deep learning technology in the identification areas, extract feature points using the identified object information. Compared with the previously proposed method of extracting feature points using stitching area for immersive contents, the proposed technique shows excellent performance gain.

Quality Characteristics of Potato and Sweet Potato Peeled by Different Methods (박피방법에 따른 감자 및 고구마의 초기 품질 비교)

  • Jeong Jin-Woong;Park Kee-Jai;Jeong Seong-Weon;Sung Jung-Min
    • Food Science and Preservation
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    • v.13 no.4
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    • pp.438-444
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    • 2006
  • This study was carried out to obtain fundamental data such as peeling efficiency and quality of potatoes and sweet potatoes peeled by hand, machine and alkali(NaOH). The weight loss by peeling was influenced by peeling methods. Weight losses by rotational brushing-type peeler showed the lowest value, 7.9% in potato, and 7.3% in sweet potato. Any significant differences in moisture content were not found in potatoes and sweet potatoes by peeling methods. The pH of potatoes and sweet potatoes just after peeling were 5.8-6.8 and 6.23-6.63, and decreased somewhat until 3 hrs after peeling. Hardness of potatoes and sweet potatoes peeled by hand with fruit knife were better than that of others. Depending upon the peeling method used the color and color differences undergo some changes in their color and browning. Color difference value of peeled potatoes by hand with a technical tools, and by mechanical peeler such as rotational cutting-type peeler and rotational brushing-type peeler showed just slightly. In particular, changes of rotor differences value of potatoes and sweet potatoes peeled by dipping with 10% NaOH solution at $100^{\circ}C$ was the highest in the samples peeled by NaOH.

Application of HACCP for Hygiene Control in University Foodservice Facility - Focused on Vegetable Dishes (Sengchae and Namul) - (대학급식시설의 위생관리개선을 위한 HACCP 적용에 관한 연구 - 생.숙채류를 중심으로 -)

  • 허영수;이복희
    • Journal of Food Hygiene and Safety
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    • v.14 no.3
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    • pp.293-304
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    • 1999
  • The purpose of this study was to evaluate the microbiological quality, and to assure the hygienic safety of the food production in the university food service facility located in Seoul in accordance with the Hazard Analysis Critical Control Point(HACCP) concepts. In the hygienic state assessment of kitchen, it has revealed that it was very important to remove water from the kitchen floor and to establish standard method for disinfection of cooking utensils. And foodservice workers were required to have training program for the safe handling of food and utensils since they did treat food without hygienic gloves. The kitchen layout had to be improved because the near distance of table with heating unit and shelf might cause the growth of microorganisms when prepared food was kept on the shelf. In terms of the timetemperature measurement and microbiological quality assessment during each of the food production phases, most of sengchae (raw vegetable dish) and namul (cooked vegetable dish) were treated within danger zone for food safeness ($5~60^{\circ}C$). It has shown that the microbiological quality of raw materials was very much inferior at the time of receiving based on the TPC($10^{5}~10^{7}$), coliform($10^{3}~1O^{6}$), which was not acceptable level(TPC:$10^{6}$, coliform:$10^{3}$) suggested by Solberg. Microbiological growth has increased in the both of sengchae and namul considerably during most of food production phase. Therefore, it is extremely important to reduce holding and serving time and to avoid treating food within the danger zone for food safeness. In addition, the prevention of cross-contamination during mixing the ingredients with improper equipments and with insanitary treatments by workers was also important to keep the food safety in this speciqic university foodservice facility.

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