• Title/Summary/Keyword: a specific gravity

검색결과 936건 처리시간 0.036초

황토를 사용한 천목소지 개발 (Development of Body for Temmoku Tea Bowl Using Hwangto)

  • 정종혁;이병하
    • 한국세라믹학회지
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    • 제47권4호
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    • pp.296-301
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    • 2010
  • The objective of the present research is to develop the body for Temmoku Teabowl, in order to manufacture the Temmoku Teabowl with the characteristics of Jian Ware, which has a rich dark brown color and has been extolled as the representative fine article of Temmoku Teabowl. Basic composition was first determined using domestically produced clay, kaolin and pottery stone as starting materials. After the addition of calcinated Hwangto, which is rich in iron, the mixture was subjected either to oxidizing calcination at $1260^{\circ}C$ to produce a body with a color suitable for Hanam ware or to reducing calcination at $1230^{\circ}C$ to produce a body with a color suitable for Jian Ware. The bodies produced in this research showed the strength value of $380{\sim}36\;Kg/cm^2$, the specific gravity of 2.304~2.310, the absorption ratio of 4.103~3.897, and the porosity of 8.608~8.207%.

Improvement of Physical and Drying Properties of Large Diameter and Long Axis Moso Bamboo (Phyllostachys pubescens) Poles Using Heat Treatment

  • Kyoung-Jung KIM;Young-Jin KIM;Se-Yeong PARK
    • Journal of the Korean Wood Science and Technology
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    • 제51권6호
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    • pp.447-447
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    • 2023
  • This study aimed to convert underutilized moso bamboo into high-value added products such as fences, interior materials, lighting fixtures, and accessories. Green moso bamboo poles with a diameter of approximately 10 cm and a length of approximately 3.7 m were heat treated at 140℃ using a large-scale kiln. The processing time was meticulously adjusted through various stages, including pretreatment (6-8 hours at 60℃), cooking (8-10 hours at 100℃), steaming (26-30 hours at 120℃), heating (4-6 hours at 140℃), and finally, cooling (below 80℃). A meticulously designed heat treatment process has enabled efficient mass production of moso bamboo poles with improved qualities, including minimal splitting, moisture levels below 3%, and a specific gravity of 1.05. The focus of this study was to present the physical and drying properties, such as color, dimensional change, specific gravity, moisture content, and splitting, observed during the heat treatment process.

원관형 토양샘플러를 이용한 토양물리특성 추정 (Estimation of Characteristic of the Soil Physical using the Pipe Type Soil Sampler)

  • 유지현;정명관;박승기
    • 한국농공학회논문집
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    • 제62권1호
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    • pp.95-104
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    • 2020
  • The purpose of this study is to develop a pipe type soil sampler that can easily collect soil cross section servey and soil samples to conduct ecological environment surveys while minimizing ecological disturbance in the area subject to soil survey. Furthermore, this study develop the exponential type estimation specific weight formula (ESWF) that uses pipe type soil sampler to easily carry out soil cross section survey and soil sample while estimating the specific weight of the area using water content and soil sample length variation ratio (SLVRs) and to obtain apparent specific gravity, hardness, and max. porosity which are used as growth of corps and ecological environment index. The calibration results of ESWF showed a high degree of significance, with NSE for actual specific weight (γ0) and calibration estimation specific weight (γec) 0.95, R2 for 0.954, and RMSE for 0.051. The verification results of ESWF showed a high significance, with NSE for actual specific weight (γ0) and verification estimation specific weight (γev) 0.881, R2 for 0.978, and RMSE for 0.055.

Gluten-Free 쌀빵의 제빵 특성에 대한 첨가 수분 온도 영향 (Effect of Added Water Temperature on Baking Characteristics of Gluten-Free Rice Bread)

  • 김상숙;정혜영
    • 한국식품영양학회지
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    • 제30권6호
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    • pp.1184-1190
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    • 2017
  • Baking characteristics of gluten-free rice bread were investigated, when 20, 30, 40, 50 and $60^{\circ}C$ water was added during mixing. The temperature of the dough before fermentation was affected by the temperature of the water and the mixing time. When $60^{\circ}C$ water was added, the specific gravity of the dough was the highest before fermentation (p<0.01). The specific gravity of the dough after fermentation was 32~39% of the specific gravity of the dough before fermentation. When $50^{\circ}C$ water was added, the volume and the specific volume of rice bread were higher than those in addition of water at other temperatures (p<0.001). In case of adding water of $50^{\circ}C$, the shape of the rice bread showed the largest volume, high appearance and a round shape. After storage for 2 and 24 hours, the addition of water of $50^{\circ}C$ resulted in the lowest hardness and chewiness values of rice bread. The sensory descriptive analysis revealed that when $50^{\circ}C$ water was added, the air cell size, springiness and hardness values of gluten-free rice bread were lower than those in addition of water at other temperatures. There was a difference in the appearance and texture of gluten-free rice bread, when 20, 30, 40, 50 and $60^{\circ}C$ water was added during mixing.

광물감별을 위한 컴퓨터프로그램 개발 (Computer Program for Mineral Identification (CPMI))

  • 채동현
    • 한국과학교육학회지
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    • 제14권2호
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    • pp.236-240
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    • 1994
  • Recently computers are transforming our classroom by means of initiating and expanding teaching and learning. Lloyd (1989) indicates that computers show great promise in a way augmenting the classroom instructional process under the guidance of the teacher. In this paper computer program for mineral identification (called CPMI) is introduced. This program is is to provide a short list of 26 minerals. These mineras are classified using some properties for mineral identification that is color, streak, hardness, specific gravity, luster, and crystal form. Mineral properties can be divided into two groups for operating this program: (1) properties with numeric values, that is hardness and specific gravity; (2) properties whith a single word, that is color, streak, luster, and crystal form.

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현미중 화학성분함량 결정요인 해석에 관한 새시도 (A New Approach in Analysis of the Factors Affecting the Chemical Components in Brown Rice)

  • 박훈;이춘영
    • Applied Biological Chemistry
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    • 제14권1호
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    • pp.103-107
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    • 1971
  • 동일비중을 갖는벼의 현미중 수개 화학성분함량은 품종의 유전적 상수로서 그값은 환경요인에의하여 영향받지 아니하고 환경요인은 비중별 분포비율만 변화시킨다는 가설을 질소함량에 대하여 결정증명하고 인산, 가리, 칼슘 및 마그네시움에 대하여 동가설의 입증가능성과 가설이 갖는 영양생리적 의의를 검토하였다.

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기포혼입방법에 따른 바텀애쉬를 사용한 기포 콘크리트의 특성 (The Properties of Foamed Concrete Slurry Using Bottom Ash According to the Methods of Mixing of Foam)

  • 강철;강기웅;곽은구;조성현;권기주;김진만
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.529-532
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    • 2004
  • As the purpose of this study is a research of series to obtain fundamental data on the development of the product of foamed concrete using bottom ash for various applications in the field, the main purpose is the light weight of product of concrete. In this experiment, method of mixing of foam is very important because it control specific gravity and strength of the product. As the test results, it was found that regardless of mixing method the grower the concentration of foaming agent the lower the specific gravity and the compressive strength of the specimen especially pre-foaming method. From a strength point of view, we knew that mix-foaming method and steam curing is efficient to obtain a adequate compressive strength of foamed concrete.

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분류식 오수관내 퇴적특성과 퇴적방지를 위한 설계법 고찰 (The Characteristics of Sediment and a Design Method for Preventing Sediment in domestic sanitary sewers)

  • 황환국;김영진;한상종;이정민
    • 상하수도학회지
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    • 제23권6호
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    • pp.779-788
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    • 2009
  • This study is the result of a field survey of four sewer networks selected from in domestic sanitary sewers. The main purpose of this study is to understand the characteristics of sediment in domestic sanitary sewers and to verify sewer design criteria using minimum Shear Stess for preventing sedimnet. This investigation was carried out at a total of 22 points in the four areas. The characteristics of the sanitary solids that were sampled for suspended solids and bedload matter showed a specific gravity of 1.09, a median particle size of 1.26mm, and 88.9% organic contents. On the other hand, deposited sediment was found at 6 points out of the 22 monitoring points. The analysis results of disposed sediment showed a specific gravity of 2.16, a median particle size of 1.31mm, and 15% organic contents. In flow velocity, the majority of deposited sites have under 0.6m/s. However, one-site which was in large-diameter collector sewers, has recorded over 0.6m/s. The analysis results of tractive force showed that the ability of tractive force has to be $1.5{\sim}2.0N/m^2$ to prevent sediment in domestic Sanitary sewers. In conclusion, to prevent sediment it is necessary to apply a design velocity criteria higher than 0.6m/s in the large diameter collector sewer.

자동차 대체연료로서의 Indolene-MPHA의 적용에 관한 연구(I) - Indolene-MPHA 연료의 물성치 특성 - (A Study on the Application of Indolene - MPHA for Automotive Engine (I))

  • 이민호;오율권;차경옥
    • 에너지공학
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    • 제12권3호
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    • pp.184-189
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    • 2003
  • 본 논문은 Indolene-Methanol Plus Higher Alcohols(MPHA)의 연료 특성에 관한 연구로서, 연료의 물성치를 측정하여 조사하였다. 특히 연료의 물성치 중에서 증류특성, 발열량, 인화점, 비중 및 내수성 등을 조사하여 나타내었다. 이때 알콜의 농도는 청정 Indolene의 용적에 따라서 0 에서부터 100%까지 변화하였다. 연료 물성치 측정에서 Indolene-MPHA 혼합물들이 일반적으로 Indolent-Methanol 혼합물과 비교해서 높은 내수성, 유사한 비중과 인화점, 서로 다른 증류특성을 가지고 있음을 알 수 있다. 여기에서 혼합물 물성치 중 상당수는 실제 값과 비교하여 성분들의 중량비를 사용하여 계산하였다.

수분확산(水分擴散)의 활성화(活性化)에너지 모델 (A Model for Activation Energy of Moisture Diffusion in Wood)

  • 강호양
    • Journal of the Korean Wood Science and Technology
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    • 제20권4호
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    • pp.21-30
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    • 1992
  • An activation energy equation for moisture diffusion in wood was developed with an assumption that activation energy is directly proportional to wood specific gravity. Theoretical activation energies obtained from the activation energy equation were revealed to be always lower than actual activation energies, which implies that activation energy isn't affected only by wood specific gravity. The other affecting factors are possibly anatomical structures of wood which determine a ratio of vapor diffusion to bound water diffusion in wood. For the convenience of estimating actual activation energy by using the activation energy equation, thirteen kinds of species were categorized into three groups according to their anatomical structures.

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