• 제목/요약/키워드: properties of the powder

검색결과 5,408건 처리시간 0.033초

실리카질 재료로서 석분 슬러지를 사용한 콘크리트의 강도 특성 (The Strength Properties of Concrete Used Stone Powder Sludge as Siliceous Material)

  • 정지용;최선미;곽은구;최세진;이성연;김진만
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
    • /
    • pp.85-88
    • /
    • 2005
  • The stone powder sludge occurred at aggregate production process is classified the specified waste, so it is disposed by appropriate method. But the problems of the shortage of the disposal-site, the environment pollution, and the increase of disposal cost can be occurred in handling process, therefore the stone powder sludge is required the development of recycling technique. The stone powder sludge includes SiO2 of about $63\%$. This characteristic is important at the production of hardened specimens under condition of hydro-thermal reaction. In this study, we investigated the strength properties of concrete used stone powder sludge as siliceous material. The test results under condition of hydro-thermal reaction shows the two main facts. The first, the stone powder sludge is affected to fluidity because the surface of the stone powder sludge has characteristics of flakily and angularity. The second, weight content of the stone powder sludge, is not effective factor to the properties of strength.

  • PDF

보강혼합토분의 물리적 특성 (Physical properties of Reinforced soil Mixture powder)

  • 이상호
    • 한국농공학회지
    • /
    • 제42권5호
    • /
    • pp.125-132
    • /
    • 2000
  • This study was performed to evaluate the physical properties of reinforced soil mixture powder. Soil sample was prepared by passing into the standard sieve of No. 200 and reinforcement materials were calcium carbonate, quicklime and portland cement. Fineness, setting time, and compressive strength test for reinforced soil mixture powder were performed and analyzed to investigate their physical properties. The main results were summarized as follow. The compressive strength of soil mixture powder itself and most reinforced was reinforced according to increasing in the mixture rate of reinforcement and the rate of increase was remarkably higher in the cement reinforced soil moisture powder. It was appeared that the early compressive strength is considering higher in the cement reinforced soil moisture powder with 2% of moisture rate of accelerator.

  • PDF

실리카 피착이 철분말의 입자형태 및 자기특성에 미치는 영향(제2보) (Effect of Silica Coating on Particle Shape and Magnetic Properties of Iron Powder (II))

  • 오재희;김종식;류병환
    • 한국세라믹학회지
    • /
    • 제23권2호
    • /
    • pp.31-37
    • /
    • 1986
  • The effect of dehydration temperature on the reduction process of silica-coated hematite was invest-igated The particle shape and magnetic properties of the products reduced from hematite at various conditions and the oxidation resistance of silica-coated iron powder were examined. It was revealed that single phase iron powder obtained over 45$0^{\circ}C$ had good magnetic properties. The iron powder manufactured between 45$0^{\circ}C$ and 50$0^{\circ}C$ displayed the maximum coercive force as a result of maintaining its acicular shaped. However the coercive force of iron powder reduced over 50$0^{\circ}C$ was decreased. The oxidation resistance of silica-coated iron powder in air was very good up to 11$0^{\circ}C$ and for 12 days.

  • PDF

Electrochemical Properties of Novel Metal Powder Electrodes for Polymer Electrolyte Membrane Electrolysis

  • Kim, Chang-Hee;Kang, Kyung-Soo;Park, Chu-Sik;Hwang, Gab-Jin;Bae, Ki-Kwang
    • 한국분말야금학회:학술대회논문집
    • /
    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
    • /
    • pp.1227-1228
    • /
    • 2006
  • The electrochemical properties of novel metal powders were investigated for the electrode materias of polymer electrolyte memebrane electrolysis. Two types of Pt black and $IrO_2$ powder electrodes were hot-pressed on the polymer electrolyte membrane to form membrane electrode assembly. The galvanodynamic polarization methode was used to characterize the electrochemical properties of both electrodes. From the experimental results, we concluded that the $IrO_2$ powder electrode exhibits better electrochemical performance than Pt black as cathode material for the electrolysis.

  • PDF

스테비아 잎 분말 첨가 오미자편의 품질 특성 및 항산화 특성 (Quality Characteristics and Antioxidant Properties of Omija-pyun (Schisandra chinensis Jelly) added with Stevia Leaf Powder)

  • 박숙현;심기현
    • 한국식품영양학회지
    • /
    • 제30권4호
    • /
    • pp.653-664
    • /
    • 2017
  • This study added stevia leaf powder at ratios of 0.5, 1.0, 1.5, and 2.0 percent to Omija-pyun (Schisandra chinensis Jelly) as a natural low-calorie sweetener instead of sugar which is added to Omija-pyun in considerable amounts to evaluate quality characteristics and antioxidant activities compared to the control group with the addition of sugar. Moisture content of Omija-pyun expanded by increasing the measurement of stevia leaf powder (p<0.001), pH (p<0.01) and sugar content (p<0.001) decreased. L-values and b-values revealed a tendency to increase by adding more stevia leaf powder, but a-value revealed a tendency to decrease (p<0.001). Hardness (p<0.001) and chewiness (p<0.05) decreased by adding more stevia leaf powder. Based on the consumer preference evaluation, Omija-pyun with the addition of 0.5 percent stevia leaf powder was the most preferable in terms of color and flavor (p<0.001). The control group and Omija-pyun with the addition of 0.5 percent stevia leaf powder was the most preferable in terms of taste and texture (p<0.001). There were significant differences in the organoleptic properties except hardness between the samples by quantitative descriptive analysis. The control group revealed the highest preference in terms of redness and transparency, and redness and transparency tended to decrease by adding more stevia leaf powder (p<0.001). Organoleptic properties on bitterness and sourness were enhanced by adding more stevia leaf powder in the principal component analysis (PCA). Regarding antioxidant properties, total phenol compounds and flavonoid contents of Omija-pyun increased by adding more stevia leaf powder, and DPPH radical scavenging capacity also increased (p<0.001). Based on results, it is preferable to serve Omija-pyun with the addition of 1.0 percent stevia leaf powder instead of sugar within the context of quality and antioxidant activity.

산화물 환원공정에 의해 제조된 Bi2Te2.7Se0.3 분말의 열전특성 (Thermoelectric Properties of Bi2Te2.7Se0.3 Powder Synthesized by an Oxide-Reduction Process)

  • 박배건;이길근;김우열;하국현
    • 한국분말재료학회지
    • /
    • 제18권5호
    • /
    • pp.437-442
    • /
    • 2011
  • The present study focused on the synthesis of Bi-Te-Se-based powder by an oxide-reduction process, and analysis of the thermoelectric properties of the synthesized powder. The phase structure, chemical composition, and morphology of the synthesized powder were analyzed by XRD, EPMA and SEM. The synthesized powder was sintered by spark plasma sintering. The thermoelectric properties of the sintered body were evaluated by measuring its Seebeck coefficient, electrical resistivity, and thermal conductivity. $Bi_2Te_{2.7}Se_{0.3}$ powder was synthesized from a mixture of $Bi_2O_3$, $TeO_2$, and $SeO_2$ powders by mechanical milling, calcination, and reduction. The sintered body of the synthesized powder exhibited n-type thermoelectric characteristics. The thermoelectric properties of the sintered bodies depend on the reduction temperature. The Seebeck coefficient and electrical resistivity of the sintered body were increased with increasing reduction temperature. The sintered body of the $Bi_2Te_{2.7}Se_{0.3}$ powder synthesized at $360^{\circ}C$ showed about 0.5 of the figure of merit (ZT) at room temperature.

시멘트 혼합재의 입도분포와 페이스트 유동특성 (The Particle Size distribution of Cement Binder and Rheological Properties of Paste)

  • 유동우;최현국;이승헌;이세진
    • 한국건설순환자원학회논문집
    • /
    • 제6권2호
    • /
    • pp.103-111
    • /
    • 2011
  • 본 연구에서는 현재 시멘트 콘크리트 혼합재로서 널리 사용되고 있는 고로수쇄 슬래그와 애쉬의 페이스트 유동특성을 파악하였다. 그 방법으로 혼합재 단독을 사용한 페이스트의 유동특성을 파악하여, 아래와 같은 결론을 얻을 수 있었다. 혼합재 단독의 페이스트 유동특성을 시험하기 위하여, 3종류의 분쇄기를 사용하여 3가지 입도로 분쇄된 분말을 제조하였다. 이 분말을 Rosin-Rammler 분포식을 사용하여 얻은 계수 n 값과 De 값을 유동특성과 비교 분석한 결과에서, 일반적으로 같은 입경 크기 일 때 Ash 분말이 Slag 분말보다 소성점도 및 항복응력이 높았으며, 또한 동일 n 값에서 Ash 분말이 Slag 분말 보다 비교적 높은 소성점도와 항복응력을 나타내었으나, 입도분포 폭의 변화에는 Slag 분말이 Ash 분말 보다 민감한 유동특성의 변화 경향을 나타내었다.

  • PDF

탈지미강을 첨가한 고추장의 저장 중 품질특성 (Quality Properties of Kochujang Added Defatted Rice Bran Powder During Storage)

  • 전은례;정난희
    • 한국식품조리과학회지
    • /
    • 제27권4호
    • /
    • pp.89-98
    • /
    • 2011
  • The physicochemical and sensory properties of kochujang added defatted rice bran powder were periodically examined during storage at 30$^{\circ}C$ for 45 days. The pH of kochujang added defatted rice bran powder increased gradually according to the added level, whereas pH decreased gradually during storage. But the acidity to be appeared opposite of pH. The L-, a and b-values of samples increased gradually according to the amount of added defatted rice bran powder, whereas they decreased gradually during storage. The salinity of samples decreased gradually according to the amount of added defatted rice bran powder and storage. Amino nitrogen content of kochujang added defatted rice bran powder was higher than that of the control during storage. Electron donating activities of kochujang added defatted rice bran powder increased gradually according to the amount added. As a result of the sensory evaluation, the 3% treatment was superior in color, aroma, and overall preference. The sensory evaluation revealed that adding 3% defatted rice bran powder was optimum for improving kochujang quality.

동결건조 $\alpha$-미분의 물성에 관하여 (Rheological Properties of Freeze Dried $\alpha$-Rice Powder)

  • 김관유
    • 한국식품영양학회지
    • /
    • 제4권2호
    • /
    • pp.199-206
    • /
    • 1991
  • Rheological properties of $\alpha$-rice powder were investigated in comparison with those of polished rice powder. Flow behavior for cooked solutions of two powdered samples(5~11%) were Binghampseudo plastic. Consistency index and yield stress of cooked solution of powdered a-rice were much lower than those of polished rice powder while flow behavior index was nearly similar. 9% cooked solution of powdered $\alpha$ -rice showed slightly weaker thixotrophic behavior and more ease tendency to relax under the steady shear than those of polished rice powder.

  • PDF

브로콜리 분말을 첨가한 설기떡의 품질 특성 (Quality Characteristics of Seolgiddeok added with Broccoli(Brassica oleracea var. italica Plen.) Powder)

  • 조경련
    • 한국식품영양학회지
    • /
    • 제22권2호
    • /
    • pp.229-237
    • /
    • 2009
  • Physical, textural and sensory properties of Seolgiddeok prepared with different amounts of broccoli(Brassica oleracea var. italica Plen.) powder were investigated during 3 days of storage. Moisture content decreased gradually during storage and was less in broccoli powder-amended samples. The color L value decreased significantly with increasing broccoli powder, whereas both redness and yellowness increased. Texture analyses revealed that hardness, chewiness, gumminess, adhesiveness and fracturability of Seolgiddeok tended to decrease in proportion to the amount of broccoli powder in the formula. Seolgiddeok gelatinization was investigated using amylographing. Break down and setback were low in broccoli powder Seolgiddeok. Sensory evaluations revealed that, Seolgiddeok prepared with broccoli powder was superior in flavor, chewiness, softness to unamended samples. Seolgiddeok prepared with 3% broccoli powder showed the highest overall acceptability score. Use of broccoli powder in Seolgiddeok preparation improves sensory characteristics and delays retrogradation.