• Title/Summary/Keyword: Slurry system

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Fabrication and Piezoelectric Strain Characteristics of PLZT Functionally Gradient Piezoelectric Actuator by Doctor Blade Process (닥터블레이드법에 의한 PLZT계 경사기능 압전 엑튜에이터의 제조와 압전 변위 특성)

  • 김한수;최승철;이전국;정형진
    • Journal of the Korean Ceramic Society
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    • v.29 no.9
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    • pp.695-704
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    • 1992
  • In (Pb, La)(Zr, Ti)O3 ceramic system, the functionally gradient material (FGM) was developed, and its processing and properties were investigated. The FGMs were successfully prepared through doctor blade method with acrylic binder system as well as mold stacking press method. The ultrasonic treatment was very effective for particle dispersion in slurry, and it lead to form clack-free green films. The strain-voltage characteristics of the FGM system was significantly improved which fabricated between a high piezoelectric-low dielectric and a low piezoelectric-high dielectric composition layer.

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Simulation of Refrigeration System with MPCM Slurry as Secondary Fluid (마이크로캡슐 잠열재 슬러리를 적용한 증기압축식 냉동기의 성능 모델링)

  • Choi, Jong-Min;Kim, Yong-Chan;Cheon, Deok-Woo;Kang, Hoon;Yoon, Joon-Sang;Cho, Han-Ho;Kim, Young-Bae;Lee, Ho-Seong;Choi, Kwang-Min;Kang, Yong-Hwa;Jeon, Jong-Ug
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.18 no.6
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    • pp.501-508
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    • 2006
  • MPCM (Microencapsulated Phase Change Material) slurries show several advantages over the sensible heat transportation system. In this study, a numerical model for a vapor compression refrigeration system using MPCM slurries as a secondary fluid through an evaporator was developed, and the system performance was compared with that using water. Generally, the MPCM system showed higher performance than the water system. The COP of the MPCM system was higher by 16.6 to 18.6% than that of the water system at all conditions. The MPCM slurry yields better performance in the aspect of heat transfer and heat transportation comparing to the sensible heat transfer medium such as water.

Compost of Swine Manure Slurry Using the Thermophilic Aerobic Oxidation (TAO) Syst

  • Lee, W.I.;Tsujii, H.;Lee, M.G.;Cha, G.C.;Chung, J.C.
    • Journal of Animal Environmental Science
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    • v.10 no.1
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    • pp.1-10
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    • 2004
  • A field-scale(8.6${\times}$2.5${\times}$2.4 m) and pilot-scale(1.39${\times}$0.89${\times}$0.89 m) thermophilic aerobic oxidation (TAO) units were installed to investigate the volume reduction efficiency of slurry, by varying the aeration and treatment temperature of swine manure, and the collected liquid was evaluated as a liquid fertilizer. In the field-scale unit, the aeration level and numbers of foam breakers made different effects on the slurry volume and temperature in the TAO system. The experiments were peformed for three cases, using different levels of aeration and numbers of foam breakers: Treat-A (aeration rate; 120 ㎥ air/hr using 2 air pumps and 2 foam breakers), Treat-B (aeration rate; 180 ㎥ air/hr using 3 air pumps and 3 foam breakers) and Treat-C (aeration rate; 180 ㎥ air/hr using 3 air pumps and 4 foam breakers). With the same input volume (5 ㎥/day) of swine manure slurry, the resulting liquid levels, temperatures and evaporation rates were 50∼100 cm, 31∼$64^{\circ}C$ and 55 $\ell/m^2$/day for Treat-A; 40∼90 cm, 29∼$52^{\circ}C$ and 75 $\ell/m^2$/day for Treat-B; and 40∼70 cm, 45∼$54^{\circ}C$ and 120.0 $\ell/m^2$/day for Treat-C. In the pilot-scale unit, semi-continuous flow of swine manure slurry was introduced. 50 $\ell$ every 2hr(T-1), 50 $\ell$ every 3hr(T-2), 40 $\ell$ every 2hr (T-3) and 60 $\ell$ every 4hr (T-4) within 24 hours, in order to find the maximum slurry volume reduction conditions.

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Selection of Lactic Starter for the Improvement of Jeungpyun Manufacturing Process (증편 제조공정 개설을 위한 스타터 선발)

  • Moon, Hye-Joon;Chang, Hak-Gil;Mok, Chul-Kyoon
    • Korean Journal of Food Science and Technology
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    • v.31 no.5
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    • pp.1241-1246
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    • 1999
  • Jeungpyun has a unique sponge-like texture and sour taste imparted by the lactic acid and alcohol that are produced by the addition of Takju(turbid rice wine) as a starter. Its consumption, however. has been decreased due to the long preparation time, the difficulties in quality control and the offensive odor derived from the Takju. The present study was carried out in order to shorten the preparation time and to improve the quality of Jeungpyun. To achieve the objectives an appropriate commercial lactic acid starter was selected and a cofermentation system with yeast was developed. A starter containing Lactococcus lactis, Lactococcus cremoris and Lactococcus diacetylactis was selected based on the acid production rate and the quality of the produced sour taste. It took 3 hr for the lactic acid fermentation of rice slurry. The optimum addition levels of the lactic acid starter and yeast were 0.45% and 0.60%, respectively. The lactic acid fermented rice slurry was mixed with the rice slurry separately fermented for 2 hr by yeast, and cofermented for another 1 hr before steaming. Jeungpyun Prepared by the developed method was superior in quality to that Prepared by conventional method using Takju. The developed method reduced the preparation time more than 50% compared with the conventional method.

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Effect of Season on Volatile Organic Compounds and Volatile Fatty Acids Concentration in finishing Pig Slurry to Grassland (초지환원용 비육돈 슬러리의 계절에 따른 휘발성유기물과 휘발성지방산 농도 분석연구)

  • Cho, Sung Back;Yang, Seung Hak;Lee, Kyung Tai;Park, Sung Kwon;Han, Duck Woo;Choi, Dong Yun;Hwang, Ok Hwa
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.34 no.2
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    • pp.125-128
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    • 2014
  • The objective of this study is to investigate the changes in levels of odorous compounds in pig slurry during different seasons. Slurry from pens of finishing pigs was sampled every 4-wk and concentration of odorous compounds was analyzed. There was no difference in the range of phenols level (123 to 156 ppm) during spring (April to May), summer (July to August) and fall (October to November). The concentration of indoles was higher (P<0.05) during spring (14.3 ppm) than summer and fall (5.4~7.6 ppm). Level of BCFA ranging from 727 to 1,194 ppm was not different at any season. Among SCFA, there was no difference in propionic acid during any season but levels of acetic acid and butyric acid were highest (P<0.05) during spring season. Concentration of odorous compounds in pig slurry was highest during spring season. Interestingly, it tended to be lower during summer season compare to fall. This result might be due to relatively lower ventilation rate in order to maintain a constant temperature during spring season. Further study will be necessary to determine the relationship between the concentration of odorous compounds and ventilation system.

Effect of Sublimable Vehicle Compositions in the Camphor-Naphthalene System on the Pore Structure of Porous Cu-Ni (Camphor-Naphthalene 동결제 조성이 Cu-Ni 다공체의 기공구조에 미치는 영향)

  • Kwon, Na-Yeon;Suk, Myung-Jin;Oh, Sung-Tag
    • Journal of Powder Materials
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    • v.22 no.5
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    • pp.362-366
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    • 2015
  • The effect of sublimable vehicle composition in the camphor-naphthalene system on the pore structure of porous Cu-Ni alloy is investigated. The CuO-NiO mixed slurries with hypoeutectic, eutectic and hypereutectic compositions are frozen into a mold at $-25^{\circ}C$. Pores are generated by sublimation of the vehicles at room temperature. After hydrogen reduction at $300^{\circ}C$ and sintering at $850^{\circ}C$ for 1 h, the green body of CuO-NiO is completely converted to porous Cu-Ni alloy with various pore structures. The sintered samples show large pores which are aligned parallel to the sublimable vehicle growth direction. The pore size and porosity decrease with increase in powder content due to the degree of powder rearrangement in slurry. In the hypoeutectic composition slurry, small pores with dendritic morphology are observed in the sintered Cu-Ni, whereas the specimen of hypereutectic composition shows pore structure of plate shape. The change of pore structure is explained by growth behavior of primary camphor and naphthalene crystals during solidification of camphor-naphthalene alloys.