• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.5
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• pp.563-568
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• 2010

Turbopump-gas generator open-loop coupled tests are performed during the development of a 30tonf-LOx/Kerosene rocket engine. In the turbopump-gas generator open-loop tests, the propellants to gas generator are supplied from the outlets of turbopump, while the gas exhausted from the gas generator is vented out to the atmosphere, instead of being used to turbine driving. This paper presents the objectives, procedure, and results of the open-loop coupled test, in addition to a schematic representation of the test apparatus and the operating conditions for the test facility system and control system. The results of turbopump-gas generator open-loop coupled test confirm chill-down procedure, startup characteristics, nominal operability and smooth shutdown of the open-loop coupled Test Plant in test conditions simulating engine system operation environment.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.125-128
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• 2008

As a interstage of the 30tonf level LOx/kerosene liquid rocket engine development, turbopump-gas generator open-loop coupled tests are performed. Test schematic and test results of open-loop coupled tests are presented. In engine system operation environment simulating combustion chamber by flow control orifice, chill-down procedure, startup characteristics, nominal operability of turbopump+gas generator open-loop coupled Test Plant are confirmed The results of open-loop coupled test were used for the preparation on turbopump+gas generator closed-loop test.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.15-18
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• 2008

This study fulfilled analysis of startup characteristics of Turbo pump unit-Gas generator open loop test from the viewpoint of simulation. The test results were investigated and the calculated results were compared to test results. The curve for RPM developing predicted by simulation agreed well with test result. The slope of transient combustion pressure of gas generator correspond with test result.

• Cement
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• s.76
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• pp.51-56
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• 1979

F.L.Smidth는 기획적인 규모로 광범위한 시험과 운용을 한 후에 신형의 크리카 밀을 개발했다. 이 밀의 미분쇄실에서는 평균 단위중량이 5$\~$7g 밖에 안되는 최적 크기의 분쇄매체가 사용된다. 이의 사용은 특수하게 설계된 밀의 출구와 전연 새로운 원리에 바탕을 둔 매우 효율적인 스크리닝 diaphragm에 의해서 가능하게 되었다. Conbidan 밀은 개회로나 폐회로식 분쇄에서 모두 최저의 분쇄 효율을 보장하기 때문에 에너지 소비량이 상당히 절감된다. 완성시멘트에서 요구되는 입도에 따라서, 그리고 채택된 분쇄방법에 따라서 Conbidan 밀의 분쇄 효율은 (kg/kwh), 기업적인 규모로 장기에 걸쳐 시험한 결과로 나타난 바와 같이, $12\%\~27\%$가 향상된다.

• Product Safety
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• s.196
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• pp.16-17
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• 2010

$\blacksquare$ 지식경제부(최경환 장관)은 에너지소비효율 등급표시를 위반한 9개 업체에 대해 생산 판매금지등의 시정명령을 했다고 밝혔음 $\circ$ (대상 및 내용) '09. 1월 ~ 10.1월간, 19개품목 179개모델 제품에 표시된 성능과 매장에서 채취한 샘플제품의 시험측정결과를 비교 검사하고 위반제품에 대해 아래와 같이 시정 명령을 요구하였음 - (생산판매금지) 최저소비효율에 미달된 5개 회사의 전기냉장고, 백열전구, 어댑터 충전기 등 6개모델 - (등급조정) 소비효율등급표시를 위반한 2개회사의 전기진공청소기, 선풍기 등 2개 모델 - (표시사항정정) 소비효율 표시사항의 허용오차를 초과한 2개회사의 선풍기 2개 모델 $\circ$ (조치의무 등) 위반업체 및 모델을 관보에 게재('10.3.10)하고 해당 제조 수입업체는 시정명령에 대한조치결과를 1개월이내 보고해야함 - 시정명령 미이행시에는 위반내용에 따라 벌금 과태료등의 벌칙에 처할 수 있음

• Transactions of the Korean hydrogen and new energy society
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• v.6 no.2
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• pp.53-63
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• 1995

A 100kW class stack consisting of 10 molten carbonate fuel cells has been fabricated. Internally manifold stack has been tested for endurance. Each cell in the stack had an electrode area of $100cm^2$ and reactant gases were distributed in each cells in a cross-flow configuration. Initial and long term operation performance of the stack was investgated as a function of gas utilization using a specially designed small scale stack test facility. It was possible to have a stack with an output of more than 100W using an anode gas of 72% $H_2/18%$ $CO_2/10%H_2O$ and cathode gas of 33% $O_2/67%$ $CO_2$ and 70% Air 30% $CO_2$. The output and voltage of the stack at a current 15A($150mA/cm^2$) and gas utilization of 0.4 showed 125.8W and 8.39V respectively by elapsed time of 310 hours operation. In long term operation characteristics, the voltage drop of 52.4mV/1000hour was observed after more than 1,840 hours operation. Among the voltage drop, the OCV loss was highest than other voltage loss such as internal resistance and electrode polarization. Non uniformity of 2voltages and degradation of cell voltage in the stack was observed in according to changing the utilization rate after a long term operation. Further work for increasing the performance prolonging the life of the stack are required.

• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.696-702
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• 2018

Recently, the current thermal battery technology needs new materials for electrodes in the power and energy density to meet various space and defense requirements. In this paper, to replace the pellet type Li(Si) anode having limitations of the formability and capacity, electrochemical properties of the lithium anode with high density for thermal batteries were investigated. The lithium anode (Li 17, 15, 13 wt%) was fabricated by mixing the molten lithium and iron powder used as a binder to hold the molten lithium at $500^{\circ}C$. The single cell with 13 wt% lithium showed a stable performance. The 2.06 V (OCV) of the lithium anode was significantly improved compared to 1.93 V (OCV) of the Li(Si) anode. Specific capacities during the first phase of the lithium anode and Li(Si) were 1,632 and $1,181As{\cdot}g^{-1}$, respectively. As a result of the thermal battery performance test at both room and high temperatures, the voltage and operating time of lithium anode thermal batteries were superior to those of using Li(Si) anode thermal batteries. The power and energy densities of Li anode thermal batteries were also remarkably improved.

• Korean Journal of Food Science and Technology
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• v.14 no.3
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• pp.203-209
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• 1982

Commercial ice creams were subjected to chemical analysis and sensory evaluation by trained panel members. Chemical composition of commercial ice creams was not much different among the makers. The average contents of fat, total solid, total protein, milk solids-not-fat, milk lactose and crude ash were 8.53%, 34.18%, 3.43%, 11.02%, 6.17% and 0.84% in Carton, and 6.54%, 34.02%. 3.29%, 10.40%, 5.84% and 0.77% in Cone, respectively. Chemical properties of fat extracted from commercial ice creams were much different among the makers. The average values of acid, saponification, iodine and Reichert-Meissl value were 0.58, 221.88, 19.63 and 29.04 in Carton, and 0.65, 219.45, 18.64 and 28.82 in Cone. According to the results of triangle, ranking and scoring tests for commercial ice creams produced by four makers, significant difference on the sensory quality among four commercial ice cream samples was recognized at over 5 percent level. C and D samples had better sensory quality than A and B in both type of Carton and Cone.

• Korean Journal of Food Science and Technology
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• v.14 no.3
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• pp.210-218
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• 1982

Correlation between the sensory quality characteristics of commercial ice creams and chemical properties of fat extracted from those was studied. The results of evaluation of preference for appearance, flavor, texture and total quality of four commercial ice cream samples by multiple paired comparison test indicated that sample C was the best among samples in both type of carton and cone. There was some correlation between the sensory quality characteristics of commercial ice creams and chemical properties of fat extracted from those in carton, but that was not shown in cone. The results showed that flavor of ice cream in carton and appearance and flavor of ice cream in cone affected total quality, but texture did not.