• 제목/요약/키워드: active pressure

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An experimental study on methanol decomposition catalysts for long distance-heat transportation (장거리 열수송을 위한 메탄올 분해 촉매에 대한 실험적 연구)

  • 문승현;박성룡;윤형기;윤기준
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.3
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    • pp.334-342
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    • 1998
  • In this experimental study, methanol was chosen as a system material for a long -distance heat transportation. Not only transition metals but also noble metals were investigated as an active component, and several metal oxides, such as ${\gamma}$-$Al_2$,$O_3$, $SiO_2$, etc. as a support. In general, transition metal catalysts absorbed more heat than noble metal catalysts. The amount of heat absorption and CO selectivity depends on temperature and methanol partial pressure, and 25$0^{\circ}C$ Ni/$SiO_2$ catalyst showed the best result for methanol decomposition reaction.

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Physio-biochemical changes correlated with cadmium adaptation and detoxification mechanism in klebsiella aerogenes (Klebsiella aerogenes의 카드뮴 적응 및 해독기작에 관련된 생리생화학적인 변화)

  • 이기성;송인극;박영식;윤성녀;최영길
    • Korean Journal of Microbiology
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    • v.28 no.3
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    • pp.249-257
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    • 1990
  • In the course of operating the accommodative and detoxifying mechanism against cadmium, its physio-biochemical changes were observed in Klebsiella aerogenes ATCC 10031. Changes of enzyme activity concerned phosphate metabolism, changes of phospholipid composition and in view of energy metabolism the changes of the nucleotide pool were examined. Activities of both alkaline and acid phosphatase were derepressed 4-10 folds under cadmium added cultures. Moreover, production of phospholipid such as lysophosphatidyl choline (LPC), phosphatidyl serine (PS) and phosphatidyl ethanolamone (PE) was increased and uridylate nucleotide pool was increased under Cd-surplus culture. These results i.e. overproduction of phosphatase catalyzing phosphate residue, increase of the production of PE and PS which have a close affinity with cadmium, and indrease of uridylate nucleotide pool used as a carrier of polysaccharide synthesis like bacterial capsule exhibited cellular responses for active defence against Cd-pressure. It was postulated that these phenomena should play another assistant roles in Cd-detoxifing mechanism.

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A Study on the Single′s Kinship Behavior (독신의 원가족과의 친족행동 및 관련변인 연구)

  • Kim, Soon-Ok
    • Journal of Families and Better Life
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    • v.20 no.6
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    • pp.173-184
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    • 2002
  • The aims of this study are to discover general aspects of the kinship behavior shown from singles and also the related variables that had influenced on the single's kinship behavior The research has based on a comprehensive survey with 78 men and 82 women who are single. Statistical methods, including frequencies, percentage, mean, standard deviation, t-test, F-test and Duncan Multiple Range test utilizing the SPSS for Windows 10.0, have been adopted for the analysis of the data compiled. The findings of this study were as follows: First, singles have shown the ordinary kinship behavior to their orientation families, those are parents, brothers and sisters. And they had more active kinship behaviors with parents than brothers and sisters. Second, variables such as pressure to marry, education level, job type, and parents' marital satisfaction, have influenced on the single's kinship behavior with parents. While income level have influenced on the single's kinship behavior with brothers, and age, income level, responsibility of care giving and reason for single, on the single's kinship behavior with sisters.

Global Star Formation Efficiency of Local Galaxies

  • Shim, Hyunjin
    • Journal of the Korean earth science society
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    • v.34 no.5
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    • pp.407-414
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    • 2013
  • This study presents the global star formation efficiency (SFE) of 272 local star-forming galaxies based on the HI gas mass, stellar mass, star formation rate (SFR), and morphology. The SFE increases as the stellar mass increases while the specific SFR decreases. The SFE is enhanced for galaxies with large H$\acute{a}$ equivalent widths, which is primarily due to the large SFR, not due to the large available amount of gas. The SFE is also enhanced by a factor of ~2 for merging systems compared to the normal spirals, showing that the merger-induced high pressure and density environment are crucial for the active star formation. Based on the SFR scaling relation, I present a SFR calibration formula using the HI gas mass.

Novel Flexible Supercapacitors Fabricated by Simple Integration of Electrodes, Binders, and Electrolytes into Glass Fibre Separators

  • Yoo, Joung Eun;Bae, Joonho
    • Journal of the Korean Electrochemical Society
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    • v.17 no.4
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    • pp.237-244
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    • 2014
  • We report novel and simple structure of supercapacitors fabricated by using flexible glass fibre separators as templates. This method does not require separate electrodes, binders and high pressure/temperature to build the supercapacitor unit cells as required by the conventional technology. The supercapacitors were fabricated by drop-casting solution mixtures of carbonaceous active materials/gel electrolytes onto two sides of glass fibre separators. Two carbonaceous materials (nanoscaled activated carbons, multi-walled carbon nanotubes) were investigated as electrode materials. The electrochemical measurements reveal that the separatorbased supercapacitors using ACs successfully demonstrated significant mass specific capacitance ($22.3F\;g^{-1}$) and energy density ($9.7Wh\;kg^{-1}$), indicating this method can be useful in fabricating flexible, wearable and stretchable energy storage devices in more straightforward and cost-effective way than current technology.

A Review on the Evaluation of Home Economics in Changing Korean Society : An Attempt for Constructing a New Paradigm (가정학의 반성적 고찰 : 새로운 패러다임의 구축을 위한 시론I)

  • 유영주
    • Journal of the Korean Home Economics Association
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    • v.34 no.3
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    • pp.1-8
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    • 1996
  • These days, Home Economics in Korea is confronted with the inner argument about its identity and the outer pressure of re-organization caused by educational reformation. Fundamentally, these internal and external challenges to Home Economics arise from that Home Economics has not been fulfilling the needs of individuals and families due to weakening of integrate perspective, insufficient practice and conservative tendency of study. To get over the current problems and construct a new paradigm of Home Economics contributing to the requirements of new era, the following prerequisites might be fulfilled; \circled1 More active concern about surmounting the alienation that threatening the modern family life and self-actualization of individuals. \circled2 An endeavor to find a new family philosophy and patterns of family culture as the basis of community restoration that harmonize the traditions with changes. \circled3 An Effort to find a highter values that contribute to symbiosis and development of global community including all human beings, creatures and eco-system on the earth.

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The Slab Waveguide $CO_2$ Laser with Unstable Resonator of Negative Branch (Negative branch의 불안정 공진기를 갖는 슬랩형 도파관 $CO_2$ 레이저)

  • 김규식;우삼용;이영우;최종운
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.12
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    • pp.586-591
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    • 2003
  • We have developed the radio frequency excited slab waveguide $CO_2$ laser, The dimension of active area is $2{\times}40{\times}400$ mm to get a laser gain. Two pieces of concave mirror are used to make the unstable resonator of negative branch. The radio frequency is 123 MHz and RF input power is from 100 to 900 W. The laser gas is set to a pressure of 10 ∼ 60 torr and the mixing ration is $CO_2$:$N_2$:He=1:1:3. The laser output power of 50.9 W was obtained with laser power to RF power efficiency of 6.5 %.

Developing Analysis Model for Evaluation of HCVT Materialization Possibility, and Examining It's Characteristics (HCVT 구현 가능성 평가를 위한 해석모델 개발 및 특성검토)

  • Noh, Daekyung;Jung, Dongsoo;Jang, Joosup
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.1
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    • pp.39-46
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    • 2016
  • This paper reviews design validity before manufacturing HCVT prototype through simulation. The component part is being devided, modeled and checked if it works well to an designer's original intent about some active modes. Also, the dynamic characteristic is examined how it changes according to alteration of pressure, friction and leak rate. Finally, HCVT design plan is being confirmed if it could be materialized through those analysis.

TRIBOCHEMICAL ACTIVITY OF NASCENT METAL SURFACES

  • Mori, Shigeyuki
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.11a
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    • pp.3-8
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    • 2000
  • Chemical nature of nascent metal surfaces which is one of the important active sources for tribochemical reactions was investigated using a newly developed method. Some enhanced activities were observed. For example, organic compounds chemisorbed on nascent gold surfaces and aromatic compounds decomposed on nascent nickel surfaces resulting in hydrogen evolution. Non-polar compounds such as organic sulfides had a higher chemisorption activity on nascent steel surfaces than polar compounds such as fatty acids and phosphates. Organic sulfides reacted directly with nascent steel surfaces and the surface was covered with metal sulfides. The activity for the chemisorption of organic compounds was closely dependent on the electronic structure of metals. Although benzene chemisorbed very easily on nascent surfaces of transition metals, it did not chemisorb ell nascent surfaces of simple metals. Boundary lubricating behaviors of extreme pressure additives were explained on the bases of the chemical activities of nascent surfaces obtained in this investigation. Under mild conditions, polar compounds such as fatty acids and phosphates were effective for boundary lubrication, because surfaces are covered with oxide layers. On the other hand, sulfides were more effective under severe conditions where the oxide layers were removed and the nascent surfaces were formed.

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Power Density Distribution Calculation of a Pressurized Water Reactor with Fullscope Explicit Modeling by MCNP Code

  • Kim, Jong-Oh;Kim, Jong-Kyung
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05a
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    • pp.179-184
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    • 1996
  • Power density distribution and criticality of a pressurized water reactor are calculated with a Monte Carlo calculation using the MCNP code. The MCNP model is based on one-eighth core symmetry. Individual fuel assemblies are modeled with fullscope three dimensional description except grid spacer. The fuel rod is divided into eight axial segments. Core internals above and below the active fuel region is represented as coolant. After 400 cycle calculations, the system converges to a k value of 1.09151$\pm$0.00066. Fission reaction rate in each rod is also calculated to use as the source term in pressure vessel fluence calculation.

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