• Title/Summary/Keyword: thermal responses

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Physiological Responses of Bacillus amyloliquefaciens Spores to High Pressure

  • Ahn, Ju-Hee;Balasubramaniam, V.M.
    • Journal of Microbiology and Biotechnology
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    • v.17 no.3
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    • pp.524-529
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    • 2007
  • Pressure inactivation behavior of Bacillus amyloliquefaciens spores was investigated in deionized water. The spores of B. amyloliquefaciens were subjected to $105^{\circ}C$ and 700 MPa. The magnitude of the decrease in viability after pressure treatment was similar to that after pressure treatment followed by heat shock. The increase of dipicolinic acid (DPA) release was correlated with the spore inactivation, and the hydrophobicity did not significantly change during the pressure-assisted thermal processing (PATP). Lag phase duration increased with increasing pressure process time. The mechanisms of spore germination and inactivation during the PATP were related to a complex physiological process.

Fabrication and characterization of ZnO-based SAW filters using various IDT metals (다양한 IDT 금속막을 이용한 ZnO-SAW 필터의 제작 및 특성 분석)

  • Lee, Myung-Ho;Lee, Hye-Jung;Lee, Jin-Bock;Park, Jin-Seok
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1390-1392
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    • 2001
  • ZnO-based SAW(surface acoustic wave) filters are fabricated with the configuration of IDT/ZnO/$SiO_2$/Si(100) using various IDT materials such as Al, Cu/Ti, and Cu/Al. Their frequency response characteristics are measured and compared. The thickness of Al IDT is varied to examine the mass loading effect. In addition, effects of thermal treatment and electrical stress on the frequency responses of the fabricated SAW filters are investigated.

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Evaluation of Indoor Environmental Factors in Office Building with Underfloor Air-Conditioning (UFAC) System

  • Chung, Kwang-Seop
    • International Journal of Air-Conditioning and Refrigeration
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    • v.9 no.3
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    • pp.36-45
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    • 2001
  • During the last decade, an increasing interest in Underfloor Air-Conditioning (UFAC) systems has emerged. The purpose of this paper is to evaluate the indoor environmental performance of office buildings with UFAC system in order to develope the design prototype of this system. The physical measurements and the Interviewing survey of occupant's sensation responses to the environment were carried out. Measurements and survey were made of the thermal environmental factors such as air temperature, relative humidity, air velocity, globe temperature, and the other several environmental factors such as the sound level and the illuminance of working plane, etc. And, the air quality was evaluated by measuring the concentration of suspended particles, carbon monoxide, and carbon dioxide in the room. Furthermore, the paper appraises the various indoor environmental factors of the room by using post-occupancy evaluation (POE) method in office building with UFAC system, and thus, it suggests the basic data for assessing the indoor comfort based on field measurements and survey .

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Effects of Processing and Genetics on the Nutritional Value of Sorghum in Chicks and Pigs - Review -

  • Kim, I.H.;Cao, H.;Hancock, J.D.;Park, J.S.;Li, D.F.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.9
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    • pp.1337-1344
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    • 2000
  • Differences in the physical structure and chemical composition of sorghums result in different nutritional values. Sorghums with high in vitro nutrient digestibility tend to have greater ileal and total tract nutrient digestibilies. Soft endosperm can improve growth and nutrient digestibility in nursery pigs and broiler chicks. However, finishing pigs respond less to endosperm hardness. Chicks benefit from waxy sorghums, but responses of swine to waxy sorghum remain controversial. Reduction of particle size benefits nursery pigs more than finishing pigs, while age of chicks affects the coarseness preference. Nutritional benefits of thermal processing in sorghum remain unclear in chicks and pigs. Although experiments have demonstrated increased efficiency with processed sorghum, processing provided only an immediate solution to the problem of reduced utilization. Long-term, solutions will be genetic improvement of physical and on chemical characteristic.

H2S Gas Sensing Properties of CuO Nanotubes

  • Kang, Wooseung;Park, Sunghoon
    • Applied Science and Convergence Technology
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    • v.23 no.6
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    • pp.392-397
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    • 2014
  • CuO nanotubes are synthesized using $TeO_2$ nanorod templates for application to $H_2S$ gas sensors. $TeO_2$ nanorod templates were synthesized by using the VS method through thermal evaporation. Scanning electron microscopy, transmission electron microscopy and X-ray diffraction showed that the synthesized nanotubes were monoclinic-structured polycrystalline CuO with diameter and wall thickness of approximately 100~300 nm and 5~10 nm, respectively. The CuO nanotube sensor showed responses of 136~325% for the $H_2S$ concentration of 0.1~5 ppm at room temperature. These response values are approximately twice as high as that of the CuO nanowire sensor for the same concentrations of $H_2S$ gas. Along with the investigation of the performance of the sensors, the mechanisms of $H_2S$ gas sensing of the CuO nanotubes are also discussed in this study.

Modelling of Power Plant Fan Pitch Blade Control Actuator (전력설비 대용량 보일러 통풍기 날개각 제어 작동기 모델링)

  • Huh, J.Y.;Son, T.H.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.4 no.2
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    • pp.28-33
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    • 2007
  • In the power plant facility which use soft coal as a power source the fan pitch blade control hydraulic actuator is used to control the inlet and outlet gas to regulate the internal pressure of the furnace and control the frequence. Sometimes malfunctions of this equipment lead to the decline of boiler thermal efficiency and unexpected power plant trip. In order to localize the fan pitch blade control hydraulic actuator specially for the 500MW large scale boiler, Analysis and modelling of the system is carried out mathematically. The responses of the system are examined by using matlab simulation fur the variation of the major parameters in view of reverse engineering. Consequently the validity of the established parameters are examined.

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Cellular and Molecular Responses of a Filamentous Fungus Neurospora Crassa to Non-thermal Plasma at Atmospheric Pressure

  • Park, Gyung-Soon;Ryu, Young-Hyo;Hong, Young-June;Uhm, Han-Sup;Choi, Eun-H.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.476-476
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    • 2012
  • Although plasma is an efficient means of microbial sterilization, mechanism of plasma effect on microorganisms still needs to be clarified. In addition, a limited number of studies are available on eukaryotic microorganisms such as yeast and fungi in relation to plasma application. Thus, we investigated cellular and molecular aspects of plasma effects on a filamentous fungus, Neurospora crassa by making use of argon plasma jet at atmospheric pressure. The viability and cell morphology of N. crassa spores exposed to plasma were both significantly reduced depending on the exposure time when treated in water. The intracellular genomic DNA content was dramatically reduced in fungal tissues after a plasma treatment and the transcription factor tah-3 was found to be required for fungal tolerance to a harsh plasma environment.

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Gas sensing characteristics of carbon nanotube gas sensor using a diaphragm structure (다이아프램 구조를 이용한 탄소나노튜브 가스 센서의 가스 감응 특성)

  • Cho, Woo-Sung;Moon, Seung-Il;Kim, Young-Cho;Park, Jung-Ho;Ju, Byeong-Kwon
    • Journal of Sensor Science and Technology
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    • v.15 no.1
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    • pp.13-19
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    • 2006
  • The micro-gas sensor based on carbon nanotubes (CNTs) was fabricated and its gas sensing characteristics on nitrogen dioxide ($NO_{2}$) have been investigated. The sensor consists of a heater, an insulating layer, a pair of contact electrodes, and CNT-sensing film on a micromachined diaphragm. The heater plays a role in the temperature change to modify sensor operation. Gas sensor responses of CNT-film to $NO_{2}$ at room temperature are reported. The sensor exhibits a reversible response with a time constant of a few minutes at thermal treatment temperature of $130^{\circ}C$.

Hybrid Coextrusion and Lamination Process for Macrochanneled Bioceramic Scaffolds

  • Koh, Young-Hag;Bae, Chang-Jun;Kim, Hyoun-Ee
    • Journal of the Korean Ceramic Society
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    • v.41 no.7
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    • pp.497-502
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    • 2004
  • A hybrid coextrusion and lamination process has been developed to fabricate macrochanneled bioceramic scaffolds. This process was mainly composed of three steps (i.e., coextrusion of thermoplastic compound, lamination, and thermal treatment), forming unique pore channels in dense bioceramic body. Pore channels were formed by removing carbon black material, while calcium phosphate or Tetragonal Zirconia Polycrystals (TZP) with a calcium phosphate coating layer were used as dense body. Two kinds of pore structures were fabricated; that is, the pore channels were formed in uni- or three-directional array. Such macrochanneled bioceramic scaffolds exhibited the precisely controlled pore structure (pore size, porosity, and interconnection), offering excellent mechanical properties and cellular responses.

Wireless Graphene Oxide-CNT Bilayer Actuator Controlled with Electromagnetic Wave (전자기웨이브에 의해 제어되는 무선형 그래핀-카본나노튜브 액츄에이터)

  • Xu, Liang;Oh, Il-Kwon
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2011.04a
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    • pp.282-284
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    • 2011
  • Based on graphene oxide and multi-walled carbon nanotube layers, a wireless bi-layer actuator that can be remotely controlled with an electromagnetic induction system has been developed. The graphene-based bi-layer actuator exhibits a large one-way bending deformation under eddy current stimuli due to asymmetrical responses originating from the temperature difference of the two different carbon layers. In order to validate one-way bending actuation, the coefficients of thermal expansion of carbon nanotube and graphene oxide are mathematically formulated in this study based on the atomic bonding energy related to the bonding length. The newly designed graphene-based bi-layer actuator is highly sensitive to electromagnetic wave irradiation thus it can trigger a new actuation mode for the realization of remotely controllable actuators and is expected to have potential applications in various wireless systems.

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