• 제목/요약/키워드: medium additive

검색결과 122건 처리시간 0.021초

첨가제를 포함한 TMA포접화합물의 열물성에 관한 기초적 연구 (A Basic Study on Thermal Properties of TMA Clathrate with Additives)

  • 고광옥;정낙규;김진홍
    • 설비공학논문집
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    • 제13권11호
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    • pp.1097-1105
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    • 2001
  • The purpose of this study is to investigate the propriety of TMA clathrate as a cold storage medium. Particularly, this is to examine the extent of subcooling improvement when the additives are added to the TMA clathrate, because water used cold storage material has low phase change temperature and subcooling. This study has been analysed and compared with TMA 30 wt% clathrate how phase change temperature, subcooling and specific heat in the various concentrations are changed. This results view to be improved phase change temperature and subcooling of TMA 30 wt% as a cold storage medium, when it had some additive. Additional1y, it is found that the additive must be controlled under available solution limit and study for new additive must be lasted to know its effect.

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3차원 프린팅 적층가공 방식에서 매질 내부 충전이 초음파 속도와 감쇠에 미치는 영향 (Effects on Changes of the Speed of Sound and the Broadband Ultrasound Attenuation on the Medium's Infilling in Additive Manufacturing Method of 3D Printing)

  • 성열훈
    • 대한방사선기술학회지:방사선기술과학
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    • 제41권1호
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    • pp.53-60
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    • 2018
  • The purpose of this study was investigating the effect of 3D printing technology that changes the speed of sound (SOS) and the broadband ultrasound attenuation (BUA) by controlling the density of the media phantom. We used 3D printers which called additive manufacturing (AM) by using material with polylactic acid (PLA). The inside of the medium phantom was filled crossly with 100%, 90%, 80%, 70%, 60%, and 50% of the material. The ultrasonic instrument measured the SOS and the BUA using a 0.55 MHz ultrasound output in opposing mode with a pair of transducers. As a result, the density of the medium phantoms with the SOS showed very high correlation (r = 0.944), but the SOS showed very low correlation (r = 0.500). It is expecting that the manufacturing and measurement method of the medium phantom using 3D printing technology will be used as basic data for ultrasonic bone mineral density.

Yeast hydrolysate as a low-cost additive to serum-free medium for the production of human thrombopoietin in suspension cultures of Chinese hamster ovary cells

  • 성윤희;이균민
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XII)
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    • pp.105-108
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    • 2003
  • To enhance the performance of a serum-free medium (SFM) for human thrombopoietin (hTPO) production in suspension cultures of recombinant Chinese hamster ovary (rCHO) cells, several low-cost hydrolysates such as yeast hydrolysate (YH), soy hydrolysate, wheat gluten hydrolysate and rice hydrolysate were tested as medium additives. Among various hydrolysates tested, the positive effect of YH on hTPO production was most significant. When 5 g/L YH was added to SFM, the maximum hTPO concentration in batch culture was 40.41 ${\mu}g/mL$, which is 11.5 times higher than that in SFM without YH supplementation. This enhanced hTPO production in YH-supplemented SFM was obtained by the combined effect of enhanced $q_{hTPO}$ and increased culture longevity. In addition YH supplementation did not affect in vivo biological activity of hTPO. Taken together, the results obtained demonstrate the potential of YH as a medium additive for hTPO production in serum-free suspension cultures of rCHO cells.

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Adjustment of Lactation Number and Stage on Informal Linear Type Traits of Holstein Dairy Cattle

  • Do, Chang-Hee;Jeon, Beong-Soon;Sang, Byung-Chan;Lee, Dong-Hee;Pearson, Ronald E.
    • Journal of Animal Science and Technology
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    • 제52권6호
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    • pp.467-473
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    • 2010
  • A total of 4,323,781 records for informal 16 primary linear descriptive traits of dairy cows in Holstein breed from 1988 to 2007 in USA were analyzed to estimate adjustment factors for lactation number and stage. While all factors in the model were highly significant (P < 0.01), major influences on linear type traits were due to lactation number and stage. The frequencies of lactation number 1 through 6 were 58.6, 22.0, 11.8, 4.8, 2.1, and 0.8%, respectively. Further, the frequencies of lactation stage were 0.7, 76.9, 15.3, 4.9, and 2.1%, respectively, for springing, early, medium, late, and dry. To adjust 16 linear traits (stature, dairy form, strength, body depth, rump width, rump angle, legs rear view, leg set, foot angle, fore udder, rear udder height, rear udder width, udder support, udder depth, and front teat placement), additive and multiplicative adjustment factors of lactation number (lactations 2 to 4) and stage (springing, medium, late and dry) were estimated with the solutions in the generalized linear model, assigning lactation 1 and stage early as base class. Additive adjustment factors of lactation number ranged from -1.23 to 2.908, while multiplicative factors ranged from 0.853 to 2.207. Further, additive and multiplicative adjustment factors for lactation stage ranged from -0.668 to 0.785, and from 0.891 to 1.154. Application of adjustment factors to 20 randomly sampled sub-data sets produced the results that additive adjustment factors for both lactation number and stage reduced more mean square of lactation number and stage over 16 linear traits than any combination of adjustments, and leaded additive adjustment factors for both lactation number and stage as a choice of methods for adjustment of informal 16 primary linear type traits collected by classifiers of AI studs.

느타리 수확 후 배지를 이용한 풀버섯 배지개발 (Development of medium for Volvariella volvacea cultivation using spent oyster mushroom medium)

  • 이한범;장명준;이윤혜;주영철
    • 한국버섯학회지
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    • 제9권1호
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    • pp.44-47
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    • 2011
  • 느타리버섯 병 재배용으로 널리 사용되고 있는 미송톱밥, 비트펄프, 면실박(50:30:20) 혼합배지에 춘추느타리 2호를 재배한 배지를 풀버섯 재배 배지인 면실피펠릿, 밀기울, 탄산칼슘분말(90:9:1)배지에 혼합하여 상자재배시험을 통한 배양 및 생육특성을 비교분석한 결과, 느타리버섯 수확 후 배지의 첨가량이 많을수록 배지의 pH는 낮아지는 경향이었고, 총질소 함량이 높아 C/N율이 낮았다. 또한 미생물 밀도는 느타리버섯 수확 후 배지 첨가량 50%일 때 가장 높았으며 오염은 첨가량 0, 25, 50%가 10~13%로 비교적 낮은 오염율을 보였다. 균사배양기간 7일, 초발이 소요일수는 11~14일, 수확기간은 3~5일로 처리 간의 차이가 적어 총 재배기간도 큰 차이를 보이지 않았다. 수량은 기본배지인 면실피 펠릿 발효 배지(대조구, 356g/상자)보다 수확 후 배지 첨가량 50%+기본배지(면실피 펠릿 발효 배지)처리구가 같은 수량을 나타냈으며, 또한 수확 개체수 및 개체중도 대조구와 동등하여 수확 후 배지를 이용한 배지재료 절감효과가 인정되었다.

Incorporation of Graphitic Porous Carbon for Synthesis of Composite Carbon Aerogel with Enhanced Electrochemical Performance

  • Singh, Ashish;Kohli, D.K.;Singh, Rashmi;Bhartiya, Sushmita;Singh, M.K.;Karnal, A.K.
    • Journal of Electrochemical Science and Technology
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    • 제12권2호
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    • pp.204-211
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    • 2021
  • We report, synthesis of high surface area composite carbon aerogel using additive based polymerization technique by incorporating graphitic porous carbon as additive. This additive was separately prepared using sol-gel polymerization of resorcinol-furfuraldehyde in iso-propyl alcohol medium at much above the routine gelation temperature to yield porous carbon (CA-IPA) having graphitic layered morphology. CA-IPA exhibited a unique combination of meso-pore dominated surface area (~ 700 m2/g) and good conductivity of ~ 300 S/m. The composite carbon aerogel (CCA) was synthesized by traditional aqueous medium based resorcinol-formaldehyde gelation with CA-IPA as additive. The presence of CA-IPA favored enhanced meso-porosity as well as contributed to improvement in bulk conductivity. Based on the surface area characteristics, CCA-8 composition having 8% additive was found to be optimum. It showed specific surface area of ~ 2056 m2/g, mesopore area of 827 m2/g and electrical conductivity of 180 S/m. The electrode formed with CCA-8 showed improved electrochemical behavior, with specific capacitance of 148 F/g & ESR < 1 Ω, making it a better choice as super capacitor for energy storage applications.

중엔트로피 합금 기지 위에 적층조형된 스테인리스강과 타이타늄 합금의 접합특성 분석 (Joint Properties of Stainless Steel and Titanium Alloys Additive Manufactured on Medium Entropy Alloys)

  • 박찬웅;;이민규;김정한
    • 한국분말재료학회지
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    • 제26권4호
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    • pp.319-326
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    • 2019
  • Additive manufacturing (AM) is a highly innovative method for joining dissimilar materials for industrial applications. In the present work, AM of STS630 and Ti-6Al-4V powder alloys on medium entropy alloys (MEAs) NiCrCo and NiCrCoMn is studied. The STS630 and Ti64 powders are deposited on the MEAs. Joint delamination and cracks are observed after the deposition of Ti64 on the MEAs, whereas the deposition of STS630 on the MEAs is successful, without any cracks and joint delamination. The microstructure around the fusion zone interface is characterized by scanning electron microscopy and X-ray diffraction. Intermetallic compounds are formed at the interfacial regions of MEA-Ti64 samples. In addition, Vicker's hardness value increased dramatically at the joint interface between MEAs and Ti-6Al-4V compared to that between MEAs and STS630. This result is attributed to the brittle nature of the joint, which can lead to a decrease in the joint strength.

Acoustic Signal based Optimal Route Selection Problem: Performance Comparison of Multi-Attribute Decision Making methods

  • Borkar, Prashant;Sarode, M.V.;Malik, L. G.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권2호
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    • pp.647-669
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    • 2016
  • Multiple attribute for decision making including user preference will increase the complexity of route selection process. Various approaches have been proposed to solve the optimal route selection problem. In this paper, multi attribute decision making (MADM) algorithms such as Simple Additive Weighting (SAW), Weighted Product Method (WPM), Analytic Hierarchy Process (AHP) method and Total Order Preference by Similarity to the Ideal Solution (TOPSIS) methods have been proposed for acoustic signature based optimal route selection to facilitate user with better quality of service. The traffic density state conditions (very low, low, below medium, medium, above medium, high and very high) on the road segment is the occurrence and mixture weightings of traffic noise signals (Tyre, Engine, Air Turbulence, Exhaust, and Honks etc) is considered as one of the attribute in decision making process. The short-term spectral envelope features of the cumulative acoustic signals are extracted using Mel-Frequency Cepstral Coefficients (MFCC) and Adaptive Neuro-Fuzzy Classifier (ANFC) is used to model seven traffic density states. Simple point method and AHP has been used for calculation of weights of decision parameters. Numerical results show that WPM, AHP and TOPSIS provide similar performance.

Cryogenic Tensile Behavior of Ferrous Medium-entropy Alloy Additively Manufactured by Laser Powder Bed Fusion

  • Seungyeon Lee;Kyung Tae Kim;Ji-Hun Yu;Hyoung Seop Kim;Jae Wung Bae;Jeong Min Park
    • 한국분말재료학회지
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    • 제31권1호
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    • pp.8-15
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    • 2024
  • The emergence of ferrous-medium entropy alloys (FeMEAs) with excellent tensile properties represents a potential direction for designing alloys based on metastable engineering. In this study, an FeMEA is successfully fabricated using laser powder bed fusion (LPBF), a metal additive manufacturing technology. Tensile tests are conducted on the LPBF-processed FeMEA at room temperature and cryogenic temperatures (77 K). At 77 K, the LPBF-processed FeMEA exhibits high yield strength and excellent ultimate tensile strength through active deformation-induced martensitic transformation. Furthermore, due to the low stability of the face-centered cubic (FCC) phase of the LPBF-processed FeMEA based on nano-scale solute heterogeneity, stress-induced martensitic transformation occurs, accompanied by the appearance of a yield point phenomenon during cryogenic tensile deformation. This study elucidates the origin of the yield point phenomenon and deformation behavior of the FeMEA at 77 K.

Fe/Zr/Mo 혼합 산화물 매체의 Redox 반응을 이용한 수소 저장 및 방출 (Hydrogen Storage and Release by Redox Reaction of Fe/Zr/Mo Mixed Oxide Mediums)

  • 제한솔;강은지;이수경;박주식;김영호
    • 한국수소및신에너지학회논문집
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    • 제22권5호
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    • pp.616-624
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    • 2011
  • Hydrogen storage and release of Fe/Zr/Mo mixed oxide mediums were investigated by hydrogen reduction and water splitting oxidation($Fe_3O_4+4H_2{\rightleftharpoons}3Fe+4H_2O$). As the results of TPR/O, Mo was an additive to enhance the reactivity of water splitting oxidation as well as the stability of the medium. On the other hand, it seemed that $ZrO_2$ additive provided the passway for the diffusion of gaseous chemicals on the medium in repeated redox cycles. Among the Fe/Zr/Mo mediums, a FeZrMo-7 medium (Fe/Zr/Mo=80/13/7mol%) exhibited the best performance with good durability during five repeated redox cycles. The amount of hydrogen evolved on the medium was maintained at ca. 10.7mmol-$H_2$/g-medium corresponding to the hydrogen storage amount of ca. 2.2wt%.