• 제목/요약/키워드: direct solution

검색결과 1,210건 처리시간 0.031초

Effect of C18-polyunsaturated Fatty Acids on Their Direct Incorporation into the Rumen Bacterial Lipids and CLA Production In vitro

  • Choi, S.H.;Song, M.K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권4호
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    • pp.512-515
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    • 2005
  • An in vitro study was conducted to determine the effect of C18-polyunsaturated fatty acid on direct incorporation into the rumen bacteria, bio-hydrogenation and production of CLA in vitro. Sixty milligrams of linoleic acid ($C_{18:2}$) or linolenic acid ($C_{18:3}$) were absorbed into the 0.5 g cellulose powder was added to the 150 ml culture solution consisting of 120 ml McDougall's buffer and 30 ml strained rumen fluid. Four uCi of 1-$^{14}C_{18:2}$ or 1-$^{14}C_{18:3}$ (1 uCi/15 mg each fatty acid) were also added to the corresponding fatty acids to estimate the direct incorporation into the bacterial lipids. The culture solution was then incubated anaerobically in a culture jar with stirrer at 39$^{\circ}C$ for 12 h. Ammonia concentration and pH of the culture solution were slightly influenced by the fatty acids. Amount of fatty acid incorporated into the bacteria was 1.20 mg and 0.43 mg/30 ml rumen fluid for $C_{18:2}$ and $C_{18:3}$, respectively during 12 h incubation. Slightly increased CLA (sum of cis-9, trans-11 and cis-10, trans-12 $C_{18:2}$) was obtained from the $C_{18:3}$ addition compared to that from $C_{18:2}$ after 12 h incubation in vitro.

Study of metal dopants and/or Ag nanoparticles incorporated direct-patternable ZnO film by photochemical solution deposition

  • Kim, Hyun-Cheol;Reddy, A.Sivasankar;Park, Hyung-Ho
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.368-368
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    • 2007
  • Zinc oxide (ZnO) has drawn much interest as a potential transparent conducting oxide (TCO) for applying to solar cell and front electrode of electro-luminescent devices. For the enhancement of electrical property of TCOs, dopant introduction and hybridization with conductive nanoparticles have been investigated. In this work, ZnO films were formed on glass substrate by using photochemical solution deposition of Ag nanoparticles dispersed or various metal (Ag, Cd, In, or Sn) contained photosensitive ZnO solutions. The usage of photosensitive solution permits us to obtain a micron-sized direct patterning of ZnO film without using conventional dry etching procedure. The structural, optical, and electrical characteristics of ZnO films with the introduction of metal dopants with/without Ag nanoparticles have been investigated to check whether there is a combined effect between metal dopants and Ag nanoparticles on the characteristics of ZnO film. The phase formation and crystallinity of ZnO film were monitored with X-ray diffractometer. The optical transmittance measurement was carried out using UV-VIS-NIR spectrometer and the electrical properties such as sheet resistance and conductivity were observed by using four-point probe.

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An efficient adaptive finite element method based on EBE-PCG iterative solver for LEFM analysis

  • Hearunyakij, Manat;Phongthanapanich, Sutthisak
    • Structural Engineering and Mechanics
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    • 제83권3호
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    • pp.353-361
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    • 2022
  • Linear Elastic Fracture Mechanics (LEFM) has been developed by applying stress analysis to determine the stress intensity factor (SIF, K). The finite element method (FEM) is widely used as a standard tool for evaluating the SIF for various crack configurations. The prediction accuracy can be achieved by applying an adaptive Delaunay triangulation combined with a FEM. The solution can be solved using either direct or iterative solvers. This work adopts the element-by-element preconditioned conjugate gradient (EBE-PCG) iterative solver into an adaptive FEM to solve the solution to heal problem size constraints that exist when direct solution techniques are applied. It can avoid the formation of a global stiffness matrix of a finite element model. Several numerical experiments reveal that the present method is simple, fast, and efficient compared to conventional sparse direct solvers. The optimum convergence criterion for two-dimensional LEFM analysis is studied. In this paper, four sample problems of a two-edge cracked plate, a center cracked plate, a single-edge cracked plate, and a compact tension specimen is used to evaluate the accuracy of the prediction of the SIF values. Finally, the efficiency of the present iterative solver is summarized by comparing the computational time for all cases.

저품위 동광석의 세균침출에 관한 연구 5 (A Study on Bacterial Leaching of Low-Grade Copper Mineral(V))

  • 민봉희;박원구;이강순
    • 미생물학회지
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    • 제12권1호
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    • pp.25-30
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    • 1974
  • It was convinced that with a relatively small capital investment and with a low operating cost, appreciable amounts of cement copper could be produced from low-grade minerals by the application of a bacterial leaching method. For the recovery of cement copper from the impure pregnant solution, direct precipitation of copper with tin plates by a bacterial leaching method was feasible. The results obtained were as follows: 1)In order to remove the cement copper from the reducing metal, aeration and agitation method were more effective and economic than shaking method. 2)The rate of copper recovery from the pregnant solution was accerelated according to increasing quantities of reducing metal. However, the excess of reducing metal reduced the grade of cement copper. 3)Among the comparative experiments of copper recovery at each reaction temperature of $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$, the recovery rate of copper at $30^{\circ}C$from the pregnant solution was highest. 4)Direct cementation method on iron-containing metal was an excellent method for the recovery of cement copper in bacterial leaching.

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Steepest Descent Method를 이용한 정전계 문제의 해석 (On the Analysis of Electrostatic Problems Using a Steepest Descent Method)

  • 안지용;정구철;김정기
    • 한국통신학회논문지
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    • 제11권6호
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    • pp.396-401
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    • 1986
  • Steepest Descent Method를 정전계 문제의 해석에 적용하였다. 반복법과 moment method와 같은 direct method와의 차이점을 기술하였다. 반복법을 이용하여 정확한 해에 단조적으로 수렴하며 대형 system의 해석에 적합함을 보였다. 정전계 문제에 대해서 해석한 수치결과를 제시하였으며 moment solution과 잘 일치하고 있음을 보였다.

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(Ba, Sr)$TiO_3$ 습식 직접 합성법 (A Study of (Ba, Sr)$TiO_3$ Synthesis by Direct Wet Process)

  • 이경희;이병하;김준수
    • 한국세라믹학회지
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    • 제23권1호
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    • pp.27-32
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    • 1986
  • This study is aimed at synthsizing high dielectric material (Ba, Sr)$TiO_3$ through direct wet process. Pure and ultra fine particle of (Ba, Sr)$TiO_3$ Powder was synthesized from $BaCl_2$ $SrCl_2$ and TiCl4 aqeous solution at KOH Solution in the $N_2$ gas atmosphere. $BaCl_2$ $SrCl_2$ and TiCl4 were Mixed with the mole ratio of 1:9, 3:7:10, 5:5:10, 7:3:10, 9:1:10 and sythesized at 4$0^{\circ}C$~9$0^{\circ}C$ for 10min~15hrs. The particle size particle shape crystallinity and synthesis condition of (Ba, Sr)$TiO_3$ powder with the variation of temperature and reaction time in the aqueous solution studied by the exprimental instruments of DTA. TGA, X-ray diffratometer SEM.

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기구학적 전이를 이용한 케이싱 오실레이터의 순기구학 해석 (Direct Position Kinematics Solution For Casing Oscillator Using the Kinematic Inversion)

  • 백재호;배형섭;이은준;박명관
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 추계학술대회 논문집
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    • pp.580-583
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    • 2002
  • This paper presents a novel pose description corresponding to the structure characteristics of parallel manipulators, which is convenient and intuitionistic to us. A class of 3-RSR parallel manipulator is considered here. Through analysis on geometry theory, we obtain a new method of the closed-form solution to the forward kinematics. The closed-form solution contains two different meanings-analytical and real-time. So we reach the goal of practical application and control. A numerical example is also presented and are verified by an inverse kinematics analysis. It shows that the method has a practical value for real-time control.

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판매자와 구매자간 직거래를 지원하는 ASP 방식의 B2B e-마켓플레이스 시스템 구현 (Implementation of the B2B e-Marketplace Application Service Providing System for Direct Transactions between Suppliers and Buyers)

  • 김중인;최정상
    • 산업경영시스템학회지
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    • 제26권1호
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    • pp.30-39
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    • 2003
  • This paper presents the business model and system functionalities of a B2B e-marketplace solution that not only can overcome some problems of the public e-marketplace, but also can be applicable to both public and private types of e-marketplaces. This solution is different from the most of the public e-marketplace solutions that their main sources of revenue are transaction commissions or transaction fees through the third-party intermediation. Instead, this solution provides an ASP (Application Service Provider) functionality for direct, disintermediated purchasing and sales-related transactions between suppliers and buyers. With this functionality, suppliers and buyers electronically commerce with each other without the disclosure of their transactions as well as transaction commissions.

Synthesis and Properties of Polybenzoxazole Copolymers Having Non Linear Units

  • Han, So Hee;Lee, Eung Jae;Choi, Jae Kon
    • Elastomers and Composites
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    • 제54권4호
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    • pp.321-329
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    • 2019
  • A series of poly(hyroxyamide)s (PHAs) was prepared by direct polycondensation reaction of 4,4'-(2,3-pyridinedioxy)dibenzoic acid and/or isophthalic acid with 3,3'-dihydroxybenzidine. The yield percentages of the products were high, and the inherent viscosities of the polymer in DMAc solution at 35℃ were 0.31-0.59 dL/g. All PHA polymers were found to be soluble in polar aprotic solvents such as DMAc, DMSO, NMP, and DMF. On the other hand, LiCl was required to dissolve IPHA-1 in aprotic solvents. Poly(benzoxazole)s (PBOs) were partially soluble in conc-H2SO4; IPBO-4, -5, and -6 were partially soluble in NMP only when LiCl was added to the solution, and the solution was heated. The PBO polymers showed a maximum weight loss in the temperature range of 654-680℃, and the char yields at 900℃ under nitrogen atmosphere exceeded 63%.

Spin-on Glass를 이용한 실리콘과 유리의 저온 접합 공정 (Low Temperature Bonding Process of Silicon and Glass using Spin-on Glass)

  • 이재학;유중돈
    • Journal of Welding and Joining
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    • 제23권6호
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    • pp.77-86
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    • 2005
  • Low temperature bonding of the silicon and glass using the Spin-on Glass (SOG) has been conducted experimentally to figure out the effects of the SOG solution composition and process variables on bond strength using the Design of Experiment method. In order to achieve the high quality bond interface without rack, sufficient reaction time of the optimal SOG solution composition is needed along with proper pressure and annealing temperature. The shear strength under the optimal SOG solution composition and process condition was higher than that of conventional anodic bonding and similar to that of wafer direct bonding.