• 제목/요약/키워드: $C^{\ast}$

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A REPRESENTATION FOR NONCOMMUTATIVE BANACH ALGEBRAS

  • PAK HEE CHUL
    • Journal of applied mathematics & informatics
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    • 제17권1_2_3호
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    • pp.591-603
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    • 2005
  • A representation for non-commutative Banach algebras is discussed, which generalizes the Gelfand representation for commutative Banach algebras and the Gelfand-Naimark representation for $C^{\ast}$-algebras. Its basic properties are also investigated. In appendix, an example of Banach algebra that is neither semi-simple nor radical is presented.

CENTRALIZING AND COMMUTING INVOLUTION IN RINGS WITH DERIVATIONS

  • Khan, Abdul Nadim
    • 대한수학회논문집
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    • 제34권4호
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    • pp.1099-1104
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    • 2019
  • In [1], Ali and Dar proved the ${\ast}$-version of classical theorem due to Posner [15, Theorem] with involution of the second kind. The main objective of this paper is to improve the above mentioned result without the condition of the second kind involution. Moreover, a related result has been discussed.

새로운 Thorium (IV)-Crown Ether 착물형성 (Formation of New Thorium (IV) Complexes with Crown Ethers)

  • 정학진;정오진;서혁춘
    • 대한화학회지
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    • 제31권3호
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    • pp.258-270
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    • 1987
  • 여러 용매(methanol, ethanol, butanol, ethylether, methylacetate, acetone, THF 및 acetylacetone)중에서 아직 보고된 바 없는 공동을 달리한 crown ether들을 리간드로 한 토륨(IV) 고체 착물을 합성하였다. 이 고체 착물에 대한 배위 화학적인 정보를 얻기 위하여 원소분석(C.H.N) 및 ICPAS법에 의한 토륨분상, 열분석과 Karl-Fischer적정법에 의한 착물중의 결정수 분석에 의해서 고체 착물들의 조성을 결정하였다. 그리고 적외선, 자외선 분광분석, $^1H$-핵자기 공명 분석 및 X-선 회절분석법에 의하여 각 합성 착물들의 결합구조에 대한 정보들을 얻었고 각 합성 착물들에 대한 용매화 현상을 논의하였다. 그 결과 아세틸아세톤 용매하에서 합성된 착물들은 아세틸아세톤을 제외한 모든 실험 용매중에서 합성된 crown ether를 가지는 토륨(IV) 착물들은 용매화 반응이 일어나지 않았다. $Th^{4+}$금속이온에 대한 리간드 결합비는 고리의 크기에 주로 영향을 받으며 12-crown-4의 경우는 1:1([$Th^{4+}$]:[lig.]) 착물, 15-crown-5의 경우는 2:3 착물 및 18-crown-6와 dicyclohexano-18-crown-6의 경우는 1:1 착물이었다. 용매화가 일어나는 15-crown-5 와 18-crown-6 착물의 경우는 1:1:1([$Th^{4+}$]:[lig.]:$[CH_3COCH_2COCH_3]$)이었다. 용매화하지 않는 모든 착물들은 crown-ether의 n-${\sigma}^{\ast}$전자전이를, 그리고 용매화된 착물은 crown-ether n-${\sigma}^{\ast}$와 acac의 $n-{\pi}^{\ast}$전자전이를 동시에 나타냈다. 반양성자성 용매에서 모든 착물들은 1:1전해질로, 물에서는 1:4전해질로 각각 행동하는 9배위자 착물임을 알 수 있다.

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Rayonmimetics 섬유의 분산염료에 의한 염색 특성 및 견뢰도 (Dyeing Characteristics and fastness of Rayonmimetics fiber by disperse dyes)

  • 김은미;최재홍;이현영;권오경;최오곤
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2008년도 제38차 학술발표대회
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    • pp.55-57
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    • 2008
  • 본 연구에서는 신규원사인 Rayonmimetics(RMM) 섬유를 상품화 된 분산염료를 가지고 염색하여 PET 섬유와 비교하였다. RMM 섬유의 염착률은 기존 PET 섬유와 비슷하였으나, critical adsorption range는 10$^{\circ}C$ 정도 낮았다. Colorimetric properties를 비교해 보면, a${\ast}$값과 b${\ast}$값에서 color에 따른 경향성을 보이며, PET 섬유와 대비하여 duller 해졌다. 견뢰도는 PET 섬유와 비슷한 견뢰도를 보였다.

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Pseudoalteromonas carrageenovora 유래 Arylsulfatase의 cloning과 재조합 E. coli에서 과발현

  • 임재명;김형락;김성구;남수완
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XII)
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    • pp.571-575
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    • 2003
  • A marine aerobic Gram-negative bacterium, Pseudoalteromonas carrageenovora, has been blown to hydrolyze carrageenans, the sulfated galactans of red algae, and to desulfate oligo kappa-carrageenans. Recently, the gene encoding arylsulfatase (aryl-sulfate sulfohydrolase, E.C.3.1.6.1) of A. carrageenovora was cloned and the nucleotide sequence was reported. Enzymatic hydrolysis of sulfate groups in agaropectin simplifies the process of agarose preparation. In order to overproduce the enzyme, the arylsulfatase gene (astA, 984 bp ORF) from P. carrageenovora genome was amplified by PCR and subcloned into the pET21a vector. When the constructed plasmid pAST-A1 was introduced into E, coli BL21(DE3), the transformant on LB plate containing IPTG showed the hydrolyzing activity for p-nitrophenyl sulfate. Most of arylsulfatase activity was found in the cell lysate, but at $50\;{\sim}\;5000\;{\mu}M$ IPTG concentration the activity was found both in the culture supernatant and the cell lysate. The molecular weight of the recombinant enzyme was estimated to be 34 kDa by SDS-PAGE.

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Hypoglycemic and Hypolipidemic Effect of Rosa rugosa Radix in Streptozotocine-induced Diabetic Rats

  • Kim, Eun-Jung;Kim, Gye-Yeop
    • 동의생리병리학회지
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    • 제24권5호
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    • pp.866-871
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    • 2010
  • The antidiabetic effects of Rosa rugosa Radix were investigated in streptozotocine-induced diabetic rats. Research methods and procedure: In the present study, effects of oral administration of Rosa rugosa Radix extract(100, 250, and 500 mg/kg body wt.) for 28 days on the level of serum glucose, total cholosterol, triglycerides, cereatinine, aspartate amino transferase(AST) and alanine amino transferase(ALT) in normal and streotozotocine-induced diabetic rats were evaluated. Oral administrations of the Rosa rugosa Radix extract significantly decreased serum glucose, total cholesterol, triglyceride, AST, and ALT levels, while increased serum insulin and HDL-C in diabetic rats(p<0.05). The hypoglycemic effect of the Rosa rugosa Radix extract was more effective than normal group. It is concluded that the Rosa rugosa Radix must be considered as excellent candidate for future studies on diabetes mellitus.

순환여과식 사육수조의 수리학적 연구 (Hydraulic Studies on Recirculating Aquaculture Basin)

  • 이종섭
    • 한국수산과학회지
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    • 제27권2호
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    • pp.173-182
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    • 1994
  • A numerical experiment on the effective discharge of waste materials caused in recirculating aquaculture basins was performed. The numerical model used in this study was a 4-level hydrodynamic and advection-diffusion model. Flow structures and settling processes of ss in the various mathematical model basins are discussed. The calculated flow fields of the numerical basin corresponded well with the measured velocity in field basin. In the cases of steep bottom slopes in 4/30, the non-dimensional tractive force($U{\ast}/U{\ast}_c$) which is all important parameter for the deposition pattern of waste materials was stronger than with the mild slope one. The settling pattern of ss depended considerably on the degree of bottom slope of basin. To concentrate deposited waste materials into the center discharge pipe, it is useful to design a cylindrical basin with a steeply conical bottom. In addition, to prevent movement of the deposit area away from the center, it is necessary to locate the circulating ducts at diametrically opposed points on the basin sides.

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Matlab/Simulink & dSpace 보드를 이용한 유도 전동기 벡터 제어 시스템의 구현 (The Implementation of the Field Oriented Control of Induction Motor Using Matlab/Simulink and dSpace board)

  • 김배선;한우용;이창구
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제49권10호
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    • pp.675-682
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    • 2000
  • An easier implementation method of the field oriented control of induction machine using Matlab/Simulink and dSpace board is proposed in this paper. The total system for the control of induction motor is modeled with the help of Matlab/Simulink. These models consist of induction motor block, SVPWM inverter block and control algorithm block, etc. And this system is simultaneously simulated and experimented in Matlab/Simulink environment with dSpace borad (DS1102). It is possible that Matlab and dSpace board compiler can make $^'{\ast}.c'\;and\;^'{\ast}.obj'$ file of models designed in Matlab/Simulink environment automatically. Both Simulation and experimental results are given.

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BRACKET FUNCTIONS ON GROUPOIDS

  • Allen, Paul J.;Kim, Hee Sik;Neggers, Joseph
    • 대한수학회논문집
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    • 제34권2호
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    • pp.375-381
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    • 2019
  • In this paper, we introduce an operation denoted by [$Br_e$], a bracket operation, which maps an arbitrary groupoid ($X,{\ast}$) on a set X to another groupoid $(X,{\bullet})=[Br_e](X,{\ast})$ which on groups corresponds to sending a pair of elements (x, y) of X to its commutator $xyx^{-1}y^{-1}$. When applied to classes such as d-algebras, BCK-algebras, a variety of results is obtained indicating that this construction is more generally useful than merely for groups where it is of fundamental importance.