• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.10
• /
• pp.929-934
• /
• 2014

Reaction force compensation (RFC) mechanism can relieve the vibration of base system caused by acceleration and deceleration of mover. In this paper, we propose a new passive RFC mechanism with a movable additional mass to reduce vibration of the system base as well as displacement of the magnet track. First, equation of motion for the new passive RFC mechanism is derived and simulated to tune design parameters such as masses and spring coefficients. Simulation results show that the vibration of the system base of the stage with the new RFC mechanism.

• Journal of the Korean Chemical Society
• /
• v.49 no.6
• /
• pp.554-559
• /
• 2005

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.239.2-240
• /
• 2003

We have recently described the novel synthetic method for N-protected amines from various ethers using chlorosulfonyl isocyanate(CSI) and found that the mechanism of our CSI reaction is a competitive reaction of SN1 and SNi mechanism according to the stability of carbocation intermediate. Forthermore. we developed the regioselective and diastereoselective one-pot synthetic method for 1,2-amino alcohol, through the reaction of di-and tribenzyl thers with CSI, and invetigated its mechanism. (omitted)

• Journal of applied mathematics & informatics
• /
• v.22 no.1_2
• /
• pp.1-20
• /
• 2006

This paper presents the interior penalty discontinuous Galerkin finite element methods (DGFEM) for solving the rotating disk electrode problems in electrochemistry. We present results for the simple E reaction mechanism (convection-diffusion equations), the EC' reaction mechanism (reaction-convection-diffusion equation) and the ECE and $EC_2E$ reaction mechanisms (linear and nonlinear systems of reaction-convection-diffusion equations, respectively). All problems will be in one dimension.

• Journal of the Korean Ceramic Society
• /
• v.20 no.3
• /
• pp.255-259
• /
• 1983

Am(rphous aluminosilicate zeolite A and hydroxysodalite were obtained by reaction of Hadong kaolin(halloysite) with IN sodium hydroxide solntion in the temperature range of 60 to 10$0^{\circ}C$ For determination of the mechanism of the reaction Various possible mechanisms were compared with the experimental results. It was observed that the reaction mechamism of zeolite A synthesis from Hadong kaolin was first order consecu-tive reaction as follows : halloysitelongrightarrowamorphous aluminosilicatelongrightarrowzeolite Alongrightarrowhydroxysodalite

• Archives of Pharmacal Research
• /
• v.26 no.9
• /
• pp.667-678
• /
• 2003

We examined the effect of p-substituents in p-substituted cinnamyl methyl ethers and 1-(p-substituted phenyl)allyl methyl ethers with CSI, and confirmed that the CSI reaction of allyl ethers (p-substituted ethers) is a competitive reaction of $S_Ni{\;}and{\;}S_N1$ mechanism according to the stability of the carbocation. And, the only terminal allylic amine was obtained through the migration reaction in thermodynamic reaction condition.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.11 no.1
• /
• pp.32-55
• /
• 1975

The ammonium salt of N-Nitrosophenylhydroxiamine, namely Cupferron, is a well-known analytical reagent which precipitates a great number of metal ions in acid medium. Various structures of electrode reduction for N-Nitrosophenylhydroxiamine have been suggested in acid and alkaline media by many researchers, but not in neutral medium. So the mechanism of electrode reaction of Cupferron was investigated by both chronopotentiometric and polarographic methods. It was estimated that the reduction of Cupferron occurs in a three-step mechanism through which a chemical step is interposed between two charge transfer, the ECE (charge transfer-chemical reaction-charge transfer) mechanism, over a range of neutral and alkaline media. The chemical reaction of the process was assumed to be acid-base catalyzed from the fact that kapp (over all rate constant) of chemical reaction is pH dependent.

• Journal of Microbiology
• /
• v.35 no.1
• /
• pp.15-20
• /
• 1997

Kinetic studies were done to elucidate the reaction mechanism of purine nucleoside phosphorylase (PNP) in Micrococcus Luteus. PNP catalyzes the reversible phosphorolysis of ribonucleosides to their respective base. The effect of alternative competing substrates suggested that a single enzyme was involved in binding to the active site for all purine nucleosides, inosine, deoxyiosine, guanosine, deoxyguanosine, adenosine and deoxyadenosine. Affinity studies showed that pentose moiety reduced the binding capacity and methylation of ring N-1 of inosine and guanosine had little effect on binding to bacterial enzyme, whereas these compounds did not bind to the mammalian enzymes. The initial velocity and product inhibition studies demonstrated that the predominant mechanism of reaction was an ordered bi, bi reaction. The nucleoside bound to the enzyme first, followed by phosphate. Ribose 1-phosphate was the first product to leave, followed by base.

• Journal of the Korean Ceramic Society
• /
• v.36 no.6
• /
• pp.655-661
• /
• 1999

${\beta}$-SiC formation mechanism in Si melt-C-SiC system with varying in size of carbon source was investigated. A continuous reaction sintering process using Si melt infiltration method was adopted to control the reaction sintering time effectively. It was found that ${\beta}$-SiC formation mechanism in Si melt-C-SiC system was directly affected by the size of carbon source. In the Si melt-C-SiC system with large carbon source ${\beta}$-SiC formation mechanism could be divided into two stages depending on the reaction sintering time: in early stage of reaction sintering carbon dissolution in Si melt and precipitation of ${\beta}$-SiC was occurred preferentially and then SIC nucleation and growth was controlled by diffusion of carbon throughy the ${\beta}$-SiC layer formed on graphite particle. Furthmore a dissolution rate of graphite particles in Si melt could be accelerated by the infiltration of Si melt through basal plane of graphite crystalline.

• Journal of the Korean Chemical Society
• /
• v.16 no.4
• /
• pp.232-240
• /
• 1972

The rate constants for the addition reaction of n-butylmercaptan to ethylacrylate have been measured by iodometry and for the proposed reaction mechanism a rate equation which can be applied over wide pH range was derived. From this rate equation, one may conclude that the reaction is started by addition of n-butylmercaptan molecule below pH 4. However, above pH 7, this addition reaction is proceeded by the n-butylmercaptide ions. At pH 4-7, the complex addition reaction mechanism can also be revealed by this rate equation.