Showing papers by "National Cheng Kung University published in 1984"
TL;DR: In this paper, the separation equations for the enrichment of heavy water in a batch-type thermal diffusion column have been derived for low-concentration operations, and the experimental works for various feed concentrations of H 2 OHDO-D 2 O system has been also conducted and the results quantitatively confirm with the prediction.
81 citations
TL;DR: Etude experimentale du transfert de chaleur a l'ebullition d'eau contenant 0,1 ou 0,5% de particules d'Al 2 O 3 de diametres 0,05-0,3 et 1 microns.
71 citations
TL;DR: In this article, the coalescence of nitrogen bubble pairs issued from neighboring nozzles submerged in water has been studied by means of high-speed photography, and it is shown that small amount of surface active additive is able to increase the bubble coalescence time greatly.
51 citations
TL;DR: Forced and naturally occurring, self-sustaining oscillations of transonic flows in two-dimensional diffusers were computed using MacCormack's hybrid method as discussed by the authors.
Abstract: Forced and naturally occurring, self-sustaining oscillations of transonic flows in two-dimensional diffusers were computed using MacCormack's hybrid method. Depending upon the shock strengths and the area ratios, the flow was fully attached or separated by either the shock or the adverse pressure gradient associated with the enlarging diffuser area. In the case of forced oscillations, a sinusoidal plane pressure wave at frequency 300 Hz was prescribed at the exit. A sufficiently large amount of data were acquired and Fourier analyzed. The distrbutions of time-mean pressures, the power spectral density, and the amplitude with phase angle along the top wall and in the core region were determined. Comparison with experimental results for the forced oscillation generally gave very good agreement; some success was achieved for the case of self-sustaining oscillation despite substantial three-dimensionality in the test. An observation of the sequence of self-sustaining oscillations was given.
42 citations
TL;DR: In this paper, a new combination of Routh stability criterion and integral squared error (ISE) criterion approach is proposed for the linear model reduction of high-order dynamic systems, which consists of a two-step computational scheme, in the first step, the Routh approximation method is used to reduce the order of the denominator polynomial of the system transfer function.
Abstract: A new combination of Routh stability criterion and integral squared error (ISE) criterion approach is proposed for the linear model reduction of high-order dynamic systems. The method consists of a two-step computational scheme. In the first step, the Routh approximation method is used to reduce the order of the denominator polynomial of the system transfer function. In the second step, the Routh table is used to derive a set of optimal coefficients of the numerator polynomial of reduced model such that the ISE between the unit step responses of the original and simplified system is reduced to a minimum. The advantages of the proposed method are that it does not actually evaluate the system time response in the step of minimizing the ISE, and the reduced model is stable if the original system is stable.
33 citations
31 citations
TL;DR: Analyse numerique du regime thermique d'une ailette constituee par une aiguille circulaire fine verticale en conduction thermique and convection forcee conjuguee as mentioned in this paper.
Abstract: Analyse numerique du regime thermique d'une ailette constituee par une aiguille circulaire fine verticale en conduction thermique et convection forcee conjuguee
28 citations
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TL;DR: This paper presents the idea of linkage path code for the identification and recognition of planar kinematic chains with simple joints and turning pairs and proposes a proposed method which can greatly simplify the procedures for obtaining the code by inspection.
27 citations
TL;DR: The operational properties of the integration and product of Chebyshev polynomials are used in the analysis of bilinear systems by the approximation of time functions by truncated ChebysHEv series and to determine the unknown parameters of a general bilinears system from the input-output data.
Abstract: The operational properties of the integration and product of Chebyshev polynomials are used in the analysis of bilinear systems by the approximation of time functions by truncated Chebyshev series The operational properties are also applied to determine the unknown parameters of a general bilinear system from the input-output data Examples with excellent results are given
25 citations
TL;DR: In this article, a method of using orthogonal shifted Legendre polynomials for identifying the parameters of a process whose behaviour can be modelled by a linear differential equation with time-varying coefficients in the form of finite-order polynomial coefficients is presented.
Abstract: A method of using orthogonal shifted Legendre polynomials for identifying the parameters of a process whose behaviour can be modelled by a linear differential equation with time-varying coefficients in the form of finite-order polynomials is presented. It is based on the repeated integration of the differential equation and the representations of ∫ 0 t s(τ) dτ = Ps(t) and ts(t) = Rs(t), where P and R are constant matrices and s(t) is a shifted Legendre vector whose elements are shifted Legendre polynomials. The differential input-output equation is converted into a set of overdetermined linear algebraic equations for a least squares solution. The results of simulation studies are included to illustrate the applicability of the method.
22 citations
TL;DR: In this paper, the authors provide numerical data which indicate the ability of a ceresin, Carnauba, paraffin and beeswax mixture to represent satisfactorily a variety of metalforming conditions.
TL;DR: In this paper, the analysis of forced convective heat transfer of power-law non-Newtonian fluids from a flat plate is studied and the results of local heat transfer are obtained by using implicit finite difference scheme to solve the nonsimilarity solution.
TL;DR: In this article, the effects of various parameters on the natural frequencies of axisymmetric clamped plates and simply supported plates subjected to initial stresses are investigated, where the initial stress is a combination of a pure bending stress plus an extensional stress in the plane of the plate.
TL;DR: In this paper, a step cooling technique for liquid phase epitaxy was used to grow In0.75Ga0.25As0.56P0.44 thin films on InP substrates.
TL;DR: In this paper, the relationship between the profile of the extrusion die and the development of the redundant shears is investigated, and points the way towards rationalisation of tooling in the process of tube extrusion.
TL;DR: In this article, the effect of alloying additional elements (Al, Si, Ti, V, Ni, Cu, Zr, Nb and Mo) was systematically studied with magnetic measurements and transmission electron microscopy (TEM), on a laboratory scale.
01 Jan 1984
TL;DR: In this paper, two stream function solutions for steady two-dimensional water waves are reviewed and compared with the algorithm developed by Chaplin (1980, Coastal Engineering,3, 179-205).
Abstract: Two stream function solutions for steady two-dimensional water waves are reviewed. The algorithm developed by Dalrymple (1974 , Proc. 6th Conf. Offshore Tech., pp. 843–856) and used by Hudspeth and Slotta (1978 , Proceedings of the American Society of Civil Engineers,104, 319–334) is compared with the algorithm developed by Chaplin (1980 , Coastal Engineering,3, 179–205). By examining more closely the near-breaking wave conditions, it is shown that celerity does not increase monotonically with increasing dimensionless wave steepness. Numerical comparisons between the two algorithms indicate that the Dalrymple algorithm is more accurate for near-breaking waves and requires less computer programming effort. Neither algorithm appears to be able to predict breaking wave conditions as accurately as the Cokelet (1977 , Philosophical Transactions of the Royal Society of London,A286, 183–230) algorithm. Numerical comparisons of the Dalrymple free surface error convergence criteria with the Chaplin significant figures convergence criteria indicate that the free surface error convergence criterion is more consistent for stream function representations.
TL;DR: In this article, a method to prepare methyl 3-arylsydnonylacetate (I) from 4-acetyl-3-ylsydnone with thallium (III) nitrate by oxidative rearrangement was investigated.
Abstract: A convenient method to prepare methyl 3-arylsydnonylacetate (I) from 4-acetyl-3-arylsydnone with thallium (III) nitrate by oxidative rearrangement was investigated.
4-Formyl-3-arylsydnones were reduced by sodium borohydride at room temperature to produce 4-hydroxymethyl-3-arylsydnones (II) in moderate yields (65%-85%), but the corresponding 3-aryl-4-sydnonecarboxaldehyde arylhydrazone (III) was obtained by the electrolytic reduction.
TL;DR: In this paper, the performance of three-phase isothermal slurry reactors with continuous gas flow and batch liquid was analyzed for the zeroth and first moments, in terms of the separate rate constants for adsorption and surface reaction and the other pertinent rate and equilibrium constants.
TL;DR: This paper discusses the application of discrete Chebyshev polynomial expansion to reduce the order of a linear time-invariant discrete system described by 2-transfer function.
Abstract: This paper discusses the application of discrete Chebyshev polynomial expansion to reduce the order of a linear time-invariant discrete system described by 2-transfer function. Two approaches are used to obtain the reduced models. One uses discrete Chebyshev spectrum matching to determine both the coefficients of the denominator and numerator of the reduced model. The other uses stable reduction methods to determine the coefficients of the denominator and discrete Chebyshev spectrum matching to determine the coefficients of the numerator. The latter has the advantage that the reduced model is stable provided the original model is stable.
TL;DR: In this article, the phase transfer catalytic preparation of benzyl benzoate from sodium benzoates and benzyl chloride with tetrabutylaramonium iodide as catalyst in a well stirred batch reactor is studied.
Abstract: The kinetics is studied for the phase transfer catalytic preparation of benzyl benzoate from sodium benzoate and benzyl chloride with tetrabutylaramonium iodide as catalyst in a well stirred batch reactor. Benzyl chloride is dissolved in toluene as the organic phase and sodium benzoate is dissolved in water as the aqueous phase. The kinetics of the overall reaction is described by a first-order model based on the concentration of benzyl chloride in the organic phase at the later time of the batch reaction. The rate constant increases with an increase of the catalyst concentration while decreases slightly with an increase of the concentration of sodium benzoate under the experimental condition.
TL;DR: Zinc-doped GaAs epilayers grown by low pressure metalorganic chemical vapor deposition (LP-MOCVD) are studied in this article, where Triethylgallium (TEG) and arsine (AsH 3 ) are used as Ga and As source, respectively.
TL;DR: Sheena, Z., Zalmanovich, A, and Unger, A., "Theoretical Stiffness Matrix Correction by Using Static Test Results," Collection of Papers of the 24th Israel Annual Conference on Aviation and Astronautics, Feb. 1982, pp 48-56 as discussed by the authors.
Abstract: Sheena, Z., Zalmanovich, A., and Unger, A., "Theoretical Stiffness Matrix Correction by Using Static Test Results," Collection of Papers of the 24th Israel Annual Conference on Aviation and Astronautics, Feb. 1982, pp. 48-56. Guyan, R. J., "Reduction of Mass and Stiffness Matrices," AIAA Journal, Vol. 3, Feb. 1965, p. 380. Rodden, W. P., McGrew, J. A., and Kalman, T. P., "Comment on 'Interpolatin Using Surface Splines'," Journal of Aircraft, Vol. 9, Dec. 1972, pp. 869-871. Baruch, M. and Bar-Itzhack, I. Y., "Reply by Authors to A. Berman," AIAA Journal, Vol. 17, Aug. 1979, p. 928. Kidder, R. L., "Reduction of Structural Frequency Equations," AIAA Journal, Vol. 11, June 1973, p. 892.
TL;DR: A new time-domain approach to the derivation of a Chebyshev scale matrix is presented, which is used to analyze differential equations containing terms with a scaled argument.
Abstract: A new time-domain approach to the derivation of a Chebyshev scale matrix is presented. The derived Chebyshev scale matrix, together with the Chebyshev integration matrix, is used to analyze differential equations containing terms with a scaled argument. The results are expressed in terms of Chebyshev series. As illustrated in the included examples, the Chebyshev series solution converges faster than that represented in Laguerre series.
TL;DR: In this article, a simple, low-cost, and flexible, automatic, deep-level transient spectroscopy (DLTS) system with an Apple II microcomputer for semiconductor devices analysis is described.
Abstract: A simple, low-cost, and flexible, automatic, deep-level transient spectroscopy (DLTS) system with an Apple II microcomputer for semiconductor devices analysis is described. By using an interactive Basic software program, all the instrument parameters including sampling aperture locations, temperatures, excitation pulse frequency, width and amplitude can be controlled automatically. The transient signals are also averaged by the software program. Furthermore, a linear square regression method is used to calculate the activation energy. The trap density, capture cross section, activation energy of n-type Sidoped GaAs, grown by molecular beam epitaxy (MBE) system, was measured and compared with conventional boxcar DLTS sytem. In addition, the DLTS signal spectra and the Arrhenius plots can be plotted by a line printer and displayed on a CRT monitor during one thermal scan. An IEEE-488 interface bus was designed for communication between personal computers and instruments. This configuration provides the advantages of ease of operation and rapid set up, especially for the purpose of data acquisition and processing.
TL;DR: In this paper, the authors reduced the kinetics of chemical-controlled radical-chain copolymerization to pseudohomopolymerization kinetics by introducing the apparent rate constants.
Abstract: In this article the kinetics of chemical-controlled radical-chain copolymerization have been reduced to pseudohomopolymerization kinetics by introducing the apparent rate constants, The methods for the determinations of the values of the apparent rate constants, mode of termination, and the methods for the calculation of molecular weights and distributions are proposed. The data required for these determinations and calculations are simply obtained by the usual steady-state method. According to the traditional kinetics along with the definitions of the apparent rate constants, these apparent rate constants as functions of traditional rate constants, monomer compositions, and copolymer compositions are derived. Further utilizing the theoretical expressions obtained, we show that the apparent rate constants are the general rate constants for both radical chain homo- and copolymerizations. The bulk radical copolymerizations of methyl methacrylate and styrene at various monomer feed compositions at 60°C are used to test the proposed model. The empirical apparent rate constants obtained are described well, by the following expressions,
and
and the mode of termination on the combination termination is
where K and K denote the apparent rate constants of propagation and termination, respectively. The term f1(= 1 − f2) stands for the mole fraction of styrene in the monomer solution fed. F1 is the copolymer composition produced at f1. β is the mode of termination.
TL;DR: In this paper, a new mathematical model of reaeration coefficient considering the effect of salts has been developed for water quality analysis in tidal rivers and estuaries, which can be used to determine the degree of wastewater treatment required for a proposed effluent discharge.
TL;DR: In this article, an extraction equilibrium model based on reaction kinetics has been developed and a nonlinear optimization method was used to fit the model equation to the experimental data of the UO/sub 2/(NO/sub 3/)/sub 2/-HNO/ sub 3/-20% TBP-kerosene system successfully.
Abstract: An extraction equilibrium model based on reaction kinetics has been developed. A nonlinear optimization method was used to fit the model equation to the experimental data of the UO/sub 2/(NO/sub 3/)/sub 2/-HNO/sub 3/-20% TBP-kerosene system successfully. The extraction equilibrium isotherms are characterized by the Langmuir type. Correlation coefficients between the experimental data and the predicted values are in the range of 0.9806 to 0.9967 and the average absolute error ranges from 2.68% to 6.73%. The parameter (Be /sup HIRT/ ) determined for the system of 20% TBP can be used to predict the equilibrium data of 30% TBP in kerosene satisfactorily. The initial slope (ABe /sup HIRT/ ) of the extraction isotherm is the maximum distribution coefficient and its quantity can be used to compare the extractive power of various solvent systems.