1,721,423 research outputs found
Error detection of structured workflow definition using set constraint system
No full textA workflow definition containing errors might cause serious problems for an enterprise especially when it involves mission critical business processes or inter-organizational interaction. So workflow definitions should be defined in a strict and rigorous way. In this paper, we develop a workflow definition language and analysis methods for the language to support strict and rigorous workflow definitions. Faults or mistakes causing communication deadlock, access conflicts, and improper exception specification in workflow definitions can be detected and notified automatically using the methods. The proposed workflow definition language borrows structured constructs of conventional programming languages because many good features of conventional programming languages also can be used effectively in expressing workflow processes. With slight modifications and scope restrictions, the developed analysis techniques in this paper can be used in any workflow definition languages and they can help workflow designers define workflow processes in much more safe and reliable manner
Stable nonconforming methods or the Stokes problem
No full textIt is the purpose of this paper to show that the mixed finite element scheme with pressure stabilization for the Stokes problem converges with an optimal order for some higher order nonconforming triangular elements. Specifically an optimal order convergence is given for the NCP4-P-3 element using nonconforming piecewise quartic velocities paired with discontinuous piecewise cubic pressures. The NCP6-P-5 element is analyzed similarly. To verify the stability condition and the error estimates for nonconforming elements, we combine the ideas of macroelement technique of Stenberg and the arguments for Galerkin least squares methods. (C) 2000 Elsevier Science Inc. All rights reserved
Orthogonality correction of planar sample scanner for atomic force microscope
No full textA planar scanner of an atomic force microscope (AFM) can move samples to within a few nm of resolution. Tube piezoelectric actuators have coupling errors, that can be eliminated by software correction; however, residual errors can deteriorate the actual information in a small-feature sample. To obtain stable AFM images of small-feature samples, a closed-loop. control cannot be used due to the large random errors of the sensor. The orthogonality of a new sample scanner having a motion guide is measured and corrected using a simple electronic circuit in open-loop scanning to reduce the scanner artifact
Effectiveness test of alginate-derived polymeric surfactants
No full textA series of alginate-derived polymeric surfactants (APSs) with a linear alkyl group (C8, C12, C16) was synthesized by oxidation followed by reductive amination of 2,3-dialdehydic alginate. The products were characterized by measuring IR spectra, NMR spectra, surface tension and critical micelle concentration (cmc). They were also tested for the solubilization of azobenzene and adsorption of heavy metal. In the case of 40% CHO-C8 APSs, the lowest interfacial tension value (31.5m Nm(-1)) was obtained at the cmc value of 1.35 g dm(-3). The dissolving capacity of 40% CHO-C8 APS towards azobenzene was 27 times greater than that of alginate. The overall cobalt (CO2+) removal efficiency by adsorption using APSs was high compared with that of sodium alginate at pH 3, 5 and 7. Equilibrium aspects of cobalt adsorption onto 10% CHO-APSs were studied, and the results show that APSs had high equilibrium capacities for cobalt uptake, 115.5mgg(-1). (C) 2002 Society of Chemical Industry
Behavior of elemental tellurium as surface generation-recombination centers in CdTe∕HgCdTe interface
No full textCalculated chemical equations using thermodynamics suggest that elemental Te-0 is easily induced during bromine-based etching process on the HgCdTe surface and the induced elemental Te-0 can be removed by chemical reaction with hydrazine, forming volatile H2Te. X-ray photoelectron spectroscopy (XPS) confirmed these chemical reactions. The induced elemental Te-0 is believed to play a role as surface generation-recombination centers in CdTe/HgCdTe interface, which was confirmed by XPS, ideality factor, and energy-dispersive interface trap density (D-it) analyses
Determination of the efficiency and removal mechanism of cobalt by crab shell particles
No full textThe effects of contact time, solution pH and ionic strength on interactions between cobalt (Co-59) ions in synthetic liquid waste and particles of raw crab shell, Portunus trituberculatus, in batch reactions were studied. Approximately 19.5 mg dm(-3) Co was removed within 6 h after contact with 1.0 g dm(-3) crab shell at an initial concentration of 20 mg dm(-3) Co. Due to the dissolution of calcium carbonate in the crab shell, the solution pH changed spontaneously to 10, leading to precipitation of cobalt ions. The efficiency of cobalt removal depended on solution pH, but was less pH sensitive than for controls without crab shell. The maximum uptake of Co at an initial pH value of 5.0 was 510 mg g(-1) crab shell. The removal efficiency was affected slightly by ionic strength up to 2.0 mol dm(-3) of NaCl. Scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) indicated that the removal mechanism of Co by crab shell resulted primarily from the dissolution of calcium carbonate followed by precipitation of cobalt on the surface of the shell. Compared with commonly used ion-exchange resins such as natural zeolite, Durasil 70, and Durasil 230, the efficiency of Co removal by a column of mixture of crab shell and activated carbon was at least three-fold greater, indicating that crab shell is a suitable biosorbent for the removal of cobalt from liquid waste. (C) 2004 Society of Chemical Industry
Investigation of Pt/Ti bottom electrodes for Pb(Zr,Ti)O-3 films
No full textPt films, as bottom electrodes for PZT capacitors, were deposited on Ti/SiO2/Si substrates using DC magnetron sputtering under various deposition conditions. The effects of post-annealing on surface morphology, element diffusion. microstructure and structural phase of the Pt films were investigated. The structure and electrical properties of PZT films deposited on Pt/Ti/SiO2/Si electrodes were also studied. As the deposition temperature of the Pt film increases and the deposition rate decreases, the film becomes dense so that Ti out-diffusion and film deformation are suppressed. The out-diffused Ti faciliates the formation of nucleation sites for perovskite PZT films. However, excess Ti out-diffusion not only decreases the total capacitance of the PZT films due to formation of an interfacial layer having a low dielectric constant but also degrades the leakage current characteristics of the PZT films due to deformation of the Pt electrode.Samsung Electronics Co
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