A Markov time related to a robot-safety device system

We consider a robot-safety device system attended by two different repairmen. The twin-system is characterized by the natural feature of cold standby and an admissible risky state. Apart from tangible results obtained in the previous Literature, we introduce a Markov time called the recovery time of the system. In order to obtain the corresponding distribution, we employ a stochastic process endowed with time dependent state probabilities related to the point availability of a renewable robot without safety device. Finally, as an example, we consider the case of Weibull repair (for the robot) and deterministic repair (for the safety device). We provide several computer-plotted graphs obtained by advanced numerical methods. Received: February 2004 / Revised version: October 2004MSC classification: 60K10     

Delay Perturbed Sweeping Process

This paper is devoted to the study of a nonconvex perturbed sweeping process with time delay in the infinite dimensional setting. On the one hand, the moving subset involved is assumed to be prox-regular and to move in an absolutely continuous way. On the other hand, the perturbation which contains the delay is single-valued, separately measurable, and separately Lipschitz. We prove, without any compactness assumption, that the problem has one and only one solution.     

Optical backward mixing in sodium nitrite

We present an experimental study of backward mixing of argon laser lines and CO laser lines to generate visible light in sodium nitrite. Angle tuning has been measured. Some special aspects of the observed super narrow band-width of backward interactions are discussed.     

Two Approaches to Scheduling Container Ships with an Application to the North Atlantic Route

The development of an interactive computer program and a heuristic optimising model for scheduling container ships on the North Atlantic is described. The constraints and multiple objective criteria governing these schedules are discussed and sample results of both approaches given.     

Updating incomplete factorization preconditioners for model order reduction

When solving a sequence of related linear systems by iterative methods, it is common to reuse the preconditioner for several systems, and then to recompute the preconditioner when the matrix has changed significantly. Rather than recomputing the preconditioner from scratch, it is potentially more efficient to update the previous preconditioner. Unfortunately, it is not always known how to update a preconditioner, for example, when the preconditioner is an incomplete factorization. A recently proposed iterative algorithm for computing incomplete factorizations, however, is able to exploit an initial guess, unlike existing algorithms for incomplete factorizations. By treating a previous factorization as an initial guess to this algorithm, an incomplete factorization may thus be updated. We use a sequence of problems from model order reduction. Experimental results using an optimized GPU implementation show that updating a previous factorization can be inexpensive and effective, making solving sequences of linear systems a potential niche problem for the iterative incomplete factorization algorithm.     

Peptide immobilization on amine-terminated boron-doped diamond surfaces

This paper reports on the formation and characterization of semicarbazide termination on aminated boron-doped diamond (BDD) surfaces, and further preparation of peptide microarray through site-specific alpha-oxo semicarbazone ligation. Hydrogen-terminated BDD electrodes were first aminated using NH3 plasma treatment and then reacted with triphosgene and Fmoc-protected hydrazine to yield a protected semicarbazide termination. Subsequent deprotection and chemical reaction with glyoxylyl peptides led to the covalent immobilization of the peptides on the surface through site-specific ligation. The resulting surfaces were characterized using X-ray photoelectron spectroscopy (XPS) and fluorescence measurements.     

Ab initio calculations on the X (1)A(') and A (1)A(") states of HPO and Franck-Condon simulation of the single vibronic level emission spectra of HPO and DPO

Minimum-energy geometries and relative electronic energies of the X (1)A(') and A (1)A(") states of HPO have been computed employing the coupled-cluster single-double plus perturbative triple excitations {RCCSD(T)} and/or complete-active-space self-consistent-field (CASSCF) multireference internally contracted configuration interaction (MRCI) methods with basis sets of up to the augmented correlation-consistent polarized-valence quintuple-zeta (aug-cc-pV5Z) quality. In addition, RCCSD(T)/aug-cc-pVQZ and CASSCF/MRCI/aug-cc-pVQZ potential energy functions, anharmonic vibrational wave functions, and energies involving all three vibrational modes for both electronic states of HPO and DPO, and Franck-Condon factors between the two electronic states, which allow for Duschinsky rotation and anharmonicity, were computed. Computed Franck-Condon factors were then used to simulate single vibronic level (SVL) emission spectra recently reported by Tackett and Clouthier [J. Chem. Phys. 117, 10604 (2002)]. Excellent agreement between the simulated and observed spectra was obtained for the A (1)A(")(1,0,0)-->X (1)A(') SVL emission of HPO and DPO, when the best estimated ab initio geometries of the two states, which include contributions from core correlation and extrapolation to the complete basis set limit, were used in the simulation, suggesting that the best estimated ab initio geometry of the A (1)A(") state of HPO, particularly the bond angle of 94.5 degrees , is more reliable than the available experimentally derived geometry. A discussion on the geometrical parameters derived from rotational constants obtained from the rotational analysis of a high-resolution spectrum and from Franck-Condon simulation of the vibrational structure of an electronic spectrum is given.     

Ab initio calculations on SnCl2 and Franck-Condon factor simulations of its ã-X and B-X absorption and single-vibronic-level emission spectra

Minimum-energy geometries, harmonic vibrational frequencies, and relative electronic energies of some low-lying singlet and triplet electronic states of stannous dichloride, SnCl(2), have been computed employing the complete-active-space self-consistent-field/multireference configuration interaction (CASSCF/MRCI) and/or restricted-spin coupled-cluster single-double plus perturbative triple excitations [RCCSD(T)] methods. The small core relativistic effective core potential, ECP28MDF, was used for Sn in these calculations, together with valence basis sets of up to augmented correlation-consistent polarized-valence quintuple-zeta (aug-cc-pV5Z) quality. Effects of outer core electron correlation on computed geometrical parameters have been investigated, and contributions of off-diagonal spin-orbit interaction to relative electronic energies have been calculated. In addition, RCCSD(T) or CASSCF/MRCI potential energy functions of the X(1)A(1), ?(3)B(1), and B(1)B(1) states of SnCl(2) have been computed and used to calculate anharmonic vibrational wave functions of these three electronic states. Franck-Condon factors between the X (1)A(1) state, and the ? (3)B(1) and B (1)B(1) states of SnCl(2), which include anharmonicity and Duschinsky rotation, were then computed, and used to simulate the ?-X and B-X absorption and corresponding single-vibronic-level emission spectra of SnCl(2) which are yet to be recorded. It is anticipated that these simulated spectra will assist spectroscopic identification of gaseous SnCl(2) in the laboratory and/or will be valuable in in situ monitoring of SnCl(2) in the chemical vapor deposition of SnO(2) thin films in the semiconductor gas sensor industry by laser induced fluorescence and/or ultraviolet absorption spectroscopy, when a chloride-containing tin compound, such as tin dichloride or dimethyldichlorotin, is used as the tin precursor.     

EPR study of copper(II) complexes of hydroxysalen derivatives in order to be used in the DNA cleavage

Two series of functionalized hydroxy-salen-copper(II) complexes with various side chain lengths have been synthesized. The first one is characterised by amino side chain protected by the tert-butyloxycarbonyl group (Boc) whereas, the second series is obtained by removal of the Boc-protecting group under acidic conditions and formation instead of it an ammonium salt. EPR studies were carried out on the copper(II) complexes. EPR signals attributed to monomers and dimers of Cu2+ species were evidenced. Determination of the copper(II) environment in each complex was attempted using all the experimental results. Square planar and tetrahedral symmetries were found for the copper(II) monomers. From the fine structure observed for the pair signal, the distance between the Cu2+ ions in the pair has been calculated (3.9-4.3A). From these values, it seems that the formation of pairs is obtained by a face-to-face bimolecular association.     

A well-defined silica-supported dinuclear tungsten(III) amido species: synthesis, characterization and reactivity

Grafting of [W(2)(NMe(2))(6)] onto dehydroxylated silica affords the well-defined surface species [([triple bond, length as m-dash]Si-O)W(2)(NMe(2))(5)], characterized by elemental analysis, and infrared, Raman and NMR spectroscopies, and the catalytic reactivity of this supported tungsten(III) d(3)-d(3) dimer and of its alkoxide derivatives towards alkynes has been probed.