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  • Articles  (98)
  • Navier-Stokes equations  (35)
  • 61.70  (33)
  • 82.65  (30)
  • 2015-2019
  • 1990-1994  (98)
  • 1915-1919
  • Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics  (98)
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  • Articles  (98)
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  • 1
    Electronic Resource
    Electronic Resource
    Some unsteady exact pseudo-plane solutions for the Navier-Stokes equations (1994)
    Springer
    Meccanica 29 (1994), S. 261-269 
    Details
    ISSN: 1572-9648
    Keywords: Beltrami motions ; pseudo-plane motions ; Navier-Stokes equations ; fluid dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Description / Table of Contents: Sommario Si studiano moti non stazionari pseudopiani e piani dell'equazioni di Navier Stokes. Questi moti sono flussi generalizzati di Beltrami con una particolare dipendenza della funzioni di corrente dalle coordinate spaziali in modo separato. Nell'ambito di questa famiglia di flussi vengono esplicitamente trovati tutti i moti pseudopiani di primo tipo e vengono anche individuate un'ampia classe di soluzioni universali piane e una classe di moti pseudopiani del secondo tipo che possiedono come flussoprimitivo i famosi vortici adocchi di gatto di Kelvin.
    Notes: Abstract Unsteady pseudo-plane and plane motions for Navier-Stokes equations have been studied, which are generalized Beltrami flows, related to separable stream functions. All the pseudo-plane motions of the first kind of such a type, a wide class of plane universal solutions, which seems to be new, and a class of pseudo-plane motions of the second kind, dependent on an arbitrary function of time, with a primitive steady plane solution which is the celebrated Kelvin's cat's eye vortices are formed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01461439
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  • 2
    Electronic Resource
    Electronic Resource
    High-resolution diffraction-space mapping and topography (1994)
    Springer
    Applied physics 58 (1994), S. 121-127 
    Details
    ISSN: 1432-0630
    Keywords: 07.85 ; 68.55 ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The importance of collecting the distribution of scattered X-rays in two dimensions with the “right probe” will be addressed. The data-collection method will be briefly covered and how this greatly assists the interpretation of structural features giving rise to the distributed X-ray scattering. The combination of diffraction-space mapping with multiple crystal topography will also be presented to show how any region of scattering can be related to lateral structural changes or crystal imperfections. The simulation of the diffraction profiles of structures with defects will be addressed as well as the interpretation of “unusual and strange” diffraction features observed in high resolution, which yield further useful information on the materials under study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324366
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  • 3
    Electronic Resource
    Electronic Resource
    Infrared holographic recording in LiNbO3:Cu (1994)
    Springer
    Applied physics 58 (1994), S. 191-195 
    Details
    ISSN: 1432-0630
    Keywords: 42.40 ; 78.20 ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Holograms may be recorded in photorefractive LiNbO3:Cu with pulsed infrared light (wavelength λ=1064 nm, Q-switched Nd:YAG laser), if the crystals are previously or simultaneously illuminated with a green (λ=532 nm) light pulse. We study refractive index changes and time constants of as-grown and thermally treated crystals with different copper concentrations. A model explaining this effect is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324375
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  • 4
    Electronic Resource
    Electronic Resource
    Positron annihilation in the quenched and electron-irradiated NiSb intermetallic compound (1994)
    Springer
    Applied physics 59 (1994), S. 163-168 
    Details
    ISSN: 1432-0630
    Keywords: 78.70. Bj ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Samples of the near equiatomic NiSb compound were irradiated by 3 MeV electrons at 20 K or quenched from 1103 K and 1333 K and subsequently annealed isochronally. The behaviour of defects created by quench or irradiation were studied by the positron annihilation technique. Only one recovery stage was found around 425 K for quenched specimens, but two distinct stages (100 K and 425 K) were observed after irradiation. The 425 K stage is ascribed to the migration of Ni vacancies giving dislocation loops. The recombination of mobile interstitials with vacancies after irradiation is assumed to occur between 100 K and 250 K. Doppler broadening and lifetime variations of positrons as a function of the measuring temperature in these irradiation samples are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00332210
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  • 5
    Electronic Resource
    Electronic Resource
    Investigation of native-oxide growth on HF-treated Si(111) surfaces by measuring the surface-state distribution (1994)
    Springer
    Applied physics 59 (1994), S. 193-197 
    Details
    ISSN: 1432-0630
    Keywords: 73.20 ; 81.60 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The evaluation of the surface state distribution of differently HF-treated Si(111) surfaces during the native-oxide growth in air is investigated by the large-signal field-modulated photovoltage technique. The surface state distribution consisting of intrinsic and extrinsic Si dangling bond defects is directly related to the state of oxidation of the Si surface. It is shown that the kind of HF treatment strongly influences the concentration of extrinsic defects with a lower state of oxidation. Special HF preparations for H termination of the Si(111) surface result in a nearly intrinsic surface state distribution. During the oxidation process three typical phases can be distinguished each characterized by specific defect structures. It was found that native-oxide growth is highly sensitive to the concentration of extrinsic defects directly after HF treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00332216
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  • 6
    Electronic Resource
    Electronic Resource
    Photorefractive properties of ruthenium-doped potassium niobate (1994)
    Springer
    Applied physics 59 (1994), S. 563-567 
    Details
    ISSN: 1432-0630
    Keywords: 61.70 ; 72.40 ; 78.20
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Photoconductivities and photovoltaic currents of ruthenium-doped KNbO3 are orders of magnitude larger than that of undoped and ion-doped crystals. KNbO3:Ru is very sensitive for holographic recording with red light and the photovoltaic current increases sublinearly with light intensity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00331912
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  • 7
    Electronic Resource
    Electronic Resource
    Depth profiling a III–V multilayered structure with an excimer laser (1994)
    Springer
    Applied physics 59 (1994), S. 295-297 
    Details
    ISSN: 1432-0630
    Keywords: 81.60 ; 82.65 ; 82.80
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A multilayered structure of GaAs and AlGaAs was depth profiled using the technique of digital etching. A single excimer laser (KrF) was used to control the etch rate and to identify each layer by monitoring the Ga ions generated during the desorption process. The Ga ions were the only ions observed and were only generated when the photon flux was in the GaAs layer. The etch rate, 0.9 monolayers (2.5 Å) per pulse, was constant with depth. The overall layer recognition resolution was 45 monolayers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00348233
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  • 8
    Electronic Resource
    Electronic Resource
    Copper as an electron trap in GaAs0.6P0.4 (1994)
    Springer
    Applied physics 59 (1994), S. 245-251 
    Details
    ISSN: 1432-0630
    Keywords: 71.00 ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract An electron trap having an energy level of 0.14 eV from the conduction band edge was found in the bulk of copper-diffused VPE-grown n-GaAs0.6P0.4 by conventional DLTS measurements and by pulse-duration dependent capacitance amplitude measurements. The capture cross section at room temperature is about 1.0×10−21 cm2 and has a weak temperature dependence. These properties are attributed to a non-repulsive center having a capturing mechanism which involves multiphonon emission processes with hardly any lattice relaxation. Evolution of the spatial distributions of the traps with time under junction electric field were studied. The results suggest that the trap is positively charged and has a high diffusivity under electric field. The center can thus be identified as positively charged interstitial copper ion rather than some form of copper complexes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00348227
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  • 9
    Electronic Resource
    Electronic Resource
    Observation of the early stages of growth and the formation of growth spirals in epitaxial YBa2Cu3O7-δ thin films by AFM (1994)
    Springer
    Applied physics 59 (1994), S. 49-56 
    Details
    ISSN: 1432-0630
    Keywords: 68.55 ; 61.70 ; 74.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Ultrathin epitaxial films of YBa2Cu3O7−δ on SrTiO3 prepared by Direct Current (DC) sputtering and pulsed laser deposition were imaged by Atomic Force Microscopy (AFM) to follow the different stages of growth of the thin films. Series of films with thicknesses between 1.2 nm and 12 nm (1–10 monolayers of YBa2Cu3O7−δ) were prepared under identical conditions, optimized with respect to electrical and structural properties, to obtain information on the mechanisms responsible for the formation of growth spirals which are commonly observed in films having a thickness of several 10 nm or more. It could be shown that few layers are formed by a layered growth mode where material is attached laterally to 2D islands which are only one c-axis unit cell in height. In a later stage of growth when about 8–10 layers have been formed, the growth process changes to a mode which is mediated by growth spirals. This could be directly monitored in the AFM images where different defect structures like vertically sheared growth fronts and dendrite-like terraces of stacked islands as well as the resulting growth spirals could be identified.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00348419
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  • 10
    Electronic Resource
    Electronic Resource
    Femtosecond excimer-laser-induced structure formation on polymers (1994)
    Springer
    Applied physics 59 (1994), S. 289-293 
    Details
    ISSN: 1432-0630
    Keywords: 42.55 ; 81.40 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Structure formation upon 500 fs 248 nm KrF-laser irradiation of PolyEthylene Terephthalate (PET) and PolyImide (PI) has been investigated. The results obtained with fs pulses have been compared to those with ns pulses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00348232
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  • 11
    Electronic Resource
    Electronic Resource
    A uniformly valid asymptotic solution of the Navier-Stokes equations (1994)
    Springer
    Applied mathematics and mechanics 15 (1994), S. 1055-1067 
    Details
    ISSN: 1573-2754
    Keywords: Navier-Stokes equations ; the potential flow ; the stream function ; the boundary correction ; the method of multiple scales
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Mathematics , Physics
    Notes: Abstract In this paper, problems of the flow over a flat plate in the large Reynolds number case are studied by using the method of multiple scales[1,2]. We have obtained N-order uniformly valid asymptotic solutions of the Navier-Stokes equations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02455397
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  • 12
    Electronic Resource
    Electronic Resource
    Tools for simulating non-stationary incompressible flow via discretely divergence-free finite element models (1994)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 18 (1994), S. 71-105 
    Details
    ISSN: 0271-2091
    Keywords: Non-stationary ; Navier-Stokes equations ; Upwind ; Divergence-free finite elements ; Multigrid ; Visualization ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: We develop simulation tools for the non-stationary incompressible 2D Navier--Stokes equations. The most important components of the finite element code are: the fractional step ϑ-scheme, which is of second-order accuracy and strongly A-stable, for the time discretization; a fixed point defect correction method with adaptive step length control for the non-linear problems (stationary Navier-Stokes equations); a modified upwind discretization of higher-order accuracy for the convective terms. Finally, the resulting nonsymmetric linear subproblems are treated by a special multigrid algorithm which is adapted to the quadrilateral non-conforming discretely divergence-free finite elements. For the graphical postprocess we use a fully non-stationary and interactive particle-tracing method. With extensive test calculations we show that our method is a candidate for a ‘black box’ solver.
    Additional Material: 33 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650180105
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  • 13
    Electronic Resource
    Electronic Resource
    Equivalence of u-p and ζ-ψ formulations of the time-dependent Navier-Stokes equations (1994)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 18 (1994), S. 471-487 
    Details
    ISSN: 0271-2091
    Keywords: Incompressible flows ; Navier-Stokes equations ; Primitive variables ; Vorticity-Streamfunction ; Compatibility conditions ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: This paper deals with the non-stationary incompressible Navier--Stokes equations for two-dimensional flows expressed in terms of the velocity and pressure and of the vorticity and streamfunction. The equivalence of the two formulations is demonstrated, both formally and rigorously, by virtue of a condition of compatibility between the boundary and initial values of the normal component of velocity. This condition is shown to be the only compatibility condition necessary to allow for solutions of a minimal regularity, namely H1 for the velocity, as in most current numerical schemes relying on spatial discretizations of local type.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650180504
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  • 14
    Electronic Resource
    Electronic Resource
    Multigrid pressure correction techniques for the computation of quasi-incompressible internal flows (1994)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 18 (1994), S. 489-507 
    Details
    ISSN: 0271-2091
    Keywords: Multigrid ; Pressure correction ; Combustion chamber ; Navier-Stokes equations ; DGS ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A study is reported on the possibility of improving the speed of convergence of existing numerical programmes for the simulation of flow in combustion chambers by applying the multigrid method to the pressure correction phase only. A version of the multigrid algorithm is introduced for this purpose which achieves a 1:10 residual reduction in a single V(1, 1) cycle. The overall decrease in computation time with respect to an industry-standard SIMPLE algorithm with single-grid pressure correction ranges from four to five times for SIMPLE itself and several other well-known algorithms to six times for a newly developed pressure correction strategy we call difference operator triangularization (DOT).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650180505
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  • 15
    Electronic Resource
    Electronic Resource
    Simulation of three-dimensional unsteady viscous free surface flow around a ship model (1994)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 19 (1994), S. 321-342 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Free surface flow ; Finite difference ; Wave resistance ; Frictional resistance ; Adaptive mesh ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: We present here a numerical method for solving the free surface flow around a ship at forward speed in calm water. The fluid is assumed to be Newtonian and the Reynolds-averaged Navier-Stokes equations are solved by a finite difference method. Modelization of turbulence is achieved by the algebraic model proposed by Baldwin and Lomax. Fully non-linear free surface conditions are satisfied in the model and a method to avoid the incompatibility between free surface conditions and no-slip conditions at the waterline is proposed. Numerical results obtained for a Wigley hull are compared with experimental results.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650190404
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  • 16
    Electronic Resource
    Electronic Resource
    Exact fully 3D Navier-Stokes solutions for benchmarking (1994)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 19 (1994), S. 369-375 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Incompressible ; Three-dimensional ; Exact solution ; Benchmarking ; Penalty formulation ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Unsteady analytical solutions to the incompressible Navier-Stokes equations are presented. They are fully three-dimensional vector solutions involving all three Cartesian velocity components, each of which depends non-trivially on all three co-ordinate directions. Although unlikely to be physically realized, they are well suited for benchmarking, testing and validation of three-dimensional incompressible Navier-Stokes solvers. The use of such a solution for benchmarking purposes is described.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650190502
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  • 17
    Electronic Resource
    Electronic Resource
    A characteristic-based method for incompressible flows (1994)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 19 (1994), S. 667-685 
    Details
    ISSN: 0271-2091
    Keywords: Incompressible flows ; Navier-Stokes equations ; Riemann solver ; Artifical compressibility ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A new characteristic-based method for the solution of the 2D laminar incompressible Navier-Stokes equations is presented. For coupling the continuity and momentum equations, the artificial compressibility formulation is employed. The primitives variables (pressure and velocity components) are defined as functions of their values on the characteristics. The primitives variables on the characteristics are calculated by an upwind diffencing scheme based on the sign of the local eigenvalue of the Jacobian matrix of the convective fluxes. The upwind scheme uses interpolation formulae of third-order accuracy. The time discretization is obtained by the explicit Runge-Kutta method. Validation of the characteristic-based method is performed on two different cases: the flow in a simple cascade and the flow over a backwardfacing step.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650190803
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  • 18
    Electronic Resource
    Electronic Resource
    Development of projection and artificial compressibility methodologies using the approximate factorization technique (1994)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 19 (1994), S. 1013-1038 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Laminar flow ; Turbulent flow ; Pseudocompressibility method ; Pressure correction method ; Projection method ; Artificial dissipation ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Predictions for two-dimensional, steady, incompressible flows under both laminar and turbulent conditions are presented. The standard k-∊ turbulence model is used for the turbulent flows. The computational method is based on the approximate factorization technique. The coupled approach is used to link the equations of motion and the turbulence model equations. Mass conservation is enforced by either the pseudocompressibility method or the pressure correction method. Comparison of the two methods shows a superiority of the pressure correction method. Second- and fourth-order artifical dissipation terms are used in order to achieve good convergence and to handle the turbulence model equations efficiently. Several internal and external test cases are investigated, including attached and separated flows.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650191105
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  • 19
    Electronic Resource
    Electronic Resource
    Entropy-controlled site occupation of CO adsorbed on Ni(100) (1993)
    Springer
    Applied physics 57 (1993), S. 499-505 
    Details
    ISSN: 1432-0630
    Keywords: 68.55 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The adsorption of CO on a Ni(100) surface has been studied by FT-IRAS in the temperature range from 85 K to 300 K. At 300 K and for Θ=0.5, the CO molecules are predominantly adsorbed in on-top sites with only a minor fraction located at two-fold bridge sites. Measurements on a Ni(100) surface pre-covered with sulphur, oxygen and carbon indicate that the occupation of bridge sites may be caused by small amounts of surface impurities. The relative broadness of the infrared bands is explained by CO molecules occupying intermediate positions at domain walls. Upon lowering the temperature, the bridge sites are increasingly occupied at the expense of terminal sites. This process is completely reversible and is explained by a contribution of the hindered translations of the adsorbed CO molecules to the entropy. At 85 K and for low initial coverages, we observe an unusual high CO stretching frequency at 2205 cm−1 which cannot be explained at present.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00331748
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  • 20
    Electronic Resource
    Electronic Resource
    Dark build-up of holograms in BaTiO3 after recording (1993)
    Springer
    Applied physics 57 (1993), S. 437-440 
    Details
    ISSN: 1432-0630
    Keywords: 78.20 ; 61.70 ; 72.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Holograms recorded under suitable conditions in photorefractive BaTiO3 exhibit an unusual dark build-up. The diffraction efficiency increases by some orders of magnitude after the recording beams are switched off, and then steadily decreases afterwards. An interpretation of this effect in terms of a two-center charge transport model is given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00331783
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  • 21
    Electronic Resource
    Electronic Resource
    Heat “superemission” and nucleation-front propagation under laser-induced crystallization of thin amorphous films (1993)
    Springer
    Applied physics 57 (1993), S. 561-566 
    Details
    ISSN: 1432-0630
    Keywords: 61.70 ; 68.35 ; 81.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The laser-induced solid-state explosive nucleation in amorphous media is studied analytically. The shapes of the temperature switching wave and that of the nucleation front as well as the formula for the front velocity are derived considering also self-consistent medium deformation. Two conditions of explosive nucleation reflecting the roles of latent heat emission and of deformation are formulated. It is shown that, in explosive nucleation, the rate of internal heat emission is proportional to the square of the latent crystallization heat (“superemission”) in analogy to photon superradiance in initially inverted two-level atomic systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00331759
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  • 22
    Electronic Resource
    Electronic Resource
    The role of excited species in UV-laser materials ablation (1993)
    Springer
    Applied physics 57 (1993), S. 367-374 
    Details
    ISSN: 1432-0630
    Keywords: 82.65 ; 82.50 ; 42.10
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract UV-laser ablation is described in terms of a two-level system in which the excitation energy is dissipated via stimulated emission, thermal relaxation, and activated desorption of excited species. For thermal relaxation times t T〉10−9 s and ΔE* ≪ ΔE (activation energies for excited-state and ground-state species) the model predicts high ablation rates at moderate surface temperatures, typically below 2000° C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00332291
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  • 23
    Electronic Resource
    Electronic Resource
    High-resolution electron microscopy of heterostructures and interfaces (1993)
    Springer
    Applied physics 57 (1993), S. 377-383 
    Details
    ISSN: 1432-0630
    Keywords: 07.80 ; 61.70 ; 81.10 ; 85.30
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract High-resolution transmission electron microscopy (HREM) allows to study a wide range of device-relevant topics in heteroepitaxial layer structures. Quantitative HREM may be used to obtain chemical information on a near-atomic scale from interfacial transition zones. The physical background is described and demonstrated on several examples in the Al x Gal1−x As/GaAs system. The HREM contrast of antiphase boundaries in InP grown on Si was studied by image simulations and has been compared to experimental images. Silicon carbide precipitates were identified by HREM at the homoepitaxial Si/Si interface. They stem from carbon contamination prior to Si layer growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00331775
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    Characterization of MOVPE-grown GaAs layers by C-V analysis (1993)
    Springer
    Applied physics 56 (1993), S. 69-72 
    Details
    ISSN: 1432-0630
    Keywords: 61.70 ; 73.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A computer simulation study of the capacitance of a surface space charge layer in undoped n-GaAs grown by metalorganic vapour phase epitaxy is presented. The effect of the deep donor level EL2 on the surface capacitance of epilayers with an ideal free surface is estimated. In order to approach the as-grown layer surface the model used is extended considering MIS and Schottky-barrier structures and their voltage-capacitance curves are analysed. The theoretical C-V dependences are compared with experimental C-V curves of a real structure including N+-GaAs substrate, undoped n-GaAs epitaxial layer containing EL2 levels and thin native oxide. Conditions are determined at which the EL2 levels as well as the native oxide film may influence the capacitance characteristics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00351905
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    The influence of surface reconstruction on the kinetics of adsorption-desorption processes: A Monte Carlo study of a simple model (1993)
    Springer
    Applied physics 56 (1993), S. 73-80 
    Details
    ISSN: 1432-0630
    Keywords: 68.35 ; 82.20 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The influence of surface reconstruction on the kinetics of adsorption-desorption processes is studied through a simple two-position model by means of Monte Carlo simulation. Effects due to constraints on the translational motion of activated complexes and to heterogeneity are particularly investigated. Heterogeneity emerges as the most important factor to explain the huge variation of the preexponential Arrhenius parameter with coverage observed in the H/W(001) system. In the present model it is conjectured that heterogeneity originates from additional interactions of H with surface or sub-surface W atoms when hydrogen is adsorbed on sites where surface W atoms are farther apart due to reconstruction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00351906
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    The role of excited species in UV-laser materials ablation (1993)
    Springer
    Applied physics 57 (1993), S. 449-455 
    Details
    ISSN: 1432-0630
    Keywords: 82.65 ; 82.50 ; 42.10
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The stability of a planar surface upon pulsed UV-laser irradiation is studied with special emphasis on polymer ablation. Here, we consider a two-level system in which the excitation energy is dissipated via stimulated emission, non-radiative transitions, and activated desorption of excited species. With thermal relaxation times t T≥10−10 s the ablation front turns out to become stable. This could explain the smooth surfaces obtained after pulsed UV-laser ablation of pure and stress free organic polymers. The situation is quite different for materials, for example metals, where fast thermal relaxation of the excitation energy within times, typically, t T〈10−11 s, gives rise to instabilities which result in surface roughening.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00331785
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    The formation of subsurface oxygen on Pt(100) (1993)
    Springer
    Applied physics 57 (1993), S. 507-511 
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    ISSN: 1432-0630
    Keywords: 68.35 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract PhotoEmission Electron Microscopy (PEEM) enables imaging a surface via its work function. If a CO covered Pt(100) surface is exposed to oxygen patches are formed which appear dark in the PEEM image due to their high work function. As the surface is heated to temperatures above 650 K we observe the conversion of these dark islands into very bright ones with work functions much lower than even that of the clean surface. These findings are attributed to a change in the dipole moment of the adsorbed oxygen induced by their migration beneath the surface. A total work-function decrease of up to 1.2 eV has been evaluated independently using a Scanning Photoemission Microscope (SPM). The properties of this new kind of oxygen were also further investigated with thermal desorption spectroscopy and with Auger-electron spectroscopy.
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    URL: http://dx.doi.org/10.1007/BF00331749
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    Deposition and characterization of diamond epitaxial thin films on silicon substrates (1993)
    Springer
    Applied physics 57 (1993), S. 483-489 
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    ISSN: 1432-0630
    Keywords: 68.55 ; 81.15 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Heteroepitaxial diamond growth has been attempted on mirror-polished monocrystalline (001), (111), and (110) silicon substrates by microwave plasma CVD. The surface morphology and the crystallographic properties of the films were characterized by means of Scanning Electron Microscopy (SEM), Raman spectroscopy, X-ray diffraction, and X-ray and Raman pole-figure analysis. The results demonstrate epitaxial growth of diamond on both (001) and (111) oriented silicon substrates. Preliminary results give strong evidence for substrate-induced orientation of the diamond crystallites also on (110) oriented silicon substrate. The heteroepitaxy can be assigned to the oriented covalent bonding across the interface between diamond and silicon.
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    URL: http://dx.doi.org/10.1007/BF00331746
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    On the magnetic after-effect (MAE) in magnetite at high temperatures (1993)
    Springer
    Applied physics 56 (1993), S. 323-327 
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    ISSN: 1432-0630
    Keywords: 61.70 ; 75.50
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Measurements of the magnetic after-effect in magnetite have been made in the temperature range 200 to 600 K. Important relaxation peaks have been observed in the temperature range 250 to 350 K (peak III) and 400 to 550 K (peak I). A study of both the dynamics and the parameters of the defects are consistent with an interpretation of peak III and peak I in magnetite as a combined after-effect due to octahedrally coordinated vacancies.
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    URL: http://dx.doi.org/10.1007/BF00324350
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    Comparison of laser-induced etching behavior of III–V compound semiconductors (1993)
    Springer
    Applied physics 56 (1993), S. 343-348 
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    ISSN: 1432-0630
    Keywords: 81.40 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Laser-induced maskless etching of III–V compound semiconductors (InSb, GaAs, and InP) in a KOH aqueous solution by irradiation with a focused argon-ion laser has been investigated to obtain high etching rates and aspect ratios of etched grooves. The etching rate at low laser power was found to depend on the carrier density of the sample and its type. With the increase of the laser power, the etching reaction becomes primarily a thermochemical reaction. High etching rates and aspect ratios have been achieved with a single scan of the laser beam. The damage induced by laser wet etching is less than that by laser dry etching, and the damage at the etched side wall is less than that at the etched bottom. Grooves with locally controlled depth and slab structures have been fabricated for application.
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    URL: http://dx.doi.org/10.1007/BF00324353
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    Ablation of polyimide (Kapton™) films by pulsed (ns) ultraviolet and infrared (9.17 μm) lasers (1993)
    Springer
    Applied physics 56 (1993), S. 417-423 
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    ISSN: 1432-0630
    Keywords: 42.60 ; 82.65 ; 73.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Ablation of the surface of a polyimide (Kapton™) film by single pulses of 248 nm or 308 nm radiation (∼20 ns) or 9.17 μm laser radiation (∼170 ns) was studied by photographing the emergence of the blast wave and the plume by a pulse (〈1 ns; 596 nm) of visible laser light. The dynamics of the blast wave was similar in the ultraviolet and in the infrared but the composition of the plume was obviously different. A mass of opaque solid material was ejected for as long as 2.6 μs following the IR pulse in contrast to the minute amount of solids that are seen in the ablation by UV laser pulses of ns duration. UV laser pulses of 50–400 μs duration interact with polyimide surfaces in a manner that is similar to IR laser pulses of ns duration or longer. Chemical analysis of the ablation products that are obtained under various conditions of ablation when compared to the known modes of thermal degradation of polyimide show that the reaction is a thermal process when IR laser pulses or UV laser pulses of long (〉10 μs) duration are employed. Ablation by ns UV laser pulses differs fundamentally in the chemistry of the products from all of the cases mentioned above.
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    URL: http://dx.doi.org/10.1007/BF00332574
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    Raman spectroscopy of macroscopic defects of GaAs grown by molecular beam epitaxy (1993)
    Springer
    Applied physics 56 (1993), S. 571-574 
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    ISSN: 1432-0630
    Keywords: 78.30 ; 68.55 ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Macroscopic defects of the GaAs surface grown by molecular beam epitaxy (MBE) have been investigated by using a micro-probing method of Raman spectroscopy. Especially, the oval defects, the most common macroscopic defects in MBE GaAs, were focused in this study. In Raman spectroscopy for the oval defect on the (100)GaAs surface, TO phonon mode of the 269 cm−1 peak was observed. This indicates that the oval defects can include the (111) growth direction or the amorphized surface. The TO/LO intensity ratios for the defects are in the range from 0.3 to 1.0. In the sample grown under the condition that the substrate temperature is 580° C with the As/Ga ratio of 20, the density of the oval defects is about 200 cm−2 at a growth thickness of 5 μm. With increasing thickness of the epilayer, the density and the size of the α-tye oval defect increased, while the TO/LO ratio decreased. From the spatial measurement by Raman spectroscopy for the α-type oval defect, it is supposed that the α-type oval defect remains in a rather good crystalline state and its orientation along the (100) growth direction is much closer to the (111) direction, but the growth direction of the defect might tend toward the (100) direction with a thicker layer.
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    URL: http://dx.doi.org/10.1007/BF00331407
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    Approximate nonreflecting inflow-outflow boundary conditions for the calculation of navier-stokes equations in internal flows (1993)
    Springer
    Acta mechanica Sinica 9 (1993), S. 289-297 
    Details
    ISSN: 1614-3116
    Keywords: nonreflecting boundary conditions ; Navier-Stokes equations ; internal flows
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract In this paper, the nonreflecting boundary conditions based upon fundamental ideas of the linear analysis are developed for gas dynamic equations, and the modified boundary conditions for Navier-Stokes equations are proposed as a substitute of the nonreflecting boundary conditions inside boundary layers near rigid walls. These derived boundary conditions are then applied to calculations both for the Euler equations and the Navier-Stokes equations to determine if they can produce acceptable results for the subsonic flows in channels. The numerical results obtained by an implicit second-order upwind difference scheme show the effectiveness and generality of the boundary conditions. Furthermore, the formulae and the analysis performed here may be extended to three dimensional problems.
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    URL: http://dx.doi.org/10.1007/BF02486857
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    Navier-Stokes computations past a prolate spheroid at incidence. II: High incidence case (1993)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 16 (1993), S. 1-27 
    Details
    ISSN: 0271-2091
    Keywords: Finite volume ; Navier-Stokes equations ; Collocative methods ; Prolate spheroid ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The computation of incompressible three-dimensional viscous flow is investigated. An iterative fully decoupled technique based on the fully elliptic mode is applied to the Reynolds-averaged-Navier-Stokes equations (RANSE) written down in a non-orthogonal curvilinear body-fitted co-ordinate system. Results of the computations are compared with experimental data past a prolate spheroid at 30° incidence.
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    URL: http://dx.doi.org/10.1002/fld.1650160102
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    A remark on the projection-3 method (1993)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 16 (1993), S. 249-253 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Projection method ; Time discretization ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: We show that the continuous (in time) form of the projection-3 scheme proposed in Reference 2 is not a proper approximation of the unsteady Navier-Stokes equations. Hence, the projection-3 scheme and its variants are not appropriate for the numerical computation of the Navier-Stokes equations.
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    URL: http://dx.doi.org/10.1002/fld.1650160308
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    Solution of the discretized incompressible Navier-Stokes equations with the GMRES method (1993)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 16 (1993), S. 507-523 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Incompressible boundary-fitted co-ordinates ; Non-symmetric linear systems ; Iterative solver ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: We describe some experiences using interative solution methods of GMRES type to solve the discretized Navier-Stokes equations. The discretization combined with a pressure correction scheme leads to two different systems of equations: the momentum equations and the pressure equation. It appears that a fast solution method for the pressure equation is obtained by applying the recently proposed GMRESR method, or GMRES combined with a MILU preconditioner. The diagonally scaled momentum equations are solved by GMRES(m), a restarted version of GMRES.
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    URL: http://dx.doi.org/10.1002/fld.1650160605
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    Incompressible low-speed-ratio flow in non-uniform distensible tubesThis research project is supported by the Dutch Foundation for Scientific Research NWO. (1993)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 16 (1993), S. 597-612 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Finite element method ; Distensible tubes ; Wave propagation ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The fluid flow in distensible tubes is analysed by a finite element method based on an uncoupled solution of the equations of wall motion and fluid flow. Special attention is paid to the choice of proper boundary conditions. Computations were made for sinusoidal flow in a distensible uniform tube with the Womersley parameter α = 5, and a ratio between tube radius and wavelenth from 0·0001 to 0·5. The agreement between the numerical results and Womersley's analytic solution depends on the speed ratio between fluid and wave velocity, and is fair for speed ratios up to 0·05. The analysis of the flow field in a distensible tube with a local inhomogeneity revealed a marked influence of wave phenomena and wall motion on the velocity profiles.
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    URL: http://dx.doi.org/10.1002/fld.1650160704
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    A least-squares finite element method for time-dependent incompressible flows with thermal convection (1993)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 17 (1993), S. 271-289 
    Details
    ISSN: 0271-2091
    Keywords: Least-squares finite element method ; Time-dependent ; Incompressible flows ; Bqussinesq approximation ; Navier-Stokes equations ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The time-dependent Navier-Stokes equations and the energy balance equation for an incompressible, constant property fluid in the Boussinesq approximation are solved by a least-squares finite element method based on a velocity-pressure-vorticity-temperature-heat-flux (u-P-ω-T-q) formulation discretized by backward finite differencing in time. The discretization scheme leads to the minimization of the residual in the l2-norm for each time step. Isoparametric bilinear quadrilateral elements and reduced integration are employed. Three examples, thermally driven cavity flow at Rayleigh numbers up to 106, lid-driven cavity flow at Reynolds numbers up to 104 and flow over a square obstacle at Reynolds number 200, are presented to validate the method.
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    URL: http://dx.doi.org/10.1002/fld.1650170402
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    Multigrid solution of the Navier-Stokes equations on highly stretched grids (1993)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 17 (1993), S. 543-566 
    Details
    ISSN: 0271-2091
    Keywords: Multigrid method ; Navier-Stokes equations ; Incomressible flow ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Relaxation-based multigrid solvers for the steady incompressible Navier-Stokes equations are examined to determine their computational speed and robustness. Four relaxation methods were used as smoothers in a common tailored multigrid procedure. The resulting solvers were applied to three two-dimensional flow problems, over a range of Reynolds numbers, on both uniform and highly stretched grids. In all cases the L2 norm of the velocity changes is reduced to 10-6 in a few 10's of fine-grid sweeps. The results of the study are used to draw conciusions on the strengths and weaknesses of the individual relaxation methods as well as those of the overall multigrid procedure when used as a solver on highly stretched grids.
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    An explicit transient algorithm for predicting incompressible viscous flows in Arbitrary Geometry (1993)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 17 (1993), S. 975-993 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Mass and momentum balance ; Non-orthogonal control volume ; Gauss-Legendre quadrature ; Pressure correction ; Flow over bluff bodies ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A numerical method for predicting viscous flows in complex geometries has been presented. Integral mass and momentum conservation equations are deploved and these are discretized into algebraic form through numerical quadrature. The physical domain is divided into a number of non-orthogonal control volumes which are isoparametrically mapped on to standard rectangular cells. Numerical integration for unsteady mementum equations is performed over such non-orthogonal cells. The explicitly advanced velocity components obtained from unsteady momentum equations may not necessarily satisfy the mass conservation condition in each cell. Compliance of the mass conservation equation and the consequent evolution of correct pressure distribution are accomplished through an iterative correction of pressure and velocity till divergence-free condition is obtained in each cell. The algorithm is applied on a few test problems, namely, lid-driven square and oblique cavities, developing flow in a rectangular channel and flow over square and circular cylinders placed in rectangular channels. The results exhibit good accuracy and justify the applicability of the algorithm.This Explicit Transient Algorithm for Flows in Arbitrary Geometry is given a generic name EXTRAFLAG.
    Additional Material: 15 Ill.
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    URL: http://dx.doi.org/10.1002/fld.1650171105
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    A problem of heat and mass transfer: Proof of the existence condition by a finite difference method (1993)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 16 (1993), S. 87-104 
    Details
    ISSN: 0271-2091
    Keywords: Heat and mass transfer ; Laminar flow ; Coupled boundary conditions ; Navier-Stokes equations ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: We solve by a finite difference method a system of simultaneous non-linear partial differential equations which modelizes the transfer of heat and mass when a fluid evaporates from the hot wall and condenses on the cold wall of an upright rectangular cavity. The need to verify a certain condition associating the physical parameters of the fluid for the existence of steady state solutions is proved.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/fld.1650160202
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    A finite element solution of the time-dependent incompressible Navier-Stokes equations using a modified velocity correction method (1993)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 17 (1993), S. 349-364 
    Details
    ISSN: 0271-2091
    Keywords: Finite elements ; Velocity correction method ; Flow past a cylinder ; Navier-Stokes equations ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A finite element solution of the two-dimensional incompressible Navier-Stokes equations has been developed. The present method is a modified velocity correction approach. First an intermediate velocity is calculated, and then this is corrected by the pressure gradient which is the solution of a Poisson equation derived from the continuity equation. The novelty, in this paper, is that a second-order Runge-Kutta method for time integration has been used. Discretization in space is carried out by the Galerkin weighted residual method. The solution is in terms of primitive variables, which are approximated by polynomial basis functions defined on three-noded, isoparametric triangular elements. To demonstrate the present method, two examples are provided. Results from the first example, the driven cavity flow problem, are compared with previous works. Results from the second example, uniform flow past a cylinder, are compared with experimental data.
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    TEM analysis of the influence of dose on damage behavior in MeV Au2+-implanted silicon (1992)
    Springer
    Applied physics 54 (1992), S. 124-131 
    Details
    ISSN: 1432-0630
    Keywords: 81.40 ; 61.70 ; 61.80
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Extended lattice damage created by implantation of 3.6 MeV Au2+ ions has been investigated using transmission electron microscopy (TEM) and Rutherford backscattering spectrometry (RBS). Systematic observations of damage for Au2+ ions implanted with varying doses into silicon are explained in terms of a model. The origin of two distinct bands of extended defects is explained in terms of annealing of the central region of implant-damage, during the course of the implantation. Two distinct bands of Au precipitates are observed in high-dose implanted samples. This observation is explained as being the result, in part, of segregation of gold in front of a recrystallizing front, and in part, of gettering of dopant-atoms to nodes in a dislocation network. The network arises as a result of dynamic annealing of damaged crystalline silicon.
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    URL: http://dx.doi.org/10.1007/BF00323898
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    High-temperature thermal evolution of SiAs precipitates in silicon (1992)
    Springer
    Applied physics 54 (1992), S. 221-224 
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    ISSN: 1432-0630
    Keywords: 61.70 ; 64 ; 72.20
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The thermal evolution of monoclinic SiAs precipitates at 1050° C in silicon samples implanted with 1 and 1.5×1017 As/cm2 was followed by transmission electron microscopy (TEM) and secondary neutral mass spectrometry (SNMS). These experiments show, for the first time, the coexistence of two different states of As in silicon, i.e., the electrically active and the inactive mobile dopant, in equilibrium with monoclinic SiAs precipitates. Moreover, they provide, for the saturation concentration of As in silicon, which includes both these states, a value of 3×1021 cm−3 at 1050° C.
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    Trench formation in surfactant mediated epitaxial film growth of Ge on Si(100) (1992)
    Springer
    Applied physics 54 (1992), S. 265-269 
    Details
    ISSN: 1432-0630
    Keywords: 68.55 ; 61.16D ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract We have used STM to study the surface morphology of thin epitaxial Ge films grown on Si(001) in the presence of the “surfactant” As. The surfactant forces layer-by-layer growth up to 12 ML Ge coverage which could partly be explained by the geometrical surface arrangement of the growing film. Beyond 12 ML coverage we observed a network of trenches which decorate the earlier described V-shaped defects inside the film. Overgrowth of such defects is studied and a mechanism discussed.
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    URL: http://dx.doi.org/10.1007/BF00323848
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    Diffusion-induced decay of disclinations and solid state amorphization in mechanically alloyed materials (1992)
    Springer
    Applied physics 54 (1992), S. 517-519 
    Details
    ISSN: 1432-0630
    Keywords: 61.70 ; 62.20.Fe ; 64.70.−p
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A theoretical model is proposed which treats the diffusion-induced decay of fragment boundary disclinations as being a micromechanism for the solid state amorphization in mechanically alloyed materials. Within the framework of the suggested model the kinetics of amorphous-phase nucleation centres (spread cores of the decayed disclinations) is studied. In doing so, kinetic equations are suggested and solved, which describe the evolution of the radius of the amorphous core of the decayed disclination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324331
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    Laser-induced defect formation in semiconductors (1992)
    Springer
    Applied physics 55 (1992), S. 161-166 
    Details
    ISSN: 1432-0630
    Keywords: 61.70 ; 81.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The electron-deformation-thermal theory of pulsed laser-induced point defect generation in strongly absorbing semiconductors is developed. The theoretical results obtained are in a good agreement with the results of experiments carried out in Ge, GaAs, and GaP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00334217
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    Photokinetic etching of polyethylene terephthalate films by continuous wave ultraviolet laser radiation (1992)
    Springer
    Applied physics 55 (1992), S. 269-273 
    Details
    ISSN: 1432-0630
    Keywords: 42.60 ; 82.65 ; 73.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Continuous wave laser radiation from an argonion laser in the wavelength range 275–330 nm can be used to etch polyethylene terephthalate (PET) films with as little thermal damage as from a pulsed, ultraviolet laser (248 nm or 308 nm) provided the beam is focussed to a spot of 10–100 kW/cm2 of power density and is moved over the surface at speeds at which the transit time over its own diameter (which can be looked upon as a “pulse width”) is on the order of 10–200 μs. In contrast to results which had been obtained previously on the photokinetic etching of polyimide and doped polymethyl methacrylate films under similar conditions, the sensitivity of PET to etching is 〉5-fold greater than either of these polymers and increases steadily with increasing pulse width. There is lateral thermal damage as the pulse widths increase to 〉200 μs. The material that is removed is vaporized in part. More than 20% is probably ejected in a molten state and resolidifies at the edge of the cut. There is no acoustic report similar to that seen in ablative photodecomposition. The process appears to be largely thermal in nature.
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    URL: http://dx.doi.org/10.1007/BF00348396
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    Effects of post-desorption collisions on the energy distribution of SiCl molecules pulsed-laser desorbed from Cl-covered Si surfaces: Monte-Carlo simulations compared to experiments (1992)
    Springer
    Applied physics 55 (1992), S. 554-560 
    Details
    ISSN: 1432-0630
    Keywords: 02.50 ; 81.60.c ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Si surfaces covered with up to a monolayer of chlorine by exposure to a low chlorine pressure have been irradiated with nanosecond excimer-laser pulses at a fluence just large enough to melt the surface. Angle-resolved time-of-flight (TOF) distributions and surface temperatures have been measured as a function of chlorine dose between laser pulses. The TOF distributions can be fitted well by Maxwell-Boltzmann (MB) distributions for all coverages and at all desorption angles. With increasing coverage, the intensity and kinetic energy distributions become increasingly peaked along the surface normal. Monte-Carlo simulations of the effect of post-desorption collisions, occurring when many molecules are desorbed within a very short time, reproduce the experimental results quite well. It is shown that just a few collisions per molecule are sufficient to convert any initial desorption distribution into a MB one.
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    URL: http://dx.doi.org/10.1007/BF00331673
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  • 50
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    TEM characterization of yttrium silicide layers synthesized by ion implantation (1992)
    Springer
    Applied physics 54 (1992), S. 527-532 
    Details
    ISSN: 1432-0630
    Keywords: 61.10 ; 61.70 ; 68.55
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The structure of Si implanted with high doses of yttrium has been investigated by varying implantation doses and energies. As implantation doses increase into the low 1017 cm−2 range, silicide precipitates form. The precipitates are thin and long and lie parallel to {111} planes in the Si matrix. As dopant concentrations increase, the precipitates themselves become more equiaxed, aspect ratios decrease, and precipitates densities increase until the precipitates coalesce to form a continuous buried layer of yttrium silicide within the Si matrix. The layer thickness is relatively uneven. As implant doses increase to ∼ 4×1017 cm−2, the layer thicknesses become more uniform although there are still defects present. As the implant doses increase further, the precipitate bands on either side of the continuous layer decrease due to gettering of yttrium to the layer. As the energy of the implant is increased, the appearance of the sample is similar to that of the lower energy implants except that the layer is buried deeper in the Si matrix. Observations of the silicide are consistent with its having the AlB2 structure with ordered vacancies on the Si sublattice.
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    URL: http://dx.doi.org/10.1007/BF00324334
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    Direct writing of Ag-lines on Mn-Zn ferrite by laser-induced thermal decomposition by CH3COOAg (1992)
    Springer
    Applied physics 54 (1992), S. 51-56 
    Details
    ISSN: 1432-0630
    Keywords: 81.40 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Laser-induced direct writing of silver lines on a ferrite surface from a silver acetate (CH3COOAg) thin layer has been investigated. The deposition is a thermochemical process and the threshold temperature for thermal decomposition of CH3COOAg is about 380° C. About 100% of Ag in the deposited lines has been achieved. The width of the deposited Ag-lines increased with the increase in laser power, and it can be accurately estimated by the temperature profile induced by laser irradiation within the power region below the melting point of ferrite. A line thickness of micron order can be formed both on a ferrite surface and on a deposited SiO2 surface, whereas the line width decreased with the increase in beam dwell time due to the vaporization of both CH3COOAg precursor and deposited Ag material.
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    URL: http://dx.doi.org/10.1007/BF00348130
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    Application of generalized differential quadrature to solve two-dimensional incompressible Navier-Stokes equations (1992)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 15 (1992), S. 791-798 
    Details
    ISSN: 0271-2091
    Keywords: Generalized differential quadrature ; Incompressible flows ; Navier-Stokes equations ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A global method of generalized differential quadrature is applied to solve the two-dimensional incompressible Navier-Stokes equations in the vorticity-stream-function formulation. Numerical results for the flow past a circular cylinder were obtained using just a few grid points. A good agreement is found with the experimental data.
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    URL: http://dx.doi.org/10.1002/fld.1650150704
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    Navier-Stokes computations of horseshoe vortex flows (1992)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 15 (1992), S. 99-124 
    Details
    ISSN: 0271-2091
    Keywords: Wing-body junction ; Horseshoe vortex flow ; Numerical solution ; Navier-Stokes equations ; Viscous-inviscid interaction ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The computation of the incompressible three-dimensional turbulent viscous flow about an aerofoil/flat plate junction is investigated. An iterative, fully decoupled technique is applied to the Reynolds-averaged Navier-Stokes equations (RANSEs) written in a non-orthogonal curvilinear body-fitted co-ordinate system. The results of the computations are compared with well-documented experiments.
    Additional Material: 22 Ill.
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    URL: http://dx.doi.org/10.1002/fld.1650150108
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    Integral transform solution for the lid-driven cavity flow problem in streamfunction-only formulation (1992)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 15 (1992), S. 399-409 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Cavity flow ; Analytical solutions ; Integral transforms ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The basic ideas in the generalized integral transform technique are further advanced to allow for the hybrid numerical-analytical solution of the two-dimensional steady Navier-Stokes equations in streamfunction-only formulation. The classical lid-driven square cavity problem is selected for illustration of the approach. The corresponding biharmonic-type non-linear partial differential equation for the streamfunction is integral transformed in one of the co-ordinates and an infinite system of coupled non-linear ODEs for the transformed potential results in the other independent variable. Upon truncation to an appropriate finite order, the ODE system is numerically solved by well-established algorithms with automatic error control devices. The convergence behaviour of the eigenfunction expansion is demonstrated and reference results are provided for typical values of Reynolds number.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/fld.1650150403
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    Invariant discretization of the incompressible Navier-Stokes equations in boundary fitted co-ordinates (1992)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 15 (1992), S. 411-426 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Incompressible ; Boundary-fitted co-ordinates ; Boundary conditions ; Invariant discretization ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: The discretization of the incompressible Navier-Stokes equation on boundary-fitted curvilinear grids is considered. The discretization is based on a staggered grid arrangement and the Navier-;Stokes equations in tensor formulation including Christoffel symbols. It is shown that discretization accuracy is much enhanced by choosing the velocity variables in a special way. The time-dependent equations are solved by a pressure-correction method in combination with a GMRES method. Special attention is paid to the discretization of several types of boundary conditions. It is shown that fairly non-smooth grids may be used using our approach.
    Additional Material: 18 Ill.
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    URL: http://dx.doi.org/10.1002/fld.1650150404
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    Overlapping grids and multigrid methods for three-dimensional unsteady flow calculations in IC engines (1992)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 15 (1992), S. 693-714 
    Details
    ISSN: 0271-2091
    Keywords: Overlapping grids ; Multigrid method ; Navier-Stokes equations ; Finite volume method ; Moving boundaries ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A new computational methodology with emphasis on using an overlapping grid technique and a multigrid method has been developed. The main feature of the present overlapping-grid system is of extended flexibility to deal with three-dimensional complex multicomponent geometries. The multigrid method is incorporated into this technique to accelerate the convergence of the numerical solution. The current scheme has been applied for computations of the laminar flows in the multicomponent configuration of internal combusion engines. The flow is governed by three-dimensional, time-dependent, incompressible Navier-Stokes equations with the continuity equation. A time-independent grid system is constructed for the moving boundary, i.e. the moving piston in the engine. This grid system is entirely different from others for the same problem in previous works. The performance of the present method has been validated by comparing the results with those from an equivalent, single-grid method and those from experiments. In addition, the flexibility and potential of the method has been demonstrated by calculating several cases which would be very difficult to be handled by other schemes.
    Additional Material: 15 Ill.
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    URL: http://dx.doi.org/10.1002/fld.1650150605
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    Dislocations on Ag(111) (1991)
    Springer
    Applied physics 52 (1991), S. 218-221 
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    ISSN: 1432-0630
    Keywords: 61.70 ; 61.70Ph
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Various dislocations on Ag(111) were imaged with a scanning tunneling microscope, e.g. screw dislocations, Lomer-Cottrell locks and stacking fault tetrahedron. The distortion field near a screw dislocation was measured.
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    URL: http://dx.doi.org/10.1007/BF00324423
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    A study of sputter-induced defects in magnetron-sputtered CoSi2 and TiSi2 Schottky barriers on n- and p-type GaP (1991)
    Springer
    Applied physics 52 (1991), S. 60-64 
    Details
    ISSN: 1432-0630
    Keywords: 73.30 ; 61.70 ; 81.15C
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Magnetron-sputtered CoSi2 and TiSi2 Schottky barriers on n- and p-type GaP were investigated. Their hitherto unknown barrier heights were determined to be 0.98 eV (for CoSi2/n-GaP and CoSi2/p-GaP), 0.91 eV (for TiSi2/n-GaP), and 0.90 eV (for TiSi2/p-GaP). It was found that magnetron-sputtering induced a compensated layer near the surface, both for n- and p-type GaP, with a thickness of about 0.05 μm. As the dependence of the shift of the Mott-Schottky intercept with the V-axis on the substrate dopant concentration obeyed some specific law, we proposed that the defects are neutral complexes of dopant ions and sputter-induced native defects. These native defects were assumed to depend on the Fermi level position, namely the PGa antisite and the VP vacancy for p-GaP and the VGa vacancy for n-GaP. The conversion between these defects occurs by nearest neighbour hopping of a phosphorus atom. The Schottky barrier heights obtained on p-GaP could be explained by Fermi level pinning at the surface due to the PGa defects. This could not be confirmed by n-GaP as the energy level position of the VGa was not available. The defects could be annealed out between 200° C and 300° C and the associated change of the Schottky barrier height corroborated the proposed model.
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    Laser-stimulated desorption of potassium atoms (1991)
    Springer
    Applied physics 52 (1991), S. 445-447 
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    ISSN: 1432-0630
    Keywords: 82.65 ; 36.40 ; 73.20
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Desorption of K atoms by laser-excitation of surface plasmons in small K particles is reported. The desorption rate has been measured for different laser wavelengths and particle sizes. Time-of-flight measurements reveal a kinetic energy of the desorbed atoms of Ekin=0.13(3) eV. From the experimental data it is concluded that the desorption mechanism is non-thermal in nature. Comparison of the results reported here with our earlier work on Na desorption is made.
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    Large area excimer laser induced deposition of titanium from titanium tetrachloride (1991)
    Springer
    Applied physics 53 (1991), S. 339-342 
    Details
    ISSN: 1432-0630
    Keywords: 68.55.G ; 82.50.-m ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Large area excimer laser induced deposition of titanium on fused silica from TiCl4 is studied with an emphasis on process modeling. We show that several TiCl4 monolayers can be adsorbed if the surface is adequately prepared and that the Ti thin film growth occurs through the photodecomposition of this adsorbed TiCl4 layer. We propose two growth regimes. During an initiation phase, up to 3 nm in thickness, the adsorbed layer is photochemically decomposed giving a growth rate of ∼ 0.015 nm/pulse. In a second phase, the deposition rate increases to between 2 and 7 nm/pulse due to the laser heating of the preceding photochemically deposited titanium film. Between consecutive pulses, TiCl4 molecules primarily from the adsorbed layer diffuse to the reaction zone leading to a new adsorbed layer ready to be transformed to solid titanium.
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    URL: http://dx.doi.org/10.1007/BF00357198
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    Properties of silicon-electrolyte junctions and their application to silicon characterization (1991)
    Springer
    Applied physics 53 (1991), S. 8-19 
    Details
    ISSN: 1432-0630
    Keywords: 82.45 ; 61.70 ; 68.45
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A number of interesting and still not fully understood phenomena occur if silicon is used as an electrode in an electrochemical cell. Effects include porous silicon layer (PSL) formation with features on a nanometer scale, surface roughening on a micrometer scale, quantum efficiencies for light generated currents much larger than 1, preferential etching of defects, electropolishing, and voltage or current oscillations. It is shown that despite the complexities of chemical reactions involved, a basic understanding of the electrode behavior is possible from a semiconductor physics point of view and that it can be advantageous to use the silicon — electrolyte junction for analytical purposes. Topics such as defect characterization, measurements of minority carrier diffusion length, or surface recombination velocities can be addressed in unique ways by taking advantage of particular properties of the silicon — hydrofluoric acid system. Based on the general description of the Si — electrolyte junction given in this paper, strengths and limitations of some electrochemical methods are discussed in some detail and illustrated by examples.
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    Angular distributions of sputtered atoms for low-energy nitrogen irradiation of silicon (1991)
    Springer
    Applied physics 53 (1991), S. 179-184 
    Details
    ISSN: 1432-0630
    Keywords: 81.15.C ; 79.20.N ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract We studied the angular distributions of silicon and nitrogen atoms emitted from a Si target subjected to reactive sputtering by N 2 + ions at primary energies of 0.5 and 2keV. The composition of the deposited material does not depend strongly on the substrate position. From a comparison with nonreactive sputtering, we show that the observed shift of the Si angular distribution is mainly due to the contribution of collision events occurring in the first monolayer. Contrary to the case of noble gas ions, the sharpness of the Si distribution depends on the N 2 + energy. The behavior of the differential sputtering yield of silicon indicates that this effect is likely to be due to a loss of recoil atoms out of the preferential direction. A possible explanation of the observed phenomena consists in assuming an anisotropic emission of Si x N y radicals. This hypothesis is very attractive as it could satisfactorily explain the similarity we observed between the angular distributions of silicon and nitrogen.
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    Electrical activity of dislocations: Prospects for practical utilization (1991)
    Springer
    Applied physics 53 (1991), S. 189-193 
    Details
    ISSN: 1432-0630
    Keywords: 61.70 ; 81.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The electrical activity of interfacial misfit dislocations in silicon has been examined using the electron beam induced current technique (EBIC) in a scanning electron microscope. “Clean” misfit dislocations, i.e. no EBIC contrast, formed during high-temperature Si(Ge) chemical vapor epitaxy were studied. These defects were subsequently decorated with known metallic impurities (Au and Ni) by diffusion at 400° C to 1130° C from a back-side evaporated layer. Qualitative analysis of the electrical activity in relation to the energy levels anticipated for the clean or decorated dislocations is presented. Of particular interest is the case of defect-induced conductivity type inversion which occurred both at the top surface and at the buried dislocated interfaces of the multilayer. The prospects for using dislocations in a beneficial manner as active elements in electronic devices are discussed.
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    Ion scattering spectroscopy and scanning tunneling microscopy: A powerful combination for surface structure analysis (1991)
    Springer
    Applied physics 53 (1991), S. 388-402 
    Details
    ISSN: 1432-0630
    Keywords: 68.35 ; 61.16 ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Low-energy ion backscattering and scanning tunneling microscopy (STM) have been used in combination to get better insight into the field of surface crystallography. The synergic effectiveness resulting from the complementing character of the two methods has been exemplified at clean NiAl(111) and for oxygen and nitrogen adsorption on Cu(110). The position of the atom cores is accessible by the low-energy noble gas impact collision ion scattering spectroscopy with neutral detection (NICISS). As a technique averaging over a macroscopic area of the sample, NICISS is better suited to supply information on features of completely developed phases, either on clean or adsorbate saturated surfaces. Additional information, on the other hand, can be gained by scanning tunneling microscopy (STM), which as a powerful local probe may be used to image surfaces with atomic resolution and to monitor defects, steps and the growth kinetics of e.g. adsorption-induced phase changes.
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    Photoconductivity and light-induced absorption in KNbO3:Fe (1991)
    Springer
    Applied physics 53 (1991), S. 81-86 
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    ISSN: 1432-0630
    Keywords: 61.70 ; 72.40 ; 78.20
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Measurements of photoconductivity and light-induced absorption in KNbO3: Fe are performed at different light intensities and crystal temperatures. The results are interpreted in terms of a two-center charge transport model. Different model parameters may be evaluated from the experimental data. A complete set of parameters is suggested explaining the dependences of photoconductivity and light-induced absorption on light intensity and temperature for the KNbO3: Fe crystal investigated.
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    URL: http://dx.doi.org/10.1007/BF00323439
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    Melting and solidification in laser-irradiated HgCdTe (1991)
    Springer
    Applied physics 53 (1991), S. 332-338 
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    ISSN: 1432-0630
    Keywords: 42.55P ; 81.40Z ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The results of the numerical analysis of the effects induced by pulsed Nd:YAG and ruby laser on Hg0.8Cd0.2Te are presented. The proposed model facilitates the planning of HgCdTe laser processing and the choice of the processing parameters such as: melt depth, melt duration of the surface layer and melt front velocity, as well as the irradiation parameters. The influence of the optical parameters and the temperature dependence of the HgCdTe thermal parameters on the results of laser irradiation are specially analyzed.
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    A new method for obtaining the exact solutions of the Navier-Stokes (NS) equations and its applications (1991)
    Springer
    Acta mechanica Sinica 7 (1991), S. 31-38 
    Details
    ISSN: 1614-3116
    Keywords: viscous flow ; Navier-Stokes equations ; simplified Navier-Stokes equations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract In this paper we propose a new method for obtaining the exact solutions of the Mavier-Stokes (NS) equations for incompressible viscous fluid in the light of the theory of simplified Navier-Stokes (SNS) equations developed by the first author[1,2], Using the present method we can find some new exact solutions as well as the well-known exact solutions of the NS equations. In illustration of its applications, we give a variety of exact solutions of incompressible viscous fluid flows for which NS equations of fluid motion are written in Cartesian coordinates, or in cylindrical polar coordinates, or in spherical coordinates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02486593
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    An upwind finite element scheme for high-Reynolds-number flows (1991)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 12 (1991), S. 305-322 
    Details
    ISSN: 0271-2091
    Keywords: Upwind finite element method ; Navier-Stokes equations ; Upwind and downwind points ; High-Reynolds-number flows ; Influence of rounding errors ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A new upwind finite element scheme for the incompressible Navier-Stokes equations at high Reynolds number is presented. The idea of the upwind technique is based on the choice of upwind and downwind points. This scheme can approximate the convection term to third-order accuracy when these points are located at suitable positions. From the practical viewpoint of computation, the algorithm of the pressure Poisson equation procedure is adopted in the framework of the finite element method. Numerical results of flow problems in a cavity and past a circular cylinder show excellent dependence of the solutions on the Reynolds number. The influence of rounding errors causing Karman vortex shedding is also discussed in the latter problem.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650120402
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    Variational formulation of three-dimensional viscous free-surface flows: Natural imposition of surface tension boundary conditions (1991)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 13 (1991), S. 691-698 
    Details
    ISSN: 0271-2091
    Keywords: Curvature ; Finite element method ; Free surface flow ; Navier-Stokes equations ; Spectral element method ; Surface tension ; Three-dimensional ; Variational form ; Viscous incompressible flow ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: We present a new surface-intrinsic linear form for the treatment of normal and tangential surface tension boundary conditions in C0-geometry variational discretizations of viscous incompressible free-surface flows in three space dimensions. The new approach is illustrated by a finite (spectral) element unsteady Navier-Stokes analysis of the stability of a falling liquid film.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650130603
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    Spectroscopic investigation of oxygen vacancies in solid oxide electrolytes (1990)
    Springer
    Applied physics 50 (1990), S. 545-549 
    Details
    ISSN: 1432-0630
    Keywords: 61.70 ; 66.30
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The primary species in both solid-state conduction and heterogeneous electrocatalysis of solid oxide electrolytes is the anion vacancy. The nature and effect of the local environment on anion vacancies in 10 m/o yttria stabilized zirconia (YSZ) and 20 m/o erbia stabilized bismuth oxide (ESB) was studied using uv-visible absorption and fluorescence spectroscopy. Partial reduction of YSZ and ordering of the oxygen sublattice in ESB is discussed. The species common to both of these phenomena, anion vacancies, was found to be luminescent and the absorption and fluorescence spectra attributable to F-center type defects is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00323446
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    On the reaction kinetics in laser-induced pyrolytic chemical processing (1990)
    Springer
    Applied physics 50 (1990), S. 385-396 
    Details
    ISSN: 1432-0630
    Keywords: 42.5 ; 68 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Reaction rates, particle densities, and temperature distribution in pyrolytic (photothermal) laser-induced microchemical processing are investigated with respect to temperature and concentration-dependent transport coefficients, and with respect to the effect of thermal diffusion. While the model employed is particularly suitable for laser-induced chemical vapor deposition (LCVD), it can also be applied to many cases of laser-induced surface modification and dry-etching.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00323596
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    The electrical properties of zinc in silicon (1990)
    Springer
    Applied physics 50 (1990), S. 151-156 
    Details
    ISSN: 1432-0630
    Keywords: 61.70 ; 17.55
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Electrically active deep levels related to zinc in silicon are investigated in n- and p-type silicon using Deep-Level Transient Fourier Spectroscopy (DLTFS) measurements. While in n-type silicon a level at E C−0.49 eV is observed, the main zinc-related levels in p-type silicon are determined to be E V+0.27 eV and E V+0.60 eV. The latter are associated with zinc situated on regular silicon lattice sites. The emission rate of these centers exhibits a field dependence which cannot be quantitatively explained with the Poole-Frenkel model. On the other hand, a shallow level at E V+0.09 eV is observed only in boron-doped silicon which may be related to a zinc-boron complex. Other zinc-related levels are found at E V+0.23 eV and E V+0.33 eV, their concentration depending on that of zinc on substitutional sites. In addition, the evaluation of depth profiles and the analysis of the field dependence of the emission rate based on the DLTFS method is presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00343410
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    Residual non-idealities in the almost ideal silicon p-n junction (1990)
    Springer
    Applied physics 50 (1990), S. 273-286 
    Details
    ISSN: 1432-0630
    Keywords: 85.30 ; 72.20 ; 73.40 ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The reproducible, mass production of almost ideal silicon p-n junctions has allowed two new phenomena to be discovered: a pure generation without recombination, and a slow capacitance-free current transient. Our present knowledge of these phenomena is reviewed and speculations about the centres responsible for them are discussed; these centres seem to be connected to ultimate, unavoidable properties of the silicon p-n junction rather than to unwanted impurities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324494
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    Metal particles on surfaces-desorption, optical spectra, and laser-induced size manipulation (1990)
    Springer
    Applied physics 51 (1990), S. 271-280 
    Details
    ISSN: 1432-0630
    Keywords: 36.40 ; 79.20 ; 82.65 ; 68.45
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Desorption induced by electronic excitation with laser light is discussed. Emphasis is placed on nonthermal desorption where surface plasma excitation in small particles precedes the rupture of the surface chemical bond. A scenario for the mechanism underlying such a process is proposed. In this context, calculations of the electronic spectra of small sodium particles are presented and the influence of different multipole orders of the collective electron oscillation, of different shapes of the clusters and of the substrate are outlined. Furthermore, manipulation of the size distribution of metal particles on supports is described as an application of the effect. This allows the preparation of very special surfaces with novel physical and chemical properties. Methods to characterize such adsorbate-substrate combinations, especially by use of the optical spectra of the particles, are also discussed. Finally, prospects for future experiments in this field are outlined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324307
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    On the interpretation of the RHEED intensity oscillations during the growth of vicinal faces (1990)
    Springer
    Applied physics 50 (1990), S. 349-352 
    Details
    ISSN: 1432-0630
    Keywords: 68.55 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A quantitative treatment of the crystallization kinetics in MBE growth of vicinal surfaces results the relation l 2=2D sτK between the surface diffusion coefficient D s, the time τ for a monolayer deposition and the interstep distance l at which the RHEED intensity oscillations disappear. The correction factor K depends on the size and the energy of the two-dimensional critical nucleus and it is estimated to be smaller than 10−2. The currently used interpretation of the RHEED intensity oscillations ignores the correction factor K and, therefore, the calculated values of D s are several orders of magnitude smaller than its real values. The surface transport during the time of growth interruption is discussed in connection with the tendency to three dimensional growth at every second interface (where a deposition of the material with strong intermolecular bonds starts) of a small period superlattice.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324505
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    Conductivity and light-induced absorption in BaTiO3 (1990)
    Springer
    Applied physics 51 (1990), S. 13-17 
    Details
    ISSN: 1432-0630
    Keywords: 61.70 ; 72.40 ; 78.20
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A charge transport model including deep and shallow traps explains both the nonlinear relation between photoconductivity and light intensity and the light-induced absorption in BaTiO3. A correlation between measurements of photoconductivity and light-induced absorption as a function of temperature yields parameters for the shallow center, among them thermal activation energy and generation rate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324459
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    Models for thermal dissociation of silane on a polysilicon surface (1990)
    Springer
    Applied physics 50 (1990), S. 215-220 
    Details
    ISSN: 1432-0630
    Keywords: 68.55 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Simple models for the thermally activated dissociation reaction of silane and silicon growth on a polycrystalline silicon surface are presented. The models are fitted to recent experimental molecular beam scattering data for the low-pressure reactive sticking coefficient. Thermally activated few-step models fit the data reasonably well, and thus, we are able to explain the temperature and pressure dependencies of the observed deposition rate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00343420
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    Light scattering topography and photoluminescence topography (1990)
    Springer
    Applied physics 50 (1990), S. 531-540 
    Details
    ISSN: 1432-0630
    Keywords: 61.70 ; 78.55 ; 78.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Two attractive methods for materials characterization are applied and discussed: (a) light scattering topography for fast and nondestructive testing of structural perfection, and (b) photoluminescence topography for evaluating the light emission characteristics of photoluminescent materials. Among the examples presented are semiconductor substrates and films of silicon, silicon-on-insulators of different kind, and III–V materials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00323444
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    On the kinetics of non-equimolecular reactions in laser chemical processing (1990)
    Springer
    Applied physics 51 (1990), S. 498-507 
    Details
    ISSN: 1432-0630
    Keywords: 42.5 ; 68 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The influence of counterdiffusion on the reaction rate in non-equimolecular laser-induced gas-phase processing is investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324733
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    The determination of dislocation density depth profiles in surface layers from broadening of X-ray diffraction profiles (1990)
    Springer
    Applied physics 50 (1990), S. 107-109 
    Details
    ISSN: 1432-0630
    Keywords: 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A method is proposed for the determination of dislocation density depth profiles in the thin surface layers comparable to the penetration depth of X-rays, with no need to remove the surface layers by chemical or electrolytic polishing. The dislocation density depth profile is modelled mathematically and the parameters determining the profile can be evaluated from the Fourier transform of the X-ray diffracted profiles with various wavelengths of radiation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00323960
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    Laser-assisted reaction of metals with oxygen (1990)
    Springer
    Applied physics 50 (1990), S. 131-139 
    Details
    ISSN: 1432-0630
    Keywords: 81.60 ; 82.65 ; 42.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The present status of experimental and theoretical work on continuous wave laser-assisted reaction of metals with oxygen is presented. Differences between this and normal isothermal oxidation of metals are emphasized. Available theoretical models are discussed. They deal with roles of thermal history, feedback effects between optical absorption and reaction rate. The nature of so-called “non-purely thermal” effects is discussed. Hints for further research are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00343408
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    Influence of electric field on heterogeneous reactions stimulated by laser light (1990)
    Springer
    Applied physics 50 (1990), S. 101-105 
    Details
    ISSN: 1432-0630
    Keywords: 81.60 ; 82.50 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract We present experimental data for vanadium and copper oxidation by cw CO2 laser light in an external electric field. Direct influence of the external field on the crystallisation process has been demonstrated in both vanadium and copper cases; the oxidation rate and surface morphology depend sensitively on the sign and strength of the external field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00323959
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    Gold diffusion in silicon by Rapid Optical Annealing (1990)
    Springer
    Applied physics 50 (1990), S. 197-205 
    Details
    ISSN: 1432-0630
    Keywords: 61.70 ; 66.30
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Gold diffusion in silicon is investigated using Rapid Optical Annealing at temperatures in the range of 800°C to 1200°C and annealing times from 300 s down to 1 s. The resulting content of substitutional gold is determined by spreading resistance measurements and analyzed by comparison with extensive numerical simulations. The profiles obtained show a broader spectrum as compared to the U-shapes after long time diffusion. The cooling process affects the profiles significantly, since they depend on the wafer thickness. An unexpected penetration depth was found after 1200°C diffusion in thick wafers, which are subject to small cooling rates. This phenomenon is due to a special combination of reverse kick-out, deep diffusion of highly supersaturated interstitial gold, and again an incorporation in lattice sites, termed the RDI effect. Numerical calculations allow us to reproduce the experimentally observed profiles only if a sensitive balance between the different temperature dependencies is obeyed. These investigations, therefore, yield new information about the equilibrium concentration and diffusion of silicon interstitials. A best set of parameters is presented. The time constant of the kick-out process is quantified for the first time.
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    URL: http://dx.doi.org/10.1007/BF00343418
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    Laser-induced trench etching of GaAs in aqueous KOH solution (1990)
    Springer
    Applied physics 51 (1990), S. 340-343 
    Details
    ISSN: 1432-0630
    Keywords: 81.40 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Maskless etching of n-type GaAs in a KOH aqueous solution by irradiation of an argonion laser has been investigated to obtain high etching rates and aspect-ratios of etched grooves. High etching rates of up to 805 μm/s and an aspect ratio of 8 have been achieved by a single scan of a laser beam. Microprobe photoluminescence (PL), Raman scattering, and Auger electron spectroscopy (AES) measurements were carried out on the trench surface to characterize damage induced by laser wet etching.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324316
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    Theory of scanning tunneling microscopy (1990)
    Springer
    Applied physics 51 (1990), S. 281-288 
    Details
    ISSN: 1432-0630
    Keywords: 68.35 ; 73.20 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The present theoretical understanding of imaging clean and adsorbate covered metal surfaces in scanning tunneling microscopy is examined with special emphasis on a possible theoretical foundation for the observed unexpectedly large corrugation on close-packed metal surfaces. Several suggestions for explaining these experimental findings are investigated. Resonance tunneling via tip d-orbitals might be a possible mechanism of amplifying small lateral structure of electronic or elastic origin. Two complementary theoretical methods are applied. The first one concentrates on a realistic description of the potential and wave functions of the sample surface whereas the second one attempts to model a more realistic transition metal tip. In the first approach the tip is represented by a Gaussian protrusion on an otherwise planar free-electron metal surface. The sample surface is built from muffin-tin potentials accounting for the atomic structure and the d-electrons. The spatial current distribution near the tip region is obtained by summing the contributions of all scattered waves. The method has been applied to study the current to Al(111) and Pd(100) surfaces. The corrugation obtained is rather small and cannot explain the experimental observations. The second approach studies two transition metal tips consisting of a single tungsten atom adsorbed on a flat W(110) surface and on a group of four other W atoms. The cluster of four W atoms is coupled to a flat W(110) surface by using an embedding method. The basis set on the W atoms includes 6s-, 6p-, and 5d-orbitals. The electronic structure of the tip exhibits a 5 d 2-resonance near the Fermi level. The effects of tip d-orbitals and resonance tunneling on the lateral contrast in STM are analyzed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324308
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    Boron doping of silicon by excimer laser irradiation in a reactive atmosphere (1990)
    Springer
    Applied physics 50 (1990), S. 479-484 
    Details
    ISSN: 1432-0630
    Keywords: 61.70T ; 79.20D ; 42.60K ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract UV excimer lasers have been used to dope semiconductors by a one-step process in which the laser serves both to melt a controlled thickness of a sample placed in dopant ambient and to photodissociate the dopant molecules themselves. Here we report the boron doping of silicon by means of an ArF (193 nm) excimer laser. Dopant atoms are obtained by photolysis of BCl3 or pyrolysis of BF3 molecules. The doping is performed both in gas ambient and using only an adsorbed layer. We have investigated the dependence of doping parameters such as laser pulse repetition and gas pressure on the subsequent boron impurity profiles and the dopant incorporation rate. These results indicate that the laser doping process is dopant-flux limited for BF3 and externally rate limited for BCl3.
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    Laser-induced etching of titanium by Br2 and CCl3Br at 248 nm (1990)
    Springer
    Applied physics 50 (1990), S. 609-615 
    Details
    ISSN: 1432-0630
    Keywords: 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract A quartz crystal microbalance (QCM) has been used to study the KrF* excimer laser-induced etching of titanium by bromine-containing compounds. The experiment consists of focusing the pulsed UV laser beam at normal incidence onto the surface of a quartz crystal coated with 1 μm of polycrystalline titanium. The removal of titanium from the surface is monitored in real time by measuring the change in the frequency of the quartz crystal. The dependence of the etch rate on etchant pressure and laser fluence was measured and found to be consistent with a two-step etching mechanism. The initial step in the etching of titanium is reaction between the etchant and the surface to form the etch product between laser pulses. The etch product is subsequently removed from the surface during the laser pulse via a laser-induced thermal desorption process. The maximum etch rate obtained in this work was 6.2 Å-pulse−1, indicating that between two and three atomic layers of Ti can be removed per laser pulse. The energy required for desorption of the etch product is calculated to be 172 kJ-mole−1, which is consistent with the sublimation enthalpy of TiBr2 (168 kJ-mole−1). The proposed product in the etching of titanium by Br2 and CCl3Br is thus TiBr2. In the etching of Ti by Br2, formation of TiBr2 proceeds predominantly through the dissociative chemisorption of Br2. In the case of etching with CCl3Br, TiBr2 is formed via chemisorption of Br atoms produced in the gas-phase photodissociation of CCl3Br.
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    URL: http://dx.doi.org/10.1007/BF00323455
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    Effect of laser light on n-GaAs photoetching (1990)
    Springer
    Applied physics 51 (1990), S. 61-63 
    Details
    ISSN: 1432-0630
    Keywords: 81.60 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The etching of n-GaAs in aqueous solutions of hydroxides stimulated by HeNe and HeCd laser light was studied. It was found that at low laser-power densities (5–10 W · cm−2) the etched depths do not depend on the wavelength of the incident light. This conclusion is related to the concentration of the photogenerated holes on the semiconductor surface. The diffusion length and absorption depths for HeNe and HeCd lasers are compared.
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    URL: http://dx.doi.org/10.1007/BF00324466
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    A positron lifetime study in quenched Pb(Ag) alloys (1990)
    Springer
    Applied physics 51 (1990), S. 141-145 
    Details
    ISSN: 1432-0630
    Keywords: 78.70 Bj ; 61.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Positron lifetime measurements have been made in quenched or irradiated pure Pb and in quenched Pb(Ag) alloys. From positron investigation of annealing behaviour, the precipitation of silver atoms in dilute alloys should be understood in terms of (Ag-Pb) interstitially migrating pairs. The presence of di-interstitials (Ag-Ag) or complexes [Ag(S)-V] as mobile defects responsible for the Ag transport process in concentrated alloys is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324278
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    A copper- and boron-related defect in silicon (1990)
    Springer
    Applied physics 50 (1990), S. 241-247 
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    ISSN: 1432-0630
    Keywords: 61.70 ; 78.30
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The resistivity of boron-doped silicon can be significantly increased by polishing such material with an appropriate amine- and copper-containing slurry. This effect is ascribed to a passivation of the boron acceptors by a defect produced or introduced by the polishing process. Three new, so far unknown localized vibrational modes at 691, 720, and 1038 cm−1 are observed in highly boron-doped silicon samples after such a polishing treatment. Two of these localized modes can be identified as due to a boron-containing defect. High concentrations of copper found in the samples after appropriate polishing indicate a participation — either directly or indirectly — of this metal in the passivation process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00324489
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    Spectral simulations of oscillatory convection at low Prandtl number (1990)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 10 (1990), S. 481-517 
    Details
    ISSN: 0271-2091
    Keywords: Spectral methods ; Chebyshev polynomials ; Navier-Stokes equations ; Time-dependent convection ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Pseudospectral methods are used for the computation of the time-dependent convective flows which arise in shallow cavities filled with low-Prandtí-number liquids when submitted to a horizontal temperature gradient. In similar situations several former numerical results have been shown to disagree about the determination of the threshold of oscillations and about the subsequent supercritical regimes. Two different tau-Chebyshev methods based on the vorticity-streamfunction formulation and using multistep time schemes are considered. Their results are discussed to assess the validity of the solutions. The physical problems concern rectangular cavities which involve either a rigid or a stress-free top wall and either conducting or insulating horizontal walls. Aside from the prediction of the onset of oscillations, which is discussed in the various situations with respect to the results of linear and non-linear analyses and to other computational results, the present study exhibits some bifurcation sequences and a hysteresis cycle at moderate Grashof numbers which are associated to the occurrence of multiple solutions.
    Additional Material: 24 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650100502
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  • 92
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    On the theory of semi-implicit projection methods for viscous incompressible flow and its implementation via a finite element method that also introduces a nearly consistent mass matrix. Part 1: Theory (1990)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 11 (1990), S. 587-620 
    Details
    ISSN: 0271-2091
    Keywords: Incompressible flow ; Navier-Stokes equations ; Projection methods ; Splitting methods ; Fractional step methods ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Ever since the time of Chorin's classic 1968 paper on projection methods, there have been lingering and poorly understood issues related to the best - or even proper or appropriate - boundary conditions (BCs) that should be (or could be) applied to the ‘intermediate’ velocity when the viscous terms in the incompressible Navier-Stokes equations are treated with an implicit time integration method and a Poisson equation is solved as part of a ‘time step’. These issues also pervade all related methods that uncouple the equations by ‘splitting’ the pressure computation from that of the velocity - at least in the presence of solid boundaries and (again) when implicit treatment of the viscous terms is employed. This paper is intended to clarify these issues by showing which intermediate BCs are ‘best’ and why some that are not work well anyway. In particular we show that all intermediate BCs must cause problems related to the regularity of the solution near boundaries, but that a near-miraculous recovery occurs such that accurate results are nevertheless achieved beyond the spurious boundary layer introduced by such methods. The mechanism for this ‘miracle’ is related to the existence of a higher-order equation that is actually satisfied by the pressure. All that is required then for projection (splitting, fractional step, etc.) methods to work well is that the spurious boundary layer be thin - as has been largely observed in practice.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650110509
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  • 93
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    Electronic Resource
    On the theory of semi-implicit projection methods for viscous incompressible flow and its implementation via a finite element method that also introduces a nearly consistent mass matrix. Part 2: Implementation (1990)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 11 (1990), S. 621-659 
    Details
    ISSN: 0271-2091
    Keywords: Incompressible flows ; Navier-Stokes equations ; Projection methods ; Consistent mass ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Ever since the expansion of the finite element method (FEM) into unsteady fluid mechanics, the ‘consistent mass matrix’ has been a relevant issue. Applied to the time-dependent incompressible Navier-Stokes equations, it virtually demands the use of implicit time integration methods in which full ‘velocity-pressure coupling’ is also inherent. The high cost of such (high-quality) FEM calculations led to the development of simpler but ad hoc methods in which the ‘lumped’ mass matrix is employed and the velocity and pressure are uncoupled to the maximum extent possible. Resulting computer codes were less expensive to use but suffered a significant loss of accuracy, caused by lumping the mass when the flow was advection-dominated and accurate transport of ‘information’ was important. In the second part of this paper we re-introduce the consistent mass matrix into some semi-implicit projection methods in such a way that the cost advantage of lumped mass and the accuracy advantage of consistent mass are simultaneously realized.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650110510
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  • 94
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    Fundamental solutions of the streamfunction-vorticity formulation of the Navier-Stokes equations (1990)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 10 (1990), S. 1-12 
    Details
    ISSN: 0271-2091
    Keywords: Fundamental solutions ; Navier-Stokes equations ; Regular boundary elements ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A new boundary element procedure is developed for the solution of the streamfunction-vorticity formulation of the Navier-Stokes equations in two dimensions. The differential equations are stated in their transient version and then discretized via finite differences with respect to time. In this discretization, the non-linear inertial terms are evaluated in a previous time step, thus making the scheme explicit with respect to them. In the resulting discretized equations, fundamental solutions that take into account the coupling between the equations are developed by treating the non-linear terms as in homogeneities. The resulting boundary integral equations are solved by the regular boundary element method, in which the singular points are placed outside the solution domain.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650100102
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  • 95
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    Electronic Resource
    Upwind discretization of the steady Navier-Stokes equations (1990)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 11 (1990), S. 99-117 
    Details
    ISSN: 0271-2091
    Keywords: Upwind schemes ; Navier-Stokes equations ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A discretization method is presented for the full, steady, compressible Navier-Stokes equations. The method makes use of quadrilateral finite volumes and consists of an upwind discretization of the convective part and a central discretization of the diffusive part. In the present paper the emphasis lies on the discretization of the convective part. The solution method applied solves the steady equations directly by means of a non-linear relaxation method accelerated by multigrid. The solution method requires the discretization to be continuously differentiable. For two upwind schemes which satisfy this requirement (Osher's and van Leer's scheme), results of a quantitative error analysis are presented. Osher's scheme appears to be increasingly more accurate than van Leer's scheme with increasing Reynolds number. A suitable higher-order accurate discretization of the convection terms is derived. On the basis of this higher-order scheme, to preserve monotonicity, a new limiter is constructed. Numerical results are presented for a subsonic flat plate flow and a supersonic flat plate flow with oblique shock wave-boundary layer interaction. The results obtained agree with the predictions made. Useful properties of the discretization method are that it allows an easy check of false diffusion and that it needs no tuning of parameters.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650110107
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  • 96
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    Numerical solution of the steady incompressible Navier - Stokes equations for the flow past a sphere by a multigrid defect correction technique (1990)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 11 (1990), S. 379-395 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Rigid sphere ; Finite difference schemes ; Accuracy ; Multigrid ; Defect corrections ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A nested non-linear multigrid algorithm is developed to solve the Navier-Stokes equations which describe the steady incompressible flow past a sphere. The vorticity-streamfunction formulation of the Navier-Stokes equations is chosen. The continuous operators are discretized by an upwind finite difference scheme. Several algorithms are tested as smoothing steps. The multigrid method itself provides only a first-order-accurate solution. To obtain at least second-order accuracy, a defect correction iteration is used as outer iteration. Results are reported for Re = 50, 100, 400 and 1000.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650110403
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  • 97
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    Electronic Resource
    A fractional-step Taylor-Galerkin method for unsteady incompressible flows (1990)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 11 (1990), S. 501-513 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Time-dependent advection-dominated flows ; Taylor-Galerkin method ; Finite elements ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: This paper describes the application of the Taylor-Galerkin method to the calculation of incompressible viscous flows. A finite element fractional-step method for the Navier-Stokes equations is combined with the Taylor-Galerkin method to achieve an accurate treatment of the convection part of the problem. A scheme of second-order accuracy in time for the non-linear convection written in non-conservative form is presented. Numerical results are provided to illustrate the quality of the computed transient solutions in two dimensions.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650110504
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  • 98
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    Discretization of incompressible vorticity-velocity equations on triangular meshes (1990)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 11 (1990), S. 823-833 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Vorticity-velocity formulation ; Voronoi diagram ; Complementary volumes ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: This paper describes a new approach to discretizing first- and second-order partial differential equations. It combines the advantages of finite elements and finite differences in having both unstructured (triangular/tetrahedral) meshes and low-order physically intuitive schemes. In this ‘co-volume’ framework, the discretized gradient, divergence, curl, (scalar) Laplacian, and vector Laplacian operators satisfy relationships found in standard vector field theory, such as a Helmholtz decomposition. This article focuses on the vorticity-velocity formulation for planar incompressible flows. The algorithm is described and some supporting numerical evidence is provided.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650110608
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