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  • 1
    Electronic Resource
    Electronic Resource
    Relative x-ray transition probabilities to theK-shell forZ=81, 92, 94, and 96 (1972)
    Springer
    The European physical journal 250 (1972), S. 191-197 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Accurate intensity measurements of the majorK x-ray groups have been performed with high resolution Ge(Li) detectors in singles and coincidence arrangements and with a high-purity Ge detector of the intrinsic type. Previously reportedK x-ray intensities forZ=96 are in error due to the presence of a 121.5 keV γ-ray in the decay of249Cf. The present results are as follows: forZ=81,K α2/K α1=0.589±0.008, $$K_{\beta _1^\prime } /K_{\alpha ^1 } = 0.344 \pm 0.008, K_{\beta _2^\prime } /K_{\alpha _1 } = 0.102 \pm 0.004$$ , andK β/K α=0.281±0.006; forZ=92 $$K_{\alpha _2 } /K_{\alpha _1 } = 0.611 \pm 0.008,K_{\beta _1^\prime } /K_{\alpha _1 } = 0.365 \pm 0.008, K_{\beta _2^\prime } /K_{\alpha _1 } = 0.125 \pm 0.004$$ , andK β/K α=0.300±0.006; forZ=94, $$K_{\alpha _2 } /K_{\alpha _1 } = 0.610 \pm 0.008, K_{\beta _1^\prime } /K_{\alpha _1 } = 0.369 \pm 0.010, K_{\beta _2^\prime } /K_{\alpha _1 } = 0.127 \pm 0.004$$ , andK β/K α=0.308±0.008; and forZ=96, $$K_{\alpha _2 } /K_{\alpha _1 } = 0.627 \pm 0.008, K_{\beta _1^\prime } /K_{\alpha _1 } = 0.372 \pm 0.009, K_{\beta _2^\prime } /K_{\alpha _1 } = 0.133 \pm 0.005$$ , andK β/K α=0.310±0.008. The error limits are the 2σ statistical errors to which a systematic error in the detector efficiencies has been added linearly. The present results are compared with recent theoretical calculations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01387455
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  • 2
    Electronic Resource
    Electronic Resource
    Adaptive noise cancellation in neuromagnetic measurement systems (1983)
    Springer
    Il nuovo cimento della Società Italiana di Fisica 2 (1983), S. 203-213 
    Details
    ISSN: 0392-6737
    Keywords: Biomagnetism (including magnetocardiography) ; Superconducting devices ; superconducting magnets
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Description / Table of Contents: Riassunto Si è studiato lo spettro del rumore di un gradiometro superconduttore a derivata secon da in un agglomerato urbano. I dati sono stati ottenuti dal gradiometro con tre accelerometri ortogonali e un magnetometro a flussometro elettronico triassiale attaccato al dewar. Questi dati sono stati analizzati usando tecniche di elaborazione dei segnali, soprattutto un cancellatore adattativo di rumori, per ridurre i rumori nei dati del gradiometro. I risultati mostrano qui che il rumore dell’esterno e/o il rumore del movimento del dewar possono essere ridotti di 40 dB in potenza di rumore. Si è anche mostrato che, nel caso di basso rapporto segnale-rumore (S/N∼1), può essere estratta un’onda sunusoidale di 10 Hz. Questa tecnica non solo promette riduzione dei rumori, ma ha anche lo scopo d’identificare i segnali di rumore che potrebbero essere veramente considerati parte del responso evocato. L’analisi dei dati che contengono i responsi evocati è ora in corso.
    Notes: Summary The noise spectrum of a superconducting second-derivative gradiometer has been investigated in an urban environment. Data have been acquired from the gradiometer with three orthogonal accelerometers and a triaxial fluxgate magnetometer attached to the dewar. These data have been analyzed by using signal processing techniques, primarily an adaptive noise canceller, to reduce noise in the gradiometer data. Results shown here indicate that the environmental noise and/or the dewar motion noise can be reduced as much as 40 dB in noise power. It is also shown, in the case of poor signal-to-noise ratio (S/N∼1), that a 10 Hz sine wave can be extracted. This technique not only shows promise for noise reduction, but also aids in the identification of noise signals which might be misconstrued as part of the evoked response. Analysis of data containing evoked response is now underway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02455924
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  • 3
    Electronic Resource
    Electronic Resource
    Eigenvalue sensitivity analysis of stiffened plates with respect to the location of stiffeners (1998)
    Springer
    Structural and multidisciplinary optimization 16 (1998), S. 155-161 
    Details
    ISSN: 1615-1488
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract This paper formulates the eigenvalue sensitivity of a stiffened plate with respect to stiffener location; the analysis is based on the generalized Rayleigh quotient of the combined platebeam system. The results show that the eigenvalue sensitivity is proportional to the force between the plate and the stiffener as well as to the slope of the eigenfunction at the interface between the plate and the stiffener.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01202826
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  • 4
    Electronic Resource
    Electronic Resource
    Optimization of nonhomogeneous facesheets in composite sandwich plates (1999)
    Springer
    Structural and multidisciplinary optimization 17 (1999), S. 199-207 
    Details
    ISSN: 1615-1488
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The optimal design of composite sandwich plates in which the facesheets are composed of a carbon fiber/epoxy net is considered. The objective of the work is to obtain minimum mass designs while maintaining constraints on the first natural frequency and selected facesheet stress components. The facesheets are assumed to be composed of an orthotropic net of unidirectional composite fiber strips and the optimal design (the least mass design) is achieved by changing the strip widths and the spacings between them. It is demonstrated that varying the spatial fiber strip distribution can lead to significant structural advantages; in the example presented, a 32% facesheet mass reduction is achieved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01195944
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  • 5
    Electronic Resource
    Electronic Resource
    Exact analytical solutions for frequency sensitivity of flat plates with respect to boundary shape change (1999)
    Springer
    Structural and multidisciplinary optimization 18 (1999), S. 256-263 
    Details
    ISSN: 1615-1488
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Exact analytical solutions for the natural frequency sensitivity of flat plates subjected to prescribed shape design changes are obtained. The results are based on the domain mapping idea and are restricted to certain simple changes in domain geometry. Since the approach is exact and analytical it may be used as a reference for a simple yet precise accuracy assessment of more sophisticated and general numerical calculations of boundary shape eigen value sensitivity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01223308
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  • 6
    Electronic Resource
    Electronic Resource
    A general approach forcing convexity of ply angle optimization in composite laminates (1998)
    Springer
    Structural and multidisciplinary optimization 16 (1998), S. 201-211 
    Details
    ISSN: 1615-1488
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract This paper deals with optimization of laminated composite structures in which the ply angles are taken as design variables. One of the major problems when using ply-angles as design variables, is the lack of convexity of the objective function and thus the existence of local optima, which implies that usual gradient based optimization procedures may not be effective. Therefore, a new general approach that avoids the abovementioned problems of nonconvexity when ply-angles are used as design variables is proposed. The methodology is based upon the fact that the design space for an optimization problem formulated in lamination parameters [introduced by Tsai and Pagano (1968)] is proven to be convex, because the laminate stiffnesses are expressed linearly in terms of the lamination parameters. However, lamination parameters have at least two major shortcomings: as yet, for the general case involving membrane-bending coupling, the constraints between the lamination parameters are not completely defined; also, for a prescribed set of lamination parameters physically realizable composite laminates (e.g. laminates with equal thickness plies) may not exist. The approach here, uses both lamination parameters and ply-angles and thereby uses the advantages of both and eliminates the shortcomings of both. In order to illustrate this approach, several stiffness optimization examples are provided.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01202831
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  • 7
    Electronic Resource
    Electronic Resource
    Formation of sheet metal-intermetallic composites by self-propagating high-temperature reactions (1994)
    Springer
    Journal of materials science 13 (1994), S. 1357-1360 
    Details
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00624495
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  • 8
    Electronic Resource
    Electronic Resource
    Precision determination of high-Z K-shell fluorescence yields from195Au,207Bi, and235Np decays (1972)
    Springer
    The European physical journal 249 (1972), S. 373-385 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A new method utilizing a cooled, high resolution, windowless Si(Li) x-ray and Auger electron detector has been developed for the accurate measurement of high-Z K-shell fluorescence yields. With this method, values of theK-fluorescence yield ω k have been determined with high accuracy atZ=78, 82, and 92 from the radioactive decay of carrier-free195Au,207Bi, and235Np, respectively. The values of ω k are 0.968±0.008, 0.972±0.008, and 0.970±0.005, respectively where the error limits represent 95% confidence. In addition, relativeK-Auger electron group intensities atZ=92 were measured and found to be(K-LL)∶(K-LX)∶(K-XY)=100∶(65.2±6.0)∶ (8.1±0.8). The experimental results for ω k are compared with the relativistic calculations of Bhalla, Ramsdale and, Rosner, and satisfactory agreement is found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01386769
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  • 9
    Electronic Resource
    Electronic Resource
    Finite element operators: Inexpensive evaluation of upwind schemes (1982)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 18 (1982), S. 77-88 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper introduces the notion of the finite element operator, and shows its application to the evaluation of several upwind finite element schemes. It is demonstrated that these operators supply good qualitative information on the performance of these schemes in an inexpensive as well as visual manner. In addition, this method gives insight into grid dependent effects which often characterize finite element solutions.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620180107
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  • 10
    Electronic Resource
    Electronic Resource
    Enhanced measurement of strain distributions (1998)
    Springer
    Experimental mechanics 38 (1998), S. 48-54 
    Details
    ISSN: 1741-2765
    Keywords: Strain gages ; weighted residuals ; strain gradients ; measurements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A theoretical approach is presented that uses multiple strain gages to accurately measure complicated strain distributions. The technique is based on the method of weighted residuals in conjunction with measured strain data and is applicable for arbitrary in-plane strain distributions. Conventional measurements using strain gages are shown to represent a particular case of the approach presented. The experimental characterization of unidimensional strain fields is discussed in detail. Two approaches are presented; these are based on linear and quadratic approximations of the strain field. The strain distribution for two important practical problems is evaluated assuming ideal conditions to assess the performance of the proposed approach. In both cases, the simulated results demonstrate that measurement error resulting from the finite size of a strain gage may be reduced. That is, a larger strain gage may be used for a given maximum admissible error. The method also allows a minimal error of measured nonlinear strains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02321267
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