30,063 research outputs found
The distance selling directive: consumer champion or complete irrelevance?
This paper investigates the origins, significant content, UK and EU implementation and outcomes of Directive 97/7/EC on distance selling, hereafter referred to as the Distance Selling Directive (DSD). The DSD has been implemented in national legislation by all EU Member States. In the UK this legislation was the Consumer Protection (Distance Selling) Regulations 2000 (SI 2000 No. 2334), hereafter referred to as the CPDSR
Grid generation strategies for turbomachinery configurations
Turbomachinery flow fields involve unique grid generation issues due to their geometrical and physical characteristics. Several strategic approaches are discussed to generate quality grids. The grid quality is further enhanced through blending and adapting. Grid blending smooths the grids locally through averaging and diffusion operators. Grid adaptation redistributes the grid points based on a grid quality assessment. These methods are demonstrated with several examples
(p -Cymene)thioglycollatoruthenium(II) dimer; a complex with an ambi-basic S,O-donor ligand
The title compound was prepared from the (p-cymene)ruthenium chloride dimer and thioglycollic acid. The structure is a centrosymmetric dimer bridged by the soft-base S atoms, with the hard-base O atoms of the carboxylate group chelating to form a five-membered twisted-ring. The coordination of the ruthenium atoms is completed by a η6-p-cymene ligand, giving an 18-electron count. The Ru–S bonds are essentially equal at 2.396(1) Å
MAG3D and its application to internal flowfield analysis
MAG3D (multiblock adaptive grid, 3D) is a 3D solution-adaptive grid generation code which redistributes grid points to improve the accuracy of a flow solution without increasing the number of grid points. The code is applicable to structured grids with a multiblock topology. It is independent of the original grid generator and the flow solver. The code uses the coordinates of an initial grid and the flow solution interpolated onto the new grid. MAG3D uses a numerical mapping and potential theory to modify the grid distribution based on properties of the flow solution on the initial grid. The adaptation technique is discussed, and the capability of MAG3D is demonstrated with several internal flow examples. Advantages of using solution-adaptive grids are also shown by comparing flow solutions on adaptive grids with those on initial grids
Platinum(II), palladium(II), nickel(II), and gold(I) complexes of the “electrospray-friendly” thiolate ligands 4-SC₅H₄N- and 4-SC₆H₄OMe-
The series of platinum(II), palladium(II), and nickel(II) complexes [ML₂(dppe)] [M = Ni, Pd, Pt; L = 4-SC₅H₄N or 4-SC₆H₄OMe; dppe = Ph₂PCH₂CH₂PPh₂] containing pyridine-4-thiolate or 4-methoxybenzenethiolate ligands, together with the corresponding gold(I) complexes [AuL(PPh3)], were prepared and their electrospray ionization mass spectrometric behavior compared with that of the thiophenolate complexes [M(SPh)₂(dppe)] (M = Ni, Pd, Pt) and [Au(SPh)(PPh₃)]. While the pyridine-4-thiolate complexes yielded protonated ions of the type [M + H]+ and [M + 2H]²+ ions in the Ni, Pd, and Pt complexes, an [M + H]+ ion was only observed for the platinum derivative of 4-methoxybenzenethiolate. Other ions, which dominated the spectra of the thiophenolate complexes, were formed by thiolate loss and aggregate formation. The X-ray crystal structure of [Pt(SC₆H₄OMe-4)₂(dppe)] is also reported
Improved throat inserts for ablative thrust chambers
Composite material development and structural design of improved throat inserts for ablative thrust chamber
An integrated eddy current detection and imaging system on a silicon chip
Eddy current probes have been used for many years for numerous sensing applications including crack detection in metals. However, these applications have traditionally used the eddy current effect in the form of a physically wound single or different probe pairs which of necessity must be made quite large compared to microelectronics dimensions. Also, the traditional wound probe can only take a point reading, although that point might include tens of individual cracks or crack arrays; thus, conventional eddy current probes are beset by two major problems: (1) no detailed information can be obtained about the crack or crack array; and (2) for applications such as quality assurance, a vast amount of time must be taken to scan a complete surface. Laboratory efforts have been made to fabricate linear arrays of single turn probes in a thick film format on a ceramic substrate as well as in a flexible cable format; however, such efforts inherently suffer from relatively large size requirements as well as sensitivity issues. Preliminary efforts to fully extend eddy current probing from a point or single dimensional level to a two dimensional micro-eddy current format on a silicon chip, which might overcome all of the above problems, are presented
Interactive solution-adaptive grid generation procedure
TURBO-AD is an interactive solution adaptive grid generation program under development. The program combines an interactive algebraic grid generation technique and a solution adaptive grid generation technique into a single interactive package. The control point form uses a sparse collection of control points to algebraically generate a field grid. This technique provides local grid control capability and is well suited to interactive work due to its speed and efficiency. A mapping from the physical domain to a parametric domain was used to improve difficulties encountered near outwardly concave boundaries in the control point technique. Therefore, all grid modifications are performed on the unit square in the parametric domain, and the new adapted grid is then mapped back to the physical domain. The grid adaption is achieved by adapting the control points to a numerical solution in the parametric domain using control sources obtained from the flow properties. Then a new modified grid is generated from the adapted control net. This process is efficient because the number of control points is much less than the number of grid points and the generation of the grid is an efficient algebraic process. TURBO-AD provides the user with both local and global controls
Novel Method of Measuring Electron Positron Colliding Beam Parameters
Through the simultaneous measurement of the transverse size as a function of
longitudinal position, and the longitudinal distribution of luminosity, we are
able to measure the (vertical envelope function at the collision
point), vertical emittance, and bunch length of colliding beams at the Cornell
Electron-positron Storage Ring (CESR). This measurement is possible due to the
significant ``hourglass'' effect at CESR and the excellent tracking resolution
of the CLEO detector.Comment: 11 pages, 4 figures, submitted to NIM
Approximations for Quantitative Feedback Theory Designs
The computational requirements for obtaining the results summarized in the preceding section were very modest and were easily accomplished using computer-aided control system design software. Of special significance is the ability of the PDT to indicate a loop closure sequence for MIMO QFT designs that employ sequential loop closure. Although discussed as part of a 2 x 2 design, the PDT is obviously applicable to designs with a greater number of inputs and system responses
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