The evaluation of manufacturing issues in the product development process

Many companies still do not achieve the success rates they desire with new product introductions to the market. A method has been developed to aid companies to self-evaluate their product development processes (PDP). The method meets an identified need for a non-prescriptive procedure to evaluate an existing or proposed PDP at a detailed level, both in the context of the company's own products, processes, procedures and markets, and in the context of accepted good practice. The specification and development of the process and facilities needed for the manufacture of a product are identified as fundamental generic issues within the PDP that must be handled effectively to achieve successful product outcomes. The paper describes the main constructs of the evaluation method in relation to manufacturing issues, and presents results and findings from trials conducted in industry. It is seen that great care is needed to ensure that company practitioners make objective assessments of the important factors. Further work is planned to develop the method as an interactive computer tool and to conduct more trials

First Measurements of Surface Nuclear Magnetic Resonance Signals in a Grounded Bipole

Surface nuclear magnetic resonance (surface NMR) soundings are geophysical techniques that offer direct detection of groundwater. Ordinary surface NMR soundings are achieved with a wire loop that acts as both transmitter and receiver. We extend the capability of the technique by using a grounded electrical bipole as the measurement sensor. We provide the first successful measurements of surface NMR signals taken with a grounded electrode pair on a beach outside Perth, Western Australia. Simple changes to existing equations are sufficient to provide forward models for the changes in measurement technique, and the resulting groundwater models are consistent with coincident loop soundings. Our result opens the field for novel sounding techniques of surface NMR signals that could have broad impact on near-surface groundwater investigations

Overscreening Diamagnetism in Cylindrical Superconductor-Normal Metal-Heterostructures

We study the linear diamagnetic response of a superconducting cylinder coated by a normal-metal layer due to the proximity effect using the clean limit quasiclassical Eilenberger equations. We compare the results for the susceptibility with those for a planar geometry. Interestingly, for $R\sim d$ the cylinder exhibits a stronger overscreening of the magnetic field, i.e., at the interface to the superconductor it can be less than (-1/2) of the applied field. Even for $R\gg d$, the diamagnetism can be increased as compared to the planar case, viz. the magnetic susceptibility $4\pi\chi$ becomes smaller than -3/4. This behaviour can be explained by an intriguing spatial oscillation of the magnetic field in the normal layer

Spinodal Decomposition in a Binary Polymer Mixture: Dynamic Self Consistent Field Theory and Monte Carlo Simulations

We investigate how the dynamics of a single chain influences the kinetics of early stage phase separation in a symmetric binary polymer mixture. We consider quenches from the disordered phase into the region of spinodal instability. On a mean field level we approach this problem with two methods: a dynamical extension of the self consistent field theory for Gaussian chains, with the density variables evolving in time, and the method of the external potential dynamics where the effective external fields are propagated in time. Different wave vector dependencies of the kinetic coefficient are taken into account. These early stages of spinodal decomposition are also studied through Monte Carlo simulations employing the bond fluctuation model that maps the chains -- in our case with 64 effective segments -- on a coarse grained lattice. The results obtained through self consistent field calculations and Monte Carlo simulations can be compared because the time, length, and temperature scales are mapped onto each other through the diffusion constant, the chain extension, and the energy of mixing. The quantitative comparison of the relaxation rate of the global structure factor shows that a kinetic coefficient according to the Rouse model gives a much better agreement than a local, i.e. wave vector independent, kinetic factor. Including fluctuations in the self consistent field calculations leads to a shorter time span of spinodal behaviour and a reduction of the relaxation rate for smaller wave vectors and prevents the relaxation rate from becoming negative for larger values of the wave vector. This is also in agreement with the simulation results.Comment: Phys.Rev.E in prin

Proximity-induced screening and its magnetic breakdown in mesoscopic hybrid structures

We derive a general microscopic expression for the non-linear diamagnetic current in a clean superconductor-insulator-normal metal structure with an arbitrary interface transmission. In the absence of electron-electron interactions in the normal metal the diamagnetic response increases monotonously with decreasing temperature showing no sign of paramagnetic reentrance down to T=0. We also analyze the magnetic breakdown of proximity induced Meissner screening. We demonstrate that the magnetic breakdown field should be strongly suppressed in the limit of small interface transmissions while the linear diamagnetic current does not depend on the transmission of the insulating barrier at low enough temperatures.Comment: 7 pages, 2 figure

Mitochondrial DNA variation in Parkinson’s disease: Analysis of “out-of-place” population variants as a risk factor

Mitochondrial DNA (mtDNA), a potential source of mitochondrial dysfunction, has been implicated in Parkinson’s disease (PD). However, many previous studies investigating associations between mtDNA population variation and PD reported inconsistent or contradictory findings. Here, we investigated an alternative hypothesis to determine whether mtDNA variation could play a significant role in PD risk. Emerging evidence suggests that haplogroup-defining mtDNA variants may have pathogenic potential if they occur “out-of-place” on a different maternal lineage. We hypothesized that the mtDNA of PD cases would be enriched for out-of-place variation in genes encoding components of the oxidative phosphorylation complexes. We tested this hypothesis with a unique dataset comprising whole mitochondrial genomes of 70 African ancestry PD cases, two African ancestry control groups (n = 78 and n = 53) and a replication group of 281 European ancestry PD cases and 140 controls from the Parkinson’s Progression Markers Initiative cohort. Significantly more African ancestry PD cases had out-of-place variants than controls from the second control group (P < 0.0125), although this association was not observed in the first control group nor the replication group. As the first mtDNA study to include African ancestry PD cases and to explore out-of-place variation in a PD context, we found evidence that such variation might be significant in this context, thereby warranting further replication in larger cohorts

Parametrically Excited Surface Waves: Two-Frequency Forcing, Normal Form Symmetries, and Pattern Selection

Motivated by experimental observations of exotic standing wave patterns in the two-frequency Faraday experiment, we investigate the role of normal form symmetries in the pattern selection problem. With forcing frequency components in ratio m/n, where m and n are co-prime integers, there is the possibility that both harmonic and subharmonic waves may lose stability simultaneously, each with a different wavenumber. We focus on this situation and compare the case where the harmonic waves have a longer wavelength than the subharmonic waves with the case where the harmonic waves have a shorter wavelength. We show that in the former case a normal form transformation can be used to remove all quadratic terms from the amplitude equations governing the relevant resonant triad interactions. Thus the role of resonant triads in the pattern selection problem is greatly diminished in this situation. We verify our general results within the example of one-dimensional surface wave solutions of the Zhang-Vinals model of the two-frequency Faraday problem. In one-dimension, a 1:2 spatial resonance takes the place of a resonant triad in our investigation. We find that when the bifurcating modes are in this spatial resonance, it dramatically effects the bifurcation to subharmonic waves in the case of forcing frequencies are in ratio 1/2; this is consistent with the results of Zhang and Vinals. In sharp contrast, we find that when the forcing frequencies are in ratio 2/3, the bifurcation to (sub)harmonic waves is insensitive to the presence of another spatially-resonant bifurcating mode.Comment: 22 pages, 6 figures, late

Universally Composable Quantum Multi-Party Computation

The Universal Composability model (UC) by Canetti (FOCS 2001) allows for secure composition of arbitrary protocols. We present a quantum version of the UC model which enjoys the same compositionality guarantees. We prove that in this model statistically secure oblivious transfer protocols can be constructed from commitments. Furthermore, we show that every statistically classically UC secure protocol is also statistically quantum UC secure. Such implications are not known for other quantum security definitions. As a corollary, we get that quantum UC secure protocols for general multi-party computation can be constructed from commitments

Singular kernels, multiscale decomposition of microstructure, and dislocation models

We consider a model for dislocations in crystals introduced by Koslowski, Cuiti\~no and Ortiz, which includes elastic interactions via a singular kernel behaving as the $H^{1/2}$ norm of the slip. We obtain a sharp-interface limit of the model within the framework of $\Gamma$-convergence. From an analytical point of view, our functional is a vector-valued generalization of the one studied by Alberti, Bouchitt\'e and Seppecher to which their rearrangement argument no longer applies. Instead we show that the microstructure must be approximately one-dimensional on most length scales and exploit this property to derive a sharp lower bound

The excitation spectrum of mesoscopic proximity structures

We investigate one aspect of the proximity effect, viz., the local density of states of a superconductor-normal metal sandwich. In contrast to earlier work, we allow for the presence of an arbitrary concentration of impurities in the structure. The superconductor induces a gap in the normal metal spectrum that is proportional to the inverse of the elastic mean free path l_N for rather clean systems. For a mean free path much shorter than the thickness of the normal metal, we find a gap size proportional to l_N that approaches the behavior predicted by the Usadel equation (diffusive limit). We also discuss the influence of interface and surface roughness, the consequences of a non-ideal transmittivity of the interface, and the dependence of our results on the choice of the model of impurity scattering.Comment: 7 pages, 8 figures (included), submitted to PR