A new art code for tomographic interferometry

A new algebraic reconstruction technique (ART) code based on the iterative refinement method of least squares solution for tomographic reconstruction is presented. Accuracy and the convergence of the technique is evaluated through the application of numerically generated interferometric data. It was found that, in general, the accuracy of the results was superior to other reported techniques. The iterative method unconditionally converged to a solution for which the residual was minimum. The effects of increased data were studied. The inversion error was found to be a function of the input data error only. The convergence rate, on the other hand, was affected by all three parameters. Finally, the technique was applied to experimental data, and the results are reported

Phase behavior of UCST blends: Effects of pristine nanoclay as an effective or ineffective compatibilizer

The effects of unmodified nanoclay (natural montmorillonite) on the miscibility, phase behavior and phase separation kinetics of polyethylene (PE)/ethylene vinyl acetate copolymer (EVA) blends have been investigated. Depending on the blend composition, it was observed that the intercalated pristine nanoclay influences the biphasic morphology either as an effective compatibilizer or just as an ineffectual modifier. In spite of the presence of micrometer-sized agglomerated tactoids, natural nanoclay can play a thermodynamic role in reducing the interfacial tension of polymer components. The addition of clay nanoparticles was found to change the phase diagram slightly and diminishes the composition dependency of the binodal temperatures. Moreover, it was observed that a small amount of unmodified layered silicate slows down the phase separation process considerably and enhances the solubility of each polymer in the domains of its counterpart. The findings of this study verify that even poorly dispersed nanoclay with high surface tension can act as a conventional compatibilizer and change the immiscible PE/EVA blends to the partially miscible ones

Fuzzy Associative Memory in Conceptual Design

Examines the feasibility of utilizing fuzzy associative memory (FAM) in conceptual design and illustrates the concept by applying it to the idea generation phase of a design activity. The mapping of fuzzy functional requirements to physical design is examined. Trigger and conflict-resolution strategies are proposed to solve the vectors association problem in a multi-FAM environment. Experiments show an extremely high rate of accuracy in retrieving fuzzy information. The simplicity of its practical implementation makes this paradigm computationally attractive for this application

Análisis de programas de mejora continua. Un estudio longitudinal en una empresa industrial

Las empresas han utilizado diversas herramientas que permiten que los operarios contribuyan al proceso de mejora continua. Entre las herramientas más usadas podemos destacar los sistemas de sugerencias tanto individuales como en grupo. En esta comunicación haremos un repaso de las principales características de ambos sistemas y los modos habituales de implantación. Nuestra ponencia pretende intentar responder a estas preguntas de investigación. ¿Qué resultados se derivan de la implantación de sistemas de sugerencias individuales o en grupo? ¿Cuál de los dos sistemas es más beneficioso para la empresa? ¿Qué problemas surgen durante el funcionamiento de estos programas? Para ello, analizaremos los datos de un caso de empresa industrial donde hemos recogido los datos históricos de 5 años de aplicación de un programa de mejora continua. Ambos programas han demostrado ser provechosos para la empresa, aunque las posibilidades de los sistemas de grupo parecen ser significativamente mayores

A New Characterization Factor for Hydrocarbons and Petroleum Fluids Fractions

Using the well-known equation of Lorentz-Lorenz and the additivity nature of the molar refraction parameter, a new characterization factor as a function of the refractive index and density is proposed for pure hydrocarbons and petroleum fractions, which uniquely specifies every hydrocarbon and oil fraction in comparison with other characterization factors. This factor can separate, precisely, the range of the values of the various hydrocarbon homologue series such as paraffins, naphthenes, and aromatics from one another without any overlap between related ranges. On the other hand a mixing rule for this parameter is presented, which has a theoretical basis whereas in the other characterization factors Kay's rule is applied, which has no theoretical basis

Comparison of a Polymer Conjugate-Enhanced Enzyme Immunoassay to Ligase Chain Reaction for Diagnosis of Chlamydia trachomatis in Endocervical Swabs

Two endocervical swabs from each of 1,123 women were collected into manufacturer-supplied transport tubes and tested for Chlamydia trachomatis by a polymer conjugate-enhanced (PCE) enzyme immunoassay (EIA) (IDEIA PCE Chlamydia; DAKO) and a ligase chain reaction assay (LCx Chlamydia; Abbott). After confirmation by the EIA blocking test, the sensitivity of the IDEIA PCE remained at 91.8% and the specificity increased from 98.2 to 99.8% compared to LCx