An integrated approach to optimise parameter design of multi-response processes based on Taguchi method and artificial intelligence

The Taguchi robust parameter design has been widely used over the past decade to solve many single-response process parameter designs. However, the Taguchi method is unable to deal with multi-response problems that are of main interest today, owing to increasing complexity of manufacturing processes and products. Several recent studies have been conducted in order to solve this problem. But, they did not effectively treat situations where responses are correlated and situations in which control factors have continuous values. This study proposed an integrated model for experimental design of processes with multiple correlated responses, composed of three stages which (1) use expert system, designed for selecting an inner and an outer orthogonal array, to design an actual experiment, (2) use Taguchi’s quality loss function to present relative significance of responses, and multivariate statistical methods to uncorrelate and synthesise responses into a single performance measure, (3) use neural networks to construct the response function model and genetic algorithms to optimise parameter design. The effectiveness of the proposed model is illustrated with three examples. Results of analysis showed that the proposed approach could yield a better solution in terms of the optimal parameters setting that results in a higher process performance measure than the traditional experimental design.     

COMPLEMENTARITY OF THE LIVING SYSTEMS AND THE DIALECTICAL SYSTEMS THEORIES: THE CASE OF PUBLIC MEDICAL CARE IN SLOVENIA

Systems science is about synthesis and integration for holism. The living systems (LST) and the dialectical systems theories (DST) are equally old. If both a quite holistic insight and creativity are needed, a combination of the LST and the DST is a better choice than using each of them separately. LST can make many details visible, while DST can make them an information basis for an innovative action. LST alone can hardly provide an action, especially one of a creative orientation. DTS alone can hardly provide all the necessary insight, but it can provide a bridge between different aspects of the process at stake and help them produce creative synergies of different professions' insights. A case of combining both LST and DST in studying public health care proves fruitful. DTS can influence people to use LST and its insight in a creative way.     

Study of curing of epoxy resins by acid anhydrides using differential scanning calorimetry

Course and kinetics of the curing of epoxy resins by acid anhydrides were studied by differential scanning calorimetry (DSC). The heat of reaction at 107.5°C was found to lie between ?302.2to ?333.2 J/g (?72.2 to ?79.6 cal/g), depending on the composition of the reaction system. For one reaction system measurements were made at three different temperatures. From DSC data the reaction order and rate constants were evaluated. Between 18 to 80% conversion the curing reaction was found to be 0.5 order, and from 80 to 98% conversion to be first order. From the rate constants using the Arrhenius equation the activation energy was calculated. The values of the activation energy are 58.2 KJ/mol (13.9 kcal/mol) for 0.5 order and 56.1 KJ/mol (13.4 kcal/mol) for first order reaction.     

Elastic properties of cement-stabilised mixes with steel slag

In this study, we evaluated the elastic and mechanical properties of a new type of cement-stabilised material made with steel slag, varying the content of cement and steel slag. To study the elastic properties of these mixes, we measured their density, compressive strength and ultrasound pulse velocity at curing ages of 7, 28 and 90 days. The aggregate type and curing age greatly affected the elastic properties and varied much depending on the cement content. The Poisson's ratio chosen in analyses had little influence on the dynamic modulus. Various expressions given by building codes were used to predict the elastic properties of the mixtures. These codes generated very different values of the static modulus of elasticity, making most of them unsuitable for predicting the elastic properties of cement-stabilised materials. Using our experimental data, we provide the best combination of existing equations to predict elastic properties, and we conclude that measuring the ultrasound pulse velocity is a suitable way to predict the mechanic and elastic properties of cement-stabilised materials.     

Routing of barge container ships by mixed-integer programming heuristics

We investigate the optimization of transport routes of barge container ships with the objective to maximize the profit of a shipping company. This problem consists of determining the upstream and downstream calling sequence and the number of loaded and empty containers transported between any two ports. We present a mixed integer linear programming (MILP) formulation for this problem. The problem is tackled by the commercial CPLEX MIP solver and improved variants of the existing MIP heuristics: Local Branching, Variable Neighborhood Branching and Variable Neighborhood Decomposition Search. It appears that our implementation of Variable Neighborhood Branching outperforms CPLEX MIP solver both regarding the solution quality and the computational time. All other studied heuristics provide results competitive with CPLEX MIP solver within a significantly shorter amount of time. Moreover, we present a detailed case study transportation analysis which illustrates how the proposed approach can be used by managers of barge shipping companies to make appropriate decisions and solve real life problems.     

Analysis of the urine proteome in patients with pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) accounts for over 213?000 deaths worldwide each year, largely due to late diagnosis. One of the risk factors for the development of PDAC is chronic pancreatitis (CP); the intense desmoplastic reaction makes differentiation between the two conditions extremely difficult. In order to identify biomarkers for noninvasive diagnosis, we performed 2-D DIGE analysis of urine samples from healthy individuals and patients with PDAC and CP. Despite considerable intersample heterogeneity, a total of 127 statistically valid (p<0.05), differentially expressed protein spots were detected, 101 of which were identified using MALDI-TOF MS. A number of these, including annexin A2, gelsolin and CD59 have already been associated with PDAC, however, their validation using immunoblotting proved challenging. This is probably due to extensive PTMs and processing thus indicating the need for raising specific antibodies for urinary proteins. Despite this, our study clearly demonstrates that urine is a valid source of noninvasive biomarkers in patients with pancreatic diseases.     

Structure prediction of the EcoRV DNA methyltransferase based on mutant profiling, secondary structure analysis, comparison with known structures of methyltransferases and isolation of catalytically inactive single mutants

The EcoRV DNA methyltransferase (M·EcoRV) is an -adeninemethyltransferase. We have used two different programs to predictthe secondary structure of M·EcoRV. The resulting consensusprediction was tested by a mutant profiling analysis. 29 neutralmutations of M·EcoRV were generated by five cycles ofrandom mutagenesis and selection for active variants to increasethe reliability of the prediction and to get a secondary structureprediction for some ambiguously predicted regions. The predictedconsensus secondary structure elements could be aligned to thecommon topology of the structures of the catalytic domains ofM·HhaI and M·TaqI. In a complementary approachwe have isolated nine catalytically inactive single mutants.Five of these mutants contain an amino acid exchange withinthe catalytic domain of M·EcoRV (Val20-Ala, Lys81Arg,Cys192Arg, Asp193Gly, Trp231Arg). The Trp231Arg mutant bindsDNA similarly to wild-type M·EcoRV, but is catalyticallyinactive. Hence this mutant behaves like a bona fide activesite mutant. According to the structure prediction, Trp231 islocated in a loop at the putative active site of M·EcoRV.The other inactive mutants were insoluble. They contain aminoacid exchanges within the conserved amino acid motifs X, IIIor IV in M·EcoRV confirming the importance of these regions.     

Carbon nanoscrolls produced from acceptor-type graphite intercalation compounds

A low-temperature wet chemistry technique for producing carbon nanoscrolls is described. The technique is based on the use of readily available acceptor-type graphite intercalation compounds. The initial graphite intercalation compound is first exfoliated to produce a suspension of graphene monolayers in ethanol which is subsequently sonicated yielding a suspension of carbon nanoscrolls. The technique does not require heating and the use of inert atmosphere thus providing an improvement compared to the previously reported methods.     

Formation and applications of stable 10 nm to 500 nm supramolecular porphyrinic materials

Nanoscaled materials of organic dyes are of interest for a variety of potential applications because of the rich photonic properties that this class of molecules can impart. One mode to form such nanoscaled materials is via self-organization and self-assembly, using reasonably well understood methods in supramolecular chemistry. But there are inherent complexities that arise from the use of organic-based supramolecular materials, including stability toward dioxygen, structural stability, and nanoarchitectures that may change with environmental conditions. Porphyrinoids have rich photonic properties yet are remarkably stable, have a rigid core, are readily functionalized, and metalation of the macrocycle can impart a plethora of optical, electronic, and magnetic properties. While there are many <10 nm porphyrinic assemblies, which may or may not self-organize into crystals, there is a paucity of 10–500 nm porphyrinic materials that can be isolated and stored. A variety of strategies towards the latter nanoscopic porphyrinic materials are discussed in terms of design, construction, and nanoarchitecture. The hierarchical structures include colloids, nanorods, nanotubes, nanorings, and nano-crystalline materials. This prolegomenon emphasizes the supramolecular chemistry, structure-stability, and structure-function relationships. The goal herein is to examine general trends and delineate general principles.     

Strong Photoacoustic Signal Enhancement by Coating Gold Nanoparticles with Melanin for Biomedical Imaging

Photoacoustics is a powerful biomedical imaging and detection technique, because it is a noninvasive, nonionizing, and low‐cost method facilitating deep tissue penetration. However, suitable contrast agents need to be developed to increase the contrast for in vivo imaging. Gold nanoparticles are often discussed as potential sonophores due to their large absorption cross‐section and their tunable plasmon resonance. However, disadvantages such as toxicity and low photoacoustic efficiency in the tissue transparency window prevail, preventing their clinical application. As a result, there remains a strong need to develop colloidal photoacoustic contrast agents which absorb in the tissue transparency window, exhibit high photoacoustic signal, and are biocompatible. Here, a facile synthetic approach is presented to produce melanin shells around various gold nanoparticle geometries, from spheres to stars and rods. These hybrid particles show excellent dispersability, better biocompatibility, and augmented photoacoustic responses over the pure melanin or pristine gold particles, with a rod‐shape geometry leading to the highest performance. These experimental results are corroborated using numerical calculations and explain the improved photoacoustic performance with a thermal confinement effect. The applicability of melanin coated gold nanorods as gastrointestinal imaging probes in mouse intestine is showcased.