Einflu? der Triaden-Konzentration auf die Glastemperatur von Copolymeren. 2. Mitt.

Ohne Zusammenfassung     

Generalization of simulation results practicality of statistical methods

The major purpose of this paper is to evaluate the practical use of statistical techniques in both the generalization or analysis of simulation results, and the design of simulation experiments. This problem is investigated with the help of a real-life system, namely the container terminus of ECT in Rotterdam. This system is modeled by a simulation program. The relationship between the simulation response and its input variables is modeled by a linear regression model: metamodel or auxiliary model. The paper summarizes regression analysis including generalized least squares which might be used for simulation responses with non-constant variances. The validity of the postulated regression metamodel is tested statistically: F- and t-statistics. The selection of the situations to be simulated, is done through experimental design methodology, permitting both quantitative and qualitative factors. The statistical techniques apply not only to simulation but also to real-life experiments.     

Modeling the dispersion of radionuclides released during reactor accidents aboard nuclear-powered vessels

Provenance determinations of pottery by chemical analysis is reviewed and shown to work well. Since pottery is produced from a well homogenized clay paste according to a certain recipe, sharp elemental patterns are expected for a series of products having the same origin. To obtain such patterns when forming compositional groups of pottery, a consideration of experimental errors, a correction for dilution and a choice of only stable elements is necessary. The patterns thus obtained will have low probability of overlap with groups of different origin. Examples for well defined groups of German stonewares and of Mycenaean wares from the Peloponnese are recorded.     

Sliding mode control of a “Soft” 2-DOF Planar Pneumatic Manipulator

This paper presents a sliding mode controller for a “Soft” 2-DOF Planar Pneumatic Manipulator actuated by pleated pneumatic artificial muscle actuators. Since actuator dynamics is not negligible, an approximate model for pressure dynamics was taken into account, which made it necessary to perform full input-output feedback linearization in order to design a sliding mode controller. The design of the controller is presented in detail, and experimental results obtained by implementing the controller are discussed Published in Prikladnaya Mekhanika, Vol. 44, No. 10, pp. 135–144, October 2008.     

Preparation of two uranium glass reference materials for fission-track dating of geological samples

The European Commission produced and certified uranium glass for fission-track dating in 1996 (Reference Material IRMM-540). This material is now out of stock and a project for the preparation of two new reference glasses is underway. The new glasses, containing nominally 15 and 55 mgkg⁻¹ uranium, were prepared from blended oxide powder, and cast using an improved method, which minimised micro-scale defects and optimised the yield. Glass rods were produced which were then cut into discs of 2 mm thickness and 15 mm diameter and subsequently polished.

Uranium homogeneity and fission-track stability are critical properties of the glass. An extensive study was carried out to verify the homogeneity by fission-track counting, investigating both within-disc and between disc effects, and to investigate potential track fading due to thermal annealing. No evidence of uranium heterogeneity was detected. The stability study, using an “isochronous” method, in which all measurements are made at the end of exposure to artificial ageing, is still underway.

The reference material will be certified for isotopic composition (natural), uranium mass fraction and neutron fluence (one disc out of each set of three will be irradiated, together with a mica foil, to induce fission tracks in a certified fluence). The reference materials will be released as IRMM-540R (15 mgkg⁻¹ U) and IRMM-541 (55 mgkg⁻¹ U).     

Atomic decomposition of the protein solvation free energy and its application to amyloid-beta protein in water

We report the development of an atomic decomposition method of the protein solvation free energy in water, which ascribes global change in the solvation free energy to local changes in protein conformation as well as in hydration structure. So far, empirical decomposition analyses based on simple continuum solvation models have prevailed in the study of protein-protein interactions, protein-ligand interactions, as well as in developing scoring functions for computer-aided drug design. However, the use of continuum solvation model suffers serious drawbacks since it yields the protein free energy landscape which is quite different from that of the explicit solvent model and since it does not properly account for the non-polar hydrophobic effects which play a crucial role in biological processes in water. Herein, we develop an exact and general decomposition method of the solvation free energy that overcomes these hindrances. We then apply this method to elucidate the molecular origin for the solvation free energy change upon the conformational transitions of 42-residue amyloid-beta protein (Aβ42) in water, whose aggregation has been implicated as a primary cause of Alzheimer's disease. We address why Aβ42 protein exhibits a great propensity to aggregate when transferred from organic phase to aqueous phase.     

Predictive modeling and analysis of HfO2 thin film process based on Bayesian information criterion using PCA‐based neural networks

Principal component analysis (PCA)‐based neural network (NNet) models of HfO₂ thin films are used to study the process of efficient model selection and develop an improved model by using multivariate functional data such as X‐ray diffraction data (XRD). The accumulation capacitance and the hysteresis index input parameters, both characteristic of HfO₂ dielectric films, were selected for the inclusion in the model by analyzing the process conditions. Standardized XRD were used to analyze the characteristic variations for different process conditions; the responses and the electrical properties were predicted by NNet modeling using crystallinity‐based measurement data. A Bayesian information criterion (BIC) was used to compare the model efficiency and to select an improved model for response prediction. Two conclusions summarize the results of the research documented in this paper: (i) physical or material properties can be predicted by the PCA‐based NNet model using large‐dimension data, and (ii) BIC can be used for the selection and evaluation of predictive models in semiconductor manufacturing processes. Copyright © 2013 John Wiley & Sons, Ltd.     

Azeotropy in Terpolymerization

Abstract

A number of polyurethanes were synthesized by reacting castor oil with isophorone diisocyanate while varying the NCO/OH ratio. All these polyurethanes were reacted with such acrylic monomers as acrylamide and methacrylamide by using ethylene glycol dimethacrylate as a crosslinker and benzoyl peroxide as the initiator. The physicochemical properties of interpenetrating polymer networks (IPNs) are reported. The durability, solvent absorption, outdoor weathering, and aging properties of IPNs have been studied. Thermogravimetric analysis was used to study the thermal behavior of IPNs and the evaluation of kinetic parameters. A number of equations, such as those of Freeman-Anderson, Broido, Piloyan-Novikova, Horowitz-Mitzger, and Coats-Redfern, have been used to determine the kinetic parameters. The degradation mechanism is discussed.     

Multiple semi‐coarsened multigrid method with application to large eddy simulation

The Multiple Semi‐coarsened Grid (MSG) multigrid method of Mulder (J. Comput. Phys. 1989; 83 :303–323) is developed as a solver for fully implicit discretizations of the time‐dependent incompressible Navier–Stokes equations. The method is combined with the Symmetric Coupled Gauss–Seidel (SCGS) smoother of Vanka (Comput. Methods Appl. Mech. Eng. 1986; 55 :321–338) and its robustness demonstrated by performing a number of large‐eddy simulations, including bypass transition on a flat plate and the turbulent thermally‐driven cavity flow. The method is consistently able to reduce the non‐linear residual by 5 orders of magnitude in 40–80 work units for problems with significant and varying coefficient anisotropy. Some discussion of the parallel implementation of the method is also included. Copyright © 2005 John Wiley & Sons, Ltd.     

He(I) and He(II) photoelectron spectra of glycine and related molecules

Photoelectron spectra obtained by He(I) and He(II) excitation of glycine, sarcosine and glycine methyl ester are presented. The p-type bands in the He(I) spectrum of glycine are interpreted in terms of localized molecular orbitals; the C 2s bands are identified in the He(II) spectrum. He(I) spectra of some N-acetylamino acids and of a variety of α-and ω-substituted amino acids are also reported.