Combination of nuclear magnetic resonance spectroscopy and nonlinear methods to analyze the copolymerization of phosphonic acid derivatives

We demonstrate in this study that the combination of modern inline monitoring methods [here: inline nuclear magnetic resonance (NMR)] with simulations gains more exact and profound kinetic results than previously used methods like linearization without that combination. The ¹H-NMR spectroscopic data (more than 100 data points) are used to construct the copolymerization diagram. The reactivity ratios are obtained applying the van Herks nonlinear least square method. The examination of the radical copolymerization of 2-hydroxyethyl methacrylate (HEMA) with (2-{[2-(ethoxycarbonyl)prop-2-en-1-yl]oxy}ethyl) phosphonic acid (ECPPA) as important adhesive monomer used in dentistry yields reactivity ratios of r_HEMA = 1.83; r_ECPPA = 0.42. The copolymerization diagram reflects nonideal, non-azeotropic copolymerization. The sequence distribution of the obtained by Monte Carlo simulation indicates the generation of statistical copolymers. As an important finding, it is demonstrated that the repeating units responsible for etching and adhesion are arranged over the whole polymer chain, which is necessary to achieve proper functionality. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48256.     

Effect of hot strip processing during direct charging of thin slabs on the properties of cold strip of LC-steel

Direct charging of thin slabs of low carbon steel (0.05%C) was investigated by using laboratory tests on a thin-slab-casting Simulator linked with the hot deformation Simulator (Wumsi). Starting with a different initial thickness of simulated thin slabs (45 down to 25 mm) the total strain ?∑ was varied. Hot deformation schedules (with and without roughing) with different finishing temperatures T_F lead to some differences in the hot strip microstructure. Nevertheless, after cold rolling and batch annealing, a rather uniform pancake-structure and a pronounced {111}-texture were achieved in the cold strip without any significant relation to the processing routs. The measurement of final mechanical properties proved that a good deep drawability of cold strip can be achieved with direct charging of thin slabs, well comparable to that after a conventional cold charging of thick slabs.     

Computing surfaces invariant under subdivision

In this paper, we propose a general subdivision algorithm for generating surfaces. The algorithm has as motivation our earlier work on the design of free form curves where similar ideas were investigated. Here we describe some properties of uniform refinement algorithms for surface generation. A detail analysis of their properties will be given later by one of us.     

Is evidence-based practice diverse enough? Philosophy of science considerations.

In its policy rationale for evidence-based practice in psychology (EBPP), the APA Presidential Task Force on Evidence-Based Practice (see record 2006-05893-001) claims to have constituted itself with "scientists and practitioners from a wide range of perspectives and traditions, reflecting the diverse perspectives within the field" (p. 273). We applaud this attention to diversity but contend that an entire perspective of the debate was omitted in the Task Force's newly approved policy and its underlying report. The failure to consider a philosophy of science perspective led the Task Force to make a number of epistemological assumptions that are not based on evidence or rationale and that thus violate the very spirit of evidence-based decision making. In this comment, we reveal a few of these assumptions and discuss their detrimental consequences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Apparatus for steady-state kinetic measurements of the catalytic reduction of nitric oxide by ammonia on iron oxide

The reduction of nitric oxide with ammonia on an unsupported iron oxide catalyst has been studied in a continuous-flow recycle reactor using simulated flue gas. The responses of the employed reactor system to step and pulse inputs of tracer indicate that the system could be regarded as a continuous stirred tank reactor (CSTR). Preliminary tests were carried out to determine the effect of temperature and particle size on the measured reaction rates. Additional experiments were performed in order to study the influence of oxygen and water concentration on these rates. A gas chromatographic system has been developed to analyze the gas components NO, N₂O, NO₂, NH₃, H₂O, O₂, CO₂ and N₂. In addition, the concentrations of NO and NO₂ were measured with a nondisperse infrared (NDUV/NDIR) analyzer.     

Solubilization of fish muscle proteins with buffers containing sodium dodecyl sulfate

Summary The extraction of fish muscle protein using SDS containing solubilization buffers was studied varying the time and the temperature of solubilization, as well as pH and SDS concentration of the buffer. At pH < 6 the myofbrillar proteins were incompletely solubilized; temperatures of 80-100 °C resulted in protein degradation observable in the SDS-PAGE.Samples of fish muscle containing high amounts of formaldehyde (50 mmoles FA/kg wet weight) could only be solubilised at 100 °C; on the other hand it was possible to solubilize cooked and/or canned products under mild conditions (2% SDS, 1% 2-ME, pH 8.9, shaking for 2 h at 60 °C).

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Solubilisierung von Fischmuskelproteinen durch Natriumdodecylsulfathaltige Puffer

Zusammenfassung Der Einfluß von Solubilisierungszeit und -temperatur, des pH-Wertes und der SDS-Konzentration des Solubilisierungspuffers auf die Extraktion von Fischmuskelproteinen wurde überprüft. Bei pH-Werten < 6 wurden die myofbrillären Proteine nur unvollständig gelöst; Solubilisierungstemperaturen von 80 bis 100 °C führten zu einem in der SDS-PAGE sichtbaren Proteinabbau. Fischmuskelproben mit hohem Formaldehydgehalt (50 mmole FA/kg Feuchtgewicht) ließen sich nur bei 100 °C vollständig solubilisieren; demgegenüber gelang die weitgehende Solubilisierung gegarter und/oder sterilisierter Produkte unter milden Bedingungen (2% SDS, 1% 2-ME, pH 8,9; 2stündiges Schütteln bei 60 °C).

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Abbreviations FA formaldehyde - IEF isoelectric focusing - 2-ME 2-mercaptoethanol - PA polyacrylamide - PAGE polyacrylamide gel electrophoresis - pI isoelectric point - SDS sodium dodecyl sulfate - TMAO trimethylamine oxide - Tris Tris (hydroxymethyl)methylamine