In-line Monitoring of Monomer and Polymer Content During Microgel Synthesis Using Precipitation Polymerization via Raman Spectroscopy and Indirect Hard Modeling.

This contribution presents in-line monitoring of microgel synthesis by precipitation polymerization based on Raman spectroscopy. The spectra are evaluated via multivariate Indirect Hard Modeling (IHM) regression. Therefore, mechanistic models of the pure component spectra for solvent, monomer, and microgel are created by a sum of adaptable parameterized peak functions (Gaussian-Lorentzian).

Is biomass fractionation by Organosolv-like processes economically viable? A conceptual design study.

In this work, the conceptual designs of the established Organosolv process and a novel biphasic, so-called Organocat process are developed and analyzed. Solvent recycling and energy integration are emphasized to properly assess economic viability. Both processes show a similar energy consumption (approximately 5 MJ/kg(dry biomass)).

An efficient process for the saccharification of wood chips by combined ionic liquid pretreatment and enzymatic hydrolysis.

A process concept combining pretreatment of wood in ionic liquids and subsequent enzymatic hydrolysis to sugars is herein investigated to identify operating conditions which allow for (i) the processing of larger wood chips of 10 mm length, (ii) low temperature, (iii) high sugar yield, and (iv) short processing time. A careful quantitative study of the interaction of pretreatment and hydrolysis reveals that hydrolysis is most effective if beech chips are first disintegrated in [EMIM][Ac] at 115 °C for 1.5 h.

State estimation for large-scale wastewater treatment plants.

Many relevant process states in wastewater treatment are not measurable, or their measurements are subject to considerable uncertainty. This poses a serious problem for process monitoring and control. Model-based state estimation can provide estimates of the unknown states and increase the reliability of measurements.

Conceptual design of distillation-based hybrid separation processes.

Hybrid separation processes combine different separation principles and constitute a promising design option for the separation of complex mixtures. Particularly, the integration of distillation with other unit operations can significantly improve the separation of close-boiling or azeotropic mixtures. Although the design of single-unit operations is well understood and supported by computational methods, the optimal design of flowsheets of hybrid separation processes is still a challenging task.

Concentration measurements in ionic liquid-water mixtures by mid-infrared spectroscopy and indirect hard modeling.

An analytical method for the quantitative characterization of binary mixtures of water and ionic liquids (ILs) is presented. Mid-infrared (mid-IR) spectroscopy in combination with indirect hard modeling (IHM) is employed to quantify the water content in 1-butyl-3-methylimidazolium chloride (BMIMCl), 1,3-dimethylimidazolium dimethylphosphate (DMIMDMP), and 1-ethyl-3-methylimidazolium acetate (EMIMAc). Despite significant nonlinear shifts of the spectral bands, a good spectral fit with calibration errors of less than 2.

Volatile methacrylates in dental practices.

Purpose: In recent years, an increase of occupational respiratory diseases, such as asthma caused by methacrylates, has been observed in dental personnel. In this study, the exposure of dental personnel to various volatile methacrylates was investigated.

Materials And Methods: The air levels of methacrylates were measured during filling treatment while bonding agents were used in 4 dental practices in Munich, Germany.

Excretion of dental resin monomers and metabolic intermediates via urine in guinea pigs.

Objective: Monomers like BisGMA (Bisphenol-A-glycidyldimethacrylate) and comonomers like TEGDMA (triethyleneglycoldimethacrylate) are used in dental restorative materials in order to build up the three-dimensional network of filling materials. Since earlier investigations revealed uptake and subsequent metabolism of unpolymerized remainders of (co)monomers, the present experiment investigates the metabolic urine pattern of guinea pigs (n=4) after application of TEGDMA or BisGMA (each dose=0.02 mmol/kg body weight=100%), respectively.

Mechanistic kinetic model for symmetric carboligations using benzaldehyde lyase.

For reactions using thiamine diphosphate (ThDP)-dependent enzymes many empirically-derived kinetic models exist. However, there is a lack of mechanistic kinetic models. This is especially true for the synthesis of symmetric 2-hydroxy ketones from two identical aldehydes, with one substrate acting as the donor and the other as the acceptor.

Automatic generation of peak-shaped models.

We describe how parametric spectral models for analytical applications can be generated by an automatic curve-fitting algorithm. The algorithm does not require initial choices of parameters or other human intervention, in contrast to established approaches that rely on deconvolution or derivative spectroscopy. This algorithm has been applied for quantitative analysis but can potentially be used in other applications that are based on parametric representations of peak-shaped models or could benefit from using such models, such as calibration transfer.

Indirect spectral hard modeling for the analysis of reactive and interacting mixtures.

We present an indirect hard modeling (IHM) approach for the quantitative analysis of reactive multicomponent mixtures with intermolecular interaction. It can be used when it is not possible to obtain calibration data in the composition region of interest. The goal of this work, specifically, is to analyze reactive systems, although the validation of the method is done with nonreactive systems.

Toxicity potentiation by H2O2 with components of dental restorative materials on human oral cells.

Toxicity potentiation of two monomers [bisphenol-A-glycidyldimethacrylate (BisGMA) and urethanedimethacrylate (UDMA)] as well as two comonomers [triethyleneglycoldimethacrylate (TEGDMA) and 2-hydroxyethylmethacrylate (HEMA)], each in combination with H(2)O(2), was investigated on the viability on human gingival fibroblasts (HGF) and human pulpal fibroblasts (HPF). The applied concentration of H(2)O(2) was 0.06 or 0.