Liquid Mixing on Falling Films: Marker-Free, Molecule-Sensitive 3D Mapping Using Raman Imaging.

Following up on a proof of concept, this publication presents a new method for mixing mapping on falling liquid films. On falling liquid films, different surfaces, plain or structured, are common. Regarding mixing of different components, the surface has a significant effect on its capabilities and performance.

Film Thickness and Glycerol Concentration Mapping of Falling Films Based on Fluorescence and Near-Infrared Technique.

Falling film evaporation processes involve high fluid velocities with continuous variations in local film thickness, fluid composition, and viscosity. This contribution presents a parallel and complementary film thickness and concentration mapping distribution in falling films using a non-invasive fluorescence and near-infrared imaging technique. The experiments were performed with a mixture of glycerol/water with a mass fraction from 0 to 0.

Marker-Free, Molecule Sensitive Mapping of Disturbed Falling Fluid Films Using Raman Imaging.

Technical liquid flow films are the basic arrangement for gas fluid transitions of all kinds and are the basis of many chemical processes, such as columns, evaporators, dryers, and different other kinds of fluid/fluid separation units. This publication presents a new method for molecule sensitive, non-contact, and marker-free localized concentration mapping in vertical falling films. Using Raman spectroscopy, no label or marker is needed for the detection of the local composition in liquid mixtures.

Visualization of Local Concentration and Viscosity Distribution during Glycerol-Water Mixing in a Y-Shape Minichannel: A Proof-of-Concept-Study.

The work presents an efficient and non-invasive method to visualize the local concentration and viscosity distribution of two miscible and non-reacting substances with a significant viscosity difference in a microchannel with a Y-shape cell. The proof-of-concept setup consists of a near-infrared (NIR) camera and cost-effective dome lighting with NIR light-emitting diodes (LED) covering the wavelength range of 1050 to 1650 nm. Absorption differences of glycerol and water and their mixtures with a mass fraction of glycerol from 0 to 0.

Expression of protein kinase HIPK2 is subject to a quality control mechanism that acts during translation and requires its kinase activity to prevent degradation of nascent HIPK2.

HIPK2 is a highly conserved, constitutively active Ser/Thr protein kinase that is involved in a broad spectrum of biological processes. We have previously reported that the expression of HIPK2 is auto-regulated by a mechanism that depends on the activity of its kinase domain, leading to decreased expression of kinase-dead versus wild-type HIPK2. We have now explored this mechanism in more detail.

Studying the Impact of Wall Shear Stress on the Development and Performance of Electrochemically Active Biofilms.

A laminar flow reactor was designed that provides constant and reproducible growth conditions for the bioelectrochemical observation of electroactive bacteria (EAB). Experiments were performed using four reactors in parallel to enable the comparison of EAB growth behavior and bioelectrochemical performance under different hydrodynamic conditions while simultaneously keeping biological conditions identical. With regard to the moderate flow conditions found in wastewater treatment applications, the wall shear stress was adjusted to a range between 0.

Optimal Geometric Parameters for 3D Electrodes in Bioelectrochemical Systems: A Systematic Approach.

In this study, the performance of electroactive bacteria (EAB), cultivated inside tubular electrode ducts, is systematically investigated to derive predictions on the behavior of EAB under conditions limited by electrochemical losses. A modeling approach is applied to assess the influence of the electrochemical losses on the electrochemical performance and scaling characteristics of complex 3D structures, such as sponges and foams. A modular flow reactor is designed that provides laminar and reproducible flow conditions as a platform for the systematic electrochemical and bioelectrochemical characterization of 3D electrodes in bioelectrochemical systems (BES).

Limited life cycle and cost assessment for the bioconversion of lignin-derived aromatics into adipic acid.

Lignin is an abundant and heterogeneous waste byproduct of the cellulosic industry, which has the potential of being transformed into valuable biochemicals via microbial fermentation. In this study, we applied a fast-pyrolysis process using softwood lignin resulting in a two-phase bio-oil containing monomeric and oligomeric aromatics without syringol. We demonstrated that an additional hydrodeoxygenation step within the process leads to an enhanced thermochemical conversion of guaiacol into catechol and phenol.

Early process development of API applied to poorly water-soluble TBID.

Finding and optimising of synthesis processes for active pharmaceutical ingredients (API) is time consuming. In the finding phase, established methods for synthesis, purification and formulation are used to achieve a high purity API for biological studies. For promising API candidates, this is followed by pre-clinical and clinical studies requiring sufficient quantities of the active component.

Fast and calibration free determination of first order reaction kinetics in API synthesis using in-situ ATR-FTIR.

In early stages of drug development only sparse amounts of the key substances are available, which is problematic for the determination of important process data like reaction kinetics. Therefore, it is important to perform experiments as economically as possible, especially in regards to limiting compounds. Here we demonstrate the use of a temperature step experiment enabling the determination of complete reaction kinetics in a single non-isothermal experiment.

Downstream processing of hyperforin from Hypericum perforatum root cultures.

Hyperforin is a major metabolite of the medicinal plant Hypericum perforatum (St. John's Wort) and has recently been found in hormone induced root cultures. The objective of this study is to identify a downstream process for the production of a hyperforin-rich extract with maximum extraction efficiency and minimal decomposition.

Chitosan-based hybrid immobilization in bienzymatic reactions and its application to the production of laminaribiose.

A hybrid-immobilization method was developed to improve the long-term stability of laminaribiose phosphorylase immobilized on epoxy supports Sepabeads EC-EP/S. Entrapment in chitosan retained all of the enzyme activity depending on the amount of entrapped solid materials and increased half-life by a factor of 10-94.4 h.

Biotechnological production of hyperforin for pharmaceutical formulation.

Hyperforin is a major active constituent of Hypericum perforatum (St. John's wort). It has amazing pharmacological activities, such as antidepressant properties, but it is labile and difficult to synthesize.

Immobilization and Characterization of E. gracilis Extract with Enriched Laminaribiose Phosphorylase Activity for Bienzymatic Production of Laminaribiose.

Immobilization methods and carriers were screened for immobilization of Euglena gracilis extract with laminaribiose phosphorylase activity. The extract was successfully immobilized on three different carriers via covalent linkage. Suitable immobilization carriers were Sepabeads EC-EP/S and ECR 8209M with epoxy groups and ECR 8309M with amino groups as functional units.

Hyperforin production in Hypericum perforatum root cultures.

Extracts of the medicinal plant Hypericum perforatum are used to treat depression and skin irritation. A major API is hyperforin, characterized by sensitivity to light, oxygen and temperature. Total synthesis of hyperforin is challenging and its content in field-grown plants is variable.

Expanding the elution by characteristic point method to columns with a finite number of theoretical plates.

The elution by characteristic point (ECP) method provides a rapid approach to determine whole isotherm data with small material usage. It is especially desired wherever the adsorbent or the adsorbate is expensive, toxic or only available in small amounts. However, the ECP method is limited to adsorbents that are well optimized for chromatographic use and therefore provide a high number of theoretical plates when packed into columns (2000 or more for Langmuir type isotherms are suggested).

Stability of the Metastable α-Polymorph in Solid Triglyceride Drug-Carrier Nanoparticles.

Colloidal dispersions of crystalline nonpolar lipids are under intensive investigation as carrier systems in pharmaceutics and nutrition. In this context, the controlled preparation of particles in a metastable polymorphic state is of some interest for the delivery of active substances. In the present study, tristearin particles stabilized with three α-polymorph-preserving emulsifier regimes ((I) sodium glycocholate/saturated long-chain phospholipids, (II) sodium glycocholate, and (III) poly(vinyl alcohol) (PVA)) were investigated concerning the stability of the metastable α-polymorph after controlled crystallization of the particles from the melt.

Preparation of calibration gas mixtures for the measurement of breath alcohol concentration.

Calibration gas mixtures for breath alcohol measuring techniques need to have a defined ethanol concentration in water-saturated air. For the calibration of evidential breath analysers in Germany, these gases are prepared at the Physikalisch-Technische Bundesanstalt according to the saturation method. The ethanol concentration is calculated via the air-liquid partition ratios of the air-water-ethanol substance system.

Structure and shear strength of microbial biofilms as determined with confocal laser scanning microscopy and fluid dynamic gauging using a novel rotating disc biofilm reactor.

The cohesive strength of microbial biofilms cultivated on a rotating disc has been measured using fluid dynamic gauging (FDG). The thickness of heterotrophic mixed culture biofilms was found to depend on substrate concentration and shear force at the biofilm surface during the cultivation. For high substrate concentrations and low shear forces the biofilm thickness increased to several 100 microm within 7 days.