This study shows an approach to estimate odour intensity in an indoor environment with a multi-gas sensor system. The sensor system uses 38 non-specific gas sensors, each of which responds to a wide range of different volatile compounds. Due to the complexity of indoor air pollution, the study focuses on emissions of building products as one of the major contributors to indoor air quality. The system has been calibrated and tested, combining measurements from gas sensor systems and assessments of odour intensity by a human panel. To find a relation between the sensor signal and the odour intensity, a data processing model has been developed comprising a classification and a class-specific regression method. The model is able to map the odour intensity to the sensor signal pattern in order to predict the odour intensity caused by the investigated building products. Investigations with varying relative humidity have shown a significant influence by the humidity level, which will be considered for future measurements. 相似文献
Chitin and its deacetylated derivative, chitosan, are nontoxic, antibacterial, biodegradable, and biocompatible biopolymers. Due to these properties, they are widely used for biomedical applications such as scaffolds for tissue engineering, wound dressings, separation membranes and antibacterial coatings. Unfortunately, there is still a lack of suitable solvent systems for the direct processing of chitin, e.g., into films and coatings. Such solvents must be nontoxic, noncorrosive, nondegrading, and allow for high chitin concentrations. Here, the potential of designed ionic liquids (IL) as solvents for chitin is outlined. Phosphonium‐ and imidazolium‐based ILs are synthesized, characterized and the influence of the cation on the solution process has been evaluated. It is shown that particularly imidazolium carboxylate‐based ILs are appropriate solvents for chitin and are suitable for the production of foils and coatings on both fabrics and foams.
Compression tests of deformation and fracture behavior of wheat grains were carried out at different loading rates that varied from 0.02 to 0.11 mm s–1. The contact model originally developed for the spherical particles was adapted to describe the deformation and fracture behavior of elliptical wheat grains. The distributions of basic fracture parameters of wheat grains such as fracture force, fracture strength, fracture energy, and fracture displacement were fitted with normal distribution function. 相似文献
With the increasing demand for alternative fuels the storage of natural gas (NG) in adsorbents like metal organic frameworks (MOFs) will become more important. In order to use MOFs as storage media in fuel delivery systems, the optimization of mass and energy transfer of the system is crucial. For rapid NG filling of a tank, molecules need to reach the adsorption sites within a reasonable time while the heat of adsorption should be dissipated to the environment. In this article, mass transfer in shaped bodies of MOFs was determined by permeability measurements and pulsed field gradient (PFG) NMR spectroscopy. The heat dissipation was also experimentally measured and both data sets were used to set up a theoretical density function theory model to predict the behavior of MOFs for NG storage. 相似文献
A generic, knowledge‐based guideline assisting downstream process synthesis for biochemical products is presented. It offers process designers a structured process design methodology supporting them in capturing potentially relevant information, which might be beyond their expertise. The guideline is based on heuristic knowledge which was collected, structured in a generic way, and clearly represented. The generation of alternative downstream routes as starting points for experiments, simulation, and cost calculation is hereby accelerated. The application of the guideline is demonstrated on the example of penicillin V downstream processing from fermentation broth. 相似文献
The compression, deformation and material behavior of moist spherical elastic‐plastic zeolite 4A granules under multiple stressing conditions at unique and random contacts were experimentally studied with the help of uniaxial diametrical compression tests. The force‐displacement curves were approximated and the coefficient of restitution was determined using appropriate mechanical models from literature. The phenomenon of cyclic hardening was studied and the critical number of cycles required to reach fracture was determined. Furthermore, the influence of particle size and moisture content on the material behavior at cyclic loading, the coefficient of restitution, and the critical number of cycles required to reach fracture were investigated. 相似文献
