Search results for "mass [target]"

Synthesis of Hyperbranched Polyglycerol in a Continuous Flow Microreactor

2007

Hyperbranched polymers have been synthesized in a microreactor for the first time, employing the known ring-opening multibranching polymerization of glycidol. Microreactors are well-known to be beneficial for highly exothermic reactions because of their capability to enhance mass and heat transfer due to short diffusion pathways and large interfacial areas per volume. The characteristics of the microstructured reaction system were utilized to engineer a continuous flow process for the preparation of well-defined hyperbranched polyglycerols with molecular weights up to 1,000 g/mol. Increased flow rates, as well as the use of highly polar solvents, led to the partial formation of very narrowl…

Photoinduced mass transport in soft materials

2011

The surface relief grating formation in amorphous As2S3 and azo-benzene polymer films strongly depends on the polarization state of recording beams. The surface relief grating formation efficiency of s-s and p-p recording beam combination can be essentially enhanced by additional illumination with orthogonal polarization. It is shown that the direction of mass transport on the film surface is determined by the direction of light electric vector.

Expanded micro-particles by supercritical antisolvent precipitation: Interpretation of results

2008

Abstract Supercritical antisolvent (SAS) micronization has been used to obtain nanoparticles and micro-particles of several kinds of materials. Sometimes hollow expanded micro-particles have also been obtained. This work is focused on the analysis of this last morphology. We organized literature data and our previous experiments and we added new experiments on previously tested compounds and on compounds never tested before. As a result, expanded micro-particles using several compounds belonging to different categories and precipitated from different solvents in laboratory and pilot scale plants were obtained with diameters between about 10 and 180 μm. They also showed different sub-structu…

The Influence of Biomass Ash on the Migration of Heavy Metals in the Flooded Soil Profile - Model Experiment

2014

Soils that have been exposed to fl ood waters can be heavily polluted by inorganic and organic compounds. They are mainly compounds which appear in dissolved or suspended form fl owing together with heavily laden fl oodwater, as well as compounds created as a result of reactions in the soil profi le, mostly due to anaerobic transformation of organic matter. Heavy metals brought with fl ood waters are absorbed by the soil and also washed out from fl ood sediments by precipitation when the fl ood recedes. This paper presents the results of research on the effects of fertilization with ash from incineration or pyrolysis of biomass on the migration process of heavy metals (Zn, Cu, Cr, Ni, Pb, C…

Formalisation and methods of analysis of the fast xenobiotic mass transfer in the body

2009

Validation of Methylmercury Determinations in Aquatic Systems by Alkyl Derivatization Methods for GC Analysis Using ICP-IDMS

2001

Isotope dilution mass spectrometry (IDMS), using an inductively coupled plasma quadrupole mass spectrometer (ICPMS) and a species-specific methylmercury spike was applied to validate the commonly used GC method for methylmercury (MeHg+) determination, which is based on the formation of volatile methylethylmercury by derivatization with NaBEt4. The spike compound, Me201Hg+, was synthesized by reaction of 201Hg-enriched mercury chloride with methylcobalamin. By analyzing different environmental aquatic samples, it was found that in most cases, transformation of MeHg+ into elemental mercury (Hg0) took place. From investigations of synthetic solutions, it could be followed that halide ions are …

Ionic Liquids on Demand in Continuous Flow

2009

We report on the development of an alternative protocol for the facile, solvent-free synthesis of various novel imidazolium-based ionic liquids (ILs) that affords highly pure products without the necessity of subsequent purification steps. The continuous approach is based on the combination of HPLC pumps with a micromixer and a capillary residence tube. Our system provides a high degree of control over the alkylation reactions due to a high surface-to-volume ratio and superior heat and mass transport. Within the scope of our studies, we focused on ionic liquids containing differently substituted phenyl rings and characterized these compounds with respect to further use for direct applicatio…

Ozone absorption in aqueous phenol solutions

1977

Abstract The rate of ozone absorption in aqueous solutions of phenol was measured in a wetted-wall laboratory absorber. The liquid and gas flow rates were fixed as well as the pH and temperature. The phenol concentration was varied in the range 2–300 ppm and the ozone partial pressure over an eight fold range. The gas phase resistance to mass transfer was determined by absorbing SO2 from an SO2N2 mixture in KOH aqueous solutions. The results have been interpreted by means of a simple kinetic assumption.

Smart Cities Atlas

2014

Nuovi e affascinanti esempi sull’innovazione nelle città che provengono dal mondo reale. Ogni parte del mondo industrializzato ha un caso di smart city da mostrare: città e reti di città saranno il punto di contatto delle più importanti iniziative economiche e finanziarie nel prossimo futuro. Il catalogo ampio di città analizzato da una sintetica rappresentazione delle misure applicate da alcune di esse negli ultimi dieci anni nel mondo. Essere una smart city è una sfida difficile da raggiungere, sia per città progettate ex novo come Masdar o Caofedian sia per quelle che hanno una lunga storia dietro, come le città europee. New and fascinating examples about innovation in cities come from t…

HOMEMADE SLOW-ACTION FERTILIZERS, AS AN ECONOMIC SOLUTION FOR ORGANIC FOOD PRODUCTION

2017

Organic plant cultivation, especially those intended for human consumption, poses new requirements for gardening. It is recommended to use organic slow-action fertilizers, which provide doses of nutrients essential for plants for a long time. Particularly valuable fertilizers are those that arise within the household, due to their high quality and the absence of costs associated with their purchase and transport. Organic matter contained in the food industry waste or arising in households, in the absence of contamination by other types of waste, can be used for self-production of organic fertilizer. The paper presents the results of testing organic fertilizers, which you can make yourself, …