Search results for "Turing"
showing 10 items of 2644 documents
Flow chemistry: Imidazole-based ionic liquid syntheses in micro-scale
2010
The quarternization of an N-atom in the 1-methyl-imidazole with different alkylating agents was investigated to form so-called Ionic Liquids. (3-Chloropropyl)-trimethoxysilane, 1-chlorobutane, diethyl sulfate and methyl trifluoromethanesulfonate were used as alkylating agents. Reaction kinetics range from very slow to instantaneous and the reaction heat from endothermal to extremely exothermal respectively. The reactions were performed under flow conditions using different types of microstructured reactors as well as pre-structurized reactants in the micro-scale. Unusual heat management with integrated heat pipes allow safer performing of highly exothermal reactions with comparably high thr…
Perfluorocarbons–graphene oxide nanoplatforms as biocompatible oxygen reservoirs
2018
Abstract 3-Pentadecafluoroheptyl,5-perfluorophenyl-1,2,4-oxadiazole (FOX) molecules were attached onto a graphene oxide (GO) via a facile aromatic substitution in alkaline environment. This approach allows achieving high degree of functionalization under mild conditions. The covalent attachment of perfluoromoieties onto GO lamellae was confirmed by spectroscopic analyses. The performance of these nanoplatforms (GOF) as oxygen reservoirs was assessed at different concentrations and temperature. The results revealed that under physiologic conditions GO and FOX synergistically operate for increasing oxygen uptake and release, either from a thermodynamic and a kinetic point of view. Even at low…
Magnetic coiffure: Engineering of human hair surfaces with polyelectrolyte-stabilised magnetite nanoparticles
2022
Here we report a spontaneous electrostatic coating of human hair with aqueous Fe3O4 colloids capable to tailor magnetic properties to hair, orienting and even moving them under the influence of the external magnetic field. Magnetite particles were modified by cationic and anionic polyelectrolytes and then successfully deposited in dense arrays, starting from cuticle gaps and spreading further over a major hair surface. These biocompatible and biodegradable magnetic nanoparticles may serve as carriers for drug loading and delivery for topical pharmaceutical treatments. The deposition process was imaged in real-time using dark-field microscopy. The hair specimens were further studied using a …
Electrochemical treatment of aqueous solutions containing one or many organic pollutants at boron doped diamond anodes. Theoretical modeling and expe…
2012
The electrochemical oxidation of organics in water at boron doped diamonds (BDD) was experimentally investigated with the aim to discuss the correlations among the conversion of the pollutants and the instantaneous current efficiency ICE with the operative conditions. A simple theoretical model previously developed for the oxidation of oxalic acid accounting for the cases of mass transfer control, oxidation reaction control and mixed kinetic regimes was adopted and extended to challenge its predictive capability in the case of organics of different nature and in systems with more pollutants. A quite good agreement, between theoretical predictions and experimental data pertaining to the elec…
Ultrasound-assisted MnO2 catalyzed homolysis of peracetic acid for phenol degradation: The assessment of process chemistry and kinetics
2013
Abstract The combination of peracetic acid (PAA) and heterogeneous catalyst (MnO 2 ) was used for the degradation of phenol in an aqueous solution in the presence of ultrasound irradiation (US). As a relevant source of free radicals (e.g. OH), peracetic acid was comprehensively studied by means of electron spin resonance (ESR) spin trapping (ST) techniques with the subsequent identification of free radicals by simulation based fitting (SBF) technique. The radical reaction mechanism, where hydroxyl radical was a primary product of O O bond rupture of PAA, was established taking into account radical reactions, occurring during sonolysis. The potential barriers and the reaction heat were deter…
Heat Pipe-Cooled Microstructured Reactor Concept for Highly Exothermal Ionic Liquid Syntheses
2010
Heat pipes used for cooling of microstructured reactors are a new approach for sustainable processing also in the lab-scale within a temperature range from ambient to more than 180 °C. The main advantage of heat pipe cooling is the dynamic behavior, i.e., the cooling rate depends on the heat released. Heat pipes can also suppress thermal runaways due to their extremely short response times on momentary temperature rises. As an example, the highly exothermal synthesis of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate from the respective reactants 1-ethyl-imidazole and methyltrifluoromethanesulfonate was investigated. By transferring the protocol to continuous-flow conditions in the mi…
A PERVAPORATION PHOTOCATALYTIC REACTOR FOR THE GREEN SYNTHESIS OF VANILLIN
2012
Abstract Pervaporation is the ideal membrane separation process to be coupled with photocatalysis for the green synthesis of vanillin from ferulic acid. In fact the operative conditions of the two processes are absolutely congruent and the integration is straightforward even operating with separate equipments. The utilization of a highly selective membrane allows the continuous recovery of vanillin by pervaporation from the reacting solution, so that its oxidative degradation is largely avoided and the yield is substantially enhanced. The effects of the main parameters are analyzed resorting to a mathematical model, which is validated by a comparison with the experimental data. In particula…
Size-activity relationship of iridium particles supported on silica for the total oxidation of volatile organic compounds (VOCs)
2019
12 Figures, 2 Tables.-- Datos suplementarios disponibles en línea en la página web del editor.-- © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
Photodegradation of Toluene, m-Xylene, and n-Butyl Acetate and Their Mixtures over TiO2 Catalyst on Glass Fibers
2012
The abatement of typical paint solvent compounds as individuals and in mixtures was carried out in an annular TiO2 supported reactor, for concentrations up to 900 mg C m–3. Two different fiberglass supports were compared, and the catalyst supported over a fiber mat showed better performance, with a lower pressure drop (>35% of reduction) and a slightly higher removal efficiency (about 2%) than that supported over glass wool. For every target compound in the whole range of relative humidity studied (4–75%), the photocatalytic activity increased with the air water content. The removal of the compounds in the binary and ternary mixtures was depressed, even >90% for toluene, compared with indiv…
On the relative sizes of learnable sets
1998
Abstract Measure and category (or rather, their recursion-theoretical counterparts) have been used in theoretical computer science to make precise the intuitive notion “for most of the recursive sets”. We use the notions of effective measure and category to discuss the relative sizes of inferrible sets, and their complements. We find that inferable sets become large rather quickly in the standard hierarchies of learnability. On the other hand, the complements of the learnable sets are all large.