A scanning system for specific absorption rate of ferrofluids with superparamagnetic nanoparticles is presented in this study. The system contains an induction heating device designed and built with a resonant inverter in order to generate magnetic field amplitudes up to 38 mT, over the frequency band 180-525 kHz. Its resonant circuit involves a variable capacitor with 1 nF of capacitance steps to easily select the desired frequency, reaching from 0.3 kHz/nF up to 5 kHz/nF of resolution. The device performance is characterized in order to compare with the theoretical predictions of frequency and amplitude, showing a good agreement with the resonant inverters theory. Additionally, the setup is tested using a synthetic iron oxide with 10 ± 1 nm diameter suspended in liquid glycerol, with concentrations at 1%. Meanwhile, the temperature rise is measured to determine the specific absorption rate and calculate the dissipated power density for each f. This device is a suitable alternative to studying ferrofluids and analyzes the dependence of the power absorption density with the magnetic field intensity and frequency.

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This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. b s t r a c tThe structure of thermally coupled distillation systems offers several control challenges arising from the transfer of vapor (or liquid) streams between columns. In particular, the presence of recycle streams for coupled schemes has led to the notion that control problems might be expected during the operation of these systems, in contrast to the rather well-known behavior of conventional distillation sequences.In this work, we analyze the control properties of thermally coupled extractive distillation schemes studied previously (Gutiérrez-Guerra, R., Segovia-Hernández, J.G. and a closed-loop analysis. The results showed that the energy savings predicted in the complex extractive distillation sequence can be achieved along with good dynamic behavior and reductions in greenhouse gas emissions.

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The synthesis of magnetic nanoparticles by thermal decomposition in organic media has been studied in this work. The analysis was focused on external parameters, like stirring rate and reaction growth kinetics, given that they are crucial for scaling up the synthesis of magnetic nanoparticles. These parameters have been shown to control magnetite nanoparticle size and size distribution. Magnetite nanoparticles were prepared by thermal decomposition of iron(III) acetylacetonate in 1-octadecene using different stirring rates. At 100 rpm, the largest particle size was achieved, ca. 10 nm, which showed superparamagnetic behavior at room temperature. Growth kinetics were studied at a stirring rate (r) of 100 rpm. Data showed that during magnetite synthesis, particle growth exhibits a sigmoidal behavior and a final Oswald ripening process. Data were fitted to the double Boltzmann function.