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.

The meat industry generates a large amount of waste that can be used to create useful products such as bio-implants, which are usually expensive. In this report, we present an economic analysis of a continuous process for large-scale chemically cross-linked collagen scaffold (CCLCS) production in a Mexican context. For this purpose, three production capacities were simulated using SuperPro Designer^® v 12.0: 5, 15, and 25 × 10³ bovine pericardium units (BPU) per month as process feedstock. Data indicated that these capacities produced 2.5, 7.5, and 12.5 kg of biomesh per batch (per day), respectively. In addition, Net Unit Production Costs (NUPC) of 784.57, 458.94, and 388.26 $USD.kg⁻¹ were obtained, correspondingly, with selling prices of 0.16 ± 0.078 USD.cm⁻², 0.086 ± 0.043 USD.cm⁻², and 0.069 ± 0.035 USD.cm⁻², in the same order. We found that these selling prices were significantly lower than those in the current market in Mexico. Finally, distribution of costs associated with the process followed the order: raw materials > facility-dependent > labor > royalties > quality analysis/quality control (QA/QC) > utilities. The present study showed the feasibility of producing low-cost and highly profitable CCLCS with a relatively small investment. As a result, the circular bioeconomy may be stimulated.

Broccoli waste (Brassica oleracea), comprising non-commercialized stems and leaves, represents a valuable substrate for bioenergy and commodity recovery within agro-industrial systems. This study evaluates the potential of dark fermentation (DF) to produce hydrogen (H₂) and carbon dioxide (CO₂) from unpretreated broccoli residues. Batch experiments (120 mL) yielded maximum gas production rates of up to 166 mL/L·d, with final compositions of 41.43 mol% and 58.56 mol% of H₂ and CO₂, respectively. Based on these results, two biorefinery models were simulated using COCO v3.10 and SuperPro Designer^® v12.0, incorporating absorption and cryogenic separation technologies in the purification stage. Two scenarios were considered: Option A (169.82 kmol/day; H₂: 0.5856 mol fraction, CO₂: 0.4143 mol fraction) and Option B (72.84 kmol/day; H₂: 0.6808 mol fraction, CO₂: 0.3092 mol fraction). In both configurations, the purities of the final streams were the same, being 99.8% and 99.8% for both H₂ and CO₂, respectively. However, energy consumption was 43.76% higher in the cryogenic H₂/CO₂ separation system than in the absorption system. Noteworthily, this difference does not depend on the stream’s composition. Furthermore, from a financial standpoint, the cryogenic system is more expensive than the absorption system. These findings confirm the feasibility of designing biorefineries for H₂ production with high CO₂ recovery from broccoli waste. However, the economic viability of the process depends on the valorization of the secondary effluent from the fermentation reactor, which may require subsequent anaerobic digestion stages to complete the degradation of residual organic matter and enhance overall resource recovery.

El efecto de la velocidad de agitación, temperatura, velocidad de alimentación de los reactivos, así como la solubilidad de los precursores en el tamaño de la síntesis de nanopartículas magnéticas (MNPs) obtenidas por coprecipitación fue investigado. El tamaño de las MNPs obtenidas fue de 7 a 15 nm. El tamaño y la morfología de las MNPs se caracterizaron mediante microscopia electrónica de transmisión (TEM). La difracción de rayos X (XRD) permitió determinar las fases de óxido presentes, así como la cristalinidad de la muestra obtenida. La técnica de espectroscopia de IR ayudó a identificar el enlace Fe–O así como las impurezas presentes en la muestra. Para determinar sus propiedades magnéticas se obtuvieron los ciclos de histéresis, los cuales se midieron a temperatura ambiente empleando un magnetómetro de muestra vibrante (VSM). Finalmente, para determinar el efecto de esta variación de parámetros operativos claves durante la síntesis, fue a través de un diseño de experimentos 2^k, tomando como variable de respuesta el tamaño de partícula. Los resultados mostraron que la combinación de reactivos que proporciona el tamaño máximo de partícula es cuando se presenta una alta solubilidad de los precursores. Además se observó que existe una relación directa entre la disminución de la polidispersidad de las partículas y la disminución de la temperatura de reacción. Finalmente estas MNPs son candidatas para ser empleadas en aplicaciones biomédicas, debido al tamaño, la polidispersidad estrecha, alta cristalinidad y una alta magnetización de saturación.

This study presents a method to recover the response function of a flexible latex membrane undergoing a dynamic event by volume oscillation using Double Digital Fringe Projection to measure the profile of the surface in a sequence of frames. By applying a frequency filter to the interference pattern, a moiré pattern was obtained. Optical phase retrieval from individual frames was performed using the Isotropic Quadrature Transform Algorithm. This fringe projection technique enables full-field measurements, including edges where other techniques could not perform due to shadows generated by the tilt angle. The procedure was devised as a non-contact system to retrieve the deformation function of a flexible surface, enhancing a valuable aspect of the methodology. The results demonstrate successful recovery of the membrane response function, highlighting the relevance of the method for accurate deformation measurements using a straightforward system. These outcomes provide significant value for the development of precise measurement techniques for flexible structures in engineering applications, such as soft robotics, biomedical devices, and material science. Este estudio presenta un método para recuperar la función de respuesta de una membrana de látex flexible sometida a un evento dinámico por oscilación de volumen utilizando Proyección de Franjas Digital Doble para medir el perfil de la superficie en una secuencia de fotogramas. Aplicando un filtro de frecuencia al patrón de interferencia, se obtuvo un patrón muaré. La recuperación de fase óptica de cuadros individuales se realizó utilizando el algoritmo de transformación de cuadratura isotrópica. Esta técnica de proyección de franjas permite realizar mediciones de campo completo, incluidos los bordes donde otras técnicas no podrían realizarse debido a las sombras generadas por el ángulo de inclinación. El procedimiento se ideó como un sistema sin contacto para recuperar la función de deformación de una superficie flexible, mejorando un aspecto valioso de la metodología. Los resultados demuestran una recuperación exitosa de la función de respuesta de la membrana, destacando la relevancia del método para mediciones precisas de la deformación utilizando un sistema sencillo. Estos resultados aportan un valor significativo para el desarrollo de técnicas de medición precisas para estructuras flexibles en aplicaciones de ingeniería, como robótica blanda, dispositivos biomédicos y ciencia de materiales.