Low-Voltage Icing Protection Film for Automotive and Aeronautical Industries.

High-performance heater films are here proposed. They manifest great applicative potentiality in the de-icing technology of aircraft and motor vehicles. The films are suitable to be integrated into composite structures for the de/anti-icing function, which can be activated if the need arises. The heating is based on the joule effect of the current flowing through the electrically conductive films. Voltage and current parameters have been set based on the generators' capacities on-board an aircraft and a car, as well as on the energy consumption during the operating conditions and the autonomy in the time. Green processes have been employed through all preparative steps of the films, which are composed of expanded graphite (60% wt/wt) and polyvinyl alcohol (PVA) (40% wt/wt). The results reveal a very significant influence of the aspect ratio of the filler on the heating and de-icing performance and suggest how to enhance the de-icing efficiency saving energy and adapting the current on-board aircraft/car generators for de-icing operations.

Heterogeneous Fenton Degradation of Patulin in Apple Juice Using Carbon-Encapsulated Nano Zero-Valent Iron (CE-nZVI).

Patulin (PAT), a mycotoxin found mainly in matured apples, is produced by different species of fungi, mainly Penicillium expansum, and is found in various fruits and vegetables used to produce juice. Little focus has been placed on nano-technological methods for the mitigation of this problem. In this work, carbon-encapsulated nano-zero valent iron (CE-nZVI) particles were synthesized and used as heterogeneous Fenton agents for the degradation of PAT in apple juice. The particles were found to have a spherical shape with a diameter of 130 ± 50 nm. In a heterogeneous Fenton degradation (involving CE-nZVI) process, a concentration of 0.05 g/L CE-nZVI with 0.5 mM H2O2 was used. Since the Fenton oxidation process is pH-dependent, placebo degradation was observed at varying pH conditions with an average percentage of PAT degradation of 27.8%, 87.0%, 98.0%, and 99.75% at pH 6, 5, 4.5, and 3.5 respectively, between 1 min to 4 h in a water matrix. In a juice matrix, at the regular pH of juice (3.6), percentage PAT degradation of 72% and 89% was obtained after a 2-h treatment using heterogeneous Fenton oxidation (CE-nZVI/H2O2) systems, using 0.5 mM H2O2 and 1 mM H2O2, respectively.

Study of the presence of PCDDs/PCDFs on zero-valent iron nanoparticles.

Studies show that nanoscale zero-valent iron (nZVI) particles enhance the formation of chlorinated compounds such as polychlorinated dioxins and furans (PCDD/Fs) during thermal processes. However, it is unclear whether nZVI acts as a catalyst for the formation of these compounds or contains impurities, such as PCDD/Fs, within its structure. We analyzed the presence of PCDD/Fs in nZVI particles synthesized through various production methods to elucidate this uncertainty. None of the 2,3,7,8-substituted congeners were found in the commercially-produced nZVI, but they were present in the laboratory-synthesized nZVI produced through the borohydride method, particularly in particles synthesized from iron (III) chloride rather than from iron sulfate. Total PCDD/F WHO-TEQ concentrations of up to 35 pg/g were observed in nZVI particles, with hepta- and octa-chlorinated congeners being the most abundant. The reagents used in the borohydride method were also analyzed, and our findings suggest that FeCl3 effectively contains PCDD/Fs at concentrations that could explain the concentrations observed in the nZVI product. Both FeCl3 and nZVI showed a similar PCDD/F patterns with slight differences. These results suggest that PCDD/Fs might transfer from FeCl3 to nZVI during the production method, and thus, care should be taken when employing certain nZVI for environmental remediation.

Heavy metal release due to aging effect during zero valent iron nanoparticles remediation.

Zero valent iron nanoparticles (nZVI) represent a promising agent for environmental remediation. Nevertheless, their application presents some limitations regarding their rapid oxidation and aggregation in the media. The aim of this study was to determine the effect that nZVI aging has in heavy metal remediation in water. Contaminants studied were Zn, Cd, Ni, Cu and Cr, which are typical elements found in ground and wastewater. Results show a high contaminant removal capacity by the nZVI in the first 2 h of reaction. Nevertheless, for longer reaction times, some of the metal ions that had already been adsorbed in the nZVI were delivered to the water. Cd and Ni show the maximum delivery percentages (65 and 27% respectively after 21 days of contact time). The starting delivery time was shortened when applying lower nZVI amounts. No re-dissolution of Cr was observed in any circumstance because it was the only element incorporated into the nanoparticles core, as TEM images showed. Contaminant release from nZVI is probably due to nanoparticles oxidation caused by aging, which produced a pH decrease and nZVI surface crystallization.

Detection of mycoplasma hominis and ureaplasma urealyticum in women sexually active or not

Los micoplasmas genitales juegan un papel importante en las infecciones del aparato genitourinario, por lo que su estudio es de gran importancia. El objetivo del presente trabajo fue aislar Mycoplasma hominis y Ureaplasma urealyticum a partir de exudados vaginales, faríngeos y de orina de personas con y sin actividad sexual. Se tomaron muestras de mujeres sin infección del aparato genitourinario (testigos) y con infección (problemas) y fueron depositadas en un mililitro de caldo E con arginina o urea y a partir de ellas se realizaron diluciones decimales (10-1 a 10-10) y se incubaron a 37ºC hasta vire del indicador. La identificación de especie se realizó con la técnica de polimerización en cadena utilizando oligonucleótidos específicos para M. hominis que corresponden al gen del RNAr 16S y oligonucleótidos específicos para U. urealyticum que corresponden al gen estructural de la ureasa, la técnica fue realizada de acuerdo con Blanchard et al. No hubo diferencias significativas (X² P > .05), en los porcentajes de aislamiento de estos microorganismos a partir de exudados vaginales, pero sí hubo a partir de muestras de orina. Estos micoplasmas fueron aislados en altos porcentajes de mujeres adolescentes y fueron recuperados hasta la quinta dilución decimal. A partir de exudados faríngeos sólo fueron aislados de mujeres con actividad sexual