Magnetic nanoparticles (MNPs) have a wide range of applications; an area of particular interest is magnetic particle imaging (MPI). MPI is an imaging modality that utilizes superparamagnetic iron oxide particles (SPIONs) as tracer particles to produce highly sensitive and specific images in a broad range of applications, including cardiovascular, neuroimaging, tumor imaging, magnetic hyperthermia and cellular tracking. While there are hurdles to overcome, including accessibility of products, and an understanding of safety and toxicity profiles, MPI has the potential to revolutionize research and clinical biomedical imaging. This review will explore a brief history of MPI, MNP synthesis methods, current and future applications, and safety concerns associated with this newly emerging imaging modality.

Properties related to the combustion, stability, and compatibility of blends composed of high-viscosity heavy fuel oil (HFO) and highly acidic pyrolysis bio-oil were determined to assess the utility of bio-oil as a marine fuel. The addition of bio-oil was shown to be fully stable with HFO at blend levels up to 50 mass % for up to 2 weeks. Bio-oil concentrations as low as 5 mass % significantly reduced the viscosity of HFO at 25 and 50 °C. Aging studies at 50 and 90 °C showed that the HFO inhibited the polymerization of bio-oil. The heating value and lubricity showed a linear dependency with bio-oil content, and combustion quality was acceptable for blends containing up to 15% bio-oil. The highly acidic bio-oil was found to be corrosive to carbon steel, 2.25Cr-1Mo steel, and 409 stainless steels, but not 304L and 316L. When blended into HFO at levels less than 19 mass %, no measurable corrosion was observed on any of the steel materials, but a 50 mass % concentration produced low-to-moderate corrosion in the carbon steel, 2.25Cr-1Mo steel, and 409 stainless steel grades. The combination of good blend stability, polymerization inhibition, reduced viscosity, and acceptable compatibility for low blend levels suggests that bio-oils may be suitable for use as a marine fuel.

To reduce the amount of greenhouse gas produced from the combustion of petroleum fuels, renewable liquid fuels are needed. Pyrolysis of biomass provides a means to produce liquid fuels to displace current petroleum products. However, common ferrous alloys are susceptible to high corrosion rates when exposed to bio-oil. This study analyzes the effects of blending bio-oil derived from loblolly pine with heavy fuel oil added to reduce corrosion of common structural alloys. Laboratory corrosion studies of six different blends of bio-oil/heavy fuel oil were performed for 1,000 hours at 50℃. Chemical characterization was also performed to determine the total acid content of each blend. Post-exposure characterizations such as changes in weight, X-ray diffraction, dye penetrant testing, and metallography were performed to provide more insight into the corrosion mechanism of bio-oil/heavy fuel oil blends. We hypothesized that the corrosion rates of ferrous alloys would increase with an increase in bio-oil concentration. The results of these characterization and corrosion studies confirmed this hypothesis and will be reported.

This work investigated the corrosivity of biomassderived liquid fuels and organic acids associated with bio-oils and conducted a corrosion compatibility evaluation of several structural ferrous alloys in the fuels and acids. The acidity parameters and solution conductivity values were higher in raw pyrolysis bio-oils than postprocessed oils with significant corrosion attack for carbon steel and Fe-2.25Cr-1Mo. However, higher-grade stainless steels, ferritic Fe-15Cr (15Cb) and austenitic types 304L and 316L, showed negligible corrosion loss, whereas lower-Cr ferritic grades 409, 410, and 416 were attacked. Metal leaching tests and electrochemical impedance spectroscopy measurements revealed superior corrosion resistance of 316 over 410 stainless steels in solutions of formic and oxalic acids that can be present in bio-oils. The corrosion evaluation methods utilized in this work provide effective screening tools to identify the compatible structural alloys for bio-oils.