The fabrication of electrodes use in proton exchange membrane fuel cells (PEMFCs) by Pt sputter deposition has great potential to increase Pt utilization and reduce Pt loading without loss of cell performance. A radio frequency (RF) magnetron sputter deposition process (RF power = 100 W and argon pressure = 10⁻³ Torr) was adopted to prepare Pt catalyst layers of PEMFC electrodes. The effects of cathode Pt and Nafion loadings on membrane electrode assembly (MEA)/cell performance were investigated using cell polarization, cyclic voltammetry, AC impedance, and microstructure analysis. Among the tested MEAs with various cathode Pt loadings (0.02–0.4 mg cm⁻²), the one with 0.1 mg-Pt cm⁻² (grain size = 3.90 nm, mainly Pt(111)) exhibited the best cell performance (320 and 285 mW cm⁻² at 0.44 and 0.60 V, respectively), which was similar to or better than those of some commercial nonsputtered/sputtered electrodes with the same or higher Pt loadings. The electrode Pt utilization efficiency increased as the Pt loading decreased. A Pt loading of greater than or lower than 0.1 mg cm⁻² yielded a lower electrode electrochemical active surface (EAS) area but a higher charge transfer and diffusion resistance. Nafion impregnation (0.1 to 0.3 mg cm⁻²) into the sputtered Pt layer (Pt = 0.1 mg cm⁻²) noticeably increased the EAS area, consistent with the decrease of the capacitance of the electrode double layer, but did not improve MEA/cell performance, mainly because of the increase in the kinetic and mass transfer resistances associated with oxygen reduction on the cathode. Copyright © 2011 John Wiley & Sons, Ltd.

The oily sludge from crude oil contains hazardous BTEX (benzene, toluene, ethylbenzene, xylene) found in the bottom sediment of the crude oil tank in the petroleum refining plant. This study uses microwave treatment of the oily sludge to remove BTEX by utilizing the heat energy generated by the microwave. The results show that when the oily sludge sample was treated for 60 s under microwave power from 200 to 300 W, the electric field energy absorbed by the sample increased from 0.17 to 0.31 V/m and the temperature at the center of the sludge sample increased from 66.5 °C to 96.5 °C. In addition, when the oily sludge was treated for 900 s under microwave power 300 W, the removal rates were 98.5% for benzene, 62.8% for toluene, 51.6% for ethylbenzene, and 29.9% for xylene. Meanwhile, the highest recovery rates of light volatile hydrocarbons in sludge reached 71.9% for C₃, 71.3% for C₄, 71.0% for C₅, and 78.2% for C₆.

Non-thermal plasma (NTP) has been widely applied in the food and agricultural industries. It is still unknown whether natural bioactive compounds in seeds are affected by NTP treatment. Our goal was to examine whether the bioactive compounds in djulis (Chenopodium formosanum Koidz.) seed are changed after NTP treatment. The betacyanin, anthocyanin, total phenolic content (TPCs), total flavonoids (TFs), 2,2-diphenyl-1-picrylhydrazyl radical scavenging effects (DPPH), gallic acid, and rutin were compared in NTP-treated seed and an untreated control. Levels of betacyanin, anthocyanin, and TPCs in the seed were found to be significantly increased after the nitrogen (N₂)-NTP treatment compared with the control (p < 0.001). Inversely, the air-NTP treatment significantly weakened the performance of these bioactive compounds in the seed as compared to the control. Levels of TFs in both the air- and N₂-NTP treated seed were significantly lower than those in the control (p < 0.001). After the NTP treatment, DPPH was still at high levels, similar to those in the control. The djulis seed extract had antioxidant and anti-inflammatory effects on THP-1 (human-monocyte-cell line) cells. N₂-NTP generated nitrogen reactive species that activated the bioactive compounds in the seed. In contrast, air-NTP produced oxygen and nitrogen reactive species inhibited the expression of these bioactive compounds.

The synthesis of aluminum nitride (AlN) powders is traditionally done via the thermal nitridation process, in which the reaction temperature reaches as high as 960 °C, with more than several hours of reaction time. Moreover, the occurrence of agglomeration in melting Al particles results in poor AlN quality and a low efficiency of nitridation. In this study, an atmosphere-pressure microwave-plasma preceded the pre-synthesis process. This process operates at 550 °C for 2–10 min with the addition of NH₄Cl (Al: NH₄Cl = 1:1) for generating a hard AlN shell to avoid the flow and aggregation of the melting Al metals. Then, the mass production of AlN powders by the thermal nitridation process can be carried out by rapidly elevating the reaction temperature (heating rate of 15 °C/min) until 1050 °C is reached. X-Ray Diffractometer (XRD) crystal analysis shows that without the peak, Al metals can be observed by synthesizing AlN via plasma nitridation (at 550 °C for 2 min, Al: NH₄Cl = 1:1), followed by thermal nitridation (at 950 °C for 1 h). Moreover, SEM images show that well-dispersed AlN powders without agglomeration were produced. Additionally, the particle size of the produced AlN powder (usually < 1 μm) tends to be reduced from 2–5 μm (Al powders), resulting in a more efficient synthesizing process (lower reaction temperature, shorter reaction time) for mass production.