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Spatially resolved optical emission spectroscopy was used to determine the atomic excitation temperature of the capacitively coupled radio-frequency (RF) plasma system. Low pressure plasmas of methane or propane in hydrogen were excited at 13.56 MHz in a parallel plate system. Ar was added as an actinometer. Optical emission lines in the 300-850 nm spectral range were investigated at typical conditions of 100 W RF power, ∼30 mTorr pressure, 20 mm electrode spacing and 50 sccm total flow rate. Two-dimensional intensity profiles of the important species were collected along the vertical and radial axes. The raw radial intensity was transformed into the actual local radiation intensity by Abel inversion. The atomic hydrogen and argon excitation temperature distributions between the power and grounded electrodes were derived from these data and distinct differences were found in methane-and propane-containing plasmas.

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This work presents a novel route for utilizing waste from power plants to create a new power source (solar cells). Bottom ash (BA) ceramic micro-particles were studied to improve an electrocatalytic activity in solar cell applications for the first time. In the counter electrodes (CE) of dye-sensitized solar cells (DSSC), bottom ash was mixed with PEDOT:PSS (PP) and polyvinylpyrrolidone (PVP) (BA/PP/PVP) in volume ratios of 3:7, 4:6, 5:5, and 6:4. We found that bottom ash has a significant impact in improving the electrocatalytic activity and DSSC efficiency of these cells. Moreover, the PP and PVP ratios have a high impact on solar cell performance. The BA/PP/PVP-(6:4) counter electrode attained a higher DSSC efficiency, 2.70%, compared to the other electrodes prepared under similar conditions and a Pt CE based DSSC (3.23%) at AM 1.5 (100 mWcm-2). The influences of bottom ash and PP/PVP ratios on film structure, electrocatalytic activity in reduction, redox reaction rate, and electron transport were characterized using scanning electron micros copy, cyclic voltammetry, Tafel, and, electrical impedance spectroscopy, respectively. The results show that low-cost BA/PP/PVP-(6:4) CE is a promising new alternative to Pt CEs in DSSCs.

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Suitable scaffolds for tissue engineering should provide a microenvironment for cell dwelling and directing cell behavior that resemble the native environment. Three-dimensional geometry of electrospun scaffolds well supports cell deposition, but they often lack biomacromolecules to induce cell responses. In this work, the repetitive collagen and fibronectin motif (rCF) peptide containing multiple repeats of Gly-Leu-Lys-Gly-Glu-Asn-Arg-Gly-Asp sequence derived from the cell adhesion motifs of collagen and fibronectin was produced as the alternative agent to induce cell-scaffold interaction. The DNA fragment encoding rCF peptide was amplified by a polymerase chain reaction using overlap primers without a DNA template, cloned into a protein expression vector, and expressed as a His-tag fusion peptide in Escherichia coli. The purified rCF peptide possessed cell adhesion activity about 1.5-fold of the commercial RGD peptide. The rCF peptide was grafted onto the electrospun PCL scaffold via RF plasma of Ar/O2 discharge and acrylic acid treatment. The immobilized rCF peptide significantly increased surface hydrophilicity and enhanced cell proliferation of the electrospun PCL scaffold. These findings suggest the potential application of rCF peptide for improving the biomimetic functions of polymeric scaffolds for tissue engineering.