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Water glasses with different modulus (mole ratio of SiO2 to Na2O) were applied as a raw material to prepare five solid base catalysts for the synthesis of glycerol carbonate (GC) by the transesterification reaction between glycerol and dimethyl carbonate (DMC). The structure and properties of the five water glass-derived catalysts were investigated by XRD, FT-IR, FESEM, BET and acid–base titration methods. The catalysts with relatively low modulus, including 1.0, 1.5 and 2.0, presented good catalytic abilities, among which the catalyst derived from water glass with 2.0 modulus (WG-2.0) was chosen as the optimal catalyst in the synthesis of GC. This was because WG- -2.0 showed the highest BET surface area, relatively high total basicity, and needed a less amount of NaOH during the preparation process. In the optimization experiments, this catalyst exhibited good catalytic ability with the glycerol conversion of 96.3 % and GC yield of 94.1 % under the condition of glycerol to DMC mole ratio of 1:4, WG-2.0 amount of 4 wt. %, reaction temperature of 348 K and reaction time of 90 min. Furthermore, the reusability experiment of WG-2.0 was also conducted and the results indicated that WG- -2.0 could be reused five times without significant reduction in its catalytic ability.

Transient plasma, or plasma during a formative true nonequilibrated phase, is studied as an ignition methodology in comparison with traditional spark ignition (2.5-3 ms and 80 mJ) in a single-cylinder gasoline internal combustion engine. Transient plasmas were generated by applying high-voltage pulses that had comparable energy but that were applied for times that were three to four orders of magnitude shorter--85-ns 60-mJ and 20-ns 57-mJ pulses. These created volume-distributed arrays of streamers, which produced electronically excited species during nanosecond time scales. Reductions in ignition delay, higher peak pressure, and increased net heat release ratio relative to conventional spark ignition were observed in these studies. Transient plasma ignition is demonstrated to initiate combustion rapidly, approaching an ideal constant volume cycle; has potential for improving lean combustion operation; is energy efficient; and is potentially useful for gasoline engine emissions reduction. Index Terms--Automobile ignition, combustion, pulsed corona, transient plasma.

Traumatic brain injury (TBI) is a major cause of mortality and disability worldwide. We validated the utility of plasma metabolomics analysis in the clinical diagnosis of acute TBI in a rat model of controlled cortical impact (CCI) using gas chromatography/mass spectrometry (GC/MS). Thirty Sprague-Dawley rats were randomly divided into two groups of 15 rats each: the CCI group and sham group. Blood samples were obtained from the rats within the first 24 h after TBI injury. GC/MS measurements were performed to evaluate the profile of acute TBI-induced metabolic changes, resulting in the identification of 45 metabolites in plasma. Principal component analysis, partial least squares-discriminant analysis, orthogonal partial least square discriminant analysis using hierarchical clustering and univariate/multivariate analyses revealed clear differences in the plasma metabolome between the acute CCI group and the sham group. CCI induced distinctive changes in metabolites including linoleic acid metabolism, amino acid metabolism, galactose metabolism, and arachidonic acid metabolism. Specifically, the acute CCI group exhibited significant alterations in proline, phosphoric acid, β-hydroxybutyric acid, galactose, creatinine, L-valine, linoleic acid and arachidonic acid. A receiver operating characteristic curve analysis showed that the above 8 metabolites in plasma could be used as the potential biomarkers for the diagnosis of acute TBI. Furthermore, this study is the first time to identify the galactose as a biomarker candidate for acute TBI. This comprehensive metabolic analysis complements target screening for potential diagnostic biomarkers of acute TBI and enhances predictive value for the therapeutic intervention of acute TBI. [ABSTRACT FROM AUTHOR]