Parallel synthesis of 2,4,5-trisubstituted thiophene-3-carbonitrile derivatives on traceless solid support

A parallel solid-phase synthesis of 2,4,5-trisubstituted thiophene-3-carbonitrile derivatives was developed. The polymer-supported synthetic route progressed using the sulfide linker via a traceless strategy. The initial synthesis utilized the Thorpe–Ziegler type cyclization of α-haloketone and polymer-supported 2,2-dicyanoethene-1,1-bis(thiolate), which was derived from the Merrifield resin. The resulting thiophene resin was introduced to one substitution by N-arylation. After oxidation of sulfides to sulfones in the thiophene resins for subsequent cleavage, nucleophilic desulfonative substitution with amines and thiols afforded the desired thiophene-3-carbonitrile derivatives in good overall yields.     

Dc current transport behavior in amorphous GeSe films

The dc electric conduction behavior of amorphous GeSe films sandwiched between the Pt bottom electrode and various counter electrodes (Pt, Cr, and Ti) was examined in a voltage as well as a time domain. The time domain investigation identified time-dependent resistance change and relaxation. The voltage domain analysis revealed that the current transport in these metal-insulator-metal junctions is probably attributed to bulk-limited band-conduction due to delocalized charge carriers.     

Lipid Production by Arctic Microalga Chlamydomonas sp. KNF0008 at Low Temperatures

A lipid-producing microalga, Chlamydomonas sp. KNF0008, collected from the Arctic was capable of growing at temperatures ranging from 4 to 20 °C, and the highest cell density was measured at 15 °C and 100 μmol photons m^?2 s^?1 light intensity under continuous shaking and external aeration. KNF0008 showed the elevated accumulation of lipid bodies under nitrogen-deficient conditions, rather than under nitrogen-sufficient conditions. Fatty acid production of KNF0008 was 4.2-fold (104 mg L^?1) higher than that of C. reinhardtii CC-125 at 15 °C in Bold’s Basal Medium. The dominant fatty acids were C16:0, C16:4, C18:1, and C18:3, and unsaturated fatty acids (65.69%) were higher than saturated fatty acids (13.65%) at 15 °C. These results suggested that Arctic Chlamydomonas sp. KNF0008 could possibly be utilized for production of biodiesel during periods of cold weather because of its psychrophilic characteristics.

     

Improved accuracy of on-line heavy water measurement using infrared spectroscopy by investigation of signal-to-noise ratio and temperature influences

Experimental protocols for the on-line measurement of heavy water concentration in nuclear power plants have been established, and important parameters, such as the temperature and signal-to-noise ratio, which govern the accuracy of measurement, have been studied. The temperature of a sample should be controlled tightly because the temperature variation introduces non-linear baseline variations and leads to an increase of the partial least squares calibration error. Furthermore, the variation in the signal-to-noise ratio of spectra sensitively influences the calibration. For reliable prediction, it is critical to maintain the signal-to-noise ratio at a certain level. When the sample spectra were collected at a higher temperature, it was possible to acquire spectra with an improved signal-to-noise ratio and better calibration. In addition, a single beam spectrum of water shifts to a lower frequency, and the maximum transmission intensity at around 2500 cm(-1)(the heavy water band location) increases at an elevated temperature. Overall, an on-line infrared spectroscopic scheme is presented for measuring heavy water. The scheme can be applied to an actual process without practical difficulties. If the spectra could be collected at elevated temperature over 2 min with the use of a high throughput light source, the prediction error could reach to 1.0 ppm.