Experimental study of the effect of slotted blades on the Savonius wind turbine performance

This study investigates the effect of Reynolds number on the performance of Savonius wind turbine with slotted blades. The turbine performance investigation was based on the torque coefficient( Ct), power coefficient( Cp), and tip speed ratio( TSR). The experiment used two number of blade configuration, blade overlap ratio of 10%, 12.5% and 20%, slotted position of 15%, 20%, 25% and 35%, and also slotted gap width of 3 mm, 5 mm, 7 mm, and 9 mm. The wind speed carried out in this experiment are 5.94 m/s, 6.46 m/s, 6.99 m/s, and 7.27 m/s, which are generated from the fan blowers as a wind source. The Savonius turbine with 10% overlap ratio shows the best performance. The highest Cp obtained is 0.138 by the variation of a 3 mm gap with Re of 1.44 × 10~4 and 0.526 TSR.     

Lipschitz Stratifications and Generic Wings

The paper shows that, for subanalytic stratifications, Lipschitzequisingularity as defined by Mostowski is preserved after intersectionwith generic wings, that is, L-regularity implies L^*-regularity.This was one of the conditions required of a good equisingularitynotion by Teissier in his foundational 1974 Arcata paper. Previous authors have shown that Lipschitz equisingularity isgeneric, implies bilipschitz triviality, and hence topologicaltriviality, and implies equimultiplicity.     

Synthesis of pyrrolo[3,2,1-hi]indazoles from indole-7-ketoximes

Treatment of the 2,4-dinitrophenyl ethers of some indole-7-ketoximes with base results in a cyclisation reaction to yield pyrrolo[3,2,1-hi]indazoles.     

A hybrid forces Quantum Mechanical Charge Field Molecular Dynamics of Cs+ ion in aqueous ammonia: A solvation lability, “structure breaking” phenomenon and hydrogen bond properties

The dynamics and structure of Cs⁺ solvation in an aqueous ammonia solution have been investigated using the Quantum Mechanical Charge Field Molecular Dynamics (QMCF-MD) simulation method. The system contained 18.6% ammonia in aqueous solution at 298.15 K. The QM region was set to a radius of 7.0 Å to include the first and second solvation shells. The Hartree-Fock (HF) level was applied to calculate the ion-ligand and ligand–ligand interactions in the QM region using the LANL2DZ-ECP basis set for the ion and DZP-Dunning for the ligands. The radial distribution revealed only one solvation shell, indicating a labile solvation structure. The various coordination number of ligands suggests an instant exchange between them. The mean residence times of 1.29 and 0.9 ps were less than in the pure water and liquid ammonia system, indicating higher mobility ligands of the aqueous ammonia system. The preferential factor 0.55 supports the hypothesis that the Cs⁺ ion prefers to be dissolved in water. As the ligands moves further away from the ion, the observed number of hydrogen bonds increases, revealing the “structure-breaking” property of the Cs⁺ ion. The minimum angle ligand-ion-ligand tends to be higher near the ion, confirming this phenomenon.     

Atomically flat gold on elastomeric substrate

We present a procedure to fabricate extremely smooth Au films supported on thin elastomeric (PDMS) substrates. Minimum rms roughness and largest grain size are obtained using Si wafers, coated with native oxide and release layers, as templates for the growth of thermally evaporated Au films. The wafers are held at a temperature of 300 degrees C during deposition. The Au films, up to 200 nm thick, are then transferred onto poly(dimethylsiloxane) substrates which have been previously surface-functionalized with a (3-mercaptopropyl)trimethoxysilane adhesion layer. The resulting Au films have been found by AFM to be extremely smooth with rms-roughness 2.5-4 angstroms and to exhibit a crystalline morphology with flat grains >500 nm in size. Thinner films, down to 20 nm, are grown at lower temperature and are comparably smooth, but with a loss in crystalline morphology. We compare the results of this optimized procedure with other gold films grown on mica sheets as templates and to those produced using Ti-O-Si interfacial chemistry.