In this research, TiO2 nanoparticles were synthesized by a simple wet chemical method. TiCl4 was used as precursor in hydrogen peroxideand ethanol. The TiO2 nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), electron dispersive spectroscopy (EDS) and UV-Vis spectrophotome...

Two new chiral pre-ligands, (R)-3,3'-bis(tetramethylcyclopentadienyl)-2,2'-bismethoxy-1,1'-bisnaphthalene (1) and (R)-3-tetramethylcyclopentadienyl-2,2'-bismethoxy-1,1'-bisnaphthalene (2), were synthesized by reaction of (R)-3,3'-dilithium-2,2'-bismethoxy-1,1'-bisnaphthalene with 2,3,4,5-tetramethyl-2-cyclopentenone at room temperature. Treatment of the pre-ligands 1 and 2 with butyllithium and...

The Me₂Si-bridged ansa-Cp/amido half-metallocene, [Me₂Si(η⁵-Me₄C₅)(NtBu)]TiCl₂, termed a "constrained-geometry catalyst (CGC)", is a representative homogeneous Ziegler catalyst. CGC derivatives with the [1,2]azasilinane framework, in which the amide alkyl substituent is joined by the Si-bridge, were prepared, and the catalytic performances of these species was studied. Me₄C₅HSi(Me)(CH₂CH=CH₂)-N...

For 20+ years, Project LISTEN (www.cs.cmu.edu/~listen) has made computers listen to children read aloud, and help them learn to read. Along the way we have learned lessons about children, reading, speech technology, intelligent tutors, educational data mining, and doing AIED research in schools. 1 Some of the Research Questions Project LISTEN Has Studied Nobel laureate Herbert Simon’s annual ta...

In this study, slurry polymerization kinetics of ethylene with TiCl4/Mg(OEt)2/AlR3 Ziegler-Natta catalysts in various conditions using the model of sum square error (SSE) (method I) and model of least square error (LSE) (Method II) was investigated. For this purpose the molecular weight distributions of the samples were deconvoluted to the minimum number of Flor...