Browsing by Subject "activation"

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Development and analysis of trapped field magnets in electromechanical devices
(0000-00-00) Davey, K.; Wienstein, R.; Sawh, R.
High temperature superconducting trapped field magnets (TFM) offer great potential as an alternative to 2>d generation YBCO wire, both in cost and performance. Attention is given to the calculation of current distribution within YBCO disks at partial and full activation and comparing this to experimental values. The best results are obtained by treating the current as a sequence of nested current rings. The fields are computed by integrating the elliptic integrals representing the fields from these rings and using variable metric optimization to choose the ring radii to best match the activation field over the on-activated material. A technique for treating the sub-regions of the TFM as voltage fed coils appears most expeditious for computing forces.
Exceptionally Efficient Catalytic Hydrodechlorination of Persistent Organic Pollutants: Application of New Sterically Shielded Palladium Carbene Complexes
(2014-10) Saberov, Vagiz Sh.; Evans, Daniel A.; Korotkikh, Nikolai I.; Cowley, Alan H.; Pekhtereva, Tatyana M.; Popov, Anatolii F.; Shvaika, Oles P.; Evans, Daniel A.; Cowley, Alan H.
A new sterically shielded carbene with branched aromatic substituents (9a) and two palladium halogenide complexes have been prepared. The single crystal X-ray structures of free carbene 9a and palladium carbene complexes 10b and 11a were determined. Very high catalytic efficiencies were evident for the sterically shielded palladium carbene complexes 10b and 11a,b when the latter complexes were employed as catalysts for hydrodechlorination of the chloroarenes p-dichlorobenzene and hexachlorobenzene. When optimized, the foregoing approach is significantly more effective than those of currently known transition metal carbene complexes. The most active catalysts were found to be the monocarbene complexes of palladium chloride and iodide, both of which feature highly branched aromatic substituents (11a,b).
Structure of the iSH2 domain of human phosphatidylinositol 3-kinase p85b subunit reveals conformational plasticity in the interhelical turn region
(2010-12) Schauder, Curtis; Ma, Li-Chung; Krug, Robert M.; Montelione, Gaetano T.; Guan, Rongjin; Krug, Robert M.
Phosphatidylinositol 3-kinase (PI3K) proteins actively trigger signaling pathways leading to cell growth, proliferation and survival. These proteins have multiple isoforms and consist of a catalytic p110 subunit and a regulatory p85 subunit. The iSH2 domain of the p85 beta isoform has been implicated in the binding of nonstructural protein 1 (NS1) of influenza A viruses. Here, the crystal structure of human p85 beta iSH2 determined to 3.3 A resolution is reported. The structure reveals that this domain mainly consists of a coiled-coil motif. Comparison with the published structure of the bovine p85 beta iSH2 domain bound to the influenza A virus nonstructural protein 1 indicates that little or no structural change occurs upon complex formation. By comparing this human p85 beta iSH2 structure with the bovine p85 beta iSH2 domain, which shares 99% sequence identity, and by comparing the multiple conformations observed within the asymmetric unit of the bovine iSH2 structure, it was found that this coiled-coil domain exhibits a certain degree of conformational variability or `plasticity' in the interhelical turn region. It is speculated that this plasticity of p85 beta iSH2 may play a role in regulating its functional and molecular-recognition properties.
Syntheses of Sterically Shielded Stable Carbenes of the 1,2,4-Triazole Series and their Corresponding Palladium Complexes: Efficient Catalysts for Chloroarene Hydrodechlorination
(2014-11) Glinyanay, Nataliya V.; Saberov, Vagiz S.; Korotkikh, Nikolai I.; Cowley, Alan H.; Butorac, Rachel R.; Evans, Daniel A.; Pekhtereva, Tatyana M.; Popov, Anatolii F.; Shvaika, Oles P.; Cowley, Alan H.; Butorac, Rachel R.; Evans, Daniel A.
The new sterically shielded 1,3,4-trisubstituted 1,2,4-triazol-5-ylidenes 8b-d were synthesized by a three step method starting from 2-phenyl-1,3,4-oxadiazole. The syntheses of palladium complexes 9a-d and 10a-d (including the sterically shielded derivatives 9c,d and 10a-d) were carried out via the reactions of the stable carbenes 8a-d with palladium halogenide salts in THF or toluene solution. Complexes 9c,d and 10a-d were found to be excellent catalysts for the reductive dechlorination (hydrodechlorination) of p-dichlorobenzene. The structures of 8c, 9a,b, and 10a were determined by single-crystal X-ray diffraction.
The Behavior of Chromium in the Activated Sludge Process
(University of Texas at Austin, 1988-08) Imai, A.; Gloyna, E.F.