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Physical Sciences and Mathematics Commons

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Chemistry

San Jose State University

2012

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

Fast Melt Cooled Superconducting Alloys: (Bi1.97pb0.03sr2can‐1cuno2n+4+Δ)2 N/N’ N<24 Intergrowth, J. Kmiec, Juana Acrivos, D. Gulamova, J. Chigvinadze Oct 2012

Fast Melt Cooled Superconducting Alloys: (Bi1.97pb0.03sr2can‐1cuno2n+4+Δ)2 N/N’ N<24 Intergrowth, J. Kmiec, Juana Acrivos, D. Gulamova, J. Chigvinadze

Faculty Publications, Chemistry

High temperature layer superconducting cuprate (HTLSC) alloys: (Bi1.97Pb0.03Sr2Can-1CunO2n+4+δ)2 called (2s:2:n-1:n) have been grown from n-oxide stoichiometric melts in concentrated sun flux, followed by rapid cooling SFQA technology that preserves the melt tiling after annealing at 845±5oC**. Synchrotron XRD at the DOE SLAC-SSRL near the Cu K-edge has identified the mixing of n ≠ n’ alloys as observed by many in thin films last century. An ideal D17 4h Space Group structure obtains {an, bn, cn} = {3.815 Å, an+ubn, 2dP(n+3)+ucn} where dP is a perovskite sandwich, (CuO2)1/2|_Ca|(CuO2)1/2, thickness, and un are the amplitudes of periodic lattice distortions, PLD also observed …


Résonance Dans Alliages Des Couches Supraconductrices Refroidi Rapidement: (Bi1.7pb0.3sr2can‐1cuno2n+4+Δ)2, N=1 To 9détecté Par Local Renforcée Atomique Xrd, Juana Acrivos, J. Chigvinadze, D. Gulamova May 2012

Résonance Dans Alliages Des Couches Supraconductrices Refroidi Rapidement: (Bi1.7pb0.3sr2can‐1cuno2n+4+Δ)2, N=1 To 9détecté Par Local Renforcée Atomique Xrd, Juana Acrivos, J. Chigvinadze, D. Gulamova

Faculty Publications, Chemistry

Lien résonance dans alliages supraconductrice à haute température (HTLSC): (Bi1.7Pb0.3Sr2Can-1CunO2n+4+δ)2,n=1-9 appelé (2s:2:n-1:n) préparé en Ouzbékistan à partir de oxide fondu par flux concentré du Soleil, suivi d'un refroidissement rapide, technologie SFQA préserve fondre carrelage. Tc,n est mesurée en Tbilissi, et atomique local renforcée synchrotron diffraction des rayons X, (XRD) à proximité de la Cu-K bord est effectuée à DOE National Laboratoire SLAC-SSRL. La structure indexé dans le groupe D17 4h démontre qui (n-1) unîtes: (CuO2)1/2/Ca/(CuO2)1/2 sont intercalés à chaque extrémité de la phase n=1: [(CuO2)1/2/SrO/Bi1.7Pb0.3O/Bi1.7Pb0.3O/SrO/(CuO2)1/2]2. Les effets de surface conduit à intercalations des different n-phase, et à des distorsions réseau …


Covalent Bonds In Superconducting Rapid Cooled Alloys: (Bi1.7pb0.3sr2can‐1cuno2n+4+Δ)2, N=1 To 9 Detected By Local Atomic Enhanced Xrd, J. Kmiec, K. Tyson, Juana Acrivos, D. Gulamova, J. Chigvinadze Apr 2012

Covalent Bonds In Superconducting Rapid Cooled Alloys: (Bi1.7pb0.3sr2can‐1cuno2n+4+Δ)2, N=1 To 9 Detected By Local Atomic Enhanced Xrd, J. Kmiec, K. Tyson, Juana Acrivos, D. Gulamova, J. Chigvinadze

Faculty Publications, Chemistry

High temperature layer superconducting cuprates (HTLSC) alloys: (Bi1.7Pb0.3Sr2Can-1CunO2n+4+δ)2,n=1-9 called (2s:2:n-1:n) prepared in Uzbekistan from melts in concentrated sun flux, followed by rapid cooling, SFQA technology that preserves melt tiling by confinement of conduction layer: |(CuO2)1/2|Ca|(CuO2)1/2]n-1| in the hard shell ||, of the n=1 phase,[(CuO2)1/2|SrO|Bi1.7Pb0.3O|Bi1.7Pb0.3O|SrO|(CuO2)1/2]2. Disproportion leads to different n-phase mixing, and periodic lattice distortions (PLD) through bond resonance covalent crystalaxes: 2(rCu+2+rO-2)=4.2Å>a=3.82Å>d(CuO)+2-3/2d(O3))=3.2Å≈(cn-c1)/2(n-1). Individual phase local bonds Cu-Ca, Cu-Sr, Cu-O-Cu are ascertained by X-Ray diffraction near Cu K-edgefollowed by Cu-Ca bond scattering. The HTLSC density, ρ decrease as n increases obtains Tc,n ~180 K, identified due to n=8 phase on …


Bond Resonance In Superconducting Rapid Cooled Alloys: (Bi1.7pb0.3sr2can‐1cuno2n+4+Δ)2, N=1 To 9 Detected By Novel Local Atomic Enhanced Xrd, K Tyson, J Kmiec, Juana Acrivos, D. Gulamova, J Chigvinadze Mar 2012

Bond Resonance In Superconducting Rapid Cooled Alloys: (Bi1.7pb0.3sr2can‐1cuno2n+4+Δ)2, N=1 To 9 Detected By Novel Local Atomic Enhanced Xrd, K Tyson, J Kmiec, Juana Acrivos, D. Gulamova, J Chigvinadze

Faculty Publications, Chemistry

We discuss bond resonance in high temperature layer superconducting cuprates, HTLSC alloys: (Bi1.7Pb0.3Sr2Can‐1CunO2n+4+δ)2,n=1‐9 called (2s:2:n‐1:n) prepared in Uzbekistan from melts in concentrated sun flux, followed by rapid cooling, SFQA technology that preserves melt tiling, Tc,n measured in Tiblisi, and local atomic enhanced synchrotron X‐ray diffraction, XRD near the Cu K‐edge at DOE National Laboratory SLAC‐SSRL. The SFQA alloys structure indexed in the ideal D17 4h Space Group indicates (n‐1) units: (CuO2)1/2/Ca/(CuO2)1/2 are intercalated at each end of the n=1 phase [(CuO2)1/2/SrO/Bi1.7Pb0.3O/Bi1.7Pb0.3O/SrO/(CuO2)1/2]2. Surface effects lead to different n‐phase mixing, and periodic lattice distortions, PLD, through bond resonance in crystal axes: 2(rCu+2+rO‐2)=4.2Å …


Silica As A Matrix For Encapsulating Proteins:Surface Effects On Protein Structure Assessed By Circular Dichroism Spectroscopy, Daryl K. Eggers, P. J. Calabretta, M. C. Chancellor, C. Torres, G. R. Abel Jr., C. Neihaus, N. J. Birtwhistle, N. M. Khouderchah, G. H. Zemede Jan 2012

Silica As A Matrix For Encapsulating Proteins:Surface Effects On Protein Structure Assessed By Circular Dichroism Spectroscopy, Daryl K. Eggers, P. J. Calabretta, M. C. Chancellor, C. Torres, G. R. Abel Jr., C. Neihaus, N. J. Birtwhistle, N. M. Khouderchah, G. H. Zemede

Faculty Publications, Chemistry

The encapsulation of biomolecules in solid materials that retain the native properties of the molecule is a desired feature for the development of biosensors and biocatalysts. In the current study, protein entrapment in silica-based materials is explored using the sol-gel technique. This work surveys the effects of silica confinement on the structure of several model polypeptides, including apomyoglobin, copper-zinc superoxide dismutase, polyglutamine, polylysine, and type I antifreeze protein. Changes in the secondary structure of each protein following encapsulation are monitored by circular dichroism spectroscopy. In many cases, silica confinement reduces the fraction of properly-folded protein relative to solution, but addition …


Silica As A Matrix For Encapsulating Proteins:Surface Effects On Protein Structure Assessed By Circular Dichroism Spectroscopy, Daryl K. Eggers, P. J. Calabretta, M. C. Chancellor, C. Torres, G. R. Abel Jr., C. Neihaus, N. J. Birtwhistle, N. M. Khouderchah, G. H. Zemede Jan 2012

Silica As A Matrix For Encapsulating Proteins:Surface Effects On Protein Structure Assessed By Circular Dichroism Spectroscopy, Daryl K. Eggers, P. J. Calabretta, M. C. Chancellor, C. Torres, G. R. Abel Jr., C. Neihaus, N. J. Birtwhistle, N. M. Khouderchah, G. H. Zemede

Daryl K. Eggers

The encapsulation of biomolecules in solid materials that retain the native properties of the molecule is a desired feature for the development of biosensors and biocatalysts. In the current study, protein entrapment in silica-based materials is explored using the sol-gel technique. This work surveys the effects of silica confinement on the structure of several model polypeptides, including apomyoglobin, copper-zinc superoxide dismutase, polyglutamine, polylysine, and type I antifreeze protein. Changes in the secondary structure of each protein following encapsulation are monitored by circular dichroism spectroscopy. In many cases, silica confinement reduces the fraction of properly-folded protein relative to solution, but addition …