35,655 research outputs found
Dr Robert King author
No full textDr. Robert King is pictured at the medical office on display at the Bishop Museum. King was the author of "A history of the practice of medicine in Manatee County, Florida", published in 1985. He was also a past president of the Manatee Historical Society
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Thomas W. Cole, Jr., Lou Rawls, and Dr. Dorcas Bowler at Summer Commencement, 1989
No full textThomas W. Cole, Jr., Lou Rawls, and Dr. Dorcas Bowler stand on stage at the summer commencement. Written on verso: CAU Summer Commencement (left to right), Thomas W. Cole, Jr., Lou Rawls, Dr. Dorcas Bowler.The Atlanta University Center Robert W. Woodruff Library acknowledges the generous support of the Council on Library and Information Resources (CLIR) in supporting the processing and digitization of a number of historic collections as part of the project: Our Story: Digitizing Publications and Photographs of the Historically Black Atlanta University Center Institutions.</em
Tight binding molecular dynamics studies of the viscosity of liquid selenium
No full textA tight binding technique is employed to study the influence of the size of the unit cell on molecular dynamics simulations of liquid selenium at 870 K. Systems with 69, 138, 276 and 552 atoms have been studied within the Fermi operator expansion method. The Green-Kubo formula has been used to calculate the shear viscosity for all systems from the off-diagonal component of the stress tensor. No dependence on the cell size could be found within the error bars defined by statistical accuracy. For the two smallest systems calculations up to 60 ps have been performed where the viscosities become identical. These findings indicate that the recently reported disagreement of DFT calculations and experiments on the viscosity of liquid selenium at 870 K must be attributed to a deficiency in the chosen exchange correlation functional rather than size effects
DSSC anchoring groups: a surface dependent decision
No full textElectrodes in dye sensitised solar cells are typically nanocrystalline anatase TiO2 with a majority (1 0 1) surface exposed. Generally the sensitising dye employs a carboxylic anchoring moiety through which it adheres to the TiO₂ surface. Recent interest in exploiting the properties of differing TiO₂ electrode morphologies, such as rutile nanorods exposing the (1 1 0) surface and anatase electrodes with high percentages of the (0 0 1) surface exposed, begs the question of whether this anchoring strategy is best, irrespective of the majority surface exposed. Here we address this question by presenting density functional theory calculations contrasting the binding properties of two promising anchoring groups, phosphonic acid and boronic acid, to that of carboxylic acid. Anchor-electrode interactions are studied for the prototypical anatase (1 0 1) surface, along with the anatase (0 0 1) and rutile (1 1 0) surfaces. Finally the effect of using these alternative anchoring groups to bind a typical coumarin dye (NKX-2311) to these TiO₂ substrates is examined. Significant differences in the binding properties are found depending on both the anchor and surface, illustrating that the choice of anchor is necessarily dependent upon the surface exposed in the electrode. In particular the boronic acid is found to show the potential to be an excellent anchor choice for electrodes exposing the anatase (0 0 1) surface
Intrinsic Oxygen Vacancy and Extrinsic Aluminum Dopant Interplay: A Route to the Restoration of Defective TiO2
No full textDensity functional theory (DFT) and DFT corrected for on-site Coulomb interactions (DFT+U) calculations are presented on aluminum doping in bulk TiO2 and the anatase (101) surface. Particular attention is paid to the mobility of oxygen vacancies throughout the doped TiO2 lattice, as a means by which charge compensation of trivalent dopants can occur. The effect that Al doping of TiO2 electrodes has in dye-sensitized solar cells is explained as a result of this mobility and charge compensation. Substitutional defects in which one Al3+ replaces one Ti4+ are found to introduce valence band holes, while intrinsic oxygen vacancies are found to introduce states in the band gap. Coupling two of these substitutional defects with an oxygen vacancy results in exothermic defect formation which maintain charge neutrality. Nudged elastic band calculations have been performed to investigate the formation of these clustered defects in the (101) surface by oxygen vacancy diffusion, with the resulting potential energy surface suggesting energetic gains with small diffusion barriers. Efficiency increases observed in dye sensitized solar cells as a result of aluminum doping of TiO2 electrodes are investigated by adsorbing the tetrahydroquinoline C2-1 chromophore on the defective surfaces. Adsorption on the clustered extrinsic Al3+ and intrinsic oxygen vacancy defects are found to behave as if adsorbed on a clean surface, with vacancy states not present, while adsorption on the oxygen vacancy results in a down shift of the dye localized states within the band gap and defect states being present below the conduction band edge. Aluminum doping therefore acts as a benign dopant for “cleaning” TiO2 through oxygen vacancy diffusion
Dr. Arthur Pindle, Spelman College, April, 2012
No full textThis video is a conversation with Dr. Arthur Pindle. Dr. Pindle talks about his book, "Bayou St. John". Daniel Le, AUC Woodruff Library, is the interviewer
Linear scaling density matrix real time TDDFT: Propagator unitarity and matrix truncation
No full textReal time, density matrix based, time dependent density functional theory (TDDFT) proceeds through the propagation of the density matrix, as opposed to the Kohn-Sham orbitals. It is possible to reduce the computational workload by imposing spatial cutoff radii on sparse matrices, and the propagation of the density matrix in this manner provides direct access to the optical response of very large systems, which would be otherwise impractical to obtain using the standard formulations of TDDFT. Following a brief summary of our implementation, along with several benchmark tests illustrating the validity of the method, we present an exploration of the factors affecting the accuracy of the approach. In particular, we investigate the effect of basis set size and matrix truncation, the key approximation used in achieving linear scaling, on the propagator unitarity and optical spectra. Finally, we illustrate that, with an appropriate density matrix truncation range applied, the computational load scales linearly with the system size and discuss the limitations of the approach
Dr. Margaret Aymer, ITC, January 2012
No full textThis video is a conversation with Dr. Margaret Aymer. Dr. Aymer talks about her book, "Confessing the Beatitudes". Brad Ost, AUC Woodruff Library, is the interviewer
Dr. Mark Ellingsen, ITC, November 2011
No full textThis video is a conversation with Dr. Mark Ellingsen. Dr. Ellingsen talks about his book, "Lectionary Preaching Workbook, Series IX, Cycle B". Brad Ost, AUC Woodruff Library, is the interviewer
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