Cellulose and cellobiose: adventures of a wandering organic chemist in theoretical chemistry (open access)

Cellulose and cellobiose: adventures of a wandering organic chemist in theoretical chemistry

The energies arising from the rotation of free hydroxyl groups in the central glucose residue of a cellulose crystalline assembly, calculated using RHF, DFT, and FMO2/MP2 methods, will be presented. In addition, interactions of this central glucose residue with some of the surrounding residues (selected on the basis of the interaction strengths) are analyzed. The mechanism of acid-catalyzed hydrolysis of cellobiose, which is the repeating unit of cellulose. Energies corresponding to the different steps of this mechanism calculated using RHF and DFT are compared with those previously reported using molecular dynamics calculations and with experimental data.
Date: April 3, 2012
Creator: Baluyut, John
System: The UNT Digital Library
Increasing the efficiency of organic solar cells by photonic and electrostatic-field enhancements (open access)

Increasing the efficiency of organic solar cells by photonic and electrostatic-field enhancements

Organic photovoltaic (OPV) technology is an attractive solar-electric conversion paradigm due to the promise of low cost roll-to-roll production and amenability to flexible substrates. Power conversion efficiency (PCE) exceeding 7% has recently been achieved. OPV cells suffer from low charge carrier mobilities of polymers, leading to recombination losses, higher series resistances and lower fill-factors. Thus, it is imperative to develop fabrication methodologies that can enable efficient optical absorption in films thinner than optical absorption length. Active layers conformally deposited on light-trapping, microscale textured, grating-type surfaces is one possible approach to achieve this objective. In this study, 40% theoretical increase in photonic absorption over flat OPVs is shown for devices with textured geometry by the simulation results. For verifying this theoretical result and improving the efficiency of OPVs by light trapping, OPVs were fabricated on grating-type textured substrates possessing t pitch and -coat PV active-layer on these textured substrates led to over filling of the valleys and shunts at the crest, which severely affected the performance of the resultant PV devices. Thus, it is established that although the optical design is important for OPV performance but the potential of light trapping can only be effectively tapped if the textures are amenable …
Date: November 3, 2012
Creator: Nalwa, Kanwar
System: The UNT Digital Library
My Spent Life's Breath: A Psychoanalytic Study of Don Carlo Gesualdo (open access)

My Spent Life's Breath: A Psychoanalytic Study of Don Carlo Gesualdo

Undergraduate thesis psychoanalyzing the composer Don Carlo Gesualdo. It focuses on the relationship between the composer and mastery of the musical task. The author examines the life and work of Don Carlo Gesualdo, Prince of Venosa, who was commonly referred to as both musician and murderer.
Date: December 3, 2012
Creator: Coronado, Sam
System: The UNT Digital Library