Property Morphology Correlations of Organic Semiconductor Nanowires

Chemically doped and non-doped P3HT nanoaggregates are studied to establish a comprehensive understanding of the interplay between their morphology and various optoelectronic properties. One-dimensional nanoaggregates of P3HT are chosen as the model systems here due to their high surface/volume ratio and suitability for microscopic investigations. Atomic force microscopy (AFM) and kelvin probe force microscopy (KPFM) are used to correlate property/morphology characteristics of non-doped P3HT nanowhiskers. Topographical measurements indicate that individually folded P3HT motifs stack via interfacial interactions to form nanowhiskers in solution. Further aging leads to multi-layered nanowhiskers with greater stability and less instances of π-π sliding of interfacial edge-on oriented motifs. KPFM measurements show higher surface potentials on portions of nanowhiskers containing local defects and stacking faults due to overlapping, and nanowhiskers that are at least triple-layered. Simultaneous UV-Vis and AFM characterizations compare the aggregation rates and morphologies of doped and non-doped P3HT nanowhiskers. Allowing fully solubilized P3HT to age without doping may produce high aspect ratio nanowhiskers containing disordered segments protruding out from the edges of the nanowhiskers. These protruding segments could also serve as “tie-molecules” between adjacent nanowhiskers. Doping fully solubilized P3HT will lead to substantially higher rates of P3HT aggregation. Doped nanowhiskers also display different morphologies. They pack tighter, are smoother, and are thicker and higher versus non-doped nanowhiskers, indicating a different aggregation mechanism. Stopped flow-kinetics was employed to investigate the reactivity of two distinctively different morphological forms of P3HT towards dopants. Fully solubilized P3HT undergoes a slow doping mechanism whereas pre-aggregated P3HT undergoes a fast doping mechanism. Pseudo-single reactant rate fittings indicate that both mechanisms appear to be 1st order in P3HT, whereby pre-aggregated P3HT mixtures will produce more doped products per P3HT monomer unit than fully solubilized P3HT. This study highlights the impact of conjugated polymer’s morphology on their doping efficiency. Density functional theory was used to investigate the charge transfer (CT) states between oligothiophene and F4-TCNQ. CT of several unreported complexes that feature two oligomers stacked in a sandwich or layered configuration is investigated. Our preliminary results suggest that these new complexes can generate substantially more charge per F4-TCNQ than previously reported

A towed, multi-frequency H.F. sonar system for scattering and ocean dynamics studies

The system described provides wide operational flexibility at any operating frequency from 5 kHz to over 800 kHz (except for a small band around 455 kHz) limited mainly by the availability of transducers. Variable pulse width, variable receiver bandwidth, low receiver noise, various time variable gain functions and wide system dynamic range characterized the system. Built-in time-sharing controls maximize flexibility of graphics display on either dry-paper or fibre-optic CRT recorders.Prepared for the NORDA under Contract N00014-77-C-0196; and for the National Oceanic and Atmospheric Administration under Grant 04-8-MO1-43

Selection of patients with cystic fibrosis for lung transplantation

Journal ArticleLung transplantation is the most aggressive therapy available for end-stage lung disease from cystic fibrosis (CF). A new predictive survival model of CF uses demographic, FEV1, nutritional, microbiologic, and acute exacerbation data to produce precise estimates of 5-year survival

Remote acoustic sensing of the particulate phase of industrial chemical wastes and sewage sludge : report on the seasonal variability of the dispersion of the particulate phase as observed from three cruises, July 1977, January-February 1978, and April 1978

The seasonal variability of the dispersion of the particulate phase of industrial chemical waste has been studied with acoustic backscattering techniques at Deep Water Dumpsite 106 (DWD 106). The vertical dispersion of the particulates has been found to be strongly dependent on the depth of the mixed layer and the magnitude of the density gradient associated with the seasonal thermocline. The horizontal dispersion of the particulates as a function of depth has been found to be strongly dependent on the shear present in the water column. Entire waste plumes have been found to be advected out of the dumpsite in less than 24 hours when the area is occupied by a warm core ring. Simple calculations based upon Stoke's law are presented to reveal the impact of variable oceanic density structure on the sink rate of particles and to indicate the need for incorporating these considerations into numerical models. A short discussion is presented on (1) the need to make field measurements on the magnitude of both turbulence and shear in the water column and (2) the need to incorporate shear and turbulence-dependent calculations for the sink rates of particles into those numerical models which may be used to predict the particulate and effluent dispersion rates at DWD 106.Prepared for the National Oceanic and Atmospheric Administration under Grants 04-7-158-44054, NA79AA-D-00030 and Ocean Dumping Grant 04-8-MOl-43

An Rb-condensin II complex mediates long-range chromosome interactions and influences expression at divergently paired genes

Interphase chromosomes are organized into topologically associated domains in order to establish and maintain integrity of transcriptional programs that remain poorly understood. Here, we show that condensin II and TFIIIC are recruited to bidirectionally transcribed promoters by a mechanism that is dependent on the retinoblastoma (RB) protein. Long-range chromosome contacts are disrupted by loss of condensin II loading, which leads to altered expression at bidirectional gene pairs. This study demonstrates that mammalian condensin II functions to organize long-range chromosome contacts and regulate transcription at specific genes. In addition, RB dependence of condensin II suggests that widespread misregulation of chromosome contacts and transcriptional alterations are a consequence of RB mutation

Lithium-Ion Electrolytes with Improved Safety Tolerance to High Voltage Systems

The invention discloses various embodiments of electrolytes for use in lithium-ion batteries, the electrolytes having improved safety and the ability to operate with high capacity anodes and high voltage cathodes. In one embodiment there is provided an electrolyte for use in a lithium-ion battery comprising an anode and a high voltage cathode. The electrolyte has a mixture of a cyclic carbonate of ethylene carbonate (EC) or mono-fluoroethylene carbonate (FEC) co-solvent, ethyl methyl carbonate (EMC), a flame retardant additive, a lithium salt, and an electrolyte additive that improves compatibility and performance of the lithium-ion battery with a high voltage cathode. The lithium-ion battery is charged to a voltage in a range of from about 2.0 V (Volts) to about 5.0 V (Volts)

An appraisal of the Poverty Reduction Strategy (PRS) Initiative

In late 1999, the World Bank and International Monetary Fund (IMF) jointly launched the Poverty Reduction Strategy (PRS) Initiative, under which low income countries (LICs) would be supported to develop multi-sectoral economic and social development plans. As such, these national PRSs would serve as the effective policy conditionality for concessional lending and the allocation of debt relief. Heralded by many as path breaking, the Initiative refocused attention on the role of the State and identified poverty reduction, as opposed to growth alone, as the primary goal of policy. However, from the outset, PRSs have been controversial. The most trenchant critics have described these plans as merely re-formulated structural adjustment packages. Other, more considered accounts, have questioned whether PRSs’ are capable of overcoming the agency problems inherent to donor-recipient relationships, and their ability to succeed in the weak policy environment typified by most LICs.In spite of the passage of some ten years, a rigorous evaluation of performance has yet to be published. This thesis aims to provide such an appraisal drawing on both quantitative and qualitative evidence. It employs cross-sectional statistical and econometric methods to examine poverty, growth and inequality outcomes based on a specially constructed dataset; and two detailed analytical case studies (for Mongolia and Vietnam) to probe the causal processes.Although some aggregate evidence is found of performance gains (relating to both poverty reduction and growth), these effects are partial and statistically fragile. Moreover, while no direct evidence is found of dis-inflationary policy biases, it is possible to detect a new narrowness within PRS policymaking. This reflects an orthodox policy consensus which favours growth over distributional improvements and places emphasis on a managed liberalization process. Additionally, it proved very difficult to find a causal link been PRS adoption and beneficial outcomes. The case study materials underline the pivotal role played by the IFIs in the design and management of PRSs, and their transitory and limited impact on actual national policy responses. Conclusions support many of the propositions put by the critical literature, and find that PRSs are poorly adapted to local institutional frameworks and neglect national political economies. As a result, their substance and longer term effectiveness is in doubt.EThOS - Electronic Theses Online ServiceGBUnited Kingdo