Fabrication of transparent conducting amorphous Zn–Sn–In–O thin films by direct current magnetron sputtering

Amorphous ZnO–SnO2–In2O3 films were grown by direct current magnetron sputtering from vacuum hot pressed ceramic oxide targets of Zn:In:Sn cation ratios 1:2:1 and 1:2:1.5 onto glass substrates. X-ray diffraction analysis showed that the microstructure remained amorphous during annealing at 200 °C for up to 5 hours. By monitoring the electrical resistivity, oxygen content and substrate temperature were optimized during deposition. The optimal films were characterized by Hall Effect, work function and optical spectroscopy measurements. Films of 1:2:1 composition showed the lowest resistivity (7.6×10−4 Ω-cm), when deposited onto substrates preheated to 300 °C. Transmissivity of all films exceeded 80% in the visible spectral region. The energy gap was 3.52–3.74 eV, and the work function ranged 5.08–5.22 eV, suitable for cathode applications in organic light emitting diodes. Overall, the film characteristics were comparable or superior to those of amorphous tin-doped indium oxide and zinc-doped indium oxide films and may serve as viable, lower-cost alternatives

Elastic properties of granular materials

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN019852 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The confrontation between the Archbishop of Cape Town, Joost de Blank, and the South African government on racial policies, 1957-1963

This study arises partly out of a pre-occupation with a period covering six impressionable years of my life - the final year at school, university days and the commencement of a teaching career; and partly from a reading of Alan Paton's Apartheid and the Archbishop which in covering the political aspects of Geoffrey Clayton's archbishopric inspired me to attempt the same for the term of Joost de Blank. The racial legislation passed since 1948 is discussed at the outset as it is the backdrop against which the whole Confrontation must be viewed. The reader might stagger under the sheer weight of detail but this is my intention since it facilitates an identification with de Blank who was overwhelmed by a plethora of legislative acts. The Anglican background to the period under discussion is of moment in that it reveals how de Blank became embroiled in a Church-State relationship which had gradually, yet perceptibly, deteriorated. Much of the material here is based on my own study of Synodal Resolutions and the Charges of Geoffrey Clayton. The biographical chapters provide the reader with the necessary factual background and, at the same time, make an independent judgement possible. de Blank's theological insights detected in the works written before his Enthronement furnish the categories into which the Confrontation naturally falls. This must be stressed because it is my conviction that de Blank's attack on apartheid represents not a departure from, but an extension of his earlier views, In conclusion, the Assessment examines the achievement of the Archbishop largely, but not exclusively, in the light of his own theological criteria

Development of the health and economic consequences of smoking interactive model

Objective-To describe the health and economic consequences of smoking model, a user friendly, web based tool, designed to estimate the health and economic outcomes associated with smoking and the benefits of smoking cessation. Results-An overview of the development of the model equations and user interface is given, and data from the UK are presented as an example of the model outputs. These results show that a typical smoking cessation strategy costs approximately pound 1200 per life year saved and pound 22 000 per death averted. Conclusions-The model successfully captures the complexity required to model smoking behaviour and associated mortality, morbidity, and health care costs. Furthermore, the interface provides the results in a simple and flexible way so as to be useful to a variety of audiences and to simulate a variety of smoking cessation methods

A low noise, high thermal stability, 0.1 K test facility for the Planck HFI bolometers

We are developing a facility which will be used to characterize the bolometric detectors for Planck, an ESA mission to investigate the Cosmic Microwave Background. The bolometers operate at 0.1 K, employing neutron-transmutation doped (NTD) Ge thermistors with resistances of several megohms to achieve NEPs~1×10^(–17) W Hz^(–1/2). Characterization of the intrinsic noise of the bolometers at frequencies as low as 0.010 Hz dictates a test apparatus thermal stability of 40 nK Hz^(–1/2) to that frequency. This temperature stability is achieved via a multi-stage isolation and control geometry with high resolution thermometry implemented with NTD Ge thermistors, JFET source followers, and dedicated lock-in amplifiers. The test facility accommodates 24 channels of differential signal readout, for measurement of bolometer V(I) characteristics and intrinsic noise. The test facility also provides for modulated radiation in the submillimeter band incident on the bolometers, for measurement of the optical speed-of-response; this illumination can be reduced below detectable limits without interrupting cryogenic operation. A commercial Oxford Instruments dilution refrigerator provides the cryogenic environment for the test facility

Ecological factors affecting the diversity of tropical tree seedlings

Seed dispersal and seedling establishment – the two stages in seedling recruitment – set the spatiotemporal distribution of new individuals in plant communities. Diversity often increases at the seed to seedling transition, making it critical for species coexistence. Debate continues regarding the effects of each stage on the community structure of diverse forests. Neutral theories postulate a strong role of dispersal, whereas niche-differentiation theories suggest that environmental conditions may be more important. This dissertation tested the effects of dispersal, competition and predation on the structure of the seedling layer in a pristine Amazonian rainforest. Seed-addition experiments broadly tested the relative importance of dispersal and environmental conditions on seedling community structure. Dispersal treatments explained more variance in community structure than did environmental conditions. This was the first variance- partitioning study to show that dispersal affects not only seedling density, but also diversity and species composition. Two more narrowly focused studies tested the intensity of competition among seedlings, and examined the effects of various mammalian predators on seedling recruitment. Evidence for inter-seedling competition was weak: individual growth and survival rates were generally unrelated to stem density, and seedlings’ zones of influence rarely overlapped substantially. As predators, small and medium-sized mammals reduced seedling density, whereas large mammals had no detectable effects. Furthermore, small mammals generated a rare-species advantage, the fundamental element of frequency dependence. Integrating the three studies, we suggest that dispersal is more important for seedling community structure than are environmental conditions. Given the low density of seedlings in xii Neotropical forests, we infer that competition among tree seedlings is largely irrelevant to their recruitment. Seed predators operated in a distinctly non-neutral manner, preferentially removing seeds of common and large-seeded species. Despite the powerful effects of predation, dispersal explained more variance in seedling recruitment than did all aspects of environmental variation (including predation). Taken together, the results of these three experiments support a view that, at least for young plants, and at small scales, dispersal may more strongly influence the species composition of tropical trees than environmental conditions, consistent with predictions from neutral models

Some recent results in aerospace vehicle trajectory optimization techniques

Algorithms and computation techniques for solving trajectory optimization problem

Initial test results on bolometers for the Planck high frequency instrument

We summarize the fabrication, flight qualification, and dark performance of bolometers completed at the Jet Propulsion Laboratory for the High Frequency Instrument (HFI) of the joint ESA/NASA Herschel/Planck mission to be launched in 2009. The HFI is a multicolor focal plane which consists of 52 bolometers operated at 100 mK. Each bolometer is mounted to a feedhorn-filter assembly which defines one of six frequency bands centered between 100-857 GHz. Four detectors in each of five bands from 143-857 GHz are coupled to both linear polarizations and thus measure the total intensity. In addition, eight detectors in each of four bands (100, 143, 217, and 353 GHz) couple only to a single linear polarization and thus provide measurements of the Stokes parameters, Q and U, as well as the total intensity. The measured noise equivalent power (NEP) of all detectors is at or below the background limit for the telescope and time constants are a few ms, short enough to resolve point sources as the 5 to 9 arc min beams move across the sky at 1 rpm

Potential Sinks for Geologic Storage of CO2 Generated in the Carolinas

This document summarizes a scoping study of the current state of knowledge of carbon storage options for our geographic area. The focus is on one aspect of carbon capture and storage—identification of deep saline aquifers in which carbon dioxide (CO2 ) generated in the Carolinas might be stored. The study does not address other aspects of CO2 storage projects, such as capture and compression of the gas, well construction and development, or injection. Transport of CO2 is touched upon in this study but has not been fully addressed. The information contained in this document is primarily from review of published geologic literature and unpublished data. No field data collection has been completed as part of this study. Further work will be necessary to increase confidence in the suitability of the potential CO2 storage sites identified in this report. This study does not address the regulatory, environmental, or public policy issues associated with carbon storage, which are under development at this time.Duke Energy, Progress Energy, Santee Cooper Power, South Carolina Electric and Gas, Electric Power Research Institute (EPRI), Southern States Energy Board (SSEB)Bureau of Economic Geolog